The Bottom Line

Harvard Study Finds Fluoride Lowers IQ - Published in Federal Gov't Journal - This 2012 REUTERS press release (since vanished from the archives) is a very effective way to grab your attention, and even though the headline is a false representation of the study's actual stated conclusions, slightly different versions are still used by fluoridation opponents.  Fear is an extremely powerful motivator.  If you are scared about your safety or the safety of your family and friends, you are likely to take the most obvious protective action quickly without wasting time studying the nuances of your possible options. 

This 'fight or flight' response is one of our most primitive survival strategies, and it is difficult to counter fear with a calmly considered discussion.  I intend to try, however, and if you are reading this page because you have heard that community water fluoridation is dangerous to your health and ineffective, I encourage you to set aside your fears and consider the following content with an open mind.  There are plenty of places you can regain that fear later, if I am unable to convince you that your fears are largely unfounded.  Fear is a powerful motivator.  This is an accurate analysis - language alert, though)

The Introduction briefly summarizes the reasons I am not convinced by the fluoridation opponents' arguments about the alleged danger we are all exposed to as a result of community drinking water fluoridation.  There is legitimate scientific disagreement about whether fluoridation is as significant a preventative measure for dental decay today as it was before the introduction of fluoride-containing toothpaste, fluoride dental treatments and other sources of the fluoride ion.
Health Organizations that Support Drinking Water FluoridationFluoridation ResourcesThis section contains over fifty links to books, articles, endorsements and position statements that describe the history, benefits, risks and costs of fluoridation.   The references provide a cross section of the wide acceptance in the scientific, medical and government communities of fluoridation as a safe and effective way to increase community dental health.  I admit I have 'cherry picked' these resources specifically to counter the claim that there is no reliable evidence to support the scientific consensus that fluoridation is a process that is both safe and effective.  The risks that have been identified are not ignored by the scientific, dental and medical communities, but the potential benefits of fluoridation at optimal levels have consistently been found to outweigh any known or suspected risks.  Over 100 national and International health organizations support fluoridation.
Links to and summaries of Published Fluoridation Studies from the National Library of Medicine 1955 - 2015:  This section contains links to over 140 published, reviewed studies that demonstrate the safety and effectiveness of community water fluoridation as well as the risks of excessive exposure.  In this section I provide a very specific example of how fluoridation opponents use fear and the misrepresentation of study results to manufacture a problem where none exists and sell the resulting illusion to the public as fact.  I am against this type of blatant manipulation of evidence to justify any belief.  If a position is scientifically valid, that position can, and should, be supported and justified using a fair presentation of the evidence - twisting evidence only confuses the issue.
One of the best example I have found to illustrate the difference between how evidence is evaluated, interpreted  and used by fluoridation supporters and opponents is to contrast the two published studies below.  Both papers examine the same hypothesis, that exposure to optimally fluoridated drinking water (0.7 - 1.0 ppm) causes a significant decrease in IQ.
The NRC Reports section is a point-by-point a comparison of the findings of the 1993 and 2006 National Research Council (NRC) Fluoride Reports.  Additional information about the reports and the  National Research Council (NRC). can be found here.  The National Academies (of which the NRC is a part} perform an unparalleled public service by bringing together committees of experts in all areas of scientific and technological endeavor. These experts serve pro bono to advise the federal government and the general public on scientific and technological issues that affect people's lives worldwide.

The Power of Fear

Harvard Study Finds Fluoride Lowers IQ - Published in Federal Gov't Journal

How do you react to this headline - is it convincing evidence that causes you to fear fluoridation?  Fluoridation opponents certainly hope so - they count on their audience accepting the claim as accurate and going to their websites to find out more about the dangers of this evil drinking water additive - and there you will find much more 'evidence' to be fearful of.  It apparently does not matter at all to fluoridation opponents that these statements are a complete misstatement of the paper's conclusions.

I created this reference page to refute claims you may have encountered that there is no evidence to support the safety and effectiveness of drinking water fluoridation as a method to enhance community dental health.  I selected this representation of articles, stories and reference papers to provide clear evidence that over sixty five years of research has, in fact, produced hundreds of studies and reviews that conclude drinking water fluoridation at optimal levels of 0.7 to 1.0 part per million (ppm) is effective and safe.  I do not claim there is no negative evidence regarding fluoridation or that all negative evidence should be ignored.  As with the study of any complex subject, it is the consensus reached after all evidence is fairly evaluated that is important - not the conclusions drawn by accepting only selected evidence.

Fear sells ideas just as effectively as it sells products.

Sex doesn't sell, it's fear. In the first episode of Mad Men (Smoke gets in your eyes) Don Draper outlines the appeal of fear as a tool for selling with chilling clarity. "Advertising is based on one thing: happiness," he calmly tells his clients. "And do you know what happiness is? - It's freedom from fear."

This has been the simple quest of consumerism for the past half-century: to pinpoint with laser-like accuracy the anxieties of the consumer at any given moment, from the nebulous (economic insecurity) to the specific (bird flu).

 One former marketing executive from a soft drinks multinational even told me how they would brainstorm these anxieties on a "whiteboard of worry". The purpose? To brilliantly, cunningly hone a product that offers temporary "freedom from fear", temporary because a new fear and a new product will be on their way soon. Here are some of the ways it is done. 

SUVs, handwash and FOMO: how the advertising industry embraced fear, Jacques Peretti, July 6 2014

Anti-fluoridation websites and literature almost exclusively present carefully selected studies and headlines they claim either do not support the effectiveness of fluoridation or allegedly demonstrate the harm exposure to the fluoride ion can cause.  As you research this complicated topic, be aware that information presented by fluoridation opponents is neither balanced or complete - it is meticulously designed to create fear of fluoridation and a distrust of all responsible parties.  

Most people who have serious questions and concerns about fluoridation and who are willing to embark on a thoughtful investigation of the answers are not scientists or medical professionals.  You may be researching this topic precisely because you have heard an anti-fluoridation presentation or encountered a website demonizing fluoridation.  You may have only encountered anti-fluoride 'evidence', and you may not have the expertise and experience (or time) to do your own exhaustive (and exhausting) evaluation of all of the available evidence.  Relatively few people are able to review all details concerning the study design, methodology, statistical analysis, etc. for research papers in a specific scientific specialty and determine for themselves the quality, accuracy, validity and relevance of the conclusions of each research paper.  Honestly, I have had years of scientific training and experience, and I find it very difficult to evaluate many of the research papers I try to examine. 

It is inevitable then, that to a greater or lesser degree, nearly everyone who has questions and concerns about fluoridation will need to depend on some Authority -- an individual or group -- to provide an understandable interpretation of the decades of accumulated evidence.  Each Authority will promote its perspective and agenda, biases and conclusions.  And that's precisely the problem.  Fluoridation supporters and opponents have completely different, diametrically opposed interpretations, and they have come to mutually exclusive conclusions about fluoridation, even though they have access to exactly the same body of evidence.  One of the conclusions must be correct and the other one wrong, but how on earth can a non-expert determine which position on fluoridation represents the best and most accurate conclusion?

And that brings us back to fear!  If you truly and passionately believe the fluoride ion is a deadly poison that is certain to cause great harm to anyone who is exposed to small amounts (or even if you have a quiet little voice nattering away in your mind,  "Gee, these are pretty scary claims."), think about how you react to new frightening evidence.  It will likely be easy to continue accepting fervently presented evidence alleged to show great harm to almost all aspects of human health from fluoridation opponents.  It will probably be quite difficult to consider accepting evidence that demonstrates benefits of better dental health that appears to be associated with very small risks of harm from fluoridation supporters. 

Another belief that will automatically cause you to accept the evidence of fluoridation opponents is that the fluoride ion is a medicine, and it is fundamentally and ethically immoral to force any medication on everyone in a community - particularly when individual doses can't easily regulated or monitored.  Belief in the freedom of choice is a legitimate ethical position.  However, fluoridation opponents have wrapped that moral conviction into claims promoting fear that the fluoride ion is a dangerous poison. 

Obviously then, according to that logic, Implementing fluoridation is equivalent to forced medication of all members of a community by adding a toxic byproduct of the fertilizer industry that is used in rat poison to their drinking water

Wow, how can any educated, caring person in their right mind be so irresponsible as to support that practice?

In addition to reinforcing fear, the argument that fluoride is a medicine enables fluoridation opponents to conveniently ignore the common practice of forced community water disinfection and other water treatment methods (which contribute some real health risks) while selectively denouncing as unethical addition of the fluoride ion to a community's drinking water.

This is a disingenuous argument.  Consider the fact that community drinking water disinfection with chlorine or chloramine forces everyone who drinks the tap water to ingest chlorine (or chloramine) and variable levels of disinfection byproducts that numerous studies have shown might cause cancer, miscarriages and birth defects in some community members.  It can be accurately stated then, "Implementing chlorine disinfection is equivalent to forcing all members of a community to drink a byproduct of the magnesium industry that has historically been used as a chemical weapon and which reacts with organic compounds in drinking water to form formaldehyde and other poisons."  Pretty scary, right?

If fluoridation opponents really believed it was unethical for community water treatment processes to add any substances that had been shown to potentially cause serious health issues at normal exposure levels, they would be morally obligated to fight against community drinking water disinfection with the same fervor they attack fluoridation and insist that everyone should be responsible for their own water disinfection process to prevent any possible harm to some members of the community.

The very specific moral indignation of fluoridation opponents against the fluoride ion only works if they are able to arbitrarily disconnect the poison fluorine from the poison chlorine in people's minds, since evidence exists that both chemicals can potentially cause serious health problems in drinking water.  Thus, fluorine is classified a medicine and chlorine a disinfectant.

Fear and moral outrage are powerful motivators.  However, science only works when fear, strong biases, beliefs, desires and preconceptions do not interfere with experimental design, methods used or the analysis and interpretation processes. 

I will try to provide a less emotional look at what is really a conversation about water treatment processes that are designed to maximize benefits for most of the members of the community while minimizing the inevitable resulting health risks and costs of any decisions that are made.

Consider this.  If exposure to low levels of the fluoride ion (or any other substance proposed to treat drinking water) were demonstrably harmful to health, it wouldn't matter whether it was classified as a water treatment additive, a natural contaminant, a nutrient, a poison or a medicine.  The scientific evidence would provide justification to keep it out of drinking water at levels shown to be harmful - EPA regulations already limit the maximum drinking water fluoride level to 4.0 ppm and has established maximum contaminant levels (MCL) of a number of other water contaminants (including chlorine, chloramine and disinfection byproducts) because of scientific evidence.  Scientific evidence should, and does, drive discussions of what constitutes harmful levels - not only of the fluoride ion but of other common water contaminants including potentially harmful disinfection byproducts. 

Conversely, if addition of the fluoride ion (or any other substance proposed to treat drinking water) is actually demonstrably beneficial to health, it wouldn't matter whether it was classified as a water treatment additive, a natural contaminant, a nutrient, a poison or a medicine,  The scientific evidence would provide justification to consider adding it to drinking water.  The addition of chlorine or chloramine (or other disinfection processes) to drinking water is justified by the collective evidence in exactly the same way fluoridation is justified

Good science provides real, measurable evidence of the benefits, risks and costs of disinfection methods, fluoridation and any other water treatment process.  And that evidence (if collected accurately and fairly) will have absolutely nothing to do with how someone chooses to classify the substances used for treatment and will not depend on their biases and beliefs, desires and preconceptions.

Accumulated scientific evidence should - and does - drive discussions about what levels of a drinking water additive provide health benefits or reduce health risks - not only of the fluoride ion but chemicals designed to kill pathogens, adjust pH, regulate hardness or any other water treatment process.  The same scientific evidence identifies potential health risks at different exposure levels and drives discussions and policy decisions about whether those inevitable risks are common &/or severe enough to counter any benefits that have been found and prevent addition of the chemical.

Characterization of the fluoride ion as a medicine is completely irrelevant - except to strengthen moral outrage and fear.  I encourage you to examine the evidence without fear or bias.  At this point you may not agree with fluoridation supporters, but try to understand the real reasons (not those suggested by fluoridation opponents) a very large majority of scientists, doctors, dentists, water treatment professionals and government representatives continue to support fluoridation.

As you evaluate the available evidence and the way that evidence is presented by fluoridation supporters and opponents, consider the following suggestions.  And, if you are currently fearful about the consequences of fluoridation because of anti-fluoridation arguments you have read or heard, please try to suspend the fear so you can at least understand why many others have evaluated the same evidence and chosen not accept that fear.

I challenge you to consider the arguments presented in support of fluoridation without fear - the actual research papers do not employ fear, unless they were written by fluoridation opponents.  I used the IQ study headline and the osteoporosis treatment example above to demonstrate how study conclusions are exaggerated, taken out of context and often completely misrepresented, to generate unwarranted fear.  

Headlines that reference the IQ study frequently state or imply the research "confirms fluoride reduces children's IQ".  The study actually concludes, "The results support the possibility of an adverse effect of high fluoride exposure on children's neurodevelopment."  In my dictionary 'confirms' and 'supports the possibility' are not synonymous.   A more accurate headline from the IQ paper would read, "A review of 27 poor quality studies, mostly from China, shows that very high fluoride exposure (along with other un-documented contaminants like arsenic) might possibly lower IQ very slightly." 

The beauty of using fear to sell an idea, though, is that you don't have to actually prove any of the claimed risks are a real, significant threat to the population.  With fluoridation, for example, opponents only have to demonstrate that there are real risks of exposure to the fluoride ion (which no supporter can deny, given a high enough dose) and list possible outcomes that can potentially cause serious harm to some individuals. 

Opponents then hint that the harm might occur at very low exposure levels, present some papers with ambiguous conclusions and challenge the fluoride supporters to prove fluoride has never caused (nor ever could cause) any harm at low exposure levels, and leave the outcome of the argument to the imagination of their audience.  Please keep this strategy in mind as you carefully examine how evidence is presented and explained on anti-fluoridation sites and on sites that support fluoridation. 

Carefully examine the affidavit an anti-fluoridation site challenges dentists to sign.  This is one of the better examples to illustrate how some fluoridation opponents apparently don't understand how science works. 

I can safely and unequivocally state that no dentist - even the most ardent supporters of fluoridation - will ever state (or believe) that there is no evidence of risk and there could never be any side effects from fluoridation - or, for that matter, any other dental treatment they might offer.

Scientists who support fluoridation are at an immediate disadvantage, because no reputable scientist can ever claim that there are no risk associated with optimal fluoridation.  They have the responsibility of explaining why they can't guarantee no one will ever by harmed by fluoridation and painstakingly leading their audience through the complex evidence that actually demonstrates how most (though not all) of the evidence shows that the health risks of fluoridation are minimal. 

After reading the Affidavit above directed to dentists, I thought I would devise one for fluoridation opponents:


"In my opinion, professional or otherwise, as an opponent of the practice of community water fluoridation, the ingestion of (or exposure to) drinking water containing hydrofluorosilicic acid or any other substance that contains the fluoride ion is dangerous to sperm, eggs, embryos, fetuses, infants, children, adults and the elderly."

"Consequently, the practice of fluoridation should be discontinued immediately in all communities." 

"Furthermore, because any exposure to the fluoride ion is dangerous and exposure levels in drinking water can't be regulated or controlled to ensure a safe dose, all water treatment facilities - public and private - must be required to immediately implement measures to remove fluoride ions from drinking water."

"I guarantee that there will be no harmful side effects to any individuals in a community if this proposed plan is executed."

Please read carefully and sign below

I hereby certify under penalty of perjury, under the laws of the state listed below, the truth and accuracy of the above statement made in this personal affidavit.

Name ______________ Date ______________
Title _______________ City/State ___________
Signature  ______________________

They must then proceed through an equally laborious process of explaining that most (though not all) evidence shows fluoridation is effective at improving dental health in a community at low levels (while admitting that exposure to the fluoride ion at high levels can cause significant harm).  Scientists seldom have the luxury of making brief, simple, easy-to-understand statements that will conclusively convince their audience a given position is absolutely correct, and there is no contradictory evidence to complicate the issue.

The fluoridation controversy is not a trivial matter.  The outcome of the decisions about community water fluoridation will have an effect on your health and the health of your family - whichever way it turns out - and you have every right to be concerned and seek scientifically accurate answers to your questions about fluoridation. 

Consider this comment in the April 2015 issue of Popular Science by editor Cliff Ranson, "I think that often we fear what we don't understand.  Gain a little insight and fear slips away.  Plus, understanding things is fun." 

As you begin (or continue) your exploration of the the pros and cons of fluoridation, please try to avoid the temptation of surrendering to fear about the possible consequences of fluoridation until you can understand both sides of the controversy and recognize how fear of the possible but unproven is used to hijack your emotions and 'guide' you to the desired conclusions. 


I have no personal stake in the drinking water fluoridation controversy in which passions can run extremely high, particularly in those individuals who oppose fluoridation.  I am only interested in presenting evidence that, to me, seems reasonable and accurate.  I can't claim that this page was constructed without any bias - if I had no opinions about drinking water fluoridation or about the controversy surrounding the practice I would not have invested hundreds of hours researching the topic and trying to figure out how to present my conclusions. 

I can, however state I have no biases or beliefs that would require me to conclude that fluoridation was harmful and not beneficial - beliefs like "our government has no business trying to provide services &/or regulations that may potentially help large segments of the population regardless of race, income, education, etc. if those services &/or regulations infringe on an individual's freedom of choice and might carry some health risks." 

I also state I have no biases or beliefs that would require me to conclude that fluoridation is beneficial and safe.  I believe there are a number of situations where government services and regulations seem appropriate to maximize public health and safety - chlorination of public water supplies, requirements for cigarette health warnings and banning smoking in public buildings, drunk driving laws, drug and medical treatment regulations, fluoridation, etc., but I don't blindly support every government recommendation for any new regulation or service.

However, I do have a very strong bias against the misuse of science to support specific ideological or political beliefs and agendas.  The processes and conclusions of science are only effective, and accurate results can only be obtained, if experiments and observations are designed and conducted and results are analyzed without the influence of strong beliefs, preconceived ideas, expectations or the personal need to reach a specific conclusion. 

The article, Identifying and Avoiding Bias in Research provides a good introduction to study bias, and how it can impact all aspects of research - and, as I discuss elsewhere, the interpretation of all published research studies.  For additional information on this important topic you can search on 'conducting scientific research without bias' or similar wording to find other articles that describe how scientists try and minimize the effects of bias on their research - and the reasons the avoidance of bias is critical.

Personally, as a result of my ongoing examination of the evidence, I continue to support the practice of drinking water fluoridation as a safe and effective way to strengthen teeth and reduce decay and associated health problems for the entire community. 

A 2015 Cochrane fluoridation review (response to feedback) and significant resulting commentary (#1, #2, #3, #4, #5, #6, #7) - clearly illustrates the complexity of the fluoridation discussion, the way a published paper can be misused by fluoridation opponents and the impact of personal biases (for and against fluoridation) on the interpretation of study results.  Contrast the 2015 Cochrane review with a 2000 literature review of fluoridation, Systematic review of water fluoridation, published in the British Medical Journal that concluded, "The evidence of a beneficial reduction in caries should be considered together with the increased prevalence of dental fluorosis. There was no clear evidence of other potential adverse effects."

Below are my responses to several common arguments from fluoridation opponents that suggest I haven't considered or just don't understand some vital components of their opinions and their evidence against fluoridation:
Thank you Randy for your information.

However, I have read several of the reports coming from 'true' independent research that there is NO evidence found that fluoride prevents cavities, actually the reverse is true.

The present day understanding is based on quite old reports that were controlled and paid for by the chemical companies.....

When you look up 'factual' research reporting how wonderful fluoride is, please note the date and who produced the report..... you may be surprised at what you find.

Thanks for your help.  Kay

I created this page in response to statements (like the one on the right) made by visitors to my website that there is NO evidence that fluoridation is effective or safe.  I have compiled, and made available, some of the evidence that fluoridation is safe and effective these visitors seem to have missed.

No competent pro-fluoridation scientist will ever claim that the only evidence that's available supports their conclusion that fluoridation is safe and effective.  They will, however, point out the specific reasons they accept the evidence supporting their position as more reliable and trustworthy than the alternatives, and they will describe the deficiencies in the evidence, evaluations and arguments presented by fluoridation opponents.

As you review these resources and compare them with the materials found on anti-fluoridation sites, consider the observations below: six of the reasons I remain unconvinced by anti-fluoridation arguments and continue to support community drinking water fluoridation. 

These reasons are explained in greater detail on my Fluoridation Discussion page.

Drinking Water Fluoridation Resources

Fluoride Resources: Related Books, Articles and Position Statements
> WHO: Fluoride and Oral Health – 2016 update
> 4/27/2015 - HHS issues final recommendation for community water fluoridation
> The Fluoride Wars
> American Academy of Dentistry
> Water fluoridation From Wikipedia
> The Story of Fluoridation
> Committee on Fluoride in Drinking Water, National Research Council - 2006
> Fluoride Science
> The Campaign for Dental Health
> Fluoride Information Network
> SCHER Review: Human Exposure to Fluoride
> Water Fluoridation Chemicals - Safety
> 2014 - Health Effects of Water Fluoridation: A review of the scientific evidence
> Australian Government National Health and Medical Research Council - 2007
> The Science of Fluoride
> Linus Pauling Institute Micronutrient Information Center
> The Canadian Dental Association (CDA)
> The Canadian Association of Public Health Dentistry (CAPHD) + 2012 Q&A paper
> World Health Organization (WHO)
> The Irish Dental Association
> The British Fluoridation Society: One in a Million
> The American Academy of Pediatric Dentistry
> The Centers for Disease Control and Prevention: Fluoridation, One of the Ten Great Public Health Achievements in the 20th Century
> National Cancer Institute
> American Cancer Society
> American Medical Association
> Pew Report
> American Public Health Association
> Healthy Teeth For A Lifetime
> Fluoridation Update 2014
> On Tap Magazine - To Fluoridate or not
> When public action undermines public health: a critical examination of antifluoridationist literature
> The Anti-Fluoridationist Threat to Public Health
> All About Fluoridation
> Response to a list of '50 Reasons to Oppose Fluoridation
> Review: '50 Reasons to oppose fluoridation'
> 2010 Interview with the general manager of the Washington Aqueduct - fluorosilicic acid comment
> Health Effects of Ingested Fluoride - 1993
> Fort Collins, Colorado, Fluoride Technical Study Group Report
> Position of the Academy of Nutrition and Dietetics: the impact of fluoride on health
> Top Cairns dentist defends fluoride
> The first community trial of water fluoridation
> History of Water Fluoridation
> Fluoridation of Water - Skeptic's dictionary
> National Fluoridation Information Services
> The National Center for Fluoridation
> FDI World Dental Federation
> Statements on Community Water Fluoridation
> Caries prevention on tap
> Review of Fluoride: Benefits and Risks
> Guide to Community Preventive Services (CWF)
> Abuse of the Scientific Literature in an Antifluoridation Pamphlet
> Fluoride exposure and IQ
> Preventing Dental Caries: Community Water Fluoridation
Wikipedia - Water Fluoridation
  - Water Fluoridation Controversy
> Drinking Water and Health, Volume 1 (1977)
> Fluoridated Water: Science, Scams and Society & other Blogs & Videos
> Water Fluoridation from Wikipedia
> Fluoridation con/pro essays & video

World Health Organization: Fluoride and Oral Health
2016 update of the 1994 report - Extensive history and review of fluoride exposure and oral health
—> At the 2007 WHO World Health Assembly, a resolution was passed that universal access to fluoride for caries prevention was to be part of the basic right to human health. There are three basic fluoride delivery methods for caries prevention; community based (fluoridated water, salt and milk), professionally administered (fluoride gels, varnishes) and selfadministered (toothpastes and mouth-rinses).
—> In revising the 1994 edition of “Fluorides and Oral Health” the increasing emphasis on an evidence-based approach is fully taken into account. In this respect the findings of published systematic reviews underpin the evidence to support the conclusions reached. In addition, account is taken of the fact that many complex public health programmes and interventions are not amenable to measurement using the classical randomised control clinical trial design; the findings of observational studies are also relevant in assessing the value of these interventions.
 —> Research suggests that fluoride is most effective in caries prevention when a low level of fluoride is constantly maintained in the oral cavity. Important reservoirs of this fluoride are in plaque, saliva, on the surfaces of the oral soft tissue, and in a loosely bound form on the enamel surfaces.
—> Fluoride is effective at controlling caries because it acts in several different ways. When present in dental plaque and saliva, it delays the demineralization and promotes the remineralization of incipient enamel lesions, a healing process before cavities become established. Fluoride also interferes with glycolysis, the process by which cariogenic bacteria metabolize sugars to produce acid. In higher concentrations, it has a bactericidal action on cariogenic and other bacteria.
—> Studies suggest that, when fluoride is ingested during the period of tooth development, it makes teeth more resistant to subsequent caries development.
—> Fluoridated water also has a significant topical effect in addition to its systemic effect (Hardwick et al. – 1982). It is well known that salivary and plaque fluoride (F) concentrations are directly related to the F concentration in drinking water. This versatility of action adds to fluoride’s value in caries prevention. Aiding remineralization is likely to be fluoride’s most important action.
—> The public health administrator seeks to maximize caries reduction while minimizing fluorosis, though in many communities the relative priority accorded to these outcomes will vary. It should also be noted that fluorosis is not the only type of disturbance found in dental enamel; enamel opacities can result from a large number of causes unrelated to fluoride use. Diagnostic skill is required to distinguish between the various causes of defects in enamel development.
—> Since [1945] hundreds of millions of people worldwide have regularly consumed artificially fluoridated water: currently around 380 million, plus approximately 50 million whose drinking water supplies naturally contain optimal fluoride concentrations
—> Studies from many different countries over the past 60 years are remarkably consistent in demonstrating substantial reductions in caries prevalence as a result of water fluoridation. One hundred and thirteen studies into the effectiveness of artificial water fluoridation in 23 countries conducted before 1990, recorded a modal percent caries reduction of 40 to 50% in primary teeth and 50 to 60% in permanent.
—> More recently, systematic reviews summarizing these extensive databases have confirmed that water fluoridation substantially reduces the prevalence and incidence of dental caries in primary and permanent teeth. Although percent caries reductions recorded have been slightly lower in 59 post-1990 studies compared with the pre-1990 studies, the reductions are still substantial.
—> The question of possible adverse general health effects caused by exposure to fluorides taken in optimal concentrations throughout life has been the object of thorough medical investigations which have failed to show any impairment of general health.

HHS issues final recommendation for community water fluoridation, April 27, 2015:  The U.S. Department of Health and Human Services today released the final Public Health Service (PHS) recommendation for the optimal fluoride level in drinking water to prevent tooth decay.  The new recommendation is for a single level of 0.7 milligrams of fluoride per liter of water.  It updates and replaces the previous recommended range (0.7 to 1.2 milligrams per liter) issued in 1962. 
The change was recommended because Americans now have access to more sources of fluoride, such as toothpaste and mouth rinses, than they did when water fluoridation was first introduced in the United States.  As a result, there has been an increase in fluorosis, which, in most cases, manifests as barely visible lacy white marking or spots on the tooth enamel.  The new recommended level will maintain the protective decay prevention benefits of water fluoridation and reduce the occurrence of dental fluorosis. 
“While additional sources of fluoride are more widely used than they were in 1962, the need for community water fluoridation still continues,” said U.S. Deputy Surgeon General Rear Admiral Boris D. Lushniak, M.D., M.P.H. “Community water fluoridation continues to reduce tooth decay in children and adults beyond that provided by using only toothpaste and other fluoride-containing products.”
Announcement | Read the Report

The Fluoride Wars: How a modest Public Health Measure Became America's Longest Running Melodrama.  R. Allan Freeze & Jay H. Lehr, published by A John Wiley & Sons, Inc. (2009) Review: "The authors provide a detailed and entertaining look at the history of water fluoridation and the rise of the anti-fluoridation movement.  They weave tales of the scientists who discovered the protective power of fluoride against dental decay, who established the fluoridation treatment processes and promoted the practice, and those who had concerns about public water fluoridation and were marginalized by the scientific and medical establishment and driven to the anti-fluoride movements." (Review 1 Review 2
Another history of fluoridation by Donald R. McNeil.
American Academy of Dentistry (ADA) - Fluoride & Fluoridation - This 72-page booklet with 358 references is a comprehensive encyclopedia of fluoridation facts. The ADA Fluoridation Facts (Free PDF Booklet) includes information from scientific research in a helpful question and answer format that addresses and rebuts the major anti-fluoride claims. Some important sections:
> Executive Summary (page 4)
> How to review and evaluate scientific research (page 7)
Additional fluoride & fluoridation resources.
Water fluoridation From Wikipedia, the free encyclopedia - Existing evidence strongly suggests that water fluoridation reduces tooth decay. There is also consistent evidence that it causes dental fluorosis, most of which is mild and not usually of aesthetic concern.  There is no clear evidence of other adverse effects. Moderate-quality research exists as to water fluoridation's effectiveness and its potential association with cancer; research into other potential adverse effects has been almost all of low quality. Little high-quality research has been performed.
A similar article from New World Encyclopedia.

The Story of Fluoridation - It started as an observation, that soon took the shape of an idea. It ended, five decades later, as a scientific revolution that shot dentistry into the forefront of preventive medicine. This is the story of how dental science discovered-and ultimately proved to the world-that fluoride, a mineral found in rocks and soil, prevents tooth decay. Although dental caries remains a public health worry, it is no longer the unbridled problem it once was, thanks to fluoride. (National Institute of Dental and Craniofacial Research)

Committee on Fluoride in Drinking Water, National Research Council - Fluoride in Drinking Water: A Scientific Review of EPA's Standards (2006): Because new research on fluoride is now available and because the Safe Drinking Water Act requires periodic reassessment of regulations for drinking water contaminants, EPA requested that the NRC evaluate the adequacy of its MCLG and SMCL for fluoride to protect public health. In response to EPA's request, the NRC convened the Committee on Fluoride in Drinking Water, which prepared this report. The committee was charged to review toxicological, epidemiologic, and clinical data on fluoride, particularly data published since 1993, and exposure data on orally ingested fluoride from drinking water and other sources.
This report presents the committee's review of the scientific basis of EPA's MCLG and SMCL for fluoride, and their adequacy for protecting children and others from adverse health effects. The committee considers the relative contribution of various sources of fluoride (e.g., drinking water, food, dental hygiene products) to total exposure, and identifies data gaps and makes recommendations for future research relevant to setting the MCLG and SMCL for fluoride. Addressing questions of economics, risk-benefit assessment, or water-treatment technology was not part of the committee's charge.  American Dental Association response to the report, 3/22/06.  Point by point comparison with the 1993 National Research Council Fluoride report.  I have read reports that in 2013, in response to continued twisting of his words by antifluoridationists, Dr. John Doull made the following statement: 'I do not believe there is any valid, scientific reason for fearing adverse health conditions from the consumption of water fluoridated at the optimal level' John Doull, MD, PhD, Chair of the National Academy of Sciences, National Research Council 2006 Committee Report on Fluoride in Drinking Water
Fluoride Science:
The Center for Fluoride Research Analysis is an educational entity dedicated to communicating the quality of fluoride-related studies and is endorsed by the American Association of Public Health Dentistry. The Center's primary goal is to provide information to practitioners and policy-makers for ensuring that all decision makers have the best information regarding the use of fluoride. To achieve this goal, the Center involves graduate students and faculty in dental public health to conduct a review of the quality of research publications and other reports.
These reviews are guided by an expert committee of mentors with extensive research publication records. Meticulous methods and predefined criteria are used to document each step to ensure objectivity, transparency and reproducibility of the process. Faculty members evaluate the work of students to support conclusions.
The Campaign for Dental Health
was created to ensure every American has access to the cheapest, most effective way to protect teeth - water fluoridation. We are a network of local children's and oral health advocates, health professionals and scientists who are working together to preserve our nation's gains in oral health. We believe, quite simply, that life is better with teeth. The organization's Dental Health Blog is an excellent resource to find up-to-date responses to anti-fluoridation materials as is their, Myths & Facts - Responses to Common Claims about Community Water Fluoridation.
Fluoride Information Network:  "Is Fluoride good to have in your drinking water?
There is a lot of information available about fluoride but the information is also sometimes conflicting. Some leads us to believe fluoride in drinking water is a good thing; and some says just the opposite! Even information in clear opposition claims to have solid scientific backing - how can this be?  This web site presents the best known, best substantiated and most truthful information about fluoride.  We are educators, medical and public health practitioners, dentists, parents and concerned citizens who have thoroughly researched the issues of fluoride in community water sources. We deeply care about dental health, safe drinking water, health equity across socio-economic groups and fiscal responsibility in homes and whole communities.  We Support Fluoride in our Community Water..."
Articles include a review of "The Fluoride Deception.
Scientific Committee on Health and Environmental Risks (SCHER): Critical review of any new evidence on the hazard profile, health effects, and human exposure to fluoride and the fluoridating agents of drinking water: Scientific evidence for the protective effect of topical fluoride application is strong, while the respective data for systemic application via drinking water are less convincing. No obvious advantage appears in favour of water fluoridation as compared with topical application of fluoride. However, an advantage in favour of water fluoridation is that caries prevention may reach disadvantaged children from the lower socioeconomic groups. (SCHER adopted this opinion by written procedure on 16 May 2011)
Conclusions specific to health effects of fluoride:

--Hydrolysis of hexafluorosilicates, used for drinking water fluoridation, to fluoride was rapid and the release of fluoride ion was essentially complete. Therefore, the fluoride ion is considered the only relevant substance with respect to this opinion.
--Enamel fluorosis seen in areas with fluoridated water (0.7-1.2 mg/L F) has been attributed to early tooth brushing behaviours, and inappropriate high fluoride intake, i.e. use of infant formula prepared with fluoridated drinking water.
--There is no clear association of bone fracture risk with water fluoridation and fluoridation at levels of 0.6 to 1.1 mg/L may actually lower overall fracture risk.
--There are conflicting reports on genotoxic effects in humans. ... The quality of the former studies [showing genotoxicity] is questionable.
--SCHER agrees that epidemiological studies do not indicate a clear link between fluoride in drinking water, and osteosarcoma and cancer in general. There is no evidence from animal studies to support the link, thus fluoride cannot be classified as carcinogenic.
--Available human studies do not clearly support the conclusion that fluoride in drinking water impairs children's neurodevelopment at levels permitted in the EU.  The limited animal data can also not support the link between fluoride exposure and neurotoxicity at relevant non-toxic doses..
--A systematic evaluation of the human studies does not suggest a potential thyroid effect at realistic exposures to fluoride. The absence of thyroid effects in rodents after long-term fluoride administration and the much higher sensitivity of rodents to changes in thyroid related endocrinology as compared with humans do not support a role for fluoride induced thyroid perturbations in humans.
--There is no new evidence from human studies indicating that fluoride in drinking water influences male and female reproductive capacity.

Water Fluoridation Chemicals:
A common argument used by fluoridation opponents is
, "After being captured in the scrubbers, the fluoride acid (hydrofluorosilicic acid), a classified hazardous waste, is barreled up and sold, unrefined, to communities across the country. Communities add hydrofluorosilicic acid to their water supplies as the primary fluoride chemical for water fluoridation."

The implication, of course, is that the products used in community water treatment plants to fluoridate the water is a witches brew of deadly chemicals.  The truth is that water treatment plants that add fluoride to drinking water do so with products that are rigorously tested and certified by NSF International to be safe and free of harmful levels of toxic chemicals.  The fluoridation chemicals are valuable co-products of the fertilizer industry, not waste products
NSF Fact Sheet on Fluoridation Chemicals: According to the latest Association of State Drinking Water Administrators Survey on State Adoption of NSF/ANSI Standards 60 and 61, 45 states require that chemicals used in treating potable water must meet Standard 60 requirements. If you have questions on your state's requirements, or how the NSF/ANSI Standard 60 certified products are used in your state, you should contact your state's Drinking Water Administrator. Standard 60 was developed to establish minimum requirements for the control of potential adverse human health effects from products added directly to water during its treatment, storage and distribution. The standard requires a full formulation disclosure of each chemical ingredient in a product. It also requires a toxicology review to determine that the product is safe at its maximum use level and to evaluate potential contaminants in the product. The standard requires testing of the treatment chemical products, typically by dosing these in water at 10 times the maximum use level, so that trace levels of contaminants can be detected. A toxicology evaluation of test results is required to determine if any contaminant concentrations have the potential to cause adverse human health effects. Table 1 documents that there is no contamination of drinking water from the fluoridation products NSF has tested and certified.
Water Fluoridation and the Environment: Scientific evidence supports the fluoridation of public water supplies as safe for the environment and beneficial to people. Reports at the local, national, and international levels have continued to support this most important public health measure. There appears to be no concern about the environmental aspects of water fluoridation among those experts who have investigated the matter. Furthermore, since the chemicals used for water fluoridation are co-products of the manufacture of phosphate fertilizers, and the raw material used is a natural resource (rocks excavated for their mineral content), water fluoridation could accurately be described as environmentally friendly, as it maximizes the use made of these natural resources, and reduces waste. (H. Pollick,  INT J OCCUP ENVIRON HEALTH, 2004)
Blood Lead Concentrations in Children and Method of Water Fluoridation in the United States, 1988–1994: Controlling for covariates, water fluoridation method was significant only in the models that included dwellings built before 1946 and dwellings of unknown age. Across stratum-specific models for dwellings of known age, neither hydrofluosilicic acid nor sodium silicofluoride were associated with higher geometric mean PbB concentrations or prevalence values. Given these findings, our analyses, though not definitive, do not support concerns that silicofluorides in community water systems cause higher PbB concentrations in children. Current evidence does not provide a basis for changing water fluoridation practices, which have a clear public health benefit. (M. Macek, et al. – Environ Health Perspect v.114(1); 2006 Jan)
Can Fluoridation Affect Lead (II) In Potable Water? Hexafluorosilicate and Fluoride Equilibria In Aqueous Solution Overall:  We conclude that no credible evidence exists to show that water fluoridation has any quantitatable effects on the solubility, bioavailability, bio- accumulation, or reactivity of lead(0) or lead(I1) compounds. The governing factors are the concentrations of a number of other species, such as (bi)carbonate, hydroxide, or chloride, whose effects far exceed those of fluoride or fiuorosilicates under drinking water conditions." (Urbansky, E.T., Schocks, M.R. - Intern. J . Environ. Studies, 2000, Vol. 57. pp. 597-637)
Health effects of water fluoridationa: A review of the scientific evidence - A 2014 report on behalf of the Royal Society of New Zealand and the Office of the Prime Minister's Chief Science Advisor:  Given the caveat that science can never be absolute, the panel is unanimous in its conclusion that there are no adverse effects of fluoride of any significance arising from fluoridation at the levels used in New Zealand. In particular, no effects on brain development, cancer risk or cardiovascular or metabolic risk have been substantiated, and the safety margins are such that no subset of the population is at risk because of fluoridation. All of the panel members and ourselves conclude that the efficacy and safety of fluoridation of public water supplies, within the range of concentrations currently recommended by the Ministry of Heath, is assured. We conclude that the scientific issues raised by those opposed to fluoridation are not supported by the evidence.  An anti-fluoridation critique, and a rebuttal.

2005: 60th Anniversary of Community Water Fluoridationn
he American Dental Association released an updated version of Fluoridation Facts.  If you have any questions about fluoridation (and are willing to consider the subject with an open mind) this paper addresses nearly all of the anti-fluoride arguments, clearly describes how to evaluate available evidence on the subject, and concludes:

"Support for fluoridation among scientists, and health professionals, including physicians and dentists, is nearly universal."

"...Opposition to fluoridation has existed since the initiation of the first community programs in 1945 and continues today with over 60 years of practical experience showing fluoridation to be safe and effective."

"...An article that appeared in the local newspapers shortly after the first fluoridation program was implemented in Grand Rapids, Michigan, noted that the fluoridation program was slated to commence January 1 but did not actually begin until January 25. Interestingly, health officials in Grand Rapids began receiving complaints of physical ailments attributed to fluoridation from citizens weeks before fluoride was actually added to the water."

A systematic review of the efficacy and safety of Fluoridation (a 189 page paper from the Australian Government National Health and Medical Research Council - 2007). The Executive Summary starting on page 12 of the Part-A pdf file provides an overview of and conclusions from the remaining 150+ pages)
NHMRC Recommendation: (2-page summary).  The paper reviews 77 studies selected from over 5,400 papers published on fluoride/fluoridation between 1996 and 2006.  Criteria for inclusion and exclusion in the review can be found in the paper, and a list of the excluded papers can be found in Part-B.
Conclusions: Fluoridation of drinking water remains the most effective and socially equitable means of achieving community-wide exposure to the caries prevention effects of fluoride. It is recommended that water be fluoridated in the target range of 0.6 to 1.1 mg/L, depending on climate, to balance reduction of dental caries and occurrence of dental fluorosis.
Queensland Health fluoridation information: Keeping your teeth in good shape not only gives you a great smile. It also helps to improve your general health. On this website you'll find out the right way to care for your teeth and gums and you'll discover the benefits of Queensland's fluoridated water program.

The Science of Fluoride: This publication pulls together the official policy statements and consumer information on fluoride from the nation's leading scientific and advocacy organizations that support community water fluoridation. It is an effort to give you the whole truth about fluoride - its benefits, its risks and its history. ...
Fluoridation of community water systems is not the only way to administer fluoride and reduce cavities. Some countries in Europe put fluoride in salt. Some invest heavily in school-based dental programs. Many countries rely on socialized medicine to ensure regular dental care and fluoride treatments. The American model allows individual states or communities to decide on the best ways to protect oral health. Since the 1940s, many have relied upon community water fluoridation. To date, about two-thirds of the nation adds fluoride to its water, one reason once common dental problems are now at an all-time low.
Linus Pauling Institute Micronutrient Information Center: Although its role in the prevention of dental caries (tooth decay) is well established, fluoride is not generally considered an essential mineral element because humans do not require it for growth or to sustain life. However, if one considers the prevention of chronic disease (dental caries) an important criterion in determining essentiality, then fluoride might well be considered an essential trace element.
The Canadian Dental Association (CDA) supports fluoridation of municipal drinking water (at minimum levels required for efficacy as recommended by the Federal-Provincial Subcommittee on Drinking Water) as a safe, effective and economical means of preventing dental caries in all age groups. Fluoride levels in the water supplies should be monitored and adjusted to ensure consistency in concentrations and avoid fluctuations.
The Canadian Association of Public Health Dentistry (CAPHD) endorses community water fluoridation as an important public health measure to prevent dental caries (tooth decay) in a population. It is safe, effective, ethical, legal, reduces oral health disparities and is cost-effective.  September 2014 statement.  Water Fluoridation Questions & Answers
World Health Organization (WHO) Guidelines for Drinking-water Quality 4th editon - ...There is no difference in absorption between natural or added fluoride in drinking-water. ...Fluoride may be an essential element for humans; however, essentiality has not been demonstrated unequivocally. Meanwhile, there is evidence of fluoride being a beneficial element with regard to the prevention of dental caries. ...Low concentrations [of the fluoride ion] provide protection against dental caries, both in children and in adults. The protective effects of fluoride increase with concentration up to about 2 mg of fluoride per litre of drinking-water; the minimum concentration of fluoride in drinking-water required to produce it is approximately 0.5 mg/l. ...There is no evidence to suggest that the guideline value of 1.5 mg/l set in 1984 and reaffirmed in 1993 needs to be revised. Concentrations above this value carry an increasing risk of dental fluorosis, and much higher concentrations lead to skeletal fluorosis. The value is higher than that recommended for artificial fluoridation of water supplies, which is usually 0.5–1.0 mg/l.  [Note - because of increased community water fluoridation over the last 70 years, exposure to the fluoride ion has increased in foods and other beverages - consequently the recommended upper level for fluoridation is now 0.7 mg/L.]
World Health Organization (WHO) - Many communities worldwide lack sufficient natural fluoride in their drinking water to prevent caries. Because of the powerful benefits of the right amount of fluoride, water fluoridation programmes have been established in many countries since the 1930s when its ability to reduce dental caries was first recognized.
Water fluoridation in low fluoride-containing water supplies helps to maintain optimal dental tissue development and dental enamel resistance against caries attack during the entire life span. Fluoride in drinking water acts mainly through its retention in dental plaque and saliva. Frequent consumption of drinking water and products made with fluoridated water maintain intra-oral fluoride levels. People of all ages, including the elderly, benefit from community water fluoridation.
In general, dental fluorosis does not occur in temperate areas at concentrations below 1.5-2 mg of fluoride per litre of drinking-water. In warmer areas, because of the greater amounts of water consumed, dental fluorosis can occur at lower concentrations in the drinking-water (IPCS, 1984; US EPA, 1985a; Cao et al. – 1992). It is possible that in areas where fluoride intake via routes other than drinking-water (e.g., air, food) is elevated, dental fluorosis will develop at concentrations in drinking-water below 1.5 mg/litre (Cao et al. – 1992).
The effective use of fluorides in public health:
Common themes are the concern to reduce demands for compliance with fluoride regimes that rely upon action by individuals and their families, and the issue of cost. We recommend that a community should use no more than one systemic fluoride (i.e. water or salt or milk fluoridation) combined with the use of fluoride toothpastes, and that the prevalence of dental fluorosis should be monitored in order to detect increases in or higher-than-acceptable levels. (Jones S, et al. – Bulletin of the World Health Organization | September 2005, 83 (9))
UNICEF Handbook on Water Quality - 2008:  Unlike arsenic, fluoride is beneficial at low doses. Higher rates of dental caries are observed below approximately 0.5 mg/L, and in many countries fluoride is routinely added to drinking water (typically from 0.7-1.2 mg/L) to improve dental health. This protective effect increases up until about 2 mg/L.
The Irish Dental Association:  In common with every other recognized national dental association across the world, the Irish Dental Association strongly supports the policy of fluoridation in Ireland as an essential element of oral health policy. The benefits of fluoridation as regards the oral health of the population, and most particularly those in deprived circumstances, are extremely well documented..
The British Fluoridation Society was founded in 1969 by a group of concerned professionals anxious to see an improvement in the dental health of the UK population by implementation of Government policy for water fluoridation. Founder members include Eric Lubbock MP (now Lord Avebury, and Vice-chair of the Parliamentary Human Rights Group). From its inception the Society has been a multi-disciplinary organisation, and has enjoyed the support of politicians from all political parties.
Water fluoridation: health monitoring report for England 2014:  Conclusion The report provides further reassurance that water fluoridation is a safe and effective public health measure. Public Health England continues to keep the evidence base under review and will use this report as part of an ongoing dialogue with local authorities before publishing a further report within the next four years. Summary, Reported in the BMJ, Commentaryry
The American Academy of Pediatric Dentistry (AAPD) - ...affirming that fluoride is a safe and effective adjunct in reducing the risk of caries and reversing enamel demineralization, encourages public health officials, health care providers, and parents/caregivers to optimize fluoride exposure.The adjustment of the fluoride level in community water supplies to optimal concentration is the most beneficial and inexpensive method of reducing the occurrence of caries. Epidemiologic data within the last half-century indicate reductions in caries of 55 to 60% and recent data still shows caries reduction of approximately 25%, without significant enamel fluorosis, when domestic water supplies are fluoridated at an optimal level. Evidence accumulated from long-term use of fluorides has demonstrated that the cost of oral health care for children can be reduced by as much as 50%.

1978: 33rd Anniversary of Community Water Fluoridation
GK Tokuhata, et al. described the anti-fluoridation sentiment,

"However, controversy (maintained by a segment of the general public and professional community) continues regarding possible adverse effects of fluoridation on human health. The National Cancer Institute and the National Heart and Lung Institute have recently issued statements that refute claims suggesting a relationship between fluoridated water and mortality from cancer and heart disease."

Their paper emphasizes the scrutiny to which fluoridation has been subject, "Fewer health measures have been accorded more clinical and laboratory research, epidemiologic study, massive clinical trials of total community populations, and public attention) both favorable and adverse) than the fluoridation of public water supplies. As a result, knowledge of the dental and nondental physiological effects of fluoridation has increased significantly since Grand Rapids, Mich., was first experimentally fluoridated in 1945. There is now considerable evidence that fluoridation of community water supplies is both effective and safe."
The Centers for Disease Control and Prevention (CDC): Community water fluoridation prevents tooth decay safely and effectively. CDC identified Fluoridation of Drinking Water as one of 10 great public health achievements of the 20th century. - Recommendations for Using Fluoride to Prevent and Control Dental Caries in the United States - The weight of the peer-reviewed scientific evidence does not support an association between water fluoridation and any adverse health effect or systemic disorder, including an increased risk for cancer, Down syndrome, heart disease, osteoporosis and bone fracture, immune disorders, low intelligence, renal disorders, Alzheimer disease, or allergic reactions. Additional information can be found on the Safety page.
National Cancer Institute: Key Points - Fluoride prevents and can even reverse tooth decay. More than 60 percent of the U.S. population on public water supply systems has access to water fluoridated at approximately 1 part fluoride per million parts water - the optimal level for preventing tooth decay. Many studies, in both humans and animals, have shown no association between fluoridated water and risk for cancer.

American Cancer Society - Water Fluoridation and Cancer Risk: The general consensus among the reviews done to date is that there is no strong evidence of a link between water fluoridation and cancer. However, the last of these reviews was published in 2006. Several of the reviews noted that further studies are needed to clarify the possible link.  ...Two more recent studies have compared the rates of osteosarcoma in areas with higher versus lower levels of fluoridation in Ireland (2011) and the United States (2012). Neither study found an increased risk of osteosarcoma in areas of water fluoridation.
American Medical Association (AMA): Fluoridation of community drinking water is a major factor responsible for the decline in dental caries (tooth decay) during the second half of the 20th century. The history of water fluoridation is a classic example of clinical observation leading to epidemiologic investigation and community-based public health intervention. Although other fluoride-containing products are available, water fluoridation remains the most equitable and cost-effective method of delivering fluoride to all members of most communities, regardless of age, educational attainment, or income level.  Safety of Water Fluoridation: Early investigations into the physiologic effects of fluoride in drinking water predated the first community field trials. Since 1950, opponents of water fluoridation have claimed it increased the risk for cancer, Down syndrome, heart disease, osteoporosis and bone fracture, acquired immunodeficiency syndrome, low intelligence, Alzheimer disease, allergic reactions, and other health conditions. The safety and effectiveness of water fluoridation have been re-evaluated frequently, and no credible evidence supports an association between fluoridation and any of these conditions. (2000) - Full Report
Pew Report Finds Majority of States Fail to Ensure Proper Dental Health and Access to Care for Children.  Report Shows Need for Low-Cost Solutions: The report highlights four proven solutions that can improve both the dental health of children and their access to care.  Solution #2 - Community water fluoridation: Water fluoridation stands out as one of the most effective public health interventions that the United States has ever undertaken. Fluoride counteracts tooth decay and, in fact, strengthens the teeth.
A 2008 study found that women who grew up in communities with fluoridated water earned approximately 4 percent more than women who did not. The effect was almost exclusively concentrated among women from low-income families, and fluoride exposure in childhood was found to have a robust, statistically significant effect on income, even after controlling for a variety of trends and community-level variables. The authors of the study attributed this difference primarily to consumer and employer discrimination against women with missing or damaged teeth. (Published February, 2010)
American Public Health Association - Community Water Fluoridation in the United States, 2008 Policy Statement: Since 1950 APHA has supported CWF as a safe and effective public health measure for the prevention of dental caries (tooth decay), reaffirming this policy in 1955, 1956, 1959, 1963, 1965, 1969, 1974, 1975, 1976, 1977,,16 1979, 1980, 1982, 1992, 1997, 2000, 2001, and 2006.
Healthy Teeth For A Lifetime:  This website contains an interesting selection of information about fluoridation benefits.

Journal of the Massachusetts Dental Society
Fluoridation Update 2014:  Fluoridation is being challenged in Massachusetts and nationwide because a vocal minority has been adept at confusing and scaring the public on the safety and effectiveness of fluoridation.  The public is being misled daily on the Internet. Antifluoridationists continue to mislead, misinform, and scare the public with poorly done studies or misinterpreted results of studies conducted by reputable individuals, organizations, or institutions. 
This update contains excellent corrections to the misrepresented results of several studies and topics regularly used by fluoridation opponents including, the 2012 Harvard IQ Study, the 2014 Lancet Neurology article, the 2005 Harvard study on osteosarcoma, infant formula and fluorosis.

1955: 10th Anniversary of Community Water Fluoridation
Francis Heyroth, M.D. wrote an early descriptions of the Fluoridation controversy in 1955,

"The extravagance of the variously motivated statements frequently heard in opposition to fluoridation wherever it is under consideration may lead officials who must explain this prophylactic measure to the public to discount the fact that many citizens still remain unconvinced of the safety of this procedure, despite the assurances of medical, dental, and public health authorities."

Heyroth concludes, "The evidence as a whole is consistent in offering assurance that bringing the fluoride concentration in communal water supplies to that known to be optimal for dental health is a prophylactic public health procedure which has an ample margin of safety."
To Fluoridate or not: Some Communities Still Struggle for Answers.  On Tap Magazine, Fall 2004
> Stronger teeth, fewer cavities - and ultimately - fewer trips to the dentist. Fluoridating public water is a community health measure that helps prevent tooth decay. How could anyone find fault with it?
> 'Fluoridation is the most cost-effective, practical, and safe means for reducing the occurrence of tooth decay in a community.' Former Surgeon General David Satcher, 2001. 
> Like many chemicals and simpler substances we encounter in life, fluoride in large doses or in a concentrated form can hurt us. Studies showing harm from ingesting excessive amounts of fluoride have helped fuel public fears. But large amounts of plenty of things can be toxic. The ADA lists normally innocent things like salt, iron, vitamins A and D, oxygen, and even plain water as being harmful in large quantities.
> CDC Asserts Safety Fluoride: "Some people worry that with all the potential fluoride sources that are available we might be overdosing on the stuff". Kip Duchon, the national fluoridation engineer with the CDC in Atlanta, says that is unlikely. 'We're not talking about a lot of fluoride in waterer,' he says. 'All the research shows that even with these other methods you're really not anywhere near overdosing.'
When public action undermines public health: a critical examination of antifluoridationist literature
SUMMARY: Water fluoridation is an important public health initiative that has been found to be safe and effective. Nonetheless, the implementation of water fluoridation is still regularly interrupted by a relatively small group of individuals who use misinformation and rhetoric to induce doubts in the minds of the public and government officials. It is important that public health officials are aware of these tactics so that they can better counter their negative effect.
Free - Full Article (2007)   Connett's comments and rebuttal
The Anti-Fluoridationist Threat to Public Health: The scientific consensus over fluoridation’s health benefits, safety, social justice, and economies has been firmly established over six decades of widespread use in the United States and elsewhere. Nevertheless, anti-science critics have never relented in their opposition — recycling previously disproven charges of harm, inventing new ones out of whole cloth, misrepresenting scientific facts and research, exaggerating risks, understating benefits, inappropriately invoking the precautionary principle, and accusing public health officials of corruption, conspiracy, and ‘mass medication’ of whole populations. (2012)
All About Fluoridation: A few fringe activists claim that fluoridation of water carries more danger than benefit.
Response to a list of '50 Reasons to Oppose Fluoridation' compiled by Dr Connett:  This report offers comments on the listed '50 Reasons to Oppose Fluoridation' by Dr Connett. The 50 reasons are put forward by Dr Connett as a 'thorough review of the scientific literature as regards both the risks and benefits of being exposed to the fluoride ion'. However, the listing is not a review, but a selection of published findings that question or use data to cast doubt on the value and safety of fluoridation. No balance of evidence for- and against- fluoridation is provided, as might be expected in a review.

ht - also here
A critical appraisal of, and commentary on, '50 Reasons to oppose fluoridation': The author of the '50 Reasons' document has stated (in one of the many versions of the '50 Reasons' document' that the '50 Reasons' offered in this article for opposing fluoridation are based on a thorough review of the scientific literature as regards both the risks and benefits of being exposed to the fluoride ion.' However, as already noted, the '50 Reasons' document fails to conform to any generally accepted principles for assembling, evaluating and interpreting medical research. There is no explicit statement of the questions being addressed; no systematic search for pertinent research; no use of a priori selection criteria to separate relevant from irrelevant research; no critical appraisal of studies to determine their validity and no integration of evidence based on sources of evidence, research design, direction and magnitude of clinical outcomes, coherence and precision. No conclusions can or should be drawn from this poor quality document. [Note that the 50 reasons document that this critique references is updated regularly.  This paper discusses versions available before 2005, but it illustrates the overall methodology of fluoridation opponents.]
Talking With The Guy Who Puts Fluoride in D.C.'s Water:  "A question that comes up from time to time has to do with the impurities in the product that we use to introduce fluoride. We, along with most utilities, use fluorosilicic acid. That is produced as a byproduct of the fertilizer industry, specifically in the mining of phosphate. We get a detailed report with each shipment showing the impurities, and the ones that draw attention are lead and arsenic. But these elements, while measurable in the product when delivered, are not detectable because of the great dilution in the finished water. So while it is important to know what impurities may be introduced in any chemical we add during water treatment (e.g., aluminum sulfate for coagulation; chlorine or sodium hypochlorite for disinfection; lime for pH control, orthophosphate for corrosion control, and various polymers to aid in effective treatment), we are completely confident that these trace impurities do not affect the safety of the drinking water."  Tom Jacobus, general manager of the Washington Aqueduct since 1994 in a 2010 interview.

Health Effects of Ingested Fluoride Free Online Book
Authors: Subcommittee on Health Effects of Ingested Fluoride, National Research Council
 Description: This 1993 book reviews the effects on health of fluoride ingested from various sources. Those health effects reviewed include dental fluorosis; bone fracture; effects on renal, reproductive, and gastrointestinal systems; and genotoxicity and carcinogenicity. The book also reviews the Environmental Protection Agency's current drinking-water standard for fluoride and considers future research needs. Point by point comparison with the 2006 National Research Council Fluoride report.
Fort Collins, Colorado, Fluoride Technical Study Group Report:
The Health District was a participant in the Fluoride Technical Study Group, which included community members with an interest in community drinking water fluoridation and with specific technical, medical or scientific capabilities. The group met at least once a month between December 2001 and December 2002. The group presented a report to the Fort Collins City Council which voted to continue fluoridation of city water supplies in July 2003. The findings of the report prompted the Health District's Board of Directors to vote to recommend that the city continue fluoridation.  Full Report
Local PBS Radio Report
on the issue
  (search on fluoride)
Fort Collins voters will soon decide on an initiative that would stop fluoridating the city's water.
Part 1) Pati Caputto, a clinical nutritionist and leader of Clean Water Advocates, a group campaigning against fluoridation, shares her perspective.
Part 2)  Dr. Greg Evans, a pediatric dentist and member of the Vote No On 2 committee, shares his perspective.
Position of the Academy of Nutrition and Dietetics: the impact of fluoride on health:  
Abstract - It is the position of the Academy of Nutrition and Dietetics to support optimal systemic and topical fluoride as an important public health measure to promote oral health and overall health throughout life. Fluoride is an important element in the mineralization of bone and teeth. The proper use of topical and systemic fluoride has resulted in major reductions in dental caries and its associated disability. Dental caries remains the most prevalent chronic disease in children and affects all age groups of the population. The Centers for Disease Control and Prevention has named fluoridation of water as one of the 10 most important public health measures of the 21st century. Currently, >72% of the US population that is served by community water systems benefits from water fluoridation. However, only 27 states provide fluoridated water to more than three quarters of the state's residents on public water systems. Fluoride also plays a role in bone health. However, at this time, use of high doses of fluoride for osteoporosis prevention is considered experimental only. Dietetics practitioners should routinely monitor and promote the use of fluorides for all age groups. (J Acad Nutr Diet. 2012 Sep;112(9):1443-53)

Top Cairns dentist defends fluoridea:  Queensland Health Cairns district director of oral health Robyn Boase said the effect dental decay had on children was far more of a concern than the effect of fluoride on the human body. "Fluoride has come up trumps in preventing dental decay and not causing any side effects," Dr. Boase said. "It helps stabilize the mineral content of bones and teeth. "I think people forget that dental decay is extremely toxic. "We have a condition called early childhood caries. It's the most frequent cause of hospitalization in children up to age 4. "People don't get hospitalized from drinking fluoridated water. They get hospitalized from dental decay."
One in a million: The first community trial of water fluoridation - January 1, 1945 in Grand Rapids Michigan.

Fluoridation of water. Hearings before the Committee on Interstate and Foreign Commerce, House of Representatives, Eighty-third Congress, second session, on H. R. 2341. A bill to protect the public health from the dangers of fluorination of water. May 25, 26, 27, 1954.  The 491 page record of a debate on water fluoridation 9 years after the introduction of community water fluoridation in Grand Rapids Michigan.  The first two thirds of the document is largely anti-fluoride arguments and the last third is the pro-fluoride rebuttal.  Things have not changed much in the decades since this debate.
History of Water Fluoridation, Joe Mullen, Dr.  (British Dental Journal 199, 1 - 4 (2005)
Water fluoridation has been described by the Centre for Disease Control as one of the ten most important public health advances of the 20th Century1. In this brief paper, I will describe the history of water fluoridation and discuss the value of this policy in the early years of the 21st Century.

Fluoridation of Water, Skeptic's dictionary
In 1950, the United States Public Health Service recommended that communities without naturally occurring fluoride add it to their public water supplies at a concentration of 1.0 ppm. Despite the fact that doing so would mean a reduction in business for those dentists who filled the cavities of youngsters, the American Dental Association supported the policy. The safety of fluoridation has been challenged many times. In the small amounts that people are likely to be exposed to from public drinking water, the main health concern that has not been exaggerated and distorted over the years is the fear of dental fluorosis. (The staining and pitting of teeth from too much fluoride does not affect adults, so concerns about fluorosis focus on the amount of fluoride children are likely to be exposed to.) In January 2011, the U.S. Department of Health and Human Services proposed to change its recommended limit for fluoride to 0.7 mg/L, replacing the current recommended range of 0.7 to 1.2 mg/L.
National Fluoridation Information Services, Review of Scientific Reviews Relating to Water Fluoridation Published between January 2000 and July 2010: With the exception of one review article (Pizzo et al. – 2007), which concluded that there may be situation in which water fluoridation is unnecessary in the developed world, all revues reviewed supported water fluoridation. (Scroll down - this 128 page document is mostly blank at the top)
The National Center for Fluoridation was developed in 1996, with the Center's Internet web site being established in 1998 to serve as a central repository for information regarding all aspects of community water fluoridation. The Center became a major program of Oral Health America in 2004. Currently, the Center's web site provides a means to link site visitors to a fairly substantial number of fluoridation, consumer protection, public health, & public health dentistry websites. Archival information, which includes consumer information, scientific documents, databases, multimedia productions, legal transcripts, educational materials, & other documents related to fluoridation research, litigation, legislation, & policy development, is being added to the web site's NCF Reference Library.
FDI World Dental Federation -  Representing over one million dentists in 134 countries. Mission: to be the worldwide, authoritative and independent voice of the dental profession.
In recognition of the importance of promoting dental health through water fluoridation, the FDI World Dental Federation states that:

"...At the fluoride concentrations recommended for the prevention of dental decay, human health is not adversely affected. ...The public health benefits of water fluoridation far outweigh the possible occurrence of very mild enamel fluorosis/enamel opacities. The FDI recognises that prevention by using fluoride is the most realistic way of reducing the heavy burden of dental decay worldwide."
Statements on Community Water Fluoridation - Position statements supporting fluoridation from a variety of organizations.

Caries prevention on tap
With nearly 50 years of fluoridation in Ireland and 65 in the US, Dr Joe Mullen PDS provides an update on the latest thinking on the public health policy:
Water fluoridation is an important public health measure. It is listed by the Centre for Disease Control in the United States as being one of the 10 most important public health initiatives of the 20th Century. It is an initiative which, from the very start, has been supported by the dental profession in Ireland. Indeed, in the 1960s the Irish Dental Association was at the forefront in making the case for what was then a radically new approach to the management of dental decay. However, it is the case that the justification for the policy water fluoridation requires constant revision. If a better way of achieving the same ends becomes available, we should not hesitate to move away from this policy. Similarly, if evidence of genuine negative health effects came to light, it would require change. We know that not fluoridating also carries health risks. We also know that if general health risks do exist, they have escaped detection in the 70 years or so that the topic has been researched. But that is not to say they do not exist. Continued scrutiny is required. (Dr Mullen 2010-2011) About 100 nationally and internationally known organizations including the Center for Disease Control, the American Dental Association, the American Medical Association, the American Public Health Association, the National Kidney Foundation, the World Health Organization, the American Cancer Society, the American Water Works Association, the National Association of City and County Health Officials as well as the last four US Surgeons General endorse water fluoridation." Go to  for the whole list. - 14 Fluoridation Facts Articles (about 1/2 way down the page), including: - Fluoridation: Don't Let the Poisonmongers Scare You!
Review of Fluoride: Benefits and Risks

Report of the ad hoc subcommittee on fluoride of the committee to coordinate environmental health and related programs.  Extensive studies over the past 50 years have established that individuals whose drinking water is fluoridated show a reduction in dental caries. Although the comparative degree of measurable benefit has been reduced recently as other fluoride sources have become available in non-fluoridated areas, the benefits of water fluoridation are still clearly evident. Fewer caries are associated with fewer abscesses and extractions of teeth and with improved health. The health and economic benefits of water fluoridation accrue to individuals of all ages and socioeconomic groups, especially to poor children. (1991)
Guide to Community PreventiveServices - Preventing Dental Caries: Community Water Fluoridation (2013 update)

Task Force Finding: The Community Preventive Services Task Force recommends community water fluoridation based on strong evidence of effectiveness in reducing dental caries across populations. Evidence shows the prevalence of caries is substantially lower in communities with CWF. In addition, there is no evidence that CWF results in severe dental fluorosis.  Complete Task Force Finding

Abuse of the Scientific Literature in an Antifluoridation Pamphlet (1988): A number of specific techniques have been used by antifluoridationists in their attempts to prevent fluoridation of public water supplies. For instance, by repeatedly alleging that fluoride causes cancer, kidney disease, heart disease, and other serious maladies, fluorophobics persuade some people that their claims are true, even though no scientifically valid evidence exists to corroborate their allegations. The public tends to believe such claims, assuming that their repeated appearance in print, most often in letters-to-the-editor columns, is evidence of their validity and that "authorities" would "never" allow unproven claims to be printed. Antifluoridationists have also become masters of the use of half-truths and innuendo. 
Among the most serious violations of the scientific ethic are those with which this monograph focuses and which can be categorized as abusive uses of the scientific literature. Opponents of fluoridation frequently quote statements that are out of date, taken out of context, or misrepresentations of legitimate scientific research. Numerous examples of this technique are apparent when one reviews closely the popular antifluoride pamphlet, "Lifesavers [sic] Guide to Fluoridation".'

As will be illustrated repeatedly in the following pages, many references for the pamphlet's claims of hazard are from obscure or hard-to-locate journals. Those articles referred to as containing the most convincing antifluoride arguments are usually not from recognized peer-reviewed journals and often are authored by the same antifluoridationists editing the controversial journals.
Painstaking library research by Wulf and colleagues has shown that many of the references used actually support fluoridation, with works of respected fluoride researchers selectively quoted and misrepresented in order to appear to discourage the use of fluorides. The average consumer, unable to properly evaluate misinformation and misrepresentations in the antifluoride literature, falls prey to what amounts to a marketing fraud.
Nothing summarizes the situation better than the often-repeated quotation from a 1978 Consumer Reports article, "The simple truth is that there's no 'scientific controversy' over the safety of fluoridation. The practice is safe, economical, and beneficial. The survival of this fake controversy represents, in CU's [Consumers' Union] opinion, one of the major triumphs of quackery over science in our generation."

[This is an interesting, though dated, analysis of 250 anti-fluoride references provided by one of the most active and influential fluoridation opponents, John Yiamouyiannis.  The original book provides an analysis of each reference - the linked article is a summary.  The specific references used by today's fluoride opponents are different, but the way that references are used and abused remain the same - RJ]
Fluoride and IQ:
One of the newer health claims made by fluoridation opponents is that fluoride exposure from drinking water, even at fluoride levels around 2.5 - 4 mg/l, can lower IQ.  Recent papers that report a correlation between high fluoride levels and low IQ scores are reviewed in the Bazian Review of IQ Studies: The summary states - The primary studies reviewed were conducted in China, Mexico, Iran and India. They sought to investigate whether high environmental exposure to fluoride or arsenic or low exposure to iodine, was associated with lower IQ and used observational (cross sectional and ecological) methods.
In our appraisals we found that the study design and methods used by many of the researchers had serious limitations. The lack of a thorough consideration of confounding as a source of bias means that, from these studies alone, it is uncertain how far fluoride is responsible for any impairment in intellectual development seen. The amount of naturally occurring fluoride in drinking water and from other sources and the socioeconomic characteristics in the areas studied is different from the UK and so these studies do not have direct application to the local population of Southampton.

--The authors of the primary observational studies have not consistently adjusted for the following confounding factors: the differences in environmental arsenic and iodine in water, parental education, and socioeconomic measures between the populations. There is a possibility that some or all of the impairment in IQ can be explained by these or other unmeasured or unknown factors.
--The authors of one of the systematic reviews have combined the results of these confounded observational studies into summary measures by meta analysis in a way that is not statistically appropriate or valid. The authors' interpretation of the results is incorrect.
--The findings are unlikely to be directly applicable to the population of Southampton because the level of fluoride found in the high fluoride areas in this research was generally higher than that intended for use in water fluoridation schemes (1ppm), or was confounded by varying levels of other chemicals in drinking water that are not a problem in the UK (iodine or arsenic).
--Sources of fluoride exposure exist in these settings that do not exist in the UK setting, for example, burning high fluoride coal and eating contaminated grain, which can substantially contribute to fluoride exposure. - Wikipedia Article
The Community Guide - Preventing Dental Caries: Community Water Fluoridation Community Water Fluoridation is strongly recommended based on its effectiveness in reducing the occurrence of dental caries within communities. Other positive effects mentioned, but not systematically evaluated, include (1) reducing disparities in caries risk and experience across subgroups defined by socioeconomic status, race or ethnicity, and other predictors of caries risk; and (2) the 'halo' or 'diffusion' benefits to residents of nonfluoridated communities by means of exposure to processed food and beverages made from fluoridated water. - Wikipedia Article
Water fluoridation is the controlled addition of fluoride to a public water supply to reduce tooth decay. Fluoridated water refers to water that contains fluoride (either naturally occurring or artificially added) at a level that is effective for preventing cavities. - Wikipedia Article
Water fluoridation controversy
refers to moral, ethical, and safety concerns regarding the fluoridation of public water supplies. The controversy occurs mainly in English-speaking countries, as Continental Europe does not practice water fluoridation, although some continental countries fluoridate salt.
Drinking Water and Health, Volume 1:  This scientific study specifically considered potential adverse health effects of substances in drinking water. The central effort of the study was an assessment of the long-term biological effects of ingesting the variety of different substances present in trace amounts in drinking water. The volume included an extensive analysis on fluoride intake and concluded that 'There is no generally accepted evidence that anyone has been harmed by drinking water with fluoride concentrations considered optimal.' Only two adverse health effects were identified including dental fluorosis and skeletal fluorosis 'occurring when fluoride is at levels in excess of the concentrations recommended for good oral health.' (Fluoride, pages 369 - 434)

Some blogs about fluoridation and anti-fluoridation claims from a variety of sources:
Healthcare Triage: Fluoride: "Another myth that refuses to die: Every once in a while chain emails or Facebook posts make their way back into prominence. It happened last year with HPV killing girls. Recently, it seems to be Fluoride. A number of you have been forwarding me a post from last year which features a meta-analysis published a few years ago on Fluoride and IQ. So let’s talk about Fluoride!" (Dr. Aaron Carroll)   Video - Fluoride in the Water Isn't Going to Hurt You The Danger du jour: Fluoride - a review of the "Harvard IQ Study"
The above information was posted on The Incidental Economist, "a blog (mostly) about the U.S. health care system and its organization, how it works, how it fails us, and what to do about it. All blog authors have professional expertise in an area relevant to the health care system. We are researchers and professors in health economics, law, or health services. By avocation and as bloggers we’re actively trying to understand our health care system and make it better. Our goal is to help you understand it too, and to empower you with research-validated information so you can be a more informed observer of or participant in the ongoing debate over how to reform our system."
Fluoridated Water: Science, Scams and Society:  "One of the most contentious issues going on in my city - Portland, OR - right now {April 2013}, is our upcoming vote this May on whether or not we should fluoridate our drinking water. Now, a little disclosure from me, first:  ...if fluoridating our drinking water will result in better overall health for our citizenry than not fluoridating, I'll be in favor of it. And if not - if the risks/bad effects outweigh any benefits - I'll be against it.' (Blog by Ethan Siegel, Starts With a BANG, 4/21/13)  Ethan presents a very complete, succinct and unbiased summary of the fluoridation evidence - RJ.
Fluoride in the Water: For Your Teeth or Government Mind Control?  "So water fluoridation is safe, effective, and saves money (and teeth). There are no physical harms for which there is any evidence for, and the government is not controlling your mind. If you need more proof, below I have outlined the history, safety, and science behind water fluoridation. But of course, that is exactly what the government would want me to do'"  (Kyle Hill, Science-Based Life, 10/17/2011)  Another good summary - RJ 
Portland is Wrong About Water Fluoridation, Kyle Hill, Scientific American, 5/22/2013
All About Fluoridation: "Today we're going to wrap our big juicy lips around the kitchen faucet, turn on the valve, and fill our bodies with a poisonous chemical placed in our water by the government: fluoride." (Brian Dunning, Skeptoid, 7/30/2007)
Anti-fluoridation crankery? How quaintly 1960s!  "I don't have a strong feeling one way or the other about water fluoridation. I tend to go where the evidence leads me, and I realize that lately fluoridation has been questioned, given the widespread use of fluoride in toothpaste, which could potentially produce the same benefits, and increasing concerns about fluorosis. I get it. The issues surrounding the benefits and risks of water fluoridation are not straightforward. They never have been, actually. However, what I don't get are the overheated simplistic arguments that come out of the anti-fluoridation movement."  (Orac, Respectful Insolence, 12/2/2010 - a related blog)
Separating fact from fiction on water fluoridation:  "For close to seven decades now, jurisdictions across the country have been supplementing naturally-occurring fluoride in community water supplies to promote oral health. Numerous studies credit water fluoridation efforts with major reductions in tooth decay during the second half of the 20th century. Many too, attest to the safety of fluoridation at optimum levels. Yet in spite of reams of scientific evidence, debate and fear remain in some places. Last year in Portland, Ore., for example, voters overturned a city council decision to fluoridate the local water supply."  (Mary Otto, Covering Health, 10/23/2014)
Real doctors know best for Dallas: Fluoride is safe and effective - "Looking back over his career in dentistry, Jim said it's easy to name his most important accomplishment - helping get fluoride added to the local water supply in the 1960s." (Steve Blow, Dallas Morning News columnist, 1/14/2015)  A related blog.
Drink the Water, Not the Kool-Aid: A Little Fluoride Won't Hurt Your Kid: "Earlier this week, Newsweek published an article about a possible link between fluoride in water supplies and ADHD. It seems to have caused quite a stir. Just three weeks ago, Newsweek published another article (by the same author) about a potential link between water fluoridation and thyroid disease. If you read the comment threads - which I wouldn't recommend, you'll see fluoride implicated in arthritis, intellectual disability, kidney disease, hip fractures, and a multitude of other maladies. (You may also notice that the vast majority of the hundreds of comments are written by the same handful of people - or that some of the comments are directly copied and pasted onto over 600 other sites - not very creative.) By the time you get to the end, you'll probably be thinking that 'fluoridation is the most monstrously-conceived and dangerous Communist plot we have ever had to face.' But don't knock that glass of water out of your kid's hand just yet.  ...I'll be honest - doctors and dentists aren't perfect. Some aren't even very good. But we're not evil, and we're not oblivious to the need to balance the benefits of our therapies with their potential risks. The thousands of pediatricians and dentists represented by the American Academy of Pediatrics and the American Dental Association aren't trying to poison your child; we've devoted our lives to protecting them." (Chad Hayes, MD, Demystifying Parenting and Pediatrics, 3/14/2015)
Water fluoridation myths - just another blog article:  "Now it's time to look at those water fluoridation myths that can be found in many corners of the internet." (SkepticalRaptorBlog, 5/23/2015)
Antifluoridation Bad Science: "The 'fluoride wars' are likely to continue as long there is a fluoridation program. This is evidence that there is no public safety measure that is so effective, safe, and cost effective that there will not be those who vigorously oppose its implementation." (Steven Novella, Science-Based Medicine, 8/1/2012)
Fluoridation wins at the polls in seven U.S. cities:  "Voters in six U.S. cities chose to retain community water fluoridation and another city opted to restart fluoridation through ballot referenda on Nov. 4. The fluoridation votes affect some 73,000 residents nationwide." (Stacie Crozier, ADA News, 11/12/2014)
Girl Not Against Fluoride: "The fluoride debate is an emotive issue, and because of this, it will probably continue to be controversial. The controversy, however, merely makes it even more important that our politicians do not bow to pressure from scare-tactic groups and appeals to emotion, but decide based on the best available evidence. And that evidence is pretty clear - just ask the WHO, the CDC, the ADA'" (Jennifer Keane, And Another Thing, 09/01/2014)  Blog about the "Girl Against Fluoride"
Girl Against Fluoride: An F minus For Effort:  "For now I'd like a quick look at its most vocal opponent, Aisling FitzGibbon, perhaps better known as the Girl Against Fluoride. She's gained attention from the Sunday World, The Journal, Hot Press, and seems to have earned the ear of politicians such as Thomas Pringle, Brian Stanley and (I note with sadness) Senator David Norris. Her main approach to publicity seems best captured by the Google image search result to the right of this text.  I was curious as to why she so vehemently opposed this safe and long-standing improvement to the dental health of the Irish nation so I travelled to her about page, where I read that FitzGibbon is a qualified 'Master Integrated Energy Therapist'". (Geoff's Shorts, 11/18/2013)
Water fluoridation from Wikipedia, the free encyclopedia: Fluoridation does not affect the appearance, taste or smell of drinking water.[1] Water fluoridation is the controlled addition of fluoride to a public water supply to reduce tooth decay. Fluoridated water has fluoride at a level that is effective for preventing cavities; this can occur naturally or by adding fluoride.[2] Fluoridated water operates on tooth surfaces: in the mouth it creates low levels of fluoride in saliva, which reduces the rate at which tooth enamel demineralizes and increases the rate at which it remineralizes in the early stages of cavities.[3] Typically a fluoridated compound is added to drinking water, a process that in the U.S. costs an average of about $1.02 per person-year

Con/Pro essays on fluoridation
Why I Changed My Mind About Water Fluoridation by John Colquhoun, Perspectives in Biology and Medicine, 41, 1, Autumn 1997 - "To explain how I came to change my opinion about water fluoridation, I must go back to when I was an ardent advocate of the procedure..."
Why We Have Not Changed Our Minds about the Safety and Efficacy of Water Fluoridation: A Response to John Colquhoun by Ernest Newbrun and Herschel Horowitz - In 1997, the journal Perspectives in Biology and Medicine published an opinion piece, "Why I changed my mind about water fluoridation," by John Colquhoun. Although the journal's stated purpose is to convey new ideas or stimulate original thought in biological and medical sciences, Colquhoun presented no new data. His paper rehashed earlier criticisms of water fluoridation, using selective and highly biased citations of the scientific and nonscientific literature.

Published Studies Related to Fluoridation

I have listed references here to some studies that demonstrate positive and negative health effects of three other common water contaminants.  These are just a few of the papers that you can find during a brief search of PubMed that can support drastically different conclusions about the health effects of these contaminants - take a look.

The National Library of Medicine makes medical and scientific journal abstracts and some entire articles available to the general public.  Most journals represented publish peer-reviewed studies for much of the medical and scientific research world wide.  Below are some examples of research papers from the 1950s into 2015 on fluoride and fluoridation to counter the argument that there is NO recent evidence that water fluoridation is beneficial or safe.  As mentioned elsewhere, there are also a few studies listed which examine possible risks. 

I discuss elsewhere details of the many concerns I have with the way fluoridation opponents present their evidence, but I included a specific example below that contrasts two recently published studies to illustrate the differences between a paper that presents evidence that fluoridation does not have a negative effect on IQ and another paper used by fluoride opponents to bolster their claim that fluoridation decreases IQ.

I encourage you to search the National Library of Medicine and evaluate for yourself the evidence for and against community drinking water fluoridation.  Search for terms related to water fluoridation.  A search on general topics like, fluoridation will return a large number of results (6,165 in November 2016), or community water fluoridation, (1,023 results), but it is a good way to find other words to include that limit the search.  For example you can reduce the number of results to a more manageable size by using more restrictive search terms like: water fluoridation caries (3,247 results); water fluoridation safety (1199 results); water fluoridation benefits (200 results); water fluoridation risk (525 results); drinking water fluoridation (910 results);  fluoridation health (2,548 results); water fluoridation cancer (157 results - note that virtually none of the papers actually study the link between fluoridation and cancer); water fluoridation brain (11 results - note the paper on fluoride-induced oxidative stress in the rat brain used concentrations of fluoride in the water 100-200 times greater than found in fluoridated water); water fluoridation IQ (1 result); water fluoridation fractures (88 results); fluoridation ethical (48 results); fluoridation cost (403 results).  If you take time to look through the medical literature on any aspect of fluoridation, I am confident you will discover that papers which support the effectiveness and safety of fluoridation outnumber those which report risks of fluoridation (at recommended levels) by many times.

Fluoridation opponents list on their websites many papers which document claims that fluoridation is harmful and not effective.  Many of these papers are not archived at the National Library of Medicine.  This typically means the papers have not been published in recognized peer-reviewed journals.  The reason usually given is that the traditional dental, medical and scientific communities are so committed to community water fluoridation that they actively block funding and publication of any research that might uncover health risks of fluoridation.  There is, of course another explanation: The majority of research that shows other health risks at optimal fluoridation besides the risks of dental fluorosis, is simply not of high enough quality to be published in a peer reviewed journal.  The publication, Fluoridation Facts, produced by the American Dental Association, describes some of the conditions under which conclusions reached by a study might not be acceptable for publication.

Below is a sample of about 200 research papers and reviews that should, without any question, dispel the myth propagated by some fluoridation opponents that there is no current evidence to support the safety and effectiveness of drinking water fluoridation.  This evidence (updated 11/6/2016) provides specific citations and conclusions from over 60 years of research (1950 - 2016).
Independent and Additive Effects of Different Sources of Fluoride and Dental Fluorosis:   CONCLUSION: In a community with water fluoridation, the factors associated with dental fluorosis are intentional toothpaste ingestion and tooth-paste applied on the whole toothbrush. (Celeste RK & Luz PB – Pediatr Dent. 2016;38(3):233-8)
Measuring the short-term impact of fluoridation cessation on dental caries in Grade 2 children using tooth surface indices:   CONCLUSIONS: Trends observed for primary teeth were consistent with an adverse effect of fluoridation cessation on children's tooth decay, 2.5-3 years post-cessation. Trends for permanent teeth hinted at early indication of an adverse effect. It is important that future data collection efforts in the two cities be undertaken, to permit continued monitoring of these trends. (McLaren L, et al. – Community Dent Oral Epidemiol. 2016 Jun;44(3):274-82)
Water fluoridation and hypothyroidism:   Commentary on the 2015 Peckham et al hypothyroidism study.
The biggest problem with this paper, however, is in the interpretation which puts far too much weight on such weak evidence. The approach used is notoriously unreliable as a way of identifying independent associations and the lack of a clearly established prior hypothesis make it very unconvincing as evidence of a causal relationship. Given the other problems we have identified, this loose interpretation is a very serious concern. Such speculation is likely to result in unfounded public anxiety about a public health intervention which currently protects the health of children's teeth in many parts of the world. (John N Newton, et al. – J Epidemiol Community Health. 2015 Jul; 69(7): 617–618)
Access to Fluoridated Water and Adult Dental Caries - A Natural Experiment:   Participants who accessed fluoridate water <50% of their lifetime presented a higher mean rate ratio of DMFT (1.39; 95% CI, 1.05-1.84) compared with those living >75% of their lifetime with residential access to fluoridated water. Participants living between 50% and 75% and <50% of their lives in fluoridated areas presented a decayed and filled teeth mean ratio of 1.34 (95% CI, 1.02-1.75) and 1.47 (95% CI, 1.05-2.04) higher than those with residential access to fluoridated water >75% of their lifetime, respectively. Longer residential lifetime access to fluoridated water was associated with less dental caries even in a context of multiple exposures to fluoride. (Peres MA, et al. – J Dent Res. 2016 Jul;95(8):868-74)
Does cessation of community water fluoridation lead to an increase in tooth decay? A systematic review of published studies:   CONCLUSIONS: Overall, the published research points more to an increase in dental caries post-CWF cessation than otherwise. However, the literature is highly diverse and variable in methodological quality. (McLaren L & Singhal S – J Epidemiol Community Health. 2016 Sep;70(9):934-40)
Comparative effectiveness of water and salt community-based fluoridation methods in preventing dental caries among schoolchildren:   CONCLUSION: Fluoridated water appears to provide a better protective effect against dental caries than fluoridated household salt among schoolchildren from developing countries. (Fabruccini A, et al. – Community Dent Oral Epidemiol. 2016 Jul 28)
Dental caries, fluorosis, oral health determinants, and quality of life in adolescents:   CONCLUSION: Increased impact on oral health-related quality of life (OHRQoL) was related to the severity of cavitated dentine lesions, but fluorosis resulting from combined fluoride exposure from early ages was not of concern for the adolescents. CLINICAL RELEVANCE: Combined fluoride exposure from fluoridated drinking water, consumption of food prepared with fluoridated water, and daily twice brushing with conventional fluoride toothpaste from early ages may be recommended to control caries progression at population level without impact on OHRQoL. This information is particularly relevant for supporting oral health police for disadvantaged populations. (Aimée NR, et al. – Clin Oral Investig. 2016 Sep 27)
Evaluation of optimal water fluoridation on the incidence and skeletal distribution of naturally arising osteosarcoma in pet dogs:   Taken together, these analyses do not support the hypothesis that optimal fluoridation of drinking water contributes to naturally occurring osteosarcoma in dogs. (Rebhun RB, et al. – Vet Comp Oncol. 2016 Jan 14)
Economic Evaluation of Community Water Fluoridation: A Community Guide Systematic Review:   EVIDENCE SYNTHESIS: The analysis was conducted in 2014. The benefit-only studies used regression analysis, showing that different measures of dental costs were always lower in communities with water fluoridation. For the six cost-benefit studies, per capita annual intervention cost ranged from $0.11 to $4.92 for communities with at least 1,000 population, and per capita annual benefit ranged from $5.49 to $93.19. Benefit-cost ratios ranged from 1.12:1 to 135:1, and these ratios were positively associated with community population size. CONCLUSIONS: Recent evidence continues to indicate that the economic benefit of community water fluoridation exceeds the intervention cost. Further, the benefit-cost ratio increases with the community population size. (Ran T, et al. – Am J Prev Med. 2016 Jun;50(6):790-6)
Cost-effectiveness of preventing dental caries and full mouth dental reconstructions among Alaska Native children in the Yukon–Kuskokwim delta region of Alaska:
Water Fluoridation: Adjusting the level of fluoride in the community water systems results in a 26-35 percent reduction in tooth decay among children receiving lifelong exposure to fluoridated water. Other estimates based earlier YK dental reviews suggests 18-40 percent reduction in tooth decay among children receiving community fluoridated water. (Charisma Y. Atkins, et al. – J Public Health Dent. 2016 Jun; 76(3): 228–240)
Public perceptions and scientific evidence for perceived harms/risks of community water fluoridation: An examination of online comments pertaining to fluoridation cessation in Calgary in 2011:   OBJECTIVES: To examine the perceived harms/risks of fluoridation as expressed in online forums relating to cessation and aftermath in Calgary, specifically, 1) which harms/risks are mentioned, 2) for those harms/risks, what kinds of evidence are cited, 3) to what extent is scientific literature cited, and what is its quality, and 4) for a subset of harms/risks, what is known from the broader scientific literature?
METHODS: Relevant online comments were identified through free-text Internet searches, and those explicitly discussing the harms/risks of water fluoridation were extracted. Types of evidence mentioned were identified, and the scientific papers cited were reviewed. Finally, the broader scientific literature on two of the harms/risks was reviewed and synthesized.
SYNTHESIS: We identified 17 distinct groups of harms/risks, which spanned human body systems, the environment and non-human organisms. Most often, no evidence was cited. When evidence was cited, types included individuals viewed as authorities and personal experiences. Reference to scientific articles was rare, and those papers (n = 9) had significant methodological concerns. Our review of scientific literature on fluoride and 1) thyroid functioning and 2) phytoplankton revealed some negative effects of fluoride at concentrations exceeding maximum recommended levels (>1.5 ppm).
CONCLUSION: The findings have implications for communication with the public about fluoridation. First, to the extent that the public consults the scientific literature, it is essential that the methodological limitations of a study, as well as its relevance to community water fluoridation, be widely and promptly communicated. Second, scientific evidence is only one component of why some people support or do not support fluoridation, and communication strategies must accommodate that reality. (Podgorny PC & McLaren L. – Can J Public Health. 2015 Jun 19;106(6):e413-25)
Long-term evaluation of the clinical effectiveness of community milk fluoridation in Bulgaria:   CONCLUSIONS: Fluoridated milk delivered daily in schools in Bulgaria resulted in substantially lower caries development compared with children in schools receiving milk without added fluoride. The nation-wide experiences from milk fluoridation indicate that such a public health scheme can be effective to the global fight against dental caries of children. (Petersen PE, et al. – Community Dent Health. 2015 Dec;32(4):199-203)
Association between estimated fluoride intake and dental caries prevalence among 5-year-old children in Korea:   CONCLUSION: The inverse association between dietary fluoride intake levels and prevalence of dental caries implies that the introduction of community caries prevention programmes may be beneficial. Such programmes would include water fluoridation and a fluoride supplementation programme. (Kim MJ, et al. – BMC Oral Health. 2015 Dec 30;15:169)
Factors attributable for the prevalence of dental caries in Queensland children:   In the full models, children in the nonfluoridated areas had significantly higher prevalence of dental caries [PR for the primary: 1.29 (1.11-1.50); PR for the permanent 1.49 (1.01-2.21)] compared with children in fluoridated areas, controlling for other factors. PAF estimates indicated that lack of water fluoridation attributed to 21% and 31% of primary and permanent dental caries, respectively in this child population. (Do LG., et al. – Community Dent Oral Epidemiol. 2015 Oct;43(5):397-405)  (full review)
Water fluoridation for the prevention of dental caries - Cochrane Review:  
The results from the caries severity data indicate that the initiation of water fluoridation results in reductions in dmft of 1.81 (95% CI 1.31 to 2.31; 9 studies at high risk of bias, 44,268 participants) and in DMFT of 1.16 (95% CI 0.72 to 1.61; 10 studies at high risk of bias, 78,764 participants). This translates to a 35% reduction in dmft and a 26% reduction in DMFT compared to the median control group mean values. There were also increases in the percentage of caries free children of 15% (95% CI 11% to 19%; 10 studies, 39,966 participants) in deciduous dentition and 14% (95% CI 5% to 23%; 8 studies, 53,538 participants) in permanent dentition. The majority of studies (71%) were conducted prior to 1975 and the widespread introduction of the use of fluoride toothpaste.There is insufficient information to determine whether initiation of a water fluoridation programme results in a change in disparities in caries across socioeconomic status (SES) levels.There is insufficient information to determine the effect of stopping water fluoridation programmes on caries levels.No studies that aimed to determine the effectiveness of water fluoridation for preventing caries in adults met the review's inclusion criteria.With regard to dental fluorosis, we estimated that for a fluoride level of 0.7 ppm the percentage of participants with fluorosis of aesthetic concern was approximately 12% (95% CI 8% to 17%; 40 studies, 59,630 participants). This increases to 40% (95% CI 35% to 44%) when considering fluorosis of any level (detected under highly controlled, clinical conditions; 90 studies, 180,530 participants). Over 97% of the studies were at high risk of bias and there was substantial between-study variation. (Cochrane Database Syst Rev. 2015 Jun 18;6) (a response to feedback)

There was significant resulting commentary (#1, #2, #3, #4, #5, #6, #7) that clearly illustrates the complexity of the fluoridation discussion, the way a published paper can be misused by fluoridation opponents and the impact of personal biases (for and against fluoridation) on the interpretation of study results.  Contrast the 2015 Cochrane review with a 2000 literature review of fluoridation, Systematic review of water fluoridation, published in the British Medical Journal that concluded, "The evidence of a beneficial reduction in caries should be considered together with the increased prevalence of dental fluorosis. There was no clear evidence of other potential adverse effects."
Community water fluoridation and health outcomes in England: a cross-sectional study: 
BACKGROUND: Six million people in England live in areas where the level of fluoride in water is adjusted to reduce the significant public health burden of dental caries. The dental effects of fluoride are well established, but evidence for suggested adverse health effects is limited, with a lack of rigorous small area population studies that control for confounding. This study aims to test the association between water fluoridation schemes and selected health outcomes using the best available routine data sources.
METHODS: Ecological level exposure to fluoridated water was estimated for standard small areas and administrative districts in England using Geographical Information Systems and digitized boundaries based on known patterns of water supply. The association between fluoridation and dental and nondental health indicators was tested using multivariable regression models including ecological level confounding variables. Health indicator data were obtained from routine sources.
RESULTS: There was strong evidence of lower prevalence of dental caries (P< 0.001) among children living in fluoridated areas, they also had fewer teeth affected on average (P < 0.001), and lower admission rates for tooth extraction (55% lower; 95% CI-73%, -27%; P = 0.001). There was no strong evidence of an association between fluoridation and hip fracture, Down syndrome, all-cancer, all-cause mortality or osteosarcoma. Fluoridation was negatively associated with the incidence of renal stones (7.9% lower; 95% CI-9.6%,-6.2%; P < 0.001) and bladder cancer (8.0% lower; 95% CI-9.9%,-6.0%; P < 0.001).
CONCLUSION: This study uses the comprehensive data sets available in England to provide reassurance that fluoridation is a safe and highly effective public health measure to reduce dental decay. Although lower rates of certain nondental outcomes were found in fluoridated areas, the ecological, observational design prohibits any conclusions being drawn regarding a protective role of fluoridation. (Young N, et al. – Community Dent Oral Epidemiol. 2015 Dec;43(6):550-9)

Community Water Fluoridation in New Zealand
A cost effectiveness analysis of community water fluoridation in New Zealand: 
This cost effectiveness analysis supports an earlier economic analysis of community water fluoridation in New Zealand by Wright et. al. (2001) 3 . CWF remained a cost effective public health intervention in New Zealand despite an overall reduction in dental caries. This finding also agrees with a number of economic analyses of CWF conducted in countries similar to New Zealand, 7, 9-11 . It should be noted however, that for smaller communities cost effectiveness was more marginal. Wright et. al. (2001) identified a ‘break even’ community size for CWF of 700-900 people 3 . In smaller communities cost effectiveness was more dependent on the risk profile of the population. CWF would be more cost effective in communities with a higher risk of dental caries. (Fyfe C, et al. – New Zealand Medical Journal 12/2015, 128(1427))
Public perceptions and scientific evidence for perceived harms/risks of community water fluoridation: An examination of online comments pertaining to fluoridation cessation in Calgary in 2011: 
OBJECTIVES: To examine the perceived harms/risks of fluoridation as expressed in online forums relating to cessation and aftermath in Calgary, specifically, 1) which harms/risks are mentioned, for those harms/risks, what kinds of evidence are cited, to what extent is scientific literature cited, and what is its quality, and for a subset of harms/risks, what is known from the broader scientific literature?
METHODS: Relevant online comments were identified through free-text Internet searches, and those explicitly discussing the harms/risks of water fluoridation were extracted. Types of evidence mentioned were identified, and the scientific papers cited were reviewed. Finally, the broader scientific literature on two of the harms/risks was reviewed and synthesized.
SYNTHESIS: We identified 17 distinct groups of harms/risks, which spanned human body systems, the environment and non-human organisms. Most often, no evidence was cited. When evidence was cited, types included individuals viewed as authorities and personal experiences. Reference to scientific articles was rare, and those papers (n = 9) had significant methodological concerns. Our review of scientific literature on fluoride and thyroid functioning and phytoplankton revealed some negative effects of fluoride at concentrations exceeding maximum recommended levels (>1.5 ppm).
CONCLUSION: The findings have implications for communication with the public about fluoridation. First, to the extent that the public consults the scientific literature, it is essential that the methodological limitations of a study, as well as its relevance to community water fluoridation, be widely and promptly communicated. Second, scientific evidence is only one component of why some people support or do not support fluoridation, and communication strategies must accommodate that reality. (Podgorny PC, McLaren L. – Can J Public Health. 2015 Jun 19;106(6))
Water Fluoridation: Safety, Effectiveness and Value in Oral Health: A Symposium at the 2014 Annual Meeting of the American and Canadian Associations for Dental Research: 
The objective of this symposium was to review the scientific evidence supporting CWF and consider the implications for optimizing the use of fluoride in public health and clinical practice. The following presentations were held at the symposium:
1. Effectiveness of fluorides - Findings of evidence-based reviews:  The use of fluoride has been associated with a substantial reduction in caries in children and adolescents. The presentation also highlighted evidence gaps for effectiveness of certain fluoride modalities, as well as the relationship among effectiveness, dose, and safety for the products. With the exception of enamel fluorosis, no other adverse effects are associated with community water fluoridation.
2. The health assessment of fluoride in drinking water: Conclusions from the National Research Council and subsequent scientific assessments by EPA: 
a) EPA estimates of RfD and the recommended benchmarks are conservative.
b) More recent studies of osteosarcoma and bone fractures confirm that water fluoridation has no impact on these outcomes.
c) Lowering fluoride exposure may lead to reduction in dental fluorosis but the question remains about its impact on caries.
3. Gaps in scientific knowledge regarding water fluoridation and other fluoride modalities: Fluoridated water reduces tooth decay in adults, even if they start drinking it after childhood. Communities that implement fluoridation can expect benefits to accrue for both future and current generations. More people in the population benefit from water fluoridation than previously was thought. The greater benefit has a significant impact on calculations of population cost-effectiveness. Recent findings from Australia add to six decades of evidence showing that community water fluoridation prevents dental caries in adults. The evidence should be considered when formulating health policies and public health programs.
4. Community water fluoridation: Translating evidence into public health practice: The translation of scientific evidence into public health practice demands ongoing efforts to update estimates of effectiveness and costs of the intervention, assure safety, identify and address gaps in knowledge, and apply data-driven approaches to monitor implementation and communicate with stakeholders.
(Presenters, Dr. Martinez-Mier, Dr. Kumar, Dr. Slade, Dr. Gooch – J Can Dent Assoc 2015;81:f16)
Does fluoride in the water close the dental caries gap between Indigenous and non-Indigenous children? 
RESULTS: Dental caries prevalence and severity for Indigenous and non-Indigenous children, in both dentitions, was lower in fluoridated areas compared to non-fluoridated areas. Among non-Indigenous children, there was a 50.9% difference in mean dmft scores in fluoridated (1.70) compared to non-fluoridated (2.86) areas. The difference between Indigenous children in fluoridated (3.29) compared to non-fluoridated (4.16) areas was 23.4%. Among non-Indigenous children there was a 79.7% difference in the mean DMFT scores in fluoridated (0.68) compared to non-fluoridated (1.58) areas. The difference between Indigenous children in fluoridated (1.59) and non-fluoridated (2.23) areas was 33.5%.
CONCLUSIONS: Water fluoridation is effective in reducing dental caries, but does not appear to close the gap between non-Indigenous children and Indigenous children. (Lalloo R, et al. – Aust Dent J. 2015 Sep;60(3):390-6)
U.S. Public Health Service Recommendation for Fluoride Concentration in Drinking Water for the Prevention of Dental Caries:   Through this final recommendation, the U.S. Public Health Service (PHS) updates and replaces its 1962 Drinking Water Standards related to community water fluoridation—the controlled addition of a fluoride compound to a community water supply to achieve a concentration optimal for dental caries prevention.1 For these community water systems that add fluoride, PHS now recommends an optimal fluoride concentration of 0.7 milligrams/liter (mg/L). In this guidance, the optimal concentration of fluoride in drinking water is the concentration that provides the best balance of protection from dental caries while limiting the risk of dental fluorosis. The earlier PHS recommendation for fluoride concentrations was based on outdoor air temperature of geographic areas and ranged from 0.7–1.2 mg/L.
Systematic reviews of the scientific evidence related to fluoride have concluded that community water fluoridation is effective in decreasing dental caries prevalence and severity. Effects included significant increases in the proportion of children who were caries-free and significant reductions in the number of teeth or tooth surfaces with caries in both children and adults. When analyses were limited to studies conducted after the introduction of other sources of fluoride, especially fluoride toothpaste, beneficial effects across the lifespan from community water fluoridation were still apparent.
Fluoride in saliva and dental plaque works to prevent dental caries primarily through topical -remineralization of tooth surfaces. Consuming fluoridated water and beverages, and foods prepared or processed with fluoridated water, throughout the day maintains a low concentration of fluoride in saliva and plaque that enhances remineralization. Although other fluoride-containing products are available and contribute to the prevention and control of dental caries, community water fluoridation has been identified as the most cost-effective method of delivering fluoride to all members of the community regardless of age, educational attainment, or income level.9,30 Studies continue to find that community water fluoridation is cost saving. (Public Health Rep. 2015 Jul-Aug; 130(4): 318–331)
Water Intake by Outdoor Temperature Among Children Aged 1-10 Years: Implications for Community Water Fluoridation in the U.S.
RESULTS: We found that total water intake was not associated with temperature. Plain water intake was weakly associated with temperature in unadjusted (coefficient 5 0.2, p=0.015) and adjusted (coefficient 5 0.2, p=0.013) linear regression models. However, these models explained little of the individual variation in plain water intake (unadjusted: R(2)=0.005; adjusted: R(2)=0.023).
CONCLUSION: Optimal fluoride concentration in drinking water to prevent caries need not be based on outdoor temperature, given the lack of association between total water intake and outdoor temperature, the weak association between plain water intake and outdoor temperature, and the minimal amount of individual variance in plain water intake explained by outdoor temperature. These findings support the change in the U.S. Public Health Service recommendation for fluoride concentration in drinking water for the prevention of dental caries from temperature-related concentrations to a single concentration that is not related to outdoor temperature. (Beltrán-Aguilar ED, et al. – Public Health Rep. 2015 Jul-Aug;130(4):362-71)
Risk perception, psychological heuristics and the water fluoridation controversy: 
OBJECTIVES: Increasingly, support for water fluoridation has come under attack. We seek an explanation, focusing on the case of Waterloo, Ontario, where a 2010 referendum overturned its water fluoridation program. In particular, we test whether individuals perceive the risks of water fluoridation based not on 'hard' scientific evidence but on heuristics and cultural norms.
METHODS: A sample of 376 residents in Waterloo were surveyed in June 2012 using random digit dialing. We use factor analysis, OLS regression, as well as t-tests to evaluate a survey experiment to test the credibility hypothesis.
RESULTS: Perceptions of fluoride as a risk are lower among those who perceive fluoride's benefits (B = .473, p < 0.001) and those whose cultural view is 'egalitarian' (B = .156, p < 0.05). The experiment shows a lower level of perception of fluoride's benefits among respondents who are told that water fluoridation is opposed by a national advocacy group (Group A) compared to those who are told that the government and the World Health Organization support fluoridation (Group B) (t = 1.6547, p < 0.05), as well as compared to the control group (t = 1.8913, p < 0.05). There is no difference between Group B and the control, possibly because people's already general support for fluoridation is less prone to change when told that other public organizations also support fluoridation.
CONCLUSION: Public health officials should take into account cultural norms and perceptions when individuals in a community appear to rise up against water fluoridation, with implications for other public health controversies.
(Perrella AM, Kiss SJ – Can J Public Health. 2015 Apr 29;106-10)
New international review supports community water fluoridation as an effective and safe dental health promotion measure:  Strong evidence supports the safety and efficacy of CWF. The benefits are most pronounced for low SES groups. However, opponents of fluoridation through dissemination of misinformation pose an ongoing threat to CWF’s continuation. Public health professionals have a responsibility to counter such misinformation and to support water fluoridation. (Howat P, et al. – Health Promotion Journal of Australia, 2015, 26, 1–3)
A 4-year assessment of a new water-fluoridation scheme in New South Wales, Australia: 
OBJECTIVE: To monitor the changes in dental caries prevalence of 5- to 7-year-old children living in a fluoridated area, a newly fluoridated area and in an area without water fluoridation, in NSW, Australia.
RESULTS: The caries prevalence changed over time. In 2008, the mean dmft index was 1.40 for the fluoridated area, 2.02 for the area about to fluoridate and 2.09 for the unfluoridated control. By 2012, these mean dmft scores were 0.69, 0.72 and 1.21, respectively. In the two areas where children received fluoridated water, the significant caries index was 2.30 for the fluoridated area and 2.40 for the newly fluoridated area. The significant caries score for children in the unfluoridated location was 3.93. Multivariate analysis showed that over time the differences in dental caries prevalence between the established fluoride area and the newly fluoridated area diminished. However, children in the unfluoridated control area continued to demonstrate significant differences in the mean number of decayed teeth compared with children in the fluoridated comparator sites, and the proportions of children free from decay were significantly higher in the fluoridated areas than in the unfluoridated area.
CONCLUSION: Fluoridation of public water supplies in Gosford and Wyong offers young children better dental health than those children who do not have access to this public health measure. (Blinkhorn AS, et al. – Int Dent J. 2015 Jun;65(3):156-63)
Does lower lifetime fluoridation exposure explain why people outside capital cities have poor clinical oral health? 
BACKGROUND: Australians outside state capital cities have greater caries experience than their counterparts in capital cities. We hypothesized that differing water fluoridation exposures was associated with this disparity.
METHODS: Data were the 2004-06 Australian National Survey of Adult Oral Health. Examiners measured participant decayed, missing and filled teeth and DMFT Index and lifetime fluoridation exposure was quantified. Multivariable linear regression models estimated differences in caries experience between capital city residents and others, with and without adjustment for fluoridation exposure.
RESULTS: There was greater mean lifetime fluoridation exposure in state capital cities (59.1%, 95% confidence interval=56.9,61.4) than outside capital cities (42.3, confidence interval=36.9,47.6). People located outside capital city areas had differing socio-demographic characteristics and dental visiting patterns, and a higher mean DMFT (Capital cities=12.9, Non-capital cities=14.3, p=0.02), than people from capital cities. After adjustment for socio-demographic characteristics and dental visits, DMFT of people living in capital cities was less than non-capital city residents (Regression coefficient=0.8, p=0.01). The disparity was no longer statistically significant (Regression coefficient=0.6, p=0.09) after additional adjustment for fluoridation exposure. (Crocombe LA, et al. – Aust Dent J. 2015 Mar 26)

Fluoridation and hypothyroidism – a commentary on Peckham et al. -  
Peckham et al. fail to understand the limitations of a poorly conducted ecological trial, and the paper contains serious biases and flaws. Literature reviews have been highly selective and critical analysis of that literature has been poor. The authors show a disturbing tendency to focus on a small number of poor quality studies that reinforce their own views, while ignoring contradictory evidence from much stronger studies and reviews. Peckham et al. should have heeded the adage ‘correlation is not causation’ before coming to a conclusion at odds with a large body of reputable evidence from around the world. In my opinion, the paper’s conclusions can and should be dismissed. (M. Foley – British Dental Journal, Vol. 219,9, 11/13/2015)
Exposure to fluoride in drinking water and hip fracture risk: a meta-analysis of observational studies: 
CONCLUSION: The present meta-analysis suggests that chronic fluoride exposure from drinking water does not significantly increase the risk of hip fracture. Given the potential confounding factors and exposure misclassification, further large-scale, high-quality studies are needed to evaluate the association between exposure to fluoride in drinking water and hip fracture risk. (Yin XH, et al. – PLoS One. 2015 May 28)
Water fluoridation, dentition status and bone health of older people in Ireland:  
RESULTS: It was found that the greater the percentage of households with a fluoridated water supply in an area, the higher the probability that respondents had all their own teeth. There was no significant relationship between the proportion of households with a fluoridated water supply in an area and bone health.
CONCLUSION: This study suggests that water fluoridation provides a net health gain for older Irish adults, though the effects of fluoridation warrant further investigation. (O Sullivan V, O Connell BC. – Community Dent Oral Epidemiol. 2015 Feb;43(1):58-67)  A description of the study can be read here/a>.
Effects of water fluoridation on caries experience in the primary dentition in a high caries risk community in Queensland, Australia:  CONCLUSIONS: After only 36 months of water fluoridation there was a significant drop in caries prevalence from 87 to 75% and a 19% reduction in caries experience in a community with one of the highest caries rates in Australia. (Koh R, et al. – Caries Res. 2015;49(2):184-91)
Perceived safety and benefit of community water fluoridation: 2009 HealthStyles survey: CONCLUSIONS: Although only a minority of the US population perceived CWF as unsafe or providing no benefit to health, perceptions regarding CWF varied by knowledge of CWF and socio-demographic factors. Oral health promotion activities should consider these differing perceptions of CWF among groups to tailor oral health messaging appropriately. (Mork N, Griffin S. – J Public Health Dent. 2015 Sep;75(4):327-36)
Hospitalizations for dental infections: Optimally versus nonoptimally fluoridated areas in Israel:  CONCLUSIONS: These results clearly indicate that there is an association between adequacy of water fluoridation and hospitalization due to dental infections among children and adolescents. This effect is more prominent in populations of lower socioeconomic status. (Klivitsky A, et al. – J Am Dent Assoc. 2015 Mar; 146(3):179-83)   Full Article
Community Water Fluoridation and Intelligence: Prospective Study in New Zealand:  
. This study aimed to clarify the relationship between Community Water Fluoridation (CWF) and IQ.
Methods. We conducted a prospective study of a general population sample of those born in Dunedin, New Zealand, between April 1, 1972, and March 30, 1973 (95.4% retention of cohort after 38 years of prospective follow-up). Residence in a CWF area, use of fluoride dentifrice and intake of 0.5-milligram fluoride tablets were assessed in early life (prior to age 5 years); we assessed IQ repeatedly between ages 7 to 13 years and at age 38 years.
Results. No clear differences in IQ because of fluoride exposure were noted. These findings held after adjusting for potential confounding variables, including sex, socioeconomic status, breastfeeding, and birth weight (as well as educational attainment for adult IQ outcomes).
These findings do not support the assertion that fluoride in the context of CWF programs is neurotoxic. Associations between very high fluoride exposure and low IQ reported in previous studies may have been affected by confounding, particularly by urban or rural status. (Broadbent JM, et al. – Am J Public Health. 2015 Jan;105(1):72-76)
The Dental Health of primary school children living in fluoridated, pre-fluoridated and non-fluoridated communities in New South Wales, Australia:   CONCLUSION: The children living in the well-established fluoridated area had less dental caries and a higher proportion free from disease when compared with the other two areas which were not fluoridated. Fluoridation demonstrated a clear benefit in terms of better oral health for young children. (Blinkhorn AS, et al. – BMC Oral Health. 2015 Jan 21;15(1):9)

Setting the Record Straight on Fluoride:  In a letter to JAMA Internal Medicine published earlier this year, two political scientists from the University of Chicago reported that 12% of Americans agree with this statement: “Public water fluoridation is really just a secret way for chemical companies to dump the dangerous byproducts of phosphate mines into the environment.” Perhaps more disturbing, fewer than half of respondents disagreed with the statement, which means there is an urgent need to steer people toward reliable sources of accurate information so they can play an informed role in decision-making around this crucial aspect of the public health infrastructure. (Valachovic R. – J Mich Dent Assoc. 2015 Apr;97(4):38-40)
Contemporary multilevel analysis of the effectiveness of water fluoridation in Australia:   RESULTS: Data from 2,214 5-8 year-olds and 3,186 9-14 year-olds from 207 schools in 16 areas were analysed. Queensland's average dmfs was 4.23 and DMFS 1.47. The lowest levels of dental caries were observed in long-term fluoridated Townsville. In the full models, Townsville children had significantly lower caries experience (RR for dmfs: 0.61 (95%CI: 0.44-0.82); RR for DMFS 0.60 (95%CI: 0.42-0.88)) compared with children in non-fluoridated areas. (Do L, Spencer AJ. – Aust N Z J Public Health. 2015 Feb;39(1):44-50)
Dental fluorosis in the Blue Mountains and Hawkesbury, New South Wales, Australia: policy implications:   CONCLUSIONS: For the group as a whole, we concluded that: (a) fluorosis prevalence (0.39) in both regions was similar; and (b) the higher-than-expected prevalence and severity of fluorosis was due mainly to two factors: (a) the higher-than-optimal fluoride level in drinking water; and (b) swallowing of fluoride toothpaste in early childhood. (Bal IS, et al. – J Investig Clin Dent. 2015 Feb;6(1):45-52)  A related letter to the BDJ

From the American Academy of Pediatrics
Fluoride Use in Caries Prevention in the Primary Care Setting:   Dental caries remains the most common chronic disease of childhood in the United States. Caries is a largely preventable condition, and fluoride has proven effectiveness in the prevention of caries. The goals of this clinical report are to clarify the use of available fluoride modalities for caries prevention in the primary care setting and to assist pediatricians in using fluoride to achieve maximum protection against dental caries while minimizing the likelihood of enamel fluorosis. (Clark M, et al. – Pediatrics Vol. 134 No. 3 September 1, 2014 pp. 626 -633)

North Carolina Medical Journall
Preventing Dental Caries Through Community Water Fluoridation:   The weight of the scientific evidence in peer-reviewed literature does not support an association between community water fluoridation and any adverse health effects or systemic disorders, including an increased risk for cancer, Down syndrome, heart disease, osteoporosis, bone fractures, immune disorders, low intelligence, renal disorders, Alzheimer disease, or allergic reactions.  Not only is community water fluoridation safe and effective, it is also cost saving, and it is the least expensive way to deliver the benefits of fluoride to all residents of a community. (White BA & Gordon SM – N C Med J. 2014;75(6):430-431) {A summary of benefits from a review of other papers} - Free Full Text
Dental Fluorosis and Dental Caries Prevalence among 12 and 15-Year-Old School Children in Nalgonda District, Andhra Pradesh, India:
BACKGROUND: Fluoride is a double edged sword. The assessment of dental caries and fluorosis in endemic fluoride areas will facilitate in assessing the relation between fluoride concentrations in water with dental caries, dental fluorosis simultaneously.
RESULTS: The caries prevalence was less among 12-year-old children (39.9%]) compared with 15-years-old children (46.7%). The prevalence was more among females (50.4% than males (35.8%. The prevalence was more in low fluoride area (60.5%) followed by very high fluoride area (54.8%), high fluoride area (32.4%]) and medium fluoride area (17.6%) in the descending order. The fluorosis prevalence increased with increasing fluoride concentration with no difference in gender and age distribution.
CONCLUSION: Low fluoride areas require fluoridation or alternate sources of fluoride, whereas high fluoride areas require defluoridation. Defluoridation of water is an immediate requirement in areas with fluoride concentration of 4 parts per million and above as dental fluorosis is a public health problem in these areas with 100% prevalence. (Sukhabogi Jr, et al. – Ann Med Health Sci Res. 2014 Sep;4(Suppl 3))
The effect of lifetime fluoridation exposure on dental caries experience of younger rural adults:   CONCLUSIONS: The higher level of lifetime fluoridation exposure was associated with substantially lower caries experience in younger rural adults, largely due to a lower number of filled teeth. (Crocombe L, et al. – Aust Dent J. 2014 Oct 20.)
Variation in fluorosis and caries experience among Lithuanian 12 year olds exposed to more than 1 ppm F in tap water: AIM: The aim of the present study was to analyze caries experience in relation to the occurrence of fluorosis in 12 year olds in a natural fluoride area. CONCLUSION: The presence of fluorosis associates with lesser caries experience in 12-year-old lifetime residents of an area with moderately-elevated natural fluoride. (Narbutaitė J, et al. – J Investig Clin Dent. 2014 Dec 1)
Fluoride retention in saliva and in dental biofilm after different home-use fluoride treatments:   In this study, we evaluated whether fluoride concentrations in saliva and dental biofilm remained significantly elevated at 8 h after four different oral hygiene procedures in volunteers living in an area with fluoridated water supply. The fluoride concentrations in saliva and in dental biofilm were not significantly different among the treatments. The frequency of brushing with a fluoride dentifrice and additional use of fluoride mouthrinse followed by brushing with a fluoride dentifrice did not affect the fluoride concentrations in biofilm and saliva at 8 h after the last procedure. The results of this study are in agreement with the findings of most of the studies conducted in areas with a fluoridated water supply.13,20,21,22 These studies also did not show a long-term effect on the fluoride concentration in saliva and in dental biofilm compared to baseline values. A possible explanation for these is that plaque-binding sites for long-term fluoride retention are occupied by fluoride ions largely in communities with fluoridated water, but not where the water contains only traces of this ion. (Souza DC & Maltz M. – Braz Oral Res. 2014 Jan-Feb;28)

British Dental Journal
Concern over limited access to water fluoridation:   The British Dental Association (BDA) and the British Society of Paediatric Dentistry (BSPD) have expressed concern that limited access to water fluoridation - only 10% of the UK's population - means we are failing children who live in communities with high levels of tooth decay. Concern over limited access to water fluoridation In its latest report on fluoridation, the BSPD highlights that 60,683 children and adolescents in England were admitted to hospital in 2012/13 to have multiple decayed teeth removed under general anaesthetic, costing the NHS at least '27.6 million. By contrast, evidence suggests that children living in fluoridated areas, such as the West Midlands, have around half the rate of tooth decay of those living in non-fluoridated areas, and thousands have been spared from traumatic and distressing operations. Research indicates that adults also benefit. (British Dental Journal 217, 616 (2014))
An alternative marker for the effectiveness of water fluoridation: hospital extraction rates for dental decay, a two-region study:  CONCLUSIONS: After ranking by IMD, DSRs of hospital admissions for the extraction of decayed or pulpally/periapically involved teeth is lower in areas with a fluoridated water supply. The analysis of routinely collected HES data may help identify the impact of water fluoridation schemes. (Elmer TB, et al. – Br Dent J. 2014 Mar;216(5))
Community water fluoridation on the Internet and social media:
In the United States, 95 percent of teens and 85 percent of adults use the Internet. Two social media outlets, Facebook and Twitter, reach more than 150 billion users. This study describes anti-fluoridation activity and dominance on the Internet and social media, both of which are community water fluoridation (CWF) information sources.
METHODS: Monthly website traffic to major fluoridation websites was determined from June 2011 to May 2012. Facebook, Twitter, and YouTube fluoridation activity was categorized as "proCWF" or "anti-CWF." Twitter's anti-CWF tweets were further subcategorized by the argument used against CWF.
RESULTS: Anti-CWF website traffic was found to exceed proCWF activity five- to sixty-fold. Searching "fluoride" and "fluoridation" on Facebook resulted in 88 to 100 percent anti-CWF groups and pages; "fluoridation" on Twitter and YouTube resulted in 64 percent anti-CWF tweets and 99 percent anti-CWF videos, respectively. "Cancer, " "useless, " and "poisonous" were the three major arguments used against fluoridation.
CONCLUSIONS: Anti-fluoridation information significantly dominates the Internet and social media. Thousands of people are being misinformed daily about the safety, health, and economic benefits of fluoridation. (Mertz A, Allukian M. – J Mass Dent Soc. 2014 Summer;63(2):32-6)
Is fluoride a risk factor for bone cancer? Small area analysis of osteosarcoma and Ewing sarcoma diagnosed among 0-49-year-olds in Great Britain, 1980-2005:  CONCLUSIONS: The findings from this study provide no evidence that higher levels of fluoride (whether natural or artificial) in drinking water in GB lead to greater risk of either osteosarcoma or Ewing sarcoma. (Blakey K1, et al. – Int J Epidemiol. 2014 Feb;43(1):224-34)
Eye cancer incidence in U.S. states and access to fluoridated water: Environmental risk factors for uveal melanomas (cancer of the iris, ciliary body, and choroid) have not been identified. To search for these, we examined the correlation of age-adjusted eye cancer incidence rates, a surrogate for uveal melanoma rates, in U.S. states with group level geographic and demographic factors using multivariate linear regression. Incidence rates for eye cancer were inversely correlated with the percentage of the population receiving fluoridated water; that is, higher rates were found in states with lower prevalences of fluoridation (P = 0.01). Fluoride is known to inhibit the growth of microbial agents that cause choroiditis and choroidal lesions in animals. We speculate that fluoridation protects against choroidal melanoma by inhibiting microbial agents that cause choroiditis and/or choroidal lesions in humans. (Schwartz GG – Cancer Epidemiol Biomarkers Prev. 2014 Sep;23(9):1707-11)
Effects of Life-long Fluoride Intake on Bone Measures of Adolescents: A Prospective Cohort Study:  The findings suggest that fluoride exposures at the typical levels for most US adolescents in fluoridated areas do not have significant effects on bone mineral measures. (Levy SM, et al. – J Dent Res. 2014 Apr;93(4):353-9)
Association of dental caries with socioeconomic status in relation to different water fluoridation levels:   CONCLUSIONS: This study supported that water fluoridation could not only lead to a lower prevalence of dental caries, but also help to reduce the effect of SES inequalities on oral health. (Cho HJ, et al. – Community Dent Oral Epidemiol. 2014 Dec;42(6):536-42)
Effectiveness of water fluoridation in caries reduction in a remote Indigenous community in Far North Queensland:   BACKGROUND: Children in remote Indigenous communities in Australia have levels of dental caries much greater than the national average. One such, the Northern Peninsula Area of Far North Queensland (NPA), had an oral health survey conducted in 2004, shortly before the introduction of fluoridated, reticular water. Children were again surveyed in 2012, following five years exposure. CONCLUSIONS: There has been considerable improvement in child dental health in the NPA over the past 6-7 years. In light of continued poor diet and oral hygiene, water fluoridation is the most likely explanation. The cost-effectiveness for this small community remains an issue which, in the current climate of political antagonism to water fluoridation in many quarters, requires continued study. (Johnson NW, et al. – Aust Dent J. 2014 Sep;59(3):366-71)
An alternative marker for the effectiveness of water fluoridation: hospital extraction rates for dental decay, a two-region study:   OBJECTIVES: To examine inpatient hospital episodes statistics for dental extractions as an alternative population marker for the effectiveness of water fluoridation by comparing hospital admissions between two major strategic health authority (SHA) areas, the West Midlands SHA-largely fluoridated--and the North West SHA--largely unfluoridated. METHOD: Hospital episodes statistics (HES) were interrogated to provide data on admissions for simple and surgical dental extractions, which had a primary diagnostic code of either dental caries or diseases of pulp and periapical tissues for financial years 2006/7, 2007/8 and 2008/9. Data was aggregated by SHA area and quinary age group. Directly standardised rates (DSR) of admissions purchased for each primary care trust (PCT) were calculated and ranked by index of multiple deprivation (IMD). RESULTS: A significant difference in DSRs of admission between PCTs in the West Midlands and North West was observed (Mann-Whitney U test [p <0.0001]) irrespective of IMD ranking. The difference in rates between the two most deprived PCTs was 27-fold. CONCLUSIONS: After ranking by IMD, DSRs of hospital admissions for the extraction of decayed or pulpally/periapically involved teeth is lower in areas with a fluoridated water supply. (Elmer TB, et al. – Br Dent J. 2014 Mar;216(5):E10)
Systemic effect of water fluoridation on dental caries prevalence:   CONCLUSIONS: While 6-year-old children who had not ingested fluoridated water showed higher dft in the WF-ceased area than in the non-WF area, 11-year-old children in the WF-ceased area who had ingested fluoridated water for approximately 4 years after birth showed significantly lower DMFT than those in the non-WF area. This suggests that the systemic effect of fluoride intake through water fluoridation could be important for the prevention of dental caries. (Cho HJ, et al. – Community Dent Oral Epidemiol. 2014 Jan 16)
Milk fluoridation for the prevention of dental caries:  CONCLUSION: These evaluations showed clearly that the optimal daily intake of fluoride in milk is effective in preventing dental caries. The amount of fluoride added to milk depends on background fluoride exposure and age of the children: commonly in the range 0.5 to 1.0 mg per day. An advantage of the method is that a precise amount of fluoride can be delivered under controlled conditions. The cost of milk fluoridation programmes is low, about - 2 to 3 per child per year. Fluoridation of milk can be recommended as a caries preventive measure where the fluoride concentration in drinking water is suboptimal, caries experience in children is significant, and there is an existing school milk programme. (Beneczy J et al. – Acta Med Acad. 2013 Nov;42(2):156-67)
Factors associated with surface-level caries incidence in children aged 9 to 13: the Iowa Fluoride Study:  CONCLUSION: More frequent tooth brushing was protective of sound surfaces, and fluoride in home tap water was also protective, but significantly more so for adolescents in low-income families. (Broffitt B, et al. – J Public Health Dent. 2013 Fall;73(4):304-10
Reduced adhesion of oral bacteria on hydroxyapatite by fluoride treatment:  The mechanisms of action of fluoride have been discussed controversially for decades. The cavity-preventive effect for teeth is often traced back to effects on demineralization. However, an effect on bacterial adhesion was indicated by indirect macroscopic studies. To characterize adhesion on fluoridated samples on a single bacterial level, we used force spectroscopy with bacterial probes to measure adhesion forces directly. We tested the adhesion of Streptococcus mutans , Streptococcus oralis , and Staphylococcus carnosus on smooth, high-density hydroxyapatite surfaces, pristine and after treatment with fluoride solution. All bacteria species exhibit lower adhesion forces after fluoride treatment of the surfaces. These findings suggest that the decrease of adhesion properties is a further key factor for the cariostatic effect of fluoride besides the decrease of demineralization. (Loskill P, et al. –  Langmuir. 2013 May 7;29(18):5528-33
Water fluoridation and oral health:  CONCLUSION: Water fluoridation is an effective safe means of preventing dental caries, reaching all populations, irrespective of the presence of other dental services. Regular monitoring of dental caries and fluorosis is essential particularly with the lifelong challenge which dental caries presents. (Harding MA, O'Mullane DM – Acta Med Acad. 2013 Nov;42(2):131-9)
The economic value of Quebec's water fluoridation program:  RESULTS: The analyses showed the water fluoridation program was cost-effective even with a conservatively estimated 1 % reduction in dental caries. The benefit-cost ratio indicated that, at an expected average effectiveness of 30 % caries reduction, one dollar invested in the program saved $71.05-$82.83 per Quebec's inhabitant in dental costs (in 2010) or more than $560 million for the State and taxpayers. CONCLUSION: The results showed that the drinking-water fluoridation program produced substantial savings. Public health decision-makers could develop economic arguments to support wide deployment of this population-based intervention whose efficacy and safety have been demonstrated and acknowledged. (Tchouaket E, et al. – Z Gesundh Wiss. 2013;21:523-533)
The economic value of Quebec's water fluoridation program:  Aim: Dental caries is a major public health problem worldwide, with very significant deleterious consequences for many people. The available data are alarming in Canada and the province of Quebec. The water fluoridation program has been shown to be the most effective means of preventing caries and reducing oral health inequalities. This article analyzes the cost-effectiveness of Quebec's water fluoridation program to provide decision-makers with economic information for assessing its usefulness. Conclusion: The results showed that the drinking-water fluoridation program produced substantial savings. Public health decision-makers could develop economic arguments to support wide deployment of this population-based intervention whose efficacy and safety have been demonstrated and acknowledged. (Eric Tchouaket, et al. – Z Gesundh Wiss. 2013; 21(6): 523-533)
Dental caries in 14- and 15-year-olds in New South Wales, Australia:  Teenagers living in fluoridated areas of NSW had lower mean DMFT rates (DMFT 1.1 versus 1.7, Table 5) and a higher percentage of children who had never experienced decay (56.0% versus 45.0%) than children in un-fluoridated areas. (John Skinner, et al. – BMC Public Health. 2013; 13: 1060)
Estimated Drinking Water Fluoride Exposure and Risk of Hip Fracture.  A Cohort Study:  Overall, we found no association between chronic fluoride exposure and the occurrence of hip fracture. The risk estimates did not change in analyses restricted to only low-trauma osteoporotic hip fractures. Chronic fluoride exposure from drinking water does not seem to have any important effects on the risk of hip fracture, in the investigated exposure range. (Nesman P, et al. – J Dent Res. 2013 Oct 1) - Free Article
Understanding Public Decision-Making on Community Water Fluoridation (CWF):  Understanding public concern and building from common ground when engaging the public can effectively build trust. 'Trust is difficult to build once a CWF campaign is already underway,' adds Dr. Swan. The report found that although public trust in scientific and medical organizations cannot be relied on, people's trust in their own practitioners remained high. 'So, discussing CWF with your patients may help build public support for CWF.' (J Can Dent Assoc. 2013 May;79:d77)
Related: Effectiveness of Population-Based Interventions to Promote Oral Health
Effects of Fluoridated Drinking Water on Dental Caries in Australian Adults: The study shows that Australian adults with more than 75% lifetime exposure to water fluoridation have significantly reduced caries experience when compared with those with less than a 25% lifetime exposure. This reduction has occurred in adult Australians born in both the pre- and post-fluoridation generation. The significance of this is that the introduction of water fluoridation to a community will benefit all residents, not only those who grow up drinking fluoridated water. (Slade GD, et al. – J Dent Res. 2013 Mar 1)
Fluoridation and dental caries severity in young children treated under general anaesthesia: an analysis of treatment records in a 10-year case series:  CONCLUSIONS: Children with severe dental caries had statistically significantly lower numbers of lesions if they lived in a fluoridated area. The lower treatment need in such high-risk children has important implications for publicly-funded dental care.. (Kamel MS, et al. – Community Dent Health. 2013 Mar;30(1):15-8)
Water fluoridation and the association of sugar-sweetened beverage consumption and dental caries in Australian children: Consumption of sugar-sweetened beverages should be considered a major risk factor for dental caries. However, increased exposure to fluoridated public water helped ameliorate the association between SSB consumption and dental decay. These results reconfirm the benefits of community water fluoridation for oral health. (Mullen J, et al. – Am J Public Health. 2013 Mar;103(3):494-500)
Caries status in 16 year-olds with varying exposure to water fluoridation in Ireland: RESULTS: With both systems of measurement, significantly lower caries levels were found in those children with the greatest exposure to fluoridated water when compared to those with the least exposure.
CONCLUSIONS: The survey provides further evidence of the effectiveness in reducing dental caries experience up to 16 years of age. The extra intricacies involved in using the Percentage Lifetime Exposure method did not provide much more information when compared to the simpler Estimated Fluoridation Status method. . (Armfield JM, et al. – Community Dent Health. 2012 Dec;29(4):293-6) - Free Article
Prevalence of dental caries and dental fluorosis among 12 and 15 years old school children in relation to fluoride concentration in drinking water in an endemic fluoride belt of Andhra Pradesh: CONCLUSION: There was a negative correlation between dental caries and fluoride concentration for the entire study population. However, in high fluoride areas, there was a positive correlation between fluoride concentration and dental caries. Water defluoridation on an urgent basis is a priority here than water fluoridation, because the prevalence and severity of dental flurorosis is very high.
According to our study, an optimum range of fluoride concentration in this area that offered maximum protection against dental caries with minimal risk for esthetically significant fluorosis, was 0.6 - 1.3 PPM. This is very close to the optimal fluoride concentration of 0.6 - 1.2 PPM, suggested by Bureau of Indian standards. (Shekar C, et al. – Indian J Public Health. 2012 Apr-Jun;56(2):122-8) - Free Article
The association between social deprivation and the prevalence and severity of dental caries and fluorosis in populations with and without water fluoridation: CONCLUSIONS: Water fluoridation appears to reduce the social class gradient between deprivation and caries experience when considering caries into dentine. However, this was associated with an increased risk of developing mild fluorosis. The use of intra-oral cameras and remote scoring of photographs for caries demonstrated good potential for blinded scoring. (McGrady MG, et al. – BMC Public Health. 2012 Dec 28;12:1122)
Decline in dental caries among 12-year-old children in Brazil, 1980-2005: CONCLUSIONS: Data showed a significant decrease in dental caries across the entire country, with an average reduction of 25% occurring every 5 years. General trends indicated that a reduction in DMFT index values occurred over time, that a further reduction in DMFT index values occurred when a municipality fluoridated its water supply, and mean DMFT index values were lower in larger than in smaller municipalities. (Lauris JR, et al. – Int Dent J. 2012 Dec;62(6):308-14) - Free Article
Fluorides - mode of action and recommendations for use: Various authors have shown that the caries decline in the industrialized countries during recent decades is based on the use of fluorides, of which local fluoride application in the form of fluoridated toothpastes is of primary importance. The caries-protective potential of fluorapatite is quite low; in contrast, dissolved fluorides in the vicinity of enamel are effective both in promoting remineralization and inhibiting demineralization. Considering the fact that the caries decline occurred at the same time that local fluoridation measures became widely used, the conclusion seems justified that regular application of F⁻ can inhibit caries. (Lussi A, et al. – Schweiz Monatsschr Zahnmed. 2012;122(11):1030-42)
Effectiveness of water fluoridation in caries prevention: CONCLUSIONS: Fewer studies have been published recently. More of these have investigated effect at the multi-community, state or even national level. The dmf/DMF index remains the most widely used measure of effect. % CR were lower in recent studies, and the 'halo' effect was discussed frequently. Nevertheless, reductions were still substantial. Statistical control for confounding factors is now routine, although the effect on per cent reductions tended to be small. Further thought is needed about the purpose of evaluation and whether measures of effect and study design are appropriate for that purpose. (Rugg-Gunn AJ & Do L. – Community Dent Oral Epidemiol. 2012 Oct;40 Suppl 2:55-64)
A model to determine the economic viability of water fluoridation: CONCLUSIONS: This model confirmed that water fluoridation is an economically viable option to prevent dental caries in South African communities, as well as conclusions over the last 10 years that water fluoridation leads to significant cost savings and remains a cost-effective measure for reducing dental caries, even when the caries-preventive effectiveness is modest. (Kroon J & van Wyk PJ. – J Public Health Dent. 2012 Fall;72(4):327-33)
Battle renewed over value of fluoridation: Linking the decision made by the United States Department of Health and Human Services to lower the recommended level of fluoride added to drinking water to the effectiveness of water fluoridation is inaccurate. This decision was based on studies showing that the levels previously accepted in the US presented a risk of dental fluorosis that was deemed unacceptable for infant formula reconstituted with tap water. The change was a dosage adjustment, not a retreat from water fluoridation. The reference to the balance of protection and risk confirms that the decision had nothing to do with 'bone effects' and everything to do with fluorosis. There is no evidence that exposure to fluoride from water fluoridation leads to bone abnormalities of any kind. (MacGregor, R. – CMAJ. 2011 July 12; 183(10): 1173. )
Fluoride in drinking water and osteosarcoma incidence rates in the continental United States among children and adolescents: CONCLUSION: Our ecological analysis suggests that the water fluoridation status in the continental U.S. has no influence on osteosarcoma incidence rates during childhood and adolescence. (Levy M, Leclerc BS. – Cancer Epidemiol. 2012 Apr;36(2):e83-8)

Drinking water fluoridation in Canada
Review and synthesis of published literature, April 2011.   Main findings may be summarized as follows:
  • Evidence for the effectiveness of drinking water fluoridation in the prevention of dental caries in Canada exists. The strongest evidence is from the original trials (e.g., Brantford-Sarnia-Stratford) in the 1940s through 1960s. These original trials were impressive for their adherence to a rigorous research protocol.
  • Since the 1970s, research on drinking water fluoridation has been complicated by the widespread availability of other sources of fluoride, most notably fluoride toothpaste. As such, more recent evidence on fluoridation is weaker than the earliest findings, though on balance it supports more than it refutes the effectiveness of the intervention.
  • Existing research consistently shows an association between exposure to drinking water fluoridation and increased risk of dental fluorosis. Case studies of fluorosis in communities with high levels of fluoride in drinking water illustrate the critical importance of monitoring fluoride concentrations, particularly in rural areas with weaker infrastructure.
  • Although there is some indication that exposure to fluoridation may have some benefit for bone density, on balance there is no clear evidence for an association between drinking water fluoridation and health outcomes other than dental outcomes.
  • To conduct research on the health impact of drinking water fluoridation, it is essential to have accurate information on exposure, including a) length of residence in the community; and b) use of other sources of fluoride. This has implications for oral health surveillance across multiple Canadian jurisdictions.
  • Although resistance to fluoridation is sometimes thought to be a recent phenomenon, well-defined opposition to fluoridation has in fact existed as long as fluoridation itself.
  • Many arguments have been put forth by those opposed to fluoridation, ranging from the relatively innocuous 'it's not effective' to the more apocryphal 'communist plot' and 'aluminum company conspiracy'. Part of the power of the anti-fluoride movement is that some of the arguments - e.g., potential harm to the environment and aquatic life - cross ideological lines and have proponents in both the political right and left.
  • We identified a large amount of material on local circumstances surrounding plebiscites or referenda. While this information may be helpful for communities undergoing a vote, it is important to recognize that fluoridation plebiscites are more likely to fail than to pass, which reflects characteristics of fluoridation and characteristics of plebiscites.
  • Contrasting with the failure of most fluoridation plebiscites is the observation, from public opinion polls, that a majority of Canadians are in favour of, or at least not opposed to, fluoridation. This suggests that anti-fluoridationists are over-represented among voters at plebiscites, and it speaks to the success of the anti-fluoridationists in persuading otherwise undecided or non-voters to vote no.
  • From an ethical point of view, drawing on principles of beneficence, autonomy, and truthfulness, the controversy over fluoridation may be un-resolvable. (McLaren L. & McIntyre L., )
    Calgary's City Council voted 10-3 to remove fluoride from the city's drinking water on Feb. 8, 2011.   Dr. McLaren has initiated a study to follow results of this decision on the city's youth - results are expected (from one source) in spring, 2015.
Drinking water fluoridation and osteosarcoma incidence on the island of Ireland: The results of this study do not support the hypothesis that osteosarcoma incidence in the island of Ireland is significantly related to public water fluoridation. However, this conclusion must be qualified, in view of the relative rarity of the cancer and the correspondingly wide confidence intervals of the relative risk estimates. (Comber H, et al. – Cancer Causes Control. 2011 Jun;22(6):919-24)
Fluoride supplements (tablets, drops, lozenges or chewing gums) for preventing dental caries in children: BACKGROUND: Dietary fluoride supplements were first introduced to provide systemic fluoride in areas where water fluoridation is not available. Since 1990, the use of fluoride supplements in caries prevention has been re-evaluated in several countries.  MAIN RESULTS: We included 11 studies in the review involving 7196 children.In permanent teeth, when fluoride supplements were compared with no fluoride supplement (three studies), the use of fluoride supplements was associated with a 24% (95% confidence interval (CI) 16 to 33%) reduction in decayed, missing and filled surfaces (D(M)FS). AUTHORS' CONCLUSIONS: This review suggests that the use of fluoride supplements is associated with a reduction in caries increment when compared with no fluoride supplement in permanent teeth. The effect of fluoride supplements was unclear on deciduous teeth. When compared with the administration of topical fluorides, no differential effect was observed. We rated 10 trials as being at unclear risk of bias and one at high risk of bias, and therefore the trials provide weak evidence about the efficacy of fluoride supplements. (Tubert-Jeannin S, et al. – Cochrane Database Syst Rev. 2011 Dec 7;12:CD007592.) (copy of the paper)
An Assessment of Bone Fluoride and Osteosarcoma: No significant association between bone fluoride levels and osteosarcoma risk was detected in our case-control study, based on controls with other tumor diagnoses.
(Kim FM, et al. – J Dent Res. 2011 Oct;90(10):1171-1176. Epub 2011 Jul 28) - Free Article 
Validation of a multifactorial risk factor model used for predicting future caries risk with Nevada adolescents: {logistic regression analysis indicated that youth living in non-fluoridated areas of Nevada had greater odds of developing tooth decay than those who lived in the county with fluoridated water - RJ}
(Ditmyer MM, et al. – BMC Oral Health. 2011; 11: 18. Published online 2011 May 20)
Related article: - Free Article
Inequalities of caries experience in Nevada youth expressed by DMFT index vs. Significant Caries Index (SiC) over time:
At the community level, action should focus on retaining and expanding the community fluoridation program as an effective preventive measure.  (Ditmyer MM, et al. – BMC Oral Health. 2011 Apr 5;11:12)
Dental caries in children: a comparison of one non-fluoridated and two fluoridated communities in NSW: The caries prevalence in the permanent dentition of Lithgow {non-fluoridated} children was significantly higher than that in children living in the fluoridated towns of Bathurst and Orange {fluoridated}. No significant differences were observed in the estimates for primary teeth.
CONCLUSION: Although the mean levels of dental caries in schoolchildren in Lithgow were low, oral health inequalities exist between children residing in non-fluoridated Lithgow and the fluoridated locations of Orange and Bathurst. The local council decided that Lithgow will have fluoridated water by December 2010. (Arora A & Evans RW – N S W Public Health Bull. 2010 Nov-Dec;21(11-12):257-62) - Free Article 
Fluoride: its role in dentistry: In spite of decades of research on fluoride and the recognition of its role as the cornerstone of dental caries reduction in the last fifty years, questions still arise on its use at community, self-applied and professional application levels. Which method of fluoride delivery should be used? How and when should it be used? How can its benefits be maximized and still reduce the risks associated with its use? These are only some of the challenging questions facing us daily. The aim of this paper is to present scientific background to understand the importance of each method of fluoride use considering the current caries epidemiological scenario, and to discuss how individual or combined methods can be used based on the best evidence available.
(Tenuta LM, Cury JA – Braz Oral Res. 2010;24 Suppl 1:9-17) {a very good summary of the role of the fluoride ion, saliva, and oral ecology on the process of tooth decay - RJ}  (requires subscription)
Geographic Variation in Medicaid Claims for Dental Procedures in New York State: Role of Fluoridation Under Contemporary Conditions: Results. Compared with the predominantly fluoridated counties, the mean number of restorative, endodontic, and extraction procedures per recipient was 33.4% higher in less fluoridated counties.  Conclusions. We found that the mean number of claims for caries related services for children in the NYS Medicaid program was correlated with the extent of fluoridation in a county. These annual decreases in claims per recipient, when applied to lifetime exposure of the whole population, have large societal benefits. These findings, when added to the already existing weight of evidence, have implications for promoting policies at the federal and state levels to strengthen the fluoridation program. (Kumar, JV, et al. – Public Health Reports, September - October 2010, Volume 125 p647)
Community Effectiveness of Public Water Fluoridation in Reducing Children's Dental Disease:
Results. Children from every age group had greater caries prevalence and more caries experience in areas with negligible fluoride concentrations in the water (<0.3 parts per million [ppm]) than in optimally fluoridated areas (>0.7 ppm).  Conclusions. This study demonstrates the continued community effectiveness of water fluoridation and provides support for the extension of this important oral health intervention to populations currently without access to fluoridated water. (Armfield, JM – Public Health Reports, September - October 2010, Volume 125 p655-664)
What we know and do not know about fluoride: Summary: There is much that we know about fluoride as it relates to human health in general and dental health in particular. Some of the information that is known concerning water fluoridation and dental fluorosis is listed. What we do not know about fluoride is discussed in more detail, namely the efficacy of lower levels of fluoride in drinking water, the effect of discontinuing fluoride in drinking water in the absence of additional preventive measures, the prevalence of fluorosis and whether or not this presents a cosmetic problem. Other issues discussed include the actual amount of fluoride ingested from all sources, whether low-fluoride dentifrices are as efficacious as conventional dentifrices in caries protection and reducing enamel fluorosis, the role of socioeconomic factors in determining caries prevalence, and the effects of bottled water use on caries prevalence in fluoridated communities. (Newbrun E. – J Public Health Dent. 2010 Jun 2. [Epub ahead of print])
The impact of changing dental needs on cost savings from fluoridation: CONCLUSION: Community water fluoridation remains a cost-effective preventive measure in Australia. (Campain AC, et al. – Aust Dent J. 2010 Mar;55(1):37-44)
Drinking water fluoridation in South East Queensland: a cost-effectiveness evaluation: CONCLUSION: Fluoridation remains still a very cost-effective measure for reducing dental decay. (Ciketic S, et al. – Health Promot J Austr. 2010 Apr;21(1):51-6)
Water fluoridation in the Blue Mountains reduces risk of tooth decay: CONCLUSIONS: Tooth decay reduction observed in the Blue Mountains corresponds to high rates reported elsewhere and demonstrates the substantial benefits of water fluoridation. (Evans RW, et al. – Aust Dent J. 2009 Dec;54(4):368-73)
The long-term effects of water fluoridation on the human skeleton: Municipal water fluoridation has notably reduced the incidence of dental caries and is widely considered a public health success. However, ingested fluoride is sequestered into bone, as well as teeth, and data on the long-term effect of exposure to these very low doses of fluoride remain inconclusive. Epidemiological studies suggest that effects of fluoride on bone are minimal. We hypothesized that the direct measurement of bone tissue from individuals residing in municipalities with and without fluoridated water would reveal a relationship between fluoride content and structural or mechanical properties of bone. However, consonant with the epidemiological data, only a weak relationship among fluoride exposure, accumulated fluoride, and the physical characteristics of bone was observed. Analysis of our data suggests that the variability in heterogenous urban populations may be too high for the effects, if any, of low-level fluoride administration on skeletal tissue to be discerned. (Chachra D, et al. – J Dent Res. 2010 Nov;89(11):1219-23) - Free Article
Epidemiology of fluorosis and dental caries according to different types of water supplies: Conclusions: Only the schoolchildren in the WTS {fluoridated water} group presented a DMFT index {the total number of teeth with caries experience, including decayed teeth} below 3, probably because of the better water fluoridation, demonstrating the efficacy of this method; thus, this preventive measure should be recommended for our population. (Franzolin Sde O, et al. – Cien Saude Colet. 2010 Jun;15 Suppl 1:1841-7)
The long-term effects of water fluoridation on the human skeleton: Abstract - Municipal water fluoridation has notably reduced the incidence of dental caries and is widely considered a public health success. However, ingested fluoride is sequestered into bone, as well as teeth, and data on the long-term effect of exposure to these very low doses of fluoride remain inconclusive. Epidemiological studies suggest that effects of fluoride on bone are minimal. We hypothesized that the direct measurement of bone tissue from individuals residing in municipalities with and without fluoridated water would reveal a relationship between fluoride content and structural or mechanical properties of bone. However, consonant with the epidemiological data, only a weak relationship among fluoride exposure, accumulated fluoride, and the physical characteristics of bone was observed. Analysis of our data suggests that the variability in heterogenous urban populations may be too high for the effects, if any, of low-level fluoride administration on skeletal tissue to be discerned. (Chachra D, Limeback H, Willett TL, Grynpas MD – J Dent Res. 2010 Nov;89(11):1219-23)
The association between community water fluoridation (CWF) and adult tooth loss: CONCLUSIONS: This study suggests that the benefits of CWF may be larger than previously believed and that CWF has a lasting improvement in racial/ethnic and economic disparities in oral health. (Neidell M, et al. – Am J Public Health. 2010 Oct;100(10):1980-5) - Free Article
A case-control study of determinants for high and low dental caries prevalence in Nevada youth: Community water fluoridation has been documented as the most cost-effective, equitable, and safe community-based approach to improving oral health. Participants living in areas without community water fluoridation in Nevada were almost 2 times more likely to present with higher DMFT indices. The benefits of water fluoridation are proportionally higher for people who do not have regular access to other sources of fluoride. Therefore, dental professionals should counsel patients living in non-fluoridated geographic areas on the importance of using other sources of fluoride. It is of special significance that several futile attempts have been made in Nevada to introduce community water fluoridation to other counties, such as Washoe County, which comprises around 15% of the population. (Ditmyer M, et al. – BMC Oral Health. 2010 Nov 11;10:24) (Full Article)
Water fluoridation: AIM: This was to present a summary of the evidence from systematic reviews of the effectiveness and safety of water fluoridation
RESULTS: Of the 59 publications identified, 3 systematic reviews and 3 guidelines were included in this review. While the reviews themselves were of good methodological quality, the studies included in the reviews were generally of moderate to low quality. The results of the three reviews showed that water fluoridation is effective at reducing caries in children and adults. With the exception of dental fluorosis, no association between adverse effects and water fluoridation has been established. Water fluoridation reduces caries for all social classes, and there is some evidence that it may reduce the oral health gap between social classes.
CONCLUSION: Water fluoridation, where technically feasible and culturally acceptable, remains a relevant and valid choice as a population measure for the prevention of dental caries. (Parnell C, et al. – Eur Arch Paediatr Dent. 2009 Sep;10(3):141-8)  Related Article Community Water Fluoridation: An Evidence Review, 2012, Campos-Outcalt, et al.
The Association Between Enamel Fluorosis and Dental Caries in U.S. Schoolchildren: Conclusion. This study's findings suggest that molars with fluorosis are more resistant to caries than are molars without fluorosis.
Clinical Implications. The results highlight the need for those considering policies regarding reduction in fluoride exposure to take into consideration the caries-preventive benefits associated with milder forms of enamel fluorosis. (Hiroko, I, et al. – J Am Dent Assoc, Vol 140, No 7, 855-862, 2009)
Appetitive-based learning in rats: lack of effect of chronic exposure to fluoride: CONCLUSION: Chronic ingestion of fluoride {by rats} at levels up to 230 times more than that experienced by humans whose main source of fluoride is fluoridated water had no significant effect on appetitive-based learning.(Whitford, GM, et al. – Neurotoxicol Teratol. 2009 Jul-Aug;31(4):210-5)
Risk perception and water fluoridation support and opposition in Australia: Objectives: A considerable body of evidence confirms that water fluoridation effectively reduces the community incidence of dental caries with minimal side effects. However, proposals to introduce this widely endorsed public-health measure are often perceived as controversial, and public opinion frequently plays a role in the outcome. Despite this, the public's perception of risk associated with water fluoridation has not been well researched and remains poorly understood. Our objectives were to determine whether risk perceptions reflecting various "outrage" factors are associated with water fluoridation support and opposition. Conclusion: Outrage factors are important aspects of the public's perception of risk in relation to water fluoridation. Given that water fluoridation appears to be a low-risk, high-outrage controversy, efforts to mitigate the level of public outrage, rather than continuing to deny possible hazards, may offer a worthwhile strategy in gaining public acceptance for the extension of water fluoridation. (Armfield, JM and Akers, HF – J Public Health Dent. 2009 Aug 20)
Assessing a potential risk factor for enamel fluorosis: a preliminary evaluation of fluoride content in infant formulas: Some infants aged between birth and 6 months who consume powdered and liquid concentrate formulas reconstituted with water containing 1.0 part per million fluoride likely will exceed the upper tolerable limit of fluoride. CONCLUSIONS: When powdered or liquid concentrate infant formulas are the primary source of nutrition, some infants are likely to exceed the recommended fluoride upper limit if the formula is reconstituted with water containing 1.0 ppm fluoride. On the other hand, when the fluoride concentration in water used to reconstitute infant formulas is below 0.4 ppm, it is likely that infants between 6 and 12 months of age will be exposed to fluoride at levels below IOM's recommended adequate intake level. (Siew, C et al. – J Am Dent Assoc. 2009 Oct;140(10):1228-36)
A controlled study of risk factors for enamel hypoplasia in the permanent dentition: PURPOSE: The purpose of this study was to investigate risk factors for enamel hypoplasia (EH) and enamel opacity (EO) in the permanent teeth of healthy schoolchildren from a nonfluoridated community in Australia.  CONCLUSIONS: Children with low socioeconomic status, histories of respiratory or chickenpox infections, exposure to cigarette-smoking, urinary tract infections, otitis, and use of adult toothpaste are predisposed to enamel hypoplasia. By contrast, drinking optimally fluoridated water at 0 to 3 years old reduces the risk for enamel opacities. (Ford, D et al. – Pediatr Dent. 2009 Sep-Oct;31(5):382-8)
Evidence that fluoride in the infant formula causes enamel fluorosis weak: CONCLUSIONS: Infant formula consumption may be associated with an increased risk of developing at least some detectable level of enamel fluorosis, but this depends on the level of fluoride in the water supply. The evidence that the fluoride in the infant formula caused enamel fluorosis was weak, as other mechanisms could explain the observed association. (Edwards, M – Evid Based Dent. 2009;10(3):73)
Association of natural fluoride in community water supplies with dental health of children in remote indigenous communities - implications for policy:  OBJECTIVE: To map the geographic distribution of fluoride in water supplies and child dental caries in remote Indigenous communities of the Northern Territory (NT). To examine the association between fluoride levels, household and community factors, access to services and child dental caries in these communities and to model the impact on the caries experience of children of introducing water fluoridation.  CONCLUSIONS AND IMPLICATIONS: Introduction of fluoridation of water supplies into communities with inadequate natural fluoride is a vital measure for improving the dental health of children living in remote NT communities. (Bailie, RS, et al. – Aust N Z J Public Health. 2009 Jun;33(3):205-11)
 Water fluoridation in Canada: past and present: Water fluoridation remains a contentious issue in Canada and many communities choose not to fluoridate their water supply. As of 2007, 45.1% of the Canadian population had access to fluoridated water supplies. The main arguments for and against fluoridation have changed very little over the years, with supporters (including the World Health Organization and Health Canada) citing evidence that shows fluoridation as a safe and effective method of caries prevention, while detractors cite high costs and potential health risks. This article provides an historical overview and a current snapshot of water fluoridation in Canada. It concludes that the ultimate advantage of fluoridation is that it helps everyone in a community, regardless of socioeconomic status. (Rabb-Waytowich D – J Can Dent Assoc. 2009 Jul;75(6):451-4)
Effects of long-term fluoride in drinking water on risks of hip fracture of the elderly: an ecologic study based on database of hospitalization episodes, OBJECTIVES: Fluoridation of drinking water is known to decrease dental caries, particularly in children. However, the effects of fluoridated water on bone over several decades are still in controversy. To assess the risk of hip fracture related to water fluoridation, we evaluated the hip fracture-related hospitalizations of the elderly between a fluoridated city and non-fluoridated cities in Korea.
CONCLUSIONS: We cannot conclude that fluoridation of drinking water increases the risk of hip fracture in the elderly. (Park EY, et al. – J Prev Med Public Health. 2008 May;41(3):147-52)
Prevalence and extent of dental caries, dental fluorosis, and developmental enamel defects in Lithuanian teenage populations with different fluoride exposures: The aim of this study was to describe the pattern of dental caries, dental fluorosis, and developmental defects of non-fluoride origin in Lithuanian children born and raised in regions with 1.1 ppm (1.1 mg/l F) and 0.3 ppm (0.3 mg/l F) water fluoride levels, respectively. All permanent surfaces/teeth of 300 teenagers were examined for dental caries, dental fluorosis, and non-fluoride developmental defects. The caries prevalence of the study population was 100%. The mean number of decayed surfaces (DS) differed only slightly and statistically insignificantly between the '1.1 ppm fluoride' and '0.3 ppm fluoride' groups (19.6 and 18.1, respectively). However, a greater number of inactive lesions and fewer fillings were found in the '1.1 ppm fluoride' group than in the '0.3 ppm fluoride' group (mean difference 1.18 and -2.80, respectively). The prevalence of dental fluorosis was 45% and 21%, respectively; the prevalence of non-fluoride opacities was 8% and 19%, respectively; and the prevalence of hypoplasia was 12% and 16%, respectively, in the '1.1 ppm fluoride' and '0.3 ppm fluoride' groups. Higher caries levels were noted in children with no fluorosis compared to those with fluorosis recorded (mean DS difference, 3.43). The results lend support to the hypothesis that the presence of fluoride in the oral environment promotes lesion arrest rather than inhibiting the initiation of new lesions. (Machiulskiene V, et al. – Eur J Oral Sci. 2009 Apr;117(2):154-60)
Public opinions on community water fluoridation: BACKGROUND: Community water fluoridation (CWF) is currently experiencing social resistance in Canada. Petitions have been publicly registered, municipal plebiscites have occurred, and media attention is growing...  RESULTS: Approximately 1 in 2 Canadian adults surveyed knew about CWF. Of these, 80% understood its intended use, approximately 60% believed that it was both safe and effective, and 62% supported the idea of having fluoride added to their local drinking water. Those with greater incomes [OR=1.4; p<0.001] and education [OR=1.6; p<0.001] were more likely to know about CWF. Those with greater incomes [OR=1.3; p<0.03] and those who visited the dentist more frequently [OR=1.8; p<0.002] were more likely to support CWF, and those with children [OR=0.5; p<0.02], those who accessed dental care using public insurance [OR=0.2; p<0.03], and those who avoided fluoride [OR=0.04; p<0.001] were less likely to support CWF.  CONCLUSION: It appears that Canadians still support CWF. In moving forward, policy leaders will need to attend to two distinct challenges: the influence of anti-fluoride sentiment, and the potential risks created by avoiding fluoride. (Quionez CR, Locker D. – Can J Public Health. 2009 Mar-Apr;100(2):96-100) {Ironically, the segment of the population most at risk for dental disease and the group most likely to benefit from water fluoridation policies is often the group most opposed to the practice. RJ}
The global increase in dental caries. A pending public health crisis: A current review of the available epidemiological data from many countries clearly indicates that there is a marked increase in the prevalence of dental caries. This global increase in dental caries prevalence affects children as well as adults, primary as well as permanent teeth, and coronal as well as root surfaces. This increase in dental caries signals a pending public health crisis. Although there are differences of opinion regarding the cause of this global dental caries increase, the remedy is well known: a return to the public health strategies that were so successful in the past, a renewed campaign for water fluoridation, topical fluoride application, the use of fluoride rinses, a return to school oral health educational programs, an emphasis on proper tooth brushing with a fluoride dentifrice, as well as flossing, a proper diet and regular dental office visits. (Bagramian RA, et al. – Am J Dent. 2009 Feb;22(1):3-8)
A systematic review of the efficacy and safety of fluoridation: SCOPE AND PURPOSE: The systematic review was commissioned by the Australian National Health and Medical Research Council (NHMRC) to evaluate the scientific literature relating to the health effects of fluoride and fluoridation. The systematic review's research questions relate to the caries-reducing benefits and associated potential health risks of providing fluoride systemically (via addition to water, milk and salt) and the use of topical fluoride agents, such as toothpaste, gel, varnish and mouthrinse. - RECOMMENDATIONS: Fluoridation of drinking water remains the most effective and socially equitable means of achieving community-wide exposure to the caries prevention effects of fluoride. It is recommended (see also that water be fluoridated in the target range of 0.6-1.1 mg/l, depending on the climate, to balance reduction of dental caries and occurrence of dental fluorosis (Yeung, CA – Evid Based Dent. 2008;9(2):39-43)  (Download Part A - Part B)
Lifetime fluoridation exposure and dental caries experience in a military population: OBJECTIVES: To determine whether exposure to fluoride in drinking water is associated with caries experience in Australian Defence Force (ADF) personnel.
CONCLUSIONS: Degree of lifetime exposure to fluoridated drinking water was inversely associated with DMFT in a dose-response manner among this adult military population. (Mahoney, G, et al. – Community Dent Oral Epidemiol. 2008 Dec;36(6):485-92) {Translation - the greater the exposure to fluoridated drinking water the lower the rate of DMFT (the number of decayed, missing and filled teeth) - RJ.}
Pharmacokinetics of ingested fluoride: lack of effect of chemical compound, CONCLUSIONS: Considered together with published reports, the present findings support the conclusion that the major features of fluoride metabolism are not affected differently by the chemical compounds commonly used to fluoridate water nor are they affected by whether the fluoride is present naturally or added artificially. (Whitford, GM, et al. – Arch Oral Biol. 2008 Nov;53(11):1037-41) - Free Article
Is Water Fluoridation Still Necessary? Water fluoridation has been promoted in many countries as an organized community effort to control dental caries. With the availability of fluorides targeted at individuals and the decline in dental caries, the need for fluoridation has been questioned. Recent reports show that water fluoridation, a community-level intervention, continues to be an efficient method for the delivery of fluoride in many countries. The advantages include its ability to deliver low levels of fluoride to saliva frequently, with high reach, at low cost, and with substantial cost savings. Water fluoridation has the potential to reduce oral health disparities by creating a healthy environment. Other forms of fluoride, such as fluoride toothpaste, and clinical interventions complement dental caries control strategies. (Kumar, JV – Adv Dent Res 20:8-12, July, 2008)
Fluorides in dental public health programs: The use of fluorides in dental public health programs has a long history. With the availability of fluoridation and other forms of fluorides, dental caries have declined dramatically in the United States. This article reviews some of the ways fluorides are used in public health programs and discusses issues related to their effectiveness, cost, and policy. (Kumar JV, Moss ME – Dent Clin North Am. 2008 Apr;52(2):387-401, vii. )
European citizens' opinions on water fluoridation: OBJECTIVES: To understand European citizens' opinions on water fluoridation, as part of research on their attitudes to the tensions between private and public interest.  CONCLUSIONS: While the vast majority of people opposed water fluoridation, this may be indicative of shifts away from public support of population interventions towards private interventions, as well as reduced trust in public agencies. Thus if research were to demonstrate more clear benefits of water fluoridation over and above that which can be achieved by use of fluoride toothpaste, then the public may become more supportive. However, lobby groups are likely to remain influential. (Griffin, M, et al. – Community Dent Oral Epidemiol. 2008 Apr;36(2):95-102)
Prospective study of the association between fluoride intake and dental fluorosis in permanent teeth: CONCLUSIONS: There was no difference between children with and without fluorosis in the permanent central incisors and first molars regarding fluoride intake. However, this study has limitations that must be recognized: fluoride intake was only measured once, and there were no children in the sample with severe degrees of dental fluorosis. (Martins, CC, et al. – Caries Res. 2008;42(2):125-33) 
Effects of long-term fluoride in drinking water on risks of hip fracture of the elderly: an ecologic study based on database of hospitalization episodes: CONCLUSIONS: We cannot conclude that fluoridation of drinking water increases the risk of hip fracture in the elderly. (Park EY, et al. – J Prev Med Public Health. 2008 May;41(3):147-52)
Dental caries of lifetime residents in Baixo Guandu, Brazil, fluoridated since 1953--a brief communication: The addition of fluoride to public water supplies was an important ally in the improvement of the oral health of Baixo Guandu inhabitants. (Saliba, NA, et al. – J Public Health Dent. 2008 Spring;68(2):119-21)
The ethical dilemma of water fluoridation: The aim of this study is to analyze some of the ethical arguments for and against water fluoridation and to determine if empirical data allow to decide if there are correct policies from a bioethical perspective. Autonomy, compulsory medication (mass medication), precautionary principle, justice in health care and ethics of protection are discussed. It is concluded that fluoridation is beneficial and that there is no ethical reason to oppose it, based on a specific kind of ethics developed to analyze and clarify complex public health issues. (Mendoza, VC – Rev Med Chil. 2007 Nov;135(11):1487-93. )
A comparison of dental treatment utilization and costs by HMO members living in fluoridated and nonfluoridated areas:
OBJECTIVES: To compare dental treatment experiences and costs in members of a health maintenance organization (HMO) in areas with and without community water fluoridation.
RESULTS: Community water fluoridation was associated with reduced total and restorative costs among members with one or more visits, but the magnitude and direction of the effect varied with locale and age and the effects were generally small. In two locales, the cost of restorations was higher in nonfluoridated areas in young people (<age 18) and older adults (>age 58). In younger adults, the opposite effect was observed. The impact of fluoridation may be attenuated by higher use of preventive procedures, in particular supplemental fluorides, in the nonfluoridated areas. (Maupom G, et al. – J Public Health Dent. 2007 Fall;67(4):224-33)  Paper discussed here.
Fluoride prevents caries among adults of all ages: CONCLUSIONS: To date, no systematic reviews have found fluoride to be effective in preventing dental caries in adults. The objective of this meta-analysis was to examine the effectiveness of self- and professionally applied fluoride and water fluoridation among adults.  ...These findings suggest that fluoride is effective in preventing caries in adults of all ages. (Yeung, CA – Evid Based Dent. 2007;8(3):72-3)
Effects of fluoridation of community water supplies for people with chronic kidney disease:
- There is no evidence that consumption of optimally fluoridated drinking water increases the risk of developing CKD, although only limited studies addressing this issue are available.
- There is no evidence that consumption of optimally fluoridated drinking water poses any health risks for people with CKD, although only limited studies addressing this issue are available
- There is limited evidence that people with stage 4 or 5 CKD who ingest substances with a high concentration of fluoride may be at risk of fluorosis.
(Ludlow M, et al. – Nephrol Dial Transplant. 2007 Oct;22(10):2763-7
Effectiveness of fluoride in preventing caries in adults: These findings suggest that fluoride {topical and water fluoridation} prevents caries among adults of all ages. (Griffin, SO, et al. – J Dent Res. 2007 May;86(5):410-5)
Community water fluoridation and caries prevention: a critical review: The aim of this paper was to critically review the current role of community water fluoridation in preventing dental caries. Original articles and reviews published in English language from January 2001 to June 2006 were selected through MEDLINE database. Other sources were taken from the references of the selected papers. For the past 50 years community water fluoridation has been considered the milestone of caries prevention and as one of the major public health measures of the 20th century. However, it is now accepted that the primary cariostatic action of fluoride occurs after tooth eruption. Moreover, the caries reduction directly attributable to water fluoridation have declined in the last decades as the use of topical fluoride had become more widespread, whereas enamel fluorosis has been reported as an emerging problem in fluoridated areas. Several studies conducted in fluoridated and nonfluoridated communities suggested that this method of delivering fluoride may be unnecessary for caries prevention, particularly in the industrialized countries where the caries level has became low. Although water fluoridation may still be a relevant public health measure in poor and disadvantaged populations, the use of topical fluoride offers an optimal opportunity to prevent caries among people living in both industrialized and developing countries. (Pizzo, G, et al. – Clin Oral Investig. 2007 Sep;11(3):189-93)
Effects of water fluoride exposure at crown completion and maturation on caries of permanent first molars: Pre-eruptive fluoride exposure has been shown to be important for caries prevention. This paper aimed to determine the relative effects of water fluoride exposure during crown completion (CC) and maturation on caries experience in first permanent molars... In conclusion a high exposure at CC was important for caries prevention irrespective of the effect of exposure at maturation and post-eruption. The strongest caries-preventive effect was produced by a high exposure at CC supplemented by a high exposure at maturation and/or post-eruption, but the latter two phases could not produce a significant caries-preventive effect on their own. Since most of the caries occurred on pit and fissure surfaces, the findings relate to this class of lesion. (Singh KA, et al. – Caries Res. 2007;41(1):34-42)
Fluoride: a controversy revisited: The purpose of this article is to provide a review of the small but loud debate that has surrounded fluoride over the past 50 years. The benefits of fluoridation and its effect on public health are well known throughout the dental community. What is far less well known are the objections from people--in the tradition of the old amalgam and radiograph radiation debates-who feel that fluoride has adverse effects serious enough to warrant a cessation of its use. This article will present both sides of the issue, not to influence the reader, but to allow the reader to realize that this issue exists and to understand what the key arguments are. (Ananian, A. et al. – N Y State Dent J. 2006 Apr-May;72(3):14-8)
Reexamination of hexafluorosilicate hydrolysis by 19F NMR and pH measurement: The dissociation of hexafluorosilicate has been reinvestigated due to recent suggestions that fluorosilicate intermediates may be present in appreciable concentrations in drinking water...  No intermediates were observable at 10(-5) M concentrations under excess fluoride forcing conditions over the pH range of 3.5-5.  ...The buffer capacity of all of these systems was found to be insufficient to prevent acidic shifts in pH when hexafluorosilicate was added. The pH change is sufficient explanation for the observed inhibition of acetylcholinesterase that was previously attributed to hexafluorosilicate hydrolysis intermediates. (Finney, WF, et al. – Environ Sci Technol. 2006 Apr 15;40(8):2572-7)
Fluoride intake from food and liquid in Japanese children living in two areas with different fluoride concentrations in the water supply:   The mean DMFT in the moderate fluoride area (MFA) was significantly lower than that in the low fluoride area (LFA). The severest grade of dental fluorosis observed was 'very mild' according to Dean's fluorosis index in both areas. The total daily fluoride intakes were 0.0252-0.0254 mg F/kg/day in the MFA [average 0.56 ppm] and 0.0126-0.0144 mg F/kg/day in the LFA [0.04 - 0.13 ppm]. Differences in the fluoride concentration of drinking water in this study were reflected in the fluoride intake from the diet in a typical Japanese diet. (Nohno K, et al. – Caries Res. 2006;40(6):487-93)
Dental caries and enamel fluorosis among the fluoridated population in the Republic of Ireland and non fluoridated population in Northern Ireland in 2002: CONCLUSIONS: In 2002 apart from 8-year-olds, caries levels were lower amongst children resident in fluoridated communities in RoI than amongst corresponding age groups in non-fluoridated NI. Caries has declined in fluoridated and non fluoridated groups in both jurisdictions since the early 1960s. In RoI fluorosis levels were higher amongst lifetime residents of fluoridated communities and have increased since 1984. (Whelton, H, et al. – Community Dent Health. 2006 Mar;23(1):37-43) - Free Full Article
Costs and savings associated with community water fluoridation programs in Colorado: CONCLUSION: Colorado realizes significant annual savings from CWFPs; additional savings and reductions in morbidity could be achieved if fluoridation programs were implemented in other areas. (O'Connell, JM, et al. – Prev Chronic Dis. 2005 Nov;2 Spec no:A06)
Blood Lead Concentrations in Children and Method of Water Fluoridation in the United States, 1988-1994: Given these findings, our analyses, though not definitive, do not support concerns that silicofluorides in community water systems cause higher PbB concentrations in children.  Current evidence does not provide a basis for changing water fluoridation practices, which have a clear public health benefit. (Macek, MD, et al. – Environmental Health Perspectives Volume 114, Number 1, January 2006)
Bioavailability of fluoride in drinking water: a human experimental study: It has been suggested that systemic fluoride absorption from drinking water may be influenced by the type of fluoride compound in the water and by water hardness. Using a human double-blind cross-over trial, we conducted this study to measure c(max), T(max), and Area Under the Curve (AUC) for plasma F concentration against time, following the ingestion of naturally fluoridated hard and soft waters, artificially fluoridated hard and soft waters, and a reference water. Mean AUC over 0 to 8 hours was 1330, 1440, 1679, 1566, and 1328 ng F.min.mL(-1) for naturally fluoridated soft, naturally fluoridated hard, artificially fluoridated soft, artificially fluoridated hard, and reference waters, respectively, with no statistically significant differences among waters for AUC, c(max), or T(max). Any differences in fluoride bioavailability between drinking waters in which fluoride is present naturally or added artificially, or the waters are hard or soft, were small compared with large within- and between-subject variations in F absorption. (Maguire, A, et al. – J Dent Res. 2005 Nov;84(11):989-93)
Position of the American Dietetic Association: the impact of fluoride on health, The American Dietetic Association reaffirms that fluoride is an important element for all mineralized tissues in the body. Appropriate fluoride exposure and usage is beneficial to bone and tooth integrity and, as such, has an important, positive impact on oral health as well as general health throughout life. The American Dietetic Association strongly reaffirms its endorsement of the appropriate use of systemic and topical fluorides, including water fluoridation, at appropriate levels as an important public health measure throughout the life span. (Palmer, C, et al. – J Am Diet Assoc. 2005 Oct;105(10):1620-8)
Current scientific evidence: Water fluoridation is not associated with osteosarcoma - The current scientific literature does not support an association between osteosarcoma and drinking water fluoridation, even though in cellular studies, fluoride acts as a mitogen on osteoblasts, and this defines a biologically plausible pathway for it to play a role in the development of osteosarcoma. (San Francisco Department of Public Health, Occupational and Environmental Health Section, October 2005)  SFPHES Reveiw of the Literature (2000 - 2005) (2006 - 2011)
Elevated Serum Fluoride Concentrations in Women Are Not Related to Fractures and Bone Mineral Density - Serum fluoride concentrations were not related to incident osteoporotic fractures with 4 y of observation. Serum fluoride concentrations were not associated with BMD or osteoporotic fractures among female residents of communities with water fluoride concentrations of 52.6 or 210.4 ml/L.  (Sowers M, et al. – J. Nutr. 135:2247-2252, September 2005)

Effective use of fluorides for the prevention of dental caries in the 21st century
The WHO approach:   Effective use of fluorides for the prevention of dental caries in the 21st century: the WHO approach Such reviews concluded that water fluoridation and use of fluoride toothpastes and mouthrinses significantly reduce the prevalence of dental caries. WHO recommends for public health that every effort must be made to develop affordable fluoridated toothpastes for use in developing countries. Water fluoridation, where technically feasible and culturally acceptable, has substantial advantages in public health; alternatively, fluoridation of salt and milk fluoridation schemes may be considered for prevention of dental caries. (Poul Erik Petersen & Michael A. Lennon – Community Dent Oral Epidemiol 2004)
Relative effects of pre- and post-eruption water fluoride on caries experience by surface type of permanent first molars: CONCLUSIONS: Pre-eruption exposure {to fluoridated water} was important for a caries preventive effect on first permanent molars in children 6-15 years old since post-eruption exposure alone could not lower caries levels significantly.  (Singh, KA, Spencer, AJ – Community Dent Oral Epidemiol. 2004 Dec;32(6):435-46)
Epidemiological studies of tooth wear and dental erosion in 14-year-old children in North West England. Part 1: The relationship with water fluoridation and social deprivation.
CONCLUSION: Children in non-fluoridated districts are 1.5 times more likely to have smooth surface wear compared with children in fluoridated districts. Fluoridation and use of fluoridated toothpaste twice a day provide added protection from dental erosion. The risk of tooth wear is greater with increasing affluence. (Bardsley, PF, et al. – Br Dent J. 2004 Oct 9;197(7):413-6; discussion 399)
Effective use of fluorides for the prevention of dental caries in the 21st century: the WHO approach: Research on the oral health effects of fluoride started around 100 years ago; the focus has been on the link between water and fluorides and dental caries and fluorosis, topical fluoride applications, fluoride toothpastes, and salt and milk fluoridation. Most recently, efforts have been made to summarize the extensive database through systematic reviews. Such reviews concluded that water fluoridation and use of fluoride toothpastes and mouthrinses significantly reduce the prevalence of dental caries.  (Petersen PE, Lennon MA – Community Dent Oral Epidemiol. 2004 Oct;32(5):319-21)
Relationship between fluorine in drinking water and dental health of residents in some large cities in China: Our results, together with the previous study, suggest that: (1) dental caries of the study population can be reduced by drinking water fluoridation and that (2) other factors such as economic level, weather, lifestyle, food habits, living condition, etc., of a city can also affect the incidence of dental caries that cannot be predicted by fluoridation alone. Research on the relation between index of fluorosis (IF) and the fluorine concentration in drinking water for the four high fluorine villages showed that the recommended concentration of fluorine in drinking water can protect from dental fluorosis. (Wang, B, et al. – Environ Int. 2004 Oct;30(8):1067-73) experience among schoolchildren in relation to community fluoridation status and town size: {in Seo Paulo State, Brazil} Caries experience and prevalence were significantly lower in fluoridated areas (1.9 DMFT, 2.1 dmft, 20% caries free) than in non-fluoridated areas (2.4 DMFT, 2.4 dmft, 13% caries free).  The results suggest that water fluoridation is an essential public health measure and that town size may affect caries distribution in the Southeast area of Seo Paulo State. (Tagliaferro EP, et al. – Acta Odontol Scand. 2004 Jun;62(3):124-8)
Caries prevalence in a rural Chilean community after cessation of a powdered milk fluoridation program: CONCLUSIONS: Termination of the powdered milk fluoridation scheme resulted in a deterioration of the dental health of children. After three years, dental caries prevalence was higher than that reached at the end of the scheme and equivalent to that of the control community without fluoride exposure. These results emphasize the need to establish and maintain an alternative mechanism of community-based fluoridation of proven effectiveness for the prevention of dental caries in communities where water fluoridation is not available.  (Marieo RJ, et al. – J Public Health Dent. 2004 Spring;64(2):101-5)
Fluoride toxicity: CONCLUSIONS: Many years have passed since domestic water fluoridation was adopted to reduce the incidence of caries in developed countries; however, since there is an additional dose of fluorides ingested with foods and drinks prepared with such waters, the problem has emerged of possible adverse effects on health associated to them, so that in some countries fluorine integrator selling is allowed only with preventive medical prescription.  ...At encephalic level, then, high doses of fluorine cause the onset of neurological symptoms and of a decreased spontaneous motor activity due to a reduction in the number of nicotinic acetylcholine receptors.  Nevertheless, epidemiological studies about fluoride toxicity have established that such oligoelement may be safely used at odontoiatric dosages.  (Giachini M, Pierleoni F – Minerva Stomatol. 2004 Apr;53(4):171-7)
Water fluoridation and dental caries in 5- and 12-year-old children from Canterbury and Wellington: Multivariable analysis confirmed the independent association between water fluoridation and better dental health. CONCLUSIONS: This results of this study show children living in a fluoridated area to have significantly better oral health compared to those not in a fluoridated area. These differences are greater for Maori and Pacific children and children of low socio-economic status.  (Lee M, Dennison PJ – N Z Dent J. 2004 Mar;100(1):10-5)
History of fluoride prevention: successes and problems (literature review):
Recent scientific views, however, confirmed a weak pre-, and peri-eruptive, as well as a strong posteruptive effect of systemically applied fluorides. In countries where caries prevalence is high, but the majority of the population cannot afford fluoridated toothpastes due to low socio-economic conditions, the introduction and extension of salt fluoridation to the whole population is well founded and recommended from a public health view. (Beneczy J, Marthaler TM – Fogorv Sz. 2004 Feb;97(1):3-10)
Optimal fluoride level in drinking water and public health: Water fluoridation is a safe, efficient, and well-proven way of preventing dental decay in the community. In countries such as Israel, where dental care is not covered by the national insurance law, this has an important role in reducing social inequalities in health care. For toddlers and children, water fluoridation is the only way of promoting dental health without a need for regular visits to dental clinics, and without regard to parent awareness and motivation. The other methods of fluoride supplementation do not succeed in reaching the level of safety and cost-efficiency of water fluoridation, and their use is successful only among upper socio-economic classes. Water fluoridation has been defined by the US CDC as one of the main achievements in health care during the 20th century. In spite of the legal difficulties raised by various activist groups, the use of water fluoridation is growing steadily among developed as well as third world countries. The Israeli bylaw of national water fluoridation that is in effect will enable the safe improvement of the overall dental health status of the population at an extremely low cost. (Karsenty E, et al. – Harefuah. 2003 Nov;142(11):754-8, 806)
Successes and drawbacks in the caries-preventive use of fluorides--lessons to be learnt from history: Water fluoridation was the first breakthrough in the practice of preventive cariology on a community level and has remained one of the cornerstones of prevention in dentistry. The concepts regarding the mechanisms of the caries-inhibitory effect, however, have changed in several respects. Today there is general agreement that topical effects on the erupted enamel are most important. The contention that there is no pre-eruptive effect whatsoever has created confusion; there is in fact evidence for a minor pre-eruptive protective effect. Around 1980 many experts believed that fluorides should not be used in high concentrations, for instance above those in dentifrices, because this could block remineralisation in the body of pre-cavity lesions. However, it is now known that such undesirable effects are negligible or non-existent. (Marthaler TM – Oral Health Prev Dent. 2003;1(2):129-40)
An update on fluorides and fluorosis: Decisions concerning use of fluoride in its many forms for caries prevention are more complicated now than in the past because of the need to balance these benefits with the risks of dental fluorosis. This article reviews pertinent literature concerning dental fluorosis (definition, appearance, prevalence), pre- and post-eruptive use of fluoride, esthetic perceptions of dental fluorosis, fluoride levels of beverages and foods, the Iowa Fluoride Study, and the U.S. Centers for Disease Control and Prevention's "Recommendations for Using Fluoride to Prevent and Control Dental Caries in the United States." Water fluoridation and use of fluoride dentifrice are the most efficient and cost-effective ways to prevent dental caries; other modalities should be targeted toward high-risk individuals. (Levy SM – Dent Clin North Am. 2003 Apr;47(2):225-43)
History of water fluoridation: Analyses showed that maximum protection against caries is obtained when teeth erupt into an environment with low concentrations of ionic fluoride. The similarity in caries reductions obtained in water fluoridation studies and long-term studies with topically administered fluoride regimens, including fluoride-containing dentifrices, indicates that the pre-eruptive effect of fluoride is of borderline significance relative to the more significant post-eruptive effect. It has taken a long time to show that water fluoridation and topical fluoride programs were thus important measures for the control of caries at the community level.
(Kargul B, et al. – J Clin Pediatr Dent. 2003 Spring;27(3):213-7)
Current and future role of fluoride in nutrition: Fluoride continues to be the cornerstone of dental caries prevention in North America and throughout the world, and there are a variety of sources of fluoride that may contribute to the dietary intakes of fluoride. Although the severe effect of chronic exposures to high levels of fluoride--skeletal fluorosis--is extremely rare in North America, dental fluorosis has become more prevalent. To address the increase in dental fluorosis prevalence, recommendations have been made to reduce fluoride ingestion early in life. These recommendations have included the introduction of lower concentration fluoride dentifrice for use by young children, labeling of the fluoride concentration of bottled water, and revised fluoride supplement guidelines to reduce or eliminate their use. Because our knowledge is incomplete regarding the amount, duration, and timing of fluoride ingestion that can result in dental fluorosis, however, further research is clearly needed before definitive recommendations can be made regarding the use of fluorides, including recommended intakes of fluoride in the diet. (Warren JJ, Levy SM – Dent Clin North Am. 2003 Apr;47(2):225-43)
Decline in enamel hypoplasia in relation to fluoridation in Australians: Enamel hypoplasias are thought to represent calcification disruption indicative of metabolic stress during development. Hypoplasias of permanent maxillary central incisors and mandibular canines have undergone a notable reduction in frequency between Euro-Australian twins born around 1965 and those born ca. 1990. Even when scored very liberally these linear defects are 3.1-4.6 times as prevalent in the earlier Australians, and the discrepancy is proportionately greater among strictly scored defects. Likely correlates of this secular trend logically include reduced childhood fevers and clinical intervention to reduce circum-natal stresses acting on cotwins. However, fluoridation of metropolitan water has emerged as the statistically strongest hypoplasia-preventing factor.   (Corruccini RS, Townsend GC – Am J Hum Biol. 2003 Nov-Dec;15(6):795-9
Fluoridation at fifty: what have we learned? The question posed by the title of this article encompasses more than just the law and science applied to fluoridation. A review of the history and present status of fluoridation policy development and implementation makes it quickly apparent that the lessons learned are applicable to a wide range of public health policy and that the public health community needs to be very concerned about the status and trends of legal precedent. Indeed, in the context of recent U. S. Supreme Court decisions, the need for a comprehensive and coordinated effort to educate the public, legislators, and jurists about the safety and efficacy of community water fluoridation is clear. Two fundamental issues are at the core of this article: (1) the use of science in formulating and defending public health policy, and (2) how to connect scientific fact with the legal process in connection with the actual circumstances regarding a community's health status. The opening section of this article presents an analysis of fluoridation's great success in preventing dental caries over the past 50 years, along with a discussion of current data scientifically demonstrating that fluoride is safe when properly utilized. A second section provides an overview of one state's legislative experience in mandating fluoridation and the political challenges encountered. A final section discusses the legal issues associated with fluoridation, including the bases of legal challenges to public laws mandating it. (Pratt, E, et al. – J Law Med Ethics. 2002 Fall;30 (3 Suppl):117-21)
This report has considered the scope for further research that could help to inform risk management decisions on water fluoridation. Our starting point was the knowledge base that is already established. Much of this was recently reviewed in the report prepared by the York NHS CRD, and we have not attempted to duplicate their work.We have, however, taken account of additional information (eg, on pharmacology and toxicology) that did not fall within the scope of the York Review.  ...There is almost universal agreement that tooth decay in children is related to social class.The majority of the research conducted to date indicates that water fluoridation reduces dental caries inequalities between high and low social class groups. Further studies are recommended that look at appropriate measures of social inequalities related to water fluoridation, dental caries and fluorosis and possible confounding factors. Water Fluoridation and Health: (Medical Research Council working group report, September 2002)

Free Article:
The York Review - A systematic review of public water fluoridation: a commentary: The body of evidence available on the efficacy and safety of water fluoridation was of lower quantity and quality than had previously been reported.
> The best available evidence (from studies that met inclusion criteria) suggests that fluoridation of drinking water supplies reduces caries prevalence but is associated with dental fluorosis.
> The balance of the evidence did not show an association between any fractures and water fluoridation.
> No associations between water fluoridation and human cancer were found. (Treasure, ET, et al. – British Dental Journal 192, 495 - 497 (2002))  another commentary
A blind caries and fluorosis prevalence study of school-children in naturally fluoridated and nonfluoridated townships of Morayshire, Scotland: CONCLUSIONS: Considerable caries benefit has accrued to those Morayshire rural children who have received naturally fluoridated water (at 1 ppm) throughout their lives, as compared to their socioeconomically similar, nonfluoridated rural counterparts. Furthermore, in spite of all but two subjects claiming to have brushed regularly with fluoridated dentifrice (and no evidence of the availability of nonfluoridated toothpaste being purchasable in the five townships), only borderline mild fluorosis disadvantages have been noted clinically, and none by the subjects' own aesthetic perceptions. Finally, no evidence was found to suggest any delay in permanent tooth eruption patterns of the F subjects. It would seem appropriate therefore, that adjustment of Scots' drinking waters' natural fluoride levels to 1 ppm should be pursued to extend similar dental advantages to the vast majority of that population (both young and old) which, it is well documented, has the worst dental health of mainland UK. (Stephen, KW, et al. – Community Dent Oral Epidemiol. 2002 Feb;30(1):70-9) - Free Article
Association of Down's syndrome and water fluoride level: a systematic review of the evidence: BACKGROUND: A review of the safety and efficacy of drinking water fluoridation was commissioned by the UK Department of Health to investigate whether the evidence supported a beneficial effect of water fluoridation and whether there was any evidence of adverse effects. Down's syndrome was one of the adverse effects reported. The aim of this review is to examine the evidence for an association between water fluoride level and Down's syndrome. - CONCLUSIONS: The evidence of an association between water fluoride level and Down's syndrome incidence is inconclusive. (Whiting P, et al. – BMC Public Health. 2001;1:6. Epub 2001 Jul 24)
Water fluoridation, osteoporosis, fractures--recent developments:   RESULTS: Thirty-three studies were identified. Adverse effects in animal feeding studies were only seen at doses much greater than those currently used in artificial water fluoridation. The majority of animal studies showed no effect or a beneficial effect of low fluoride doses. The results of ecological studies were conflicting. One of the two cohort studies showed an increase in fracture incidence at fluoride levels four times greater than optimal water fluoridation and the other showed no effect after 20 years' optimal fluoridation. The cross-sectional studies showed a favourable effect on bone mineral density. The clinical trials predominantly showed increased bone density in several sites associated with fluoride treatment of 9-22.6mg fluoride per day for one-four years.
CONCLUSION: These studies provide a substantial body of evidence that fluoride at up to 1ppm does not have an adverse effect on bone strength, bone mineral density or fracture incidence. (Demos LL, et al. – Dent J. 2001 Jun;46(2):80-7)
Water fluoridation: Community fluoridation - are there benefits? Objective: To compare changes in dental health between non-fluoridated Stourbridge and the towns of Dudley, Sedgeley and Coseley, Brierley Hill and Kingswinford, and Halesowen that were artificially fluoridated in 1987. Conclusion: Drinking water fluoridation is associated with an increase in the percentage of 5-year-old children with no experience of tooth decay (Treasure, E – British Dental Journal 190, 26 (2001)
Effect of long-term exposure to fluoride in drinking water on risks of bone fractures: It is concluded that long-term fluoride exposure from drinking water containing > or =4.32 ppm increases the risk of overall fractures as well as hip fractures. Water fluoride levels at 1.00-1.06 ppm decrease the risk of overall fractures relative to negligible fluoride in water; however, there does not appear to be similar protective benefits for the risk of hip fractures. (Li Y, et al. – J Bone Miner Res. 2001 May;16(5):932-9)  Free Article
Systematic review of water fluoridation: OBJECTIVE: To review the safety and efficacy of fluoridation of drinking water. DESIGN: Search of 25 electronic databases and world wide web. Relevant journals hand searched; further information requested from authors. Inclusion criteria were a predefined hierarchy of evidence and objectives. Study validity was assessed with checklists. Two reviewers independently screened sources, extracted data, and assessed validity.
RESULTS: 214 studies were included. The quality of studies was low to moderate.
CONCLUSIONS: The evidence of a beneficial reduction in caries should be considered together with the increased prevalence of dental fluorosis.  There was no clear evidence of other potential adverse effects. (McDonagh MS, et al. – BMJ. 2000 Oct 7;321(7265):855-9)
Can Fluoridation Affect Lead(II) In Potable Water? Hexafluorosilicate and Fluoride Equilibria In Aqueous Solutions: Conclusion - Recent reports on the possible effects of water fluoridating agents, such as hexafluorosilicic acid, sodium hexafluorosilicate, and sodium fluoride are inconsistent with accepted scientific knowledge, and the authors fail to identify or account for these inconsistencies.  Many of the chemical assumptions are scientifically unjustified, and alternate explanations (such as multiple routes of Pb exposure) have not been satisfactorily addressed.  At present, there is no evidence to suggest that the common practice of fluoridating drinking water has any untoward health impacts via effects on lead(II) when done properly under established guidelines so as to maintain total water quality.  Our conclusion supports both EPA and PHS/CDC policies on water fluoridation. (Urbansky E.T. & Schock M.R. – Intern. J . Environ. Studies, 2000, Vol. 57. pp. 597-637
The prevalence of dental caries and fluorosis in Japanese communities with up to 1.4 ppm of naturally occurring fluoride:   RESULTS: The prevalence of dental caries was inversely related and the prevalence of fluorosis was directly related to the concentration of fluoride in the drinking water. The mean DMFS in the communities with 0.8 to 1.4 ppm fluoride was 53.9 percent to 62.4 percent lower than that in communities with negligible amounts of fluoride. Multivariate analysis showed that water fluoride level was the strongest factor influencing DMFS scores. The prevalence of fluorosis ranged from 1.7 percent to 15.4 percent, and the increase in fluorosis with increasing fluoride exposure was limited entirely to the milder forms. (Tsutsui A, et al. – J Public Health Dent. 2000 Summer;60(3):147-53) Free Article
Community water fluoridation, bone mineral density, and fractures: prospective study of effects in older women: CONCLUSIONS: Long term exposure to fluoridated drinking water does not increase the risk of fracture. (Phipps KR, et al.- BMJ. 2000 Oct 7;321(7265):860-4)
RE: "Safe Drinking Water Act", June 29, 2000: Numerous large-scale epidemiological studies of water fluoridation have been conducted, making fluoridation one of the most widely studied public health measures. Because these large investigations have been consistently validated, water fluoridation is not as frequently studied as in past decades. Water fluoridation is a perfect example of how well designed studies stand the test of time and scientific scrutiny. Studies included in the review articles listed continue to be referenced today and have become "classics" in the public health field. Many well-documented studies have compared the decay rates of children before and after fluoridation in the same community, as well as with children in naturally fluoridated and/or nonfluoridated communities. Because of the high geographic mobility of our populations and the widespread use of fluoride toothpastes, supplements and other topical agents, such comparisons are becoming more difficult to conduct. (Richard F. Mascola, DDS and John S. Zapp, DDS – ADA 2000)  Free Article
Risk of enamel fluorosis in nonfluoridated and optimally fluoridated populations: considerations for the dental professional:  CONCLUSIONS: Enamel fluorosis in the nonfluoridated study sample was attributed to fluoride supplementation under the pre-1994 protocol and early toothbrushing behaviors. Enamel fluorosis in the optimally fluoridated study sample was attributed to early toothbrushing behaviors, inappropriate fluoride supplementation and the use of infant formula in the form of a powdered concentrate. CLINICAL IMPLICATIONS: By advising parents about the best early use of fluoride agents, health professionals play an important role in reducing the prevalence of clinically noticeable enamel fluorosis. (David G. Pendrys – J Am Dent Assoc. 2000 Jun;131(6):746-55.
Indigenous Australian dental health: a brief review of caries experience:  Abstract - The indigenous community in Australia is an at risk population for oral diseases such as dental caries. The majority of communities are isolated and dental services in these areas are limited. Oral hygiene standards are poor and this combined with a diet rich in refined carbohydrates has led to high incidences of dental caries. In addition, diabetes, which is related to obesity (and a diet high in sugar and fat) has been linked to increases in oral disease. Caries prevalence was found to be low in areas where fluoridation levels in the water were high. The fact that the fluoride supplementation appears to improve oral health to a significant degree suggests that implementation of fluoride treatment programmes for school children and, where viable, fluoridation of water sources would be appropriate. In addition, dental education programmes should receive high priority. (Martin-Iverson N, et al. – Aust Dent J. 2000 Mar;45(1):17-20.)
Why We Have Not Changed Our Minds about the Safety and Efficacy of Water Fluoridation: A Response to John Colquhoun - The opponents of fluoridation are a heterogeneous group and cannot easily be categorized by any single characteristic. Among their number are right-wing extremists, misguided environmentalists ("Greens"), chiropractors, persons concerned about the costs of fluoridation, food faddists, and antiscience "naturalists." Other opponents have emerged, including the self-proclaimed "neutrals" who try to portray an image of dispassionate open-mindedness but clearly have accepted the opposition's arguments irrespective of whether they have been adequately tested and answered [6,31,32]. Others have been described as the "born-again antifluoridationists" [33], who previously accepted the mainstream belief in the benefits of fluoridation but have experienced an epiphany so that the scales have fallen from their eyes and they have seen the light [2,34,35]. Clearly Colquhoun falls in this latter category. However, it is important to recognize that simply by claiming to be a former advocate and now clearly being a dedicated opponent of fluoridation in no way validates his judgment nor excuses his distortion of the literature. (Ernest Newbrun, D.M.D., Ph.D.and Herschel Horowitz – Perspectives in Biology and Medicine 42:526-541, 1999)
The effect of fluoride treatment on bone mineral in rabbits: Fluoride therapy has been used clinically for many years, but its use remains controversial and many basic questions remain unanswered. Accordingly, this study returns to an animal model to study the effects of high doses of fluoride on bone mineral in rabbits. Twelve rabbits, aged 3(1/2) months at the start of the study, received drinking water fluoridated at 100 ppm {note - that's 100 times the recommended level - rj} while their 12 control counterparts drank distilled water. All rabbits were sacrificed after 6 months. Fluoride was readily incorporated into femoral cortical bone (7473 +/- 966 ppm F versus 1228 +/- 57 ppm in controls; P < 0.00005). Fluoride therapy led to increased mineralization, as measured by density fractionation (P < 0.0005 for the distributions). The bone mineral itself was altered, with a significant increase in the width of crystals (66.2 +/- 2.0 A versus 61.2 +/- 0.9 A; P < 0.01). The microhardness of both cortical and cancellous bone in the femoral head of fluoride-treated rabbits was greater than that in the controls (P < 0.05). The phosphate, calcium, and carbonate contents in the bone was the same in both groups. Finally, fluoride administration did not affect the architecture or connectivity of cancellous bone in the femoral head. Previously published data [1] indicated that the mechanical properties of bone were adversely affected; this suggests that the effect of high doses of fluoride on the strength and stiffness of bone may be mediated by its effect on bone mineral. (Chachra D, et al. – Calcif Tissue Int. 1999 Apr;64(4):345-51)
Drinking water fluoridation and bone: Accordingly, in most epidemiological studies in humans bone mass was not altered by optimal drinking water fluoridation. In contrast, studies on the effect on hip fracture rate gave conflicting results ranging from an increased fracture incidence to no effect, and to a decreased fracture rate. As only ecological studies have been performed, they may be biased by unknown confounding factors -- the so-called ecological fallacy.  However, the combined results of these studies indicate that any increase or decrease in fracture rate is likely to be small. It has been calculated that appropriately designed cohort studies to solve the problem require a sample size of >400,000 subjects. Such studies will not be performed in the foreseeable future. Future investigations in humans should, therefore, concentrate on the effect of long-term drinking water fluoridation on bone fluoride content and bone strength. (Allolio B, Lehmann R – Exp Clin Endocrinol Diabetes. 1999;107(1):12-20)

Achievements in Public Health, 1900-1999: Fluoridation of Drinking Water to Prevent Dental Caries - Fluoridation of community drinking water is a major factor responsible for the decline in dental caries (tooth decay) during the second half of the 20th century. The history of water fluoridation is a classic example of clinical observation leading to epidemiologic investigation and community-based public health intervention. Although other fluoride-containing products are available, water fluoridation remains the most equitable and cost-effective method of delivering fluoride to all members of most communities, regardless of age, educational attainment, or income level. (Reported by Div of Oral Health, National Center for Chronic Disease Prevention and Health Promotion, CDC., October, 1999)
Fluoridation--the Israel experience: There have been suggestions, mainly in the lay press, that fluoridation might affect immunity. Careful examination of various studies on fluoride and immune function do not support this suggestion. Whilst fluoride at high concentrations can have inhibitory effects on lymphocyte and polymorphonuclear leucocyte function, these concentrations are many times higher than levels which would be expected from fluoridation. Fluoride can act as an immunological adjuvant. There is no evidence of any deleterious effect on specific immunity following fluoridation nor any confirmed reports of allergic reactions. (Challacombe SJ – Community Dent Health. 1996 Sep;13 Suppl 2:69-71)
Fluoridation--the Israel experience: Epidemiological studies have shown that 5- and 12-year-old children living in fluoridated areas (in Israel) have considerably less dental caries than those receiving unfluoridated water. (Kelman AM – Community Dent Health. 1996 Sep;13 Suppl 2:42-6)
The effectiveness of community water fluoridation in the United States: Grand Rapids, the first city in the world to implement controlled water fluoridation, has served as a model for thousands of other communities. Fluoridation is one of the greatest public health and disease-preventive measures of all time. Its advantages include effectiveness for all, ease of delivery, safety, equity, and low cost. Today, nearly 56 percent of the US population lives in fluoridated communities (62% of those on central water supplies). Previously observed caries reductions of one-half to two-thirds are no longer attainable in the United States because other fluoride methods and products have reduced the caries prevalence in all areas, thus diluting the measurement of effectiveness, and because benefits of fluoridation are dispersed in many ways to persons in nonfluoridated areas. Water fluoridation itself, however, remains as effective as it ever was among groups at high risk to dental caries. Contrary to early beliefs that stressed the importance of preeruptive fluoride exposure, fluoridation also provides an important source of topical fluoride and facilitates remineralization. Although data on effectiveness and safety are compelling, future progress of water fluoridation will be affected by economic, political, and public perception factors. (Horowitz, HS – J Public Health Dent. 1996;56(5 Spec No):253-8)
Water fluoridation and osteoporotic fracture: Data on the relationship between fluoride intake and hip fracture risk at the individual level, and data relating fluoridation to bone mineral density are required. Until these become available, the burden of evidence suggesting that fluoridation might be a risk factor for hip fracture is weak and not sufficient to retard the progress of the water fluoridation programme.
(Hillier S, Inskip H, Coggon D, Cooper C. – Community Dent Health. 1996 Sep;13 Suppl 2:63-8)
Cancer and fluoridation: The present paper gives a brief overview of the evidence that fluoride in drinking water has not been shown to cause an increase in the risk of developing cancer and of the errors in the analyses that purport to show such an increase. (Cook-Mozaffari P. – Community Dent Health. 1996 Sep;13 Suppl 2:56-62)
Thirty-eight years of water fluoridation--the Singapore scenario: Singapore is the first country in Asia to institute a comprehensive fluoridation programme which covers 100 per cent of the population. The water was fluoridated at 0.7 ppm fluoride using sodium silicofluoride. The ten year study on the effects of water fluoridation in Singapore showed a decrease in caries prevalence in the children. In the permanent dentition the reduction was 52.3 per cent for Chinese and 31 per cent for Malays in the 7 to 9 year old age group. A similar trend was observed in the mixed dentition in which the decrease was 32.5 per cent for Chinese and 30.6 per cent for Malays. Because of the availability and use of other fluoride products, dental fluorosis was observed in children in later years. Although the decline in dental caries after 10 years of water fluoridation was not comparable to those achieved in other countries, this study further documents water fluoridation as the most cost-effective public health measure for the prevention of dental caries. (Loh, T – Community Dent Health. 1996 Sep;13 Suppl 2:47-50)  Free Article
Drinking water and cancer:  Any and all chemicals generated by human activity can and will find their way into water supplies. The types and quantities of carcinogens present in drinking water at the point of consumption will differ depending on whether they result from contamination of the source water, arise as a consequence of treatment processes, or enter as the water is conveyed to the user. Source-water contaminants of concern include arsenic, asbestos, radon, agricultural chemicals, and hazardous waste. Of these, the strongest evidence for a cancer risk involves arsenic, which is linked to cancers of the liver, lung, bladder, and kidney. The use of chlorine for water treatment to reduce the risk of infectious disease may account for a substantial portion of the cancer risk associated with drinking water. The by-products of chlorination are associated with increased risk of bladder and rectal cancer, possibly accounting for 5000 cases of bladder cancer and 8000 cases of rectal cancer per year in the United States. Fluoridation of water has received great scrutiny but appears to pose little or no cancer risk. (Morris RD – Environ Health Perspect. 1995 Nov;103 Suppl 8:225-31)  Free Article
Fluoride exposure and childhood osteosarcoma: a case-control study; CONCLUSIONS: Fluoride exposure does not increase the risk of osteosarcoma and may be protective in males. The protective effect may not be directly due to fluoride exposure but to other factors associated with good dental hygiene. There is also biologic plausibility for a protective effect. (Gelberg KH, et al. – Am J Public Health. 1995 Dec;85(12):1678-83)
Dental fluorosis and caries prevalence in children residing in communities with different levels of fluoride in the water:   CONCLUSIONS: The ingestion of water containing 1 ppm or less fluoride during the time of tooth development may result in dental fluorosis, albeit in its milder forms. However, in these times of numerous products containing fluoride being available, children ingesting water containing 1 ppm fluoride continue to derive caries protection compared to children ingesting water with negligible amounts of fluoride. Thus, the potential for developing a relatively minor unesthetic condition must be weighed against the potential for reducing dental disease. (Jackson RD, et al. – J Public Health Dent. 1995 Spring;55(2):79-84)
Effects of fluoridated drinking water on bone mass and fractures: the study of osteoporotic fractures: Our results do not support the findings from recent ecological studies which showed an increased risk of hip fracture among individuals exposed to fluoridated public water. (Cauley JA, et al. – J Bone Miner Res. 1995 Jul;10(7):1076-86)
Fluorides and Oral Health – Report of a WHO Expert Committee on Oral Health Status and Fluoride Use, 1994:   Conclusion of ‘Fluoride in drinking-water’ section: Community water fluoridation is safe and cost-effective and should be introduced and maintained wherever socially acceptable and feasible.
2016 update of Fluoride and Oral Health: Provided that a community has a piped water supply, water fluoridation is the most effective method of reaching the whole population, so that all social classes benefit without the need for active participation on the part of individuals. Water fluoridation has been endorsed by the world’s leading science and health organizations, including WHO, the International Association for Dental Research (IADR) and FDI World Dental Federation.  Free Article
Acute fluoride poisoning from a public water system: In May 1992, excess fluoride in one of two public water systems serving a village in Alaska caused an outbreak of acute fluoride poisoning.  ...We estimated that 296 people were poisoned; 1 person died.  ...The fluoride concentration of a water sample from the implicated well was 150 mg per liter {150 times normal}, and that of a sample from the other system was 1.1 mg per liter. Failure to monitor and respond appropriately to elevated fluoride concentrations, an unreliable control system, and a mechanism that allowed fluoride concentrate to enter the well led to this outbreak.  Discussion: 'The findings of our investigation should be of concern both to health care providers of patients with acute fluoride poisoning and to public health and other officials responsible for water fluoridation. The efficacy of fluoridation in preventing dental caries has been well documented, and the safety of this practice is supported by the extreme rarity of incidents of overfluoridation. We believe that the practice of fluoridation of public water systems should continue. However, public health officials must make certain that standard safety equipment is installed, that water-system operators are properly trained, and that routine, systematic monitoring and follow-up of fluoride concentrations in water systems and inspection of fluoridation units are undertaken. (Gessner BD, et al. – N Engl J Med. 1994 Jan 13;330(2):95-9)
Efficacy of preventive agents for dental caries. Systemic fluorides: water fluoridation: The effectiveness of fluoridation has been documented by observational and interventional studies for over 50 years. Data are available from 113 studies in 23 countries. The modal reduction in DMFT values for primary teeth was 40-49% and 50-59% for permanent teeth. The pattern of caries now occurring in fluoride and low-fluoride areas in 15- to 16-year-old children illustrates the impact of water fluoridation on first and second molars. The secular changes in caries in Hartlepool, a natural fluoride area in the North East of England, shows only a modest change between 1949 and 1989. Information on the pre-eruptive effects of water fluoridation has been reviewed, suggesting that fluoridation should start at birth to provide optimal protection to primary teeth. At 15 years of age, the maximum DMFS reduction in a fluoridated area was due about half to the pre-eruptive and about half to the post-eruptive effect of fluoride. (Murray JJ – Caries Res. 1993;27 Suppl 1:2-8
Dental caries and fluoride exposure in Western Australia: Bivariate analysis revealed all fluoride exposure to be associated with reduced caries experience, but there were large correlations between some variables. When unconditional logistic regression analysis was used, the most important (p less than 0.05) odds ratios associated with no caries experience were for residence in a fluoridated area from four to 12 years of age and early use of toothpaste. (Riordan, PJ – J Dent Res. 1991 Jul;70(7):1029-34)
A half-century of community water fluoridation in the United States: review and commentary: Abstract - The nearly 50-year history of community water fluoridation is reviewed with the major emphasis on the benefits and safety of fluoridation. Other aspects of water fluoridation also described include the apparent reduction in measurable fluoridation benefits because of the abundance of other fluoride sources, the diffusion of fluoridation effects into fluoride-deficient communities, preeruptive and posteruptive effects, technical and cost aspects, sociopolitical and legal issues that affect the successful fluoridation of communities, and alternatives to community water fluoridation. The majority of studies have evaluated the effectiveness of water fluoridation on the permanent teeth of children, while there are fewer studies on deciduous teeth and in adults; the relationship between fluoride ingestion and bone health needs further clarification; the sociopolitical issues of fluoridation need to be better understood. (Ripa LW – J Public Health Dent. 1993 Winter;53(1):17-44)
Caries prevention--fluoride: reaction paper: Although the prevalence of caries has declined in young persons in developed countries, there is still a need for water fluoridation. The effectiveness of fluoride is dependent on the ambient levels of fluoride in the oral cavity. Fluoride appears to exert the bulk of its protective effect locally by promoting remineralization of early carious lesions. Nevertheless, fluoride tablets continue to be prescribed as if the action of fluoride is expressed systemically. There is an urgent need to explore the clearance of fluoride from the mouth and to develop methods to ensure constant levels of fluoride in the oral cavity, thereby reducing both the need for frequent exposure and the amount necessary for clinical effect. (Bowen WH – Adv Dent Res. 1991 Dec;5:46-9) {Often, when controversial papers are published, like the Clarkson paper below, others are offered an opportunity to respond immediately} 
Caries prevention--fluoride: Convincing evidence exists that fluoride has a major effect on the demineralization and remineralization of dental hard tissues, and that it interferes with the acid production from "cariogenic" bacteria. However, it has also been shown to be physiologically harmful if fluoride concentrations and/or exposure periods are inappropriate.  ...The benefits and problems associated with the systemic route of fluoride administration are discussed with special reference to caries control and fluoride's mechanism of action and its toxic effect. The same discussions are focused on the role of the topical effects of fluoride, with particular emphasis placed upon: low vs. high fluoride concentrations; calcium fluoride vs. fluorhydroxyapatite; and fluoride distribution, in both the mouth and in the teeth. The benefits and problems associated with the systemic route of fluoride administration are discussed with special reference to caries control and fluoride's mechanism of action and its toxic effect. The same discussions are focused on the role of the topical effects of fluoride, with particular emphasis placed upon: low vs. high fluoride concentrations; calcium fluoride vs. fluorhydroxyapatite; and fluoride distribution, in both the mouth and in the teeth. The benefits and problems associated with the systemic route of fluoride administration are discussed with special reference to caries control and fluoride's mechanism of action and its toxic effect. The same discussions are focused on the role of the topical effects of fluoride, with particular emphasis placed upon: low vs. high fluoride concentrations; calcium fluoride vs. fluorhydroxyapatite; and fluoride distribution, in both the mouth and in the teeth.  (Clarkson BH – Adv Dent Res. 1991 Dec;5:41-5)
Recent trends in dental caries in U.S. children and the effect of water fluoridation:  The decline in dental caries in U.S. schoolchildren, first observed nationwide in 1979-1980, was confirmed further by a second national epidemiological survey completed in 1987. Mean DMFS scores in persons aged 5-17 years had decreased about 36% during the interval, and, in 1987, approximately 50% of children were caries-free in the permanent dentition. Children who had always been exposed to community water fluoridation had mean DMFS scores about 18% lower than those who had never lived in fluoridated communities. When some of the "background" effect of topical fluoride was controlled, this difference increased to 25%. The results suggest that water fluoridation has played a dominant role in the decline in caries and must continue to be a major prevention methodology. (Brunelle JA1, Carlos JP. – J Dent Res. 1990 Feb;69 Spec No:723-7)
NTP Toxicology and Carcinogenesis Studies of Sodium Fluoride (CAS No. 7681-49-4)in F344/N Rats and B6C3F1 Mice (Drinking Water Studies): There was no evidence of carcinogenic activity in female F344/N rats receiving sodium fluoride at concentrations of 25, 100, or 175 ppm (11, 45, or 79 ppm fluoride) in drinking water for 2 years. There was no evidence of carcinogenic activity of sodium fluoride in male or female mice receiving sodium fluoride at concentrations of 25, 100, or 175 ppm in drinking water for 2 years. Dosed rats had lesions typical of fluorosis of the teeth and female rats receiving drinking water containing 175 ppm sodium fluoride had increased osteosclerosis of long bones. (Natl Toxicol Program Tech Rep Ser. 1990 Dec;393:1-448) 
Fluoride: Benefits And Risks of Exposure: Together, these studies indicate that fluoride in drinking water is beneficial to dental health. However, recent studies have reported declines in caries prevalence in nonfluoridated areas that are comparable in magnitude to declines noted in fluoridated areas. While these estimates of caries decreases in nonfluoridated areas appear accurate, conclusions cannot be drawn from these studies concerning the independent effects of fluoridated drinking water on caries prevalence since other possible sources of fluoride exposure were not measured. Fluoride sources, other than in drinking water, may provide a level of caries protection similar to fluoridated drinking water. (Laurence S, et al. – Crit Rev Oral Biol Med. 1990;1(4):261-81)
Effectiveness of water fluoridation:  Abstract - The efficacy of communal water fluoridation in reducing dental caries has been reviewed based on surveys conducted in the last decade of caries prevalence in fluoridated and nonfluoridated communities in the United States as well as in Australia, Britain, Canada, Ireland, and New Zealand. The efficacy is greatest for the deciduous dentition, with a range of 30-60 percent less caries in fluoridated communities. In the mixed dentition (ages 8 to 12), the efficacy is more variable, about 20-40 percent less caries. In adolescents (ages 14-17), it is about 15-35 percent less caries. Current data on caries prevalence in adults and seniors are extremely limited and include several populations living in communities with higher than optimal fluoride levels. For these adults and seniors, a range of 15-35 percent less caries would also apply. Viewed in toto, the current data for children, adolescents, adults and seniors show a consistently and substantially lower caries prevalence in fluoridated communities. For an accurate measurement of the efficacy of water fluoridation in reducing dental caries, it is essential that only persons with a record of continuous or long-term residency in fluoridated versus nonfluoridated areas be included in such assessments. Because of the high geographic mobility in our society and the widespread use of fluoride dentifrices, supplements, and other topical fluoride agents, such comparisons are becoming more difficult to conduct. Accordingly, the effectiveness (rather than the efficacy) of water fluoridation has decreased as the benefits of other forms of fluoride have spread to communities lacking optimal water fluoridation. (Newbrun E – J Public Health Dent. 1989;49(5 Spec No):279-89)
Treatment of Bone Weakness in Patients with Femoral Neck Fracture by Fluoride, Calcium, and Vitamin D:  Twenty-three of 46 patients, aged 56 to 95 years, with fracture of the femoral neck (FNF) completed the first trial of 10 months treatment with oral sodium fluoride 60 mg and calcium 1800 mg on alternate days and 1 ıtg of vitamin D1 daily.  In 17 patients the treatment improved the amount and quality of trabecular bone. Cortical thickness increased in nine patients and there were no losses of amount or mineralisation. The treatment was well tolerated by most patients and there were no major side-effects or signs of bone demineralisation. The study also revealed an unexpected rapid post-fracture deterioration of bone tissue in untreated FNF patients; thus there is an increased risk of further fractures which calls for the use of an effective treatment to increase bone mass. (Mackie et al. – J Bone Joint Surg Br 1989 71-B (1): 111)  Free Article
Fluorides, facts and fanatics: public health advocacy shouldn't stop at the courthouse door: One of the more controversial American public health issues is fluoridation of municipal water supplies. Opponents occasionally succeed in halting fluoridation through local referenda, but the courts usually uphold fluoridation laws. In 1982, however, an Illinois trial judge ruled that a state law authorizing fluoridation was unconstitutional. Although unimpressed by the plaintiff's evidence purporting to show fluoridation's risks, the judge was compelled to rule against the state because it had failed to counter with evidence on the safety of fluoridated water. Christoffel analyzes the trial court's decision and its subsequent reversal by the Illinois Supreme Court. He urges public health professionals to assume advocacy roles by ensuring that the scientific rationale behind public health regulations becomes part of the legislative record and by forcefully supporting public health policies in all forums, including the courts. (Christoffel T – Am J Public Health. 1985 Aug;75(8):888-91)  Free Article
Thirty years of fluoridation: a review: Fluoride contributes to stability of both teeth and bones and to reduction of caries, especially if ingested before eruption of teeth. Reduction of caries continues at about 60% in persons drinking fluoridated water only as long as fluoride washes over teeth. One-half the population of the US does not have access to water with an optimal fluoride concentration of about 1 mg/L. Misinformation about fluoridation contributes to reluctance of communities to supplement the natural but inadequate fluoride of those water supplies. Fluoridation of water has no positive or negative effect on incidence or mortality rates due to cancer, heart disease, intracranial lesions, nephritis, cirrhosis, mongoloid births, or from all causes together. The collective decision to increase the natural fluoride content of water supplies is not an infringement of civil rights, nor does it establish a precedent in the binding sense of the law. Supplemental fluoride in water makes it available to all members of the community in a safe, practical, economical and reliable manner. Fluoridation saves money in dental costs and time lost from work. Fluoridation is an appropriate action of government in promoting the health and welfare of society. (Richmond VL – Am J Clin Nutr. 1985 Jan;41(1):129-38)

Fluoridation of Water and Cancer: A Review of the Epidemiological Evidence - The justification for such a measure as the addition of fluoride to the water supplies of entire communities must rely on strong scientific evidence pointing not only to its effectiveness but to its safety, even though the recommended level in the public water supply is similar to that yielded by many natural sources. From the first, therefore, the safety of the fluoridation of water to the optimum concentration (1 milligram per litre) has been a paramount consideration, and fluoridation programmes were both preceded and accompanied by investigations ofthe health of populations exposed to fluoride in water. Allegations that fluoridation causes cancer have naturally given rise to great public concern. Authoritative advice on all aspects of the evidence, in relation to the addition of fluoride to the drinking water of whole communities to achieve a concentration of 1 milligram per litre, has recently been obtained from the Department's independent expert scientific advisers. They considered all the available evidence on the biological effects of fluoride in short-term tests, and animal carcinogenicity tests, as well as the direct and extensive studies of human populations reviewed in the present Report. They concluded that there is no evidence leading to an expectation of hazard through the induction of heritable abnormalities, and no reliable evidence of any hazard to man in respect of cancer. (1985 Report of the Working Party )  Other download options
Fluorine and thyroid gland function: a review of the literature: Published data failed to support the view that fluoride, in doses recommended for caries prevention, adversely affects the thyroid. (Bergi H, et al. – Klin Wochenschr. 1984 Jun 15;62(12):564-9)  Free Article
The alleged association between artificial fluoridation of water supplies and cancer - a review: Since 1945, artificial fluoridation of water supplies has been used with success to reduce the incidence of dental caries in many areas where the natural fluoride content of the water is low. However, since 1975, it has been maintained that such artificial fluoridation is followed by an increased risk of cancer. These allegations originate from a single source. The present review, which covers re-examinations of the same data as well as evidence from scientific and governmental bodies in many countries, shows these assertions to be erroneous. (J. Clemmesen – Bull World Health Organ. 1983; 61(5))  Free Article
Fluoridation of water supplies and cancer mortality I: A search for an effect in the UK on risk of death from cancer: Claims that the mortality from cancer has been increased in urban populations as a result of the fluoridation of water supplies have been given publicity in the press and on the radio and television, and questions have consequently been asked in Parliament with a view to stopping plans for further fluoridation. These. claims have been based on an analysis of the trend in cancer mortality rates in American towns by Yiamouyiannis and Burk1" and more recently on an analysis of crude cancer mortality in two British towns-Birmingham, where the water supply was fluoridated in October 1964, and Manchester, where there has been no fluoridation. CONCLUSION: Examination of the trend in mortality for cancer in the seven cities in England and Wales with populations of over 400 000* and in England and Wales as a whole between 1959-63 and 1974-8 provides no reason to suppose that any unique factor, such as fluoridation of the water supplies, has affected the death rate for cancer in Birmingham since 1964. (Paula Cook-Mozaffari, et al. – Journal of Epidemiology and Community Health, 1981, 35, 227-232)  Free Article
Fluoridation of water supplies and cancer mortality II: Mortality trends after fluoridation:  In the past two years much publicity has been given to Burk's claim that the mortality from cancer in Birmingham increased sharply following fluoridation of the water supply in 1964 and, specifically, that it increased more sharply than in other British towns. This claim is not supported by detailed examination of age-standardised mortality rates in England and Wales' and we have, therefore, re-examined the data to see what led Burk to his conclusion. Conclusions Claims that unusual increases in cancer mortality have occurred in England after fluoridation have been examined and have been shown to rest on incorrect arithmetic, on the use of inappropriate statistical methods, and on examination of too restricted a part of the available data. Studies from other parts of the world which have examined trends in cancer mortality after fluoridation, or which have made geographical comparisons between fluoridated and unfluoridated areas, have been reviewed. There is no evidence either from England and Wales or from elsewhere in the world that the addition of fluoride to water supplies has increased the risk of dying from cancer. (Paula Cook-Mozaffari – Journal of Epidemiology and Community Health, 1981, 35, 233-238)  Free Article
Fluoridation and mortality--an epidemiologic study of Pennsylvania communities: Fewer health measures have been accorded more clinical and laboratory research, epidemiologic study, massive clinical trials of total community populations, and public attention )both favorable and adverse) than the fluoridation of public water supplies. As a result, knowledge of the dental and nondental physiological effects of fluoridation has increased significantly since Grand Rapids, Mich., was first experimentally fluoridated in 1945. There is now considerable evidence that fluoridation of community water supplies is both effective and safe. In 1975, the Council on Foods and Nutrition of the Americal Medical Association updated its earlier statement confirming the efficacy and safety of fluoridation under controlled administration. Jackson provides a list of 22 statements and findings supportive of fluoridation from lay, legal, and professional groups throughout the world. However, controversy (maintained by a segment of the general public and professional community) continues regarding possible adverse effects of fluoridation on human health. The National Cancer Institute and the National Heart and Lung Institute  have recently issued statements that refute claims suggesting a relationship between fluoridated water and mortality from cancer and heart disease. No clear evidence was found to suggest that fluoridation under controlled administration adversely affects overall mortality or diabetes mortality. Under controlled administration, fluoridation may have no significant effect on either mortality rate. The inconsistent relationships found between high levels of fluoride and cerebrovascular disease mortality require further investigation. (Tokuhata, GK, et al. – Public Health Reports, Vol. 93, January-February 1978, pp. 60-68)

 Free Article
Statewide Antifluoridation Initiatives: A New Challenge to Health Workers - Fluoridation of municipal drinking waters remains an issue of contention in the western United States. Spirited campaigns recently have been waged in Oregon and Washington by those who oppose fluoridation. The approach of the opposition was unique: statewide prohibition campaigns launched simultaneously in neighboring states. The enabling vehicle for introduction of these campaigns was the public initiative process. ...A disquieting aspect of these recent campaigns was the central role in each state of the National Health Federation. The Federation, based in Monrovia, California, is "dedicated to the protection of health freedoms," emphasizing that the patient should be free to choose alternate forms of health care, and that the choice should be free of governmental restriction or "monopolistic control". ...The Federation challenges pasteurization of milk, fluoridation of public water supplies and immunizations, and promotes Laetrile, Krebiozen, mega-vitamin therapy, naturopathic medicine, chelation therapy, and a variety of alternative health care practices. (Caswell A, et al. – AJPH January, 1978, Vol. 68, No. 1)
Water fluoridation and congenital malformations: no association -The incidence of selected congenital malformations in areas with fluoride supplementation of public water supplies was compared with the incidence in areas where the water supply is deficient in fluoride. Comparison of the incidences of several common birth defects (including Down's syndrome) in fluoridated and nonfluoridated areas revealed no substantial or significant differences in which there was a consistent pattern for both sets of data. (Erickson JD – J Am Dent Assoc. 1976 Nov;93(5):981-4)  Free Article
Urinary fluoride levels associated with use of fluoridated waters:
Surveys in two areas contribute additional evidence that no hazard of cumulative toxic fluorosis is associated with the use of fluoridated water containing 100m fluoride. Within 1 week, the concentration of fluoride in the urine equaled that in the drinking water for adults. For children, the period of adjustment was considerably longer {3-5 years}.. (Zipkin, RC – Public Health Rep. 1956 August; 71(8))  Free Article
Toxicological Evidence for the Safety of the Fluoridation of Public Water Supplies: The extravagance of the variously motivated statements frequently heard in opposition to fluoridation wherever it is under consideration may lead officials who must explain this prophylactic measure to the public to discount the fact that many citizens still remain unconvinced of the safety of this procedure, despite the assurances of medical, dental, and public health authorities. CONCLUSIONS: The results of animal experimentation show that the prolonged intake of quantities of fluoride too small to induce dental fluorosis does not give rise to any of the nondental manifestations of chronic intoxication by fluorides. Epidemiologic data and clinical and radiographic examinations of exposed industrial workers indicate that only when the fluoride content of a water supply exceeds 5 or 6 ppm will its prolonged usage give rise to detectable osseous changes and then only in the most susceptible persons. The evidence as a whole is consistent in offering assurance that bringing the fluoride concentration in communal water supplies to that known to be optimal for dental health is a prophylactic public health procedure which has an ample margin of safety. (Francis F. Heyroth, M.D. – Am J Public Health Nations Health. 1952 December; 42 (12))

Free Article
Studies on Mass Control of Dental Caries Through Fluoridation of the Public Water Supply: Summary -  Fluoridation of the Grand Rapids public water supply began in January 1945. Analysis of the 1949 dental examinations at Grand Rapids shows a reduced amount of dental caries experience when compared with the pre-fluoridation rates of 1944-45. The findings indicate that the reduction is most pronounced in the younger age groups whose dentition was largely calcified following the addition of one part per million of fluoride (F) to the previously fluoride-free public water supply. Sufficient time has not elapsed to evaluate water fluoridation in the older age groups. (Dean HE, et al. – Public Health Rep. 1950 October 27; 65(43)) [This article starts about 1/2 way through the document - RJ]

Free Article
The Newburgh-Kingston Caries Fluorine Study (Dental Findings after Three Years of Water Fluoridation): SUMMARY
1) The DMF rate for permanent teeth shows a consistent downward trend in Newburgh from 21.0 to 14.8 per 100 permanent teeth. This indicates a saving of 6.5 permanent teeth per 100 in Newburgh as compared with a rate of 21.3 per 100 in Kingston at the last examination. This represents a saving of 30 per cent.
2) Among first molars, which account for the major part of the caries problem in children, after three years of fluoride experience, Newburgh's rate was 48.0 DMF per 100 first molars, while Kingston's was 58.7, or a difference of 10.7 DMF per 100 first molars. This represents a saving of 18 per cent in DMF first molars.
3) The greatest benefits are noted in the younger age groups.
4) The differences between Newburgh and Kingston as represented in these data suggest the possibility of benefits from exposure to fluoridated water subsequent to enamel calcification and subsequent to eruption of the first molars.
5) We cannot entirely rule out the possibility of variation in the interpretations of the examiners. The fact that more than one examiner was used might alter the differences between Newburgh and Kingston to some extent. However, the size of the differences in the DMF rates of the two cities is such that it is unlikely that an examiner bias could vitiate them.
6) These data are preliminary and it will be necessary to continue collecting data for the proposed duration of the study, that is, through 1954 to 1956, to obtain additional information concerning the caries prophylactic value of fluorine.  (David B, et al. – Am J Public Health Nations Health. 1950 June; 40(6))

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Studies of three other common water contaminants on health: Caffeine, Alcohol/Wine, and Sugar
Compared the potential health risks or benefits of exposure to caffeine, alcohol and sugar with fluoride. These are just a few of the papers that you can find during a brief search of PubMed.  I searched for both health risks and health benefits of the different contaminants.

This is not an attempt to start a crusade for or against these contaminants, rather it's a demonstration to show how nearly any scientific topic can generate research papers that support nearly any conclusion possible.  Reliable conclusions about complex issues can not be drawn from a quick overview of the research or by relying on a list of papers that has been collected to support a specific viewpoint. 

In the rather haphazard listing below you can find references to support claims of harm from the contaminants or references that demonstrate no harm or even health benefits.  One would need to carefully study the context, design, methods, results and analyses of each paper and have expert knowledge of the topics to determine which studies were well conducted with valid conclusions and which were not.  Without the understanding to personally evaluate all of the evidence for a topic one can rely on the believability and trustworthiness of the expert scientific community to make a decision on what to believe. 

Or, you can rely on the believability and trustworthiness of small groups that have strong philosophical agendas that are in opposition to mainstream science and medicine.

In the case of water fluoridation, the mainstream dental, scientific, and medical communities support drinking water fluoridation precisely because nearly all subject experts have determined that the evidence of safety and effectiveness is more substantial, better and outweighs the evidence presented for harm and ineffectiveness at optimal levles. 

Coffee and Caffeine

Health Benefits of Methylxanthines in Cacao and Chocolate: (2013)  The physiological effects of methylxanthines have been known for a long time and they are mainly mediated by the so-called adenosine receptors. Caffeine and theobromine are the most abundant methylxanthines in cacao and their physiological effects are notable. Their health-promoting benefits are so remarkable that chocolate is explored as a functional food.

Coffee, but not caffeine, has positive effects on cognition and psychomotor behavior in aging: (2013)  The presence of several bioactive compounds, such as polyphenols and caffeine, implicates coffee as a potential nutritional therapeutic in aging. Moderate (three to five cups a day) coffee consumption in humans is associated with a significant decrease in the risk of developing certain chronic diseases.

Caffeine for treatment of Parkinson disease, A randomized controlled trial: (2012) Objective: Epidemiologic studies consistently link caffeine, a nonselective adenosine antagonist, to lower risk of Parkinson disease (PD). However, the symptomatic effects of caffeine in PD have not been adequately evaluated.  Conclusions: Caffeine provided only equivocal borderline improvement in excessive somnolence in PD, but improved objective motor measures. These potential motor benefits suggest that a larger long-term trial of caffeine is warranted.

Increased caffeine consumption is associated with reduced hepatic fibrosis: (2010)  Conclusion: A reliable tool for measurement of caffeine consumption demonstrated that caffeine consumption, particularly from regular coffee, above a threshold of approximately 2 coffee-cup equivalents per day, was associated with less severe hepatic fibrosis.

Caffeine suppresses β-amyloid levels in plasma and brain of Alzheimer's transgenic mice: (2009) Recent epidemiologic studies suggest that caffeine may be protective against Alzheimer's Disease (AD).  Our conclusion is two-fold. First, that both plasma and brain Aβ levels are reduced by acute or chronic caffeine administration in several AD transgenic lines and ages, indicating a therapeutic value of caffeine against AD. Second, that plasma Aβ levels are not an accurate index of brain Aβ levels/deposition or cognitive performance in aged AD mice.

Caffeine Use in Children: What we know, what we have left to learn, and why we should worry: (2009) Caffeine is a widely used psychoactive substance in both adults and children that is legal, easy to obtain, and socially acceptable to consume. Although once relatively restricted to use among adults, caffeine-containing drinks are now consumed regularly by children. In addition, some caffeine-containing beverages are specifically marketed to children as young as four years of age. Unfortunately, our knowledge of the effects of caffeine use on behavior and physiology of children remains understudied and poorly understood.

Maternal Consumption of Coffee and Caffeine-containing Beverages and Oral Clefts: (2009) A Population-based Case-Control Study in Norway: Compared with that for no coffee consumption, the adjusted odds ratios for cleft lip with or without cleft palate were 1.39 (95% confidence interval: 1.01, 1.92) for less than 3 cups a day and 1.59 (95% confidence interval: 1.05, 2.39) for 3 cups or more.

High dietary caffeine consumption is associated with a modest increase in headache prevalence: (2009) In the multivariate analyses, adjusting for age, gender, smoking, and level of education as confounding factors, a weak but significant association (OR = 1.16, 95% CI 1.09-1.23) was found between high caffeine consumption and prevalence of infrequent headache.  

The face of chronic migraine: epidemiology, demographics, and treatment strategies: (2009) Aside from analgesic overuse, other modifiable risk factors associated with the development of chronic migraine and CDH must be addressed including obesity and caffeine use...

Caffeine Induces Cell Death via Activation of Apoptotic Signal and Inactivation of Survival Signal in Human Osteoblasts: (2008) Caffeine consumption is a risk factor for osteoporosis... Here, we show that cell viability decreases in osteoblasts treated with caffeine in a dose-dependent manner.  

Comparing the benefits of Caffeine, Naps and Placebo on Verbal, Motor and Perceptual Memory: (2008)  These findings provide evidence of the limited benefits of caffeine for memory improvement compared with napping. We hypothesize that impairment from caffeine may be restricted to tasks that contain explicit information; whereas strictly implicit learning is less compromised.

Coffee and cardiovascular disease risk: yin and yang: (2008)
Many epidemiological studies have addressed the effects of coffee on cardiovascular disease. Most case-control studies suggest an increased risk in high coffee consumers, whereas cohort studies indicate no clear association with cardiovascular risk... Moreover, coffee contains several biologically active substances that may have either beneficial or harmful effects on the cardiovascular system. The development of complete/partial tolerance to some caffeine effects in habitual drinkers adds to the complexity of coffee effects. Variation in cup size and methods of coffee preparation may also explain some conflicting results.

Habitual coffee consumption and blood pressure: An epidemiological perspective: (2008) This paper summarizes the current epidemiological evidence on coffee consumption in relation to blood pressure (BP) and risk of hypertension.  Free Article

Coffee and caffeine intake and the risk of ovarian cancer: the Iowa Women's Health Study: (2008) Our results suggest that a component of coffee other than caffeine, or in combination with caffeine, may be associated with increased risk of ovarian cancer in postmenopausal women who drink five or more cups of coffee a day. Free Article

Potential teratogenic and neurodevelopmental consequences of coffee and caffeine exposure: a review on human and animal data: (1994)  The teratogenic effect of caffeine has been clearly demonstrated in rodents. The sensitivity of different animals species is variable. In humans, caffeine does not present any teratogenic risk. The increased risk of the most common congenital malformations entailed by moderate consumption of caffeine is very slight. However, caffeine potentiates the teratogenic effect of other substances, such as tobacco, alcohol, and acts synergistically with ergotamine and propranolol to induce materno-fetal vasoconstrictions leading to malformations induced by ischemia. Therefore, even though caffeine does not seem to be harmful to the human fetus when intake is moderate and spread out over the day, some associations, especially with alcohol, tobacco, and vasoconstrictive or anti-migraine medications should be avoided. Maternal consumption of caffeine affects brain composition, especially in case of a low-protein diet and also seems to interfere with zinc fixation in brain. Maternal exposure to caffeine induces also long-term consequences on sleep, locomotion, learning abilities, emotivity, and anxiety in rat offspring, whereas in humans, more studies are needed to ascertain long-term behavioral effects of caffeine ingestion by pregnant mothers.

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Alcohol & Wine

Wine, Beer, Alcohol and Polyphenols on Cardiovascular Disease and Cancer: (2012) Since ancient times, people have attributed a variety of health benefits to moderate consumption of fermented beverages such as wine and beer, often without any scientific basis. There is evidence that excessive or binge alcohol consumption is associated with increased morbidity and mortality, as well as with work related and traffic accidents. On the contrary, at the moment, several epidemiological studies have suggested that moderate consumption of alcohol reduces overall mortality, mainly from coronary diseases. However, there are discrepancies regarding the specific effects of different types of beverages (wine, beer and spirits) on the cardiovascular system and cancer, and also whether the possible protective effects of alcoholic beverages are due to their alcoholic content (ethanol) or to their non-alcoholic components (mainly polyphenols). Epidemiological and clinical studies have pointed out that regular and moderate wine consumption (one to two glasses a day) is associated with decreased incidence of cardiovascular disease (CVD), hypertension, diabetes, and certain types of cancer, including colon, basal cell, ovarian, and prostate carcinoma. Moderate beer consumption has also been associated with these effects, but to a lesser degree, probably because of beer's lower phenolic content. These health benefits have mainly been attributed to an increase in antioxidant capacity, changes in lipid profiles, and the anti-inflammatory effects produced by these alcoholic beverages.

Moderate Ethanol Ingestion and Cardiovascular Protection: (2011)  While ethanol intake at high levels (3-4 or more drinks), either in acute (occasional binge drinking) or chronic (daily) settings, increases the risk for myocardial infarction and ischemic stroke, an inverse relationship between regular consumption of alcoholic beverages at light to moderate levels (1-2 drinks per day) and cardiovascular risk has been consistently noted in a large number of epidemiologic studies.
The effects of light to moderate ethanol consumption appear to be most clearly related to cardiovascular benefits, with most studies reductions in risk for heart disease by 30-35%. Regular alcohol consumption at low to moderate levels is associated with significant reductions in the incidence of myocardial infarction in both males and females, regardless of age in adults. Importantly, this effect was noted in higher risk populations, including individuals with diabetes, hypertension, hypercholesterolemia, known heart disease, or who are overweight, as well as in cigarette smokers.  In addition to reducing the incidence and severity of myocardial infarction, low to moderate alcohol consumption is also associated with lower risk for ischemic stroke, dementia, congestive heart failure, peripheral artery disease, intestinal and hepatic I/R injury, and frequency of Raynaud's phenomenon. Heart rate variability, a marker of autonomic imbalance, is also improved by consumption of alcoholic beverages, with wine intake demonstrating a stronger association with this effect than beer or spirits. Reductions in C-reactive protein, fibrinogen, interleukin-6, and tumor necrosis factor alpha also occur with regular moderate alcohol consumption. The aforementioned observations clearly indicate that the health benefits of alcohol consumption extend beyond the heart.

Alcohol in Moderation, Cardioprotection and Neuroprotection: Epidemiological Considerations and Mechanistic Studies: (2008)  In contrast to many years of important research and clinical attention to the pathological effects of alcohol (ethanol) abuse, the past several decades have seen the publication of a number of peer-reviewed studies indicating beneficial effects of light-moderate, non-binge consumption of varied alcoholic beverages, as well as experimental demonstrations that moderate alcohol exposure can initiate typically cytoprotective mechanisms. A considerable body of epidemiology associates moderate alcohol consumption with significantly reduced risks of coronary heart disease and, albeit currently a less robust relationship, cerebrovascular (ischemic) stroke. Experimental studies with experimental rodent models and cultures (cardiac myocytes, endothelial cells) indicate that moderate alcohol exposure can promote anti-inflammatory processes involving adenosine receptors, protein kinase C (PKC), nitric oxide synthase, heat shock proteins, and others which could underlie cardioprotection. Also, brain functional comparisons between older moderate alcohol consumers and non-drinkers have received more recent epidemiological study. In over half of nearly 45 reports since the early 1990's, significantly reduced risks of cognitive loss or dementia in moderate, non-binge consumers of alcohol (wine, beer, liquor) have been observed, whereas increased risk has been seen in only a few studies.

Increased systemic and brain cytokine production and neuroinflammation by endotoxin following ethanol treatment: (2008)  Conclusion Acute increases in serum cytokines induce long lasting increases in brain proinflammatory cytokines. Ten daily doses of ethanol exposure results in persistent alterations of cytokines and significantly increases the magnitude and duration of central and peripheral proinflammatory cytokines and microglial activation. Ethanol induced differential anti-inflammatory cytokine IL-10 responses in liver and brain could cause long lasting disruption of cytokine cascades that could contribute to protection or increased risk of multiple chronic diseases.

First-trimester maternal alcohol consumption and the risk of infant oral clefts in Norway: (2008) Compared with nondrinkers, women who reported binge-level drinking (>or=5 drinks per sitting) were more likely to have an infant with cleft lip with or without cleft palate (odds ratio = 2.2, 95% confidence interval: 1.1, 4.2) and cleft palate only (odds ratio = 2.6, 95% confidence interval: 1.2, 5.6).

Maternal periconceptional alcohol consumption and risk for orofacial clefts: (1999) However, for women who reported weekly or more frequent episodes of consuming >/=5 drinks per drinking occasion compared with those who did not, we observed increased risks for isolated (no other major congenital anomaly) cleft lip with or without cleft palate, odds ratio = 3.4 (95% confidence interval, 1.1 to 9.7); multiple cleft lip with or without cleft palate, odds ratio = 4.6 (1. 2 to 18.8); and "known syndrome" clefts, odds ratio = 6.9 (1.9 to 28. 6). Carcinogenicity of acetaldehyde in alcoholic beverages: (2009) In addition to being produced in ethanol metabolism, acetaldehyde occurs naturally in alcoholic beverages. Limited epidemiological evidence points to acetaldehyde as an independent risk factor for cancer during alcohol consumption, in addition to the effects of ethanol.

Chronic effects of low to moderate alcohol consumption on structural and functional properties of the brain: (2009) beneficial or not?  The changes reported in brain shrinkage, grey matter and white matter volume, as a result of low to moderate alcohol consumption sooner offer support for the contention that such drinking decreases brain health than for its beneficial effect.

The role of alcohol in oral carcinogenesis with particular reference to alcohol-containing mouthwashes: (2008) On the basis of this review, we believe that there is now sufficient evidence to accept the proposition that alcohol-containing mouthwashes contribute to the increased risk of development of oral cancer and further feel that it is inadvisable for oral healthcare professionals to recommend the long-term use of alcohol-containing mouthwashes.

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Sugar, disease and cancer

Glycemic index, glycemic load and cancer risk: (2013)  RESULTS: Dietary GI was positively associated with the risk of prostate cancer (OR, 1.26 for the highest versus the lowest quartile). A higher dietary GL significantly increased the risk of colorectal (OR, 1.28), rectal (OR, 1.44) and pancreatic (OR, 1.41) cancers. No other significant associations were found. CONCLUSIONS: Our findings suggest that a diet high in GI and GL is associated with increased risk of selected cancers.

Does high sugar consumption exacerbate cardiometabolic risk factors and increase the risk of type 2 diabetes and cardiovascular disease? (2012)  In conclusion, data from prospective cohort studies published in the years 2000 - 2011 suggest that sugar-sweetened beverages probably increase the risk of type 2 diabetes. For related metabolic risk factors, cardiovascular disease or all-cause mortality and other types of sugars, too few studies were available to draw conclusions.

Is sugar consumption detrimental to health? A review of the evidence 1995-2006: (2010)  Many countries set quantitative targets for added sugars, justifying this by expressing concern about the likely impact of sugar on weight control, dental health, diet quality, or metabolic syndrome. This review considers whether current intakes of sugar are harmful to health, and analyses recent literature using a systematic approach to collate, rank, and evaluate published studies from 1995-2006. Results from high quality obesity studies did not suggest a positive association between body mass index and sugar intake. Some studies, specifically on sweetened beverages, highlighted a potential concern in relation to obesity risk, although these were limited by important methodological issues. Diet adequacy appeared to be achieved across sugar intakes of 6 to 20% energy, depending on subject age. Studies on metabolic syndrome reported no adverse effects of sugar in the long-term, even at intakes of 40-50% energy. The evidence for colorectal cancer suggested an association with sugar, but this appeared to have been confounded by energy intake and glycemic load. There was no credible evidence linking sugar with attention-deficit, dementia, or depression. Regarding dental caries, combinations of sugar amount/frequency, fluoride exposure, and food adhesiveness were more reliable predictors of caries risk than the amount of sugar alone. Overall, the available evidence did not support a single quantitative sugar guideline covering all health issues.

Soft drink and juice consumption and risk of pancreatic cancer: the Singapore Chinese Health Study: (2010)  CONCLUSION: Regular consumption of soft drinks may play an independent role in the development of pancreatic cancer.

Dietary habits and risk of pancreatic cancer: an Italian case-control study: (2009)  CONCLUSIONS: The present study supports an inverse association between fruits and vegetables and pancreatic cancer risk, and it confirms a direct relation with meat. The increased risk for table sugar suggests that insulin resistance may play a role in pancreatic carcinogenesis.

Glycemic index, carbohydrates, glycemic load, and the risk of pancreatic cancer in a prospective cohort study: (2009)  Participants with high free fructose and glucose intake were at a greater risk of developing pancreatic cancer. Our results do not support an association between glycemic index, total or available carbohydrate intake, and glycemic load and pancreatic cancer risk. The higher risk associated with high free fructose intake needs further confirmation and elucidation.

Sweets, sweetened beverages, and risk of pancreatic cancer in a large population-based case-control study: (2009) CONCLUSION: These results provide limited support for the hypothesis that sweets or sugars increase pancreatic cancer risk.

Added sugar and sugar-sweetened foods and beverages and the risk of pancreatic cancer in the National Institutes of Health-AARP Diet and Health Study: (2008)  CONCLUSION: Our results do not support the hypothesis that consumption of added sugar or of sugar-sweetened foods and beverages is associated with overall risk of pancreatic cancer.

Glycemic index, glycemic load, and risk of digestive tract neoplasms: a systematic review and meta-analysis: (2009) 
BACKGROUND: Habitual consumption of diets with a high glycemic index (GI) and a high glycemic load (GL) may influence cancer risk via hyperinsulinemia and the insulin-like growth factor axis. CONCLUSIONS: The findings from our meta-analyses indicate that GI and GL intakes are not associated with risk of colorectal or pancreatic cancers. There were insufficient data available regarding other digestive tract cancers to make any conclusions about GI or GL intake and risk.

Glycemic index, glycemic load, and cancer risk: a meta-analysis: (2008)  CONCLUSION: This comprehensive meta-analysis of Glycemic Index and Glycemic Load and cancer risk suggested an overall direct association with colorectal and endometrial cancer.

Glycemic index, glycemic load, and chronic disease risk--a meta-analysis of observational studies: (2008)  CONCLUSIONS: Low-GI and/or low-GL diets are independently associated with a reduced risk of certain chronic diseases (type 2 diabetes, coronary heart disease. In diabetes and heart disease, gallbladder disease & breast cancer), the protection is comparable with that seen for whole grain and high fiber intakes. The findings support the hypothesis that higher postprandial glycemia is a universal mechanism for disease progression.

Pancreatic cancer: a review of the evidence on causation: (2008)  Pancreatic cancer kills more than 250,000 people each year worldwide and has a poor prognosis. The aim of this article is to critically review the epidemiologic evidence for exposures that may either increase or decrease the risk. A Medline search was performed for epidemiologic studies and reviews published up to April 2007. Consistent evidence of a positive association was found for family history and cigarette smoking. Many studies documented a positive association with diabetes mellitus and chronic pancreatitis, although the etiologic mechanisms are unclear. Other associations were detected, but the results were either inconsistent or from few studies. These included positive associations with red meat, sugar, fat, body mass index, gallstones, and Helicobacter pylori, and protective effects of increasing parity, dietary folate, aspirin, and statins. There was no evidence linking alcohol or coffee consumption with an increased risk of pancreatic cancer. The associations with many exposures need to be clarified from further epidemiologic work in which there is both precise measurement of risk factors, adjustment for potential confounders, and, for dietary studies, information recorded on the method of food preparation and pattern of consumption. Such work is important to reduce the incidence of this fatal disease.

Glycemic load, glycemic index, and pancreatic cancer risk in the Netherlands Cohort Study: (2008)  CONCLUSIONS: Overall, our findings do not support the hypothesis that GL, GI, or intake of carbohydrates and mono- and disaccharides are positively associated with pancreatic cancer risk. This is in agreement with previous prospective studies that investigated the relation between GL and GI and pancreatic cancer risk.

Added sugar and sugar-sweetened foods and beverages and the risk of pancreatic cancer in the National Institutes of Health-AARP Diet and Health Study: (2008)  BACKGROUND: Although it has been hypothesized that hyperglycemia, hyperinsulinemia, and insulin resistance are involved in the development of pancreatic cancer, results from epidemiologic studies of added sugar intake are inconclusive. CONCLUSION: Our results do not support the hypothesis that consumption of added sugar or of sugar-sweetened foods and beverages is associated with overall risk of pancreatic cancer.

Dietary glycemic load, added sugars, and carbohydrates as risk factors for pancreatic cancer: the Multiethnic Cohort Study: (2007)  Discussion: In the Multiethnic Cohort Study, high sugar intake-specifically, fructose intake was associated with a greater risk of pancreatic cancer. This association was not reflected in the consumption of sodas, but we did observe a greater risk with a higher intake of fruit and juices. Statistical evidence for an interaction of sucrose intake with BMI was present, and it showed a higher risk of pancreatic cancer in overweight or obese study participants with higher sucrose consumption. To date, 4 prospective studies have investigated dietary GL and various carbohydrates in relation to pancreatic cancer risk. Two of these studies found no association for GL, GI, total carbohydrates, total sugar, sucrose, or fructose, and one study found a greater risk with higher dietary GL, GI, and fructose intake in sedentary women with a BMI 25, but not in the overall cohort. In the present study, fructose intake was associated with the highest risk of pancreatic cancer. A subsequent analysis of high consumption of soft drinks in this same study population showed significantly greater risks in women but not in men. The present study also found a positive association between fructose intake and pancreatic cancer risk, but we did not see a greater risk with higher intake of sodas; these results did not differ significantly between men and women. ...The finding of a greater risk with higher fruit and juices intake was surprising, and it merits some discussion. Fruit, most often in combination with vegetables, generally is thought to have beneficial effects in terms of cancer prevention at various sites, including the pancreas. To date, 7 prospective studies have reported on fruit intake and pancreatic cancer risk, and none detected a significant association, either positive or inverse. A recent study from Sweden included 135 pancreatic cancer cases in a cohort of 81 922 men and women . When the highest and lowest quartiles were compared, overall fruit intake was not significantly associated with pancreatic cancer risk, nor was citrus fruit intake. CONCLUSIONS: High fructose and sucrose intakes may play a role in pancreatic cancer etiology. Conditions such as overweight or obesity in which a degree of insulin resistance may be present may also be important.

Glycemic load, glycemic index, and carbohydrate intake in relation to pancreatic cancer risk in a large US cohort: (2007)  CONCLUSION: Overall, our data do not support the hypothesis that glycemic load or index, or carbohydrate intake are associated with a substantial increase in pancreatic cancer risk; however, a weak positive association cannot be ruled out.

Consumption of sugar and sugar-sweetened foods and the risk of pancreatic cancer in a prospective study: (2006)  CONCLUSION: High consumption of sugar and high-sugar foods may be associated with a greater risk of pancreatic cancer.

Sugar-sweetened soft drink consumption and risk of pancreatic cancer in two prospective cohorts: (2005)  CONCLUSION: Although soft drink consumption did not influence pancreatic cancer risk among men, consumption of sugar-sweetened soft drinks may be associated with a modest but significant increase in risk among women who have an underlying degree of insulin resistance.

Glycemic index, glycemic load, and pancreatic cancer risk: (2005)  Our data suggest that overall lycemic index and glycemic load, as well as total sugar and total carbohydrate intake, are not associated with pancreatic cancer risk. However, given the limited literature regarding the role of diet in the etiology of pancreatic cancer, particularly with respect to glycemic index/load, further investigation is warranted.

Epidemiology of pancreatic cancer: (2004)  A known cause of pancreatic cancer is tobacco smoking. This risk factor is likely to explain some of the international variations and gender differences. A number of studies observed a reduction in pancreatic cancer risk within a decade after smoking cessation, when compared to current smokers. With tobacco smoking as an exception, risk factors for pancreatic cancer are not well-established. ...Chronic pancreatitis and diabetes mellitus are medical conditions that have been consistently related to pancreatic cancer. Data from numerous studies suggest that these conditions are likely to be causally related to pancreatic cancer, rather than being consequences of the cancer. Recent cohort studies, which are less prone to biases than case-control studies, suggest that obesity increases the risk of pancreatic cancer. Other studies support the hypothesis that glucose intolerance and hyperinsulinemia are important in the development of pancreatic cancer. Other potential risk factors include physical inactivity, aspirin use, occupational exposure to certain pesticides, and dietary factors such as carbohydrate or sugar intake.

Dietary sugar, glycemic load, and pancreatic cancer risk in a prospective study: (2002)  CONCLUSION: Our data support other findings that impaired glucose metabolism may play a role in pancreatic cancer etiology. A diet high in glycemic load may increase the risk of pancreatic cancer in women who already have an underlying degree of insulin resistance

The Interpretation of Evidence

One of the best example I have found to illustrate the difference between how evidence is evaluated and used by fluoridation supporters and opponents is to contrast the two published studies below.  Both examine the effects of exposure to fluoride ions in drinking water on IQ, and the second example is the paper selectively used by Fluoridation Opponents to create fear that fluoridation is a harmful process.

  1.   Full Article
    Community Water Fluoridation and Intelligence: Prospective Study in New Zealand:  
    . This study aimed to clarify the relationship between Community Water Fluoridation (CWF) and IQ.
    Methods. We conducted a prospective study of a general population sample of those born in Dunedin, New Zealand, between April 1, 1972, and March 30, 1973 (95.4% retention of cohort after 38 years of prospective follow-up). Residence in a CWF area, use of fluoride dentifrice and intake of 0.5-milligram fluoride tablets were assessed in early life (prior to age 5 years); we assessed IQ repeatedly between ages 7 to 13 years and at age 38 years.
    Results. No clear differences in IQ because of fluoride exposure were noted. These findings held after adjusting for potential confounding variables, including sex, socioeconomic status, breastfeeding, and birth weight (as well as educational attainment for adult IQ outcomes).
    These findings do not support the assertion that fluoride in the context of CWF programs is neurotoxic. Associations between very high fluoride exposure and low IQ reported in previous studies may have been affected by confounding, particularly by urban or rural status. (Broadbent JM, et al. – Am J Public Health. 2015 Jan;105(1):72-76)
  2.    Full Article
    Developmental fluoride neurotoxicity: a systematic review and meta-analysis - A review of 27 obscure, studies mostly from China on the effects of fluoride exposure on IQ, published in October, 2012 by researchers from the Department of Environmental Health, Harvard School of Public Health - it's often referenced as the Harvard IQ study.  This study is frequently used by fluoridation opponents and the conclusions are presented as conclusively demonstrating a significant negative effect of the fluoride ion on human intelligence.
    Objective: We performed a systematic review and meta-analysis of published studies to investigate the effects of increased fluoride exposure and delayed neurobehavioral development.
    Results: The standardized weighted mean difference in IQ score between exposed and reference populations was -0.45 (95% confidence interval: -0.56, -0.35) using a random-effects model. Thus, children in high-fluoride areas had significantly lower IQ scores than those who lived in low-fluoride areas. Subgroup and sensitivity analyses also indicated inverse associations, although the substantial heterogeneity did not appear to decrease.
    Conclusions: The results support the possibility of an adverse effect of high fluoride exposure on children's neurodevelopment. Future research should include detailed individual-level information on prenatal exposure, neurobehavioral performance, and covariates for adjustment.  (Choi AL, et al. – Environ Health Perspect. 2012 Oct; 120)

Before I offer my thoughts and evaluation, please compare the conclusions of the two studies above.  The complete papers are available, so you can also examine the methods, analyses and conclusions for yourself.  An important difference to be aware of is the study by Broadbent JM, et al. is part of the Dunedin Multidisciplinary Health and Development Study and followed a group of people born in the early 1970s and measured childhood IQ at the ages of 7, 9, 11 and 13 years, and adult IQ at the age of 38 years. The 27 papers reviewed by Choi AL, et al. examined data collected at single, unrelated points in time from various locations, mostly in China.


My thoughts:

Choi, et al. Review:
When you read through the second paper (Choi, et al.), the qualifications the authors make about the data quality throughout the paper should be sufficient to give you pause - for example, "The estimated decrease in average IQ associated with fluoride exposure based on our analysis may seem small and may be within the measurement error of IQ testing.", "Although most reports were fairly brief and complete information on covariates was not available, the results tended to support the potential for fluoride-mediated developmental neurotoxicity at relatively high levels of exposure in some studies.", "Our review cannot be used to derive an exposure limit, because the actual exposures of the individual children are not known.", "Still, each of the articles reviewed had deficiencies, in some cases rather serious ones, that limit the conclusions that can be drawn.",  "The fact that some aspects of the study were not reported limits the extent to which the available reports allow a firm conclusion. Some methodological limitations were also noted." 

Despite Choi and the other author's admitted limitations of their review and the complete lack of any clear evidence that fluoride exposure causes lowered IQ, even at levels far higher than levels encountered in fluoridated communities, actual headlines like, "Harvard Study Confirms Fluoride Reduces Children's IQ" and "Harvard Study: Fluoride Lowers Children's Intelligence By 7 IQ Points" are commonly used by fluoridation opponents.  These exaggerated claims are much more effective at instilling fear than an accurate headline which might read, "A review of 27 poor quality studies, mostly from China, shows that very high fluoride exposure (or other un-documented contaminants like lead and arsenic) might possibly be very slightly correlated with a lower IQ."

In a later summary statement, (9/11/2012) the primary authors, Anna L. Choi and Philippe Grandjean, added a significant qualification they failed to mention in the original paper, "These results do not allow us to make any judgment regarding possible levels of risk at levels of exposure typical for water fluoridation in the U.S.  On the other hand, neither can it be concluded that no risk is present.  We therefore recommend further research to clarify what role fluoride exposure levels may play in possible adverse effects on brain development, so that future risk assessments can properly take into regard this possible hazard."  The authors' admission that their study has no bearing on U.S. community water fluoridation is completely ignored by fluoridation opponents.

Their additional comment that the study can't conclude there is "no risk" of fluoridation is completely meaningless - and frankly rather surprising.  No scientist would ever expect or claim that any study on any health intervention could ever conclude that no risk is present.  There is always some risk that must be assessed, and the scientific challenge is to determine whether the benefits outweigh the risks and costs of any health intervention (whether it is for an individual or a community).  Some fluoridation opponents would have you believe that since adding small quantities of the fluoride ion to drinking water can't be demonstrated to be 100% risk free, 100% effective, for 100% of the population 100% of the time, the practice should be banned or discontinued.  If that were the acceptable threshold for making informed decisions about health interventions there would be no drinking water disinfection, no medicines, no dentistry, no surgeries, no science...

A 2013 statement by the  Deans of Harvard Medical School, Harvard School of Dental Medicine and the Harvard School of Public Health stated, "we continue to support community water fluoridation as an effective and safe public health measure for people of all ages.  Numerous reputable studies over the years have consistently demonstrated that community water fluoridation is safe, effective, and practical. Fluoridation has made an enormous impact on improving the oral health of the American people."
This article, The danger du jour: Fluoride, by Dr, Aaron Carroll has a good critique of the paper.

August 2015 - a close-to-home update:
On June 29, 2015 Denver Water sponsored a Community Water Fluoridation (CFW) Information Session (video - the meeting doesn't start until 16 minutes into the video, agenda) to review the latest evidence on the safety and effectiveness of CWF.  Paul Connett, a leading fluoridation opponent and activist, was invited to present.  Unfortunately I was unable to attend the meeting, but I was able to review the video and examine the slides he presented.  A significant component of Connett's presentation centered on the alleged negative effect the fluoride ion has on IQ.  He used data from the the review by Choi, et al. (the Harvard Study) discussed above.  Data for a slide that appears to demonstrate a dramatic negative impact of the fluoride ion on the IQ of children ( shown on the right) was extracted from one of the study paper included in the review, Effect of Fluoride in Drinking Water on Children's Intelligence, Q Xiang, et al. – 2003.

A significant problem with Connett's conclusion (discussed frequently by critics of his presentation) is that the real body of evidence in the actual paper he references is far messier than his nicely edited graph above  Specifically, the Q Xiang study apparently does not control for either lead or arsenic exposure as claimed by Connett (neither term is mentioned in the paper, and the arsenic data was collected at a later time from different individuals), nor for an immense number of other possible causes (confounding factors) that could explain the very small alleged IQ differential reported. The only potentially correlated variables addressed by the authors were mentioned in the statement, "The children's IQs were not related to urinary iodine, family income, or parent's education level.

It is interesting that a scatter graph of the 512 individual 'IQ vs. Water F' data points used to produce the 'IQ v water F' graph above is not included in the Q Xiang paper.  However, graph of individual data points for urinary fluoride levels and IQ (which was shown to be related to drinking water fluoride levels) was included in the paper, and it shows a much more complex - and far less compelling - picture of the real evidence than the one Connett used in his presentation. 

I looked at the evidence actually presented, and I considered all of the unknown potential risk factors that might effect IQ that were not examined by the study yet might well have contributed to the very small reported correlation between fluoride levels and IQ.  It it extremely difficult for me to become too worked up about an alleged correlation that provides no real viable cause other than a premeditated anti-fluoridation bias to explain the results. 

Ken Perrott posted a more complete dissection of Connetts use of data from the Q Xiang paper.  Perrott also provides a critique of the Choi Harvard Study paper

An extensive fluoridation debate between Ken Perrott and Paul Connett can be read here.  The difference between this debate and Connett's recent presentation in Denver is striking - Connett was unable to present his agenda without any challenges in Denver.

To demonstrate the possible fallacy of Connett's correlation = causation argument, I was able to very quickly put together a graph that demonstrated a very strong correlation between bottled water consumption and the incidence of autism in the United States between 1992 through 2007 (larger graph).  Is it reasonable to conclude that drinking bottled water causes autism just because a correlation can be demonstrated?  Perhaps the rise of autism causes more bottled water use.  Can you think of other potential causes of autism besides drinking bottled water?  Similarly, can you think of other possible causes that might explain a very small measured difference in average IQ between two cities in China?  Others have made similar cause and effect speculations that can be studied on the Spurious Correlations website.

Without extremely meticulous data collection and very careful controls to account for as many confounding factors as possible - particularly in studies conducted in environments very different from typical US cities - it would be impossible to draw any valid cause and effect relationships.  From everything I can determine, all of the study papers referenced in the Choi review paper and all of the conclusions drawn from them fall way short of demonstrating a real correlation - and certainly don't prove a cause and effect relationship - between fluoride ion levels and IQ.


Broadbent, et al. study:
Predictably, fluoridation opponents were not pleased by results of the Broadbent JM, et al. study and quickly posted several critiques, one on, another on and a similar press release

This blog does a good job of addressing the criticisms specifically stated in the press release, many of which are also stated in the other critiques. 

I encourage you to read this presentation on false and misleading claims about water fluoridation reducing IQ scores from the The Campaign for Dental Health.  Their comments address the study referenced above and a related 2014 study, Neurobehavioural Effects of Developmental Toxicity in which the Choi, et al. review was mentioned

In 2014, Dr. Angeles Martinez-Mier of the Indiana University School of Dentistry described preliminary results of another fluoridation study, "More recently, concerns have been expressed regarding the effect of fluoride on intelligence. I am part of a group of scientists that is investigating this claim. Initial results of our study show no significantly association between fluoride in mothers during pregnancy and the mental development scores of their children at ages one, two, or three."

Below is my commentary on critiques of the Broadbent JM, et al. study by fluoridation opponents:

Critique 1 from         Critique 2 from

Paul Connett, PhD, FAN Executor Director says, 'Even if this study was high quality science, which it is not, it could not cancel out over 100 animal and 45+ human studies showing fluoride can cause brain deficits. Broadbent's research has serious weaknesses.'

My Thoughts (MTs):  There are three completely separate, non-related issues in these two sentences that admirably demonstrate how the tangled logic of fluoridation opponents makes it difficult to respond to their arguments.  Like the entanglement of fear, ethics and effectiveness discussed elsewhere, these sentences tangle three different concepts:

  1. The claim that one study "could not cancel out" a number of other studies that were used to support a different conclusion is false.  Of course it could if it provided valid and relevant data and conclusions and the others did not.

  2. The idea that the number of studies is somehow important, and the implication that 45+ studies automatically proves they provide valid supporting evidence for some position.  This statement demonstrates a fundamental misunderstanding of the concept of 'weight of evidence'.  According to Dr. Schrager, "it's the fit of evidence that is key rather than its weight."  The validity, quality and relevance of each of those 45+ studies allegedly "showing fluoride can cause brain deficits" must be independently evaluated.  So far, the consensus of the scientific, medical and dental communities is that those 145+ studies are either not relevant (i.e. fluoride exposure in the studies is far higher than found in fluoridated communities) or of poor quality -- as criticisms of the paper by Choi, et al. demonstrate -- and thus are not valid.

  3. The study by Broadbent, et al. must be evaluated separately, on its own merits, in the same way that each of the 45+ studies must be evaluated.

Critique examples of Broadbent, et al. alleged study weakness:

1) "The study's small sample size of non-water-fluoridated subjects (99 compared to 891 water-fluoridated subjects) means it has low ability to detect an effect. Even worse, 139 subjects took fluoride tablets, but Broadbent does not say which."

MTs:  Broadment's paper clearly states, "In childhood, no statistically significant difference in IQ existed between participants who had or had not resided in areas with CWF, used fluoride toothpaste, or used fluoride tablets, both before and after adjusting for potential confounding variables.", and again, "Statistics Mean IQ subscale scores for verbal comprehension, perceptual reasoning, working memory, and processing speed did not significantly differ by exposure to CWF, use of fluoride toothpaste, or fluoride tablet consumption (Table 4)."  The statistical analyses used to arrive at those conclusions take into consideration which subjects took fluoride tablets and which did not.

2) "Broadbent falsely criticizes 27 previous studies linking fluoride to children's lower IQ - implying they didn't adjust for any potentially confounding variables like lead, iodine, arsenic, nutrition, parent's IQ, urban/rural and fluoride from other sources. In fact, several of the studies did control for these factors. A good example is Xiang's work, which has controlled for lead, iodine, arsenic, urban/rural, fluoride from all sources, parent's education, and socio-economic status (SES)."

MTs: According to this fluoridealert list, there were only two documents (doc a doc b) with Xiang listed as the primary author, and I did not see evidence the authors adjusted (or controlled) for the most serious potential confounding variables, lead and arsenic exposure in the primary study (doc a).  It appears the 'control' for lead was an afterthought (doc b), and that the second randomly selected groups was not same as in the original study.  There was no mention of arsenic exposure in either document, and the primary study did not 'control' for other sources of fluoride it just stated, "Neither village has fluoride pollution from burning coal or other industrial sources. None of the residents reported drinking brick tea."  Controlling for something means actually measuring levels and using statistics to determine relevance - as was done in the Broadbent, et al. study.

The fluoridealert page above also claims, 'Indeed, the two studies that controlled for the largest number of factors (Rocha-Amador 2007; Xiang 2003a,b) reported some of the largest associations between fluoride and IQ to date.' I looked up the Rocha-Amador paper, and it appears that, not only were the fluoride levels in the two high fluoride towns 7 and 13 times higher than the optimal fluoridation level, the arsenic levels were also nearly 17 and 20 times greater than the EPA's maximum contaminant level - this is hardly a paper that can legitimately be used to support claims that optimally fluoridated water can have a harmful effect on IQ.

3) "Of the four factors Broadbent did adjust for, most were only crudely controlled. For example, SES was determined solely by the father's occupation and classified into just 3 levels. Inadequate adjustment for SES could obscure a lowering of IQ caused by fluoride, because almost all of the non-water-fluoridated children came from one outlying town that had lower SES than the fluoridated areas."

MTs: It looks as though Connett, or whoever wrote the critique, had another source of information, or can't differentiate between fathers and parents, since the only mention in the paper of how SES was determined is, 'Childhood measures included SES, birth weight, and breastfeeding. SES was based on parental occupation (and the educational level and income associated with that occupation in the New Zealand census) and categorized into 3 groups.

Closing critique) "Broadbent is one of New Zealand's leading political promoters of fluoridation. He is a dentist not a developmental neurotoxicologist,' says Connett."

MTs: If Dr. Broadbent understands that the evidence demonstrates the benefits of fluoridation are significantly greater than the risks, it would be irresponsible for him not to promote fluoridation.

Apparently Dr. Connett, a retired chemistry professor, who has evidently never published any experimental research papers on effects of the fluoride ion, does not understand the basics of research design, methodology and analysis.  Since Dr. Broadbent's study did not examine the biochemical effects of the fluoride ion on brain development and function, enlisting a developmental neurotoxicologist would not have been necessary.  A dentist is perfectly capable of leading a research study, particularly when he is part of a team that included epidemiologists, statisticians and other specialists critical to formulating a valid study design, collecting the evidence and analyzing the results.   

Critique 2 from and My Thoughts (MTs):
It is unclear why this missive was addressed to Dr. Broadbent, since most of the arguments on this page are not directly relevant to the study by Broadbent, et al.  Several, however will be addressed below.

1-4) MTs: These are generic anti-fluoridation arguments and do not directly address methodology or conclusions of the study by Broadbent, et al.

5) "The very first experiment in 1950s NZ which claimed to have proven that fluoridating water was a success was unequivocally shown, by Auckland's Principal Dental officer and whistleblower, Dr John Colquhoun, to be poor science and a manipulated experiment. That was in 1983 and fluoridation promoters are still making the claim that fluoridation is based on sound science."

MTs: Dr. Colquhoun's opinions were not mentioned in the paper by Broadbent, et al. – but this website provides a different perspective than the one presented on the fluoridefree site.

6) MTs: This is a generic anti-fluoridation argument and does not directly address methodology or conclusions of the study by Broadbent, et al.

7) "It may have been valid for the Ministry of Health to take a snap shot in time if they were looking at a large population. But the 2009 Oral Health Survey only contained about 60 children in each age group. In comparison, the New Zealand School Dental statistics that are collected every year, and freely available on the MoH website, have about 45,000 children in each age group. Therefore, it is misleading for the MoH, or anyone else, to use data from the 2009 Oral Health Survey"

MTs: According to the 2009 Oral Health Survey summary it, "was not designed as an in-depth water fluoridation study, [however] analysis showed that children, adolescents and adults living in fluoridated areas had significantly less lifetime decay than those in non-fluoridated areas, and there were no significant differences in the prevalence of fluorosis (a possible side-effect of having too much fluoride during early tooth development) between people living in fluoridated areas and those in non-fluoridated areas.

The executive summary stated, "Overall, 4906 New Zealanders aged 2 years and over participated in the survey interview, with 3196 respondents completing a dental examination.  Page 60 states, "A total of 4906 New Zealanders completed the face-to-face interview for the 2009 NZOHS, including 3475 adults aged 18 years and over and 1431 children and adolescents aged 2-17 years." 

I may not be a math wizard, but that averages nearly 90 in each age group overall, and the numbers work out to about 58 individuals in each age group between 18 and 77.  The value of 60 children in each age group actually refers to the number of children who were 'dentally examined', not just surveyed.  The point is, these are strong numbers for statistically identifying trends.  Normally too, individuals are aggregated into relevant age groups to improve statistical significance.

8) MTs: This is a generic anti-fluoridation argument and does not directly address methodology or conclusions of the study by Broadbent, et al.

9) "Lastly, why have you not disclosed how many of the 99 children in the non-fluoridated sample were the same children that were in the sample of the 139 children who were taking fluoride tablets? Without this knowledge it is logical for us to assume that most of the children taking fluoride tablets were living in the non-fluoridated area. Since fluoride tablets would give a child a similar dose as drinking fluoridated water it would appear that your study is seriously flawed."

MTs: That's an interesting question, but lack of this knowledge doesn't invalidate the study results.  Table 1 clearly shows that the IQ of individuals who took fluoride tablets before age 5 showed no differences from those who did not - both as children and as adults.

A Comparison of the 1993 and 2006 National Research Council Fluoride Reports

Health Effects of Ingested Fluoride - 1993
Subcommittee on Health Effects of Ingested Fluoride

Committee on Toxicology Board on Environmental Studies and Toxicology commission on Life Sciences
National Research Council

Executive Summary:
Fluoridation of drinking water has been a subject of controversy for decades. Over the past 50 years, the incidence of dental caries (cavities) has declined considerably in the United States, an important health advance that most scientists attribute principally to increased access to fluoridated water and dental products. According to the U.S. Centers for Disease Control and Prevention, approximately 132 million Americans now receive drinking water that contains fluoride, either naturally occurring or added, at concentrations of 0.7 milligrams per liter (mg/L) or higher.

 This report deals with the possible toxic effects of ingested fluoride in humans. It does not attempt to weigh fluoride's well-documented health benefits against its possible adverse health effects.

Fluoride in Drinking Water - 2006
A Scientific Review of EPA's Standards

Committee on Fluoride in Drinking Water

 National Research Council 

Executive Summary:
Fluoride is one of the drinking-water contaminants regulated by EPA. In 1986, EPA established an MCLG and MCL for fluoride at a concentration of 4 milligrams per liter (mg/L) and an SMCL of 2 mg/L. These guidelines are restrictions on the total amount of fluoride allowed in drinking water. Because fluoride is well known for its use in the prevention of dental caries, it is important to make the distinction here that EPA's drinking-water guidelines are not recommendations about adding fluoride to drinking water to protect the public from dental caries. Guidelines for that purpose (0.7 to 1.2 mg/L) were established by the U.S. Public Health Service more than 40 years ago. Instead, EPA's guidelines are maximum allowable concentrations in drinking water  intended to prevent toxic or other adverse effects that could result from exposure to fluoride.

 Because new research on fluoride is now available and because the Safe Drinking Water Act requires periodic reassessment of regulations for drinking-water contaminants, EPA requested that the NRC again evaluate the adequacy of its MCLG and SMCL for fluoride to protect public health.

Dental fluorosis
In general, the evidence supports the conclusion that fluoridation at the recommended concentrations, in the absence of fluoride from other sources, results in a prevalence of mild-to-very-mild (cosmetic) dental fluorosis in about 10% of the population and almost no cases of moderate or severe dental fluorosis. At 5 or more times the recommended concentration, the proportion of moderate-to-severe dental fluorosis is substantially higher.

Dental fluorosis
Since 1993, there have been no new studies of enamel fluorosis in U.S. communities with fluoride at 2 mg/L in drinking water.   Earlier studies indicated that the prevalence of moderate enamel  fluorosis at that concentration could be as high as 15%.

Skeletal Fluorosis
Not addressed in the 1993 review

Skeletal Fluorosis
Skeletal fluorosis is a bone and joint condition associated with prolonged exposure to high concentrations of fluoride. Few clinical cases of skeletal fluorosis in healthy U.S. populations have been reported in recent decades, and the committee did not find any recent studies to evaluate the prevalence of the condition in populations  exposed to fluoride at the MCLG.  'more research is needed to clarify the relationship between fluoride ingestion, fluoride concentrations in bone, and stage of skeletal fluorosis before any conclusions can be drawn.

Bone strength and the risk of bone fracture
In view of the conflicting results and limitations of the current data base on fluoride and the risk of hip or other fractures, the subcommittee concludes that there is no basis at this time to recommend that EPA lower the current standard for fluoride in drinking water for this end point. However, the subcommittee  recommends additional research to improve the current data base.

Bone fractures
Overall, there was consensus among the committee that there is scientific evidence that under certain conditions fluoride can weaken bone and increase the risk of fractures. The majority of the committee concluded that lifetime exposure to fluoride at drinking-water concentrations of 4 mg/L or higher is likely to increase fracture rates in the population, compared with exposure to 1 mg/L, particularly in some demographic subgroups that are prone to accumulate fluoride into their bones (e.g., people with renal disease).  There were few studies to assess fracture risk in populations exposed to fluoride at 2 mg/L in drinking water. The best available study, from Finland, suggested an increased rate of hip fracture in populations exposed to fluoride at concentrations above 1.5 mg/L. However, this study alone is not sufficient to judge fracture risk for people exposed to fluoride at 2 mg/L.  Thus, no conclusions could be drawn about fracture risk or safety at 2 mg/L.

Reproductive effects in animals
The subcommittee concludes that the fluoride concentrations associated with adverse reproductive effects in animals are far higher than those to which human populations are exposed. Consequently, ingestion of fluoride at current concentrations should have no adverse effects on human reproduction.

Reproductive and Developmental Effects
A large number of reproductive and developmental studies in animals have been conducted and published since the 1993 NRC report, and the overall quality of that database has improved significantly. Those studies indicated that adverse reproductive and developmental outcomes occur only at very high contractions that are unlikely to be encountered by U.S. populations. A few human studies suggested that high concentrations of fluoride exposure might be associated with alterations in reproductive hormones, effects on fertility, and developmental outcomes, but design limitations make those studies insufficient for risk evaluation.

Neurotoxicity and Neurobehavioral Effects
Not addressed in the 1993 review

Neurotoxicity and Neurobehavioral Effects
A few epidemiologic studies of Chinese populations have reported IQ deficits in children exposed to fluoride at 2.5 to 4 mg/L in drinking water. Although the studies lacked sufficient detail for the committee to fully assess their quality and relevance to U.S. populations, the consistency of the results appears significant enough to warrant additional research on the effects of fluoride on intelligence. More research is needed to clarify the effect of fluoride on brain chemistry and function.

Endocrine Effects
Not addressed in the 1993 review

Endocrine Effects
The chief endocrine effects of fluoride exposures in experimental animals and in humans include decreased thyroid function, increased calcitonin activity, increased parathyroid hormone activity, secondary hyperparathyroidism, impaired glucose tolerance, and possible effects on timing of sexual maturity. Some of these effects are associated with fluoride intake that is achievable at fluoride concentrations in drinking water of 4 mg/L or less, especially for young children or for individuals with high water intake. Many of the effects could be considered subclinical effects, meaning that they are not adverse health effects. However, recent work on borderline hormonal imbalances and endocrine-disrupting chemicals indicated that adverse health effects, or increased risks for developing adverse effects, might be associated with seemingly mild imbalances or perturbations in hormone concentrations. Further research is needed to explore these possibilities.

Effects on the gastrointestinal system
The subcommittee concludes that the available data show that the

concentrations of fluoride found in drinking water in the United States are not likely to produce adverse effects in the gastrointestinal system 

Effects on Other Organ Systems
The committee also considered effects on the gastrointestinal system, kidneys, liver, and immune system.
There were no human studies on drinking water containing fluoride at 4 mg/L in which gastrointestinal, renal, hepatic, or immune effects were carefully documented. Case reports and in vitro and animal  studies indicated that exposure to fluoride at concentrations greater than 4 mg/L can be irritating to the gastrointestinal system, affect renal tissues and function, and alter hepatic and immunologic parameters. Such effects are unlikely to be a risk for the average individual exposed to fluoride at 4 mg/L in drinking water. However, a potentially susceptible subpopulation comprises individuals with renal impairments who retain more fluoride than healthy people do.

.Effects on the renal systems
However, human epidemiological studies have found no increase in renal disease in populations with long-term exposure to fluoride at concentrations of up to 8 mg/L of drinking water.  The subcommittee concludes that available evidence shows that the threshold dose of fluoride in drinking water for renal toxicity in animals is approximately 50 mg/L. The subcommittee therefore believes that ingestion of fluoride at currently recommended concentrations is not likely to produce kidney toxicity in humans.

Effects on the immune systems
Reports of hypersensitivity reactions in humans resulting from exposure to sodium fluoride are mostly anecdotal.  The weight of evidence shows that fluoride is unlikely to produce hypersensitivity and other immunological effects.

The subcommittee concludes that the genotoxicity of fluoride should not be of concern at the concentrations found in the plasma of most people in the United States.

Many assays have been performed to assess the genotoxicity of fluoride. Since the 1993 NRC review, the most significant additions to the database are in vivo assays in human populations and, to a lesser extent, in vitro assays with human cell lines and in vivo experiments with rodents. The results of the in vivo human studies are mixed. The results of in vitro tests are also conflicting and do not contribute significantly to the interpretation of the existing database. Evidence on the cytogenetic effects of fluoride at environmental concentrations is contradictory.

Carcinogenicity in animals and humans
The subcommittee concludes that the available laboratory data are insufficient to demonstrate a carcinogenic effect of fluoride in animals. The subcommittee also concludes that the weight of the evidence from the epidemiological studies completed to date does not support the hypothesis of an association between fluoride exposure and increased cancer risk in humans. Nonetheless, the subcommittee recommends conducting one or more carefully designed analytical epidemiological (case-control or cohort) studies to more fully evaluate the relation between fluoride exposure and cancer, 

Genotoxicity and Carcinogenicity
A relatively large hospital-based case-control study of osteosarcoma and fluoride exposure is under way at the Harvard School of Dental Medicine and is expected to be published in 2006. That study will be an important addition to the fluoride database, because it will have exposure information on residence histories, water consumption, and assays of bone and toenails. The results of that study should help to identify what future  research will be most useful in elucidating fluoride's carcinogenic potential.

Based on its review of available data on the toxicity of fluoride, the subcommittee concludes that EPA's current MCL of 4 mg/L for fluoride in drinking water is appropriate as an interim standard. At that level, a small percentage of the U.S. population will exhibit moderate or even severe dental fluorosis. However, the question of whether to consider dental fluorosis a cosmetic effect or an adverse health effect and the balancing of the health risks and health benefits of fluoride are matters to be determined by regulatory agencies and are beyond the charge or expertise of this subcommittee. The subcommittee found inconsistencies in the fluoride toxicity data base and gaps in knowledge. Accordingly, it recommends further research in the areas of fluoride intake, dental fluorosis, bone strength and fractures, and carcinogenicity. The subcommittee further recommends that  EPA's interim standard of 4 mg/L should be reviewed when results of new research become available and, if necessary, revised accordingly.

The committee's conclusions regarding the potential for adverse effects from fluoride at 2 to 4 mg/L in drinking water do not address the lower exposures commonly experienced by most U.S. citizens. Fluoridation is widely practiced in the United States to protect against the development of dental caries; fluoride is added to public water supplies at 0.7 to 1.2 mg/L. The charge to the committee did not include an examination of the benefits and risks that might occur at these lower concentrations of fluoride in drinking water.

    Copyright - 2005, Randy Johnson. All rights reserved.


Updated November 2016