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TITLE: Dental fluorosis among persons exposed
to high- and low-fluoride drinking water in western Norway.
AUTHORS: Bardsen A; Klock KS; Bjorvatn K
SOURCE: Community Dent Oral Epidemiol 1999 Aug;27(4):259-67
ABSTRACT: The aim of this project was to study the prevalence and severity
of dental fluorosis among persons exposed to moderate- to high- or low- fluoride
drinking water in western Norway, and to assess the risk factors involved.
Subjects aged 5 to 18 years who had been lifelong consumers of moderate-
to high-fluoride groundwater (> or = 0.50 mg F/L) were selected for the
study (n = 113). A comparison group (n = 105) was chosen among consumers
of low-fluoride surface water (approximately 0.10 mg F/L) in the same district.
The Thylstrup- Fejerskov (TF) Index was used to score dental fluorosis. A
questionnaire was used to obtain information on fluoride exposure and other
relevant factors. Among the consumers of low-fluoride water 14.3% showed
dental fluorosis (TF score 1-2) as compared to 78.8% in the group consuming
moderate- to high-fluoride water (TF scores 1-7). Premolars were most frequently
affected, but severe cases (TF scores 3- 7) were equally prevalent in maxillary
central incisors and first molars. In logistic regression analysis with TF
score 0 or TF score > or = 1 as the dependent variable, only fluoride
concentration in the drinking water was associated with a statistically increased
risk of dental fluorosis (odds ratio: 18.9; 95% CI: 8.85-40.44). In the study
area, which was characterised by multiple fluoride SOURCEs, uncontrolled
groundwater with moderate to high fluoride content was the most important
factor in the development of dental fluorosis. In order to prevent dental
fluorosis, groundwater wells should routinely be analysed for fluoride.
TITLE: Fluoride exposure and dental fluorosis
in Newburgh and Kingston, New York: policy implications.
AUTHORS: Kumar JV; Swango PA
SOURCE: Community Dent Oral Epidemiol 1999 Jun;27(3):171-80
ABSTRACT: OBJECTIVES: This analysis was conducted to determine the changes
in the effect of exposure to fluoridation and other sources of fluoride on
dental fluorosis in children attending Newburgh and Kingston school districts
in New York State. METHODS: Data for this analysis were obtained from two
surveys conducted in the 1986 and 1995 school years. Analyses were limited
to 3500, 7-14-year-old lifelong residents of a fluoridated or a nonfluoridated
community. Dean's classification and DMFS index were used for recording dental
fluorosis and caries, respectively. A questionnaire was used to collect fluoride
exposure data. Regression procedures were used to estimate the effect of
fluoridation, fluoride supplements, and brushing before the age of 2 years
on dental fluorosis. RESULTS: Children examined in 1996 were at higher risk
for both questionable and very mild to severe dental fluorosis if they received
fluoride from water or daily tablet use, or started brushing before the age
of 2 years. The increase in risk from 1986 to 1995 was greater for
African-American children. CONCLUSION: This analysis showed that the risk
of developing dental fluorosis did not decline over time in these communities.
Continuous exposure to water fluoridation had an observable effect on dental
fluorosis. However, implementation of fluoridation in Newburgh Town did not
result in an increase in dental fluorosis prevalence.
TITLE: The effect of water fluoridation and
social inequalities on dental caries in 5-year-old children.
AUTHORS: Riley JC; Lennon MA; Ellwood RP S
OURCE: Int J Epidemiol 1999 Apr;28(2):300-5
ABSTRACT: BACKGROUND: Many studies have shown that water fluoridation
dramatically reduces dental caries, but the effect that water fluoridation
has upon reducing dental health inequalities is less clear. The aim of this
study is to describe the effect that water fluoridation has upon the association
between material deprivation and dental caries experience in 5-year-old children.
METHODS: It is an ecological descriptive study of dental caries experience
using previously obtained data from the British Association for the Study
of Community Dentistry's biennial surveys of 5-year-old children. This study
examined the following data from seven fluoridated districts and seven comparable
non-fluoridated districts in England: 1) dental caries experience using the
dmft (decayed, missing, filled teeth) index; 2) the Townsend Deprivation
Index of the electoral ward in which the child lived; 3) whether fluoride
was present at an optimal concentration in the drinking water or not. RESULTS:
A statistically significant interaction was observed between material deprivation
(measured by the Townsend Deprivation Index) and water fluoridation (P <
0.001). This means that the social class gradient between material deprivation
and dental caries experience is much flatter in fluoridated areas. CONCLUSION:
Water fluoridation reduces dental caries experience more in materially deprived
wards than in affluent wards and the introduction of water fluoridation would
substantially reduce inequalities in dental health.
TITLE: Fluoride supplements and caries in a
non-fluoridated child population.
AUTHORS: Wang NJ; Riordan PJ
SOURCE: Community Dent Oral Epidemiol 1999 Apr;27(2):117-23
ABSTRACT: In Norway, there is no water fluoridation and little naturally
occurring fluoride in drinking water. Fluoride toothpaste is used by 95%
of the population and there is a long tradition of use of fluoride supplements.
The purpose of this study was to analyse whether children who used fluoride
toothpaste regularly and complied with the recommendations for use of fluoride
supplements had less caries than other children at the age of 8 years. Most
fluoride supplements sold in Norway are lozenge-type tablets, which allow
for extended enamel exposure to fluoride. All children (n = 551) born in
1988 living in a suburban community in Norway were invited to participate.
In those who participated (n = 470), caries was registered clinically and
radiographically and parents provided data on use of supplements. Thirty-eight
percent of the children had used fluoride supplements regularly during the
period 0.5 to 4.0 years of age and 66% used supplements regularly at the
age of 6 to 8 years. Multivariate analyses showed that the children complying
with the recommendations for use of fluoride supplements during the period
0.5 to 4.0 years of age had lower caries experience (dmfs) and fewer decayed
surfaces (ds) in primary teeth than other children. No significant associations
were found between supplement use in childhood and caries prevalence (DMFS)
or number of decayed surfaces (DS) in permanent teeth at the age of 8 years.
Supplement use from 6 to 8 years of age was not associated with caries occurrence
either in primary or in permanent teeth. Both mother's education and the
quality of dental hygiene were inversely associated with caries occurrence.
TITLE: Water fluoridation, bone mass and fracture:
a quantitative overview of the literature.
AUTHORS: Jones G; Riley M; Couper D; Dwyer T
SOURCE: Aust N Z J Public Health 1999 Feb;23(1):34-40
ABSTRACT: OBJECTIVE: To use the technique of meta-analysis to address the
following research questions: Is water fluoridation associated with altered
fracture risk at a population level and are the differences between studies
consistent with confounding or chance variation between studies? METHOD:
The data sources utilised were Medline 1966-97, reviews and bibliographies.
The search terms were fluoridation, bone mass and/or fracture. We included
all observational studies published in English relating water fluoridation
to bone mass and/or fracture in the initial assessment. RESULTS: Water
fluoridation had no evident effect on fracture risk (RR 1.02, 95% CI 0.96-1.09,
n = 18 studies). There was marked heterogeneity between studies which could
be explained, in part, by the combination of gender, urbanicity and study
quality (R2 0.25, p = 0.05, weighted analysis). CONCLUSIONS: Water fluoridation
both at levels aimed at preventing dental caries and, possibly, at higher
naturally occurring levels appears to have little effect on fracture risk,
either protective or deleterious, at a population level. The small effect
on bone mass seen in studies performed at the individual level is consistent
with this finding. Variation between studies is also likely to be due to
differences in the distribution of other recognised fracture risk factors
between different populations. Confirmation of these findings is required
in large studies performed at the individual level.
TITLE: Drinking water fluoridation and bone.
AUTHORS: Allolio B; Lehmann R
SOURCE: Exp Clin Endocrinol Diabetes 1999;107(1):12-20
ABSTRACT: Drinking water fluoridation has an established role in the prevention
of dental caries, but may also positively or negatively affect bone. In bone
fluoride is incorporated into hydroxylapatite to form the less soluble
fluoroapatite. In higher concentrations fluoride stimulates osteoblast activity
leading to an increase in cancellous bone mass. As optimal drinking water
fluoridation (1 mg/l) is widely used, it is of great interest, whether long-term
exposition to artificial water fluoridation has any impact on bone strength,
bone mass, and -- most importantly -- fracture rate. Animal studies suggest
a biphasic pattern of the effect of drinking water fluoridation on bone strength
with a peak strength at a bone fluoride content of 1200 ppm followed by a
decline at higher concentrations eventually leading to impaired bone quality.
These changes are not paralleled by changes in bone mass suggesting that
fluoride concentrations remain below the threshold level required for activation
of osteoblast activity. 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.
TITLE: Changes in dental fluorosis and dental
caries in Newburgh and Kingston, New York.
AUTHORS: Kumar JV; Swango PA; Lininger LL; Leske GS; Green EL; Haley VB
SOURCE: Am J Public Health 1998 Dec;88(12):1866-70
ABSTRACT: OBJECTIVES: This study sought to determine whether the prevalence
of dental fluorosis and dental caries had changed in a fluoridated community
and a nonfluoridated community since an earlier study conducted in 1986.
METHODS: Dental fluorosis and dental caries data were collected on 7- to
14-year-old lifelong residents (n = 1493) of Newburgh and Kingston, NY. RESULTS:
Estimated dental fluorosis prevalence rates were 19.6% in Newburgh and 11.7%
in Kingston. The greatest disparity in caries scores was observed between
poor and nonpoor children in nonfluoridated Kingston. CONCLUSIONS: The prevalence
of dental fluorosis has not declined in Newburgh and Kingston, whereas the
prevalence of dental caries has continued to decline.
TITLE: Risk periods in the development of dental
fluorosis.
AUTHORS: Bardsen A; Bjorvatn K
SOURCE: Clin Oral Investig 1998 Dec;2(4):155-60
ABSTRACT: In order to study the age-related susceptibility to dental fluorosis,
40 children who had been lifelong consumers of moderate- to high- fluoride
water (0.55-8.48 mg F/l) were examined, as well as a group of older siblings
(n = 40) who were born 6 months to 6 years before the fluoride-containing
drinking water was introduced to the household. Background information was
obtained through a structured questionnaire. Dental fluorosis was scored
according to the TF index. Among the 80 children examined, the permanent
incisors were erupted in 66, while 67 had permanent first molars present.
As compared to their older siblings, the prevalence of dental fluorosis was
significantly higher in the children who had consumed moderate-to high-fluoride
water throughout their lives. In a multiple regression analysis, the variable
"age when introduced to moderate- to high-fluoride water" came out as the
only significant risk factor associated with dental fluorosis. This variable
was divided into three categories according to the first exposure to moderate-
to high-fluoride drinking water (1) 0-12 months of age, (2) 13-24 months
of age and (3) after 24 months of age. Category 3 was used as the reference
group. Fluoride exposure starting during the 1st year of life showed the
highest odds ratio as compared to exposure only after 2 years of age. The
findings indicate that early mineralizing teeth (central incisors and first
molars) are highly susceptible to dental fluorosis if exposed to fluoride
from the first and--to a lesser extent--also from the 2nd year of life.
TITLE: [Epidemiology of dental caries in children]
AUTHORS: Obry-Musset AM
SOURCE: Arch Pediatr 1998 Oct;5(10):1145-8
ABSTRACT: Epidemiological surveys showed a marked decrease of caries prevalence
in French children during the last 20 years. One of the main factor of this
improvement appears to be the extension of the prevention based on fluoride
use. Nevertheless, the prevalence in caries in children remains higher in
France than in many other countries. At the same time, no severe cases of
dental fluorosis were observed, recent surveys showing that 97% of children
had no sign of dental fluorosis, and 3% mild, very mild or doubtful fluorosis
without esthetic consequences. In order to improve the dental status of French
children, caries prevention by fluoride must therefore be reinforced and
extended to all infants and children. However, medical fluoride prescriptions
must take into account the possible other sources of fluoride resulting from
salt fluoridation and water with high fluoride content, in order to prevent
dental fluorosis.
TITLE: Estimation of optimal concentration of
fluoride in drinking water under conditions prevailing in Chile.
AUTHORS: Villa AE; Guerrero S; Villalobos J
SOURCE: Community Dent Oral Epidemiol 1998 Aug;26(4):249-55
ABSTRACT: The purpose of this comparative study of caries and dental fluorosis
experience in Chilean children was to estimate the optimal range of fluoride
concentration in tap water under conditions currently prevailing in Chile.
The sample included 2431 schoolchildren 7, 12 and 15 years old, life-long
residents of five communities with fluoride concentrations in their tap water
in the range 0.07-1.1 mg/L. The study population received an oral clinical
examination including caries experience and an enamel fluorosis evaluation
of the permanent dentition (Dean's scoring system). For 15-year-old children,
the DMFT index changed from 5.06 to 2.60, and for 12-year-olds it changed
from 3.10 to 1.36 when fluoride water concentration changed from 0.07 to
1.10 mg/L. For 7-year-old children the dmft index correspondingly changed
from 3.67 to 1.59. The relationship between DMFT for 12-year- olds and water
fluoride concentration was best fitted by a logarithmic function (r2=0.98).
The Community Fluorosis Index (CFI) was used to assess enamel fluorosis in
the study population, and it showed a linear relationship (r2=0.983) with
increasing fluoride concentration of water for the 12-year-old group. Results
obtained suggest that under current Chilean conditions, the optimal range
of fluoride concentration in potable water should lie in the 0.5-0.6 mg/L
range.
TITLE: Dental fluorosis in Chilean children:
evaluation of risk factors.
AUTHORS: Villa AE; Guerrero S; Icaza G; Villalobos J; Anabalon M
SOURCE: Community Dent Oral Epidemiol 1998 Oct;26(5):310-5
ABSTRACT: The purpose of this case-control study was to determine the association
between very-mild-to-moderate enamel fluorosis and exposure during early
childhood to fluoridated water, mainly through ingestion of powdered milk.
Analysis was performed on 136 residents of the optimally fluoridated community
of San Felipe in the Chilean Fifth Region, who were categorised into one
of three groups according to their age when water fluoridation was introduced
in 1986: Group I was born after 1986; Group II was 16-24 months old in 1986;
and Group III was >24 months of age. The case and control subjects were
selected on the basis of a clinical examination given in July 1996. Dean's
scoring system was used to determine fluorosis status. Risk factor exposure
was ascertained by a questionnaire used in interviews with mothers of
participating children. Logistic regression analysis, after adjustment for
confounding variables, revealed that very-mild-to-moderate enamel fluorosis
of permanent central maxillary incisors (CMI) was strongly associated both
with the age of the subjects when water fluoridation began and with
breast-feeding duration for children belonging to Group I. Subjects in Group
I were 20.44 times more likely (95% CI: 5.00- 93.48) to develop CMI fluorosis
than children who were older than 24 months (Group III) when fluoridation
began. Subjects who were between 16 and 24 months old when water fluoridation
began were 4.15 times more likely (95% CI: 1.05-16.43) to have CMI fluorosis
than children older than 24 months. An inverse association was found with
breastfeeding duration (OR=0.86, 95% CI: 0.75-0.98) among Group I subjects
but not in Groups II and III. Results obtained suggest that the current fluoride
concentration in drinking water may be contributing to fluorosis. Further
studies will be necessary to determine the relative competing risks of dental
fluorosis and dental caries in Chilean children in order to establish the
most appropriate water fluoridation level in Chile.
TITLE: Risk factors for fractures in the elderly.
AUTHORS: Jacqmin-Gadda H; Fourrier A; Commenges D; Dartigues JF
SOURCE: Epidemiology 1998 Jul;9(4):417-23
ABSTRACT: We report the results of a 5-year prospective cohort study of risk
factors for fractures, including drinking fluoridated water, in a cohort
of 3,216 men and women aged 65 years and older. We studied risk factors for
hip fracture and fractures at other locations separately. We found a higher
risk of hip fractures for subjects exposed to fluorine concentrations over
0.11 mg per liter but without a dose- effect relation (odds ratio (OR) =
3.25 for a concentration of 0.11- 0.25 mg per liter; OR = 2.43 for > or
= 0.25 mg per liter]. For higher thresholds (0.7 and 1 mg per liter), however,
the OR was less than 1. We found no association between fluorine and non-hip
fractures. Non-hip fractures were associated with polymedication rather than
with specific drug use, whereas fracture was associated with polymedication
and use of anxiolytic and antidepressive drugs. Subjects drinking spirits
every day were more likely to have hip fractures. Tobacco consumption increased
the risk for non-hip fractures.
TITLE: Drinking water fluoridation: bone mineral
density and hip fracture incidence.
AUTHORS: Lehmann R; Wapniarz M; Hofmann B; Pieper B; Haubitz I; Allolio B
SOURCE: Bone 1998 Mar;22(3):273-8
ABSTRACT: The role of drinking water fluoride content for prevention of
osteoporosis remains controversial. Therefore, we analyzed the influence
of drinking water fluoridation on the incidence of osteoporotic hip fractures
and bone mineral density (BMD) in two different communities in eastern Germany:
in Chemnitz, drinking water was fluoridated (1 mg/L) over a period of 30
years; in Halle, the water was not fluoridated. BMD was measured in healthy
hospital employees aged 20-60 years (Halle: 214 women, 98 men; Chemnitz:
201 women, 43 men, respectively) using dual-energy X-ray absorptiometry.
Hip fractures in patients > or = 35 years admitted to the local hospitals
in the years 1987-1989 were collected from the clinic registers. There was
no difference in age, anthropometric, hormonal, or lifestyle variables between
the two groups. Mean fluoride exposure in Chemnitz was 25.2 +/- 7.3 years.
No correlation was found between fluoride exposure and age-adjusted BMD.
We found no significant difference in spinal or femoral BMD between subjects
living in Halle and Chemnitz [lumbar spine: 0.997 +/- 0.129 (g/cm2) vs. 1.045
+ 0.171 (g/cm2), p = 0.08, for men; 1.055 +/- 0.112 (g/cm2) vs. 1.046 +/-
0.117 (g/cm2), p = 0.47, for women]. The fracture incidence showed an exponential
increase with aging in men and women with an incidence about 3.5 times higher
for women. In Chemnitz, we calculated an age-adjusted annual incidence of
142.2 per 100,000 for women and 72.5 per 100,000 for men, respectively. In
Halle, the incidences were 178.5 per 100,000 for women and 89.2 per 100,000
for men. There was a lower hip fracture incidence after the age of 85 in
women in Chemnitz (1391 per 100,000 in Chemnitz vs. 1957 per 100,000) in
Halle, p = 0.006). Using the age-adjusted incidences, significantly fewer
hip fractures occurred in Chemnitz in both men and women. In conclusion,
our study suggests that optimal drinking water fluoridation (1 mg/L), which
is advocated for prevention of dental caries, does not influence peak bone
density but may reduce the incidence of osteoporotic hip fractures in the
very old.
TITLE: Dental caries and dental fluorosis among
schoolchildren who were lifelong residents of communities having either low
or optimal levels of fluoride in drinking water.
AUTHORS: Selwitz RH; Nowjack-Raymer RE; Kingman A; Driscoll WS
SOURCE: J Public Health Dent 1998 Winter;58(1):28-35
ABSTRACT: OBJECTIVE: This paper reports findings for dental caries and dental
fluorosis in 8-10- and 13-16-year-old schoolchildren who were lifelong residents
of communities having either naturally occurring low (Broken Bow and Holdrege,
NE; < 0.3 ppm) or optimal (Kewanee, IL; 1 ppm) levels of fluoride in drinking
water. METHODS: Findings are reported for participants who received both
dental caries and dental fluorosis examinations (n = 495). The DMFS and TSIF
indices, respectively, were used to assess dental caries and dental fluorosis.
RESULTS: The mean DMFS score adjusted for age, sealant presence, and fluoride
use was significantly lower in Kewanee (1.8) than was the adjusted mean caries
score in either Holdrege (2.9) or Broken Bow (3.6). Adjusted mean DMFS scores
in Broken Bow and Holdrege were not statistically different. The mean percent
of fluorosed tooth surfaces per person, adjusted for age and use of dietary
fluoride supplements, was similar in the three communities (approximately
15%); more than 80 percent of tooth surfaces in all participants were
fluorosis-free. CONCLUSIONS: Findings from the present study suggest that
water fluoridation still is beneficial and that dental sealants can play
a significant role in preventing dental caries. In addition, findings from
this survey appear to support the premise that the difference in dental fluorosis
prevalence between fluoridated and nonfluoridated communities has narrowed
considerably in recent years.
TITLE: Dental caries and dental fluorosis at
varying water fluoride concentrations [see comments]
AUTHORS: Heller KE; Eklund SA; Burt BA
SOURCE: J Public Health Dent 1997 Summer;57(3):136-43 Comment in: J Public
Health Dent 1998 Summer;58(3):199
ABSTRACT: OBJECTIVES: The purpose of this study was to investigate the
relationships between caries experience and dental fluorosis at different
fluoride concentrations in drinking water. The impact of other fluoride products
also was assessed. METHODS: This study used data from the 1986-87 National
Survey of US School-children. Fluoride levels of school water were used as
an indicator of the children's water fluoride exposure. The use of fluoride
drops, tablets, professional fluoride treatments, and school fluoride rinses
were ascertained from caregiver questionnaires. Only children with a single
continuous residence (n = 18,755) were included in this analysis. RESULTS:
The sharpest declines in dfs and DMFS were associated with increases in water
fluoride levels between 0 and 0.7 ppm F, with little additional decline between
0.7 and 1.2 ppm F. Fluorosis prevalence was 13.5 percent, 21.7 percent, 29.9
percent, and 41.4 percent for children who consumed < 0.3, 0.3 to <
0.7, 0.7 to 1.2, and > 1.2 ppm F water. In addition to fluoridated water,
the use of fluoride supplements was associated with both lower caries and
increased fluorosis. CONCLUSIONS: A suitable trade-off between caries and
fluorosis appears to occur around 0.7 ppm F. Data from this study suggest
that a reconsideration of the policies concerning the most appropriate
concentrations for water fluoridation might be appropriate for the United
States.
TITLE: Symptoms experienced during periods of
actual and supposed water fluoridation.
AUTHORS: Lamberg M; Hausen H; Vartiainen T
SOURCE: Community Dent Oral Epidemiol 1997 Aug;25(4):291-5
ABSTRACT: Fluoridation of water is a controversial measure because of the
suspicion that it has harmful effects on health. Opinions differ as to the
reality of these fears. In Kuopio, after distressing disputes over the
fluoridation issue, the City Council decided to stop fluoridation at the
end of 1992. In fact, however, it was discontinued at the end of November,
one month early, without the public being told. The aim of this study was
to find out whether the occurrence of 25 selected symptoms was connected
with exposure to fluoridated water. In order to do this we compared the
prevalence of symptoms during the months before and after the undisclosed
cessation of fluoridation and after the cessation had been officially announced.
Postal inquiries concerning symptoms were sent to 1000 randomly selected
adults in November, to a further 1000 in December 1992 and again to the same
2000 people in March 1993. The response rates were 40-26%. The percentage
of those with two or more symptoms was the same (45%) in November and in
December but decreased to 32% in March. The mean number of symptoms per
respondent decreased from 1.9 in November to 1.4 in March (P < 0.001)
and in December-March from 1.8 to 1.2. The decrease was most significant
for symptoms related to the skin. Since the occurrence and mean number of
symptoms were fairly similar during actual and supposed fluoridation, the
results do not support the theory that the symptoms considered in this study
are caused by the physical effect of fluoridated water. On the other hand,
the significant reduction in the number of symptoms only after the respondents
had become aware of the discontinuation of fluoridation reveals that fluoridation
may have psychological effects which present as perceived symptoms. {I
found this study most interesting - RJ}
TITLE: New evidence on fluoridation [see comments]
AUTHORS: Diesendorf M; Colquhoun J; Spittle BJ; Everingham DN; Clutterbuck
FW
SOURCE: Aust N Z J Public Health 1997 Apr;21(2):187-90 Comment in: Aust N
Z J Public Health 1997 Jun;21(3):345-6 Comment in: Aust N Z J Public Health
1997 Jun;21(3):346 Comment in: Aust N Z J Public Health 1997 Aug;21(5):548
ABSTRACT: A review of recent scientific literature reveals a consistent pattern
of evidence--hip fractures, skeletal fluorosis, the effect of fluoride on
bone structure, fluoride levels in bones and osteosarcomas--pointing to the
existence of causal mechanisms by which fluoride damages bones. In addition,
there is evidence, accepted by some eminent dental researchers and at least
one leading United States proponent of fluoridation, that there is negligible
benefit from ingesting fluoride, and that any (small) benefit from fluoridation
comes from the action of fluoride at the surface of the teeth before fluoridated
water is swallowed. Public health authorities in Australia and New Zealand
have appeared reluctant to consider openly and frankly the implications of
this and earlier scientific evidence unfavourable to the continuation of
the fluoridation of drinking water supplies.
TITLE: Solving the mystery of the Colorado Brown
Stain.
AUTHORS: Peterson J
SOURCE: J Hist Dent 1997 Jul;45(2):57-61
ABSTRACT: The life and work of Dr. Frederick S. McKay in solving the mystery
of the Colorado Brown Stain changed the objectives of restorative and preventive
dentistry. McKay was an intellectually diversified man whose personal interests
ranged from economics to opera. Professionally his strong commitment to research
led to dedicate thirty years of his life to the search for the mysterious
agent that caused the Colorado Brown Stain which mottled but also produced
caries-free teeth. His discovery of fluoride in drinking water and its effect
on enamel was a critical breakthrough in understanding the etiology and
prevention of dental caries. This discovery is the foundation for water
fluoridation which is the single most effective public health measure to
inhibit tooth decay.
TITLE: The fluoridation war: a scientific dispute
or a religious argument?
AUTHORS: Newbrun E
SOURCE: J Public Health Dent 1996;56(5 Spec No):246-52
ABSTRACT: Communal water fluoridation is not considered controversial by
the vast majority of the scientific community; however, politically it has
persisted as an issue that many legislators and community leaders have avoided
because of an aura of dispute, it has been a battleground for vigorous opposition
by a very small but outspoken minority who have fought it with the dedication
of religious zealots. This paper reviews the nature of the opposition, who
they are, the broad thrust of their arguments, some of the specific issues
they have raised, and their techniques.
TITLE: Relationship between fluoride concentration
in drinking water and mortality rate from uterine cancer in Okinawa prefecture,
Japan [published erratum appears in J Epidemiol 1997 Sep;7(3):184]
AUTHORS: Tohyama E
SOURCE: J Epidemiol 1996 Dec;6(4):184-91
ABSTRACT: The Okinawa Islands located in the southern-most part of Japan
were under U.S. administration from 1945 to 1972. During that time, fluoride
was added to the drinking water supplies in most regions. The relationship
between fluoride concentration in drinking water and uterine cancer mortality
rate was studied in 20 municipalities of Okinawa and the data were analyzed
using correlation and multivariate statistics. The main findings were as
follows. (1) A significant positive correlation was found between fluoride
concentration in drinking water and uterine cancer mortality in 20 municipalities
(r = 0.626, p < 0.005). (2) Even after adjusting for the potential confounding
variables, such as tap water diffusion rate, primary industry population
ratio, income gap, stillbirth rate, divorce rate, this association was
considerably significant. (3) Furthermore, the time trends in the uterine
cancer mortality rate appear to be related to changes in water fluoridation
practices.
TITLE: The effect of drinking water fluoridation
on the natural course of hearing in patients with otosclerosis.
AUTHORS: Vartiainen E; Vartiainen J
SOURCE: Acta Otolaryngol (Stockh) 1996 Sep;116(5):747-50
ABSTRACT: The effect of drinking water fluoridation on the course of hearing
of non-operated otoscl ears was assessed in an area where the natural
waters have a very low fluoride content. The study population consisted of
150 patients with surgically proven otosclerosis. Patients having an additional
known cause of hearing loss were excluded from the study. Every patient had
a follow-up of at least 5 years, the mean follow-up period being 8.8 years.
At last follow-up examination, air conduction thresholds of patients drinking
fluoridated tap water were found to be significantly better than those of
patients drinking fluoride-poor water, likewise there were significant
differences in bone conduction thresholds at 1, 2, and 4 kHz. It was concluded
that drinking water fluoridation has a beneficial effect on hearing levels
of non-operated otoscl ears.
TITLE: Water fluoridation and osteoporotic fracture.
AUTHORS: Hillier S; Inskip H; Coggon D; Cooper C
SOURCE: Community Dent Health 1996 Sep;13 Suppl 2:63-8
ABSTRACT: Osteoporotic fractures constitute a major public health problem.
These fractures typically occur at the hip, spine and distal forearm. Their
pathogenesis is heterogeneous, with contributions from both bone strength
and trauma. Water fluoridation has been widely proposed for its dental health
benefits, but concerns have been raised about the balance of skeletal risks
and benefits of this measure. Fluoride has potent effects on bone cell function,
bone structure and bone strength. These effects are mediated by the incorporation
of fluoride ions in bone crystals to form fluoroapatite, and through an increase
in osteoblast activity. It is believed that a minimum serum fluoride level
of 100 ng/ml must be achieved before osteoblasts will be stimulated. Serum
levels associated with drinking water fluoridated to 1 ppm are usually several
times lower than this value, but may reach this threshold at concentrations
of 4 ppm in the drinking water. Animal studies suggest no effect of low-level
(0-3 ppm) fluoride intake on bone strength, but a possible decrease at higher
levels. Sodium fluoride has been used to treat established osteoporosis for
nearly 30 years. Recent trials of this agent, prescribed at high doses, have
suggested that despite a marked increase in bone mineral density, there is
no concomitant reduction in vertebral fracture incidence. Furthermore, the
increase in bone density at the lumbar spine may be achieved at the expense
of bone mineral in the peripheral cortical skeleton. As a consequence, high
dose sodium fluoride (80 mg daily) is not currently used to treat osteoporosis.
At lower doses, recent trials have suggested a beneficial effect on both
bone density and fracture. The majority of epidemiological evidence regarding
the effect of fluoridated drinking water on hip fracture incidence is based
on ecological comparisons. Although one Finnish study suggested that hip
fracture rates in a town with fluoridated water were lower than those in
a matching town without fluoride, a later study failed to show differences.
Ecological studies from the United States and Great Britain have, if anything,
revealed a weak positive association between water fluoride concentration
and hip fracture incidence. Two studies examining hip fracture rates before
and after fluoridation yielded discordant results, and are complicated by
underlying time trends in hip fracture incidence. Only two studies have attempted
to examine the relation between water fluoride concentration and fracture
risk at an individual level. In one of these, women in a high fluoride community
had double the fracture risk of women in a low fluoride community. In the
other, there was no relationship between years of fluoride exposure and incidence
of spine or non-spine fractures. In conclusion, the epidemiological evidence
relating water fluoridation to hip fracture is based upon ecological comparisons
and is inconclusive. However, several studies suggest the possibility of
a weak adverse effect, which warrants further exploration. 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.
TITLE: Cancer and fluoridation.
AUTHORS: Cook-Mozaffari P
SOURCE: Community Dent Health 1996 Sep;13 Suppl 2:56-62
ABSTRACT: Early geographical studies of cancer in areas that have naturally-
occurring fluoride at different levels gave no indication of an effect on
cancer rates associated with higher intakes of fluoride. Following widespread
fluoridation to improve dental health in the United States and Britain,
non-epidemiologists presented analyses of cancer data which they claimed
demonstrated such an effect. However, subsequent large-scale comparisons
of cancer rates in fluoridated and non- fluoridated areas for successive
periods following fluoridation have not indicated any increase, either for
all cancer or for malignancies across the range of individual sites. Studies
undertaken specifically to examine the claims of the non-epidemiologists
have, time-and-again, shown that, with the use of accurate data and correct
statistical methods, the purported effects cease to be apparent. Details
of the earlier evidence and claims are given in the 'Report of a Working
Party on the Fluoridation of Water and Cancer' by Professor George Knox (1985)
and of more recent analyses in Hoover et al. (1991a; 1991b; unpublished internal
US PHS Memo, 1993). 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.
TITLE: Thirty-eight years of water fluoridation--the
Singapore scenario.
AUTHORS: Loh T
SOURCE: Community Dent Health 1996 Sep;13 Suppl 2:47-50
ABSTRACT: The high caries rate in Singapore school children was of great
concern to dental administrators. Remedial measures alone were not the solution.
The success of water fluoridation in Grand Rapids, USA and in Brantford,
Canada in reducing dental caries in children in the early 1950s prompted
Singapore to introduce fluoride into its drinking water. 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.
TITLE: Patterns of fracture among the United
States elderly: geographic and fluoride effects.
AUTHORS: Karagas MR; Baron JA; Barrett JA; Jacobsen SJ
SOURCE: Ann Epidemiol 1996 May;6(3):209-16
ABSTRACT: The purpose of this study was to examine whether geographic area
or water fluoride were related to the occurrence of fractures among the elderly
in the United States. We used a 5% sample of the white U.S. Medicare population,
aged 65 to 89 years during the period 1986-1990, to identify fractures of
the hip, proximal humerus, distal forearm, and ankle. The association of
geographic region and fluoridation status with fracture rates was assessed
using Poisson regression. We found that rates of hip fracture were generally
lower in the northern regions of the United States and higher in the southern
regions. For fractures of the distal forearm and proximal humerus, lower
rates were found in the Western states, and higher rates in the East. No
discernible geographic pattern was found for ankle fractures. Adjustment
for water fluoridation did not influence these results. Independent of geographic
effects, men in fluoridated areas had modestly higher rates of fractures
of the distal forearm and proximal humerus than did men in nonfluoridated
areas; no such differences were observed among women, nor for fractures of
the hip or ankle among either men or women. In conclusion, our data suggest
that fractures of the distal forearm and proximal humerus have etiologic
determinants distinct from those of fractures of the hip or ankle.
TITLE: Fluoridation of communal water
supplies.
AUTHORS: Scott DB
SOURCE: J Public Health Dent 1996;56(5 Spec No):235-8
ABSTRACT: This paper reviews the scientific events culminating in the
fluoridation of communal water supplies. Dental and medical studies completed
by 1942 had established the safety and benefits of exposure to drinking water
naturally containing fluoride. Researchers and public health workers concluded
that it was possible to test the hypothesis that the dental benefits attained
where fluoride levels around 1 ppm occurred naturally in drinking water could
be safely replicated in low- fluoride areas by raising the level to this
optimal concentration. Grand Rapids became the first test site and by the
time the demonstration ended in 1959, around 40 million people in about 2,000
communities already were drinking water with fluoride levels that had been
adjusted to optimal. The success of fluoridation brought the dawn of the
era of caries control and created great opportunities for research and public
health.
TITLE: Fluoride in drinking water and the bone
mineral density of women in Taiwan.
AUTHORS: Lan CF; Lin IF; Wang SJ
SOURCE: Int J Epidemiol 1995 Dec;24(6):1182-7
ABSTRACT: BACKGROUND: The current evidence on effect of fluoridation in drinking
water on bone is inconsistent. This study was undertaken to assess the effect
of fluoride concentration in drinking water on bone mineral density (BMD)
in Taiwanese women. METHODS: The study subjects included 248 women aged >
or = 40 years who reside in naturally fluoridated and adjacent areas. The
individual fluoride concentration of the drinking water and the BMD of the
subjects' lumbar spines were assessed. RESULTS: Women aged 46-65 years living
in areas which have fluoride levels < 0.6 mg/l (mean = 0.18 mg/l; n =
130) had slightly lower bone densities than women living in areas with levels
> or = 0.6 mg/l (mean 0.98 mg/l, n = 118). Only the age groups 46-50 and
61-65 years proved to be statistically significant. After controlling for
age and body mass index, the BMD of those who had a dose > or = 1.0 mg/l
is notably higher than the reference group (< or = 0.6 mg/l). After
stratification by menopausal status, fluoride appeared to have no association
with bone density in postmenopausal women. CONCLUSIONS: The BMD of the subjects
from the area with a fluoride dose > 1 mg/l were significantly higher
than those from the reference group (fluoride < 0.6 mg/l) for premenopausal
women. There is no significant association between BMD and fluoride for
postmenopausal women in Taiwan.
TITLE: [Dental health status of students living
in places supplied with drinking water of very high and very low levels of
fluorides]
AUTHORS: Azcurra AI; Battellino LJ; Calamari SE; de Cattoni ST; Kremer M;
Lamberghini FC SOURCE: Rev Saude Publica 1995 Oct;29(5):364-75
ABSTRACT: The results of a cross sectional epidemiological survey for the
purpose of evaluating the state of dental health of schoolchildren (aged
6-7 and 12-13) living in Sampacho and Portena, two towns in the Province
of Cordoba (Argentina), supplied with drinking water containing quite different
levels of fluoride, are described and analized. In Sampacho, F- level is
9.05 mg/l. while in Portena the concentration is of 0.19 mg/l. The proportion
of schoolchildren (aged 6-7 and 12-13) without caries was significaticantly
higher in Sampacho than in Portena, while the dmf-t, dmf-s, DMF-T and DMF-S
indexes were considerably higher in the latter place. The severity of caries
in children (age 12-13) living in Sampacho ranged from low to moderate (DMF-T
= 2.53), whilst in Portena the range went from moderate to high (DMF-T =
4.41). No cases of dental fluorosis were recorded in Portena; but in Sampacho,
there was a high proportion of children with mild fluorosis (aged 6-7) and
mild or severe fluorosis (aged 12-13). Calcium, phosphate, thiocyanate, protein
and secretory Ig A salivary levels were similar not only among schoolchildren
of both towns but also among those with different experience of caries and
different degrees of severity of fluorosis. It is concluded that urgent
(preventive and/or curative) sanitary measures are necessary for the purpose
of reducing or controlling caries in Portena as well as dental fluorosis
in Sampacho.
TITLE: Fluoride reduces bone strength in older
rats.
AUTHORS: Turner CH; Hasegawa K; Zhang W; Wilson M; Li Y; Dunipace AJ
SOURCE: J Dent Res 1995 Aug;74(8):1475-81
ABSTRACT: In response to recent concerns about the effect of water fluoridation
on hip fracture rates, we studied the influence of fluoride intake on bone
strength. Four groups of rats were fed a low-fluoride diet ad libitum and
received 0, 5, 15, or 50 ppm {note - that concentration is 50 times the optimal
recommended level - RJ} of fluoride in their drinking water. Animals were
euthanized after 3, 6, 12, or 18 months of treatment. Mechanical strength
of the right femur was measured by three- point bending. Fluoride content
for the left femur was measured, and static histomorphometric measurements
were made on a lumbar vertebra. Femoral failure load was not significantly
decreased in rats treated for 3 and 6 months, but was decreased as much as
23% in rats treated 12 and 18 months at 50 ppm fluoride. Extrapolation from
regression equations predicted that older rats lose 36% of femoral bone strength
when bone fluoride content is increased from 0 to 10,000 ppm, while younger
rats will lose only 15%. Thus, the decreased strength appeared to be due
to the combined effects of fluoride intake and age on bone tissue and was
not associated with a decrease in bone density or mineralization defects.
There were only small effects of fluoride on bone histomorphometry. Fluoride
intake at high levels had no negative effects on bone mineralization. Fluoride
intake was associated with slight increases in trabecular bone volume and
trabecular thickness, but these effects could not be demonstrated consistently.
The mechanism by which large amounts of fluoride affect bone strength more
severely in older animals is unknown.
TITLE: [Effect of preventive fluoride treatment
in childhood on dental conditions in adults]
AUTHORS: Radnai M; Fazekas A; Boda K
SOURCE: Fogorv Sz 1995 Aug;88(8):271-6
ABSTRACT: The purpose of the study was to compare the dental health status
of three groups of adults aged 18-47. In the first group belonged the population,
that consumed in their childhood salt containing 250-350 mg fluoride per
kg. The second group consisted of those who drank water with an optimal fluoride
concentration (1 mg/kg). The individuals without fluoride prevention formed
the third group. The results showed, that the consumption of fluoridated
drinking water or salt in childhood has a life-long beneficial effect on
the dental health of the adult population.
TITLE: Infants' fluoride intake from drinking
water alone, and from water added to formula, beverages, and food.
AUTHORS: Levy SM; Kohout FJ; Guha-Chowdhury N; Kiritsy MC; Heilman JR; Wefel
JS
SOURCE: J Dent Res 1995 Jul;74(7):1399-407
ABSTRACT: In infants, the majority of total ingested fluoride is obtained
from water, formula and beverages prepared with water, baby foods, and dietary
fluoride supplements. Few studies have investigated the distribution of fluoride
intake from these sources among young children at risk for dental fluorosis.
The purpose of this study was to assess estimated water fluoride intake from
different sources of water among a birth cohort studied longitudinally from
birth until age 9 months. Parental reports were collected at 6 weeks, 3 months,
6 months, and 9 months of age for water, formula, beverage, and other dietary
intake during the preceding week. Fluoride levels of home and child-care
tap and bottled water sources were determined. This report estimates daily
quantities of fluoride ingested only from water--both by itself and used
to reconstitute formula, beverages, and food. Daily fluoride intake from
water by itself ranged to 0.43 mg, with mean intakes < 0.05 mg. Water
fluoride intake from reconstitution of concentrated infant formula ranged
to 1.57 mg, with mean intakes by age from 0.18 to 0.31 mg. Fluoride intake
from water added to juices and other beverages ranged to 0.67 mg, with means
< 0.05 mg. Estimated total daily water fluoride intake ranged to 1.73
mg fluoride, with means from 0.29 to 0.38 mg.
TITLE: Effects of fluoridated drinking water
on bone mass and fractures: the study of osteoporotic fractures.
AUTHORS: Cauley JA; Murphy PA; Riley TJ; Buhari AM
SOURCE: J Bone Miner Res 1995 Jul;10(7):1076-86
ABSTRACT: To determine if optimal fluoridation of public water supplies
influences bone mass and fractures, we studied 2076 non-black women, all
aged > or = 65 years recruited into the Study of Osteoporotic Fractures
at the Pittsburgh clinic. Information on fluoride exposure was limited to
community water supplies. The variable used in the analysis was years of
exposure to fluoridated water in community drinking water supplies. Bone
mineral density (BMD) was measured at the spine and hip using dual energy
X-ray absorptiometry and at the midpoint and ultradistal radius and calcaneus
using single photon absorptiometry. Prevalent and incident vertebral fractures
were determined by morphometry. Incident nonspine fractures were ascertained
every 4 months and confirmed by radiographic report. Exposure to residential
fluoridated water had no effect on bone mass. Women exposed to fluoride for
> 20 years had similar axial and appendicular bone mass to women not exposed
or women exposed for < or = 20 years. There was some suggestion that women
exposed to fluoride for > 20 years had a lower relative risk of nonspine
fractures (relative risk, RR, = 0.73; 95% confidence interval [CI] 0.48-1.12),
osteoporotic fractures, RR = 0.74 (CI 0.46-1.19), and hip fractures, RR =
0.44 (CI 0.10-1.86), compared with women not exposed, but none of these relative
risks was statistically significant. There was no association with wrist
or spinal 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.
TITLE: Fluoride: is there a limit?
AUTHORS: Kimmelman BB
SOURCE: Compend Contin Educ Dent 1995 Apr;16(4):376, 378, 381-6 PASSIM; QUIZ
394 ABSTRACT: In the 103 years since the appearance of the philosopher Benedetto
Croce's observations of "denti-scritti" marring the teeth of Neapolitan women,
the scientific investigations of fluoride have advanced from discovery to
cure to prevention. These advances have been largely the achievements of
dentists in public health, research, clinical practice, and academia. Water
fluoridation is acknowledged to be one of the greatest public-health measures
of the century.
TITLE: Fluoridated drinking water and maturation
of permanent teeth at age 12.
AUTHORS: Campagna L; Tsamtsouris A; Kavadia K
SOURCE: J Clin Pediatr Dent 1995 Spring;19(3):225-8
ABSTRACT: Dental age was evaluated in 88 children aged 12 years + 6 months
in both areas of Boston with fluoridated drinking water and nonfluoridated
areas surrounding Athens, Greece. Fluoridation of drinking water in the Boston
areas was 1.0 ppm, a level considered 'optimal' in the USA. Girls from the
fluoridated Boston area were shown in this study to have a significantly
(p<0.05) delayed dental age when compared to their chronological age according
to the tables of Nolla. Boys from the Boston area and boys and girls from
the Athens area showed no significant difference when comparing dental age
to chronological age.
TITLE: Fifty years of water fluoridation.
AUTHORS: Burt BA
SOURCE: Br Dent J 1995 Jan 21;178(2):49-50
ABSTRACT: On January 25, 1945, the city of Grand Rapids, Michigan, began
adding sodium fluoride to its drinking water. This action culminated a 14-year
period of research which continues to have far-reaching effects on both public
health and the practice of dentistry. The fact that the oral health of children
and young adults today has never been higher is a direct consequence of this
research. These events, and the group of rather extraordinary people who
were the principal actors in them, are so important a part of dentistry's
development that they are worth a brief retelling. |
