FLUORIDE Vol. 30 (1), February, 1997, p 67.
THE PLACE OF FLUORIDE SUPPLEMENTS IN CARIES PREVENTION TODAY
PJ Riordan, Como, West Australia
Abstract from Australian Dental Journal 41 (5) 335-342 1996
There are very few scientifically good clinical trials of fluoride supplements, and those that can be considered methodologically adequate suggest that the contribution of fluoride supplements to caries prevention is slight. This may be partly a consequence of the fact that fluoride is much more widely available today than was the case a generation ago when fluoride toothpaste was not widely used and water fluoridation was not fully implemented. Although some families are conscientious in their use, compliance with fluoride supplement recommendations is generally poor over longer periods, making them a poor public health measure. There is substantial evidence that supplements cause dental fluorosis when used in accordance with recommendations for infants and small children. If the public becomes concerned about dental fluorosis as an aesthetic problem, all fluoride use may be put at risk. Supplements should no longer be recommended for caries prevention in children in areas with little fluoride in water but may be useful for persons with intractable caries risks. If supplements are recommended for children, a more cautious dosage schedule should be used. The fact that supplements have been recommended uncritically for many years on the basis of inadequate research raises questions about the standards of dental science.
Key words: Dental caries; Enamel mottling; Fluoride supplements; Prevention. Reprints: P J Riordan, Dental Service, PO Box 50, Come, WA 6152, Australia.
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FLUORIDE Vol. 29 (2), May 1996, p. 114
RISK OF FLUOROSIS IN A FLUORIDATED POPULATION -
IMPLICATIONS FOR THE DENTIST AND HYGIENIST
DG Pendrys, Farmington, Connecticut, USA
Abstract from Journal of the American Dental Association 126 (12) 1617-1624 1995
The prevalence of enamel fluorosis has increased in optimally fluoridated areas in recent years. This has led to efforts to identify the cause or causes and to make recommendations that seek to maintain the caries-preventive effectiveness of fluoride use while minimizing the risk of fluorosis. In this study, the author estimated the potential direct impact that dental practitioners could have on reducing the amount of enamel fluorosis in U.S. children. The findings suggest that dental practitioners could have an important impact on reducing the prevalence of enamel fluorosis by guiding the public toward the most appropriate use of fluoride products.
Key words: Dental caries; Dental fluorosis; Fluoridation; Supplements; Toothpaste.
Reprints: D G Pendrys, Department of Behavioral Sciences and Community Health, School of Dental Medicine, University of Connecticut Health Center, Farmington 06030, USA.
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FLUORIDE Vol. 29 (2), May 1996, p. 114
FLUORIDE SUPPLEMENT USE BY CHILDREN
IN FLUORIDATED COMMUNITIES.
D G Pendrys and D E Morse Farmington, Connecticut, USA
Abstract from Journal of Public Health Dentistry 55 (3) 160-164 1995
OBJECTIVES: The purpose of this study is to describe patterns of inappropriate fluoride supplementation among a sample of Connecticut schoolchildren living in optimally fluoridated areas.
METHODS: Fluoride exposure histories were obtained via a written questionnaire with a response rate of 89 percent and an overall reliability of 87 percent agreement.
RESULTS: A total of 575 subjects lived the entire first eight years of life in a fluoridated community. Of these, 26.1 percent had a history of inappropriate supplementation sometime during that period, including 31.8 percent of subjects with mild to moderate fluorosis and 22.8 percent of subjects without fluorosis. There were no significant supplement history differences related to current age, sex, or socioeconomic: status. Overall, 71 percent of these subjects used only vitamins with fluoride, while only 14 percent were reported to have used fluoride supplements alone. Sixty-eight percent of the subjects who were supplemented while breast feeding, continued supplementation after cessation of breast feeding.
CONCLUSIONS: These findings reinforce the need for health professionals to be targeted more aggressively at the school, residency, and private practice levels to better promote a full understanding of the proper utilization of fluoride supplements.
Key words: Dental fluorosis; Fluoridation; Supplements.
Reprints: D G PENDRYS, Department of Behavioral Sciences and Community Health, School of Dental Medicine. University of Connecticut Health Center Farmington 06030, USA.
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FLUORIDE, Vol 29 (2), May 1996, p. 115
RISK FACTORS FOR DENTAL FLUOROSIS
IN PEDIATRIC DENTAL PATIENTS
M C Skotowski, R J Hunt and S M Levy, Iowa City, Iowa, USA
Abstract from Journal of Public Health Dentistry 55 (3) 154-159 1995
OBJECTIVES: Concerns have been raised recently about whether a substantial amount of dental fluorosis is resulting from the increased use of fluoride from various sources. The purposes of this study were to determine the prevalence and severity of dental fluorosis in a sample of pediatric patients seeking dental treatment in a university pediatric dental clinic and to evaluate sources of fluoride as risk factors for dental fluorosis.
METHODS: A convenience sample of 157 children aged 8 to 17 years were examined for dental fluorosis using the Tooth Surface Index of Fluorosis (TSIF). Fluoride history questionnaires assessing previous exposure to fluoride during the first eight years of life were completed by the children's parents. Fluoride exposures were compared among 54 cases and 54 matched controls using a case-control retrospective design.
RESULTS: Fluorosis was found in 72 percent of the children, but was generally quite mild. The risk of fluorosis was significantly greater for children who had greater exposure to fluoridated water and who used larger amounts of fluoridated toothpaste up to age eight.
CONCLUSIONS: This study provided evidence that increased use of fluoride toothpaste may be a risk factor for dental fluorosis. The results suggest prudent use of dentifrice by young children to minimize the risk of fluorosis.
Key words: Dental fluorosis; Pediatric patients; Toothpaste.
Reprints: M C Skotowski, Department of Pediatric Dentistry, College of Dentistry, University of Iowa, Iowa City 52242-1001, USA
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FLUORIDE, Vol 29 (2), May 1996, pp 115-116
FLUORIDE CONTENT OF INFANT FORMULAE IN AUSTRALIA
M Silva and E C Reynolds, Melbourne, Australia
Abstract from Australian Dental Journal 41 (1) 37-42 1996
The prevalence of dental fluorosis in Australia and the United States of America has increased in both optimally fluoridated and non-fluoridated areas. This has been attributed to an increase in the fluoride level of food and beverages through processing with fluoridated water, inadvertent ingestion of fluoride toothpaste, and the inappropriate use of dietary supplements. A major source of fluoride in infancy is considered to be infant formula which has been implicated as a risk factor for fluorosis in a number of studies. In this study the fluoride content of the infant formulae commonly used in Australia was determined. The acid diffusible fluoride of each powdered formula was isolated by microdiffusion and measured using a fluoride ion-specific electrode. The fluoride content of milk-based formulae ranged from 0.23 to 3.71 ug F/g and for soy-based formulae from 1.08 to 2.86 ug F/g. When reconstituted, according to the manufacturer's directions, with water not containing fluoride, the formulae ranged in fluoride content from 0.031 to 0.532 ppm, with the average fluoride content 0.240 ppm. Using average infant body masses and suggested volumes of formula consumption for infants 1-12 months of age, possible fluoride ingestion per kg body mass was estimated. None of the formulae, if reconstituted using water containing up to 0.1 ppm F, should provide a daily fluoride intake above the suggested threshold for fluorosis of 0.1 mg F/kg body mass. However, if reconstituted with water containing 1.0 ppm F they should all provide a daily fluoride intake of above the suggested threshold for fluorosis with intakes up to 2-3 times the recommended upper 'optimal' limit of 0.07 mg/kg body mass. Under these conditions the water used to reconstitute the formulae would provide 65-97 per cent of the fluoride ingested. These figures are likely to be overestimates due to the intake of nutrients from other sources reducing formulae consumption and also due to the lower bioavailability of fluoride from milk-based formulae. Further, it is generally believed that the maturation stage of enamel formation is the critical period for fluorosis development by chronic, above-threshold fluoride exposure. The maturation stage for the anterior permanent teeth, however, is after the first twelve months of life where fluoride intake from infant formula consumption per kg body mass is highest. The level of fluoride in the commonly used Australian formulae would suggest that infant formula consumption alone is unlikely to be a risk factor for dental fluorosis in a non-fluoridated community, but could make a major contribution to an infant's daily fluoride intake. However, prolonged consumption (beyond 12 months of age) of infant formula reconstituted with optimally-fluoridated water could result in excessive amounts of fluoride being ingested during enamel development of the anterior permanent teeth and therefore may be a risk factor for fluorosis of these teeth.
Key words: Dental fluorosis; Infant formulae.
Reprints: M Silva, University of Melbourne, School of Dental Science, 711 Elizabeth St, Melbourne, Vic 3000, Australia.
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FLUORIDE, Vol 29 (2), May 1996, p. 113
INFANTS FLUORIDE INGESTION FROM WATER,
SUPPLEMENTS AND DENTIFRICE
S M Levy, F J Kohout, M C Kiritsy, J R Heilman and J S Wefel
Iowa City, Iowa, USA
Abstract from Journal of the American Dental Association 126 (12) 1625-1632 1995
Concerns about dental fluorosis and the paucity of detailed fluoride intake data prompted this longitudinal study of fluoride intake in infants from birth to 9 months of age. On average, water fluoride intake greatly exceeded that from dietary fluoride supplements or fluoride dentifrice. However, fluoride supplements and dentifrice contributed substantial proportions of fluoride intake among children using them. Some children had estimated fluoride intake from water, supplements and dentifrice that exceeded the recommended "optimal" intake (a level that has yet to be determined scientifically). Practitioners should estimate fluoride ingestion from all these sources if considering systemic fluoride supplementation.
Key words: Dental fluorosis; Dentifrice; Fluoride ingestion; Infants; Optimal Intake; Toothpaste; Water fluoride.
Reprints: S M Levy, University of Iowa, College of Dentistry, Department of Preventive and Community Dentistry, Iowa City, IA 52242, USA.
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FLUORIDE, Vol 26 (3), July 1993, pp 231-232
DENTAL FLUOROSIS, DENTAL CARIES AND
FLUORIDE EXPOSURE AMONG 7-YEAR-OLDS
PJ Riordan Come, West Australia.
Abstract from Caries Research 27 71-77 1993
Mild dental fluorosis is frequently linked to fluoridated water, but
discretionary fluoride sources may also be important. The aim of this study
was to record age of weaning and fluoride exposure from water, toothpaste
and supplements, and to relate these to the presence of caries and fluorosis
in children born in 1983. In Perth (Western Australia) 14 school classes
were selected. The 350 children (mean age 7.5 years) ultimately included
gave fluoride exposure data for the period birth to 4 years of age. Caries
(DMFT, WHO criteria, no radiographs) and dental fluorosis (TF index, dry
permanent incisors) were registered clinically. Most (89%) children had
lived at least 2.5 years in a fluoridated area. Supplement use was minimal
and unrelated to caries or fluorosis. Mean age of weaning of those who had
been breastfed was 7.7 months; by 9 months, 74% had been weaned. Eighty-five
percent liked toothpaste, 60.7% had swallowed it, and the mean age of
starting to use it was 1.5 (SD 0.96) years. Caries prevalence was 0.1 and
mean DMFT was 0.13. The prevalence of fluorosis was 0.48; 63% of fluorosis
was TF score 1. Residence in a fluoridated area for greater-than-or-equal-to
2.5 of the first 4 years of life had an odds ratio (OR) of 4.9 for
fluorosis. Weaning before 9 months of age, swallowing toothpaste and liking
toothpaste were also statistically significant risk factors. Major risk
factors for more severe fluorosis (TF greater-than-or-equal-to 2) were early
weaning and swallowing toothpaste (ORs 2.77 and 2.64, respectively).
Residence in a fluoridated area (OR 2.2) was not a statistically significant
risk factor. These findings confirm a high prevalence of mild fluorosis
among children who have been exposed to fluoride in their earliest years.
High attributable proportions associated with age of weaning and toothpaste
use suggest that elimination of fluoride from formula and a reduced fluoride
concentration in toothpaste would contribute significantly to reducing the
prevalence of more visible fluorosis.
Key words: Epidemiology; Infant formula; TF Index; Toothpaste.
Reprints: P J Riordan, Health Department of Western Australia,
Community Dental Service, POB 50, Como, WA 6152, Australia.
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FLUORIDE Vol. 27(3), July 1994 pp 162-163
*APPROPRIATE USES OF FLUORIDES FOR CHILDREN
GUIDELINES FROM THE CANADIAN WORKSHOP ON THE EVALUATION
OF CURRENT RECOMMENDATIONS CONCERNING FLUORIDES
DC Clark Vancouver, British Columbia, Canada.
Abstract from Canadian Medical Association Journal 149(12) 1787-1793 1993
Objective: To prevent fluorosis caused by excessive fluoride ingestion by revising recommendations for fluoride intake by children. Options Limiting fluoride ingestion from fluoridated water, fluoride supplements and fluoride dentifrices.
Outcomes: Reduction in the prevalence of dental fluorosis and continued prevention of dental caries.
Evidence: Before the workshop, experts prepared comprehensive literature reviews of fluoride therapies, fluoride ingestion and the prevalence: and causes of dental fluorosis. The papers, which were peer-reviewed, revised and circulated to the workshop participants, formed the basis of the workshop discussions.
Values: Recommendations to limit fluoride intake were rigorously debated before being adopted as the consensus opinion of the workshop group. Benefits, harms and costs: Decrease in the prevalence of dental fluorosis with continuing preventive effects of fluoride use. The only significant cost would be in preparing new, low-concentration fluoride products for distribution.
Recommendations: Fluoride supplementation should be limited to children 3 years of age and older in areas where there is less than 0.3 ppm of fluoride in the water supply. Children in all areas should use only a "'pea-sized'" amount of fluoride dentifrice no more than twice daily under the supervision of an adult.
Validation: These recommendations are almost identical to changes to recommendations for the use of fluoride supplements recently proposed by a group of European countries.
Sponsors: The workshop was organized by Dr D Christopher Clark, of the University of British Columbia, and Drs Hardy Limeback and Ralph C Burgess, of the University of Toronto, and funded by Proctor and Gamble Inc., Toronto, the Medical Research Council of Canada and Health Canada (formerly the Department of National Health and Welfare). The recommendations were formally adopted by the Canadian Dental Association in April 1993.
Key words: Dental fluorosis; Fluoride ingestion; Fluoride supplements.
Reprints: D C Clark, University of British Columbia, Faculty of Dentistry, 2199 Westbrook Mall, Vancouver V6T 1Z3, BC, Canada.
*For a more recent assessment, see FLUORIDE 27 (2) 1994 p121. Also letters FLUORIDE 27(3) pp 180-182.
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FLUORIDE, Vol. 27(2), April 1994, p. 121
THE CASE FOR ELIMINATING THE USE OF DIETARY
FLUORIDE SUPPLEMENTS AMONG YOUNG CHILDREN
Abstract of paper presented at Dietary Fluoride Supplement Conference,
American Dental Association, Chicago, Illinois, January 31-February 1, 1994
Brian A. Burt, Ann Arbor, Michigan, USA
Fluoride supplements have been used for years to prevent dental caries, but there are three reasons why their use is inappropriate today among young children in the United States. They are (a) the evidence for the efficacy of fluoride supplements in caries prevention is not strong, (b) supplements are a clear risk for dental fluorosis, and (c) fluoride's pre-eruptive effects in caries prevention are weak.
There are many studies published on the caries-preventive efficacy of supplements, but few meet the standards for acceptable clinical trials. Well-conducted studies showing supplements to be efficacious have been conducted with school-age children in supervised programs, with chewable tablets or lozenges for slow dissolution to achieve topical effects. The evidence to show that supplements are a risk factor for enamel fluorosis is strong, and so is the evidence to show that fluoride prevents caries principally through post-eruptive effects. North American children are today exposed to fluoride from many sources: drinking water, toothpaste, gels, rinses, and a considerable amount in foods and beverages.
The additional cariostatic benefits that would accrue from supplement use is marginal at best, while the risk of fluorosis is strong. There is evidence that the public is more aware of the milder forms of fluorosis than was previously thought, so dental policies should be aimed at reducing fluorosis. The risks of using fluoride supplements in young children outweigh the benefits. Since there are alternative forms of fluoride to use in high-risk individuals, fluoride supplements should no longer be used for young children in North America.
Key words: Dental fluorosis; Dental Caries; Fluoride supplements.
Reprints: Dr. Brian A. Burt, Program in Dental Public Health, School of Public Health, The University of Michigan, Ann Arbor MI 48109-2029, USA
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FLUORIDE, Vol. 27(3), July 1994, Letters to the Editor pp 180-182
For well over ten years it has been apparent that fluoride supplements are unwise for young children. Indeed, a Rand Corporation literature review in 1981 found that supplements are "simply not warranted" by the results (RAND report N 1732-RWJF Dec 1981). Furthermore, their use clearly increases the risk of dental fluorosis, which is now at an all time high in the US. It is equally clear that there is little or no evidence of any dental benefits from pre-eruptive supplementation. For these reasons, fluoride supplements are banned or strictly regulated in Africa, Europe, Canada, Japan, and India.
It is heartening, therefore, to read that a long time fluoride advocate agrees that "fluoride supplements should no longer be used for young children in North America" (Abstract in Fluoride 27 (2) 1994). The question that Dr. Burt should now address is: Given the uselessness and risk of fluoride supplements, why should the practice of giving young children the same fluoride dissolved in water (fluoridation) be continued?
John R Lee MD
9620 Bodega Hwy
Sebastopol CA 95521
USA
Professor Burt responds:
The American Dental Association (ADA) conducted a workshop to consider its schedule for dietary fluoride supplementation on Jan 31-Feb 1, 1994. Dr. Lee has circulated some inferences from my paper at that workshop which stray far from the sense of my presentation, and which could be interpreted to imply that I am opposed to water fluoridation as a public health measure in the United States. That is not the case, and this response is to comment briefly on Dr. Lee's inferences.
Dr. Lee has quoted accurately from the abstract, but it seems that he has not read the full paper. (Along with other papers from the workshop, this is to be published in the Journal of Public Health Dentistry in due course). My conclusion, correctly quoted by Dr. Lee, was that the risks of using fluoride supplements in young children outweigh the benefits. "Risk" was described as the likely develop development of the mildest forms of fluorosis from regular use of supplements by infants and young children, while "benefits" were the minor (at best) cariostatic effects likely to result from this use. Dr. Lee then goes on to extrapolate that line of thinking to the use of water fluoridation, but this does not follow because with water fluoridation the benefits outweigh the risks.
Dr. Lee seems to be suggesting that the relative lack of cariostatic effect of systemic fluoride is a new finding, but this is not true. The first review of literature that I know of to point this out was in 1976 (Levine RS. The action of fluoride in caries prevention: a review of current concepts. British Dental Journal 140 9-14 1976). The evidence for a primarily topical cariostatic effect of fluoride has grown and has been cited many times since then, culminating with the 1989 Georgia conference (proceedings in Journal of Dental Research 69 special issue 1990).
There is considerable evidence that vehicles like fluoridated water and
table salt have powerful topical cariostatic effects. These methods are
highly effective public health approaches to caries control, though they are
accompanied by about 12% prevalence of the mildest forms of fluorosis. I
consider the benefits of water fluoridation exceed the risks associated with
its use, and my argument about eliminating supplements for young children in
fact depends partly upon the effectiveness of fluoride in water and
toothpaste. Supplements are unlikely to add much to this existing
effectiveness, but do increase the risk of fluorosis.
I would like to finish by summarizing my philosophy on fluoride use,
which I believe is well-based on published evidence. I hope that this will
counter any wrong impression that Dr. Lee's inferences may have produced.
Fluoride most effectively controls caries when a low concentration can be
maintained consistently in the oral environment. While any method of using
fluoride which helps achieve this state will be effective, fluoridated water
and fluoride toothpaste rank first as public health measures in the United
States.
Fluoride continues to be a major reason why the oral health of Americans
is today better than ever and continues to improve.
Fluoridation of water to appropriate levels, and the regular use of
fluoride toothpaste, as the two most effective public health means of
controlling dental caries. The majority of Americans need little or no extra
fluoride to maintain oral health.
Public health uses of fluoride mean that some systemic absorption of
fluoride is inevitable. In the amounts associated with water fluoridation,
there will be some dental fluorosis of the mildest varieties. This condition
is minor when compared to the accompanying benefits of reduced tooth decay.
It is incumbent on dentistry to reduce the risk of fluorosis as far as
possible while not compromising the benefits of fluoride. My view is that
eliminating supplements use for infants and young children will be a step
toward achieving this goal.
I wish to thank Dr Burt for his acknowledgement of the accuracy of my use
of the quotations from his published summary (despite his objections to my
inferences of them) and for his further comments defending the continued
practice of public water fluoridation. Further, I appreciate his
acknowledgement that water fluoridation has little or no systemic dental
benefit but, rather, supposedly works solely by its topical effects. It is
good that this aspect of the argument be addressed.
Common sense would dictate that the amount of fluoride touching the teeth
during the act of swallowing fluoridated water is extremely small. In fact,
I doubt that it would even be measurable. It is certainty uncommon for
children to swish their drinking water back and forth through their teeth
while imbibing a drink. One would think that brushing with fluoridated
toothpaste would be more effective in bringing fluoride into contact with
the teeth.
The argument that fluoride in public drinking water is responsible for
the observed decline in children's dental caries is contrary to numerous
studies in the US and world-wide which find that the same decline occurred
also in unfluoridated communities. (See references 1 - 11 in the list that
follows below.) In fact, I have continuously challenged any dental authority
to provide one valid study of the past two decades justifying the
presumption of fluoridation's dental benefits and none has been forthcoming.
Dr. Burt's statement that fluoridation results in only "12 % prevalence
of the mildest forms of fluorosis" is contradicted by the US Public Health
Service (the Hoover. report) indicating a fluorosis prevalence of 22.3% in
fluoridated communities and by other authoritative reports in which dental
fluorosis prevalence was variously found to be 30-60 % In communities with
supposedly "optimal" fluoridation. (See references 4 and 12-15 in list below.)
Dr. Burt is seemingly unaware that dental fluorosis connotes fluoride
toxicity far more important than mere dental disfigurement. Dental.
fluorosis is a visible indicator in developing teeth of generalized fluoride
toxicity throughout the body, including damage to connective tissue, bone
tissue, immune functions, and enzyme functions. As such, any rise in the
prevalence of dental fluorosis is cause for concern.
I shall look forward to continuing this discussion when Dr. Burt's full
paper is published (in due course) in the Journal of Public Health Dentistry.
John R Lee MD
References
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FLUORIDE Vol. 28(4), November 1995, p 215
COMMENTARY ON AND RECOMMENDATIONS
FOR THE PROPER USES OF FLUORIDE
Fluorosis has been associated with the fluoride concentration of drinking
water, use of dietary fluoride supplements, early use of dentifrices, and
prolonged use of infant formula. The literature, however, does not show
associations between fluorosis and use of fluoride mouthrinses,
professionally applied fluorides, bottled waters, carbonated beverages, and
juices. It is unwise to issue laundry lists of items that may be implicated
as problem-causing when, in fact, they may not be. Although usually
classified without fluorosis, children in Dean's "questionable" category
would be classified with the condition if the TFI or TSIF were used.
Accordingly, Dean, in 1942, really reported only 52.8 percent of children
without fluorosis in Kewanee, a community with 0.9 ppm fluoride in drinking
water. Because the morbidity and sequelae of dental caries have declined,
undue emphasis has been placed recently on the risks of using fluoride
rather than on its profound beneficial effects. Although of paramount
importance, conclusions cannot be drawn on whether fluoride protects
against, contributes to, or has no effect on bone fractures or is valuable
in treating osteoporosis. Careful thought is required before making
recommendations that may reduce health benefits because of unfounded
concerns about perceived risks. There should be greater regulation of
extraneous fluoride sources, rather than reliance on educational efforts or
recommendations to eliminate use of highly effective preventive regimens.
Key words: Benefits; Fluorosis; Pediatric toothpastes; Regulations; Supplements.
Reprints: HS Horowitz, 6307 Herkos Court, Bethesda, MD 20817 USA.
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FLUORIDE Vol. 28(4), November 1995, pp 215-216
SOURCES OF FLUORIDE INTAKE IN CHILDREN
Wide variations in fluoride intake among children make estimating fluoride
intake difficult. This paper discusses the various sources of fluoride
intake among children, beginning with a review of the fluoride
concentrations of water and other beverages, foods, and therapeutic fluoride
products. A review of previous studies' estimates of fluoride intake from
diet, dentifrice, fluoride supplements. fluoride mouthrinses, and gels, as
well as total fluoride intake also is presented. Then, estimates of fluoride
intake among young children of different age groups are summarized and
examples demonstrating the high level of variability of fluoride intake,
both from individual sources and in total, are presented. Lastly, this paper
discusses the implications of our current level of knowledge of children's
fluoride intake, and presents recommendations for the use of fluoride for
children in light of this current knowledge. The major recommendations are
that: (1) the fluoride content of foods and beverages, particularly infant
formulas and water used in their reconstitution, should continue to be
monitored closely in an effort to limit excessive fluoride intake; (2)
ingestion of fluoride from dentifrice by young children should be
controlled, and the use of only small quantities of dentifrice by young
children should be emphasized; and (3) dietary fluoride supplements should
be considered a targeted preventive regimen only for those children at
higher risk for dental caries and with low levels of ingested fluoride from
other sources.
Key words: Dentifrice; Diet; Exposure: Fluoride supplements; Ingestion: Intake.
Reprints: S M Levy, Department of Preventive and Community Dentistry, College of
Dentistry, University of Iowa, Iowa City IA 52242, USA.
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FLUORIDE Vol 28(4), November 1995, p. 216
THE CARIOSTATIC MECHANISMS OF ACTION
OF FLUORIDES. A REVIEW
In the past the inhibition of caries by fluorides was ascribed to the
reduced solubility of enamel due to the incorporation of F- into the enamel
mineral. During the last years the understanding of the cariostatic
mechanism has changed fundamentally. Based on these new findings the loosely
bound fluorides, which are present in the surroundings of the teeth after
application of topicals, are regarded as decisive for the caries preventing
effect by causing an inhibition of demineralization, enhancing the
remineralization process and supporting the precipitation of CaF2. The
formation of CaF2 is induced after application of topicals, and the material
stays relatively stable in the mouth, due to adsorbed
HPO[subscript]4[superscript]2- ions at the surface of CaF2. During the
cariogenic challenge, CaF2 releases F- ions due to the reduced concentration
of HPO[subscript]4[superscript]2- ions at acidic pH values. The CaF2
therefore functions as a pH- controlled F- -reservoir and is the most
important supplier of free F- ions during the cariogenic challenge.
Key words: Calcium fluoride; Cariostatic mechanisms; Dental caries;
Remineralization.
Reprints: C Fischer, Klinik fur Zahnerhaltung, Universitat Bern Berlin, Germany.
[NOTE: F- was F superscript- in the original and it means fluoride ion]
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FLUORIDE Vol 28(4), November 1995, p. 216
CHARACTERIZATION OF FLUOROSED HUMAN ENAMEL
BY COLOR REFLECTANCE, ULTRASTRUCTURE,
AND ELEMENTAL COMPOSITION
Mature fluorosed human enamel has been described as a subsurface: enamel
hypomineralization, with porosity increasing relative to the degree of
fluorosis. The purpose of the current study was to quantitatively measure
the color of the fluorosed enamel by light reflectance, and to further
characterize the enamel by scanning electron microscopy. Teeth with varying
degrees of fluorosis were obtained and divided in groups of mild, moderate
and severe fluorosis using Dean's Index for fluorosis. The color of the
labial enamel surface was measured using a Minolta Chroma Meter CR241
(Minolta, Ramsey, N.J., USA). The teeth were further characterized for
elemental composition using an energy-dispersive spectrometer, and imaged in
both secondary and backscattered electron modes.
The results of this study showed that the moderately and severely fluorosed
enamel contained an uneven distribution of areas which were more
electron-absorbent with a relative\ increased carbon content. The changes in
the physical characteristics of the teeth could be quantitated by
measurements of light reflectance. The color of the teeth was significantly
different between groups, with all groups significantly different than normal.
Key words: Colorimeter; Dental fluorosis; Enamel morphology; Scanning
electron microscopy.
Reprints: PK Denbesten, Eastman Dental Center, 625 Elmwood Ave, Rochester NY
14620, USA.
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FLUORIDE Vol. 29(1), February 1996, p 54
INFANTS' FLUORIDE INTAKE FROM DRINKING WATER
ALONE, AND FROM WATER ADDED TO FORMULA,
BEVERAGES, AND FOOD
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.
Fluoridelevels 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 i 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.
Key words: Dental fluorosis; Fluoride ingestion; Fluoride intake; Water
fluoride.
Reprints: S M Levy, University of Iowa, College of Dentistry, Department
Preventive
and Community Dentistry, DSB N330 Iowa City, IA 52242 USA.
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FLUORIDE Vol. 27(1), January 1994, pp 54-55
PERCEPTIONS OF DENTAL FLUOROSIS
Mild dental fluorosis has long been accepted as a side-effect of water
fluoridation and, more recently, has been recognized as a consequence of the
use of other fluoride-based caries-preventive strategies. Traditionally,
dental health professionals have not seen this as being of public health
importance, but members of the public have not been asked their opinion. The
purpose of the present study was to gather the opinions of lay groups
concerning the appearance of the teeth of children with various degrees of
fluorosis. Twenty eight children, born in 1978, who had earlier participated
in a study of fluorosis in Perth (Western Australia), allowed 10 observers
to look at their upper central incisors under good viewing conditions.
Fluorosis in these teeth ranged from TF score 0 (no fluorosis) to TF score
3. The observers were university students, parents, public servants, or
dentists. They responded to statement items about the appearance of the
teeth. The results, based on just over 3000 responses, showed that lay and
dental observers could distinguish between different fluorosis levels. In
response to a statement that the teeth appeared pleasing, a large majority
agreed when the TF score was 0, but agreement declined as the TF score
increased; when the TF score was 3, most people disagreed. Similarly,
observers felt that the appearance would increasingly embarrass the child as
the TF score increased. Observers, except the dentists, tended to feel that
higher TF scores indicated neglect on the part of the child. Most observer
groups felt that fluorosis would be no greater an esthetic problem for girls
than for boys, but for more severe fluorosis, the dentists saw the
appearance as being a greater problem for girls. The dentists responded that
most fluorosis did not require any treatment, but when the TF score was 3, a
majority of them felt that esthetic treatment would be warranted. The
results suggest that, for these observers, fluorosis score TF = 2 or greater
was easily noticed, and when the TF score was 3, fluorosis aroused concern
in most observers. Recent epidemiological studies reported TF scores of2 or
more in 11.3% of 12-year-olds and 17.5% of 7-year-olds in Perth. Strategies
to reduce the prevalence of fluorosis with TF score 2 and avoid fluorosis
with TF score 3 - including reduction of toothpaste ingestion, removal of
fluoride from infant formulae, and avoidance of inappropriate supplement
use-should be devised and implemented.
Key words: Dental fluorosis; Fluoridation; Fluoride supplements; Lay opinion.
Reprints: P J Riordan, Health Department of Western Australia, Dental Service,
P O Box 50, Como, WA 6152, Australia.
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FLUORIDE Vol. 27(1), January 1994, p. 55
ENAMEL DEFECTS IN 4-YEAR-OLD TO 5-YEAR-OLD CHILDREN IN
FLUORIDATED AND NON-FLUORIDATED PARTS OF CHESHIRE, UK
The aim of this study was to compare the prevalence of developmental
defects of enamel in the deciduous dentition of 4- to 5-year-old children
residing in fluoridated (1 ppm F) and non-fluoridated (less than 0.2 ppm Fl
communities in Cheshire, UK. The significant difference in the prevalence of
developmental defects of enamel between the two communities was accounted
for by the higher prevalence of diffuse opacities in fluoridated Nantwich
(29%), than in non-fluoridated Northwich (14%). The results also showed that
when controlling for the age at which parents claimed toothbrushing
commenced, the children in fluoridated Nantwich still had significantly more
diffuse defects than the children in Northwich.
Key words: Deciduous dentition; Dental fluorosis; Enamel defects; Fluoride.
Reprints: M A Lennon, University of Liverpool Department of Clinical Dental
Science,
P O Box 147, Liverpool L69 3BX, England.
[NOTE: "diffuse opacities" is dental fluorosis]
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FLUORIDE Vol. 27(4) October 1994 p. 236
DENTAL TISSUE EFFECTS OF FLUORIDE
It is now well-established that a linear relationship exists between
fluoride dose and enamel fluorosis in human populations. With increasing
severity, the subsurface enamel all along the tooth becomes increasingly
porous (hypomineralized), and the lesion extends toward the inner enamel. In
dentin, hypomineralization results in an enhancement of the incremental
lines. After eruption, the more severe forms are subject to extensive
mechanical breakdown of the surface. The continuum of fluoride-induced
changes can best be classified by the TF index, which reflects, on an
ordinal scale, the histopathological features and increases in enamel
fluoride concentrations. Human and animal studies have shown that it is
possible to develop dental fluorosis by exposure during enamel maturation
alone. It is less apparent whether an effect of fluoride on the stage of
enamel matrix secretion, alone, is able to produce changes in enamel similar
to those described as dental fluorosis in man. The clinical concept of
post-eruptive maturation of erupting sound human enamel, resulting in
fluoride uptake, most likely reflects subclinical caries. Incorporation of
fluoride into enamel is principally possible only as a result of concomitant
enamel dissolution (caries lesion development). At higher fluoride
concentrations, calcium-fluoride-like material may form, although the
formation, identification, and dissolution of this compound are far from
resolved.
It is concluded that dental fluorosis is a sensitive way of recording
past fluoride exposure because, so far, no other agent or condition in man
is known to create changes within the dentition similar to those induced by
fluoride. Since the predominant cariostatic effect of fluoride is not due to
its uptake by the enamel during tooth development, it is possible to obtain
extensive caries reductions without a concomitant risk of dental fluorosis.
Key words: Dental caries; Dental fluorosis; Dose-response relationship;
Enamel; Post-eruptive effects; Pre-eruptive effects; TF index.
Reprints: O Fejerskov, Royal Dental College, Faculty of Health Sciences,
University
of Aarhus, Vennelyst Boulevard, DK-8000 Aarhus C, Denmark.
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FLUORIDE Vol. 27(4) October 1994 pp 236-237
ERUPTION OF DECIDUOUS TEETH: INFLUENCE OF
UNDERNUTRITION AND ENVIRONMENTAL FLUORIDE
A house to house survey in six rural villages in South India was conducted
to asses the influence of undernutrition and environmental fluoride on
deciduous dental eruption. Three villages surveyed were from the endemic
fluorosis area where the estimated fluoride concentration was 5 +- 1.2 ppm.
Oral cavities of all the children in the age group 5-48 months were examined
and a tooth was marked erupted when it was visible emerging through the
gingiva. Undernutrition, as classified by Gomez classification, was widely
prevalent among preschool children in the surveyed area (n = 708; normal:
5.1%; grade-I 29.1%; grade-II. 53.1% and grade-III. 12.7%). Children in the
severe grade of malnutrition possessed fewer teeth at a given age. Analysis
of variance revealed that fluoride has significant (P < 0.005) detrimental
effects on dental eruption among children in the 18-30 month age group. The
efficacy of Bailey's formula (age in months =number of teeth erupted + 6) in
indicating the chronological age was evaluated in the 5-24 month aged
children (n=347). Bailey's formula failed to assess the age correctly in 87%
with underassessment in 58% and overassessment in 29%. Its efficacy did not
differ between the endemic and nonendemic areas. We conclude that i)
undernutrition is a prevalent problem in rural areas in South India, ii) age
calculation by Bailey's formula did not indicate the chronological age in
the majority of children and hence is not useful in undernourished
populations, and iii) undernutrition compounded by high water fluoride may
delay the eruption of teeth.
Key words: deciduous dentition; dental health surveys; fluoride; India;
nutritional
status; nutrition surveys; preschool child; tooth eruption.
Reprints: Venkata R R Kodali, Consultant Diagnostician, Apollo Hospital,
Muthukur
Road, Nellore, Pin-524 004, Andhra Pradesh, India.
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FLUORIDE Vol. 28(2), May 1995
THE FLUORIDE CONTENT OF BOTTLED DRINKING WATERS
Sales of bottled drinking waters in the United Kingdom have tripled over
the last 5 years. The fluoride content of 12 bottled waters purchased from
two Leeds super-markets was determined by both the direct and acid diffusion
methods and found to vary from 0.10-0.80 mg/L fluoride (i.e. ppm fluoride).
This article shows that bottled drinking waters contain differing
concentrations of fluoride. There is no apparent difference between the
direct and acid diffusion methods for the determination of fluoride
concentrations of drinking waters. The manufacturers' labelling of fluoride
concentrations are mainly inaccurate. Dentists should be aware of the
fluoride concentrations of the drinking water of their child patients, be
they municipal or bottled drinking water, when prescribing fluoride
supplements. Also, some parents are using bottled waters to prepare baby
milk formulations which themselves may contain high levels of fluoride and
subject their children to the risk of dental fluorosis.
Key words: Bottled water; Fluorides analysis; Great Britain.
Reprints: K J Toumba, Department of Paediatric Dentistry,
Leeds Dental Institute, Leeds LS2 9LU England.
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FLUORIDE Vol. 28(2), May 1995, p 116
DENTAL CARIES AND FLUOROSIS IN 7-9 AND 11-14 YEAR OLD
CHILDREN WHO RECEIVED FLUORIDE SUPPLEMENTS FROM BIRTH
One hundred and sixty children who had lived from birth in a region with
low fluoride levels in the drinking water, and who had been offered sodium
fluoride supplementation in the form of drops for daily use, were examined
to evaluate dental caries and dental fluorosis. Two age ranges were
selected: 7-9 years and 11-14 years. In addition to the dental examinations,
questionnaires were mailed to the parents, followed-up by telephone
interviews, to gather information on compliance with the fluoride
supplementation program. The results showed no statistically significant
differences in dental caries activity between the regular and irregular
users of fluoride supplementation. Considerable dental fluorosis was found
in both regular and irregular user groups of the fluoride supplement (38 to
63 per cent of the children seen), however, with no statistical difference
between the user groups. Most of the fluorosis detected was of a mild
degree. Fluoride supplementation under the daily control of a parent or
child is not recommended because of the difficulty maintaining regular
compliance and the risk of fluorosis.
Key words: Canada; Dental caries; Dental fluorosis; Fluoride supplements.
Reprints: M A Awad, University of Alberta, Canada.
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FLUORIDE Vol. 28(2), May 1995, p 117
REVIEW OF FLUORIDE EXPOSURES AND INGESTION
Key words: Fluoridation; Fluoride intake/ingestion; Fluorosis.
Reprints: S M Levy, Department of Preventive and Community
Dentistry, College of Dentistry, University of Iowa, Iowa City, USA.
FLUORIDE Vol. 28(2), May 1995, p 117-118
FLUORIDE SUPPLEMENTS: CURRENT EFFECTIVENESS,
SIDE EFFECTS, AND RECOMMENDATIONS
A critical review of the literature was conducted to determine the
current effectiveness of fluoride supplements in caries prevention and their
role as risk factors for dental fluorosis. Use of fluoride supplements by
young children is idiosyncratic and all of the studies which investigated
the effectiveness of this regimen suffered from a significant drop in the
number of participants receiving daily supplements. The scientific evidence
supports the efficacy of fluoride supplements in caries prevention but there
is weaker support for their effectiveness. Fluoride supplements are a risk
factor for dental fluorosis, though their contribution to the increase in
fluorosis prevalence is less than that of water fluoridation and fluoridated
dentifrices because of their more limited and shorter use. There is also
evidence that fluoride supplements are used inappropriately in fluoridated
areas. The availability of optimal levels of fluorides in beverages in
non-fluoridated communities raises the question of whether fluoride
supplements are needed in the 1990s, and whether it is time to consider the
total fluoride intake not only from water but also from foods, beverages,
and dentifrices, when recommending supplements. A re-evaluation of the need
for and dosage schedules of fluoride supplements is warranted.
Key words: Canada; Dental fluorosis; Fluoride supplements.
Reprints: A I Ismail, Faculty of Dentistry, Dalhousie University, Halifax,
NS, Canada.
[Editor: Fluoride 23 (3) 1990 page 106 listed 7 studies which reported
dental fluorosis prevalences in 12 fluoridated communities. The average
prevalence was 29%. One of the studies, co-authored by Dr Burt, reported
dental fluorosis prevalences in 3 Michigan fluoridated communities of 32%,
49% and 51% (Journal of Dental Research 67 802-806 1988).]
HS Horowitz Bethesda, Maryland, USA
Abstract from Journal of Public Health Dentistry 55 (1) 57-62 1995
S M Levy, M C Kiritsy and J J Warren Iowa City, Iowa, USA
Abstract from Journal of Public Health Dentistry 55 (1) 39-52 1995
C Fischer, A Lussi and P Hotz Berlin, Germany
Abstract from Schweizer Monatsschrift fur Zahnmedizin 105 (3) 31 1-317 1995
N J Giambro, K Prostak and P K Denbesten Rochester, New York, USA
Abstract from Caries Research 29 (4) 251-257 1995
S M Levy, F J Kohout, N Guhachowdhury, M C Kiritsy,
J RHeilman and J S Wefel Iowa City, Iowa, USA
Abstract from Journal of Dental Research 74 (7) 1399-1407 1995
PJ Riordan, Como WA, Australia
Abstract from Journal of Dental Research 72 (9) 1268-1274 1993
K J Weeks, K M Milsom and M A Lennon Liverpool, England
Abstract from Caries Research 27 4 317-320 1993
O Fejerskov, M J Larsen, A Richards and V Baelum
Aarhus, Denmark
Abstract from Advances in Dental Research 8(l) 15-31 1994
Venkata Ranga Rao Kodali, K A V R Krishnamachari and J Gowrinathsastry
Osmania, Hyderabad, India
Abstract from Ecology of Food and Nutrition 30 (2) 89-97 195)3
K J Toumba, S Levy and M E Curzon Leeds, England
Abstract from British Dental Journal 176 (7) 266-268 1994
M A Awad, J A Hargreaves and G W Thompson Alberta, Canada
Abstract from Journal of the Canadian Dental Association 60 (4) 318-322 1994
SM Levy Iowa City, Iowa, USA.
Abstract from Community Dentistry and Oral Epidemiology 22 (3) 173-180 1994
The literature on fluoride intake/ingestion was reviewed critically to
determine the current exposure to fluorides for children living in
non-fluoridated and fluoridated areas in North America. Fluoride from all
sources except mouthrinses and professionally applied topical fluorides was
considered, including ingestion from foods and beverages, as well as intake
from the use of fluoride dentifrice and dietary fluoride supplements. Data
from all of these sources were used to produce estimates of mean daily
ingestion. Studies consistently have identified substantial variation in
ingestion among individuals. These analyses demonstrated that a substantial
pro portion of individuals had exposure or ingestion well beyond that of the
mean for each source, and often 10-20% received up to several times as much
exposure as the mean. Some children probably ingest sufficient fluoride from
a single source to exceed the "optimal" fluoride intake recommended from all
sources, and are therefore at increased risk of fluorosis. This review
highlighted the substantial variation and complexity of fluoride ingestion.
Appropriate consideration of these aspects is warranted in efforts to ensure
a margin of safety favoring dental caries prevention while limiting
objectionable fluorosis.
A I Ismail, Halifax, Nova Scotia, Canada
Abstract from (Community Dentistry and Oral Epidemiology 22 (3) 164-172 1994