Google Fluoride Alerts
Scientific studies show fluoridation's claimed benefits are in dispute
Tooth decay has declined world-wide regardless of fluoridation status
Many of the abstracts below are from staunch fluoride proponents in the dental community. While the list below is not exhaustive, several clear messages emerge:
See flteeth.htm for more data on above statements. Information on Canadian tooth decay rates are in caries3.htm. The links have been provided below as well.
Angelillo IF, Torre I, Nobile CGA, Villari P, Caries and fluorosis prevalence in communities with different concentrations of fluoride in the water, Caries Research 33(2):114-122, 1999
The need to defluoridate and fluoridate the water supplies in areas with drinking water naturally containing above-optimal (greater than or equal to 2.5 mg/l) and suboptimal (less than or equal to 0.3 mg/l) fluoride concentration and caries and fluorosis prevalence of 12-year-old schoolchildren were assessed in Italy. In the low-fluoride area, 48.4% children were caries-free (DMFT = 0) and the DMFT and DMFS were 1.5 and 2.6; in the high-fluoride area, 46.8% had a DMFT = 0 and the values of the indices were 1.4 and 1.6, respectively. Multiple logistic regression analysis showed a significant association in the caries-free status according to parents' employment status (OR = 1.2, 95% CI = 1.1-1.3) and children's sweets consumption, since children who consumed sweets at least once a day had an adjusted odds ratio of 1.8 (95% CI =1.4-2.3) compared to those with a lower consumption. Multiple linear regression analysis showed that DMFT and DMFS were significantly higher in children with a lower socioeconomic status and in those who consumed sweets at least once a day, with the DMFS significantly associated also with the area of residence. DT and FT scores were higher in the high- and low-fluoride areas, respectively. No evidence of fluorosis was reported in 94.5 and 55.3% of children in the low- and high-fluoride areas, respectively. The Community Fluorosis Index (CFI) for all permanent teeth was significantly higher in the high-fluoride area, 0.8, than the value, 0.1, found in the low-fluoride community. Our results substantiate the difficulties in defining universal guidelines for the fluoridation or defluoridation of drinking water and the need for an epidemiological approach to the decision as to fluoridate and defluoridate the water supply. [References: 45]
Author's keywords: Dental caries, Fluorosis, Italy, Public health dentistry, Water fluoridation. Reprint available from: Angelillo IF Univ Catanzaro, Sch Med, Chair Hyg Via Tommaso Campanella I-88100 Catanzaro Italy
Cahen PM, Obry-Musset AM, Grange D, Frank RM, Caries prevalence in 6- to 15-year-old French children based on the 1987 and 1991 national surveys, J Dent Res, 1993 Dec, 72 (12), 1581-1587.
The caries prevalence in a multi-stage probability sample of 18,786 children representative of all French children 6-15 years of age was studied in 1991 and compared with the results of a similar survey made in 1987. A significant decline in dental caries in France became evident. This decline, observed in primary as well as in permanent teeth, was of variable magnitude among the different age groups. At the age of 6, 48.6% of the children were totally caries-free in 1991. At the age of 12, the DMFT and DMFS indices were 2.59 and 4.72, respectively, representing a corresponding decrease of 38% and 37%. In 1991, more caries-affected teeth or surfaces were filled, whereas fewer caries-affected teeth or surfaces were untreated. Females and children living in rural areas had a higher caries prevalence in both surveys. Pit-and-fissure lesions were the predominant caries types. Dental fluorosis was very uncommon; 96.1% of the 18,786 children examined in 1991 were totally free of any such lesions. Average plaque and calculus indices were similar in 1987 and in 1991, but a decrease of 25% was observed in the average gingival indices. Although the relative contributions of various preventive factors leading to this caries reduction are not clear, it should be noted that use of fluoridated salt (250 mg/kg KF) started in January, 1987. The sale of fluoridated dentifrices and the use of fluoride tablets and sugar substitutes increased during the period from 1987 to 1991.
Colquhoun J, Influence of social class and fluoridation on child dental health, 1985 Feb, Comm Den Oral Epidem, 13(1), 37-41.
In this study in oral epidemiology, officially collected statistics are presented which show that, 15 yr after fluoridation commenced in Auckland, New Zealand, there was still a significant correlation between dental health of children and their social class. They also show that treatment levels have continued to decline in both fluoridated and unfluoridated areas, and are related to social class factors rather than to the presence or absence of water fluoridation. In the unfluoridated areas all the children, and in the fluoridated areas only selected children, had received regular topical fluoride treatments. In both areas the use of fluoride tooth-pastes and oral hygiene had been encouraged. When the socioeconomic variable is allowed for, child dental health appears to be better in the unfluoridated areas.
Colquhoun J, Child Dental Health Differences in New Zealand, Community Health Studies, 1987, XI:2, 85-90
The School Dental Service provides regular dental care to 98 per cent of 5-13-year-old school children and 68 percent of pre-school children in New Zealand. Officially collected statistics are presented for the six main population areas showing:1) the dental status of all 12- and 13-year-old patients completing their final year of treatment, and
2) the permanent tooth filling rates of all patients with permanent teeth (aged 6-13 years).
These suggest that child dental decay differences are not closely related to the presence or absence of water fluoridation. Official census information on the above and other communities suggests that dental health differences could be related to demographic, especially socio- economic, factors.
Colquhoun J, Mann R, The Hastings Fluoridation Experiment: Science or Swindle?, The Ecologist, 1986, 16:6, 243-248, 1987, 17:2, 125-126, Updated and presented to the 56th Congress, Australian and New Zealnd Association for the Advancement of Science at Massey University, Palmerston North, New Zealand, 1987 Jan, Postscript 1987 Nov.
Abstract: A dentist and an environmental scientist examine the Hastings fluoridation experiment. The official Information Act has made available for public perusal archives of government departments. These and other sources reveal information not in agreement with the published version of the trial. The claimed reductions in dental decay were brought about partly if not mainly by a change in diagnostic procedure following the introduction of fluoridation. A reduction in decay occurred in non-fluoridated places during the trial.
Conclusion: From the above considerations it seems clear that the Hastings fluoridation study did not, as it was purported to do, demonstrate the effectiveness of water fluoridation in reducing dental decay in a typical New Zealand population. The reported reductions were at least partly, if not wholly, the result of factors other than fluoridation. Today proponents of fluoridation will concede that there were other factors operating to cause the reductions, over and above any fluoridation effect. But that fact, although known to those responsible for the study, was never reported in official and scientific published reports on it. The study was, it seems, more a public relations exercise than a scientific one. Nonetheless, it is still cited in scientific literature and textbooks as being the latter. Deserving of consideration is the extent to which the same situation might apply to the man "no control" fluoridation studies in other countries. The authors suggest further re-examinations like those of Diesendorf.
de Liefde B, The decline of caries in New Zealand over the past 40 years, NZ Dental Journal, 1998 Sept 94 (417):109-13
In New Zealand, as elsewhere, caries prevalence has declined since the 1950s; this has been accompanied by a change in the intra-oral pattern of the disease. This is illustrated by analysis of data for 12-year-old children. However, because treatment services for children in New Zealand are so comprehensive, the DMF index is primarily a count of restorations placed. This treatment overlay can distort the true caries prevalence and has been a confounding factor in assessment of the change in caries over time. Measurement of the fine gradations of ongoing change in the present low-caries-prevalence population requires the use of a more sensitive indicator than the DMF indices. When the timing of various forms of fluoride supplementation is correlated with the decline in caries, the decline continues beyond the time of maximum population coverage with fluoridated water and fluoridated toothpaste. Thus an explanation of the convergance of caries prevalence in fluoridated and non-fluoridated areas since the 1970s may require a re-assessment of the fluoride effect.
This convergence, and the overall decline during the last decade without known additional fluoride supplementation, suggest that factors other than fluoride, such as food additives and antibiotics, may have contributed.
Diesendorf M, Colquhoun J, Spittle BJ, Everingham DN, Clutterbuck FW, New evidence on fluoridation, Aust NZ J Public Health, 1997 Apr, 21(2),187-190.
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.
Diesendorf M, Anglesey Fluoridation Trials Re-examined, Fluoride, 1989 Apr, 22:2, 53-58
Although recognized by several national authorities as a potential environmental and health hazard, water fluoridation is usually justified on the grounds of its reputedly enormous dental benefits. Recent evidence suggests that the benefits from fluoridation in reducing dental caries may have been overestimated; consequently, there is need for scientific evaluation of the experimental design of previous fluoridation trials.
The often-cited Anglesey fluoridation surveys are re-examined as a case study. In the 1974 and 1983 surveys, the non-random choice of a "control," 19 years after fluoridation, negated the benefit of blind examinations. Instead of a longitudinal controlled trial, there remain two cross-sectional surveys for which the test population was mainly rural while the "control" population was entirely urban. Two different categories of secular reduction in caries, which cannot be attributed to fluoridation, occurred between 1974 and 1983. So, It is doubtful that these Anglesey studies, or the earlier 1955-1967 study, provide evidence of large benefits from fluoridation.
Disney JA, Bohannan HM, Klein SP, Bell RM, A case study in contesting the conventional wisdom: school-based fluoride mouthrinse programs in the USA, Comm Den Oral Epidemiology, 1990, 18, 46-56
Abstract: This paper presents the events surrounding the dissemination of the results of a major preventive dentistry demonstration program designed and conducted to provide evidence of the effectiveness and actual costs of a combination of commonly used preventive procedures. It then reviews the controversy provoked when the results of that program were counter to the conventional wisdom of the day, prevailing national policy, and public health practice. An analysis of possible reasons for this reaction follows. The paper concluded with some observations about how such a situation might be approached to minimize similar controversy in the future.
Excerpts: None of the program's classroom procedures consistently prevented a practically significant amount of decay. Even to this day, many dental public health administrators continue to support school based mouthrinse programs in the face of convincing evidence of reduced need and marginal effectiveness of this procedure. Future public preventive programs must then be targeted on those children identified as being most susceptible to dental caries rather than being provided indiscriminately to all children without regard to individual risk.
Foch CB, The Costs, Effects, And Benefits of Preventive Dental Care: A Literature Review, 1981 Dec, N-1732-RWJF, A Rand Corporation Report for the Robert Wood Jonson Foundation.
Gray AS, Fluoridation: time for a new baseline? J Canadian Dental Association, 1987, 53:10 763-765.
Haikel Y, Cahen PM, Turlot JC, Frank RM, Dental caries and fluorosis in children from high and low fluoride areas of Morocco, Assoc J Dent Child, 1989 Sept-Oct, 56:5, 378-381
The purpose of this study was to estimate the prevalence and the severity of dental caries and dental fluorosis in primary and permanent teeth of 582 subjects, aged 7 to 16 years, from the fluorosis areas of Khouriba and the non-fluorosis area of Beni Mellal, Morocco. At age-group 7- 10, where 67.8 percent of primary teeth were present, about 35 percent of the children were affected in the high-fluoride area and the community fluorosis index was 0.86. The percentage and average number of erupted permanent teeth were higher in Beni Mellal than in Khouriba for 11-12 and 13-14-year-old age-groups. Significant differences in caries prevalence were observed between the high and low-fluoride areas. In both regions, high and low prevalence of dental caries was observed in the primary and permanent teeth, respectively. [emphasis added]
editor's note: delayed tooth eruption with higher fluoride intake means less cavities are recorded because teeth have not been exposed to cariogenic challenge for as long. Is this the "benefit" fluoridation proponents saw in the early "trials"? Drs R. Feltman and G. Kosel (1961), after a fourteen-year study of fluoride supplements and children, reported that there was: "...a delay in the eruption of the teeth in some cases by as much as a year from the accepted eruption dates." (footnote 1) Related articles are:
Hildebolt CF, Elvin-Lewis M, Molnar S, McKee JK, Perkins MD, Young KL, Caries prevalences among geochemical regions of Missouri, Am J Phys Anthropol, 1989 Jan, 78(1), 79-92.
Our objectives were to determine how the prevalences of caries in elementary school children vary between geochemically defined regions of the state of Missouri and to compare this variation with that found for prehistoric Missouri inhabitants (Hildebolt et al.: Am. J. Phys. Anthropol. 75:1-14, 1988). Caries data on 6,584 school children were used in the study of second and sixth graders drinking optimally and suboptimally fluoridated water. Geochemical regions were based on maps recently published by the United States Geological Survey. Differences in mean caries scores and proportions of children with caries were tested by analysis of covariance, analysis of variance, Student, and chi-squared tests. We found that caries prevalences do vary between the geochemical regions of the state. In the total sample, however, there were no significant differences between those children drinking optimally fluoridated water and those drinking suboptimally fluoridated water. We conclude that there is variation in caries rates among geochemically defined regions of the state and that geochemical factors associated with young parent materials may be antagonizing the action of fluoride. [emphasis added]
editor's note: Perhaps if the mind-set were taken off this absurd notion that communities have "suboptimally fluoridated water", researchers might see that it is exactly the varying geochemical factors in the environment (eg., calcium and other nutrients in water and soil) which are likely to be responsible for some of the differences in tooth decay rates between communities, not fluoridation. For more information about how calcium and fluoride interact, see "Dental caries: a disorder of high fluoride and low dietary calcium interactions" in isfr.htm and a related study in adverse.htm
Ismail AI, Shoveller J, Langille D, MacInnis WA, McNally M, Should the drinking water of Truro, Nova Scotia, be fluoridated? Water fluoridation in the 1990s, Community Dental Oral Epidemiology, 1993, 21:118-125
Johnston DW, et al., The Decline of Dental Caries in Ontario School Children, J Can Dent Assn, 1986, 5, 411-417
Kalsbeek H, Verrips, GHW, Dental Caries Prevalence and the Use of Fluorides in Different European Countries, J Dental Research, 1990 Feb, 69(Spec Issue), 728-732
Data in a WHO report relating caries prevalence and the use of fluorides in different European countries were compared with data obtained directly from investigators in the field of oral epidemiology. The reliability of DMFT indices of 12-year-old children, mentioned in the WHO report, appeared sufficient to make comparisons between countries on the basis of these data. The WHO data files on the different applications of fluoride were incomplete. When figures were present, they were not always in agreement with those from the investigators. A decrease of the DMFT indices could be shown in a large number of countries. In further comparative studies between European countries, cultural differences (in dietary habits, for instance) should be taken into account.
Kalsbeek H, Kwant GW, Groeneveld A, Backer Dirks O, van-Eck AA, Theuns HM, Caries Experience of 15-Year-Old Children in The Netherlands after Discontinuation of Water Fluoridation, Caries Research, 1993, 27::201-205
In 1973 the fluoridation of drinking water in the Dutch town of Tiel was discontinued. In order to monitor the effect of this measure, the caries experience in 15-year-old children was investigated annually from 1979 to 1988, both in Tiel and in Culemborg. In the latter town the drinking water had never been fluoridated. The caries data of 15-year-old children examined between 1968 and 1969 in Tiel (children having used fluoridated water from birth) and Culemborg were used as historical controls. In Tiel the mean number of DMFS increased between 1968/69 and 1979/80 from 10.8 to 12.7 (+18%) and decreased to 9. 6 (-26%) in the following years; in 1987/85 the mean DMFS was 11% lower than in 1968/69. In Culemborg the mean DMFS score decreased between 1968/69 and 1987/88 from 27.7 to 7.7 (-72%). In 1968/69 the mean DMFS score in Tiel was 61% lower and in 1987/88 17% higher than in Culemborg. The question as to whether water fluoridation would have had an additional effect if it had been continued (presuming the application of existing preventive measures) cannot be answered, as there are no remaining communities with fluoridated water in The Netherlands.
Koch G, Petersson LG, Kling E, Kling L, Effect of 250 and 1000 ppm fluoride dentifrice on caries, Swedish Dent J, 1982, 6, 233-238
In a 3-year clinical trial, the caries prophylactic effect of two dentifrices containing 1000 ppm F and one containing 250 ppm F was compared. 541 twelve and thirteen-year-old children took part in the study. The children were randomly divided into three groups. Each group of children and their families used one of the dentifrices daily at home. The children were examined for caries at the start of the study and again after an interval of one year. The caries increment was equal in the three groups during the experimental period. This indicates that a 250 ppm F dentifrice has the same caries preventive effect as a 1000 ppm F dentifrice.
editor's note: See below and the related article Winter GB, et al., Clinical trial of a low-fluoride toothpaste for young children.
Konig KG, New recommendations concerning the fluoride content of toddler toothpaste - consequences for systemic application of fluoride [Article in German], Gesundheitswesen. 2002 Jan;64(1):33-8. Institut fur Praventive und Konservierende ZahnmedizinFakultat der Medizinischen Wissenschaften, Universitat Nijmegen, Niederlande, The Netherlands.
A group of experts from 4 European countries who gathered at a convention at Basel in November 1998, arrived at the recommendation to increase the fluoride (= F) content of toddler toothpastes from 250 ppm to 500 ppm. It was recommended to make parents brush the children's teeth with a pea-size piece of this toothpaste once a day, starting when the first deciduous teeth were erupting. Routine application of F-tablets would no longer be routinely prescribed, but restricted to individual indications in special high caries risk cases. This recommendation did not consider previous ones and was based exclusively on new scientific, mainly epidemiological evidence. In April 2000 the recommendation was officially issued by the German scientific dental association DGZMK.A careful case-control study resulted in the analysis of the risk to develop mottling of enamel under the influence of fluoridated water (1 ppm F) and fluoride toothpaste (1000 ppm F) when used in early childhood. It was found that excessive use of the fluoride toothpaste doubled the fluorosis risk, whereas when fluoride supplements (tablets, drops) were given the risk was about 20 times higher than without a fluoride supplement. Experiments in Germany and the Netherlands had shown that remineralisation of enamel under influence of 500 ppm F is achieved much more quickly than under application of 250 ppm F. A panel of WHO experts came to the conclusion that there was no evidence for the effectiveness of toothpastes containing less than 500 ppm. Statistics from the Netherlands have shown that the amount of fluoride tablets sold there is barely sufficient for the use by a quarter of all children 0 to 4 years old. In contrast to this low level of acceptance of fluoride tablets, fluoride toothpastes is widely accepted. It is their extensive use which explains the marked improvement of dentitions among the youth in this country during the last 20 years; the influence of topical fluoride gels, varnishes and other preventive measures was much less, and a reduction of sugar consumption (by the way less than 10 % of what it was in 1970) seems to have been the least important factor.The new recommendations based on topical rather than systemic fluoride application are better for preventive, toxicological, psychological and didactic reasons and should be implemented as soon as possible.
Kortelainen-S, Larmas-M, Effect of fluoride on caries progression and dentin apposition in rats fed on a cariogenic or non-cariogenic diet. Scandinavian J. Den Research, 1993 101(1): 16-20.
The effect of fluoride in drinking water on the progression of dentinal caries and dentin apposition was studied in Wistar rats. The initiation of enamel caries lesions was first induced for 2 wk with S. sobrinus and a 43% sucrose diet after weaning. Thereafter the animals were fed on either a cariogenic or a non-cariogenic diet and distilled water supplemented with 0, 1, 7 or 19 ppm fluoride. The areas of dentinal caries and dentin apposition were quantified after tetracycline staining. Fluoride reduced dentinal caries progression after the initiation of lesions in the presence of a cariogenic diet at a concentration of 19 ppm F, and without sucrose at 1 ppm F. The effect of fluoride in reducing dentin apposition with a cariogenic diet was dose-dependent, whereas fluoride in non-cariogenic groups had practically no effect on dentin formation. These results suggest that fluoride together with a high concentration of sucrose in the diet might have an odontoblast-mediated effect on the regulation of the progression of dentinal caries.
Krook L, Maylin GA, Lillie JH, Wallace RS, Dental fluorosis in cattle, Cornell-Vet, 1983 Oct., 73:4, 340-362
Five expressions of dental fluorosis are described in cattle exposed to industrial fluoride pollution: 1. Hypercementosis with tooth ankylosis, cementum necrosis and cyst formation; 2. Delayed eruption of permanent incisor teeth; 3 Necrosis of alveolar bone with recession of bone and gingiva; 4. Oblique eruption of permanent teeth, hypoplasia of teeth with diastemata; and 5. Rapid progression of dental lesions. The five entities are not recognized in the "standard for the classification of dental fluorosis" by the National Academy of Sciences. Since this classification is too limited and superficial, adherence to this standard has left severe cases of fluoride intoxication in cattle undetected in field surveys [emphasis added].
editor's note: delayed tooth eruption with higher fluoride intake means less cavities are recorded because teeth have not been exposed to cariogenic challenge for as long. Is this the "benefit" fluoridation proponents saw in the early "trials"? See related articles and sutton.htm:
Künzel W, Fischer T., Rise and fall of caries prevalence in German towns with different F concentrations in drinking water, Caries Research 1997, 31:3, 166-173
The rise and fall of caries prevalence (DMFT) and its relation to changing F concentration of drinking water and other health-related factors is analysed based on dental findings of more than 286,000 subjects of either sex (6-15 years old) from the two industrial towns Chemnitz and Plauen. Water fluoridation (1.0 ± 0.1 ppm F) was implemented in Chemnitz (formerly Karl-Marx-Stadt) in 1959. It was in operation until autumn 1990 with an interruption lasting 22 months around the year 1971. In the F-poor town of comparison, Plauen, 55% of the citizens were supplied with F-enriched drinking water (0.9 ppm F) during the years 1972-1984. Another 20% received F-containing mixed water (0.4-0.7 ppm F). During the first three decades of the study the level of caries prevalence was strictly correlated with the availability of an optimal caries preventive F concentration in the drinking water. Water fluoridation was followed by a decrease of caries, and interruptions in fluoridation were followed by increasing caries levels. A different caries trend was observed in the years from 1987 to 1995. There was a significant caries decrease down to the lowest DMFT (2.0) since 1959 in spite of the fact that only F-poor water was available over years in both towns. This improvement of oral health is explained by changes in caries-preventive and environmental conditions.
Künzel W. Fischer T. Caries prevalence after cessation of water fluoridation in La Salud, Cuba, Caries Res 2000;34:20-25.
In the past, caries has usually increased after cessation of water fluoridation. More recently an opposite trend could be observed: DMFT remaining stable or even decreasing further. The aim of the present study conducted in La Salud (Province of Habana) in March 1997 was to analyse the current caries trend under the special climatic and nutritional conditions of the subtropical sugar island Cuba, following the cessation, in 1990, of water fluoridation (0.8 ppm F). Diagnostic evaluations were carried out using the same methods as in 1973 and 1982. Boys and girls aged 6-13 years (N = 414), lifelong residents in La Salud, were examined. Between 1973 and 1982 the mean DMFT had decreased by 71.4%, the mean DMFS by 73.3% and the percentage of caries-free children had increased from 26.3 to 61.6%. In 1997, following the cessation of drinking water fluoridation, in contrast to an expected rise in caries prevalence, DMFT and DMFS values remained at a low level for the 6- to 9-year-olds and appeared to decrease for the 10/11-year-olds (from 1.1 to 0.8) and DMFS (from 1.5 to 1.2). In the 12/13-year-olds, there was a significant decrease (DMFT from 2.1 to 1.1; DMFS from 3.1 to 1.5), while the percentage of caries-free children of this age group had increased from 4.8 (1973) and 33.3 (1982) up to 55.2%. A possible explanation for this unexpected finding and for the good oral health status of the children in La Salud is the effect of the school mouthrinsing programme, which has involved fortnightly mouthrinses with 0.2% NaF solutions (i.e. 15 times/year) since 1990.
Leverett DH, Adair SM, Vaughan BW, Proskin HM, Moss ME, Randomized clinical trial of the effect of prenatal fluoride supplements in preventing dental caries. Caries Res, 1997;31(3):174-179.
This randomized, double-blind study tested the caries-preventive efficacy of prenatal fluoride supplementation in 798 children followed until age 5. Initially, 1,400 women in the first trimester of pregnancy residing in communities served by fluoride-deficient drinking water were randomly assigned to one of two groups. During the last 6 months of pregnancy the treatment group received 1 mg fluoride daily in the form of a tablet and the control group received a placebo. Both treatment and control subjects were encouraged to use postnatal dietary fluoride supplements. Caries was measured in children at age 3 and 5 while fluorosis was assessed at age 5. Caries activity was very low in both study groups: 92% of children remained caries-free in the treatment group and 91% remained caries-free in the placebo group. Fluorosis was observed in 26 subjects, all classified as very mild. Overall, there were no statistically significant differences in the study groups with respect to caries and fluorosis in deciduous teeth. The study had sufficient power to detect an absolute risk reduction of 5.1% while only a 1.5% reduction was observed. These findings do not support the hypothesis that prenatal fluoride has a strong caries-preventive effect.
Levy SM, Review of fluoride exposures and ingestion, Community Dental Oral Epidemiology, 1994, 27, 173-80
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 proportion 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.
Manji F, Fejerskov O, Dental Caries in Developing Countries in Relation to the Appropriate Use of Fluoride, Journal Dental Research, 1990 February, 69(Special Issue):733-741.
Although it is widely believed that caries prevalence in developing countries is increasing rapidly, a review of studies from Africa and China provides equivocal evidence. Data from child and adult populations indicate that the disease is almost ubiquitous but with a slow rate of progression. Theoretically, administration of fluoride in such populations should result in reducing caries progression rates but too little is known about the magnitude of the effect, and therefore about the cost-effectiveness of different methods of fluoride administration. The lack of a developed infrastructure and of trained personnel in many developing countries limits the applicability of many strategies. Methods of fluoride administration that mimic systemic exposure are to be recommended where affordable or practical. In the light of economic constraints and slow caries lesion progression rates, however, improvements in oral hygiene practices may be the most important method of controlling the disease whether or not fluoride is available or accessible.
Marthaler TM, O'Mullane DM, Vrbic V, The Prevalence of Dental Caries in Europe 1990-1995, Caries Research, 1996, 30:4, 237-255
Caries prevalence data from recent studies in all European countries showed a general trend towards a further decline for children and adolescents. However, in several countries with already low caries prevalence in primary teeth, there was no further decrease. Regarding the permanent dentition, further reductions were observed in the 12-year age group, these being even more evident at the ages of 15-19 years. In some Central and Eastern European countries, caries prevalence in children and adolescents was still high. Few data were available on young adults, but the benefits of prevention are becoming manifest. The available data on the use of toothbrushes, fluorides and other pertinent items provided few clues as to the causes of the decline in caries prevalence.
Mathiesen AT, Øgaard B, Rølla G, Oral Hygiene as a Variable in Dental Caries Experience in 14-Year-Olds Exposed to Fluoride, Caries Research, 1996, 30:29-33.
The aim of the study was to examine the relationship between oral hygiene level and caries experience in 14-year-olds using fluoride dentifrices on a regular basis. Oral hygiene expressed as Gingival Bleeding Points (GBP) was recorded in 267 individuals in the county of Lillehammer in Norway Total caries experience as DMFS and approximal carious lesions in the outer half of the enamel (D1), in the inner half of the enamel (D2), in dentin (D3), and filled approximal surfaces were registered clinically and on standardized bite-wing radiographs. Using multiple regression analysis, oral hygiene level expressed as GBI was the only factor that could account for variation in caries experience (DMFS). Any significant effect of consumption of sweets on caries experience could not be demonstrated with the multivariate analysis. The average percentage of GBP (plus or minus SD) was 35.7+10.0%. The individuals were divided into one group with good oral hygiene (GBP < 35.7%) and one group with poor oral hygiene (GBP greater than or equal to 35.7%). Significantly fewer carious lesions and filled approximal surfaces were demonstrated in the group with good oral hygiene compared with the group with poor oral hygiene. About 16% of the study population used fluoride tablets or fluoride mouthrinses in addition to a fluoride toothpaste. Only in the good oral hygiene group, additional fluoride resulted in a lower caries experience compared with those using only a fluoride toothpaste. In the group with poor oral hygiene, additional fluoride did not result in lower caries experience. The study thus supported the view that during regular fluoride exposure oral hygiene level is an important variable to explain caries risk.
Maupomé G, Clark DC, Levy SM, Berkowitz J. Patterns of dental caries following the cessation of water fluoridation. Community Dent Oral Epidemiol 2001 Feb;29(1):37-47. Faculty of Dentistry, University of British Columbia.
Objectives: To compare prevalence and incidence of caries between fluoridation-ended and still-fluoridated communities in British Columbia, Canada, from a baseline survey and after three years.
Methods: At the baseline (1993/4 academic year) and follow-up (1996/7) surveys, children were examined at their schools. Data were collected on snacking, oral hygiene, exposure to fluoride technologies, and socio-economic level. These variables were used together with D1D2MFS indices in multiple regression models.
Results: The prevalence of caries (assessed in 5,927 children, grades 2, 3, 8, 9) decreased over time in the fluoridation-ended community while remaining unchanged in the fluoridated community. While numbers of filled surfaces did not vary between surveys, sealed surfaces increased at both study sites. Caries incidence (assessed in 2,994 life-long residents, grades 5, 6, 11, 12) expressed in terms of D1D2MFS was not different between the still-fluoridating and fluoridation-ended communities. There were, however, differences in caries experienced when D1D2MFS components and surfaces at risk were investigated in detail. Regression models did not identify specific variables markedly affecting changes in the incidence of dental decay.
Conclusions: Our results suggest a complicated pattern of disease following cessation of fluoridation. Multiple sources of fluoride besides water fluoridation have made it more difficult to detect changes in the epidemiological profile of a population with generally low caries experience, and living in an affluent setting with widely accessible dental services. There are, however, subtle differences in caries and caries treatment experience between children living in fluoridated and fluoridation-ended areas.
Editorial Note: In response to a request from Dr. Maupome, what follows is a commentary from him:
"This comment is being mailed to you as a response to information disseminated through a website that is associated with your e-mail address. I want to clarify inaccurate information that has been propagating over diverse internet websites, mostly anti-fluoridation sites, with regard to the findings of the Comox/Courtenay/Campbell River Defluoridation Longitudinal Study. The most common distortion of the findings is that we concluded that communities served by fluoridated water and those without fluoridated water have the same experience of tooth decay (Maupomé G, Clark DC, Levy SM, Berkowitz J. Community Dentistry and Oral Epidemiology 2001;29(1):36-46, and Maupomé G, Shulman, JD, Clark DC, Levy SM, Berkowitz J. Caries Research 2001;35(2):95-105).
"This simplistic assertion is a misrepresentation of the research reported in the publications. The important conclusion from these analyses is that even in a low disease activity population such as these Canadian children, and even over a relatively short time interval such as three years, water fluoridation still had a noticeable effect in reducing tooth decay incidence. Incidence analyses used all participants from baseline who were re-examined at follow-up and who were lifelong residents in their study sites. A total of 2,994 grades 5&6 and 11&12 children were examined. Follow-up rate at 3 years was 64.2%. While trends from both fluoridation-ended (F-E) and still-fluoridated (S-F) sites showed that D1 (uncavitated decay) and D2 (cavitated decay) changes over time were not large, the F-E site always had small negative changes, while the S-F site remained static or had little increment. These phenomena were offset by more filled surfaces in the F-E site, so that total treated and untreated decay incidence was about 20% higher in the F-E site for both grades 5&6 and 11&12. The incidence of untreated decay was lower in the F-E community than in the S-F community because a substantial proportion of the overall decay in the former had become fillings by the time participants were re-examined.
"I'll be grateful if you may add this short piece of text next to the description of the abstract for the Community Dentistry and Oral Epidemiology paper."
Miyazaki H, Morimoto M, Changes in caries prevalence in Japan. Eur J Oral Sci, Aug 1996, 104 (4 Pt 2), 452-458
In Japan, the mean DMFT at 12 years of age increased from 2.8 in 1957 to 5.9 in 1975. From the 1981 survey (DMFT = 5.43), conversely, the mean DMFT decreased and reached 3.64 in 1993. The increase in caries prevalence can, without doubt, be explained by an increment of sugar consumption, since the intake of sugar increased after World War II and exceeded 18.25 kg/year (50 g/day) in 1965 and reached a maximum value (29.3 kg/year) in 1973 in Japan. On the other hand, the reason why the DMFT has decreased since 1981 is not clear. In many industrialized countries, a caries reduction has been achieved with acceptable fluoride exposure, although sugar consumption was still at a high level. However, fluoride usage was still limited during the last 2 decades in Japan. There is no community where fluoridated drinking water has been supplied since 1972. Fluoride tablet use was also discontinued for children in the 1970s. Fluoride mouthrinsing programs were available for only 1% of school children in 1992. Moreover, the market share of fluoridated dentifrices stayed at 10% until 1986 and became 30% only in 1988. An excellent correlation (r = 0.91; P < 0.01) is observed between the DMFT in 12-year-olds and per capita sugar consumption per year between 1957 and 1987 in Japan.
Riordan PJ, Fluoride supplements for young children: an analysis of the literature focusing on benefits and risks, Comm Dent & Oral Epidemio 27(1):72-83, 1999
Seppa L, Karkkainen S, Hausen H, Caries frequency in permanent teeth before and after discontinuation of water fluoridation in Kuopio, Finland, Community Dental Oral Epidemiology 1998 August, 26:4, 256-62 (Institute of Dentistry, University of Oulu, Finland)
The piped water of Kuopio, Finland, was fluoridated in 1959. Owing to strong opposition by different civic groups, water fluoridation was stopped at the end of 1992.
OBJECTIVES: The aim of this study was to examine the consequences of the discontinuation on dental health.
METHODS: In 1992 and 1995, independent random samples of all children aged 6, 9, 12 and 15 years were drawn from Kuopio and Jyvaskyla, a nearby low fluoride town whose distribution of demographic and socio-economic characteristics was fairly similar to Kuopio's. The total number of subjects examined was 550 in 1992 and 1198 in 1995. Caries was registered clinically and radiographically by the same two calibrated dentists in both towns.
RESULTS: In 1992, the mean DMFS values were lower in the fluoridated town for the two older age groups, the percentage differences for 12- and 15-year-olds being 37% and 29%, respectively. For the two younger age groups no meaningful differences could be found. In 1995, the only difference with possible clinical significance was found in the 15-year-olds in favor of the fluoridated town (18%). In 1995, a decline in caries was seen in the two older age groups in the nonfluoridated town. In spite of discontinued water fluoridation, no indication of an increasing trend of caries could be found in Kuopio. The mean numbers of fluoride varnish and sealant applications decreased sharply in both towns between 1992 and 1995. In spite of that caries declined.
CONCLUSIONS: These findings suggest that the decline of caries has little to do with professional preventive measures performed in dental clinics.
Spencer AJ, Slade GD, Davies M, Water fluoridation in Australia, Community Dent Health, 1996 Sep, 13(Suppl 2), 27-37.
This paper reviews the rationale, context and support for water fluoridation in Australia, and examines current Australian evidence concerning the caries-preventive effects of fluoridation and trends in dental fluorosis. Nearly two thirds of the Australian population resides in an area with adjusted levels of fluoride in the water supply. However, public knowledge about fluoridation is poor and opinion polls demonstrate declining support for fluoridation. In the press and scientific literature there has been questioning of fluoridation, although the most recent Australian review reasserted its safety and effectiveness. Results from Australian oral epidemiological studies consistently support the accumulated evidence on the effectiveness of water fluoridation. This includes recent evidence that lifetime exposure to fluoridation is associated with average reductions of 2.0 dmfs and between 0.12 and 0.30 DMFS per child compared with non-exposed children. Water fluoridation has been found to reduce socio-economic inequalities in caries, reducing the differential between high and low socio-economic status groups by approximately 1.0 dmfs and 0.2 DMFS per child. The prevalence of dental fluorosis may have increased, prompting renewed consideration of overall exposure to fluorides. Action is currently being taken to reduce the exposure to discretionary fluoride among pre-school children as part of a targeted approach to adjusting the benefit-risk relationship of exposure to fluorides for that age group. Community water fluoridation continues to be the most effective and socially equitable measure for caries prevention among all ages by achieving community-wide exposure to the caries preventive effects of fluoride.
editor's note: most of the dental surveys which have been conducted recently have not found any statistically significant or relevant differences in tooth decay rates between fluoridated and unfluoridated communities. As in this study, what little "benefit" is found for permanent teeth is less than 1.0 Decayed Missing Filled Surface (DMFS) . There are over 100 tooth surfaces in a full set of teeth.
Szpunar SM, Burt BA , Evaluation of appropriate use of dietary fluoride supplements in the US, Community Dent Oral Epidemiol, 1992 Jun, 20(3), 148-154.
Recent epidemiologic and related evidence suggests the following trends: 1. the prevalence of caries continues to decline in children of the US and several other developed countries; 2. the prevalence of mild dental fluorosis is increasing; 3. the majority of the cariostatic effects of fluoride are topical; and 4. dietary fluoride supplements are a risk factor for dental fluorosis. These trends, and the scientific evidence on fluoride and fluorosis, suggest that it is time to re-evaluate the use of dietary fluoride supplements. This paper examines the evidence for each of the four trends and the use of fluoride supplements in caries prevention today. [emphasis added]
Steiner M, Menghini G, Marthaler T, Bandi A, The dental health of permanently resident schoolchildren in 16 Zurich rural communities in 1992, Schweiz Monatsschr Zahnmed, 1995, 105 (11), 1403-1411, [Translated from German]
Between 1964 and 1992, caries prevalence (DMFT) of permanently resident school children in 16 communities in the Canton of Zurich decreased by 85 to 87%. In the ten- to fourteen-year-olds, the reduction amounted to 25-29% in the period of 1988 to 1992. In 1992, the fourteen-year-olds had only 1.90 DMFT and 2.49 DFS, the average DS being 0.28. The 21% children with the highest caries experience showed only 9 DFS on average. Such a low caries activity does not favour positive cost-benefit results for individual intensive prevention. From 1964 to 1984 caries prevalence in primary teeth of 7-year-old children decreased to the level of 1.81 dmft; the further reduction to 1.55 dmft in 1992 was not significant. Few primary molars were lost prematurely. According to a saliva-test, 59% of the children aged 10 to 12 with high concentrations of mutans streptococci were free of caries; by comparison, 80% of the children with the lowest mutans-test value, were free of caries. In spite of the easy availability and the multiple usages of fluorides (dentifrices with either 250 or 1000-1500 ppm F, domestic salt, gels with 12,500 ppm F and rinsing solutions with 230 ppm F since 1986-88), only 16% of the children showed signs of dental fluorosis.
Teotia SPS, Teotia M, Dental Caries: A Disorder of High Fluoride And Low Dietary Calcium Interactions (30 years of Personal Research), Fluoride, 1994 Apr, 27:2, 59-66. the largest study on dental caries in the world
Thylstrup A, Boyar RM, Homen L, Bowden GH, A light and scanning electron microscopic study of enamel decalcification in children living in a water-fluoridated area, J Dent Res, 1990 Oct, 69:10, 1626-1633
Eleven children, each having one or two pairs of premolars to be extracted for orthodontic purposes, participated in the study. The model involved placement of a special orthodontic band that allowed the accumulation of plaque in a defined area between the band and the buccal enamel. Examination of enamel changes was carried out in experimental teeth that had been exposed to local plaque accumulation for one, two, four, eight or 14 days. The specimens were examined under the light (LM) and the scanning electron microscope (SEM). All teeth had signs of very mild dental fluorosis. No indications of demineralization were noted after one day. SEM examination showed signs of crystal dissolution in some of the two-day specimens. Six of eight four-day specimens exhibited surface dissolution. All eight- and 14-day specimens showed signs of surface demineralization in the LM as well as in the SEM. these observations documented that undisturbed bacterial deposits are capable of initiating enamel demineralization within short time periods, even in children living in a water-fluoridated area. [emphasis added]
editor's note: The old hypothesis was that incorporating fluoride into developing enamel by drinking fluoridated water or taking supplements made the teeth "stronger" and more resistant to acid attack. Is this borne out by this study, or does oral hygiene have more to do with reduced tooth decay than fluoridation ever did?
Winter GB, Holt RD, Williams BF, Clinical trial of a low-fluoride toothpaste for young children, International Dental Journal, 1989 December, 39(4):227-35.
In this double-blind trial, the anticaries effectiveness of a test toothpaste formulated for young children with 550 ppm F was compared with that of a positive control toothpaste containing 1055 ppm fluoride. More than 3000 2-year-old children were enrolled in the study and after 3 years of toothpaste use, 2177 (72 per cent) were examined. From a clinical and radiographic assessment, more than half the children were found to be caries free and only 32 (1.5 per cent) had evidence of rampant caries. There appeared to be little or no difference between children who had used test or control pastes, either in caries or in plaque levels. On the basis of this clinical trial the experimental toothpaste with 550 ppm fluoride would appear to have a similar anticaries efficacy to that of the control toothpaste. Differences were seen in relation to sex of the child and to social class. Girls had lower levels of plaque than boys but more carious teeth. Children from families in higher social classes had fewer carious teeth and lower levels of plaque.
editor's note: several questions should be asked in light of this study:
Yiamouyiannis JA., Water Fluoridation And Tooth Decay: Results From The 1986-1987 National Survey of U.S. Schoolchildren, Fluoride, 1990 Apr, 23:2, 55-67
Ziegelbecker R, and Ziegelbecker RC, WHO Data on Dental Caries and Natural Water Fluoride Levels," Fluoride, 1993 Oct, 26:4, 263-266
FOOTNOTE 1: Feltman R. Kosel G, 1961, J. Dental Medicine, vol 16, as quoted in "The Greatest Fraud Fluoridation" by Philip RN Sutton, ISBN 0949491128, 1996. For more information on delayed eruption see sutton.htm