Effect of chewable fluoride tablets on dental caries in schoolchildren: results after six years of use

Screening, Referral, Behavioral Counseling, and Preventive Interventions for Oral Health in Children and Adolescents Aged 5 to 17 Years: A Systematic Review for the US Preventive Services Task Force

Importance

Dental caries is common in children and adolescents aged 5 to 17 years and potentially amenable to primary care screening and prevention.

Objective

To systematically review the evidence on primary care screening and prevention of dental caries in children and adolescents aged 5 to 17 years to inform the US Preventive Services Task Force.

Data Sources

MEDLINE, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews (to October 3, 2022); surveillance through July 21, 2023.

Study Selection

Diagnostic accuracy of primary care screening instruments and oral examination; randomized and nonrandomized trials of screening and preventive interventions and systematic reviews of such studies; cohort studies on primary care oral health screening and preventive intervention harms.

Data Extraction and Synthesis

One investigator abstracted data; a second checked accuracy. Two investigators independently rated study quality. Random-effects meta-analysis was performed for fluoride supplements and xylitol; for other preventive interventions, pooled estimates were used from good-quality systematic reviews.

Main Outcomes and Measures

Dental caries, morbidity, functional status, quality of life, harms; diagnostic test accuracy.

Results

Three systematic reviews (total 20 684 participants) and 19 randomized clinical trials, 3 nonrandomized trials, and 1 observational study (total 15 026 participants) were included. No study compared screening vs no screening. When administered by dental professionals or in school settings, fluoride supplements compared with placebo or no intervention were associated with decreased change from baseline in the number of decayed, missing, or filled permanent teeth (DMFT index) or decayed or filled permanent teeth (DFT index) (mean difference, -0.73 [95% CI, -1.30 to -0.19]) at 1.5 to 3 years (6 trials; n = 1395). Fluoride gels were associated with a DMFT- or DFT-prevented fraction of 0.18 (95% CI, 0.09-0.27) at outcomes closest to 3 years (4 trials; n = 1525), fluoride varnish was associated with a DMFT- or DFT-prevented fraction of 0.44 (95% CI, 0.11-0.76) at 1 to 4.5 years (5 trials; n = 3902), and resin-based sealants were associated with decreased risk of carious first molars (odds ratio, 0.21 [95% CI, 0.16-0.28]) at 48 to 54 months (4 trials; n = 440). No trial evaluated primary care counseling or dental referral. Evidence on screening accuracy, silver diamine fluoride, xylitol, and harms was very limited, although serious harms were not reported.

Conclusions and Relevance

Administration of fluoride supplements, fluoride gels, varnish, and sealants in dental or school settings improved caries outcomes. Research is needed on the effectiveness of oral health preventive interventions in primary care settings and to determine the benefits and harms of screening.

Impact of 24-month fluoride tablet program on children with disabilities in a non-fluoridated country

The aim of this study was to evaluate the caries preventive effects of a school-based fluoride tablet program in children with disabilities. Two hundred and seventeen children with disabilities were divided into two groups: the intervention group (IG) ingested 1.0mg fluoride tablet daily while the control group (CG) ingested a placebo. The initial oral examinations were conducted prior to fluoride intake and 24-month follow-up examinations were conducted to evaluate the effectiveness of fluoride tablet ingestion. The results from this study demonstrated significant reductions in the DMFT index (the sum of decayed, missing, and filled permanent teeth), 0.63, as well as the DMFS index (the sum of decayed, missing, and filled surfaces of the permanent dentition), 1.25, when compared with the CG. A statistically significant reduction in the DMFT index and DMFS index (30.42% and 36.84%, respectively) suggested an anti-cariogenic benefit to fluoride tablet administration. Greater caries reduction occurred on mesio-distal and bucco-lingual surfaces (53.27% and 52.57%, respectively). Fluoride tablets should be considered as a caries preventive strategy in school-based caries prevention programs for children with disabilities in fluoride deficient areas.

Fluoride supplements (tablets, drops, lozenges or chewing gums) for preventing dental caries in children

BACKGROUND

Dietary fluoride supplements were first introduced to provide systemic fluoride in areas where water fluoridation is not available. Since 1990, the use of fluoride supplements in caries prevention has been re-evaluated in several countries.

OBJECTIVES

To evaluate the efficacy of fluoride supplements for preventing dental caries in children.

SEARCH METHODS

We searched the Cochrane Oral Health Group's Trials Register (to 12 October 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 3), MEDLINE via OVID (1950 to 12 October 2011), EMBASE via OVID (1980 to 12 October 2011), WHOLIS/PAHO/MEDCARIB/LILACS/BBO via BIREME (1982 to 12 October 2011), and Current Controlled Trials (to 12 October 2011). We handsearched reference lists of articles and contacted selected authors.

SELECTION CRITERIA

We included randomised or quasi-randomised controlled trials comparing, with minimum follow-up of 2 years, fluoride supplements (tablets, drops, lozenges) with no fluoride supplement or with other preventive measures such as topical fluorides in children less than 16 years of age at the start. The main outcome was caries increment measured by the change in decayed, missing and filled tooth surfaces (DMFS).

DATA COLLECTION AND ANALYSIS

Two review authors, independently and in duplicate, assessed the eligibility of studies for inclusion, and carried out risk of bias assessment and data extraction. In the event of disagreement, we sought consensus and consulted a third review author. We contacted trial authors for missing information. We used the prevented fraction (PF) as a metric for evaluating the efficacy of the intervention. The PF is defined as the mean caries increment in controls minus mean caries increment in the treated group divided by mean caries increment in controls. We conducted random-effects meta-analyses when data could be pooled. We assessed heterogeneity in the results of the studies by examining forest plots and by using formal tests for homogeneity. We recorded adverse effects (fluorosis) when the studies provided relevant data.

MAIN RESULTS

We included 11 studies in the review involving 7196 children.In permanent teeth, when fluoride supplements were compared with no fluoride supplement (three studies), the use of fluoride supplements was associated with a 24% (95% confidence interval (CI) 16 to 33%) reduction in decayed, missing and filled surfaces (D(M)FS). The effect of fluoride supplements was unclear on deciduous or primary teeth. In one study, no caries-inhibiting effect was observed on deciduous teeth while in another study, the use of fluoride supplements was associated with a substantial reduction in caries increment.When fluoride supplements were compared with topical fluorides or with other preventive measures, there was no differential effect on permanent or deciduous teeth.The review found limited information on the adverse effects associated with the use of fluoride supplements.

AUTHORS' CONCLUSIONS

This review suggests that the use of fluoride supplements is associated with a reduction in caries increment when compared with no fluoride supplement in permanent teeth. The effect of fluoride supplements was unclear on deciduous teeth. When compared with the administration of topical fluorides, no differential effect was observed. We rated 10 trials as being at unclear risk of bias and one at high risk of bias, and therefore the trials provide weak evidence about the efficacy of fluoride supplements.

A half-century of community water fluoridation in the United States: review and commentary

The nearly 50-year history of community water fluoridation is reviewed with the major emphasis on the benefits and safety of fluoridation. Other aspects of water fluoridation also described include the apparent reduction in measurable fluoridation benefits because of the abundance of other fluoride sources, the diffusion of fluoridation effects into fluoride-deficient communities, preeruptive and posteruptive effects, technical and cost aspects, sociopolitical and legal issues that affect the successful fluoridation of communities, and alternatives to community water fluoridation. The majority of studies have evaluated the effectiveness of water fluoridation on the permanent teeth of children, while there are fewer studies on deciduous teeth and in adults; the relationship between fluoride ingestion and bone health needs further clarification; the sociopolitical issues of fluoridation need to be better understood.

Fluorides in dental public health programs

The use of fluorides in dental public health programs has a long history. With the availability of fluoridation and other forms of fluorides, dental caries have declined dramatically in the United States. This article reviews some of the ways fluorides are used in public health programs and discusses issues related to their effectiveness, cost, and policy.

Practitioner's guide to fluoride

The current health care trend is to provide evidence-based recommendations and treatment. Many literature reviews have shown fluoride's effectiveness against caries. The current use of fluoride in the prevention of dental caries is based on community, professional, and individual strategies. Personalized fluoride regimens should include a risk analysis and a review of the patient's current fluoride exposure. The future of fluoride may be found in its slow release and retention in the oral cavity through various modalities. Because of the many uncertainties still associated with fluoride, further research is needed.

The role of dietary fluoride supplements in caries prevention

Nearly all dental researchers and public health authorities agree that fluoride supplements are highly effective in reducing dental caries in primary and permanent teeth, that benefits to all teeth are greater when administration begins at 2 years of age or younger, that both preeruptive and posteruptive exposure is important in imparting cariostatic benefits, that effectiveness is neither enhanced nor reduced by their being combined with vitamins, and that benefits to the offspring of pregnant women who take supplements are uncertain. Several studies show that fluoride supplements delivered in school-based programs effectively reduce dental caries, and benefits are greater to teeth that receive preeruptive exposure in addition to posteruptive exposure. Many parents who, for a variety of reasons, did not administer fluoride supplements at home will enroll their children in school-based fluoride tablet programs. Effectiveness of fluoride supplements today is undoubtedly smaller than observed previously because of dilution and diffusion effects from other fluoride sources; nevertheless, they still have the same potential efficacy. It is apparent that the current ADA dosage schedule is too high and requires modification; however, the availability of this known-to-be-effective regimen should not be eliminated or restricted.

The case for eliminating the use of dietary fluoride supplements for young children

Fluoride supplements have been used for years to prevent dental caries; nevertheless, there are three reasons why their use is inappropriate today among infants and young children in the United States. Evidence for the efficacy of fluoride supplements when used from birth or soon after is weak, supplements are a risk factor for dental fluorosis, and fluoride has little preeruptive effect in caries prevention. While there are many reports on the caries-preventive efficacy of supplements, few meet standards for acceptability as clinical trials, and those that do have tested chewable tablets or lozenges under supervision in school-aged children. North American children today are exposed to fluoride from many sources--drinking water, toothpaste, gels, rinses, and in processed foods and beverages. The additional cariostatic benefits that accrue from using supplements are marginal at best, while there is strong risk of fluorosis when young children use supplements. Available evidence suggests that the public is more aware of the milder forms of fluorosis than was previously thought; thus, it is prudent for caries-preventive policies to aim to maximizing caries reductions while minimizing the risk of fluorosis. It is therefore concluded that the risks of using supplements in infants and young children outweigh the benefits. Because alternative forms of fluoride for high-risk individuals exist, fluoride supplements should no longer be used for young children in North America.

Fluoride supplements for young children: an analysis of the literature focusing on benefits and risks

The use of fluoride supplements to prevent caries has been advised for more than 100 years, but serious promotion of this strategy occurred only after the effectiveness of water fluoridation was established, in the late 1950s and 1960s. Although the effectiveness of fluoride supplements was apparently endorsed by many small clinical studies, closer examination of the experimental conditions of these, their methods and the analysis of their results undermined confidence in their findings. It is likely that confounding resulted in spurious conclusions in many of them. More modern, well-conducted clinical trials of supplements suggest that today, in children also exposed to fluoride from other sources such as toothpaste, the marginal effect of fluoride supplements is very small. There is evidence that fluoride lozenges, designed to maximise any local effect, may have a small caries preventive effect, particularly in deciduous teeth. Overall, poor compliance makes fluoride supplements a poor public health measure. Supplement use by young children is associated with a substantial risk of dental fluorosis. Fluorosis is an issue about which the public is becoming concerned in several countries and this concern, if translated into opposition to all fluoride use, could jeopardise the most successful caries preventive aid we have. The potential for dental fluorosis, concern about the public's reaction to this, the poor effectiveness of supplements and the public's poor compliance with their use are persuasive arguments for a radical reduction in the use of supplements by young children. Recent changes in fluoride dosage schedules and deferment of the age of commencing the use of supplements, implemented in many countries, have followed from these concerns. Supplements formulated as lozenges maximise topical exposure of enamel to fluoride and such products may offer older children and some adults a way of maintaining an elevated fluoride level in saliva at times when toothbrushing is not practical.

The place of fluoride supplements in caries prevention today

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.

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.

Caries risk assessment by a cross-sectional discrimination model

Although the prevalence of dental caries is continuing to decline, it still affects a majority of the US population and can be a serious problem for those afflicted. The objective of this project was to develop and perfect a model for assessment of risk of dental caries onset in children. In the first study, reported herein, a set of clinical, microbiological, biochemical, and socio-demographic variables was identified that distinguished, with an acceptable level of sensitivity and specificity, between children who had no previous caries experience and children who had high caries levels. A total of 313 children--age 12-15 years, 140 from a fluoridated community and 173 from a fluoride-deficient community--was selected on the basis of previous caries experience, either zero DMFS or high DMFS (> or = 6 in the fluoridated or > or = 8 in the fluoride-deficient community). Clinical exams for DMFS, dental fluorosis, and plaque were conducted. Stimulated whole saliva was collected for analysis of mutans streptococci, lactobacilli, total viable flora, and fluoride concentration. A questionnaire was used for collection of demographic data as well as information on prior fluoride exposure, dietary habits, and oral hygiene practices. By means of discriminant analyses, with use of seven key clinical and laboratory variables, it was possible for zero-DMFS subjects to e classified correctly (specificity) in 77.6% of cases in the fluoridated community and in 86.1% of cases in the fluoride-deficient community. High-caries subjects were classified as such (sensitivity) in 79.3% and 88.1% of cases, respectively.

A comparison of the caries-preventive effects of fluoride mouthrinsing, fluoride tablets, and both procedures combined: final results after eight years

This paper presents final results of an eight-year clinical trial designed to compare the caries-preventive benefits of two self-administered fluoride procedures when used separately and in combination with one another. Children in kindergarten and first grade residing in Springfield, Ohio, a nonfluoridated community, were assigned randomly within school to one of three groups that either (a) rinsed once a week in school with a 0.2 percent neutral NaF solution; (b) chewed, rinsed with, and then swallowed daily in school a neutral 2.2 mg NaF tablet; or (c) carried out both procedures. At baseline (1981), 1,640 participants were examined clinically using the DMF surface index. Findings for 640 children remaining after eight years show that subjects in the combination group experienced a mean caries increment of 2.40 DMFS, 15.2 percent lower than the mean score of 2.83 DMFS for children in the tablet group and 32.8 percent lower than the 3.57 DMFS for those in the rinse group. Only the difference in incremental caries scores between the combined fluoride procedure and the fluoride rinse was statistically significant (P less than .05). The pattern of these findings is similar to that found on the two interim examinations. Even though the combined regimen showed an additional caries-preventive benefit compared with the rinse, considerations of cost effectiveness and feasibility do not support changing an ongoing rinse program to one that employs both procedures. For new programs the best choice appears to be the tablet procedure alone.

Evaluation of the comparative effectiveness of fluoride mouthrinsing, fluoride tablets, and both procedures in combination: interim findings after five years

This article presents five-year interim findings of an eight-year clinical trial designed to compare the relative caries-preventive benefits of weekly fluoride mouthrinsing, daily fluoride tablet administration, and both procedures combined. Children in kindergarten and first grade residing in Springfield, Ohio, a nonfluoridated community, were assigned randomly in school to one of three groups that (1) rinses once a week in school with a 0.2 percent neutral NaF solution; (2) chews, rinses with, and then swallows daily in school a neutral 2.2 mg NaF tablet; or (3) carries out both procedures. At baseline (1981), 1,640 participants were examined clinically using the DMF surface index. After five years, 789 children were available for reexamination. Findings show that subjects in the combination group experienced a mean caries increment of 1.47 DMFS, 16.5 percent lower than the mean score of 1.76 DMFS for children in the tablet group and 31.3 percent lower than the 2.14 DMFS for those in the rinse group. Only the difference in incremental caries scores between the combined fluoride procedure and the fluoride rinse was statistically significant (P less than .05). Despite the finding of an additive caries-preventive benefit among children who followed the combined regimen, it would be premature to judge which procedure is best before results of the final examinations become known.

Effectiveness of school water fluoridation and dietary fluoride supplements in school-aged children

School water fluoridation and school-based fluoride tablet programs both have been shown in many studies to be effective in preventing dental caries. These studies indicate that school water fluoridation reduces dental decay by approximately 40 percent and school-based fluoride tablet programs by about 30 percent. However, nearly all the studies were done when the prevalence of caries among US schoolchildren was greater than it is today, which makes it difficult to assess their current effectiveness. Data from dental surveys of school-aged children conducted during the past 30 years indicate that overall caries prevalence has declined by more than 75 percent and that of approximal tooth surfaces by more than 90 percent. Recent national data indicate the difference in caries prevalence between children with lifetime residence in either fluoridated or nonfluoridated areas has also diminished, which raises questions about the cost effectiveness of initiating school-based fluoride programs for all areas. There are still groups of children, however, seriously affected by dental caries. It is safe to assume that implementation of school water fluoridation or fluoride tablet programs will result in traditionally reported benefits among these children. Ongoing school-based fluoride programs should not be discontinued until it is known what impact their cessation will have on dental disease.

Relationships between exposure to additional fluoride, social background and dental health in 7-year-old children

The relationship between social background, water fluoridation, use of fluoride tablets and dmf scores was studied in a birth cohort of 7-yr-old New Zealand children. This analysis showed that the level of exposure to additional fluoride was a complex variable influenced by at least three factors: the use of fluoride toothpaste; the child's length of residence in a fluoridated area; the length of time for which the child had been provided fluoride tablets. Log linear modelling of the data suggested the presence of a relatively complex relationship between exposure to additional fluoride, social background and dental health. First, both duration of residence in a fluoridated area and the provision of fluoride tablets made significant net contributions to the variability in the dmf score. However, exposure to additional fluoride from these sources was differentially influenced by social background: while there were relatively strong associations between social background and the use of fluoride tablets, there was no significant association between duration of residence in a fluoridated area and social background. Finally, independently of an association with exposure to additional fluoride, family social background made a significant net contribution to the variability in dmf scores.

Prevalence of developmental defects of enamel and dental caries in New Zealand children receiving differing fluoride supplementation

A survey of the prevalence of dental caries and developmental enamel defects in 666 New Zealand children aged 9 years and with differing histories of fluoride supplementation was carried out in 1982. In the LF (low fluoride) group 22.8% of children had diffuse white opacities compared with the WF (water fluoridation) group, 36.7%, and the CT (continuous use of fluoride tablets) group 49.4% (P = 0.0018). When the tooth prevalence was determined, the differences were more marked with 4.9% of teeth affected in the LF group and 24.7% in the CT group. Dental caries prevalence in the fluoride history groups displayed an inverse relationship with fluoride supplementation, the LF group had a DMFT of 2.4, the WF group, 1.7 and the CT group, 1.2. The prevalence of both diffuse opacities and of dental caries in the PT group where tablets had been used to 5-6 yr of age was anomalous. The survey confirmed that diffuse opacities occur in children with a low fluoride intake but the prevalence increases in groups of children given fluoride supplements.