The need for change became apparent as credible and concerned investigators presented sound arguments for restricting the use of fluoride supplements in children.¹ The committee on community and institutional dentistry (CID) was tasked with reviewing the current CDA position on fluoride supplements (drops, tablets and lozenges) in light of differences between CDA’s fluoride supplementation schedule and that of Health Canada’s Medical Services Branch, which does not recommend fluoride supplements.

CID reviewed the evidence^2-6 supporting both caries reduction and the risk of dental fluorosis associated with the use of fluoride supplements. Based on the clinical research available at the end of 1999, the committee confirmed that the use of dietary fluoride supplements in children is associated with fluorosis while the caries protection effect of supplements is considered variable. Fluoride supplements need only be considered for patients at high risk for dental caries and even then may be unnecessary if patients are receiving adequate fluoride from other sources.

In young children, there is a risk that the use of fluoride supplements prior to the eruption of the first permanent tooth will cause fluorosis of the permanent teeth at the front of the mouth. The traditional fluoride supplementation schedules based on age and the concentration of fluoride in the drinking water do not take into account the significant variation in both children’s body weight and the total daily intake of fluoride from all sources. As a result, the traditional dosage schedules have been abandoned in favour of dosages based on body weight and total daily fluoride intake. The threshold at which fluoride causes dental fluorosis is not precisely known but has been estimated at 0.10 mg fluoride/kg body weight. The most frequently used standard of 0.05-0.07 mg fluoride/kg body weight has generally been accepted as the upper limit of intake for minimizing dental fluorosis. The requirement to estimate the daily fluoride intake from all sources in the context of the present-day widespread exposure to multiple sources of fluoride is viewed by some as unrealistic. This may very well be true, and in those cases where it is not possible to confidently do so, fluoride supplements would not be indicated.

For older children whose first permanent tooth has erupted and for adults, fluoride supplements provide an intraoral fluoride dose before being ingested. This intraoral level of fluoride promotes post-eruptive enamel protection and has a therapeutic effect on dental caries. The topical exposure from a 1-mg fluoride tablet dissolved in the mouth is equivalent to brushing with an average adult brush load (1 gm) of 1,000 ppm fluoride dentifrice. Individuals with limitations that restrict standard oral hygiene practices may benefit from using chewable tablets or lozenges, although the evidence supporting this use is not yet available.

The adoption of these new recommendations require a change in the clinical protocols of dentists and others who recommend fluoride supplements for their patients. Evidenced-based dentistry requires us all to continually update our clinical protocols as new knowledge becomes available. The CDA recommendations are consistent with a worldwide trend to lower fluoride supplement dosages so as to minimize the risk of dental fluorosis. These recommendations allow for the integration of clinical judgement, patient preference, and the best available evidence to guide clinical decisions regarding the use of fluoride supplements in the management of dental caries for Canadians of all ages.

Dr. Swan is currently chair of the committee on community and institutional dentistry.

References

1. Lewis DW. Fluoride supplements: review, comments and recommendations. A report to Health Canada (Medical Services Branch), March 30, 1999.

2. Report of the CDA Committee on Community and Institutional Dentistry. Fluoride Supplementation. October 1998.

3. Limeback H, Ismail A, Banting D, DenBesten P, Featherstone J, Riordan PJ. Canadian Consensus Conference on the appropriate use of fluoride supplements for the prevention of dental caries in children. J Can Dent Assoc 1998; 64:636-9.

4. Appropriate use of fluoride supplements for the prevention of dental caries. Proceedings of the Consensus Conference of the Canadian Dental Association, Toronto, Canada, 28-29 November 1997. Community Dent Oral Epidemiol 1999; 27:25-83.

5. Review of water fluoridation and fluoride intake from discretionary fluoride supplements. Review for the National Health and Medical Research Council by the Royal Melbourne Institute of Technology – Key Centre for Applied and Nutritional Toxicology in conjunction with the Monash University Medical School’s Centre for Epidemiology and Preventive Medicine. Melbourne. 15 April 1999.

6. Recommendations for the use of fluoride to prevent and control dental caries in the United States. Centers for Disease Control and Prevention. National Center for Chronic Disease Prevention and Health Promotion. Division of Oral Health. DRAFT 8/20/99.

7. Burt BA, Eklund SA. Dentistry, dental practice, and the community. 5th ed. Philadelphia: WB Saunders; 1999.

1) Fluoride supplements are only required for high dental caries risk patients and may be unnecessary if the patient is receiving adequate fluoride from other sources.

2) Before prescribing fluoride supplements, a thorough clinical examination, dental caries risk assessment and informed consent with patients/caregivers are required.

3) The Canadian Consensus Conference on the Appropriate Use of Fluoride Supplements for the Prevention of Dental Caries in Children, held in November 1997, suggested that high caries risk individuals or groups may include those who do not brush their teeth (or have them brushed) with a fluoridated dentifrice twice a day or those who are assessed as susceptible to high caries activity because of community or family history, etc.

4) The estimation of fluoride exposure from all sources should include use of fluoridated dentifrice and all home and child care water sources. Dentists should be aware of the average fluoride exposure in their area. The possible impact of fluoride reducing factors within the home such as the use of unfluoridated bottled water of some reverse osmosis devices should be taken into account.

5) Lozenges or chewable tablets are the preferred forms of fluoride supplementation. Drops may be required for individual patients with special needs.

6) The use of fluoride supplements before the eruption of the first permanent tooth is generally not recommended. When, on an individual basis, the benefit of supplemental fluoride outweighs the risk of dental fluorosis, practitioners may elect to use these supplements at appropriate dosages on younger children. In doing so, the total daily fluoride intake from all sources should not exceed 0.05-0.07 mg F / kg body weight in order to minimize the risk of dental fluorosis.