Systemic fluoride therapy for caries prevention.

A lthough recent data suggest that the incidence rate of dental caries has begun to decline dramatically in developed nations' Canadians still have a moderate to high rate of the disease.2 Fluoridation of communal water supplies is the most cost-effective measure to prevent dental caries; it reduces dental decay by 30% to 60% yet costs only about 15¢ per person per year.3 Unfortunately, only about one third of the Canadian population benefits from this measure.4 This places a major responsibility for caries prevention on the physician who in a US survey was found to be more likely than the dentist to prescribe dietary fluoride supplements.5 However, only 37% considered fluoride supplements for children to be very effective, whereas 66% considered fluoridation of the community water supply very effective. Fluoride supplements can be as effective as fluoridation of the community water supply in preventing dental decay,5'6 but they must be prescribed and taken properly. Physicians' lack of confidence in dietary fluoride supplements may be attributed to concerns about patient compliance and proper dosage. Dental caries is characterized by demineralization of tooth enamel or cementum, with eventual destruction of the underlying dentin and possible damage to the pulp. Before the teeth erupt they can incorporate systemic fluoride during enamel formation and in the phase of rapid mineralization to form fluoroapatite, a mineral that is more stable and more resistant to demineralization than hydroxyapatite, the usual constituent of enamel. After the teeth erupt, fluoride from such sources as water, toothpaste, mouthwashes and dietary supplements is incorporated as fluoroapatite in the