Evaluation of topical fluoride preparations

For practical reasons, evaluation of topical fluoride products must depend upon clinical and laboratory assessments. While not always a good predictor of clinical efficacy by itself, fluoride uptake is the most commonly used laboratory test. A consideration of the relationship between possible anticaries mechanisms of fluoride, different product types, and the meaning of various kinds of fluoride uptake data suggests that both the amount of fluoride taken up by early lesions and the amount of ambient fluoride present at a cariogenic site may play key roles in determining the efficacy of a product. While formulations applied annually or semi-annually probably depend on fluoride deposition, those used daily might not. There are no clear data supporting the superiority of one fluoride compound over another, even for infrequently used products, although there are significant differences among them in fluoride uptake by enamel. This suggests that fluoride uptake in vivo at a cariogenic site might actually be different from that suggested by in vitro data, or that larger differences are required for a clinical effect to be observable. Clinical data support the conclusion that a large increase in the fluoride concentration of a product will somewhat increase its anticaries effectiveness, although the increase will not be linearly related to concentration. There also are no obvious differences in clinical effectiveness caused by the addition of gelling agents to topical solutions. Fluoride varnishes are clinically effective but have not been shown to be superior to topical solutions or gels.(ABSTRACT TRUNCATED AT 250 WORDS)