Fluoride in deciduous teeth from an anti-caries clinical study.

The fluoride content of both sound and white-spot enamel was determined in deciduous teeth collected from an anti-caries clinical trial which compared a 0.243% NaF dentifrice, a 0.4% SnF2 dentifrice, and a placebo. A microdrill enamel biopsy technique was developed for the analysis of white spots. No correlations were found between caries increment scores and the fluoride content of sound enamel. The enamel in white spots from users of the 0.243% NaF dentifrice had a mean fluoride content higher than that from users of the 0.4% SnF2 dentifrice. There was a negative correlation between fluoride found in white-spot enamel and caries increment scores. It is hypothesized that fluoride affects the caries rate by its control over the rate of remineralization in previously demineralized areas.