Abstract

The inhibitory effect of fluoride on dental caries is well established, but the exact mechanism of caries prevention is unknown. It has been hypothesised that the effectiveness of topically applied fluoride depends upon its ability to incorporate fluoride into tooth enamel. The purpose of this study was to determine the extent of fluoride uptake in enamel achieved by the topical application of stannous fluoride on Naval Recruits.

The 112 Naval Recruits were randomly divided into two equal groups for the study. The experimental group underwent supervised toothbrushing with an 8.9 per cent stannous fluoride prophylaxis paste followed by a 15 second application of a 10 per cent stannous fluoride solution. The control group received no fluoride. Enamel samples were taken from one maxillary central inc;sor of each group initially and again 18 hours after fluoride treatment from the opposite central incisor.

The in vivo enamel biopsy technique devised by Brudevold and modified by IVIellberg for measuring fluoride concentrations in enamel was used. The samples were obtained by abrading a limited area of enamel, on the labial surface of the maxillary central incisor teeth, with a rotary felt cone and silicone carbide. The slurry was then collected and analysed for calcium and fluoride content, using an atomic absorption spectrophotometer and a fluoride specific electrode, respectively.

An increase in fluoride content of 5 per cent for the group with fluoride witheld, and 13 per cent for the group with fluoride applied were not s:gnificant.

The average mean depth for enamel samples was 4.7µm ± 0.7. The differences between depths of the various groups was not significant.

Although no significant fluoride uptake was found, it was concluded, because of consistent results obtained with the biopsy technique, that it is a useful tool for further studies of his nature.