Evaluation of a fluoride-containing varnish in children with low caries incidence

The purpose of the present study was to investigate the caries-preventive effect of four applications during 2 years of the fluoride-containing varnish, Fluor Protector. The final series examined during the 2-year follow-up period comprised 76 girls and 87 boys, whose average age at the onset of the experiment was 12.8 +/- 0.6 years. The test was carried out as a blind study, using a half-month technique. The fluoride content of the surface enamel was measured in 40 children. The results obtained by the conventional fluoride electrode technique were compared with those obtained by the sensitive physical technique based on proton beam bombarding using bovine primary teeth. The teeth were cut longitudinally into two halves; one half was treated with Fluor Protector and the other half served as a control. Clinical examinations of the children showed that the number of carious lesions requiring active treatment was low on both the control and experimental side of the mouth. Varnish treatment did not reduce caries in these children. The fluoride content of the surface enamel was relatively high on the untreated control side, but no increasing trend was observed during the 2-year follow-up period. The fluoride content of the treated teeth was markedly elevated throughout the follow-up period. The in vitro experiments with the bovine teeth showed that etching did not release all the fluoride present in the tooth enamel.