Clinical evaluation of a restoration containing fluoride: two-year results.

Fluoride-containing restorations were placed on the distal surface of primary second molars to evaluate their effectiveness in controlling caries on the mesial surface of the approximating permanent first molars. A half-mouth study design was used with the control primary second molars in the same arch, either restored with amalgam or left sound. After two years, radiographs of 56 pairs of permanent first molars in 48 children were evaluated independently by three examiners blind to whether they were examining study or control surfaces. In 15 matched pairs, the study restoration had the effect of preventing a carious lesion on the mesial surface of a permanent first molar. In six matched pairs, the study restoration had the effect of not preventing progression of a carious lesion on the mesial surface of a permanent first molar. In 35 matched pairs, there was no effect observed. At the two-year evaluation, the study restorations with added fluoride controlled caries progression significantly on the adjacent mesial surfaces of permanent first molars when compared to the controls using the Sign test (P less than 0.05).