[Clinical controlled trial for secondary caries preventive effect of Duraphat on cavity walls].

On a base of a clinical controlled trial the secondary caries preventive effect of a topical application of fluoride varnish (Duraphat) was verified. 255 pairs of amalgam restorations were placed in 191 patients, 152 (79.6%) of whom returned for assessment after a 24 month follow-up period. This group of 152 patients received 188 (73.7%) pairs of restorations. The cavity walls of one restoration of each pair were covered with an thin layer of a fluoride containing varnish. The secondary caries rate of the untreated restorations in such manner was four time greater than the treated ones. The results suggest that the topical application of a fluoride varnish on the cavity walls can be an effective measure for secondary caries prevention.