RADIOGRAPHIC SECONDARY CARIES PREVALENCE IN TEETH WITH CLINICALLY DEFECTIVE RESTORATIONS

Decisions to replace existing restorations are often based on clinical findings of margin discrepancies and other restoration defects. Previ ous studies have suggested that such findings do not correlate well wi th the actual presence of secondary caries, and that treatment should be deferred until caries is clinically or radiographically evident. Th e purpose of this study was to assess the frequency with which clinica lly defective restorations are associated with radiographic secondary caries. As part of a study to assess the efficacy of guidelines for th e ordering of dental radiographs, 6285 restored teeth in 490 subjects were examined clinically and radiographically by three calibrated inve stigators. Specific criteria were used to determine whether restoratio ns were intact or defective. Of the total, 822 teeth (13%) were judged to have clinically defective restorations. Of these, 113 teeth (14%) had radiographic secondary caries. Of the 5463 teeth with intact resto rations, 5% had radiographic secondary caries. We found that the likel ihood of radiographic secondary caries was nearly three-fold higher fo r defective restorations than for intact restorations. The large perce ntage (86%) of defective restorations with no radiographic secondary c aries suggests, however, that replacement of all defective restoration s due to risk of secondary caries may constitute overtreatment. The us e of defective restoration status and presence of radiographic seconda ry caries as a combined criterion for replacement may potentially redu ce such overtreatment. The prevalence of secondary caries under defect ive restorations should be determined clinically so that the usefulnes s of combining the criteria of defective restoration with those of rad iographic secondary caries can be evaluated.