Influence of finishing and polishing procedures on the decision to replace old amalgam restorations: an in vitro study.

The purpose of this study was to establish the influence that finishing and polishing of existing amalgam restorations might have on the decision to replace them. Forty extracted teeth, in which amalgam restorations had been placed in vivo, were individually examined by 60 practitioners and students prior to and following standard finishing and polishing procedures. Examiners, who had not been informed of the study's methodology or objective, opted either for maintaining or replacing the restoration in question. The main reasons for replacement were also registered. Finishing and polishing significantly reduced the number of decisions to replace restorations in all groups and for all practitioners. "Appearance" (anatomic shape) was the most frequently cited reason for replacing restorations before finishing and polishing, followed by marginal defects and secondary caries.