A comparison of different techniques for finishing and polishing amalgam

Three different methods for finishing and polishing amalgam surfaces were studied by determining the roughness (Ra) of specimens at different stages of the procedures. Method I consisted of green stone, followed in sequence by finishing bur and pastes of pumice, powdered chalk, and SnO2. Method II was similar to method I but included brown and green Shofu polishers after the finishing bur. In method III medium and fine sandpaper and fine cuttle-paper discs were used before the pastes. A dramatic decrease in the Ra values was observed after the specimens had been ground with green stones, finishing burs, and sandpaper discs. Pumice resulted in a further reduction in Ra values. However, no significant differences in Ra values were found between the brown Shofu polisher, the fine cuttle-paper disc, and the different pastes. The lowest Ra value--that is, the highest smoothness--was obtained with green Shofu polisher.