The wear of dental amalgam by a smear mechanism and amalgam transfer onto the opposing cusp was confirmed by simulated studies in an artificial mouth. The coefficient of wear for dental amalgam was 4.89×10-5. Calculation of the coefficient of friction for the enamel/amalgam couple indicated that friction was overcome by shallow slippage and shear within the amalgam. On the basis of these facts, the good wear performance of both the amalgam and the opposing enamel was rationalized. A retrospective clinical correlation of amalgam wear in an artificial mouth showed a correlation coefficient of 0.938 as far as the mean wear values were concerned. Further the wear rates in both studies were linear except in a narrow region at time zero. The variances, however, in the 2 studies were very different. The desirability of in vitro studies to reproduce the same variance, as well as the same mean values, is a point for further discussion and experimentation.
- artificial mouth
- clinical correlation