Differences in Surface Roughness between Up and Down Cutting and Grinding on Composite Resins

The differences in finished surfaces produced by cutting and grinding instruments were studied with respect to up and down cutting and grinding with a constant load for conventional and microfilled composite resins. Surface roughness obtained with the cutting instrument was considerably dependent upon the particle size of dispersing phase and thereby the heterogeneity of composite resins. Finished surfaces of the up cutting and grinding with both instruments were smoother than those with down cutting and grinding, indicating the infleneces of the direction of tangential cutting and grinding resistances.