Wear test combining simulated occlusal wear and toothbrush wear.

A new wear testing system, which carries out toothbrush wear and simulated occlusal wear tests alternately, was developed. Differences in wear behavior among three modes of wears, combined wear, toothbrush wear and simulated occlusal wear, were investigated using polymethylmethacrylate (PMMA) and two commercial resin composites (Z100, APX). The area of the material loss after each test was measured on the worn surfaces to evaluate the different modes of wears.

Development of casting investment preventing blackening of noble metal alloys part 1. Application of developed investment for Ag-Pd-Cu-Au alloy.

The objective of this study is to develop a casting investment that prevents the blackening of the cast surface of noble metal alloys. The experimental investments were prepared using a gypsum-bonded investment in which the metallic powders such as boron (B), silicon (Si), aluminum (Al) and titanium (Ti) were added as oxidizing agents. An Ag-Pd-Cu-Au alloy was cast into the mold made of the prepared investment.