抄録
Among many dental metallic materials used for superstructures to be placed on Ti implant abutments,12% Au-Ag-Pd alloy can be considered one of the best material choices, based on both electrochemical and mechanical properties. In this study,the relationship between the wall thickness of cast and fitness of 12% Au-Ag-Pd alloy was investigated, using waxes prepared at a trail base. The wall thickness of cast was varied with 0.4,0.6, and 0.8mm. The investment material used in this study was a raid heating-type gypsum bonded investment.Surface roughness of casts was also measured.The solidification expansion of the investment and its related stress, and the thermal expansion coefficient of the investment, were also measured.
Main results were as follows:
1. The stress that developed in the investment after the mixing increased over time. But the wax pattern was not deformed by force.
2. The trial wax C exhibited the best accuracy,because of large flow, a low melting temperature,and large thermal expansion.
3. It was also found that the fitness got worse when the wall thickness of the cast became thicker.
