[The influence of surface treatments on non-precious metal-ceramics alloys (author's transl)].

In this study, the author attempted to find out the suitable methods of surface treatments for non-precious metal-ceramics alloys. Three Ni-Cr system alloys in the market, (Gemini II, Euro-ceram and Wiron S) were used. The shear bond strength was measured under the various conditions, varying the heating temperatures of pre-oxidation treatment and finishing methods of the metal surface. A specially designed apparatus which had been improved by the author, was used to measure the shear bod strength of the metal-ceramics. The following results were obtained. 1. The testing method improved was found better as a means of measuring the bond strength. Because the shear bond strength which was obtained by this testing method was hardly affected by the compressive force originating from porcelain contraction or the strength of alloys. 2. In the case of Gemini II and Euro-ceram, the influence of the finishing treatment on the properties was great. The coarser the surface roughness, the greater the value of the shear bond strength. 3. In the case of Wiron S, the influence of the pre-oxidation treatment was great. The higher the temperature of treatment, the greater the value of shear bond strength. 4. The optimum surface treatment of metal was obtained among three alloys respectively. The shear bond strength of Gemini II was greater than the others under any condition. In the case of Euro-ceram, the highest bond strength was obtained under the coarser surface condition regardless of the temperature of pre-oxidation treatment. In the case of Wiron S, the highest bond strength was obtained by the surface which was finished by the #600 emerypaper and the higher temperature of pre-oxidation treatment.