As-casting performance of gold alloys and their de-bonding strengths in metal-ceramic systems

This study characterized noble gold casting alloys and evaluated the de-bonding strength of metal-ceramic composite structures. A casting metal plate was prepared from three commercial alloys with similar constitutions: BegoStar, Argedent 500 (Argen500), and Jelenko Cameo (Cameo). The physical properties of strengths, modulus and recovery angle were tested by three-points bending mode. Vickers microhardness of the cast alloys were measured across the samples. The de-bonding strengths of metal-ceramic composite structures and failure surfaces were also evaluated. The as-casting Argen500 alloy represented the more ductile, stronger and better porcelain bonding properties with highest values of the ultimate strength, yield strength, recovery angle, and lower coefficient of thermal expansion (CTE). An Indium (In) contained alloy (Argen500) possesses more compatible CTE and smaller grain size with higher hardness in the oxide effect layer would be an advantage to porcelain fused-to-metal alloys applied in fixed partial dentures.