Effect of electrodeposition of gold on porcelain-to-metal bond strength.

The effect of electrodeposition of two different thicknesses of gold on porcelain-metal bond strength with three different base metal alloys was determined and compared to a control high gold alloy. The following conclusions can be drawn. Mean porcelain-metal bond strengths of all four alloys were in the same range when conventional porcelain application techniques were used. However, the base metal porcelain-metal bond is clinically suspect because of adhesive failure through the porcelain-metal interface. A thin 180A gold coat increased the porcelain-metal bond strength and generally resulted in cohesive failure through the porcelain. A thicker gold coat (720A) decreased the bond strength and generally resulted in adhesive failure. The mechanism of action of the gold coat on bond strength is likely its effect on the oxide layer on the surface of the base metal alloy.