Corrosion of amalgams with special regard to zinc

Five dental amalgams were studied in an in vitro corrosion test. Cylindrical test specimens were stored in weak lactic acid solutions at different pH for 1 month. The solutions were analyzed for zinc, the specimens were inspected and examined in SEM. The results showed that zinc was dissolved rather quickly from the amalgams and the amount was highest for the conventional one. Some amalgams had a low tendency for corrosion products to adhere to the surfaces. The presence of zinc did not seem to reduce their corrosion resistance.