In vitro corrosion of dental amalgams

A series of dental alloys were characterized with respect to chemical composition, microstructure and corrosion resistance in artificial saliva. The following types of amalgams were studied: conventional and high copper dispersed phase dental alloys. Anodic polarization curves were recorded on these samples and periodic polarization resistance measurements were performed during a test of immersion in artificial saliva. The results are in accordance with extensive clinical findings, which attribute a greater corrosion resistance to the dispersion phase alloys. Examination by scanning electron microscopy and electron probe microanalysis allowed the identification of the various phases present on the amalgams and of the main corrosion products.