Galvanic corrosion of dental alloys and amalgam in artificial saliva containing citric acid

الملخص EN

In this work galvanic corrosion potentials and currents were measured using polarization curves of some dental alloys (amalgam, Co-Cr-Mo, Ni-Cr-Mo, SS 316L, Ti-6 Al-4V alloys) in artificial saliva containing citric acid with three concentrations 3, 6 and 9 g / l at 37oC.

All galvanic corrosion data were measured to coupling of amalgam and other alloys to investigate the galvanic corrosion between filling and other dental devices such as partial-denture framework, crowns, bridges, and endodontic instruments.

The results of galvanic corrosion show that the coupling between amalgam and Ni Cr-Mo alloy gives higher galvanic corrosion current than other metallic contact, and then the contact between amalgam and Co-Cr-Mo alloy was heavier compared with coupling of SS 316L and Ti-6Al-4V alloy with amalgam.

The increasing of corrosion for alloys containing chromium due to rapidly converting of Cr6+ to Cr3+ and this phenomenon decreases the concentration of chromium ions at surface and then increases the dissolution of metal atoms, while decreasing of galvanic corrosion of Ti-alloy coupled with amalgam due to the passive oxide surface layer (TiO2).