Electrochemical characterization of some copper based dental materials in accelerated test solutions

Abstract

The aim of this study is to investigate the electrochemical behaviour of a three copper based dental alloys (NPG, AM +2, Gaudent alloys) in artificial saliva (AFNOR, pH = 8), acidified saliva (pH = 2.5) and fluoridated acidified saliva (1000 ppm F, pH = 2.5)Open Circuit potential (E(OC)) measurement; potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) are the electrochemical procedures selected for this work. Our results have shown that copper based dental alloys have a relatively good corrosion resistance in artificial saliva, but in acidified saliva and fluoridated acidified saliva the corrosion currents increase. This suggested that the dental alloy retained its protective oxide film. Corrosion currents are also higher in fluoridated acidified saliva as expected because the presence of fluoride ions. The EIS results show that copper based dental alloys exhibit passivity at open circuit potential in artificial saliva but in acidified saliva and fluoridated acidified saliva, the protectiveness of oxide film was no more present.