[The electrochemical behavior of titanium and dental casting in modelling oral conditions]

The electrochemical behavior of titanium and dental casting alloys in modelling oral conditions With applying dental implants in the oral cavity the direct contact of various metals (titanium and other casting alloys) is unavoidable. Considering the electrolyte characteristic of the saliva, the chances are given that electrochemical processes might occur under such circumstances. The aim of this study was to investigate the electrochemical behavior of titanium and other dental alloys being in direct contact with the oral environment. Nickel-chromium, cobalt-chromium, high palladium content and gold alloys as well as CP grade I titanium cast samples respectively were involved in the study. Test models were made from these metals. As an electrolyte solution (set to pH 4) artificial saliva and 0.9 % NaCl solution were used. The type and the rate of corrosion were assessed with laboratory immersion test and electrochemical polarization method. In case of polarization method a three-electrode measuring-cell was applied. Laboratory exposure tests revealed that titanium resisted corrosion; there was no sign of corrosion at all. The high palladium content alloy and gold alloy behaved similarly. The nickel-chromium and cobalt-chromium alloys showed some signs of corrosion, especially in sites with damaged surface or inhomogeneities on the surface. Results of the laboratory electrochemical experiments correlated with immersion studies graphically illustrated in the paper.