Analytical and electrochemical evaluation of the in vitro corrosion behavior of nickel-chrome and cobalt-chrome casting alloys for metal-ceramic restorations.

In this study we examined the hypothesis based on relevant literature survey that the in vitro corrosion behavior of a Cobalt-chrome dental casting alloy for metal-ceramic restorations is better than that of a Nickel-chrome dental casting alloy. The corrosion released metal ions were analysed by Inductively Coupled Plasma-Atomic Emission Spectroscopy. Moreover, the specimens were electrochemically tested by linear polarization. The statistical analysis of the results showed statistically significant differences in corrosion rates of Nickel-chrome alloy and Cobalt-chrome alloy calculated by analytical and electrochemical measurements. The hypothesis was confirmed and the results showed that the corrosion rates of the Cobalt-chrome alloy were lower than that of the Nickel-chrome alloy.