Abstract:

Objective To study the effect on the corrosion resistance of Cr alloy in the artificial saliva with different pH value in vitro. Methods Compared to Ti alloy，electrochemical technique was used to measure the electric potential of corrosion（Ecorr ） , current density of corrosion（Icorr ） Cr alloy in the artificial saliva with different pH value. The corrosion and corrosion resistance mechanism on Cr alloy in the artificial saliva with different pH value had been investigated by the EIS curves． Results The corrosion resistance of Co-Cr alloy was better than Ti alloy. The value of Icorr was lower and the value of Rp was larger than Ti alloy. The corrosion resistance of Ni-Cr alloy was worse than Ti alloy. The value of Icorr was larger and the value of Rp was lower than Ti alloy. The pH value in the artificial saliva was decreased, the Icorr value of three types of alloy increased, the Rp value of three types of alloy decreased. But the changes of Co -Cr alloy was smaller than that of Ti alloy or Ni -Cr alloy. Conclusion The corrosion resistance of Co-Cr alloy was superior to that of Ni-Cr alloy and Ti alloy． In the acid artificial saliva, the corrosion resistance of three types of alloy descended evidently．

Key words: dental alloy, corrosion, polarization curve, electrochemical impedance spectroscopy