[Study of dental alloys in the artificial saliva using an electrochemical impedance spectroscopy].

PURPOSE

With the help of electrochemical impedance spectroscopy (EIS), the purpose of the study was to investigate the corrosion resistance of CoCr alloys ,NiCr alloys and commercially pure Ti(cp Ti) in the artificial saliva(AS).

METHODS

With the EIS, a test was made on the three alloys/metals in the AS (See Bode plot and Nyquist plot). And then, an analysis was made on what was known in the test by the software of ZSimpWin, after which the corrosion resistance of the alloys/metals was evaluated against the parameters of equivalent circuit [R(CR)].

RESULTS

In the Nyquist plot, the capacitance arc radius was in the sequence of cp Ti>CoCr>NiCr. From the Bode plot, an one time constant was able to be obtained. That was the capacitor layer. According to the equivalent circuit[R(CR)], there was no significant difference in the capacitor layer of the three alloys/metals. And the sequence of the impedance value of the three alloys/metals was cp Ti>CoCr>NiCr.

CONCLUSIONS

The EIS results suggest that the three alloys/metals have a great corrosion resistance with cp Ti having the highest corrosion resistance and that CoCr alloys is better than NiCr alloys in the corrosion resistance. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality (Grant No.08DZ2271100) and Shanghai Leading Academic Discipline Project(Grant No.T0202).