Effect of chloride ion on corrosion of two commonly used dental alloys / 中南大学学报(医学版)

ABSTRACT

Objective: To investigate the effect of chloride concentration on the corrosion of Co-Cr alloy and pure Ti in a simulated oral environment. Methods: The electrochemical corrosion tests of pure Ti and Co-Cr alloy were carried out in neutral artiifcial saliva solutions with different NaCl concentrations (0.9%, 2.0%, and 3.0%). hTe morphologies of corroded surface for pure Ti and Co-Cr alloy were observed by scanning electron microscope (SEM). Results: hTe changes in the self-corrosion potentials (Ecorr) for pure Ti and Co-Cr alloy in three kinds of artificial saliva solutions was not obvious. However, the self-corrosion current densities (Icorr) of pure Ti were much lower than those of Co-Cr. TheIcorr of Co-Cr alloy increased in a concentration-dependent manner of NaCl, whereas the breakdown potential (Eb) of Co-Cr alloy decreased in a concentration-dependent manner. hTe potential ranged for the breakdown of oxide film (Ev) was shortened in a concentration-dependent manner of NaCl. There was no obviousdifference in theIcorr of pure Ti with different concentrations of NaCl. hTe breakdown potential was not seen according to the polarization curves. Conclusion: In a certain range, the increase of the concentration of Cl- leads to accelerate the corrosion behavior of Co-Cr alloy, but it does not affect pure Ti.