Experimental Study and Mathematical Modeling for Corrosion of Amalgam at Different Periods

Abstract

This work involves experimental study for corrosion of amalgam as filling material after different period time (0, 7, 14, 21, 35, 42 days) in artificial saliva by electrochemical method to estimate corrosion parameters such as corrosion potential Ecorr, corrosion current density icorr, and Tafel slopes bc & ba. The results of polarization resistance which calculated according to Stern- Geary equation indicates that the resistance of amalgam was increased during the experimental period due to stable phases which produced between mercury and other powders in amalgam such as Sn–Hg and Ag–Hg, in addition to Ag–Cu and Ag–Sn phases. Cyclic polarization test shows that the reverse scan curves meet the forward scan curve along the passive range.Numerical modeling was achieved to estimate the corrosion behavior of amalgam in artificial saliva through longer period time, the results of this modeling shows that values of polarization resistance for amalgam at long time of filling decreases with time, but after 2200 days of filling, i.e. after at least 6 years.