Corrosion behaviour of an indigenous Ag-Sn-Cu cast dental alloy in artificial saliva.
The corrosion behaviour of an indigenous cast alloy of Ag-Sn-Cu, developed for crown and bridge prostheses, was studied in artificial saliva, with and without the addition of 0.1 M lactic acid, using a potentiostatic technique, and compared with that of the standard cast alloy of Ag-Pd (Ney 76). The values of different parameters such as corrosion potential and corrosion current density were determined for the indigenous alloy of Ag-Sn-Cu and the Ag-Pd alloy. The rate of corrosion of the indigenous alloy was found to be relatively higher than that of the Ag-Pd alloy up to an applied potential of + 400 mV. However, while the indigenous alloy showed a distinct tendency for passivation below + 200 mV at the current level of 0.5 mA/cm2 in the artificial saliva (pH 5.7) at 37 degrees C, no such tendency for passivation was shown by the Ag-Pd alloy even up to + 400 mV. The tendency for passivation by the indigenous Ag-Sn-Cu alloy, however, was not shown in the artificial saliva in the presence of 0.1 M lactic acid (pH. 2.7) at 37 degrees C. Minor variation was observed in the corrosion behaviour of the indigenous Ag-Sn-Cu alloys of different grades prepared by alloying elements of varying purity.
Patro
T K
TK
Department of Dentistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
Singh
B P
BP
Singh
V
V
D003300:Copper; D003343:Corrosion; D003722:Dental Alloys / Q000737:chemistry*; D019344:Lactic Acid; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010165:Palladium; D012464:Saliva, Artificial; D012834:Silver
D003722:Dental Alloys; D012464:Saliva, Artificial; D019344:Lactic Acid; D012834:Silver; D010165:Palladium; D003300:Copper