Influence of Temperature and pH on Corrosion Behavior of Ni–Cr and Co-Cr Dental Alloys

The aim of this study was to evaluate the influence of temperature and pH on corrosion resistance of Ni-Cr and Co-Cr dental alloys used for fixed and removable partial dentures using potentiodynamic polarization and surface analysis by scanning electron microscopy. The three materials analyzed were Ni-Cr and Co-Cr dental alloys: Kera NH®, Kera 501® and PD Casta H®, which were tested in Fusayama-Meyer artificial saliva with different values of temperature and pH. Our results have shown that Kera 501® and PD Casta H® alloys , which contain Co and a high Cr content, shows the best corrosion resistance in Fusayama-Meyer artificial saliva compare with that of Kera NH® alloy. In acidifid saliva and artificial saliva at 37 °C, the corrosion resistance of Kera NH®, Kera 501® and PD Casta H® alloys was low compare with that of referance solution, but the effect of temperature and pH on the corrosion resistance of Co-Cr alloy was low compared with that of Ni-Cr alloy. On the basis of the results obtained, our advise would be to recommend to avoid an increase in the oral temperature and reduced the taking of acid food which are likely to lower the oral pH and enhance the corrosion of the Ni-Cr and Co-Cr alloys when the fixed and removable partial dentures treatment. Experimental article (J Int Dent Med Res 2013; 6: (1), pp. 9-14)