Use of Simple Binary Co-xCr Alloys (0≤x≤30wt.%) for Exploring the Influence of the Chromium Content in Dental Cobalt-Based Alloys on Their Passivation Behavior in a Fusayama Artificial Saliva | Biomedgrid

More and more Predominantly Base alloys are used instead the expensive dental alloys containing high concentration in noble metals. Among these PB alloys the ones based on cobalt and chromium are rather interesting since they bring high mechanical resistance, and do not risk induce any nickel release in mouth. Their corrosion resistance is due to the presence of chromium the content of which may be optimized. In this work contribution to a better knowledge of the critical Cr content to necessarily exceed for a corrosion resistance high enough is done by exploring the direct relationship between the corrosion behavior and the Cr content, by choosing a particularly aggressive artificial saliva and a series of binary alloys with an increasing Cr content, in order to exclude all other possible parameters susceptible to interfere. The different electrochemical results - free potential follow-up, Stern-Geary results and the cyclic polarization curves - demonstrate that 20wt.%Cr should be enough to allow cobalt-based dental alloys rapidly developing a protective passivation layer and showing a good resistance against corrosion in the buccal milieu. This suggests that the current chromium contents of commercial cobalt-based dental alloys may be lowered down to this threshold value without loss of their good corrosion resistance.