Corrosion of galvanic couples of stainless steels with non-precious alloys in the oral cavity

ABSTRACT

In the restoration of lost or misaligned dental pieces, dissimilar dental alloys are frequently used in the oral cavity, which form galvanic couples that corrode due to the effect of saliva and dentin fluids. In this work, the microstructure of ten non-precious dental alloys was analyzed by optical microscopy, the open-circuit corrosion potential of each alloy was measured against a saturated calomel electrode, they were subjected to accelerated corrosion processes in aerated artificial saliva and plotted the potentiodynamic polarization curves of these alloys. Then, the corrosion potential and current density of the galvanic couples formed by stainless steels 304 and 316L with non-precious dental alloys of Ni-Cr, Co-Cr, and Cu base alloys (Cu-Ni, Cu-Zn and Cu-Al), using the Evans method whose results were not compatible with the principle of galvanic couples, so the Mansfeld equations were used with which results consistent with the aforementioned principle were obtained.

Keywords
Non-precious dental alloys; galvanic couples; artificial saliva; polarization curves