Evaluation of the Tribocorrosion Behavior of Ti-6Al-4V Biomedical Alloy in Simulated Oral Environments

The sliding wear of Ti-6Al-4V alloys coexisting with dental amalgam in a simulated temperature-controlled cell was evaluated. Disc-shaped samples of Ti-6Al-4V (n = 30) and spherical silver amalgam (n = 30) were prepared. Discs were subjected to wear while immersed in artificial and fluoridated saliva as follows: Ti-6Al-4V-Ti-6Al-4V (G1); amalgam-amalgam (G2), and Ti-6Al-4V-amalgam (G3). Samples were analyzed for mass variation, volume loss, and surface roughness. Wear tracks were characterized by scanning electron microscopy. Wearing induced significant mass loss for all groups except G3 in fluoridated saliva: Ti-6Al-4V (p = 0.045) and amalgam (p = 0.732). These samples presented an increase in mean surface roughness (p = 0.032 and 0.010, respectively). Overall, Ti-6Al-4V showed 0.07 mm3 (95% CI: [0.06-0.07]) higher wear track volume. Ti-6Al-4V has a higher mass loss when subjected to fluoridated media but no significant roughness variation. Fluor-containing substances should be avoided over Ti-6Al-4V alloys placed in areas of mechanical wear, especially if dental amalgam is also present.