Wear behavior of crown restoration materials and bovine tooth enamel opposed by pure titanium

The purpose of this study was to investigate the wear behavior of pure titanium when opposed to six different crown restorative materials. Abrader specimens were prepared by casting pure titanium and these were paired with substrates including pure titanium, resin composite, lithium disilicate, zirconia, silver-palladium-copper (Ag-Pd-Cu) alloy, and bovine enamel. The wear volume of each abrader and substrate specimen was measured using the two-body wear test, and factors affecting wear behavior, such as microstructures and hardness, were evaluated. Results indicated that titanium-to-titanium abrasion caused significant wear in both the abrader and the substrate. In contrast, no significant wear was observed for the zirconia and Ag-Pd-Cu alloy against titanium. SEM images showed linear wear marks in most specimens other than zirconia and resin composite, microcracks in enamel, and filler fall in resin composite. A strong correlation between the wear volume and Vickers hardness was found for ceramics, resin composites, and enamel. However, due to the small slope of the approximate straight line in this correlation suggests that the wear behavior of materials when abraded by titanium is only partially influenced by the microstructure and hardness of the material.