ABSTRACT
The aim of this in vitro study was to investigate the wear behavior of the abrader when tetragonal zirconia polycrystal (TZP), cp-titanium (CpTi) and Ti-6Al-4V alloy (TiAlV) were used as the antagonist on fixed dental prostheses (FDPs). Both hemisphere abrader and flat substrate specimens were prepared using TZP, CpTi and TiAlV. Two-body wear tests were performed in distilled water, and the wear volume of the abrader specimen was measured to evaluate the wear behavior. In addition, scanning microscopic observation and an electron probe micro-analysis were performed to elucidate the underlying mechanism of the wear. The wear volume of CpTi and TiAlV abrader specimens was approximately 20 times larger than that of TZP abrader specimen against all substrate specimens. This is due to the differences in hardness between the ultra-hardness of TZP and the comparatively low hardness of CpTi and TiAlV. The wear volume of CpTi and TiAlV abrader specimens against the TZP substrate was significantly smaller than for the CpTi and TiAlV substrates despite the hardness of TZP being much larger than those of CpTi and TiAlV. This phenomenon may be based on the adhesive wear mechanism. Elements of Ti, Al and V originating in the TiAlV substrate were detected adhering to the abrader CpTi specimen. These results suggest that FDPs of CpTi and TiAlV are susceptible to wear against not only TZP but also CpTi and TiAlV in contrast to TZP FDPs.
Subject(s)
Dental Prosthesis/methods , Prosthesis Design , Titanium/chemistry , Tooth Wear , Zirconium/chemistry , Alloys , Dental Enamel/chemistry , Electron Probe Microanalysis , Hardness , Materials Testing , Microscopy, Electron, Scanning , Surface Properties , Water/chemistryABSTRACT
The aim of this study was to clarify the influence of tetragonal zirconia polycrystal (TZP) on the two-body wear behavior of titanium (Ti). Two-body wear tests were performed using TZP, two grades of cp-Ti or Ti alloy in distilled water, and the cross-sectional area of worn surfaces was measured to evaluate the wear behavior. In addition, the surface hardness and coefficient of friction were determined and an electron probe microanalysis performed to investigate the underlying mechanism of wear. The hardness of TZP was much greater than that of Ti. The coefficient of friction between Ti and Ti showed a higher value than the Ti/TZP combination. Ti was more susceptible to wear by both TZP and Ti than TZP, indicating that the mechanism of wear between TZP and Ti was abrasive wear, whereas that between Ti and Ti was adhesive wear. No remarkable difference in the amount of wear in Ti was observed between TZP and Ti as the opposite material, despite the hardness value of Ti being much smaller than that of TZP.