Qualitative and quantitative wear rate analysis of direct restorative materials

The aim of this in vitro study was to analyze the wear rate of three direct restorative materials (Dispersalloy,Z250 and Surefil) using two methods of evaluation: visual M-L scale and profilometry. The occlusal surfaces of twelve human molars were ground flat using diamond disc. Standardized cavities were prepared using no 721PM diamond bur and restored according to the manufacturers’ instructions. They were then stored in distilled water at 37oC for 24 hours, polished, replicated and mechanical cycled. Wear assessment was performed using the ML scale and profilometry. Different values were observed for the tested materials depending on the method of evaluation. For the M-L scale no difference was found among Dispersalloy, Surefil and Z250, whereas the profilometer showed that Dispersalloy had lower wear than Surefil and Z250 (p<0.01). The M-L scale demonstrated poor accuracy when compared to the profilometer method (p<0.05) to evaluate the wear rate of restorative materials.