Effects of two-body wear on microfill, nanofill, and nanohybrid restorative composites

Background: The purpose of this study was to investigate two-body wear resistance and hardness of different three modern composite materials. Methods: In the conditions recommended by the manufacturer five pieces were produced from each material. All samples were kept in distill water for 1 week and determined Vickers hardness (HV) before two-body wear test. Then, two-body wear tests were performed using a computer controlled chewing simulator. In this study, the chewing simulator was programmed to provide a 2 mm vertical movement and a 0.7 mm horizontal movement. For each wear test, Al2O3 with a diameter of 6 mm was used as antagonist material. The mean volume loss of all samples after the wear tests was determined with three dimensional profilometry. In addition to a random specimen was selected from each test group and SEM images were taken for analysis of wear tracks. Mean and standard deviation values were calculated and evaluated with the one-way ANOVA. Results: The hardness values of the materials tested in this study were measured between about 49 HV and 78 HV. Significantly, lowest mean volume loss was detected for the Heliomolar at about 3.1 μm3 whereas the highest mean volume loss was detected for the Silorane at about 6.4 μm3 after 360.000 chewing cycles. Conclusions: However, among the materials tested in this study suggested correlations between HV and two-body wear resistance are not significant