Localized wear of compomer restorative materials

Purpose: To determine and compare the localized wear of six compomer restor ative materials. Materials and Methods: Ten specimens of Dyract, Dyract AP, F2000, Compoglass F, Elan and Hytac were prepared in a custom fixture and polished. A pretest surface profile was generated using an MTS 3-D surface profilometer and the specimens were subjected to 400,000 cycles in a Leinfe lder wear machine equipped with a conical stylus tip to simulate localized wear. A post-test profile was generated and the before and after profiles w ere fitted and analyzed using AnSur 3-D software. The total volume loss and depth of the wear facet on each specimen was calculated and statistical an alysis was accomplished (ANOVA and Tukey's test). Results: Volume loss (mm) was as follows: F2000, 0.027 +/- 0.002; Hytac, 0.007 +/- 0.023; Elan, 0.05 4 +/- 0.013; Compoglass F, 0.135 +/- 0.006; Dyract AP, 0.135 +/- 0.023; Dyr act, 0.185 +/- 0.032. Maximum depth of the wear facets (mum) was as follows : F2000, 112.2 +/- 10.2; Hytac, 132.8 +/- 9.3; Elan, 144.3 +/- 23.1; Compog lass F, 168.3 +/- 13.0; Dyract AP, 194.0 +/- 19.7; Dyract, 220.6 +/- 15.8. There was not a difference (P > 0.05) in volumetric loss between F2000 and Hytac or between Hytac and Elan. The volume loss and maximum depth of the w ear facets of F2000, Hytac and Elan was significantly less (P < 0.05) than Compoglass F, Dyract AP and Dyract The results of this study indicate that there are significant differences in the in vitro wear rates of compomer ma terials.