Evaluation of the wear characteristics of three different materials used for provisional implant supported restorations

Purpose: This study was conducted to comparatively evaluate the wear resistance of three different materials used for provisional implant supported restorations. Materials and Methods: Thirty natural mandibular first premolar teeth were considered as antagonist teeth specimens. Ten samples each of milled Polymethylmethacrylate (milled PMMA, GROUP I), milled Polyetheretherketone (milled PEEK, GROUP II) and indirect composite resin (SR ADORO, GROUP III) were designated as disc samples. The samples were subjected to wear test in a pin-on- disc machine. Surface roughness wear rate coefficient of friction and volume loss were measured after wear testing. The results were analyzed using paired ‘t test, Analysis of variance, and Post- hoc Tukey s HSD analysis. Scanning electron microscopic analysis was done for one representative tested sample from each test group. Results: Mean surface roughness (Ra) values before and after wear test for GROUPS I, II and III were 0.827 μm, 6.021 μm, 0.473 μm, and 1.194 μm, 0.455μm and 1.407 μm respectively. Mean wear rates (mg/min) of GROUPS I, II & III were 0.000 ,0.010 and 0.011 respectively. Mean coefficients of friction (μ) of Groups I, II & III were 0.979, 0.864 and 0.840 respectively. Mean volume loss (mm3) of GROUPS I, II & III were 6.709, 7.726 and 5.244 respectively. Scanning electron microscopic analysis revealed prominently roughened surface for GROUP I, moderately roughened surface for GROUP III and smoother surface for GROUP II. Milled Polymethylmethacrylate exhibited significantly higher surface roughness both before and after wear test as compared to both milled Polyetheretherketone and composite materials, which was corroborated by surface profilometry and Scanning electron microscopic analysis. Conclusions: Milled Polymethylmethacrylate showed significantly higher wear as compared to other two materials indicative of least wear resistance among the test materials. Milled Polyetheretherketone exhibited a marginally smoother surface compared to composite. Milled Polyetheretherketone and composite showed marginal differences in wear resistance which was statistically insignificant, indicative of similar wear resistance of these two test materials.