THE INFLUENCE OF ANTAGONISTIC SURFACE ROUGHNESS ON THE WEAR OF HUMAN ENAMEL AND NANOFILLED COMPOSITE RESIN ARTIFICIAL TEETH

Statement of problem. Depending on the applied finishing technique, ceramics may have different values of surface roughness; therefore, their abrasive effect on antagonists may vary. However, different materials may be affected differently by the surface roughness of ceramics. Purpose. The purpose of the present study was to evaluate and correlate the wear of human enamel and nanofilled composite resin teeth with the surface roughness of the antagonistic ceramic after simulated mastication. Material and methods. Three groups of 8 human teeth and 3 groups of 8 nanofilled composite resin teeth were tested against 3 sets of 16 zirconia ceramic balls with different average surface roughness values. Each group was loaded for 300,000 cycles in a mastication simulator. Wear resistance was analyzed by measuring volume and vertical substance lost, determined with a laser scanner. Data were statistically analyzed using 2-way ANOVA. The Pearson correlation test was used to determine whether there was a relationship between the antagonistic surface roughness and the degree to which the materials had worn. Results. An increase in the antagonistic surface roughness significantly increased the wear of composite resin and human enamel. The effect of the antagonistic surface roughness on the wear was significant (P<.001). The correlation between the volume loss and antagonistic surface roughness was significant (r=0.667, P<.001). Conclusions. Nanofilled composite resin and human enamel exhibited different amounts of wear. In general, human enamel showed less wear than nanofilled composite resin. Surface roughness of the antagonistic ceramic influenced the wear of human enamel more than it affected the wear of composite resin. (J Prosthet Dent 2009;101:342-349)