Progressive Tooth Wear Against Bulk-Fill Resin Composite

Objectives: To characterize human tooth wear behavior against a bulk-fill restorative (BF) compared to a conventional resin composite (RC) and a CAD/CAM resin nano ceramic (RN).
Methods: Square-shaped specimens of each material were prepared and sub-divided according to the testing time (n=8): 100,000, 250,000, and 500,000 cycles. The test was performed using a chewing simulator, with 49 N, 2 Hz, in 37°C distilled water. Human premolar cusps were used as antagonists. Micro-CT and laser scanner were used to scan antagonists and specimens, respectively. Wear volume was assessed using a software and the wear pattern was examined with SEM. Softening in solvent was measured for the materials. Wear data were analyzed with two-way ANOVA and Student-Neuman-Keuls test (α=0.05).
Results: For tooth and specimen volume loss, there was statistical significance for material and time, but not for the interaction between factors. BF resulted in less tooth and specimen wear than RN and RC, which were statistically similar. Volume loss increased from 100,000 to 500,000 cycles. BF showed the lowest microhardness (KHN1) and %ΔKHN similar to RC, but greater than RN.
Conclusions: BF resulted in a more favorable tooth and specimen wear behavior. The wear pattern and damage progression were mild for all materials.