Method: 20 inlays cavities were prepared into fresh extracted natural teeth. CAD/CAM inlays (n=10/ series) were fabricated from either a monolithic ceramic (leucite reinforced) or a hybrid polymer (resin nanoceramic). Two groups of each material were defined according to bonding options: flash polymerized and polished (FP), wiped removal of resin cement excess, polymerized and polished (WP). Two-body wear tests (10N, 100000 cycles, 1,5 Hz) with standardized lithium disilicate antagonist cusps were performed in a sliding wear simulator modified with a liquid chamber. The sliding movement was determined around the resin cement joint to investigate this specific area. 3D confocal profilometry was performed before and after the wear test to measure the volume of material loss. Scanning electron microscopy was applied for evaluating wear performance of inlays, resin cement, enamel borders and antagonist cusps.
Result: Mean relative wear volumes were 1 mm3 (±0.21) for ceramic inlay specimens, and 0.9 mm3 (±0.23) for resin nanoceramic inlay specimens. Mean relative wear volumes of antagonist cusps were 0.30 mm3 (±0.09) and 0.27 mm3(±0.26) respectively. Student T-test showed no significant differences between the two specimen groups (p=0.29) and between antagonists (p=0.78). SEM observations after wear simulation showed various types of marginal deficiencies, independent of the bonding method (FP, WP).
Conclusion: Within the limits of this study, one can conclude that the resin nanoceramic tested seems to be a suitable alternative to the ceramic, in terms of wear performance.