Fracture resistance of manually and CAD/CAM manufactured ceramic onlays.

PURPOSE: This in vitro study aimed to evaluate fracture resistance in lithium disilicate onlays fabricated with IPS e.max Press and IPS e.max CAD systems and luted with different adhesive cements. MATERIAL AND METHODS: Fifty maxillary first molars were prepared using a mesio-occluso-disto-lingual onlay cavity model. Ten onlays from each group were cemented using etch-and-rinse adhesives and high-viscosity composite resin cement, and 10 were cemented with self-adhesive, dual-curing universal resin cement. Fracture resistance was measured. RESULTS: Significant differences were observed between resin cements (p < 0.05) and between materials (p < 0.05), but the interaction of these variables did not produce a significant difference. The fracture resistance of pressable ceramics was significantly higher than that of CAD/CAM onlays (p < 0.05), and Syntac Variolink was significantly higher than that of Multilink Sprint (p < 0.05). CONCLUSION: All groups showed clinically acceptable fracture strength results. According to the study, both the onlay fabrication system and adhesive cements can be a viable treatment option.