Influence of restorative techniques on fracture load of endodontically treated premolars.

UNLABELLED: OBJECTIVE. This study evaluated the influence of restorative techniques on the fracture load and fracture mode of endodontically treated premolars with MOD cavities.

MATERIALS AND METHODS: Sixty maxillary premolars were divided into groups: G1 - sound teeth; G2 - direct technique using Four Season; G3 - Adoro inlays; G4 - Adoro onlays; G5 - Empress inlays; G6 - Empress onlays. The specimens were submitted to compressive axial loading until failure. The fracture mode was analyzed. RESULTS. According to ANOVA and Tukey's test (α=0.05), the sound teeth (1370.61 N) showed the highest fracture load mean, which did not differ statistically from IPS Empress onlays (1304.21 N). Intermediate values were obtained for IPS Empress inlays (918.76 N), Adoro onlays (861.15 N), Adoro inlays (792.71 N) which did not differ statistically among them. The lowest fracture load was obtained for direct restorations with Four Seasons (696.08 N), which did not differ statistically from the Adoro inlays. CONCLUSIONS. The ceramic restorations provided higher fracture load and more incidences of catastrophic fractures. Cuspal coverage increased teeth fracture load. The results were similar for direct and indirect inlays with composite resin.