Influência da abertura oclusal na resistência à fratura de restaurações cerâmicas implanto-suportadas

Abstract

This study aims to evaluate the influence of occlusal opening in the fracture resistance of implant-supported crowns with zirconia (YZ) and metal (MC) infrastructure (IE), screw-retained or cemented. The IEs were porcelain veneered. Four experimental groups (n = 12) were evaluated: YZc and MCc - cemented YZ and MC crowns; and YZs and MCs - screw-retained YZ and MC crowns. All crowns were tested under compressive load to failure in 37°C distilled water. Fractured surfaces were examined to determine the crack origin. The maximal fracture loads were evaluated using two-way analysis of variance (ANOVA) and Tuckey (α = 0.05). The type of crown fixation (cementation or screw-retained) influenced the fracture resistance. MCc and YZc groups had greater mean values than the screw-retained groups. The material IE (Y-TZP or metal) did not influence the resistance of the crowns. In conclusion, the occlusal opening showed a negative influence on the maximum fracture load of crowns, irrespective to the IE material type, confirming the study hypothesis.