Influence of Cavity Preparation on Fracture Resistance of Leucite Reinforced Ceramic Onlay Restorations
Authors: Marcelo Martins , Liana Claudia Britta , Roberta Tarkany Basting and Fabiana Mantovani Gomes Franša
Abstract: Purpose: The aim of this study was to assess the fracture resistance of onlay restorations fabricated of leucite reinforced ceramic according to three different cavity preparation configurations. Methods: Sixty human third molars were divided into 4 groups: Control: sound teeth; G1: MOD preparation with occlusal and proximal cavities, reduction of 1.8 mm for functional and 1.5 mm for non-functional cuspids; G2: MOD preparation without cavities, reduction of 1.0 mm for functional and non-functional cuspids; G3: Similar to G2 and reduction of 1.8 mm for functional and 1.5 mm for non-functional cuspids. After onlays cementation, fracture resistance tests were performed in a universal test machine at 0.5 mm/min. Results: The data were submitted to ANOVA and there was no statistically significant difference in the fracture resistance among the groups. The preparation without occlusal and proximal boxes resulted in fracture modes with less compromised tooth structure. It could be concluded that it is feasible to make more conservative preparations for partial ceramic restorations without loss of their fracture resistance and without compromising the resistance of the tooth.