Fracture strength of hybrid ceramic occlusal veneers using two preparation designs on different dental substrates

Abstract

This study was designed to evaluate the effect of different preparation designs including non anatomical and anatomical with different bonding substrate on fracture resistance of poymer infiltrated ceramic occlusal veneer restorations. Twenty eight extracted human mandibular molars without caries or visible fracture lines were selected based on the teeth having similar bucco-lingual (BL) and mesio-distal(MD) dimensions. The selected teeth were divided into 2 main groups according to the occlusal preparation designs and then each group of teeth was subdivided into 2 subgroups according to the different bonding substrate. For all teeth, the CNC milling machine was adjust to reduce fourteen teeth with 90º butt margin (flat) and other fourteen follow the occlusal anatomy of the teeth with an angle 150º between cusps.