effect of Preparation Design effect on Emax Occlusal Veneers fracture resistance

Abstract

Aim: the objective of our study is to investigate the effect of two preparation designs on Emax occlusal veneers fracture resistance.Materials and methods: Fourteen epoxy dies were duplicated from two Typodont acrylic teeth.Two preparation designs were used.Group (1): represented butt margin occlusal preparation.Group (2): represented occlusal preparation with chamfer finish line.Seven dies duplicated from each group.Occlusal veneer restorations were constructed from CAD/CAM system.Each occlusal veneer cemented to the corresponding die.Universal testing machine was used to measure fracture resistance values.Load to fracture for all samples was recorded in Newton.Results: Butt joint samples (1649.84±349.53)had significantly higher fracture resistance value than chamfer samples (1273.63±232.58)(p=0.039).Conclusion: Within the limitations of this in-vitro investigation, it might be concluded that butt margin design provides better fracture resistance values that chamfer finish line design using lithium disilicate occlusal veneers.