Influence of Restoration Thickness and Auxillary Retentive Means on Fracture Resistance of Occlusal Ceramic Veneers

Objectives:To evaluate the influence of restoration thickness and auxillary retentive means on fracture resistance of occlusal ceramic veneers. Materials and Methods: Forty sound molars were chosen which are free from caries, The teeth were divided into two classes and restored with CAD/CAM lithium disilicate ceramic occlusal veneers. Group (1) has no finish line, while Group (2) has a finish line. Each category consisted of 10 molars with buccal groove extension and 10 molars without it, with two thicknesses of 1 and 1.5 mm.Usage of a universal testing machine to measuring the fracture strength of lithium di silicate material after loading till fracture. Results: Only specimens in the group with the thickest thickness of (1.5 mm ) survived cyclic loading without any damage. Survival rates in the remaining sub-groups ranged from 50 to 100% for surviving with some damage and from 12.5 to 75% for surviving without any damage. Medians of final fracture resistance ranged from 772 to 902 N. In groups with larger ceramic thickness (1.5 mm) provided statistically significant (p ≤0.05) higher fracture resistance than smaller one. Significance: Usage of 1.5mm thickness buccally retentive lithium disilicate ceramic occlusal veneers can restore successfully severely abraded teeth. Article information Received: 13 February 2021 Revised: 21 April 2021 Accepted: 20 April 2021