الفهرس 
Composite resin restorationsOnly 14 pages are availabe for public view
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Abstract
Purpose: to evaluate the fatigue resistance of high translucent zirconia and hybrid ceramic posterior occlusal veneer. Materials and methods: Forty freshly extracted human molars were received Standardized tooth preparations replicating a worn occlusal table by using a diamond saw by removing all coronal tooth structure 4 mm occlusal to the CEJs leaving exposed dentin centrally and peripheral enamel. Intraenamel indexing notches were created proximally. The specimens were divided into 2 groups based on restorative materials each group included twenty teeth for each group (group I: high translucent zirconia (Bruxzir Anterior), group II: polymer infiltrated ceramic (Vita Enamic). The estoration thickness was 1 mm at the fossa and 1.5 mm at the cusp tip. Cementation of the specimens were done by self-etch resin cement (Panavia F2.0). Half of the specimens of each group were subjected to fracture resistance test while the other half subjected to thermocycling (15000 cycles, 5-55 C, 30 sec dwell time) and chewing simulator with a load 150 N which was applied for 600,000 cycles to simulate 2.5-5 years with a loading frequency 6 HZ. Specimens that survived cyclic loading were loaded to failure to calculate the residual fracture strength after fatigue. Mean values for each group were calculated, and differences between the groups were tested for statistical significance by use of 2-way analysis of variance (ANOVA). Results: Both material and fatigue test had significant effect on the fracture resistance (P-value<0.001). According to the material type the Pvalue was high significant as the Bruxzir Anterior had a higher mean of fracture resistance than the Vita Enamic.