الفهرس Only 14 pages are availabe for public view
 |  | from | 174 |  |  |
| | | from | 174 | | |
Abstract
Statement of problem: Veneered Zirconia restorations exhibit very high modulus of elasticity and high incidence of veneering layer chipping. Therefore, the continuous search for high strength esthetic restorations is never ending. Purpose: To evaluate the fracture resistance and mode of failure of of CAD/CAM milled PEEK core veneered by milled High impact polymer composite compared to CAD-On Zirconia core veneered by lithium disilicate. Material and Methods: Fourteen freshly extracted molars were mounted in epoxy blocks and uniformly prepared with a circular deep chamfer finish line of 1.0 mm width. They were divided in to two groups according to the type of crown material (n=7): group A: Teeth restored by ZirCAD core veneered by e.max-CAD and group B: Teeth restored by PEEK BioHPP core veneered by HIPC. All crowns were adhesively cemented. The crowns were then subjected to thermo-mechanical aging using a chewing simulator then static compressive loading till failure using a universal testing machine and failure types were determined