الفهرس | Only 14 pages are availabe for public view |
Abstract The aim of the study is to evaluate the effect of different repair techniques and aging on the bond strength of the composite resin repair to composite nano ceramic material. A total of 30 samples were constructed from lava ultimate blocks (resin nano ceramic) for this study with standardized dimensions (7 X 7 X 2 mm3). Samples were divided according to surface treatment into 3 groups: group I: Surface treatment using silica blasting (Cojet) technique. group II: Surface treatment using sandblasting technique (50 æm alumina). group III: No treatment (control) . Then surface roughness was measured by profilometer and a random selected sample from each group was scanned by electron microscope. Then repair layer was applied in accordance with the manufacturers{u2019} recommendations. All samples were stored in distilled water at 370c for 24 hours. Each group was further sub divided into 2 subgroups according to aging. Subgroup 1: Not subjected to aging. Subgroup 2: Subjected to aging. Then subgroups were aged by being subjected to thermo cycling for 500 cycles between 5 and 550C with interval time of 30 second. Each sample was subjected to a shear force at a crosshead speed of 0.5 mm / min using a universal testing machine until failure |