الفهرس 
Implant Abutment:
Ceramic-zirconia abutment.Only 14 pages are availabe for public view
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Abstract
Background: The advantage of potential retrievability of cement-retaine implant restorations using provisional cement has raised question about it ’s capability to retain restoration for a long period of time in between periodic check up.Purpose: To evaluate the effect of various surface treatments of implant abutment and metal cope fitting surface on their bond strength to provisional resin cement.Materials and Methods: Sixty implant analogs and standard titanium abutments of 6 mm height were embedded vertically in autopolymerizing acrylic resin blocks. Metal copings with a loop on the occlusal surface were fabricated using nickel chromium (Ni-Cr) alloy. Samples were divided according to their surface treatment into three groups (n=20 for each group);Group (1) air borne particle abrasion with 50 μm Al2O3 powder. Group (2)air borne particle abrasion with 50 μm Al2O3 powder plus alloy primer(Kuraray, Japan). Group (3) samples were silicoated and silanated using cojet system (3M ESPE). Each group was subdivided into two subgroups (n=10 for each subgroup) according to storage condition and stressing; Subgroup (A)short term water storage and Subgroup (B) short term water storage and thermocycling plus mechanical loading. The copings were luted using provisional resin cement (Sensitemp, Sultan health care, USA) under stati load of 3 kg. Before tensile test all samples were stored in distilled water for 24 hours at 37oC. Samples were tested for tensile bond strength using a universal testing machine at a crosshead speed of 0.5 mm/min. Tensile failure of the copings were recorded in megapascals. Samples were examined under digital microscope to detect the mode of failure. Statistical analysis of the results and comparison between each two groups were performed using One Way ANOVA (significance at P≤0.05) followed by post-hoc tests. T-test