الفهرس 
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Abstract
Objective: The aim of the present study was to evaluate translucent ytteriastabilized zirconia (Y-TZP) bonded to resin cement after its surface
treatment with air-borne particle abrasion, CO2 laser and zirconate coupling agent. Materials and methods: A total number of forty disc shaped specimens were prepared for this study from monolithic Y-TZP (15 mm diameter x 2 mm thickness). The XRD method was used to analyze crystalline microstructure of four specimens (one specimen from each group) before and after different surface treatments. Surface roughness measurement was carried out on twenty specimens to measure Ra (average roughness height) in micrometer using an electro-mechanical profilometer before and after different surface treatments.
For micro-shear bond strength test the forty specimens were used (twenty specimens were used for bonding to the first type of resin cement and the other twenty were bonded to the second type). Each twenty specimens were divided into four groups (five specimens each) according to the previously mentioned surface treatment used prior to bonding to the resin cement. The micro-shear bond strength was measured by applying an axial load with stainless steel wire 0.3 mm diameter looped around the bonded interface using a universal testing machine. Results : from x-ray analysis the control specimen showed average crystal size= 169 A°. An increase in average crystal size resulted after all surface treatments. After air-abrasion surface treatment= 335 A°, after CO2 laser surface treatment= 297 A° and after zirconate coupling agent surface treatment= 272 A°. For surface roughness (Ra), carbon dioxide treated specimens recorded the highest mean values (1.965±0.195) while airabrasion surface treated specimens recorded the lowest mean values (0.655±0.165). For micro-shear bond strength air-abrasion recorded the highest mean values for type I and type II resin cements (25.75± 4.59) and (22.72± 3.72); the lowest mean value was for control groups (14.9± 0.97) and (10.53± 1.15). Student t-test revealed that there was no significant difference between values of both types of cements when bonded to either control (P= 0.2103) or air-abrasion (P= 0.0660) treated groups. However, there was significant difference between CO2 (P= 0. 0027) and zirconate coupling agent (P= 0.0002) treated groups. Conclusion : Surface treatments caused changes on microstructure of tested groups. Surface roughness and micro-shear bond were significantly affected due to different surface treatments as air-abrasion, CO2 laser and zirconate coupling agent surface treatments. Air-abrasion provided the highest bond strength with the self-adhesive resin cements. CO2 laser showed the highest value of surface roughness. There were no significant correlation between surface roughness and micro-shear bond strength.