Abstract
Aim: The aim of this study is to evaluate the interactive influence of different types of cement and surface treatments on bond strength of zirconia. Materials and Methods: Thirty cylindrical zirconia blocks (Diameter4mm& thickness4mm)were fabricated for the study. All the specimens were ground with 600 grit silicone carbide polishing paper. Zirconia specimens were randomly divided into three main groups. 1stcontrol (600grit) no surface treatment. 2ed the specimens were air-abrasion with 50um aluminum oxide particles (Al2O3). 3 rd the specimens were air-abrasion with 50um aluminum oxide particles (Al2O3)+ silane .Then ,each group was divided into two groups according to the luting cement used which are( Reinforcd glass ionomer cement and dual cure resin cement).The zirconia blocks bonded to the composite blocks using these types of cements. Then each pair of zirconia block and composite was applied to load of( 15 Kg) for 15 minutes in order to standardized the applied pressure for each type of cement . The resin cement was then light polymerized for 30s with LED light at 500mW/cm2 (Ledition, Ivoclar Vivadent, Liechtenstien) at the distance of 1mm from each direction. The specimens were stored for 24 hours at 37℃. Shear bond strength was measured by using Universal Testing Machine, and mode of failure examined by a stereomicroscope. Results: All the zirconia blocks were bonded to the composite blocks by self adhesive resin cement revealed results more preferable than zirconia blocks were bonded to the composite blocks by Reinforced glass ionomer cement. The shear bond strength between Zirconia and self-adhesive resin cement for the surface were treated with Aluminum-oxide air abraded alone, and zirconia surface were treated with Aluminum-oxide air abraded + silane more preferable than shear bond strength cement between Zirconia and Rinforeced glass ionomer cement for the surface were treated with Aluminum-oxide air abraded alone, and zirconia surface were treated with Aluminum-oxide air abraded + silane. Conclusion: Zirconia was more durable with Self-adhesive resin cement than Reinforced glass ionomer cement. Zirconia Surface treatments were very critical for improvement bond strength with cement in addition to the properties of that cement .
