| Objective:The aim of this study was to investigate the influence of contaminations and cleaning methods on the shear bond strength (SBS) and durability to airborne particle-abraded zirconia ceramic with resin cement.Methods:After immersion in saliva,blood or the use of a silicone disclosing agent, the airborne particle-abraded zirconia specimens were cleaned with additional airborne particle abrasion (AB),1.0 wt% sodium hypochlorite (SHC) or water-spray rinsing (W) only. Specimens without contamination served as controls (NC). A universal primer (Monobond N) was applied to the zirconia surfaces and then the specimens were bonded to dentine with luting resin (Variolink N).All specimens were were tested for shear bond strength(SBS) after 24 hours or 5000 thermal cycles (TC). The fractured surfaces were observed using an optical and scanning electron microscope (SEM). Statistical analysis was performed using one-way ANOVA with a=0.05.Results:1. The shear bond strength of group B-W and S-W showed significantly lower than the group NC (P<0.05)2. The shear bond strength of group B-AB and group B-SHC were higher than group B-W (P<0.05)3. Before artificial aging, bond strengths of the group B-AB and group B-SHC were have no significant difference (P> 0.05); After artificial aging, The shear bond strength of group B-AB showed significantly higher than the group B-SHC (P< 0.05)4. The shear bond strength of group S-SHC were significantly higher than the group S-W, and have no significant difference from group NC (P>0.05)5. Before artificial aging, The shear bond strength of group S-AB showed significantly higher than the group S-W (P< 0.05); After artificial aging, bond strengths of the group S-AB and group S-W were have no significant difference (P> 0.05).6. The shear bond strength of group B-W were higher significantly than group S-W (P <0.05).7. After artificial aging, the shear bond strength of group B-W and group S-W showed significantly lower than before.8. Before artificial aging, The failure mode were cohesive mainly in group NC(95%), group B-SHC(70%), group B-AB(76%), group S-SHC(66%) and group S-AB(63%). However, group B-W and group S-W were mainly adhesive failure mode.The adhesive failure mode observed in bebond zirconia surface were increased after artificial aging.Conclusions:1. Saliva, blood and silicone fit-indicators, espically saliva and blood contamination significantly affected resin bonds to zirconia ceramic and its durability.2. Airborne-particle abrasion and SHC were effective cleaning method for cleaning siliva and blood contamination on zirconia surfaces. Airborne-particle abrasion is better than SHC.3. SHC can remove fit-indicators contamination effectively and enhancing the resin bond strength. |
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