الفهرس 
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Abstract
Summary and Conclusion
This study was conducted to evaluate the influence of different application modes (self-etching, etch-and-rinse wet, etch-and-rinse dry) and different curing protocols (Light-curing, and dual-curing) of a universal adhesive on shear bond strength of dual-cured composite resin bonded to bovine dentin.
A total of 60 bovine anterior teeth were used. Flat dentin surfaces were prepared by removing enamel over #180 grit SiC paper with copious water irrigation. The teeth were randomly assigned into 6 groups, according to the two experimental factors investigated in the study, factor 1: application modes, factor 2: curing protocols. Adhesive was applied to detin according to its manufacturer instructions. Each tooth received one dual cured resin composite cylinder (2mm x 2mm). Shear bond strength was run at crosshead speed of 0.5mm/min. Statistical analysis was performed using Two-Way ANOVA and Tukey HSD test. The results of this study showed that the application mode had no statistically significant effect on bond strength (P=0.525). However, the curing protocol and the interaction between these two independent variables (application mode x curing protocol) showed statistically significant effect on bond strength (P=0.020 and P=0.002 respectively). Failure mode analysis showed that mixed failure mode was the predominate failure mode by 55%, followed by the adhesive failure mode which represented 43.3%, while cohesive failure represented 1.7% from the total failure modes.
Under the limitation of this study the following conclusions could be suggested:
1- In light curing protocol, it seemed better to apply the universal adhesive used in this study in etch-and-rinse mode rather than the self-etching mode.
2- The different application modes used in this study did not affect the bond strength of the dual-cured resin composite to bovine dentin, when the adhesive was used in its dual-curing protocol.
3- When the universal adhesive was used in conjunction with dual-cured resin composite, the use of the DC activator seemed to be unnecessary.