ABSTRACT
Statement of the Problem: The bond strength of composites with different adhesive systems with dentin is an important factor in long term durability of composite restorations. The effect of titanium tetrafluoride [TiF4] as anti caries agent and sodium hypo-chlorite [NaOCl] as disinfectant on the shear bond of nanofilled and silorane based composite resins have not been investigated in previous studies
Purpose: This study was conducted to determine bond strength between dentin and two composite systems, by means of shear bond test using TiF4 and NaOCl
Materials and Method: Middle dentin of 60 intact extracted maxillary premolar teeth were exposed by sectioning the crowns at a depth of 2mm from central groove and parallel to the occlusal surface. Standardized smear layer was created using a 600-grit silicon carbide paper and then samples were embedded in acrylic resin blocks. Then the samples were randomly divided into 6 groups summarized as Group I: Z350, Group II: Z350+ NaOCl, Group III: Z350+ TiF4, Group IV: P90, Group V: P90+ NaOCl, Group VI: P90+ TiF4 according to manufacturer's instruction. Then samples were subjected to shear bond strength [SBS] test using universal testing machine and data were analyzed using ANOVA and Tukey tests [p< 0.05]
Results: Application of 5% NaOCl caused a significant decrease in SBS of nanofilled composite resin [p= 0.004], and also silorane based composite resin [p= 0.006]. Appli-cation of 4% TiF4 caused a significant increase in SBS of silorane based composite resin [p= 0.001]. The effect of TiF4 on nanofilled composite was not statistically significant
Conclusion: Using TiF4 has a positive effect on increasing the shear bond while NaOCl has negative effect on bond strength