Flexural Strength Comparison of Silorane- and Methacrylate-Based Composites with Pre-impregnated Glass Fiber

Statement of the Problem: Sufficient adhesion between silorane/methacrylate-based composites and methacrylate impregnated glass fiber increases the benefits of fibers and enhances the mechanical and clinical performance of both composites.
The aim of this study was to evaluate the compatibility of silorane and methacrylate-based composites with pre-impregnated glass fiber by using flexural strength (FS) test.
A total of 60 bar specimens were prepared in a split mold (25×2×2 mm) in 6 groups (n=10). In groups 1 and 4 (control), silorane-based (Filtek P90) and nanohybrid (Filtek Z350) composites were placed into the mold and photopolymerized with a high-intensity curing unit. In groups 2 and 5, pre-impregnated glass fiber was first placed into the mold and after two minutes of curing, the mold was filled with respective composites. Prior to filling the mold in groups 3 and 6, an intermediate adhesive layer was applied to the glass fiber. The specimens were stored in distilled water for 24 hours and then their flexural strength was measured by 3 point bending test, using universal testing machine at the crosshead speed of 1 mm/min. Two-way ANOVA and post-hoc test were used for analyzing the data (p A significant difference was observed between the groups (p Significant improvement in FS was achieved for both composites with glass fiber. Additional application of intermediate adhesive layer before composite build up seems to increase FS. Nanohybrid composite showed higher FS than silorane-based composite.