Comparison of Effect of C-Factor on Bond Strength to Human Dentin Using Different Composite Resin Materials

Background: The study was planned to assess the use of low shrinkage composites for restoring cavities with high configuration factor (C-factor) which are subjected to high stresses. Aim: The aim of the study was to evaluate the effect of C- factor on tensile bond strength to human dentin using methacrylate based nanohybrid and low shrinkage silorane composite. Materials and Methods: In this study 40 non carious human molar teeth were selected and assigned into two main groups - cavity (Class I cavity with high C-factor) and flat group (flat surface with low C-factor). Two different composite materialsmethacrylate based and silorane low shrinkage composite were used to restore the teeth. Dentin surface was treated, adhesive application was done and composite was applied as per manufacturer’s instructions. Samples were stored in distilled water then subjected to tensile bond strength measurement using universal testing machine. Results: Statistical analysis was done using Independent sample t-test. The mean bond strength in methacrylate based and silorane composite was significantly higher in flat preparation (Low C-factor) than cavity preparation. The mean bond strength in both cavity (High C-factor) and flat preparation(Low C-factor) was significantly higher in silorane than in conventional methacrylate based composite. Conclusion: The bond strength of composites to dentin is strongly influenced by C-factor and type of composite resin material used.