Influence of cavity configuration factor (C-factor) on polymerization stress using smart bulk-fill composites

Background: The design of the cavity affects the polymerization shrinkage stress, which is a major issue with resin composite restorations. Stress generation during polymerization is influenced directly by the cavity configuration factor (C-factor), which is the ratio of bound to unbonded surfaces in a cavity preparation. Aim: Our goal is to assess how the C-factor, or cavity configuration factor, affects the polymerization stress experienced by smart bulk-fill composite material restorations. Materials and Methods: The experimental investigation used 60 extracted human molars and was carried out in a laboratory setting. Group I had a low C-factor, Group II a moderate C-factor, and Group III a high C-factor; each group had 20 samples. The C-factor values of the standardized cavity preparations were varied. Smart bulk-fill composite resin was applied in a single step and light-cured to repair cavities. Using a universal testing machine, we evaluated cuspal deflection and marginal gap development to assess polymerization stress. The significance level for the data was set at P < 0.05, and one-way analysis of variance and post hoc Tukey tests were used for analysis. Results: The tension during polymerization rose sharply as the C-factor rose. The mean stress values were found to be greatest in cavities with a high C-factor and lowest in cavities with a low C-factor. All groups showed statistically significant differences ( P < 0.05). Conclusion: The amount of stress that polymerizes in smart bulk-fill composite restorations is greatly affected by the geometry of the cavity. Greater stress at the tooth-restoration contact may weaken marginal integrity and cavities with a higher C-factor cause this.