Comparative Evaluation of Fracture Resistance of Class Ii Cavities Restored with Three Different Classes of Composite Resins – An in Vitro Study

Abstract

Objectives: This study aimed to evaluate and compare the fracture resistance of Class II dental cavities restored with three different composite systems: Fibrafil, Filtek Bulk Fill, and Estelite Sigma Quick.

Methods: Fifty-five intact mandibular molars were divided into: positive control (unprepared, n=5), negative control (unrestored, n=5), and three experimental groups (n=15 each) restored with Filtek Bulk Fill (Group C), Estelite Sigma Quick (Group D), or Fibrafil (Group E). Standardized Class II cavities were prepared, restored, and stored in distilled water (37°C, 24 hours). Fracture resistance was measured using an INSTRON machine (load in Newtons) and analyzed via one-way ANOVA and Bonferroni post-hoc tests (α=0.05).

Results: The highest mean fracture resistance was observed in Group A (positive control: 218.40±8.20 N), followed by Fibrafil (Group E: 657.07±7.41 N), Estelite Sigma Quick (Group D: 446.80±8.03 N), and Filtek Bulk Fill (Group C: 438.27±4.92 N). The negative control (Group B: 676.80 ± 4.32 N) exhibited the lowest resistance. Fibrafil’s performance was statistically superior to other composites (p<0.001).

Conclusions: Fibrafil demonstrated significantly higher fracture resistance, likely due to its fiber-reinforced structure, which mimics the dentino-enamel junction.