Comparison of Fracture Toughness of A Fiber Reinforced Composite and Bulk Filling Composites

Objectives: The aim of this study was to evaluate and compare the resistance to crack propagation as measured by fracture toughness (FT) of a fiber-reinforced composite (everX Posterior; eXP) with different commercial bulk-filled composites including Filtek Bulk Fill (FB), X-tra Fil (XF), Fill-Up (FU) and Tetric N-Ceram Bulk Fill (TB).
Methods: Resin-composites (n=10/gp) were prepared to single-edge notch beam specimens (2x25x2mm) in 1mm-preformed notch acrylic mold. Specimens were light-cured (manufacture recommendations), stored (distilled water, 37^○C, 24h), FT tested (3-point bending, Universal testing machine, 0.13mm/m) and statistically analyzed (Kruskal-Wallis test, Mann-Whitney U test, p<0.05).
Results: Mean FT value (MPam½) of eXP, FB, XF, FU and TB were 1.77±0.28, 1.43±0.20, 1.23±0.16, 0.96±0.03 and 0.83±0.10 respectively. eXP had significantly higher mean FT compared to XF, FU and TB . No significant difference was found between mean FT of eXP and FB, FB and XF, FU and TB.
Conclusions: This study concluded that a fiber-reinforced composite exhibited superior fracture toughness compared to other bulk filling composites tested.