Evaluation of the effect of different fiber reinforced composite resins on the flexural strength of bulk fill composite resin

Objective: The aim of this study was to evaluate the effect of reinforcing a bulk fill composite resin material with different fiber reinforced composite resins (FFRCs) on flexural strength. Materials and Methods: For the flexural strength test, 60 specimens were prepared using 4x4x8 mm polymethyl methacrylate (PMMA) blocks in accordance with the standards and the specimens were divided into four study groups. Bulk Fill Composite Resin (Group 1), Bulk Fill Composite Resin + Glass Fiber in Braided Structure (Group 2), Bulk Fill Composite Resin + Polyethylene Fiber in Leno Woven Structure (Group 3), Bulk Fill Composite Resin + Short Glass Fiber Reinforced Composite Resin (Group 4). The specimens were soaked in distilled water at 37 °C for 24 hours and subjected to three-point bending test with Universal Testing machine. Data were statistically analyzed using Mann-Whitney U and Kruskal Wallis-H tests. Results: The mean flexural strength values were 654.72 Newton (N), 682.33 N, 643.87 N and 1003.91 N in Groups 1, 2, 3 and 4, respectively. The effect of short glass fiber reinforced composite resin + bulk fill composite resin group on bending resistance was statistically significantly better than all other groups (p>0,05). There was no statistically significant difference between the other groups in terms of bending resistance. Conclusion: Within the limits of this in vitro study, it was concluded that short glass fiber reinforced composite resin increases the flexural strength of bulk fill composite resin as a base material. Key Words: Excessive Loss Of Substance, Bulk Fill Composite Resin, FRCR, Fibers, Three-Point Bending Test