Fracture resistance of a short fiber-reinforced flowable resin composite compared with different types of flowable resin composites.

Abstract

This study aimed to evaluate the fracture resistance of a short fiber-reinforced flowable resin composite and compare it with that of different types of flowable resin composites. A total of 10 commercially available flowable resin composites were used, including a flowable short fiber-reinforced resin composite (SFRC), five bulk-fill flowable resin composites, two injectable resin composites, and two single-shade flowable resin composites. The flexural strength (σ_F), flexural modulus, and resilience (R) were measured using a three-point bending flexural test. Additionally, a fatigue flexural strength (FFS) test was performed using repeated subcritical loading at a frequency of 20 Hz for 50,000 cycles. The fracture toughness (K_IC) was measured using the single-edge notched beam three-point bending test. All tests were performed after 24 h of storage or 10,000 thermal cycles. The flowable SFRC demonstrated significantly higher σ_F, FFS, and K_IC than the other flowable resin composites. However, all the flowable resin composites demonstrated statistically significant reductions in σ_F, R, FFS, and K_IC after thermal cycles compared with those at baseline. The flowable SFRC had superior fracture resistance under external force, not only under a monotonic static load but also under repeated subcritical load stress. The findings indicate that the flowable SFRC is a promising resin composite due to its superior outcomes in the FFS test and other fracture resistance tests.