Microtensile bond strength of fiber-reinforced composite with semi-interpenetrating polymer matrix to dentin using various bonding systems

Abstract

This study investigated the microtensile bond strength (μTBS) of fiber-reinforced composite (FRC) to dentin using various adhesive systems. Forty eight (n=8/group) human molars were flattened to expose dentin. A layer of preimpregnated unidirectional FRC (everStick) was applied on the dentin surface after treatment with either a single-step self-etching adhesive, two-step self-etching system, or a conventional three-step adhesive system. For the control, particulate filler composite (PFC) (Filtek Z250) layering without FRC was used. After 24-hour water storage at 37°C, the specimens were sectioned, further water-stored at 37°C for 30 days and then tested. Data were analyzed using ANOVA and Tukey's test, and reliability was analyzed with Weibull distribution. μTBS values differed significantly according to the adhesive material used (p<0.05). Single-step self-etching adhesive showed the lowest bond reliability and μTBS values with both FRC and PFC, whereas conventional three-step and two-step self-etching systems showed higher bond reliability and μTBS with both materials.