Effect of adhesive systems, direct resin composites and artificial aging on tensile bond strength between different resin composites and human dentin

Abstract

Abstract Purpose The purpose of this study was to evaluate the tensile bond strength of universal, flowable and bulk-fill resin composites on dentin using different adhesive systems and after artificial aging. Materials and methods 360 extracted human wisdom teeth were prepared to specimens and divided into 36 groups (n=10). One half of the specimens (180) were treated by using one-step adhesive systems and the other half (180) with multi-step adhesive systems. Sleeves where placed on the dentin and filled with either universal, flowable or bulk-fill resin composite. Tensile bond strengths were measured after 24 h water storage and after thermal cycling (10,000x, 5°C–55 °C). Fracture types were analyzed by stereomicroscope. The data were analyzed using Kolmogorov-Smirnov, three- and one-way ANOVA followed by the Scheffe post-hoc test, unpaired two-sample t-test and Chi2 test (p Results The type of the resin composite had the strongest influence on tensile bond strength (partial eta squared ηP2=0.648, p Conclusion The combination of flowable resin composites and multi-step adhesives is recommended. The high number of cohesive fractures in the flowable groups underlines the strong adhesion of flowable resin composites to dentin.