Resin–resin microtensile bond strength after different surface treatments to clean blood contamination

Abstract

ObjectivesThe aim of this in vitro study was to evaluate the effect of different surface treatments on the resin–resin bond strength of a composite resin previously contaminated with blood. MethodsSixty bar-shaped specimens were fabricated. Two 2-mm-thick layers of an A3.5 shade composite (TPH3) were inserted on a silicon matrix, photoactivated and subjected to different surface treatments (n=12): (1) no contamination, control; (2) blood contamination and air drying; (3) blood contamination, rinsing with water, and air drying; (4) blood contamination, rinsing with water, air drying, and application of the bonding agent of an adhesive system (Adper Scotchbond Multi-Purpose Adhesive); and (5) blood contamination, rinsing with water, air drying, phosphoric acid etching, and application of the bonding agent of an adhesive system. Then, two 2-mm-thick layers of an A1 shade composite (TPH3) were inserted and photoactivated. After storing in water for 24h, the samples were subjected to a microtensile bond strength test in a universal testing machine. Failure modes were evaluated in a stereomicroscope. Data were analyzed using one-way ANOVA and the Tukey test (p<0.05). ResultsThere were statistically significant differences between the treatments. Blood contamination and air drying provided the lowest bond strength values; only blood contamination, rinsing with water, air drying, phosphoric acid etching, and application of the bonding agent of an adhesive system provided bond strength similar to the control. ConclusionsThe use of a full adhesive protocol involving phosphoric acid etching and the application of the bonding agent of an adhesive system provided adequate resin–resin bond strength of the composite tested.