Purpose: To evaluate the microtensile bond strength (µTBS) of three universal adhesives to dentin contaminated with a hemostatic agent.
Materials and Methods: Ninety-six human premolars were cut to expose mid-coronal dentin. The teeth were randomly divided into a control group (uncontaminated dentin) and an experimental group in which a hemostatic agent was applied (contaminated dentin). Each group was further divided into 6 subgroups according to universal adhesives – SBU (Single Bond Universal), OPU (OptiBond Universal), CBQ (Clearfil Universal Bond Quick) – and etching mode, either etch-and-rinse (ER) or self-etch (SE). Following adhesive application, composite was placed in two increments and light cured. The specimens were stored in distilled water at 37°C for 24 h. The µTBS test was performed using a universal testing machine. Failure mode was assessed using a light microscope. The data were statistically analyzed using three-way ANOVA followed by Scheffe’s test (p < 0.05). The resin-dentin interface was observed using scanning electron microscopy.
Results: Significantly lower bond strength was observed when the universal adhesives were bonded to contaminated dentin in SE mode (p < 0.05). In contrast, the µTBS of the universal adhesives in ER mode was not affected by contamination (p > 0.05). The µTBS of CBQ to contaminated dentin was significantly lower than that of the other adhesives. Observation of the resin-dentin interface revealed limited resin penetration when the universal adhesive was applied in SE mode on contaminated dentin.
Conclusion: Contaminating the dentin with a hemostatic agent significantly reduced the µTBS of the universal adhesives in SE mode. However, this adverse effect was not found when the universal adhesives were used in ER mode.
Palabras clave: adhesion to dentin, hemostatic agent, microtensile bond strength, scanning electron microscopy, universal adhesive.
