RESUMO
OBJECTIVES: The present study was conducted to evaluate the effect of nanosized aluminum trioxide (Al2O3) particles when added to the Nano-Bond adhesive system and its effect on the microshear bond strength of nanocomposite resin to dentin. MATERIALS AND METHODS: A newly developed adhesive (Nano-Bond) and one type of light-cured resin restorative material (nanocomposite resin) were used in this study. The occlusal surfaces of extracted human molar teeth were ground perpendicular to the long axis of each tooth to expose a flat dentin surface. The adhesives were applied to the dentin surfaces according to manufacturers' instructions. The nanocomposite resin was then placed and light cured for 40 s. After immersion in water at 37°C for 24 h, the specimens were subjected to thermocycling before testing, and a microshear bond test was carried out. The recorded bond strengths (MPa) were collected, tabulated, and statistically analyzed. A one-way analysis of variance and Tukey's tests were used to test for significance between the means of the groups; statistical significance was assumed when the P ≤ 0.05. RESULTS: The mean microshear bond strength of the Nano-Bond adhesive system containing nanosized Al2O3 at a concentration of 2% was 23.15 MPa (Group B), which was significantly greater than that of the Nano-Bond adhesive system without additives (15.03 MPa, Group A). CONCLUSIONS: These results indicate that nanosized Al2O3 added to the Nano-Bond adhesive system at a concentration of 2% increases the microshear bond strength.
