A BSTRACT Aim: To evaluate the effect of air abrasion on the bond strength of composite to human dentin using two different adhesive systems and to access the mode of failure using scanning electron microscopy. Materials and Methods: In this in vitro investigation, 38 human permanent mandibular molars were extracted so that the dentin was visible through the removal of the buccal and lingual superficial enamel. Buccal surfaces of all teeth were pretreated with air abrasion (50 μm aluminum oxide) while lingual surfaces serve as control without air abrasion before application of adhesive and were divided randomly into two groups ( n = 19). GROUP 1- Etch and rinse adhesive; GROUP 2 – Self etch adhesive. Following application of adhesive, 76 “composite cylinders were made and bonded to the tooth (19 buccal and 19 lingual for each group), and light cured. Shear bond strength has been determined by using universal testing machine at crosshead speed of 1.0 mm per min” till failure. Type of failure has been then identified by SEM (scanning electron microscopy). Results: Specimens treated with etch and rinse adhesive with air abrasion showed highest shear bond strength with a mean value of 25.8 Mpa when compared to those treated with self-etch adhesive with air abrasion with a mean value of 17.36 Mpa. Conclusion: The Etch and Rinse adhesive is recommended for air-abraded dentin because it demonstrated markedly higher bond strengths than the Self-Etch adhesives.
Gopinath et al. (Sat,) studied this question.