In Vitro Dentin Bond Strength/Application Effects of Different Adhesives

Objective: To evaluate dentin bond strengths and application effects of a one-step, two-step, and three-step adhesive system after seven days (in vitro). Material and Methods: Forty-eight human molars were prepared to expose dentin by removing the occlusal third of the crown with a low speed diamond saw (South Bay Technology) in a gypsum stone cylinder. The exposed dentin surfaces were ground flat under water with 400 and 600 grit SIC papers and randomly distributed into six groups. The first group was tested with Adper Single Bond Plus(3M-ESPE), the second group with PQ1 (Ultradent . Inc.), the third group with Optibond Fl (Kerr), and the fourth with Scotchbond Multipurpose (3M-ESPE), according to the manufactures instructions. The fifth group was treated with Amalgambond Plus and the sixth group was treated with Clearfil Tri S Bond all- in-one adhesive (Kurary). The samples were restored with composite (Z-250 Shade A3, 3M-ESPE) and stored in water at 37°C for seven days before testing. The shear bond strength was determined by a Universal Testing Machine (Instron Corporation) and data was analyzed using One-way ANOVA and Tukeys. Results: The bond strengths were: PQ1 34.22 MPa; Amalgambond Plus 40.39 MPa; Optibond Fl 53.44 MPa; Adper Single Bond 55.76 MPa; Clearfil Tri S Bond 63.5 Mpa; and Scotchbond Multipurpose 65.89 Mpa. Scotchbond Multipurpose showed higher bond strength than Optibond Fl (p<0.05). The two-step adhesive Adper Single Bond Plus showed significantly higher bond strength than PQ1 and Amalgambond Plus (p<0.005). Conclusion: Scotchbond Multipurpose showed higher bond strength to dentin compared to Optibond Fl and Amalgambond Plus. However, the all- in-one adhesive showed the highest bond strength and seemed to be less technique sensitive and time saving for clinical use. The three step system may take more time clinically but appears to have a higher dentin bond strength.