Effect of Air Blowing Pressure on Dentin Bond Strength of Universal Adhesives

Aim: This study investigated the shear bond strength of universal adhesive systems applied to dentin at different air-blowing pressures. Materials and Methods: Flat dentin surfaces were prepared from 120 freshly extracted, caries-free human molar teeth. Three universal adhesives were used: G-Premio Bond (GP), Clearfil S3 Bond Universal (CU), and Scotchbond Universal (SU). The samples were randomly divided into groups according to the adhesives and the air blowing pressures (0.14 MPa, 0.28 MPa and 0.41 MPa) (n=10). In each adhesive system, an unpressurized group was designated as the control group (n = 10). The shear bond strength values were measured using a universal testing device (Instron 3344, Instron Corp, Wilmington, USA). The data were analyzed using ANOVA and Tukey’s post hoc test at a significance level of 0.05. Results: No statistically significant difference was found based on all variables and their interactions (p>0.05), only the material groups showed a significant difference (P=0.000). The highest mean value was obtained at a pressure of 0.41 MPa in the SU group (17.40±6.01), 0.14 MPa in the CU group (17.52±4.46), and 0.28 MPa in the GP group (10.05±3.89). Conclusion: Different air-blowing pressures in universal adhesives significantly influence bond strength.