Effect of air-blowing duration on the bond strength of current one-step adhesives to dentin

ObjectivesTo evaluate the influence of different air-blowing durations on the micro-tensile bond strength (μTBS) of five current one-step adhesive systems to dentin.MethodsOne hundred and five caries-free human molars and five current one-step adhesive systems were used: ABU (All Bond Universal, Bisco, Inc.), CUB (CLEARFIL™ Universal Bond, Kuraray), GPB (G-Premio BOND, GC), OBA (OptiBond All-in-one, Kerr) and SBU (Scotchbond Universal, 3M ESPE). The adhesives were applied to 600 SiC paper-flat dentin surfaces according to each manufacturer's instructions and were air-dried with standard, oil-free air pressure of 0.25 MPa for either 0 s, 5 s, 15 s or 30 s before light-curing. Bond strength to dentin was determined by using μTBS test after 24 h of water storage. The fracture pattern on the dentin surface was analyzed by SEM. The resin-dentin interface of untested specimens was visualized by panoramic SEM image. Data from μTBS were analyzed using two-way ANOVA (adhesive vs. air-blowing time), and Games-Howell (a = 0.05).ResultsTwo-way ANOVA revealed a significant effect of materials (p = 0.000) and air-blowing time (p = 0.000) on bond strength to dentin. The interaction between factors was also significantly different (p = 0.000). Maximum bond strength for each system were recorded, OBA/15 s (76.34 ± 19.15 MPa), SBU/15 s (75.18 ± 12.83 MPa), CUB/15 s (68.23 ± 16.36 MPa), GPB/30 s (55.82 ± 12.99 MPa) and ABU/15 s (44.75 ± 8.95 MPa). The maximum bond strength of OBA and SUB were significantly higher than that of GPB and ABU (p < 0.05).SignificanceThe bond strength of the current one-step adhesive systems is material-dependent (p = 0.000), and was influenced by air-blowing duration (p = 0.000). For the current one-step adhesive systems, higher bond strengths could be achieved with prolonged air-blowing duration between 15-30 s.