The effect of air-blowing on the μTBS to dentin of four different adhesive systems

Purpose: To evaluate the technique sensitivity of four different adhesive systems using different air blowing pressure. [LP] (3M ESPE, USA) and an experimental adhesive, SSB-200 [SSB] (Kuraray, Japan). Twenty-four extracted molars were used. After grinding the coronal enamel surface, the teeth were divided into two equal groups. The first group's teeth were randomly assigned for bonding with the different adhesives using gentle air blowing (g). For the teeth of the second group, the four adhesive systems were applied using strong air blowing (s). After storage overnight in 37°C water, the bonded specimens were sectioned into sticks (1mm x 1mm wide) which were subjected to microtensile bond strength testing (μTBS) at a crosshead speed of 1mm/min. The load at failure of each specimen was recorded and the data were analyzed by one-way ANOVA and Tukey HSD tests. The surfaces of the fractured specimens were observed using SEM to determine the failure mode. Results: The results of the μTBS test showed that the highest bond strengths tended to be with SE for both gentle and strong air blowing, and the significantly lowest for SSB with strong air streaming. Comparing the two techniques, significant differences were noted only for SSB-200 (p<0.05). For each material, the SEM evaluation did not show distinct differences in the nature of the fractures between the two techniques, except for SSB-200. Conclusions: The adhesives tested are not technique sensitive, except SSB-200, with regards to the air blowing step.