Influence of adhesive properties on resin-dentin bond strength of one-step self-etching adhesives

To evaluate the association between the resin-dentin bond strength (microtensile bond strength, μTBS) and the physical properties (ultimate tensile strength [UTS] and microhardness [VHN]) of the cured adhesive resin using five commercial one-step self-etching systems.

Futurabond NR, Go, G Bond, 1-step All Bond SE and Clearfil S3 Bond were applied on flat superficial dentin surfaces. Each adhesive system was applied in five teeth. A resin buildup was then made. After 24 h, resin-dentin beams (0.9 mm2) were prepared to be tested immediately at 0.5 mm/min. For the UTS measurement, hourglass specimens were prepared with each adhesive system (n = 5) to be tested under tensile stress at 0.5 mm/min. The fractured specimens from the UTS test were taken to a Vickers microhardness tester (25 gf/20 s). μTBS, UTS, and VHN values were submitted to a one-way ANOVA and Tukey's test (α = 0.05) for pairwise comparisons. Correlations between μTBS, UTS and VHN were analyzed using the Pearson product moment correlation test (α = 0.05).

Significantly higher μTBS values were observed for 1-step All Bond SE and Clearfil S3 Bond (p > 0.05). The adhesive All Bond SE showed the highest UTSmean among all systems (p < 0.05). The adhesives All Bond SE and G-Bond showed the highest microhardness mean among all systems (p < 0.05). A strong (r = 0.93) and significant (p = 0.021) correlation was only found between the μTBS and UTS values.

The ultimate tensile strength of one-step self-etching systems correlates with the resin-dentin bond strength values.