Influence of Application Methods of Self-etching Adhesive Systems on Adhesive Bond Strength to Dentin

Purpose: To assess the influence of variations in the application technique of self-etching adhesive systems on the shear bond strength to dentin. Materials and Methods: The buccal surface of 255 extracted bovine teeth was ground to expose a flat dentin surface; the teeth were divided into four experimental groups. The self-etching adhesive systems One Up Bond F Plus, Clearfil SE Bond, Xeno III, and FuturaBond NR were used, and the etch-and-rinse adhesive Adper Single Bond 2 was used as the control group. One or two layers of the self-etching systems were actively or passively applied. Cylinders of composite resin were bonded to dentin, and after 24 h, specimens were shear tested in a universal testing machine at a crosshead speed of 1 mm/min. The data were submitted to two-way ANOVA, Dunnett's and Tukey's test (5%). Results: There were significant differences for the factors adhesive type, application method, and their interaction. All adhesive systems showed significant differences. The active application of two layers of self-etching bonding systems resulted in a significantly higher mean than the passive application method. Conclusion: The active application of self-etching adhesive systems tends to increase the dentin shear bond strength, and the influence of the application method depends on the tested adhesive. Parole chiave: self-etching adhesives, bond strength, dentin