Influence of saliva contamination on bond strength of adhesives systems to enamel

Abstract

The objective of this study was to evaluate the effects of human saliva (HS) contamination, at different moments, on the bond strength (BS) of two adhesive systems, an etch-and-rinse system system [Adper Single Bond 2 - 3M ESPE, St. Paul, MN, EUA- (SB)] and a self-etch system [Clearfil SE Bond- Kuraray Co., Kurashiki, Okayama, Japão- (SE)]. Sixty bovine incisors were embedded in acrylic resin and divided into six groups (n=10). For SB, G1= no saliva (control), G2= HS after acid etching and G3= HS after bond application. For SE, G4= no saliva (control); G5= HS after primer application and G6= HS after bond application. Composite resin (Filtek Z-250, 3M ESPE, St. Paul, MN, EUA)was applied, specimens were stored in distilled water for 24 hours (37^oC) and debonded in tension. Statistical analyses were performed using ANOVA, and group comparisons were performed using Tukey´s test (p < 0.05). Results (Mean± standard deviation- MPa): G1 = 21.993±2.797, G2 = 11.431±0.685, G3 = 10.489±0.811, G4 = 15.834±1.571, G5 = 17.49±3.22 and G6 = 18.16±4.07. Based on the obtained results, we conclude that the SB etch-and-rinse system was highly influenced by saliva contamination in both tested steps of the bond procedure. In contrast, the SE system was less sensitive to saliva contamination on enamel than the etch-and-rinse adhesive system.