Shear bond strength of four dentinal adhesives applied in vivo and in vitro

Objectives: The purpose of this study was to determine whether dentine bonding performed under clinical conditions is as reliable as laboratory bonding. Methods: Freshly cut dentine was used in vivo or in vitro as a substrate for the bonding of various adhesive systems. Bond strength was measured in shear loading. Results: Clearfil Liner Bond, Optibond and All Bond 2 showed better results when applied in vivo than in vitro. Scotchbond Multipurpose showed the opposite effect but the bond strength was, for both conditions, superior to the other three products. Only All Bond 2 presented statistically significant differences in bond strength between in vivo and in vitro applied bonding. Conclusion: The results indicate that, with the new hydrophilic dentine bonding systems, in vitro application does not lead to substantially different results when compared with in vivo application.