Comparative study of the microtensile bond strength of three different total etch adhesives with different solvents to wet and dry dentin (in vitro test).

The aim of this study was to compare the microtensile bond strength of three different total etch adhesives: XP Bond (Caulk-Dentsply) versus Excite (Ivoclar/Vivadent) and Prime & Bond NT (Caulk-Dentsply). Forty two (42) third human molars were cut to expose the dentinal surface. They were divided into three groups of 14 teeth (GI: XP Bond, G2: Excite, G3: Prime & Bond NT) and two groups of seven teeth for each moisture condition: moist dentin (GM) and dry dentin, (GD). The total-etch technique was used with each moisture variation. The adhesives and composites A3 (Ceram Duo GI, G3 and Tetric Ceram G2) were applied according to manufacturer's instructions. Teeth were cut with an ISOMET 1000 (Buehler Ltd.) to obtain 1 mm2 x 10 mm bars, which were subject to a traction test at 5 mm/min in a universal testing machine (Adamel Lhomargy DY 36). The collected data were recorded and analyzed using an experimental design for studying two factors offixed effrcts with software Statgraphics version 5.1. For the variable type of adhesive, we found p = 0.000, for the variable substrate condition, p = 0.0012, and for interaction between both factors, p = 0.0457, which indicates significant statistical differences. The values for microtensile bond strength were G1M = 55.0642 MPa Standard deviation (SD) 3.09768; G1D 39.115 MPa SD 2.86789; G2M 34.1607 MPa SD 2.86789; G2D = 32.7373 MPa SD 2.77065; G3M 3 7.3407 MPa SD 2.86789 and G3D = 31.0593 MPa SD 2.77065. XP Bond showed the greatest values of micmtensile bond strength under both conditions. Moist substrate increases the values of micmtensile bond stren gth]br the adhesives tested; howeve, Excite shows lower susceptibility to variation of dentinal moisture.