Method: Two commercial all-in-one adhesive systems (Xeno JP, Dentsply-Sankin, Japan, Xeno V+, Dentsply-Sankin, Japan) were used according to manufacture's instructions in this study. A proximal dentin of the extracted human molar was flatly eliminated with wet carborndum paper. Approximately 3 mm in diameter and 1.5 mm depth cylindrical cavity was prepared in the proximal dentin. Prior to resin composite filling, apply 2 different types of bonding agent into cavity, respectively. The width of the contraction gap was measured with a screw micrometer mounted on the light microscope. The maximum contraction gap was presented as the sum of the opposing gap widths as a percentage of the cavity diameter. 10 specimens for each bonding system were prepared. A flat dentin surface was prepared on an extracted human molar embedded in epoxy resin with wet carborundum paper. A split Teflon mold with an inner diameter of 3.6 mm and height of 8 mm was fixed on the substrate. Prior to resin composite filling, apply 2 different types of bonding agent through the hole of mold. After the specimens stored in water for 24 h, the tensile bond strength were measured by universal testing machine at cross-head speed of 5 mm/min. The results of the gap measurement and the tensile bond strength measurement were analyzed statistically by one-way ANOVA and Fisher's PLSD test (p<0.05).
Result: The marginal adaptation of the composite was not complete in 8 (Xeno JP) or 7 (XenoV+) of 10 specimens. In the tensile bond measurement, no significantly difference were observed in all groups.
Conclusion: As demonstrated in this study, marginal integrity was not observed with the newly developed commercial all-in-one adhesives.