Objectives:
Dental adhesive systems continue to improve the bond of restorative materials to tooth structure. The purpose of this study was to evaluate the microtensile bond strength (MTBS) of two all-in-one adhesive systems and two 2-step self-etching systems to dentin. Methods: Extracted human molars were prepared to expose flat dentin surfaces with 600-grit SiC paper. The adhesive systems used in this study were Opti Bond Solo plus (OP: Kerr), AQ Bond Plus (AQ+: Sun Medical), G-Bond (G: GC) and Clearfil SE Bond (SE: Kuraray). The adhesive systems were applied according to manufacturer's instructions and the dentin surfaces were incrementally covered with four layers of resin composite (Clearfil AP-X: Kuraray). After 24 hours of storage in deionized water, the bonded test specimens were sectioned perpendicular to the adhesive joint by means of a low speed diamond saw, producing six to seven thin slabs per tooth. These dentin/adhesive/composite resin slabs were trimmed to obtain the bonding interface areas of approximately 1mm2. Then microtensile bond test was carried out at a crosshead speed of 1mm/min. The data were analyzed by one-way ANOVA and Tukey's HSD test (p<0.05). Results: The MTBS (mean±SD in MPa) of tested adhesives were:|
Adhesive |
OP |
AQ+ |
G |
SE |
|
MTBS |
24.6±11.94 (a) |
29.8±4.29(a, b) |
43.9±12.95 (b, c) |
50.8±2.99 (c) |
|
Values designed with the same letter were not statistically different; p>0.05. |
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Conclusion: MTBS of OP, AQ+ and G did not exceed that of SE. However, there was no statistically significant difference between G and SE.
(Supported by Grant-in-Aid for Scientific Research #15390573 from the Ministry of Education, Japan.)