IADR Abstract Archives
Evaluation of Bond Strength of Multi-Step Adhesives Under Moist Condition
Objectives: In recent years, dental bonding materials have been improving its bond strength with advances in technology. However, it is generally concerned bond strength to tooth structure is affected by moisture in oral environment. If the moisture management isn’t done properly such as misalignment of rubber dam, tooth adhesion of bonding materials may be hindered by moisture. To solve this issue, we developed new two-step self-etching adhesive "G2-BOND Universal", designed for moisture tolerance with HEMA-free technology. This study evaluated the effect of moisture to shear bond strength (SBS) of tooth structure on multi-step adhesives.
Methods: G2-BOND Universal (GC, G2B) and SE BOND2 (Kuraray, SE2) were examined. Bovine dentin surface was ground with 400-grit SiC paper. Adhesive was applied on grinded surface according to manufacturer’s instructions, and then it was light-cured via the ultradent mold. Composite resin was filled in the mold and light-cured to prepare SBS specimen. SBS specimen preparation were performed under following temperature and humidity, (1) 30 degree-C, 50 %RH (50RH), (2) 30 degree-C, 70 %RH (70RH). Specimens were immersed in water at 37 degree-C for 24 hours and then SBS was measured by SHIMADZU Autograph (n=10). Data were analyzed using 2-way ANOVA followed by Tukey post-hoc test (α=0.05).
Results: Results were shown in Fig. 1. G2B showed significantly higher SBS than SE2 under 70RH and showed equal SBS between under 50RH and 70RH. As the humidity increased, SBS of SE2 was decreased significantly. It is considered that G2B has better moisture tolerance than SE2, because G2B doesn’t contain HEMA and HEMA-free composition may bring less water sorption. In contrast, SE2 contains HEMA, and it can absorb water quickly in oral environment, and SBS of SE2 might be easily affected by moisture.
Conclusions: G2-BOND Universal has high bond strength under humidity condition. It is expected that G2B has durability in clinical practice.
Methods: G2-BOND Universal (GC, G2B) and SE BOND2 (Kuraray, SE2) were examined. Bovine dentin surface was ground with 400-grit SiC paper. Adhesive was applied on grinded surface according to manufacturer’s instructions, and then it was light-cured via the ultradent mold. Composite resin was filled in the mold and light-cured to prepare SBS specimen. SBS specimen preparation were performed under following temperature and humidity, (1) 30 degree-C, 50 %RH (50RH), (2) 30 degree-C, 70 %RH (70RH). Specimens were immersed in water at 37 degree-C for 24 hours and then SBS was measured by SHIMADZU Autograph (n=10). Data were analyzed using 2-way ANOVA followed by Tukey post-hoc test (α=0.05).
Results: Results were shown in Fig. 1. G2B showed significantly higher SBS than SE2 under 70RH and showed equal SBS between under 50RH and 70RH. As the humidity increased, SBS of SE2 was decreased significantly. It is considered that G2B has better moisture tolerance than SE2, because G2B doesn’t contain HEMA and HEMA-free composition may bring less water sorption. In contrast, SE2 contains HEMA, and it can absorb water quickly in oral environment, and SBS of SE2 might be easily affected by moisture.
Conclusions: G2-BOND Universal has high bond strength under humidity condition. It is expected that G2B has durability in clinical practice.
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