ABSTRACT
Aims: To evaluate the effect of air-drying time of adhesives on shear bond strength of different adhesive systems. Methodology: The occlusal surfaces of 175 mandibular third molars were ground to obtain flat dentin surfaces and then divided into three groups according to three adhesive systems used: (1) Conventional three-step adhesive (Scotchbond Multi-purpose Plus); 2) Self-etch adhesive (Adper Easy Bond) and 3) Single bottle self-etch adhesive (Scotchbond Universal adhesive). Regarding the application of adhesives before resin composite application, it was gently air-dried for 3 s in Groups 1, whereas, the adhesive was left wet in Group 2. The group 3, that was air-dried until the liquid did not move (5 s), was served as control. Following bonding of resin cement (Filtek Supreme) to dentin, the specimens were light cured for 20s with a LED. After storage in water at 37ºC for one week, the strength measurements were accomplished with universal testing machine (Lloyd LRX) until the failure occurs. Failure modes were examined using a stereomicroscope and scanning electron microscope. The data were analyzed with two-way analysis of variance Original Research Article British Journal of Medicine & Medical Research, 4(27): 4523-4532, 2014 4524 (ANOVA) and TukeyHSD tests (α=0.05). Results: The two-way ANOVA revealed that adhesive systems had a significant effect on shear bond strength values (p<0.001). However, air-drying time did not influence shear bond strength (p=0.442). Additionally, there was no interaction effect between adhesive systems and air-drying time (p=0.835). Conclusion: The data suggests that increased air-drying time of adhesives does not significantly affect bond strength.
ABSTRACT
OBJECTIVES: To investigate the effect of dentin moisture degree and air-drying time on dentin-bond strength of two different one-step self-etching adhesive systems. MATERIALS AND METHODS: Twenty-four human third molars were used for microtensile bond strength testing of G-Bond and Clearfil S3 Bond. The dentin surface was either blot-dried or air-dried before applying these adhesive agents. After application of the adhesive agent, three different air drying times were evaluated: 1, 5, and 10 sec. Composite resin was build up to 4 mm thickness and light cured for 40 sec with 2 separate layers. Then the tooth was sectioned and trimmed to measure the microtensile bond strength using a universal testing machine. The measured bond strengths were analyzed with three-way ANOVA and regression analysis was done (p = 0.05). RESULTS: All three factors, materials, dentin wetness and air drying time, showed significant effect on the microtensile bond strength. Clearfil S3 Bond, dry dentin surface and 10 sec air drying time showed higher bond strength. CONCLUSIONS: Within the limitation of this experiment, air drying time after the application of the one-step self-etching adhesive agent was the most significant factor affecting the bond strength, followed by the material difference and dentin moisture before applying the adhesive agent.