Does the Period of Air-Drying Affect Dentin Bond Strength of Different Adhesive Systems?
Emre Nagas
Hacettepe University, Faculty of Dentistry, Department of Endodontics, Ankara, Turkey.
Isil Cekic-Nagas *
Gazi University, Faculty of Dentistry, Department of Prosthodontics, Ankara, Turkey.
Gulfem Ergun
Gazi University, Faculty of Dentistry, Department of Prosthodontics, Ankara, Turkey.
Pekka K. Vallittu
University of Turku, Institute of Dentistry, Department of Biomaterials Science and Turku Clinical Biomaterials Centre – TCBC, Turku, Finland.
Lippo V. J. Lassila
University of Turku, Institute of Dentistry, Department of Biomaterials Science and Turku Clinical Biomaterials Centre – TCBC, Turku, Finland.
*Author to whom correspondence should be addressed.
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 (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.
Keywords: Air-drying time, adhesive, bond strength, dentin.