Effects of Chitosan on Micro-Shear Bond Strength of Self-Adhesive Cements

Background: The long-term success of bonding of self-adhesive cement to the tooth is questionable. Different conditioning methods were suggested to improve the bonding durability of these cements. This study aimed to investigate the effect of 1% chitosan solution on micro-shear bond strength of self-adhesive resin cements to dentin. Methods: 28 human sound premolar teeth were divided into 4 groups. The occlusal surfaces of the teeth were ground to expose the dentine surface. In control groups, BF (Bifix) and EB (Embrace) dual-cure self-adhesive cements were applied to the dentin surface using a microtube and were light cured. In the EB+Ch and BF+Ch test groups, dentin surfaces were conditioned with 1% chitosan solution before using resin cements. The specimens were thermocycled for 2000 times between 5-55°C and their bond strength was measured by a mechanical testing machine at strain rate of 0.5 mm. Failure modes were determined using a stereo-microscope at 40X magnification. Data were analyzed using Two-Way ANOVA and Tukey’s tests (α=0.05). Results: The results have revealed maximum bond strength in the EB+Ch test group (13.73±0.42 Mpa) and the minimum strength in the BF control group (8.01±0.42 Mpa). Data analysis showed the maximum bond strength in groups where dentin had been pretreated with chitosan solution (p<0.001). The failure mode was mainly adhesive type in all groups. Conclusion: Dentin surface treated with 1% chitosan solution prior to application of self-adhesive cements increases the cement-dentin bond strength.