The effect of chitosan incorporation on some properties and antibacterial activity of dental adhesive

Abstract

OBJECTIVE: To evaluate the antibacterial activity of adhesive resin incorporating chitosan as well as the adhesive characteristics. METHOD AND MATERIALS: Modified adhesive was prepared by adding 0.05%, 0.1%, and 0.2% (w/w) chitosan solution to Heliobond adhesive resin. The solution of chitosan was prepared by dissolving 2 g of chitosan powder in 1 liter of 1% (v/v) acetic acid. Heliobond without chitosan was used as a control. The antibacterial activity was evaluated using a direct contact test against Streptococcus mutans. The viscosity, degree of conversion, pH, and microshear bond strength values of modified adhesive to enamel and dentin were evaluated. Data were analyzed using the ANOVA and Tukey’s tests. Statistical significance was set at the .05 probability level. RESULTS: The antibacterial properties of adhesives incorporating chitosan were found to exhibit an inhibitory effect on the growth of Streptococcus mutans compared with the unmodified adhesive resin (P < .05). The viscosity of adhesives increased with increasing the concentrations of chitosan incorporation into the adhesive. However, the degree of conversion and pH values and microshear bond strength values of modified adhesive to enamel and dentin decreased with increasing the concentrations of chitosan incorporation into the adhesive. CONCLUSION: Under the limitations of the present investigation, the following conclusion can be drawn: modified Heliobond adhesive resin with 0.2 wt % chitosan exhibit the best antibacterial activity. The antibacterial properties of modified Heliobond adhesive depend on their pH value. By increasing the concentration of chitosan into Heliobond adhesive system, pH, degree of conversion and bond strength significantly decreased.