The Use of Collagen Cross-Linking Agents to Enhance Dentin Bond Strength

Type I collagen is a major component of the hybrid layer, and improvement of its mechanical properties may be advantageous during bonding procedures. Objective: To investigate the effect of three different cross-linking agents (Glutaraidehyde [GD], Grape seed extract [GSE], and Genipin [GE]) on the tensile bond strength (TBS) of resin-dentin bonds. Materials and Methods: Sixty-four sound human molars were collected and their occlusal surfaces were ground flat to expose dentin. Dentin surfaces were etched using a phosphoric acid and then teeth were randomly divided according to the dentin treatment: Control group (no treatment), 5% GD, 6.5% GSE, or 0.5% GE. Teeth were restored either with One Step Plus or Adper Single Bond Plus adhesive systems and resin composite. After 24 h, teeth were sectioned to produce a cross-sectional surface area of 1.0 mm(2) and tested for tensile bond strength. Data were statistically analyzed using ANOVA and Fisher's PLSD tests (P < 0.05). There was a statistically significant interaction between factors (treatment and adhesive p < 0.001). Treatment affected TBS (p < 0.0001), while no differences were observed between the adhesive systems (p = 0.6961). Conclusion: Chemical modification to the dentin matrix promoted by GD and GSE, but not GE, resulted in increased bond strength. The application of selective collagen cross-linkers during adhesive restorative procedures may be a new approach to improve dentin bond strength properties. (C) 2009 Wiley Periodicals. Inc. J Biomed Mater Res Part B: Appl Biomater 91B: 419-424, 2009