Effect of chemical irrigants and medicaments for endodontic treatment on dentin bonding

Purpose: To evaluate the bond strengths of two different types of resin luting cements to dentin treated with chemical irrigants and medicaments for root canal treatment. Materials and Methods: The bovine incisors were ground with silicon carbide paper to expose a dentin. Dentin surface was treated with either 3% hydrogen peroxide (H2O2), 5% sodium hypochlorite (NaOCl), the combination of H2O2 and NaOCl (H2O2/NaOCl), formocresol (FC), or calcium hydroxide (Ca(OH)2) for 60 s, then rinsed and air dried. Dentin without any treatment was used as the control group. The area for bonding was then demarcated with a vinyl tape (4 mm-in-diameter hole), and bonded using one of two resin cement, Super-Bond C&B or Panavia F according to the manufactures’ instructions. After storage in water for 1 day, tensile bond strengths were measured using a universal testing machine. Results: For Super-Bond C&B, statistically lower early bond strengths were obtained in the experimental group compared with the control. In the case of Panavia F, the early bond strengths decreased significantly in H2O2, H2O2/NaOCl, and Ca(OH)2, while no influence of NaOCl and FC on early bond strengths was observed. However, the visual inspection showed a large increase of adhesive failures between the resin and dentin occurred with the experimental groups, which was marked for both resin cements. Conclusion: The early bond strengths of resin cements to dentin were adversely influenced by the chemical irrigants and medicaments for root canal treatment. (Int Chin J Dent 2003; 3: 7-12.)