Continuous chelation irrigation improves the adhesion of epoxy resin-based root canal sealer to root dentine

Abstract

Aim To test the impact of continuous chelation by NaOCl+ etidronic acid (HEBP) during instrumentation, and a final rinse of EDTA or NaOCl+HEBP on the dentine bond strength of an epoxy resin sealer (AH Plus). Methodology Single-rooted teeth (n=100) were divided into five groups (n=20) based on the irrigation protocol and their root canals instrumented using a rotary Ni-Ti system: 2.5% NaOCl during instrumentation followed by bi-distilled water (G1) or 17% EDTA (G2) as final rinse; 1:1 mixture of 5% NaOCl and 18% HEBP during instrumentation, and the same mixture (G3), 17% EDTA (G4) or bi-distilled water (G5) as final rinse. Canals were filled with AH Plus. Roots were sectioned, and push-out tests were performed in coronal, middle and apical root thirds. Results were analysed using analysis of variance (anova) and Bonferroni test for multiple comparisons. The alpha-type error was set at 0.05 for all the analyses. Results Push-out bond strength was highest in coronal and lowest in apical root thirds (P<0.05). Groups that used NaOCl+HEBP irrigation during instrumentation had significantly higher bond strengths than groups following the NaOCl-EDTA irrigation in all root thirds (P<0.05). The use of astrong chelator as final flush further increased bond strengths (G4, P<0.05). Conclusion The continuous chelation irrigation protocol optimizes the bond strength of an epoxy resin sealer to dentine. © 2012 International Endodontic Journal.