Effect of root canal irrigants on cervical dentine permeability to hydrogen peroxide

Abstract

Aim To examine the effects of various root canal irrigants on cervical dentine permeability by monitoring the diffusion of hydrogen peroxide (H 2O2). Methodology Sixty cervical dentine discs were prepared from human third molar teeth. After removal of enamel and cementum, the outer dentine surface was etched with 17% ethylenediamine tetraacetic acid (EDTA) for 1 min. The dentine discs were randomly assigned to five groups according to the irrigant used: A, saline solution; B, 2.5% sodium hypochlorite solution (NaOCl); C, 5% NaOCl; D, 17% EDTA and 2.5% NaOCl; E, 17% EDTA and 5% NaOCl. After irrigation on the inner dentine surface with the various solutions, the diffusion of 30% H2O2 was evaluated through each disc using a plastic-split chamber. H2O2 was applied to the inner-side chamber, while the outer-side chamber was filled with de-ionised water. After 30 min of application of H2O2, the solution in the outer-side chamber was collected to determine the concentration of H 2O2 using a spectrophotometer. Results The penetration of H2O2 through dentine in group E was significantly highest, followed by groups D, C, B and A respectively (one-way anova, P < 0.05). Conclusions Among the irrigants used, 17% EDTA and 5% NaOCl had the greatest effect in increasing dentinal permeability to H2O2. © 2008 International Endodontic Journal.