The Effect of Peracetic Acid on Removing Calcium Hydroxide from the Root Canals

Introduction: The goal of this study was to evaluate the efficiencies of different irrigation solutions in the removal of calcium hydroxide (CH). Methods: Forty-eight maxillary central incisor teeth were used. Root canals were prepared with the ProTaper system (Dentsply Maillefer, Baillagues, Switzerland). Five milliliters 2% NaOCl, 5 mL 17% EDTA, and 10 mL saline were used for final irrigation. The canals were filled with CH paste. Specimens were randomly divided into 4 experimental groups (n = 10) according to irrigation protocols. Positive and negative control groups (n = 4) were used. Group 1 used 2.5 mL 17% EDTA, group 2 used 2.5 mL 2.5% NaOCl + 2.5 mL 17% EDTA, group 3 used 2.5 mL 1% peracetic acid (PAA), and group 4 used 2.5 ml 0.5% PM. The specimens were evaluated with scanning electron microscope analysis and scored. Kruskal-Wallis and Student Newman-Keuls post hoc tests were used for Statistical analysis. Results: In the apical thirds, 1% PAA was superior to the other groups (P < .05); however, there were no significant differences among the other groups (P > .05). In the middle thirds, no significant differences were found among the groups (P > .05). In the coronal thirds, 1% PM was superior to the other groups. There were significant differences among all the other groups (P < .05). Conclusions: According to the findings of the present study, 1% PM could be recommended for the removal of CH from the root canals. (J Endod 2012;38:1197-1201)