Effect of solvent use on postoperative pain in root canal retreatment: a randomized, controlled clinical trial

Objectives The aim of this randomized clinical trial was to assess the effect of solvent use during the removal of root canal filling on postoperative pain after retreatment. Materials and methods Ninety patients scheduled for root canal retreatment were randomly assigned to one of the following two groups according to the root canal filling removal procedure used: ProTaper retreatment (Dentsply Maillefer, Ballaigues, Switzerland) instruments or ProTaper retreatment instruments in combination with gutta-percha solvent. A single operator performed the retreatments in a single visit. The incidence and intensity of the postoperative pain were rated on a numeric rating scale by patients at 24, 48, and 72 h after retreatment. The analgesic tablet intake number was also recorded. Data were analyzed using Mann‑Whitney U , Wilcoxon, and chi-square tests. Results For the intensity of postoperative pain, the difference between the two groups was not statistically significant. Moreover, no statistically significant difference was found between the two groups in terms of analgesic medication intake ( P > 0.05). Conclusions The processes involving the use and non-use of a solvent in the removal of root canal fillings were found to be equivalent in terms of postoperative pain intensity and analgesic intake. Clinical relevance Some in vitro studies claimed that the use of a gutta-percha solvent in the removal of root canal fillings tends to reduce postoperative pain since extrusion of debris was significantly less. This randomized clinical trial indicates that the removal of root canal fillings with or without the use of a solvent was associated with equivalent postoperative pain intensity and analgesic intake. This study is registered in the www.ClinicalTrials.gov database with the identifier number NCT03756363.