Effect of intracanal heating of sodium hypochlorite alone and in combination with ultrasonic activation on postoperative endodontic pain: A randomized clinical trial

Aim: This study was conducted to evaluate the effect of intracanal heating (IH) of sodium hypochlorite (NaOCl), alone, and in combination with passive ultrasonic irrigation (PUI), on postoperative pain (PP) in teeth with symptomatic irreversible pulpitis (SIP). Materials and Methods: Ninety-two patients diagnosed with SIP were randomly divided into 4 groups on the basis of the method of activation, i.e., syringe irrigation, PUI, IH, and heating and PUI (HPUI) (combination of IH and PUI). Pain was assessed up to 1 week. Friedman and Wilcoxon tests (intragroup), Kruskal-Wallis and Mann-Whitney test (intergroup), and Chi-square test (categorical variables) were used for statistical analysis. Results: day compared to other groups. At 6 h, pain in the PUI group was significantly higher than HPUI group. No significant difference was found between the groups at all other postoperative time points. Conclusion: Activation of NaOCl by IH, PUI, and combination of both (HPUI) results in lesser PP compared to conventional irrigation alone. However, no additional benefit in terms of pain was obtained when the two activation techniques were combined.