Evaluation of the effect of intracanal cryotherapy on postoperative pain after retreatment: a randomized controlled clinical trial

Objectives This randomized controlled clinical trial aimed to evaluate the effect of intracanal cryotherapy using cold saline (2.5 degrees C) as a final irrigant on postoperative pain and analgesic consumption following single-visit nonsurgical endodontic retreatment of asymptomatic mandibular premolars. Materials and methods Sixty systemically healthy patients with asymptomatic apical periodontitis in previously treated single-rooted mandibular premolars were enrolled and randomly assigned to two groups (n = 30 each). Both groups underwent standardized retreatment protocols, with the cryotherapy group receiving final irrigation with cold saline (2.5 degrees C) and the control group with room-temperature saline, both for 5 min. Postoperative pain was assessed using a 10-point Visual Analog Scale (VAS) at 6, 12, 24, 48, 72, and 168 h. Analgesic intake was also recorded. Statistical analysis was performed using the Chi-Square and Mann-Whitney tests with a significance level set at 0.05. Results The cryotherapy group exhibited significantly lower pain scores at 6 h (p = 0.014) and 12 h (p = 0.028) postoperatively compared to the control group. No significant differences were observed at 24, 48, 72, or 168 h. Although fewer patients in the cryotherapy group reported analgesic use, this difference was not statistically significant (p = 0.278). No adverse events were reported. Conclusions Intracanal cryotherapy using cold saline effectively reduced short-term postoperative pain following endodontic retreatment but did not significantly influence long-term pain or analgesic intake.