Intracanal Cryotherapy Reduces Postoperative Pain in Teeth with Symptomatic Apical Periodontitis: A Randomized Multicenter Clinical Trial

Introduction: A prospective, multicentered, randomized clinical trial was designed to assess if controlled irrigation with cold saline could result in less incidence and intensity of postoperative pain in patients presenting with pulp necrosis and symptomatic apical periodontitis. Methods: A total of 210 patients (presenting with necrotic uniradicular teeth with a diagnosis of symptomatic apical periodontitis and a preoperative visual analog scale (VAS) score higher than 7) were randomly allocated in the control or experimental group after the completion of shaping and cleaning procedures. The experimental group received a final irrigation with 20 mL sterile cold (2.5 degrees C) saline solution delivered to the working length with a sterile, cold (2.5 degrees C) Endovac microcannula (Kerr Endo, Orange Country, CA) for 5 minutes. The same protocol was used in the control group with room temperature saline solution. Patients were instructed to record the presence, duration and level of postoperative pain, and analgesic medication intake. A logistic regression was used to compare the incidence of postoperative pain and the need for painkillers between groups. Differences in general pain intensity between groups were analyzed using the ordinal (linear) chi-square test. Postoperative pain after 6, 24, and 72 hours (recorded in a VAS scale) and the need for analgesic medication intake between the 2 groups were assessed using the Mann-Whitney U test. Results: Patients in the control group presented a significantly higher incidence of postoperative pain, intensity, and need for medication intake (P < .05). Conclusions: Cryotherapy reduced the incidence of postoperative pain and the need for medication intake in patients presenting with a diagnosis of necrotic pulp and symptomatic apical periodontitis.