International Journal of Health Sciences & Research (www.ijhsr.org) 83 Vol.8; Issue: 2; February 2018 International Journal of Health Sciences and Research www.ijhsr.org ISSN: 2249-9571 Original Research Article The Effect of Intracanal Cryotherapy in Reducing Postoperative Pain in Patients with Irreversible Pulpitis: A Randomized Control Trial Duaa S. Bazaid 1 , Laila M. M Kenawi 2 1 Dental Intern, Faculty of Dentistry, Umm Al-Qura University, Kingdom of Saudi Arabia. 2 Assistant Professor, Endodontic Division, Faculty of Dentistry, Umm Al-Qura University Lecturer, Department of Endodontic, Faculty of Oral and Dental Medicine, Cairo University Corresponding Author: Duaa S. Bazaid ABSTRACT Introduction: An important aspect in endodontic practice is controlling pain during and after root canal treatment; to control the postoperative pain several strategies have been developed including the use of analgesics long-standing anaesthesia and different techniques in root canal preparation. This study was conducted to evaluate and compare the effect of intracanal cryotherapy in reducing postoperative pain in patients with irreversible pulpitis with and without apical periodontitis. Method: A randomized control trial had been conducted among 40 patients with irreversible pulpitis. The patients were randomly divided according to the temperature of the final irrigant used, into two groups control (1) using saline at room temperature, and study group (2) using cold saline. Then further subdivided into two subgroups according to pulpal diagnosis, either irreversible pulpitis with apical periodontitis (subgroup a) or irreversible pulpitis without apical periodontitis (subgroup b). Visual analogue scale (VAS) was used to evaluate and compare postoperative pain. Results: A statistically significant difference was found when comparing the pain level in cryotherapy group (subgroup 2a) with control group (subgroup 1a) 24, 48 hours postoperatively. But there was no statistically significant difference when comparing the pain level in cryotherapy (subgroup 1b) with control (subgroup 1b) after 24, 48 hours postoperatively (p>0.05). Conclusion: Using intracanal cryotherapy is effective in reducing postoperative pain in patients with irreversible pulpitis with apical periodontitis. But it does not affect patients with irreversible pulpitis without apical periodontitis Key words: Intracanal cryotherapy, postoperative pain, Irreversible pulpitis. INTRODUCTION Cryotherapy is a term derived from a Greek word that means “cold therapy”. In physiotherapy, cryotherapy means reducing tissue temperature as a treatment method. It is efficient in reducing inflammation, pain, edema and recovery time in the short-term application. (1,2) Cryotherapy is a common technique used in abdominal, hernia, gynecological and orthopaedic operation; its mechanism of action is by affecting the nerve conduction capacity. The cold application on the skin stimulates the thermo receptors (temperature sensitive receptors), and the stimulation of these receptors can block nociception within the spiral cord spiral cord. (2) Controlling the pain during root canal treatment and after is an important aspect in endodontic practice. (3) Postoperative pain is recorded as high incident rate ranging from 3-58% of the cases. (4) It is affected by different factors like the periapical tissues condition, the