Efficacy comparison of periapical infiltration injection of dexamethasone, morphine and placebo for postoperative endodontic pain

Objective: To evaluate the efficacy of periapical infiltration injection of dexamethasone and morphine in reducing postoperative endodontic pain. Method: Ninety patients participated in this double‐blind randomised controlled clinical trial. They were referred to the dental school of Shahid Beheshti Medical University, Tehran, Iran for conventional endodontic treatment of molar teeth. The canals of each tooth were completely prepared with cleansing and shaping. The patients were randomly divided into three experimental groups to receive dexamethasone, morphine or normal saline (1 mL). Patients were then instructed to complete a pain diary 4, 8, 24 and 48 h after the appointment. Statistical analysis consisted of chi‐squared test, analysis of variance and Kruskal–Wallis test. Results: There was a statistically significant correlation between dexamethasone or morphine treatment and decreased levels and incidence of endodontic pain at 4, 8 and 24 h, but not at 48 h (P