effect of dexamethasone intraligamentary injection on post-endodontic pain in patients with symptomatic irreversible pulpitis: a randomized controlled clinical trial

introduction: the aim of this randomized-controlled clinical trial was to assess the effect of intraligamentary (pdl) injection of dexamethasone on onset and severity of post-treatment pain in patients with symptomatic irreversible pulpitis. methods and materials: a total number of 60 volunteers were included according to the inclusion criteria and were assigned to three groups ( n =20). after administration of local anesthesia and before treatment, group 1 (control) pdl injection was done with syringe containing empty cartridge, while in groups 2 and 3 the pdl injection was done with 0.2 ml of 2% lidocaine or dexamethasone (8 mg/2 ml), respectively. immediately after endodontic treatment patients were requested to mark their level of pain on a visual analogue scale (vas) during the next 48 h (on 6, 12, 24 and 48-h intervals). they were also asked to mention whether analgesics were taken and its dosage. considering the 0-170 markings on the vas ruler, the level of pain was scored as follows: score 0 (mild pain; 0-56), score 1 (moderate pain; 57-113) and score 3 (severe pain; 114-170). the data were analyzed using the kruskal-wallis and the chi-square tests and the level of significance was set at 0.05. results: after 6 and 12 h, group 1 and group 3 had the highest and lowest pain values, respectively ( p <0.01 and p <0.001 for 6 and 12 h, respectively). however, after 24 and 48 h the difference in the pain was not significant between groups 1 and 2 ( p <0.6) but group 3 had lower pain levels ( p <0.01 and p <0.8 for 24 and 48 h, respectively). conclusion: pretreatment pdl injection of dexamethasone can significantly reduce the post-treatment endodontic pain in patients with symptomatic irreversible pulpitis.