Effect of Back-Pressure Anesthesia on Postoperative Pain after the Endodontic Treatment in Patients with Symptomatic Irreversible Pulpitis: Randomized Double-Blind Clinical Trial

Introduction: The present study evaluated the effect of 2 different back pressure-based supplemental anesthesia on postoperative pain in patients receiving endodontic treatment for a mandibular molar with symptomatic irreversible pulpitis. Methods: One-hundred-thirty-five adult patients with symptomatic irreversible pulpits in a mandibular first or second molar, received an initial inferior alveolar nerve block (IANB) injection with 2% lidocaine with 1:80,000 epinephrine. Ten minutes following the injection, access to cavity preparation began. Lip numbness was a must for all patients. The Heft-Parker visual analogue scale (HP-VAS) was used to measure pain during endodontic therapy. Success of primary injections was defined as no or mild pain (less than 55 mm on HP-VAS) during access preparation. The patients with initial successful anesthesia served as control and received endodontic treatment. Ninety-five patients with unsuccessful primary anesthesia randomly received either intraligamentary injections of 2% lidocaine with 1:80,000 epinephrine or intrapulpal injections with similar anesthetic solution. Endodontic treatment was re-initiated and canals were instrumented till working length under copious irrigation. Intracanal medicament of calcium hydroxide was placed and teeth received a temporary restoration. Postoperative pain was measured at 2 hours, 4 hours, 6 hours, 24 hours, and 3 days. Data were analyzed using the Pearson chisquare test, one-way analysis of variance, and one-way repeated measures analysis of variance. Results: The initial initial inferior alveolar nerve block was successful in 40 cases (out of 135). The intraligamentary injections were successful in 33 out of 47 cases (70%), and intrapulpal injections were successful in all cases (45/45). The patients receiving intraligamentary injections reported significantly higher pain scores at all intervals till 24 hours. After 3 days, the pain significantly reduced in all the groups with no significant difference between them. Conclusions: Patients receiving supplementary intraligamentary injections can experience increased postoperative pain till 24 hours after the endodontic treatment. The pain scores reduced to the level of the control group after 3 days. (J Endod 2024;50:1037- 1043.)