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

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. 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 chi-square test, one-way analysis of variance, and one-way repeated measures analysis of variance. 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. 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.