Anesthetic effectiveness of the supplemental intraligamentary injection, administered with a computer-controlled local anesthetic delivery system, in patients with irreversible pulpitis

The purpose of this study was to determine the anesthetic effectiveness of the supplemental intraligamentary injection, administered with a computer-controlled local anesthetic delivery system, in mandibular posterior teeth diagnosed with irreversible pulpitis when the conventional inferior alveolar nerve block failed. Fifty-four emergency patients, diagnosed with irreversible pulpitis of a mandibular posterior tooth, received an inferior alveolar nerve block and had moderate to severe pain upon endodontic access. A computer-controlled local anesthetic delivery system was then used to administer intraligamentary injections of 1.4 ml of 2% lidocaine with 1:100,000 epinephrine. Success of the intraligamentary injection was defined as none or mild pain upon endodontic access or initial instrumentation. The results demonstrated that anesthetic success was obtained in 56% (30 of 54) of the patients. We concluded that when the inferior alveolar nerve block failed to provide profound pulpal anesthesia in mandibular posterior teeth of patients presenting with irreversible pulpitis, the intraligamentary injection administered with a computer-controlled local anesthetic delivery system was successful approximately 56% of the time.