Comparative evaluation of the efficacy of 2% lidocaine containing 1:200,000 epinephrine with and without hyaluronidase (75 IU) in patients with irreversible pulpitis

Introductions: The purpose of this study was to determine the anesthetic efficacy of lidocaine containing epinephrine compared with lidocaine containing epinephrine plus hyaluronidase (75 IU) when performing an inferior alveolar nerve block. Methods: Patients complaining of pain in the mandibular posterior teeth were selected. Based on their chief complaint, proper clinical and radiographic examinations were performed. Among them, 40 subjects diagnosed with irreversible pulpitis were selected. The inferior alveolar nerve block was induced using 3 mL 2% lidocaine with epinephrine. Hyaluronidase (75 IU) or a placebo was injected 30 minutes after the beginning of pulpal anesthesia (randomized and double-blind trial). The duration of the effect in the pulpal and gingival tissues was evaluated by the response to painful electrical stimuli applied to the adjacent premolar and by mechanical stimuli (pinprick) to the buccal gingiva, respectively. Results: In both pulpal and gingival tissues, the duration of the anesthetic effects with hyaluronidase was longer than with placebo. Conclusions: Hyaluronidase increased the duration of the effects of lidocaine in inferior alveolar nerve blocks.