Hyaluronidase Increases the Duration of Mepivacaine in Inferior Alveolar Nerve Blocks

PurposeTo evaluate the duration of the effect of mepivacaine when hyaluronidase is injected immediately prior to the end of pulpal anesthesia.Patients and MethodsForty bilateral, symmetrical third molar surgeries were performed in 20 healthy patients. Inferior alveolar nerve block was induced using 2.8 mL 2% mepivacaine with epinephrine. Hyaluronidase (75 turbidity-reducing units) or a placebo was injected 40 minutes after the beginning of pulpar anesthesia (randomized and double-blind trial). The duration of effect in the pulpal and gingival tissues was evaluated by response to painful electrical stimuli applied to the adjacent premolar, and by mechanical stimuli (pin prick) to the vestibular gingiva, respectively.ResultsIn both tissues, the duration of anesthetic effect with hyaluronidase was longer (P < .01) than with the placebo.ConclusionHyaluronidase increases the duration of mepivacaine in inferior alveolar nerve blocks.