Comparison of the Anesthetic Efficacy of Mepivacaine and Lidocaine in Patients with Irreversible Pulpitis: A Double-blind Randomized Clinical Trial.

INTRODUCTION: The objective of this study was to compare the anesthetic efficacy of 2% mepivacaine combined with 1:100,000 epinephrine with 2% lidocaine combined with 1:100,000 epinephrine during pulpectomy of mandibular posterior teeth in patients with irreversible pulpitis.

METHODS: Forty-two patients with irreversible pulpitis who were admitted to the Emergency Center at the University of São Paulo School of Dentistry volunteered to take part in the study and were randomized to receive conventional inferior alveolar nerve block containing 1.8 or 3.6 mL of either 2% mepivacaine with 1:100,000 epinephrine or 2% lidocaine with 1:100,000 epinephrine. We recorded patients' subjective assessments of lip anesthesia, absence/presence of pulpal anesthesia tested by using electric pulp stimulation, and absence/presence of pain during the subsequent pulpectomy by using a verbal analogue scale.

RESULTS: All patients tested reported lip anesthesia after application of either type of inferior alveolar nerve block. Pulpal anesthesia success rates measured by using the pulp tester were satisfactory for both solutions (86% for mepivacaine and 67% for lidocaine). Success rates according to patient report of no pain or mild pain during pulpectomy were higher for mepivacaine solution (55%) than for lidocaine solution (14%). The differences between mepivacaine and lidocaine were statistically significant.

CONCLUSIONS: Mepivacaine resulted in effective pain control during irreversible pulpitis treatments. The success rates with either solution were not high enough to ensure complete pulpal anesthesia.