Anesthetic Efficacy of 1.8 mL versus 3.6 mL of 4% Articaine with 1:100,000 Epinephrine as a Primary Buccal Infiltration of the Mandibular First Molar

Introduction: No study has compared 1.8 mL and 3.6 mL 4% articaine with 1:100,000 epinephrine in a mandibular buccal infiltration of the first molar. The authors conducted a prospective, randomized, single-blind, crossover study comparing the degree of pulpal anesthesia obtained with 1.8 mL and 3.6 mL 4% articaine with 1:100,000 epinephrine as a primary infiltration in the mandibular first molar. Methods: Eighty-six asymptomatic adult subjects randomly received a primary mandibular buccal first molar infiltration of 1.8 mL or 3.6 mL 4% articaine with 1:100,000 epinephrine in two separate appointments. The authors used an electric pulp tester to test the first molar for anesthesia in 3-minute cycles for 90 minutes after the injections. Results: Compared with the 1.8-mL volume of 4% articaine with 1:100,000 epinephrine, the 3.6-mL volume showed a statistically higher success rate (70% vs 50%). Conclusions: The anesthetic efficacy of 3.6 ml 4% articaine with 1:100,000 epinephrine is better than 1.8 mL of the same anesthetic solution in a primary mandibular buccal infiltration of the first molar. However, the success rate of 70% is not high enough to support its use as a primary injection technique in the mandibular first molar. (J Endod 2011;37:588-592)