Prospective, Randomized Single-blind Study of the Anesthetic Efficacy of 1.8 and 3.6 Milliliters of 2% Lidocaine with 1:50,000 Epinephrine for Inferior Alveolar Nerve Block

IntroductionThe purpose of this prospective, randomized study was to compare the degree of pulpal anesthesia obtained in vital, asymptomatic teeth by using 1.8 mL and 3.6 mL of 2% lidocaine with 1:50,000 epinephrine compared with 1.8 mL of 2% lidocaine with 1:100,000 epinephrine for inferior alveolar nerve (IAN) block.MethodsThirty adult subjects randomly received IAN blocks of 1.8 mL and 3.6 mL of 2% lidocaine with 1:50,000 epinephrine and 1.8 mL of 2% lidocaine with 1:100,000 epinephrine at 3 separate appointments in a crossover design. An electric pulp tester was used to test for anesthesia in 3-minute cycles for 60 minutes of the first molars, first premolars, and lateral incisors. Anesthesia was considered successful when 2 consecutive 80 readings were obtained within 15 minutes, and the 80 reading was continuously sustained through the 60th minute.ResultsBy using 1.8 mL of 2% lidocaine with 1:50,000 epinephrine, successful pulpal anesthesia ranged from 33%–50%, and when using 3.6 mL of 2% lidocaine with 1:50,000 epinephrine, success ranged from 40%–60%. When using 1.8 mL of 2% lidocaine with 1:100,000 epinephrine, success ranged from 40%–60%, with no significant difference among the 3 anesthetic formulations.ConclusionIncreasing the epinephrine concentration to 1:50,000 epinephrine or increasing the volume to 3.6 mL of 2% lidocaine with 1:50,000 epinephrine did not result in more successful pulpal anesthesia when compared with 1.8 mL of 2% lidocaine with 1:100,000 epinephrine by using the IAN block.