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

Introduction: The 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.

Methods: Thirty 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.

Results: By 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.

Conclusion: Increasing 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.