Anesthetic Efficacy of a Combination of 0.9 M Mannitol Plus 68.8 mg of Lidocaine With 50 μg Epinephrine in Inferior Alveolar Nerve Blocks: A Prospective Randomized, Single Blind Study

Abstract

The purpose of this prospective randomized, single blind study was to determine the anesthetic efficacy of 68.8 mg of lidocaine with 50 μg epinephrine compared to 68.8 mg lidocaine with 50 μg epinephrine plus 0.9 M mannitol in inferior alveolar nerve (IAN) blocks. Forty subjects randomly received 2 IAN blocks consisting of a 1.72-mL formulation of 68.8 mg lidocaine with 50 μg epinephrine and a 5-mL formulation of 68.8 mg lidocaine with 50 μg epinephrine (1.72 mL) plus 0.9 M mannitol (3.28 mL) in 2 separate appointments spaced at least 1 week apart. Mandibular anterior and posterior teeth were blindly electric pulp tested at 4-minute cycles for 60 minutes postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Total percent pulpal anesthesia was defined as the total of all the times of pulpal anesthesia (80 readings), for each tooth, over the 60 minutes. One hundred percent of the subjects had profound lip numbness with both inferior alveolar nerve blocks. The results demonstrated that the 5 mL-formulation of 68.8 mg lidocaine with 50 μg epinephrine plus 0.9 M mannitol was significantly better than the 1.72-mL formulation of 68.8 mg lidocaine with 50 μg epinephrine for all teeth, except the lateral incisor. We concluded that adding 0.9 M mannitol to a lidocaine with epinephrine formulation was significantly more effective in achieving a greater percentage of total pulpal anesthesia (as defined in this study) than a lidocaine formulation without mannitol. However, the 0.9 M mannitol/lidocaine formulation would not provide 100% pulpal anesthesia for all the mandibular teeth.