Anesthetic efficacy of combinations of 0.5 mol/L mannitol and lidocaine with epinephrine for inferior alveolar nerve blocks in patients with symptomatic irreversible pulpitis.

INTRODUCTION: The purpose of these 2 prospective, randomized, single-blind studies was to determine the anesthetic efficacy of lidocaine with epinephrine compared with a combination lidocaine with epinephrine plus 0.5 mol/L mannitol for inferior alveolar nerve (IAN) blocks in patients experiencing symptomatic irreversible pulpitis.

METHODS: In study one, 55 emergency patients randomly received IAN blocks by using a 3.18-mL formulation containing 63.6 mg of lidocaine with 31.8 μg epinephrine or a 5-mL formulation containing 63.6 mg of lidocaine with 31.8 μg epinephrine (3.18 mL) plus 1.82 mL of 0.5 mol/L mannitol. In study two, 51 emergency patients randomly received IAN blocks by using a 1.9-mL formulation containing 76.4 mg of lidocaine with 36 μg epinephrine or a 3-mL formulation containing 76.4 mg of lidocaine with 36 μg epinephrine (1.9 mL) plus 1.1 mL of 0.5 mol/L mannitol. Endodontic access was begun 15 minutes after the IAN block, and all patients had profound lip numbness. Success was defined as no or mild pain (visual analogue scale recordings) on endodontic access or instrumentation.

RESULTS: The 1.9 mL of lidocaine (76.4 mg) with epinephrine plus 0.5 mol/L mannitol had a significantly (P = .04) better success rate of 39% when compared with the lidocaine formulation without mannitol (13% success rate).

CONCLUSIONS: For mandibular posterior teeth in patients with symptomatic irreversible pulpitis, the addition of 0.5 mol/L mannitol to 1.9 mL of lidocaine (76.4 mg) with epinephrine resulted in a statistically higher success rate. However, the combination lidocaine/mannitol formulation would not result in predictable pulpal anesthesia.