Background and Aim: Clinical studies concerning the effect of intraoral injection of phentolamine mesylate on the duration of soft tissue anesthesia and its related functional deficits after using a plain local anesthetic are scarce. This study is to evaluate the efficacy and safety of phentolamine mesylate as a local anesthesia reversal agent after plain mepivacaine using mental/incisive nerve block.
Methods: Twenty patients who received plain mepivacaine as a local anesthetic were randomly assigned into two groups: group I (sham injection group) and group II (phentolamine mesylate group). Sham injection or phentolamine mesylate injection was given 30 minutes after mepivavaine injection. Time to return to normal soft tissue sensation and normal oral functions was recorded to assess efficacy of phentolamine mesylate. Intraoral assessment, monitoring hemodynamic vital signs and presence of any drug-related adverse effects were used to assess safety of phentolamine mesylate.
Results: there were statistically significant differences (p< 0.001) in the mean duration to recovery of normal sensation in the lower lip, chin and gums between group I and group II. Also there were statistically significant differences (P<0.001) in the mean duration to perceive normal sensation and in the mean duration to demonstrate normal oral functions between the two groups. No statistically significant differences were observed in hemodynamic vital signs between periods of measurements in each group nor between the two groups. No changes were observed on intraoral examination and no drug related adverse events occurred. All patients were satisfied with the rapid recovery of normal sensation and oral functions.
Conclusion: Phentolamine mesylate is efficient and safe for rapid recovery of normal sensation and oral functions after using plain mepivacaine

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