Soft tissue and pulpal anesthesia induced by the administration of local anesthetic agents containing a vasoconstrictor (epinephrine or levonordefrin) is an essential part of outpatient dentistry. 1 – 3 A shortcoming of most dental local anesthetic agents is that the duration of soft tissue anesthesia (numbness to the lip and tongue) typically lasts for 3–5 hours. 4 Persistent anesthesia, which is often associated with difficulty in eating, drinking, and speaking and with inadvertent biting of the lips, tongue, and/or cheek, is considered