How do I select an appropriate local anesthetic for a given patient and procedure?

Two factors are particularly important:

1. The duration of pain control required to complete the procedure painlessly, and the possible need for posttreatment pain control (e.g., after surgical procedures). Box 4.1 lists currently available local anesthetic formulations by their approximate duration of action—for both soft tissue and pulpal anesthesia.

2. The patient’s physical status (e.g., American Society of Anesthesiologists [ASA] classification), hypersensitivity, methemoglobinemia, or sulfur allergy, which may preclude the use of specific drugs.

For most patients the duration of desired pain control is the ultimate deciding factor in local anesthetic selection, because usually there are no contraindications to the administration of any particular agent.