Local anesthetics: special considerations in endodontics.

Local anesthetics are essential for successful endodontic treatment, and their pharmacologic characteristics have special implications for the treatment of painful, chronically-inflamed or necrotic teeth. Their dosages must be limited to prevent toxicity, which may be enhanced by the coadministration of sedative agents or drugs which affect hepatic drug metabolism. Endodontic patients with established central and peripheral sensitization represent special challenges for pain control, since morphogenetic changes resulting from neurogenic inflammation can render pain fibers more resistant to local anesthesia. The use of vasconstrictors with conventional and alternative injection techniques, e.g., intraosseous injections, are necessary to prolong the duration of action of local anesthesia but can place patients with cardiovascular disease at some risk. An appreciation of all of these aspects of local anesthesia in endodontics will better prepare the operator for predictably safe and effective patient care.