Managing local anesthesia problems in the endodontic patient.

Root canal therapy has a poor public image related to occasional and sometimes severe pain, and to dentists' inability to obtain profound anesthesia. Patients' apprehension, in combination with tissue inflammation, significantly lowers the pain threshold, which decreases the anesthetic's effectiveness. The best and also the first approach to achieving anesthesia is to administer a conventional block or infiltration. If profound anesthesia does not occur after this attempt, use a supplemental technique such as lingual infiltrations, PDL or intrapulpal injections. Because infiltrations are generally not effective, PDL and intrapulpal injections are preferred. The PDL is better than the intrapulpal injection because it is non-painful, safe and usually effective. The intrapulpal injection is limited and may be uncomfortable. Administer both the PDL and intrapulpal injections under back-pressure to achieve effective, but short-lived anesthesia. Special injection devices (for example, pressure syringes for the PDL) are not required for either technique. Two anesthetic types are useful. Administer 2 percent lidocaine with epinephrine for conventional and supplemental injections. For emergencies and long procedures, administer 0.5 percent bupivacaine with epinephrine to provide effective, long-lasting anesthesia and analgesia.