Analgesic Effects of Peripherally Administered Opioids in a Clinical Model of Chronic Inflammation

The effectiveness of local anesthetics is reduced if inflammation is present, making it difficult to control pain during such procedures as root canals and wisdom teeth removal. This set of studies will assess the effectiveness of the opioid (synthetic narcotic) fentanyl in enhancing the local anesthetic lidocaine (delivered with epinephrine) when used on inflamed molar teeth.

In the first study, a topical anesthetic patch or a placebo will be placed on the gum tissues next to four or five lower posterior teeth. The patch will removed at either 5, 10, or 15 minutes. An electronic test that sends a light electronic impulse into the tooth, lip sensitivity testing ("Is your lip numb?"), and discomfort reports will be started immediately after removal of the patch and repeated every 5 minutes for 30 minutes. An oral surgeon will then remove the patient's wisdom teeth (tooth).

In the second and third studies, a topical anesthetic will be placed on the gum tissue. An electronic test that sends a light electronic impulse into the tooth, lip sensitivity testing ("Is your lip numb?"), and discomfort reports will be started and done several times throughout the test. Then two small openings, one on each side of the tooth, will be drilled into the bony tissues surrounding the tooth. A narcotic drug fentanyl or a placebo drug will be delivered through these openings, allowing placement of the drug next to the nerves that are difficult to numb. Lidocaine, along with a small amount of epinephrine, will be delivered. An oral surgeon will then remove the patient's wisdom teeth or tooth (study 2) or do a root canal (study 3).

In the fourth study, a topical anesthetic will be placed on the gum tissue. Then two small openings, one on each side of the tooth, will be drilled into the bony tissues surrounding the tooth. A narcotic drug fentanyl or a placebo drug will be delivered through these openings. Lidocaine, along with a small amount of epinephrine, will be delivered at one of three rates (15 patients for each rate). Blood pressure, heart rate, and breathing rate will be taken before the topical anesthetic patch is applied, 2 minutes after, and every 5 minutes for the next 45 minutes. Blood samples will be taken 6 times over the course of 60 minutes. When testing is complete, an oral surgeon will remove the wisdom teeth (tooth). One month later, blood samples will be taken using a different drug delivery method in order to compare results.