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).