Capsaicin to Control Pain Following Third Molar Extraction

This study will test the effectiveness of the drug capsaicin in controlling pain after third molar (wisdom tooth) extraction. Capsaicin, the ingredient in chili peppers that makes them "hot," belongs to a class of drugs called vanilloids, which have been found to temporarily inactivate pain-sensing nerves. Healthy normal volunteers between 16 and 40 years of age who require third molar (wisdom tooth) extraction may be eligible for this study. Participants will undergo the following procedures in three visits: Visit 1: Patients will have touch (sensory) testing by the following three methods: 1) a warm sensor applied to the gums and the patient will rate when they first feel heat and when the heat feels painful; 2) the bristles of a small paint brush will be gently stroked across the gums, and the patient will say whether it feels painful; 3) a light touch will be applied to the gums with a small needle, and the patient will rate the pain intensity following the touch. After testing, patients will be numbed with a local anesthetic (bupivacaine) and then capsaicin or placebo (an inactive solution) will be injected next to the tooth. The tooth then will be extracted one day later. Visit 2: Patients will return to the clinic after 24 hours to repeat the same type of sensory testing. After testing, patients will be sedated and numbed with a local anesthetic (lidocaine) and given an intravenous injection of either saline or ketorolac (30 mg). After the extraction, pain ratings will be recorded every 20 minutes, for up to 6 hours. During this time, patients will be monitored for numbness, pain, side effects and vital signs (heart rate, blood pressure, respiration, etc.). Those who request pain medicine will receive acetaminophen and codeine. Patients will be required to stay for up to 3 more hours after this and then they will then be discharged with pain medicine. Visit 3: Patients will return to the clinic after another 48 hours to repeat the same sensory testing