IRCT201204199515N1 IRCT 2013-01-15 Vice chancellor for research, Hamedan University of Medical Sciences Evaluation of the effect of injection of bupivacaine by patient into the tooth socket on pain management after surgical extraction of impacted lower third molar Clinical trial to comparison of bupivacaine(local) and mefnamic acid on mean pain score reported during the first 24 hours after surgical extraction of third molar, in patients with similar bilateral impacted lower third molar. 2012-04-19 anticipated 48 Complete https://irct.ir/trial/10086 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Crossover, Purpose: Other. 2-3 impacted teeth. Intervention 1: Intervention group: Placebo of mefnamic acid 250 mg, every 8 hours during 24 hours following surgery. Intervention 2: Intervention group: Injection of 0.3 cc bupivacaine 0.5% in to the tooth socket, every 2 hours during 12 hours following surgery. Intervention 3: Control group: Injection of 0.3cc normal saline in to the tooth socket, every 2 hours during 12 hours following surgery. Intervention 4: Control group: Mefnamic acid 250 mg, every 8 hours during 24 hours following surgery.