Effect of prophylactic amoxicillin on endodontic flare-up in asymptomatic,necrotic teeth

The purpose of this prospective, randomized, double-blind, placebo-controll ed study was to determine the effect of prophylactic amoxicillin on the occ urrence of endodontic flare-up in asymptomatic, necrotic teeth. Seventy pat ients participated and had a clinical diagnosis of an asymptomatic, necroti c tooth with associated periapical radiolucency. One hour before endodontic treatment, patients randomly received either 3 g of amoxicillin or 3 g of a placebo control in a double-blind manner. After endodontic treatment, eac h patient received: ibuprofen; acetaminophen with codeine (30 mg); and a 5 1/2-day diary to record pain, swelling, percussion pain, and number and typ e of pain medication taken. The results demonstrated 10% of the 70 patients had a flare-up characterized by moderate-to-severe postoperative pain or s welling that began similar to 30 h after endodontic treatment and persisted for an average of 74 h. Of the seven patients who had flare-ups, 4 were in the amoxicillin group and 3 were not. Prophylactic amoxicillin did not sig nificantly (p = 0.80) influence the endodontic flare-up. We concluded that a prophylactic dose of amoxicillin before endodontic treatment of asymptoma tic, necrotic teeth had no effect on the endodontic flare-up.