Jordan Journal of Pharmaceutical Sciences, Volume 4, No. 3, 2011 - 191 - © 2011 DAR Publishers/University of Jordan. All Rights Reserved. Received on 1/8/2010 and Accepted for Publication on 30/8/2010.  E-mail: alomirim@yahoo.co.uk Relationship between Route of Antibiotic Administration and Post-surgical Complications Following Removal of Lower Third Molars. Ziad Malkawi 1 , Mahmoud K. AL-Omiri 1  1 Faculty of Dentistry, The University of Jordan, Amman 11942, Jordan. ABSTRACT This prospective clinical trial aims at evaluating the effects of antibiotic therapy following different administration routes on the postoperative complications of surgical removal of lower impacted third molars. Two hundred and fourty eight consecutive patients (100 males and 148 females) aged 18 to 38 years old (mean=24±5 years) were recruited into this study. The lower third molars of all recruited patients were surgically extracted. Participants received preoperative antibiotic cover either as intravenous Cephradine injection (1 gram) or oral dose of 500 mg Cephalexin. Immediate and late complications following the surgery; including pain, swelling, trismus, paraesthesia, bleeding, dry socket, infection and fracture of mandible; were assessed 3 days and 7-14 days following the surgery. The most frequent complications were slight pain, swelling, and trismus. Oral route of antibiotic administration was associated with more immediate and late complications (p<0.001). Oral route of antibiotic administration was associated with more pain, swelling, trismus, and dry socket (p<0.05). Following surgical extraction of third molars, intravenous antibiotic administration was more effective in reducing the post surgical complications than oral antibiotic administration. Keywords: Antibiotic Route, Third Molar, Post-Surgical Complications. INTRODUCTION The removal of lower third molars is the most common intervention in oral surgery 1 . It is usually associated with significant post-operative complications that have biological and social impacts 2,3 . Complications incorporate pain, swelling, trismus, dysaesthesia, fracture of mandible, infection, dry socket, hemorrhage, damage to adjacent teeth, and displaced teeth 4,5 . The use of antibiotics in the presence of an ongoing infection is not in dispute 6 . However, the effectiveness of antibiotics in the prevention of postoperative infection for cases in which third molars are removed is still controversial. Some studies oppose the use of antibiotics and showed no benefit of prescribing them for third molar surgery 7-12 . On the other hand, some studies demonstrated significant effects of antibiotics in the reduction of post operative complications following third molar surgery 13-15 . The use of antibiotics is still thought to affect the incidence of complications after third molar surgical removal 4,5 . Different antibiotics were used following third molar extraction including metronidazole, penicillins, lincomycin, tetracyclins, neomycin, azithromycin, cephalosporins and others. Systemic administration is still the most frequent form of antibiotic prophylaxis in third molar surgery, although antiseptic mouthwashes and locally administered antibiotics are used to prevent postoperative infection 4,5,14,16 .