n 1 Eur J Oral Implantol 2010;3(2):xxx–xxx RANDOMISED CONTROLLED CLINICAL TRIAL Marco Esposito DDS, PhD Senior Lecturer, Oral and Maxillofacial Surgery, School of Dentistry, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK and Associated Professor, Department of Biomaterials, The Sahlgrenska Academy at Göteborg University, Göteborg, Sweden Gioacchino Cannizzaro MD, DDS Private practice, Pavia, Italy Paolo Bozzoli DDS Private practice, Caronno Pertusella (VA), Italy Luigi Checchi MD, DDS Head and Professor, Depart- ment of Periodontology and Implantology, University of Bologna, Bologna, Italy Vittorio Ferri MD, DDS Private practice, Modena, Italy Stefano Landriani DDS Private practice, Magenta (MI), Italy Michele Leone MD, DDS Private practice, Pavia, Italy Marzio Todisco DDS Private practice, Desenzano sul Garda (BS), Italy Cinzia Torchio DDS Private practice, Alessandria, Italy Marco Esposito, Gioacchino Cannizzaro, Paolo Bozzoli, Luigi Checchi, Vittorio Ferri, Stefano Landriani, Michele Leone, Marzio Todisco, Cinzia Torchio, Tiziano Testori, Fabio Galli, Pietro Felice Effectiveness of prophylactic antibiotics at placement of dental implants: a pragmatic multicentre placebo-controlled randomised clinical trial Key words amoxicillin, antibiotic prophylaxis, dental implants, immediate post-extractive implants, multicentre randomised placebo-controlled clinical trial Purpose: To evaluate the eficacy of prophylactic antibiotics for dental implant placement. Materials and methods: Thirteen dentists working in private practices agreed to participate in this trial, each centre providing 50 patients. One hour prior to implant placement patients were ran- domised to assume orally 2 g amoxicillin or identical placebo tablets. Patients needing bone aug- mentation at implant placement were not included. Outcome measures were prosthesis and implant failures, adverse events and post-operative complications. Patients were seen 1 week, 2 weeks and 4 months post-operatively. Results: Two centres did not deliver any data, two centres did not manage to include the agreed quota of patients and three patients had to be excluded. Two-hundred and ifty-two patients were evaluated in the antibiotic group and 254 in the placebo group, and none dropped out at 4 months. Four prostheses and seven implants (in ive patients) failed in the antibiotics group versus 10 pros- theses and 13 implants (in 12 patients) in the placebo group. Eleven complications were reported in the antibiotic group versus 13 (in 12 patients) in the placebo group. No side effects were reported. There were no statistically signiicant differences for prosthesis failures, implant losses and complica- tions. Patients receiving immediate post-extractive implants had an increased failure risk compared with patients receiving delayed implants (9% versus 2%). Conclusions: No statistically signiicant differences were observed, although trends clearly favoured the antibiotic group. Immediate post-extractive implants were more likely to fail. n Introduction It is still debated whether early failures of den- tal implants and post-operative infections can be reduced by antibiotic prophylaxis. While it is impor- tant to minimise implant failures, there are concerns associated with the widespread use of antibiotics, since adverse events may occur. Adverse events are usually minor (diarrhoea, erythema multiforme, urticaria, etc.) but life-threatening allergic reactions may occur. In addition there is the risk of selecting antibiotic-resistant bacteria. A recent Cochrane review 1 on this topic concluded that 2 g of amoxicillin given orally 1 h preopera- tively signiicantly reduces failures of dental implants placed under ordinary conditions. In particular, giv-