RESUMEN
INTRODUCTION: Postoperative infection is the most common postsurgical oral complication but no double-blind, randomized, placebo-controlled trial has been made yet to assess amoxicillin prophylaxis for oral surgery. The aim of this pilot study was to assess the effectiveness of prophylactic amoxicillin 3g per os versus placebo in the prevention of postoperative oral infections. METHODS AND MATERIALS: A 5-year, multicentric, randomized, double-blind clinical trial was made on healthy patients undergoing complex oral surgery. Final analysis was by intention to treat. RESULTS: The 286 patients were randomly assigned to the amoxicillin or placebo group. After a mean follow-up of two weeks, 11 patients in the control group and three patients in the amoxicillin prophylaxis group developed a postoperative infection (P=0.001 in unilateral test). The hazard ratio was 0.27 [95% CI: 0.07-0.94]. CONCLUSION: Amoxicillin prophylaxis seems to be effective in preventing postoperative infection in complex oral surgery, especially when mandibular third molars and multiple avulsions are involved.