Relationship between Timing of Antibiotic Administration and Complications Following Surgical Extraction of Lower Third Molars

Aim: the aim of this prospective clinical trial was to evaluate the effects of antibiotic therapy following different administration times on the postoperative complications of surgical removal of lower impacted third molars.materials and methods: three hundred and twenty seven consecutive patients (128 males and 199 females) aged 18 to 40 years old (mean=23.1±3.9 years) were recruited into this study. the lower third molars of all recruited patients were surgically extracted. participants received either intravenous velocef 1 gram or intra-oral 500 mg cephalexin pre- (group a, n=122), pre- (group b, n=70) or post operatively (group c, n=135). 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.results: the most frequent complications were slight pain, swelling, and trismus. the most frequent complications were associated with post-operative antibiotic administration and least complications were associated with pre-operative antibiotic administration (p=0.000). post-operative administration of antibiotic was associated with more pain (r=0.186, p=0.001), swelling (r=0.181, p=0.001), trismus (r=0.277, p=0.000), and dry socket (r=0.335, p=0.000).conclusions: following surgical extraction of third molars, preoperative antibiotic administration is more effective in reducing the post-surgical complications than pre-operative antibiotic administration which in turn is more effective than post-operative antibiotic administration.