No abstract

Purpose Antibiotic use in impacted lower third molar removal is controversial, and surgical site infection (SSI) is a common postoperative complication. The purpose of this study was to evaluate the relationship between the duration of amoxicillin use and SSI in impacted lower third molar removal. Patients and Methods This was a retrospective study of patients who had more than one impacted lower third molar removed in the outpatient setting and were prescribed amoxicillin for less than 48 hours between January 2016 and December 2018. Patients were stratified by duration of antibiotic use. The primary outcome was the incidence of SSI. Other variables evaluated were demographics, pre‐ and post‐operative antibiotic use, pre‐ and intra‐operative variables, and tooth anatomy. Results In a total 907 separate operations, amoxicillin was given preoperatively within 24 hours of surgery in 84/430 cases (17.6%). SSI occurred in eight cases (0.88%). After adjusting for differences between the two groups that used preoperative amoxicillin within 24 hours or over 24 hours and used amoxicillin preoperatively or postoperatively, no significant difference was seen in SSI. Bivariate analysis showed that only deeply impacted third molars were significantly associated with the development of SSI. Conclusions The result in this study suggests that amoxicillin use within 24 hours is adequate for prevention of SSI after impacted lower third molar removal. When considering the risk factors of SSI in each case, it is necessary to use antibiotics for an appropriate duration.