Preventive Efficacy of Antibiotics after Impacted Mandibular Third Molar Surgery.

OBJECTIVE: To explore the preventive efficacy of antibiotics following surgical removal of the impacted mandibular third molars and screen the potential risk factors. STUDY DESIGN: A cohort trial. Place and Duration of the Study: Department of Oral and Maxillofacial Surgery, Zhejiang University School of Medicine, Stomatology Hospital, Hangzhou, China, from August 2021 to 2022. METHODOLOGY: Cases with impacted mandibular third molar were divided into two groups based on antibiotics use. The primary outcome variable post-operative infection, secondary clinical parameter analgesics intake, and other variables (the operative time, the history of pericoronitis, and wound closure) were documented. RESULTS: The post-operative infections occurred in 3.64% (n = 12) of the 330 cases (n = 330); 3.01% in the antibiotic group (n = 166) and 4.27% in the control group (n = 164, OR = 1.44, 95% CI: 0.49 to 4.06; p = 0.54). Concerning secondary outcome measures, the analgesics that the antibiotic group took was 5.40, and the control group took was 5.95 (95% CI = -0.21 to 1.30; p = 0.16). For those with post-operative infections, the average operative time was 22.83 minutes, whereas for those without post-operative infections it was 14.87 minutes (95% CI = -0.26 to 15.67; p = 0.04). When the operative time was greater than or equal to 15 minutes, it was related to more analgesics use (95% CI: -0.43 to 1.93; p <0.05), also was the history of pericoronitis (95% CI = 0.04 to 1.54; p = 0.04). CONCLUSION: Antibiotics are unnecessary for preventing post-operative infections or minimising analgesic requirements following extraction of the impacted mandibular third molars; operative time and pericoronitis showed a suppressive influence on post-operative recovery. KEY WORDS: Impacted molars, Antibiotics, Analgesics, Operative time, Pericoronitis.