Does the use of amoxicillin/amoxicillin-clavulanic acid in third molar surgery reduce the risk of postoperative infection? A systematic review with meta-analysis.

The objectives of this systematic review were to investigate the efficacy of amoxicillin/amoxicillin-clavulanic acid for reducing the risk of postoperative infection after third molar surgery and to evaluate the adverse outcomes in these patients, as well as in healthy volunteers. A systematic search of four databases was performed on May 26, 2017. Eleven studies qualified for the qualitative analysis and eight were found suitable for meta-analysis. The results suggest that both amoxicillin-clavulanic acid and amoxicillin significantly reduce the risk of infection after third molar extraction (overall relative risk (RR) 0.25, P<0.001). However, with the exclusion of randomized controlled trials with a split-mouth design (due to an inadequate crossover period after antibiotic treatment), only amoxicillin-clavulanic acid was found to be effective (RR 0.21, P<0.001). The risk of adverse effects was significantly higher in the amoxicillin-clavulanic acid group (RR=4.12, P=0.023) than in the amoxicillin group (RR 1.57, P=0.405). In conclusion, amoxicillin-clavulanic acid and amoxicillin may significantly reduce the risk of infection after third molar extraction. However, their use in third molar surgery should be viewed with caution, as recent clinical trials on healthy volunteers have shown evidence of the negative impact of amoxicillin use on bacterial diversity and antibiotic resistance.