In vitro studies support clinical trials showing platelet-rich fibrin-mediated local delivery of antibiotics improves outcomes in impacted mandibular third molar surgery.

Our previous clinical observations showed that platelet rich fibrin (PRF) can be used to deliver antibiotics to attenuate postoperative complications after unilaterally impacted mandibular third molar surgery (IMTMS). In order to begin understanding the mechanism involved in the beneficial in vivo effects of PRF-mediated delivery of antibiotics, in vitro studies were performed, which showed that PRF preparations containing amoxicillin/clavulanic acid or clindamycin significantly inhibited the growth of S. aureus bacteria. In our previous study, comparisons were made between control and treated groups. However, since variations among individual patients could possibly affect the results, the current study included patients with bilaterally symmetric impacted mandibular third molars, allowing us to compare control and antibiotic treatment within each patient. The effects of PRF preparations containing amoxicillin/clavulanic acid or clindamycin on IMTMS was tested in 60 clinical cases. Antibiotic-injected PRF treatment after bilaterally IMTMS resulted in significantly reduced pain, less use of analgesics, and reduced swelling and trismus compared to the control group (PRF without antibiotics) confirming our previous results after unilaterally IMTMS. The in vitro results support the hypothesis that in vivo delivery of antibiotics using PRF produces therapeutic effects after IMTMS by attenuating bacterial infection and inflammation.