Benefit of azithromycin with platelet-rich fibrin in clinical osteoimmunology regarding autogenous bone grafting: A retrospective cohort study.

Introduction: Autogenous bone grafting in oral surgery poses significant challenges, particularly in maintaining long-term bone stability. Osteoimmunology, which emphasises the role played by the immune system in bone formation and resorption, has gained attention for improving graft success rates. Azithromycin, a macrolide antibiotic, exhibits immunomodulatory properties, whereas platelet-rich fibrin contains growth factors that promote bone healing.

Methods: The present retrospective study analysed 275 patients treated between 2014 and 2023 at a primary care centre in Paris, France. The inclusion criteria required patients to be aged over 18 years and to have undergone autogenous bone grafting using the split bone block technique. Three antibiotic regimens were compared: the standard of care, standard of care combined with platelet-rich fibrin, and standard of care combined with platelet-rich fibrin and azithromycin. The primary outcome was the occurrence of bone resorption or locoregional complications within a 4-month follow-up period.

Results: The overall success rate was 75.3%, with major bone resorption observed in 24.7% of cases. Multivariate analysis identified penicillin allergy (P 0.01) and posterior bone defects (maxilla and mandible, P = 0.02 and P = 0.001, respectively), as predictors significantly associated with higher failure rates. In contrast, the combination of platelet-rich fibrin and azithromycin improved outcomes significantly (adjusted odds ratio 8.38, P 0.001).

Conclusion: The combination of platelet-rich fibrin and azithromycin markedly enhanced the success of autogenous bone grafts, likely due to the immunomodulatory effects of azithromycin on the receptor activator of nuclear factor NF-κB ligand pathway. These findings support further investigation into this approach, particularly guided bone regeneration.