Platelet-derived concentrates in the immunological management of periodontitis: from dysbiosis to personalized approaches.

Periodontitis is a multifactorial inflammatory disease driven by microbial dysbiosis and host immune dysregulation. Although conventional therapies, such as scaling and root planing or open-flap debridement, focus on biofilm control, they often fail to fully restore immune homeostasis. Consequently, platelet-rich fibrin (PRF) and its derivatives have gained increasing attention as biomaterials with both regenerative and immunomodulatory activity. This review summarizes contemporary insights into the immunopathogenesis of periodontitis, highlighting neutrophil dysfunction, Th17/Treg imbalance, and complement-mediated hyperinflammation as key drivers of tissue destruction. It also synthesizes current evidence on the biological and immunological roles of PRF, including its capacity to promote regulatory T-cell differentiation, modulate macrophage polarization toward an M2 phenotype, and regulate osteoimmunological pathways. Clinical studies show that adjunctive PRF improves probing pocket depth (PPD) reduction, clinical attachment level (CAL) gain, and patient-reported outcomes; however, heterogeneity in preparation protocols and defect characteristics limits comparability across studies. This review uniquely integrates the immunomodulatory mechanisms of platelet-derived concentrates with emerging personalized periodontics, emphasizing how biomarker-based individualization may enhance the predictability of regenerative outcomes.