Dental pulp cell–derived conditioned culture media promotes periodontal repair through immunomodulation and bone regeneration

Introduction Periodontitis is a chronic inflammatory disease characterized by progressive destruction of periodontal tissues, including alveolar bone. Although various regenerative approaches have been explored, effective and clinically applicable strategies for periodontal regeneration remain limited. Conditioned culture media (CM) derived from mesenchymal stem cells contains diverse paracrine factors, including extracellular vesicles (EVs), proteins, and soluble molecules that contribute to tissue repair and immunomodulation. This study aimed to evaluate the safety and therapeutic potential of freeze-dried dental pulp stem cell–derived CM as a cell-free treatment for periodontitis using in vivo and histological analyses. Methods In this study, we evaluated the safety and therapeutic potential of freeze-dried CM derived from cultured human dental pulp stem cells. Systemic and local toxicity were assessed in mice following intravenous and gingival administration. Therapeutic efficacy was investigated using a ligature-induced periodontitis mouse model. Alveolar bone morphology and osteoclast activity were analyzed using micro-computed tomography and histological staining. In addition, comparative proteomic analyses were performed between CM and purified EV fractions to explore molecular characteristics associated with tissue regeneration. Results Administration of freeze-dried CM showed no significant systemic or local toxicity in mice. In the experimental periodontitis model, CM treatment reduced inflammatory cell infiltration, suppressed osteoclast activity, and improved alveolar bone surface morphology. Although crestal bone height recovery was not observed, CM promoted periosteal activation and surface-oriented bone remodeling. Proteomic analyses revealed that CM retained molecular signatures related to inflammation regulation and tissue repair, while EV fractions were enriched in pathways associated with tissue remodeling and angiogenesis. Conclusions Freeze-dried dental pulp stem cell–derived CM demonstrates favorable safety and promotes periodontal tissue repair through immunomodulatory and regenerative mechanisms. These findings highlight CM as a practical and scalable cell-free therapeutic strategy for periodontal regeneration.