Early Pulp Healing after Direct Pulp Capping with Concentrated Platelet-Rich Fibrin: A Preliminary Study.

BACKGROUND: Direct pulp capping preserves pulp vitality after pulp exposure. Mineral trioxide aggregate (MTA) is widely used but relies mainly on host-mediated repair. Concentrated platelet-rich fibrin (C-PRF), an autologous plasma-derived biomaterial, may actively modulate the local healing microenvironment through sustained delivery of bioactive factors, but its biological performance in direct pulp capping has not been fully characterized. METHODS: Human dental pulp cells (hDPCs) were treated with PBS, MTA, or C-PRF to assess viability, proliferation, migration, and mineralization via live/dead staining, CCK-8, scratch and transwell assays, ALP and Alizarin Red S staining, as well as qPCR for genes encoding ALP, RUNX2, and COL1A1. Furthermore, an in vivo rabbit direct pulp capping model was utilized and treated with MTA or C-PRF. Pulp regenerative potential was evaluated using H&E, Masson's trichrome, and CD31 immunohistochemistry, with quantitative analysis of vascularization. RESULTS: C-PRF demonstrated good biocompatibility and enhanced hDPCs migration, proliferation, and mineralization compared with MTA. In vivo, the C-PRF group exhibited increased CD31-positive staining, suggesting enhanced early vascular responses. CONCLUSION: Within the limitations of this study, C-PRF enhanced cellular responses, including migration and mineralization, and showed potential to promote early vascularization. These findings suggest that C-PRF may serve as a biologically active adjunct for direct pulp capping.