Tantalum Coating Enhances Proliferation, Osteogenesis, and Antimicrobial Properties of Periodontal Ligament Stem Cells.

Background: Porous tantalum (Ta) is highly promising for dental implants and bone regeneration because of its excellent corrosion resistance and osseointegration. However, existing studies remain inconclusive regarding whether Ta biomaterials outperform titanium (Ti) in periodontal applications. Objectives: This study aimed to explore whether porous Ta modulates hPDLSC proliferation/differentiation and to elucidate its molecular mechanisms to inform clinical translation. Materials and Methods: Human periodontal ligament stem cells (hPDLSCs) were isolated and characterized. Cells were cultured on control, Ti, or Ta surfaces. Proliferation was assessed by Cell Counting Kit-8 (CCK-8) and colony formation; migration/invasion by Transwell assays. Antimicrobial activity was evaluated by colony-forming unit counting and CCK-8 in bacteria-material co-culture. Cytokines (IL-6, TNF-α, IL-4) were quantified by ELISA. Osteogenic differentiation was induced, with alkaline phosphatase (ALP) activity measured spectrophotometrically. Osteogenic markers (ALP, RUNX2, OCN) were analyzed by RT-qPCR and Western blot. Results: At days 3, 5, and 7, the Ta group showed higher OD than the control and Ti groups. It reduced bacterial CFUs and, at day 14, increased ALP activity and upregulated osteogenic markers (ALP, RUNX2, OCN). Ta also decreased IL-6/TNF-α and increased IL-4, indicating modulation of the inflammatory microenvironment and activation of osteogenic programs in hPDLSCs. Conclusion: Ta enhances hPDLSC proliferation, migration, invasion, and osteogenic differentiation while exhibiting antimicrobial, antioxidant, and anti-inflammatory properties, demonstrating varying degrees of superiority over Ti. These combined effects support its clinical translation for periodontal regeneration and for mitigating peri-implant inflammatory and infectious complications.