Surface Modification of PEEK by Zn/Mg Ion Implantation for Improved Osteogenic and Antibacterial Performance

ABSTRACT

Because its elastic modulus is closer to that of cortical bone, polyetheretherketone (PEEK) has been considered a potential alternative to titanium for dental implants. However, the biological inertness and lack of intrinsic antibacterial activity of pristine PEEK limit its osseointegration and increase the risk of peri‐implant infection. In this study, Zn‐, Mg‐, and Zn/Mg‐implanted PEEK were prepared using a metal vapor vacuum arc ion source, with untreated PEEK as the control. Surface chemical composition, ion release, roughness, and wettability were characterized, and the osteogenic responses of MG‐63 cells and antibacterial activity against Staphylococcus aureus and Fusobacterium nucleatum were evaluated. Ion implantation introduced Zn and/or Mg into the near‐surface region of PEEK and was accompanied by increased surface roughness and improved hydrophilicity. Mg‐containing surfaces, particularly the Zn/Mg group, promoted cell spreading, proliferation, alkaline phosphatase activity, and the expression of osteogenesis‐related genes, including ALP , IBSP , and BGLAP. Antibacterial activity was more evident on Zn‐containing surfaces, whereas Mg alone showed only limited antibacterial effects. Although Zn alone showed stronger inhibition of Fusobacterium nucleatum , Zn/Mg co‐implantation achieved a more favorable overall balance between osteogenic and antibacterial performance. Zn/Mg co‐implantation improved osteogenesis‐related responses while adding antibacterial activity to PEEK surfaces, suggesting its potential as a coating‐free modification strategy for PEEK‐based implant materials.