Biological performance enhancement of Ni-free Zr-based bulk metallic glass for dental implants via nitrogen plasma immersion ion implantation
Abstract
Background/purpose
Improving the biocompatibility of bulk metallic glass (BMG) alloys is critical for expanding their applications in biomedical fields, particularly in dental implants. This study systematically investigated the suitability of nitrogen plasma immersion ion implantation (NPIII)-treated Zr-based BMG alloy for next-generation dental implant applications, focusing on protein adsorption, platelet responses, and cell behavior.
Materials and methods
NPIII was employed as a surface modification approach to enhance the biological performance of a Ni-free Zr62.5Cu22.5Fe5Al10 BMG alloy. The effects of NPIII treatment on surface characteristics, including crystallinity, chemical composition, layer thickness, roughness, and hydrophilicity, were comprehensively analyzed. Protein adsorption behavior was evaluated using fibrinogen and fibronectin as model proteins. Platelet responses were assessed through platelet adhesion and platelet activation studies. Cell responses, including adhesion, proliferation, and early osteogenic differentiation, were examined using human bone marrow mesenchymal stem cells. One-way ANOVA was used, with statistical significance set at P < 0.05.
Results
NPIII treatment preserved the amorphous bulk structure of the Zr-based BMG while maintaining surface roughness and hydrophilicity. A thin nitride-containing oxide layer (~10 nm thick), primarily composed of ZrO2/ZrN/Zr(N,O), was successfully formed on the NPIII-treated surface. This surface modification significantly enhanced protein adsorption and promoted platelet aggregation and activation, as well as cell adhesion and proliferation, without significantly affecting early-stage differentiation.
Conclusion
These findings demonstrate that NPIII is an effective and promising surface modification strategy for improving the biological performance of Zr-based BMG alloy for dental implant applications.