Facile and versatile strategy for fabrication of highly bacteriostatic and biocompatible SLA-Ti surfaces with the regulation of Mg/Cu coimplantation ratio for dental implant applications

Multifunctional surface of the nano-morphic PEEK implant with enhanced angiogenic, osteogenic and antibacterial properties

Polyetheretherketone (PEEK) is a high-performance polymer suitable for use in biomedical coatings. The implants based on PEEK have been extensively studied in dental and orthopedic fields. However, their inherent inert surfaces and poor osteogenic properties limit their broader clinical applications. Thus, there is a pressing need to produce a multifunctional PEEK implant to address this issue. In response, we developed sulfonated PEEK (sPEEK)-Cobalt-parathyroid hormone (PTH) materials featuring multifunctional nanostructures. This involved loading cobalt (Co) ions and PTH (1-34) protein onto the PEEK implant to tackle this challenge. The findings revealed that the controlled release of Co2+ notably enhanced the vascular formation and the expression of angiogenic-related genes, and offered antimicrobial capabilities for sPEEK-Co-PTH materials. Additionally, the sPEEK-Co-PTH group exhibited improved cell compatibility and bone regeneration capacity in terms of cell activity, alkaline phosphatase (ALP) staining, matrix mineralization and osteogenic gene expression. It surpassed solely sulfonated and other functionalized sPEEK groups, demonstrating comparable efficacy even when compared to the titanium (Ti) group. Crucially, animal experiments also corroborated the significant enhancement of osteogenesis due to the dual loading of cobalt ions and PTH (1-34). This study demonstrated the potential of bioactive Co2+ and PTH (1-34) for bone replacement, optimizing the bone integration of PEEK implants in clinical applications.

Hydroxyapatite-Based Coatings on Silicon Wafers and Printed Zirconia

Dental surgery needs a biocompatible implant design that can ensure both osseointegration and soft tissue integration. This study aims to investigate the behavior of a hydroxyapatite-based coating, specifically designed to be deposited onto a zirconia substrate that was intentionally made porous through additive manufacturing for the purpose of reducing the cost of material. Layers were made via sol-gel dip coating by immersing the porous substrates into solutions of hydroxyapatite that were mixed with polyethyleneimine to improve the adhesion of hydroxyapatite to the substrate. The microstructure was determined by using X-ray diffraction, which showed the adhesion of hydroxyapatite; and atomic force microscopy was used to highlight the homogeneity of the coating repartition. Thermogravimetric analysis, differential scanning calorimetry, and Fourier transform infrared spectroscopy showed successful, selective removal of the polymer and a preserved hydroxyapatite coating. Finally, scanning electron microscopy pictures of the printed zirconia ceramics, which were obtained through the digital light processing additive manufacturing method, revealed that the mixed coating leads to a thicker, more uniform layer in comparison with a pure hydroxyapatite coating. Therefore, homogeneous coatings can be added to porous zirconia by combining polyethyleneimine with hydroxyapatite. This result has implications for improving global access to dental care.

Adjusting the Dose of Ag-Ion Implantation on TiN-Ag-Modified SLA-Ti Creates Different Micronanostructures: Implications on Bacteriostasis, Biocompatibility, and Osteogenesis in Dental Implants

The prevention of aseptic loosening and peri-implantitis is crucial for the success of dental implant surgery. In this study, different doses of Ag-implanted TiN/Ag nanomultilayers were prepared on the sandblasting with large grit and acid etching (SLA)-Ti surface using a multiarc ion-plating system and an ion-implantation system, respectively. The physical and chemical properties of the samples were assessed using various techniques, including scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy, inductively coupled plasma atomic emission spectrometry, and water contact angle measurements. In addition, the applicability and biosafety of the SLA/1 × 1017-Ag and SLA/1 × 1018-Ag surfaces were determined via biocompatibility testing in vivo and in vitro. The results demonstrated that the physical and chemical properties of SLA/1 × 1017-Ag and SLA/1 × 1018-Ag surfaces were different to some extent. However, compared with SLA-Ti, silver-loaded TiN/Ag-modified SLA-Ti surfaces (SLA/1 × 1018-Ag) with enhanced bacteriostatis, osteogenesis, and biocompatibility have great potential for dental applications.