Development of Dual-Functional Titanium Implant for Osseointegration and Antimicrobial Effects via Plasma Modification

Introduction and aims

Titanium dental implants are widely used in clinical practice; however, they still face challenges such as implant loosening and infection. Recent studies focus on improving integration and infection resistance. In this study, a low-temperature plasma treatment was employed to fabricate a dual-functional modification layer on the titanium implant surface, offering a promising strategy that simultaneously promoted bone integration and effectively inhibited bacterial infection.

Materials and methods

This was achieved by depositing a hexamethyldisilazane (HMDSZ) film on the surface of titanium implants and grafting a thermosensitive composite hydrogel designed as a drug delivery system. The natural cross-linker genipin was used to immobilize chlorhexidine on the implant collar (2 mm in length). Meanwhile, bone morphogenetic protein-2 was immobilized on the implant body (6 mm in length), ensuring controlled release to promote bone regeneration and provide strong antibacterial effects. Various experimental analyses were conducted to characterize the samples, including assessments of hydrophilicity, functional groups, elemental composition, and surface morphology. Validation was carried out through in vitro tests (cytotoxicity, mineralization, and antibacterial assays) and in vivo animal experiments (bone-to-implant contact and Periotest measurements).

Results

Biocompatibility tests indicated that the plasma-treated surfaces did not exhibit cytotoxicity and facilitated osteoblast differentiation and osseointegration. The hydrogel effectively served as a carrier for the controlled release of growth factors and antibacterial agents, thereby boosting the osseointegration and antibacterial properties of the titanium implants. In vivo studies in swine models demonstrated superior bone integration and antibacterial efficacy compared to untreated and commercial implants within 2 weeks.

Conclusion

The surface modification method proposed in this study successfully produced titanium implants with dual-functional surfaces, enhancing both osseointegration efficiency and antibacterial capability.

Clinical Significance

This approach enables implants to perform specific functions through the use of growth factors and antimicrobials, potentially advancing implant technology and improving clinical outcomes.