Overview
Titanium and its alloys are widely used in orthopedic and dental implants because of their low density, high strength, non-toxicity, and excellent corrosion resistance. Compared to stainless steel and cobalt-based alloys, titanium alloys have a lower elastic modulus, which reduces stress shielding effects and promotes better osseointegration, making them highly suitable for clinical applications.
Challenges
Despite these advantages, titanium implants exhibit poor wear resistance in long-term clinical use. Friction-induced wear particles can lead to inflammation and potential toxicity, which limits the clinical performance of titanium-based implants.
Surface Modification as a Solution
To improve the biological and tribological performance of titanium alloys, surface modification techniques are applied to enhance:
- Bioactivity
- Wear resistance
- Antibacterial properties
This approach is cost-effective and practical for meeting the evolving clinical demands of biomedical implants.
Common Surface Modification Techniques
- Diamond-Like Carbon (DLC) Coatings
- High hardness and excellent wear resistance
- Low friction coefficient
- Good biocompatibility
- Clinical applications include artificial joint components, improving both wear and corrosion resistance.
- Titanium Nitride (TiN) Coatings
- Good wear and corrosion resistance
- Originally used in cutting tools, later applied to medical implants (orthopedic and dental) due to biocompatibility
- Common fabrication methods:
- Physical Vapor Deposition (PVD)
- Chemical Vapor Deposition (CVD)
- Thermal spraying
Conclusion:
Surface modification with coatings such as DLC and TiN significantly enhances the wear and corrosion resistance of titanium implants while maintaining biocompatibility. This strategy provides a promising path for next-generation biomedical titanium implants that meet higher clinical demands.