Main Applications of Titanium in the Medical Field

Titanium is primarily used in the following areas:

1. Orthopedic Implants
This is the most extensive and well-established application of titanium.

• Artificial Joints: Hip joints, knee joints, shoulder joints, elbow joints, etc. Critical load-bearing components such as femoral stems and acetabular cups are largely made of titanium alloys.

• Trauma Repair: Bone plates, screws, and intramedullary nails for internal fracture fixation. These devices stabilize fractures and promote bone healing.

• Spinal Fusion: Interbody fusion devices, titanium mesh, and pedicle screw systems used in surgeries for scoliosis correction and disc replacement.

2. Dental Implants and Prosthetics

• Dental Implants: Titanium implants are the "gold standard" in dentistry. They are embedded into the jawbone to serve as artificial roots, forming a strong osseointegration with the bone, onto which crowns are later mounted.

• Denture Frameworks: Metal frameworks for removable dentures, as well as bases for crowns and bridges, often use titanium due to its lightness, durability, and low allergenicity.

• Orthodontic Appliances: Some orthodontic brackets and archwires are also made from titanium alloys.

3. Cardiovascular Interventional Devices

• Pacemaker and Defibrillator Casings: Titanium casings provide excellent sealing, protecting internal精密 electronic components while being biocompatible with human tissues, reducing rejection reactions.

• Vascular Stents: Although cobalt-chromium alloys and biodegradable materials are currently mainstream, nickel-titanium alloys (Nitinol) are used for self-expanding vascular stents due to their unique superelasticity and shape memory effect, particularly in areas like the carotid and lower limb arteries.

4. Surgical Instruments and Equipment

• Surgical Instruments: Titanium forceps, scissors, retractors, etc., are lighter than stainless steel instruments, offer high fatigue strength, and are corrosion-resistant, able to withstand repeated high-temperature sterilization.

• Medical Device Components: Internal components of MRI scanners, robotic surgical arms, etc. Titanium’s non-magnetic property is crucial for safety in MRI environments and avoids imaging interference.

5. Craniofacial Reconstruction

• Titanium meshes and plates used to repair skull and facial bone defects caused by trauma or surgery. They can be precisely shaped to restore both function and appearance.

2. Core Advantages of Titanium Materials

Titanium’s irreplaceable role in the medical field stems from its exceptional properties:

1. Excellent Biocompatibility
This is titanium’s most important advantage. Its surface naturally forms a dense, stable titanium oxide passive film that is chemically inert, rarely reacting with human tissues or fluids. This prevents inflammation, allergies, or rejection reactions. It enables direct and functional bonding with living bone tissue, known as osseointegration, which is critical for the long-term stability of implants.

2. High Strength-to-Weight Ratio and Low Elastic Modulus

• High Strength-to-Weight Ratio: Titanium’s strength is comparable to many steels, but its density (~4.5 g/cm³) is only about 60% that of steel, making implants lighter and reducing the patient’s burden.

• Low Elastic Modulus: Titanium’s elastic modulus (~110 GPa) is closer to that of human bone (10-30 GPa) and much lower than stainless steel or cobalt-chromium alloys. This reduces the stress shielding effect—where stiff implants bear most of the stress, causing surrounding bone to become porous and resorb due to lack of mechanical stimulation. Titanium implants allow more natural stress transfer to the bone, promoting healing and long-term stability.

3. Outstanding Corrosion Resistance
Body fluids are a corrosive environment containing chloride ions (e.g., sodium chloride). Titanium’s passive film gives it extremely high corrosion resistance in physiological environments, making it nearly impervious to corrosion. This means:

• Long Implant Lifespan: No failure due to corrosion.

• High Biocompatibility: Avoids tissue toxicity and allergic reactions (e.g., nickel allergies) caused by metal ion release.

4. Non-Magnetic Property
Titanium is paramagnetic and does not magnetize in strong magnetic fields. This allows patients with titanium implants to safely undergo MRI scans without concerns about implant heating, displacement, or imaging interference, which is vital for post-operative diagnosis and monitoring.

5. Good Machinability and Formability
Although pure titanium is soft, alloying (e.g., with aluminum and vanadium to form Ti-6Al-4V) and advanced processing techniques enable the production of complex-shaped implants to meet personalized surgical needs. The shape memory effect of nickel-titanium alloys offers unique solutions for applications like self-expanding stents.

Summary and Future Outlook

Future Trends: