Titanium and Titanium Alloys as Biomaterials
1. Introduction
titanium and its alloys have become the "gold standard" for orthopaedic and dental implants ". Their unique combination of mechanical properties and biocompatibility make them superior to stainless steel and cobalt-chromium alloys in many clinical applications.
2. Main advantages
titanium in medicine is due to four main factors:
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Biocompatibility:has a natural ability to integrate with human bone (osseointegration).
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corrosion resistance:When exposed to oxygen, titanium forms a protective $TiO_2 $ (titanium dioxide) oxide layer, which blocks the release of metal ions into the body.
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Mechanical strength:it provides a high strength to weight ratio.
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modulus of elasticity:titanium ($~ 110 $ GPa) is closer to that of human bone ($~ 10 $-$30 $ GPa) than other metals, which helps reduce "stress shielding" (peri-implant bone loss).
3. Common medical grade
| Grade/Alloy | composition | Main Uses |
| Class 1-4 (CP Ti) | industrial pure titanium | dental implants, pacemaker cases, heart valves. |
| Ti-6Al-4V (Level 5) | 6% aluminium, 4% vanadium | hip/knee replacement, spinal fixation, bone screws. |
| Ti-6Al-7Nb | 6% aluminum, 7% niobium | was developed as a more biocompatible alternative to Level 5. |
| β-type alloy | For example, ti-nb-zr-ta | next generation implants with lower modulus of elasticity. |
4. Main applications
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Orthopedics:artificial joint replacement (hip, knee), bone plate and intramedullary nail.
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Dental:dental implants, abutments and orthodontic filaments.
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Cardiovascular:stents, prosthetic heart valves and pacemaker housings.
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craniofacial surgery:rebuild the plate and mesh.
5. Future Trends
current research focuses onsurface modification(such as 3D printed porous structures) to promote faster bone growth and developmentNickel-free/Vanadium-free alloyeliminate any potential long-term toxicity or allergic reactions.
