What Are The Common Applications Of Medical Titanium Alloy?

Titanium alloys are the key materials for implantable devices in orthopedics, dentistry, cardiovascular medicine, and other fields. The grades of medical titanium alloys has the various of differences in chemical composition, microstructure, and performance. Each grade matches with specific clinical needs and application scenarios.

 

 

It is made from high-purity titanium with extremely low impurity content. Pure titanium gains excellent biocompatibility from its natural oxide film and exhibits no significant cytotoxicity.

 

Key grades include Gr1 and Gr2, among which Gr2 is more widely used. With higher strength than Gr1 and excellent ductility, it is suitable for most low-stress implantation scenarios.

 

It has long-term structural stability in human body fluids without the risk of excessive release of metal ions.

It is suitable for scenarios requiring low strength and high biocompatibility, like dental implant abutments, skull repair plates, and subcutaneous implantable devices. But its insufficient strength prevents its use in load-bearing core orthopedic implants.

 

(I) α+β titanium alloys

α+β titanium alloys optimize their structure through alloying with aluminum, vanadium, and other elements. They combines with high strength, high toughness, and good processability. They are the most commonly used medical titanium alloys in clinical practice, suitable for medium-to-high load implants.

 

Gr5 ELI :The design reduces the impact of impurities like oxygen and nitrogen on toughness and maintains excellent corrosion resistance as well.

Mainly used in orthopedic/trauma implants like artificial joint stems, spinal nail-rod systems, and bone trauma plates.

 

(II) Near-β Titanium Alloys

Near-β titanium alloys replace vanadium with niobium, eliminating vanadium toxicity chemically while enhancing wear resistance and biocompatibility. They are upgraded materials of α+β titanium alloys.

 

Ti-6Al-7Nb :Tensile strength comparable to Ti-6Al-4V ELI, superior wear resistance, good cytocompatibility, and no release of toxic elements, making it suitable for long-term implantation.

 

Used in artificial acetabular cups, bone trauma plates, high-end dental implants, etc., especially for patients sensitive to vanadium or requiring long-term implants. Its application in joint replacement is expanding.

 

(III) β Titanium Alloys

β titanium alloys form a stable β phase through elements such as molybdenum, niobium, and aluminum. Their greatest advantage is ultra-low elastic modulus, which can significantly reduce the "stress shielding effect," avoid bone atrophy, and is suitable for special populations.

 

Ti-15Mo-3Nb-3Al mainly used in orthopedic implants for adolescents and spinal fusion devices. The low modulus reduces interference with adolescent bone development and promotes bone fusion while lowering subsidence risks in spinal fixation.

 

 

Degradable titanium alloys are a research hotspot in recent years. Through alloy design, they achieve controlled degradation, eliminating the need for secondary surgical removal. Degradation products can be metabolized by the human body, while providing temporary support for bone tissue regeneration.

 

Mg-Ti-Zn alloy is currently in clinical trials, with no unified international standard yet established.

During degradation, it releases beneficial trace elements to promote bone regeneration. Its mechanical properties match the requirements of temporary bone repair, with no harmful residues.

 

Suitable for short-term supportive implants such as temporary bone plates and fracture fixation screws. It is expected to address the pain and risks associated with secondary surgery for traditional implants and has shown promising results in small-scale clinical trials in trauma orthopedics.