Using zirconium dioxide to build strength without the friction for medical implants

While the ceramics industry consumes over half of the zircon produced globally, there is much more to this naturally-occurring mineral than the bathrooms and interiors it adorns through its ability to produce whiter and brighter ceramic tiles.

Zircon (zirconium silicate) and its derivative substances have unique properties of toughness, hardness and chemical resilience which make them ideal for use in a variety of today’s technically demanding applications. This ranges from industrial applications like oxygen sensors, fuel rod cladding in nuclear power reactors and components of space vehicles, to more decorative uses such as gemstones, and dental crowns & veneers.

In the biomedical field specifically, zirconium dioxide (or zirconia) provides a high strength, wear resistant, chemically inert and non-toxic surface for implants.

A biomedical marvel

Materials used in biomedical implants for procedures like knee and hip replacements traditionally include metals like titanium, cobalt-chromium alloys, or cobalt mixed metals with a plastic (polyethylene) socket. Over time, the alloy can wear the socket surface, which may result in the patient requiring replacement surgery.

Implants using zirconia are initially forged out of a special zirconium alloy. The alloy is then heat-treated to cause oxidization that transforms the metallic Zr-2.5NB alloy surface into a stable, durable, low-friction ceramic (zirconia) outer layer. The result is an implant that is:

Highly corrosion resistant, so the implant remains intact over time
Superior in terms of strength. For example, the hardness of zirconia is over twice that of the alternative cobalt-chromium alloy
High wear resistant due to its low friction
Highly biocompatible, reducing the likelihood of the implant being rejected
A nickel-free material, addressing the needs of patients with sensitivities to metals.

By combining the desirable characteristics of alternative materials used in the manufacture of biomedical implants, the use of a zirconia surface creates an implant with superior performance and durability.

Safety considerations

When considering the use of zirconia for medical use, safety of the material is paramount. In terms of device deterioration, biomedical implants using oxidized zirconium alloy are durable, strong and wear resistant. This makes them a reliable option than more brittle pure ceramic alternatives, as well as longer lasting than other metal alternatives.

A new lease of life

With an ever-ageing population, the number of people needing hip and knee replacements is increasing. They are also doing more, living longer and expecting more than ever before.

Oxidized zirconium alloy biomedical implants really do have the power to change lives. Their successful use can lead to recipients experiencing pain-free movement and being able to return to their active and fulfilling lives including activities such as walking or cycling. In turn, leading to better mental well-being, overall physical health and quality of life.

To find out more about how zircon is used, check out Zircon applications - What is Zircon used for?

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