Products made of Al2O3 and ZrO2 ceramics, mixed ceramics based on the two oxides and piezoceramics are used in medical engineering today as machine components in diagnostic systems and radiotherapy, as bioinert products in implantology and, for instance, also for the destruction of stones and deposits. In special applications, they also form part of the instruments used by doctors.
Depending on the application, the properties of the materials must meet special requirements that go beyond their general performance profile like, for example, high electrical insulation as machine and plant components, as well as high mechanical strength and reliability over long periods.
For decades now, in imaging diagnostic processes, for example in angiography as electrically insulating casing components of an X-ray image intensifier, the technical properties of high-grade Al2O3 ceramics have enabled image quality with exceptionally high detail resolution combined with minimized local exposure to radiation for the patient.
In the application of an open magnet resonance imager for surgical interventions, the magnetizability of the instruments used plays an important role. As high-purity Al2O3 and ZrO2 ceramics are non-magnetizable, the use of instruments made of such materials for these purposes is logical.
In equipment for therapy with heavy ions, today synchrotrons can be used, which at certain positions of the accelerator ring are equipped with high-vacuum-tight tubes made of Al2O3 ceramics brazed to metal parts.
Implant products made of monolithic ceramic materials, for example hip joints, exhibit other properties as a precondition for their usability:
- Approved in compliance with medical product laws
- High resistance to abrasion
- Stability in sterilizing conditions
For dental applications, aesthetic aspects must also be considered insofar as the visible part of the teeth is concerned. As an oxide ceramic material, high-strength ZrO2 is frequently used as this also has the advantage that it can be coloured to match the shade of any existing teeth.
Looking at medical engineering overall, it is foreseeable that the use of products and components made of high-quality technical oxide ceramics and presumably non-oxide ceramics will continue to increase considerably in line with growing life expectancy.