Materials and products implanted into the human body have to meet special requirements as, in addition to their technical properties, on account of the required biocompatibility, regulatory approval in compliance with Medical Products Act is also stipulated. To this end, CE labelling is required on the European market.
Ceramic implants with regulatory approval feature the following properties depending on application and material:
- High mechanical strength
- High edge stability
- Long-term resistance to wear, also in sliding systems
- High damage tolerance
- High geometric precision
- Low surface roughness
- Dimensionally stable over long periods of time
- Resistant to corrosion
- Stable in sterilizing conditions
- Suitability with regard to aesthetic aspects
Development of ceramic materials for implantology goes back to the 1970s and in some cases even further. Since this time, thanks to the steady further development of the properties of oxide and non-oxide ceramic materials, an ever growing field of application for biologically inactive ceramic materials has grown up, which is no longer limited solely to the replacement of dental roots or hip joints.
Today, depending on the specific requirements for implants, both oxide and non-oxide materials such as Al2O3, Al2O3-ZrO2 mixed ceramics, doped ZrO2 and Si3N4 are used. For special requirements, the fabrication of translucent or transparent ceramics is possible, for example on the basis of Al2O3.
Biologically active materials such as hydroxyapatite and tricalcium phosphate are used in implantology both as coating materials to promote growing of an implant into the bone and as direct bone replacement materials, which enable the formation of new bone tissue in regenerative therapy.