Current Trends in Processing and Shaping of Bioceramics

In the recent past advanced materials with innovative processing techniques are being developed for applications starting from day to day home appliances to space shuttle. One of the most important and direct usage of advanced materials is for solving problems in human health care, particularly in replacement of the damaged or lost bone tissues. In this direction, the development of synthetic materials known as biomaterials, fabrication of their structures for bone implants and for tissue engineering (Scaffolds) followed by their implantation in human body is a highly interdisciplinary subject and is addressed jointly by material scientists, engineers as well as by the surgeons.

This chapter gives an introduction about the advanced materials that are used as biomaterial, their requirements and materials-tissue interactions. This is followed by the discussion on bioceramic materials and their classification as nearly inert, bioactive and resorbable materials with examples. Among the number of materials developed for bioapplications, those showing higher compatibility with the tissues and which proliferate the growth of tissues play a prominent role. Among these, some of the ceramics like hydroxyapatite and tricalcium phosphate are widely used due to their chemical similarity to bone and good biocompatibility. In this context, a review on preparation methods, processing and forming, thermal stability and densification and some of the characteristic properties of hydroxyapatite ceramics has been presented.

The chapter also deals with the processing and shaping aspects of bioceramic materials including basic principles, experimental result and discussions. Colloidal processing, slip casting, gel casting and mouldless casting methods are discussed as applied to Al₂O₃, hydroxyapatite and tricalcium phosphate as specific examples of bioceramic materials to fabricate differently shaped dense and porous samples intended for implant and scaffold applications.

Keywords: Bioceramics, Bioactive ceramics, Resorbable ceramics, Calcium phosphate, Hydroxyapatite, Alumina, Synthesis of HA, Thermal stability of HA, Processing of HA, Shaping of bioceramics, Nano hydroxyapatite, Colloidal processing, Zeta potential, Viscosity, Slip casting, Gel casting, Solid freeform fabrication, Porous ceramics, Scaffold, Osteoporosis, Tissue engineering.