Properties of bioactive glasses and glass-ceramics

A bioactive material is one that elicits a specific biological response at the interface of the material which results in the formation of a bond between the tissues and the material. A common characteristic of bioactive glasses, bioactive glass-ceramics, and bioactive ceramics is that their surface develops a biologically active hydroxy carbonate apatite (HCA) layer which bonds with collagen fibrils. The HCA phase that forms on bioactive implants is equivalent chemically and structurally to the mineral phase of bone. It is that equivalence which is responsible for interfacial bonding .  

Handbook of Biomaterial Properties. Edited by J. Black and G. Hastings. Published in 1998 by Chapman Hall, London. ISBN 0 412 60330 6. 

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Sakamoto, O. Ito, S. (1990). Mechanical properties of bioactive glass-ceramic composite by SiC whiskers. In T. Yamamuro, L.L. Hench J. Wilson. Handbook of Bioactive Ceramics, Vol. 1, Bioactive Glasses and Glass Ceramics, (155-60). Boca Raton, FL. CRC Press. 

The situation with regard to glass-ceramics for restorative dental applications is different. These materials must also fulfill the standards for biomaterial use, such as compatibility with the oral environment. Bioactivity on the surface of the dental restoration, however, must not occur. More importantly, the surface properties of the glass-ceramics, such as shade, translucency, toughness, and wear, must correspond to those of natural teeth. Even higher standards are placed on the chemical durability of the material compared with that of natural teeth, since cavities should not occur in the new glass-ceramics. 

E. Claxton, B. A. Taylor, R. D. Rawlings, Processing and Properties of a Bioactive Glass-ceramic Reinforced with Ductile Silver Particles, J. Mat. Sci. 37, 3725—3732 (2002). 

In the development of biocompatible and bioactive glass-ceramics for medical uses, two different types of materials must be addressed that differ in their application environment and preferred properties materials for use in implantology (medical prostheses) and materials used in restorative dentistry (dental prostheses). For reasons of clarity, the difference between the two different groups of biomaterials must be addressed at this stage. The first... 

Development of nano-structured alumina and zirconia ceramics and composites as well as nano-structured calcium phosphate ceramics and porous bioactive glasses, possibly as composites with organic constituents, will provide desired properties for bone substitution and tissue engineering for the next 20 years (Chevalier and Gremillard, 2009). 

S. Marano, S. Ban, Y.-F. Wang, H. Iwata and H. Itoh, Properties of Functionally Gradient Composite Consisting of Hydroxyapatite Containing Glass Coated Titanium and Characters for Bioactive Implant, J. Ceram. Soc. Japan 100, 362-367 (1992). 

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