12.1. Introduction and history
Bioceramics are meant to be used as implants in living organisms or, more
generally, during prolonged contact with biological fluids or tissues. This broad
definition includes ceramics which are or could be used in extracorporeal circulation
systems (dialysis for example) or engineered bioreactors. However, this chapter will
deal essentially with ceramics used as implants.
The substitution of faulty organs or tissues has always been man’s
preoccupation. The first attempts at implantation probably date back to prehistoric
periods and most probably involved teeth, on account of their easy accessibility,
their nutritional role, and due to their social function, of course, and their place in
the collective imagination. We find traces of surgical attempts on skeletons,
particularly in such civilizations where it was customary to mummify the dead. The
most elaborate applications were carried out by Larrey, with the use of plaster of
Paris particularly for setting internal bone fractures. However, the extensive use of
bioceramics began after World War II, when the development of the medical
insurance system and the rapid technological progress led to a widespread use and
an improvement of these surgical interventions benefiting a larger number of people.
Biomedical ceramics used today essentially come from other fields of application.
However, various adaptations were necessary and ceramics for exclusively medical
use began to be developed. The place held by ceramics and polymers as well as
ceramic-polymer composites in the field of biomaterials will probably increase in
Chapter written by Christèle COMBES and Christian REY.
494 Ceramic Materials
the coming years at the expense of metals, whose physicochemical characteristics,
both mechanical and biological, are generally unsuitable for use as biomaterials,
apart from a few exceptions.
In practice, biomaterials are classified into three types depending on the reaction
of biological tissues with which these are in contact: biotolerated, bioinert and
bioactive materials. Biotolerated materials induce tissue alterations and are isolated
by a covering of fibrous tissue. Several metals and certain polymers come under this
category. Bioinert materials do not induce any visible tissue reactions; the majority
of ceramics belong to this group. Bioactive materials, on the other hand, favor tissue
repairs and the integration of associated devices. Some ceramics and various
polymers belong to this last category. Bioactive effects are aimed at very specific
tissues and the applications of these materials are oriented and limited to specific
organs or tissues. As far as ceramics are concerned, bioactivity is essentially used in
orthopedics. It favors bone repair and the integration of implants in bone tissue
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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