Introduction

Abstract

The wordbiomaterialscan be defined in two ways: as commonplace biological materials such as tissues and woods or as any materials that replace the function of the living tissues or organs. In legal terms (Clemson Advisory Board for Biomaterials “Definition of the word ‘biomaterials,’” The 6th Annual International Biomaterial Symposium, April 20–24, 1974) “a biomaterial is a systemically, pharmacologically inert substance designed for implantation within or incorporation with a living system.” This definition clearly emphasizes biomaterials as implant materials although the conventional usage of the prefixbiois somewhat violated; for example, biochemistry and biophysics refer to the study of biological materials rather than man-made materials. In order to avoid confusion,biomaterialswill refer to implants replacing and restoring living tissues and their functions. From this definition, (implantable)biomaterialsincludes anything that is intermittently or continuously exposed to body fluids although they may actually be located outside of the body proper. Included in this category are most dental materials although traditionally they have been treated as separate entities. Devices such as external artificial limbs, hearing aids, and external facial “prostheses” are not implants.