Introduction

Biomaterials include all materials that are used as surgical implants, dental materials and prosthetic implants. The applicability of a material as a biomaterial is determined by its chemical and mechanical properties, by its behaviour in contact with body fluids, cells and tissues, and by the eventual release of toxic components during biodegradation.

Biomaterials science is, therefore, concerned with tissue reactions that occur when artificial, manufactured devices are brought into contact with the living body.

Various microscopical techniques, including light microscopy, transmission electron microscopy and scanning electron microscopy are applied to study these tissue reactions. X-ray microanalysis is of special value in studies on phenomena occurring during biodegradation, i.e. the release and accumulation of chemical trace elements, and also to study the process of calcium phosphate deposition in bone bonding implants. In this chapter, the role of X-ray microanalysis in biomaterials research is discussed, specifically in reference to the biological evaluation of materials in a tissue culture system and post-implantation in experimental animals.

The total alloplastic middle ear

Implants routinely consist of various types of biomaterial, as shown, for example, by the artificial Total Alloplastic Middle Ear implant (TAM) (Bakker, 1988).

The TAM was developed to reconstruct in one operation the canal wall, the tympanic membrane and the ossicle chain in patients that suffer from chronic otitis media. It consists of a hydroxyapatite canal wall as suspension system to which a hydroxyapatite ossicular chain is connected.