ABSTRACT
This chapter presents the structure of hard tissues-enamel, dentine, and bone tissue-and how chemically bonded bioceramics (CBBCs) interact with hard tissues. The features of CBBCs as injectable in situ-, in vivo-formed biomaterials will be treated in some detail. A detailed description of CBBC materials will be presented in Chapters 3 and 6-8. 2.1 Hard Body Tissue Structures: An OverviewHard tissue is basically divided into three major groups: enamel, dentine, and bone structures [compact and spongy (trabecular or cancelleous)] [1]. The main purpose of hard tissue is to carry loads or have the ability to withstand mechanical pressure or stress. For the dental tissues, enamel and dentine, resistance against wear and chemical attack are also important features. The hard chemical component in all hard tissues is apatite. Apatite can appear in nature and in living beings in several modifications, as the basic structure hydroxyapatite (HA), Ca5(PO4)3(OH) easily forms solid solutions [2]. Examples are in Table 2.1.
