Organic Matrix of Tooth Enamel

Abstract

LITTLE is known about the chemical nature of the organic matrix of enamel, although it presumably plays an essential part in the initiation and organization of the growth of hydroxyapatite crystals. The mature enamel finally resulting from these processes is the hardest and most highly mineralized of vertebrate tissues. Other mineralized tissues, bone¹ and dentine², contain 15–26 per cent of persistent organic matrix, at least 90 per cent of which is collagen. Mature human enamel contains only some 0.6 per cent of organic matter and 0.36 per cent of proteins, approximately half of which are soluble in acid decalcifying fluids³. Investigations of the composition of enamel proteins have been largely confined to insoluble residues from the demineralization of the mature tissue^3–5, A recent finding, in this laboratory, that partly mineralized enamel from developing teeth in the human fœtus contains approximately 20 per cent of material of protein character was followed by a preliminary investigation of its amino-acid composition.