A SECONDARY-ION MASS SPECTROSCOPIC STUDY OF THE ELEMENTAL COMPOSITIONPATTERN IN RAT INCISOR DENTAL ENAMEL DURING DIFFERENT STAGES OF AMELOBLAST DIFFERENTIATION

In most earlier studies on the elemental composition pattern of dental enamel, a picture is presented which describes a limited region. In t his study, estimates of the incorporation of some critical elements in to enamel were correlated with the differentiation stages of the amelo blasts through out the whole tooth. Elemental analyses of rat incisor dental enamel during the secretory, transitional and maturation phases were performed using two different modes of secondary ion mass spectr ometry (SIMS). The results were presented as ion images and three-dime nsional spatial resolution graphs. In the elemental images of Na-23, ( CN)-C-26, Cl-35 and K-39, counts were detected during the secretory an d maturation phases of amelogenesis. Variations were interpreted as re sulting from secretion of elements during the secretory phase and reso rption during the maturation phase. In line scans the ion yield from e namel during different stages of differentiation of the ameloblasts wa s analysed. The elements investigated were C-12, F-19, Na-23, P-31, K- 39 and (CaCl)-Ca-77. As seen in the images, most elements exhibited a higher ion yield during the earlier stages of secretion, and lower yie lds during the maturation-phase resorption. Cl, together with P, incre ased during the phases of maturation. In the most epical portions of t he teeth, corresponding to a presecretory phase, an inverse pattern wa s seen for most of the elements. If the surface yield was high at the onset of the secretory phase, the presecretory yields were lower, and vice versa. (C) 1998 Elsevier Science Ltd. All rights reserved.