| 1. |
- Bäckman, B, et al.
(författare)
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The absence of correlations between a clinical classification and ultrastructural findings in amelogenesis imperfecta.
- 1993
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Ingår i: Acta odontologica Scandinavica. - 0001-6357. ; 51:2, s. 79-89
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Tidskriftsartikel (refereegranskat)abstract
- This study was performed to examine whether a clinical classification of different phenotypes of amelogenesis imperfecta could be discernible at the ultrastructural level. Seventeen primary teeth from 16 children with hypomineralization, hypomaturation, or hypoplastic variants of the disease were collected for histologic studies of the enamel by means of polarized light microscopy, scanning electron microscopy (SEM), and secondary ion mass spectrometry (SIMS). Polarization microscopy showed that the enamel was hypomineralized; in six teeth a wavy configuration of the enamel prisms also appeared. Three histomorphologic main types could be discerned. In 10 of the teeth extensive hypomineralization of the bulk of the enamel was found. One tooth had an unusually thick enamel with only a thin normally mineralized surface layer. SIMS images showed less pronounced signals from Ca2+ and Na+ but with stronger signals from Cl- and CN-, representing the organic component of enamel. The SEM images showed an irregular prism pattern with marked interprismatic areas. Irrespective of the clinical appearance or the hereditary pattern the main findings were hypomineralized enamel with or without wavy bands. Neither of the analytical methods used in this paper distinguishes between the clinical phenotypes of amelogenesis imperfecta.
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| 2. |
- Chabala, J M, et al.
(författare)
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Elemental imaging of dental hard tissues by secondary ion mass spectrometry.
- 1988
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Ingår i: Swedish dental journal. - 0347-9994. ; 12:5, s. 201-12
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Tidskriftsartikel (refereegranskat)abstract
- High resolution imaging by secondary ion mass spectrometry (SIMS) has been employed in a chemical-microstructural pilot study of different classes of hard tissues from human and rat. The special scanning ion microprobe instrumentation permitted the recording of element-resolved images with a lateral resolution of about 50 nm. Sharp distribution micrographs were obtained for Ca+, F- and CN-, and in selected specimens for Na+, K+, Mg+, O-, Cl-, C- and PO-. Several trends in the elemental kinetics of mineralization were comprehensively illustrated and new aspects were indicated. The paper points out the broad scope of interest, and the potentialities of unique applications, in SIMS imaging of biomineralized tissues, the conditions for efficient employment of the recently developed technique are briefly discussed and demonstrated.
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| 3. |
- Lundgren, Ted, 1959, et al.
(författare)
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A secondary ion mass spectroscopic study of the elemental composition pattern in rat incisor dental enamel during different stages of ameloblast differentiation.
- 1998
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Ingår i: Archives of oral biology. - 0003-9969. ; 43:11, s. 841-8
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Tidskriftsartikel (refereegranskat)abstract
- In most earlier studies on the elemental composition pattern of dental enamel, a picture is presented which describes a limited region. In this study, estimates of the incorporation of some critical elements into enamel were correlated with the differentiation stages of the ameloblasts 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 spectrometry (SIMS). The results were presented as ion images and three-dimensional spatial resolution graphs. In the elemental images of 23Na, 26CN, 35Cl and 39K, counts were detected during the secretory and maturation phases of amelogenesis. Variations were interpreted as resulting from secretion of elements during the secretory phase and resorption during the maturation phase. In line scans the ion yield from enamel during different stages of differentiation of the ameloblasts was analysed. The elements investigated were 12C, 19F, 23Na, 31P, 39K and 77CaCl. As seen in the images, most elements exhibited a higher ion yield during the earlier stages of secretion, and lower yields during the maturation-phase resorption. Cl, together with P, increased during the phases of maturation. In the most apical portions of the teeth, corresponding to a presecretory phase, an inverse pattern was 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.
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| 4. |
- Lundgren, Ted, 1959, et al.
(författare)
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The use of the stable isotope 44Ca in studies of calcium incorporation into dentin.
- 1994
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Ingår i: Journal of microscopy. - 0022-2720. ; 173:Pt 2, s. 149-54
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Tidskriftsartikel (refereegranskat)abstract
- The incorporation into rat incisor dentin of two calcium isotopes, the stable 44Ca and the radioactive 45Ca, was studied using secondary ion mass spectrometry (SIMS) step-scanning and imaging, and autoradiography, respectively. The results demonstrated a time-dependent incorporation of the calcium isotopes into the mineral phase of dentin. With the SIMS step-scanning, detecting 44Ca, the ion yield was high in the odontoblasts 2 min after intravenous injection. After 10 min a marked increase in signal intensity was found at the dentin mineralization front. This result was consistent with those obtained by 45Ca autoradiography; a peak of incorporation occurred 10 min after injection of the isotope. Likewise, localization of 44Ca to the mineralization front could be demonstrated 10 min after injection by SIMS imaging. In images obtained at earlier intervals, no such increase in ion yield could be detected. The results show that the nonradioactive, stable isotope 44Ca can be used as a marker for biomineralization in a similar way to radioactive 45Ca.
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