Microprobe analysis of calcifying matrices and formative cells in developing mouse molars

Engel, Milton B.

doi:10.1007/bf00501786

Cited by 24 publications

(9 citation statements)

References 26 publications

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“…On the contrary, the dentin-enamel junction showed highest Ca and P concentrations in a layer of first secreted enamel matrix. A similar gradient of mine ral content increasing from enamel surface towards dentinenamel junction was found by Engel [ 16] in vivo. Bronckers et al [ 11 ] confirmed this gradient of mineral content in vitro by von Kossa staining using hamster second-or third-day explants of M: cultured according to the Trowell method in serum-supplemented BGJh medium.…”

Section: Enamelsupporting

confidence: 57%

Electron Probe X-Ray Microanalysis of Calcium and Phosphorus Distribution in Developing Hamster Tooth Germs in vitro and in vivo

Stratmann

Barckhaus²,

Lyaruu³

et al. 1991

Cells Tissues Organs

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The aim of the present study was to investigate the spatial distribution of Ca and P in dentin and enamel of developing first (M¹) and second (M²) maxillary hamster molars (age: 3–5 days) in comparison with cultured molars. For culturing the germs were dissected from 3-day-old hamsters and incubated for 1 and 2 days, respectively, in a modified BGJ_b medium. Electron probe X-ray measurements were carried out on 3 regions extending in a vertical axis from cusp tip over cusp middle to cusp base next to the cervical loop region. Neither the in vivo nor the in vitro group was statistically different in the Ca and P concentration in the regions of dentin. In both groups the measurements in enamel showed a gradient with an increase in Ca and P from enamel surface towards dentin-enamel junction and a gradient with an increase from cusp base towards cusp tip. Direct comparison of the in vivo group with the in vitro group did not demonstrate a statistical difference between the mineral content of the 4-day-old germs and the 1-day culture germs, respectively the 5-day-old germs and the 2-day culture germs. The results indicate a high correspondence between the mineralization process of in vitro and in vivo tooth germ development.

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Section: Enamelsupporting

confidence: 57%

Electron Probe X-Ray Microanalysis of Calcium and Phosphorus Distribution in Developing Hamster Tooth Germs in vitro and in vivo

Stratmann

Barckhaus²,

Lyaruu³

et al. 1991

Cells Tissues Organs

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“…the tubules which coincided with the detection of sulfur by EPMA and ESI. Sulfur has been previously detected in the enamel of rats by EPMA (Takuma et al, 1972;Suga, 1983;Boyde and Reith, 1978;Engel, 1981;Sasaki et al, 1987) and has been shown to decrease during the maturation stage of amelogenesis (Reith and Cotty, 1967;Suga et al, 1970;Engel, 1981;Sasaki et al, 1987). The present study is a first report of the detection of sulfur related to enamel tubules, and the elemental detection was carried out on maturationstage enamel where sulfur is reportedly reduced in other mammals that have been examined.…”

Section: Composition and Distribution Of Intrinsic Elementsmentioning

confidence: 55%

Tubule formation and elemental detection in developing opossum enamel

1992

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Most marsupials and some placental mammals possess enamel characterized by the presence of tubules, and the cellular origin of these structures has been the subject of a number of previous studies (See, for example, Lester, 1970; Azevedo and Goldberg, 1987). In the present report, tooth germs of the American opossum were examined to determine the structure and composition of enamel tubules during development and to analyze the enamel matrix relative to that of placental mammals with atubular enamel. For this purpose, tissues prepared by aqueous (decalcified and undecalcified) and anhydrous (undecalcified) methods were investigated by conventional transmission (TEM) and high voltage electron microscopy (HVEM), as well as by electron probe x-ray microanalysis (EPMA), selected-area electron diffraction (SAED), and electron spectroscopic imaging (ESI). Results indicate that most enamel tubules in the opossum begin as cytoplasmic remnants of Tomes' processes of ameloblasts. During development of the matrix, some of the tubules do not appear to be continuous throughout the prismatic layer. Sulfur is detectable around the lumen of the tubule in decalcified sections by EPMA and in and around the tubule by ESI. Calcium/phosphorus (Ca/P) molar ratios of the mineralizing matrix are generally higher than those found in enamel of other mammals and appear to decrease rather than increase with enamel maturation. The summary of data indicates the presence of sulfated glycoproteins or proteoglycans in this tissue, specifically around enamel tubules. Calcium and phosphorus are also present within the tubules, with the sulfated groups possibly binding calcium to prevent mineralization of the enamel tubules themselves.

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“…Because peak heights were compared in identical thin sections of constant thickness, they are though to reflect relative amounts of the elements in the individual analyzed points; x-ray microanalysis also detected S peaks in the endocytotic vacuoles and M e d borders of odontoclasts that contained crystals but not in lysosomes in the perinuclear cytoplasm. Because x-ray microanalysis of 15-nm beam spot size was done on individual crystal clusters, the detected S peak is thought to originate from sulfated carbohydrates bound to apatite crystals (Takagi et al, 1981;Engel, 1981;Goldberg and Escaig, 1985;Goldberg and Septier, 1986). It seems reasonable, therefore, that these lysosomes are involved in the intracellular digestion of material that accompanies the incorporated crystals.…”

Section: Discussionmentioning

confidence: 97%

Dentin resorption mediated by odontoclasts in physiological root resorption of human deciduous teeth

et al. 1988

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Extracted human deciduous teeth undergoing physiological root resorption were fixed with a mixture of formaldehyde and glutaraldehyde and processed for scanning (SEM) and analytical transmission electron microscopy, as well as acid trimetaphosphatase cytochemistry. The granulated tissues, which are rich in multinucleated odontoclasts and capillary vessels, formed various resorption lacunae on the resorbing dentin surfaces. SEM observations of dentin surfaces treated with sodium hypochlorite revealed two types of resorption lacunae: deep, round lacunae in which the peritubular matrix of dentinal tubules was strongly dissolved; and shallow, irregular lacunae with intact peritubular matrix. In trypsin-treated materials, the resorption surfaces were characterized by the presence of numerous collagen fibers in both the peritubular and intertubular matrices, suggesting demineralization of the surface dentin. Odontoclasts were characterized by the presence of abundant mitochondria, perinuclear stacks of Golgi membranes, various lysosomes, numerous endocytotic vacuoles, and a well-developed ruffled border against the resorption lacunae. Most endocytotic vacuoles were distributed in the cytoplasm between the ruffled border and the nuclei. In undemineralized ultrathin sections, the surface dentin of resorption lacunae consisted of collagen fibers and apatite crystals and had a lower packing density than those in unresorbed, deeper dentin. Many apatite crystals were demonstrated to be present in the extracellular channels of the ruffled border and in adjacent endocytotic vacuoles derived from it. Lysosomes located in the perinuclear cytoplasm of odontoclasts contained amorphous dense material and/or a small amount of crystals. An energy-dispersive x-ray microanalysis of apatite crystals in undemineralized sections indicated that the energy spectrum peaks of Ca and P detected from crystals in resorbing dentin were much lower than those in unresorbed dentin. Similarly, lower spectrum peaks of Ca and P were obtained from crystals found in the ruffled border and endocytotic vacuoles of odontoclasts. A slight trace Ca peak also was detected in the amorphous dense material in lysosomes of odontoclasts. The enzyme cytochemistry of lysosomal acid trimetaphosphatase indicated that odontoclasts had intense enzymatic activity in the Golgi membranes, endoplasmic reticulum cisternae, lysosomes, and endocytotic vacuoles. Dense reaction precipitates of enzymatic activity also were found along the dentin surfaces of resorption lacunae occupied by odontoclast ruffled borders.(ABSTRACT TRUNCATED AT 400 WORDS)

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Microprobe analysis of calcifying matrices and formative cells in developing mouse molars

Cited by 24 publications

References 26 publications

Electron Probe X-Ray Microanalysis of Calcium and Phosphorus Distribution in Developing Hamster Tooth Germs in vitro and in vivo

Electron Probe X-Ray Microanalysis of Calcium and Phosphorus Distribution in Developing Hamster Tooth Germs in vitro and in vivo

Tubule formation and elemental detection in developing opossum enamel

Dentin resorption mediated by odontoclasts in physiological root resorption of human deciduous teeth

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