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Biomedical subjects

B Kerebel

Publications and source records attributed to B Kerebel.

At least 55 records · Page 3Linked to original sources
PubMed1983

Soft-tissue calcifications of the dental follicle in regional odontodysplasia: a structural and ultrastructural study.

Soft-tissue calcifications of the dental follicle in regional odontodysplasia were studied via the correlated techniques of light microscopy, scanning electron microscopy (SEM), calcium x-ray cartography, and high-resolution transmission electron microscopy (TEM). The study revealed several types of calcification, mostly located within an area normally occupied by enamel formation. Some of them are produced without collagen being involved; others result from the mineralization of collagen fibers. Sometimes they were surrounded by a structureless homogeneous zone and resulted from the fusion of several smaller globules. High-resolution TEM revealed two different types of calcifications: a few composed of platelike crystallites, presenting a "sheath" characteristic of apatite formation, most of them poorly crystallized. The calcifications were in close contact with the cytoplasm of the neighboring connective tissue cells in which an abundance of microfilaments was found. It is suggested that these filaments might be involved in the formation of dystrophic soft-tissue calcifications.

Adolescent↗
PubMed1982

Structural, ultrastructural, microradiographic, and electron-probe studies of an unusual case of regional odontodysplasia.

Structural, ultrastructural, microradiographic, and electron microprobe studies of an unusual case of odontodysplasia were performed. Two cusps were absent from one molar. Normal prismatic enamel and mantle dentin were present on the two others. The dentinal mass resembled osteodentin. The mineral content of enamel and dentin was decreased compared to that of the controls.

Child, Preschool↗
PubMed1982

Apatites in heterotopic calcifications.

Calcified material obtained from three patients suffering from calcifications of the shoulder tendon sheath and from a subcutaneous with calcinosis was studied. A panel of different techniques was applied to this study: scanning electron microscopy, X-ray diffraction, infrared spectrometry, scanning and transmission wavelength dispersive X-ray spectrometry, high resolution transmission electron microscopy and electron microdiffraction. These calcifications, made of carbonate containing apatite, are heterogeneous and composed of at least two separate phases the crystallinity of which appear different.

Apatites↗
PubMed1981

Effects of fluoride on human enamel and selachian enameloid in vitro: a high-resolution TEM and electron diffraction study.

The effects of fluoride on human enamel and selachian enameloid in vitro were visualized in TEM and analyzed with electron diffraction. It is demonstrated that under precise pH conditions, inducing concentration balance between F-ions and apatite, calcium fluoride is no longer formed, and crystalline changes occur instead. A secondary growing process, inducing a twofold increase in crystal size, involves all crystal faces, altering the hexagonal symmetry. It is suggested that the mechanism involved is not a dissolution/precipitation process but rather a secondary growth of residual crystallites induced by apatite dissolution.

Animals↗
PubMed1981

Enamel in odontodysplasia.

Microradiographs of a tooth affected by odontodysplasia showed a clear delineation between the hypoplastic enamel and dentin. Two different zones, one presenting a prismatic structure and the other a globular structure, were found in the enamel layer. In areas where normal prismatic enamel was found, a scalloped dentinoenamel junction and a normal mantle dentin layer were present. Crystallites in those areas were of normal size but the intercrystalline spaces were enlarged. Hypoplastic globular enamel consisted of smaller, closely packed crystallites resembling a type of enameloid found in teleost fishes. Round calcified bodies attached or unattached to the hypoplastic enamel were composed of still smaller irregularly distributed crystallites. It is suggested that the outer hard tissues in odontodysplasia involve different processes. The prismatic enamel zones are formed by the first differentiated ameloblasts. The hypoplastic enamel is due to a decrease in the number of ameloblasts. A localized loss of ameloblasts induces lack of enamel in places. The round calcified bodies attached or unattached to the hypoplastic enamel are most likely formed without any involvement of the ameloblasts.

Ameloblasts↗
PubMed1981

The inorganic phase in dentinogenesis imperfecta.

The inorganic phase in dentin with dentinogenesis imperfecta was investigated, using the correlated techniques of high resolution TEM, X-ray diffraction analyses, infrared absorption spectroscopy, thermogravimetry, and chemical and electron microprobe analyses. It was shown that crystallites in dentin with dentinogenesis imperfecta are of normal size (from 3 to 6 lattice planes thick), but less numerous than in normal dentin. Electron microprobe analyses indicated significant differences in the mineral content of dentin with dentinogenesis imperfecta compared to normal dentin. A higher Ca/P ratio, a loss in Ca and P, and a severe significant loss in Mg, corroborated by chemical analyses, were recorded. The main component of the inorganic phase in dentin with dentinogenesis imperfecta was found to be poorly crystallized carbonated apatite. It is suggested that the water content, greatly increased in dentin with dentinogenesis imperfecta, is at least partly related to lattice water tightly bound to the inorganic phase.

Adolescent↗
PubMed1981

[Effect of vitamin D3 and vitamin D3 sulfate on dental and bone tissues in the pig].

The repairing effects of vit. D3 and vit. D3 sulfate upon the hard tissues of vit. D3 deficient pigs have been studied using SEM and electron microprobe analyses. It was demonstrated that a vit. D3 therapy could balance lesions induced by vit. D3 deficiency. The effects of vit. D3 sulfate were not so clear. Results obtained were varying, sometimes similar to those obtained with vit. D3 but not always statistically significant. The rate of mineralization of dentine and bone was higher in animals having received vit. D3 and vit. D3 sulfate compared to the deficient group. In dentine and bone, the Ca/P ratio, thus the crystalline phases, wee modified, which was not the case for enamel and acellular cementum. It was shown that dentine and bone, which both include cells and cell processes in the calcified matrix, undergo similar modifications in the course of vit. D3 deficiencies and their therapy. On the contrary, enamel and acellular cementum in vit. D3 deficiency presented a lower rate of mineralization without any structural defects or modifications in Ca, P, Mg and F- ratios. Repair of lesions due to vit. D3 deficiencies by vit. D3 and, to a lower degree, by vit. D3 sulfate, concern, in order, bone, dentine, cementum and very little enamel.

Animals↗