ISSN:
1432-0878
Schlagwort(e):
Osteodentinogenesis
;
Osteodentine
;
Teleost teeth
;
Esox
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
,
Medizin
Notizen:
Summary The organic matrix of osteodentine forms in two stages. Coarse fibril bundles (α matrix) (fibril diameter 1,000–2,000 Å) oriented parallel to long axis of the tooth are formed first by scleroblasts of types 1 and 2. Type 1 is a stellate pulp cell with sparse RER; type 2 a rounded cell containing packed arrays of RER develops from type 1. When bundles of coarse fibrils reach a diameter of 20–30 μ, a second type of matrix with fineβ fibrils (fibril diameter about 500 Å) forms circumferentially around the coarse fibril bundles. Associated scleroblasts of type 3 contain arrays of RER and have numerous short blunt processes at the cell-matrix interface. Matrix deposition forces type 3 scleroblasts into canals surrounding blood vessels (dental osteons or denteons). After organic matrix deposition is completed, calcification occurs throughout the coarse and fine matrix. Coarse fibril matrix is less heavily calcified than fine fibril matrix. The fibrils in coarse (α) matrix are less heavily calcified than the surrounding interfibrillar matrix. Calcification is not an incremental process. In mature osteodentine, associated cells, scleroblasts of type 4, have only small amounts of RER and show no cytoplasmic processes. Osteodentine is compared to vasodentine, orthodentine and bone.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00665617
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