Ultrastructural characterization of extracellular matrix vesicles in the mineralizing fronts of apical cementum in cats.
Fine structure and the organic-inorganic relationship in mineralized fronts of cementum was studied with post-embedding demineralization and staining method. Typical matrix vesicles were observed between apical cementum and cementoblasts. Some vesicles were enclosed by a unit membrane; others contained needle-like crystals. Cementum crystals were found on unstained sections as filament- and needle-like structures which disappeared completely on EDTA treatment; similarly-shaped structures re-appeared following uranyl and lead staining. These findings suggest that matrix vesicles might act as initiators of additional cementogenesis and that crystal ghosts seen in cementum consist of organic materials.
D000818:Animals; D002415:Cats; D003739:Dental Cementum / Q000648:ultrastructure*; D005109:Extracellular Matrix / Q000648:ultrastructure*; D008854:Microscopy, Electron; D014092:Tooth Root / Q000648:ultrastructure*