Electron microscopic observation of initial dentine forming area stained with ruthenium hexammine trichloride (RHT).

Abstract

: In the present study, the initial dentine forming areas were stained with ruthenium hexammine trichloride (RHT) and examined under an electron microscope , consequently, the following conclusions were obtained. 1) Basal lamina had a marked affinity for RHT , in particular, and lamina lucida reacted intensely rather than lamina densa.2) The intercellular spaces between preodontoblasts were filled with electron opaque materials which were intensely stained with RHT and appeared almost homogeneous.On the other hand , RHT-positive granules, approximately 30 nm in diameter, from which faint filamentous structures extended radially, were scattered in the predentine matrix. Some of them were situated on the surface of collagen fibrils in the periodic array.3) Large amounts of RHT-positive materials were attached to the outer surface membrane of matrix vesicles.