A contribution to the histological study of hypercementosis using metal staining.

After studying hypercementosis, in detail using metallic staining procedures, the authors reached the following conclusions: (1) The histology of hypercementosis, observed by metallic staining reveals remarkable and characteristic microscopical alterations. (2) The Rio Hortega12 procedures, the mitochondria technique of Polak,10 and the method of Achucarro-Hortega13 are of great value for the study of the morphology of cementum. (3) Among the technical procedures used, we consider the 1916 method of Achucarro-Hortega as affording the best view of cementocytes. (4) The Sharpey fibers, revealing great irregularity in course, shape and size, and frequent interruptions could be clearly observed; heavily stained lacunae were frequently observed along the cementum-dentin border; a direct deposit of cellular cementum on the dentin in the middle third of the root was frequently observed. Curiously, an acellular cementum deposit next to a cellular cementum layer could be observed; we also noted numerous cementocytes of different shapes and sizes, at times exhibiting alterations of a degenerative type, particularly fragmentation of protoplasmic prolongations. (5) The techniques used also showed the frequency of blood vessels in the texture of hyperplastic cementum and the presence of capillaries near cementum-dentin junction.