Human tooth intersect with each other. Their length is dictated by the radius of the tooth. The three dimensional configuration of the dentinal tubules is genetically determined. Cementum is a specialized bone like substance covering the root of a tooth. It is approximately 45% inorganic material (mainly hydroxyapatite), 33% organic material (mainly collagen) and 22% water. Cementum is excreted by cementoblasts within the root of the tooth and is thickest at the root apex. Its coloration is yellowish and it is softer than dentin and enamel. The principal role of cementum is to serve as a medium by which the periodontal ligaments
The Outermost House The Outermost House The Outermost House is a book by naturalist writer Henry Beston. It was published in 1928 by Doubleday and Doran and is now published by Henry Holt and Company in New York City. It chronicles a season spent living on the dunes of Cape Cod. Beston's "Fo'castle," the 20x16 beach cottage which served as the setting for the book "The Outermost House", was built in June 1925 and then claimed by the sea in February 1978. Beston (born Henry Beston Sheahan in 1888; died 1968) named the cottage "the Fo'castle" because its ten windows and its commanding