[Superficial structure of dental cement as shown by acid etching and scanning electron microscope]

The superficial layer of the cement is made up of a mineralised structure in which are included organic fibres which would seem to serve as the intracemental anchorage of Sharpey's fibre. The appearance seen on sweep electron microscopy after acid demineralisation confirm those seen using the electron microscope by Selvig. These fibres included in the cement have a variable diameter ranging from a few microns and 45 microns on our pictures (10 microns according to Selvig). They consist of a numerous fibrils with a diameter of the order of 0.3 microns. In the cement these fibers are parallel to the surface of the tooth, this confirming Selvig's finding. Finally, our observations show that, in the superficial part of the cement, these fibres form a markedly flattened three-dimensional network.