The Presence of Nerve Fibres in the Dentinal Tubules of Mammalian Teeth

Abstract

For these studies, a number of different forms and methods of preparation were employed. The teeth used were from human, dog, cat, and rodent. Methods utilized included supra- and intra-vital methylene blue, various modifications of the Cajal technique, and iron hematoxylin preparations, following in large part the various studies on this subject by other workers. By only one method was it possible to stain the structures in such a way as to make the evidence incontrovertible. By means of pyridine fixation, the Cajal technique of silver impregnation, and very careful grinding instead of decalcification, it was possible to so prepare the mammalian tooth as to show adequate evidence that the dentinal tubules contained definite, unmyelinated fibers. These could be traced in separate portions of the same preparation from their arborizations around the odontoblast, extending thence into the dentinal tubules, following these tubes to the dento-enamel junction, where they apparently dichotomize between the dentin and enamel. By careful grinding technique, it was found to be possible to prepare sections by this method sufficiently thin that the oil immersion lens with very high power magnification could be used.