The American text-book of operative dentistry / In contributions of eminent authorities. Ed. by Edward C. Kirk.

Edward Cameron Kirk

Date:: 1900

Credit: The American text-book of operative dentistry / In contributions of eminent authorities. Ed. by Edward C. Kirk. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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$are in structure like large capillaries (Fig. 113). This peculiarity of the bloodvessel walls is of great importance, as it renders the tissue specially liable to such pathologic conditions as hyperemia and inflammation. XEEVE OF THE TULP. Several comparatively large bundles of medullated nerve fibers, con- taining from six or eight to fifteen or twenty fibers, enter the pulp in com pan V with the bloodvessels and pass occlusally through the central j)ortion of the tissue. These bundles branch and anastomose with each other very freely. Most of the fibers lose their medullary sheath before reaeliing the layer of AVeil, in which position they form a plexus of non-nieduUated fibers ; from these fibers free endings are given off, which penetrate between the odontoblasts. In some cases these have been followed over on to the dentinal ends of tiie odontoblasts, but in no instance have they been followed into the dentinal tubules. THE FUNCTIONS OF THE PULP. The pulp performs two functions, a vital and a sensory. The vital function is the formation of dentin, and is performed bv the layer of odontoblasts. This is the principal function of the pulp, and it is first manifested in the development of the tooth before the dentinal papilla is converted into the dental jnilp by being inclosed in the formed dentin. After the tooth is fully formed the vital func- tion is not manifested unless the pulp is stimulated by some excitation affecting trophic centres and which causes the formation of secondary dentin. There are some exceptions where the formation is entirely local. The Sensory Function.—In regard to sensation, the pulp resembles an internal organ. It has no sense of touch or localization, and re- sponds to stimuli only by sensations of pain. The pain is usually localized correctly with reference to the median line, but, aside from that, is localized only as it is referred to some known lesion. If several pulps on the same side of the mouth and in teeth of both the npj)er and lower arches were exposed so that they could be irritated without im])n'.-sions reaching the peridental membrane, and the patient were blindfolded, it would l)e impossible for him to tell which of the pulps was touched. The \x\\\\ originating from a tooth pulp may be referred to the wrong tooth or to almost any point on the same side supplied by the fifth cranial nerve. The pulp is especially sensitive to changes of temperature, but is incapable of differentiating between heat and cold ; this fact is often made use of in differential diagnoses (see Chapter XVI.). The pulj) is$