The student's guide to dental anatomy and surgery / by Henry Sewill.

  • Sewill, Henry.
Date:
1876
Catalogue details

Licence: Public Domain Mark

Credit: The student's guide to dental anatomy and surgery / by Henry Sewill. Source: Wellcome Collection.

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    processes which, either anastomose or become ex¬ tremely minute, and are lost beneath the enamel, into which tissue*however a few may penetrate. In the root they end beneath the cement, by opening- into the irregular spaces of the granular layer. The intertubular substance or matrix is translucent and finely granular, resembling compact bony tissue. It contains the greater part of the earthy constituents of the dentine. The granular layer of the root (fig. 5), which exists between the dentine and cement, may he said to constitute the line of transition where these tissues blend. The layer is made up of granules or minute globules, and contains numerous spaces apparently due to imperfect coalescence of these elements. Into these spaces (as above mentioned) the dentinal tubes open, and the spaces are again connected with the lacunae of the cement by fine canaliculi. Dentine is endowed with a considerable amount of sensibility, due to the soft fibrils which permeate its tubes, and which, as we have seen, directly emanate from the pulp. It is more sensitive immediately beneath the enamel than deeper, until the pulp cham¬ ber is approached. The sensibility disappears when the death of the pulp takes place. The cement forms a thin layer, which, commencing at the neck, where it slightly overlaps the enamel, gradually increases towards the apex of the root. It is a true bone structure, having the same che¬ mical and microscopical characters as that tissue. Existing only in a thin layer in man, cement is, however, destitute of Haversian canals. It contains, as a rule, canaliculi throughout, and lacunae at its thicker parts, hut either or both of these may be