A work on operative dentistry .. / By G.V. Black.

  • Black, G. V. (Greene Vardiman), 1836-1915.
Date:
1908
Catalogue details

Licence: In copyright

Credit: A work on operative dentistry .. / By G.V. Black. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    the spiculsB of cusps will stand mucli closer together than the cusps of the normal tooth. The whole of the occlusal surface of the tooth is dwarfed, often discolored and sunken into the tooth crown. The pulp chamber will be nearer to the occlusal surface than in the normally developed tooth in proportion to the sinking of this part into the body of the crown. Figure 30. All around this the enamel of second formation wells out in the form of a broad collar to the normal size of the tooth crown at or about the base of what would have been the normally devel- oped cusps. The whole of the injured area is apt to be rough and pitted, and the pits and grooves are very apt to be wide open. This condition gives unusual opportunity for the beginning of caries and the early exposure of the pulp. It is for this reason particularly that they are so often destroyed very early. In cases occurring a little later, but before the completion of the occlusal surface, the conditions inviting the beginning of caries are equally bad. The cusps will stand further apart, are stronger, but the central part of the occlusal surface and the outer slopes of the cusps are in very bad shape. At a still later date, after the completion of the occlusal surface, the injury appears as a groove around the crown of the tooth and is gen- erally of less consequence. In all of these cases the zone of injury in the dentin is one of the very grave features, for the reason that caries reaching this zone of interglobular spaces spreads through it quickly. It has been exceedingly difficult to get material for the illustration of this for the reason that very generally the occlusal surfaces of these teeth are destroyed by caries before their removal, rendering them useless for this purpose. Figures 31, 32 and 33, with their descriptions, serve, however, to illustrate the condi- tion of the tissue injuries fairly well, though neither of them are of the severer forms of atrophy. Figure 31 particularly shows the line of interglobular spaces in the dentin extending across the occlusal surface and dipping down gingivally along the axial portions of the dento-enamel junction. This figure also shows well the shortening of the crown between the pulp of the tooth and the occlusal surface. From the position of the injuries in atrophy, it will be realized, from a careful study of the lines of the injury to the dentin, that the total shortening of the crown of the tooth is between the pulp and the occlusal surface in the molars. It is also between the pulp and the incisal edge, where it occurs in the incisors and cuspids. This is the reason that pulps are so frequently exposed in the preparation of cavities