Transactions of the Illinois State Dental Society, 1892 . PLATE of Superior First Bicuspid. Mesial View (3 In. objective). THE ENAMEL AT THE GINGIVAL LINE. 119 gradually becoming thicker as it approaches the morsal plates VII. and VIII. It also gives to the teeth the form above mentioned. The thick-ness of the enamel is in a direct ratio to the amount of work whichthe tooth from its location is expected to perform, being thinnest inlower incisors and thickest in molars. The dentine when denuded of the enamel presents, in a labialor buccal view, either the form of a par
Transactions of the Illinois State Dental Society, 1892 . PLATE of Superior First Bicuspid. Mesial View (3 In. objective). THE ENAMEL AT THE GINGIVAL LINE. 119 gradually becoming thicker as it approaches the morsal plates VII. and VIII. It also gives to the teeth the form above mentioned. The thick-ness of the enamel is in a direct ratio to the amount of work whichthe tooth from its location is expected to perform, being thinnest inlower incisors and thickest in molars. The dentine when denuded of the enamel presents, in a labialor buccal view, either the form of a parallelogram or a truncatedcone with its base presented to the gingival line. In a mesial ordistal view the incisors or cuspids present the form of cones, andthe bicuspids and molars those of truncated cones with their basesat the gingival line. In the labial or buccal view we find exceptions to this rule inthe incisors and bicuspids. See plates I. to VI., also plate PLATE Incisor. Labial View. Denuded of Enamel on Mesial Surface (3 In. objective). The enamel at the gingival line terminates in a thin edge, meet-ing the cementum at this point, and usually we find the cementumslightly overlapping the enamel. In examining a large number ofspecimens we are struck with the sudden thickening of the enamel,especially in those sections presenting a labial view. See plate VII. 120 ILLINOIS STATE DENTAL SOCIETY. As the rods of which the enamel is composed have their gen-eral direction at right angles with the surface of the dentine, espe-cially upon plane surfaces, and as the tendency of the enamel rodsis to separate in thin chips from the mass, under well-directedforce with properly-shaped instruments, when a break has oncebeen made, we find but little difficulty in denuding the dentine ofenamel when the tooth has been cut or broken off near the gums. Our illustrations teach us that when this is thoroughly accom-plished we have a properly shaped
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectdentist, bookyear1865
