The Dental cosmos . probably has a matrix of glue-giving material similar to cementum anddentine. I have never been able to make out lacunae satisfactorily. 9° THE DENTAL COSMOS. dark lines which seem to mark imperfect cementing of the rods. Therods themselves are granular and imperfectly formed. Such a linehas but little physical strength. In Fig. 13 I present another form of imperfect fusion of the enamel-plates. In this case a first bicuspid, a young tooth well developed,with long cusps, removed to make room in a case of irregularity, wasso cut as to obtain a section parallel with the ename
The Dental cosmos . probably has a matrix of glue-giving material similar to cementum anddentine. I have never been able to make out lacunae satisfactorily. 9° THE DENTAL COSMOS. dark lines which seem to mark imperfect cementing of the rods. Therods themselves are granular and imperfectly formed. Such a linehas but little physical strength. In Fig. 13 I present another form of imperfect fusion of the enamel-plates. In this case a first bicuspid, a young tooth well developed,with long cusps, removed to make room in a case of irregularity, wasso cut as to obtain a section parallel with the enamel-rods near thesummit of the buccal ridge on a line from the point of the buccalcusp to the mesial angle. The cut is across the mesial triangulargroove. (See Fig. 17, e.) This particular portion of the bicuspidhas been chosen for illustration because it is a point at which errorin shaping large proximate cavities is common. This kind of faultseems not very uncommon, if I may judge from the number found in Fig. Section across the junction of the enamel-plates of an upper hicuspid cut on a line from thesummit of the huccal cusp to the angle, a, Dentine ; b, Enamel; c, Globular masses of calcificmaterial in the line of junction of the enamel-plates; d. Long-shaped bodies; <?, Hyalinematerial between the enamel-rods. The illustration shows only about half the thickness ofthe enamel. The surface half was regularly formed, and the apparent groove only a slightdepression. grinding about twenty sections for the purpose of examining theselines of junction. Also the number of cases met with in practicewhere the enamel has broken along this line of junction after moderatelylarge proximal fillings have been made, indicate frequency of faultyjunctions not appreciable by ordinary examination. In this case there is no fissure. The surface half of the enamel isapparently good, and the slight groove is smooth. The fault couldbe detected only with the microscope. Furthermore, in grindin
Size: 2159px × 1157px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthor, bookcentury1800, bookdecade1890, booksubjectdentistry
