A practical treatise on artificial crown- and bridge-work . and, with the aid of a spoon, placedaround in the mouth on the crowns, caps, and parts to beincluded in the bridge, and the antagonizing teeth occludedtightly and so held until the plaster sets. The mouth is thenopened and the plaster carefully removed, the pieces beingadjusted together should it break. The crowns and caps (thelatter held more firmly by the protruding ends of the pins) areremoved in it. The plaster is then varnished, and, on the sidecontaining the crown-, a model is run, composed of equal partsof calcined marble-dust
A practical treatise on artificial crown- and bridge-work . and, with the aid of a spoon, placedaround in the mouth on the crowns, caps, and parts to beincluded in the bridge, and the antagonizing teeth occludedtightly and so held until the plaster sets. The mouth is thenopened and the plaster carefully removed, the pieces beingadjusted together should it break. The crowns and caps (thelatter held more firmly by the protruding ends of the pins) areremoved in it. The plaster is then varnished, and, on the sidecontaining the crown-, a model is run, composed of equal partsof calcined marble-dust and plaster, to which is added a littlesulphate of potassium,—less than the proportion of salt generallyused,—which causes the mixture to set hard quickly. When the CONSTRUCTION OF BRIDGE-WORK. 155 model has set, it is mounted with plaster on an articulator, andthe other side of the colored plaster impression giving thearticulation is run with plaster and the opposite section of thearticulator adjusted, all at the same time. When the impres- Fio sion plaster is removed (an operation which is greatly facilitatedby its having been colored with carmine), a correct model andarticulation of the case will he found, with the crowns and / / ^£PS m exact position as in the mouth (Fig. 298). ?y ^Another method is to first take / the impression in an impression-tray, and then the articulation inwax. and make a model and ar-ticulation from them in the usual Fig. 299. The pins protruding from thecape on the model are next cut ofl*short. Teeth are selected,—ordi-naryf plate teeth for the incisors andcuspids, and partial teeth, repre-senting the front section of thetooth and styled porcelain facings, which were specially designed for crown- ai*# bridge-work, forthe bicuspids and molars (Fig. 299). Cuspids are sometimesused to form the fronts for bicuspids. The teeth are fitted to the model and articulation, so that the labial
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Keywords: ., bookcentury1800, bookdecade1880, bookpublisherphila, bookyear1889
