A practical treatise on mechanical dentistry . probable, from the fact that it is absolutely jointless, and securesimmediate solidity, even while the amalgam is semi-plastic. Thesecrowns are capable of resisting the force of biting or mastication,because they are supported nearly to the cutting edge or grindingsurface, the triangular opening from the concave base nearly to thecutting edge allowing the pin to be imbedded in the labial face ofthe crown where there is the greatest amount of porcelain. The amalgam to be used as the medium of union must setquickly and be very hard. Thus far I have
A practical treatise on mechanical dentistry . probable, from the fact that it is absolutely jointless, and securesimmediate solidity, even while the amalgam is semi-plastic. Thesecrowns are capable of resisting the force of biting or mastication,because they are supported nearly to the cutting edge or grindingsurface, the triangular opening from the concave base nearly to thecutting edge allowing the pin to be imbedded in the labial face ofthe crown where there is the greatest amount of porcelain. The amalgam to be used as the medium of union must setquickly and be very hard. Thus far I have found nothing betterthan the alloys I have specially prepared for this line of work, and, ARTIFICIAL CROWNS. 489 though they are costly, the superior results obtained by their useamply repay the cost. I use No. 1 generally. If mixed thick, itwill set so quickly that the operator must work rapidly to preventits being wasted. In incisor cases I use No. 3 at the gum line andmake a close joint. Fig. 326. Fig. 328. Fig. 329. © Fig. 327. Fig. Fig. 331. Fig. 326.—End view of a canal prepared for the improved combination-metalpin. Fig. 327.—End view of same canal as in Fig. 326, prepared for a triangularpin, showing how much more of the mesial and distal surfaces have been cutaway from it than in Fig. 326 for the improved pin. Fig. 328.—Sectional view of an incisor crown and root, with the improvedpin in its relative position to each,* with the depressions made by wheel-bur. Fig. 329.—Sectional view of a superior molar, with the large angular pin inpalatal root and two square pins in the buccal roots, one being shorter and notpassing through the crown. Fig. 330.—Block of a molar and bicuspid, showing the countersunk holes forpins in the molar, and the hole in the mesial side of the second bicuspid where apin is alloyed in and set into a decayed cavity in the distal surface of the firstbicuspid, being held upon the molar roots and attached to the bicuspid by th
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectdentist, bookyear1903
