A practical treatise on artificial crown- and bridge-work . d slightlyunder its margin if it is desirable to conceal the joining of thecrown with the root. The sides are shaped the same as for acollar crown (Fig. 199). A die of the end of the root is thenmade. For this purpose an impression of the part is taken withgutta-percha on the end of a piece of woodtrimmed to the proper size, or by placingthe gutta-percha in a tube formed of a stripof copper about one and one-half inches inlength and three-eighths of an inch in di-ameter, cut out on the sides to the dej^th ofhalf an inch, with the flan
A practical treatise on artificial crown- and bridge-work . d slightlyunder its margin if it is desirable to conceal the joining of thecrown with the root. The sides are shaped the same as for acollar crown (Fig. 199). A die of the end of the root is thenmade. For this purpose an impression of the part is taken withgutta-percha on the end of a piece of woodtrimmed to the proper size, or by placingthe gutta-percha in a tube formed of a stripof copper about one and one-half inches inlength and three-eighths of an inch in di-ameter, cut out on the sides to the dej^th ofhalf an inch, with the flange for the palatalside shortened (Fig. 200). The impressionthus taken will be confined almost entirelyto the end of the root to be capped. Whenthe gutta-percha has cooled, a strip of paper is tied around thewood or tube and a die cast with the fusible metal. When cool,the die is removed from the mold, and the metal is trimmed,with file and chisel, a little deeper than the gum has permittedthe impression of the root to be taken, and without altering the104. THE QOLD SEAMLESS CAP CROWN. 105 form of the end of the root (Fig. 201). A counter-die is thenmade by punching a hole in the surface of a block of pure lead,and with a few blows of a hammer driving the die into it. A cap of gold can be formed by placing a piece of gold plate(preferably pure, No. 32 U. S. standard gauge) of suitable sizeupon a block of lead, and with an oval-shaped punch one-fourth ofan inch in diameter gradually driving it into the lead until the goldhas assumed the shape of a cap about a quarter-inch in depth (A,Fig. 201). The gold should be withdrawn from under the punchand annealed several times during the process. Caps can also bemade with a stamping-press such as was introduced by Dr. J. Patrick, of Belleville, 111. (See page 112.) Fig. 201. Fig. 202. Fig. 204.
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectcrowns, bookyear1889
