A practical treatise on artificial crown- and bridge-work / By George Evans. With 500 illustrations.
- George Evans
- Date:
- 1888
Licence: Public Domain Mark
Credit: A practical treatise on artificial crown- and bridge-work / By George Evans. With 500 illustrations. Source: Wellcome Collection.
Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.
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acking porcelain fronts. Gold plate, slightly alloyed,—about 23 (.'arats fine,—in crown- work, if less iiexibility of the metal is required. Gold plate, 22 carats, No. 32 to JSTo. 34 standard gauge, in constructing collars for crowns with porcelain fronts and all- gold crowns constructed in sections. Gold plate, 20 carats, in construction of bridge-work. Gold plate, 24 carats, with a very thin lining of platinum, oi' iridio-platinum plate, can be used in any of the processes con- nected with crown- and bridge-work, and is especially reconi- mendedto the inexperienced, for the reason that the melting of a part of a crown in the soldering process is prevented by its use. It is formed by placing together an annealed gold plate and a plat- inum plate (the gold about ]^o. 20 gauge and the i)latinum Xo. 30) and passing them through a rolling-mill, in which process the plates are welded and reduced to the desired thickness. Pure platinum rolled very thin is used for forming caps to collars, backing teeth, and for various purposes connected with this class of operations. Iridio-platinum wire is used for [livots. pins, or posts, being more rigid than pure platinum. A wire of gold and platinum alloy is used on account of its elasticity for split or spring pivots or posts in removable bridge-work. Solders.—Gold solder, 22 carats fine, is used for crown-woik 20 carats for crown- and bridge-work.](https://iiif.wellcomecollection.org/image/b21223105_0249.jp2/full/800%2C/0/default.jpg)
