Principles and practice of crowning teeth : a practical, systematic and modern treatise upon the requirements and technique of artificial crown work, including some incidental reference to bridgework. With 459 illustrations / By Hart J. Goslee.

  • Goslee, Hart J., 1871-1930.
Date:
1903
Catalogue details

Licence: Public Domain Mark

Credit: Principles and practice of crowning teeth : a practical, systematic and modern treatise upon the requirements and technique of artificial crown work, including some incidental reference to bridgework. With 459 illustrations / By Hart J. Goslee. 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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    Gold solders are alloys of gold so compounded Gold Sold^fS* as to fuse slightly lower than plate of the same fine- ness or karat; should be composed of the same metals to preserve a close resemblance in color, and differ only in the incorporation of a metal which will reduce the fusing point and impart flowing properties. Thus a 20 K. solder, for instance, should fuse read- ily on plate of the same K., otherwise it would not be a solder in the sense of the meaning. Zinc is mostly used for the purpose of reducing the fusibility and imparting the requisite flowing properties, but should not be in pro- portion more than i^ to 2 parts in 24; because if in greater quantity the alloy would be rendered brittle, the strength thus diminished, and the susceptibility to chemical influences when exposed to the action of the secretions increased. Solder 01 a lower K. than is absolutely neces- sary should never be used, because the lower the K., the greater the affinity for oxidation and the susceptibility to chemical action; and in consequence the seam of union and the surface exposed are always rendered more or less conspicuous; hence it is desirable to begin with as high a karat as possible, so that subsequent solderings may be made with those of a degree of fineness which will aid in precluding this ten- denc}^ And as the grades which are prepared for our use invariably run lower than the karat stamp upon them, those of so-called 16 and 14 karat have but a very limited sphere of usefulness. The following formulae give the average composition of the vari- ous grades of dental solders: 22 K. Solder. 18 K. SoId( sr. Pure gold, 22 dwt. Pure gold, 18 dwt. Brass, 2 (( silver. 3 Coin Solder. copper, I Coin gold, 5 dwt. Brass, 2 Brass, i <( 16 K. Sold. sr. 20 K. Solder. Pure gold, II dwt.. 12 gr- Pure gold, 20 dwt. silver, 3 Dorrance's alloy, 4 (( copper, zinc. I 12 12 gr. gr. 14 K. Solder. Pure gold, 14 dwt. silver, 5 copper, 3 12 gr. zinc, I 12 gr.