A treatise on the use of A.J. Watts' crystal gold / by W.H. Dwinelle.

  • Dwinelle, W. H.
Date:
1855
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on the use of A.J. Watts' crystal gold / by W.H. Dwinelle. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    means, may be made absolutely so, becoming more dense even than coin. Foil is sometimes comparatively integrated ; that is, each part is resolved into the unity of the whole. Crystal Gold can always be so completely integrated, as to endure every test that coined gold can withstand. When the best foil stopping is removed from the tooth and crushed by a heavy lateral or sliding pressure, it is partially separated into irregular and laminated forms. This is very distinctly seen whenever the stopping is broken up in the mouth. The order, or manner of its disintegration, is as follows : The fluids of the mouth penetrate through and beneath the lamina, or around and about the borders of the pellets, gradually upheaving and disrupting the integrity of the whole. A gold stopping, when properly made, has the quality of oneness so complete, each ultimate particle being so thoroughly united and integrated into the whole, that it is no more likely to break up or sepa- rate from itself than any other equal bulk of pure solid gold. In case an angle or portion of it should be broken off, it would be the same as though an equal amount should be separated from any other piece of highly tempered gold. If desirable, the lost portion can be replaced ; if not, it may be filed and burnished down to a new surface, and left, without in the least endangering the remaining portion of the stopping. It is a fact well known to the Profession, that when foil is broken up into angles and formed into coils or pellets, it thereby often becomes so tempered, so hard and harsh, that it is worked only with great difficulty; the laminated structure of the gold is so bent and angulated into thou- sands of arches, in-archings and bracings, as to resist a large force applied to the top of the mass, without materially breaking up the structure at the bottom. To obviate this, it is necessary to introduce the gold in smaller masses of less degree of density, and to forcibly work them together with the most delicate pointed instruments. Stoppings made by our best artists, when placed under the microscope, will be found to have their inner surface entirely traced over with irregular, sinuous, concave groovings, extending from the centre to its borders—the remains of the angular presentation of the foil to the sur- face of the cavity. When these semi-tubular groovings arc too small to absorb the fluids of the mouth, their presence is not injurious ; but when larger, the ultimate disruption of the stopping is inevitable. Crystal Gold has a peculiar quality which permits it to be introduced into the cavity in comparatively large masses, which may afterwards be thoroughly condensed in their place. When properly worked, it gives the sharpest impression of all the irregularities and most delicate markings of of the inner surface of the cavity, and absolutely insinuates itself into the texture of the tooth. This fact is easily demonstrated by the microscope. In using Crystal Gold, it will, however, be necessary in order to secure the highest degree of success, to take into consideration the nature and character of the article to be used ; wherein it differs from foil; and the peculiar manner of treatment it requires; for, in many respects, the system of manipulation which would secure the best foil stopping, would utterly fail of success when applied to Crystal Gold. Crystal Gold, as its name indicates, is made up of a combination of crystals of pure gold, so interlaced and interwoven that upon being sub- mitted to pressure, it readily welds into a solid mass. By leaving its upper surface rough in the act of filling, layer may may be built upon layer, until any desirable thickness is attained. As the arrangement of the crystals of the gold here mentioned, are in