Prosthetic dentistry / by James Harrison Prothero.

  • Prothero, James Harrison.
Date:
1916
Catalogue details

Licence: Public Domain Mark

Credit: Prosthetic dentistry / by James Harrison Prothero. Source: Wellcome Collection.

    194/1222 (page 168)
    sary rigidity. This method of forming a double base is fre- quently followed in partial cases, but is seldom required in full dentures. GauGES oF GoLp Usrep ror DrentTURE Baszs For full upper dentures, 28, 27, and 26 gauges of gold are used as conditions require. ‘T'wenty-eight-gauge, 20-carat plate is sufficiently rigid for narrow arches where the stress of mastication is light to medium heavy. Twenty-seven-gauge, 20-carat is indicated for arches of medium width, medium stress, and in narrow arches when stress is heavy. Twenty- six-gauge is indicated for wide arches when the denture will be subjected to heavy stress. Full lower dentures seldom require heavier than 28-gauge plate, since the vuleanite which furnishes attachment for the teeth usually covers the entire base, and this, together with the peripheral wiring, supplies the needed_rigidi F re- quently 29-gauge will prove satisfactory. That one may form a just estimate of the relative thick- ness of the gauges mentioned, their value according to the Brown & Sharp micrometer scale is here given. This microm- eter scale is given entire in the section on metallurgy. 26 gauge equals .01594 of an inch Pa RE ee TAO ease eee Difference between 26 and 27 gauge equals .00175 “é “ec “ce OT “é 98 “ce “eé .00 231 pe Bae 01264 eal 29 sé cé .01126 ee “e oe «“é 28 cé 29 ce ce .00138 80 tO Ue Otte eae Opie ensue * 00128 To gain rigidity within restricted ‘areas, partial denture bases are fzequently formed of two pieces of plate, swaged separately, then together, and finally soldered. Usually two pieces of 30-gauge or one of 30 and one of 29 gauge are com- bined in this manner. The two pieces of 30-gauge equal .0200, or approximately 24-gauge, which is .0201. The other com- bination equals .0212, or about 2314 gauge. Various other combinations of gauges can be utilized, as the conditions of individual cases demand, broad bases requiring thin, while narrow bases call for thicker gauges of plate. ANNEALING THE PLATE Gold plate, as usually furnished by the supply houses, is not in its softest possible condition, and therefore should be annealed before attempting to adapt it to the die, as well as at various times during the swaging process. Hammering, rolling, bending, burnishing and polishing tend to stiffen and render the gold, as well as other metals,