. Dental t excess of mercury upon an alloythat shrinks is to increase the shrinking. The effect of a slight excess of mercury upon an alloythat expands is to increase the expansion.—Dental Cosmos. THE DENTAL SUMMARY 843 BICUSPID RESTORATION A. J. Cottrell Knoxville, Teiin. The following method of restoration, which is a crossbetween the Richmond crown and an inlay, is, in the opinionof the writer, the most practical yet suggested. It may bemade by casting or by soldering, but owing to the greatdifficulty in getting an accurate wax model the soldering seemspreferable. Take for instanc
. Dental t excess of mercury upon an alloythat shrinks is to increase the shrinking. The effect of a slight excess of mercury upon an alloythat expands is to increase the expansion.—Dental Cosmos. THE DENTAL SUMMARY 843 BICUSPID RESTORATION A. J. Cottrell Knoxville, Teiin. The following method of restoration, which is a crossbetween the Richmond crown and an inlay, is, in the opinionof the writer, the most practical yet suggested. It may bemade by casting or by soldering, but owing to the greatdifficulty in getting an accurate wax model the soldering seemspreferable. Take for instance a case with the buccal wallbroken away. Remove the irregularities in the remainingwall, giving the base such a shape that the finished piece willbe firmly seated, and extend the bucco-cervical wall slightlyunder the free margin of the gum. Slightly shorten thepalatal wall (Fig. i), giving its end a semi-tenon-like shape(see a. Fig. i), this to be firmly engaged by the finished piece. PiP- i Fig. 2 Fig. 3 Fig. 4. Fit a platinum pin to one root canal, then burnish a platinummatrix to the prepared tooth, being careful to burnish it wellover the prepared end of the palatal wall, push the pin throughthe matrix and into the root. Then with a cone of paraffinwax, the point being slightly warmed so that it will adhere tothe matrix and pin, thoroughly swage the matrix to the faceof the root and wall, being careful to carry it well over theprepared end of the palatal wall. Remove the wax, matrixand pin together; invest, solder the pin and reinforcethe matrix (see Fig. 2). Notice the extra amount of solderplaced at the point (a, Fig. 2) ; unless this were done itwould be very difficult to carry the solder well over this pointin the invested piece. Place the matrix in place on the tooth,again burnish the edges, take a plaster impression and waxbite, make a model, mount on the articulator, grind and fitthe facing, back with platinum, wax together and build up 844 THE DENTAL SUMMARY with
Size: 3037px × 823px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookiddent, booksubjectdentistry
