The Dental cosmos . devised a set of diamond-chargedtrephines (Fig. 1) for cutting circular inlays of different sizes from any portionof a porcelain tooth,—a circular form being the most easily fitted, and in a largemajority of cases which come under our notice the cavity can be cut to thisshape. i6o THE DENTAL COSMOS. By means of these trephines, which are made in the same manner as thediamond disks, any old, otherwise useless, porcelain tooth may be utilized,and by placing a small piece of cork, rubber, or wood inside the trephine,allowing the instrument to cut only a given depth, we can hav
The Dental cosmos . devised a set of diamond-chargedtrephines (Fig. 1) for cutting circular inlays of different sizes from any portionof a porcelain tooth,—a circular form being the most easily fitted, and in a largemajority of cases which come under our notice the cavity can be cut to thisshape. i6o THE DENTAL COSMOS. By means of these trephines, which are made in the same manner as thediamond disks, any old, otherwise useless, porcelain tooth may be utilized,and by placing a small piece of cork, rubber, or wood inside the trephine,allowing the instrument to cut only a given depth, we can have the inlay theexact thickness required. Then in grinding the back portion of the tooth,—behind the dotted line,—(Fig. 2) away on the lathe we have something tohandle,—something large enough to get hold of until the grinding is com-pleted. By shaping the cavity with wheel-burs (Fig. 3) of exactly the samesize as the inlays, we secure an accurate fit (Fig. 4), and, if every part of the Fig. 3. Fig. 4. Fig. 1 3 5 7 9 operation has been carefully performed, there should be no necessity of trim-ming after the inlay is set, and in this way we retain intact the smooth andfinished surface of the porcelain. When a cavity of decay extends below the gum on the labial surface of atooth, a very satisfactory result may be obtained by cutting an inlay from agum tooth in such a way that a portion of the gum festoon may be included(Fig. 5). Very often the entire inlay may be cut from the gum-colored por-tion. Many oblong-shaped cavities can be fitted with two small circular inlaysplaced side by side and carefully jointed at the point of contact.—Geo. , , Cornwall, Ontario, Canada. A New Bing Bridge.—The setting of an ordinary Bing bridge betweenany of the oral teeth is both troublesome and unsatisfactory because of thedifficulty of building the wings into the natural teeth, the sides of which fit soclose to the bridge-tooth that there is not room for filling arou
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectdentist, bookyear1890
