The Dental cosmos . which may be filed slightly to give it a wedge shape, andby frequent trials with careful corresponding cuttings of the groovewith the bur be made at least to go to its- seat so tightly as to besecure against dislodgment in use. It will be noticed that the post is materially strengthened by thefeather, which reinforces the post in the line of resistance to outwardthrust during the acts of incising or grinding with the crown. Special cases, where the root is small and short, as in Fig. 7, and FEATHERED POSTS FOR TOOTH-CROWNS. 367 the crown subjected to hard usage by the deep
The Dental cosmos . which may be filed slightly to give it a wedge shape, andby frequent trials with careful corresponding cuttings of the groovewith the bur be made at least to go to its- seat so tightly as to besecure against dislodgment in use. It will be noticed that the post is materially strengthened by thefeather, which reinforces the post in the line of resistance to outwardthrust during the acts of incising or grinding with the crown. Special cases, where the root is small and short, as in Fig. 7, and FEATHERED POSTS FOR TOOTH-CROWNS. 367 the crown subjected to hard usage by the deep under-bite of theopposite tooth, will be well met by the feathered post, which affordsthe maximum strength of crown attachments with the least possibleremoval of root-substance. Whenever the root end is somewhat decayed, the feather seat maybe cut at the soundest part. In greatly wasted cases the root may becollared, filled, and the filling drilled and prepared as first described. Fig. 11. Fig. 12. Fig. 13. Fig. If the canal is unusually large, as in Fig. 8, a narrow strip of platemay be bent around the post and pinched close upon it. A suitableclamp will hold the plate ends together while they and the plate arebeing soldered on the post. The piece is then filled to the shapeshown in Fig. 9. Before drilling the root, it is well to drill a trial-pieceof bone, and with a large round bur, followed by an inverted conebur, form the enlargement of the socket, and with a fissure-bur cutthe groove for the feather. Of course, the better way is to make a Fig. 15. Fig. 16. Fig. 17. Fig. i<s. Fig. 19. Fig. 20.
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectdentist, bookyear1890
