US 3085334 A
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Description (OCR text may contain errors)
April 1963 J. L. Bl SCHOF ETAL 3,085,334
DENTURE ATTACHMENT Filed March 16. 1960 PIGS FIGS
INVF/VTOKS JULIUS L. 515C110? WILMAA. POSENBACH ATTORNEY United States Patent 3,085,334 DENTURE ATTACHMENT Julius L. Bischof, 424i Lawn Ave, St. Louis, M0,, and
Wilma A. Dosenhach, 5324 Gladstone Ave, Normandy, Mo.
Filed Mar. 16, W60, Ser. No. 15,364 4 Claims. (Cl. 32-4) This invention relates to dentures generally, but more especially to the construction of the same so that they will be accurately fitted into the mouth so as to minimize accidental displacement from their originally fitted position.
One of the important objects of our invention is to so construct said denture, with an attachment means, whereby there will be little or no tendency for the attached denture to rock, jump, rotate or wobble while in the mouth.
Another object of the invention is to so construct said denture that it is easily and readily attachable and removable from a predetermined fixed position in the mouth, with full assurance and certainty that each such replacement will always position the denture in its originally fitted position.
A further object of our invention is to so construct said dentures with attaching means, in such a way that there is a minimum of bulk that the wearer must carry in the mouth.
Other objects of the invention are to so construct such dentures that they will be extremely simple in construction, readily made by the dental technician, long-lasting, and which will be otherwise satisfactory and efficient for use wherever found applicable.
Many other objects and advantages of the construction .herein shown and described, and the uses for the same, -will be obvious to those skilled in the art to which the resent like or corresponding parts thoughout the views,
FIGURE 1 is a pespective view, showing the lower jaw portion, with the dowels anchored in place therein;
FIGURE 2 is a cross-sectional detail, showing a tooth therein, cut down and having its top face planar, ready to be drilled to provide the dowel-receiving opening therein;
FIGURE 3 is an enlarged detail view of said tooth, with the dowel inserted in the same and anchored in place;
FIGURE 4 is a perspective view of the impression taken from that portion of the jaw having the dowels anchored therein, and showing a dowel detachably posi- .tioned head-end first into one of the cylindrical openings therein made by the dowel head previously anchored in the mouth;
FIGURE 5 is a model made from said impression, of the conformation indicated in FIG. 1, with one of the plastic caps removably mounted on one of the head ends of the dowels;
FIGURE 6 is an enlarged detail, showing the dowel with a cap mounted thereon; and
FIGURE 7 is a perspective view of the finished denture made to conform to said model, with the caps bonded in place therein.
Although the device hereinafter shown and described is equally applicable to the maxilla and the mandible portions, or to a portion of either, wherein it is necessary to fit a plate or denture thereto, yet the drawings and description are directed to the mandible, for the reason that dentures therefor are usually more difficult to retain in the mouth, on account of the relatively smaller contact area 3,085,334 Patented Apr. 16, 1963 thereat between the jaw and denture, as compared with dentures for the maxilla.
Referring more particularly to the drawings, wherein we have illustrated a preferred embodiment of the invention, A indicates a lower jaw or mandible portion, in which there is at least one tooth structure remaining, and in this instance there are two such teeth 1-1, indicated in dotted lines in FIG. 1, and in full lines in FIGS. 2 and 3, said pair of teeth being spaced apart laterally along the gum 4, these teeth being intended as anchorages for permanent implacement of attachment dowels, as will be more clearly set forth.
The first step in the preparation of the mouth to receive our device, is to cut down said selected tooth or teeth to a flat or planar upper face 5 to slightly below the crest or free marginal edge of the gum as indicated at 6, say to approximately .010" to .040" below said crest (as indicated in FIG. 2), exposing the root canal 7 of the tooth structures.
Then, each said root canal is drilled out to provide the cylindrical bore =18 thereinto, from said face 5, and the diameter of said bore may be slightly in excess of the maximum diameter of the shank portion 8 of a pin or dowel that is provided with a radially enlarged head 9, preferably cylindrical as shown, said shank being preferably tapered to its reduced free or terminal end and provided with threads or other suitable lateral projections 10 along said tapered portion. It might be again mentioned that it is necessary to have the depth of the bore '18 at least equal to the length of the shank portion 8 of the dowel, as indicated most clearly in FIG. 3.
A shoulder, collar or flange 11 is provided intermediate the ends of the dowel, at the juncture of its shank, and head portions, said flange projecting radially outwardly thereat, the top and bottom faces of said flange being flat or planar as shown.
Although said dowel may be made of any metal that will not tarnish,-rust or otherwise corrode, we have found it highly desirable that it be made of stainless or surgical steel, as this material is not only sufficiently sturdy and durable, is not unduly expensive, but in addition meets all of the purposes required of it.
One of the dowels is inserted, shank-first, into one of said bored holes 8, until its flange seats on the flat top face 5 of the previously prepared tooth, there being suitice.
.able cemetitious substance 12 in said bore. JAlthough said cement enters into the grooves or spaces between the adjacent threads of the shank portion of the dowel, this cement also fills the space between said shank and the side or bounding wall of the bore hole, and in this way more firmly anchors the dowel in its fixed intended placement relatively of the tooth, upon setting of the cement.
Where a second tooth is employed as an anchorage, said tooth is manipulated in the same manner as described for the first tooth, and a dowel permanently set therein.
The next step is to make an impression 13, of the jaw structure having the dowels permanently placed therein, and this is done in any manner thought advisable by the operator, and it is obvious that said impression will have the cylindrical holes, openings or recesses 14-14 formed therein, of precisely the same size, contour and depth as that of the projecting portions of the dowels already implanted in the jaw.
Now, a model B of the jaw structure must be made, using the impression previously made, to form a pattern from which the denture itself is to be made, said model being made by the operators in any well-known manner that is found most convenient at the time, said resultant model being indicated in FIG. 5 and being a workable replica of the jaw structure to which the denture is to be applied, said model having a replica of the jaw gum structurelS', extending therealong, with a replica of the gum line or crest 16 thereon.
However, before making said model and before filling said 'impressionwith-the soft materialoutof which the model is to be formed, dowels ,thatare exact replicas of those imbeddedjinthe; jaw, are, inserted head-first into the holes.14-.-14 (one such dowel being shown as already inserted in one of said holes, in FIG. 4), so that the .dowel shanks project axially above said holes. when said impression .tray or holder is filled with the .hardenable material from which the model is made, and
compacted into place, and left to set for the required :period, and the impression then separated from the model, it will be found that .the dowels will remain anchored in said model, as indicated in FIG. 5, inasmuch as there is algreater tendency for said threaded shanks to bond to the model materialthan for the heads to cling to said impression. Thus, it will be seen that the size, shape and spacing of the dowels in the model will be precisely the 'same as that of the dowels inthe jaw structure itself.
Fin'ally, the operator is ready to make the denture C itself, preferably of a suitable plastic, anacrylic resin Before performing thisstep however, caps-19 are de- ,These caps are preferably made of a suitable plastic,
'and it has been found desirable that they be inexpandjible; for a reason soon to be more clearly set forth.
Each cap has its open end flat or planar to seat perfectly on the flange of the dowel with which it cooperates,
saidfiatend being indicated at 17, and there is a diametrally reduced neck 20 intermediate the ends of the cap.
The acrylic or'other plastic material that forms the denture is of course applied while soft, to engage and cover the desired portion of the model, so that after the denture material has set andthe denture then removed from said model, said caps will be found to have become permanently anchored in the denture, and spaced apart to correspond precisely to the spacingapart of the dowels firstimplanted into the jaw.
. One-of theimportant reasons formaking the cap of a plastic material isv such material has a betterv bonding quality to the plastic of the denture itself, than if the two elementswere of different materials,. andthere is practically no likelihood of any displacement of the caps from their anchorage in-the denture. Further, the plastic cap will have a minimum of friction withthe dowelhead,
.' thereby resulting in a minimum of wearbetween said .parts.
'being extremely suitable for'the purpose, from said model that already has said dowels anchored therein.
5O 7 first into said recess, making a model from said impression whereby the dowelheld in the impression becomes No matter how many times the denture is replaced,
there is assurance that it will have a perfect cooperating fit between'the caps and dowels, thus maintaining exact relative positioning in the mouth and with consequent 'goodstabilization of the denture, with no lateral rotation of the denture when mounted;- and no possibility of the implanted dowels and that might result in said denture becoming jumpy or have other defects of an ill-fit.
Inasmuch as the interfitting dowels and caps are cylindrical at their cooperating portions, with substantiallya minimum tolerance therebetween, there is less likelihood of food particles getting into said cooperating portions, than if there was a yieldably resilient interconnection between said elements, as in our devicethe cooperating elements must that each replacement. and there is no danger of distortion of either element due to accidental springing of the parts.
Weclaim: I l
1. A detachable artificial vdenture means comprising a .dowel permanently anchorableinthemouth and having ,an elongated shank with a headatone. end, said head .being of substantially same cross-sectional area throughout, the shank anchorable in atooth-root canal so that said headwill project outwardly beyondsaid canal, a
.denture, anda. cup-shaped: recessedv cap. permanently .anchored in said denture with .the depth .and diameter of said recess of the cap .being oftfixed size substantially 'tlange seatable on the top-face ofsaid: tooth.
3. Detachable artificial 'denture means comprising a;
pair of metal dowels to'be permanently anchored in laterally spaced-apart relation in the mouth,.-.ea'ch-dowel having anelongated shank with'a radially 'enlarged subj 'stantially cylindrical head at oneend, to be anchored in a tooth root canal and a denture for 'fittingthat portion of the mouth thathas said dowelstherein, and a pair of hollow cup-shaped caps permanently anchored in said denture and spaced apart to conform exactly to the spacing between said dowels and said'caps having'su-bstantially cylindrical recesses of such depth and diameter to snuglyreceive the dowel heads substantially without lateral movement therebetween, the exterior of said cap provided with a diametrally reduced neck'intermediate its ends to form an annular groove to receive the material of said denture therein and interlock therewith.
4. In the method of preparing a removable artificial denture, the steps of anchoring a'metal dowel in a tooth 'in the mouth so that the head of said dowel projects permanently above said tooth, then making an impression whereby said projecting portion of thedowel forms a recess in the impression, inserting a metal dowel exactly of the size and shape asthe first-mentioned dowel, headanchored in said model upon separation of the model from the impression, placing a plastic cap removably on the dowel that is in the model, makinga plastic denture to fit over said modelas so capped, whereby said cap remains anchored in the denture on setting of'the latter and removal from the model, and finally removing said denture from the model.
References Cited in the file of'this patent UNITEDSTATES PATENTS 581,335 Carr Apr. 27, 1897 711,324 Lacy Oct. 14, 1902 2,112,007 Adams Mar. 22, 1938