Assembly for attaching a dental prosthesis to teeth

• US 4,324,549 A
• Filed: 09/26/1980
• Issued: 04/13/1982
• Est. Priority Date: 11/13/1978
• Status: Expired due to Term

• Current Assignee: George W. Madray
• Original Assignee: George W. Madray
• Inventors: Madray, George W.
• Primary Examiner(s): Peshock, Robert
• Application Number:
  US06/191,019
• Time in Patent Office: 564 Days
• Field of Search: 433/177, 433/172, 433/193, 433/169, 433/170
• US Class Current: 433/169
• CPC Class Codes: A61C 13/2656 Snap attachments

Abstract

The invention has two main parts. First, there is an assembly of elements including a prefabricated precision stud, or male element, preferably made of metal, as stainless steel for example, securely anchored by a specially designed cap fitting onto a prepared matching outer end of a tooth, and a second assembly of elements including a prefabricated thimble, or female part, preferably made of plastic material. The thimble element is provided, at its outer upper region, with burrs, or projections, so that the thimble element may be rigidly held in the denture material, but the skirt or lower region of the thimble element does not contact the denture material and may thus flex, or stretch, circumferentially, and thus expand radially, to receive the stud element with a snap action, so that the two main parts are snap retained to each other.

The thimble element should be made available in a tissue-resilient type, and somewhat more non-resilient type, to match the need, for example, in the tissue-resilient type it would be used when the denture is supported more by the gum than by the teeth, whereas in the non-resilient type it would be used when the denture is supported more by the teeth than by the gum.

The anchor provided by this invention creates a favorable crown-root ratio where there is minimal inter-occlusal space, approximately 3 mm. for both forms.

With this invention all fitting fabrication is performed chairside, all parts are relatively inexpensive, and are easy to service.

Claims

1. In combination, an assembly of elements for removably securing a denture in the mouth of a person who needs to wear a denture, comprising a tooth cap having a selected bottom contour so that the cap may be securely cemented to a prepared surface on the outer end of an anchor tooth, the prepared surface on the anchor tooth being made to accurately match the selected contour on the cap, said cap including, a stud element, having a head portion and a narrow neck portion, projecting from the tooth cap in a direction away from the anchor tooth, an elastic member having a ring portion with an internal diameter less than the head portion of the stud element but slightly greater than the neck portion of the stud element, so that the elastic member may be forced over the head portion to the neck portion and thus be held in place, the denture material above the head of the stud element being hollowed out sufficiently so that the pressure load on the dentures during use is not transferred to the head of the stud element, means for securing the outer region of the elastic member to the denture, the tooth cap also including, at its lower outer peripheral region, a ring portion in the shape of a frustum of a cone having an upper load receiving surface during use engaging the bottom of the ring portion of the elastic member to thus during use take some of the denture load on the gums onto the shoulder region of the anchor tooth, the ring portion of the cap also having a lower surface in the shape of the frustum of a cone to thus, when cemented to the matching surface on the anchor tooth, firmly circumferentially grips the anchor tooth to strengthen the anchor tooth against splitting.

2. The device of claim 1, wherein the anchor tooth at the prepared surface is provided with a projection surrounding the pulp canal of the tooth and the stud element is hollowed out centrally to receive, with a fit, the peripheral region of the projection in the prepared surface, but where the hollowed out depth is greater than the height of the projection in the prepared surface so as not to interfere with any medicated closure material of the pulp canal, and wherein a plurality of pins are rigidly secured to the region of the lower surface in the cap having the shape of a frustum of a cone, said pins being directed in the same general direction as the pulp canal and fit in matching holes in the shoulder region of the anchor tooth.

3. In combination, an assembly of elements for removably securing a denture in the mouth of a person who needs to wear a denture, comprising a rigid tooth cap having a selected contour at the bottom surface, namely, the surface that faces the anchor tooth selected for anchorage of the denture, said anchor tooth being provided, at the surface facing the cap, with a contour matching the said selected contour on the cap, so that the anchor tooth and cap may be securely cemented to each other, said cap having a stud element projecting away from the anchor tooth and at its outer peripheral region being shaped substantially like the surface of a truncated cone sloping over the shoulder region of the anchor tooth toward the periphery of the anchor tooth, the matching contour on the anchor tooth is provided with a projection surrounding the outer end of the pulp canal, and the stud element is hollowed out centrally to receive, with a snug fit, the peripheral region of the projection on the anchor tooth, but the hollowed out depth in the stud element is greater than the height of the projection on the anchor tooth so that the central region of the anchor tooth does not, during use of the denture, ever engage the end of the hollowed out region in the stud element, an elastic member, in the shape of an annulus, at its outer periphery firmly secured in the denture material and at the inner region engaging the rigid tooth cap at the outer surface of the projecting stud element and also engaging the top surface on the rigid tooth cap having the shape of a truncated cone, so that, during use of the denture, any pressure load relieved from the gums, is transmitted to the shoulder region of the anchor tooth.

4. The device of claim 3, wherein the rigid tooth cap is provided with a pin at the surface facing the anchor tooth in the region shaped like the surface of truncated cone, that fits into a matching hole in the anchor tooth.