FR2658070A1 - Metal-plastic attachment for dental prostheses - Google Patents

Abstract

The invention relates to intra-coronal attachments for adjoining dental prostheses, whether partial or complete, of the type comprising: a) a male part (1) which is made of a calcinable material and is converted to a metal by simultaneous casting with the metal framework (3) of the contiguous part of the prosthesis; b) an interchangeable sheath (2) which is made of plastic and is intended to connect the said male part to the female part (4) of the attachment which is made by simultaneous casting with the metal framework (5) of the contiguous part of the prosthesis. According to the invention, a metal ring (6) is interposed between the plastic sheath (2) and the metal male part (1), this metal ring (6) being of conical shape and having axial slots (7) providing for its flexibility.

Description

METALLO-PLASTIC ATTACHMENT FOR DENTAL PROSTHESES
The invention relates to intra-coronary attachments for assistant dental prostheses, partial or total, of the kind comprising a) a male part, made of burnable material, generally of disc shape with rounded edges, which is transformed into metal by simultaneous casting with the metal reinforcement of the joint part of the prosthesis b) a sheath, of interchangeable plastic material, of generally cylindrical or cylindro-conical external shape, intended to ensure the connection and articulation between said metallic male part and the female part of the attachment which is produced by simultaneous casting with the metal frame of the adjoining part of the prosthesis, from the duplicate of said sheath serving as a model in its functional position on the metallic male part of the attachment.

 The known attachments of the genus in question are of the types described in patent applications FR-86.00973 and FR-86.15784 of the same applicants relating, for the first, to the technique of producing prostheses from attachments using a burn-out male part and an interchangeable plastic sheath, for the second, with an intra-coronary attachment for assistant prostheses.

 After many months of use in the mouth, it appeared a first phenomenon of wear of the plastic material of the sheath in contact with the metallic male part and a second phenomenon of loss of elasticity of this same material, to such an extent that the initial retention of the female part on the male part was no longer ensured, thus modifying the physiological functioning of the assembly and consequently necessitating the change of the sheath by intervention of the practitioner.

 It is to remedy these various drawbacks and increase the durability performance of the sheath (wear and elasticity) that the applicants have designed and produced a metal ring which comes to be interposed between the plastic sheath and the metallic male part of the sheath. 'attachment. Said ring, of conical shape, has axial slots opening on the side through which the male part is introduced and which corresponds to the small diameter of the cone. The metal-metal contact therefore eliminates the wear of the plastic sheath and the metal ring, thanks to its slots, eliminates the loss of elasticity of the sheath essentially by crushing the latter by compression. We therefore separated the aspect of flexibility linked to the ring from that of -linking the male part linked to the sheath.

 The characteristics and advantages of the invention will appear more clearly on reading the detailed description which follows, of a preferred embodiment of the invention given by way of example only and shown in the appended drawing.

 The attachment shown comprises: a) a male part (1), made of burnable material, generally of disc shape with rounded edges, which is transformed into metal by simultaneous casting with the metal frame (3) of the joint part of the prosthesis b) a sheath (2), of interchangeable plastic material, of generally cylindrical or cylindro-conical external shape, intended to ensure the connection and the articulation between said metallic male part and the female part (4) of the attachment which is made by simultaneous casting with the metal frame (5) of the adjoining part of the prosthesis, from the duplicate of said sheath serving as a model in its functional position on the metal male part of the attachment, c) interposed between the plastic sheath (2), of cylindrical or cylindro-conical inner shape, and the metallic male part (1) of the attachment, a metallic ring (6), of conical shape, comprising fen your axles (7) opening on the side through which the metallic male part is introduced, side corresponding to the small diameter of the cone.

Said metal ring comprises, on the side opposite to that on which the
The axial slots, ~ a peripheral flange (8) which is housed in a peripheral cavity (9), arranged in the bottom of the plastic sheath, capable of holding the metal ring.

 The sheath is made of biocompatible plastic. It can be obtained by injection, by screw cutting or by any other technique.

 The ring is made of biocompatible metal. It can be obtained by bar turning, stamping or any other technique.

 The sheath-ring assembly constitutes a new interchangeable element placed between the male part and the female part of the attachment.

 It was designed, dimensionally, to be able to replace the sheaths already sold as defined in the above-mentioned patent application.

 For example: - the average dimensions of the ring are of the order of 1.6 mm for the diameter and 1.6 mm for the length - the average dimensions of the sheath are of the order of 3, 4 mm for the outside diameter and 1.8 mm for the length.

 The operation of said attachment is as follows - the metallic male part is introduced into the metallic ring by deformation of the latter (flexibility due to the axial slots) to end up in the enlarged part of the cone in physiological position.

Thus, the ring, sheath and female part of the attachment assembly is maintained, via the male part, on the joint prosthesis. There can be relative displacement, with deformation of the ring, between the female part and the male part of the attachment, with or without permanent support of the base of the sheath on the base of the male part which is integral with the joint prosthesis.

 Of course, the invention is not limited to the embodiment described and shown for which we can provide other variants and extend it to other explanations, without thereby departing from the scope of the invention.

Claims (2)

 1- Intra-coronary attachment for dental prostheses, partial or total, of the kind comprising a) a male part (1), in burnable material, generally of disc shape with rounded edges, which is transformed into metal by simultaneous casting with metal frame (3) of the joint part of the prosthesis; b) a sheath (2), of interchangeable plastic material, of generally cylindrical or cylindro-conical external shape, intended to ensure the connection and the articulation between said metallic male part and the female part (4) of the attachment which is made by simultaneous casting with the metal frame (5) of the adjoining part of the prosthesis, characterized in that it comprises, interposed between the plastic sheath (2) and the metallic male part (1) of the attachment, a metal ring (6), of conical shape, comprising axial slots (7) opening on the side through which the metal male part is introduced, side corresponding to the small diameter of the cone.  2- Attachment according to claim 1, characterized in that the metal ring comprises, on the side opposite to that where the axial slots open, a peripheral flange (8) which is received in a peripheral cavity (9), arranged in the bottom plastic sheath, able to hold the metal ring.