WO2002069834A1

WO2002069834A1 - Method for making and fixing final or interim mobile dentures

Info

Publication number: WO2002069834A1
Application number: PCT/FR2002/000805
Authority: WO
Inventors: Marc Bachmann; Sonia Bachmann; Noémie Bachmann
Original assignee: Carbotech; Marc Bachmann; Sonia Bachmann
Priority date: 2001-03-07
Filing date: 2002-03-06
Publication date: 2002-09-12
Also published as: WO2002069834A8; FR2821739A1

Abstract

The invention concerns a device for fixing final or interim mobile dentures and a method for making same. The invention also concerns the resulting mobile or interim dentures. The inventive fixing device is characterised in that it consists of a ring made of shrinkable polymeric material comprising on its external surface at least a protuberance forming means for catching and retaining the fixing element into the mobile or interim denture obtained finally. The invention is applicable in dentistry.

Description

Manufacturing process and attachment for permanent or temporary mobile dental prostheses.

The invention relates to an attachment for mobile prostheses. It also relates to a process for manufacturing mobile prostheses, as well as the mobile prostheses obtained.

Mobile prostheses are removable prostheses which must be able to be put on and removed by the patient. They are intended to replace one or more teeth absent from the patient. They can be final or provisional. The practitioner is required to make provisional prostheses, most often made of synthetic resin to avoid the patient remaining toothless before placing his final prosthesis, and to establish an aesthetic guide which will be a model for the final prosthesis.

Also, the practitioner places temporary prostheses to be able to do the preparatory work for the final prosthesis and in particular gingival surgery when necessary.

Currently, these temporary prostheses are sealed with a cement, also temporary, which allows the dentist to deposit and reseal them easily. Gingival surgeries, especially around the abutment teeth, are frequently necessary. They end with sutures. It is then customary not to seal the provisional prosthesis in order to promote hygiene and avoid inflammations which are obstacles to wound healing. In this case, the prosthesis is just fitted onto the dental stumps, with gentle friction. The patient can take it off and put it back on, thus ensuring proper maintenance of dental hygiene.

However, this process has a major defect. Indeed, after a certain time of use, that is to say a certain number of withdrawals and rests of the provisional prosthesis, the friction of the resin, of which it is made, on the dental stumps, causes wear the underside of the resin prosthesis. The provisional prosthesis then loses its retention and becomes mobile during chewing and phonation.

As for the so-called definitive mobile prostheses, they are secured to a prosthesis fixed in the mouth by devices which are called attachments.

These attachments consisting of a male part and a female part which fit into each other are currently made of precious metal. However, the metal against metal friction of the male and female parts during their insertion and disinsertion, creates wear which ends up making their retention ineffective.

The invention aims to overcome the drawbacks of permanent or temporary mobile prostheses of the prior art.

To this end, the invention provides an attachment for permanent or temporary mobile dental prostheses for the replacement or restoration of one or more teeth, characterized in that it consists of a ring of heat-shrinkable polymeric material and intended for be heat shrunk, and in that it comprises on its external periphery at least one protuberance forming a means of attachment and retention of the attachment in the prosthesis.

Preferably, it further comprises on its internal periphery at least one protuberance forming a means of attachment and retention of the prosthesis on its support. According to a first embodiment of the attachment of the invention, each protrusion extends over the entire circumference of the ring.

The protrusions present on the outer periphery of the attachment of the invention and the protrusions present on the inner periphery of the attachment of the invention can be arranged alternately along the vertical wall of the ring.

Alternatively, they can be arranged opposite one another along the vertical wall of the ring.

The attachment according to the invention is preferably made of a heat-shrinkable polymeric material chosen from the group consisting of polyethylene, polypropylene, polyvinyl chloride (PNC), polytetrafluoroethylene (PTFE), a silicone, a fluoropolymer, a fluoride. modified polyvinylidene or an irradiated or modified polyolefin.

A heat-shrinkable material of choice is an irradiated polyolefin or the modified TUGA Type ^®. Preferably the attachment according to the invention is made of a heat-shrinkable polymeric material having a retraction ratio of between 6: 1 and 2: 1, before retraction.

Most preferably, the heat-shrinkable polymeric material preferably has a shrink ratio of about 2: 1, before shrinking. The invention also provides a method of manufacturing permanent or temporary mobile prostheses for the replacement or restoration of one or more teeth, characterized in that it comprises the following steps: a) manufacture of an impression of the point (s) of anchoring the prosthesis in the patient's mouth, b) placing an attachment according to the invention, not heat-shrunk, around this imprint, c) heating this attachment to retract it tightly onto this imprint , d) filling the hollow internal part of the prosthesis with a polymerizable, non-polymerized resin, e) placing the prosthesis filled with non-polymerized resin on the heat-shrink attachment on the impression, f) polymerization - hardening of the resin, g) removal of the prosthesis provided with the attachment.

The method of the invention may further comprise, after the step of heating the attachment to heat shrink it tightly, a step consisting in making at least one vertical incision on the heat-shrunk ring, this incision extending as far as possible '' at the mid-thickness of the heat-shrink attachment.

The invention also provides a permanent or temporary mobile prosthesis for the replacement of one or more teeth, characterized in that it comprises at least one prosthetic element having a hollow internal part provided with an attachment according to the invention. The invention finally provides a permanent or temporary mobile prosthesis for the replacement of one or more teeth, characterized in that it comprises at least one prosthetic element manufactured according to the method of the invention.

The invention will be better understood and other objects, details and characteristics thereof will be better understood on reading the detailed description which follows, made with reference to the figures in which:

FIG. 1 schematically represents a perspective view of a first type of attachment of the prior art, that is to say an attachment of the tenon-mortise type, FIG. 2 schematically represents a front view of a mobile prosthesis provided with the attachment of FIG. 1,

FIG. 3 schematically represents a partially cutaway front view of a mobile prosthesis provided with a second type of attachment according to the prior art, that is to say an attachment of the press button type,

FIG. 4 represents a sectional view of a mobile prosthesis provided with a third type of attachment according to the prior art,

- Figure 5 shows a sectional view of a mobile prosthesis provided with a fourth type of attachment according to the prior art, that is to say an attachment for endosseous implant;

FIG. 6 schematically represents a sectional view of a first embodiment of the attachment according to the invention, heat-shrunk on the imprint of the tooth that it is intended to cover,

FIG. 7 represents a perspective view of the first embodiment of the attachment according to the invention shown in FIG. 6,

FIG. 8 represents a sectional view of the first step of the process for manufacturing mobile prostheses according to the invention, carried out with a second embodiment of the attachment according to the invention,

FIG. 9 schematically represents a sectional view of a first variant of the second step of the method for manufacturing a mobile prosthesis according to the invention, produced with an attachment according to the second embodiment of the invention,

FIG. 10 schematically represents a sectional view of a second variant of the second step of the method for manufacturing mobile prostheses of the invention, produced with an attachment according to the second embodiment of the invention,

- Figure 11 schematically shows a sectional view of the first variant of the second step of the invention, produced with a third embodiment of the attachment of the invention, - Figure 12 shows a second variant of the second step of the process for manufacturing a mobile prosthesis of the invention, carried out with the third mode of attachment of the invention, and

- Figure 13 schematically shows a sectional view of a mobile prosthesis according to a first variant of the invention. First of all, the attachments for mobile prosthesis according to the prior art will be described with reference to FIGS. 1 to 5.

A first type of attachment of the prior art is shown in Figure 1.

It is a tenon type attachment, noted 1 in FIG. 1, and a mortise type, noted 2 in FIG. 1.

As shown in FIG. 2, with this type of attachment, the male part constituted by the post 1 is fixed to the crown, denoted 3 in FIG. 2, covering the stump with a tooth still present in the mouth of the patient. This crown 3 represents the fixed prosthesis which secures the mobile prosthesis. Indeed, it is fixed "in the mouth" by being fixed on the tooth by the root noted 8 in FIG. 2. In FIG. 2, the patient's gum is noted 5.

The female or mortise part noted 2 in Figures 1 and 2 of this attachment is itself attached to the artificial tooth, noted 4 in Figure 2, which is itself secured to one or more other artificial teeth having no attachment, noted 5 in FIG. 2. These artificial teeth rest on a support, denoted 6 in FIG. 2, adapting to the toothless gum 7 of the patient.

As seen in Figure 2, this type of attachment is positioned laterally on the artificial tooth 4 and on the crown 3 fixed in the mouth and the movable part of the prosthesis can be inserted and removed from the mouth by inserting and removing the mortise 2 on the post 1.

When inserting the mobile prosthesis which, in the case where several teeth are to be replaced, comprises at least two crowns 3 and two artificial teeth 4, the mortises 2 are inserted with gentle friction in the tenons 1 and hold the mobile prosthesis in place. But, first of all, this type of attachment is made of a precious alloy, and the metal-to-metal friction creates wear which ultimately makes their retention ineffective.

However, the major defect of this attachment is their position on the side of the tooth or more exactly of the dental stump coated with the crown 3, as can be seen in FIG. 2. This position transmits the forces to the dental stump and to the root 8 exercised in particular during chewing with a mechanically offset lever arm, which is harmful for the dental stump and the root 8. To overcome this drawback, an attachment of the pressure button type has already been proposed. This attachment acts like the snaps used for clothing. This time it is in the axis of the tooth.

This attachment consists, as shown in Figure 3, of a female part 12 fixed inside the artificial tooth 10 which is itself, as in the case of the mobile prosthesis shown in Figure 2, fixed to teeth artificial 9, 5 resting on a support 6 fitting onto the toothless gum 7 of the patient.

The mobile prosthesis shown in FIG. 3 is secured in the patient's mouth by fitting onto the male part, denoted 11 in FIG. 3, of the female part, denoted 12 in FIG. 3, placed in the artificial tooth 10. The male part 11 is secured to the root 13 of a patient's tooth, as shown in FIG. 3.

However, this type of attachment also has drawbacks: to be effective it must cross a very hard point of friction to be engaged and disengaged. It tends to act in the direction of the extraction of the dental root 13 which it ends up mobilizing.

In addition, the retention is only active when the interlock point is crossed. Beyond there is a slight clearance at height. In this place there is no retention, this creates a space between the prosthesis and the mucosa, which is a source of discomfort, irritation, or even inflammation of the gingival mucosa.

Another type of attachment according to the prior art is shown in FIG. 4. It is an attachment for a telescope prosthesis.

To make this attachment for telescope prosthesis, two metal caps are made, denoted 16 and 17 in FIG. 4. The cap 16 is made to be sealed on a dental stump, denoted 15 in FIG. 4, still present in the patient's mouth and is secured in the patient's mouth through the dental root, noted 13 'in Figure 4.

The crown, denoted 14 in FIG. 4, of the tooth to be replaced and which must cover the dental stump 15 provided with its metal cover 16 is provided, in its hollow internal part, with a metal cover 17, which fits perfectly on the metal yoke 16. The mobile prosthesis provided with this type of attachment is therefore fixed by being secured to the dental stump 15 by fitting onto the metal yoke 16.

With this type of attachment, the insertion of the prosthesis fits the yokes 16 and 17 between them, their friction keeps the prosthesis in place. With this type of attachment, the teeth receive the loads and work along their long axis, which is mechanically favorable. However, this type of attachment has several drawbacks. First of all, the metal constituting the caps 16 and 17 wears out and therefore the prosthesis loses its retention capacity. The metallic yokes 16 and 17 transmit the charges fully to the dental stump 15 and to the root 13 'without attenuating them. In addition, these yokes 16 and 17 can only be metallic because they must be made to measure according to the shape of the dental stump 15.

There is a particular type of telescope prosthesis using another type of attachment. These are telescope prostheses produced when the patient is completely toothless, or when there are not enough dental stumps left in his mouth that can be used as anchoring points for the prosthesis. In this case, what is called an endosseous implant is produced. This endosseous implant is, as shown in FIG. 5, where it is noted 19, a metal part which is fixed in the bone, noted 18 in FIG. 5, of the jaw of the patient. It replaces the missing tooth. The center of the implant 19 is drilled and tapped and receives a superstructure, denoted 20 in FIG. 5, which is equivalent to the yoke 16 represented in FIG. 4. The superstructure 20 receives in its center a screw, denoted 21 in FIG. 5, which allows the superstructure 20 to be secured to the part of the endosseous implant placed in the jaw bone.

Prostheses on endosseous implant can be either fixed or mobile, either transient or final. They represent a particular type of telescope prosthesis.

These attachments for this particular type of telescope prosthesis have the same advantages and disadvantages as the attachment for the telescope prosthesis described above.

In contrast to these attachments of the prior art, the attachments of the invention not only allow the loads, exerted in particular during chewing, to be exerted in the axis of the tooth, which is mechanically favorable but also they act as shock absorbers for these loads, thus relieving the patient's teeth or jaw. In addition, the clamping force of the mobile prosthesis on its support constituted either by the endosseous implant shown in FIG. 5, or by the dental stumps represented in FIGS. 3 and 4, can be chosen and adjusted. Also, with the attachments of the invention, the tightening is constant over the entire attachment, which minimizes its wear, and therefore increases its longevity.

Furthermore, they can be replaced easily, in the event of wear, without requiring the manufacture of a new complete prosthesis. In addition, the attachments according to the invention can be made to measure, whatever the shape of the support, that is to say the remaining dental stump or the endosseous implant. They allow the stresses to be absorbed and protect the remaining tooth on which the fixed prosthesis rests. They allow great ease of implementation and replacement.

In fact, the invention proposes an attachment consisting of a ring made of a heat-shrinkable material, intended to be heat-shrunk on the endosseous implant or on the dental stump. The attachment of the invention during its retraction exactly matches the shape of this dental stump or this endosseous implant.

The attachment according to the invention is secured to the mobile prosthesis and must not be separated from it. To do this, the attachment consisting of the ring of a heat-shrinkable polymeric material according to the invention comprises, on its external periphery at least one protuberance 24. A first type of attachment according to the invention is, as shown in FIG. 8 where it is denoted 27, a ring made of a heat-shrinkable polymeric material, the external surface of which has several protuberances denoted 28.

These protrusions 28 can be localized and punctual. However, preferably, each protuberance 28 extends over the entire circumference of the ring 27.

However, in a second embodiment of the attachment of the invention, it also further comprises, on its internal periphery, protuberances forming means for attaching and retaining the prosthesis on its support.

By support is meant in the above and in the following, either the dental stump prepared by grinding and covering a metal cap, or the superstructure of an endosseous implant, as previously described.

Thus, in a first variant of the second embodiment of the attachment of the invention, as shown in Figures 6 and 7, is constituted of a ring denoted 26 in a heat-shrinkable polymeric material having corrugated walls. These corrugated walls therefore comprise these protrusions, denoted 24 in FIGS. 6 and 7, projecting outwards and protuberances, denoted 25 in FIGS. 6 and 7, protruding inwards, of the ring 26. It can be seen that in this variant of the attachment of the invention, the protrusions 24 and the protrusions 25 are arranged alternately along the vertical wall of the attachment 26.

However, in a second variant of the second embodiment of the invention, and as shown in FIGS. 11 and 12, the attachment of the invention consists of a ring, denoted 31 in FIG. 11 and 36 in FIG. 12, in a heat-shrinkable polymeric material, having on its outer wall protrusions, noted 33 and 34; which are arranged opposite the protrusions, denoted 32 and 35, present on its internal wall.

In the two variants of the second embodiment of the attachment of the invention, the protrusions 32, 35 have the function of promoting retention on the prepared dental stump of the patient's tooth or, where appropriate, on the implant. endosseous placed in the patient's mouth.

The rings forming the attachments of the invention are manufactured by any means known to those skilled in the art, such as injection molding or extrusion of the chosen heat-shrinkable polymeric material.

Those skilled in the art will readily understand that any heat-shrinkable polymeric material can be used to form the attachments according to the invention.

However, a heat shrinkable polymeric material suitable for the attachments of the invention is polyethylene, polypropylene, polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), silicone, a fluoropolymer, a modified polyvinylidene fluoride or an irradiated polyolefin. or modified.

A suitable modified polyvinylidene fluoride is the modified polyvinylidene fluoride sold under the trademark Kynar ^® marketed by RAYCHEM company.

However, the attachments of the invention are most preferably formed in an irradiated or modified polyolefin of the type sold under the trade mark ^® TUGA by RAYCHEM company. Depending on the shape of the dental stump or the endosseous implant to be covered by the mobile prosthesis, the ring constituting the attachment of the invention may have a cylindrical shape or a frustoconical shape.

The attachment of the invention in a heat-shrinkable polymeric material is intended to be heat-shrink to exactly match the shape of the dental stump or the endosseous implant on which the mobile prosthesis is to be fixed in the mouth.

We will choose an attachment in a heat-shrinkable polymeric material based on the one hand on the clamping force, after retraction, that we want it to exert on the dental stump or the endosseous implant and, on the other hand depending on the shape of the dental stump or the endosseous implant to be covered.

Thus, we will choose an attachment in a heat-shrinkable material having a retraction ratio of 6: 1, that is to say whose thickness will be multiplied by 6, after retraction from its initial thickness, when we want obtain a large clamping force. Such an attachment will also be chosen when the stump to be covered has uneven shapes or when there is a very large difference between its diameter external to the collar and its diameter external to the occlusal phase, that is to say when the stump is very conical.

We can also use, to obtain a lower clamping force, an attachment in a heat-shrinkable material having a ratio of 4: 1 or 3: 1.

However, it is preferred, in the usual cases, to use an attachment made of a heat-shrinkable material having a shrink ratio of 2: 1. This means that after complete retraction, the thickness of the attachment according to the invention will be doubled compared to its initial thickness.

Its thickness, before heat shrinking, will be chosen according to the desired thickness after shrinking. The thickness after retraction of the attachment according to the invention will depend on the one hand, on the shrinkage ratio of the heat-shrinkable polymeric material of which it is made and on the other hand, on the difference between its largest internal diameter and the diameter the largest external endosseous implant or dental stump on which the prosthesis is to be fixed.

To better understand the object of the invention, we will now describe, by way of purely illustrative and nonlimiting examples, several modes of implementation. EXAMPLE 1 Manufacture of a mobile prosthesis on a dental stump

The manufacturing method according to a first embodiment, will now be described with reference to Figures 8, 9 and 13. The mobile prosthesis itself is manufactured by known methods.

To be fixed in the mouth, it comprises at least two hollow artificial teeth intended to fit onto at least two dental stumps on the patient's mouth.

The dental stumps are prepared in a conventional manner by stripping the part of the tooth which is to receive the part of the mobile prosthesis in the form of a truncated cone and grinding of the upper face called the occlusal face of the tooth. The dental stumps thus prepared are then covered with a metal screed.

Optionally, an exact replica, noted 23 in the figures, of the dental stumps coated with their metal cap is then made, generally of dental plaster. It rests on a support plate, noted 22 in the figures.

The process of the invention then consists, as shown in FIG. 8, in a first step, of placing around the metal cap which will be placed in the mouth or on the replica 23, a ring marked 27, made of a heat-shrinkable polymeric material and not retracted, which forms the attachment according to the invention.

As part of this example, the attachment is a modified polyolefin of the kind TUGA ^® marketed by RAYCHEM company.

This attachment has a slightly frustoconical shape to adjust and give substantially the same thickness, after retraction, to the attachment, over the entire surface covered with the replica 23, and therefore with the dental stump covered with its metallic yoke.

Generally, a frustoconical ring will be chosen when the dental stump has a very accentuated cone shape, which is generally the case for canines.

The cone angle of the attachment and therefore of the ring 27 is preferably between 4 and 6 °, before retraction.

As seen in Figure 8, the ring constituting the attachment 27 of the invention has a height greater than the height of the replica 23 and its diameter the largest internal diameter is greater than the largest external diameter of the replica 23.

The difference in height between the attachment 27, before retraction and the height of the replica 23 is proportional to the width of the occlusal table of the replica 23 to be covered by the attachment 27 according to the invention.

Of course, this difference in height also depends on the shrinkage ratio of the heat-shrinkable material constituting the attachment 27 according to the invention, the aim here being to completely cover the occlusal table with the replica 23 and therefore the dental stump covered with its metallic yoke . In fact, the second step of the method consists in heating the attachment 27, with a heating appliance without direct flame, such as a heating appliance blowing hot air or with infrared or with radiant electric heating.

While heating the attachment 27, the technician rotates the replica 23 and folds the attachment 27 onto the occlusal table of the replica 23 by tapping it lightly.

The attachment 27 shown in Figure 8, has four point protrusions 28 on its outer face.

When the attachment 27 is heated and closed on the occlusal table of the replica 23, the attachment 27 retracts and tightly encloses the replica 23. In this case, as shown in FIG. 9, the thermoretracted attachment noted 27 is obtained. 'tightly enclosing the replica 23 and completely covering the occlusal table of this replica 23.

This operation is repeated on the replica of the second dental stump on which the mobile prosthesis is also to be fixed. The third step of the process then consists in filling the hollow artificial teeth, intended to fit onto the dental stumps, with a polymerizable resin, preferably a self-polymerizing resin, not polymerized.

The fourth step of the process then consists in placing the hollow artificial tooth filled with unpolymerized resin on the replica 23 provided with its heat-shrink attachment 27 ′.

The fifth step in the process is to polymerize the resin. During this polymerization, the resin hardens and creates an intimate bond between the artificial tooth and the attachment 27 '. This attachment of the attachment of the invention thermoretracte 27 'with the artificial tooth is due to the presence of the protrusions, noted 28' in figure 9, on the attachment of the invention.

The last step of the method of the invention then consists in removing the prosthesis from the replica 23. Finally, a mobile prosthesis is obtained, comprising at least two artificial teeth such as that shown in FIG. 13 where it is noted 34, in the hollow part internal of which is attached and retained the heat-shrinkable attachment 38 according to the invention.

The mobile prosthesis can then be placed in the patient's mouth and can be easily inserted and removed, without mobilizing the dental stumps on which it is placed because of the inherent elasticity of the material making up the attachment according to the invention.

In addition, still due to the inherent elasticity of the material constituting the attachment according to the invention, the stresses exerted on the remaining teeth are absorbed. Furthermore, as the tightening is constant throughout the attachment according to the invention, its wear is minimized.

In addition, thanks to the attachment of the invention, the mobile prostheses work in the axis of the tooth, which is mechanically favorable.

EXAMPLE 2 Manufacture of a final movable prosthesis according to a second variant of use of the attachment of the invention

The second variant of implementation of the attachment and of the method of the invention will now be described with reference to FIGS. 8 and 10.

The dental stumps, the mobile prosthesis and the replica of the dental stump are prepared as in Example 1.

To implement the method of the invention, an attachment is chosen here on which each protuberance, present on its external surface, extends over the entire circumference of the attachment.

Also, it will be chosen from a lower height. Indeed, we do not want to cover the occlusal table with the dental stump.

The first step of the process of the invention consists in placing this attachment around the replica of the dental stump. As already said, the attachment, noted 29 in FIG. 10, where it is already shown heat-shrunk has a height, before retraction, only slightly greater than the height of the dental stump. Indeed, according to this second mode of implementation of the method of the invention, there is no attempt here to obtain a heat-shrink attachment 29 covering the occlusal table of the replica 23 of the dental stump.

Also the attachment according to the invention used here has a cylindrical shape, before heat shrinking. Indeed, the dental stump to be covered has a low taper, as is often the case when it comes to the dental stump of large teeth, such as molars.

The attachment according to the invention, before heat shrinking, has an internal diameter greater than the largest external diameter of the dental stump 12.

As in the case of Example 1, the second step of the process of the invention then consists in heating the attachment according to the invention by rotating the replica 23 on its support plate 22. We then obtain, as shown in FIG. 10 , the attachment 29 thermoretracte on the replica 23 and enclosing this replica only on its frustoconical part.

The other steps of the process of the invention are the same as those described in Example 1, that is to say that the hollow internal part of the artificial tooth of the mobile prosthesis is filled with a non-polymerizable resin. polymerized, the replica 23 provided with its heat-shrunk attachment 30 is capped with this artificial tooth filled with unpolymerized resin and the polymerization - hardening of the resin is carried out.

Finally, the mobile prosthesis comprising in the hollow artificial teeth the attachment according to the invention is removed from the replica 23.

The final prosthesis according to the invention is obtained.

EXAMPLE 3 Manufacture of a final mobile prosthesis according to a third embodiment of the invention.

This embodiment of the attachment and of the method of the invention will be described with reference to FIGS. 6 and 7.

The dental stump, the mobile prosthesis and the replica of the prepared dental stump are produced as in Example 1. The difference here is that the attachment shown in FIG. 7 is used as attachment 26.

This attachment 26 is in an irradiated polyolefin or the modified TUGA Type ^®. It is a cylindrical attachment whose walls are wavy, as shown in Figure 7.

This attachment 26 therefore includes protrusions 24 on its outer wall and also, due to the undulation of these walls, protrusions 25 protruding on its outer wall, corresponding to the hollow parts 25 shown in Figure 7. This means that the attachment according to the invention comprises, on its outer wall protrusions 24 projecting outwards, which will serve, as in the case of Example 1 and of Example 2 above, of attachment means and retention of the attachment in the hollow artificial teeth of the final movable prosthesis and, alternately, along the vertical wall of the attachment 26, protuberances 25 projecting from its internal wall. These protuberances 25, better visible in FIG. 6, will serve as means of retention and attachment of the mobile prosthesis to the dental stump on which the mobile prosthesis is intended to fit.

For the other shape characteristics and for the other process steps, the procedure is as in Example 2.

Finally, as shown in FIG. 6, a mobile prosthesis is obtained, at least two artificial teeth of which comprise a hollow part comprising the thermoretracted attachment 24 and retained and hung in its hollow internal part. Once in place in the mouth, the mobile prosthesis according to this embodiment encloses tightly and elastically, due to the protuberances 25 of the attachment 26 thermoretracts the prepared dental stump having its metallic cap as it encloses the replica 23 of this dental stump, as shown in figure 6.

EXAMPLE 4 Manufacture of a temporary mobile prosthesis

These temporary prostheses are also a type of mobile prostheses because, as explained previously, these temporary prostheses must be able to be inserted and removed from the tooth to be restored, by the patient, to maintain correct hygiene, especially after gum surgery, while waiting for the final prosthesis.

The tooth stump, the temporary prosthesis and the replica of the dental stump were prepared as in Examples 1 to 3. However, as shown in Figure 11, attachment denoted 31, is constituted of a cylindrical ring TUGA ^®, comprising on its outer surface of the protrusions 33, each of these protrusions extending over the entire circumference of the attachment 31 and also, on its inner surface, of the protrusions denoted 32, each of these protrusions extending over the entire circumference of the internal surface of the attachment 31. Here each protuberance 32 is arranged opposite a protuberance 33.

The procedure is as in Example 1, that is to say that the entire width of the occlusal table of the dental replica 23 is covered.

A temporary prosthesis is then obtained comprising in its hollow part an attachment 31 retained and hooked in the hollow internal part of the temporary prosthesis by the protuberances 33 and which will easily and flexibly fit onto the dental stump prepared thanks to the protuberances 32.

However, as shown in FIG. 12, the attachment according to the invention, once heat-shrunk, may not cover the entire width of the occlusal table of the replica 20 and therefore of the prepared dental stump on which the provisional prosthesis is to be placed.

There is then obtained, as shown in FIG. 12, an attachment according to the invention denoted 36, enclosing the replica 23 but not covering its occlusal table. Of course, the attachments 31 and 32 described here can be used for the production of mobile prostheses, too.

Although in all of the foregoing examples, reference has been made to a dental stump, the same methods can be used to fabricate temporary mobile prostheses intended to cover endosseous implants. The method and the attachments of the invention will be identical to those described above.

An additional advantage of the attachment of the invention is that its clamping force can be changed and adjusted as desired. Indeed, the clamping force of the attachments of the invention depends first of all on the ratio of retraction of the material used but also of the difference between the largest internal diameter of the attachment and the largest external diameter of the support on which it is retracted.

In fact, an attachment made of a material whose retraction ratio is 2: 1, that is to say which is tightened by half its diameter, will exert a less clamping force than an attachment made of a material whose the retraction ratio is 3 to 1 or 4 to 1, of course retracted on a support of identical diameter.

Also, the clamping force, after retraction, will be greater the greater the diameter of the support than the larger internal diameter of the attachment when it is fully retracted.

Indeed, the attachment is all the more useful since it cannot reach its minimum diameter.

So, by choosing the material and the difference in diameter between the internal diameter of the attachment and the external diameter of the support on which it is to be placed, the technician will be able to adjust the desired clamping force.

However, if, after having retracted the attachment according to the invention, the technician realizes that the clamping force is still too great for the desired application, he may still adjust this clamping force by practicing at least one vertical incision on the external surface of the heat-shrink attachment, this vertical incision must not exceed half the thickness of the heat-shrink attachment.

The effect of such an incision is to allow relaxation of the clamping stresses and therefore to reduce the clamping force.

Preferably, several symmetrical incisions will be made to balance the relaxation of the constraints on the retracted attachment. Depending on their number, a tightening amplitude ranging from more or less gentle friction to a non-existent tightening while retaining an adaptation of the retracted attachment to the shape of the support on which it is applied can be obtained.

This property is particularly useful in the manufacture of temporary prostheses.

Thus, the process for manufacturing permanent or temporary mobile prostheses according to the invention may also include, if necessary, a step consisting in making such incisions on the heat-shrink attachment in place on its replica to obtain the desired clamping force. . In addition, the attachment according to the invention can be easily replaced in the event of wear, which was not the case for the attachments of the prior art.

In fact, when the attachment according to the invention loses its retention, it suffices to remove it by scraping off the polymerized resin and to replace only the attachment, by the methods described above, these operations being more difficult. and longer in the prior art.

Indeed, the attachment being in a flexible and non-abrasive material, the dental stump or the endosseous implant as well as the artificial teeth are not damaged. Only attachment wears out. The internal diameter of the attachments according to the invention before retraction can be chosen at will. Generally, this internal diameter is between 6 to 18 mm. In addition, the thickness of the attachment according to the invention before retraction is generally between 250 to 400 μm. The attachment according to the invention can be made of a transparent or colored material. The mobile prosthesis according to the invention can be used for replacing or restoring one or more teeth. This means in particular that it can consist simply of a single artificial tooth comprising the attachment of the invention.

Of course, the invention is in no way limited to the embodiments described which have been given only by way of examples.

Indeed, it is possible, to obtain the desired thickness of the final attachment, to use several attachments according to the invention superimposed. These will be intimately linked during the heating carried out to heat shrink them.

On the contrary, the invention includes all the technical equivalents of the means described and their combinations if these are carried out according to the spirit.

Claims

1. Attachment for mobile dental prosthesis, characterized in that it consists of a ring (26, 27, 27 ', 29, 31, 36, 38) of a heat-shrinkable polymeric material intended to be heat-shrink, and in that that it comprises on its external periphery at least one protuberance (24, 28, 28 ', 30, 33', 34) forming a means of attachment and retention of the attachment in the prosthesis.

2. Attachment according to claim 1, characterized in that it further comprises on its internal periphery at least one protuberance (25, 32, 35) forming a means of attachment and retention of the prosthesis on its support.

3. Attachment according to claim 1 or 2, characterized in that each protuberance (24, 28, 28 ', 30, 33', 34, 25, 32, 35) extends over the entire circumference of the ring ( 26, 27, 27 ', 29, 31, 36, 38).

4. Attachment according to any one of the preceding claims, characterized in that the protrusions (24, 28, 28 ', 30, 33', 34) and the protrusions (25, 32, 35) are arranged alternately along the vertical wall of the ring (26).

5. Attachment according to any one of claims 1 to 3, characterized in that the protrusions (24, 28, 28 ', 30, 33', 34) and the protrusions (25, 32, 35) are arranged vis-à-vis opposite each other along the vertical wall of the ring (31, 36).

6. Attachment according to any one of the preceding claims, characterized in that said heat-shrinkable polymeric material is polyethylene, polypropylene, polyvinyl chloride (PNC), polytetrafluoroethylene (PTFE), silicone, a fluoropolymer, a fluoride. modified polyvinylidene or an irradiated or modified polyolefin.

7. Attachment according to any one of the preceding claims, characterized in that said heat-shrinkable material is an irradiated or modified polyolefin of the TUGA ^® type.

8. Attachment according to any one of the preceding claims, characterized in that said heat-shrinkable polymeric material has a shrink ratio of between 6: 1 and 2: 1, before shrinking.

9. Attachment according to any one of the preceding claims, characterized in that said heat-shrinkable polymeric material has a shrink ratio of approximately 2: 1, before shrinking.

10. A method of manufacturing permanent or temporary mobile prostheses for the replacement or restoration of one or more teeth, characterized in that it comprises the following stages: a) manufacture of an exact replica (23) of the points of anchoring (15, 16, 19) of the prosthesis in the patient's mouth, b) placing at least one attachment according to any one of claims 1 to 9, not heat-shrunk, around the replica (23), c) heating of this attachment to shrink it tightly on this replica (23), d) filling of the hollow internal part of the prosthesis with a non-polymerized polymerizable resin, e) placing of the prosthesis filled with non-polymerized resin on the heat-shrink attachment on the replica (23), f) polymerization - hardening of the resin, g) disinsertion of the prosthesis provided with the attachment.

11. The method of claim 10, characterized in that it further comprises, after step c) of heating the attachment for the heat shrink in tightness, a step of making at least one vertical incision on the heat shrunk ring , this incision extending to a maximum of half the thickness of the heat-shrink attachment.

12. Final or temporary mobile prosthesis for the replacement or restoration of one or more teeth, characterized in that it comprises at least one prosthetic element having a hollow internal part provided with at least one attachment according to any one of claims 1 to 9.

13. Final or temporary mobile prosthesis for the replacement or restoration of one or more teeth, characterized in that it comprises at least one prosthetic element manufactured according to the method according to claim 10 or claim 11.