EP3914186A1

EP3914186A1 - Retention device comprising a retention apparatus and positioning keys, and method for producing such a retention device

Info

Publication number: EP3914186A1
Application number: EP20705237.4A
Authority: EP
Inventors: Dominique SIREIX; Christophe SIREIX
Original assignee: Biotech Dental SAS
Current assignee: Biotech Dental SAS
Priority date: 2019-01-23
Filing date: 2020-01-22
Publication date: 2021-12-01
Also published as: US20220087779A1; WO2020152421A1; FR3091817A1; FR3091817B1

Abstract

The present invention concerns a retention device (20) comprising at least one retention apparatus (21), designed to be bonded on a portion of a dental arch (10), and at least two clips (22), positioned apart from one another; each clip (22) being a rigid hook and rigidly attached to the retention apparatus (21), and configured to fasten to the dental arch (10). The invention also concerns a method for producing such a retention device (20).

Description

Restraint device comprising a restraint device and positioning riders, and method of making such a restraint device

The present invention relates to a restraint device comprising a restraint device, as well as to a method of making such a restraint device.

In the field of orthodontics, an active treatment plan, that is to say to correct a bad posture of the teeth, for a functional or aesthetic purpose, is established using various means, for example such as than :

• fixed appliances, which are stuck to the teeth by rings (metal, ceramic or elastomer) and which are connected to each other by a cable, or metal rod for example; or

• removable devices, often transparent, in the form of gutters, made of plastic.

Once the active orthodontic appliance has been removed, it is necessary to maintain the results acquired by a retainer, otherwise the initial anomaly will recur or a new pathology will appear.

This restraint device can also be fixed or removable.

If it is removable, it will be worn according to a prescription, permanently (i.e. 24 hours a day), or part of the time (for example 3 pm / 24 or at night or 8 am / 24h). The wearing time is a minimum of one year. Sometimes it is necessary to keep it for 5 years, 10 years or for life. In this case, it is for example a simple palatal plate, or a Hawley's plate, or activators, or gutters, that is to say a kind of mouthguard which can be made of soft resin or transparent polymer for example.

If it is fixed, it is often a restraint device, polymerized or stuck in the mouth of an individual, which stabilizes the results obtained. In this case, it may be, for example, a twisted metal wire bonded directly to each of the teeth that it covers, or a metal wire bonded to two metal facets which are themselves bonded directly to two teeth, for example the canines, or a lingual arch on a bar, that is to say a metal wire directly welded to the canine or premolar rings.

In addition, a restraint device in adults is strictly individualized.

However, such restraints have several limitations, for example: - Those which are made of metal have a gray, dull color which is eventually transmitted to the teeth and which affects their iridescent appearance.

- Metal restraints are too rigid and for example cause detachment phenomena, and / or immobilization of the teeth which induces bone loss and potentially, in the long term, tooth loss.

- The metal wires can scratch the teeth and / or induce cavities and / or the risk of cracking, affecting their resilience.

- Those which are polymerized in the mouth of an individual require substantial material specific to the practitioner. In addition, polymerization in the mouth is difficult to control. Often the layers are too thick to allow good polymerization. Polymerization under the fiber is very difficult, if not impossible in some cases. Polishing is complicated. The thickness of the restraint is difficult, if not impossible, to control. Material gets between teeth, which is very difficult, if not impossible, to clean.

The object of the present invention is to improve at least in part the aforementioned drawbacks, further leading to other advantages.

To this end, there is proposed, according to a first aspect, a retention device comprising at least one retention device configured to be bonded to a part of a dental arch.

According to the invention, the restraint device further comprises at least two riders, positioned at a distance from each other, each rider being a rigid hook and integral with the restraint device, and configured to hook onto the dental arch.

Such a “fixed” type restraint device (because it will then be fixed in the mouth of the individual), produced beforehand, is thus very easy to put in place in order to then be glued to the teeth of an individual, it is that is to say on a part of the dental arch.

The presence of at least two riders allows precise positioning of the retainer on the dental arch portion before bonding the retainer to the corresponding teeth.

Such a restraint device is thus very simple and makes it possible to avoid using other tools or elements for the placement of the restraint device.

In addition, the relative flexibility of the material of the restraint device makes it possible in particular to achieve a one-piece restraint, for example from premolar to premolar, which would be impossible to achieve in metal because such a restraint device would then induce too many constraints on the teeth. Such a retention device is also very discreet, even invisible, and it is both sufficiently rigid so as to clamp the teeth but with relative flexibility, which makes it possible in particular to make it much less traumatic for the teeth or the tissues. and / or less restrictive for its wearer.

Preferably, the restraint device has an average thickness of at least 0.3 mm, for example between 0.5 mm and 0.9 mm, for example about 0.8 mm.

The thickness of the restraint device is for example at most equal to 3 mm and at least equal to 0.3 mm.

The restraint device here is preferably a tape.

A strip here denotes a bar of which one dimension, for example a thickness e, among a height h, a length L and a thickness e of the apparatus, is much less than the two other dimensions, for example the length L and the height h. Thus, here, the length L corresponds to the dimension of the appliance according to the dental arch and corresponds for example to the number of teeth covered by the appliance while the height h corresponds to a transverse dimension along a height of one tooth. ; a thickness e thus corresponds to the third dimension. By comparison, an apparatus in the form of a wire would have a height substantially equal to its thickness.

In a particular exemplary embodiment, the height h is also much greater than the thickness e.

The retainer is thus configured to cover a larger area of each tooth depending on its height, which allows a more stable hold of the tooth.

In an interesting exemplary embodiment, the restraint device has a shape corresponding to a set of the rear faces, also called posterior, of the teeth of the portion of the dental arch that it is configured to cover.

It is thus possible to minimize any discomfort that could be caused by the presence of such a device in the mouth for an individual.

In an exemplary implementation, the retainer is configured to cover 2, or 4, or 6, or even 8 teeth, or even more, depending on the case; This involves, for example, covering an area from one canine to another canine, or from one premolar to the other premolar, with the same dental arch.

The retention device includes at least two riders to ensure stability of the retention device positioned on the dental arch. The restraint may however have three or more riders.

According to a preferred exemplary embodiment, each rider extends as far as possible up to halfway up the restraint device. Such a length of the riders makes it possible to facilitate the subsequent positioning of the retention device on a dental arch.

According to another preferred exemplary embodiment, at least one of the jumpers is configured to anchor on an interface between two consecutive teeth.

For example, for a restraint device comprising three riders, one of the three riders can be located between the two middle incisors and the two other riders can be located between a lateral incisor and the neighboring canine.

Such positioning of the riders helps to ensure a more stable balance of the retainer positioned on a dental arch.

In a preferred embodiment, the restraint device comprises at least one breakable rupture initiator located at an intersection between one of the riders and the restraint device in order to facilitate removal of the rider.

Such a breakable rupture initiator is for example a notch and / or a section narrowing of the jumper.

According to an exemplary embodiment, at least the restraint device is made of a composite polymer material.

For example, the composite polymeric material includes a cross-linking amorphous composite polymeric material.

In a particular example, the composite polymer material comprises an amorphous composite polymer material cross-linked with a methacrylate base.

The methacrylate here is a mixture of liquid monomers, the crosslinking of which is initiated by a peroxide. Curing of the mixture of monomers, depending on the level of peroxide, takes place either at room temperature or at low temperature, or even at negative temperature. Crosslinked mixtures are characterized in particular by:

- very fast commissioning;

- hardening possible at low temperature, or even at negative temperature;

- good mechanical and chemical resistance;

- more or less flexibility;

- strong adhesion on many supports. An interesting material is, for example, the material sold under the reference Bredent HIPC® (High Impact Polymer Composite).

While such a material was known for other applications, it has proven to be particularly advantageous for the production of a bar-type restraint device, in particular by its color close to that of tooth enamel and by its mechanical properties, and in particular for bending stresses.

In a case of making the compression device by three-dimensional printing, interesting materials to use are for example the material sold under the reference “NextDent C&B” ® or the material sold under the reference “NextDent C&B MFH (Micro Filled Hybrid) »®, both from Nextdent®.

There is also proposed, according to another aspect, a method of making a restraint device comprising all or part of the characteristics described above.

According to an interesting example, the method comprises a step of machining a wafer of material configured to produce at least part of the retention device.

In a preferred example of implementation, the machining is carried out in a wafer of amorphous composite polymer material, with cross-linking, as described above. Such a material is for example marketed under the reference Bredent HIPC® (High Impact Polymer Composite)).

In a preferred example of implementation, the machining is carried out with a so-called "laboratory" machine, such as for example sold under the name Roland DWX 510® or even IMES-ICORE CORITEC 350i®.

According to another interesting example, the method comprises a step of three-dimensional printing of at least part of the retention device.

Machining and three-dimensional printing can be combined depending on the shape to be given to the retention device, for example.

For example, at the end of orthodontic treatment, the method comprises a step of taking an impression of at least part of a dental arch of an individual. At least one digital file allowing 3D modeling is then obtained.

For example, the impression-taking step involves taking a physical impression of at least part of an individual's dental arch to obtain a mold.

The method can then include a step of casting plaster in the mold to obtain a plaster model of the part of the arch, also called a matrix. Then, for example, the impression-taking step may include a step of digital scanning of the matrix.

The digital file is for example extracted by means of a three-dimensional scan for example (for example of the Imetrics® type).

According to another advantageous possibility, the impression-taking step comprises a step of taking an impression of at least part of a dental arch of an individual directly in the mouth using an intraoral scan, for example. by a CONDOR® camera.

The matrix representing at least part of the dental arch is also possibly produced by 3D printing. For example, the matrix can be printed in resin, for example with a Stratasys Eden 50® printer.

If necessary, the 3D file of the impression of the dental arch part thus obtained (following the scan of a matrix or directly in the mouth), i.e. the digital model of the dental arch part , is included in software (such as for example Dental-Wings®).

The orientation of the arch is possibly optimized to reduce undercuts on the buccal surfaces of the teeth relative to a theoretical vertical axis; in other words, this operation makes it possible to "open" the internal face of the teeth, in particular where a restraint device according to an exemplary implementation of the invention will be positioned.

The method can then include a step of modeling the restraint device; this step thus provides a digital model of the restraint device.

To this end, the method comprises for example a step of modeling the restraint device as described above as a function of the digital model of the dental arch part, the step thus providing a digital model of the restraint device. .

For example, the step of modeling the restraint apparatus comprises a step of identifying the geometries of the posterior surfaces of the teeth, that is to say on the side of the tongue, on which the restraint apparatus is to to place.

For example, the step of modeling the restraint apparatus includes a step of defining a thickness of the restraint apparatus.

This thickness can however vary according to the needs.

Then, the method comprises, for example, a step of modeling the riders, as a function of the digital model of the dental arch part and of the digital model of the restraint device. The retention device can then be produced.

For the production of at least one restraint device, a CAD file, for example a file in STL format, presenting at least one model of the restraint device as described above, and preferably several, is transferred, for example to a machining preparation software, for example Work-NC® software, and / or three-dimensional printing.

An orientation of the restraint model is possibly made so as to provide the lingual or palatal face without an undercut relative to an axis of attack of a bur.

Such an embodiment is advantageous because there is thus no discontinuity in the geometry of the restraint device which can be machined, or printed, in a single stroke, for example without turning over the wafer of material in which the machining is carried out.

Optionally, the method may include a step of adjusting the jumpers by positioning the retention device on the matrix.

According to an interesting option, the method further comprises a step of polishing the retention device thus obtained.

The polishing step may for example include a step of sanding a face of the restraint device configured to be bonded to the teeth in order to increase the roughness of this face and therefore the adhesion of the device to the teeth. .

According to an interesting option, the method further comprises a step of cleaning the restraint device.

The cleaning step is, for example, carried out by an ultrasonic bath.

It is then ready to be placed in the mouth of an individual.

Once the retainer is glued, it is then possible to remove the jumpers.

An interesting glue is, for example, an adhesive marketed under the name “Panavia V5 KURARAY”.

The glue is then photopolymerized.

The removal of the riders can be done by a simple snap action or, for example, by milling, directly in the mouth of the individual.

Such a restraint can then be kept temporarily or for life. The mimicry is very good due to the natural color of the material used and the thinness of the restraint which allows even more adaptation to the color of the teeth by transparency.

In addition, the material can have different shades which allow it to best match that of the teeth of the individual for whom the retainer is intended.

Such a retainer is thus much more aesthetic, resistant and comfortable and adapts much better to a dental arch.

The invention, according to an exemplary embodiment, will be well understood and its advantages will appear better on reading the following detailed description, given as an indication and in no way limiting, with reference to the appended drawings in which:

Figure 1 shows a digital model of a dental arch;

FIG. 2 illustrates an extraction of the geometries of the posterior faces of the teeth on which a retainer is to be placed;

FIG. 3 represents a digital modeling of a restraint device according to an exemplary embodiment of the invention;

FIG. 4 schematically represents a positioning of the riders on a dental arch;

FIG. 5 illustrates an exemplary embodiment of a restraint device according to the invention, comprising a restraint device and three riders;

Figure 6 illustrates a front view of the restraint device of Figure 5;

FIG. 7 shows an example of positioning of the retention device of FIG. 5 on a dental arch;

Figure 8 illustrates, in section view, a placement of the restraint device for positioning as illustrated in Figure 7;

Figure 9 shows a sectional view of Figure 7; and

Figure 10 schematically illustrates the retention device from the retention device shown in Figure 5 on a dental arch as shown in Figure 7.

Identical elements shown in the aforementioned figures are identified by identical numerical references.

FIG. 1 represents a digital, three-dimensional model of the dental arch 10 '. Such a digital, three-dimensional model of the dental arch 10 ′ is for example produced from an intra-oral scan, for example using a CONDOR® camera.

The digital file of the impression thus obtained is possibly used in software, for example Dental-Wings® software.

A model of a restraint device 20 can then be carried out.

It is then a question of defining a geometry of the restraint device, that is to say of the restraint apparatus and the riders.

To this end, a step of modeling the restraint apparatus includes a step of identifying the geometries of the posterior surfaces of the teeth on which the restraint apparatus is to be placed.

In Figure 2, this step is represented by the definition of the surface 20 ”, hatched, which is used to define an outline of the restraint device.

The method then includes a step of defining the thickness of the restraint device.

This thickness ("e", indicated in Figure 8 for example) may be constant for the restraint device, but it is preferably variable to better adapt the restraint device to the shape of the dental arch, for better wearer comfort for example, and / or depending on the forces that the restraint device must withstand.

Thus, the average thickness is for example between 0.5 mm and 0.9 mm, and at all points, the thickness is preferably at least equal to 0.3 mm and at most equal to 3 mm.

The thickness e being considered very small compared to a height h (defined according to the height of the teeth) and a length L (defined according to the number of teeth covered by the restraint device) of the restraint device, the a restraint device is here considered to be a tape.

The retainer is here configured to cover 6 teeth; This involves, for example, covering a sector from one canine to another canine with the same dental arch, as illustrated in Figures 2 to 7.

The step of modeling the restraint device also includes a step of modeling the jumpers, shown for example in Figure 3.

Here, the device has three jumpers.

The jumpers are modeled to be positioned at an interface between two consecutive teeth. Thus, in the present exemplary embodiment, two jumpers are arranged between an incisor and the neighboring canine, and a jumper is positioned between the two middle incisors.

Their geometry is defined according to the shape of the dental arch.

The geometry of the riders is adapted and modeled on those of the teeth so as to generate only intimate contact.

Thus, the absence of stress generated by the riders allows the restraint device to be able to apply perfectly to the faces of the teeth and to be able to control their passivity.

As shown in Figure 4, each rider preferably extends as far as possible to the equator of the outer face of the teeth to facilitate positioning of the device on a dental arch.

For example, the length of the jumpers is configured to ensure sufficient stability for the restraint device and to prevent a tilting phenomenon. The length of a rider is generally sufficient when it comes to half the height of the restraint.

In addition, the jumpers are configured so that a retention force allows intimate contact between the retention device and the dental arch so as not to generate a tilting phenomenon, ie the jumpers are preferably not under stress on the teeth. teeth so as not to induce a force which would interfere with the positioning of the device and a bonding of the retention device on the rear faces of the teeth.

The method further includes a step of defining a breakable initiator at an intersection between one of the jumpers, preferably each of the jumpers, and the restraining device to facilitate subsequent removal of the jumper.

FIG. 3 represents a digital model of a restraint device 20 'according to an exemplary embodiment of the invention, comprising a digital model of a restraint device 21' and a digital model of jumpers 22 '(three in number) .

Figures 5 and 6 show by way of illustration a restraint device 20 obtained from the digital model of a restraint device 20 ′ of Figure 3 for example.

The restraint device 20 comprises a restraint device 21 and riders 22, here three riders. For the production of at least one retention device 20 as described above, a CAD file, for example a file in STL format, presenting at least one retention device 20, and preferably several, is transferred, for example machining preparation software, for example Work-NC® software, and / or three-dimensional printing software.

Production by machining and / or three-dimensional printing is advantageous because there may thus be no discontinuity in the geometry of the restraint device and even of the restraint device.

In a preferred example of implementation, the machining is carried out in a wafer of amorphous composite polymer material, with cross-crosslinking. Such a material is for example marketed under the reference Bredent HIPC® (High Impact Polymer Composite)).

For example, the machining is carried out with a so-called "laboratory" machine, such as for example marketed under the name Roland DWX 510® or even IMES-ICORE CORITEC 350i®.

The restraint apparatus 20 can also be at least partly produced by three-dimensional printing.

It is thus possible to produce several retention devices together, each retention device being specific for a different dental arch.

In an exemplary implementation, the retention apparatus 20 thus produced is then polished and cleaned.

The positioning of the retention device 20 is typically done vertically, as illustrated in FIG. 8, without forcing, without deformation of the retention device, taking into account a natural undercut of the part of the dental arch considered. , on the buccal and palatal or lingual surface.

For example, glue is applied to the teeth and / or to the anterior face of the retainer 21.

Such an adhesive is for example marketed under the name Panavia V5 KURARAY®.

The glue is then photopolymerized.

It is then possible to remove the jumpers, for example by a simple snap action or for example by milling, directly in the mouth of the individual.

By way of illustration, Figure 10 shows the restraint device 21, in place on a dental arch 10, which then corresponds to the digital dental arch 10 'model illustrated in Figures 1 to 4.

Claims

1. A restraint device (20) comprising at least one restraint device (21) configured to be bonded to a part of a dental arch (10), characterized in that the restraint device (21) is configured to cover at least two teeth and in that it further comprises at least two riders (22), positioned at a distance from each other, each rider (22) being a rigid hook and integral with the restraint device ( 21), and configured to hook onto the dental arch (10).

2. A restraint device (20) according to claim 1, characterized in that the restraint device (21) has an average thickness of at least 0.3 mm, for example between 0.5 mm and 0.9 mm, for example about 0.8 mm.

3. A restraint device (20) according to any one of claims 1 or 2, characterized in that the restraint device (21) is a tape and has a shape corresponding to a set of rear faces, also called posterior, teeth of the dental arch portion (10) which it is configured to cover.

4. A restraint device (20) according to any one of claims 1 to 3, characterized in that it comprises at least one breakable initiator located at an intersection between one of the jumpers (22) and the device. retainer (21) to facilitate removal of the rider (22).

5. A restraint device (20) according to any one of claims 1 to 4, characterized in that at least the restraint device (21) is made of a composite polymer material comprising an amorphous cross-linking polymeric composite material. .

6. A method of making a restraint device (20) according to any one of claims 1 to 5 comprising:

- a restraint device modeling step (20) providing a restraint device model (20 '), the step comprising:

o a step of modeling the retention device (21) according to a digital model of the dental arch part (10 ') providing a digital model of the restraint device (21'), and

o a step of modeling the riders (22) according to the digital model of the dental arch part (10 ’) and the digital model of the restraint device (21’)

a step of machining a wafer of material configured to produce at least part of the retention device (20) and / or a three-dimensional printing step of at least part of the retention device (20) depending on the model of a restraint device (20 ') provided by the step of modeling the restraint device (20).