WO2002030647A2

WO2002030647A2 - Composite material, method for making same and uses thereof

Info

Publication number: WO2002030647A2
Application number: PCT/FR2001/003137
Authority: WO
Inventors: Marc Bachmann; Sonia Bachmann; Noémie Bachmann
Original assignee: Carbotech
Priority date: 2000-10-12
Filing date: 2001-10-11
Publication date: 2002-04-18
Also published as: FR2815352A1; WO2002030647A3; AU2001295681A1

Abstract

The invention concerns a composite material, the method for making same and uses thereof. The inventive composite material is of the type comprising fibre bundles whereof the fibres impregnated with non-cured resin are enclosed in a sheath maintaining them and compressing them to the desired shape, the sheath being made of a flexible and closed material. The invention is particularly applicable for making bra stays or prosthetic, in particular dental, elements.

Description

Composite material, its manufacturing process and its uses

The invention relates to a composite material, a method of manufacturing this composite material as well as the use of this composite material for the manufacture of prosthetic elements, in particular dental and for the manufacture of brassiere frames. It also relates to a method for manufacturing prosthetic elements, in particular dental and a device for manufacturing prosthetic elements, especially dental.

The so-called composite materials are materials whose matrix is a polymerizable resin, comprising mineral fillers of glass, quartz or ceramic in the form of particles of various shapes and sizes. A particular class of composite materials is the class of so-called fiber composite materials. Fiber composite materials also consist of a polymerizable resin matrix, but the filler consists not of particles of various shapes and sizes, but of fibers, in the form of discontinuous or, better still, continuous threads, woven, braided or unidirectional.

Fiber or non-fiber composite materials are used in many areas of the industry due to their mechanical strength and low weight. For example, in the chemical industry, it is necessary to manufacture many parts from composite materials because of their excellent mechanical, chemical resistance, etc.

Furthermore, in dentistry, the current trend is to eliminate the use of metal in order to avoid the problems linked to corrosion due to the galvanic currents that metals and their alloys can generate.

Thus, composite materials with a polymerizable resin matrix comprising mineral fillers of glass, quartz or ceramic in the form of particles of various shapes and sizes and not in the form of fibers are attractive alternatives from an aesthetic point of view, functional and economical, with dental reconstructions in precious or non-precious metal covered or not with pure ceramic.

However, these composite materials with a polymerizable resin matrix comprising mineral fillers of various shapes and sizes, hereinafter also called cosmetic composite materials, must be strong enough to withstand the forces which they support during masticatory function. It is why it is necessary to create a rigid frame on which the cosmetic composite materials are then applied and to which they adhere.

This reinforcement which has a role of mechanical reinforcement is, for its part, made of the composite materials called fibers described above. In addition, in the field of female lingerie, the so-called underwired bras include cups having a metal frame.

However, the metal frames of the caps twist in the wash, rust, pierce the fabrics, lose their elasticity over time and break by fatigue of the metal. Thus, for many years, brassiere manufacturers have wanted to replace these metal frames with frames made of other materials which do not have these drawbacks.

At present, the so-called fiber composite materials are used in the form of woven or braided fibers, which are already pre-impregnated with non-polymerized polymerizable resin or which can be embedded in the non-polymerized polymerizable resin at the time of their use: they are put into the desired shape then the resin is hardened (polymerized) either by heat when it is a thermosetting resin, or by light irradiation when it is a photopolymerizable resin or in certain cases by both. These resin-impregnated products have several drawbacks:

- They appear as wicks of fibers or sheets of fabrics impregnated with an unpolymerized resin which has the consistency of honey. Their handling is therefore difficult because the assembly is sticky, pasty, sticky, difficult to implement, - when they are handled, the fibers move apart, slide over each other, and the assembly loses its cohesion, which makes the mechanical properties of the object obtained random and not reproducible, and

- the polymerization of certain resins is inhibited on contact with air, during the polymerization of the object to be obtained, which results in the formation of a surface layer (that which is in contact with air, during of polymerization) of unpolymerized resin of viscous appearance and sticking to the surface of the final part obtained after hardening of the composite material. This layer of unpolymerized resin, even very fine, must be removed, for example by grinding, until reaching the polymerized resin which must then be repolished, which leads to additional manufacturing steps for the object to be obtained. But above all, the manufacture of curved parts, or of complicated shapes in these fiber composite materials currently requires specific and very expensive tools which can only be used for large series. More particularly, it is difficult and very expensive at present to obtain complicated curved parts such as springs.

Indeed, at present, the manufacture of curved profiles in thermosetting composites is done by the curved pultrusion method called "pull forming" which allows to manufacture simple shapes with specific tools studied for a particular shape and is very expensive and can only be used for large series.

The pultrusion method is a process consisting in pulling the resin impregnated fibers to the desired shape.

However, by this method, complex shapes such as springs cannot be obtained. Also known is the technique of bag molding or "bag molding" which consists of enclosing webs of woven or nonwoven fibers impregnated with polymerizable resin between two sheets of polyethylene, or another polymeric material, then pressing them in a mold to get a unitary piece. Here again, however, this widely used technique does not allow curved profiles such as springs to be produced. In the foregoing and in the following, the terms "polymerizable" and "curable" as well as their derivatives and grammatical variants will be used interchangeably to designate the curing of the resin.

The invention aims to overcome the drawbacks of the prior art by providing a composite material called fiber composite which allows the production of parts of the most complex curved shapes, with constant mechanical properties and reproducible throughout the part, industrially or on request, and whose handling is easy.

To this end, the invention provides a composite material of the type comprising fibers impregnated with a resin curable by application of at least one stress, characterized in that:

the fibers are in the form of substantially unidirectional parallel fibers, or wicks or twists or braids or woven or nonwoven ribbons, or sheets of woven or nonwoven fibers, the fibers impregnated with uncured resin are wrapped in a sheath holding in place and compressing the fibers impregnated with resin and giving and maintaining the desired shape for the fibers impregnated with resin,

the sheath is made of a flexible material to allow the sheath containing the fibers impregnated with resin not hardened to be shaped to the shape of the object to be obtained, and

- the sheath is closed after introduction of the fibers and the resin

Preferably the fibers are selected from the group consisting of glass fibers, quartz fibers, silica fibers, aramid fibers, kevlar fibers, polyethylene fibers, carbon fibers, and mixtures. of these.

Particularly preferred fibers are glass fibers based on zirconium oxide.

In this case, the glass constituting the fibers contains between 16.8% and 17.1% by weight of zirconium oxide relative to the total weight of the glass.

According to a characteristic of the composite material of the invention, the curable resin is a resin curable by the application of heat and or light.

A particularly preferred curable resin is Bis-GMA resin.

Advantageously, the composite material of the invention contains between 40% and 80% by volume of fibers relative to the total volume of the fibers and of the polymerizable resin.

As for the sheath, it is preferably made of a transparent polymeric material. It can also be made of a polymeric material resistant to a temperature above about 100 ° C. Preferably, the sheath will be made of an airtight polymeric material.

In a preferred embodiment, the sheath is made of a heat-shrinkable polymeric material.

Advantageously, the composite material of the invention will also be wrapped in a package made of a light-tight material. The composite material of the invention can be used for the manufacture of prosthetic elements, in particular dental.

In this case, an advantageous manufacturing method according to the invention for the manufacture of these prosthetic elements, in particular dental, comprises the steps of: a) shaping of the composite material according to the invention, in its sheath, to the shape of the prosthetic element to be obtained, b) hardening of the resin by application of the appropriate stress (es), c) removal of the sheath, and d) optionally, machining of the prosthetic element thus obtained.

Another method according to the invention for manufacturing prosthetic elements, in particular dental elements, comprises the steps of: a) placing the impression of the prosthetic element to be obtained on a rotary axis, b) cutting at least one end of the sheath of the composite material of the invention, c) winding, on the imprint of the prosthetic element to be obtained, fibers impregnated with resin leaving the cut end of the sheath, by rotation of the rotary axis, until the desired shape of the prosthetic element is obtained, d) hardening of the resin by application of the appropriate stress (es), on the impression, e) separation of the prosthetic element thus obtained and the impression, f) removal of the sheath, and g) optionally, machining of the prosthetic element thus obtained. The invention also provides a device for manufacturing prosthetic elements, in particular dental elements, characterized in that it comprises:

- a support base supporting a horizontal bar, this bar being movable from front to back and from left to right on the support and can be fixed in place on this support, - a first vertical bar, fixed at its lower end, by a clamping screw, at a first end of the horizontal bar, and movable relative to this horizontal bar from left to right and from front to back, and being able to be immobilized on this horizontal bar by the clamping screw, this first vertical bar supporting at its upper end a device allowing the rotary axis which is fixed to it to rotate, the rotary axis being an extension of the device and being provided with a jaw for detachably fixing the imprint of the prosthetic element to be obtained, on the axis of rotation,

- a second vertical bar, fixed at its lower end by a clamping screw, at the second end of the horizontal bar previously mentioned, and movable relative to it from left to right and from front to back and capable of be immobilized on this horizontal bar by the clamping screw, this second vertical bar supporting at its upper end a ball bearing device receiving a horizontal axis in free rotation in the device, this horizontal axis bearing, at its end facing the rotary axis supported by the first vertical bar, a stop plate perpendicular to the horizontal axis and at its other end a blocking device allowing the blocking of the movable horizontal axis from front to back in the ball bearing device, at the desired position,

- The stop plate and the rotary axis being aligned to allow positioning between them of the impression of the prosthetic element to be obtained.

The stop plate for blocking the movable horizontal axis from front to back in the ball bearing device can have various shapes. It is preferably removable. Thus the stop plate can be a plate with parallel faces. The stop plate allowing the blocking of the movable horizontal axis from front to back in the ball bearing device may also be provided with a centering and positioning cone, to allow positioning of the element footprint prosthetic to obtain and is removable.

It can also have the shape of a truncated cone. It can have the shape of a half-sphere.

In all the embodiments, the stopper plate is preferably made of an elastically deformable material and / or non-adherent to the fibers and / or non-adherent to the non-polymerized resin.

In the same way, the jaw allowing the fixing of the imprint of the prosthetic element to be obtained in a removable manner can have various shapes.

Thus, the jaw can be a device allowing the engagement in tightness of the total external surface of one end of the impression.

It can also be a device allowing the clamping of one end of the imprint on only part of its surface. It can also be a cone-shaped device, the pointed end of the cone engaging tightly in a portion of the end of the cavity.

Preferably, the jaw will be removable and provided with a clamping screw for its fixing and its blocking on the rotary axis.

The composite material of the invention can also be used for the manufacture of brassiere frames. The invention therefore thus relates to brassiere frames characterized in that they are made of the composite material of the invention, hardened.

The invention also relates to a method of manufacturing the composite material of the invention characterized in that it comprises the step of introduction by pressure extrusion of fibers impregnated with an uncured curable resin in a sheath and the sealing of the open ends of the sheath by stapling or heat sealing.

A particularly preferred method for manufacturing the composite material of the invention is characterized in that it comprises the steps of: a) introduction, into one end of a longitudinal sheath, of a portion of hollow rigid tube having an external section substantially equal to the internal section of the sheath, the other portion of the hollow rigid tube leaving the sheath, b) fixing the hollow tube in the sheath by any appropriate means, c) introduction, into the sheath, of a rigid wire and resistant to traction, this wire having a section allowing it to slide freely in the sheath and having a length greater than the length of the sheath and coming out at the two ends of the latter, d) fixing of the free end of the wire rigid leaving the rigid tube at one end of the bundle of fibers to be introduced into the sheath, e) impregnation of the fibers, before their entry into the sheath with the uncured curable resin, f) introduction of the impregnated fibers es of hardenable resin not hardened in the sheath by pulling on the free end of the wire leaving the sheath, g) sliding, along the sheath, during the introduction of the resin fibers, of a hollow element whose shape and the internal dimensions correspond to the shape and to the external dimensions to be obtained for the uncured composite material, in its sheath.

Preferably, the sheath is made of a heat-shrinkable material and it is heated after the introduction of the fibers impregnated with resin and before, at the same time or after the step of shaping desired by sliding the hollow element.

The invention will be better understood and other objects, characteristics, details and advantages thereof will appear more clearly during the description. explanatory which will follow which is made with reference to the appended figures in which:

FIG. 1 represents a sectional view of a first embodiment of the composite material of the invention, FIG. 2 represents a top view of the composite material of the invention according to a second embodiment,

FIG. 3 represents a sectional view, along the axis III-III, of the composite material of the invention represented in FIG. 2,

FIG. 4 schematically represents a sectional view of a first dental prosthetic element obtained with the composite material of the invention,

FIG. 5 represents a schematic sectional view of a second prosthetic element obtained with the composite material of the invention,

FIG. 6 represents a schematic sectional view of a third dental prosthetic element obtained with the composite material of the invention, FIG. 7 represents a first embodiment of the composite material of the invention,

FIG. 8 represents the prosthetic element obtained by the use of the composite material of the invention as shown in FIG. 7,

FIG. 9 represents the first step in the manufacture of a reinforcement made of composite material according to the invention,

FIG. 10 represents an intermediate step in the manufacture of the reinforcement in composite material according to the invention, the first step of which is shown in FIG. 9,

FIG. 11 schematically represents the device of the invention for manufacturing a prosthetic element with the composite material of the invention,

FIG. 12 schematically represents a first variant of the stop plate of the device of the invention,

FIG. 13 schematically represents a second variant of the stop plate of the device of the invention, FIG. 14 schematically represents another means of using the composite material of the invention for the manufacture of prosthetic elements,

FIG. 15 represents yet another embodiment of the composite material of the invention, for the manufacture of a dental prosthetic element,

FIG. 16 schematically represents a process for manufacturing composite material of the invention, FIG. 17 schematically represents a process for manufacturing the composite material of the invention,

FIG. 18 schematically represents a third variant of the stop plate of the device of the invention, FIG. 19 schematically represents a fourth variant of the stop plate of the device of the invention,

FIG. 20 schematically represents a first variant of the jaw of the device of the invention,

FIG. 21 schematically represents a second variant of the jaw of the device of the invention, and

- Figure 22 schematically shows a third variant of the jaw of the device of the invention.

The invention solves the problems of composite materials of the prior art by providing a composite material for easy handling, in which the fibers form a homogeneous whole, which makes it possible to obtain an object having homogeneous mechanical properties and also all forms of 'possible objects.

Indeed, as can be seen in FIG. 1, the composite material of the invention consists of fibers 1 substantially unidirectional and parallel or in the form of wicks or twists or braids or woven or nonwoven ribbons or ribbons, impregnated with resin 2 curable and not hardened and wrapped in a sheath 3 keeping the fiber plus resin assembly in the desired shape. The fibers 1 and the resin 2 form, in their sheath 3, a homogeneous assembly which when handled does not lose its homogeneity thanks to the sheath 3 which prevents the fibers from spreading and sliding over each other. In addition, the handling of the composite material of the invention is easy because the contact with the uncured resin 2 is no longer tacky.

Thus, the composite material of the invention makes it possible to obtain an object whose mechanical properties are homogeneous and reproducible. The most complex shapes required can be obtained with reproducibility and reliability.

The sheath 3 enveloping the fibers impregnated with resin is made of a flexible material in order to allow the composite material of the invention to be put, before hardening, to all the desired shapes of objects.

Obviously, the sheath 3 will be closed at its ends so as to prevent the fibers 1 and the uncured resin 2 from leaving the sheath 3 during the handling of the composite material of the invention and also to maintain the homogeneity of the fiber assembly 1 plus resin 2 during its handling and its subsequent hardening.

The fibers 1 could be all types of fibers which are suitable for obtaining the mechanical, optical, and elastic and other properties of the object to be obtained.

The resin 2 will be a resin which can be hardened by applying at least one stress in order to allow the shape of the object to be frozen to be fixed, by applying the appropriate stress. The resin 2 may therefore be a thermosetting resin, that is to say one which can be hardened by the application of heat. It can also be a photocurable resin, that is to say curable by application of light. Finally, it can be both photo- and thermosetting.

When the resin is a photocurable resin, the sheath 3 will be made of a material transparent to light of the appropriate wavelength. When the resin 2 is a thermosetting resin, the sheath 3 will be made of a material resistant to the curing temperature of the resin. As already explained in the foregoing and in all that follows, the terms hardening and polymerization as well as their grammatical variants will be used interchangeably and will signify the hardening of the resin 2. In the case of photo- and thermo-resins curable, the sheath 3 will be made of a material which is both transparent to light of the appropriate wavelength and resistant to the curing temperature of the resin.

While in Figure 1 the composite material of the invention is shown as composed of substantially longitudinal fibers impregnated with resin, Figures 2 and 3 show another embodiment of the material of the invention.

As can be seen in FIG. 2, the composite material of the invention can also be in the form of woven or non-woven fiber plates, impregnated with resin, of rectangular, round, oval, etc. shape. which are wrapped in the sheath 3, the sheath 3 perfectly matching the shape of the plates. Again, the sheath 3 is closed at the edges. The fibers 1, the resin 2 and the sheath 3 will have the same properties as in the case of the substantially longitudinal fibers described above. FIG. 2 represents a top view of the composite material of the invention in the form of plates while FIG. 3 represents a sectional view of the composite material of the invention comprising a plate of woven or nonwoven fibers 1 impregnated with resin 2 curable and not hardened and wrapped in a sheath 3 closed on the edges.

In all of the embodiments of the composite material of the invention, when the resin 2 is a light-curable resin, the composite material of the invention is additionally wrapped in a package opaque to light, to avoid any hardening of the resin during storage and / or transport.

Such packaging is, for example, an aluminum sachet.

In addition, as we have seen, certain resins being sensitive to oxidation and therefore undergoing an inhibition of their ability to polymerize, the sheath 3 will preferably be made of an oxygen-tight material to avoid any oxidation during the transport or storage of the composite material of the invention.

Although the variety of objects and uses of the composite material of the invention is very wide and that it can be used in all fields of industry, a first preferred field of use of the composite material of he invention is for the manufacture of prosthetic elements, in particular dental.

Indeed, these prosthetic elements must be manufactured on demand and cannot be manufactured in an industrial manner.

For the manufacture of dental prosthetic elements, the preferred fibers used in the composition of the composite material of the invention are glass fibers, quartz fibers, silica fibers, aramid fibers, kevlar fibers, polyethylene fibers, carbon fibers and mixtures thereof.

Preferably, glass fibers will be used because they have the advantage, in particular compared to carbon fibers, of having a color closer to the color of the natural tooth. In fact, the glass fibers are off-white in color, which makes them particularly suitable for dental use.

The particularly preferred glass fibers for the manufacture of prosthetic elements, in particular dental, are glass fibers made from a glass based on zirconium oxide. Indeed, such glass fibers are radiopaque, that is to say visible on a dental radiography.

A preferred glass is a glass whose starting materials include zirconium oxide, the zirconium oxide being melted at the same time as the other components of the glass during the manufacture of the glass which is then itself transformed into fibers . Thus, the fibers preferably used in the invention are fibers produced from a glass containing between 16.8% and 17.1% by weight of zirconium oxide relative to the total weight of the glass.

These glass fibers, thanks to their zirconium oxide content, are particularly suitable for dental use.

In fact, saliva makes the oral cavity a more corrosive environment than sea air, which is the reference environment for corrosion resistance tests of industrial products.

In the same individual, the salivary pH can be alternately acidic or basic. Any object in permanent contact with saliva is in a 100% humid environment, at a temperature of 37 ° C, and is subjected to a phenomenon of corrosion by hydrolysis. In addition, this medium contains aerobic and anaerobic bacteria capable of secreting all kinds of alkane substances, ketones, and others which are also corrosion agents. Glass fibers containing zirconium oxide are preferred in the composite material of the invention, because they have a high resistance to acidic and alkaline agents due to their proportions of zirconium oxide.

This resistance is of the order of 10 times that of a glass fiber that does not contain zirconium oxide. They also have better resistance to hydrolysis in a humid environment, and moreover better mechanical properties, in particular better resistance to fatigue, which makes them particularly suitable for use in the manufacture of dental reinforcement.

Finally, these glass fibers enriched with zirconium oxide have an average diameter of 14 to 20 μm and have the property of disintegrating into microparticles but while keeping a size greater than 3 μm when they are ground by machining or attacked by hydrolysis, which makes them non-inhalable (not breathable). This is very important for a material intended to remain in the mouth for years and also for the health of professionals who have to work, machine and grind the parts obtained with the composite material of the invention.

Particularly suitable fibers are those sold under the brand name "Cem-FIL ^® Fibers" by the company VETROTEX, a subsidiary of the company Saint-Gobain. The resin 2 used for the composite material of the invention is any resin curable by the application of at least one stress.

Preferably, this constraint will be heat or light, whether visible, infrared or UN. It may also be a resin which is both photopolymerizable and thermosetting. A resin 2 suitable in the context of the composite material of the invention is chosen from epoxy, polyester or vinyl ester resins which are thermosetting resins or polymethacrylate or diurethane resins which are photo- and thermosetting resins or derivatives thereof. -this. The resin 2 preferably has a viscosity of between 400 and

800 centipoises. The viscosity can be adjusted by adding fillers such as micro- or macro-particles of quartz, barium glass, ceramic or others, of sizes between 0.3 and 10 μm.

The elastic modulus or Young's modulus of this resin will be between 30 Gpa and 150 Gpa.

A preferred resin for the manufacture of dental prostheses is a Bis-GMA resin. This is used in dentistry for the prophylactic sealing of wells and cracks and is referred to as "flowable composite". It is sold under the brands "HELIOSEAL F" from Vivadent or CONCISE WHITESEALANT from 3M.

The choice of this resin is justified for at least two reasons. The first reason is that the Bis-GMA resin has the same chemical nature as the resin of the cosmetic composite material which will be attached to it. This allows chemical bonding between them, that is to say a fusion of the two materials, which eliminates the problems of decoalescence between these materials.

The second reason is that the Bis-GMA resin shrinks when it sets (hardening). The larger the volume of resin, the greater the shrinkage.

This withdrawal was considered until now as the major handicap of obturation composites which, after hardening, decrease in volume with the formation of spaces between the composite and the edges of the cavity which encloses them, hence salivary infiltration and resumption possible cavities.

In the case of the composite material of the invention, this withdrawal when taken is an advantage because it will promote the sliding and the release of the hardened part out of its sheath when it is desired to separate them. For this purpose, the volume of fibers in the reinforcement will preferably be advantageously between 40 and 80% by volume relative to the total volume of fibers plus resin. Preferably and most advantageously, the volume of resin in the composite material will be 40 to 50%. The dental prosthetic element obtained must have the following minimum mechanical properties:

- flexural strength: more than 1000 Mpa,

- flexural module: more than 40 Gpa.

The sheath of the composite material of the invention is a sheath made of a flexible polymeric material and capable of being put into the desired shape. Among the polymeric materials which can be used, mention will be made of polyolefins, polyvinyl chloride, polyethylene, polypropylenes, silicones, silicone rubbers, etc. As said, preferably, the sheath 3 is airtight and, for use with a thermosetting resin, withstands the curing temperature of the resin.

Generally, the sheath will have to resist a temperature higher than 100 ° C, preferably higher than 140 ° C.

When the resin 2 is photocurable, the sheath is transparent to light of the appropriate wavelength. The ability of the composite material of the invention to be shaped in its sheath will be determined by the choice of the polymeric material making up the sheath as well as the thickness of the sheath. However, the thickness of the sheath must be sufficient so as not to break during the shaping of the prosthetic elements to be obtained. For this purpose, preferably, the sheath has a thickness of between 0.2 mm and 1.5 mm.

Advantageously, the sheath will be heat-shrinkable, which has the advantage of compressing and condensing the composite material during its polymerization (hardening), thus optimizing the mechanical properties of the prosthetic element obtained. The preferred heat shrink tubing is made of a modified polyolefin, irradiated polyolefin, silicone, polytetrafluoroethylene (PTFE), or polypropylene material.

In general, the sheath will be made of a polymeric material such as polyvinyl, polyvinyl chloride (PVC), polyethylene, polypropylene, polyurethane, a polyolefin, polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE, teflon), a silicone rubber, an elastomer, a silicone and their derivatives.

The composite material of the invention therefore consists of fibers 1 impregnated with curable and uncured resin 2, introduced into a sheath 3 made of a flexible material capable of being shaped. This fiber composite material is introduced into the sheath 3, for example by pressure extrusion, in order to obtain a product free of air bubbles and with constant proportions of resin and fibers. The resin must be unpolymerized (not hardened) and for this purpose, the sheath will, as described above and according to the nature of the resin, be transparent to light of desired wavelength and / or resistant to temperature. hardening of the resin.

In addition, when the resin is a resin whose polymerization is inhibited by oxidation by contact with air, and this is the case for the preferred Bis-GMA resin, in particular for use in dentistry, the sheath protect the resin from such contact with air. Indeed, the polymerization of the resin takes place while the fiber composite material is in its sheath. There is then no contact with air during the polymerization of the resin.

In order to avoid any oxidation and any exit of the composite material, the sheath will be closed at both ends by heat sealing or mechanical stapling and brought to the desired length. In the case of a composite material having the form of a plate, the sheath will be heat-sealed according to the desired shape and then cut at its periphery, as shown in FIG. 3.

In order to avoid pre-hardening (pre-polymerization) of the resin during storage or transport of the composite material of the invention, the composite material of the invention in its sheath will also be packaged in a package opaque to the light. An appropriate material for this packaging is for example aluminum.

As has already been said, the composite material of the invention finds more particularly use in dentistry, in the fields of endodontics, prosthetics, orthodontics and periodontology.

It can in particular be used for the production of compression splints in orthodontics or periodontology, crown frames or bridges in composite material in joint prosthesis, reinforcement, coronoradicular reconstruction (called post-posts) in dentistry restorative. However, of course the composite material can be used to manufacture prosthetic elements other than dental, as will appear to those specialized in the art.

Another field of application of the composite material of the invention is the manufacture of resistant parts in a corrosive atmosphere, as in the field of the chemical industry. The composite material of the invention can be used to manufacture parts of curved, complex shapes such as for example springs.

This will be obtained by winding the composite material of the invention, in its sheath, on a mandrel, having the desired dimensions for the spring, hardening of the resin by application of the appropriate stress on the composite material in its sheath, and separation of the hardened composite material and the mandrel and finally removal of the sheath.

Another particularly preferred field of application of the composite material of the invention is the manufacture of brassiere cup frames.

In fact, for years, brassiere manufacturers have wanted to replace the metal frames of cups that twist in the wash, rust, pierce fabrics, lose their effectiveness over time and break through fatigue of the metal.

There are many imperatives to respect: the underwire of the bra cups must resist very corrosive washing agents, mechanically resist washing the machine (test of 50 washes) and this at 50 ° C, they must keep the same elasticity over time and be non-toxic and non-allergenic to the skin.

In addition, there are 20 sizes per model and more than 50 models that change with the new collections, which excludes making bras underwire by injection because of the cost of the molds.

Furthermore, the shape of the brassiere cup frames is asymmetrical and non-nestable: they cannot be cut from the plates because this leads to unacceptable losses of material.

The composite material of the invention makes it possible to manufacture reinforcements economically while overcoming the drawbacks mentioned above of metallic reinforcements. In this case, the fibers 1 of the composite material will be chosen from carbon fibers, glass fibers or aramid fibers, of the kevlar type.

Resin 2 will be chosen from polyester, vinylester and epoxy resins which are thermosetting. The sheath 3 will preferably be made of a polymeric material such as polyethylene, polyeturethane, polypropylene, PTFE, silicones or their derivatives. The sheath 3 may be transparent or opaque. In addition, its color may be in harmony with the color of the fabric that covers it.

Thus, for the manufacture of brassiere cup frames, the composite material of the invention, in its sheath and not hardened, will be wound on a mandrel which has the shape of two frames to be obtained face to face. The winding finished, the mandrel with the composite material to be wound will be placed in a heated enclosure where the material hardens.

The mandrel covered with the hardened composite material in its sheath is then placed on a device which comprises two diamond saws which, by translation, cuts the composite releasing the completed reinforcements. For this purpose, the mandrel has two slots for the passage of diamond saws.

Thus, with the composite material of the invention, it is possible to produce, at a very advantageous cost, reinforcements of brassiere cups in a composite material having all the required properties. Indeed, with the composite material of the invention, the mandrels can be designed as fixed cores which can receive the different shapes to be obtained, these shapes being removable and their production by mechanic welding or by machining as described above being of an unparalleled cost price with injection molds.

Furthermore, the reinforcements produced with the composite material of the invention do not need to be painted, unlike the metallic reinforcements of the prior art, which were painted to avoid their oxidation and corrosion in the washing baths and also to improve user comfort. Currently, moreover, the ends of the metal frames are painted with a thick plastic paint which erases the roughness, which moreover reappears with use and washing and which can thus injure the user or tear the fabric. , when the dye flakes off. This is, moreover, to make it possible to differentiate the reinforcements to be posed on the left cup of the reinforcements to be posed on the right cup, because the ends are coated with paints of different colors at each end in order to differentiate them and to be able to distinguish them during assembly in the cups.

The brassiere frames obtained with the composite material can be painted in the same way at the ends. However, advantageously, to allow this distinction between the left and right reinforcements, the ends of the reinforcements produced with the composite material of the invention will be covered with caps in a heat-shrinkable plastic material with a thickness of 1 to 2 mm. The heat-shrinkable plastic will then be heated to round the ends. These caps will of course be of different colors as desired.

These operations can be fully automated and do away with painting operations, which represent not only an economic advantage, but also from the point of view of safety and the environment, since this avoids the release of vapors from paint solvents. The composite material of the invention can be produced, as already mentioned, by introducing fibers impregnated with resin into their sheath by extrusion under pressure. The invention however provides a method for introducing the fibers into their sheath. The principle of this process is, as shown in Figure 16, to introduce the fibers 1 impregnated with resin in their sheath 3 by pulling them in and through the sheath 3 using a fiber puller noted 40 in figure 16.

More precisely, and as shown in FIG. 17, the method of manufacturing the composite material of the invention consists in introducing into one end of the sheath 3, a portion of a hollow rigid tube noted 41 in FIG. 17, having a outer section substantially equal to the inner section of the sheath 3, the other portion of the tube 41, leaving the sheath 3. The hollow tube 41 is fixed by any suitable means 42 to the sheath 3. This clamping means 42 can be for example a hose clamp. The hollow tube 41 is held in a horizontal position by any suitable means 43. The portion of the tube 41 leaving the sheath 3 comprises an opening 44 allowing the introduction of resin 2 into the hollow tube 41. The resin 2 is placed, for example , in a tank 45 opening through the opening 44 in the tube 41. The fiber puller 40, which can be a metal wire or any other material but which allows the guidance and the traction of the fibers in the tube 41 and the sheath 3, is introduced into the tube 41 and the sheath 3. The fiber puller 40 has a section whose external dimensions are smaller than the dimensions of the internal section of the sheath 3 and of the tube 41 to allow the translational movement of the fiber puller 40 in the tube 41 and the sheath 3. The fiber puller 40 has a length greater than the tube 41 and sheath 3 assembly. As shown in FIG. 17, the fiber puller 40 is linked at its end coming out of the tube 41 with fibers 1. It is then pulled by its end leaving the sheath 3. The fibers 1 then enter the tube 41. They are impregnated with resin 2 during their passage under the orifice 44 and they penetrate impregnated with resin 2 in the sheath 3 where they are pulled to the desired length of the composite material of the invention. In order to obtain a composite material according to the invention having regular and homogeneous dimensions, the sheath 3 is moreover placed in a hollow element 45 sliding on the sheath having a shape and internal dimensions corresponding to the shape and the dimensions to be obtained. for the uncured composite material of the invention.

In a preferred embodiment of the process for manufacturing the composite material of the invention, the sheath 3 will be made of a heat-shrinkable material. Indeed, it is possible in this case to choose a sheath having an internal section of dimensions greater than those of the composite material to be obtained, which allows easier introduction of the fibers impregnated with resin, thanks to the fiber puller 40, in the sheath.

The sheath is then, after introduction of the fibers impregnated with resin and removal of the fiber puller, heated for example using a device blowing hot air, before, or at the same time, or after the sliding of the 'hollow element 45. The sheath thus retracts, to the desired dimensions and shape, on the fibers impregnated with non-polymerized resin.

To better understand the object of the invention, several modes of implementation will now be described by way of purely illustrative and nonlimiting examples.

EXAMPLE 1 Manufacture of compression splints by direct shaping

The composite material of the invention here consists of longitudinal fibers, unidirectional, parallel, made of glass made from zirconium oxide such as glass sold under the brand Cem-FIL ^® of Saint Gobain. They are impregnated with Bis-GMA resin. These resin-impregnated fibers are contained and maintained, in a sheath conforming to their shape, closed at both ends.

The composite material of the invention, in its sheath, is then put into the shape of the desired splint on a plaster model which is an imprint of the patient's teeth.

As illustrated in FIGS. 7 and 8, this shaping can be a direct shaping. In this case, the dentist or prosthetist receives the composite material in its sheath and wrapped in a sachet which protects it from light (for example aluminum to prevent the onset of photocuring). He chooses the preform or the profile and the length he needs. After opening the protective packaging, the composite material of the invention is, for example, like a flexible tube filled with fibers impregnated with unpolymerized resin and closed at both ends.

One end of the sheath denoted 3 in FIG. 7, containing the non-hardened fiber composite material, is fixed by bonding to the plaster imprint denoted 5 in FIG. 7, then the fibers impregnated with resin contained in the sheath 3 are shaped, on imprint 5, to the desired shape.

It may be useful to pierce the sheath slightly to create a vent, the contained resin can thus flow and give flexibility. The composite material having been shaped, the resin at the vent is light-cured. It hardens and can no longer flow. The imprint 5 and composite material assembly in its sheath is then light-cured in a laboratory light chamber and then thermoset in an enclosure at 100 ° C. for the time necessary to complete the hardening. The sheath 3 is then cut, removed and the splint denoted 6 in FIG. 8 released from the sheath is ready for use. Indeed, the polymerization took place with the composite material in its sheath, no non-polymerized surface layer is present. It is therefore not necessary, as with the process and the composite material of the prior art, to remove this surface layer. It is also possible in this way, in addition to a compression splint, a bridge reinforcement.

Of course, these elements can be produced with a composite material whose resin 2 is different from the Bis-GMA resin, for example an epoxy resin. EXAMPLE 2 Manufacture of compression splints by indirect shaping

In the same way as before, the dentist or the prosthetist receives the composite material in its sheath and wrapped in a sachet which protects it from light in order to avoid a light-curing start. He chooses the preform or the profile of the length he needs.

However, in this case, as shown in FIG. 9, the exact relief model, noted 7 in FIG. 9, of the desired compression splint is first made in wax on the plaster impression 5 ′ of the teeth. Then, a hollow imprint of the compression splint to be obtained is produced by molding the imprint 5 'provided with the relief model of the splint to be obtained in a mold made of unhardened transparent silicone. The transparent silicone is then hardened, the imprint released and the relief wax model is removed from the silicone mold and the plaster imprint by scalding.

The composite material of the invention in a sheath is then placed in the hollow imprint 8 of the silicone mold. As shown in FIG. 10, the plaster imprint 5 ′ from which the raised model 7 has been eliminated, is then again pressed into the silicone imprint 9, comprising the composite material of the invention in the intaglio imprint 8 of the splint to obtain. The composite material of the invention in its sheath is then light-cured through the silicone mold 9 and then released from the mold. It is then thermoset. The transparent sheath is removed. The splint is finished.

It is thus possible to make compression splints in half-rod very precisely adapted, from a round sheath. We can also make crown copings with preformed plates in a circle.

EXAMPLE 3 Manufacture of bridge reinforcements

As shown in Figure 4, a bridge consists of a) two pillar elements noted 10 in Figure 4, supported on machined teeth, noted 11 in Figure 4, present on each side of a toothless sector and b) a part, denoted 12 in FIG. 4, called pontic replacing one or more missing teeth. Then, the final shape of the bridge is obtained by applying a cosmetic part 13 made of a cosmetic composite material to the reinforcement of composite material, this latter part constituting the anatomy and the color of the abutment teeth and of the tooth (s). ) absent, noted 14 in FIG. 4. To manufacture a bridge, it is therefore necessary, beforehand, to manufacture a reinforcement or reinforcement. This manufacturing is done as explained for the compression splint from a plaster impression of the patient's teeth.

More precisely, the abutment teeth 11 are cut in a substantially conical shape in order to be able to insert and remove the prosthetic element to be obtained. To make the frame 10, 12, each cut 11 tooth 11 must first be covered with a yoke 10, the yokes 10 then being connected together by the deck of the bridge 12. The production of these yokes 10 is complex: they must be completely surrounded with the fiber composite material, the thickness of the fiber composite material must be small at the collar to increase at the top, and the quantity of fibers must be constant.

There are currently glass fiber fabrics impregnated with resin in the form of pellets which are applied by pressing on the cut teeth. This system has two drawbacks, there remains a hiatus at the neck of the teeth because of the viscosity of the resin 2 and on the other hand, the fiber fabric 1 not being contained in an envelope, the thickness of the reinforcement obtained is irregular.

It is also possible to use a wick of fibers impregnated with resin, but the fibers compressed on the surface and on the corners of the cut tooth move apart under the effect of the pressure and moreover, they cannot surround the entire preparation.

These two ways of operating with a viscous and sticky material are difficult to use and give inconsistent results.

With the material of the invention contained in a sheath, it is possible to manufacture regular and precise screeds whatever the shape of the stump of the abutment teeth 11 with perfect control of their thickness and of the orientation of the fibers. This can be done by the manufacturing method by indirect shaping as described in Example 2 or the lost wax method, using the preform assembly for screeds 10 and profile for pontic 12, juxtaposing them and superimposing certain parts stripped of their sheath, of the composite material of the invention, to weld them to each other, as shown in FIG. 14.

However, it is also possible to use the manufacturing method of the invention. With the method of the invention, it will be possible to manufacture screeds 10 precise, perfectly surrounding the cut teeth and whose thickness, as well as the orientation of the fibers, are controlled.

To this end, as shown in FIG. 15, the composite material of the invention is used comprising unidirectional continuous fibers or in the form of braids. At least one end of the sheath will be cut to allow the exit of the fibers impregnated with resin and their winding on the abutment teeth 11. This operation will be carried out on each two cut teeth or more precisely, on the plaster impression of the two cut teeth 11 of the patient to obtain the yokes 10. Then, the sheath containing the composite material will be cut at its two ends as shown in FIG. 15 and we will manufacture, as shown in FIG. 15, the reinforcement arch 12 ', to manufacture the outline of the pontic.

In this manufacturing process, the sheath is used to handle the composite material of the invention. More precisely, as illustrated in FIG. 11, a perfect replica 14 is made of plaster of the tooth cut in the mouth. This plaster replica 14 is provided with a metal fixing rod denoted 15 in FIG. 11 which allows it to be repositioned in the overall impression of the teeth.

This imprint 14, 15 is then placed on a mechanical, manual or electrical device which rotates it on itself like a coil. The dentist or prosthetist can then wind the resin-impregnated glass fibers which emerge from the sheath as and when taking the sheath by the part still protected by the sheath and unwinding the material as desired on the model 14 of the cut tooth. A stop plate 27 abuts against the free part of the replica 14, to hold the composite material on this replica 14. When the result is satisfactory, the dentist or the prosthetist polymerizes the assembly as previously described.

The pillar yokes are then connected to each other by the thicker reinforcement of the pontic. We previously cleared the ends of the sheath to allow its bonding to the screeds, as shown in Figure 15. This pontic is made as described above either directly from a suitable profile, or by the lost wax method and molding as described for the compression splints.

A particularly advantageous device for implementing the method of the invention is a device as shown in FIG. 11. This device comprises a base or support denoted 16 supporting a horizontal bar or upright denoted 17. The bar 17 is movable from front to back and from left to right on the support 16. The bar 17 can be fixed at the desired position on the support 16 by any suitable fixing means, such as for example a clamping nut 18, 18 '.

A first vertical or upright bar, noted 19, is fixed at its lower end, for example by a clamping screw 20, to a first end of the bar 17 (on the right in FIG. 11). The vertical bar 19 is movable relative to the bar 17 from left to right and from front to back. It can be immobilized in position on this horizontal bar 17 by the clamping screw 20.

The vertical bar 19 supports at its upper end a device noted

21 allowing the rotation of a rotary axis denoted 22 which is fixed to it, the rotary axis 22 being in the extension of the device 21, and comprising a jaw 23,

23 ', 23 ", 23'" allowing the fixing of the impression 14, 15 of the prosthetic element to be obtained.

The jaw is any device allowing the gripping and fixing of the impression of the prosthetic element to be obtained on the axis of rotation 22.

It can, as shown in FIG. 20, be a device 23 ′ comprising at one end a hollow part 50 allowing the engagement in tightness of the end 15 of the impression and, at the other end, a hollow part 51 provided a fixing means 52 such as a screw for fixing the jaw 23 'on the axis of rotation 22.

The jaw can also be, as shown in FIG. 21, a device comprising at its end 50 ′ a device 23 "with articulated jaws allowing the gripping and fixing of the end 15 of the tip of the prosthetic element to be obtained, thus that a tightening, for example by means of a nut 53 and, at its other end, a hollow part 51 provided with a fixing means 52 of the jaw 23 "on the axis of rotation 22.

The jaw can also be, as shown in FIG. 22, a device 23 ′ "whose end 50" comprises an outgoing cone for fixing the end 15 and at the other end the same device 51, 52 as described for jaws 23 'and 23 ".

A second vertical bar denoted 24 is fixed, at its lower end, by a clamping screw 20 ', to the free end of the horizontal bar 17 (on the left in FIG. 11). The vertical bar 24 is movable relative to the horizontal bar 17 from left to right and from front to back and can be immobilized on the horizontal bar 17 by the clamping screw 20 '. The vertical bar 24 supports at its upper end a device 25 with ball bearing receiving a horizontal axis noted 26. The horizontal axis 26 rotates freely in the device 25 and can slide from left to right in this device. The horizontal axis 26 can be locked in translation but not in rotation by any suitable means such as a nut 20 ".

The horizontal axis 26 faces, and is aligned with, the rotary axis 22 and carries at its end facing the rotary axis 22 a stop plate denoted 27, 27 ', 27 ", 27" "perpendicular to Tax horizontal 26. The plate 27, 27 ', 27 ", 27'" and the rotary axis 22 are aligned to allow the positioning between them of the cavity 14, 15, 14 ', 15', 14 ", 15" of the prosthetic element to obtain. The plate 27, 27 ', 27 ", 27'", serves to maintain in position the impression 14, 15, 14 ', 15', 14 ", 15" of the prosthetic element to be obtained, while maintaining the material to the composite on the imprint and allows the rotation of the imprint 14, 15, 14 ', 15', 14 ", 15" on itself, thanks to the rotary axis 22.

The plate 27 can be a plate with parallel faces as represented in FIG. 12 holding the impression in place or, preferably having an element 28 in the shape of a cone to allow the centering and the engagement of the impression of the prosthetic element. to obtain, as shown in Figure 13 where it is noted 27 '. It can also have the shape of a truncated cone 27 "as shown in FIG. 18. It can also have the shape of a hemisphere 27 '" as shown in FIG. 19.

In all cases, it will preferably be made of an elastically deformable material, which will not only allow the blocking of the imprint and that of the composite material on the imprint, but, also, this will make it possible to cover almost all of the 'imprint 14, 14', 14 ".

In practice, the stop plate 27 with parallel faces of elastically deformable material will preferably be used, as shown in FIG. 12 for the impressions 14, 15 of the teeth, such as the incisors and the premolars. The stop plate 27 ′ will preferably be used, as shown in FIG. 13, for the impressions 14 ", 15", teeth with a large occlusal table, just like the stop plate

27 ", as shown in FIG. 18. The stopper plate 27", as shown in FIG. 25, can be used in all cases, depending on its diameter.

Advantageously, the stopper plate 27, 27 ′, 27 ″, 27 ″ ″ will be made of a material that is not adherent with the resin 2, hardened or uncured. The rotary axis 22 can be rotated by the device 21 which can be an electric motor or a crank.

Thus, with the method and the device of the invention, it will be possible to produce the copings of the abutment teeth as well as the pontics for the bridge reinforcements.

EXAMPLE 4 Manufacture of reinforcements of coronoradicular reconstruction called tenons-intraradicular.

A post consists, as shown in Figures 5 and 6 respectively, of a rod of glass fibers embedded in a matrix of hardened resin.

This tenon 28, 28 'is then, as shown in Figures 5 and 6, placed in the plaster cavity 30 of the stump of the tooth to be reconstructed. As in the case of the bridge, a resin in cosmetic composite material 13 ′, 13 "is then applied to the post to give the shape of the desired tooth. During the manufacture of these intraradicular posts and as shown in FIG. 5, the resin of the material making up the post 28, may be different from the cosmetic resin 13 'for reconstitution. This is called heterogeneous restoration. However, in such a case, there is a risk of decoalescence between the cosmetic resin 13' for reconstitution and the post resin 28.

It is therefore particularly advantageous in the context of the invention, to use, as shown in FIG. 6, a cosmetic composite material and a fiber composite material according to the invention both having as resin, a Bis-GMA resin. Indeed, the pin 28 'is then made of a composite material whose resin is identical to the cosmetic resin 13'. This makes it possible to carry out a tailor-made, monolithic and homogeneous reconstitution, the elements of which adhere chemically to each other, which is a great advantage compared to the studs and associated products of heterogeneous nature capable of dissociating as shown in FIG. 5. In summary , the invention provides a fiber composite material contained in a sheath or an envelope which gives it the desired shape. Preferably, the fibers of the fiber composite material are zirconia-based glass fibers which have qualities much superior to those of conventional glass fibers, resistant to acid and alkaline corrosion agents, to hydrolysis in a humid medium and which have better mechanical properties, higher strength fatigue and which can be worked without endangering human health. The resin matrix is most advantageously a Bis-GMA resin of the same kind as the sealing resin used for bonding the prosthetic element and the cosmetic reconstitution material. In fact, there is then a real chemical adhesion between the prosthetic element and the cosmetic composites which are added thereto and a homogeneous restoration is therefore obtained without risk of dissociation.

The method of manufacture and presentation of the composite material of the invention, more particularly in a transparent sheath, makes it possible to obtain various profiles and preforms which can be used as such or transformed on demand, and which allows their photopolymerization on protected from oxygen, which reinforces their resistance to corrosion and finally simplifies the handling of these composites and their final machining.

In fact, in all the manufacturing methods of the invention, the prosthetic element obtained can then be, if necessary, machined to polish it and perfect its final shape.

The composite material of the invention is less sensitive to corrosion, easier to use and therefore more economical than the metals used until now. It also has better results than microcharged dental composites whose mechanical properties are insufficient. The invention therefore provides a solution to this problem and opens the way to a more aesthetic prosthesis, more affordable than the conventional ceramic on metal prosthesis.

In addition, the mechanical behavior of fiber composite materials with elastic moduli closer to that of the tooth makes them less fragile than metal or ceramic, which immediately and fully transmit forces, increasing the risk of fractures of the restored teeth.

The reinforcements made of fiber composite material of the invention are a happy medium between the requirements of solidity, durability and esthetics of dental prostheses and allows lighter treatments on mechanical as well as financial planes.

Of course, the invention is in no way limited to the embodiments described and illustrated which have been given only by way of examples. Thus, although the invention has been described in the examples with reference to dental prosthetic elements, any other prosthetic element can be manufactured with the composite material of the invention, due to its biocompatibility with the human body.

In addition, as we have seen, it can be used in other fields of industry, such as for example to manufacture profiles of complex shapes, such as fiber springs or brassiere frames. This means that the invention includes all the technical equivalents of the means described as well as their combinations if these are carried out according to the spirit.

Claims

1. Composite material of the type comprising fibers (1) impregnated with a resin (2) curable by application of at least one stress, the fibers (1) being in the form of unidirectional, parallel fibers or wicks or twists or woven or non-woven braids or ribbons, or woven or non-woven fiber plates, and being wrapped in a sheath (3) of a flexible material to allow the sheath containing the impregnated fibers (1) to be shaped resin (2) in the form of an object to be obtained, characterized in that the sheath (3):

- maintains and compresses the fibers (1) impregnated with resin (2) not hardened to the desired shape,

- is closed after introduction of the fibers (1) impregnated with resin (2) not hardened and, - is made of an airtight material.

2. Composite material according to claim 1, characterized in that the fibers (1) are selected from the group consisting of glass fibers, quartz fibers, silica fibers, aramid fibers, kevlar fibers , polyethylene fibers, carbon fibers and mixtures thereof.

3. Composite material according to claim 1 or 2, characterized in that the fibers (1) are glass fibers based on zirconium oxide.

4. Composite material according to claim 3, characterized in that the glass constituting the fibers (1) contains between 16.8% and 17.1% by weight of zirconium oxide relative to the total weight of the glass.

5. Composite material according to any one of the preceding claims, characterized in that the hardenable resin (2) is a resin hardenable by the application of heat and / or light.

6. Composite material according to any one of the preceding claims, characterized in that the hardenable resin (2) is Bis-GMA resin.

7. Composite material according to any one of the preceding claims, characterized in that it contains between 40% and 80% by volume of fibers (1) relative to the total volume of the fibers (1) and of the curable resin (2 ).

8. Composite material according to any one of the preceding claims, characterized in that the sheath (3) is made of a transparent polymeric material.

9. Composite material according to any one of the preceding claims, characterized in that the sheath (3) is made of a polymeric material resistant to a temperature above about 140 ° C.

10. Composite material according to any one of the preceding claims, characterized in that the sheath (3) is made of a heat-shrinkable material.

11. Composite material according to any one of the preceding claims, characterized in that it is also wrapped in a packaging made of a light-tight material.

- 12. Use of the composite material according to any one of the preceding claims for the manufacture of prosthetic elements, in particular dental.

13. A method of manufacturing prosthetic elements, in particular dental, characterized in that it comprises the following steps: a) shaping of the prosthetic element to obtain composite material according to any one of claims 1 to 1 1 , in its sheath (3), b) hardening of the resin (2) by application of the appropriate stress (es), through the sheath (3), c) removal of the sheath (3) , and d) optionally machining of the prosthetic element thus obtained.

14. Method for manufacturing prosthetic elements, in particular dental elements, characterized in that it comprises the following steps: a) placement of the impression of the prosthetic element to be obtained on a rotary axis, b) cutting of at least one end of the sheath (3) of the composite material according to any one of claims 1 to 11, c) winding, on the imprint of the prosthetic element to be obtained, fibers (1) impregnated with resin (2) emerging from the cut end of the sheath, by rotation of the rotary axis, until the shape is obtained desired prosthetic element to be obtained, d) hardening of the resin (2) by application of the appropriate stress (es), on the impression, e) separation of the prosthetic element thus obtained and of the impression, and f) optionally machining of the prosthetic element thus obtained

15. Device for manufacturing prosthetic elements, in particular dental elements, characterized in that it comprises: - a base or support (16) supporting a horizontal bar (17), the bar (17) being movable from front to back and from left to right on the support (16) and can be fixed on this support (16), by a clamping screw (18, 18 '),

- A first vertical bar (19), fixed at its lower end by a clamping screw (20) to a first end of the horizontal bar (17) and movable relative to the latter from left to right and from before rear, and can be immobilized on the horizontal bar (17) by the clamping screw (20 '), this first vertical bar (19) supporting at its upper end a device (21) allowing the rotation of a rotary axis (22) which is fixed to it, the rotary axis (22) being in the extension of the device (21) and being provided with a jaw (23) for removably fixing the imprint (14, 15, 14 ', 15 ', 14 ", 15") of the prosthetic element to be obtained, on the axis of rotation 22,

- a second vertical bar (24) fixed at its lower end by a clamping screw (20 ') to the second end of the horizontal bar (17), and movable relative to the latter from left to right and from before behind and able to be immobilized on the horizontal bar (17) by the clamping screw (20 '), this second vertical bar (24) supporting at its upper end a device (25) with ball bearings receiving a horizontal axis (26 ) with free rotation in the device (25), the horizontal axis (26) carrying at its end facing the rotary axis (22), a stop plate (27, 27 ', 27 ", 27"") perpendicular at the horizontal axis (26) and at its other end a blocking device (20 ") allowing blocking the horizontal axis (26) movable from front to rear in the ball bearing device (25), in the desired position,

- the plate (27, 27 ', 27 ", 27'") and the rotary axis (22) being aligned to allow positioning of the imprint (14, 15, 14 ', 15', 14 "between them, 15 ") of the prosthetic element to be obtained and the rotary axis (22) carrying at its end a jaw (23, 23 ', 23", 23' ") to hold this impression (14, 15, 14 ', 15 ', 14 ", 15") by part 15, 15', 15 ".

16. Device according to claim 15, characterized in that the stop plate (27) is a plate with parallel faces.

17. Device according to claim 16, characterized in that the plate (27 ') comprises a centering element (28) in the shape of an outgoing cone to allow positioning of the impression of the prosthetic element to be obtained.

18. Device according to claim 15, characterized in that the stop plate (27 ") has a truncated cone shape.

19. Device according to claim 15, characterized in that the stop plate (27 '") has the shape of a hemisphere.

20. Device according to any one of claims 15 to 19, characterized in that the stop plate (27, 27 ', 27 ", 27'") is made of an elastically deformable material.

21. Use of the composite material according to any one of claims 1 to 11 for the manufacture of brassiere cup frames.

22. Underwired bras, characterized in that they are made of the composite material according to any one of claims 1 to 11, hardened.

23. A method of manufacturing the composite material according to any one of claims 1 to 11, characterized in that it comprises the introduction by pressure extrusion of fibers (1) impregnated with hardenable resin (2) which is not hardened in the sheath (3) and the welding of the open ends of the sheath (3) by stapling or heat sealing.

24. A method of manufacturing the composite material according to any one of claims 1 to 11, characterized in that it comprises the following steps: a) introduction into one end of the sheath (3) of a portion of a tube rigid hollow (41) having an external section substantially equal to the internal section of the sheath (3), the other portion of the tube (41) leaving the sheath (3), b) fixing the tube (41) in the sheath (3) by any suitable means (42), c) introduction into the sheath (3), through the tube (41) of a fiber puller (40), the fiber puller (40) having a length greater than the length of the sheath (3) and of the tube (41) and exiting at one end of the sheath (3) and at the other end of the tube (41), the fiber puller (40) having a section allowing it to slide freely in the sheath (3) and the tube (41), d) fixing the free end of the fiber puller (40) leaving the sheath (3) at one end of the bundle of fibers (1) to be introduced into the sheath (3), e) impregnation of the fibers (1) before their entry into the sheath (3) with the uncured curable resin (2), f) introduction of the fibers (1) impregnated with resin (2) into the sheath (3) by pulling on the free end of the fiber-puller (40) leaving the tube (41), g) sliding of the sheath (3), during the introduction of the fibers (1) impregnated with resin (2) into a hollow element (45) whose internal section has the shape and dimensions of the external section of the composite material in its sheath, not hardened, to be obtained.

25. The method of claim 24, characterized in that the sheath (3) is made of a heat-shrinkable material and in that it further comprises, after stage f) and before, at the same time, or after step g), a step of heating the sheath (3).