EP2453829A1

EP2453829A1 - Fixed dental prosthesis

Info

Publication number: EP2453829A1
Application number: EP10752181A
Authority: EP
Inventors: Stephan Givel
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-07-13
Filing date: 2010-07-13
Publication date: 2012-05-23
Also published as: WO2011007317A1

Abstract

The invention relates to a fixed dental prosthesis comprising at least one artificial tooth (15) and a means for rigidly connecting the latter to at least two natural abutment teeth (1 and 2) in the mouth, the specific features of which are that said means includes a framework comprising at least one metal part (7) provided with circular perforations, wherein said piece forms a perforated guide, as well as metal rods with round cross-section (A, B, C, D, E, F), the diameter of which is selected so as to slidingly engage with said perforations of the perforated guide. Among said rods, certain ones referred to as anchoring rods (A and B) extend outside the pontic and, by means of the position and size thereof, firstly engage with the top perforations of the perforated guide. The various aforementioned elements form a periodontal splint and are arranged relative to each other such that the relative position of the artificial tooth or teeth with regard to the splint to which the former is/are attached is selected such that the rods engaging with the top perforations can occupy an intratooth position in the abutment teeth. The anchoring rods of the prosthesis are subsequently placed in recesses forming two occlusal-proximal cavities.

Description

FIXED DENTAL PROSTHESIS

This application claims the priority of the earlier Swiss applications N ° 01101/09, 01102/09, 01103/09, 01104/09, all filed on July 13, 2009 and the earlier Swiss application N ° 00557/10 of April 19, 2010 to the name of the present applicant, the contents of these applications being incorporated by reference in their entirety in the present application.

Technical area

The present invention relates to a fixed dental prosthesis and also relates to a set of components, namely perforated guide (s) and rods for producing the prosthesis.

Prior art

There are many techniques available in dentistry to replace missing teeth, in order to maintain a functional and aesthetic dental arch. When there are teeth on the arch, these are pillars on which it is possible to support to retain and stabilize the prosthesis. It is called a fixed prosthesis when the prosthesis is not intended to be removed and put back in the mouth by the patient himself. The pontic is the part of the fixed prosthesis that is external to the (or) tooth (s) pillar (s) and which has the artificial tooth (s).

Fixed prostheses are those that will most resemble the natural state. These are also the most expensive solutions because they require a great time of preparation in the mouth by a qualified dentist with a specific training. These solutions also give rise to significant laboratory costs. To make a fixed prosthesis between pillars, or a cantilever extension supported on pillars, it is necessary to prepare the pillars to fix an anchor. An alternative anchor is to make a crown for each of the pillars, another variant is to set up "in / onlays" in the pillars, a third variant is to stick an applique in a generally lingual position on the pillars, for example the "Maryland Bridge".

When the pillars are primed, according to one of the variants mentioned, one can either achieve in one piece and by casting the armature of the anchors and the pontic, or individually realize several separate parts, which are then welded together. This gives the frame of the prosthesis, which is rigid and fixed. In either case, full casting or welding, it is necessary that the insertion axes relating to each of the prepared pillars are compatible, which is very demanding and represents a great difficulty, requiring a lot of experience and experience. practical to be mastered. In addition, when this operation is performed, whether by casting or welding, it is excluded to think about folding or deforming the armature of the prosthesis. If by chance the insertion axes are not what they should be, especially if the frame can not fit fully and simultaneously on the pillars, we can at best only grind the pillars or cut the frame to weld it back to a better position. The impossibility of bending, bending or warping the armature, respectively the prosthesis, is very penalizing and it is partly in order to remedy this aspect that the present invention was born.

The axes of the pillars can also be simply incompatible, because too divergent. We then retain an embodiment in two elements, which will not be welded, but secured by means of a slide. In this hypothesis, not only the dentist must be trained and practiced, but the same goes for the laboratory technician for whom this operation is always a challenge. The solution of fixed prostheses is in itself expensive, but it also has the potential for a serious increase in cost because of the difficulty of implementation. The cosmetic part of the prosthesis, or the covering, partially or totally covers the frame, that is to say the pontic frame and often also the pillar frame; which is not the case for a Maryland bridge. The variants of the state of the art briefly mentioned above have, to more or less pronounced degrees, a major drawback which is their cost. Indeed, they consume all a considerable time of realization, that must devote the dentist, the prosthetist, and most often both. We think less about it, but we must also take into account the fact that the patient also spends a lot of time on his treatment and that it has a cost. Finally, when crowns must be made on healthy teeth in order to fix a prosthesis, mutilation heavy teeth in good condition objectively remains a waste. Purpose of the invention

The object of the present invention is to provide a family of prostheses whose characteristics allow three things, and allow a fourth, without loss of performance compared to the state of the art. In the first place, a substantial reduction in the cost of implementation. In the second place, a better ease and security of realization thanks to a lesser degree of sophistication or technicality. Thirdly, an improved reversibility. And fourthly, the possibility of making prostheses not completely rigid, that is to say prostheses with limited mobility, but noticeable, abutment teeth between them, which allows each to "move" according to the nature and to the extent claimed by nature.

For this purpose, the fixed dental prosthesis comprises at least one artificial tooth and means of securing it with at least two natural abutment teeth of the mouth, and it is distinguished by the fact that said means comprise a frame comprising a at least one metal part provided with circular perforations, said part forming a perforated guide, and secondly metal rods of round section whose diameter is chosen to collaborate in sliding with said perforations of the perforated guide; Among these rods, some, called anchorage, extend outside the pontic and, by their position and size, collaborate in a privileged manner with the perforations of the perforated guide, the various elements together forming a periodontal splint and being arranged relative to one another such that the relative position of the artificial tooth (s) relative to the splint on which it is (are) fixed (s) is chosen so that the stems collaborating with the apical perforations can occupy, in the abutment teeth, an intra-dental position; when the anchoring rods of the prosthesis are subsequently placed in housings forming two occluso-proximal cavities, housing also provided for this purpose in each of the natural abutment teeth. For the same purpose, the present invention also relates to a set of components intended for producing a fixed dental prosthesis whose particularity is to comprise at least one perforated guide and two rods.

Description of the invention

The following description refers to the drawing in which:

- Figure 1 shows in perspective three possibilities of preparing a pillar tooth intended to accommodate, alone, or in combination with another pillar, a prosthesis according to the invention.

- Figure 2 shows, in four planks a simple example of

the assembly of the framework of the prosthesis according to the invention, for an interposed artificial tooth.

- Figure 3 shows in two boards, the top and side views of the prosthesis according to the invention, for an interposed artificial tooth. FIG. 4 shows, by two perspective views, a transfer guide for prostheses according to the invention, alone and then as at the final sealing.

FIG. 5 is a perspective view of a detail of the prosthesis according to the invention.

FIG. 6 is a perspective view of three details of the prosthesis according to the invention.

FIG. 7 shows, by a profile view (a), a view from above (b) of a framework of the prosthesis according to the invention and finally, by a profile view (c) and from above (d) the same frame example but made this time to allow the movement of the abutment teeth relative to each other.

- Figure 8 shows, in four views from above and a side view, a prosthesis according to the invention for an artificial tooth extension.

- Figure 9 shows in a side view, a top view and another side view, a framework of the prosthesis according to the invention for a double interleaved with two artificial teeth.

Before embarking on the presentation of the prosthesis according to the invention, it seems appropriate to examine from the outset the manner in which it is necessary to prepare the abutment tooth or teeth with which the prosthesis can collaborate. In Figure 1, commented below, is drawn only one tooth, while in most cases intercalated prosthesis two teeth are involved. This duplicity is translated by the split marks 1 and 2 which designate the tooth itself and the split marks 5 and 6 which designate the cavity which is hollowed out there.

In FIG. 1, it is observed in the three cases a, b and c that a pillar 1, 2 has been primed in a very elementary manner since an occluso-proximal cavity has simply been made 5, 6, which represents the simplest exercise a student in dentistry can learn. It is noted in passing that, in all three cases, the cavities 5, 6 are made at a point in the tooth that has often been damaged by decay and is closed. This is how one often has in fact an old filling that is eliminated to form the cavity 5, 6 and this makes it possible not to touch, or to touch very little, to the healthiest parts of the abutment teeth.

The pillar tooth illustrated in FIG. 1a represents the most elementary primer, the size of the cavity being simply related to the expected dimensions of the retention member to be implanted, this taking into account the additional volume necessary for the introduction of a compact mass of composites (white filling) and / or glass ionomer intended to seal the anchorage in the tooth. The abutment tooth illustrated in Figure 1b was primed as in the case of Figure 1a, but with creation of a box 10, while in Figure 1c, it is a boxing flared 11.

The boxes 10 and 11 of Figure 1 constitute, independently of any occluso-proximal cavity, a technique taught in dentistry to close proximal caries. This step is therefore well mastered, even if the purpose in which it is used here has nothing to do with the cause of teaching. FIG. 2a shows, from above and in profile, two pillar teeth 1 and 2 in which cavities, 5 and 6 respectively, have been made, in this case as illustrated in FIG. 1c. FIG. 2b shows a perforated guide 7. This perforated guide consists of a metal part made of a dental quality metal or alloy allowing permanent implantation, for example a stainless steel quality implant Aisi 316L, ISO 5832/1 .

The metal piece is provided with circular perforations forming as many tunnels in which metal rods of round section and the same dental quality can be introduced in sliding. The diameter of the metal rods will be chosen immediately below that of the perforations, so that each rod can slide and be placed easily, but without excessive freedom within the housing that constitutes each perforation. As long as the diameter of each perforation is related to that of the rod that is intended for it, and conversely, all combinations, configurations and arrangements are imaginable.

However, the configuration illustrated in Figure 2b represents an excellent compromise in which the perforated guide 7 has five perforations for receiving rods whose primary purpose is to participate in the pontine frame; these five perforations being distributed in "T". The perforated guide 7 further comprises two top perforations located above the horizontal bar of the "T", which are intended to accommodate two rods whose primary purpose is to form the framework of the anchor that will take place in the cavities 5 and 6 of pillars 1 and 2.

In Figure 2c is seen in profile the perforated guide 7, crossed by six rods. Going from the top to the bottom of the figure, there are two rods A and B (the second being hidden by the first) collaborating with the perforations of the guide located above the horizontal bar of the "T". Stems A and B have the primary purpose of constituting the framework of the anchors which, on both sides pontic, will be sealed in the cavities 5 and 6 of the abutment teeth 1 and 2, the length of the rods A and B is chosen in relation to their function.

There is a central rod C, housed in the perforation at the intersection of the two bars of the "T". As mentioned above, given its position, the stem C is primarily intended to participate in the Pontic framework, but in this case its length is greater than that would require this single mission so that the stem C extends beyond pontic and secondary vocation to participate also in the constitution of the framework of the anchorage.

In the perforations near the ends of the horizontal bar of the "T" are housed two rods D and E which occupy a lateral position and participate only in the pontic framework. Finally, a last rod F is placed in the perforation located at the foot of the "T" formed by the perforated guide 7 and this rod F participates only in the pontine framework.

We find in Figure 2d the same elements as in Figure 2c, but seen from above this time.

FIG. 3a shows, placed in the cavities of the abutment teeth, the various elements presented in FIG. 2d, accompanied by an artificial tooth 15 fixed to the pontic framework.

It is the same in Figure 3b where this time are presented in position the elements seen in Figure 2c.

It may be noted, for the sake of clarity, that for the configuration presented as a simple example in FIGS. 2 and 3, the width of the perforated guide 7 measured along the axis of its perforations is 3 mm, the tunnel diameter 0.8 mm; while the diameter of the rods is 0.78 mm and the length of the various rods is respectively: A and B 15 mm; C 9 mm; D, E and F 5 mm.

As mentioned in the review of the prior art, it is highly desirable to be able to bend, bend or warp the framework of the prosthesis to perfect the implantation. And the prior art did not allow it. The bending and warping of round wire is a technique well mastered by dentists and dental technicians and they use it daily for other achievements than fixed prostheses.

The folding of the rods used for the framework of the prosthesis according to the invention is thus already acquired even if nobody knows it yet and nothing will limit the faculty of giving to the stems, particularly to the stems participating in the framework. anchoring, the ideal shape according to the needs of each case.

In terms of the concrete realization of the prosthesis, we can perfectly, to dress the framework of the pontic, choose artificial teeth

prefabricated, such as there is a wide range on the market. It will also be possible to make an artificial tooth in the laboratory as is usually done using composite materials, which will offer more possibilities to match the artificial tooth to the rest of the dentition.

The realization of the prosthesis according to the invention naturally requires, upstream as downstream, that the dentist performs the necessary gestures, which are part of the logical sequence described below.

For starters, the dentist can choose between two approaches in the upstream phase. Or the dentist begins, by means of his well-known instruments, to make the occluso-proximal cavities in the abutment teeth, then he takes an impression. Either the dentist starts by taking an impression, in which case the cavities are practiced in the laboratory in the model derived from impression (these cavities will in this case be replicated in the mouth later by the dentist according to the model).

In both approaches above, the impression can be made using an alginate imprint, the cost of which is insignificant. At this stage already, the realization of the prosthesis according to the invention allows a net saving compared to the prior art which requires impressions silicone, or polyether, or hydro-colloids, etc., the price is much higher, both in terms of material supplies and the time of taking.

In the two approaches mentioned above, the rest of the operations take place in the laboratory. The technician first constructs the framework of the prosthesis by introducing stems, in appropriate numbers and positions, into the perforated guide and adapting the length and possibly the shape of the stems.

This construction is primarily intended to ensure that the stems of the anchoring framework occupy an appropriate place in the occluso-proximal cavities of the abutment teeth to be covered by sufficient filling materials, such as composites or other material of the dressing. The purpose of the construction is also to ensure that the pontic framework has an appropriate configuration in the edentulous space to be covered by the cladding forming the artificial tooth (s) while ensuring their optimum fixation. the skeleton of the pontic. As the reader will have noted, there has been no mention of welding, bonding or other sealing between the rods and the perforated guide, and in fact there is no rigid, fixed and autonomous solidarity of the structure. This is why we preferred to speak of frame rather than frame. Of course the prosthesis will have once finished the required rigidity, but its structure is not alone in charge of providing it. The solidification of the framework begins with the creation of the artificial tooth that will seal the pontic bone. The prefabricated teeth that are commercially available, often used for the manufacture of prostheses, including removable prostheses, are generally made of resin, composites or a combination of resin with other components, such as composites or porcelain . If the choice is made, especially to reduce the cost as far as possible, on prefabricated teeth, as described above, they will be fixed on the pontic frame by gluing with resin and / or composites. If the choice is made of fully laboratory-made teeth, they will be built directly on / around the pontic framework either by using composites and / or resins or by producing traditional metal-ceramic teeth. . The technique remains the same, but the cost will be higher in the latter case, without approaching that of the prostheses of the prior art involving crowns.

Returning to the logical flow of operations, the technician is faced with a model with cavities useful in the abutment teeth 1 and 2 (whatever the two approaches mentioned above that has been adopted) and the frame that comes to realise. It will position and fix the artificial tooth 15 on the pontic framework so that the upper surface of the artificial tooth is where it absolutely must be according to all the canons of dentistry and, d on the other hand, so that the rods of the anchoring framework (A and B Figure 3) occupy a position in the cavities, without touching any of the walls of said cavities, at a relative height which allows a sufficient accumulation of material between the top of the stems and the upper surface of the natural teeth, so that the seal is effective and resistant. During this process, both the dentist and the technician have every opportunity to give the various stems the exact shape they want. In this way, once the prosthesis is in place, the parts constituted by the stems of the anchoring frame can be entirely in position.

intradentary, and it is exactly the proper of the prosthesis according to the invention. Depending on the thickness of the covering, the technician deposits an opaque coating on the metal parts, for example a varnish or a lacquer

pigmented, intended to hide their presence and prevent them from being seen in transparency. In addition to the supplies generally available for making fixed prostheses, the prosthesis according to the invention makes it possible to use supplies that hitherto were excluded from fixed prostheses, such as, in particular, prefabricated teeth made of resins, composites or mixtures intended for the manufacture of removable prostheses or materials intended for direct use in the mouth.

Taking again once again the logical course of things, the dentist receives the finished prosthesis given him by the technician and proceeds, if necessary, with the possible adjustments, such as correction of the cavities of the abutment teeth, then drowns the stems of the frame of anchoring the prosthesis then placed in position in a compact mass of glass ionomer and / or composites (white filling) and / or other dental glue, and allows the hardening to be completed. He controls and adjusts the occlusion according to the usual techniques to complete his work.

The proper positioning of the prosthesis before final sealing is not the easiest exercise, so that an additional arrangement is provided to make this operation easier and therefore faster and safer. With reference to FIG. 4, it is observed that the artificial tooth 15 of the prosthesis is provided with a transfer guide 16-17. This transfer guide is intended to make it safer and easier to place the prosthesis in order to seal it. The transfer guide is made by the laboratory technician according to the model of the patient's dentition. The technician may use laboratory resin, or composite, to make the transfer guide. The transfer guide and the prosthesis are secured temporarily, by means of sticky wax, for example, so that the transfer guide can be removed once the seal has been secured.

The transfer guide preferably comprises two wings or lateral extensions 16 and 17, which are adapted to the shape of the natural abutment teeth 1 and 2 so that they will fit exactly said natural teeth ensuring a perfect positioning of the prosthesis with respect to teething and cavities. The transfer guide itself, and in particular its wings, are actually partial traditional prints.

When he benefits from the option provided by the transfer guide, the dentist continues his work by verifying that the prosthesis equipped with his transfer guide, and positioned perfectly thanks to him, is as he wishes. Then he removes the prosthesis and introduces into the bottom of the cavities a mass, glass ionomer and / or composites and / or dental adhesive, up to a height that will allow the rods of the anchoring framework, when pressed in exact position thanks to the transfer guide, to sink roughly halfway up their section. After hardening of this first mass, the transfer guide is disengaged and removed from the teeth. The dentist then finishes filling the cavities in one or more layers and finally finishes his work by optimizing the occlusion.

A variant in the process of constructing the prosthesis is to cover the laboratory at the same time as the manufacture of artificial tooth (s), the anchor rods with composites, while forming inlays entering the occluso-proximal cavities of the pillars. The mouth sealing steps described above do not change, but are made even easier. The simplest and probably the most popular variant of the prosthesis according to the invention has heretofore been described, but there are cases in which a more complex execution is judicious. We think in particular of the execution a prosthesis for a tooth interposed wide, or for two teeth interposed and also for a prosthesis in extension.

These various executions are described below, but they share certain aspects which should be introduced in the preamble.

Here, neither the existence of occlusal-proximal cavities which are a constant nor the use of at least one perforated guide in association with stems is questioned.

The perforated guide 7 illustrated in Figure 2b is the basic variant of the perforated guide. But it is possible, and judicious, to make evolve this basic variant towards more specialized executions and better adapted to certain specific functions. Two lines of distinct evolutions are intended for the first to highlight the possible cooperation between the perforated guide and the abutment teeth, and for the second to privilege the intermediate guide function integrated into the Pontic framework, when it becomes longer than in the basic variant. In Figure 5 is illustrated a perforated guide intended to work closely with a pillar tooth and therefore we will speak of perforated guide pillar. In this embodiment, the perforated pillar guide 8 no longer occupies a central position in the Pontic framework, as was the case in FIGS. 2 and 3, but instead occupies a position at the end of the rods forming the framework of the pontic. For a prosthesis with one or more inserted teeth, there will be a perforated guide of abutment at each end of the pontic. On the other hand, for a prosthesis in extension, there will be only one perforated guide of pillar. Compared to the basic perforated guide of FIGS. 2 and 3, there is seen in FIG. 5 only one visible difference, namely that the zone of the two top perforations 9 is offset relative to the body of the "T" and that the part of the metal part in which are performed the top perforations is an overhanging protuberance 10. This part of the perforated pillar guide can be introduced into the cavity of the pillar. The advantage of this evolution is that the solidity of the anchoring is no longer entrusted to the only rods A and B, but indeed to the guide itself which will be partly sealed also in the abutment tooth.

Of course, it is quite possible to give the overhanging portion 9-10 more or less length and the width 11 at the offset, and the width of the "T" portion of the perforated pillar guide can also be varied. ; all this according to each specific case.

In FIG. 6 are illustrated as simple examples three interposed perforated guides, namely a simple "T" intermediate perforated guide 12, an interposed in-line perforated guide 13, which can be summed up in reality at the single vertical bar of the "T" Of the basic variant and finally the basic variant itself.

The originality of the present invention proceeds from two combined ingredients which are on the one hand an anchoring design making use of occluso-proximal cavities and on the other hand a framework consisting of perforated guides and elementary rods whose assembly is made as easy as a simple construction game. To bring creative thinking to a successful conclusion, it is advisable to offer users a variety of perforated guides, pillars and spacers, all manufactured and ready to use, offering a variety of widths, perforation diameters, offsets and overhangs that can respond to all cases. In addition, it will always be possible for the technician or dentist to cut, mill or shape a portion of the perforated guide that would be too present in a particular case. The assortment also advantageously comprises rods of various diameters and various lengths.

With this store of ready-to-use elements, the technician can limit himself to choosing the perforated manufactured guides which seem to him the best adapted and to choose rods of good length in the useful diameter, or failing to cut them to the desired length.

The use of interspersed perforated guides, such as the use of more rods or stems in all available perforations, is intended to increase the rigidity and flexural strength of the pontic, i.e. oppose more to dental occlusal forces.

As announced above, there is described in Figure 7 a tooth prosthesis inserted, in which we find the elements already presented, profile 7a and top 7b. It can be seen that the two perforated pillar guides 8 have an offset 11 and an overhanging portion 9-10. It is also observed that this time the rods A and B of the anchoring framework do not extend over the entire length of the prosthesis, but have instead been cut so as not to participate in the pontic, so we logically found two rods A 'and B' at the other end. FIG. 7 shows that three pillars are involved, namely two adjacent pillars 1 and one on one side and an opposite pillar 2 on the other side. It is only to take advantage of varying presentation and show that the involvement of more than one pillar per side is perfectly possible.

Finally we can observe that some anchor rods A and B have been bent and are no longer straight. Figures 7c and 7d are revisions of Figure 7a and 7b respectively and should be compared to highlight a constructive difference and especially a very significant faculty that is made possible. As this is a recovery, anchor rods A and B are also shown to be non-rectilinear, but it is of no importance or consequence and straight rods are equally suitable.

Comparing FIG. 7c to FIG. 7a, it can be seen that the overhanging part 9-10 which cooperates with the rods A and B (that is to say the combination represented in FIG. 5) is no longer housed in the box 11 (see Figure 1 c) of the adjacent abutment tooth 1 (and its neighbor 1 ', if there is a second pillar of the same side), but is instead positioned so that its end is flush with the outer surface of the prosthetic tooth not shown (15 with reference to the other figures). But that's what we can not see which is the major interest of this variant. Indeed, in this variant of construction, the rods A and B are not made integral with the perforated guide pillar 8, quite the contrary is it avoided any bonding or welding and can even go partially coat the stems A and B with petroleum jelly (also to prevent another substance from seeping in) when they are introduced into the perforations of the perforated pillar guide 8. In this way, the two stems A and B are completely integral with the adjacent abutment tooth 1, as in the variant of Figure 7a, but they can slide freely in the top perforations in the overhanging part. As a result, the adjacent abutment tooth 1, as well as its neighbor V, are no longer in fixed solidarity with the pontic and are no longer in fixed solidarity, via the pontic, with the opposite pillar tooth 2. This is exactly what effect that is sought because it allows a perceptible and natural movement of the abutment teeth 1, 2 adjacent and opposite to each other. One can obviously think of doubling this characteristic by positioning and assembling the other perforated guide of pillar in the same way. However, what is decisive is that this positioning and this assembly in free sliding are executed on at least one of the two sides as illustrated in FIGS. 7c and 7d. A fixed and rigid solidarity between the anchoring rods A and B and the top perforations of the perforated guide of pillar 8 not being sought after, but on the contrary combated, it will be avoided to use components such as acids, silane or binders (bonding) at their interface, components also used during the production and / or fixing of the artificial tooth on the pontic.

The total rigidity of the prostheses can be at the origin of genes for the patient, and it is also at the origin of most cracks and breaks of reinforcement, that due to the fact that the teeth have natural movements that the prosthesis fights and prevents. The prosthesis according to the invention, in its configuration and according to the assembly methods set forth with reference to FIGS. 7c and 7d, constitutes a major advantage.

In Figure 8, we can see an extension prosthesis made with a single perforated guide pillar 8, but with an anchor frame involving not only the adjacent pillar 1, but also a second tooth 1 '. For an achievement of this kind, the solidarity between the artificial tooth and the half pontic who wears it is essential. Therefore, as shown from above and in profile, it is recommended in this case to form a rod by "U" folding 18 and to accommodate both ends in the

perforations of the perforated guide of the pillar 8. It is also possible to place other rods, for example C, or to install a second "U" rod to further improve the grip. Finally, in FIG. 9, a very complex construction variant for a prosthesis intended for two intercalated artificial teeth is illustrated. This embodiment involves all kinds of perforated perforated guides shown in FIG. 6, as well as perforated pillar guides 8 of FIG. 5. It can be observed that the introduction of the basic perforated guide 7 as an intermediate element makes it possible to extend a pair of anchor rods into only part of the pontic. In general, the number of rods to be included in the framework of the prosthesis according to the invention is left to the discretion of the practitioner, as well as the use of stems of larger or smaller section than the standard. The same goes for the number, the shape and the location of any interspersed perforated guides

As was explained above during the presentation of its purpose, the invention aims to obtain three kinds of advantages, which is detailed below by commenting on them.

Substantially reducing the cost of accomplishment is certainly the economic purpose of the invention, but it results from the ease and security of achieving better through a lesser degree of sophistication or technicality.

Whether it is taking an alginate impression, milling occluso-proximal cavities, making the prosthesis itself by the laboratory technician, then setting it up, especially guided by the guide recommended transfer, there is, in the following tasks of the dentist and the technician, no operation that does not fall within the basic capabilities of the profession of each. In particular, the technician does not work at all on the micrometric scale that is usually his daily life, but on the contrary with a level of tolerance incomparably easier to meet, resulting in a speed of execution multiplied. In addition, the technician has a range of manufactured parts ready for use, and this single assembly will allow in the daily reality to meet the vast majority of cases without embarking on the custom.

In order to give a graphic illustration of the economic gain provided by the prosthesis according to the invention, a traditional embodiment with its counterpart according to the invention will be compared below. It is thus the realization of a traditional prosthesis for a tooth interposed involving two crowns on the pillars, with gold-based casting frame. On the other side, it is opposed to a prosthesis according to the invention, equivalent performance, with artificial tooth prefabricated. In the traditional variant, the total effective working time of the dentist, with the patient in the chair, can be estimated on average at 4 hours. In this variant, the technician's bill consists of his working time, ie 10 hours on average, and the cost of the supplies, which is also expressed in technician hours, approximately 2.5 hours. The cost of the traditional variant is thus the addition of 4 hours of dentist and 13 hours of technician.

With the prosthesis according to the invention, the working time of the dentist is 1 hour and a half (30 minutes during the impression taking and the realization of the cavities, and 60 minutes during the final pose). The technician's time, including supplies, is 3 hours.

With the prosthesis according to the invention, the cost related to the work of the dentist is divided by a factor equal to or greater than 2, while the cost of the work of the technician is divided by a factor equal to or greater than 4. Under these conditions, the substantial reduction in the cost of production is really not a usurped qualifier.

Improved reversibility has also been reported, which can be further illustrated by comparison of the traditional and the invention variants, as both described a few lines above. It is assumed that, following an accident for example, the artificial tooth must be removed and replaced. According to the traditional variant, it will be possible to saw the armature of the prosthesis in order to separate the armature crowns covering the pillars. Since it is obviously impossible to weld anything into the patient's mouth, the two crowns will not be reusable and they must be destroyed (sawn) to be removed. The whole of all the treatment will have to be restarted.

With the prosthesis according to the invention, it is sufficient for the dentist to remove the ionomer glass and / or composite mass with his cutter until dislodging the anchor rods, or, more radically, to also mill the rods. In either case, the prosthesis is removed within minutes. The dentist must in no case attack the body of the natural teeth and will simply clean the two cavities which will then be ready to accommodate a new prosthesis according to the invention. The improvement in reversibility is thus expressed in two ways, in the first place by the elementary simplicity of the operation of removing the prosthesis and secondly by the fact that, as already mentioned, the cost of replacement of the prosthesis will be less to the same extent at least than was the one of his first achievement.

Reversibility improvement is thus both technical and economic.

For patients who have in any case the financial means necessary to consider a fixed prosthesis, the benefit of the prosthesis according to the invention will be expressed by a significant saving.

In addition, a significant proportion of patients who could not afford a fixed prosthesis because of the lack of financial means will have access to what was previously forbidden. What is true for patients is also mutatis mutandis for their insurer.

On the other hand, it is very likely that the solution of the prosthesis will be freely preferred over other options, especially when it comes to rebuild a missing tooth interposed by the installation of an implant and a crown, or when a very dilapidated tooth requires a root treatment then a false stump and a crown to be saved, to name just two examples. One of the major advantages of the prosthesis according to the invention is to offer a restricted mobility, but perceptible, abutment teeth between them, which allows each to "move" according to nature and to the extent claimed by nature. Certainly mobility is only possible in axial expression, since the rods A and B can only slide in the top performances of the perforated pillar guide, but this mobility exists and that makes all the difference.

Of course, the embodiments of the invention are given by way of non-limiting examples and variants are possible within the scope of the claimed protection, in particular by the use of equivalent means.

Claims

claims

1. Fixed dental prosthesis comprising at least one artificial tooth (15) and means for securing it with at least two natural abutment teeth (1 and 2, or 1-1 'and 2, or 1 and 1') of the mouth, characterized in that said means comprising a frame comprising on the one hand at least one preferably metal part (7, 8) provided with preferably circular perforations, said piece forming a perforated guide, and secondly rods of preferably of preferably circular section (A ₁ B ₁ C, D, E, F, A ', B ¹ ) whose section, preferably the diameter, is chosen to collaborate in sliding with said perforations of the perforated guide; Among these rods, some, called anchorage, extend outside the pontic and, by their position and size, collaborate in a privileged manner with the perforations of the perforated guide, the various elements together forming a periodontal splint and being arranged relative to one another such that the relative position of the artificial tooth (s) relative to the splint on which it is (are) fixed (s) is chosen so that the stems collaborating with the top perforations can occupy, in the abutment teeth, an intra-dental position; when the anchoring rods of the prosthesis are subsequently placed in housings forming two occluso-proximal cavities, housing also provided for this purpose in each of the natural abutment teeth.

2. Fixed dental prosthesis according to claim 1, characterized in that at least one perforated guide is shaped to fit in part the shape of an occluso-proximal cavity, namely that the area of the workpiece carrying the top perforations s extends overhanging beyond the body of the perforated guide, the whole piece then constituting a perforated guide pillar.

3. Fixed dental prosthesis according to claim 2, characterized in that at least one perforated guide is devoid of top perforations so that it can in no way collaborate with anchor rods, but can with stems participating only in Pontic bone; said guide then forming a perforated intermediate guide.

4. fixed dental prosthesis according to one of claims 1 to 3, characterized in that no perforated guide is welded or glued to any rod to form the framework of the prosthesis and that on the contrary the collaboration between a guide and a rod takes place only by sliding.

5. fixed dental prosthesis according to claim 2, characterized in that at least one perforated guide pillar is positioned relative to the anchor rods and the artificial tooth, so that the overhanging part is fully included in the artificial tooth and that the end of the overhanging portion is substantially flush with the outer surface of the artificial tooth.

6. fixed dental prosthesis according to claim 5, characterized in that the anchoring rods are not fixed, glued or welded to the top perforations of the perforated guide pillar, but instead they are engaged in free sliding in these perforations .

7. Fixed dental prosthesis according to claim 6, characterized in that the portion of the anchor rods intended to collaborate with the top perforations of the perforated pillar guide are coated with lubricant before being engaged in said perforations.

8. Prosthesis according to claim 1, characterized in that the prosthesis is provided with a transfer guide fixed in temporary solidarity on at least one artificial tooth, said transfer guide being shaped according to an impression of at least one tooth pillar so that when applied in support on said pillar via the transfer guide, the prosthesis is in the exact position in which it must be secured permanently.

9. Prosthesis according to claim 1, characterized in that at least one rod, assumed initially rectilinear, can be bent, curved or warped at will and without damaging consequences for the realization of the prosthesis.

10. Set of components for producing a prosthesis according to one of claims 1 to 9, characterized in that it comprises at least one perforated guide and two rods.

11. Set of components according to claim 10, characterized in that it comprises at least rods, perforated pillar guides and interspersed perforated guides.