WO2010106251A1

WO2010106251A1 - Dental implant, and prosthetic assembly including such an implant

Info

Publication number: WO2010106251A1
Application number: PCT/FR2010/000229
Authority: WO
Inventors: Jean- François BOREL; Philippe Duchatelard; Jean-Pilippe Picon; Roméo CASIMIRO; Yves Douillard
Original assignee: Tekka; Douillard, Martine
Priority date: 2009-03-18
Filing date: 2010-03-18
Publication date: 2010-09-23
Also published as: FR2943242A1; EP2408393A1; FR2943242B1

Abstract

The invention relates to a dental implant (40), and to an assembly including such an implant and a prosthetic element. The implant includes a threaded self-tapping anchoring body (41) lying flat about an axis (42) and rigidly connected to a head (43) for supporting a prosthetic element, the head including a collar (44) with an annular groove (45) on which is mounted a connection end with a frusto-conical lug having a taper converging towards the top of said head. The anchoring body (41) includes a cylindrical apical top end segment (48) coupled to a frusto-conical cervical segment (49) for connecting to the head. The collar (44) includes a first convex portion (50) with a toroidal portion shape for joining with the body, as well as a second concave portion (57) forming said annular groove.

Description

DENTAL IMPLANT AND PROSTHETIC ASSEMBLY COMPRISING SUCH AN IMPLANT

The present invention relates to a dental implant comprising a self-tapping threaded anchoring body elongated around an axis integral with a support head of a prosthetic element, the head comprising a neck having an annular groove surmounted by an end. connection comprising a tapered conical tenon converging towards its distal portion.

It also relates to an assembly formed of a prosthetic element and such an implant, as well as a method of using such a set. It finds a particularly important application although not exclusive, in the field of reconstructive dental surgery making the implant undetectable from an aesthetic point of view.

It is known that research on this point in implantology has shown that the natural root of the tooth must not be imitated.

In 1964 the Swedish professor Brânemark revolutionized the approach of dental implantation by proposing to use a material that can be integrated into the bone structure in the framework of what was later called "osseointegration".

To favor the latter, the choice of the body shape of the implant was then made because of the similarity between the tibial bone and the mandibular bone with a dense bone cortex. This density has oriented the choice on a metal mechanical logic bolt type screw nut tight. It is understood that the implant surface formed by the machined surface was then the result of the mechanical milling performed for the realization of the implant.

In the same logic, and to ensure the screwing of the implant, the choice of professionals then turned to the external hexagon or hexagon nut, a form that could serve as a basis for the development of the connection between implant and prosthetic pillar.

The surgical imperatives fixed for a perfect osseointegration, however, required the closure of the gum flaps above the implant. The latter being thus buried, a second surgical phase was then necessary to allow to put in place the prosthetic abutment. Recall that the prosthetic pillar is

The spacer compensating the thickness of the mucosa and allowing the attachment of the prosthetic element itself.

The implant structure was therefore composed of two parts: the implant and the abutment.

The complexity of this assembly, however, required the choice of a screwed prosthesis allowing control and monitoring of the assembly formed by the implant and the prosthetic element during its implementation. In 1974, Dr. Schrder from the world of periodontology proposed an implant structure consisting of a single piece.

The implant using the sealing technique was formed of a honeycomb structure. It was placed in the borehole resulting from drilling, bone biology subsequently making its sealing work by healing.

The support element of the trans- gingival was of small diameter to avoid the risk of contamination. The particularity of this assembly, however, required the choice of a sealed prosthesis. These two opposing concepts have long divided the world of implantology.

In the mid-1980s, mechanical assemblies more efficient because more stable and reducing the risk of unscrewing have been proposed. They used the Morse taper and the internal hexagon, a weak taper below 5% preventing subsequent disassembly, the low tapered abutment / implant assembly then resembling a one-piece implant, with the only difference being that could choose the most suitable prosthetic abutment.

In the meantime, the importance of the system of attachment of mucous structures to the periphery of the tooth and the concept of biological space appeared. It was thus discovered that this epithelio-connective set comprised collagen fibers oriented perpendicular to the dental structures to provide a sealed protective barrier with respect to the septic oral medium. Subsequently, it was further demonstrated that the presence of organized bacteria in the form of plaque was what actually caused inflammation of the gum.

These two discoveries will not find their importance in implantology until later. Indeed, it is only at the end of the 1980s that the bone loss resulting from implant activation is highlighted. bones being kept away from the connection at the bone, generating connection of infectious products by the interposition of a granulation tissue. Studies have shown that healing around implants is different from that seen around the teeth.

The fibers did not anchor on the surface of the tooth, but were circularly organized around the implant. Thus it was observed during the removal of the healing abutment, a contraction of the elastic fibers contributing to the reduction of the access port to the connection with the implant.

But the causes of bone cratering and therefore the resulting gingival resorption are not limited to the type of connection.

Many other factors are responsible, namely and especially assembly and disassembly, micro-movements related to the game necessary for mechanical assembly, or occlusive stress affecting the neck bone.

To obtain an optimal result, it would be necessary to reduce or even eliminate these various factors, which are not all clearly identified. It must therefore be admitted that it is difficult to establish the real share of each of these factors in the quality of the result.

For example, is it the precise geometry of the implant, the surface condition, the geometry used, or another factor not listed?

It is clear that the implants of the prior art do not achieve the expected clinical results. FIGS. 1A, 1B, 2 and 3 of the present description show typical radiographs of prostheses on patients with various implants of the prior art, showing the partial non-reconstitution of bone at the level of the connection between bone and gum. characterizing peripheral craterization.

More specifically, the radiographs IA and IB show an implant 1 at the time of laying with preparation of the reception 2 of the flange of the implant by flaring 3 (Figure IA) and after three months (Figure IB).

A craterized bone lense 4 then appears clearly at the junction 5 between the head and the body of the implant, all around the cervical periphery of the latter.

FIG. 2 shows another implant 6 of the prior art and the phenomenon of cratering 7.

Finally, FIG. 3 again shows, on two implants side by side 8 and 9, the poor reconstitution of the osseous neck 10.

The present invention aims to provide an implant, an assembly comprising an implant and a prosthetic element, and a method of using such an assembly, which responds better than those previously known to the requirements of the practice, in particular in that it authorizes excellent bone reconstitution and optimized tissue integration, while allowing great prosthetic modularity. With the invention, exceptional bone scarring around the implant (see FIGS. with a lasting result whether with a single implant 11 (bone collar 12) or with two implants 13, 14 placed side by side, with perfect reconstitution of the osseous neck both at the outer periphery 15 and between the two implants 16.

We see that this is particularly interesting by comparing, for the same patient, the failure of an implant 17 of the prior art (FIG. 6) and the success of the implant 18 of the invention having a reconstituted bone densification of exceptionally close to the implant head (Figure 7).

The perfect seal of the connection allows prosthetic forms close to natural teeth and perfect mucosal reconstitution as can be seen in the picture of Figure 8A.

Here, the mucosa 19 adopts a shape 20 that perfectly marries the prosthetic crown as well as the adjacent natural teeth 21. The mucosa 19 also has a granite appearance identical to that of the mucosa covering said teeth, which is a clear indicator of its perfect reconstitution.

FIG. 8B gives the radiograph of the implant 22 according to the invention, the end of the head of which appears in FIG. 8A, with its prosthesis 23. The bone neck 24 is perfectly reconstituted.

In addition, it will be possible with the invention to provide for the placement of implants side by side at distances less than those commonly accepted, without cratering, as shown on the X-rays of FIGS. 9A to 9C illustrating the evolution of ossification between the moment of the placement of both implants 25 (Figure 9A), implants at one month (Figure 9B) and at three months (Figure 9C).

It is thus noted that with the implants of the invention, the bone defect existing between the alveolar bone ridge and the implants placed in place gradually fills with the neoformed bone, the type of healing being similar, whatever the implantation conditions. .

FIG. 10 illustrates the perfect tissue regrowth observed with the invention, with the closely spaced proximal implants, FIGS. 9A to 9C.

The gingiva 26 is indeed perfectly reconstituted even between the implants. To further illustrate the exceptional bone response with the implant according to the invention, which response also generates a very good gingival reconstitution, it is shown with reference to Figures HA and HB, on the one hand radiography (Figure HA) two implants 27 and 28, namely an implant according to the invention 27 and an implant of the prior art 28, and secondly the photograph (Figure HB) of the corresponding gingiva. With the invention there is excellent bone healing at 29 with bone locking and perfect tissue response 30.

On the other hand, with the implant of the prior art, there is a circular bone lysis 31 from which cratering and a black hole at 32.

In order to overcome all these disadvantages, the present invention proposes in particular a dental implant comprising a self-threaded anchoring body. tapping elongated around an axis secured to a support head of a prosthetic element, said head comprising a neck having an annular groove surmounted by a connecting end comprising a tapered frustoconical tenon converging towards its distal portion, characterized in the anchoring body comprises a cylindrical apical end portion connected to a frustoconical neck portion of connection with the head, and in that the neck comprises a first convex portion of junction with the body, said first convex portion being in the form of a toric portion tangent or substantially tangential to the generatrix of the profile of the cervical portion of the body and obtained by the rotation of a portion of a first circle of radius ri about the axis and a second concave portion forming said throat annular tangent on one side to said convex portion and connected to the other to the large base of the frustoconical tenon of the connection end. It has thus surprisingly been observed that with such characteristics taken in combination, and for reasons that are not clearly identified, perfect tissue integration was obtained by avoiding the usual constraints of positioning the implant without risking disturbing the result. final esthetics, with stability and sealing of the prosthetic connection, excellent and repetitive.

It is also observed, with the invention, a strengthening of the conjunctive shield, the circular fibers crimping the collar making an O-ring around it by favoring certainly thus a reduction of the infectious risks while allowing a centering of the constraints.

Rapid and low - traumatic implantation of this type of implant is also observed, limiting the risk of surgeon errors while reducing drilling and trauma - induced heating.

Also with these characteristics, it becomes possible to modulate the burial, which will allow better prosthetic management while reducing the risk of contamination during prosthetic tests.

In advantageous embodiments, one and / or the other of the following provisions is also used:

the angle at the apex of the cone of the frustoconical tenon of the head is of the order of 5 ° (conicity of the order of 10%). By the order of it is meant to within ± 1 ° and preferably equal to 5 ° ± 0.2 °; - The threaded anchor body has a self-tapping thread pitch increasing depth of the head at its distal end, for example with a cone angle at the top of the order of 1 °;

- ri is such: 0.5 mm <ri <1 mm; r 1 = 0.7 mm;

the body has a triple self-tapping thread with a pitch of between 1 and 2.5 mm, advantageously 1.8 mm;

the thread has an opening of 60 ° and a curvilinear base with a radius of between 0.05 and 0.15 mm, advantageously 0.08 mm; the body has from one to three tapping slots distributed radially.

It is thus formed a triple self-tapping pilot head, further facilitating insertion; the tapping notches consist of longitudinal recesses formed from the distal end of the body and defined by two perpendicular faces having a lower right portion and a curved upper portion; the distal end of the body has a spherical profile;

- The distribution between the cylindrical apical section and the frustoconical cervical section is of the order of 60/40, with advantageously a constant height of the conical cervical section for the entire range of implants.

This height is for example 3 to 5 mm, advantageously 4 mm. The implants are indeed always provided in the form of a range having several dimensions or diameters allowing a choice on the part of the surgeon according to the patient and the state of his jaw. - the threading depth varies from 0.2 to 1 mm; the head comprises indexing means with the prosthetic element formed by an equilateral triangle triangular cross section polygon with rounded vertices, and height between 0.8 and 1.2 mm. This triangular indexing allows great ease of positioning and connection with a screwdriver, reducing the need for radiological control as well as easy training of the implant during its installation;

the second concave portion has a curvilinear cross-sectional area having at least two radii of curvature, namely a first portion of concave curve, of continuous junction with said first convex portion, having a second radius of curvature r2, and a second portion of concave curve, neck bottom, having a third radius of curvature r3;

- The second concave portion further comprises a third portion of concave curve, junction continuously with the second concave curve portion having a fourth radius of curvature r4 and connected to the base of the frustoconical tenon;

r2 varies from 0.8 to 2.8 mm and r3 from 0.3 to 0.7 mm;

r4 varies from 2 mm to 3 mm;

ri = 0.7mm, lmm <r2 <2.5mm, r3 = 0.5mm and r4 = 2.5mm; the diameter of the base of the frustoconical tenon is less than the largest external diameter of the thread of the body, for example between 3 and 4 mm; the frustoconical tenon comprises a threaded axial duct whose lower end is located substantially halfway up the neck and which is adapted to receive a fixing screw of the prosthetic element.

The invention also relates to an assembly formed of a prosthetic element and an implant as described above, characterized in that the prosthetic element comprises a frustoconical junction lower part of complementary shape with the formed connection end. by the frustoconical tenon of the implant and arranged to provide external continuity between the revolution surface of the neck and the outer lower face of the prosthetic element.

Such an arrangement is particularly favorable to avoid any contamination.

The implant according to the invention indeed allows a large range of prosthetic solutions that further promote tissue integration, allowing an exceptional aesthetic result, thanks in particular to positioning the implant in mesiodistal, vestibulo-lingual and / or optimized burial level.

Advantageously, the prosthetic element is formed by a piece and a removable protective ring, said protective ring being made of synthetic material or biocompatible plastic, and forming said frustoconical junction lower part.

This ring ensures the physical protection of the cone of the implant and preserves the surface thereof until the establishment of the prosthetic part. It also makes it possible to prepare the gingival cicatrization by conforming the tissues so that they can receive the prosthetic part, without the need to compress the tissues excessively.

Finally the junction between the ring and the implant is neat to be tight to bacteria. It is the same with the junction between the ring and a prosthetic part based on the proximal surface of the cone of the implant, which is the smallest face of the cone. Still advantageously the ring with an ovoid profile being arranged to condition the emergence profile of the prosthetic element.

Also advantageously the synthetic material is PEEK or based on PEEK, for example slightly loaded PEEK (for example 2%) in radioactive element such as barium sulfate.

In an advantageous embodiment the ring is arranged to allow the detection of the burial height by its color difference with the implant.

Advantageously, the ring is slightly undersized with respect to the distal portion of the common prosthetic parts between the base and the apex of the cone of the tenon.

In an advantageous embodiment, the prosthetic element is composed of a pillar whose proximal portion is formed of a cone angle at the apex of between 30 ° and 60 °, associated with a sheath provided with a duct. crosspiece of a screw arranged to be screwed directly into the implant, said pillar thus being held by clamping between the sheath and 1 'implant.

Also advantageously the prosthetic element is formed by a false anatomical stump.

In another advantageous embodiment, the prosthetic element is formed by an implant-bearing abutment provided with anti-rotation faces of the order of 5 to 10 mm in height, laser-marked at the level of said faces.

Advantageously the prosthetic element is formed by a pillar (standard, anatomical, angulated, or customized), a sheath and a screw. The invention also proposes a dental prosthesis kit comprising an implant as described above, characterized in that it further comprises a drill of homothetic shape to that of the bottom thread generator of the implant in its part. intraosseous. The active volume of the drill corresponding to the portion buried in the bone is equal to the intraosseous volume of the implant composed of the cervical and apical sections previously described. These elements make it possible to minimize the risk of locking the implant during screwing and to limit radial stresses.

The invention also proposes a method of placing a dental implant of the type described above. It also proposes a method for placing an implant comprising, in combination, an external conical connection, a transmucosal collar with a concave profile without aggressive angles arranged to allow the colonization and stabilization of the peri-implant tissues and a conical body. cylindrical with triple thread of increasing depth, in which process, drilling is carried out with a drill provided with a marking, for example black in color, so that said marking is slightly below crestal with respect to the buccal bone boundary, the drill bit used at the end of drilling being homothetic to the profile of the bottom of the threads of the thread of the body, one checks the burying of the future implant using a phantom tool, then one puts in place the implant by screwing to using an implant-bearing abutment with antirotation faces, after insertion of a ring of removable intermediate protection, the lower limit of the neck of the implant being placed slightly subcrestal, then the healing screw is placed on the intermediate ring. Subsequently, and after removal of the screw and the ring is put in place a false anatomical stump, the female, conical, junction, comes to cooperate with the male cone of the corresponding complementary shape of the corresponding implant. With the invention, a progressive bone condensation grip is thus observed, while observing a high primary stability even in the case of post-extraction implantation. Moreover a fast insertion is possible. In one embodiment, the surface condition is improved, for example by sand blasting with high-purity corundum microspheres, which promotes attachment and retention of the implant in its threaded body and convex portions of the neck. The invention will be better understood on reading the following description of embodiments given below, by way of non-limiting examples.

The description refers to the accompanying drawings in which, in addition to FIGS. 1 to HB illustrating the results of the prior art and those of the invention:

FIG. 12 is a partial perspective view of an embodiment making it possible to illustrate the characteristics of the implants according to the invention;

FIG. 13 shows an enlarged side view of the neck of FIG. 12.

FIG. 14 is a side view of a mode of embodiment of an implant according to the invention of the type of that shown in FIG.

- Figures 15 to 18B are side views of implant assemblies and prosthetic element, according to various embodiments of the invention.

- Figures 19 to 22 are side views of implant heads according to the invention with false stubs.

Figure 23 is a schematic sectional view of an implant and the terminal drill profile used according to the embodiment of the invention more particularly described.

FIG. 12 shows in partial axionometric view the implant 40 corresponding to the embodiments more particularly described.

This dental implant 40 monoblock comprises a solid anchoring body 41, threaded self-tapping, elongated about an axis 42.

The thread is formed by a groove or a recessed groove with respect to the face of the workpiece, and not an external protruding rib.

The body is secured to a support head 43 of a prosthetic element (not shown). The head 43 comprises a neck 44 having an annular groove 45 surmounted by a connecting end 46 comprising a tapered frustoconical stud 47 converging towards the top of the head.

This taper may be that of a Morse taper (i.e. 5%) but advantageously is of the order of 10% (α = 2.5 °, with a half-angle at the top).

The anchor body 41 comprises a cylindrical apical end portion 48 terminated on one side by a solid top and connected on the other side to a cervical section 49 frustoconical, binding with the head.

The neck 45 comprises a first convex portion 50 of junction with the body, this first portion being in the form of a solid, non-perforated, ring-shaped portion of a continuous surface tangent or substantially tangential to the generatrix 52 of the external profile of the thread of the frustoconical cervical part of the body. It is obtained by rotation (radius circle

R1) of a portion 55 of a first circle 56 of radius ri about the axis 42.

The neck 44 comprises a second concave portion 57 forming the annular groove 45, tangent on one side to said convex portion 50, and connected on the other to the large base 58 of the frustoconical tenon 47 of the connection end.

The thread 59 of the body 41 is self-tapping.

More precisely it is a triple helical thread of increasing depth in the frustoconical neck portion 49 (e '> e) and in the cylindrical apical portion 48 (f> f) with f = e'.

Recall that the triple threading is a technique to have the apparent profile of a single thread while allowing screwing three times faster, since it is formed of three propellers tapped shifted by 120 °, for example not 1.8 mm, giving the impression of an apparent pitch of 0.6 mm. Such threading, in combination with the other characteristics of the implant, generates good bone condensation and excellent primary grip even in the apical zone while allowing quick insertion.

The conical-cylindrical shape of said body also contributes to the exceptional grip and the better locking of the implant at the end of screwing. The concave portion of the annular groove will now be described more specifically with reference to FIG. 13.

In the following description, we can use the same reference numbers to designate the same elements or similar elements.

The concave part more particularly described here is formed (cf figure 13) by portions of O-rings, and more particularly by their internal faces 60, 61 and 62, turned on the side of the axis 42, namely a first portion 60 of radius of curvature r2, junction with the convex ring portion and formed around a circle rotating about the axis 42 of radius R2, a second portion 61 tangent to the first and also formed by a second concave portion of the ring surface, of radius of curvature r3, rotating around a circle of radius R3 about the axis 42, and a third portion 62 of concave toroidal surface of radius of curvature r4 formed around a circle of radius R4, tangent to the second and ending on the base 58 of the tenon.

The convex / concave curve of the cervix is a curve entirely of revolution. As the convex part connected to the upper part of the body is ring-shaped ring simple enough, as the concave portion may itself consist of several portions of torus inverted although all of them being in the continuity of one of the other without point of inflection, can form around circles of different radii.

FIG. 14 shows the implant 40 according to the embodiment more particularly described here, whose body 41 therefore comprises a triple thread 59.

This is for example with a pitch 1 = 1.8 mm, an opening β = 60 °, and a conical bottom 63 with a radius of 0.08 mm.

The frustoconical cervical portion 49 furthermore has a groove of increasing height at an angle α 1 of, for example, the cylindrical apical portion 48 having in turn a groove of increasing height, at an angle OC2 of identical value, or slightly greater at a _± , for example 1.2 °.

The taper γ of the cervical portion 49 is of vertex directed towards the apical end portion 48 of the body, and of a value equal to a few degrees, for example from 6 to 8 °. The body 41 also terminates in the lower part by an apical apex 64, spherical of large radius and comprises three notches 65 tapping, radially distributed star with three branches. The notches consist of longitudinal recesses 66 formed from the apical apex 64 and delimited by two perpendicular faces 67 and 68, the latter having a lower portion 69 and a right upper portion 70 curved. Also referring again to FIG. 12, the head 43 comprises, for its part, means 71 for indexing and connecting with a tool, said means 71 being formed of a protruding block on the top of the post 47, of equilateral triangular cross section having rounded vertices 72, of height h. This block and the frustoconical tenon 47 of the head are pierced with a conduit or axial bore 73, threaded, whose lower end 74 is located substantially halfway up the neck 44. (cf Figure 23)

It is seen that the bore 73 is adapted to receive a screw 75 for fixing the prosthetic element as will be described more fully below.

Referring back to FIG. 14, it is noted that the implant may present a rough surface condition to the burial limit 76, which allows for better osseointegration, while indicating the burial limit of the burial. visually implant the surgeon.

The material used is a biocompatible metal (Titanium for example) or a material known under the name TA6V ELI [ISO Standard 4832-3] which also corresponds to grade 5 ELI according to the ASTM classification (Titanium base alloy with 6% of Aluminum and 4% Vanadium), which again allows great biocompatibility, while ensuring high mechanical strength.

In the embodiment more particularly described with reference to FIG. 14, there is for example an indexing height h of 0.9 mm, a cone height H of 1.3 mm and a neck height b of 1. 5 mm, for an annular diameter of 2.7 mm and a length of implant body L of 10 mm. Regarding the overall diameters of the implant itself, ie the body, the range of diameters 2.8; 3.5; 4; 4.5 and 5.5 mm is for example proposed, the other parameters of the product remaining unchanged, which allows standardization.

FIGS. 15 to 18 show a range of transfers showing in FIG. 15 the upper part of the implant 40 with a removable protective ring 77 made of PEEK, said protective ring being of oval external shape for adaptation to the gingiva and comprising an internal bore of complementary shape to the pin 47 of the frustoconical head.

Advantageously (but not shown as such in the figures) the ring 77 has a lower periphery 78 in the extension or substantially in the extension of the concave curve 62 of the neck.

A prosthetic abutment phantom 79 of small height constituted in a manner known per se is shown in FIG.

Figure 16 shows the head of the implant 40 with a healing screw 80, for example of height 2.6 mm, which is placed on the ring 77 removable protection. The screw is fixed inside the bore 73 (see the half-section) via the external thread 81 which will cooperate with the internal thread of the bore of the head of the implant, to allow its screwing via a tool known in itself.

FIG. 17 shows a pillar 82 of the type used more particularly with the invention surmounted by a sheath 83.

It is fixed by an internal screw 84 passing through the sheath 83.

The screw 84 also passes through the conical pillar 82 and is screwed into the tapping of the bore 73. Figure 18A shows an implant head 40 having in the upper part a conical abutment transfer 85 to take the impression of the implant assembly 40 and conical abutment 82 .

Figure 18B shows the base of the implant 40, the PEEK ring 77 which supports an implant holder 86 also playing the role of impression transfer and temporary false stump.

This is antirotational indexed on the triangle of the implant and has on its side faces marking lines 87 for example laser. A horizontal laser marking 87 'of identification of the emergence level of the healing screw 80 is also provided.

FIGS. 19 to 22 show a range of "implant + prosthetic element" assemblies, the prosthetic elements 90, 91, 92, 93 being of the false abutment type. These are attached to the head of the implant 40 by a screw 94 (see Figure 21).

Figure 23 shows schematically in section an implant 40 according to the embodiment of the invention more particularly described. The volume of the drill, shown diagrammatically at 95, and used according to one embodiment of the invention, is homothetic to that of the thread base, the profile of which is shown in dashed line 96. The volume of the body of the implant is itself equal to the volume of the homothetic drill of equal length below the burial limit 76.

Also shown in FIG. 23, is the profile 97 of the implant which, compared to the bottom thread profile 96, makes it possible to highlight the increasing values of the depths of the threads before and after the inflection plane 98 between the cervical frustoconical zone 49 and the apical cylindrical zone 48. The so-called terminal drill is of a type known per se, for example a helical drill. 0.9 mm longer than the implant, provided with means of identifying the diameter for example, by color code, and a mark of the limit of depression (blackened band). Partly intraosseous and of equal length, the volume of the forest corresponds to that of the implant.

Finally, the anatomical abutments of Figures 19 to 22 are anatomically shaped corresponding to a molar 90, a premolar 91, a central incisor 92 and a lateral incisor 93.

As is obvious and as it also follows from the foregoing, the present invention is not limited to the embodiments more particularly described. On the contrary, it embraces all the variants and in particular those where the angles α, α1, σ, β and γ are different from the values indicated above.

Claims

1. Dental implant (40) comprising an anchoring body (41) threaded self-tapping elongate about an axis (42) integral with a head (43) for supporting a prosthetic element, said head comprising a neck (44) having an annular groove (45) surmounted by a connecting end (46) comprising a frustoconical tenon (47) of convergent conicity upwards from said head, characterized in that the anchoring body (41) comprises a cylindrical apical end section (48) connected to a frustoconical neck section (49) connected to the head, and in that the neck comprises a first convex portion (50) of connection with the body, said first convex part being in the form of a tangent tangent portion or substantially tangent to the generatrix (52) of the profile of the cervical portion of the body and obtained by the rotation of a portion of a first circle (51) of radius ri about the axis and a second concave portion (57) forming said annular groove (45 ) tangent on one side to said convex portion (50) and connected on the other to the large base (58) of the frustoconical tenon (47) of the connection end.

2. Implant according to claim 1, characterized in that the angle 2α at the top of the frustoconical tenon of the head (43) is of the order of 5 °.

3. Implant according to any one of the preceding claims, characterized in that the anchoring body (41) threaded has a self-tapping thread pitch (e, f) increasing depth of the head at its distal end.

4. Implant according to any one of the preceding claims, characterized in that ri is such: 0.5 mm <1 mm.

5. Implant according to claim 4, characterized in that ri = 0.7 mm.

6. Implant according to any one of the preceding claims, characterized in that the body (41) has a triple thread self-tapping with a pitch of between 1 and 2.5 mm.

7. Implant according to any one of the preceding claims, characterized in that the thread has an opening of 60 ° and a curvilinear bottom radius between 0.05 and 0.15 mm.

8. Implant according to any one of the preceding claims, characterized in that the body comprises three notches (65) tapped radially.

9. Implant according to claim 8, characterized in that said notches (65) tapping consist of longitudinal recesses formed from the distal end of the body and defined by two faces (67, 68) perpendicular having a lower right portion and a curved upper portion.

10. Implant according to any one of the preceding claims, characterized in that the distal end (64) of the body has a spherical profile.

11. Implant according to any one of the preceding claims, characterized in that the distribution between the apical section (48) cylindrical and the frustoconical cervical section (49) is of the order of 60/40.

12. Implant according to any one of the preceding claims, characterized in that the depth of the thread varies from 0.2 mm to 1 mm.

13. Implant according to any one of the preceding claims, characterized in that the head (43) comprises means (71) of indexing with the prosthetic element formed by an equilateral triangular triangular cross section polygon (72) rounded , and height between 0.8 and 1.2 mm.

14. Implant according to any one of the preceding claims, characterized in that the concave second portion (57) has a curvilinear cross-sectional area having at least two radii of curvature, namely a first portion (60) of concave curve, junction continuously with said first convex portion, having a second radius of curvature r2, and a second portion (61) concave curve, neck bottom, having a third radius of curvature r3.

15. Implant according to claim 14, characterized in that the second concave portion further comprises a third portion (62) concave curve, junction continuously with the second concave curve portion having a fourth radius of curvature r4 and connected to the base of the frustoconical tenon.

16. Implant according to any one of claims 14 and 15, characterized in that r2 ranges from 0.8 to 2.8 mm and r3 from 0.3 to 0.7 mm

17. Implant according to claim 16 dependent on the 15, characterized in that r4 varies from 2mm to 3 mm.

18. Implant according to claim 17, characterized in that ri = 0.7mm, lmm <r2 <2.5mm, r3 = 0.5mm and r4 = 2.5mm.

19. Implant according to any one of the preceding claims, characterized in that the diameter of the base of the frustoconical tenon (47) is smaller than the largest outer diameter of the thread of the body.

20. Implant according to any one of the preceding claims, characterized in that the frustoconical tenon (47) comprises a threaded axial duct (73) whose lower end (74) is located substantially halfway up the neck (44). and which is adapted to receive a screw (75, 80) for fixing the prosthetic element

21. A prosthetic element and implant assembly according to any one of the preceding claims, characterized in that the prosthetic element (80, 82, 85, 86, 90, 91, 92, 93) comprises a frustoconical junction lower part complementary shape with the connection end formed by the frustoconical tenon (47) of the implant and arranged to provide external continuity between the revolution surface of the neck and the outer lower face of the prosthetic element .

22. An assembly according to claim 21, characterized in that the prosthetic element is formed by a piece (79, 80) and a removable protective ring (77), said protective ring being made of synthetic material and forming said lower part of frustoconical junction.

23. The assembly of claim 22, characterized in that the synthetic material is PEEK.

24. An assembly according to any one of claims 22 and 23, characterized in that said ring (77) is arranged to allow the detection of the height of burial by its color difference with the implant.

25. Assembly according to any one of claims 22 to 24, characterized in that the ring (77) is slightly undersized with respect to the distal portion of the prosthetic parts between the base and the top of the cone of the tenon.

26. The assembly of claim 21, characterized in that the prosthetic element is formed by a false anatomical stump (90, 91, 92, 93).

27. The assembly of claim 21, characterized in that the prosthetic element is formed by a pillar (86) implant holder provided with anti-rotation faces 5 to 10 mm high, laser-marked (87) at said level. faces.

28. The assembly of claim 21, characterized in that the prosthetic element is formed by a pillar (82), a sheath (83) and a screw (84).

29. The assembly of claim 21, characterized in that the prosthetic element is composed of a pillar (82) whose proximal portion is formed of a cone of conicity between 30 ° and 60 ° associated with a sheath (83). ) of a crosspiece of a fixation screw of the implant, said screw being arranged to be screwed directly into the implant, said pillar thus being held by clamping between the sheath and the implant.

30. dental prosthesis kit comprising an implant according to any one of claims 1 to 19, characterized in that it further comprises a drill bit of homothetic shape to that of the generatrix of the mesh of the implant in its intraosseous part and whose active volume, corresponding to the part buried in the bone of the same length as that of the intraosseous part of the implant, is equal to the intraosseous volume of the implant composed of the cervical and apical