WO2008043899A2

WO2008043899A2 - Endosseous implant provided with axially extending reliefs to promote its osseointegration, and method for obtaining such an endosseous implant

Info

Publication number: WO2008043899A2
Application number: PCT/FR2007/001627
Authority: WO
Inventors: Jean-Claude Yeung Wai Ping
Original assignee: Jean-Claude Yeung Wai Ping
Priority date: 2006-10-05
Filing date: 2007-10-04
Publication date: 2008-04-17
Also published as: FR2906709A3; SMP200900032B; MA30863B1; SMAP200900032A; FR2906709B3; WO2008043899A3

Abstract

The invention relates to an endosseous implant comprising a body (1) provided with at least one peripheral longitudinal cavity (7) whose cross section is defined by a circle and whose lateral aperture forms a window (8) for passage of the bone substance for osseointegration of the implant. The transverse dimension of the window (8) is smaller than the diameter defining the cross section of the cavity (7), being defined by a chord (10) of the circle that corresponds to a segment delimited by an angle of less than 180°. The cavity (7) is formed by drilling the body (1) and then reducing the diameter of the body (1) until the lateral aperture of the cavity (7) forming the window (8) is obtained.

Description

Endo-osseous implant provided with axially extended reliefs promoting osteointegration, and method of obtaining such an endosseous implant.

Technical Field of the Invention

The invention is in the field of bone surgery and more particularly endosseous implants intended to support a medical device, such as implants used in dental surgery, in reconstructive surgery and / or in ENT (otolaryngology) surgery. for example. It relates to such an endosseous implant, which is provided with reliefs to promote osseointegration. It also relates to a method of manufacturing such an endosseous implant.

State of the art

Endosseous implants are used in surgery to implant a medical device in a patient, such as for example a prosthesis in the dental field. Such implants are likely to be of intra-oral type for use in the dental field in particular, or of the extra-oral type for use in the field of reconstructive surgery and / or ENT surgery, for example. These applications are given by way of example and are not restrictive as to the scope of the present invention. These implants consist of an elongate body which has at its air end means for joining the medical device, and at its end endosseous means for anchoring inside a bone tissue, such as the bone of the jaw for a dental application for example.

There is the problem of the quality of the anchoring of the implant in the bone. The implant is placed inside a housing previously made in the bone by the practitioner, inside which housing is introduced the endosseous end of the bone. body. The anchoring means combine mechanical anchoring means and histological anchoring means.

The mechanical anchoring means are in particular of the impaction type and / or of the screw type, preferably self-tapping. In general, these mechanical anchoring means implement fixing reliefs which are arranged to hold the implant in position inside the bone when it is put in place. Such fixing reliefs consist for example of a thread and / or annular members such as alternating lips and grooves. To promote the mechanical anchoring of the implant, it has for example been proposed by US2005 / 0164146

(CANTOR STANTON R.) doubling the threads formed on the body, one being an internal thread and the other being an external thread.

To reinforce the mechanical anchoring of the implant and to prohibit the use of its spontaneous removal from the bone, the endo-osseous end of the body is provided with histological anchoring means, which are intended to promote an osteotomy. integration of the implant from an exploitation of bone cell development. For this purpose, it is desired to increase the surfaces of the implant in contact with the bone tissue, in addition to the surfaces already offered by the mechanical anchoring means. Reliefs specifically dedicated to osseointegration are therefore provided on the endosseous end of the body, to form niches for colonization by bone cells that develop after placement of the implant. These osseointegration reliefs are organized so that any spontaneous removal of the implant is prohibited because of the integration in intimate contact of the endosseous end of the body into the bone mass.

Among these reliefs of osseointegration, those are known which are arranged in cavities formed longitudinally on the periphery of the body. These cavities open laterally at the periphery of the body to form longitudinal windows that extend parallel to the axis of extension of the body, through which windows the bone material is able to migrate for osseointegration of the implant. We can refer to the documents EP0437401 (SOFAMOR), EP1057456 (BRESSMAN RA, MEGERT D.) and WO00 / 47127 (ASHMAN A. LINKOW L.) which describe such osteointegration reliefs.

Such an organization of osseointegration reliefs axially extended at the periphery of the implant deserves to be improved to promote the histological anchoring of the implant. Such improvements, however, must not induce a complexity of the implant structure which consequently may make it difficult to obtain. These improvements must not only relate to the robustness of the histological anchoring obtained, but also allow osseointegration of the implant as quickly as possible after installation in the bone material. This speed of histological anchoring aims to avoid any risk of spontaneous removal of the implant during the period when it is only maintained in the bone by means of mechanical anchoring means. The arrangement and the manufacturing methods on the body of both the mechanical anchoring means and the osseointegration means, must allow an implementation of the implant which is easy and at a lower cost without affecting the qualities required for these different means.

The arrangement and the methods for producing the osteointegration means must optimize the histological taking of the implant by the bone tissues without affecting the efficiency of the mechanical anchoring means, must take into account the desired manufacturing tolerances. widest possible without affecting the quality of the overall anchoring of the implant in bone. The procedure for manufacturing the implant must enable it to be obtained with the lowest possible production costs.

Object of the invention

The purpose of the present invention is to provide an endosseous implant provided with mechanical anchoring means for its installation in the bone and histological anchoring means promoting its osteointegration, as well as a manufacturing method of such an implant that allows its obtaining at lower costs despite the improvements brought to promote its osteo-integration, both in robustness and speed.

It is more particularly the object of the present invention to provide such an implant, the arrangement of which means of osseointegration allows their exploitation with any means of mechanical anchoring, gives them reliable and long-lasting efficiency, promotes osteointegration fast, robust, reliable and durable implant, and allows a lower cost of the implant from manufacturing operations that are simple and easy to implement. The osteointegration means must be able to be easily formed on the body of the implant while promoting their effectiveness and the speed of the histological anchoring of the implant. It is therefore also the object of the present invention to provide a process for obtaining this implant. More particularly, another object of the present invention is to provide a method for obtaining an endosseous implant with axially extended osteointegration clearances, the implementation of which takes into account all the constraints that have been stated.

The endosseous implant of the present invention comprises an elongated body whose air end is provided with means for joining a medical device and whose endosseous end is provided with means for anchoring in the bone. The anchoring means combine mechanical anchoring means for fixing the implant in the bone during implantation, and histological anchoring means for osseointegration of the implant. The histological anchoring means comprise at least one cavity that extends longitudinally inside the body. This cavity opens out along its dimension of longitudinal extension, laterally at the periphery of the body for the formation of a longitudinal window of passage of the bone material to and inside the cavity. This cavity also opens through the end face of the endo-osseous end of the body. The cross section of the cavity is more particularly defined by a circle, so that the transverse dimension of the window is defined by a cord of this circle. The histological anchoring of the implant is done from a migration bone material inwardly of the body laterally to its axis of extension, by passing through the window which opens at its periphery.

The longitudinal extension of the cavity corresponds to the longitudinal extension of the body and its direction of implantation in the bone. This longitudinal extension is oriented parallel to the axis of general extension of the body, and the cavity extends radially offset relative to the axis of extension of the body to allow its lateral outlet at the periphery thereof.

According to the present invention, such an endosseous implant is mainly recognizable in that the rope defining the transverse dimension of the window corresponds to a segment delimited by an angle of less than 180 °. The transverse dimension of the window is smaller than the diameter defining the section of the cavity.

The longitudinal conformation of the cavity in circular section opening laterally on the body along a rope of dimension smaller than its diameter taken inside the body, makes it possible to optimize the volume of the cavity relative to the overall volume of the end. endosseous implant, and consequently optimizes the amount of bone material that can nest inside the body for the osseointegration of the implant. The edges of the window can be used to form impaction reliefs of the implant, and / or reliefs for collection and delivery of the bone material to the inside of the cavity during the placement of the implant. implant, especially in case of implantation of the body by screwing. The position of the cavity in the vicinity of the periphery of the body does not prevent the possible passage of the means of joining the body with the medical device, which may be arranged axially inside the endo-osseous end of the body to less partially adjacent to the cavity. The optimization of the volume of the cavity with regard to the overall volume of the endosseous end of the implant, and consequently the optimization of the amount of bone material that can nest inside the body in order to osteointegration of the implant, are supported from optimizing the useful volume of the cavity and from the obstacle formed by the edges of the window for the bone material nested inside the cavity. These provisions are intended to optimize the capacity of the cavity to receive bone material, while maintaining a satisfactory surface extension of the window for the passage of this bone material. In the case where the cavity is single, the angle defining the rope is preferably close to 180 °. For a plurality of angularly distributed cavities on the body, a satisfactory compromise resides in a cord corresponding to a segment delimited by an angle which is between 15 ° and 60 ° with respect to the diameter of the circular section of the cavity.

The cavity at least may be single, or be in even or odd number plurality. This cavity preferably extends parallel to the axis of extension of the body, but may also extend inclined with respect to this axis and / or helical. The at least one cavity may extend continuously or discontinuously along the body. The plurality of cavities may be the same or different, being disposed symmetrically or asymmetrically on the body. Each cavity is likely to have a section conformation of its own.

According to an alternative embodiment, the cavity is unique and has a section of the order of one-half, more or less 30% weighted, of the overall section of the endo-osseous end of the body taken in the same plane of section. . This variant embodiment is rather intended to be applied to a body of small diameter.

According to another embodiment, the cavities are in plurality being angularly distributed within the body. Such angular distribution is likely to be regular or not, and / or to be performed concentrically or not with respect to the axis of the cavity. This variant embodiment is rather intended to be applied to a body of larger diameter than the previous one. In this case, the connecting means equipping the body are likely to extend inside the endo-osseous end of the body, adjacent cavities.

More particularly, in the case of an implant whose body is of small diameter, the cavity is unique being formed in an area of the body located in extension of a receiving area of the means for joining the body with the medical device . This cavity, although unique, is radially offset from the general axis of extension of the body, to allow its lateral opening and the formation of the window. In the case where the diameter of the body is sufficiently large to allow it, the cavities are in plurality.

For example, the cavities are three in angularly distributed regularly and concentrically at an angle of 120 °. These provisions offer a compromise between the overall volume offered by the cavities for receiving the bone mass inside the body during osteointegration of the implant, and the size of these cavities with regard to the area. axial body left available to house the connecting means equipping the body.

The cavity comprises in particular secondary osteo-integration reliefs constituted by the threads of an internal thread which extends at least partly along the cavity. The threads provide between them a plurality of successive chambers for retention of the bone mass during the osseointegration of the implant.

Such secondary reliefs of osseointegration are oriented transversely to the direction of longitudinal extension of the cavity and therefore transversely to the direction of insertion and extraction of the implant, to prevent removal of the implant after its osteointegration from the resistance offered by the bone material bearing axially against each of the threads of the anchoring relief. Such osseointegration is rendered robust because of the lateral opening of the chambers on the periphery of the body towards the outside of the implant, and of the faculty offered a lateral migration of the bone material from the bone to the interior volume of the rooms delimited between two successive nets.

Each of the chambers is delimited by the wall of the cavity in the space between two successive threads, and opens out laterally around the endo-osseous end of the body. Such internal threading of the cavity makes it possible to easily increase the overall surface of the implant that can be enveloped by the bone material during its osseointegration. The lateral communication with the outside of the body of this internal thread through the window, allows each of the nets to be placed in individual contact with the bone material, which can migrate simultaneously and individually to each of these nets during the osseointegration of the implant, according to a development of the bone material from the outside laterally to the implant with respect to its axis of extension, and consequently to occupy progressively and simultaneously all the successive chambers retention of bone mass during osseointegration of the implant.

The quality of the histological anchorage obtained makes the installation of the implant robust, reliable and durable, with the possibility of withstanding the long-term repeated and important forces, such as chewing forces in the case of use dental. The internal threading of the cavity for the formation of secondary osteointegration reliefs may be completed by at least one anchoring relief of another nature, such as grooves and / or radial grooves and / or or perforations arranged radially through the body. Such anchoring reliefs may be successively arranged along the longitudinal extension of the cavity, at least in part along its length.

The provisions of the invention relating to the organization of the means of anchoring by osseointegration make it possible to freely organize not only the connecting means inside the body, but also the mechanical anchoring means, thanks to the optimization of the internal volume of the cavities and the presence of secondary osteointegration reliefs formed inside the cavities. Ways mechanical anchoring may be indifferently means for anchoring by screwing and / or impingement anchoring means.

In the case where the mechanical anchoring means are of the screw type, the thread formed inside the cavity is indifferently arranged in the same direction and / or in the opposite direction of the thread direction of the mechanical anchoring means. Similarly, the pitch of the thread formed inside the cavity is indifferently the same and / or is different from the thread pitch of the mechanical anchoring means.

The connecting means are likely to be arbitrary. For example, the joining means consist of at least one connecting member, such as an internal thread, which is formed in the body extending in extension or inside the endo-osseous end . For example still, the assembly member is an element that emerges at the air end of the body, and which is reported or integrated therewith. Several assembly members are likely to be associated.

The body has in particular a generally circular conformation section, possibly conical. Such a conformation of the body is however not restrictive, the body being able to present in a similar way a polygonal conformation section, especially in case of implantation by impaction.

The body is preferably formed from a cylinder inside which are easily formed the cavity and the threading it comprises by drilling and tapping. Drilling operations of the cavity or cavities, and their possible tapping to form the thread constituting the secondary reliefs of osseointegration, are performed from the end face of the corresponding end of the cylinder. Then, the diameter of this cylinder is reduced until laterally open the cavity and accordingly to form the window. These modalities obtaining histological anchoring means allow easy obtaining of the implant at lower costs.

A surface treatment, such as by corrosion and / or sandblasting, or even a contribution of material such as by projection, can be applied to the surfaces of the cavity and / or anchoring reliefs for the formation of micro-reliefs on these surfaces to improve the osseointegration of the implant.

It is more specifically proposed a method for obtaining an implant as just described. Such a method is mainly recognizable in that it consists, from a raw body of gross section S1 greater than a finite section S2 of a finite body, to carry out successively the following operations: *) forming by drilling the cavity on the raw body, from the end face of the endo-osseous end of the body so that the axis of the cavity is radially offset relative to the median axis of the body.

*) reduce the raw section S1 of the raw body to a section corresponding to the finite section S2 of the finished body, until a radial outlet of the cavity is obtained on the periphery of the body for the formation of the longitudinal window of passage of the bone material to and inside the cavity. *) to provide the periphery of the finished body mechanical anchoring means.

The raw section S1 and the raw body correspond to the characteristics of a blank from which is removed from the material for the formation of the anchoring means and the means of joining with the medical apparatus, and for obtaining the finished body of finished section S2 implantable in the bone material.

The formation of the cavity is performed before any step to obtain the finite section S2 of the finished body and to provide the mechanical anchoring means, to preserve the surfaces of the implant used for its implantation in the bone material and its mechanical retention. waiting for his osteo-integration. This preservation makes it possible to avoid any alteration of the finished body and mechanical anchoring means likely to affect the effectiveness of the positioning and reliable maintenance of the implant in bone prior to osseointegration.

The precision of the radial extension of the cavity is inexpensively and sufficiently obtained to guarantee the effectiveness of the osseointegration of the implant, while allowing the subsequent obtaining of the finite section S2 of the finished body and mechanical fixing relief with optimized precision. More precisely, a rigor of dimensional tolerances is only applied for the surfaces necessary for the installation of the implant in the bone material waiting for its osseointegration. The recovery operations of the body are limited: the formation of the cavity, incidentally its tapping and the reduction of the raw section of the raw body can both be made from the same phase of holding the body on tooling, that is to say without removal of the body of this tool. The formation of the cavity by drilling from the end face of the implant is performed without risk of bursting of the blank, despite the lateral opening of this cavity for the formation of the window, this lateral outlet being obtained at from a reduction in the diameter of the raw body. More particularly, the hole formed by drilling is non-emerging on the periphery of the body, then the window is obtained by reducing the gross section of the body. The precision of the emergent surface of this window at the periphery of the body is obtained easily and at lower cost, from a reduction of the section of the gross body achievable with imperatives of dimensional tolerances that are not very restrictive and easy to implement. .

Preferably, a complementary operation consists in providing along the cavity secondary reliefs of osseointegration, this complementary operation being performed after the formation of the cavity and prior to the reduction of the raw section S1 of the raw body to avoid to alter the finite body.

The secondary reliefs of osseointegration are advantageously formed by tapping the cavity prior to the reduction of the gross section of the raw body. Such a tapping operation is likely to be operated simultaneously with the drilling operation by means of a self-tapping drill, or after the drilling operation by means of a specific tap. The formation of secondary osteointegration reliefs is achieved by preserving the mechanical anchoring means and the finished body from any alteration, the tapping of the cavity being easily achieved prior to their obtaining. The secondary reliefs of osseointegration are obtained with low production costs for optimized osteointegration faculties of the implant.

Incidentally, the method comprises an auxiliary operation of bevelling the axial edges of the radial outlet of the cavity. This auxiliary operation is performed after the reduction of the gross body section, or even the formation of the mechanical anchoring means. Such beveling aims to debur the edges of the window and to provide scraping organs of the bone material during the installation of the implant by screwing.

The method also comprises at least one terminal operation consisting of arranging on the finished body the junction means of the medical device. This end operation comprises, where appropriate, a completion of the endosseous end of the body in the case in particular of an implant placed by impaction, this completion consisting in conferring on the endo-osseous end of the body a shape adapted to an impaction of the implant, such as a rounded conformation or other similar conformation. The terminal operation is performed after the formation of the mechanical anchoring means.

The terminal operation may also comprise a precision operation consisting of providing a junction relief with an adherent surface for receiving a junction relief with adherent surface complementary to the medical device. Such junction relief with adherent surface is in particular a relief of the type with Morse taper or similar relief.

The use of such a junction relief for the connection between the implant and a medical device aims to prohibit any movement between the implant and the medical device, or to analogous way between the implant and an intermediate junction piece equipping the medical device.

At least one finishing operation is incidentally carried out, and consists of a surface treatment of the endo-osseous end of the body, such as by corrosion and / or sandblasting, or even by a contribution of material by projection in particular. This finishing operation aims to provide micro-reliefs on the treated surfaces to improve the osseointegration of the implant, and is performed after the formation of the mechanical anchoring means and where appropriate prior to the operation of precision not to affect the adhesion of the junction relief surface.

Description of the figures.

The present invention will be better understood on reading the description which will be given of exemplary embodiments, in relation to the figures of the attached plates, in which:

Fig.1 to Fig.3 are illustrations of an endosseous implant according to a first embodiment of the present invention, respectively axially viewed from the side, axially front view and sectional view.

Fig.4 and Fig.5 are illustrations of an endosseous implant according to a second embodiment of the present invention, respectively axially viewed from the front and sectional view.

Fig.6 is a side illustration of an endosseous implant according to a third embodiment of the present invention.

Fig.7 to Fig.11 are axially oriented diagrams illustrating successively respective steps of a method for obtaining an endosseous implant according to a preferred embodiment of the present invention.

Fig.12 to Fig.15 are illustrations of an end seen implant at different stages of the process of obtaining this implant respectively shown in Fig.7 to Fig.10. In FIGS. 1 to 6, an endo-osseous implant is used in surgery to supply a medical device to a patient, and more particularly to the exemplary embodiments illustrated, but not exclusively, is intended for a patient. dental use while carrying a prosthesis. This implant is mainly constituted by an elongated body 1, whose aerial end 2 is intended to receive the medical device while the endo-osseous end 3 is intended to be anchored in the bone. The aerial 2 and endo-osseous ends 3 of the body 1 will be located with regard to the axially opposite position of their respective end face in the longitudinal direction of extension of the body 1. The aerial end 2 of the body 1 is provided with means junction 4 with the medical device, directly or through a specifically dedicated organ. In the exemplary embodiments illustrated, these joining means 4 consist of an axial thread formed in the body 1, raised by a nut. In general, the structure of the joining means 4 is indifferent with regard to the specific provisions of the present invention. The endo-osseous end 3 of the body 1 is provided with means for anchoring in the patient's bone, associating mechanical anchoring means 5 used during the placement of the implant, and means for Histological anchoring 6 to strengthen the maintenance of the implant in the bone by osteointegration.

In FIGS. 1 to 5, the mechanical anchoring means 5 are of the screw type, and consist of a thread formed at the periphery of the body 1. In FIG. 6, the mechanical anchoring means 5 are of impaction type, and comprise rings formed on the body 1 successively in its longitudinal direction of extension. In general, the structure of the mechanical anchoring means 5 is indifferent with regard to the structure of the histological anchoring means 6 proposed by the present invention.

The histological anchoring means 6 consist mainly of at least one cavity 7 which extends longitudinally in the direction of extension of the body 1. This cavity 7 at least is formed inside the body 1 by opening laterally to its periphery, so as to provide a window 8 longitudinally extended for the passage of bone during osteointegration of the implant. This window 8 extends in particular along the direction of longitudinal extension of the body 1, to allow osseointegration of the implant which is fast and effective.

It will be understood by cavity 7 a clearance formed in the body 1 whose section, taken either individually for a single cavity 7, or cumulatively for a plurality of cavities 7, has a significant surface area in relation to the overall surface of the corresponding section endosseous end 3 of the body 1.

The cavity or cavities 7 are of circular section, being formed by drilling preferably supplemented by a tapping. The axis A1 of any cavity 7 is radially offset relative to the axis A of the body 1 to open laterally at its periphery so as to form the window 8. The conformation in moon portion of the section of the cavities 7 promotes homogeneous migration of bone cells during osseointegration of the implant. In addition, in the preferred case of a threaded organization of the mechanical anchoring means 5, the moon-shaped conformation of the cavity or cavities 7 promotes the collection of bone tissue during implant placement, the edges of the window forming tools for collecting and bringing bone tissue into the cavity 7 during rotation of the body.

The cavity or cavities 7 are formed by drilling from the end face of the endo-osseous end 3 of the body 1, and are threaded to provide in their wall secondary reliefs of osseointegration 9 which consist of the threads thus formed and which are successively arranged along the longitudinal extension of the body 1. Such secondary reliefs of osseointegration 9 delimit successively between them inside the cavity 7 of the chambers which are intended to independently receive the bone material during the Osteo- integration of the implant. This independent reception of the bone material by the chambers is in particular obtained thanks to their individual lateral outlet to the outer periphery of the body 1.

In Fig.1 to Fig.3, the implant is of the small diameter type and has a single cavity 7. The joining means 4 being formed axially inside the body 1 from its aerial end 2, the axial zone of the body 1 is occupied by these junction means 4. A longitudinal adjacency of the junction means 4 and the cavity 7 being made difficult because of the small diameter of the body 1. In this case, the connecting means 4 and the cavity 7 are arranged in extension of each other. The longitudinal extension of the cavity 7 being further restricted because of the presence of the joining means 4, the surface of its section is optimized to represent a surface of the order of half of the overall surface of the section. of the endo-osseous end 3 of the body 1. The transverse dimension of the window 8 corresponds to a cord 10 of the circle determining the section of the cavity 7, the segment of which is delimited by an open angle towards the outside of the body which is less than 180 °, so that the rope 10 defining the transverse dimension of the window is smaller than the diameter of the cavity 7.

In FIGS. 4 to 6, the implant is of the large-diameter type, allowing an extension of a plurality of cavities 7 in longitudinal adjacency of the joining means 4. These arrangements make it possible to increase the longitudinal extension of the cavities 7, whose individual diameter is reduced but the cumulative surfaces of the sections of the set of cavities 7 can provide a significant capacity for receiving the bone material during osseointegration of the implant. In the exemplary embodiments illustrated, the cavities 7 are three in number being angularly evenly distributed over the body at an angle of 120 °.

On the exemplary embodiments illustrated in Fig.1 to Fig.6, the conformation and the individual dimensions of the cavities 7 formed on the same body 1 are identical. However, these conformation and individual dimensions are likely to be different for cavities 7 formed on the same body 1. Moreover, the relative position of the various cavities 7 relative to the axis A of extension of the body 1 is likely to vary from one cavity 7 to another.

In FIGS. 4 and 5, the transverse dimension of each of the windows 8 corresponds to a cord 10 of the circle defining the section of the cavities 7, the segment of which is delimited by angles of the order of 45.degree. to the diameter of the corresponding cavity 7, on either side of the transversely median axis of this cavity 7. According to this variant embodiment, the capacity of the cavities 7 is optimized despite their restricted diameter, the transverse dimension of the window 8 being limited but sufficient.

In general, the choice of the number of cavities 7, their diameter and the dimension of the chord segment defining the transverse dimension of the window 8, are chosen according to the type of implant, and in particular according to the diameter of the endo-osseous end 3 of the body 1, and as a function of the position and the arrangement of the joining means 4, so as to best satisfy the necessary compromise between an overall volume of the cavity 7 which is optimized and a transverse dimension of the window 8 which allows a rapid migration of the bone material to the secondary osteointegration reliefs 9 constituted by the threads of the internal threading which comprises the cavity or cavities 7.

In Fig.11, the body 101 of the implant has at its air end junction means 102 with a medical device, and at its end endosseous means for anchoring within a bone tissue. In the exemplary embodiment illustrated, the joining means 102 combine a threaded hole 103 and a junction relief 104 with an adherent surface of the Morse taper type. The aerial end of the implant also comprises a driving relief 105 of the implant in rotation, as shaped in a polygon, for placing the implant in the bone material by screwing. The anchoring means comprise mechanical anchoring means 106 constituted by an external thread formed at the periphery of the body 101. In the variant embodiment illustrated in FIGS. fig.15, the mechanical anchoring means 106 are formed of peripheral rings for impaction implant placement of the implant.

In Fig.7 and Fig.12, a blank consisting of a blank body 110 of rough section S1 is placed on a tool for the formation of cavities 108 by drilling. This operation is carried out from the end face of the endo-osseous end of the raw body 110, and is completed by a bulging operation of the cavities 108 to form the internal thread constituting the secondary osteointegration reliefs 111. The cavities 108 are formed in full material to preserve the raw body 110 from any risk of bursting.

In Fig.8 and Fig.13, the body 110 is machined to reduce its section S1 to a section S2 corresponding to the section of a finite body 112 implantable in the bone material. This operation aims not only to adjust the section S2 of the finished body 112, but also to open the cavities 108 on the periphery of the body to spare the windows 109.

On fig.9 and fig.14 on the one hand, and on fig.10 and fig.15 on the other hand, the mechanical anchoring means 106 are formed at the periphery of the finished body 112. An appendage bevel operation edges of the windows 109 is preferably made. In FIGS. 9 and 14, the mechanical anchoring means 106 consist of an external thread formed at the periphery of the finished body 112. In FIGS. 10 and 15, the mechanical anchoring means 106 are formed peripheral rings 113 which are formed concomitantly with the reduction of the section S1 of the raw body 110 to obtain the finished body 112. In this case, the endo-osseous end 114 is completed by giving it a shape favoring the impaction of the implant, such as a rounded shape on the exemplary embodiment illustrated.

In Fig.11, the implant is completed by a terminal operation of forming the junction means 112 of the implant with the medical device and if necessary the driving relief 115 in rotation of the implant. Incidentally, a finishing operation is performed to achieve a surface treatment of the implant promotes its osteo-integration. Then an end operation is optionally performed, to form the junction relief 114 with adherent surface.

Claims

claims

1.- Endosseous implant comprising an elongated body (1) whose aerial end (2) is provided with connecting means (4) with a medical device and whose endosseous end (3) is provided with means anchoring means (5, 6) in the bone which combine mechanical anchoring means (5) to fix the implant in the bone during implantation, and histological anchoring means (6) for an osteo -integration of the implant which comprise at least one cavity (7) which extends longitudinally inside the body (1) and which opens, on the one hand according to its dimension of longitudinal extension laterally on the periphery of the body ( 1) for forming a longitudinal window (8) for passage of bone material to and within the cavity, and secondly through the end face of the endo-bone end (3) of the body (1), the cross section of the cavity (7) being defined by a circle so that the transverse dimension of the window (8) is deflected inie by a rope (10) of this circle, characterized in that the rope (10) corresponds to a segment defined by an angle less than 180 °, the transverse dimension of the window (8) being smaller than the diameter defining the section of the cavity (7).

2.- endosseous implant according to claim 1, characterized in that the cavity (7) comprises secondary reliefs of osseointegration (9) consisting of threads of an internal thread which extends at least in part the along the cavity (7), the threads between them a plurality of successive chambers of retention of bone mass during the osseointegration of the implant.

3. Endo-osseous implant according to any one of the preceding claims, characterized in that the mechanical anchoring means (5) are indifferently means for anchoring by screwing and / or impingement anchoring means.

4.- endo-osseous implant according to claims 2 and 3, characterized in that the mechanical anchoring means (5) being of the screw type, the thread formed inside the cavity (7) is indifferently in the same direction and / or in the opposite direction of the thread direction of the mechanical anchoring means.

5.- endo-osseous implant according to claims 3 and 4, characterized in that the mechanical anchoring means (5) being of the screw type, the thread formed inside the cavity (7) is indifferently to a same pitch and / or a pitch different from the thread pitch of the mechanical anchoring means (5).

6. A process for obtaining an endosseous implant according to any one of claims 1 to 5, characterized in that it consists of a raw body (110) of gross section Sl greater than one section. Finite S2 of a finite body (112), to successively perform the following operations: *) Piercing the cavity (108) on the raw body (110), from the end face of the endo-osseous end of the body so that the axis of the cavity (108) is radially offset from the center axis A of the body. *) reducing the gross section Sl of the raw body (110) to a section corresponding to the finite section S2 of the finished body (112), until a radial outlet of the cavity (108) is obtained on the periphery of the body (110) for forming a longitudinal window (109) for passage of bone material to and within the cavity (108).

*) to provide the periphery of the finished body (112) the mechanical anchoring means (106).

7. A method for obtaining an endosseous implant according to claim 6, characterized in that it comprises the complementary operation of providing along the cavity (108) secondary reliefs (111) osteo - Integration, this complementary operation being performed after the formation of the cavity (108) and prior to the reduction of the gross section S_l of the raw body (110).

8. A method for obtaining an endosseous implant according to claim 7, characterized in that the secondary reliefs (111) of osseointegration are formed by tapping the cavity (108) prior to the reduction of the raw section Sl of the raw body (110).

9. A process for obtaining an endosseous implant according to any one of claims 6 to 8, characterized in that it comprises an auxiliary operation of bevelling the axial edges of the radial outlet of the cavity (108), this additional operation being performed subsequent to the reduction of the gross section Sl of the raw body (110) and the formation of the mechanical anchoring means (106).

10. A process for obtaining an endosseous implant according to any one of claims 6 to 9, characterized in that it comprises at least one terminal operation consisting in providing the finished body (112) with the means of junction (102) and where appropriate to complete the endosseous end (114) of the body (112), this terminal operation being performed after the formation of the mechanical anchoring means (106).

11. A process for obtaining an endosseous implant according to claim 10, characterized in that the terminal operation comprises a precision operation consisting in providing a junction relief (104) with an adherent surface for the reception of a junction relief with adherent surface complementary to the medical device.

12. A process for obtaining an endosseous implant according to any one of the preceding claims, characterized in that it comprises at least one finishing operation consisting of a surface treatment of the endosseous end of the body (112), this finishing operation being performed after the formation of the mechanical anchoring means (106) and if necessary prior to the precision operation.