WO1997018772A1

WO1997018772A1 - Tooth implant

Info

Publication number: WO1997018772A1
Application number: PCT/FR1996/000761
Authority: WO
Inventors: Sylvain Bordes
Original assignee: Sylvain Bordes
Priority date: 1995-11-22
Filing date: 1996-05-22
Publication date: 1997-05-29

Abstract

A tooth implant comprising an elongate body (10) extending along axis X-X' and provided with an axial bore (11) open at one end; a resilient member (12) positioned at the bottom (13) of the axial bore in the body; an elongate mounting insert (14) extending along axis X-X', mounted in the axial bore in the body and engaging the resilient member (12), said insert having a hole (16) open at one end and comprising an outer circumferential wall (17) provided with rotational locking means (18) that engage complementary means (19) on the wall (11a) of said axial bore in said body in order to prevent rotation of the mounting insert therein while enabling limited translation of said insert in the axial bore along axis X-X'; and a connecting means (20) integral with the body and surrounding the upper portion (14a) of the mounting insert while defining a circumferential gap for receiving a tooth holder (22) to enable mounting thereof on said insert. Said tooth holder comprises a through-bore (25) aligned with the hole in said mounting insert to enable an assembly member to be mounted therein via the through-bore of the tooth holder.

Description

DENTAL IMPLANT

The present invention relates to a dental implant.

Dental implants of known types generally comprise a body shaped to be inserted into the alveolar maxillary bone. The body of the implant carries a tooth support capable of receiving a prosthesis tooth, the body and the tooth support constituting a rigid assembly.

Such a dental implant described in particular in document WO-87 06816 comprises a metal tube capable of being impacted in the maxillary bone, inside of which is positioned a pellet on which is supported the tooth support. At the upper opening of the metal tube, a plastic envelope surrounds the tooth support so as to fix it to the metal tube. In addition, a plug ensuring the obturation of the implant exerts pressure on the plastic envelope surrounding the support of the implant. This plastic envelope does not provide real flexibility at the tooth support.

Numerous studies have shown that teeth naturally exhibit some mobility. This mobility results from the configuration of the alveolar maxillary bone and the periodontal ligament which give the tooth stiffness and damping. This mobility makes it possible to attenuate the forces transmitted to the maxillae during chewing.

The present invention proposes a new type of dental implant which has a simple configuration and which makes it possible to find the mobility characteristics normally exhibited by a natural tooth in order to limit the forces transmitted to the maxillary bone.

More particularly, according to the invention, the dental implant comprises:

- a body elongated along an axis XX ′, provided with an axial bore open at one end, - an elastically deformable element positioned in the bottom of the axial bore of the body,

a mounting insert elongated along the axis XX ′, mounted in the axial bore of the body in abutment against the elastically deformable element, said insert being pierced with an orifice open at one end and comprising a peripheral external wall provided with rotation locking means cooperating with means complementary to the wall of the axial bore of the body in order to lock said rotation mounting insert in the latter, while allowing limited translation along the axis XX 'of said insert in said axial bore,

a means of connection coming from formation with the body to form a single piece and surrounding the upper part of the mounting insert while leaving an annular space capable of receiving a tooth support for its mounting on said insert,

- Said tooth support having a through passage aligned with the orifice of said mounting insert to ensure the mounting of an assembly member in the orifice of said insert via the through passage of the tooth support.

Thus according to the invention, the assembled tooth support and mounting insert are mounted in a flexible manner in the body of the implant, that is to say that they can slightly move in vertical translation in said body. Therefore, when the prosthetic tooth mounted on the tooth support is subjected to forces due for example to chewing, these forces are transmitted to the elastically deformable element via the insert which compresses it elastically.

The description which follows with reference to the appended drawings, given by way of nonlimiting examples, will make it clear what the invention consists of and how it can be implemented.

Figure 1 is a schematic exploded perspective view of a dental implant of the type of the invention, with a cutaway at the body of the implant. Figure 2 is a schematic perspective view of the dental implant of Figure 1 in the assembled state with a partial cutaway.

Figure 3 is a schematic perspective view of the dental implant according to the invention in the assembled state with a partial cutaway.

Preliminary, it will be noted that from one figure to another the identical or similar elements have been designated as far as possible by the same reference signs and will not be described each time.

Referring to Figures 1 and 2, there is shown a dental implant which comprises a body 10 elongated along a vertical axis XX 'corresponding to the axis of mounting of the implant in the jawbone. This body 10 intended to be implanted in the maxillary bone, comprises a main part 10a essentially cylindrical of revolution around the axis XX '. The peripheral external wall of the main part 10a of the body 10 of the implant is here a smooth wall, this body 10a being intended to be impacted in the maxillary bone. Of course, according to other variants not shown, it is conceivable that this external wall is provided with a thread for a screwing of the body in the maxillary bone, or else is shaped in steps and if necessary coated with '' a material promoting anchoring and osteointegration, for example a titanium plasma. The main part 10a of the body 10 is pierced with an axial bore 1 1 open at one end, here in the upper part, and comprising a bottom 13. This axial bore 1 1 has a wall l ia generally cylindrical of revolution around the axis X-X '.

At least one area of the internal wall l ia is necessarily shaped with a particular profile to ensure the joining with other parts of the dental implant, as will be described later. Below the main part 10a, the body 10 is extended by a secondary part 10b pierced with channels substantially transverse to the axis XX ′, which provide blood supply. These irrigation channels form cavities in which bone regrowth takes place, which blocks the body in the jawbone.

The body of the implant being intended to be in contact with the gum, it is made of an alloy based on titanium and preferably pure titanium.

In addition, the dental implant comprises an elastically deformable element 12 positioned on the bottom 13 of the axial bore 11 of the body of the implant 10. This element 12 has the shape of a cylindrical sleeve of revolution around the axis X -X ', and of a height determined so that once positioned on the bottom of the bore 11, the elastically deformable element 12 only fills part of the height of the axial bore 1 1. For this purpose, note that the external diameter of the elastically deformable sleeve 12 is substantially equal to the diameter of the axial bore 11 of the body 10 so that when the latter is placed on the bottom 13 of said bore, the cylindrical peripheral surface of revolution of the sleeve 12 comes against the cylindrical wall of revolution of the axial bore 11.

This sleeve 12 is advantageously made of a polymeric material, in particular based on polyethylene. The dental implant also includes a mounting insert 14 which has an elongated shape along the axis XX ′. This insert 14 is mounted in the axial bore 1 1 of the body 10 bearing against the upper surface of the elastically deformable sleeve 12. The mounting insert 14 comprises over a part of its height a peripheral external wall 17 of cylindrical revolution around the axis XX 'provided, in the embodiment shown, with ribs 18. These ribs 18 extend vertically over a part of the height of said cylindrical peripheral wall of revolution 17 and are distributed regularly around its periphery. They cooperate with grooves of complementary shape 19 formed in the wall 1a of the axial bore 1 1, over only part of its height by providing a smooth part near the opening of said bore. This cooperation makes it possible to block the mounting insert 14 in rotation in the axial bore 11, while leaving said insert free in translation along the axis XX ′. It can be seen in FIG. 1 that an annular groove 19a is advantageously produced in the wall l ia of the axial bore 11 of the body 10, just below said grooves 19. This annular groove 19a facilitates the formation of grooves 19 in the wall internal ia of the axial bore 11.

It will be noted that the elastically deformable sleeve 12 has a height such that its upper surface arrives at the level of the annular groove 19a, and the mounting insert 14 has below the ribs 18 a cylindrical part which during its mounting in the bore axial 1 1 is introduced into the central orifice of the sleeve 12, the ribbed part of the insert 14 then resting on the upper annular surface of the sleeve 12.

The mounting insert 14 extends above its cylindrical part of revolution 17 provided with ribs 18 by a part comprising a polygonal peripheral external wall 14a, here with eight sides.

In addition, the mounting insert 14 is pierced with an axial orifice 16, here only open at one mounting end, the upper end. It is conceivable in another embodiment that the mounting insert 14 is pierced with a through hole. This orifice 16 is in the embodiment described and shown provided with a thread.

The part of the insert 14 provided with the polygonal external wall 14a is positioned outside the axial bore 11 of the body 10.

This insert 14 is a mounting part which must have particular mechanical resistance characteristics and is preferably made of a titanium-based alloy.

The dental implant includes a connecting means, here a ring link 20 made of titanium-based alloy or preferably titanium, which, according to the embodiment shown in Figures 1 and 2, has the shape of two sleeves 21a, 21b superimposed and offset radially. The upper sleeve 21a of larger diameter of the connection ring 20, has an external diameter equal to the external diameter of the body 10. The lower sleeve 21b of smaller diameter of the connection ring 20, has an external diameter substantially equal to the diameter internal of the axial bore 1 1 of the body 10 and an internal diameter substantially greater than the external dimensions of the insert 14 so that it is force fitted or screwed into said axial bore 1 1 between the peripheral external wall 17 of the 'insert 14, above the ribs 18, and the wall l ia of the axial bore 11. It will be noted here that the lower sleeve 21b of the connecting ring 20 makes it possible to limit the translation along the axis XX' of l insert 14 in the axial bore 1 1, towards the open end of the latter, by abutment cooperation with the ribs 18 of said insert 14. The upper portion of larger diameter in the form of a sleeve 21 a of the connecting ring 20 is then mounted ée on the body 10 so that its outer peripheral surface ensures the continuity of the cylindrical outer peripheral surface of revolution of the body 10 of the implant. This upper part 21a surrounds the upper part 14a of the mounting insert 14, leaving an annular space capable of receiving a mounting part 23 of a tooth support 22 for its positioning on said insert 14.

In the implant according to the present invention more particularly shown in Figure 3, the connecting means 20 is a sleeve-like element which comes to form with the body 10 of the implant, forming a single piece, so that said sleeve extends superiorly along the axis XX 'said body 10 ensuring the continuity of the external peripheral surface 10a of cylindrical revolution of said body 10 and the axial bore 1 1. In this case, a locking ring 21 is provided which has an external diameter substantially equal to the internal diameter of the axial bore 1 1 of the body 10 and an internal diameter substantially greater than the external dimensions of the insert 14 so that it is force fitted or screwed into said bore 1 1 between the peripheral external wall 17 of the insert 14, above the ribs 18, and the wall l ia of the axial bore 1 1. This locking ring 21 has a function identical to that of the lower sleeve 21 b of the connecting ring 20 according to the embodiment of Figure 2, that is to say limit the translation along the axis XX 'of the insert 14 in the axial bore 1 1, towards the open end of the latter, by cooperation of abutment with the ribs 18 of the insert _14.. As can be seen in Figure 3, the sleeve 20 forming a single piece with the body 10 surrounds the upper part 14a of the mounting insert 14 leaving an annular space adapted to receive a mounting part 23 of a support tooth 22 for its installation on the insert.

In particular, the tooth support 22 is the periodontal ring, produced for reasons of resistance of the materials, preferably made of titanium-based alloy, which comprises a part 24 projecting towards the outside of the gum, produced in a conventional manner and intended to receive a prosthetic tooth. This periodontal ring 22 has a mounting part 23 in the form of a cylindrical sleeve which is introduced into the annular space formed between the connecting ring 20 and the insert 14 to be mounted on the upper part 14a of the insert 14 The internal face of this mounting part 23 of the periodontal ring 22, which is applied against the polygonal peripheral external wall 14a of the insert 14, has a complementary polygonal shape so that the periodontal ring is locked in rotation on the 'insert. However, when mounting the periodontal ring on the insert, its angular position with respect to the insert can be adjusted by pivoting it around the axis XX 'by an angle corresponding to a section of the wall polygonal.

It can be seen in FIG. 2 that the internal wall of the upper sleeve 21a of the connection ring 20 has a recess 21 c projecting from said internal wall. This recess 21c limits the translation along the axis XX 'of the insert 14 and the periodontal ring 22 assembled, towards the bottom 13 of the axial bore 1 1, by abutment cooperation with the mounting part 23 of the periodontal ring 22. In FIG. 3, it can be seen that the upper end surface 21 'of the locking ring 21 makes it possible to limit the translation along the axis XX' of the insert 14 and of the periodontal ring 22 assembled towards the bottom 13 of the axial bore 11, by abutment cooperation with the mounting part 23 of the periodontal ring 22. The periodontal ring 22 has an axial passage 25 which allows the introduction of an assembly member here not shown which passes through the periodontal ring 22 and is blocked in the orifice 16 of the insert 14. In the embodiments shown, the assembly member is a screw which is screwed into the internal thread 16 of the insert 14.

Of course, according to a variant not shown, an expandable assembly member can be provided which is blocked by expansion in the orifice 16 of the insert.

Thus, the periodontal ring 22 is assembled with the mounting insert 14 which rests on the elastic sleeve 12. This insert 14 is locked in rotation in the axial bore 11 of the body 10, while being free in translation along the axis XX ′ inside the body 10, within the limit imposed by the connection ring 20. When this dental implant, impacted or screwed into the maxillary bone and carrying a prosthetic tooth on the periodontal ring, is subjected to forces due to chewing, the assembly formed by the periodontal ring and the insert transmits these essentially vertical forces to the elastic sleeve 12 forming a damping cushion.

The present invention is not limited to the embodiment described and shown, but a person skilled in the art can envisage any variant in accordance with his spirit.

For example, it can be envisaged in a variant not shown that the peripheral external wall of the insert represents a polygonal shape which cooperates with the wall of the axial bore of the body, also polygonal, so as to obtain a rotation blocking of the 'insert inside the bore of the body. In addition, it is conceivable as another anti-rotary solution of the insert in the body, an oblong section of the axial bore of the body which cooperates with an oblong shape of the peripheral external wall of the insert.

Claims

1. Dental implant characterized in that it comprises:

- a body (10) elongated along an axis XX ', provided with an axial bore (11) open at one end, - an elastically deformable element (12) positioned in the bottom

(13) of the axial bore (11) of the body (10),

- A mounting insert (14) elongated along the axis XX ', mounted in the axial bore (11) of the body (10) bearing against the elastically deformable element (12), said insert (14) being pierced with an orifice (16) open at one end and comprising a peripheral external wall (17) provided with rotation locking means (18) cooperating with complementary means (19) of the wall (lia) of the axial bore (11) of the body (10) in order to block said mounting insert (14) in rotation therein, while allowing limited translation along the axis XX 'of said insert (14) in said axial bore (11),

a connecting means (20) coming from formation with the body (10) to form a single piece and surrounding the upper part (14a) of the mounting insert while leaving an annular space capable of receiving a tooth support ( 22) for mounting on said insert

(14),

- said tooth support (22) having a through passage (25) aligned with the orifice (16) of said mounting insert (14) to ensure the mounting of an assembly member in the orifice (16) of said insert (14) via the through passage of the tooth support (22).

2. Dental implant according to claim 1, characterized in that the orifice (16) of the mounting insert (14) is a thread, and the member for assembling the tooth support (22) and the mounting insert (14) is a screw which is screwed into said thread via the through passage (25) of the tooth support (22).

3. dental implant according to one of claims 1 or 2, characterized in that the means for locking in rotation of said mounting insert (14) comprise ribs (18) extending vertically over at least part of the height of the peripheral external wall (17) of said insert (14) and distributed over a circumference of the latter, these ribs (18) cooperating with grooves (19) of complementary shape formed in the wall (lia) of the axial bore (11 ), of the body (10) over part of its height.

4. Dental implant according to claim 3, characterized in that the mounting insert (14) extends above the peripheral external wall (17) provided with the ribs (18) by a part having a peripheral external wall (14a ) of polygonal shape which cooperates with an internal surface complementary to the tooth support (22) so as to block the rotation of the tooth support (22) mounted on the mounting insert (14) while authorizing the mounting of said tooth support (22) an angular adjustment around the axis XX 'thereof on said insert (14).

5. dental implant according to one of claims 1 or 2, characterized in that the peripheral external wall (17) of the mounting insert (14) has a polygonal shape which cooperates with the wall (l ia) of complementary shape of the axial bore (11) to ensure the locking in rotation of said insert (14) in the body (10).

6. dental implant according to one of claims 1 or 2, characterized in that the peripheral external wall (17) of the mounting insert (14) has an oblong shape which cooperates with the wall (l ia) of complementary shape of the axial bore (11) to ensure the locking in rotation of said insert (14) in the body (10).

7. Dental implant according to any one of claims 1 to 6, characterized in that there is provided a locking ring (21) positioned in force in the axial bore (1 1) of the body (10) of the implant, able to limit an axial translation of the insert (14) and the tooth support (20) inside said axial bore (11).

8. Dental implant according to any one of claims 1 to 7, characterized in that the elastically deformable element (12) has a sleeve shape and is made of a polymeric material in particular based on polyethylene.

9. dental implant according to any one of claims 1 to 8, characterized in that the body (10) and the connecting means (20) are made of pure titanium or a titanium-based alloy, and the insert mounting (14) and the tooth support (22) are made with a titanium-based alloy.

10. Dental implant according to one of claims 1 to 1 1, characterized in that the tooth support (20) is the periodontal ring.