IMPROVED SELF-TAPPING DENTAL IMPLANT

Abstract

A dental implant includes an implant body extending along a longitudinal axis between a crown end and an apical end, the implant body having a core along which a helical thread extends with at least one thread, the core being tapered towards the apical end on at least one section of the length of the dental implant. At least two tapping grooves are arranged in the thread. The grooves interrupt the thread, so that the thread includes a series of consecutive thread arcs. Each thread arc has an apical surface oriented towards the apical end of the dental implant, and a crown surface oriented towards the crown end of the dental implant. A peripheral lateral surface connects the apical surface and the crown surface of the thread arc. In at least one section of the dental implant in which the core is tapered, at least one thread arc has a radial offset.

Claims

1-13. (canceled)

14. Dental implant comprising an implant body extending along a longitudinal axis (I-I) between a coronal end and an apical end, said implant body having a core, along which there extends a helical threading having at least one thread, said core being tapered in the direction of the apical end over at least one segment of the length of the dental implant, in which: at least two tapping grooves are formed in the threading and interrupt said at least one thread, such that said at least one thread has a succession of consecutive thread arcs, a thread arc being separated from a thread arc consecutive to it by one of said at least two tapping grooves, each thread arc has an apical surface oriented towards the apical end of the dental implant and a coronal surface oriented towards the coronal end of the dental implant, each thread arc has a peripheral lateral surface connecting the apical surface and the coronal surface of said thread arc and developing from a leading end to a trailing end, wherein, in said at least one segment of the dental implant in which the core is tapered, at least one thread arc has a radial setback, such that the peripheral lateral surface of said at least one thread arc having a radial setback is at all points situated at a distance from the longitudinal axis (I-I) that is less than the maximum distance, from the longitudinal axis (I-I), of the peripheral lateral surface of a thread arc which is consecutive to said at least one thread arc having a radial setback.

15. Dental implant according to claim 14, wherein said at least one thread has an alternation of thread arcs that each have a radial setback and thread arcs that are without a radial setback.

16. Dental implant according to claim 14, wherein: the dental implant comprises a plurality of thread arcs having a radial setback, the thread arcs having a radial setback are distributed in a balanced manner all around the longitudinal axis (I-I).

17. Dental implant according to claim 14, wherein said at least one thread arc has a radial setback such that all the points of its peripheral lateral surface are situated substantially at the same distance from the longitudinal axis (I-I).

18. Dental implant according to claim 14, wherein the radial setback of said at least one thread arc having a radial setback is less than or equal to 30% of the maximum height of the apical surface in the vicinity of the trailing end or leading end of a thread arc which is consecutive to said at least one thread arc having a radial setback.

19. Dental implant according to claim 14, wherein: in a part of the threaded length of the dental implant, the dental implant has an apical segment, developing from the apical end in the direction of the coronal end, the apical segment is without thread arcs having a radial setback.

20. Dental implant according to claim 14, wherein the threading comprises a plurality of threads, preferably two.

21. Dental implant according to claim 14, wherein three tapping grooves are formed in the threading.

22. Dental implant according to claim 14, wherein said at least two tapping grooves extend over more than half of the threaded length of the dental implant.

23. Dental implant according to claim 14, wherein said at least two tapping grooves extend helically.

24. Dental implant according to claim 14, wherein the core is tapered at a cone angle.

25. Dental implant according to claim 14, wherein the threading is tapered, preferably at a cone angle.

26. Dental implant according to claim 14, wherein the threading is cylindrical.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Other objects, features and advantages of the present invention will become clear from the following description of particular embodiments, given with reference to the accompanying figures, in which:

[0035] FIG. 1 is a side view of a particular embodiment of a dental implant according to the invention, in a first orientation about the longitudinal axis;

[0036] FIG. 2 is a side view of the dental implant from FIG. 1, in a second orientation about the longitudinal axis;

[0037] FIG. 3 is a side view of the dental implant from FIG. 1, in a third orientation about the longitudinal axis;

[0038] FIG. 4 is a perspective view of the dental implant from FIG. 1;

[0039] FIG. 5 is the view from FIG. 3, on which broken lines illustrate the outer envelope of the dental implant in the absence of a radial setback on its thread arcs;

[0040] FIG. 6 is a partial longitudinal sectional view of a thread arc of the dental implant from FIG. 1; and

[0041] FIG. 7 is a partial side view of the dental implant from FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] FIGS. 1 to 7 illustrate a particular embodiment of a dental implant 1 according to the invention.

[0043] As is illustrated in FIGS. 1 to 5, the dental implant 1 comprises an implant body 2 extending along a longitudinal axis I-I between a coronal end 2a and an apical end 2b. The implant body 2 has a core 3, along which there extends a helical threading 4 with at least one thread. In this case, the threading 4 here comprises two threads F1 and F2.

[0044] In FIG. 5, broken lines have been used, to illustrate the outer envelope 5 of the implant body 2 or envelope of the peripheral lateral surfaces of the threads F1 and F2. The envelope of the core 3 has also been illustrated by means of broken lines. It can thus be seen that the implant body 2 comprises five segments T1 to T5 from its coronal end 2a to its apical end 2b.

[0045] In the segment T1, the core 3 is substantially cylindrical, while the threading 4 is conical with a taper oriented toward the coronal end 2a. The height of the threads F1 and F2 (taken in a plane substantially perpendicular to the longitudinal axis 1-1) thus decreases in the direction of the coronal end 2a. The progressive decrease in the cross section of the dental implant 1 in the vicinity of its coronal end 2a makes it possible to take into account the volume of bone which is reduced at the vicinity of the osseous crest of the maxillary or mandibular bone in the vestibular-palatal direction, for esthetic integration of the dental implant 1.

[0046] In the segment T2, the core 3 tapers in the direction of the apical end 2b, being conical with a taper oriented toward the apical end 2b, while the threading 4 is substantially cylindrical. The height of the threads F1 and F2 (taken in a plane substantially perpendicular to the longitudinal axis I-I) thus increases in the direction of the apical end 2b.

[0047] In the segment T3, the core 3 is also conical. Its taper is the same as in the segment T2. The threading 4 is also tapered in the direction of the apical end 2b, being conical with a taper oriented toward the apical end 2b. The variation in the height of the threading 4 depends on the relationship between the respective cone angles A3 and A4 of the core 3 and of the threading 4: [0048] when the cone angle A3 of the core 3 is greater than the cone angle A4 of the threading 4, the height of the threading 4 increases in the direction of the apical end 2b, [0049] when the cone angle A3 of the core 3 is equal to the cone angle A4 of the threading 4, the height of the threading 4 is substantially constant in the direction of the apical end 2b, [0050] when the cone angle A3 of the core 3 is less than the cone angle A4 of the threading 4, the height of the threading 4 decreases in the direction of the apical end 2b.

[0051] In the particular embodiment illustrated in the figures, the cone angles A3 and A4 are substantially equal.

[0052] In the segment T4, the core 3 is still conical and tapers toward the apical end 2b. Its taper is the same as that in the segments T2 and T3. The threading 4 is for its part rounded and has a substantially zero height at the junction of the segments T4 and T5.

[0053] The segment T5 is convex, in the form of a half-lens. It is completely optional.

[0054] The core 3 is thus tapered in the direction of the apical end 2b over at least one segment of the length of the dental implant 1, in this case over the segments T2 to T4.

[0055] As will be seen from FIGS. 1 to 3, which show the dental implant 1 in three different orientations, at least two tapping grooves are formed in the threading 4. In this case, there are three tapping grooves R1 to R3 interrupting the threads F1 and F2. The threads F1 and F2 thus respectively have a succession of consecutive thread arcs AF, a thread arc AF being separated from a thread arc AF which is consecutive to it by one of said at least two tapping grooves R1, R2 or R3. In the figures, only some of the thread arcs are indicated by the reference AF, so as not to affect the clarity of the presentation.

[0056] The tapping grooves R1 to R3 extend over more than half (in this case about 85%) of the threaded length of the dental implant 1.

[0057] The grooves R1 to R3 are not straight, but extend helically along the dental implant 1, about the longitudinal axis I-I.

[0058] As can be seen better in FIG. 6, each thread arc AF has an apical surface SA oriented toward the apical end 2b of the dental implant 1, and having a height HSA (taken in a plane substantially perpendicular to the longitudinal axis I-I). Each thread arc AF also has a coronal surface SC oriented toward the coronal end 2a of the dental implant 1, and having a height HSC (taken in a plane substantially perpendicular to the longitudinal axis I-I). Each thread arc AF has a peripheral lateral surface SLP connecting the apical surface SA and the coronal surface SC of said thread arc AF.

[0059] As can be seen better in FIG. 7, the peripheral lateral surface SLP of a thread arc AF develops helically from a leading end EA to a trailing end EF. The leading end EA is intended to penetrate the bone first during the insertion of the dental implant 1 by screwing into the bone, and is intended to cut into the bone in order to tap it.

[0060] In the segments T2 and T3 of the dental implant 1, in which segments the core 3 is tapered, thread arcs AF (of which the peripheral lateral surface SLP is colored black in order to identify them) have a radial setback RR such that the peripheral lateral surfaces SLP (in black) of said thread arcs AF having a radial setback RP are at all points situated at a distance from the longitudinal axis that is less than the maximum distance, from the longitudinal axis I-I, of the peripheral lateral surface SLP of a thread arc AF which is consecutive to a thread arc AF having a radial setback RR.

[0061] The radial setbacks RR of some thread arcs are clearly shown in FIG. 5 by means of the outer envelope 5 of the dental implant 1.

[0062] This feature is better illustrated in FIG. 7 using three thread arcs AF1, AF2 and AF3 located in the segment T2. The thread arcs AF1 and AF2 are separated from each other by the tapping groove R1, while the tbread arcs AF2 and AF3 are separated from each other by the tapping groove R2. The thread arcs AF1 and AF3 are thus consecutive to the thread arc AF2.

[0063] The threading 4 being cylindrical in the segment T2, the peripheral lateral surfaces SLP of the thread arcs AF1 and AF3 are situated at a constant distance from the longitudinal axis I-I equal to the radius R of the cylindrical segment T2. For its part, the thread arc AF2 has a radial setback RR which means that its peripheral lateral surface SLP (shown in black to retake it easier for the reader to understand) is situated at all points at a distance less than the radius R with respect to the longitudinal axis I-I. More precisely, the thread arc AF2 has a racial setback such that all the points of its peripheral lateral surface SLP are situated substantially at the same distance R′ from the longitudinal axis I-I, with R′ less than R.

[0064] Thus, during the insertion of the dental implant 1 by screwing into a hole made in the bone, the thread cuts into the bone, compresses the bone away from the longitudinal axis I-I, and leaves behind it a helical path into which then penetrates, due to the rotation of the dental implant 1, the thread arc AF2. On account of its radial setback, the peripheral lateral surface SLP of the thread arc AF2 will not rub against the bone that the peripheral lateral surface SLP of the thread arc API has previously shaped. The insertion torque of the dental implant 1 into the bone is thus reduced.

[0065] By contrast, the apical and coronal surfaces of the thread arc AF2 will rub against the bone that the apical and coronary surfaces of the thread arc AF1 have previously shaped and will therefore maintain good stability of the dental implant along the longitudinal axis I-I.

[0066] A similar construction with a radial setback RR is also provided in a part of the segment T3, the radial setback RP this rime being relative to the outer envelope 5, which is frustoconical.

[0067] For a good compromise between reduction of the insertion torque and stability of the dental implant along the longitudinal axis I-I, the radial setback RR of the thread arc AF2 is less than or equal to 30% of the maximum HSA height of the apical surface SA in the vicinity of the trailing end EF of the consecutive thread arc AF1, or less than or equal to 30% of the maximum HSA height of the apical surface SA in the vicinity of the leading end EA of the consecutive thread arc AF3.

[0068] To confer a radial setback RR on a thread arc AF, it is possible, for example, to rework said thread arc AF using a milling cutter which radially trims the thread arc AF.

[0069] In the embodiment illustrated in the figures, the threads F1 and F2 have an alternation of thread arcs AF having a radial setback RR and thread arcs AF that are without a radial setback RR. In other words, each thread arc AF having a radial setback RR is preceded and followed by thread arcs AF without a radial RR setback.

[0070] The dental implant 1 comprises a plurality of thread arcs AF having a radial setback RR, and it will be noted that the thread arcs AF having a radial setback are distributed in a balanced manner all around the longitudinal axis I-I. This promotes good coaxial alignment of the longitudinal axis I-I of the dental implant 1 with the drilling axis of the hole made in the bone.

[0071] In FIG. 5, it will be noted that the dental implant 1 comprises an apical segment TA which develops from the apical end 2b in the direction of the coronal end 2a and which is without thread arcs AF having a radial setback RR. Here, the apical segment TA includes the entirety of the segments T4 and T5 and also a part of the segment T3.

[0072] The present invention is not limited to the embodiments explicitly described but includes the diverse variants and generalizations thereof that fail within the scope of the attached claims.