WO2025062391A1

WO2025062391A1 - Dental implant removal tool

Info

Publication number: WO2025062391A1
Application number: PCT/IL2024/050903
Authority: WO
Inventors: Eran GABAY; Hadar Zigdon-Giladi
Original assignee: Rambam Med Tech Ltd
Current assignee: Rambam Med Tech Ltd
Priority date: 2023-09-21
Filing date: 2024-09-09
Publication date: 2025-03-27
Anticipated expiration: 2026-03-21
Also published as: IL325274A

Abstract

A dental implant removal tool (10, 110) is provided for removing a broken dental implant (20) from a jawbone. The tool (10, 110) includes an implant gripper (14, 114) and an implant-hole engager (40). The implant gripper (14, 114) includes a core (16) defining a core non-circular interface surface (32); a collet (22) coupled to the core (16) and shaped so as to at least partially accept a lateral external surface (26) of a neck (28) of the broken dental implant (20); and a sleeve (34, 134) longitudinally moveable with respect to the core (16) and the collet (22) so as to tighten a grip of the collet (22) on the lateral external surface (26) of the neck (28). The implant-hole engager (40) is shaped so as to define a proximal head (42), which defines a proximal-head non-circular interface surface (44) couplable to the core non-circular interface surface (32); and a distal body (46) defining a distal-body external thread (48) that is couplable to a hole (50) within the broken dental implant (20). Other embodiments are also described.

Description

DENTAL IMPLANT REMOVAL TOOL

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from US Provisional Application 63/539,676, filed September 21, 2023, which is assigned to the assignee of the present application and incorporated herein by reference.

FIELD OF THE APPLICATION

The present invention relates generally to dental tools and surgical methods, and specifically to dental tools and methods for extracting dental implants.

BACKGROUND OF THE APPLICATION

Dental implants often experience technical complications, including breakage of the implant screw within the implant post (also known as the implant fixture) and fracture of the implant post itself. The most common way to remove a broken dental implant is to rotate the implant in the opposite direction to screwing in the implant. This action requires breaking the bone-implant connection, known as osseointegration. In cases where the implant screw breaks inside the implant post or there is a fracture of the implant post itself, it is not possible to obtain sufficient anchoring of the conventional removal tool. In such situations, an attempt is made to extract the implant by drilling and removing the bone around the implant, a process that results in significant damage to the jawbone at the site.

EP 2283792 A2 to Anitua Aldecoa describes an implant removal tool which allows removing an implant from a patient’s bone. The implant removal tool comprises a head, to which a torque-providing system is attached, and a threaded body preferably with a decreasing diameter. The threaded body preferably has a thread to the left and is intended to be threaded into the hole of the implant. The extraction of the implant is relatively simple to carry out, removing the implant in an almost clean manner and leaving a very small cavity in the patient’s bone. Therefore, the implant removal tool according to the invention is described as making the removal of an implant a far less traumatic procedure for the patient. SUMMARY OF THE APPLICATION

Embodiments of the present invention provide a dental implant removal tool for removing a broken dental implant from a jawbone of a subject, such as after the broken dental implant has been osseointegrated into the jawbone. The dental implant removal tool is configured to achieve maximum preservation of the jawbone at the implant site. The dental implant removal tool typically comprises an implant gripper and an implant-hole engager. As described below, the implant gripper and the implant-hole engager together tightly coupled the dental implant removal tool to the broken dental implant.

For some applications, the implant gripper comprises a core, a collet coupled to the core, and a sleeve. The core has a distal portion that is shaped so as to define a core noncircular interface surface. The collet is shaped so as to at least partially accept, via a distal opening of the collet, a lateral external surface of a neck of the broken dental implant. The sleeve is longitudinally moveable with respect to the core and the collet so as to tighten a grip of the collet on the lateral external surface of the neck when the lateral external surface is at least partially within the collet. Typically, the implant gripper is shaped so as to define a gripper non-circular interface surface for coupling to a torque tool.

For some applications, the implant-hole engager is shaped so as to define a proximal head and a distal body. The proximal head is shaped so as to define a proximal -head noncircular interface surface shaped so as to be couplable to the core non-circular interface surface of the core. The distal body shaped so as to define a distal-body external thread that is couplable to a hole within the broken dental implant.

For some applications, a proximal longitudinal portion of the core is shaped so as to define a core external thread. The implant gripper further comprises a nut, which is shaped so as to define the gripper non-circular interface surface. The nut is threadingly coupled to the core external thread such that rotation of the nut in a rotational direction moves the nut distally, such that the nut distally pushes the sleeve with respect to the core and the collet.

In order to confirm that the dental implant removal tool described herein is able to perform implant extraction, the inventors performed two ex-vivo, pre-clinical experiments as validation. A fresh bovine rib bone was used as an in-vitro model in both experiments. In each of the experiments, the inventors drilled an osteotomy having a depth of 10 mm and a diameter of 2.8 mm, and manually implanted a respective SEVEN® dental implant (MIS Implants Technologies Ltd., Bar-Lev Industrial Park, Misgav, Israel) into the osteotomy using a torque-controlled ratchet, at a very high torque (great than 50 Ncm). The implants had a length of 10 mm and a diameter of 3.3 mm.

In the first experiment, the inventors drilled, using a 1.1 mm drill, a preparation channel along the implant axis of the implanted implant. A counterclockwise-tapping 1.3 mm implant-hole engager, having characteristics of the implant-hole engager described herein, was inserted into the previously prepared channel. The inventors then mounted an implant gripper, having characteristics of the implant gripper described herein, on the implant neck and the implant-hole engager, and tightened the collet of the implant-hole engager on the implant neck by counter clockwise rotation. The implant was successfully pulled out of the bone by rotating the implant gripper.

In the second experiment, the neck of the implanted implant was broken, in such a way that the implant's internal hexagonal connection lacked two sides of the hexagon (measuring 120 degrees circumferentially). The inventors drilled, using a 1.1 mm drill, a preparation channel in the center of the implanted broken implant along the implant axis. A counterclockwise tapping 1.3 mm implant-hole engager, having characteristics of the implant-hole engager described herein, was inserted into the previously prepared channel. The inventors then mounted an implant gripper, having characteristics of the implant gripper described herein, on the residual implant neck, as described in the first experiment. The broken implant was successfully pulled out of the bone by rotating the implant gripper, in the same manner as the pristine implant of the first experiment described above.

These experimental results demonstrate that the techniques described herein are effective for removing even a heavily damaged implant from bone.

There is therefore provided, in accordance with an application of the present invention, a dental implant removal tool for removing a broken dental implant from a jawbone of a subject, the dental implant removal tool for use with a torque tool, the dental implant removal tool including:

(i) an implant gripper, which includes:

(a) a core, which has a distal portion that is shaped so as to define a core non-circular interface surface;

(b) a collet, which is coupled to the core and shaped so as to at least partially accept, via a distal opening of the collet, a lateral external surface of a neck of the broken dental implant; and (c) a sleeve, which is longitudinally moveable with respect to the core and the collet so as to tighten a grip of the collet on the lateral external surface of the neck when the lateral external surface is at least partially within the collet; and (ii) an implant-hole engager, which is shaped so as to define:

(a) a proximal head, which is shaped so as to define a proximal-head non-circular interface surface shaped so as to be couplable to the core non-circular interface surface of the core, and

(b) a distal body shaped so as to define a distal-body external thread that is couplable to a hole within the broken dental implant.

For some applications, the core non-circular interface surface is accessible via the distal opening of the collet, and the proximal head of the implant-hole engager is shaped and sized so as to be insertable into the collet via the distal opening.

For some applications, the distal-body external thread is left-handed.

For some applications, the core non-circular interface surface is female and the proximal-head non-circular interface surface is male.

For any of the applications described above: a proximal longitudinal portion of the core may be shaped so as to define a core external thread, and the implant gripper may further include a nut, which is: shaped so as to define a gripper non-circular interface surface, and threadingly coupled to the core external thread such that rotation of the nut in a rotational direction moves the nut distally, such that the nut distally pushes the sleeve with respect to the core and the collet.

For some applications, the distal -body external thread and the core external thread have a same thread handedness. For example, the same thread handedness may be lefthandedness.

For some applications, the dental implant removal tool is configured such that after the rotation of the nut in the rotational direction maximally pushes the sleeve with respect to the core and the collet, further rotation of the nut in the rotational direction rotates the collet and the implant-hole engager in the rotational direction.

For any of the applications described above: a proximal longitudinal portion of the core may be shaped so as to define a core external thread, and the sleeve may be: shaped so as to define a gripper non-circular interface surface, and threadingly coupled to the core external thread such that rotation of the sleeve in a rotational direction moves the sleeve distally with respect to the core and the collet.

For any of the applications described above, the dental implant removal tool may be for use with a torque tool, and the implant gripper may be shaped so as to define a gripper non-circular interface surface for coupling to the torque tool. For some of these applications, the gripper non-circular interface surface is polygonal.

In some applications of the present invention, a dental implant removal system is provided that includes the dental implant removal tool described above, the dental implant removal system further including the torque tool. For some of these applications, the torque tool includes a wrench.

In some applications of the present invention, a dental implant removal system is provided that includes the dental implant removal tool described above, the dental implant removal system further including a rotating cutting instrument configured to tap the hole in the dental implant.

There is further provided, in accordance with an application of the present invention, a method for removing a broken dental implant from a jawbone of a subject, the method including: coupling, to a hole within the broken dental implant, a distal-body external thread of a distal body of an implant-hole engager of a dental implant removal tool; coupling an implant gripper of the dental implant removal tool to the broken dental implant by: coupling a core non-circular interface surface of a distal portion of a core of the implant gripper to a proximal-head non-circular interface surface defined by a proximal head of the implant-hole engager, inserting a lateral external surface of a neck of the broken dental implant at least partially into a collet of the implant gripper via a distal opening of the collet, wherein the collet is coupled to the core, and tightening a grip of the collet on the lateral external surface of the neck by longitudinally moving a sleeve of the implant gripper with respect to the core and the collet; and rotating the implant gripper to remove the broken dental implant from the jawbone.

For some applications, rotating the implant gripper includes coupling a torque tool to the implant gripper and rotating the torque tool.

For some applications: the core non-circular interface surface is accessible via the distal opening of the collet, the proximal head of the implant-hole engager is shaped and sized so as to be insertable into the collet via the distal opening, and coupling the core non-circular interface surface to the proximal-head non-circular interface surface includes inserting the proximal head of the implant-hole engager into the collet via the distal opening.

For some applications, coupling the distal -body external thread of the distal body of the implant-hole engager to the hole within the broken dental implant includes rotating the implant-hole engager. For some of these applications, the distal-body external thread is left-handed, and coupling the distal-body external thread of the distal body of the implanthole engager to the hole within the broken dental implant includes rotating the implant-hole engager counterclockwise. For some of these applications, rotating the implant gripper includes rotating the implant gripper counterclockwise.

For some applications: a proximal longitudinal portion of the core is shaped so as to define a core external thread, and the implant gripper further includes a nut, which is: shaped so as to define a gripper non-circular interface surface, and threadingly coupled to the core external thread, and longitudinally moving the sleeve with respect to the core and the collet includes rotating the nut in a rotational direction to move the nut distally, such that the nut distally pushes the sleeve with respect to the core and the collet. For some of these applications, rotating the nut includes coupling a torque tool to the gripper non-circular interface surface. For some of these applications, the torque tool is a wrench, and coupling the torque tool includes coupling the wrench to the gripper noncircular interface surface.

For some of these applications, the distal -body external thread and the core external thread have a same thread handedness. For example, the same thread handedness may be left-handedness.

For some of these applications, rotating the nut in the rotational direction includes: rotating the nut in the rotational direction until the rotating of the nut in the rotational direction maximally pushes the sleeve with respect to the core and the collet; and thereafter, further rotating the nut in the rotational direction to rotate the collet and the implant-hole engager in the rotational direction.

For some of these applications, the gripper non-circular interface surface is polygonal.

For some applications: a proximal longitudinal portion of the core is shaped so as to define a core external thread, and the sleeve is: shaped so as to define a gripper non-circular interface surface, and threadingly coupled to the core external thread, and longitudinally moving the sleeve with respect to the core and the collet includes rotating the sleeve in a rotational direction to move the sleeve distally with respect to the core and the collet.

For some applications, the method further includes, before coupling the distal-body external thread of the distal body of the implant-hole engager to the hole within the broken dental implant: tapping the hole in the dental implant using a rotating cutting instrument.

The present invention will be more fully understood from the following detailed description of embodiments thereof, taken together with the drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS

Figs. 1A-B are schematic isometric and cross-sectional illustrations, respectively, of a dental implant removal system, in accordance with an application of the present invention;

Fig. 2 is a schematic isometric illustration of an implant gripper of the dental implant removal system of Figs. 1A-B, in accordance with an application of the present invention;

Figs. 3A-H are schematic illustrations of a method for removing a broken dental implant from a jawbone of a subject, in accordance with an application of the present invention; and

Fig. 4 is a schematic cross-sectional illustration of another dental implant removal system, in accordance with an application of the present invention.

DETAILED DESCRIPTION OF APPLICATIONS

Figs. 1A-B are schematic isometric and cross-sectional illustrations, respectively, of a dental implant removal system 2, in accordance with an application of the present invention. Dental implant removal system 2 comprises a dental implant removal tool 10 for removing a broken dental implant 20 from a jawbone of a subject. Dental implant removal system 2 typically further comprises a torque tool 12, which may, for example, comprise a wrench 72 or a surgical motor. Broken dental implant 20 is not an element of dental implant removal system 2. As used in the present application, including in the claims, the "jawbone" is either the maxilla or the mandible.

Dental implant removal tool 10 typically comprises an implant gripper 14 and an implant-hole engager 40. As described below, implant gripper 14 and implant-hole engager 40 together tightly coupled dental implant removal tool 10 to broken dental implant 20.

Reference is still made to Figs. 1A-B and is further made to Fig. 2, which is a schematic isometric illustration of implant gripper 14, in accordance with an application of the present invention. For some applications, implant gripper 14 comprises:

• a core 16, which has a distal portion 18 that is shaped so as to define a core noncircular interface surface 32; for example, core non-circular interface surface 32 may be polygonal, e.g., hexagonal; a collet 22, which is coupled to core 16 and shaped so as to at least partially accept, via a distal opening 24 of collet 22, a lateral external surface 26 of a neck 28 of broken dental implant 20; and

• a sleeve 34, which is longitudinally moveable with respect to core 16 and collet 22 so as to tighten a grip of collet 22 on lateral external surface 26 of neck 28 when lateral external surface 26 is at least partially within collet 22.

As is known, a collet is a slotted cylindrical clamp, which is shaped to as to define one or more slits (also called kerfs) cut along its length to the free end of the collet, in order to allow the collet to expand and contract. Implant gripper 14 may optionally be considered an implant clamp.

For some applications, implant gripper 14 is shaped so as to define a gripper noncircular interface surface 36 for coupling to torque tool 12; for example, gripper noncircular interface surface 36 may be polygonal, e.g., hexagonal.

For some applications, implant-hole engager 40 is shaped so as to define:

• a proximal head 42, which is shaped so as to define a proximal-head non-circular interface surface 44 shaped so as to be couplable to core non-circular interface surface 32 of core 16, and

• a distal body 46 shaped so as to define a distal-body external thread 48 that is couplable to a hole 50 within broken dental implant 20.

For some applications, distal-body external thread 48 is left-handed, as shown in Figs. 1A-B. This left-handedness may aid with removal of broken dental implant 20, because implants typically have right-handed external threads. The left-handedness of distal-body external thread 48 allows implant-hole engager 40 to be rotated counterclockwise, resulting in counterclockwise rotation of broken dental implant 20, as appropriate for removal in view of the implant's right-handed external thread.

For some applications, such as shown in Figs. 1A-B and 2, core non-circular interface surface 32 is accessible via distal opening 24 of collet 22, and proximal head 42 of implant-hole engager 40 is shaped and sized so as to be insertable into collet 22 via distal opening 24.

For some applications, core non-circular interface surface 32 is female and proximal-head non-circular interface surface 44 is male, such as shown in Figs. 1A-B. For some applications, such as shown in Figs. 1A-B and 2: a proximal longitudinal portion 52 of core 16 is shaped so as to define a core external thread 54, and

• implant gripper 14 further comprises a nut 60, which is (a) shaped so as to define gripper non-circular interface surface 36, and (b) threadingly coupled to core external thread 54 such that rotation of nut 60 in a rotational direction moves nut 60 distally, such that nut 60 distally pushes sleeve 34 with respect to core 16 and collet 22.

Typically, distal-body external thread 48 and core external thread 54 have a same thread handedness. For example, the same thread handedness may be left-handedness.

For some applications, dental implant removal tool 10 is configured such that after rotation of nut 60 in the rotational direction maximally pushes sleeve 34 with respect to core 16 and collet 22, further rotation of nut 60 in the rotational direction rotates collet 22 and implant-hole engager 40 in the rotational direction.

For some applications, all components of dental implant removal tool 10 comprise metal, such as stainless steel.

For some applications, dental implant removal system 2 further comprises a rotating cutting instrument 74 configured to tap hole 50 in dental implant 20. For example, rotating cutting instrument 74 may comprise a drill bit, such as a dental drill bit; or a burr, such as a dental burr. Optionally, rotating cutting instrument 74 has a diameter of 1 to 1.2 mm, such as 1.1 mm. Optionally, rotating cutting instrument 74 comprises stainless steel.

Reference is now made to Figs. 3A-H, which are schematic illustrations of a method for removing broken dental implant 20 from a jawbone 80 of a subject, in accordance with an application of the present invention. Broken dental implant 20 may be any type of dental implant, and may for example, be shaped so as to define an internal hexagonal connection, an external hexagonal connection, or a conical connection.

As shown in Figs. 3A-B, the method typically begins by tapping hole 50 in dental implant 20, such as using rotating cutting instrument 74, which is typically driven by a conventional dental drill. Hole 50 is typically tapped into the proximal end of broken dental implant 20, i.e., the end accessible within the mouth. If possible, before hole 50 is tapped, the implant screw of broken dental implant 20 is removed from the implant post (also known as the implant fixture), and hole 50 is tapped into the hidden threaded channel from which the implant screw was removed. If the implant screw cannot be removed from the implant post, hole 50 is tapped through both the implant screw and implant post.

As shown in Figs. 3C-D, distal-body external thread 48 of implant-hole engager 40 is coupled to hole 50 within broken dental implant 20, typically by rotating implant-hole engager 40 via proximal-head non-circular interface surface 44 of proximal head 42. Optionally, distal-body external thread 48 is left-handed, and implant-hole engager 40 is rotated counterclockwise, as viewed from the distal end of proximal head 42, such as shown. Optionally, torque tool 12, e.g., wrench 72, is used to rotate implant-hole engager 40.

As shown in Figs. 3E-F, implant gripper 14 is coupled to broken dental implant 20 by:

• coupling core non-circular interface surface 32 of distal portion 18 of core 16 of implant gripper 14 to proximal -head non-circular interface surface 44 defined by proximal head 42 of implant-hole engager 40, as schematically indicated by the arrow in Fig. 3E,

• inserting lateral external surface 26 of neck 28 of broken dental implant 20 at least partially into collet 22 of implant gripper 14 via distal opening 24 of collet 22, as shown in Fig. 3F, and

• tightening a grip of collet 22 on lateral external surface 26 of neck 28 by longitudinally moving sleeve 34 of implant gripper 14 with respect to core 16 and collet 22, as also shown in Fig. 3F.

Typically, collet 22 is highly resilient in order to tightly grip lateral external surface 26 of neck 28.

As shown in Figs. 3G-H, implant gripper 14 is rotated to remove broken dental implant 20 from jawbone 80. For example, implant gripper 14 may be rotated by coupling torque tool 12 to implant gripper 14 and rotating torque tool 12. The rotation of implant gripper 14 forces broken dental implant 20 to break its connection with jawbone 80.

As described hereinabove with reference to Figs. 1A-B and 2, for some applications core non-circular interface surface 32 is accessible via distal opening 24 of collet 22, and proximal head 42 of implant-hole engager 40 is shaped and sized so as to be insertable into collet 22 via distal opening 24. For these applications, core non-circular interface surface 32 is coupled to proximal-head non-circular interface surface 44 by inserting proximal head 42 of implant-hole engager 40 into collet 22 via distal opening 24.

As described hereinabove with reference to Figs. 1A-B, for some applications, distal-body external thread 48 is left-handed. For these applications, distal-body external thread 48 of distal body 46 of implant-hole engager 40 is coupled to hole 50 within broken dental implant 20 by rotating implant-hole engager 40 counterclockwise.

For applications in which implant gripper 14 further comprises nut 60, sleeve 34 is longitudinally moved with respect to core 16 and collet 22 by rotating nut 60 in a rotational direction to move nut 60 distally, such that nut 60 distally pushes sleeve 34 with respect to core 16 and collet 22.

For some of these applications, rotating nut 60 in the rotational direction comprises:

• rotating nut 60 in the rotational direction until the rotating of nut 60 in the rotational direction maximally pushes sleeve 34 with respect to core 16 and collet 22; and

• thereafter, further rotating nut 60 in the rotational direction to rotate collet 22 and implant-hole engager 40 in the rotational direction.

For applications in which sleeve 34 is shaped so as to define a gripper non-circular interface surface, sleeve 34 is longitudinally moved with respect to core 16 and collet 22 by rotating sleeve 34 in a rotational direction to move sleeve 34 distally with respect to core 16 and collet 22.

Reference is now made to Fig. 4, which is a schematic cross-sectional illustration of a dental implant removal system 102, in accordance with an application of the present invention. Dental implant removal system 102 comprises a dental implant removal tool 110 for removing broken dental implant 20 from a jawbone of a subject. Other than as described below, dental implant removal system 102 and dental implant removal tool 110 are identical to dental implant removal system 2 and dental implant removal tool 10, respectively, described hereinabove with reference to Figs. 1A-3H, and may implement any of the features thereof, mutatis mutandis. Dental implant removal system 102 may be used as described in Figs. 3A-H, mutatis mutandis. Dental implant removal system 102 typically further comprises torque tool 12, as described hereinabove. Broken dental implant 20 is not an element of dental implant removal system 102. Dental implant removal tool 110 typically comprises an implant gripper 114 and implant-hole engager 40, as described hereinabove with reference to Figs. 1A-3H. Other than as described below, implant gripper 114 is identical to implant gripper 14, described hereinabove with reference to Figs. 1A-3H, and may implement any of the features thereof, mutatis mutandis.

For some applications, implant gripper 114 comprises core 16, collet 22, and a sleeve 134. Core 16 and collet 22 are described hereinabove with reference to Figs. 1A- 3H. Other than as described below, sleeve 134 is identical to sleeve 34, and may implement any of the features thereof, mutatis mutandis.

As described above for implant gripper 14, proximal longitudinal portion 52 of core 16 of implant gripper 114 is shaped so as to define core external thread 54. Sleeve 134 is shaped so as to a define gripper non-circular interface surface 136. For example, gripper non-circular interface surface 136 may be polygonal, e.g., hexagonal. Sleeve 134 is threadingly coupled to core external thread 54 such that rotation of sleeve 134 in a rotational direction moves sleeve 134 distally with respect to core 16 and collet 22. Unlike implant gripper 14, implant gripper 114 typically does not comprise nut 60; instead, in a sense, the functionality of nut 60 is integrated into sleeve 134.

Although dental implant removal systems 2 and 102 and dental implant removal tools 10 and 110 have been described herein for removing a broken dental implant 20 from a jawbone, the removal systems and removal tools may also be used, mutatis mutandis, from removing other non-dental implants, such as orthopedic fixation implants. For these other implants the sizes of the parts of the removal system and removal tool may need to be adjusted, e.g., enlarged, appropriately.

It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art, which would occur to persons skilled in the art upon reading the foregoing description.

Claims

1. A dental implant removal tool for removing a broken dental implant from a jawbone of a subject, the dental implant removal tool for use with a torque tool, the dental implant removal tool comprising:

(i) an implant gripper, which comprises:

(b) a collet, which is coupled to the core and shaped so as to at least partially accept, via a distal opening of the collet, a lateral external surface of a neck of the broken dental implant; and

(c) a sleeve, which is longitudinally moveable with respect to the core and the collet so as to tighten a grip of the collet on the lateral external surface of the neck when the lateral external surface is at least partially within the collet; and

(ii) an implant-hole engager, which is shaped so as to define:

2. The dental implant removal tool according to claim 1, wherein the core non-circular interface surface is accessible via the distal opening of the collet, and the proximal head of the implant-hole engager is shaped and sized so as to be insertable into the collet via the distal opening.

3. The dental implant removal tool according to claim 1, wherein the distal-body external thread is left-handed.

4. The dental implant removal tool according to claim 1, wherein the core non-circular interface surface is female and the proximal-head non-circular interface surface is male.

5. The dental implant removal tool according to any one of claims 1-4, wherein a proximal longitudinal portion of the core is shaped so as to define a core external thread, and wherein the implant gripper further comprises a nut, which is: shaped so as to define a gripper non-circular interface surface, and threadingly coupled to the core external thread such that rotation of the nut in a rotational direction moves the nut distally, such that the nut distally pushes the sleeve with respect to the core and the collet.

6. The dental implant removal tool according to claim 5, wherein the distal-body external thread and the core external thread have a same thread handedness.

7. The dental implant removal tool according to claim 6, wherein the same thread handedness is left-handedness.

8. The dental implant removal tool according to claim 5, wherein the dental implant removal tool is configured such that after the rotation of the nut in the rotational direction maximally pushes the sleeve with respect to the core and the collet, further rotation of the nut in the rotational direction rotates the collet and the implant-hole engager in the rotational direction.

9. The dental implant removal tool according to any one of claims 1-4, wherein a proximal longitudinal portion of the core is shaped so as to define a core external thread, and wherein the sleeve is: shaped so as to define a gripper non-circular interface surface, and threadingly coupled to the core external thread such that rotation of the sleeve in a rotational direction moves the sleeve distally with respect to the core and the collet.

10. The dental implant removal tool according to any one of claims 1-9, for use with a torque tool, wherein the implant gripper is shaped so as to define a gripper non-circular interface surface for coupling to the torque tool.

11. The dental implant removal tool according to claim 10, wherein the gripper non- circular interface surface is polygonal.

12. A dental implant removal system comprising the dental implant removal tool according to claim 10, the dental implant removal system further comprising the torque tool.

13. The dental implant removal system according to claim 12, wherein the torque tool comprises a wrench.

14. A dental implant removal system comprising the dental implant removal tool according to any one of claims 1-9, the dental implant removal system further comprising a rotating cutting instrument configured to tap the hole in the dental implant.

15. A method for removing a broken dental implant from a jawbone of a subject, the method comprising: coupling, to a hole within the broken dental implant, a distal-body external thread of a distal body of an implant-hole engager of a dental implant removal tool; coupling an implant gripper of the dental implant removal tool to the broken dental implant by: coupling a core non-circular interface surface of a distal portion of a core of the implant gripper to a proximal-head non-circular interface surface defined by a proximal head of the implant-hole engager, inserting a lateral external surface of a neck of the broken dental implant at least partially into a collet of the implant gripper via a distal opening of the collet, wherein the collet is coupled to the core, and tightening a grip of the collet on the lateral external surface of the neck by longitudinally moving a sleeve of the implant gripper with respect to the core and the collet; and rotating the implant gripper to remove the broken dental implant from the jawbone.

16. The method according to claim 15, wherein rotating the implant gripper comprises coupling a torque tool to the implant gripper and rotating the torque tool.

17. The method according to claim 15, wherein the core non-circular interface surface is accessible via the distal opening of the collet, wherein the proximal head of the implant-hole engager is shaped and sized so as to be insertable into the collet via the distal opening, and wherein coupling the core non-circular interface surface to the proximal-head non- circular interface surface comprises inserting the proximal head of the implant-hole engager into the collet via the distal opening.

18. The method according to claim 15, wherein coupling the distal-body external thread of the distal body of the implant-hole engager to the hole within the broken dental implant comprises rotating the implant-hole engager.

19. The method according to claim 18, wherein the distal-body external thread is left-handed, and wherein coupling the distal-body external thread of the distal body of the implanthole engager to the hole within the broken dental implant comprises rotating the implanthole engager counterclockwise.

20. The method according to claim 19, wherein rotating the implant gripper comprises rotating the implant gripper counterclockwise.

21. The method according to claim 15, wherein the core non-circular interface surface is female and the proximal-head non-circular interface surface is male.

22. The method according to claim 15, wherein a proximal longitudinal portion of the core is shaped so as to define a core external thread, and wherein the implant gripper further comprises a nut, which is: shaped so as to define a gripper non-circular interface surface, and threadingly coupled to the core external thread, and wherein longitudinally moving the sleeve with respect to the core and the collet comprises rotating the nut in a rotational direction to move the nut distally, such that the nut distally pushes the sleeve with respect to the core and the collet.

23. The method according to claim 22, wherein rotating the nut comprises coupling a torque tool to the gripper non-circular interface surface.

24. The method according to claim 23, wherein the torque tool is a wrench, and wherein coupling the torque tool comprises coupling the wrench to the gripper non-circular interface surface.

25. The method according to claim 22, wherein the distal-body external thread and the core external thread have a same thread handedness.

26. The method according to claim 25, wherein the same thread handedness is lefthandedness.

27. The method according to claim 22, wherein rotating the nut in the rotational direction comprises: rotating the nut in the rotational direction until the rotating of the nut in the rotational direction maximally pushes the sleeve with respect to the core and the collet; and thereafter, further rotating the nut in the rotational direction to rotate the collet and the implant-hole engager in the rotational direction.

28. The method according to claim 22, wherein the gripper non-circular interface surface is polygonal.

29. The method according to claim 15, wherein a proximal longitudinal portion of the core is shaped so as to define a core external thread, and wherein the sleeve is: shaped so as to define a gripper non-circular interface surface, and threadingly coupled to the core external thread, and wherein longitudinally moving the sleeve with respect to the core and the collet comprises rotating the sleeve in a rotational direction to move the sleeve distally with respect to the core and the collet.

30. The method according to claim 15, further comprising, before coupling the distal- body external thread of the distal body of the implant-hole engager to the hole within the broken dental implant: tapping the hole in the dental implant using a rotating cutting instrument.