Drill and method for performing an osteotomy using this drill

Description

1 / 44 “DRILL BIT AND METHOD FOR PERFORMING AN OSTEOTOMY USING THIS DRILL BIT” TECHNICAL FIELD

[0001] This disclosure refers to a drill for preparing a dental implant site. It also refers to performing an osteotomy to prepare an implant site. FUNDAMENTALS OF THE INVENTION

[0002] Before the insertion of a dental implant, a recess in the upper or lower jaw of a patient needs to be prepared. This osteotomy is an important step in providing a dental implant and has a significant influence on the osseointegration of the implant and its long-term success.

[0003] Since bone density, orientation, and quality differ from patient to patient, it is often necessary to use multiple tools to prepare an appropriate implant recipient recess. However, the more interdependent tools used to create a recess, the more extensive the treatment protocol becomes. This makes deciding on the details of such a protocol quite complex and time-consuming. Furthermore, aligning these various tools to prepare an implantation site can become quite difficult.

[0004] It should be taken into account that the maxilla has a comparatively hard outer layer (i.e., the cortical bone) and underneath a weaker, sponge-like bony structure (i.e., the spongy bone). The cortical bone that provides the hard cortex is much denser and less elastic than the spongy bone. When preparing a recess Petition 870250084460, dated 09 / 19 / 2025, page 6 / 64 2 / 44 of the bone to receive a dental implant, a drill has to create this recess that extends from the cortical bone to the cancellous bone. Thus, a drill must be able to machine different types of bone tissue in a patient during an osteotomy.

[0005] During the creation of the osteotomy, the drill is guided by a dental professional. Consequently, there is also an influence from the dental professional in performing the osteotomy.

[0006] In view of the above, there has been a constant effort to improve the process of creating a recess within the bone tissue in preparation for the insertion of a dental implant. In this regard, WO 2017 / 129828 A1 discloses a drill for the preparation of a bone recess that is configured to simultaneously condense and cut the bone tissue. SUMMARY

[0007] Generally, the aim has been to provide a drill that facilitates performing an osteotomy regardless of varying bone quality in a patient's jaw, as well as in different jaws of a patient or between patients, so that a bone recess to receive the dental implant comes out as desired, that is, the bone recess should not be underprepared or overprepared.

[0008] It has also been an objective to provide feedback to the dental professional on the progress of implant recess preparation.

[0009] With these objectives in mind, a drill and a method for performing an osteotomy are provided as defined in the independent claims. The Petition 870250084460, dated 09 / 19 / 2025, page 7 / 64 3 / 44 dependent claims specify preferred features of the claimed invention.

[0010] The present disclosure according to a first aspect provides a drill comprising an apical end, a coronal end, and a longitudinal axis extending between the apical end and the coronal end. Additionally, the drill includes a drill core extending along the longitudinal axis, at least two grooves, each groove being defined by a concave surface forming a recess along the drill core, and an apical end face on the apical end. The apical edges of the concave surfaces and an apical edge of the drill core define the shape of the apical end face such that the apical end face defines a profile of retaining arms on the apical end, wherein each retaining arm is formed between the concave surfaces of adjacent grooves.At least one of the at least two grooves extends, along the longitudinal axis, from the apical end, for at least 70% of the length of the drill bit configured to interact with bone tissue, preferably along the entire length of the drill bit configured to interact with bone tissue.

[0011] Along the longitudinal axis, the linear distance between the most apical point of at least one groove and the most coronal point of said groove is at least 50% of the total linear distance of the drill bit.

[0012] Preferably, at least one groove extends, along the longitudinal axis L, along the entire length of the (operating part of the) drill bit. In other words, a first end of at least one Petition 870250084460, dated 09 / 19 / 2025, page 8 / 64 4 / 44 groove is located at one apical end of the drill bit and a second end of said groove is located at the coronal end of the drill bit. At least one groove may extend continuously between said first and second ends. The drill bit may comprise two or more grooves having the same characteristics mentioned above.

[0013] Having at least one cutting groove that extends over a significant portion of the drill bit allows for cutting bone tissue along the entire length of the groove. The shape / volume of the osteotomy created by the cutting groove can substantially match the shape / volume of the implant core. When an implant is subsequently placed into the prepared osteotomy, only the implant thread(s) (and not the implant core) compress the bone tissue. This results in the preservation of a maximum amount of bone tissue. In other words, when the implant is placed into the osteotomy, only the implant thread pushes the bone radially relative to the implant axis. A large portion of the bone tissue is therefore preserved from destructive overcompression, and ultimately this leads to better osseointegration.This is particularly important for dense bone tissue, as overcompression damages dense bone tissue and can even fracture a portion of the patient's mandible. The drill bit according to the invention is particularly adapted for preparing an osteotomy in this type of hard bone.

[0014] The aforementioned advantages are increased in an embodiment of the present invention in which at least one cutting groove extends along the entire length of the drill bit. Petition 870250084460, dated 09 / 19 / 2025, page 9 / 64 5 / 44

[0015] Each groove extends from the apical end face to the coronal end. In a cross-section perpendicular to the longitudinal axis, the concave surface of a groove forms a concavity along the profile of the drill core. On the apical end face, each groove causes a concavity in the end face profile.

[0016] Between adjacent concavities, the end face profile is arm-shaped and represents a retention arm profile. This profile preferably has a longitudinal extension in a radial direction (relative to the longitudinal axis) and extends from a central area of ​​the apical end face to the outer edge of the apical end face (generally defined by an apical edge of the bur core). The number of retention arms is equal to the number of grooves. Preferably, the bur comprises three grooves.

[0017] The end face provides a blunting effect to the bur tip, resulting in at least a reduced forward cutting ability of the bur. In other words, the end face increases the force and torque required to further advance the bur through contact of the apical end face with the bone tissue.

[0018] Furthermore, the drill core is preferably tapered in the apical direction of the drill bit along at least a portion of the drill core. This tapered portion serves to increase the diameter of the hole in the bone tissue as the drill bit advances. Additionally, the cutting groove that extends along this tapered portion of the drill bit cuts the bone tissue at each point of the Petition 870250084460, dated 09 / 19 / 2025, page 10 / 64 6 / 44 its cutting edge and creates an osteotomy or hole. The osteotomy is enlarged at each point by the shape of the drill bit and prepared for the size of the dental implant.

[0019] By contacting the apical end face with the bottom of a pilot hole in the bone tissue of the implantation site, the retention arms are configured to interact with the bone tissue creating a retention force that counteracts a drive torque applied to the drill. In other words, the retention arms cause a frictional force with the bone tissue at the bottom of the pilot hole by contact, in particular surface contact, which resists the drive torque applied to the drill.

[0020] As a result, the retention arms at the apical end of the drill provide feedback indicating to a user that the end of a previously prepared hole (i.e., pilot hole) within the bone tissue has been reached and thus serve to prevent the osteotomy from being underprepared or overprepared.

[0021] The drill may further comprise at least one guide thread projecting from the drill core. The guide thread extends helically along the drill core and preferably tapers apically. The guide thread is, in particular, a single thread.

[0022] The drill guide screw allows for enhanced control of the drill bit advancing into bone tissue, as the guide screw converts one rotation of the drill bit into a predetermined feed rate. More specifically, each rotation advances the drill bit by a distance that corresponds to the pitch of the guide screw. This Petition 870250084460, dated 09 / 19 / 2025, p. 11 / 64 In a 7 / 44 shape, the guide thread particularly facilitates the insertion of the drill bit into a previously prepared pilot hole at the implantation site.

[0023] The guide thread may taper in the apical direction of the bur. That is, the outer diameter of the guide thread decreases in a coronal-apical direction. Preferably, the thread height of the guide thread is substantially constant in the direction of the longitudinal axis. It may also, or alternatively, decrease in height in this direction. Preferably, the guide thread does not extend to the apical end of the bur or to the portion where the retaining arms are located.

[0024] The guide screw is preferably shaped so that the forward driving force resulting from the conversion of torque into an advance of the drill bit in a previously prepared hole is insufficient to advance the drill bit into unprepared bone tissue. Instead, the guide screw loses grip when it reaches a certain torque limit and begins to rotate freely without drilling deeper into the tissue.

[0025] Therefore, the guide screw can intensify the aforementioned effect of providing feedback when reaching the end of a previously drilled hole or pilot hole, increasing the torque until the screw loses grip and rotates. Thus, the apical end face, the retaining arms, and the guide screw interact with each other in providing a neutralizing feedback torque.

[0026] The radial height of the guide thread is particularly smaller than the radial extension of the retaining arm profile on the apical end face. Petition 870250084460, dated 09 / 19 / 2025, p. 12 / 64 8 / 44

[0027] As described above, the profile of the retaining arms on the apical end face extends from a central area to the outer edge of the apical end face. The length of the profile from the central area to the outer edge is preferably greater than the radial height of the guide thread. In general, longer retaining arms increase the counteracting torque when the drill reaches the bottom of a previously drilled hole.

[0028] Each retention arm may have a radial extension that is greater than the circumferential width at its tip formed by the apical edge of the drill core.

[0029] The guide thread may have a non-circular outer circumferential profile, the non-circular outer circumferential profile preferably being a trioval profile.

[0030] A non-circular profile, and in particular a trioval profile, has the advantage of acting as a guide thread that forms thread grooves more easily than a regular thread. It also acts by gradually condensing the bone tissue in the thread path of the guide thread. In this way, the bone tissue can be preserved instead of being cut, which reduces the impact of the guide thread on the shape of the hole formed by the drill bit.

[0031] Furthermore, the drill core may have a non-circular profile in a cross-section perpendicular to the longitudinal axis, wherein in the longitudinal direction of the drill, the non-circular profile preferentially rotates around the longitudinal axis creating a twisted non-circular drill core.

[0032] Such a non-circular profile of the core of Petition 870250084460, dated 09 / 19 / 2025, page 13 / 64 The 9 / 44 drill uses the elasticity of bone tissue to create a recess in the bone tissue by inserting the drill while it is rotating. Without wishing to be limited by theory, the non-circular profile aids in creating a recess that allows the drill to maintain its insertion direction. It can also have a positive effect on the primary stability of a dental implant that is inserted into this recess due to a condensation effect on the bone tissue. The non-circular profile of the drill core can also provide the core with a relief angle that aids in cutting the bone tissue.

[0033] A twisted non-circular drill core has the advantage of distributing the forces resulting from the non-circular profile by inserting the drill into the bone tissue along its circumference. This particularly prevents the drill from being displaced when entering the pilot hole.

[0034] The non-circular profile of the drill core and the non-circular profile of the guide thread can be formed with a circumferential offset. This configuration also intensifies the distribution of forces along the circumference of the drill and prevents the drill from becoming misaligned or displaced from its desired insertion path.

[0035] Preferably, an apical edge or circumferential edge of the apical end face is arranged in a plane perpendicular to the longitudinal axis.

[0036] This structural feature results in the retaining arms contacting the bottom of a previously drilled hole essentially simultaneously. As a result, the counteracting torque increases more rapidly and provides clearer feedback. In this respect, Petition 870250084460, dated 09 / 19 / 2025, page 14 / 64 10 / 44 at least the apical surface of the retention arms and preferably the apical end face is flat to cause surface contact with the bone tissue at the bottom of the pilot hole.

[0037] The concave surface of each groove and the circumferential surface of the drill core preferably form a cutting edge. If a guide thread is provided, the cutting edge even more preferably also includes the profile of the guide thread.

[0038] Consequently, such a groove not only forms the retention arms on the apical end face, but can also be a cutting groove that assists in preparing a recess in the bone tissue that corresponds substantially to the rotational shape of the drill core. The cutting edge facilitates the formation of the bone recess and also allows the retention arms and, if present, the guide thread, to cause a more detectable increase in torque that resists further rotation of the drill upon contact with the bottom of the previously drilled hole.

[0039] The concave surface and the apical end face may form at least partially a cutting edge on the apical edge of each concave surface, the cutting edge having a forward tilt angle and substantially no forward relief angle.

[0040] Since there is basically no forward relief angle on the edge formed on the apical end face of the bur, the forward cutting ability of the apical end face is significantly reduced.

[0041] In addition, the angle of inclination for Petition 870250084460, dated 09 / 19 / 2025, page 15 / 64 The 11 / 44 front is relatively large due to the grooves that extend in the longitudinal direction of the drill bit. As a result, the surface of the retaining arms on the edges formed between the concave surfaces and the apical end face, the surface facing in a predetermined rotational direction of the drill bit, collects or scrapes the bone tissue at the bottom of the previously drilled hole. This bone tissue tends to create friction and a torque that counteracts the rotation of the drill bit and thus provides feedback.

[0042] The at least two grooves extend particularly helically along the drill core. The angle between the apical end face of the drill and the concave surface of the groove, the angle being formed due to the helical extension of the groove, supports the functionality of the retention arms by collecting or scraping bone tissue at the apical edge, where the apical end face and the concave surface are joined. Furthermore, the helical path of the grooves provides a more uniform load distribution along the circumference of the drill. This is particularly advantageous when drilling at a slow speed and thus results in controlled preparation of the bone recess or implant recess. In this respect, three grooves are preferable.

[0043] In addition, the present disclosure provides a method for creating an osteotomy using a drill, in particular a drill as described above. The method comprises the steps of drilling a hole with a pilot drill and increasing the size of the hole for the insertion of a dental implant using the drill. The drill comprises a drill core, at least two grooves, wherein each groove is Petition 870250084460, dated 09 / 19 / 2025, page 16 / 64 12 / 44 defined by a concave surface forming a longitudinal recess along the drill core, an apical end face at the apical end of the drill, and retaining arms extending coronally from the apical end face. Each retaining arm is formed between adjacent groove concave surfaces. Upon contact of the apical end face with the bottom of the hole drilled with the pilot drill, the retaining arms generate a braking force that can be used to stop the drill's rotation.

[0044] Upon contact with the bottom of the hole, the apical end face acts as a stop. In addition, rotating retention arms collect bone tissue or bone debris at the bottom, causing a torque that counteracts the drive torque of the drill. This provides feedback, either to a dental professional using the drill or to a sensor or mechanism, such as a torque limiter, as a signal to stop the drilling process.

[0045] Preferably, the tip of the pilot drill has a larger diameter than the diameter of the apical end face. This has the advantage that, at the beginning of bone recess preparation using the drill, the apical end face does not come into contact with the bone tissue until the drill reaches the end of the pilot hole. Otherwise, the apical end face of the drill would hinder the drilling process due to its forward drilling capacity being at least significantly reduced. In addition, the torque signal indicates the end of the preparation more clearly.

[0046] The diameter at the tip of the pilot drill Petition 870250084460, dated 09 / 19 / 2025, page 17 / 64 13 / 44 refers to the diameter at the edge between the front cutting edges formed due to the point angle of the pilot drill (if present) and the circumferential surface extending in one direction along the longitudinal axis of the pilot drill. BRIEF DESCRIPTION OF THE FIGURES

[0047] The following figures illustrate preferred embodiments of features according to the present disclosure. These embodiments should not be interpreted as limiting, but are only to enhance understanding of the disclosure.

[0048] Figure 1 is a partial side view of a drill bit according to the present disclosure;

[0049] Figure 2 is a partial view of the drill depicted in Figure 1, illustrating the apical end of the drill in perspective;

[0050] Figure 3 is a front view of the apical end face of the drill bit;

[0051] Figure 4 is a cross-sectional view of a drill bit according to the present disclosure;

[0052] Figure 5 is another cross-sectional view of a drill bit according to the present disclosure; and

[0053] Figure 6 is yet another cross-sectional view of a drill bit according to the present disclosure. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0054] Exemplary embodiments of a tool for preparing a recess in bone tissue, and in particular embodiments of a drill bit 1 according to this disclosure, will be described below with reference to the accompanying figures. Petition 870250084460, dated 09 / 19 / 2025, p. 18 / 64 14 / 44

[0055] Figure 1 shows an exemplary embodiment of a drill 1 according to the present disclosure. The drill 1 has an apical end 2 and a coronal end (not shown). It extends along a longitudinal axis L which also acts as an axis of rotation. The coronal end is preferably configured to be coupled to a dental drill (not shown) to transmit a drive torque to the drill 1.

[0056] The drill bit 1 includes a drill core 20 with a circumferential surface 21. The drill core 20 tapers preferentially in a coronal-apical direction (i.e., towards the apical end 2). The drill bit 1 comprises at least two grooves 40. Each groove 40 is defined by a concave surface 41. The concave surface forms a longitudinal recess (i.e., a groove 40) that begins at the apical end 2 and extends along the drill core 20. Consequently, each groove 40 has a concave profile defined by the concave shape of the concave surface 41.

[0057] The drill core 20 preferably has a substantially continuous profile along the longitudinal axis L of the drill 1. The profile of the drill core 20 is made substantially continuous due to the grooves 40 and a guide thread 30 (if present). In other words, the profile does not comprise a discontinuity, for example, a discontinuity that is basically arranged perpendicular to the longitudinal axis L, such as a step in the diameter of the drill core 20.

[0058] At the apical end 2, the drill 1 Petition 870250084460, dated 09 / 19 / 2025, p. 19 / 64 15 / 44 includes an apical end face 10. The apical end face 10 is preferably oriented substantially perpendicular to the longitudinal axis L of the bur 1. As illustrated in Figure 2, the profile of the apical end face 10 is defined by the apical edges 42 of the concave surfaces 41 and by the apical edge 22. On the apical edge 22 of the bur core 20, the bur core 22 may include a chamfer or rounded edge 23. The chamfer 23 is not part of the apical end face 10.

[0059] The apical edges 42 of the concave surfaces 41 and the apical edge 22 of the drill core 20 provide a shape to the profile of the apical end face 10 which includes radial extensions similar to arms 12 (in the exemplary embodiment of figure 2, the apical end face 10 has three arms). Each of these radial arm-shaped extensions 12 has a tip edge 14a defined by the apical edge 22 of the drill core 20 and two lateral edges 14b and 14c that are defined by apical edges 42 of concave surfaces 41 of two adjacent grooves 40. In particular, the opposite lateral edges 14b and 14c of each arm 12 may be defined by substantially half the length of an apical edge 42 of a groove 40. Preferably, each arm-shaped extension 12 is substantially symmetrical with respect to a radial axis of symmetry extending from the longitudinal axis L.

[0060] The arm-shaped extensions 12 extend from a central area 11 of the apical end face 10. Preferably, the central area 11 is defined by a virtual circle (shown in Figures 2 and 3 as a circle with dashed lines) that is fitted into the Petition 870250084460, dated 09 / 19 / 2025, page 20 / 64 16 / 44 apical edges 42 of the concave surfaces 41.

[0061] Each of the arm-shaped extensions 12 defines a profile of a retention arm 50 to collect bone debris or to scrape bone tissue by contacting the bone tissue at the bottom of a pilot hole. This pilot hole is created before using the drill 1 to prepare a bone recess that can be fitted to insert a dental component, such as a dental implant.

[0062] Each retention arm 50 extends from the apical end face 10 along a portion of the drill core 20 at the apical end 2 of the drill 1. Upon rotation of the drill 1, one side 51 of each retention arm 50 that is facing in the direction of rotation collects bone debris which, in turn, neutralizes the drive torque applied to the drill 1 (e.g., by a dental handpiece). Therefore, the apical portion of the drill core 20 comprising the retention arms extends along a distance from the drill suitable for collecting bone tissue at the bottom of a pilot hole. Each retention arm 50 extends longitudinally from the apical end face 10 to the corresponding guide thread 30.

[0063] In general, the longer the radial extension of the retention arms 15, the greater the torque created by scraping or collecting bone tissue that counteracts the drive torque that drives the drill 1.

[0064] If a pilot hole is formed as a blind hole (i.e., with a flat bottom), the retaining arms 50 are collecting and accumulating bone debris when the apical end face 10 is in contact with the bottom of the pilot hole and the drill bit 1 is rotated. Petition 870250084460, dated 09 / 19 / 2025, page 21 / 64 17 / 44

[0065] If the drill bit used to drill a pilot hole has a conical tip, the pilot hole tapers at its end. Due to this tapering, the drill bit 1 will collect and accumulate bone debris by contacting the conical wall of the bottom of the pilot hole. The drill bit 1 will also advance further into the pilot hole, reshaping its bottom to be a blind hole. This results in the apical end face 10 coming into superficial contact with the bone tissue.

[0066] Thus, regardless of the shape of the pilot hole bottom, drill bit 1 will show an increase in torque when it reaches the end of the pilot hole. This increase in torque can serve as a feedback signal to stop the drilling process. For example, this increase in torque can activate a torque limiting device that automatically stops the rotation of drill bit 1.

[0067] Therefore, such a design of drill bit 1 can ensure that the recess created by drill bit 1 is neither under-prepared nor over-prepared.

[0068] Furthermore, due to the surface contact of the apical end face 10 of the drill with the bone tissue, the apical end face 10 is essentially designed without a forward drilling capability, that is, the apical face 10 of the drill 1 has essentially no significant capacity to cut a bone tissue surface that is arranged parallel to the apical end face 10.

[0069] In this respect, a flat surface of the arms basically means that the apical end face 10 has no forward relief angle (i.e., a 0° relief angle) at the apical edge 42 of each Petition 870250084460, dated 09 / 19 / 2025, page 22 / 64 18 / 44 groove 40. Depending on the extension path of the grooves 40 along the drill core 20, the apical end 2 of the drill 1 may also not have a forward tilt angle at the apical edge 42 of each of the grooves 40 (i.e., it has a tilt angle of 0°).

[0070] Preferably, the grooves 40 extend helically around and along the longitudinal axis L along the drill core 20. Here, the apical edges 42 of the grooves 40 may have a non-zero forward tilt angle. However, this forward tilt angle is quite small (preferably less than 20°, 15°, 10°, or 5°). As a result, the apical edges 42 tend primarily to scrape and collect bone tissue and thus contribute to the creation of a torque that counteracts the drive torque of the drill 1.

[0071] The grooves 40 can also change their pitch in an apical-coronal direction. In particular, their pitch can decrease in this direction, so that the forward tilt angle at the apical edges 42 is reduced.

[0072] The exemplary embodiment illustrated in the figures comprises three grooves. Alternatively, two, four or five grooves 40 may be provided. At the apical end 2 of the drill 1, these grooves 40 define two, four or five arms, respectively. It has been found that a number of three grooves 40 is particularly advantageous for preparing the bone recess with the drill 1.

[0073] The grooves 40 preferentially form a cutting edge 43 with the drill core 14. More specifically, the surface side of the groove facing the Petition 870250084460, dated 09 / 19 / 2025, page 23 / 64 The 19 / 44 direction of rotation forms a cutting edge with the circumferential surface 21 of the drill core 20. Therefore, the drill 1 has a radial cutting capability through its rotation.

[0074] As described above, at least a portion of the drill core 20 may be tapered in a coronal-apical direction. In combination with the grooves 40, this provides a forward cutting capability for the drill 1. In other words, such a configuration of a drill 1 cuts bone tissue as it is advanced into the bone tissue, so that the insertion of the drill 1 is facilitated.

[0075] However, such forward cutting ability of the drill bit 1 due to the interaction of the concave surfaces 41 and the circumferential surface 21 of the drill core 20 does not affect the limited cutting ability of the apical end face 10 at the apical end 2 due to its blunt configuration. Thus, the cutting ability of the cutting edges 43 at the edges of the circumferential surface 21 and the concave surfaces 41 serves to provide the bone recess with a desired shape.

[0076] As shown in the attached figures, the drill 1 may include a guide thread 30. The guide thread extends radially from the drill core 20 and extends at least along a portion of the drill core 20 around and along the longitudinal axis L. The guide thread 30 preferably does not extend to or into the portion comprising the retaining arms 50 at the apical end 2 of the drill.

[0077] The guide thread 30 extends along the drill core 20 and is configured to pull the drill 1 into Petition 870250084460, dated 09 / 19 / 2025, p. 24 / 64 20 / 44 the bone tissue at a predetermined rate. This rate depends on the rotation-to-feed ratio, which is defined by the pitch of the guide thread 30. Preferably, the pitch of the guide thread 30 is in a range of 0.4 mm to 3 mm, more preferably in a range of 0.8 to 1.5 mm, and even more preferably in a range of 1.0 to 1.2 mm. The guide thread 30 is preferably configured as a single thread, but it can also be designed as a double or triple thread. The guide thread 30 provides a self-drilling capability for the drill bit 1.

[0078] The guide thread 30 is preferably configured to create a feed force that is less than a feed force required to overcome the resistance of the apical end face 10 by means of the surface contact of the apical end face 10 with the bone tissue at the bottom of the pilot hole.

[0079] In a cross-section, the guide thread 30 has a thread profile with an average thread height from the ground thread to the tip of the guide thread 30 that is less than the diameter of the apical end face 10 of the drill bit 1 (cf. figures 2 and 3). The average thread height of the guide thread is particularly in a range of 1% or 2%, to 5%, 10% or 30% of the diameter of the apical end face 10.

[0080] Furthermore, the maximum height of the guide thread 30 must not exceed 50% of the diameter of the apical end face 10.

[0081] The height of the guide thread 30 has the effect that, upon contact of the apical end face 10 with the bottom of a pilot hole, the feed force generated by the guide thread 30 is insufficient to overcome the resistance. Petition 870250084460, dated 09 / 19 / 2025, p. 25 / 64 21 / 44 against the advance of the drill bit 10 caused by a surface contact of the apical end face 10 with the bottom of the pilot hole. As a result, an increase in torque occurs and can be used as a feedback signal to a user, a sensor, a mechanism, etc., in order to stop the application of a drive torque to the drill bit 1 or to indicate that the bottom of the pilot hole has been reached.

[0082] In other words, once the apical end face 10 of the drill bit 1 comes into contact with the bone tissue at the bottom of a pilot hole, the drive torque needs to increase to allow continuous rotation of the drill bit 1. In particular, this necessary increase in torque can be detected and used as a feedback signal.

[0083] For example, an increase in torque can be generated automatically by a motor, in particular an electric motor, driving drill 1. Preferably, a torque limiter is included in the drive train of drill 1 which will react to such an increase by stopping the rotation of drill 1. Otherwise, such an increase in drive torque may cause the guide thread 30 to slip or rotate. Even in such a scenario, the advance of drill 1 can be stopped by contact between the bottom of the pilot hole and the apical end face of drill 1.

[0084] As previously described and illustrated in the figures, the guide thread 30 can be formed at least partially as a tapered thread tapering in a coronal-apical direction (i.e., apically). The guide thread 30 is preferably tapered along a portion where the drill core 20 is also tapered. Furthermore, the Petition 870250084460, dated 09 / 19 / 2025, page 26 / 64 22 / 44 guide thread taper 30 and drill core taper 20 preferably correspond to each other. In other words, guide thread taper 30 and drill core taper 20 preferably have the same angle with respect to the longitudinal axis L or run along parallel paths in a cross-section along the longitudinal axis L.

[0085] Furthermore, the guide thread 30 may have a non-circular profile, in particular a trioval profile. Such a non-circular profile of a guide thread 13 may also be twisting around the longitudinal axis L along the drill bit 1.

[0086] A non-circular profile has the advantage, particularly in combination with the grooves 40, of creating a thread path in the bone tissue based on cutting and condensation. In other words, the thread path is partially created based on an elastic deformation of the bone tissue. Due to the creation of a thread path based on the elastic deformation of the bone tissue, the apical end face 10 reaching the end or bottom of the pilot hole can cause an increase in torque over a longer period of time, since even when rotating, the guide thread 30 of the drill 1 may tend to deform the bone tissue instead of cutting it as soon as the drill 1 starts rotating.

[0087] Additionally or alternatively, the drill core 20 may at least partially have a non-circular profile in cross-sections perpendicular to the longitudinal axis L. Such a configuration of the drill core 20 may also be twisted, i.e., the non-circular profile rotates around the longitudinal axis L in cross-sections along the Petition 870250084460, dated 09 / 19 / 2025, p. 27 / 64 23 / 44 coronal-apical direction. In addition, and if present, a non-circular profile guide thread 30 and a non-circular profile drill core 20 may be twisted relative to each other (i.e., one or both are twisted around the longitudinal axis).

[0088] At the apical end (i.e., on the apical end face) the drill core 20 and preferably the portion along the drill core 20 forming the retention arms 50 may have a circular profile. This circular profile changes coronally to the non-circular profile.

[0089] The non-circular profile of the drill core can cause the drill 1 to remain in its position along its trajectory when preparing the bone recess on the apical end face 10 reaching the bottom of the pilot hole. The non-circular profile in combination with the grooves 40 including the cutting edge 43 are configured to form a bone recess based on bone tissue cutting and elastic deformation of the bone tissue. The elastic deformation can keep the drill 1 in position by means of contact with the bone tissue of the apical end face 10. If the drill 1 continues to rotate, it can also prevent the agitation of the drill 1 and thus the additional cutting action of the drill 1.

[0090] The effects of a non-circular profile on recess formation and drill bit cutting behavior are described in more detail in document EP 21 208 105 A, which is incorporated into this document by reference.

[0091] More specifically, the relationship between the grooves 40 and the non-circular cross-section of the drill core 20 advantageously affects the way the drill 1 forms Petition 870250084460, dated 09 / 19 / 2025, page 28 / 64 24 / 44 the desired bone recess by cutting and deforming the bone tissue.

[0092] Figures 4 to 6 illustrate cross-sectional views of drill 1 at different positions along the longitudinal axis L. The cross-sectional views illustrate cross-sections of drill 1 perpendicular to the longitudinal axis L as seen in an apical-coronal direction. Each of these cross-sectional views shows a contour 3 of drill 1, wherein the contour may include contour sections originating from features such as a groove 40 or a guide thread 30.

[0093] The cross-sectional views of figures 4 to 6 each include, for comparison purposes, a basic outline 25 of the drill core 20, that is, an outline of the drill core 20 representing its basic shape without any additional features, such as a groove 40 or a guide thread 30. In the cross-sectional view of figure 6, the basic outline 3 allows one to indicate where an outermost point 24' of the drill core 20 without a groove 40 would be located.

[0094] A contour 3 of a cross-section of the drill core 20 preferably comprises at least one outermost point 24. The at least one outermost point 24 is substantially located at a first radial distance r1 from the longitudinal axis L. Consequently, the radial distance r1 at the outermost point 12 represents a maximum radial distance of a point on the basic contour 25 (or on the contour 3) relative to the longitudinal axis L.

[0095] In figures 4 to 6, the basic outline 25 Petition 870250084460, dated 09 / 19 / 2025, page 29 / 64 25 / 44 of the cross-sections of the drill core 20 comprises three outermost points 24. However, any other number of outermost points 12 may be formed, such as one, two (i.e., oval), three (i.e., trioval), four, five, or six outermost points 12. Preferably, the outermost points 12 are uniformly distributed along the contour of the drill core 20.

[0096] The cross-sectional views in Figures 4 to 6 each illustrate a cross-section in a different portion of drill bit 1 along the longitudinal axis L. In these cross-sectional views, a predetermined direction of rotation of drill bit 1 is defined in the counterclockwise direction, as indicated by the curved arrows.

[0097] Drill 1 may comprise at least a portion along the longitudinal axis L in an apical-coronal direction, where the diameter and / or the first radial distance r1 of the drill core 20 increases. This increase preferably corresponds to an increase in the diameter of a dental implant (not shown) to be implanted in the recess created by means of drill 1.

[0098] In addition, drill 1 may comprise at least a portion along the longitudinal axis L, where the diameter and / or the first radial distance r1 of the drill core 20 remains substantially the same. Such a portion may also be shaped to match an implant to be implanted.

[0099] At a coronal end 4 of a portion of the drill bit 1 that is configured to interact with bone tissue, the shape of the drill bit 1 can be adapted to be substantially the same size as the dental implant. Petition 870250084460, dated 09 / 19 / 2025, page 30 / 64 26 / 44 in this location in an implanted state. At the apical end 2, the drill bit 1 can be adapted to be smaller in size than the dental implant. The latter is to enhance the primary stability of the implant, causing a pressure fit between the patient's bone tissue and the implant.

[0100] Generally, it is advantageous to adapt the shape of drill bit 1 along the longitudinal axis L to the geometry of a dental implant to be inserted into a bone recess that must be prepared with drill bit 1. Preferably, this adaptation takes into account the type of bone that will be located adjacent to the implant after implantation. In particular in soft bone, drill bit 1 is undersized relative to the implant to support the anchorage of the implant within the bone tissue.

[0101] A (medium) drill size 1 that is basically the same as the dental implant at the coronal end 4 reduces tension in the cortical bone tissue after implantation to prevent bone resorption and promote bone growth.

[0102] A smaller drill bit size 1 relative to the dental implant at the apical end 2 achieves good initial stability of the dental implant within the bone recess.

[0103] A non-circular drill core 20 comprises at least one compression zone 27 and at least one relaxation zone 28 (see figure 4).

[0104] In the predetermined direction of rotation of drill bit 1, at least one compression zone 27 extends along a portion of the contour of a cross-section. Petition 870250084460, dated 09 / 19 / 2025, page 31 / 64 27 / 44 of the drill core 20 starting at the innermost point 29a with a radial distance r3a from the longitudinal axis L preferably to an outermost point 24 along the contour and at a maximum radial distance r1 between the contour and the longitudinal axis L.

[0105] Also in the predetermined direction of rotation of the drill bit 1, at least one relaxation zone 28 extends along a portion of the contour of a cross-section of the drill core 20 starting at an outermost point 24 at a maximum radial distance r1 from the longitudinal axis L to the innermost point 29b having a radial distance r3b from the longitudinal axis L. The distances r3a and r3b may be equal.

[0106] The boundary between an innermost point 29 and an outermost point 24 of the compression zone 27 and / or relaxation zone 28 is preferably smooth (e.g., (only) curved). However, one or both zones 27 and 28 may have at least one straight subsection.

[0107] It should be noted that a cross-sectional outline of the drill core having more than one outermost point 24 that are located directly adjacent to each other, i.e., they form a circular line section, is also encompassed since all such outermost points 24 have the first radial distance r1 (maximum radial distance). The same applies to the innermost point 29 at the minimum radial distance r3 from the longitudinal axis L. However, having singular outermost points 24 and / or innermost points 29 is preferable.

[0108] The number of compression zones 27 in the cross-sections of the drill core 20 can generally be Petition 870250084460, dated 09 / 19 / 2025, page 32 / 64 28 / 44 equals the number of relaxation zones, 28. In this context, the term is generally used since one or both zones 27 and 28 may be interrupted by a cutoff zone 45, which will be described in more detail below.

[0109] In compression zone 27, drill bit 1 is configured to compress bone tissue in a radially outward direction, i.e., to exert a densification or condensation effect on the bone tissue. By rotating the drill bit, a predetermined point in the bone tissue (not shown) is driven radially outward due to the increasing radial distance of the cross-sections of the drill core 20 from radial distance r3 to radial distance r1. This outward movement relative to the bone tissue causes the bone tissue to condense.

[0110] In the relaxation zone, drill 1 allows the compressed bone tissue to recover by the contour 3 of the drill core 20 moving radially inward. In other words, by rotating the drill, a predetermined point in the bone tissue (not shown) is able to follow radially inward due to the decreasing radial distance of the drill core contour from the outermost point 24 to the innermost point 29.

[0111] Without wishing to be limited to theory, it has been found that bone tissue with high density, for example, cortical bone, generally recovers more quickly than bone tissue with low density, for example, spongy bone. In other words, in the relaxation zone of the drill bit 1, bone tissue with a higher density relaxes and extends radially inward faster than bone tissue with a lower density. Petition 870250084460, dated 09 / 19 / 2025, p. 33 / 64 29 / 44

[0112] At least part of a cross-sectional contour of drill core 20 is preferably noncircular (but is preferably round or curved). Therefore, at least a portion of drill core 20 along the longitudinal axis L has a cross-section that is at least partially noncircular.

[0113] A cross-sectional outline of the drill core 20 may also be noncircular along its entire length or at least along substantially the entire length of the drill core 20 along the longitudinal axis L. For example, the noncircular outline may be oval or trioval. However, other noncircular outline shapes are also possible, in particular a substantially round outline. However, and as discussed earlier, the drill core 20 may also comprise a cross-sectional outline at least along a portion of the longitudinal axis L, which is substantially circular.

[0114] A non-circular contour allows defining at least one compression zone 27 and relaxation zone 28. That is, the portion of the contour of a cross-section of the drill core 20 in a predetermined direction of rotation of the drill 1 from a minimum radial distance r3a to a maximum radial distance r1 is defined as a compression zone 27, that is, it is configured to compress adjacent bone tissue. The portion of the contour of a cross-section of the drill core 20 in a predetermined direction of rotation of the drill 1 from a maximum radial distance r1 to a minimum radial distance r3b is defined as a relaxation zone 28, that is, it is configured to Petition 870250084460, dated 09 / 19 / 2025, page 34 / 64 30 / 44 allow relaxation of previously compressed bone tissue. The non-circular contour shape 3 can be designed so that a plurality of compression zones 27 and relaxation zones 28 along a cross-sectional contour of the drill core 20 is defined.

[0115] Drill bit 1 can be configured differently at the coronal end 4, where drill bit 1 is interacting with cortical bone tissue with a compact structure and comparatively high density, than at the apical end, where drill bit 1 is generally preparing cancellous bone tissue with a trabecular structure and generally lower density. Thus, it is possible to prepare these different bone tissue regions in a single step when preparing the bone recess for dental implant insertion. In this way, complex drilling protocols can be avoided in most patients. Preferably, a pilot drill bit can be used before drill bit 1 to facilitate preparation.

[0116] Drill bit 1 comprises a cutting portion that extends at least partially along (preferably along the whole of) groove 40. Thus, at least a part of groove 40 can be configured as a non-cutting groove, i.e., a groove with an edge that does not form a cutting edge 43.

[0117] The cutting portion may be present along substantially the entire length of the drill core 20 along the longitudinal axis L from the apical end 2 to the coronal end 4, that is, along the portion that is configured to interact with bone tissue. Petition 870250084460, dated 09 / 19 / 2025, p. 35 / 64 31 / 44

[0118] Preferably, groove 40 extends, along the longitudinal axis L, along the entire length of the (operating part of the) drill. In other words, a first end of at least one groove is at an apical end 2 of the drill and a second end of said groove is at the coronal end of the drill that is configured to interact with bone tissue. Groove 40 may extend continuously between said first and second ends. The drill may comprise two or more grooves having the same characteristics mentioned above.

[0119] As previously described, the cutting portion preferentially tapers apically, that is, the cross-sections of the cutting portion perpendicular to the longitudinal axis L decrease in size from the coronal end of a cutting portion to an apical end of a cutting portion. As a result, when the drill drills bone tissue, the cutting portion increases the size of the hole that is created by cutting the adjacent bone tissue. If a guide thread 30 is present, the cutting motion is performed with a particular constant feed.

[0120] The cutting portion may at least partially or wholly also be configured to condense bone tissue. Therefore, a cross-section of such a cutting portion comprises a compression zone 27 and a relaxation zone 28. Thus, such a cutting portion is configured to compress bone tissue in the compression zone 27 and to allow bone tissue to relax in the relaxation zone 28 while rotating in the predetermined direction of rotation of the drill bit 1. Petition 870250084460, dated 09 / 19 / 2025, p. 36 / 64 32 / 44

[0121] As mentioned above, the profile along and / or the transition between the compression zone 27 and the relaxation zone 28 is preferably (only) curved, i.e., it cannot include a straight section or a discontinuity (except for a cutting zone 45). This has a positive effect on the structural integrity of the bone tissue that is treated with the drill bit 1.

[0122] However, at least one part or portion of the cut portion may also be configured as a cut portion without being configured to condense bone tissue by rotation or in a direction of rotation. Such a cut portion is configured without compression and relaxation zones 27 and 28.

[0123] However, the contour of a cross-section of the drill core 20 along at least part or all of the cutting portion is preferably non-circular and includes a compression zone 27 and a relaxation zone 28. This results in the contour being configured to have a condensation effect on the bone tissue upon rotation. Depending on the configuration of the non-circular contour, a plurality of compression zones and relaxation zones along a cross-sectional contour of the drill core 20 can be defined.

[0124] If not configured for condensation in a direction of rotation, the cross-sectional outline of the drill core 20 may be substantially circular. The cross-sectional outline of a cutting portion that is not configured to condense bone tissue in a direction of rotation is substantially circular if a groove 40 and / or a guide thread 30 is present.

[0125] Along a section contour Petition 870250084460, dated 09 / 19 / 2025, page 37 / 64 33 / 44 transverse of a cutting portion of the drill core 20, the cutting portion preferably comprises at least one cutting zone 45 including a cutting point 44. The cutting zone 45 is defined by a groove 40 forming a concave recess in the contour of the cutting portion and comprising a cutting edge 43. Therefore, the cutting portion comprises at least one groove 40. As described above, the groove 40 is preferably formed as a recess or groove and extends along the drill core 20. Furthermore, the groove 40 may be straight, but preferably extends helically around the drill core 20. The latter case distributes the cutting force along the circumference of the drill 1 and facilitates orientation during insertion.

[0126] Preferably, the cutting zone 45 including the cutting point 44 is located in the compression zone 27 of the contour 3 of the cutting portion of a drill that is also configured to condense bone tissue. In this case, the contour of the compression zone 27 is interrupted by the cutting zone 45.

[0127] At least one cutting point 44 is located at a second radial distance r2 from the longitudinal axis L in a cross-sectional view of the drill core 20 along the cutting portion. A contour 3 of the cross-sections of the drill core 20 along the cutting portion may comprise two or three pairs of outermost points 24 and cutting points 44, wherein each pair comprises an outermost point 24 and a cutting point 44.

[0128] A cutoff point 44 preferably represents a discontinuity along the boundary. Petition 870250084460, dated 09 / 19 / 2025, page 38 / 64 34 / 44 of a cutting portion. Therefore, cutting point 44 comprises a clearance angle, a flange angle, and a rake angle.

[0129] At least one cutting point 44 located at a second radial distance r2 allows cutting bone tissue along a circle within the cross-section having the second radial distance r2 from the longitudinal axis L as a radius. If the second radial distance r2 is less than the first radial distance r1 from an outermost point 24 described in more detail below, the drill bit 1 is not configured to cut bone tissue in an area with a radial distance that is greater than the second radial distance r2.

[0130] Thus, the second radial distance r2 may be less than the first radial distance r1 from the outermost point 24 in a cross-section of the drill core 20 in at least part of the cutting portion along the longitudinal axis L, that is, in at least some of the cross-sections along the longitudinal axis L. In other words, the drill 1 and the cutting portion may comprise a portion along the longitudinal axis L with a negative clearance angle.

[0131] Alternatively, the first radial distance r1 and the second radial distance r2 may also be substantially equal in a cross-section of the drill core 20 in at least a portion of the cutting portion along the longitudinal axis L. In other words, the outermost point 24 and the cutting point 44 may substantially coincide. In this case, the drill 20 and the cutting portion may comprise a portion along the longitudinal axis, Petition 870250084460, dated 09 / 19 / 2025, page 39 / 64 35 / 44 where the 44 cutting point has a positive clearance angle.

[0132] The ratio between the first radial distance r1 from the outermost point 24 and the second radial distance r2 from the cutting point 44 may change from cross-section to cross-section of the drill core 20 along the cutting portion.

[0133] In one embodiment, where the second radial distance r2 is less than the first radial distance r1, the drill bit 1 and the cutting portion comprise a non-cutting zone 46 where the drill bit 1 is not configured to cut bone (cf. cross-section of figure 4).

[0134] The radial extension of the non-cutting zone 46 defines a ring-shaped area between the second radial distance r2 and the first radial distance r1. Within this non-cutting zone 46, the drill bit 1 is configured to alternately compress or allow relaxation of the bone tissue, that is, to exert a force on the bone tissue in the radial direction without cutting the bone tissue. As described above, in the compression zone 27, the bone tissue adjacent to the compression zone is radially pushed outwards by rotating the drill bit 1 in the predetermined direction of rotation, while in the relaxation zone 28, recovery of the bone tissue in a radially inward direction is allowed.

[0135] Without wishing to be limited by theory, drill 1 takes advantage of the observation that bone tissue with a higher density recovers more quickly, that is, moves radially inward faster, than bone tissue with a lower density. Subsequent to compression of the bone tissue in the compression zone 27 in a radially outward direction, the compressed bone tissue Petition 870250084460, dated 09 / 19 / 2025, pp. 40 / 64 36 / 44 recovers radially inward in the relaxation zone 28. Due to the difference in recovery time, drill bit 1 has an inclination to cut bone tissue with a higher density (e.g., cortical bone tissue).

[0136] The allowed recovery time depends on the circumferential position of the cutting point 44 and the outermost point 24 (and the rotation rate and / or speed of the drill bit 1) and thus on the location of the compression zone 27 and the relaxation zone 28 along the contour 3 of a cross-section of the drill core 20 relative to the cutting point 44. Bone tissue that recovers within the predetermined allowed recovery time to a radial distance less than the second radial distance r2 must be cut at the next passing cutting point 44, while bone tissue that recovers to a point between the second radial distance r2 and the first radial distance r1 must not be cut at the next cutting point 44. Thus, the cutting point 44 is capable of cutting bone tissue to a varying degree according to its properties, i.e., cutting hard bone tissue to a higher degree than soft bone tissue.This effect can be adjusted by means of the geometry of the drill core 20, that is, the magnitude of the first and second radial distances r1 and r2, as well as their circumferential positions.

[0137] In one case, where the second radial distance r2 is substantially equal to the first radial distance r1, the drill bit 1 and the cutting portion have a cutting behavior that is different from the cutting behavior described previously. Since the cutting point 44 and the outermost point 24 coincide substantially, the cutting point 44 Petition 870250084460, dated 09 / 19 / 2025, p. 41 / 64 37 / 44 is located in the outermost radial position. In other words, all other points on a cross-sectional contour of drill core 20 are located more radially inward than cutting point 44 (see figures 5 and 6). Therefore, drill 1 is not configured to compress or allow relaxation of bone tissue, but instead cuts bone tissue in a circular area defined by the first radial distance r1 or the second radial distance r2.

[0138] This is structurally illustrated in figures 5 and 6. In the cross-section of figure 6, the theoretical outermost point 24' of the basic contour 25 of the drill core 20 (i.e., the contour that does not consider a guide thread 30 and / or a cutting groove 40), as well as the outermost point 24 of the drill contour 3 coincide with the cutting point 44 of the drill contour 3.

[0139] It should be noted that the determination of the outermost point 24 of the contour 3 of the drill does not take into account a guide thread 30, if present (cf. cross-sections of figures 4 to 6). Furthermore, although cross-sections perpendicular to the longitudinal axis along the cutting portion may generally comprise a predetermined number of compression zones 27, relaxation zones 28, cutting zones 45, non-cutting zones 46, outermost points 24 and / or cutting points 44, certain cross-sections may not include all of these features due to the influence of other structural features of the drill 10, in particular a guide thread 30 (cf. figure 4 missing a relaxation zone and part of a compression zone due to the guide thread 30). Petition 870250084460, dated 09 / 19 / 2025, page 42 / 64 38 / 44

[0140] Returning to figure 6, the theoretical outermost point 24' of the basic contour 25 of the drill core 20 is located along the cutting zone 45, where the groove 40 along the contour 3 of the drill 1 is formed. Thus, the theoretical outermost point 24' does not coincide with the outermost point 44 of the contour 3 of the drill. However, also in this case, the outermost point 24 coincides with the cutting point 44.

[0141] It should be noted that the cross-section of figure 6 does not include a compression zone 27 or a relaxation zone 28. Although part of the contour structurally corresponds to a relaxation zone 28, it does not act as one in terms of its functional configuration. In other words, contour 3 lacks a compression zone 27 with the function of compressing bone tissue so that there cannot be a relaxation zone 28 that allows relaxation of bone tissue that has been previously compressed by a compression zone 27 of the drill bit 1.

[0142] Those skilled in the art will appreciate from the above explanation that the cutting behavior of drill bit 1 changes with a change in the ratio between the first radial distance r1 and the second radial distance r2. Therefore, it is possible to adjust the cutting behavior of drill bit 1 along the longitudinal axis L, in particular by taking into account different regions in the direction of bone depth at an implantation site.

[0143] Preferably, a cutting portion comprises a first part along the longitudinal axis L with the second radial distance r2 from the cutting point 44 being less than the first radial distance r1 from the point Petition 870250084460, dated 09 / 19 / 2025, pp. 43 / 64 39 / 44 outermost 24. In this first part, the cutting portion may comprise a negative clearance angle at the cutting point 14. Furthermore, the first part of the cutting portion may also be configured to condense bone tissue by rotation. Therefore, a cross-sectional outline of the first part of the cutting portion preferably comprises at least one compression zone 27 and at least one relaxation zone 28.

[0144] The cutting portion may additionally comprise a second part. In the second part of the cutting portion, a second radial distance r2 may be substantially equal to the first radial distance r1. The second part of the cutting portion may additionally comprise a cutting point 44 with a positive clearance angle. Preferably, the first part of the cutting portion is positioned apically to the second part of the cutting portion.

[0145] Due to the difference in the ratio of the first radial distance r1 and the second radial distance r2 between the first part and the second part of the cutting portion, the cutting behavior of these parts differs from each other.

[0146] In particular, the contour of the first part of the cutting portion is configured, by rotating the drill bit, to compress the bone tissue in the compression zone 27, allow the bone tissue to relax in the relaxation zone 28, and then cut the bone tissue at the cutting point 44 of the cutting zone 45. As a result, the amount of bone tissue being cut by rotation depends on the relaxation properties of the bone tissue, that is, how much and how quickly the bone tissue relaxes after being Petition 870250084460, dated 09 / 19 / 2025, pp. 44 / 64 40 / 44 tablet.

[0147] Without wishing to be limited by theory, the inventors observed that spongy bone with a relatively low bone density is cut less. Consequently, more of the soft bone tissue remains to support the dental implant to be inserted.

[0148] The second part of the cutting portion is not configured to compress bone tissue by rotation, but instead cuts bone tissue at the outermost point 24 corresponding to the cutting point 44.

[0149] Without wishing to be limited by theory, this feature is advantageous in cortical bone with a relatively high bone density, where additional condensation of bone tissue has less effect. Therefore, the second part preferentially creates a bone recess in the cortical region of the bone tissue with a size substantially corresponding to the size of a dental implant to be implanted in order to prevent bone resorption and thus faster inward growth of the dental implant.

[0150] In the predetermined direction of rotation of drill bit 1, the cutting point 44 along the first part may be located along the contour of the drill bit's cross-section, so that, upon rotation, the cutting point 44 passes through a bone tissue location before or at the same time as the outermost point 24. After the relative position of the outermost point 24 and the cutting point 44 has changed along the contour so that they correspond to each other, the theoretical outermost point 24' may continue to change its relative position to pass through a tissue location. Petition 870250084460, dated 09 / 19 / 2025, page 45 / 64 41 / 44 bone before the cutting point. This causes a continuous change in the clearance angle from a negative to a positive clearance angle.

[0151] As explained above, the geometry of drill bit 1 and, in particular, the magnitude of the first and second radial distances r1 and r2, as well as their circumferential positions, define the cutting behavior of drill bit 1.

[0152] As mentioned above, the cutting groove can extend helically around the drill bit 1. Consequently, the cutting points 44 also extend helically around the drill bit 1, in particular with a first step. The first step can be the same step as the cutting groove step 15 (cutting groove with a constant size) or it can be different from the cutting groove step (cutting groove with a variable size). In particular, the first step can be smaller than the cutting groove step (i.e., the cutting groove size increases in an apical-coronal direction).

[0153] For a change in cutting behavior, the outermost points 24 of the cross-sections of the drill core 20 along the longitudinal axis L may be located along a helical line with a second pitch around the longitudinal axis L. Alternatively, the outermost points 24 of these cross-sections may also be located along a substantially straight line that is preferably arranged parallel to the longitudinal axis L.

[0154] Preferably, the first step and the second step of the cutting points 44 and the points more Petition 870250084460, dated 09 / 19 / 2025, pp. 46 / 64 42 / 44 external 24, respectively, differ from each other. Specifically, the first step is smaller than the second step. Alternatively, the first and second steps may be substantially the same.

[0155] In an embodiment in which the first step and the second step differ from each other, the relative circumferential position of the outermost point 24 and the cutting point 44 changes along the longitudinal axis L of the cutting portion of the drill bit 1. It is thus possible to continuously adjust the cutting behavior of the drill bit 1 along the longitudinal axis L for different regions of the bone.

[0156] With drill bit 1 according to the present disclosure, it is possible to reduce the complexity of a drilling protocol. Sequential use of a plurality of different tools and complex drilling protocols can thus be avoided, and misalignment of sequentially used tools can be more easily prevented. In addition, drill bit 1 makes it possible to prevent the bone recess to be formed from being oversized or undersized. REFERENCE SIGNS

[0157] The following lists the reference signs used in the description and drawings. Throughout the drawings, these reference signs refer to features that have the same or equivalent function and / or structure. apical end drill contour coronal end of the bone interaction portion apical end face Petition 870250084460, dated 09 / 19 / 2025, pp. 47 / 64 43 / 44 central area radial extension in arm shape of the apical end face circumferential border of the apical end face 14th tip of an arm of the apical end face 14b lateral border of an arm of the apical end face 14c opposite lateral border of an arm of the apical end face 20 drill core 21 circumferential surface of the drill core 22 apical edge of the drill core 23 chamfer 24 outermost point 24' theoretical outermost point 25 basic contour of the drill core 27 compression zone 28 relaxation zone 29 innermost point 30 guide thread 40 groove 41 concave surface 42 apical edge of the concave surface 43 cutting edge 44 cutting point 45 cutting zone 46 non-cutting zone 50 retention arm Petition 870250084460, dated 09 / 19 / 2025, pp. 48 / 64 44 / 44 r1 first radial distance r2 second radial distance r3 smaller radial distance L longitudinal axis Petition 870250084460, dated 09 / 19 / 2025, page 49 / 64

Claims

1 / 5 CLAIMS 1. Drill (1), characterized in that it comprises: an apical end (2), a coronal end and a longitudinal axis (L) extending between the apical end and the coronal end, a drill core (20) extending along the longitudinal axis (L), at least two grooves (40), each groove being defined by a concave surface (41) forming a recess along the drill core (20);and an apical end face (10) at the apical end (2), wherein - apical edges (42) of the concave surfaces (41) and - an apical edge (22) of the drill core (20) define the shape of the apical end face such that the apical end face defines a profile of retention arms (50) at the apical end (2), each retention arm being formed between the concave surfaces of adjacent grooves (40) and wherein at least one of the at least two grooves (40) extends along the longitudinal axis, along the entire length of the drill (1) configured to interact with the bone tissue.; 2. Drill (1), characterized in that it comprises: an apical end (2), a coronal end and a longitudinal axis (L) extending between the apical end and the coronal end, a drill core (20) extending along the longitudinal axis (L), at least two grooves (40), each groove being defined by a concave surface (41) forming a recess along the drill core (20);and an apical end face (10) at the apical end (2), wherein - apical edges (42) of the concave surfaces (41) and - an apical edge (22) of the drill core (20) define the shape of the apical end face such that the apical end face defines a profile of retention arms (50) at the apical end (2), each retention arm being formed between the concave surfaces of adjacent grooves (40), the drill further comprising a cutting portion extending along the entirety of at least one of the at least two grooves (40), said cutting portion being present along substantially the entire length of the drill core (20) along the longitudinal axis (L) from the apical end (2) to the coronal end of the drill portion configured to interact with bone tissue.

3. Drill (1), according to claim 1 or 2, characterized in that it further comprises at least one guide thread (30) projecting from the drill core (20) and extending helically along the drill core (20), the guide thread (30) preferably tapering apically.

4. Drill (1), according to claim 3, characterized in that the radial height of the guide thread (30) is less than the radial extension of the retaining arm profile on the apical end face (10).

5. Drill (1), according to claim 3 or 4, characterized in that the guide thread (30) has a non-circular outer circumferential profile, the non-circular outer circumferential profile preferably being a trioval profile.

6. Drill (1), according to any of the preceding claims, characterized in that each retaining arm (50) has a radial extension that is greater than its circumferential width.

7. Drill (1), according to any of the preceding claims, characterized in that a circumferential edge (14) of the apical end face (10) is arranged in a plane perpendicular to the longitudinal axis (L).

8. Drill (1), according to any of the preceding claims, characterized in that the drill core (20) has a non-circular profile in a cross-section perpendicular to the longitudinal axis (L), wherein in the longitudinal direction of the drill (1), the non-circular profile preferably rotates around the longitudinal axis (L) creating a twisted non-circular drill core.

9. Drill (1), according to any of the preceding claims, characterized in that the drill core (20) is tapered towards the apical end (2). Petition 870250084460, dated 09 / 19 / 2025, page 52 / 64 4 / 5 10. Drill bit (1), according to any of the preceding claims, characterized in that the concave surface (41) of each groove (40) and the circumferential surface (21) of the drill bit core (20) form a cutting edge (43).

11. Drill (1), according to any of the preceding claims, characterized in that on the apical edge of each concave surface (41), the concave surface and the apical end face (10) partially form a cutting edge, the cutting edge having a forward inclination angle and substantially no forward relief angle.

12. Drill bit (1), according to any of the preceding claims, characterized in that at least two grooves (40) extend helically along the drill bit core (20).

13. Drill (1), according to claim 8, as dependent on claim 5, characterized in that the non-circular profile of the drill core (20) and the non-circular outer circumferential profile of the guide thread (30) are formed with a circumferential offset.

14. Method for creating an osteotomy using a drill (1), in particular a drill according to any of the preceding claims, characterized in that the method comprises: drilling a hole with a pilot drill; increasing the size of the hole for the insertion of a dental implant using the drill (1), the drill comprising a drill core (20), at least two grooves (40), each Petition 870250084460, dated 09 / 19 / 2025, page.53 / 64 5 / 5 groove defined by a concave surface (41) forming a longitudinal recess along the drill core (20), an apical end face (10) at the apical end (2) of the drill and retention arms (50) extending coronally from the apical end face, each retention arm being formed between the adjacent groove concave surfaces (40), wherein by contact of the apical end face (10) with the bottom of the hole drilled with the pilot drill, the retention arms (50) generate a braking force to stop the rotation of the drill (1).

15. Method according to claim 13, characterized in that the tip of the pilot drill has a larger diameter than the diameter of the apical end face (10). Petition 870250084460, dated 09 / 19 / 2025, pp. 54 / 64

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