Drill bits

Abstract

The drill bit (10) includes an apical end (1), a coronal end (2), a longitudinal axis (L) extending between the apical end and the coronal end, a drill bit core (11), and a cutting portion (C) extending at least partially along the drill bit core. Along the cutting portion, a cross-sectional outline of the drill bit core perpendicular to the longitudinal axis includes at least one outermost point (12) that is a first radial distance (r1) from the longitudinal axis and at least one cutting point (14) that is a second radial distance (r2) from the longitudinal axis. Along the first portion of the cutting portion, the second radial distance is less than the first radial distance, and along the second portion of the cutting portion, the second radial distance is substantially equal to the first radial distance.

Description

[Technical field]

[0001] The present disclosure relates to drill bits that can be used in dentistry to prepare a cavity for receiving a dental implant. [Background technology]

[0002] In dentistry, cavities in a patient's bone tissue need to be prepared in various circumstances, particularly for the insertion of dental implants. It is known that the preparation of the cavity to receive the implant has a significant influence on the osseointegration of the implant and its long-term success.

[0003] Given that bone density, orientation, and quality vary from patient to patient, preparing an appropriate implant-receiving cavity usually requires the use of several tools. However, the more interdependent the tools used to create the cavity, the more extensive the treatment protocol. Furthermore, alignment of subsequently used tools can be difficult.

[0004] Furthermore, the jawbone has a relatively hard outer layer, or cortical bone, and a weaker cancellous bone structure underneath. The cortical bone, which provides the hard cortex, is much denser and less elastic than the cancellous bone. As a result, when preparing a bone cavity to receive a dental implant, the drill bit must create this cavity extending from the cortical bone into the cancellous bone. In other words, the drill bit encounters different types of bone not only between different patients, but even within a single patient.

[0005] In view of the above, continuous efforts have been made to improve the process of creating recesses in bone tissue in preparation for the insertion of implants. In this regard, WO2017 / 129828 A1 discloses a drill bit for preparing bone tissue configured to simultaneously condense and cut the bone tissue. Summary of the Invention

[0006] Nonetheless, there remains a need for a drill bit that enhances the process of creating a recess in bone tissue for the insertion of a dental implant. In particular, it is desirable to enhance the drilling process by taking into account the different bone layers in which the implant will be secured.

[0007] In response to the above, the present disclosure discloses a drill bit including an apical end, a coronal end, a longitudinal axis extending between the apical end and the coronal end, a drill bit core, and a cutting portion extending at least partially along the drill bit core. An outline of a cross section of the cutting portion perpendicular to the longitudinal axis includes at least one outermost point that is a first radial distance from the longitudinal axis and at least one cutting point that is a second radial distance from the longitudinal axis, the cross section being located along the cutting portion. Further, along the first portion of the cutting portion, the second radial distance is less than the first radial distance, and along the second portion of the cutting portion, the second radial distance is substantially equal to the first radial distance.

[0008] The drill bit core may be substantially cylindrical or conical, the cone may have a circular, non-circular, spherical, and / or non-spherical cross-section perpendicular to the longitudinal axis of the drill bit.

[0009] The outermost point of the cross section of the cut portion is the point on the outline of the cross section of the drill bit core that has the greatest radial distance from the longitudinal axis. There may be multiple outermost points, i.e., there may be multiple points that have the greatest radial distance from the longitudinal axis, such as two, three, four, or five outermost points. In other words, there are several distinct outermost points along the outline of the cross section of the drill bit core.

[0010] The cutting portion of the present disclosure relates to a portion of a drill bit configured to cut bone tissue. In this regard, the cutting point should be understood as the maximum extension of the cutting edge. In general, the cutting point defines a radial distance (second radial distance) from the longitudinal axis along the outline of the cross section of the drill bit core, the drill bit core being configured to cut bone tissue. Points along the outline of the cross section of the drill bit core that have a radial distance greater than the second radial distance are preferably not configured to cut bone tissue.

[0011] Stated another way, the first portion of the cutting portion is configured to cut bone tissue along a circle having the second radial distance as a radius, and further, the first portion of the cutting portion is not configured to cut bone within a ring-shaped region between the second radial distance and the first radial distance.

[0012] In this ring-shaped region, where the drill bit is not configured to cut bone, deformation of bone tissue is preferably caused by the drill bit while the drill bit rotates in a predetermined direction, in particular, after the cutting point has passed in the rotation direction, bone tissue located radially outward relative to the cutting point (i.e. located within the ring-shaped region) is compressed radially outward until the next outermost point is reached.

[0013] This compaction of bone tissue is advantageous as it increases bone density, leading to improved initial stability.

[0014] After the outermost point, the profile of the cross section is configured to allow the radially compressed bone tissue to relax (i.e., expand radially inward relative to the longitudinal axis). Before the next cut point, the profile extends around the longitudinal axis specifically inside a cut circle having the radial distance of the cut point as the radius.

[0015] Without wishing to be bound by theory, it is believed that the drill bit takes advantage of the effect that bone tissue, i.e., hard bone tissue, which has a high density, generally relaxes or rebounds faster than bone tissue, i.e., cartilage tissue, which has a low density. As a result, hard bone tissue tends to cut more than cartilage tissue. In other words, the drill bit tends to cut bone tissue according to the density of the tissue.

[0016] In the second portion of the cutting portion, the drill bit has a different cutting performance than in the first portion of the cutting portion. Since the radial distances of the outermost point and the cutting point are substantially equal, the cross-sectional outline of the second portion of the cutting portion is generally configured to cut bone tissue without compressing the bone tissue or to cut only bone tissue. This is essentially achieved by having the outermost point and the cutting point substantially coincident.

[0017] As a result, the drill bit has varying cutting performance along its longitudinal axis that can be adapted to different bone tissues at different depths.

[0018] The first portion of the cutting portion may be positioned apical to the second portion of the cutting portion.

[0019] In this preferred configuration, the above-mentioned cutting performance of the first part of the cutting portion is mainly applied to the more apical region of the bone where the bone recess is to be formed, i.e. in particular to the cancellous bone tissue. The cutting performance is obtained as a result of the cancellous bone being compressed and cut. Thus, the bone tissue is cut to a lesser extent. Without wishing to be bound by theory, it is assumed that the combination of compression and cutting by the drill bit allows the bone tissue to be condensed before the implant is inserted, thus increasing the primary stability.

[0020] The second part of the cutting portion is located in a more coronal region of the bone, for example in the region of the cortical bone, and since the second part of the cutting portion does not essentially condense bone tissue, it can form a recess of substantially the same shape as the drill bit, which can generally conform to the shape of the implant to be implanted. This can reduce stress and trauma in this region of the bone, resulting in less bone resorption. This allows for faster bone ingrowth of the dental implant, especially when combined with the primary stability provided in the apical region.

[0021] The drill bit may further include a non-cutting portion extending along the drill bit core, and along the non-cutting portion a cross-sectional outline of the drill bit core perpendicular to the longitudinal axis may include at least one outermost point that is a first radial distance from the longitudinal axis.

[0022] The non-cutting portion refers to a portion along the longitudinal axis of the drill bit that is not configured to cut bone tissue, whereby this portion is adapted to primarily or solely provide a condensing effect on bone tissue without any intentional cutting action, i.e. without a cutting point existing along the outline of the cross section.

[0023] The non-cutting portion may be positioned apically of the cutting portion. As a result, the non-cutting portion is the first part of the drill bit that enters the implant site to prepare the implant site for insertion of the implant. In the resulting recess of the drill bit, the apical end prepared by the non-cutting portion provides a stable primary fixation of the implant. In the case of the non-cutting portion at the apical end, it is preferable to prepare it with a pilot drill before using the drill bit.

[0024] In another aspect of the disclosure, the drill bit includes an apical end, a coronal end, a longitudinal axis extending between the apical end and the coronal end, a drill bit core, a cutting portion, and a non-cutting portion. The cutting portion and the non-cutting portion extend along the drill bit core. Along the cutting portion and the non-cutting portion, a profile of a cross section of the drill bit core perpendicular to the longitudinal axis includes at least one outermost point that is a first radial distance from the longitudinal axis. The profile of the cutting portion further includes at least one cutting point that is a second radial distance from the longitudinal axis. The non-cutting portion is positioned apical to the cutting portion.

[0025] The non-cutting portion being located apical to the cutting portion allows for pre-compression of the bone tissue before it is cut by the cutting portion, which has the advantage that it is possible to exert a condensing effect on the more apical regions of the bone tissue, i.e. the regions where the cancellous bone is located, without cutting the bone tissue, thereby forming a bone recess for receiving the dental implant which enhances the osseointegration of the dental implant.

[0026] The cut portion can include at least a portion along the longitudinal axis where the second radial distance is less than the first radial distance.

[0027] In other words, the cutting portion may comprise a portion along the longitudinal axis having a ring-shaped region between the second radial distance and the first radial distance, as already mentioned above.

[0028] The uncut and / or cut portions of the drill bit core along the longitudinal axis may include compression zones and relaxation zones.

[0029] The compression zone extends along the outline of the drill bit core in a cross section perpendicular to the longitudinal axis. In the compression zone, the radial distance of the outline from the longitudinal axis increases as one follows the outline to the outermost point. Thus, when the drill bit is rotated relative to the bone tissue (or a point adjacent to the drill bit core), the outline of the drill bit pushes the bone tissue (or point) outward, i.e., compresses the bone tissue.

[0030] In other words, the compression zone is defined by increasing radial distance of the outline of the drill bit core from the longitudinal axis to the outermost point of the outline in a direction along the outline opposite to the predetermined direction of rotation of the drill bit.

[0031] The compression zone is a zone along the cross-sectional outline of the drill bit core that is configured to perform a radially outward movement toward adjacent bone tissue upon rotation of the drill bit, thereby exerting a force in a radially outward direction on the bone tissue, causing the adjacent bone tissue to be compressed.

[0032] After the outermost point of the profile passes through the material (or point), i.e., in the direction opposite to the given rotational direction of the drill bit, a relaxation zone along the profile of the drill bit may begin, decreasing the radial distance of the profile from the longitudinal axis. Thus, when the drill bit is rotated relative to the surrounding bone tissue, the profile of the drill bit core will move relatively radially inward (away from the bone tissue). This allows the bone tissue to relax after being compressed in the compression zone.

[0033] The relaxation zone is therefore defined by the decrease in distance of the outline of the drill bit core from the longitudinal axis opposite the given rotational direction of the drill bit after the outermost point of the outline in a direction along the outline.

[0034] The relaxation zone is a zone along the cross-sectional contour of the drill bit core that is configured to move radially inwardly away from adjacent bone tissue upon rotation of the drill bit, thereby allowing adjacent compressed bone tissue to relax and thereby follow the radial displacement of the contour of the drill bit core in the radially inward direction.

[0035] Preferably, the cut point is located within the compression zone.

[0036] Locating the cutting point within the compression zone allows for selective cutting of bone tissue that has been radially compressed away from the longitudinal axis to the distance of the outermost point and then healed back toward the longitudinal axis of the drill bit, thus allowing the cutting behavior of the drill bit to be tailored to different regions or types of bone tissue.

[0037] The cross-sectional profile along the uncut portion of the drill bit core and perpendicular to the longitudinal axis may be non-circular.

[0038] Additionally, the cross-sectional outline of the drill bit core taken along the cut portion and perpendicular to the longitudinal axis may be non-circular.

[0039] The non-circular outline of the cut and / or uncut portions may be elliptical, trioval, quadrioval or greater.

[0040] A non-circular outline in this context refers to an outline that is different from a circular outline, except that the non-circular outline is preferably substantially curvilinear, i.e. it has no sharp edges (except in the case of cuts, the part of the outline relative to the cut point that represents the cut zone).

[0041] The non-circular contour line allows the formation of at least one compression zone and at least one relaxation zone, thereby exerting a compacting effect on the bone tissue. As described above, the compression zone is defined along the contour line of the cross section of the drill bit core in a given rotational direction from a maximum radial distance to a minimum radial distance. The relaxation zone is defined along the contour line of the cross section of the drill bit core in a given rotational direction from a minimum radial distance to a maximum radial distance. Depending on the shape of the contour line, multiple compression zones and relaxation zones may be formed. In particular, two, three, four or five pairs of compression zones and relaxation zones may be formed.

[0042] The drill bit core may include a guide portion, the cross section of which perpendicular to the longitudinal axis is preferably circular.

[0043] In one embodiment where the drill bit is configured with substantially no cutting behavior (cutting point) at the apical portion, a pilot drill is preferably used to create a pilot hole into which the drill bit can be inserted. A guiding portion of the drill bit, which generally does not have cutting or compacting capabilities, facilitates insertion and guiding of the drill bit and enhances alignment of the drill bit with the pilot hole.

[0044] A cross section of the drill bit core perpendicular to the longitudinal axis may have two or three pairs of outermost points and cut points, each pair including an outermost point and a cut point.

[0045] Thus, multiple compression and relaxation zones can be created. Furthermore, the recovery time of the bone tissue can be adjusted by the circumferential location of the cutting point and the outermost point, which adapts the cutting behavior of the drill bit.

[0046] For a given rotational orientation of the drill bit, the location of the cutting point can vary in the apical-coronal direction from a position before the outermost point to a position at the same as the outermost point.

[0047] Depending on the relative positions of the outermost point and the cutting point with respect to the given rotation direction, the adjustment of the type of bone tissue cut is achieved at least primarily by changing the recovery time of the bone tissue. More specifically, if the cutting point is located after the outermost point of the given rotation direction of the drill bit (i.e. in the compression zone mentioned above, such that the cutting point passes through the location of the bone tissue before the outermost point), the relaxation time of the bone is longer compared to an arrangement in which the cutting point is located at the outermost point of the given rotation direction of the drill bit. Thus, the cutting behavior can be adjusted to different types of bone tissue.

[0048] Additionally, the relative locations of the outermost point and the cutting point may be continuously varied, for example, allowing the cutting behavior of the drill bit to be tailored in response to changes in bone structure or density along the insertion path of the drill bit.

[0049] The ratio of the first radial distance to the second radial distance between the cross-sections of the cut portions along the longitudinal axis may preferably vary continuously.

[0050] The ratio of the first radial distance to the second radial distance of the cross-section of the drill bit core defines the cutting characteristics of the drill bit core along the longitudinal axis of the drill bit, i.e., a change in the ratio of the first radial distance to the second radial distance along the longitudinal axis will result in a change in the cutting behavior of the drill bit.

[0051] The cutting portion may include at least one cutting groove. Preferably, the at least one cutting groove extends helically around the drill bit core.

[0052] The cutting groove allows easy creation of the cutting point and allows collection of cut bone material when preparing the bone cavity prior to implant treatment.

[0053] The kerfs are recessed into the contour of the drill bit in a cross section perpendicular to the longitudinal axis. The kerfs form a cutting zone along the contour of the drill bit.

[0054] One side of the recess or cutting zone establishes the cutting point of the drill bit. In particular, the cutting point is formed as a discontinuity along the profile, i.e. at the intersection of the outer surface of the drill bit core and the surface of the cutting groove. The cutting point is preferably located at the end of the profile of the groove which continues when viewed in a given rotation direction of the drill bit. If the groove extends helically around the drill bit, the cutting point of the cross section of the cutting portion also extends around the drill bit, in particular at the first pitch.

[0055] Preferably, the number of kerfs is equal to the number of outermost points and cut points. The outermost points of the cross section may be located along a helical line having a second pitch, the first pitch and the second pitch being different from each other and the first pitch being preferably smaller than the second pitch.

[0056] When the first pitch and the second pitch are different from each other, the relative circumferential positions of the cutting point and the outermost point change continuously. As described above, the relative positions of the cutting point and the outermost point define the cutting behavior of the drill bit. Thus, the difference between the first pitch and the second pitch can continuously adjust the cutting behavior of the drill bit along the cutting portion of the drill bit, preferably in response to changes in bone density.

[0057] The drill bit may further include at least one leading thread helically formed around the drill bit core, preferably formed as a single thread, although double or triple threads may also be envisaged.

[0058] The guide thread is configured as a protruding portion from the drill bit core that, upon rotation in a predetermined direction, draws the drill bit into the bone tissue or into a pilot hole in the bone tissue. The predetermined speed of the drill bit into the bone tissue is adjustable by the pitch of the guide thread.

[0059] The guiding thread has the advantage of defining the feed rate of the drill bit into the bone tissue and eliminating the dependency on the force applied by the user. In particular, potential adverse effects caused by the user driving the drill bit too fast or too slow into the patient's bone are avoided. This may enhance the osseointegration of the dental implant.

[0060] Also disclosed is a method of preparing an osteotomy, the method including drilling a hole in the jawbone with a non-spherical drill having a contour as described above. [Brief description of the drawings]

[0061] With the aid of the following figures and description, the embodiments are explained in more detail in order to better understand the present disclosure. For this purpose, the features appearing in the figures are labeled with reference signs. In this context, essentially the same reference signs are used for different exemplary embodiments if the features of these embodiments are the same or achieve the same effect.

[0062] [Figure 1] 1 shows an exemplary embodiment of a tool for preparing a recess in bone tissue and in cross-section at different positions along a longitudinal axis of the tool; [Diagram 2] 1 shows the relationship between a bone cavity prepared by a tool according to the present disclosure and an implant to be inserted into said cavity; [Diagram 3] 1 shows an exemplary sequence of tools and implants used in implant treatment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0063] In the following, exemplary embodiments of a tool for preparing a recess in bone tissue, and in particular an embodiment of a drill bit according to the present disclosure, are described with reference to the accompanying drawings.

[0064] 1 is a perspective view of a drill bit 10 according to the present disclosure. The drill bit 10 includes an apical end 1, a coronal end 2, and a longitudinal axis L extending between the apical end 1 and the coronal end 2. Additionally, the drill bit 10 includes a drill bit core 11. The drill bit core 11 preferably extends substantially along the longitudinal axis L between the apical end 1 and the coronal end 2 of the drill bit 10. Adjacent to the coronal end of the drill bit core 11, the drill bit 10 may include a coupling portion 5 for coupling the drill bit 10 to another tool (not shown) for applying a predetermined rotation to the drill bit 10.

[0065] FIG. 1 shows a front view (a) of the drill bit 10 at different positions along the longitudinal axis L, and furthermore cross-sectional views (b)-(e). The cross-sectional views shown in FIG. 1 show cross-sections of the drill bit 10 perpendicular to the longitudinal axis L when viewed in the apical-coronal direction. Each of these front views (a) and cross-sectional views (b)-(e) shows the outline 3 of the drill bit 10, which may include outline portions resulting from features such as cutting grooves 15 or guide threads 19. The cross-sectional views (c)-(e) further include, for comparison, each of the basic outlines 4 of the drill bit core 11, which generally represents the basic shape of the drill bit core 11 without additional features such as cutting grooves 15 or guide threads 19. In the cross-sectional view (e), the basic outline 3 makes it possible to show where the outermost point 12 of the drill bit core 11 without the cutting grooves 15 would be located.

[0066] The outline of the cross-section of the drill bit core 11 preferably includes at least one outermost point 12. The at least one outermost point 12 is located substantially a first radial distance r1 from the longitudinal axis L. As a result, the radial distance r1 at the outermost point 12 of the core represents the maximum radial distance of the outline to a point where the longitudinal axis L intersects the cross-section.

[0067] 1, the drill bit core 11 includes three outermost points 12. However, any other number of outermost points 12 may be formed, such as one, two (i.e., an ellipse), three (i.e., a tri-ellipse), four, five, or six outermost points 12. Preferably, the outermost points 12 are evenly distributed along the outline of the drill bit core 11.

[0068] The cross-sectional views include cross-sections at different portions of the drill bit 10 along the longitudinal axis L. As will be explained in more detail below, the front view (a) shows an essentially circular outline of the non-cut portion N of the drill bit 10. In other words, the outline does not have an outermost point 12. The cross-sectional view (b) shows the outline in a cross-section along the non-cut portion, which includes three outermost points. The cross-sectional view (c) shows a cross-section along a cut portion C in the condensed portion D of the drill bit 10. The cross-sectional views (d) and (e) show coronal cross-sections of the condensed portion D along the cut portion C.

[0069] Furthermore, in these figures (a)-(e), the predetermined rotational direction of the drill bit 10 is defined as the counter-clockwise direction as indicated by the curved arrow in FIG.

[0070] Referring again to the outermost point 12, the drill bit 10 may include at least a portion where the diameter and / or the first radial distance r1 of the drill bit core 11 increases along the longitudinal axis L in the apical-coronal direction. This increase preferably corresponds to an increase in the diameter of a dental implant 50 (see FIG. 2) to be embedded in the recess created with the drill bit 10.

[0071] Additionally, the drill bit 10 may include at least a portion along the longitudinal axis L where the diameter of the drill bit core 11 and / or the first radial distance r1 remain substantially the same. Such a portion may also be shaped to conform to the implant 50 to be implanted.

[0072] At the coronal end 2, the shape of the drill bit 10 may be adapted to have substantially the same size as the dental implant 50 in its situ state when implanted. At the apical end 1, the drill bit 10 may be adapted to be smaller in size than the dental implant 50. The latter is to enhance the primary stability of the implant 50 by creating a press fit between the patient's bone tissue and the implant 50.

[0073] In general, it is advantageous to adapt the shape of the drill bit 10 along the longitudinal direction L to the geometry of the dental implant 50 to be inserted into the bone cavity prepared with the drill bit 10. Preferably, this adaptation takes into account the type of bone that will be located adjacent to the implant 50 after the implant treatment. In particular, for cartilage, the drill bit 10 is undersized relative to the implant 50 to support the fixation of the implant 50 in the bone tissue.

[0074] The same size of the drill bit 10 as the dental implant 50 at the coronal end 2 reduces distortion in the cortical bone tissue after implant treatment, prevents bone resorption and promotes bone ingrowth.

[0075] Due to the smaller size of the drill bit 10 at the apical end 1 than the dental implant 50, a good initial stability of the dental implant 50 in the bone recess is achieved.

[0076] As already mentioned above, the drill bit core 11 may include at least one compression zone 17 and at least one relaxation zone 18 (eg, cross-sectional view (b) of FIG. 1).

[0077] For a given rotational orientation of the drill bit 10, at least one compression zone 17 begins at an innermost point 21 having a radial distance r3 from the longitudinal axis L and extends along a portion of the outline of the cross-section of the drill bit core 11, preferably to an outermost point 12 along the outline and to a maximum radial distance r1 between the outline and the longitudinal axis L.

[0078] Also, for a given rotational orientation of the drill bit 10, at least one relaxation zone 18 begins at an outermost point 12 that is at a maximum radial distance r1 from the longitudinal axis L and extends along a portion of the outline of the cross section of the drill bit core 11 to an innermost point 21 that has a radial distance r3 from the longitudinal axis L.

[0079] The contour line between the innermost point 21 and the outermost point 12 of the compression zone 17 and / or the relaxation zone 18 is preferably smooth, i.e. (only) curved. Nevertheless, either or both of the zones 17 and 18 may have at least one straight subsection.

[0080] It should be noted that the cross-sectional outline of the drill bit core having multiple outermost points 12 located immediately adjacent to each other, i.e. forming a circular linear cross-section, is also included since all these outermost points 12 have a first radial distance r1 (maximum radial distance). The same applies to the innermost point 21 which is at a minimum radial distance r3 from the longitudinal axis L. Nevertheless, it is also possible to have distinct outermost point(s) 12 and / or innermost point(s) 21.

[0081] Preferably, the number of compression zones 17 in the cross-section of the drill bit core 11 is generally equal to the number of relaxation zones 18. In this context, the term is used generally because either or both zones 17 and 18 may be interrupted by a cutting zone 13, which will be described in more detail below.

[0082] In the compression zone 17, the drill bit 10 is configured to compress the bone tissue in a radially outward direction, i.e., to exert a densifying or compacting effect on the bone tissue. Upon rotation of the drill bit, a predetermined point (not shown) in the bone tissue is pushed radially outward as the radial distance of the cross-section of the drill bit core 11 increases from radial distance r3 to radial distance r1. This outward movement relative to the bone tissue causes the bone tissue to compact.

[0083] In the relaxation zone, the drill bit 10 allows the compressed bone tissue to recover by moving radially inwardly of the outline 3 of the drill bit core 11. In other words, upon rotation of the drill bit, a given point in the bone tissue (not shown) can continue radially inward as the radial distance of the outline 3 of the drill bit core decreases from the outermost point 12 to the innermost point 21.

[0084] Without wishing to be bound by theory, it has been found that bone tissue having a higher density, such as cortical bone, generally relaxes or rebounds faster than bone tissue having a lower density, such as cancellous bone. In other words, in the relaxation zone of the drill bit 10, bone tissue having a higher density will relax and extend radially inward faster than bone tissue having a lower density.

[0085] At least a portion of the cross-sectional contour of the drill bit core 11 is preferably non-circular. Thus, at least a portion of the drill bit core 11 along the longitudinal axis L has an at least partially non-circular cross-section.

[0086] The cross-sectional profile of the drill bit core 11 may also be non-circular along the entire or at least substantially the entire extension of the drill bit core 11 along the longitudinal direction L. For example, the non-circular profile may be elliptical or tri-elliptical. However, other shapes of non-circular profile are also possible, in particular substantially spherical profiles. Nevertheless, and as mentioned above, the drill bit core 11 may also include a cross-sectional profile that is substantially circular along at least a portion of the longitudinal axis L.

[0087] The non-circular profile makes it possible to define at least one compression zone 17 and a relaxation zone 18. That is, a portion of the cross-sectional profile of the drill bit core 11 from a minimum radial distance r3 to a maximum radial distance r1 in a given rotational orientation of the drill bit 10 is defined as a compression zone 17, i.e., it is configured to compress adjacent bone tissue. A portion of the cross-sectional profile of the drill bit core 11 from a maximum radial distance to a minimum radial distance in a given rotational orientation of the drill bit 10 is defined as a relaxation zone 18, i.e., it is configured to allow relaxation of previously compressed bone tissue. The shape of the non-circular profile 3 can be designed such that multiple compression zones 17 and relaxation zones 18 along the cross-sectional profile of the drill bit core 11 are defined.

[0088] In some embodiments, the drill bit 10 includes a guide thread 19 along at least a portion of the drill bit 10 along the longitudinal axis L. The outline of the guide thread 19 projects radially from the core and extends helically around the drill bit core 11. The guide thread is preferably not intended to be a screw tap for a subsequently placed implant.

[0089] The guide threads 19 are formed at a predetermined pitch around the drill bit core 11. The guide threads 19 are preferably formed as a single thread. As mentioned above, the guide threads 19 may also be formed as double or triple threads.

[0090] The guide thread preferably starts at the apical end. Moreover, the guide thread terminates apically, particularly relative to the coronal end of the cutting groove 15, which will be described in more detail below. In the coronal direction of the coronal end of the guide thread, the drill bit 10 preferably includes an extension portion E. Thus, the extension portion may include the cutting groove 15, but preferably does not include a thread. The extension portion may further be configured to substantially not cause further modification to the recess formed in the adjacent bone tissue. Alternatively, the drill bit 10 may not include a guide thread 19.

[0091] By means of the guide thread 19, the drill bit 10 is drawn or guided into the bone tissue at a predetermined speed. The pitch of the guide thread 19 is preferably adapted so that the drill bit 10 draws itself into the bone tissue at a predetermined speed (feed per revolution) to create a satisfactory and reproducible implant-receiving hole. As a result, the user does not need to apply force to the drill bit 10 to force it into the bone tissue. This has the advantage of facilitating the use of the tool. In other words, the user does not need to worry about feeding the tool into the bone tissue too quickly or too slowly.

[0092] In particular, when the drill bit 10 is inserted into a previously prepared pilot hole (not shown), the guide thread 19 also assists in aligning the drill bit 10 with the hole, thereby more effectively preventing misalignment of the tool by the user, which may contribute to achieving the desired shape of the bone recess and promote osseointegration of the implant and its long-term success.

[0093] Along the longitudinal axis L, the drill bit 10 includes a cutting portion C. The drill bit 10 may further include a condensation portion D, a non-cutting portion N, and / or an extension portion E along the longitudinal axis L and the guide region 16. The condensation portion D may partially or completely overlap with the cutting portion C and / or the non-cutting portion N.

[0094] The inclusion of some or all of the above-mentioned portions along the longitudinal axis of the drill bit 10 allows the drill bit 10 to be adapted to different densities of bone tissue. In particular, the drill bit 10 is configured differently at the coronal end 2, where the drill bit 10 prepares a compact structure and relatively dense cortical bone, than at the apical end, where the drill bit 10 generally prepares a trabecular structure and generally less dense cancellous bone tissue. It is therefore possible to prepare these different regions of bone tissue in just one step when preparing a bone cavity for inserting a dental implant. In this way, complex drilling protocols can be avoided in most patients. Nevertheless, a pilot drill 30 can be used before the drill bit 10 to facilitate preparation.

[0095] All parts of the drill bit 10 along its longitudinal axis are described in more detail below with reference to FIG.

[0096] The drill bit 10 includes at least one cutting portion C. The cutting portion C preferably extends at least partially along the drill bit core 11 along the longitudinal axis L. Preferably, the cutting portion C does not extend to the apical end 1 of the drill bit 10 or drill bit core 11. In other words, the drill bit 10 may not be configured to cut bone tissue at the apical end 1. Instead, the cutting portion C may be present along substantially the entire length of the drill bit core 11 along the longitudinal axis L (i.e., without the connecting portion 5).

[0097] In either case, the apical end may be used to guide the drill bit 10 into the patient's bone tissue.

[0098] The cutting portion C may at least partially overlap with the condensation portion D. That is, the cutting portion C may be at least partially configured as the condensation portion D of the drill bit 10, or vice versa.

[0099] As shown in Fig. 1, the cutting portion C is apically tapered, i.e., a cross-section of the cutting portion C perpendicular to the longitudinal direction L decreases in size from the coronal end of the cutting portion C to the apical end of the cutting portion C. As a result, when the drill bit drills into the bone tissue, the cutting portion increases the size of the hole created by cutting the adjacent bone tissue. When the guiding thread 19 is present, the cutting movement is performed in a specific helical manner with a specific steady feed.

[0100] Even if the cutting portion C is at least partially or completely configured as a condensation portion D, the cross section of this cutting portion C preferably includes a compression zone 17 and a relaxation zone 18. Such cutting portion C is thereby configured to compress bone tissue in the compression zone 17 and allow the bone tissue to relax in the relaxation zone 18 while rotating the drill bit 10 in a predetermined direction.

[0101] The contour lines along and / or the transition between the compression zone 17 and the relaxation zone 18 are preferably (only) curvilinear, i.e. the contour lines may not include straight sections or discontinuities (except for the cut zone 13 in the case of cut portion C, which will be explained in more detail below). This has a positive effect on the structural integrity of the bone tissue treated with the drill bit 10.

[0102] It should be noted that in the present disclosure, if present, and if having a compression zone 17 and a relaxation zone 18, the condensation portion D includes both the compression zone 17 and the relaxation zone 18 (i.e., not just the compression zone 17, and not just the relaxation zone 18).

[0103] Nevertheless, at least a portion of the cut portion C or the entire cut portion C may be configured as a cut portion C without being configured as a condensed portion D. Consequently, such a cut portion is configured without a compression zone and a relaxation zone.

[0104] Preferably, the cross-sectional profile of the drill bit core 11 along at least a portion of the overall cutting portion C is non-circular. Even more preferably, the profile is non-circular and includes a compression zone 17 and a relaxation zone 18. As a result, the profile is configured as a condensation portion D, whereby the drill bit 10 can exert a condensing effect on the bone tissue. Depending on the configuration of the non-circular profile, multiple compression and relaxation zones can be defined along the cross-sectional profile of the drill bit core 11.

[0105] The cross-sectional outline of the drill bit core 11 may be substantially circular if it is not configured as a condensation part D, in particular if it is not also configured as a cutting part C. The cross-sectional outline of a cutting part C not configured as a condensation part D should be understood as being substantially circular if cutting grooves 15 and / or guide threads 19 are present.

[0106] Along the cross-sectional contour of the cutting portion of the drill bit core 11, the cutting portion C preferably comprises at least one cutting zone 13 including a cutting point 14. The cutting zone 13 may be defined by a cutting groove 15 forming a concave recess in the contour of the cutting portion C. Thus, the cutting portion C may further comprise at least one cutting groove 15. The cutting groove 15 is preferably formed as a recess or groove in the drill bit core 11 and extends along the drill bit core 11. Furthermore, the cutting groove 15 may be straight, but preferably extends in a spiral around the drill bit core 11. In the latter case, it distributes the cutting force along the circumference of the drill bit 10 and facilitates guidance during insertion.

[0107] Preferably, the cutting zone 13 including the cutting point 14 is located in a compression zone 17 of the contour 4 of the cutting section C, which is also configured as the condensation section D. In this case, the contour of the compression zone 17 is interrupted by the cutting zone 13.

[0108] At least one break point 14 is located a second radial distance r2 from the longitudinal axis L in a cross-sectional view of the drill bit core 11 along the cut portion C. The outline 4 of the cross-section of the drill bit core 11 along the cut portion C may include two or three pairs of outermost points 12 and break points 14, each pair including an outermost point 12 and a break point 14.

[0109] The cut points 14 preferably represent discontinuities along the contour 4 of the cut portion C. Thus, the cut points include a clearance angle, a cut angle, and a rake angle.

[0110] The at least one cutting point 14 located at the second radial distance r2 enables cutting of bone tissue along a circle in the cross section having a radius of the second radial distance r2 from the longitudinal axis L. If the second radial distance r2 is less than a first radial distance r1 of the outermost point 12, which will be described in more detail below, then the drill bit 10 is not configured to cut bone tissue in an area having a radial distance greater than the second radial distance r2.

[0111] Thus, the second radial distance r2 may be less than the first radial distance r1 of the outermost point 12 in the cross section of the drill bit core 11 in at least a portion of the cutting portion C along the longitudinal axis L, i.e., at least a portion of the cross section along the longitudinal axis L. In other words, the drill bit 10 and the cutting portion C may include a portion along the longitudinal axis L that has a negative clearance angle α.

[0112] Alternatively, the first radial distance r1 and the second radial distance r2 may also be substantially equal within the cross section of the drill bit core 11 at least a portion of the cut portion C along the longitudinal axis L. In other words, the outermost point 12 and the cut point 14 may be substantially coincident. In this case, the drill bit 10 and the cut portion C may include a portion along the longitudinal axis where the cut point 14 has a positive clearance angle α.

[0113] Preferably, the ratio of the first radial distance r1 of the outermost point 12 to the second radial distance r2 of the cut point 14 varies from cross-section of the drill bit core 11 along the cut portion C.

[0114] In one embodiment where the second radial distance r2 is less than the first radial distance r1, the drill bit 10 and cutting portion C include a non-cutting zone 22 where the drill bit 10 is not configured to cut bone (see cross section (c) in FIG. 1). The non-cutting zone 22 is preferably part of the compression zone 17.

[0115] The radial extension of the non-cutting zone 22 defines a ring-shaped region between the second radial distance r2 and the first radial distance r1. Within this non-cutting portion 22, the drill bit 10 is configured to alternately compress the bone tissue or allow relaxation of the bone tissue, i.e., to apply a force to the bone tissue within the radial distance without cutting the bone tissue. As described above, in the compression zone 17, the bone tissue adjacent the compression zone is pushed radially outward upon rotation of the drill bit 10 in a given rotational direction, while in the relaxation zone 18, the bone tissue is allowed to recover in a radially inward direction.

[0116] Without wishing to be bound by theory, the drill bit 10 takes advantage of the observation that bone tissue having a greater density relaxes, i.e., moves radially inward, faster than bone tissue having a lower density. After compressing the bone tissue in a radially outward direction in the compression zone 17, the compressed bone tissue recovers (i.e., moves) radially inward in the relaxation zone 18. Due to the difference in recovery time, the drill bit 10 tends to cut through the bone tissue having a greater density (e.g., cortical bone tissue).

[0117] The time allowed for recovery depends on the circumferential position of the cutting point 14 and the outermost point 12 (as well as the rotation rate or speed of the drill bit 10) and thus the position of the compression zone 17 and the relaxation zone 18 along the cross-sectional outline 4 of the drill bit core 11 relative to the cutting point 14. Bone tissue that recovers to a radial distance less than the second radial distance r2 within a given allowed recovery time will be cut at the next cutting point 14 passed, while bone tissue that recovers to a point between the second radial distance r2 and the first radial distance r1 will not be cut at the next cutting point 14 passed. Thus, the cutting points 14 can cut bone tissue to different degrees, i.e., cut bone tissue to a higher degree than cartilage tissue. This effect can be adjusted by the geometry of the drill bit core 10, i.e., the magnitude of the first and second radial distances r1 and r2, as well as its circumferential position.

[0118] When the second radial distance r2 is substantially equal to the first radial distance r1, the drill bit 10 and the cutting portion C have a cutting behavior different from the above-mentioned cutting behavior. Since the cutting point 14 and the outermost point 12 are substantially coincident, the cutting point 14 is located at the most radially outer position. In other words, all other points on the outline of the cross section of the drill bit core 11 are located more radially inward than the cutting point 14. Thus, the drill bit 10 is not configured to compress bone tissue or allow bone tissue relaxation, but instead cuts bone tissue within a circular area spanned by the first radial distance r1 or the second radial distance r2.

[0119] This is structurally shown in cross sections (d) and (e) of Figure 1. In cross section (d), the theoretical outermost point 12' of the basic profile 4 of the drill bit core 11 (i.e. the profile without taking into account the guide threads 19 and / or cutting grooves 15) and the outermost point 12 of the profile 3 of the drill bit coincide with the cutting point 14 of the profile 3 of the drill bit.

[0120] It should be noted that the determination of the outermost point 12 of the drill bit profile 3 does not take into account the guide threads 19, if present (see cross sections (c)-(e) of FIG. 1). Furthermore, even if a cross section perpendicular to the longitudinal axis along the cut portion C generally includes a given number of compression zones 17, relaxation zones 18, cut zones 13, non-cut zones 22, outermost points 12, and / or cut points 14, a particular cross section may not include all of these features due to the influence of other structural features of the drill bit 10, in particular the guide threads 19 (see cross section (c) of FIG. 1, which is missing a portion of one relaxation zone and one compression zone due to the guide threads 19).

[0121] Thus, the profile is not configured to include a compression zone 17 and a relaxation zone 18. Along the portion of the profile where the compression zone 17 would be located, there is instead a recess formed by the cutting groove 15. In other words, instead of the compression zone 17, the cutting zone 13 is disposed along the profile of the drill bit 10.

[0122] With reference to cross section (e) of FIG. 1, the theoretical outermost point 12' of the basic contour line 4 of the drill bit core 11 is located along the cutting zone 13 where the cutting groove 15 is formed along the contour line 3 of the drill bit 10. Thus, the theoretical outermost point 12' does not coincide with the outermost point 12 of the contour line 3 of the drill bit. However, in this case, the outermost point 12 also coincides with the cutting point 14. Similarly, cross section (e) does not include the compression zone 17 or the relaxation zone 18. Although the part of the contour line coincides with the relaxation zone 18 in structure, the part of the contour line does not coincide in terms of its functional configuration. In other words, the contour line 3 lacks the compression zone 17 having the function of compressing bone tissue, so that there cannot be a relaxation zone 18 that allows the relaxation of bone tissue previously compressed by the compression zone 17 of the drill bit 10.

[0123] Those skilled in the art will appreciate from the above description that the cutting behavior of the drill bit 10 changes with the change in the ratio of the first radial distance r1 to the second radial distance r2. Thus, it is possible to adjust the cutting behavior of the drill bit 10 along the longitudinal axis L, particularly taking into account different depth regions of the bone tissue.

[0124] Preferably, the cut portion C includes a first portion C1 along the longitudinal axis L, where the second radial distance r2 of the cut point 14 is smaller than the first radial distance r1 of the outermost point 12. In this first portion C1, the cut portion C may include a negative relief angle α at the cut point 14. Furthermore, the first portion C1 of the cut portion C may also be configured as a condensation portion D. Thus, the cross-sectional profile of the first portion C1 of the cut portion C preferably includes at least one compression zone 17 and at least one relaxation zone 18.

[0125] The cutting portion C may further include a second portion C2. In the second portion C2 of the cutting portion C, the second radial distance r2 may be substantially equal to the first radial distance r1. The second portion C2 of the cutting portion C may further include a cutting point 14 having a positive clearance angle α. The second portion C2 of the cutting portion C may not form a condensation portion D of the drill bit 10. Thus, the second portion C2 of the cutting portion C preferably does not include a compression zone 17 or a relaxation zone 18. Preferably, the first portion C1 of the cutting portion C is positioned apically of the second portion C2 of the cutting portion.

[0126] Due to the difference in the ratio of the first radial distance r1 to the second radial distance r2 between the first portion C1 and the second portion C2 of the cutting portion C, the cutting behaviors of these portions are different from each other.

[0127] In particular, the contour of the first portion C1 of the cutting portion C is configured to compress the bone tissue in the compression zone 17, allow relaxation of the bone tissue in the relaxation zone 18, and then cut the bone tissue at the cutting point 14 of the cutting zone 13 upon rotation of the drill bit. As a result, the amount of bone tissue that is cut upon rotation depends on the relaxation properties of the bone tissue, i.e., how much and how quickly the bone tissue relaxes after being compressed.

[0128] Without wishing to be bound by theory, the inventors have observed that less cancellous bone, which has a relatively low bone density, is cut away, thus leaving more cartilage tissue to support the dental implant to be inserted.

[0129] The second portion C2 of the cutting portion C is not configured to compress bone tissue when rotated, but instead cuts the bone tissue at an outermost point 12 that coincides with the cutting point 14.

[0130] Without wishing to be bound by theory, this feature is advantageous in cortical bones having a relatively high bone density, where the effects of further condensation of bone tissue are less. Thus, the second portion preferably avoids bone resorption and thus creates a bone recess in the cortical region of the bone tissue having a size that substantially matches the size of the dental implant 50 for faster ingrowth of the dental implant 50.

[0131] For a given method of rotation of the drill bit 10, the cutting point 14 along the first portion C1 may be located along the outline of the cross section of the drill bit such that, upon rotation, the cutting point 14 passes through a bone tissue location before or at the same time as the outermost point 12. After the relative positions of the outermost point 12 and the cutting point 14 change along the outline such that they coincide with one another, the theoretical outermost point 12' may continue to change its relative position to pass through a bone tissue location in front of the cutting point. This results in a continuous change in the clearance angle α from a negative clearance angle to a positive clearance angle.

[0132] As mentioned above, the geometry of the drill bit 10, and in particular the magnitude of the first and second radial distances r1 and r2 and their circumferential positions, define the cutting behavior of the drill bit 10.

[0133] In the case of a change in the cutting behavior, the outermost points 12 of the cross-section of the drill bit core 11 along the longitudinal axis L may lie along a helical line with a second pitch around the longitudinal axis L. Alternatively, these outermost points 12 of the cross-section may lie along a substantially straight line, preferably arranged parallel to the longitudinal axis L.

[0134] As mentioned above, the cutting grooves may extend helically around the drill bit 10. Thus, the cutting points 14 also extend helically around the drill bit 10 at a first pitch. The first pitch may be the same pitch as the second pitch of the outermost points 12 or may be different from the second pitch of the outermost points 12. In particular, the first pitch may be smaller than the second pitch.

[0135] Preferably, the first pitch of the cut points 14 and the second pitch of the outermost points 12 are different from each other. In particular, the first pitch is smaller than the second pitch. Alternatively, the first and second pitches may be substantially equal.

[0136] In one embodiment where the first pitch and the second pitch are different from one another, the relative circumferential positions of the outermost point 12 and the cutting point 14 vary along the longitudinal axis L of the cutting portion C of the drill bit 10. Thus, it is possible to continuously adjust the cutting behavior of the drill bit 10 along the longitudinal axis L to different regions of the bone.

[0137] The drill bit 10 may further include a non-cutting portion N extending along the longitudinal axis L of the drill bit 10. At the non-cutting portion N, the drill bit 10 does not include a cutting point 14 or a cutting zone 13. In other words, the drill bit 10 is not configured to cut bone tissue within this non-cutting portion N.

[0138] Preferably, the non-cut portion N is located apically to the cut portion C.

[0139] The non-cut portion N may at least partially overlap with the condensed portion D of the drill bit 10. Thus, the non-cut portion N may be at least partially configured as the condensed portion D of the drill bit 10. Thus, the cross-sectional profile of the drill bit core 11 along the non-cut portion N may include at least one compression zone 17 and at least one relaxation zone 18.

[0140] Thereby, it is possible to exert a condensing effect on the bone tissue along the uncut portion. Depending on the shape of the non-circular profile, the profile may further be configured to include a plurality of compression zones 17 and relaxation zones 18, as already mentioned above.

[0141] If the non-cutting portion N is located apical to the cutting portion C, it is possible to exert a condensing effect on the bone tissue before cutting it, whereby the bone tissue may already be compressed before the bone tissue is first cut, which on the one hand enhances the guidance of the drill bit 10 into the bone tissue due to the absence of cutting forces and pre-condenses the bone tissue.

[0142] Thus, the cross-sectional outline of the drill bit core 11 along at least a portion of the uncut portion N along the longitudinal axis L or along the entire uncut portion N may be non-circular.

[0143] The non-cut portion N may also include a cross-section along at least a portion or the entirety of the cross-section having a substantially circular outline. The non-cut portion N may further include a substantially circular guide portion 16. In this case, the cross-sectional outline of the drill bit core 11 along the guide portion 16 is substantially circular.

[0144] Preferably, the guide portion 16 is located apical to the cutting portion C, and more preferably, apical to a portion of the non-cutting portion N that includes a non-circular profile in a cross-section of the drill bit core 11 perpendicular to the longitudinal axis L. In other words, the guide portion 16 may be the most apical portion of the drill bit 10.

[0145] The guide portion 16 may also be formed as or include a conical guide tip (not shown) at the apical end of the drill bit 10. Alternatively, the drill bit 10 may not include a guide portion 16.

[0146] If the drill bit 10 has an apical portion that is not configured to cut bone tissue, then a pilot hole is preferably drilled using a pilot drill prior to preparing the bone recess using the drill bit 10. Particularly here, the guide portion 16 enhances alignment of the drill bit 10 with the pilot hole and facilitates insertion of the drill bit 10.

[0147] As already mentioned above, the drill bit 10 may include a condensation portion D extending along a portion of the drill bit core 11. The condensation portion D may at least partially overlap with the non-cut portion N and / or the cut portion C. In a preferred embodiment, the condensation portion D at least partially overlaps with a first portion C1 of the cut portion C. Even more preferably, the condensation portion D at least partially overlaps with the non-cut portion N that includes a non-circular outline.

[0148] The condensation portion D is configured to induce cycles of compression and relaxation of bone tissue upon rotation of the drill bit 10 used to prepare a bone cavity for implant treatment.

[0149] Condensation portion D may not be included in the apical portion of the drill bit 10, i.e., condensation portion D may not be present within the leading portion 16 of the non-cutting portion N and / or within the coronal portion of the drill bit core 11. Preferably, condensation portion D is not present along the second portion C2 of the cutting portion C. Instead, condensation portion D may extend along the entire drill bit core 11.

[0150] As mentioned above, the cross-sectional profile of the drill bit core 11 along the condensed portion D preferably includes at least one compression zone 17 and at least one relaxation zone 18. In the condensed portion D, the cross-sectional profile of the drill bit core 11 may not be non-circular. Furthermore, the break points 14 may or may not be present in at least a portion of the condensed portion D. When at least a portion of the condensed portion D includes the break points 14, the first radial distance r1 of the outermost points 12 is preferably greater than the second radial distance r2 of the break points 14.

[0151] 2 shows a bone recess prepared by a drill bit 10 according to the present disclosure, two different lengths of a dental implant 50, and the relationship of the dental implant 50 to be inserted into the recess. The dental implant 50 includes an external thread 51 that secures the dental implant within the surrounding bone tissue.

[0152] 2, the drill bit 10 preferably has at its coronal end portion (i.e., in the coronal region of the bone tissue) substantially the same size as the dental implant 50. In other words, the coronal end portion at the coronal end 2 of the drill bit 10 may have substantially the same size as the outer diameter of the corresponding portion of the dental implant 50.

[0153] These dimensions of the drill bit 10 for the dental implant are configured to allow for an adequate seal at the opening of the prepared recess in the bone tissue and minimize or reduce distortion of the cortical bone portion that would cause bone resorption, which positively impacts healing times and serves as a basis for enhancing bone ingrowth into the dental implant 50 in this area.

[0154] As also shown in FIG. 2, the drill bit 10 may be reduced in size relative to the dental implant 50. More specifically, the relative size of the cross section of the drill bit along the longitudinal direction in the coronal-apical direction is smaller. That is, on the apical side, the drill bit 10 may include a maximum extension perpendicular to the longitudinal axis that is less than 30%, less than 40%, less than 50%, less than 60%, or less than 70% of the outer diameter of the dental implant 50. Preferably, this relationship in size between the drill bit 10 and the dental implant 50 extends along 40%, 50%, or 60% of the length of the drill bit 10 and / or dental implant 50, starting from the apical end 1 towards the coronal end 2.

[0155] The larger the outer diameter of the dental implant 50 in the cancellous bone portion compared to the size of the drill bit 10, the greater the initial stability of the dental implant 50 in the bone cavity, which promotes fixation of the dental implant 50 by providing a base for bone ingrowth.

[0156] 3 is a perspective view showing the relationship between the pilot drill 30, the drill bit 10, and the dental implant 50. More specifically, FIG. 3 shows the overlap of the pilot drill 30, the drill bit 10, and the dental implant 50 as they are inserted into bone tissue, and thus an exemplary procedure for preparing a bone cavity for the dental implant 50.

[0157] The pilot drill 30 may be used in a first step to drill a pilot hole in the bone having a diameter generally smaller than the corresponding size of the drill bit 10. However, the guide portion 16 of the drill bit 10 may have a diameter that is equal to or less than the diameter of the pilot drill. The pilot hole created by the pilot drill 30 serves as a guide hole for subsequent steps.

[0158] The exemplary drill bit 10 shown in FIG. 3 includes a non-cutting portion N at its apical end 1 such that the guide portion 16 in combination with the guide threads 19 in the drill bit 10 or the non-cutting portion N of the drill bit 10 guides the drill bit in a previously drilled pilot hole.

[0159] The drill bit 10 may then be used to enlarge the pilot hole created by the pilot drill 30 to prepare the bone cavity for insertion of the dental implant 50. Thus, the drill bit 10 is inserted into the pilot hole and the guide threads 19 of the drill bit 10 preferably draw the drill bit 10 into the pilot hole at a predetermined speed that corresponds to the rotation of the drill bit 10. If present, the guide threads have the advantage of eliminating the need for a user to apply force to the drill bit 10 to move the drill bit 10 into the pilot hole.

[0160] After preparation of the bone cavity, the dental implant 50 is inserted.

[0161] The drill bit 10 according to the present disclosure allows the drilling protocol to be reduced to a minimum of three steps, thus avoiding the sequential use of multiple different tools and complex drilling protocols, and making it easier to prevent misalignment of the tools used in sequence. [Explanation of symbols]

[0162] 1 Apical end 2 coronal end 3 Drill bit outline 4 Basic outline of drill bit core 5 Connecting part 10 Drill Bits 11 Drill bit core 12 Outermost point 12' Theoretical outermost point 13 Cutting Zone 14 Cutting point 15 Cutting groove 16 Induction part 17 Compression Zone 18 Relaxation Zone 19 Guide Thread 21 Innermost point 22 Non-cut zone 30 Pilot Drill 50 Dental Implants 51 External Thread C Cut section C1 First part of the cut C2 Second part of the cut D Condensation part E Stretched part L Longitudinal axis N Uncut part r1 First radial distance r2 Second radial distance r3 Minimum radial distance α Clearance angle

Claims

1. an apical end (1), a coronal end (2), and a longitudinal axis (L) extending between said apical end and said coronal end; a drill bit core (11); a cutting portion (C) extending at least partially along the drill bit core; A drill bit (10) comprising: a cross-sectional outline of the cut portion perpendicular to the longitudinal axis comprises at least one outermost point (12) at a first radial distance (r1) from the longitudinal axis and at least one cut point (14) at a second radial distance (r2) from the longitudinal axis; along a first portion of the cut, the second radial distance is less than the first radial distance, and along a second portion of the cut, the second radial distance is substantially equal to the first radial distance; Drill bit (10).

2. The drill bit (10) of claim 1, wherein the first portion of the cutting portion (C) is positioned apically of the second portion of the cutting portion.

3. 3. The drill bit (10) of claim 1 or 2, wherein the drill bit further comprises a non-cutting portion (N) extending along the drill bit core (11), and along the non-cutting portion, a cross-sectional outline of the drill bit core perpendicular to the longitudinal axis (L) comprises at least one outermost point (12) at a first radial distance (r1) from the longitudinal axis (L).

4. The drill bit (10) of claim 3, wherein the non-cutting portion (N) is positioned apically of the cutting portion (C).

5. an apical end (1), a coronal end (2), and a longitudinal axis (L) extending between said apical end and said coronal end; a drill bit core (11); A cut portion (C); a non-cutting portion (N), wherein the cutting portion and the non-cutting portion extend along the drill bit core; A drill bit (10) comprising: Along the cut and uncut portions, a cross-sectional outline of the drill bit core perpendicular to the longitudinal axis comprises at least one outermost point (12) at a first radial distance (r1) from the longitudinal axis, and the outline of the cut portion further comprises at least one cut point (14) at a second radial distance (r2) from the longitudinal axis; the non-cutting portion is positioned apically of the cutting portion; Drill bit (10).

6. 6. The drill bit (10) of claim 5, wherein the cutting portion (C) includes at least a portion along the longitudinal axis where the second radial distance (r2) is less than the first radial distance (r1).

7. The drill bit (10) according to claim 5 or 6, wherein the non-cutting portion (N) of the drill bit core (11) comprises a compression zone and a relaxation zone.

8. 7. The drill bit (10) according to claim 5 or 6, wherein the outline of a cross section taken along the uncut portion (N) of the drill bit core (11) and perpendicular to the longitudinal axis (L) is non-circular.

9. The drill bit (10) according to claim 1 or 2, wherein the cutting portion (C) of the drill bit core (11) comprises a compression zone (17) and a relaxation zone (18).

10. The drill bit (10) of claim 9, wherein the cutting point (14) is positioned within the compression zone.

11. 3. The drill bit (10) according to claim 1 or 2, wherein the outline of a cross section taken along the cutting portion (C) of the drill bit core (11) and perpendicular to the longitudinal axis (L) is non-circular.

12. 3. The drill bit (10) according to claim 1 or 2, wherein the drill bit core extending from the apical end (1) to the coronal end (2) further comprises a guide portion (16), the cross section of which perpendicular to the longitudinal axis (L) is preferably circular.

13. 3. The drill bit (10) of claim 1 or 2, wherein the cross section of the drill bit core (11) perpendicular to the longitudinal axis (L) has two or three pairs of outermost points (12) and cutting points (14), each pair comprising an outermost point and a cutting point.

14. 3. The drill bit (10) of claim 1 or 2, wherein, for a given rotational direction of the drill bit, the position of the cutting point (14) changes in an apical-coronal direction from a position in front of the outermost point (12) to a position after the outermost point.

15. 3. The drill bit (10) according to claim 1 or 2, wherein the ratio of the first radial distance (r1) to the second radial distance (r2) between the cross sections of the cutting portion (C) along the longitudinal axis (L) varies.

16. The drill bit (10) according to claim 1 or 2, wherein the cutting portion (C) comprises at least one cutting groove (15).

17. 17. The drill bit (10) of claim 16, wherein the at least one cutting groove (15) extends spirally around the drill bit core (11) at a first pitch.

18. 18. The drill bit (10) of claim 17, wherein along the longitudinal axis (L) the outermost points (12) of the cross-section lie along a helical line having a second pitch, the first pitch and the second pitch being different from each other and preferably smaller than the second pitch.

19. 3. The drill bit (10) according to claim 1 or 2, wherein the drill bit further comprises at least one guide thread (19) formed helically around the drill bit core (11), preferably formed as a single thread.

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