Dental implants

Abstract

The present disclosure relates to a dental implant including a core body having an apical end, a coronal end, and an outer surface. The core body extends along a longitudinal axis between the apical end and the coronal end. The dental implant further includes a first thread extending from the outer surface of the core body, the first thread being formed at least partially along the core body. The first thread includes an apical thread end, a coronal thread end, and a front surface at the apical thread end. The front surface includes at least one cutting edge.

Description

[Technical field]

[0001] The present disclosure relates to dental implants for insertion into bone tissue. [Background technology]

[0002] Dental implants are used as artificial roots for tooth restoration, i.e. they provide anchorage for artificial teeth in the maxilla or mandible of a patient. It is known that proper anchoring of dental implants to bone is crucial not only for the stability of the implant, but also for the osseointegration of the implant and thus for the long-term success of the tooth restoration.

[0003] During implant surgery, the dentist typically uses a drill to create a recess in the bone tissue and then inserts the dental implant into the previously prepared recess. To insert the dental implant into the bone tissue, the dental implant typically includes a screw thread formed on the outer surface of the dental implant, which thread screws the dental implant into the bone.

[0004] The dental implant may further comprise a cutting flute formed in an apical portion of the implant and having a cutting edge for cutting into bone tissue. Such cutting flute intersects a number of turns of the thread, where the thread forms a part of the cutting edge. During the process of inserting the implant, rotation of the implant causes the cutting edge to cut into the bone tissue.

[0005] Bone conditions, such as density, orientation, and quality, vary from patient to patient. Thus, dentists may be faced with relatively high or relatively low bone density depending on the patient they are treating. Furthermore, the condition of the teeth also influences the treatment. For example, partially or completely edentulous patients may experience a significant reduction in bone height, which may result in the need for short implants, i.e. implants with a relatively short longitudinal length. Particularly for such implants, stable fixation is essential for the success of the treatment.

[0006] In cases where the bone is dense or when short implants are used, dental implants with standard cutting flutes tend to wobble during insertion, in other words are difficult to align and insert into the prepared bone recess. Moreover, known implants have been shown to deviate from the desired insertion path. Furthermore, during the insertion of the dental implant into the bone recess, there is a risk of overtightening the dental implant, which means that the insertion torque decreases rapidly and the dental implant exhibits a rotational degree of freedom (around the longitudinal axis) in the final position, a so-called free-running implant. Such effects make the installation of these implants more difficult, even when the bone recess is previously prepared. Summary of the Invention

[0007] In view of the above, there remains a need for a dental implant that enhances the stability of the implant during and after insertion. It is therefore an object of the present invention to provide a dental implant that specifically addresses the above-mentioned adverse effects observed.

[0008] To this end, the present disclosure provides a dental implant according to the subject matter of the independent claims, the dependent claims defining preferred embodiments.

[0009] The present disclosure provides a dental implant including a core body having an apical end, a coronal end, and an outer surface, the core body extending along a longitudinal axis between the apical end and the coronal end. The dental implant also includes at least one thread, also referred to as a first thread, extending from the outer surface of the core body and formed at least partially along the core body. The first thread includes an apical thread end, a coronal thread end, and a front face at the apical thread end. At the apical thread end, the front face may extend, preferably radially, between the apical flank of the first thread and the coronal flank of the first thread. The front face forms or constitutes at least one cutting edge.

[0010] The core body may have a substantially cylindrical, conical or frustoconical shape along the longitudinal axis. It is also possible for the core body to have a different shape along the longitudinal axis, for example the crown portion of the core body is cylindrical and the apical portion of the core body has a tapered, conical or frustoconical shape. The cross-sectional profile of the core body perpendicular to the longitudinal axis may preferably be substantially circular, more preferably substantially circular or elliptical. It is particularly preferred that the cross-sectional profile of the apical portion of the core body is substantially circular or elliptical. Nevertheless, the cross-sectional profile of the core body, in particular the cross-sectional profile of the apical portion of the core body, may include at least one straight line portion. The term substantially is therefore used since the profile may include at least one straight line portion (due to grooves or flutes as further described below) that causes the profile to deviate from an exact circle or circular shape.

[0011] The core body may have a cross-section along the longitudinal axis, the cross-section being perpendicular to the longitudinal axis, with the apical end having a substantially round, preferably substantially circular, cross-section.

[0012] The substantially round or substantially circular contour of the apical portion, especially the apical end portion, of the core body facilitates the guiding and centering effect of the implant. In other words, the substantially round or circular contour has substantially no edges protruding in a direction perpendicular to the longitudinal axis, so that the apical portion or end portion of the core body can achieve centering or guiding in the bone recess. Furthermore, the insertability of the implant into the bone recess is improved. Moreover, the substantially round or circular contour further avoids excessive compression of the bone.

[0013] The apical end of the core body is preferably formed as a rounded tip.

[0014] By rounded tip is meant that the edge connecting the apex surface of the core body to the outer surface of the core body is substantially rounded. In other words, there is preferably no discontinuity between the apex surface of the core body and the outer surface. The apex of the core body may also be formed substantially spherically.

[0015] This further improves the insertability of the dental implant into the bone recess.

[0016] The first thread of the dental implant extends or protrudes from the outer surface of the core body, i.e., protrudes outward from the core body in a direction substantially perpendicular to the longitudinal axis (i.e., radially). Thus, the outer surface of the core body forms the root of the first thread.

[0017] Furthermore, the first thread is formed at least partially along the core body, which means that the first thread does not have to be present along the entire length of the core body, but may nevertheless extend along the entire length of the core body.

[0018] The first thread is preferably formed helically around the core body. Moreover, the first thread may be formed with a coronal flank, an outer flank and an apical flank, the outer flank connecting the coronal flank and the apical flank. However, the first thread may be formed such that the coronal flank and the apical flank cross each other. In this case, the outer flank is substantially absent or at least linearly reduced. It is also possible that the flanks of the first thread may be formed differently along the longitudinal axis. For example, in the apical part of the first thread, the coronal flank and the apical flank may be more angled with respect to each other and / or in the coronal part of the first thread, the radial outer flank may be smaller.

[0019] The first thread may be formed as a single thread, which means that a single thread path is formed from the coronal thread end to the apical thread end. It is further possible for the first thread to be formed as a multiple thread, preferably as a double thread. In this case, multiple thread paths, preferably two thread paths, of the first thread are formed from the coronal thread end to the apical thread end. Thus, at the apical thread end, such a multiple first thread includes multiple front faces, preferably two front faces. The multiple front faces are preferably arranged at equal intervals from each other along the circumference of the core body.

[0020] The angle of the front surface of the first thread relative to the outer surface of the core body may be in the range of 75° to 105°, 80° to 100°, 85° to 95°, or 87° to 93°, and preferably is substantially 90°. The angle is measured at the cross-sectional profile between a line formed by the front surface and a line tangent to the outer surface of the core body at the intersection of the front surface line and the outer surface line of the core body.

[0021] At least one cutting edge on the front face is for cutting bone tissue. The cutting edge extends along the periphery of the front face. The front face may be composed of (exactly) three cutting edges, for example, on the coronal flank, the apical flank and the lateral flank of the first threaded portion, the lateral flank connecting the coronal flank and the apical flank. Alternatively, the front face may be composed of (exactly) two or (exactly) one cutting edge. In the case of an embodiment with a first thread in the form of a multiple thread, each front face may be composed of at least one cutting edge.

[0022] According to the present disclosure, the first thread has a front surface at the apical thread end. The front surface of the first thread at the apical thread end forms a cutting edge that defines the thread height at the front surface. In other words, the apical thread end does not continuously approach the outer surface of the core body, but is discontinuous. In particular, the first thread is not formed with a typical thread runout at its apical end, i.e., a portion where the height of the first thread relative to the core body of the dental implant decreases continuously to zero over at least 1 / 4 turn of the thread. Those skilled in the art will understand that the reduction in the height of the first thread resulting from a front surface that is angled relative to the core body is not understood as a typical thread runout in the present context.

[0023] This creates a cutting edge that cuts into the bone tissue immediately at a predetermined height when the dental implant is inserted. This makes it easier to fix the dental implant in the bone tissue compared to threads formed with a typical thread runout. More specifically, the thread path of the first thread cuts into the bone tissue at a predetermined height, which also makes it easier for the bone tissue to be satisfactorily seated during the turns of the first thread. Furthermore, the cutting by the front face with a predetermined height also limits the compression of the bone that would otherwise be exerted by the first thread.

[0024] The front surface of the first thread at the apical thread end further reduces the risk of the implant spinning. In other words, it has surprisingly been shown that dental implants with such a front surface are less prone to spinning, i.e. undesirable rotational movement around the longitudinal axis in the final position in the bone recess. This is believed to be facilitated by the more aggressive cutting edge cutting with a relatively large height in the bone tissue, and therefore better fixed (especially in the rotational direction) in the bone recess.

[0025] The front face of the first thread at the apical thread end further provides the following advantageous effect: the dental implant may shift out of position near the final insertion position due to bone fragments or changes in bone density. This may cause the implant to shift out of its intended insertion path due to a shift in the center of rotation, leading to a risk of the dental implant's seating being displaced in the bone recess. Without wishing to be bound by theory, the cutting action of the front face more easily bites into such bone tissue portions, thus preventing the implant from shifting out of position in an undesired direction.

[0026] In particular, in embodiments of dental implants that include two or more, i.e., multiple front surfaces and, consequently, multiple cutting edges, the risk of incorrect insertion of the dental implant into a bone recess that may result from a single cutting edge protruding outward from the core body is reduced.

[0027] The dental implant core body may further include a first portion and a second portion, the first portion and the second portion extending along a longitudinal axis, the second portion being apical to the first portion, and the first thread extending at least partially along the first portion.

[0028] Preferably, the second portion extends from the apical end toward the coronal end.

[0029] As described above with respect to the core body, the first and / or second portions of the core body may have a substantially cylindrical and / or tapered shape. Preferably, the first and / or second portions are substantially tapered, conical or frusto-conical in shape. The first and second portions may have different outer shapes. For example, the first portion may be cylindrical while the second portion is tapered. In another example, both the first and second portions may be tapered. The taper angle measured from the longitudinal axis to the outer surface of the second portion may be greater than, equal to or less than the taper angle of the first portion.

[0030] It is also possible for the first and second portions to have similar or substantially the same outer profile, preferably cylindrical or tapered.

[0031] Preferably, the apical thread end is located within the first portion.

[0032] The first thread, particularly the apical thread end of the first thread, is preferably formed at a predetermined distance from the apical end of the core body. If a second portion is present, the first thread preferably does not extend into the second portion. However, as will be further described below, the first thread may be adjacent to the second thread of the second portion.

[0033] This configuration allows the dental implant to be inserted before the implant threads come into contact with the bone tissue, especially after formation of the bone recess (e.g., the so-called pilot hole). The apical portion of such a first unthreaded dental implant can be inserted into the bone recess without any rotational movement of the implant.

[0034] During insertion of the implant, the apical part of the dental implant inserted into the bone recess may advantageously achieve a guiding and centering effect until the first thread contacts the bone tissue, thereby facilitating the insertion of the dental implant and in particular reducing the risk of the dental implant becoming loose during insertion.

[0035] Furthermore, the absence of a first thread at the apical portion of the dental implant has the effect that a predetermined insertion torque is less likely to be exceeded, while the second portion already provides guidance during insertion and a surface for providing stability, in particular a surface for bone growth after implantation (secondary stability).

[0036] The centering and guiding effect can be further adapted by a predefined distance from the apical end of the core body, at which the first thread, in particular the apical thread end of the first thread, is formed, or, for example in dental situations where good guiding and centering of the implant is of primary importance, by a longitudinal and lateral extension of the second part. Furthermore, it is possible to form dental implants with substantially similar first thread designs, even for dental implants of different lengths, i.e. such dental implants may differ only in the design of the apical part of the implant that does not have the first thread.

[0037] The dental implant may further include a spiral groove extending at least partially along the core body.

[0038] The spiral groove is recessed inwardly from the outer surface of the core body and extends at least partially spirally along the core body. The dental implant may include a single or multiple, preferably two or three, spiral grooves.

[0039] The helical groove preferably forms the root of the second thread. In particular, a line connecting points along the helical groove that is recessed from the outer surface of the core body to the innermost side may form the root of the second thread. In the case of a helical groove, the outer surface of the core body preferably forms the outer diameter of the second thread. In other words, the second thread defined by the helical groove does not extend outward from the outer surface of the core body of the dental implant in a direction perpendicular to the longitudinal axis, but is instead recessed into this outer surface.

[0040] Adjacent turns of the helical groove preferably have the same pitch as the pitch of the first thread.

[0041] The second thread is preferably offset by half a pitch with respect to the first thread, or it may extend along the projected path of the first thread, i.e. along the theoretical path of the first thread if it were to continue beyond the apical thread end.

[0042] The second thread can be formed as a single thread or multiple threads, preferably two or three threads. This means that there may be one or multiple, preferably two, thread paths for the second thread along the core body, each thread path being formed by a separate helical groove. The number of second threads is preferably equal to the number of first threads (e.g., the first thread being a double thread results in the second thread being a double thread).

[0043] According to the present disclosure, the second thread and / or helical groove may extend at least partially along the second portion.

[0044] Thus, the second thread may be formed on the first portion, i.e. on the apical side of the first thread. However, the second thread may be formed to extend at least partially into the first portion. In contrast, the first thread may not extend apically beyond the first portion. However, it may extend (with its apical flank) to the boundary between the first and second portions.

[0045] Preferably, the second thread extends along the core body to an apical end of the core body, however, it is also possible for the core body to include an apical end where there is no second thread, i.e. where the second thread is located away from the apical end.

[0046] The second thread may support the insertion of the dental implant by drawing the implant into the bone recess upon contact with the bone tissue of the previously prepared bone recess, while at the same time allowing the apical part of the implant, i.e. the second part, to be inserted into the bone recess with or without rotation of the implant, still functioning as a guide and for centering before the first thread comes into contact with the bone tissue.

[0047] Furthermore, the second part with the second thread allows to displace and distribute bone fragments that may still remain in the bone recess from the procedure of preparing the bone recess. The distribution of bone fragments leads to improved and promoted osseointegration caused by biologically significant bone fragments that are collected from the bottom of the osteotomy and distributed coronally along the osteotomy. The axial distribution of bone fragments has the advantage of preventing an increased area of ​​compression due to accumulation of bone fragments at the apical end of the osteotomy. The radial distribution of bone fragments around the implant reduces the risk of the implant slipping in the final position or of the implant not being seated correctly in the bone tissue. Furthermore, the combination of the first and second threads leads to a bicortical fixation of the implant.

[0048] Preferably, the height of the first thread is greater than the height of the second thread.

[0049] The height of the first and second threads according to the present disclosure is measured from the root of the respective thread to the radially outer flank in a direction perpendicular to the outer surface of the core body.

[0050] The second thread preferably has a thread height smaller than the first thread height. This allows the apical portion of the implant to be partially inserted into the bone recess without rotating the implant for guiding and centering the implant. However, the second thread height still allows the implant to be drawn into the bone recess upon rotation in a softer manner than the first thread. This softer manner enhances the guiding of the implant towards the planned insertion path.

[0051] Preferably, the first thread is helically formed around the core body with a first pitch and the second thread is helically formed around the core body with a second pitch, the first pitch being substantially equal to the second pitch. The first and second pitches may be different, i.e. the first pitch may be greater or less than the second pitch.

[0052] The dental implant, in particular the core body, may further comprise cutting flutes, which may comprise at least one cutting edge. The at least one cutting edge of the front face of the first thread preferably forms part of the at least one cutting edge of the cutting flute.

[0053] A cutting flute in the context of this disclosure generally refers to a recessed or flat portion along the core body (e.g., longitudinally) of a dental implant to form an edge, i.e., a cutting edge, configured to cut bone tissue. The cutting flute may be formed along a substantially straight line, or may be formed along a curved or spiral line.

[0054] The cutting flutes facilitate the insertion of the dental implant into the bone tissue and contribute to achieving a desired insertion torque during the insertion of the implant, while at the same time, the cutting flutes can also limit the compaction of the bone tissue by cutting the bone tissue.

[0055] The cutting flutes are preferably of the shallow type (i.e. the depth of the recess or flat portion of the core body along the circumference of the core body is relatively small) so that the effectiveness of the front face of the first thread is not reduced and it is easy for the cross-sectional profile of the apical end portion, preferably the cross-sectional profile of the apical end of the core body, to remain substantially circular or elliptical.

[0056] Preferably, the cutting flutes extend along the first portion and the second portion, and more preferably, the cutting flutes extend from the apical end towards the coronal end and may extend beyond the second portion into the first portion.

[0057] This provides the dental implant with cutting capabilities starting from the second portion, i.e. the portion of the implant that first comes into contact with bone tissue during insertion of the implant.

[0058] The cutting flutes may intersect with 3 turns, preferably 2 turns, and most preferably 1 turn of the first thread.

[0059] In other words, 3 turns, 2 turns or 1 turn of the thread path of the first thread may be interrupted by the cutting flute. The interrupted thread turn thereby also forms a cutting edge that influences the cutting behavior of the cutting flute. Preferably, the first thread turn starts from the cutting flute. Thus, the first thread turn may only have a forward cutting ability without a backward cutting ability (i.e., uninterrupted). In other words, the first thread turn cuts the bone tissue only while the implant is screwed into the bone tissue, but has no cutting ability when rotating the implant in the reverse direction due to the absence of a cutting line. The latter may be performed temporarily during implant insertion, for example to reduce the torque if it exceeds a predetermined value.

[0060] As a result, it may be the case that the cutting flute does not interrupt any turns of the first thread, but the apical thread end having the front face of the first thread is positioned (directly) adjacent to the cutting flute (in other words, the cutting edge of the cutting flute is connected with the cutting edge of the first thread).

[0061] Thus, the first thread may have a front surface at its apical end and may be interrupted by a cutting flute. Nevertheless, if the first thread is not interrupted by a cutting flute and the front surface at the apical end of the first thread is located in the cutting flute, then at least the apical portion of the first thread is a continuous thread. This corresponds to the case where the cutting flute does not affect the apical portion of the first thread or where there is no cutting flute. In either case, the first thread has a (single) thread surface at its apical end.

[0062] The cutting flutes may further intersect the turns of the second thread, preferably all the turns of the second thread. The turns of the second thread preferably have forward cutting capability and / or backward cutting capability.

[0063] Thereby also, the second thread turn preferably forms a cutting edge that has a different cutting effect with respect to the interrupted turn of the first thread due to the limited thread height and pitch shift. Furthermore, the second thread may be equipped with forward and backward cutting capabilities, which may be advantageous for reducing torque during insertion of the implant.

[0064] The cutting ability of the second thread helps to limit the compression of bone tissue that would otherwise be caused by this portion of the implant. This also applies to the cutting ability of the first thread, and particularly aids in establishing secondary stability.

[0065] The first thread may define an outer radius, and the front surface is formed at a point along the longitudinal axis where the outer radius is at a minimum or minimum value.

[0066] The outer radius of the first thread refers to the distance between the outer flank of the first thread and the longitudinal axis in a direction perpendicular to the longitudinal axis. The first thread may be formed with a constant outer radius along the longitudinal axis, but is not limited thereto. The outer radius of the first thread may also be tapered in a direction from the coronal end to the apical end.

[0067] The first thread may increase in height in a direction from the coronal end to the apical end, in which case the first thread has the greatest height thereby forming a front surface.

[0068] The size of the outer radius and the thread height, as well as their variation along the first thread, makes it possible to predefine the compression of the bone tissue that occurs during insertion of the dental implant.

[0069] At least one cutting edge on the front face may have a positive or negative rake angle and / or may have a positive or negative clearance angle.

[0070] In a cross-section of the implant perpendicular to the longitudinal axis, the rake angle is the angle at the cutting edge defined between a line representing the front face and a line connecting the longitudinal axis and the cutting edge, i.e., the outermost point of the line representing the flank face. As a result, if the front face extends outward from the outer surface of the core body at an angle of 90° to the core body (i.e., the angle to the tangent at the point where the front face and the outer surface of the core body intersect), the rake angle is 0° (neutral rake angle). A positive (or negative) rake angle is formed when the cutting edge is located forward (or backward) or inclined from the intersection point of the front face and the core body in the cutting direction.

[0071] The rake angle affects the cutting behavior of the flank: a positive rake angle generally makes the cutting edge sharper and act more penetrating, whereas a negative rake angle makes the cutting edge act more blunt (i.e. the action of the cutting edge may shift in the direction of compression rather than cutting).

[0072] The clearance angle is also defined as the distance between the tangent to the outer flank of the actual thread (thread with decreasing, constant or increasing radius) and the tangent to the outer flank of the thread if one were to assume a thread with a constant radius, when measured at the outermost point of the line representing the front surface in a cross section of the implant perpendicular to the longitudinal axis.

[0073] Thus, a thread with a constant radius has a clearance angle of 0°, and a thread with a decreasing (increasing) radius in the coronal to apical direction has a negative (positive) clearance angle.

[0074] The clearance angle also influences the cutting behaviour of the flank: a positive clearance angle makes the cutting edge sharper and a negative clearance angle makes the cutting edge duller, with the effects already explained above. [Brief description of the drawings]

[0075] The following figures show embodiments of dental implants according to the present disclosure. These embodiments are not to be construed as limiting the scope of the claims, but are intended to enhance the understanding of the invention in conjunction with the following description. In these figures, the same reference numbers refer to features throughout the figures that have the same or equivalent functions and / or structures. It should be noted that repeated descriptions of these components are generally avoided for reasons of brevity.

[0076] [Figure 1] FIG. 1 is a perspective view of a dental implant according to the present disclosure. [Diagram 2] FIG. 2 is a perspective view of the apical portion of the dental implant shown in FIG. 1. [Diagram 3] FIG. 3 is a side view of the apical portion of the dental implant shown in FIG. 2. [Figure 4] FIG. 2 is an apical-coronal bottom view showing the apical side of the dental implant of the previous figure. [Diagram 5] 1 is a perspective view of an apical portion of another embodiment of a dental implant according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0077] Exemplary embodiments of dental implants according to the present disclosure will now be described in detail with reference to the accompanying drawings.

[0078] 1 and 2 are perspective views of a dental implant 1 according to the present disclosure. The dental implant 1 includes a core body 2 having an apical end 3 and a coronal end 4. The core body 2 extends along a longitudinal axis L between the apical end 3 and the coronal end 4. The core body 2 has an outer surface 5 that circumscribes the longitudinal axis L. This outer (circumferential) surface 5 generally defines the core body 2. Some of the other features of the dental implant described below are defined in relation to this core body 2 (e.g., threads, grooves).

[0079] At the coronal end 4, the dental implant 1 may comprise an engagement portion (not shown) configured for engagement with a further component of a dental replacement (eg an abutment, a dental restoration).

[0080] The outer shape of the core body 2 along the longitudinal axis L is not limited to a particular shape. As mentioned above, the core body 2 may be substantially cylindrical or tapered. In particular, the core body 2 may have a conical or frustoconical shape.

[0081] In some embodiments, the core body 2 may also include multiple, in particular two, portions along the longitudinal axis. Such portions of the core body 2 may have a substantially cylindrical or tapered, preferably conical or frustoconical, profile. Each portion of the core body 2 may have a different profile, or all portions may have substantially the same or similar profiles. For example, the crown portion of the core body 2 may be substantially cylindrically formed, and the apical portion of the core body 2 may be tapered. However, other combinations of the above-mentioned shapes are also possible. In another example, the core body 2 may be tapered with different taper angles along the longitudinal axis, i.e., the crown portion of the core body 2 may have a lower taper angle than the apical portion of the core body 2 (or vice versa). It is also possible that the crown portion and the apical portion have the same taper angle.

[0082] In a preferred embodiment, the core body 2 may include a first portion 10 and a second portion 11 extending along the longitudinal axis L. Preferably, the second portion 11 is located apical to the first portion 10. In particular, the second portion 11 may extend from the apical end 3 towards the coronal end 4 of the core body 2. The first portion 10 and / or the second portion 11 may comprise a continuous contour or a combination of contours as described above.

[0083] The core body 2 may further include a cross-section along the longitudinal axis L. The cross-section referred to is generally a cross-section perpendicular to the longitudinal axis L. The cross-sectional profile 25 of the core body 2 is not limited to a particular shape. Preferably, the cross-section of the apical end 3 of the core body 2 includes a substantially round or substantially circular profile 25 (as shown in FIG. 4 ).

[0084] The term "substantially" is used because there may be additional features, such as grooves or flutes, described in more detail below, that cause the cross-sectional contour 25 of the core body 2 to deviate from a strictly round or circular contour 25 (e.g., including at least one straight portion), particularly at the apex portion of the core body 2.

[0085] The substantially round or substantially circular shaped cross-sectional contour of the apical end 3 of the core body 2 facilitates insertion of the dental implant 1 into the bone recess. Furthermore, the substantially round or circular contour of the apical end 3 facilitates centering of the implant during insertion.

[0086] As best shown in Fig. 5, the apical end 3 of the dental implant 1 may also be formed as a rounded tip 12. This means that the edge or edges between the face of the core body 2 at the apical end 3 and the outer surface 5 of the dental implant 1 are substantially rounded and / or chamfered. It is also possible for the apical end 3 to be formed spherically. In any case, the skilled person will understand that the threads 6, 16 extending to such substantially rounded and / or chamfered edges will follow this shape in this region.

[0087] These edges of the dental implant 1 at the apical end 3 are first inserted into bone tissue or into a pre-prepared bone recess, such as a so-called pilot hole, so that the rounding and / or chamfering facilitates the insertion of the dental implant 1.

[0088] The dental implant 1 further includes a first thread 6 extending or protruding from the outer surface 5 of the core body 2. In other words, the first thread 6 is formed as an external thread on the outer surface 5 of the core body 2, with the outer surface 5 forming a root of the first thread 6.

[0089] The first thread 6 includes an apical thread end 7 and a coronal thread end (not shown) formed at least partially along the core body 2. The apical thread end 7 and the coronal thread end may or may not coincide with the apical end 3 and / or the coronal end 4, respectively. Furthermore, the first thread 6 is formed helically around the core body 2 with a first pitch p1 (see FIG. 3 ).

[0090] As particularly shown in Figure 1, in the apical portion of the implant, the first thread 6 is preferably formed as a continuous thread with an apical thread end 7. Nevertheless, the first thread 6 may also be formed as an interrupted thread by cutting flutes 14, as will be further explained below. Such a first thread 6 is a discontinuous thread having a front surface 8 at the apical end 7, a coronal end, and an interruption between the apical end 7 and the coronal end.

[0091] 3, the first thread 6 may be formed with a coronal flank 17, a radially outer flank 18, and an apical flank 19. The radially outer flank 18 may be straight and / or rounded. The straight outer flank may have a constant or variable width and / or may be at least partially defined by forming an edge (i.e., forming an edge connecting the apical flank 19 and the coronal flank 17).

[0092] The first thread 6 has a height h1 measured between the root of the first thread 6, i.e. the outer surface 5 of the core body 2, and the radially outer flank 18 in a direction perpendicular to the outer surface 5. The height h1 of the first thread 6 may or may not be constant along the extension of the first thread 6. If not constant, the height of the first thread 6 preferably increases in a direction from the coronal end 4 towards the apical end of the dental implant 1.

[0093] The first thread 6 also has an outer radius r1. The outer radius r1 is measured between the longitudinal axis L and the radial outer flank 18 in a direction perpendicular to the longitudinal axis L. The outer radius r1 of the first thread 6 may or may not be constant along the extension of the first thread 6. If it is not constant, the outer radius preferably decreases in a direction from the coronal end 4 towards the apical end of the dental implant 1, i.e. the dental implant tapers in this direction along the first thread 6.

[0094] The first thread 6 allows the dental implant 1 to be drawn into the prepared bone recess upon rotation of the dental implant 1 in a predefined rotational direction 26. The predefined rotational direction 26 is the direction in which the dental implant 1 is rotated to advance the dental implant 1 into the bone recess. Once inserted, the first thread 6 also provides fixation of the dental implant 1 in the bone recess.

[0095] At the apical thread end 7, the first thread 6 comprises a front face 8. In other words, the first thread 6 terminates at the apical thread end 7 at a certain thread height h1, preferably at the maximum thread height h1 of the first thread 6. The front face 8 is formed at an angle with respect to the outer surface 5 of the core body 2. In a preferred embodiment, the angle of the front face 8 with respect to the outer surface 5 is substantially 90°. However, the front face 8 may also be formed at an angle of substantially 80°, 85°, 95° or 100° with respect to the outer surface 5, or within one of the angle ranges defined above.

[0096] The front face 8 includes at least one cutting edge 9. The cutting edge 9 may be configured to cut bone tissue. In particular, the front face 8 may include exactly one, two or three cutting edges. For example, an edge portion / entire edge of the coronal flank 17 and / or an edge portion / entire edge of the radially outer flank 18 and / or an edge portion / entire edge of the apical flank 19 may form the cutting edge 9 along the front face 8 at the periphery of the front face 8.

[0097] It is possible that the connecting edges between the three flanks 17, 18, 19 are substantially rounded and / or chamfered at the front face 8. If the transitions between the three flanks 17, 18, 19 are rounded such that the transitions from the edge of flank 17 to the edge of flank 18 to the edge of flank 19 form a continuous edge at the front face 8, a single cutting edge 9 is formed. Nevertheless, the cutting edge may also be formed by juxtaposed cutting edges, in which case the transition between these cutting edges is discontinuous (e.g. in the case of a transition between the flanks at a chamfer or apex).

[0098] Due to the presence of a front surface 8 at the apical thread end 7, the first thread 6 does not constitute a continuous runout at the apical thread end 7. A typical runout is understood as an end portion of a thread where the height of the thread decreases from a certain height to zero over at least a quarter or eighth of a turn. Thus, a person skilled in the art will understand that the discontinuous decrease in height h1 of the first thread 6 due to the front surface 8 being angled relative to the outer surface 5 of the core body 2 does not constitute a runout.

[0099] As shown in the figure, since the first thread 6 is not formed with a typical run-out, the front surface 8 of the first thread 6 easily forms a cutting edge 9 with a defined height. Thus, when the dental implant 1 is inserted and rotated in the bone recess, the front surface 8 immediately cuts into the bone tissue at a constant height, preferably at the maximum height of the first thread 6. It has been determined that this arrangement advantageously results in a cutting behavior with a reduced risk of spinning when the dental implant is fully inserted. By preventing spinning of the implant, i.e. by rotating the dental implant 1 without advancing the implant into the bone tissue according to the pitch of the first thread 6, the fixation of the dental implant 1 is enhanced.

[0100] Furthermore, the anterior surface 8 also significantly affects the insertion torque of the dental implant 1 and promotes the initial stability and osseointegration of the dental implant 1. As a result, even a dental implant 1 with a length-to-diameter ratio of less than 2 provides sufficient fixation for secure attachment to the surrounding bone tissue.

[0101] Furthermore, the cutting action of the front surface 8 at the apical thread end 7 of the first thread 6 cuts the bone tissue in an optimal manner, which improves the fixation of the dental implant 1 in the patient's bone tissue.

[0102] The front surface 8 is preferably such that the outer radius r1 of the first thread 6 is the smallest (r min Additionally or alternatively, the front face 8 defines a height h1 of the first thread 6, which is preferably maximum.

[0103] This makes it possible to advantageously modify the cutting behavior of the front surface 8, i.e., the extent to which the front surface 8 cuts into bone tissue, in order to enhance fixation of dental implants 1, particularly those that are relatively short (e.g., having a length-to-diameter ratio of approximately 2 or less).

[0104] The front surface 8 of the first thread 6 is configured as a leading cutting tooth 27 upon rotation of the dental implant 1 in a given rotational direction 26. Furthermore, the dental implant 1 and / or the first thread 6 does not comprise a trailing cutting edge, i.e. a thread surface facing the front surface 8. In other words, the dental implant 1 and / or the first thread 6 does not comprise a trailing cutting edge along the projected path of the first thread 6 beyond the apical thread end 7. This means that the front surface 8 is not formed by an interruption of the first thread 6 such that the first thread 6 is separated into two adjacent parts, thus establishing another thread surface acting as a trailing cutting edge.

[0105] The front cutting blade is defined in the present context as a blade that is configured to cut bone tissue when the dental implant 1 is rotated along a predetermined rotational direction 26, but is configured not to cut bone tissue when the dental implant 1 is rotated in a direction opposite to the predetermined rotational direction 26.

[0106] In figures 1 and 2, the first thread 6 is illustrated as a single thread. In other words, the first thread 6 constitutes only a single thread path from the coronal thread end to the apical thread end 7. In an alternative embodiment, the first thread 6 may be formed as a multiple thread, in particular a double thread. This means that multiple thread paths, in particular two thread paths, are formed between the coronal thread end and the apical thread end 7. In other words, the first thread is formed along multiple parallel thread paths.

[0107] In such an embodiment, the first thread 6 includes a plurality of, preferably two, front faces 8, each front face 8 including at least one cutting edge 9. The plurality of front faces 8 are preferably evenly distributed around the circumference of the core body 2.

[0108] The first thread 6 comprising multiple threads provides a more balanced cutting behavior and therefore reduces the risk that the dental implant 1 may tilt unintentionally during insertion.

[0109] Preferably, the first thread 6 extends at least partially along the first portion 10. An apical thread end 7 of the first thread 6 may be located within the first portion 10. In other words, the first thread 6 may terminate within the first portion 10, preferably at the apical end of the first portion 10. The term "inside" in the present context therefore also encompasses the end of the first portion 10 along the longitudinal axis.

[0110] In particular, the first thread 6 does not extend beyond the first portion 10 in the apical direction of the dental implant 1. Moreover, the first thread 6 is preferably not formed up to the apical end 3 of the core body 2. In other words, the dental implant 1 preferably comprises an apical portion, preferably the second portion 11, where the first thread 6 is not present.

[0111] This configuration allows the apical end 3 of the dental implant 1 to be inserted into the bone recess without the first thread 6 coming into contact with the bone tissue. Moreover, such an apical part of the dental implant 1 may be inserted into the bone recess without rotating the dental implant 1. This has the advantageous effect that when the first thread 6 comes into contact with the surrounding bone tissue, the apical part of the dental implant 1 inserted into the bone recess already provides guiding and centering during the rotational movement of the dental implant. This reduces the risk of misalignment of the dental implant 1 relative to the bone recess.

[0112] Furthermore, the apical portion of the dental implant 1 may be formed with a different shape (eg, different shape, taper angle) as the second portion 11 to enhance the guiding and centering effect of the dental implant 1 .

[0113] Due to the guiding and centering effect of the apical portion of the dental implant 1 when already inserted in the bone recess, the risk of "wobble" movements of the dental implant 1 can be significantly reduced.

[0114] As shown in Figures 1 and 2, the dental implant 1 may further comprise a spiral groove 13 extending at least partially along the core body 2. The spiral groove 13 is preferably recessed inwardly with respect to the outer surface 5 of the core body 2. A cross-sectional profile or contour 23 perpendicular to the extension direction of the spiral groove 13 is not limited to a particular shape, but is preferably circular, in particular substantially circular or substantially elliptical. The spiral groove 13 is formed along a spiral path around the core body 2. In the exemplary embodiment shown in the figures, the core body 2 is formed with (just) one spiral groove 13. However, it is also possible for the core body 2 to comprise more than one, preferably two, spiral grooves 13.

[0115] The helical groove 13 preferably forms a root 24 of the second thread 16. More specifically, the root 24 of the second thread 16 is formed by the line of the helical groove 13 along its most recessed point from the outer surface 5. The helical groove 13 is recessed from the outer surface 5 of the core body 2 and preferably extends helically around the core body 2, thereby forming the second thread 16. For example, a portion of one turn of the helical groove 13 forms a crown flank 20 of the second thread 16, and a portion of an adjacent turn of the helical groove 13 forms an adjacent apex flank 22 of the second thread 16.

[0116] The radially outer flank 21 of the second thread 16 is preferably formed by the outer surface 5 of the core body 2. This means that the second thread 16 does not have to extend outwardly from the outer surface 5 of the core body 2 in a direction perpendicular to the longitudinal axis L.

[0117] The second thread 16, like the spiral groove 13, is formed with a height h2, which is measured between the root 24 and the radial outer flank 21 of the second thread 16 in a direction perpendicular to the longitudinal axis L. The height h2 of the second thread 16 may be constant or may not be constant along the extension of the second thread 16. As already explained in connection with the spiral groove 13, the height h1 of the first thread 6 is preferably greater than the height h2 of the second thread 16.

[0118] Furthermore, according to the arrangement of the helical groove 13, the second thread 16 extends helically around the core body 2 with a second pitch p2. The second pitch p2 may be substantially the same as the first pitch p1 of the first thread 6. Preferably, the second thread 16 is offset by half a pitch with respect to the first thread 6 (as shown in Figures 1 and 2). As a result, the root 24 of the second thread 16 is on the same helical line as the crest of the first thread 6.

[0119] Nevertheless, the second thread 16 may also not be offset relative to the first thread 6. In the latter case, the second thread 16 is formed along the projected path (i.e., helical line) of the first thread 6. In other words, the second thread 16 may or may not extend along the same path as the first thread 6.

[0120] The second thread 16 and the helical groove 13 extend at least partially along the second part 11. Moreover, the second thread 16 and / or the helical groove 13 are preferably formed only on the apical side of the first thread 6. It should be noted that the second thread 16 and / or the helical groove 13 may extend beyond the second part 11 in the coronal direction. Thus, the second thread 16 and / or the helical groove 13 may be present in the first part 10 and may or may not overlap at least partially with the first thread 6. Preferably, the second thread 16 and / or the helical groove 13 extends at least in the coronal direction adjacent to the first thread 6. In this respect, the transition from the first thread 6 to the second thread 16 and / or the helical groove 13 is preferably abrupt, i.e. discontinuous without continuous deformation.

[0121] The second thread 16 achieves the advantageous effect of at least partially drawing the dental implant 1 into the prepared bone recess upon rotation of the dental implant 1. At the same time, due to the limited thread height of the second thread 16, the dental implant 1 can be at least partially inserted into the bone recess without rotation. As mentioned above, this achieves a centering and / or guiding effect and / or a bicortical fixation effect when the first thread 6 comes into contact with the surrounding bone tissue.

[0122] To achieve this effect, it is advantageous if the second thread 16 and / or the spiral groove 13 is formed through at least one eighth, one quarter, one third, one half, one, two or three turns. The greater the number of turns, the more pronounced the advantageous effect of the second thread 16 and / or the spiral groove 13. Nevertheless, the second thread 16 and / or the spiral groove 13 may extend less than one eighth of a turn around the circumference of the second part 11.

[0123] It is also advantageous if the second thread 16 and / or the spiral groove 13 extend substantially to the apical end of the dental implant 1. Substantially in this context means that the apical-most tip of the dental implant 1 may be rounded, such that the second thread 16 and / or the spiral groove 13 does not end exactly at the apical end 3 of the dental implant 1.

[0124] The second thread 16 further allows for the removal or advantageous placement of bone chips in a pre-prepared bone recess, which may for example be left in the recess from a step of preparing the bone recess, thereby preventing bone chips from causing misalignment of the dental implant 1 during insertion of the dental implant 1 or from causing the implant to spin out in its final position.

[0125] In another embodiment of the dental implant 1 according to the present disclosure, as best shown in Fig. 2, the dental implant 1 may comprise cutting flutes 14. The cutting flutes 14 may be recessed portions from the outer surface 5 along the core body 2 or flat portions on the outer surface 5, in particular extending at least partially along the first portion 10 and the second portion 11. The cutting flutes 14 preferably have a longitudinal direction in the apical-coronal direction of the dental implant 1. The cutting flutes 14 comprise at least one cutting edge 15 configured to cut bone tissue. Preferably, the at least one cutting edge of the front surface 8 forms a part of the cutting edge 15 of the cutting flutes 14, and more preferably is continuous with the cutting edge of the flutes 14.

[0126] The cutting flutes 14 may be adapted to allow a predetermined limit of compression of the bone tissue and thus promote osseointegration of the dental implant 1 .

[0127] Preferably, the cutting flutes 14 are formed such that the cross-sectional profile of the apical end 3 of the core body 2 remains substantially circular (except for any straight or curved interruptions caused by the cutting flutes 14), thereby ensuring that the effect of the front face 8 of the first thread 6 is not diminished and that the apical portion of the dental implant 1 still achieves a guiding and centering effect.

[0128] In a preferred embodiment, the cutting flute 14 extends from the apical end 3 towards the coronal end 4. In particular, the cutting flute 14 may intersect three turns, two turns or one turn of the first thread 6. The edge between the flank 17, 18, 19 of the intersecting turn and the front face 8 of the first thread 6 preferably forms part of the cutting edge 15. The front face 8 may thus form part of the cutting flute 14.

[0129] The cutting flute 14 may further intersect at least one turn of the second thread 16, and preferably all turns of the second thread 16. Similar to the first thread 6, the edges between the flanks 20, 21, 22 and the front face 28 of the second thread 16 also preferably form part of the cutting edge 15. Thus, the front face 28 of each turn of the second thread 16 may also result in forming a cutting flute 14.

[0130] As can be best seen in Fig. 2, the second thread 16 may form not only the leading cutting edge 15 but also the trailing cutting edge 29 according to a predefined rotation direction 26 of the dental implant 1 during the insertion process of the dental implant 1 into the bone recess. The leading cutting edge 15 and the trailing cutting edge 29 may form part of the cutting edge 15 of the cutting flute 14. However, the trailing cutting edge 29 preferably has a negative rake angle, so that the trailing cutting edge is blunt compared to the leading cutting edge 15.

[0131] During rotation of the dental implant 1 (predetermined rotation direction 26) during the insertion process of the dental implant 1, the front cutting edge 15 is configured to cut the bone tissue. During rotation of the dental implant 1 against the predetermined rotation direction 26, for example when the torque applied to the dental implant 1 exceeds a predetermined value, the rear cutting edge 29 serves to remove bone material from the helical path of insertion that may have caused the increased torque by cutting and / or tracing (compressing) the threads cut into the bone tissue.

[0132] The cutting edges 15 of the cutting flutes 14 and / or the cutting edges 9 of the front face 8 may have a positive or negative rake angle and / or a positive or negative clearance angle. [Explanation of symbols]

[0133] 1. Dental Implants 2 Core body 3 Top end 4 coronal end 5 External surface 6 First Thread 7 Apical thread end 8 Front 9 Cutting edge 10 First Part 11 Second Part 12 Rounded Tip 13 Spiral groove 14 Cutting flute 15 Cutting edge 16 Second Thread 17 Crown flank of first thread 18 Radial outer flank of first thread 19 Crest flank of first thread 20 Crown flank of second thread 21 Radial outer flank of second thread 22 Crest flank of second thread 23 Contour 24 Second Thread Root 25 Contours 26 Prescribed Rotation Direction 27 Front cutting teeth 28 Anterior cutting teeth / front surface 29 Rear cutting edge

Claims

1. top end (3), a coronal end (4), and It has an outer surface (5), and a core body (2) extending along a longitudinal axis (L) between said apical end (3) and said coronal end (4); a first thread (6) extending from the outer surface (5) of the core body (2) and formed at least partially along the core body (2); A dental implant (1) comprising: the first thread (6) comprises an apical thread end (7), a coronal thread end and a front face (8) at the apical thread end (7); A dental implant (1), wherein said front surface (8) comprises at least one cutting edge (9).

2. The core body (2) comprises a first portion (10) and a second portion (11), the first portion (10) and the second portion (11) extending along the longitudinal axis (L), the second portion (11) being located on the apex side of the first portion (10); 2. Dental implant (1) according to claim 1, wherein said first thread (6) extends at least partially along said first portion (10).

3. 3. Dental implant (1) according to claim 2, wherein the apical thread end (7) is located within the first portion (10).

4. Dental implant (1) according to claim 2 or 3, wherein said second portion (11) extends from said apical end (3) towards said coronal end (4).

5. Dental implant (1) according to claim 2 or 3, wherein said second portion (11) comprises a substantially tapered, conical or frustoconical profile.

6. Dental implant (1) according to any of claims 1 to 3, wherein the dental implant (1) further comprises a spiral groove (13) extending at least partially along the core body (2).

7. 7. The dental implant (1) according to claim 6, wherein the spiral groove (13) forms the root of a second thread (16), the second thread (16) being preferably offset by half a pitch relative to the first thread (6).

8. 7. Dental implant (1) according to claim 6, wherein the second thread (16) and / or the spiral groove (13) extend at least partially along the second portion (11).

9. 8. Dental implant (1) according to claim 7, wherein the height (h1) of the first thread (6) is greater than the height (h2) of the second thread (16).

10. The first thread (6) is spirally formed around the core body (2) with a first pitch (p1), and the second thread (16) is spirally formed around the core body (2) with a second pitch (p2); 8. Dental implant (1) according to claim 7, wherein said first pitch (p1) is substantially equal to said second pitch (p2).

11. The dental implant (1) further comprises a cutting flute (14), the cutting flute (14) comprising at least one cutting edge (15); The dental implant (1) according to any one of claims 1 to 3, wherein the at least one cutting edge (9) of the front surface (8) forms part of the at least one cutting edge (15) of the cutting flute (14).

12. 12. Dental implant (1) according to claim 11, wherein the cutting flutes (14) extend along the first portion (10) and the second portion (11).

13. 12. Dental implant (1) according to claim 11, wherein the cutting flutes (14) extend from the apical end (3) towards the coronal end (4).

14. 12. Dental implant (1) according to claim 11, wherein said cutting flute (14) intersects with 3 turns, preferably 2 turns, most preferably 1 turn of said first thread (6).

15. 4. The dental implant (1) according to any one of claims 1 to 3, wherein the first thread (6) has an outer radius (r1) and the front surface (8) is formed at a point along the longitudinal axis where the outer radius (r1) is at a minimum (rmin).

16. Dental implant (1) according to any of claims 1 to 3, wherein the at least one cutting edge (9) of the front surface (8) has a positive or negative rake angle and / or a positive or negative clearance angle.

17. The core body (2) has a cross section along the longitudinal axis (L), the cross section being perpendicular to the longitudinal axis (L); Dental implant (1) according to any of claims 1 to 3, wherein said apical end (3) has a substantially round, preferably substantially circular cross section.

18. Dental implant (1) according to any of claims 1 to 3, wherein the apical end (3) is formed as a rounded tip (12).

Images