DENTAL IMPLANT

Description

[0001] The invention relates to a dental implant that can be inserted into a jawbone, preferably to serve as a support for a dental prosthesis such as a crown. The dental implant then assumes, in particular, the function of an artificial tooth root.

[0002] A dental implant comprises an implant body that is inserted into the jawbone to provide a secure anchorage. An implant body may have a screw thread for screwing into the jawbone or may have a smooth surface for inserting into the jawbone. Once inserted, the implant body of a dental implant typically bonds to the surrounding bone within a few months and is then anchored in the jawbone to form a stable support for a dental prosthesis.

[0003] A dental implant may also include an abutment, which is connected to the implant body anchored in the jawbone, for example, by means of a screw or cementation. A crown can be attached to the abutment, replicating the original geometry of the replaced tooth and ensuring good functionality and aesthetics in conjunction with the patient's other adjacent and opposing teeth.

[0004] In order for a dental implant to be inserted into the jawbone at the intended location, a drill hole is usually prepared using various preparation instruments. The creation of the drill hole and, if necessary, an internal thread for the dental implant at the prepared location is typically achieved by first using a pilot drill to pre-punch the bone and then make a primary hole for directional orientation. A depth drill with a diameter smaller than that required for the dental implant is then used to enlarge the drill hole to the depth required for the dental implant. A final depth drill is used to laterally expand the diameter of the drill hole. A countersink can then be used to enlarge the cortical bone. Finally, an internal thread can be cut into the bone using a thread cutter.

[0005] A dental implant can therefore typically only be inserted into a jawbone after a series of steps have been carried out to first create the drill hole for the dental implant.

[0006] To reduce the number of steps required for the actual insertion of the dental implant, self-tapping dental implants have been proposed. These self-tapping implants cut their own threads when the implant is inserted into a drilled hole. Such dental implants are described, for example, in EP 1161197 B1, EP 0786967 A1, and EP 1052948 A1. However, a drilled hole must still be created first to insert these dental implants.

[0007] To further reduce the number of steps required for hole preparation, dental implants that are both self-cutting and self-drilling have been proposed. Such dental implants are described, for example, in EP 1480575 B1 and WO 99 / 39653.

[0008] The dental implant described in EP 1480575 B1 has an intermediate threaded portion adjoining a tip portion, followed by a guide threaded portion and a distal threaded portion, the threads of which include a cutting edge. The dental implant further comprises grooves extending from the tip portion along the longitudinal direction of the dental implant and serving to receive bone chips. However, the grooves themselves do not have a cutting edge.

[0009] The implant described in WO 99 / 39653 also features self-tapping threads in an external thread section. The implant's notches serve to accommodate bone chips, but are not suitable for direct removal of bone chips.

[0010] When a dental implant as described in EP 1480575 B1 and WO 99 / 39653 is inserted into a jawbone, it may happen that bone chips created during cutting remain, at least to a large extent, in the jawbone. Since only a dental implant is inserted into the jawbone, but no corresponding bone material has been removed, it can be assumed that the jawbone with the dental implant inserted is subjected to a comparatively high mechanical load, i.e., in particular, compression of the surrounding bone.

[0011] US Pat. No. 5,087,201 A describes a self-tapping post for screwing into the maxillary bone for the implantation of a dental prosthesis. The self-tapping post has a threaded shaft portion, a drive head at one end of the shaft portion, and a drill at the other end of the shaft portion.

[0012] The invention is based on the object of providing an improved or at least alternative dental implant that is both self-healing and self-drilling. Preferably, the self-healing and self-drilling dental implant should exert as little mechanical stress on the jawbone as possible when inserted.

[0013] According to the invention, this object is achieved by a dental implant having the features of claim 1. Advantageous further developments of the dental implant according to the invention can be found in the dependent claims.

[0014] According to the invention, a dental implant is proposed with an implant body that extends in a longitudinal direction of the implant body from its apical end to its coronal end. The implant body has a drill portion in which the implant body is designed to drill a hole in a jawbone. The implant body further has a shaft adjoining the drill portion in the coronal direction, which shaft comprises a first threaded portion in which the implant body has an external thread.

[0015] The implant body comprises, in the first threaded section, at least one thread-cutting groove which interrupts the external thread and runs helically around at least one axial section of the shaft, and has, at least in the first threaded section, a self-tapping thread-cutting edge arranged at the transition between the thread-cutting groove and the external thread.

[0016] The drill section serves, in particular, to create a drill hole in a jawbone into which the dental implant can be at least partially inserted. The dental implant itself is thus designed to create a drill hole in a jawbone.

[0017] The apical end of the implant body refers to the end of the implant body that penetrates the jawbone first and is located deepest in the drill hole when the dental implant is inserted.

[0018] The coronal end of the implant body refers to the end opposite the apical end of the implant body. The coronal end of the implant body is typically located outside the drill hole, especially when the dental implant is in place. For example, the implant body can be connected at its coronal end to an abutment of the dental implant, which in turn can be connected to a dental prosthesis such as a crown.

[0019] The drill section therefore has at least one and typically two drilling cutting edges arranged on the apical end face of the implant body, which are formed at the transition between the apical end face of the implant body and the chip grooves of the drill section. These drilling cutting edges are designed for machining with an axial feed direction along the longitudinal axis of the implant body. The thread cutting edge, on the other hand, is formed at the transition between the circumferential surface of the thread and the thread cutting groove and serves to produce a radial widening of the drilled hole with the contour of the thread by machining. The machined bone material created during the drilling process can be transported away via the chip grooves and then further, together with the machined bone material created during the thread cutting process, via the thread cutting grooves.

[0020] The at least one thread-cutting edge of the first threaded section therefore serves in particular to enlarge the diameter of the drill hole created by the drill section to a desired internal thread contour. With the at least one thread-cutting edge, a jawbone can be machined in such a way that an internal thread corresponding to the external thread of the first threaded section can be turned into the surrounding jawbone. The thread-cutting edge is provided in particular as an edge between the thread-cutting groove and the external thread. The external thread of the first threaded section is accordingly designed as a self-tapping thread. The thread-cutting edge is preferably located on the rear edge in the direction of rotation of the external thread of the first threaded section, between the thread-cutting groove and the external thread.The thread cutting edge therefore has a serrated profile corresponding to the thread profile and follows the helical course of the thread cutting groove around the shaft.

[0021] If the implant body has a thread-cutting edge in each of several thread sections between the thread-cutting groove and the external thread, the thread-cutting edges of the several thread sections preferably merge into one another and form a common thread-cutting edge. If there are several thread-cutting grooves, there can be a common thread-cutting edge between each of the thread-cutting grooves and the external thread. If there are several thread-cutting edges, one of the thread-cutting edges can be provided only in the first thread section, while another of the thread-cutting edges can be provided, for example, only in the second thread section, or also in the first and second thread sections and / or the third thread section.

[0022] This has the advantage that bone material can be removed over the entire length of the first threaded section and picked up and transported away by the thread-cutting groove. The function of the external thread, which consists in anchoring the dental implant in a jawbone, is preferably decoupled from the function of creating a drill hole and cutting the thread using the thread-cutting edge. The anchoring of the dental implant in a jawbone is preferably achieved in particular by the interaction of the external thread designed for this purpose in the first threaded section with the internal thread cut into the jawbone.

[0023] In the first threaded section, but also in further optional second and / or third threaded sections, a plurality of thread-cutting grooves interrupting the external thread can also be provided, for example two or three thread-cutting grooves that run helically around at least one axial section of the shaft. Preferably, the plurality of thread-cutting grooves each have a self-tapping thread-cutting edge at least in the first threaded section. If a plurality of thread-cutting grooves are provided in the first threaded section and in further optional second and / or third threaded sections, a self-tapping thread-cutting edge can be provided between one of these thread-cutting grooves and the external thread, or else between a plurality of these thread-cutting grooves and the external thread.

[0024] At least one thread cutting groove can branch in the first thread section and / or in a second thread section and / or in a third thread section toward the coronal end of the implant body. By having at least one thread cutting groove branch from apical to coronal in at least one of the thread sections, the removal of bone chips through the thread cutting groove can be further improved. Branching here means that two or more thread cutting grooves emerge from one thread cutting groove, which extend around the shaft.

[0025] When drilling into the jawbone, bone chips are generated, which must be removed from the hole during the drilling process. If the bone chips are not effectively removed, some of them would be displaced from the dental implant as the implant is further inserted. This results in compression of the surrounding bone. This may be desirable in some cases, but if the compression is too great, it can damage the surrounding bone tissue. This can lead to necrosis, or tissue death.

[0026] The at least one thread-cutting groove serves, in particular, to collect bone chips and transport them away toward the apical end of the implant body. The bone chips can be transported away by the at least one thread-cutting groove, in particular, to such an extent that at least most of them can be removed from the jawbone. Thus, a drill hole with the dimensions appropriate for the dental implant can be created without bone chips remaining in the drill hole in quantities that would expose the jawbone to comparatively high mechanical stress.

[0027] Because the thread cutting groove extends helically around the shaft, bone chips can be particularly effectively picked up and transported away toward the coronal end of the implant body when the dental implant is rotated into the jawbone. In particular, during the screwing of the dental implant into a jawbone, bone chips can be effectively and continuously picked up by the at least one helical thread cutting groove, with the picked-up bone chips being pushed toward the coronal end of the implant body by subsequent bone chips due to the rotation of the dental implant and thus transported away.

[0028] The dental implant according to the invention is thus effectively self-drilling and self-tapping, without the dental implant causing excessive compression of a surrounding bone, which leads to tissue death, when it is rotated into a jawbone.

[0029] The dental implant according to the invention can be inserted into a jawbone directly after opening the gums, without the need to first create a drill hole using additional preparation instruments.

[0030] This significantly reduces the number of steps required to insert the dental implant into the jawbone compared to a conventional approach. Furthermore, the risk of infection, which can be increased by preparing the drilling site using multiple instruments, can be reduced. Each additional instrument typically increases the risk of introducing germs if sterilization is inadequate or if sterilization has been delayed for too long. There is also a risk that germs can migrate through the exposed drill hole, for example, via the air, during an instrument change.

[0031] By reducing the number of steps required to place a dental implant, the amount of labor and time required to place a dental implant can also be significantly reduced. This typically results in lower costs and less discomfort for the patient.

[0032] A further advantage of the dental implant according to the invention is that it creates a drill hole with a diameter and depth appropriate for the dental implant. In contrast, the conventional approach carries the risk that the final depth drill may not always achieve a drill hole with the correct diameter. If the drill hole diameter is too small, the bone can be severely deformed when the dental implant is screwed in. Conversely, if the drill hole diameter is too large, the dental implant's attachment may not be sufficiently stable.

[0033] The dental implant according to the invention can be used independently of special instruments that are often required to create a drill hole for a specific type of dental implant. Typically, a dentist who wishes to use dental implants from different manufacturers requires a variety of different instruments, each of which is specific to a specific type of dental implant.

[0034] Since the dental implant according to the invention is usually implanted only once, the risk of excessive heating of the tissue and thus necrosis, which occurs due to the multiple use and the resulting wear of drills, such as deep drills, can also be reduced.

[0035] The first threaded section is preferably arranged directly adjacent to the drill section.

[0036] The implant body is preferably designed as a twist drill in the drill section. A drill section designed as a twist drill preferably has at least one helically extending chip groove and at least one main cutting edge. The at least one thread-cutting groove and the at least one chip groove are preferably designed as a continuous groove. It is therefore preferred that the at least one thread-cutting groove of the first threaded section in the drill section is continued by the at least one chip groove of the twist drill. It is further preferred that, if the implant body is designed as a twist drill in the drill section, the grooves of the twist drill merge helically into the thread-cutting groove of the first threaded section.

[0037] If the implant body is designed as a twist drill in the drill section, the removal of bone chips can be implemented particularly efficiently. Bone chips can be removed through the groove profile of the drill section, which is designed as a twist drill, as well as through the groove profile of the thread-cutting groove of the first thread section. These different grooves, i.e. the chip groove and the thread-cutting groove, are preferably arranged such that a groove from the drill section merges into a groove in the first thread section. If several chip grooves are formed in the drill section and several thread-cutting grooves in the first thread section, it is preferred if one groove each from the drill section merges into a groove in the first thread section.

[0038] During the drilling process, bone chips are initially collected by the chip groove in the drilled section. When the dental implant is screwed in, bone chips are pressed from the chip groove into the groove profile of the thread cutting groove. The portion of bone chips displaced by the thread cutting edge of the first thread section can escape from the drilled hole, particularly from the drilled bone entry opening.

[0039] Preferably, the direction of rotation of the groove profile of a chip groove of the twist drill continues in the direction of rotation of the groove profile of the thread cutting groove of the first thread section.

[0040] The direction of rotation of the grooves is understood in particular to be the direction along which the groove rotates helically around the longitudinal axis of the implant body, starting from the apical end of the implant body.

[0041] The direction of rotation of the grooves preferably runs counter to the direction of insertion of the dental implant. In other words, the direction of rotation of the grooves preferably corresponds to the direction of rotation of the external thread in the first threaded section. In particular, the direction of rotation of the chip groove can correspond to the direction of rotation of the external thread of the first threaded section. This orientation of the grooves has the advantage of promoting the removal of bone chips from the drill hole.

[0042] Jawbone is structured in such a way that it consists of a hard and dense outer layer (the cortical layer) and a more porous, softer inner layer (the cancellous layer). Therefore, the implant body preferably has no thread in the drill section.

[0043] The length of the drill section is preferably at least three, preferably at least four millimeters. This minimum length exceeds the typical thickness of the cortical bone layer of the jawbone. Since the implant body preferably has no thread in the drill section, it is possible for the implant body and its drill section to initially work their way through the cortical area before the first threads, in particular of the first thread section, begin to engage. This has the advantage that the threads of the external thread of the first thread section only begin to engage once the drill has reached the softer cancellous area of the bone. This in turn has the advantage that the feed resulting from the pitch of the external thread in the first thread section for one drill rotation is no greater than the feed of the drill due to the cutting movement.This can prevent excessive axial counterforce at the drill tip from advancing the thread pitch, which could lead to the first thread turns in the jawbone being torn out.

[0044] It is therefore preferred that the implant body be designed in the drill section as a threadless drill with a length of at least 3 mm. With a length of at least 3 mm, there is typically no longer any risk that, once the drill section has reached the softer, cancellous area, the advance due to the thread pitch will lead to the breakage of the freshly cut thread.

[0045] If the implant body is designed as a twist drill in the drill section, it is preferred if the twist drill has a spiral angle between 10° and 45°, preferably between 15° and 40°, particularly preferably between 20° and 35°. The spiral angle of the twist drill is determined in particular by the angle between the longitudinal axis of the implant body and the secondary cutting edges. The secondary cutting edge forms, in particular, the transition from the guide bevel to the chip groove. This ensures even more reliable removal of bone chips.

[0046] It is also possible that the removal of bone chips can be further improved by the spiral angle of the twist drill corresponding to the angle between the longitudinal axis of the implant body and the thread cutting edge in the first thread section.

[0047] If the implant body is designed as a twist drill in the drill section, it is further preferred if the twist drill has a tip angle that is between 105° and 170°, preferably between 115° and 150°, particularly preferably between 120° and 135°. The tip angle of the twist drill is, in particular, the angle between the main cutting edges at the tip of the drill. Accordingly, a small tip angle typically means comparatively long main cutting edges, while a large tip angle means comparatively short main cutting edges. The larger the tip angle, the shorter the time required for drilling.

[0048] A comparatively small tip angle is particularly preferable when the dental implant is not to be placed centrally or vertically in the alveolar ridge. This ensures that the transition from the main cutting edges to the secondary cutting edges at the periphery of the drill section does not come into contact with the bone before, for example, a centering tip optionally provided at the apical end of the implant body allows for secure guidance of the dental implant. This has the advantage that the dental implant can be inserted into the jawbone in a controlled manner at the intended location.

[0049] If the implant body is designed as a twist drill in the drill section, it can have two or more main cutting edges, preferably three or more. This allows the drill's feed rate to be increased, as more bone material can be removed per rotation of the implant.

[0050] Preferably, a core diameter of the implant body tapers in the first threaded section towards the apical end. Preferably, a core diameter of the implant body tapers conically in the first threaded section. Since the implant body has a thread-cutting groove in the first threaded section, the diameter of a drill hole is successively increased when the implant body, which tapers in the first threaded section towards the apical end, is screwed into a jawbone. A drill hole can thus be enlarged bit by bit and in a comparatively gentle manner to a specific diameter. It can be provided that the core diameter and / or the outer diameter of the thread in the thread-cutting section of the implant body is smaller than the core diameter or the outer diameter of the thread in the non-cutting section of the implant body located coronally therefrom.This achieves targeted compression, which increases primary stability and can promote the ingrowth of the implant body. In other embodiments, it is advantageous if the core diameter and / or the outer diameter of the thread in the thread-cutting section of the implant body corresponds to the core diameter or the outer diameter of the thread in the non-cutting section located coronally to it, which enables largely compression-free insertion.

[0051] In preferred embodiments, the thread-cutting groove can be provided as a chip transport groove in the non-thread-cutting threaded section of the implant body. In this case, the chip transport groove is formed with a non-cutting (e.g., rounded) edge toward the thread's peripheral surface and serves only to transport chips.

[0052] The implant body can have an undercut located adjacent to the self-tapping thread cutting edge of the first threaded section toward the coronal end. An undercut has the advantage of reducing frictional resistance during insertion of the dental implant. An undercut can be created, for example, by radially grinding back the tooth profile in the circumferential direction.

[0053] The shaft may comprise a second threaded portion, which preferably adjoins the first threaded portion toward the coronal end. The implant body preferably has an external thread in the second threaded portion. The thread-cutting groove of the first threaded portion may continue spirally around the shaft in the second threaded portion. The implant body may be configured such that it does not have a self-tapping thread-cutting edge in the second threaded portion.

[0054] Alternatively, however, it can also be provided that the implant body has a self-tapping thread-cutting edge in the first threaded section and in the second threaded section. The at least one thread-cutting edge of the first threaded section is then preferably continued as a thread-cutting edge in the second threaded section.

[0055] If the implant body has a self-tapping thread cutting edge in the first thread section and in the second thread section, this has the advantage of further improving the removal of bone chips by transporting bone chips into the thread cutting groove of this second thread section. Furthermore, the excess bone chips displaced by the dental implant can escape from the drilled bone entry opening during the screwing of the dental implant into the jawbone.

[0056] The second threaded portion of the shaft preferably has a cylindrical core diameter. The second threaded portion of the shaft is particularly intended for anchoring the dental implant in a jaw conch.

[0057] The implant body preferably has an external thread in the second threaded section that merges into the external thread of the first threaded section. The external thread of the second threaded section preferably has a constant thread depth.

[0058] Preferably, a core diameter of the implant body in the second threaded portion has a constant radius. If the implant body tapers in the first threaded portion toward the apical end and the implant body has a second threaded portion, the implant body in the first threaded portion preferably tapers starting from the radius of the core diameter of the implant body of the second threaded portion. In other words, the core diameter of the external thread in the first portion preferably increases from apically toward the second threaded portion until it reaches the radius of the core diameter of the implant body in the second threaded portion.

[0059] The shaft may comprise a third threaded portion that adjoins the second threaded portion toward the coronal end. If no second threaded portion is present, the third threaded portion adjoins the first threaded portion.

[0060] In the third threaded section, the implant body preferably has an external thread which merges into the external thread of the second threaded section.

[0061] Preferably, the thread-cutting groove of the first and second threaded sections continues into the third threaded section. The thread-cutting groove preferably extends helically around the shaft in the third threaded section. Preferably, the implant body does not have a self-tapping thread-cutting edge in the third threaded section.

[0062] In the event that the dental implant has a third threaded portion with an external thread, the external thread in the third threaded portion is preferably designed such that it has the same pitch as the external thread in the second threaded portion.

[0063] The external thread of the third thread section can also be designed as a multi-start external thread. A multi-start external thread, in particular, has more than one thread start. A multi-start external thread generally has several chamfers and threads but only one pitch. Several threads of the multi-start external thread run, in particular, parallel to one another. Preferably, the external thread of the third thread section is designed as a multi-start, preferably two-start, external thread that has the same pitch as the external thread in the first thread section.

[0064] If a third threaded section with an external thread and / or a thread-cutting groove is arranged on the second threaded section toward the coronal end of the implant body, the removal of bone chips can be further improved, e.g., by continuing the thread-cutting groove of the second threaded section as a thread-cutting groove in the third threaded section. In this case, bone chips are transported into the thread-cutting groove of the third threaded section during implantation of the dental implant. Excess bone chips displaced by the dental implant can also escape from the drilled bone entry opening during screwing of the dental implant into the jawbone.

[0065] The implant body can have a core diameter with a cylindrical shape or with a conical shape in the third thread section.

[0066] The thread cutting groove or - if several thread cutting grooves are present - the several thread cutting grooves can have in at least one of the thread sections, i.e. in particular in the first, second and / or third thread section, a groove base with a surface roughness which is between 0.8 µm and 3.2 µm.

[0067] Alternatively, the thread cutting groove or - if several thread cutting grooves are present - the several thread cutting grooves in at least one of the thread sections, i.e. in particular in the first, second and / or third thread section, can have a groove base with a surface roughness of less than 0.8 µm and more than 0.1 µm.

[0068] It is possible for the groove base of a thread cutting groove to have the same surface roughness as the implant body in the first and / or second threaded section. This has the advantage that the surface roughness, which is only applied after the dental implant has been shaped, particularly by etching and / or blasting with corundum, can be applied uniformly to these areas. Therefore, the grooves do not require special measures to protect them from roughening. Furthermore, the rough surface in the groove base enhances bone ingrowth, thus improving the bonding of the newly formed bone.

[0069] Alternatively, the groove base of a thread cutting groove can also be smooth. This means that the machined surface is retained. This can be achieved, for example, by masking the groove base of a thread cutting groove, which was created to accommodate and transport bone chips, during a roughening process of the external thread areas of the shaft by etching and / or blasting with corundum. A smooth groove base of a thread cutting groove has the advantage of reducing frictional resistance, thus facilitating the removal of bone chips.

[0070] The dental implant is preferably designed such that the bone chips generated during screwing into a jawbone can be removed through the at least one thread-cutting groove with comparatively less compression of the bone chips in the drill hole. Greater compression of the bone chips entails the risk of necrosis, the death of tissue in the surrounding bone. Furthermore, improved removal of the bone chips also leads to a reduction in drilling resistance. Thus, less torque is required to screw the implant into the jaw. These advantages are realized in particular by a dental implant that, as described above, has a twist drill in a drill section whose chip groove transitions into a thread-cutting groove that runs helically around the shaft of the implant body.

[0071] The shaft may have an optional fourth section, which preferably adjoins the third threaded section toward the coronal end. If the implant body does not have a third threaded section, the fourth section preferably adjoins the first or, if present, the second threaded section.

[0072] In the fourth section, the shaft preferably has a smooth surface, i.e., in the fourth section, the surface of the shaft has neither an external thread nor a thread-cutting groove. In particular, there is no thread-cutting groove in the fourth section, which can be seen as a continuation of the thread-cutting groove of one of the other thread sections, for example, the third thread section. The core diameter of the shaft can be, for example, conical or cylindrical over the length of the fourth section.

[0073] The dental implant may further comprise an abutment which is connected to the coronal end of the implant body and which is firmly, preferably materially, connected to the shaft.

[0074] The abutment is preferably designed so that a prosthetic restoration can be directly attached to it, preferably by cementation or adhesive bonding. This means that no intermediate element needs to be attached to the implant by a screw connection in order to attach a prosthetic restoration such as a crown or bridge.

[0075] Optionally, the dental implant can further comprise a receiving structure that is configured to transmit torque around the longitudinal axis of the implant body. The receiving structure is preferably a receptacle accessible via the coronal end of the dental implant, which is configured to receive an insertion tool. The receiving structure can be formed as part of the abutment, preferably as a groove formed in the abutment that is open to receive an insertion tool.

[0076] An insertion tool, particularly one designed to complement the receiving structure, can be inserted into the receiving structure to screw the dental implant into the jawbone. An insertion tool can be, for example, a hand ratchet or an electrically operated device designed to apply the necessary torque and contact force to screw the dental implant into the jaw.

[0077] The implant body preferably has a centering tip at its apical end. The drill section is then connected to the centering tip and extends towards the coronal end of the implant body. The centering tip is preferably designed such that the dental implant can be aligned relative to a jawbone by means of the centering tip. The centering tip can, in particular, enable precise drilling and prevent the dental implant from becoming dislodged. Dislodgement of the dental implant is particularly possible if the dental implant is to be placed in a jaw ridge that is too narrow, or if it is not to be inserted perpendicularly into the jaw ridge, or if the dental implant is to be placed lingually or buccally offset from the jaw ridge.

[0078] The centering tip preferably has a length of between 1 mm and 3 mm, preferably between 1.5 mm and 2.5 mm.

[0079] Preferably, the centering tip is aligned centrally with the main cutting edges of the drill in the longitudinal direction of the dental implant. In particular, the centering tip has an angle of less than 90°, preferably less than 60°. The centering tip can, for example, have a conical shape or the shape of a three-sided or four-sided pyramid.

[0080] Additionally or alternatively, the centering tip can have an extension perpendicular to the longitudinal axis of the implant body in a contact area with the drill section, which extension is less than one-third of the diameter of the implant body in the drill section, preferably less than one-quarter of the diameter of the implant body in the drill section. The centering tip can, in particular, be designed to be rotationally symmetrical and pointed.

[0081] Preferred embodiments of the invention are explained below by way of example with reference to the accompanying figures. The figures show: Fig. 1: a schematically illustrated dental implant with a twist drill and several threaded sections, in which a flute of the twist drill continues as a thread-cutting groove; and Fig. 2: a schematically illustrated dental implant with a twist drill and several threaded sections and an abutment with a receiving structure into which an insertion tool can be inserted for implanting the dental implant.

[0082] Figure 1 shows a schematic side view of a dental implant 100. The dental implant 100 comprises an implant body 102 and an abutment 104. The implant body 102 extends in a longitudinal direction of the implant body 102 from its apical end 106 to its coronal end 108.

[0083] The implant body 102 comprises a drill section 110 and a shaft 112. The drill section 110 of the implant body 102 is configured for drilling a hole into a jawbone. The drill section 110 makes the dental implant 100 self-drilling. Therefore, it is not necessary to create a hole using additional preparation instruments to insert the dental implant 100 into a jawbone. Instead, the dental implant 100 can be inserted into a jawbone directly after opening the gums.

[0084] The drill section 110 is located adjacent to the apical end of the shaft 112. The shaft 112 thus connects the drill section 110 to the abutment 104. The implant body 102 comprising the drill section 110 and the shaft 112 is preferably made from a single piece. The abutment 104 is firmly and firmly connected to the shaft 112.

[0085] The shaft 112 comprises a first threaded portion 114, which is arranged directly adjacent to the drill portion 110 toward the coronal end 108 and in which the implant body 102 has an external thread. Adjoining the first threaded portion 114 toward the coronal end 108, the shaft 112 comprises a second threaded portion 116. The shaft 112 also has a third threaded portion 118, which adjoins the second threaded portion 116 toward the coronal end 108. Between the abutment 104 and the third threaded portion 118, the shaft has a fourth portion 120.

[0086] The shaft 112 has an external thread in the first threaded section 114, the second threaded section 116, and the third threaded section 118. The external thread serves to anchor the dental implant 100 in a jawbone. Once the dental implant 100 is inserted into a jawbone, a prosthetic restoration such as a crown or bridge can be attached to the abutment 104 by cementing or adhesive bonding. The dental implant 100 then serves as a support for the crown or bridge and fulfills the function of an artificial tooth root.

[0087] In the fourth section 120, the shaft 112 has a smooth surface and in particular no external thread.

[0088] In the drill section 110, the implant body 102 is designed as a twist drill with a helical chip groove 122 and two main cutting edges 124. The chip groove 122 begins from the main cutting edges 124 and runs helically around the implant body 102 toward the coronal end 108. The chip groove 122 has a groove profile that serves to receive and remove bone chips.

[0089] The helix angle of the twist drill is 25°. In other embodiments not shown here, the helix angle is between 10° and 45°, in particular between 15° and 40°, particularly preferably between 20° and 35°.

[0090] The tip angle of the twist drill, i.e., the angle between the two main cutting edges 124, is 122°. Alternatively, the tip angle can be between 105° and 170°, preferably between 115° and 150°, and particularly preferably between 120° and 135°.

[0091] The drill section 110 has a length of 4 mm, but can also be shorter or longer in alternative embodiments, but has a length of at least 3 mm. A length of at least 3 mm is advantageous because with such a length, it can be assumed that when the drill section 110 has reached the softer, cancellous region of a jawbone during implantation of the dental implant 100, the advance due to the thread pitch of the external thread, in particular of the first thread section 114, will not lead to the breakout of the freshly cut thread.

[0092] The chip groove 122 of the twist drill 110 continues into a thread-cutting groove 126, which runs helically around the shank 112 in the first threaded section 114, the second threaded section 116, and the third threaded section 118. The chip groove 122 and the thread-cutting groove 126 form a common continuous groove. The thread-cutting groove 126 interrupts the external thread in the first threaded section 114, the second threaded section 116, and the third threaded section 118.

[0093] In the first threaded section 114 of the implant body 102, the core diameter of the external thread increases from the outer diameter of the implant body 102 in the drill section 110 to the core diameter of the second threaded section 116.

[0094] In the first threaded portion 114, the shaft 112 has a self-tapping thread cutting edge 128. The thread cutting edge 128 is the edge at the transition between the thread cutting groove 126 and the external thread. The self-tapping thread cutting edge 128 causes the external thread of the shaft 102 to be turned into the jawbone when the dental implant 100 is implanted, and also increases the diameter of the hole drilled with the twist drill. The self-tapping thread cutting edge 128 is attached to the thread cutting groove 126 of the first threaded portion 114. The dental implant 100 is thus not only self-drilling but also self-tapping.

[0095] The chip groove 122 of the drill section 110 merges into the thread-cutting groove 126 of the first threaded section 114, so that during implantation of the dental implant 100, bone chips can be transported from the drill section 110 into the first threaded section 114. This effectively removes bone chips and prevents compression of the surrounding bone.

[0096] The thread cutting groove 126 has the same angle of rotation as the chip groove 122. Furthermore, the thread cutting groove 126 also has the same angle as the chip groove 122. The direction of rotation of the chip groove 122 and the angle of rotation of the thread cutting groove 126 correspond to the direction of rotation of the external thread in the first thread section 114.

[0097] In the second threaded portion 116 of the implant body 102, the thread cutting groove 126 continues from the first threaded portion 114, wherein the thread cutting groove 126 of the second threaded portion 116 has the same groove angle.

[0098] The groove base of the thread cutting groove 126 in the first threaded section 114 and the second threaded section 116 are roughened by blasting with corundum and subsequent etching. The drill section 110 and a centering tip 132 of the implant body 102 arranged apically on the drill section 110 were masked, so that these areas exhibit the originally machined surface.

[0099] In the third threaded section 118, the shaft 112 of the implant body 102 has a double-start external thread. The threads of the double-start external thread have smaller groove widths than the groove widths of the external threads of the first threaded section 114 and the second threaded section 116. Since the pitch of the threads of the double-start external thread in the third threaded section 118 corresponds to the pitch of the external thread in the second threaded section 116, a double-start external thread is introduced here, whereby the web width is reduced accordingly. In the third threaded section 118, the shaft 112 of the implant body 102 is cylindrical. Alternatively, the shaft 112 in the third threaded section 118 can also have a different shape, such as a cone.

[0100] In the fourth section 120, which is arranged between the third threaded section 118 and the abutment 104, the shaft 112 of the implant body 102 has a smooth surface and, in particular, has neither an external thread nor a thread-cutting groove 126. The fourth section 120 is provided so that after the dental implant 100 has been implanted in this area, the gum can adhere to the shaft 112. The remaining part of the implant body 102, i.e., in particular, the drill section 110, the first threaded section 114, the second threaded section 116, and the third threaded section 118, are then located within the drill hole in the jawbone to firmly anchor the dental implant 100. Since the fourth section 120 does not have a thread-cutting groove 126, it does not serve to further transport bone chips from the third threaded section 118.During the implantation of the dental implant 100, bone chips can be removed from the drill hole as long as the thread cutting groove 126 of the third threaded section 118 is at least partially outside the drill hole.

[0101] The implant body 102 has a centering tip 132 at its apical end 106, which adjoins the drill section 110 in the direction of the apical end 106. The centering tip 132 can be used to align the dental implant 100 relative to a jawbone. The centering tip 132 has a length of 1 mm. Alternatively, a centering tip with a length greater than 1 mm and preferably less than 3 mm can also be provided. The centering tip 132 has a conical shape, but could also have another shape, such as a three-sided or four-sided pyramid.

[0102] The abutment 104 is integrally connected to the shaft 112 and serves to attach a dental prosthesis, such as a crown or part of a bridge, to the dental implant 100. The abutment 104 comprises a receiving structure that is open toward the coronal end 108 for receiving an insertion tool. The insertion tool preferably has a part complementary to the receiving structure, which can be inserted into the receiving structure in order to apply the necessary torque and contact force with the insertion tool to screw the dental implant 100 into a jawbone.

[0103] Figure 2 shows a dental implant 200 which is like that in relation to Figure 1The dental implant 100 described has an implant body 202 with a drill section 204 designed as a twist drill and a shaft 206, and an abutment 208 connected to the shaft 206. The abutment 208 has a receiving structure 210. The shaft 206 is identical to that described with reference to Figure 1The drill bit 204 is formed like the shaft 112 of the dental implant 100 described above and has, in particular, an external thread in a first, second, and third threaded section. The twist drill 204 comprises a chip groove that continues in the first, second, and third threaded sections as a thread-cutting groove 212, which runs helically around the shaft toward the coronal end and serves to remove bone chips. A thread-cutting edge 213 is attached to the thread-cutting groove 212 in the first threaded section. This edge serves to rotate the external thread of the shaft 206 into the jawbone during implantation of the dental implant 200 and to enlarge the diameter of a hole drilled with the twist drill bit.

[0104] Additionally, an insertion tool 214 is provided, which is designed to be inserted into the receiving structure 210 with a part 216 complementary to the receiving structure 210 of the dental implant 200, and then to be positively connected to the receiving structure 210. When the insertion tool 214 is connected to the dental implant 200, a torque can be transmitted to the dental implant 200 by rotating the insertion tool 214, thus inserting the dental implant 200 into a jawbone.

[0105] The receiving structure 210 is designed such that grooves are arranged within the circumference of a bore aligned along the longitudinal axis of the implant body 202. The insertion tool 214 has, at one end, a part 216 that is complementary to the receiving structure 210 of the dental implant 200. The part 216 has a cylindrical cross-section that matches the bore of the receiving structure 210 and has at least two elevations that are offset by 180° and have an axial extension that allows the complementary part 216 to be inserted into the grooves of the receiving structure 210, thus creating a positive connection between the dental implant 200 and the insertion tool 214. List of reference symbols

[0106] 100 Dental implant 102 Implant body 104 Abutment 106 Apical end 108 Coronal end 110 Drill section 112 Shaft 114 First threaded section 116 Second threaded section 118 Third threaded section 120 Fourth section 122 Chip groove 124 Main cutting edges 126 Thread cutting groove 128 Self-tapping thread cutting edge 132 Centering point 200 Dental implant 202 Implant body 204 Twist drill 206 Shaft 208 Abutment 210 Receptacle structure 212 Thread cutting groove 213 Thread cutting edge 214 Insertion tool 216 Part of the insertion tool complementary to the receiving structure

Claims

1. A dental implant (100, 200), comprising an implant body (102, 202) extending in a longitudinal direction of the implant body (102, 202) from its apical end (106) to its coronal end (108), wherein the implant body (102, 202) - has a drill section (110, 204) arranged at the apical end (106), in which the implant body (102, 202) is formed for drilling a drill hole in a jaw bone, and - has a shaft (112, 206) which adjoins the drill section (110, 204) in the direction of the coronal end (108) and which comprises - a first threaded section (114) in which the implant body (102, 202) has an external thread, wherein the implant body (102, 202) has, in the first threaded section (114), at least one thread-cutting groove (126, 212) which interrupts the external thread and which extends helically around at least one axial section of the shaft (112, 206) and comprises, at least in the first threaded section (114), a self-cutting thread-cutting edge (128) extending between the thread-cutting groove (126, 212) and the external thread.

2. Dental implant (100, 200) according to claim 1, wherein the implant body (102, 202) in the drill section (110, 204) is designed as a twist drill with at least one helically extending chipping groove (122) and at least one main cutting edge (124), wherein the at least one thread-cutting groove (126, 212) and the at least one chipping groove (122) are designed as a continuous groove.

3. Dental implant (100, 200) according to one of the preceding claims, wherein a core diameter of the implant body (102, 202) in the first threaded portion (114) tapers conically in the direction of the apical end (106).

4. Dental implant (100, 200) according to one of the preceding claims, wherein the shaft (112, 206) comprises a second threaded portion (116) which adjoins the first threaded portion (114) in the direction of the coronal end (108), wherein the implant body (102, 202) has an external thread in the second threaded portion (116), and wherein the thread-cutting groove (126, 212) of the first thread section (114) continues in the second threaded section (116) in a helical shape around the shaft (112, 206), but does not have a self-cutting thread-cutting edge (128) in the second thread section (116), or has a self-cutting thread-cutting edge (128).

5. Dental implant (100, 200) according to one of the preceding claims, wherein the shaft (112, 206) comprises a third threaded portion (118) which adjoins the second threaded portion (116) in the direction of the coronal end (108) and in which the implant body (102, 202) has an external thread which merges into the external thread of the second threaded portion (116), wherein the thread-cutting groove (126, 212) of the first thread section (114) and of the second thread section (116) continues in the third threaded section (118) and also extends helically around the shaft (112, 206) in the third threaded section (118), but does not have a self-cutting thread-cutting edge (128) in the third threaded section (118).

6. Dental implant according to claim 5, wherein the external thread of the third threaded section (118) is formed as a multi-start, preferably two-start external thread, which has the same pitch as the external thread in the first threaded portion (114).

7. Dental implant (100, 200) according to one of the preceding claims, wherein the shaft (112, 206) has a fourth section (120) which adjoins the first, second or third threaded section (114, 116, 118) in the direction of the coronal end (108) and in which the implant body (102, 202) has no external thread and also no thread-cutting groove (126, 212).

8. Dental implant (100, 200) according to one of the preceding claims, further comprising an abutment (104, 208) which adjoins the coronal end (108) of the implant body (102, 202) and which is firmly, preferably materially, connected to the shaft (112, 206).

9. Dental implant (100, 200) according to one of the preceding claims, further comprising a receiving structure (210) which is designed to be form-fit for torque transmission about the longitudinal axis of the implant body (102, 202).

10. The dental implant (100, 200) according to claim 9, wherein the receiving structure (210) is formed as part of the abutment (104, 208) and for receiving an insertion tool (214), preferably as a groove formed in the abutment (104, 208).

11. The dental implant (100, 200) according to any one of the preceding claims, wherein a rotational direction of the chipping groove (122) corresponds to a rotational direction of the external thread of the first threaded portion (114).

12. The dental implant (100, 200) according to any one of the preceding claims, wherein the thread-cutting groove (126, 212) in the first threaded portion (114) and / or in the second threaded portion (116) branches towards the coronal end (108).

13. Dental implant (100, 200) according to one of the preceding claims, wherein the implant body (102, 202) in the drill section (110, 204) is formed as a twist drill having two or more main cutting edges (124), preferably three or more main cutting edges (124).

14. Dental implant (100, 200) according to one of the preceding claims, wherein the implant body (102, 202) has a centering tip at its apical end (106) and the drill section (110, 204) adjoins the centering tip and extends towards the coronal end (108), wherein the centering tip is designed such that the dental implant (100, 200) can be aligned relative to a jawbone by means of the centering tip.

15. The dental implant (100, 200) according to any one of the preceding claims, wherein the implant body (102, 202) comprises an undercut arranged adjacent to the self-cutting thread-cutting edge (128) of the thread-cutting groove (126, 212) of the first threaded portion (114) in the direction of the coronal end (108).