SUBSTITUTION AND MODULAR DENTAL IMPLANT

Description

field of technology

[0001] The invention relates to a component for a modular dental implant, a corresponding manufacturing process, a base body for a modular dental implant and a modular dental implant. Technological background

[0002] Dental implants can be designed as one-piece or multi-piece implants. Generally, multi-piece dental implants have become more prevalent due to their advantages over one-piece implants. Multi-piece implants can be better adapted to the specific intended use and offer better protection against unwanted stress during the healing process.

[0003] The multi-part dental implants known from the prior art are often composed of three parts: a base body that is inserted into the jawbone, an abutment that is attached to the base body, and a superstructure that is placed on top of the abutment. The base body, also known as the implant body, is designed to functionally replace the tooth root and is usually cylindrical or conical in shape. It typically has a thread that allows it to be screwed into the jawbone. The abutment, also known as the implant abutment, serves as an intermediate component between the base body and the superstructure and is usually screwed and / or bonded into the base body. The superstructure is the actual dental prosthesis, usually in the form of a crown, bridge, or denture.A dental implant can also have two or more base bodies for anchoring a superstructure, for example in the case of bridges and dentures. The base body and abutment are embedded in the jawbone or covered by the superstructure. The superstructure itself is exposed in the oral cavity.

[0004] A modular dental implant is known, for example, from US 2019 / 0223986 A1.

[0005] In dental prosthetics, biocompatible and / or bioinert materials are preferred. Titanium or titanium alloys, and ceramic materials, especially zirconium oxide ceramics, are very commonly used. The base of a dental implant is particularly advantageous when made of such a bioinert material to ensure that the base can be inserted with as few complications as possible and, in particular, to prevent gum or bone resorption. Both the material and the structure of the base should allow for a high degree of osseointegration and periointegration. The aforementioned requirements regarding high biocompatibility and bioinertness also apply to the abutment and the superstructure.

[0006] The advantage of using titanium for implants placed in the jawbone lies in its well-documented biocompatibility, proven over decades. Titanium implant bodies place minimal stress on the patient's body. Furthermore, titanium has the advantage of being tough and not brittle. However, its dark gray color can make it appear as a foreign body in the oral cavity. Therefore, titanium is preferred for dental implants placed in the jawbone, where they are covered by the gums and thus not visible in the mouth.

[0007] Ceramic restorations also exhibit excellent biocompatibility and are therefore well tolerated by the body. The advantage of ceramics is that they can be colored to closely match natural tooth color, thus being perceived less as a foreign body in the oral cavity, or even not at all. Furthermore, the absence of metal is increasingly important due to the avoidance of allergies. Ceramic restorations are preferred for tooth reconstruction and other visible components in the oral cavity, such as abutments, healing components, locators, etc.

[0008] For the long-term success of a dental implant, a reliable connection between the abutment and the base, sealed against bone and gum tissue, is crucial. A faulty connection between the abutment and base can lead to loosening or damage of the dental implant. Leaky connections allow bacteria to penetrate the implant, which can lead to peri-implantitis and thus, for example, to jawbone loss.

[0009] Furthermore, the forces occurring in the dentition place high demands on materials and design. Dental implants must be able to withstand all the high forces occurring in the dentition without breaking, tearing, or loosening.

[0010] Ceramics, especially zirconium oxide, are significantly harder than titanium. Due to standard processing methods, ceramic components exhibit fine, sharp-edged structures on their surface. When ceramic and titanium elements come into contact, these sharp-edged surface structures can damage the titanium. This is particularly relevant because dental implants are subjected to strong forces, for example, during chewing, and some movement of the elements relative to each other is unavoidable. This movement can include rotational movements around the longitudinal axis of the base or abutment, as well as axial movements. The titanium implant is then continuously damaged, especially by chewing movements. Therefore, it is known that ceramic and metallic materials in a dental implant should ideally have no contact surfaces.They should have contact points with each other, especially if abrasion from the contact surfaces, in the form of very fine titanium shavings, can enter the oral cavity and thus the patient's body.

[0011] DE 102010019582 A1 discloses a multi-part dental implant comprising a post and an abutment. The two parts are made of metal or ceramic and are connected by a screw. To achieve smooth and functional rotational self-centering of the two parts, which is achieved solely by tightening the connecting screw, the friction between the contact surfaces is reduced by a surface coating on one or both contact surfaces. The use of lubricants and polishing has proven insufficient.

[0012] EP3187145A1 discloses a dental implant made of a ceramic, in particular an oxide ceramic material based on zirconium dioxide, ZrO₂, or its composite ceramics. It consists of an anchoring element and an abutment with an integrated neck, formed by means of a threaded pin and a threaded sleeve. The layer located between the anchoring element and the neck of the abutment is designed as a facet and provided with a buffer layer of a silicate glass solder, which covers a portion of the facet. The glass solder is applied to at least one of the surfaces of the facet using a 3D printer, airbrush technology, or similar methods, and the layer is subsequently welded, for example, with a laser, to create an antibacterial seal.Local stresses in the ceramic of the two interfaces are absorbed by the silicate glass solder coating, which has partially diffused into the surface.

[0013] There is a general need for improvements in this area. Description of the invention

[0014] One object of the invention is to provide a component for a modular dental implant which does not have the aforementioned and other disadvantages.

[0015] In particular, such a component for a modular dental implant should enable its combination with a metallic base body to form a modular dental implant.

[0016] Such a modular dental implant should be reliable, durable and well-tolerated.

[0017] These and other problems are solved by an inventive component for a modular dental implant and an inventive modular dental implant, as well as an inventive manufacturing method, according to the independent claims. Further advantageous embodiments will become apparent from the dependent claims and the description.

[0018] The inventive solution can be further improved by various embodiments, each advantageous in itself and, unless otherwise stated, arbitrarily combinable with one another. These embodiments and their associated advantages are discussed below.

[0019] A first aspect of the invention relates to a component for a modular dental implant.

[0020] In the case of an abutment for a modular dental implant, wherein the modular dental implant comprises: a base body that can be anchored in a jawbone and is made of a metallic material suitable for implants; and the abutment, which is intended to be connectable to the base body of the modular dental implant, the abutment is made of a ceramic material suitable for implants. The surface of the abutment is designed, in a contact area, to touch a surface in a contact area of ​​a base body when the modular dental implant is assembled, or to rest on the surface in the contact area of ​​the base body.The surface of the abutment in the aforementioned contact area is machined such that it has a mean roughness value Ra which, during the operational use of the modular dental implant, prevents damage to the surface of the base body in the aforementioned contact area by the abutment, in particular material removal. In the contact area, the mean roughness value Ra of the surface of the abutment is ≤ 0.08 micrometers, advantageously ≤ 0.04 micrometers, and particularly advantageously ≤ 0.02 micrometers.

[0021] A large contact area between the base and abutment of a modular dental implant is advantageous because it results in higher friction between the two elements and simultaneously lower surface pressure. This leads to greater stability of the assembled dental implant. Furthermore, a large contact area results in lower contact pressure for the same applied force. Consequently, the relative movements of the base and abutment during use of the dental implant result in lower shear forces, which also reduces unwanted mechanical material loss. However, the contact area between the base and abutment should not be too large, as a smaller contact area leads to higher contact pressure for the same applied force. Higher contact pressure creates a bacteria-tight seal between the patient's oral cavity and the implant's interior.The contact pressure should therefore be at least high enough to ensure a bacteria-proof seal.

[0022] An inventive component advantageously consists of zirconium oxide, in particular of yttrium-stabilized zirconium oxide.

[0023] Such advantageous components make it possible to combine two advantageous materials—namely, the metallic material, in particular titanium, of a base body and the ceramic material, in particular zirconium oxide, of an abutment—for a modular dental implant without the problems known from the prior art arising from direct contact. Due to the titanium-friendly design of the ceramic surface of the abutment in the contact area according to the invention, the significantly harder ceramic material of the abutment does not corrode the metal surface of the base body. This can be achieved by rounding off the sharp-edged grains of the ceramic material.

[0024] In an advantageous variant, the average roughness value Ra in the contact area of ​​the component lies between 0.02 and 0.04 micrometers.

[0025] The arithmetic mean roughness value Ra is standardized by DIN EN ISO 4287:2010.

[0026] The surface of the component in the contact area can be coated, for example with metal vapor coating or plasma coating.

[0027] The surface of the component in the contact area can also be glazed. A glaze can be achieved by applying one or more glaze layers to the ceramic part and then melting them together. Another possibility is to apply a substance or mixture of substances, such as a salt, to the surface of the ceramic part, which locally lowers the melting point of the ceramic material below the sintering temperature, thus creating a corresponding glass layer. Such a substance can also be applied via the gas phase.

[0028] Due to the smoother surface of the component in the contact area, the abrasion of the surface of the base body in contact area is lower.

[0029] Advantageously, a component according to the invention has no edges in the contact area.

[0030] An advantage of a component according to the invention is that the surface of the component in the contact area is continuous and / or rounded.

[0031] Advantageously, in a component according to the invention, the surface of the component in the contact area has a geometric continuity G1 (tangential continuity).

[0032] A G1 continuity of the surfaces in the contact area means in particular that there are no edges (continuity G0) on any of the surfaces in the contact area which, in the event of even a small relative displacement of the elements or components of a modular dental implant to each other, could catch on the opposite surface and shear off material, or be sheared off particularly easily themselves.

[0033] Particularly advantageous in a component according to the invention is that the surface of the component in the contact area has a geometric continuity G2 (curvature continuity).

[0034] Such G2 consistency of the surfaces in the contact area has the advantage that, even with a small relative displacement of the elements or components of a modular dental implant, the contact pressure remains approximately constant. The uniformly acting forces lead to a reduced asymmetrical mechanical force and thus also to a reduction in mechanically induced material removal from the surface.

[0035] In an advantageous embodiment of a component according to the invention, the surface of the component is polished in the contact area.

[0036] The polishing of the component is discussed in more detail in the inventive method discussed below.

[0037] Advantageously, a component according to the invention is manufactured using a powder injection molding process.

[0038] Powder injection molding of such a ceramic component or element results in a significantly smoother surface on the ceramic part produced by powder injection molding than is possible with subsequent subtractive machining processes, especially subtractive machining processes such as milling, grinding, or drilling, due to the advantageously very smooth surface of the injection mold. This primary shaping of the ceramic part without mechanical material removal thus avoids the corresponding machining marks that would otherwise increase the average roughness (Ra). Additionally, subtractive machining processes can stress the material structure of the ceramic component and thus lead to damage in the material structure, such as stresses or cracks. Such damage can reduce the strength of the ceramic part. With ceramic powder injection molding, this risk of damage is either eliminated or significantly reduced.

[0039] Advantageous freeform shapes on the elements or components of a modular dental implant are also much easier to produce using powder injection molding than with the aforementioned subtractive machining processes.

[0040] In a further advantageous embodiment of a dental implant according to the invention, the abutment has a projection which, in the assembled state of the dental implant, is inserted into a recess of the base body.

[0041] A second aspect of the invention relates to a method for manufacturing an abutment for a modular dental implant, wherein the modular dental implant comprises: a base body that can be anchored in a jawbone and is made of a metallic material suitable for implants, and an abutment that is intended to be connected to the base body of the modular dental implant.

[0042] Such a process according to the invention comprises the following steps: Providing a sintered ceramic abutment, for example made of zirconium oxide; treating a surface of the ceramic abutment at least in a contact area of ​​the abutment in which, in an assembled state of the modular dental implant, the abutment and the base body of the modular dental implant touch, or in which the base body of the modular dental implant and the abutment are arranged lying against each other; The surface in the aforementioned contact area of ​​the abutment is processed such that the surface has a mean roughness value Ra which, during the operational use of the modular dental implant, prevents damage to the surface of the base body of the modular dental implant by the abutment, in particular material removal; and the surface of the abutment in the contact area is processed such that the surface has a mean roughness value Ra ≤ 0.08 micrometers, advantageously ≤ 0.04 micrometers, and particularly advantageously ≤ 0.02 micrometers.

[0043] In an advantageous variant, the mean roughness value Ra lies between 0.02 and 0.04 micrometers.

[0044] A reduction in the mean roughness value can be achieved by rounding, smoothing, blasting or polishing the sharp-edged ceramic surface. In an advantageous embodiment of the process, the surface of the component is polished in the contact area.

[0045] Advantageously, polishing in the contact area is carried out by vibratory finishing, brushing or lapping.

[0046] Vibratory finishing is a mechanical-chemical process for deburring, rounding, smoothing, or polishing individual and mass-produced parts. In this process, vibration and agitation cause the loose workpieces to move relative to the grinding or polishing media, resulting in a smoothed surface. Vibratory finishing can therefore be used to grind and polish components made of ceramic materials.

[0047] The vibratory finishing process can be carried out, for example, in a rotary vibrator. Rotary vibrator equipment is offered by various manufacturers such as RÖSLER Oberflächentechnik GmbH or Walther Trowal GmbH & Co. KG. These manufacturers also supply the consumables necessary for operating these devices, such as abrasive media, compounds, and additives.

[0048] For example, a long vibratory finishing process of at least 48-72 hours on the surface of the ceramic component can achieve a mean roughness value Ra according to the invention. Such a mean roughness value prevents damage to the surface of the base body by the abutment in the aforementioned contact area during the operative operation of the dental implant, in particular preventing material removal.

[0049] To achieve the desired average surface roughness, abrasive media are added to the workpieces, in this case the components, during the vibratory finishing process. Preferably, the shape of the abrasive media is matched to the geometry of the workpiece surface. Care must be taken to ensure that all essential contours are reached and that no jamming can occur between the abrasive media or between the abrasive media and the workpieces. The abrasive media can have flat, round, or pointed shapes. Pointed shapes allow the abrasive media to polish even angular surfaces of the workpieces. Flat or round shapes prevent the polishing of angular areas on the workpiece surface.

[0050] For vibratory finishing, the polishing stones are advantageously shaped in such a way that they are suitable for gripping the surfaces to be polished effectively.

[0051] The shape of the abrasive media influences its grinding behavior. Curved, round shapes are less aggressive than angular abrasive geometries. Generally speaking, the larger and heavier the abrasive media, the more intense and powerful the grinding action, and the coarser and rougher the resulting surface finish.

[0052] The abrasive media used for vibratory finishing the surface of the component in the contact area can be made of ceramic, such as aluminum oxide. Preferably, the ceramic of the abrasive media has a higher hardness than the components to be polished. However, abrasive media made of plastic, stone, or metal, such as brass or stainless steel, can also be used for the vibratory finishing process.

[0053] The size difference between the ceramic components and the grinding media is advantageously chosen so that, after the vibratory finishing process, it is possible to easily separate workpieces and grinding media according to size.

[0054] Advantageously, in such a process according to the invention, a polishing agent is additionally used during polishing, to which an abrasive powder is optionally added.

[0055] The polishing compound, also called a compound or treatment agent, can consist of a soapy or oily liquid. The polishing compound keeps the surface of the abrasive media and workpieces clean and maintains consistent quality in the vibratory finishing process. If abrasive powder is added to the polishing compound, it is evenly distributed on the abrasive media, thus optimizing the polishing process.

[0056] Suitable abrasive powders for addition to the vibratory finishing process include diamond powder or ceramic powder. The ceramic powder can consist of materials such as aluminum sulfide, silicon nitride, zirconium oxide, boron carbide, or boron nitride. The abrasive powder can also be incorporated into the grinding media. Different abrasive powders can also be mixed.

[0057] The polishing compound is selected according to the material being processed and the desired finishing result. Possible compounds for the vibratory finishing process for the disclosed advantageous components are ARF-S or M10 from Walther Trowal or IMR4 from Rösler. The manufacturers do not publish the ingredients of the compounds. Liquid compounds are most commonly used, as they best meet the requirements of modern dispensing systems. However, vibratory finishing can also be supplemented with powdered or paste-like compounds in specific cases.

[0058] Additives can also be added to further enhance the grinding performance. These additives are added in batches of approximately 0.5-1.0 kg per 100 kg of grinding media.

[0059] In a process according to the invention, the ceramic component is advantageously manufactured using a powder injection molding process.

[0060] Powder injection molding of a ceramic component or element results in a significantly smoother surface finish on the ceramic part produced using this method, due to the very smooth surface of the injection mold. This is more achievable with subtractive machining processes, particularly subtractive machining processes such as milling or drilling. Furthermore, subtractive machining processes can stress the material structure of the ceramic component, leading to damage such as stresses or cracks. Such damage can reduce the strength of the ceramic part. With ceramic powder injection molding, this risk of damage is either eliminated or significantly reduced.

[0061] Advantageous freeform shapes on the components are also significantly easier to produce than with the aforementioned subtractive machining processes.

[0062] One aspect of the description concerns a base body for a modular dental implant.

[0063] A base body for a modular dental implant is designed to be anchored in the jawbone and connected to an abutment of the dental implant. The base body is made of a metallic material suitable for dental implants. When the modular dental implant is assembled, the surface of the base body is designed to contact a surface of the abutment of the dental implant within a contact area of ​​the abutment, or to rest on the surface of the abutment within that contact area.

[0064] An advantage of such a base body is that the surface of the base body is continuous and / or rounded in the contact area.

[0065] Alternatively or additionally, such a base body has no edges in the contact area.

[0066] Advantageously, the surface of a base body exhibits geometric continuity G1 (tangential continuity) in the contact area. Particularly advantageous is the surface of the base body exhibiting geometric continuity G2 (curvature continuity) in the contact area. Reference is made to the corresponding explanations in connection with the superstructure.

[0067] It is advantageous if the surface of a base body in the aforementioned contact area is coated, for example plasma-coated or enamelled, and / or hardened or anodized.

[0068] A hardened surface on the metal base body results in less abrasion on the metal component due to contact with the harder ceramic component in the contact area. The type of coating or hardening process is advantageously chosen so that the resulting hardness of the base body surface in the contact area is similar to the hardness of the surface of the component in the contact area. This minimizes abrasion of the metallic base body.

[0069] An enamel coating of the base body in the contact area results in a smooth surface, which prevents protruding structures on the contact surface of a component from hooking in and shearing off material.

[0070] Advantageously, such a base body is made of titanium or a titanium alloy.

[0071] In another embodiment, the base body can be made of ceramic material. In such an embodiment, the specifications regarding the surface in the contact area of ​​the superstructure also apply to the surface in the contact area of ​​the base body.

[0072] A third aspect of the invention relates to a modular dental implant.

[0073] A modular dental implant according to the invention comprises a base body that can be anchored in a jawbone, as well as an abutment according to the invention that can be connected to the base body.

[0074] The surface of the abutment is machined in the contact area in such a way that, depending on the hardness of the metallic material of the base body and the hardness of the ceramic material of the abutment, it has a mean roughness value Ra which, in the operational use of the dental implant, prevents or largely excludes damage to the surface of the base body in the aforementioned contact area by the abutment, in particular abrasive material removal.

[0075] A large contact area between the base and the abutment is advantageous because it leads to higher friction between the two elements and simultaneously to lower surface pressure. This results in greater stability of the assembled dental implant. Furthermore, a large contact area results in lower contact pressure for the same applied force. Consequently, the relative movements of the base and abutment during use of the dental implant result in lower shear forces, which also reduces unwanted mechanical material loss. However, the contact area between the base and abutment should not be too large, as a smaller contact area leads to higher contact pressure for the same applied force. Higher contact pressure creates a bacteria-tight seal between the patient's oral cavity and the implant's interior.The contact pressure should therefore be at least high enough to ensure a bacteria-proof seal.

[0076] Dental implants according to the invention make it possible to use two advantageous materials, namely the metallic material, in particular titanium, and the ceramic material, in particular zirconium oxide, in combination for the dental implant without the problems known from the prior art occurring in direct contact. Due to the titanium-friendly design of the ceramic surface in the contact area of ​​the abutment according to the invention, the significantly harder ceramic material does not corrode the metal surface in the contact area of ​​the base body.

[0077] An advantage of a dental implant according to the invention is that the surface of the harder component or element is rounded in the contact area between the abutment and the base body.

[0078] In an advantageous embodiment of a dental implant according to the invention, the abutment has a projection which, in the assembled state of the dental implant, is inserted into a recess of the base body.

[0079] The base body and / or the superstructure of a dental implant according to the invention advantageously consists of two or more elements or components.

[0080] Advantageously, in the assembled state of a dental implant according to the invention, there is a torsion-resistant positive locking connection between the base body and the abutment.

[0081] In an advantageous embodiment of a dental implant according to the invention, the base body and the superstructure are connected by a connecting screw in the assembled state of the dental implant.

[0082] Further aspects of the present invention will also become apparent from the following description. Brief description of the drawings

[0083] The dental implant according to the invention will be explained below with reference to drawings. Figure 1 Figure 1 schematically shows a longitudinal section through a possible embodiment of a dental implant according to the invention. Figure 2 schematically shows a detailed view from the longitudinal section of the Figure 1 , in which the contact area between the base body and the superstructure is shown. Figure 3 schematically shows a longitudinal section of the dental implant. Figure 1 in exploded view. Ways to implement the invention

[0084] The examples given below serve to better illustrate the invention, but are not suitable to limit the invention to the features disclosed herein.

[0085] An advantageous embodiment of a dental implant 1 according to the invention is described in the Figures 1, 2 and 3The dental implant 1 consists of a metallic base body 2 and a ceramic abutment 3, which are operatively connected by a connecting screw 4 along the longitudinal axis 11.

[0086] The base body 2, which is designed to be permanently fixed in a jawbone, has an external thread 22 with which the base body 2 can be screwed into a previously drilled blind hole in the jawbone during implantation. Depending on whether a thread has been cut into this blind hole or not, the external thread 22 of the base body 2 can be selected accordingly. For example, the external thread can be designed as a cutting thread, so that no separate internal thread needs to be provided in the borehole in the jawbone.

[0087] Aligned with the longitudinal axis 11, a substantially cylindrical blind hole 26, open towards the coronal longitudinal end, is arranged in the base body 2, with an internal thread 25, which is intended to interact with an external thread 41 of a connecting screw 4 in the assembled state of the dental implant 1.

[0088] The blind hole 26 of the base body 2 widens outwards into a concave recess 23, which is essentially shaped like a hollow cone. In the assembled state of the dental implant 1, the conical surface of the conical apical projection 33 of the ceramic abutment 3 rests on the conical surface of the recess 23.

[0089] The conical shape of recess 23 and projection 33 has the advantage that, during assembly of the dental implant 1, the base body and abutment 3 self-center along the longitudinal axis 11. At the same time, the play between the base body and abutment is minimized both longitudinally 11 and transversely to it. This is advantageous with regard to preventing abrasion.

[0090] The abutment 3 comprises a body 34 with a through-hole 35. At the apical end of the abutment, a substantially conical projection 33 is arranged, which, in the assembled state of the dental implant 1, lies flush in the conical recess 23 of the base body. At the coronal end of the abutment, a recess is arranged in which the screw head 43 of the connecting screw 4 rests.

[0091] The surfaces 21, 31 of the conical outer surfaces of recess 23 and projection 33, which come into contact during normal operative operation of the dental implant 1, define the contact area 5 and 5' respectively. Recess 23 and projection 33 are designed such that the contact area is as large as possible and essentially conical.

[0092] A large contact area leads to more precise positioning and thus greater stability of the assembled implant. Furthermore, a large contact area results in higher static friction, again contributing to greater stability of the assembled implant. At the same time, a large contact area leads to a relatively lower contact pressure, and therefore lower frictional forces, resulting in less undesirable mechanical material loss.

[0093] However, the contact area should not be too large, because a smaller contact area results in higher contact pressure for the same force. This higher contact pressure ensures a good, bacteria-tight seal between the patient's oral cavity and the implant's interior. Therefore, the contact area should be sufficiently small so that the resulting contact pressure guarantees a bacteria-tight seal.

[0094] Simultaneously, in the illustrated embodiment, the recess 23 and the projection 33, and in particular their surfaces in the contact areas 5, 5', are designed such that the surface is continuous, i.e., has no edges or discontinuities. Such edges and discontinuities are problematic with regard to mechanical abrasion. Edges on the harder ceramic component can penetrate the softer metallic material of the base body during relative movement of the overlapping surfaces and shear off material. Conversely, edges on the softer base body can be more easily sheared off by the ceramic material. Continuous surfaces minimize this source of mechanical material removal.

[0095] In the example shown, the recess 23 of the base body 2 is conically shaped. The contact area 5 of the projection 33 of the superstructure 3 is also conically shaped, matching the shape of the recess 23. At the apical end of the projection 33, however, the slope of the conical surface decreases in an edge region of the contact surface 5 with respect to the longitudinal axis 11, so that a continuously increasing gap forms between the surface 5' of the recess 23 and the surface 5 of the projection 33 towards the longitudinal axis 11 (see arrow B in Figure 1). Figure 2 Similarly, at the coronal end of the projection 33, in a marginal region of the contact surface, the slope of the conical surface increases with respect to the longitudinal axis 11, so that a continuously increasing gap also arises (see arrow C in Figure 2As a result of this design of the contact area 5, 5', there are no edges at the end of the contact area 5, 5' of recess 23 and projection 33 which can scrape off material or which can be sheared off.

[0096] In an alternative embodiment not shown, the surface of the recess 23 can alternatively or additionally be designed such that the angle of inclination of the conical surface of the recess 23 relative to the longitudinal axis 11 increases towards an apical end of the recess, and the angle of inclination of the conical surface of the recess 23 relative to the longitudinal axis 11 decreases towards a coronal end of the recess, so that a continuously increasing gap between recess 23 and projection 33 also results at the ends of the contact area 5, 5'.

[0097] In the two aforementioned embodiments, the surfaces of base body 2 and superstructure 3 exhibit at least one geometric continuity G1 in the contact area 5', 5. The geometric continuity G2, as shown in the example in the figures, is particularly advantageous.

[0098] A connecting screw 4 serves to form a positive and force-fit connection between the base body 2 and the abutment 3 of the dental implant 1. The connecting screw 4 comprises a cylindrical bolt 44 with an external thread 41 and a screw head 43. In the example shown, the screw head has a concave recess for a hexagonal key, allowing the screw to be tightened and loosened. Other methods of connecting a screw with a screw tool are also known to those skilled in the art.

[0099] The connecting screw 4 is preferably made of metal, but it can also be made of ceramic. However, ceramic screws are significantly more sensitive to shear forces.

[0100] The inner diameter of the through-hole 35 of the abutment 3 is selected such that, in the assembled state of the dental implant 1, the unthreaded section of the screw bolt 44 lies flush in the through-hole 35. The screw 4 pulls the base body and the abutment together with a certain tensile force, so that the conical projection 33 of the abutment 3 is pressed into the complementary conical recess 23 of the base body 2. This results in a firm and force-fit connection between the base body 2 and the abutment 3, which simultaneously seals the interior of the dental implant, consisting of the blind hole 26 and the through-hole 35, with respect to the connection between the base body and the abutment.

[0101] On the assembled modular dental implant 1 as in Figure 1 As shown, a superstructure, for example a ceramic dental crown, can then be mounted on the abutment 3, for example by bonding. Advantageously, this superstructure seals the abutment 3 externally, so that the connecting screw 4 lies completely within the modular dental implant 1.

[0102] The scope of the present invention is not limited to the specific embodiments described herein. Rather, the description and accompanying figures reveal to the person skilled in the art various further modifications of the present invention, in addition to the examples disclosed herein, which also fall within the scope of the claims. Furthermore, the description cites various references, the disclosure content of which is hereby incorporated into the description in its entirety by reference. Reference symbol list

[0103] 1 Dental implant 11 Longitudinal axis 2 Base body 21 Surface of the base body in the contact area 22 External thread 23 Recess 25 Internal thread 26 Blind hole 3 Abutment 31 Surface of the abutment in the contact area 33 Projection 34 Body of the abutment 35 Through hole 4 Connecting screw 41 External thread 43 Screw head 44 Screw bolt 5 Contact area of ​​the abutment 5' Contact area of ​​the base body

Claims

1. An abutment (3) for a modular dental implant (1), the modular dental implant (1) comprising: - a main part (2), which can be anchored in a jawbone and is made of a metal material suitable for implants, and - the abutment (3), which is intended to be connectable to the main part (2) of the modular dental implant (1); wherein the abutment (3) is made of a ceramic material suitable for implants (3); wherein the surface (31) is intended in a contact region (5) of the abutment (3) to contact a surface (21) in a contact region (5') of the main part (2), or to lie on the surface (21) in the contact region (5') of the main part (2), when the modular dental implant (1) is in an assembled state; and wherein the surface (31) of the abutment (3) in the mentioned contact region (5) of the abutment (3) is machined such that the surface (31) has a roughness average Ra which, when the modular dental implant (1) is in operation, prevents damage, in particular the removal of material, by the abutment (3) to the surface (21) of the main part (2) in the mentioned contact region (5') of the main part (2), characterized in that the roughness average Ra of the surface (31) of the abutment (3) in the contact region (5) is ≤ 0.08 micrometers, advantageously ≤ 0.04 micrometers, and is particularly advantageously ≤ 0.02 micrometers.

2. The abutment (3) according to claim 1, wherein the surface (31) of the abutment (3) is continuous and / or rounded in the contact region (5).

3. The abutment (3) according to any one of the preceding claims, wherein the surface (31) of the abutment (3) has G1 continuity in the contact region (5), and advantageously G2 continuity.

4. The abutment (3) according to any one of the preceding claims, wherein the surface (31) of the abutment (3) is polished in the contact region (5).

5. The abutment (3) according to any one of the preceding claims, wherein the abutment (3) is produced by means of powder injection molding methods.

6. A method for producing an abutment (3) for a modular dental implant (1), wherein the modular dental implant (1) comprises: a main part (2), which can be anchored in a jawbone and is made of a metal material suitable for implants, and an abutment (3), which is intended to be connected to the main part (2) of the modular dental implant (1); the method comprising the steps of: - providing a sintered ceramic abutment (3), for example comprising zirconium oxide; - treating a surface (31) of the ceramic abutment (3) at least in a contact region (5) of the abutment (3) in which, when the modular dental implant (1) is in the assembled state, the abutment (3) and the main part (2) of the modular dental implant (1) contact, or in which the main part (2) of the modular dental implant (1) and the abutment (3) are arranged adjacent to each other; wherein the surface (31) in the mentioned contact region (5) of the abutment (3) is machined such that the surface (31) has a roughness average Ra which, when the modular dental implant (1) is in operation, prevents damage, in particular the removal of material, by the abutment (3) to the surface (21) of the main part (2) of the modular dental implant (1), characterized in that the surface (31) of the abutment (3) in the contact region (5) is machined such that the surface (31) has a roughness average Ra ≤ 0.08 micrometers, advantageously ≤ 0.04 micrometers, and particularly advantageously ≤ 0.02 micrometers.

7. The method according to claim 6, wherein the surface (31) of the abutment (3) is polished in the contact region (5).

8. The method for producing an abutment (3) according to claim 7, wherein the polishing in the contact region takes place by vibratory grinding, lapping or brushing.

9. The method according to claim 7 or 8, wherein a polishing agent is additionally used during polishing.

10. The method according to claim 9, wherein a grinding powder is additionally added to the polishing agent.

11. The method according to any one of claims 7 through 10, wherein polishing stones made of ceramic, stone, plastic or metal are used for vibratory grinding.

12. The method according to any one of claims 7 through 11, wherein the polishing stones are shaped such that they are suitable for gripping the surfaces to be polished well.

13. The method according to any one of claims 6 through 12, wherein the abutment (3) is produced by means of powder injection molding methods.

14. A modular dental implant (1), having a main part (2), which is intended for the purpose of being anchored in a jawbone and being connected to an abutment (3) of a dental implant (1); wherein the main part (2) is made of a metal material suitable for dental implants; and wherein the surface (21) of the main part (2) is intended in a contact region (5') of the main part (2) to contact a surface (31) of the abutment (3) of the dental implant in a contact region (5) of the abutment (3), or to lie on the surface (31) in the contact region (5) of the abutment (3), when the modular dental implant (1) is in an assembled state, and having an abutment (3) according to any one of claims 1 to 5 that can be connected to the main part (2).