Adapter for connecting a dental implant to a tooth crown

Abstract

The invention relates to an adapter for connecting a dental implant to a tooth crown, comprising a retaining member which is arranged on the crown side and which defines an insertion axis for the tooth crown running transversely to the base surface of the adapter on the implant side, and a point of intersection is formed by the insertion axis with the plane defined by the base surface, and the point of intersection lies on an axis of rotation, wherein, in the usage position of the adapter, once the base surface is supported on the dental implant, the orientation of the insertion axis can be changed by a rotation of the adapter about this axis of rotation. The base surface (16) has a blind hole (20) which is rotationally symmetrical about the point of intersection (S) and receives, similar to a pivot bearing, a connection piece (52) of the dental implant (50) in said usage position, and a part of the blind hole (20) serves as a contact surface (22) for the connection piece (52).

Description

[0001] Adapter for connecting a dental implant to a dental crown

[0002] The invention relates to an adapter for an implant-supported implant structure for holding at least one dental crown.

[0003] Background of the invention

[0004] Dental implants are increasingly used in the provision of dentures. These implants, also simply called dental implants, form an artificial tooth root and are anchored in the jawbone. Adapters based on this invention form an intermediate piece between the oral end of the dental implant (facing the mouth) and an implant abutment (also called abutment) for holding a removable or fixed denture. In this description, the term "denture" is synonymous with a dental crown, several crowns joined together, a bridge, or a bar construction, which are collectively referred to as superstructures.

[0005] For the fabrication of removable dentures – referred to here as dental prosthetics – a double crown technique is widely used. In this context, double crowns are telescopic crowns, consisting of an inner and an outer telescope. The telescopic crowns can be milled parallel or conically, the latter being called conical crowns and offering the advantage of a durable, removable, friction-fit connection with the implant abutment.

[0006] Cost-effective implant-supported dentures utilize an adhesive abutment with machine-fabricated crowns. These crowns are planned "on-site" in the dental practice, next to the dental chair, using a CAD / CAM process and milled from a standardized blank. The resulting crown features a standardized receptacle or metal core for bonding to the implant abutment. Many dental implant manufacturers offer specially designed one-piece implants or two-piece, manufacturer-specific implants with an integrated connector that provides a form-fitting bonding surface for crowns fabricated using this method.

[0007] The abutment can be integrated with the implant as a single unit, effectively preventing bacteria from penetrating the dental implant. The dental implant is placed in the mouth where sufficient bone volume is present. This often requires the implant to be positioned at an angle in the jaw that deviates significantly from the axis of the tooth being replaced. Especially when multiple implants are used, the angles relative to each other can vary considerably. However, for removable dentures, a very similar insertion angle should be achievable to allow for easy removal and reinsertion of the prosthesis. To achieve this, the implant-supported abutments are usually extensively prepared and thus customized. Damage, repairs, modifications, or extensions to the prosthesis, such as a multi-unit bridge, require very expensive custom fabrication.

[0008] There is therefore a need for prefabricated abutments for implant-supported dentures. An adapter is intended to compensate for the angular differences between the angle of the inserted implant(s) and the insertion direction for the dental prosthesis.

[0009] State of the art

[0010] A generic adapter is known from DE 10 2018 001 195 A1. This known adapter for connecting a dental implant to a dental crown is provided with a retaining element arranged on the crown side, which defines an insertion axis for attaching the dental crown to the retaining element, wherein the insertion axis runs transversely to the implant-side base surface of the adapter, and an intersection point is formed between the insertion axis and the plane defined by the base surface, and the intersection point lies on a rotation axis intersecting the plane, wherein, in the operating position of the adapter after the base surface is supported on an oral end – facing the oral cavity – of the dental implant, a rotation of the adapter about this rotation axis changes the orientation of the insertion axis with respect to the dental implant.

[0011] This previously known adapter has a complex geometry and is held in its operating position on the dental implant by a screw connection, with an insertion screw forming a rotational axis of the adapter around the implant. By rotating the adapter around this axis, any angular position of the dental implant relative to the tooth axis defined by the prosthesis can be corrected, as the insertion axis is adjustable in relation to the inserted implant.

[0012] This previously known adapter is part of a prefabricated abutment kit. This kit comprises a variety of different components, which make dental prosthetics quite expensive.

[0013] German patent DE 41 41 128 A1 discloses an adapter for aligning an insertion axis with respect to the dental implant to facilitate the insertion and removal of the dental prosthesis. The insertion axis thus describes a thrust direction of the dental crown when it is placed on the abutment as well as when it is withdrawn. For this purpose, the implant has a shaft protruding from it, onto which the adapter is rotatably mounted and provides an internal shaft that is inclined relative to the base of the adapter. By rotating the adapter, the inner cone of the double crown is set into a wobbling motion with respect to the implant, and the insertion axis can be adjusted by means of its outer contour.

[0014] This solution is hardly practical for hygienic reasons, primarily due to the large gap between the implant and the adapter. Correcting the implant's angle is only possible above the gum line. Therefore, this approach is generally unsuitable for situations with limited space or smaller incisors. This "late" angulation results in the crown of the implant lying outside the axis of the tooth being replaced, making the crown appear more prominent. Furthermore, high torques are exerted on the implant when chewing pressure is applied to the bone, which can lead to bone loss beneath the implant.

[0015] The object of the present invention is to provide an adapter as part of an implant-supported abutment that avoids the disadvantages described above using simple technical means. This object is achieved by the features of the main claim.

[0016] The base of the adapter according to this invention is penetrated by a blind hole, which is rotationally symmetrical about the point of intersection and is designed to receive, in the aforementioned operating position, a connecting piece protruding from the dental implant in the manner of a rotary bearing, with at least a portion of the blind hole serving as a contact surface for the connecting piece. The point of intersection can be located at the geometric center of the base. The blind hole, open to the base, thus forms a rotary bearing, and its perpendicular bisector defines the axis of rotation.

[0017] The adapter allows for a change in the orientation of the insertion axis relative to the dental implant. The retention element defines the insertion axis in relation to the dental implant. The retention element is usually designed as a regular body, taking the form of a post, cylinder, multi-sided rod, cone, or tapered cone, with its central longitudinal axis defining the insertion axis.

[0018] In the case of an internal cone, a ball anchor or a locator as a holding element, the final friction-locking or force-locking anchoring movement of the tooth crown, determined by its external shape, defines the insertion axis.

[0019] When the adapter rotates around its axis of rotation, the insertion axis traces a conical surface, with the intersection point forming the cone's apex. The axis of rotation is essentially defined by the blind hole. In the patient's mouth, the intersection point, when in use, is always located below the gingival margin and can be positioned at the level of the oral end of the implant.

[0020] The key to the invention is the improvement of the rotary bearing to better guide the rotation and achieve an almost degree-accurate alignment of the abutment.

[0021] In the simplest case, the inserted implant is a single piece and has a connecting piece protruding from the dental implant. This connecting piece can be used by the blind hole in the base of the adapter practically like a guide pin for a door or window fitting. The connecting piece can be provided by the manufacturer for connection to the crown or abutment and, according to the invention, serves as part of the pivot bearing. The connecting piece can have a rotationally symmetrical cross-section and be, for example, a round, oval, square, rectangular, quadrilateral, or polygonal cylinder. A dentist or dental technician could also shorten the connecting piece extraorally—outside the oral cavity—before implantation or shape it into a rotationally symmetrical external geometry. A positive-locking connection with the adapter is achieved by contacting at least two points connected by a line through the axis of rotation.When the adapter is rotated, these two contact points can remain permanently in place or be replaced by constantly changing, opposing points, all of which, however, share only a single axis of rotation at the center of the connecting lines. These contact points all lie on the surface of the adapter that defines the blind hole.

[0022] The fact that numerous implant manufacturers offer compatible dental implants with a correspondingly adapted connector for the commercially available "Cerec" system from Dentsply Sirona, particularly for CAD / CAM-fabricated crowns, can be exploited. This compatible connector essentially forms a "constant" starting geometry for connection with the attached adapter according to the invention and enables precise rotation around the axis of rotation defined by the blind hole. It can represent an "interface" between the adapter and the dental implant. Thus, an adapter according to the invention fits virtually a large number of manufacturer-specific implants for the aforementioned "Cerec" system, eliminating the need to stock a large number of adapters.

[0023] The position achieved after rotating the adapter and aligning the insertion axis can then be fixed by screwing the insertion screw into the dental implant. For this purpose, the insertion screw recommended and / or supplied by the dental implant manufacturer can be used.

[0024] Alternatively, a shaped component with a blind hole specifically adapted to the implant manufacturer's connector can be glued into the blind hole of the adapter. After aligning the insertion axis of the adapter, it is possible to firmly connect the adapter to the implant if the connector is glued or cemented to the contact surface in the blind hole.

[0025] Advantageously, the insertion axis is inclined at an angle of 4° to 8°, preferably 6°, or at 14° to 18°, preferably 16°, or at 24° to 28°, preferably 26°, to the axis of rotation. A first adapter according to the invention with an inclination angle of 6° can compensate for the aforementioned angular position in the range of 0° to 12° by rotating it 360 degrees with respect to the inserted dental implant.

[0026] Other adapters with different angular angles are placed on the implant without any dental laboratory work, allowing the insertion axis of the adapter to be aligned by simply rotating it around its axis of rotation by, for example, 10° to approximately 22°. Another adapter with, for example, a 26° angular angle could change the insertion axis by rotating it around its axis by between 20° and approximately 32° relative to the aforementioned angular position of the dental implant in the patient's mouth.

[0027] An implant abutment can also comprise more than three adapters with, for example, inclination angles of 5°, 10°, 15°, 20°, 25° and 30° and / or an angular position of ±5°, ±4° or ±3° can be compensated for by a 360° rotation of an adapter around the axis of rotation, without leaving the scope of protection of the invention defined herein.

[0028] Studies suggest that for long-term stability of the connection between implant-supported dentures and the jawbone, it is not always necessary to schedule a healing phase after implantation of the dental implant in the bone. For example, a molar lost in an accident can be "copied" by a machine-milled crown that is bonded to an implant placed in the gap using the adapter according to the invention.

[0029] The adapter according to the invention has a pyramidal, conical, truncated cone-shaped, or cone-shaped base body, with the base surface being provided by the largest surface of the base body and the retention element being supported by another side of the base body. The adapter according to this invention thus becomes progressively smaller from the base surface supported on the implant towards the oral cavity and gingival margin, deviating from the common "tulip shape" of conventional abutments. This ensures, firstly, better retention of the gingival margin on the base body and, secondly, reduces the risk of the dark color of the adapter showing through when looking at the gingiva, particularly in the area of ​​the incisors.

[0030] A veneer on the dental prosthesis can extend below the gum line, as the adapter does not protrude beyond the occlusal mechanism. With a thin wall thickness of up to 0.3 mm, the veneer can even be used in the area of ​​the incisors and no longer appears "prominent." It is even possible to extend the occlusal mechanism towards the oral cavity.

[0031] A passage opening within the blind hole runs inside the base body and is open to a side of the adapter opposite the base surface. This passage in the adapter's base body can accommodate the insertion screw for a multi-part implant.

[0032] After placing the adapter on the oral end of the dental implant (the end facing the mouth) and aligning the insertion axis, cement or adhesive can be applied to the contact point in the blind hole to create a permanent, twisted connection with the abutment of the dental implant. The established "rotation" of the adapter on the implant is retained.

[0033] For superstructures and dentures with multiple crowns, several implants are necessary to connect them to the jawbone. Once the required implants have been placed, an impression is taken for the dental technician, who uses this impression to create a working model with at least one laboratory analog. This provides the dental technician with information about the orientation of the implants, their distance from the gum line, and the shape of the tooth sockets.

[0034] Advantageously, after being connected to the adapter's blind hole, the connecting piece forms a single unit, and a cylindrical end of the connecting piece protruding from the adapter's base is received by an implant body of the multi-part dental implant in the aforementioned position. The connecting piece is inserted into the laboratory analog with its cylindrical end and—after all adapters have been aligned, for example, with a parallelometer—joined to the adapter by bonding, thus preserving its alignment with the implant. Chairside, the treating dentist simply inserts the prepared adapters into the corresponding implant bodies.

[0035] A method according to the invention for manufacturing an adapter for connecting a dental implant to a dental crown comprises

[0036] - Creation of a laboratory analog with at least one integrated dental implant

[0037] - Insertion of one inlay of a two-part implant into the impressions of the laboratory-made implants.

[0038] - Placing an adapter according to this invention onto each of the previously inserted inlays

[0039] - Aligning all retaining elements of the attached adapters onto a common insertion axis using a parallelometer

[0040] - Bonding of all inlays to the previously aligned adapters.

[0041] Preferably, a retaining screw is screwed into the implant body within the adapter's passage and supported by a screw channel in the connecting piece. After the superstructure has been tentatively placed on the implants with the prepared adapters, its arrangement on the dental implant can be secured using the retaining screw.

[0042] Following a further advantageous development of the adapter, a radially outward-curving collar is positioned between the connecting piece and an integrated inlay, thereby increasing the contact area between the adapter and the connecting piece. The inlay can provide the aforementioned screw channel and is held within the implant body in the specified position of use. The collar can seal the two-part implant against the ingress of bacteria into the implant body. A gap can also be provided between the collar and the implant or adapter, which is filled by newly formed bone material.

[0043] If the side of the collar facing the base rests on the base of the adapter, this side of the collar can be used for secure bonding. Even under high loads from chewing forces in the molar region, loosening or twisting of the connection between the connector and the adapter is impossible.

[0044] The implant bodies of multi-part dental implants are equipped with an anti-rotation device. Advantageously, the inlay or cylinder end has a stop surface that interacts with an anti-rotation device located within the implant body, preventing rotation of the connecting piece relative to the implant body. This anti-rotation device can, for example, be a square or hexagonal hole.

[0045] If this structure is transferred to the laboratory analogues of the working model during the impression taking of the implanted implant body, the orientation of the adapter set in the laboratory can be transmitted with "degree precision" to the patient's mouth. In the aforementioned examples of anti-rotation design, the adapter can only be inserted into the implanted implant body in 90° or 60° increments. The retaining elements of the adapters are clearly not parallel when inserted "rotated," and a "correct," i.e., "parallel," arrangement is easily discernible to the naked eye.

[0046] An advantageous adapter design is achieved when the cylinder end or the inlay tapers conically on its outer surface and features an interference fit to ensure a secure connection with the implant body. Once the correct positioning of the adapters on the implants is determined, the adapter can be held in this position using the retaining screw. To permanently secure this position, the interference fit allows for a "cold weld" between the implant body and the inlay via the screw connection.

[0047] To create different configurations with the adapter, the holding element can be fitted with a component in a form-fitting and rotationally resistant manner, whereby the component forms a locator, ball anchor or internal cone.

[0048] The component can also be used to make minor angular corrections to the insertion axis if the orientations specified by the laboratory were not adopted with pinpoint accuracy. A combination of adapter and component allows for an increase in the achievable angular positions of the insertion axis relative to the implant. For example, if an adapter allows the angle between the insertion axis and the axis of rotation to be changed by 2° to 10° during a 360° rotation around the axis of rotation, the component allows for a further adjustment of ± 2° without having to change the adapter. This combination then enables a range of 0° to 12°.

[0049] Further advantageous embodiments of the invention are shown in the accompanying drawings. The invention will now be described in more detail with reference to exemplary embodiments and the accompanying drawings.

[0050] The drawings show:

[0051] Fig. 1 shows a side view of an implant-supported dental prosthesis with a first embodiment of an adapter according to the invention shown in cross-sectional view;

[0052] Fig. 1 a a sectional view of Figure 1 ;

[0053] Fig. 2 shows a sectional view of a multi-part dental implant;

[0054] Fig. 2a shows a sectional view of part of a second embodiment of the adapter as shown in Fig. 2b;

[0055] Fig. 2b shows a partially cut-away side view of a second embodiment of the adapter;

[0056] Fig. 3 shows a side view of an embodiment of part of an adapter as shown in Fig. 2a;

[0057] Fig. 4 shows a side view of another component of a third embodiment of the adapter;

[0058] Fig. 4a shows a sectional view of the component shown in Figure 4;

[0059] Fig. 5 shows a side view of another embodiment of a component of the adapter in sectional view; and

[0060] Fig. 5a shows a sectional view of the component shown in Figure 5. Unless otherwise stated below, the following description always refers to all embodiments and Figures 1 to 5a, where the same reference numerals describe the same design features.

[0061] Figure 1 shows a one-piece adapter 10 with a dental implant 50, wherein the implant 50 is provided with ribs 51 on its outer surface and, unlike the root of a natural tooth, is anchored transversely in a bone structure of the jaw. The ribs 51 increase the interface between the implant 50 and the jawbone, thus supporting a durable connection that can withstand the forces that occur.

[0062] The adapter 10 serves to connect the dental implant 50 to a dental crown 100 and forms a structure with a crown-side retention element 12, which provides an insertion axis 14 for attaching the dental crown 100 to the retention element 12 as the central longitudinal axis of a cylinder.

[0063] The adapter 10 is milled from a single piece and is a prefabricated part made of titanium or a gold alloy. The adapter 10 is a cylindrical body that is adapted to the metal core 102 of a veneered dental crown 100.

[0064] The insertion axis 14 runs transversely to the implant-side base surface 16 of the adapter 10, which forms an inclined plane. An intersection point S is defined by the insertion axis 14 and the inclined plane defined by the base surface 16. In the operating position of the adapter 10, after the base surface 16 is supported on an oral end of the dental implant 50, the intersection point S lies on a rotation axis 18 intersecting the plane. A rotation of the adapter 10 about this rotation axis 18 changes the orientation of the insertion axis 14 with respect to the dental implant 50 and allows the crown 100 to be aligned with a gingival margin, other adjacent teeth, or dental prostheses in the mouth of the implant recipient.

[0065] The base 16 is pierced by a blind hole 20, which is rotationally symmetrical about the intersection point S and defines the axis of rotation 18. This axis of rotation 18 is a perpendicular bisector of the blind hole 20 lying on the inclined plane, which provides a rotational bearing for the connecting piece 52.

[0066] For this purpose, the blind hole 20 is designed in such a way that, in the aforementioned position of use, it receives a connecting piece 52 protruding from the dental implant 50 in the manner of a rotary bearing, and at least a part of the blind hole 20 serves as a contact surface 22 for the connecting piece 52.

[0067] The connecting piece 52 protruding from the implant 50 has a rectangular, square, polygonal, round, or oval cross-section that is rotationally symmetrical with respect to the axis of rotation 18 and is preferably positively engaged with the blind hole 20 to form the largest possible contact surface 22. In the simplest case, the adapter 10 and the connecting piece 52 are bonded together after the insertion axis 14 has been aligned. With other cross-sections of the manufacturer-specific connecting piece 52, at least two opposing contact surfaces 22 are formed in the operating position of the adapter 10, and the spaces between them can be filled with a cement compound when the adapter 10 is bonded to the implant 50.

[0068] The blind hole 20, as part of the rotary bearing, defines the movement of the insertion axis 14 about the intersection point S. In this embodiment, the blind hole 20 is located at the geometric center of the base surface 16, as shown in the sectional view of Figure 1a. In this sectional view, the connecting piece 52 completely fills the blind hole 20. The contact surface 22 is circular and fully circumferential.

[0069] The axis of rotation 18 defined by the blind hole 20 forms an angle α of 80° to 100°, preferably 90°, with the plane of the adapter 10. The point of intersection S lies at the level of the oral end of the implant 50 in the operating position, and the adjustment of the insertion axis 14 thus takes place below the gingival margin.

[0070] The implant manufacturers specify a maximum angulation – i.e., tilt – of the dental implant 50 for tooth replacement of up to 30° to reliably prevent subsequent damage to the implant 50, in particular cracking or bone loss. The adapter 10 in Figure 1 has an inclination angle β of 16° between the insertion axis 14 and the rotation axis 18. In order to compensate for the aforementioned tilt in the range of 0° to approximately 30° with the adapter 10, a prefabricated set comprises, for example, three or more adapters 10: one adapter 10 with an inclination angle β of 4° to 8°, preferably 6°; one adapter 10 with an insertion axis 14 inclined by 14° to 18°, preferably 16°; and one adapter 10 with an insertion axis 14 inclined by 24° to 28°, preferably 26°.

[0071] This previously described set of adapters forms an implant abutment with at least three adapters 10, which have an angular distance of 8° to 12°, preferably 10°, from each other at the inclination angle β between the base surface 16 and the insertion axis 14. It has been found that a 360° rotation on the implant 50 with the adapter 10 only compensates for a small area of ​​approximately 3° to 6°, since otherwise the base surface 16 protrudes beyond the outer dimensions of typical dental implants 50 and creates an undercut that prevents veneering of the tooth crown 100 up to the dental implant 50 or can at least have a negative aesthetic effect. Figure 2 shows a sectional view of an implant body 54 of a multi-part dental implant 50. Figure 2a shows the connecting piece 52, which, after being connected to the blind hole 20 of the adapter 10 shown in Figure 2b, forms a complete unit.This entire unit is then securely and releasably screwed into a thread 60 on the implant body 54 using the retaining screw 28 and a screw thread 60a.

[0072] Figure 2b shows the adapter 10 with a cone-shaped base body 11, wherein the base surface 16 is provided by the largest surface of the base body 11 and forms a truncated cone with an inclined plane. The retaining element 12 is supported by another side of the base body 11, with the base surface 16 defining the orientation of the insertion axis 14. A passage 26 opening within the blind hole 20 runs inside the base body 11 and is open to a side of the adapter 10 opposite the base surface 16. The passage 26 is traversed centrally by the axis of rotation 18, and after the retaining screw 28 is screwed in, its screw head 29 fills the passage 26 to more than 50%, preferably to more than 75%.

[0073] Figure 2a shows the connecting piece 52, which is integrally formed with an inlay 30 and separated by a circumferential collar 32. The inlay 30 and the connecting piece 52 form a screw channel 56, which, after the connecting piece 52 and the blind hole 20 of the adapter 10 are joined, aligns with the passage 26 of the adapter 10. The retaining screw 28 is supported by the screw channel 56 after being screwed into the implant body 54. A screw thread 60a at one end of the screw shaft 27 serves for screw insertion, and a thread 60 in the base of the implant body 54 serves for the implant side. The screw channel 56 is almost completely filled by the screw shaft 27, and the inlay 30 fills a cavity 55 defined by the implant body 54. All cavities inside the adapter 10, the inlay 30 and the implant body 54 are thus largely filled and ensure sufficient long-term stability; in particular, screw breakage is reliably prevented.When the inlay 30 is connected to the adapter 10, the collar 32 comes into contact with the base 16 of the adapter 10, thus increasing the contact area 22 and further improving the adhesive bond between the adapter 10 and the connecting piece 52. After the retaining screw 28 is screwed in, the underside of the collar 32, facing the implant 50, seals the implant body 54 and prevents the ingress of fluid and the formation of bacteria.

[0074] With reference to Figures 2 to 2b, a method according to the invention for connecting a dental implant 50 with a dental crown 100 will be described.

[0075] Once the implant 50 is implanted, an impression is taken showing the position of the implant 50 in the jaw, and a working model is fabricated using a laboratory analog. The laboratory analog is combined with the inlay 30, and the connecting piece 52 protruding from the dental implant 50 is inserted into the blind hole 20 of the adapter 10. According to the invention, the adapter 10 is rotated about the axis of rotation 18 relative to the implant 50 until the insertion axis 14 aligns with the position of the surrounding teeth and the crown 100, mounted on the retention element 12, is inserted. An adhesive is applied to the contact surface 22 between the connecting piece 52 and the blind hole 20, creating an adhesive bond.

[0076] Multi-part dental implants 50 often feature an anti-rotation device 58 that prevents rotation of the crown 100. According to the invention, the position of the anti-rotation device 58 is transferred to the laboratory analogues of the working model. The inlay 30 has a stop surface 24 that interacts with the anti-rotation device 58 located within the implant body 54 and prevents rotation of the connecting piece 52. After the inlay 30 is bonded to the adapter 10, a complete unit is formed, wherein the protruding cylindrical end of the inlay 30, which is received by the implant body 54 in the working position, fits into the implant 50 in a patient's mouth only in certain positions with the stop surface 24 and prevents rotation of the adapter 10 relative to the dental implant 50.

[0077] If the anti-rotation device 58 consists of a symmetrically shaped hexagonal recess inside the implant body 54, the entire unit consisting of adapter 10 and inlay 30 can only be inserted in 60° increments due to its stop surface 24. The retaining element 12 is clearly visible to the clinician in each increment, and the correct orientation, corresponding to the orientation chosen on the laboratory analogue of the working model, can be easily identified. The retaining screw 28 is then inserted and screwed to the implant body 54.

[0078] Since CNC-manufactured dental crowns 100 are now widely used, implant manufacturers offer so-called bases for their multi-part implants 50. These bases are compatible with their manufacturer-specific anti-rotation device 58 and provide a practically standardized connecting piece 52 for the milled dental crowns 100. The adapters 10 of the implant abutment according to the invention have blind holes 20 corresponding to the standard connecting piece 52. The connecting piece 52 from the implant manufacturer may only need to be shortened before being bonded to the inlay 30. The custom-made dental crown 100 is finally connected to the retention element 12 of the adapter 10.

[0079] Figure 3 shows another variant of the inlay 30. A tube section 57 is integrally formed with the connecting piece 52 and is traversed by the screw channel 56 for the retaining screw 28. This part of the inlay 30 is received by a bore 36 in the inlay 30, which has a radially outwardly extending collar 22 at one end and supports the connecting piece 52. The stop surface 24 is located at the opposite end. The part of the inlay 30 that receives the tube section 57 tapers conically on its outer surface and has an interference fit for a force-fit connection with the implant body 54. After the inlay 30 has been fully aligned in the patient's mouth, the retaining screw 28 is screwed into the implant body, resulting in a type of cold welding between the inlay 30 and the implant body 54.

[0080] Figure 4 shows a component 40 that is to be attached to the retaining element 12 of the adapter. The component 40, which supports the tooth crown 100, is provided with a recess 42 for attachment and is designed as a ball anchor, since a ball head 45 is attached to its upper surface. The component 40 can also be designed in the form of a locator or as an internal cone for a telescopic crown in order to support superstructures such as a bridge as a prosthetic. The upper surface of the component 40 has an inclination 48 towards its lower surface and tilts the insertion axis 14 of the retaining element 12.

[0081] Figure 4a shows a sectional view through component 40 of Figure 4, revealing that at least three evenly spaced recesses 44, open towards the recess 42, are provided in component 40, with a locking lug 34 being received by one of the recesses 44. The retaining element 12, as shown in Figure 2b, has at least one radially outwardly directed locking lug 34, which, when component 40 is placed onto the retaining element 12, causes a predetermined change in the orientation of the insertion axis 14. These recesses 44 could also be arranged asymmetrically around the central axis of component 40. It is also clear to those skilled in the art that a reverse arrangement – ​​recess 44 in the retaining element 12 and locking lug 34 within the recess 42 of component 40 – is possible. With an inclination 48 of 1° to the underside, the component 40 shown in Figures 4 and 4a could tilt the insertion axis by 0.25° with each rotation by 90° relative to the holding element 12.This is particularly useful for superstructures that are simultaneously supported by two or more implants 50 with the adapter 10. The individual insertion axes 14 can then be adjusted very precisely using the components 40 with inclination 48. The insertion axis 14 of the retention element 12 runs rotationally symmetrically through the recess 42 of the component 40 shown in Figure 5, and its outer contour has an inclination 48 of 1° to 4°, preferably 3°, to the insertion axis 14.

[0082] The base body 11 of the adapter 10 has a top surface – hereinafter referred to as plateau 15 – and represents a truncated cone with two sections. After the component 40 is attached, the retention element 12 is fully and securely held in the recess 42. The plateau 15 surrounding the retention element 12 is designed such that the underside of the component 40 is flush with the outer surface of the adapter 10 on the vestibular side. A vestibular outer surface formed by the adapter 10 and the attached component 40 creates a straight, continuous line, thus preventing any undercut and allowing the veneer to be extended with a virtually constant wall thickness to below the gingival margin. Aesthetically undesirable "dark" shadows at the joint between component 40 and adapter 10 also do not occur.

[0083] As can be seen particularly in Figure 5a, component 40 provides a screw hole 47 extending transversely to the recess 42 and is detachably attached to the retaining element 12 by means of a screw. Component 40 can thus be attached to the adapter 10 in a practically degree-accurate position, and the inclination 48 allows for adjustment of the orientation of various implant-supported adapters 10 to an accuracy of one-tenth of a degree in order to create a secure frictional retention of a double crown prosthesis.

[0084] The present invention provides a prefabricated implant abutment that enables alignment of the insertion axis and compensation of angulations of multiple dental implants without time-consuming, handcrafted individual fabrications. The number and design of the components are quite simple, allowing for mass production by machine, thus significantly reducing the price of an implant-supported denture. If a malfunction occurs due to an accident or poor care, individual parts of the implant abutment can be replaced easily and quickly.

[0085] Reference symbol list

[0086] adapter

[0087] basic body

[0088] Holding device

[0089] insertion axis

[0090] plateau

[0091] Base area

[0092] axis of rotation

[0093] Dead end

[0094] Contact surface

[0095] Stop surface

[0096] passage

[0097] screw shaft

[0098] retaining screw

[0099] screw head

[0100] inlay

[0101] collar

[0102] Rastnose

[0103] Drilling

[0104] component

[0105] in-depth

[0106] Exclusion

[0107] Ball head 6 Cap 7 Screw hole 8 Inclination 0 Dental implant 1 Rib 2 Connecting piece 4 Implant body 5 Cavity 6 Screw channel 7 Tube section

[0108] 58 Anti-rotation device 0 Thread 60a Screw thread

[0109] 100 dental crown 102 metal core

[0110] S Intersection point a Angle β Inclination angle

Claims

Patent claims 1. Adapter (10) for connecting a dental implant (50) to a dental crown (100) with a retaining element (12) arranged on the crown side, which provides an insertion axis (14) for attaching the dental crown (100) to the retaining element (12), wherein the insertion axis (14) runs transversely to the implant-side base surface (16) of the adapter (10), and an intersection point (S) is formed by the insertion axis (14) with the plane defined by the base surface (16), and the intersection point (S) lies on a rotation axis (18) intersecting the plane, wherein, in the operating position of the adapter (10), after the base surface (16) is supported on an oral end of the dental implant (50), a rotation of the adapter (10) about this axis of rotation (18) the orientation of the insertion axis (14) in relation to the dental implant (50) is variable, characterized in that the base surface (16) is perforated by a blind hole (20) which is rotationally symmetrical about the intersection point (S) and is designed to receive, in the said position of use, a connecting piece (52) projecting from the dental implant (50) in the manner of a rotary bearing and at least a part of the blind hole (20) serves as a contact surface (22) for the connecting piece (52).

2. Adapter (10) according to claim 1 , characterized in that the axis of rotation (18) defined by the blind hole (20) forms an angle (a) of 80° to 100°, preferably 90° with the plane of the adapter (10).

3. Adapter (10) according to claim 1 or 2, characterized in that the insertion axis (14) is inclined by an angle of inclination (β) of 4° to 8°, preferably 6° or by 14° to 18°, preferably 16° or by 24° to 28°, preferably 26° to the axis of rotation (18).

4. Adapter (10) according to one of claims 1 to 3, characterized in that the adapter (10) has a pyramidal, conical, truncated cone or cone-shaped base body (11), wherein the base surface (16) is provided by the largest surface of the base body (11) and the retaining element (12) is supported by a further side of the base body (11), and a passage (26) opening within the blind hole (20) runs within the base body (11) and is open to a side of the adapter (10) opposite the base surface (16).

5. Adapter (10) according to one of claims 1 to 4, characterized in that the connecting piece (52) forms a complete unit after being connected to the blind hole (20) of the adapter (10) and a cylindrical end of the connecting piece (52) projecting from the base surface (16) of the adapter (10) is received by an implant body (54) of the multi-part dental implant (50) in the said position of use.

6. Adapter (10) according to one of claims 1 to 5, characterized in that the passage (26) of the adapter (10) is connected to a screw channel (56) of the The connecting piece (52) supports a retaining screw (28) for screwing into the implant body (54).

7. Adapter (10) according to one of claims 1 to 6, characterized in that a radially outwardly extending collar (32) is positioned between the connecting piece (52) and an integrally formed inlay (30), which increases the contact area (22) between the adapter (10) and the connecting piece (52).

8. Adapter (10) according to claim 7, characterized in that a stop surface (24) of the inlay (30) interacts with an anti-rotation device (58) arranged within the implant body (54) and prevents rotation of the connecting piece (52).

9. Adapter (10) according to claim 7 or 8, characterized in that the inlay (30) tapers conically on its outer side and has an interference fit for force-fit connection with the implant body (54).

10. Adapter (10) according to one of the preceding claims, characterized in that the retaining element (12) has at least one radially outwardly directed locking lug (34).

11. Adapter (10) according to claim 10, characterized in that a component (40) supporting the tooth crown (100) and which is to be placed on the holding element (12) is provided with a recess (42) for placement and has at least three has recesses (44) that are unevenly or evenly distributed and open to the depression (42), wherein the locking lug (34) is received by one of the recesses (44).

12. Adapter (10) according to claim 11, characterized in that the insertion axis (14) of the retaining element (12) runs rotationally symmetrically through the recess (42) of the component (40) and its outer contour has an inclination (48) of 1° to 4°, preferably 3° to the insertion axis (14).

13. Adapter (10) according to one of the preceding claims, characterized in that the component (40) is designed as a ball anchor, a locator or an internal cone for a telescopic crown, wherein the component (40) provides a screw hole (47) extending transversely to the recess (42) and is detachably fastened to the retaining element (12) by means of a screw.

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