Method for establishing a connection between an inserted dental implant and a crown and method for the production of a crown

Abstract

The aim of the invention is to devise a method for providing a connection between an inserted dental implant and a crown, which makes it particularly simple to establish a reliable and secure connection between the crown and the inserted implant. For this purpose, according to the invention, the crown is provided with an associated recess suitable for accommodating a connecting element of the dental implant. Following the insertion of the dental implant into the jawbone of the patient, the intraoral data characteristic of the oral situation of the patient including the inserted dental implant is captured. Using this intraoral data, the geometric data defining the intermediate space formed by the connecting element and the associated recess when the crown is correctly placed is determined, and, using this data, an intermediate body is produced that fills the intermediate space.

Description

[0001] Description

[0002] Methods for creating a connection between an inserted dental implant and a crown, as well as methods for manufacturing a crown

[0003] The invention relates to a method for producing a connection between a dental implant inserted in a patient's mouth and a crown. It further relates to a method for producing a connecting piece, in particular for use with such a crown, as well as a method for producing a crown.

[0004] In the event of tooth loss, the usual aim is to replace the missing teeth or at least close the resulting gaps. This can be achieved, for example, with bridges. In this process, the teeth adjacent to the gap are prepared (ground down), and crowns are fabricated to replace the missing teeth with corresponding pontics (bridge units). The bridge is mechanically anchored to the prepared teeth. A cantilever can also be attached to a bridge to address a free-end situation. Such a situation can also be treated with removable partial dentures, which are typically supported by natural teeth.

[0005] In addition to bridge designs, missing teeth can also be replaced using e-nosseous implants. These typically use threaded posts as artificial tooth roots, onto which the prosthesis can be anchored.

[0006] This anchorage can be either fixed (screwed, cemented, or bonded) or removable. In removable solutions, the retention forces that hold the prosthesis in place are usually based on negative pressure, friction, and / or retention. Depending on the primary stability of an inserted implant, a prosthetic restoration—especially a temporary one—such as a crown, can be placed on the implant immediately after implantation or after a healing period of, for example, four to six weeks. Such a temporary crown can then be replaced by the final crown at a later date. In particular, the so-called "navigated implantation" technique can be used when providing such a restoration based on an inserted dental implant.In this type of navigated implantation, the planned implant positions in the patient's jaw are first virtually planned using previously acquired CBCT or CT data depicting the patient's oral situation, with a view to the intended use of implants inserted into the patient's jawbone as abutments for the restoration. Based on this plan, a surgical guide (usually bone-supported, mucosa-supported, or tooth-supported) is fabricated for the actual navigated implantation, and a temporary prosthesis is also created, allowing the patient to be fitted with fixed teeth on the day of surgery or implant insertion. For crown or bridge restorations, a tooth-supported surgical guide is considered the simplest and therefore preferred option.

[0007] The template is used to guide the drill holes in the jawbone for the implants and to define their final position. In a subsequent step, the implant(s) are inserted through this template, ensuring they are automatically placed in the correct positions corresponding to the previously drilled holes.

[0008] Typically, regardless of whether navigation or conventional techniques are used, a conventional or digital impression is taken immediately after the insertion of each implant. This impression captures data about the patient's oral situation and is taken at the level of the implant or abutment. Based on this precise data, which accurately reflects the oral situation including the implants, the final prosthesis or crown can be planned and fabricated. Following this data acquisition, the temporary prosthesis should be attached to the inserted implant on the same day, specifically by screwing it in place.

[0009] During the fabrication of the prosthesis, bridge, or crown, preferably the provisional one, a suitable recess or cavity is provided at the position intended for connection to the implant serving as an abutment, specifically at the "implant head." Suitable connecting elements for attaching the prosthesis to the respective implant head or abutment can be inserted into this recess or cavity. This recess or cavity of the provisional crown is then filled with a resin adhesive, modeling resin, cement, or similar material and fixed to the abutment using this material. The connection between the inserted dental implant and the crown is thus created as a material-bonded connection.

[0010] In view of the inaccuracies that usually occur during data acquisition and processing, as well as the almost unavoidable manufacturing tolerances and tolerances during implant insertion, the recesses or cavity in the crown are usually made comparatively generous and generally oversized, especially in the basal direction, not least to provide the practitioner with degrees of freedom for fine-tuning the crown, particularly to compensate for almost unavoidable inaccuracies during implant insertion (navigated or freehand).

[0011] The invention is therefore based on the objective of providing a method for establishing a connection between an inserted dental implant and a crown of the type mentioned above, with which a reliable and secure connection of the crown to the inserted implant can be achieved in a particularly simple manner.

[0012] This problem is solved according to the invention by providing the crown with a recess associated with the dental implant and suitable for receiving a connecting element of the dental implant, wherein, after the insertion of the dental implant into the patient's jawbone, the intraoral data characteristic of the patient's oral situation, including the inserted dental implant, are recorded, wherein, based on these intraoral data, the geometric data defining the space formed by the connecting element and the associated recess when the crown is correctly placed are determined, and based on these data, an intermediate body filling the space is manufactured.

[0013] The invention is based on the premise that a significant simplification in providing the connection between the inserted implant and the prosthetic restoration can be achieved by ensuring a particularly high degree of accuracy in the components intended for the patient's treatment, preferably combined with minimal further correction or rework requirements, at a very early stage. To this end, and based on known geometric information, the necessarily resulting gap between the connecting element of the implant on the one hand and the corresponding recess in the crown on the other should be filled as completely as possible by a provided filler.According to this aspect of the invention, it should be manufactured as precisely as possible and thus based on the determined actual data, so that, among other things, the amount of material required to fill the remaining gaps can be reduced as much as possible.

[0014] Depending on requirements, the intermediate body can be made from a plastic or a particularly durable material (e.g., ceramic, metal, titanium, or similar). It can be manufactured subtractively (e.g., using a machining process) or additively (e.g., through a laser sintering process).

[0015] The aspect that the crown, preferably the crown intended for final restoration, is pre-fabricated is considered particularly advantageous and inventive, so that the actual values ​​can be used for the manufacture of the crown; this enables a particularly needs-based and therefore efficient and resource-saving production.

[0016] In an alternative variant, considered to be independently inventive, instead of producing an intermediate or filler body that fills the gap as much as possible or almost completely, a positioning framework body can also be provided. This framework body can be designed, particularly with regard to its contouring and / or surface finish, such that contact with the surrounding components is established in the assembled system, thereby ensuring the precise and correct orientation and spatial positioning of these components relative to one another. Such a positioning framework body, provided according to this aspect of the invention, thus ensures the correct positioning of the components, and the gaps left behind by this framework-like body can be filled with adhesive or cement during installation or integration.Advantageously, the positioning framework body can be provided with a channel, preferably designed as an internally or externally mounted thread, through which excess adhesive or cement material can flow away or be removed. If the intermediate body, and in this specific case the positioning framework body, is manufactured using an additive manufacturing process (3D printing, laser sintering, etc.), the manufacturing time for the positioning framework body is significantly reduced compared to the manufacturing time for the entire framework body. Preferably, the positioning framework body fills less than 70%, advantageously less than 50%, and particularly less than 30% of the volume of the intermediate piece, so that the manufacturing time can be minimized accordingly.

[0017] For the sake of clarity, the following explanations refer to the intermediate body. Of course, the following further training and aspects can also be applied analogously to the aforementioned positioning framework body.

[0018] The dental implant could, in principle, be designed as a so-called one-piece implant, in which the connecting element located at the abutment is integral with the post that is inserted or can be inserted into the patient's jawbone. However, advantageously, and to promote particularly high flexibility in the configuration or manufacture of the components, the dental implant is designed as a so-called two-piece implant, in which the respective connecting element is designed as an abutment and can be attached to the inserted post of the implant via suitable connecting means, such as a connecting pin that can be inserted into an abutment channel. Preferably, such an abutment is used as the connecting element.For the provision of a merely temporary crown or prosthesis, i.e. a provisional crown that can later be replaced by the final one, so-called "provisional abutments" can also be provided as connecting elements, which can be (temporarily) inserted into the implant and attached in the manner of an intermediate support body, preferably screwed in place.

[0019] According to one aspect of the invention, after implant insertion, whether using navigation or conventional methods, intraoral data are acquired as directly as possible, for example, by taking a digital impression or by taking a conventional impression and scanning the fabricated master model. The resulting data set, describing the current position of the implants within the oral cavity, can then be superimposed with the data of the desired implant position. This allows the space between the crown—which, as explained below, has already been fabricated according to a particularly advantageous aspect—and the abutment forming the connecting element to be captured data-wise in the basal cavity. A significant advantage of the present invention is that, with the concept now envisaged, the crown can be fabricated in advance and provided as a prefabricated component during insertion.

[0020] Using suitable software, preferably computer simulation software, the transitions from the abutment to the crown – preferably already fabricated – can be calculated and the gap determined. This characteristic data set can then be used as the basis for the subsequent fabrication of the intermediate piece or abutment. Following this, the fabricated intermediate piece, which, according to one aspect of the invention, can also be fixed in a clearly defined rotational position, can be fixed to the abutment and the crown, preferably by bonding or cementing. The abutment can then be screwed onto the implant with the crown. It is also possible to attach the crown and / or the intermediate piece to the abutment in the patient's mouth.

[0021] A particularly advantageous benefit achievable with the present method is that the connection between the connecting element or abutment of the implant, on the one hand, and the preferably already manufactured crown, on the other, can be established with minimal effort and, in particular, relatively quickly. To further facilitate this, a particularly efficient and, especially, rapid production of the respective intermediate piece or body is highly desirable. To enable this rapid and cost-effective production, the intermediate body can be manufactured using a 3D printing process, according to a concept considered to be independently inventive. Manufacturing with a 3D printer is particularly simple, fast, and inexpensive.

[0022] According to one aspect of the invention, the crown is bonded to the intermediate body or to the connecting element or abutment of the implant extraorally. In other words (also in the case of the framework), the printed material can be bonded into the crown; the adhesive then does not run into the abutment or the other components. The crown can then be inserted. The framework allows for the time-saving creation of a guide element that ensures precise positioning.

[0023] This design could be particularly advantageous in cases where the crown already exists. Alternatively, it might be more economical to manufacture the crown from ceramic or titanium, preferably by machining or additive manufacturing. Regarding the machining method, a further advantageous development could utilize blanks that already have the intended connection to the implant or abutment, so that only the connection for the prosthesis needs to be fabricated.

[0024] In a particularly preferred embodiment, the abutment (final or preferably also provisional) can be clamped into a 3D printer, which prints the space-filling intermediate piece, the intermediate body, or the positioning framework directly onto the abutment, so that the latter can then be fixed directly into the crown. In other words, according to this aspect of the invention, the intermediate body can be printed directly onto the connecting element of the dental implant, thus eliminating the need for cementing the intermediate body to the abutment.

[0025] In a further concept, considered independently inventive, it is also possible to eliminate the need for crown fabrication prior to treatment. According to one aspect of this embodiment of the invention, after implant insertion, either with navigation or conventionally, intraoral data, preferably for both jaws, are acquired, for example, by taking a digital impression or by taking a conventional impression and scanning the fabricated master model. The resulting data set, describing the current position of the implants within the oral cavity, can then be used in software or computer simulation software to calculate the entire crown or prosthetic restoration. This data set, describing the current situation, can be superimposed, for example, with the data on the planned position and shape of the entire prosthetic restoration in the mouth.

[0026] This allows the desired design of the crown, its position on the implant, and its orientation relative to the implant, including the abutment forming the connecting element, to be captured digitally. Using suitable software, preferably computer software, the entire crown can be calculated based on this information. The resulting data set can then be used as the basis for the subsequent fabrication of the crown. Following this, the fabricated crown, according to one aspect of the invention, can also be fixed in a clearly defined rotational position and then fixed to the abutment, preferably by bonding or cementing. This can be done intraorally or extraorally.

[0027] Even in this embodiment, which is considered to be independently inventive, a particularly preferred further development allows the (possibly temporary) abutment to be clamped into a 3D printer, which prints the crown directly onto the abutment. In other words, according to this aspect of the invention, the crown can be printed directly onto the connecting element of the respective dental implant.

[0028] A printer suitable for such an application, considered to be independently inventive in this case, has, according to aspects of the invention, a rotary axis ("C-axis") which accommodates the abutment or connecting element to be printed. This rotary axis can also be moved in the axial direction ("X-axis"). To check the exact dimensions of the abutment or connecting element, this rotary axis can preferably be moved via the X-axis to a distance sensor (or a similar measuring instrument such as an optical micrometer). The component can be measured at the area to be printed via the rotation and the C-axis. According to one aspect of this independent invention, an additional Z-axis allows the print head (preferably designed as a print element or filament holder) of the 3D printer to be moved to the correct distance to apply the material, preferably plastic.

[0029] The actual printing element, in particular the so-called filament holder or similar component, should, according to a further aspect of the invention, also be able to be moved up and down via a Z-axis (preferably oriented at an angle of 90° to the X-axis). According to another aspect of the invention, the 3D printer can also have a pivoting axis ("B-axis"), which can pivot the axis of rotation up to an angle of 90° to the X-axis, particularly if the entire crown is to be printed. With a printer designed in this way, the intermediate piece can be printed directly onto the abutment, which significantly simplifies and speeds up the manufacturing process. In this way, the crown, as well as the intermediate piece with or without a screw channel, can be produced. It is possible that after printing the intermediate piece, or...The abutment of the positioning framework body must be shortened further in the occlusal direction.

[0030] In an alternative embodiment, considered to be independently inventive, the provision of a final crown, in the sense of a definitive prosthetic restoration, can also be provided. According to one aspect of the invention, the crown can be designed as a ceramic body. In this case, instead of the aforementioned fabrication of the crown by printing directly onto the abutment, the crown can be fabricated by a laser sintering process directly onto the abutment. This constitutes an additive process, and in one embodiment of the invention, the ceramic materials can be applied and, during the rotation of the abutment, preferably by a laser, melted and bonded to the abutment or to the ceramic materials already applied.

[0031] In an alternative embodiment, also considered independently inventive, the respective connecting element or abutment can be provided in the form of a blank or intermediate product for subsequent subtractive machining. Such a blank can comprise a base body made of a biocompatible, high-strength material, preferably titanium or a titanium alloy, which is additionally provided with a plastic coating. This coating can then be machined away according to one aspect of the invention in such a way that the remaining plastic coating represents the aforementioned intermediate body and thus appropriately fills the gap determined by the data.

[0032] According to another aspect considered to be independently inventive, the method can be used in conjunction with training or education for the practitioner. In this context, the invention allows the practitioner to draw conclusions about the quality of their insertion procedure, as well as the components and tools used, based on information about the dimensions of the aforementioned gaps or the wall thicknesses and dimensions of the spacers to be manufactured for filling them. In particular, this makes it possible to obtain information regarding the (individual or objective) accuracy and precision of the navigated implantation.Especially when systematically comparing relevant quality indicators or statements derived from them over a certain period or a certain number of treatments, the practitioner can also gain insights in the form of feedback.

[0033] If, based on such an evaluation, the practitioner determines that they have succeeded in improving this precision over time or through treatments, so that the intermediate pieces to be produced become increasingly smaller or thinner-walled, it becomes possible after a certain period to even dispense with the temporary prosthesis altogether and fabricate the final crown directly in advance. This final crown can then be inserted into the patient's mouth on the day of implantation using the fabricated intermediate pieces. In other words, such a feedback system can enable the practitioner, after acquiring the necessary skills and experience, to plan the fabrication of the final prosthesis from the outset; the targeted guidance of the practitioner towards this goal can be considered an independently inventive basic concept of the training system.This would significantly and sustainably reduce the costs of such treatment.

[0034] To enable such systematic information processing, according to one aspect of the invention and in a particularly advantageous embodiment, the geometric data defining the gaps can be stored in a database. According to another aspect of the invention, a characteristic value for the fit of the components can be determined based on the geometric data defining the gaps. This value can then be used as a success criterion for the precision of the manufacturing process and / or for the quality of the treatment. This allows conclusions to be drawn about the overall quality of the insertion, which could, for example, be reflected in a decreasing volume or wall thickness of the spacers required for compensation over time or with each trial.Alternatively or additionally, systematic errors caused individually by the practitioner, such as a pre-drilling that is always slightly too deep or the like, can also be identified and used as a basis for compensation.

[0035] If, for example, the practitioner notices that all their implants are consistently inserted at least 1.0 mm too high or too low, this can be determined by a computer and taken into account when designing future surgical guides. Similarly, if the axial angle is always buccally inclined or always tilted in the same direction, the practitioner can consider this in future insertions and thus increase their precision. The same applies, of course, to all other spatial directions where a pattern is recognized by the software (preferably a computer).

[0036] Possible parameters to be considered in such an evaluation could include, but are not limited to:

[0037] 1. Wall thickness of the intermediate body, especially in the area of ​​space laterally surrounding the connecting element

[0038] 2. Volume or weight of the intermediate body (primarily an indicator of height accuracy)

[0039] 3. Wall thickness uniformity or tolerance

[0040] 4. Centricity of the abutment's male matrix in the recess of the prosthetic body

[0041] Advantageously, for a number of treatments, the characteristic parameters for the fit of the components are stored together with reference data characteristic of the respective treatment in a database. This allows for an evaluation of the stored data at a later time, for example, linked to pattern recognition or analysis, in order to identify aspects or factors that contribute to treatments considered particularly successful, as well as those considered unsuccessful or substandard. As a result, a recommendation for action can be generated for the user based on a number of the stored characteristic parameters for fit, in a manner considered to be independently inventive. This allows, among other things, the provision of personalized or individualized correction data, which leads to correction suggestions for the respective practitioner.

[0042] In a treatment system appropriately equipped for this purpose, user-specific parameters of the above-mentioned type can be stored in an independently inventive manner, so that individualized recommendations for action, in the form of individualized training or education, can be provided.

[0043] Alternatively or additionally, according to another aspect of the invention, the stored data and parameters can be used to determine and calculate possible improvements and adjustments to the template used for navigation, i.e., to modify the template's manufacturing process. If a navigated procedure is not used for implant insertion, the basal cavity in the already fabricated crown is designed to be somewhat larger, according to another aspect of the invention. In this case, after implant insertion and superimposition of the data sets, either the most suitable abutment for the restoration is selected, or a CAD / CAM abutment including an intermediate body is fabricated directly.

[0044] The embodiments described above are particularly suitable for cases where the intermediate body is also intended as a temporary measure, for use only on a temporary basis. In an advantageous embodiment, the intermediate piece produced in this way can subsequently be removed and replaced by a final fitting made of a particularly durable material (e.g., ceramic, titanium, or the like). This can be manufactured subtractively (e.g., by machining) or additively (e.g., by laser sintering). According to an inventive aspect, the geometric data acquired during the aforementioned production of the intermediate body and stored in the database can be reused for the production of the final intermediate body, since, by design, it contains the geometric data actually required for the restoration.According to one aspect of the invention, the recorded intraoral data are therefore appropriately stored in the database, in particular provided with a suitable identifier and linked data-wise, which also contains the exact assignment to the respective patient, and / or further treatment-relevant information, even at a later time, possibly even after years.

[0045] The advantages achieved with the invention lie particularly in the fact that, by capturing intraoral data after implant insertion, especially when using a prefabricated crown, the positioning and alignment-enhancing intermediate body can be manufactured with exceptional accuracy and precision, as well as quickly and flexibly, based on the processing of existing data. This enables high-quality provisional restoration of the patient on the day of implant insertion in a particularly cost-effective manner. A further advantage of the method is that, after fabrication, the intermediate body can be bonded extraorally to the crown or bridge and the connecting element to the implant, for example, an abutment, rather than having to be positioned correctly in the patient's mouth during intraoral bonding.

Claims

Claims 1. Method for providing a connection between an inserted dental implant and a crown, which is provided with an associated recess suitable for receiving a connecting element of the dental implant, wherein, after the insertion of the dental implant into the patient's jawbone, the intraoral data characteristic of the patient's oral situation, including the inserted dental implant, are recorded, wherein, based on these intraoral data, the geometric data defining the space formed by the connecting element and the associated recess when the crown is correctly placed are determined, and based on these data, an intermediate body filling the space is manufactured.

2. A method for manufacturing a crown intended for attachment to an inserted dental implant, wherein, after insertion of the dental implant into the patient's jawbone, the intraoral data characteristic of the patient's oral situation, including the inserted dental implant and, if applicable, an associated connecting element, are recorded, wherein, based on these intraoral data, the geometric data defining the crown correctly placed on the connecting element and providing the planned prosthetic restoration with regard to the dentition situation are determined, and the crown is manufactured based on these data.

3. Method according to claim 1 or 2, wherein an abutment associated with the dental implant is used as the connecting element of the dental implant.

4. Method according to any one of claims 1 to 3, wherein the intermediate body or the crown is manufactured using a 3D printing process.

5. Method according to claim 4, wherein the intermediate body or crown is printed directly onto the connecting element of the dental implant.

6. Method according to any one of claims 1 to 5, wherein the geometry data defining the gap are stored in a database.

7. Method according to one of claims 1 to 6, wherein a characteristic value for the fit of the components is determined on the basis of the geometry data defining the gap.

8. Method according to claim 7, wherein, for a plurality of treatments, the characteristic values ​​for the fit of the components are stored together with reference data characteristic for the respective treatment in a database.

9. Method according to claim 8, wherein a recommendation for action for the user is determined on the basis of a plurality of the stored characteristic values ​​for the accuracy of fit.