Method for providing a patient with a prosthetic restoration in one session using a laboratory semi-finished product

Abstract

The invention relates to a method for producing prosthetic restorations, together with the software and hardware modifications required for carrying out the method. By means of the method, the clinical surface of the required restoration is produced and finalised before the treatment session in a commercial laboratory, a practice laboratory, or laboratory-type facilities within a dental practice, while the side facing the cavity (the preparation interface) is adapted to the actual intraoral situation of the patient in the dental practice during the treatment session. The restoration partially finished in the dental laboratory is thus delivered to the dental practice as a semi-finished product and is completed there during the treatment session, so that the patient can be provided directly with the final restoration in one session, without a provisional restoration and within a short period of time.

Description

[0001] Procedure for the prosthetic treatment of a patient in one session based on a laboratory-prepared semi-finished product

[0002] Summary

[0003] For the fabrication of prosthetic restorations, a process with the necessary software and hardware modifications is provided. This process allows the clinical surface of the required restoration to be fabricated and finalized in a commercial laboratory, a dental practice laboratory, or in laboratory-like facilities within a dental practice prior to the treatment appointment. During the treatment appointment, the cavity-facing surface (preparation interface) is adapted to the actual situation in the patient's mouth. The restoration, partially prepared in the dental laboratory, is thus delivered to the dental practice as a semi-finished product and completed there during the treatment appointment. This allows the patient to receive their final restoration directly in a single appointment, without a temporary restoration, and in a short amount of time.

[0004] State of the art

[0005] Two variants are generally used to provide a patient with inlays, onlays, crowns, partial crowns, veneers and bridges [Beuer et al. 2008]:

[0006] 1. The dental practice prepares the tooth(s), takes a traditional or digital impression, and sends it, along with the order, physically or digitally to a dental laboratory [Zuercher et al 2023]. The patient receives a temporary restoration while the necessary restoration is being fabricated. The laboratory fabricates the restoration and sends it to the dental practice, where it is then fitted to the patient in a second appointment.

[0007] Advantages:

[0008] • Reduced workload for the dental practice (know-how, equipment, materials, time) through delegation of production to a laboratory

[0009] Disadvantages:

[0010] Costs, time and effort for 2 treatment sessions, clinical disadvantages of the temporary prosthesis,

[0011] Laboratory costs

[0012] 2. The dental practice operates digitally: A digital impression is taken of the prepared teeth, and the restorations are designed and adjusted on the computer. The desired restoration is then manufactured directly in the practice and inserted into the patient's mouth [Zaruba, Mehl 2017].

[0013] Advantages:

[0014] • Treatment in one session,

[0015] • No temporary restoration is required: this also eliminates disadvantages regarding adhesive bonding and the risk of fracture to the remaining tooth structure.

[0016] • The entire value creation takes place in the dental practice.

[0017] Disadvantages:

[0018] • The manufacturing process takes a long time.

[0019] • Post-processing, including polishing and color characterization of the restorations after production, is also time-consuming and requires experience.

[0020] • The practice procedures must be changed and adapted to the process.

[0021] • Dental practice needs dental technology expertise.

[0022] • The dental practice itself must correct any prosthetic defects. It cannot hold its laboratory liable.

[0023] • A grinding machine must be available in the practice.

[0024] There are proposals for variations of these procedures that aim to overcome some disadvantages: For example, US2007243503A1 proposes a method in which the outer surface, especially the occlusal surfaces, is shaped directly in the mouth using a plastic material. This surface is then scanned and used for the final restoration. The advantage of an optimally adapted occlusal surface is offset by a significantly longer time expenditure with the patient and a steep learning curve and increased expertise for the practitioner. US10456223B2 proposes supplying the blocks used for the milling process pre-fabricated to minimize the amount of material that needs to be removed for the final restoration, thus reducing milling time and extending the service life of the milling instruments.This technique, known from engineering and called Near Net Shape (NNS), can be implemented by selecting the block from the designed restoration in such a way that it still encompasses the entire restoration but requires the least amount of material removal. However, this approach does not solve the problem that surface finishing, such as color characterization and polishing, is still necessary.

[0025] Description of the procedure for the prosthetic treatment of a patient in one session based on a laboratory-prepared semi-finished product.

[0026] The present invention relates to a method for prefabrication of the surface of a restoration in a dental laboratory, provision of the semi-finished product in the dental practice at the time of the treatment session and completion of the restoration in the treatment session (LSVD - Lab-involved Single Visit Dentistry).

[0027] Prefabrication of the restoration surface can be carried out using data typically available in the dental practice during the decision-making process, i.e., days or weeks before the actual treatment appointment. The dental laboratory can be a commercial lab, an in-house lab, or a lab-like structure within the dental practice. Additionally, it is conceivable that specialized service providers or centers could handle both the design and planning work and / or the manufacturing. Cloud-based architectures allow for various divisions of labor to be implemented effectively. Therefore, digital data capture is helpful, as it can be transferred to the dental laboratory or other units without time or data loss and processed directly there.

[0028] The invention combines the advantages of both existing methods. The dental laboratory uses its expertise to produce the surface of the restoration, and the dental practice utilizes a digital process to adapt it to the preparation of the tooth being treated. This division of labor is possible because all patient data required for the fabrication of the restoration surface is already available during the consultation and decision-making session or can be easily acquired. Such data can include, in addition to digital impression data of the (partial) jaw and the bite registration, recordings of jaw movements or functional temporomandibular joint parameters, the desired occlusal relationship to the opposing jaw, facial scans, various types of color measurements, or even color data from the intraoral scan.In the dental laboratory, a restoration / prosthesis is designed and constructed based on this data, and then a semi-finished product is manufactured – namely, a restoration with unworked preparation-facing surfaces and, ideally, an already optimally finished outer surface that meets the anatomical, functional, and aesthetic requirements of the clinical situation being treated. The unworked preparation-facing surfaces of the restoration are then adapted to the tooth preparation during the treatment appointment at the dental practice. In addition to the restoration and CAD data, the laboratory also provides a transfer holder, which allows the partial restoration to be clamped into an existing milling and / or milling machine (Chairside Milling Unit I CMU) or a specially designed milling and / or milling machine.The restoration is then clamped into the machine for initial partial fabrication and finished grinding using a digital or physical marker in a clearly determined spatial grinding position.

[0029] For the sake of clarity, it should be noted again that the claims use the term "grinding" as a representative machining process and the term "grinding machine" or "manufacturing machine" as a representative example. However, these terms are intended to encompass milling, milling machines, and other machining processes and machines (e.g., laser machining, etc.). A combination of 3D printing and grinding is also conceivable among the manufacturing processes, provided that they can be meaningfully combined and implemented using the methods and devices listed in the patent claims.

[0030] Possible embodiments of the invention are described in more detail below.

[0031] This list is not exhaustive, and other possible and obvious applications are conceivable. Similarly, the following primarily refers to single-tooth restorations as examples, but the processes can also be applied to larger restorations such as bridges, etc. The blocks mentioned below encompass—according to the current state of knowledge—all possible variations of material blocks, such as discs.

[0032] Several options are conceivable for secure positioning and fixation:

[0033] - Remaining of the semi-finished product on the initial block holder (Fig. 1 ),

[0034] - A negative mold of the outer surface, which enables secure positioning of the semi-finished product by means of a two-part fixation (Fig. 2, Fig. 3),

[0035] - The bonding of a negative mold to a partial surface of the semi-finished product, whereby the bonding can be dissolved again after completion, e.g. by mechanical, thermal or chemical processes (Fig. 4).

[0036] - Bonding a partial surface of the semi-finished product to the transfer holder using a plastic, sufficiently hardening fixing compound (Fig. 5).

[0037] - A combination of the above-mentioned variants.

[0038] The restoration of the identical grinding position or the superposition of the coordinate systems of the semi-finished product, restoration and grinding machine depends on the fixation of the semi-finished product by

[0039] - The semi-finished restoration remains on the initial block holder. The outer contour of the semi-finished restoration is fully prepared, and the partially prepared restoration remains connected to the block holder at the point of separation. In practice, after inserting the block holder (= transfer holder), the preparation surface is first ground down, then the restoration is separated, and the point of separation and any subsequently processed areas are polished (Fig. 1). This method is particularly useful for semi-finished restorations with unprocessed or merely polished or painted / glazed surfaces.

[0040] - Markings are applied to the semi-finished product and the transfer holder to provide a unique reference to the outer surface. These markings allow for unambiguous positioning in a grinding machine, for example, using a 3D measuring device or a negative key, without the need for complex clamping fixtures (Fig. 6). A similar approach would be to adhere the semi-finished product to a transfer holder, then clamp the transfer holder in the grinding machine and perform a 3D scan of the surfaces. This scan captures existing structures or markings in the vicinity of the clamping device (i.e., permanently attached to the grinding machine) to enable unambiguous referencing of the position of the semi-finished product, including the transfer holder, relative to the grinding machine. A possible implementation of the individual referencing processes is shown in Figure 14, although individual processes can be omitted depending on the processing steps.

[0041] - Scanning the cervical surface and areas of the restoration that have not changed in relation to the surfaces of the holder: These areas of the semi-finished product are measured three-dimensionally using a scanner integrated into the milling machine or an external scanner, whereby the block holder or reference structures of the block holder are also captured. This allows the position of the outer contour in the milling machine to be precisely determined using special software, thus enabling the calculation of the milling paths for processing the inner surface of the preparation in a positionally accurate manner (Fig. 7). The software enables the semi-finished product to be milled to completion. It links the manufacturing step of the semi-finished product in the laboratory with the preparation performed by the dentist.

[0042] - Designing and grinding an asymmetrical, e.g., pentagonal, bar on a suitable side of the semi-finished product. This bar clearly defines the position of the semi-finished product in a grinding machine or transfer device and is ground away during the final grinding of the restoration in the dental practice (Fig. 8). Alternatively, material blocks can be used that already have an advantageously shaped bar (with clearly defined rotation and translation protection) (Fig. 9).

[0043] This pentagonal rod, for example, is referred to as the transfer rod because it facilitates the transfer from the digital manufacturing process to the manual finishing of the semi-finished product. It simplifies handling and can be inserted into a suitably manufactured model, allowing, for example, easy verification of the occlusal and proximal contacts of the partial restoration. Furthermore, color and / or veneering layers can be applied if the semi-finished product has been milled down in a reduced design or as a framework or coping.

[0044] - Assignment of the original block holder to the transfer holder in a special transfer device (Fig. 10). The semi-finished product is only separated from the original block holder or transfer rod after it has been glued onto the transfer holder in the transfer device (Fig. 10).

[0045] - a combination of the above-mentioned variants.

[0046] Depending on the previously described procedure, all or some of the exemplary processes shown in Fig. 14 can be used for the referencing steps in the CAD software. Further similar referencing steps are also conceivable, depending on the state of the art. This step of the procedure requires neither dental nor dental technology expertise. It can be completely delegated to a staff member in the practice.

[0047] Advantages:

[0048] • Treatment in one session,

[0049] • no temporary solution required,

[0050] • No adjustments to practice procedures are necessary,

[0051] • No dental technology expertise required,

[0052] • simpler grinding machine,

[0053] • Added value in the dental practice

[0054] Disadvantages:

[0055] • Grinding machine required

[0056] If the dental practice has the necessary design software, manufacturing expertise, and time, the restoration design can be created there, and the restoration file can then be sent to the laboratory. Alternatively, the entire fabrication of the semi-finished restoration can be carried out directly in the dental practice before the treatment appointment. Restorations can be inlays, onlays, crowns, bridges, or veneers. Inlays and onlays place special demands on the transfer holder and the final milling of the restoration in a milling machine already available in the practice or in a milling machine specifically designed for this purpose (CMU). Veneers do not require a transfer holder. They can be delivered in their original material block (Fig. 11).

[0057] Time can be saved during the completion of the restoration by predicting the anticipated preparation interface using suitable software and milling it into the semi-finished product. This can be achieved by: a. using knowledge-based methods from machine learning (ML), or more generally, neural networks based on comparable restorations or with the aid of suitable X-ray scans; b. manually entering the preparation surface; or c. using a combination of both methods.

[0058] Regarding a): These knowledge-based or AI-driven suggestions can either be derived from a large number of preparation data or tailored to the typical preparation techniques of the practice / practitioner. Furthermore, by incorporating X-ray data or other imaging systems such as OCT (optical coherence tomography), at least certain areas of the pulp can be preserved and ground away as the inner surface, or carious areas can be advantageously considered when shaping the anticipated preparation margin.

[0059] Regarding b) The practice or laboratory can use the available data to interactively determine the approximate course of the preparation margin before the actual preparation session. Alternatively, it would also be conceivable to define the possible area (e.g., as a band of surface, etc.) within which the preparation margin can run. This also allows portions of the outer surface to be ground away (e.g., for inlays / onlays) that will not be needed for the subsequent restoration. This approach also offers the opportunity to verify, before the actual preparation, whether the desired type of preparation makes sense: e.g., regarding minimum layer thickness, residual wall thickness, position of the occlusal contacts, material selection via FEM analysis, etc. Regarding c) Any possible combination of b) and c) is conceivable in order to remove as much material as possible from the semi-finished product from the outset (optimized NNS design).

[0060] If build-up fillings are to be carried out in advance of a finally planned restoration, these preliminary preparations or resulting cavity shapes can also be scanned and the desired preparation shape and preparation margin can be further restricted and predicted more accurately in the scan based on the remaining tooth structure.

[0061] This preparation surface is usually oversized to ensure sufficient material is available for the final adaptation to the actual situation in the patient's mouth. It is ground down as much as possible during the partial fabrication of the restoration in the laboratory (Fig. 12).

[0062] To complete the restoration, the dental practice, according to the invention, has access to CAD software, or a corresponding plug-in for the CAD software available in the practice, in which the anticipated preparation surface of the semi-finished product is replaced by the actual preparation scan from the patient's mouth. This is achieved by superimposing the CAD data of the restoration fabricated in the laboratory with the scan data of the intraoral scan of the preparation.

[0063] Furthermore, this superimposition allows for advantageous verification of whether the preparation meets certain criteria, such as sufficient material layer thickness, quality and contour of the preparation margin, avoidance of undercuts, etc. This gives the practitioner the opportunity to make adjustments directly during the preparation. Since the outer surface of the restoration is already present in the inventive method, it does not need to be calculated and / or designed separately. In this sense, the inventive method presented here also offers a number of advantages for optimally planned preparation and, consequently, for a long-lasting restorative restoration.

[0064] Another technical option that allows the dentist to best adhere to a pre-planned preparation shape could be, for example, navigated preparation systems or augmented reality procedures. This enables a further reduction in the necessary post-processing grinding time in the practice. The semi-finished restoration is then clamped into a grinding machine available in the dental practice. In one possible embodiment of the invention, a custom transfer holder is manufactured in the dental laboratory, which adequately secures the partial restoration on one side and fits into the block holder of the grinding machine on the other. In other possible embodiments, pre-fabricated transfer holders from the manufacturer can be used.As part of the described procedure, the dental laboratory delivers the manufactured semi-finished product to the dental practice, either together or separately with the transfer holder and together with the CAD data of the restoration.

[0065] Any dental milling machine is suitable for completing the restoration. However, since the requirements for the milling machine are significantly lower for this purpose, a Chairside Milling Unit (CMU) specifically designed for dental practices can also be used. This allows the use of all common ceramic, composite, and hybrid materials approved for dental CAD / CAM restorations.

[0066] A comparison of the procedures over time is shown in Fig. 13.

[0067] A procedure is claimed for the prosthetic treatment of a patient in one session based on a laboratory-prepared semi-finished product, consisting of the following steps:

[0068] (a) Transmission of the data required for the production of the surface of a restoration to a commercial laboratory, a dental practice laboratory, a laboratory-like structure in a dental practice or specialized service providers,

[0069] (b) Design, manufacture and delivery of the semi-finished product, together with a transfer holder, separately or connected, and the associated CAD data of the restoration,

[0070] (c) Recording of the preparation during the treatment session,

[0071] (d) Superposition of preparation scan and CAD data of the restoration and / or semi-finished product, as well as adaptation of the

[0072] (e) Restoration / semi-finished product to the scan data, (e) Completion of the restoration by grinding down the preparation interface.

[0073] A method according to claim 1 is also claimed, wherein the transfer holder is adapted to the block holder of the grinding machine used in practice and is manufactured by the semi-finished product manufacturer completely or with the aid of purchased parts from a suitable material with sufficient strength, or can be obtained as a purchased part and can be machined with the grinding machine available in practice or the CMU.

[0074] A method according to one of the preceding claims is also described, wherein the program for the design of the transfer holder can be a plug-in for a commercially available proprietary CAD software or cloud-based software, either independently or as a plug-in.

[0075] A method according to one of the preceding claims is also claimed, wherein the transfer holder holds the semi-finished product by force-fit or form-fit (generally in multiple parts and connected to each other in a suitable manner. Fig. 2,3).

[0076] A method according to one of the preceding claims is also described, wherein a partial surface of the semi-finished product is suctioned into the form-fitting semi-finished product holder by means of negative pressure, or is bonded to the form-fitting semi-finished product holder, or is received by a curable, plastic material on a semi-finished product holder with a fixing plate or fixing cup, wherein the bonds can be dissolved mechanically, thermally or by means of solvents (Figs. 4, 5).

[0077] A method according to one of the preceding claims is also claimed, wherein the semi-finished product and / or semi-finished product holder have optical markings, suitable shapes or form elements by which the orientation of the semi-finished product in the grinding machine is optically and / or mechanically detected - for example by means of joint scans of semi-finished product and transfer holder - (Figs. 6, 7) and the coordinate systems of the finally constructed restoration (after preparation scan) and of the semi-finished product used in the grinding machine are brought into alignment.

[0078] A method according to one of the preceding claims is also claimed, wherein the coordinates of the semi-finished product are aligned with the coordinates of the preparation scan via a form key (Fig. 2,3).

[0079] A method according to one of the preceding claims is also claimed, wherein a rod with a unique, preferably always identical, cross-sectional profile is attached or directly manufactured (ground or printed) on a suitable side (preferably on the side facing the preparation) of the semi-finished product, which clearly indicates the position of the restoration in relation to the CAD design and clearly positions it on the transfer holder using a transfer device (Figs. 8, 9).

[0080] A method according to one of the preceding claims is also claimed, wherein the transfer rod is used for the transfer to further manual dental processing (fitting into a dental model, waxing, staining, polishing, and scanning the semi-finished product in relation to the adjacent teeth) and is manually removed or ground away in practice before grinding down the surfaces facing the cavity.

[0081] A method according to one of the preceding claims is also claimed, wherein the semi-finished product remains connected to the original block holder via a cervical bridge with sufficient strength and is thus fixed in the transfer device with fixing compound on the transfer holder with unambiguous assignment (Fig. 10) and the bridge is removed manually or in the grinding machine before the final grinding of the semi-finished product, wherein the Z-coordinate can be detected by contacting the restoration with a grinder or milling cutter at a defined point on the semi-finished product.

[0082] A transfer holder for the force-fit mounting or form-fit enclosure of the semi-finished product is also claimed, which is characterized in that the transfer holder consists of a fixing plate and an adapter, and the fixing plate has a marking or a shape with which a unique position determination between semi-finished product and fixing plate for the force-fit mounting or form-fit enclosure of the semi-finished product on the fixing plate is made, and the adapter has a mounting for clamping the holder in a grinding machine or in a CMU.

[0083] A method according to one of the preceding claims is also described, wherein the program derives the preparation interface to be ground out with sufficient excess (adjustable and modifiable with typical CAD tools) from the anticipated preparation design and can be a standalone proprietary software or a plug-in for a commercially available CAD software or cloud-based software - standalone and / or as a plug-in.

[0084] A method according to one of the preceding claims is also claimed, wherein a prospective preparation interface is generated on the basis of a database or AI-supported from the preparation scans of the dental practice or several dental practices, or can be freely drawn on the basis of the assessment of the practice or the manufacturing laboratory, or can be derived from the superposition of the scanned tooth with an intraoral radiograph, a panoramic radiograph, a CBCT scan, an MRI scan or diaphanoscopy image, which lies outside the actual preparation interface captured in the treatment session and reduces the processing time for the semi-finished product in the treatment session (Fig. 12).

[0085] Also described is a device in which the preparation margin and the inner surface of the preparation are automatically calculated and visualized, and interactively adjusted, in a proprietary or cloud-based standalone software or as a plug-in, and various parameters of the restoration such as material layer thickness, occlusal and approximate contacts, functional contacts, results of strength simulations (FEM analyses) and color design can be checked and displayed.

[0086] A method according to one of the preceding claims is also claimed, wherein a software plug-in or direct programming in the dental CAD software superimposes the CAD restoration data with the preparation scan based on the adjacent teeth and / or the opposing dentition, which must be included in the preparation scan, and enables the display of the expected and actual preparation interface as well as the penetration of the two interfaces.

[0087] A method according to one of the preceding claims is also claimed, wherein the laboratory's restoration design is adapted to the preparation scan.

[0088] A transfer holder according to claim 9 is also claimed, which is characterized in that it automatically links the scanned preparation surface and the surface of the semi-finished product to a restoration, whether proprietary or cloud-based, in stand-alone software or as a plug-in, and visualizes and interactively adjusts the restoration and / or semi-finished product and / or preparation scan.

[0089] A device is also described in which the software indicates whether the preparation scan provides sufficient data for superposition and marks or otherwise displays areas of the preparation that still need to be removed in the preparation scan.

[0090] Also described is a device in which various parameters of the restoration, such as material layer thickness, occlusal and approximate contacts, functional contacts, results of strength simulations (FEM analyses) and / or color design, can be checked and displayed.

[0091] A method according to any of the preceding claims is also claimed, wherein the grinding of the preparation interface in the dental practice is performed with a simplified Chairside Milling Unit (CMU) in the smallest possible form, the technical design of which takes into account the reduced grinding forces, which can process older, commonly used restorative materials, and whose block holder and transfer holder provide a large contact area to minimize bending forces on the holder. A method according to any of the preceding claims is also claimed, wherein markings are provided in the milling machine that enable unambiguous referencing of the transfer holder and / or semi-finished product in relation to the milling machine.

[0092] A device for receiving the semi-finished product and manufacturing the restoration is also described.

[0093] List of illustrations

[0094] Fig. 1 shows a semi-finished product with a positive-locking connection to the original block holder. The cross-section of the adapter must be designed to ensure a secure and reliable connection.

[0095] Figure 2 shows a transfer holder with a form-fitting fixation of the semi-finished product. The semi-finished product is clamped between the occlusal (upper) and cervical (lower) transfer holders, with the two holders being appropriately connected (e.g., screws, clip fastener, etc.). The adapter serves to clamp the holder in a grinding machine. OTH and ZTH can be manufactured using grinding or 3D printing; the adapter can be manufactured along with the transfer or subsequently glued in as a purchased part.

[0096] Fig. 3 shows the holder variant for the horizontal access of the grinding instruments using the example of inlays and onlays with mesial and distal transfer holder (MTH and DTH).

[0097] Fig. 4 shows a transfer holder with (A) an integrated and (B) glued-in adapter for the form-fitting adhesive fixation of the semi-finished product.

[0098] Figure 5 shows a semi-finished product (here, for example, a crown) glued to a clamping plate. The clamping plate ensures the secure clamping of the semi-finished product in a milling machine. The clamping plate and adapter are called a transfer holder. The orientation of the semi-finished product on the transfer holder depends on the milling direction in the milling machine in the dental practice or CMU: (5a) vertical milling direction, (5b) horizontal milling direction. Figure 6 shows a semi-finished product that is glued to a special clamping plate with markings. The markings can be rods or other geometric shapes suitable as references for establishing a clear position between the semi-finished product and the transfer holder in an optical scan of the glued-on semi-finished product. This ensures precise positioning in the milling machine.

[0099] Figure 7 shows a semi-finished product being glued onto a special fixing plate with a specific shape. This specific shape serves as a reference for an optical scan of the glued semi-finished product, enabling unambiguous positioning between the semi-finished product and the transfer holder.

[0100] Figure 8 shows a transfer device, which can be cup-shaped or U-shaped. The transfer rod, integrated into or attached to the semi-finished product, ensures a clear positional relationship between the manually applied semi-finished product and the transfer holder. For this to work, the transfer rod needs a specific geometry (illustrated in the image as an asymmetrical pentagon). The transfer device must be suitable for connecting components (e.g., screws, U-bolts, etc.). Generally, the position of the transfer rod relative to the transfer holder can be configured at any angle, depending on the grinding machine, e.g., 90°. The 180° position shown here is an example.

[0101] Fig. 9 shows a variant in which the ceramic block already has an integrated transfer rod.

[0102] Fig. 10 shows a semi-finished product in a transfer fixture, where the semi-finished product initially remains on the block holder after the initial grinding process in the laboratory. Due to the unique geometry of the block holder and transfer holder, a clear positional relationship is established between the semi-finished product and the transfer holder when the semi-finished product is glued onto the holder in the transfer fixture.

[0103] Figure 11 shows that the semi-finished veneer can remain on the initial block holder. If heat treatment is required for aesthetic reasons, the block holder must be made of ceramic. Alternatively, the veneer can be fabricated in two parts and bonded together during insertion.

[0104] Figure 12 shows that the anticipated preparation margin should lie within and below the actual preparation margin. Overlaps in the inner lumen are generally unproblematic, as the cavities created during insertion are filled with the luting material. Figure 12 also shows that for a secure marginal seal of the restoration, the anticipated preparation margin must lie below (cervically) the actual preparation margin.

[0105] Fig. 13 shows a comparison of the invention (LSVD) with the traditional and the single visit treatment method.

[0106] Fig. 14. Possible implementation of referencing the semi-finished product to the inside of the preparation:

[0107] 1. Restoration optimally designed based on the scans and other data sets. The restoration data set is uniquely referenced to the adjacent teeth / remaining dentition (29).

[0108] 2. Production of the semi-finished product: Through colour characterisation, possible implementation of veneers / cut-back technology and surface refinement through morphological accentuation and polishing / glazing, the outside can be changed from the original constructed surface (30).

[0109] 3. Scanning the surface of the semi-finished product and reorienting it to the data set with the adjacent teeth or remaining dentition (31).

[0110] 4. Positioning the semi-finished product on a transfer holder for the grinding machine and also scanning this situation (32).

[0111] 5. To provide the semi-finished product with transfer holder and the data sets (3.) and (4.) for practical use (33).

[0112] 6. Preparation session with preparation and scanning of the situation on the patient (34).

[0113] 7. Referencing scan data set 3 with scan data set 6; Linking the outer contour of the semi-finished product from scan data set 3 with the inner surface of the preparation from scan data set 6 results in the

[0114] Restoration data set (35).

[0115] 8. Referencing the restoration data set from 7 with the data set from 4: This uniquely determines the position of the preparation inner surface in relation to the semi-finished product for the grinding machine or CMU available in practice (36).

[0116] Reference symbol list

[0117] Reference sign characteristic

[0118] 1 transfer holder

[0119] 1a Upper transfer holder

[0120] 1 b Lower transfer holder

[0121] 1c Distal Transfer Holder

[0122] 1 d Mesial transfer holder

[0123] 1 e transfer holder with integrated adapter

[0124] 1f transfer holder with glued-in adapter

[0125] 1g transfer holder with specific holder shape

[0126] 2 Semi-finished product

[0127] 2a Constructed semi-finished product

[0128] 2b Finished semi-finished product

[0129] 3 Ground inner lumen

[0130] 4 brackets

[0131] 5 Suitable connection

[0132] 5a Vertical grinding direction

[0133] 5b Horizontal grinding direction

[0134] 6 adapters

[0135] 7 fixing plates

[0136] 8 Fixing compound

[0137] 9 F five-sided transfer rod

[0138] 10 Mark

[0139] 11 Transfer device

[0140] 11 a Base body of the transfer device

[0141] 11 b Cover of the transfer device 12 Transfer rod

[0142] 13 ceramic blocks

[0143] 14 Veneers

[0144] 15 Preparation interface

[0145] 15a Expected preparation interface

[0146] 16 Traditional

[0147] 17 Single Visit Dentistry (SVD)

[0148] 18 Production of a semi-finished product in the laboratory (LSVD)

[0149] 19th preparation session

[0150] 20 Production in the laboratory

[0151] 21 Second session

[0152] 22 Preparation

[0153] 23 IO-Scan

[0154] 24 Temporary

[0155] 25 Final Supply

[0156] 26 Intraoral impression taking using an intraoral scanner

[0157] 27 treatments in one session

[0158] 28 Manufacturing in practice

[0159] 28a Completion in practice

[0160] 29 Optimally designed restoration

[0161] 30 Production of the semi-finished product

[0162] 31 Scanning the surface of the semi-finished product

[0163] 32 Positioning the semi-finished product

[0164] 33 Provision of the semi-finished product with transfer holder

[0165] 34th preparation session

[0166] 35 Referencing scan data set

[0167] 36 Referencing the restoration data set

[0168] Glossary:

[0169] Semi-finished product: A partially manufactured restoration that is adapted to the preparation surface in the dental practice. Transfer holder: The semi-finished product is fixed to the transfer holder and inserted into the

[0170] Grinding machine in practice or clamped into the CMU.

[0171] Block holder: The block from which a restoration or semi-finished product is milled is fixed to a block holder that fits into the grinding machine of the laboratory or practice.

[0172] Transfer rod: A rod attached to the restoration that facilitates the handling of the

[0173] It facilitates restoration in the laboratory and can be used for matching semi-finished products and grinding machines.

[0174] CMU: Chairside Milling Unit. A grinding machine adapted to the specific requirements of finish grinding.

[0175] Literature:

[0176] • Zaruba, M., Mehl, A.: Chairside systems: a current review. Int J Comput Dent. 20(2): 123-149 (2017).

[0177] • Zuercher, A. N, loannidis, A., Hüsler, J., Mehl, A., Hämmerle, Ch., Thoma, D.: Randomized controlled pilot study assessing efficacy, efficiency, and patient-reported outcomes measures of chairside and labside single-tooth restorations. Journal of Esthetic and Restorative Dentistry, 35(1):74-83. (2023).

[0178] • Beuer, F., Schweiger, J., Edelhoff, D.: Digital dentistry: an overview of recent developments for CAD / CAM generated restorations. British Dental Journal 204, 505-511 (2008).

Claims

1. Patent claims 1. Procedure for the prosthetic treatment of a patient in one session based on a laboratory-prepared semi-finished product, consisting of the following steps: (a) Transmission of the data required for the production of the surface of a restoration to a commercial laboratory, a dental practice laboratory, a laboratory-like structure in a dental practice or specialized service providers, (b) Design, manufacture and delivery of the semi-finished product, together with a transfer holder, separately or connected, and the associated CAD data of the restoration, (c) Recording of the preparation during the treatment session, (d) Superposition of preparation scan and CAD data of the restoration and / or semi-finished product, as well as adaptation of the restoration / semi-finished product to the scan data, (e) Completing the restoration by grinding down the preparation interface.

2. Method according to claim 1, wherein the transfer holder is adapted to the block holder of the grinding machine used in practice and is manufactured by the semi-finished product manufacturer completely or with the aid of purchased parts from a suitable material with sufficient strength, or can be obtained as a purchased part and can be machined with the grinding machine available in practice or the CMU.

3. Method according to one of the preceding claims, wherein the transfer holder holds the semi-finished product by force-locking or form-locking.

4. Method according to one of the preceding claims, wherein the semi-finished product and / or semi-finished product holder have optical markings, suitable shapes or form elements by which the orientation of the semi-finished product in the grinding machine is optically and / or mechanically detected and the coordinate systems of the final constructed restoration according to The preparation scan and the semi-finished product used in the grinding machine are brought into alignment.

5. Method according to one of the preceding claims, wherein the coordinates of the semi-finished product are aligned with the coordinates of the preparation scan via a form key.

6. Method according to one of the preceding claims, wherein a rod with a unique, preferably always the same, cross-sectional profile is attached or directly manufactured on a suitable side (preferably on the side facing the preparation) of the semi-finished product, which uniquely indicates the position of the restoration in relation to the CAD design and uniquely positions it on the transfer holder using a transfer device.

7. Method according to one of the preceding claims, wherein a transfer rod is used for the transfer to further manual dental processing and is manually removed or ground away in practice before grinding down the surfaces facing the cavity.

8. Method according to one of the preceding claims, wherein the semi-finished product remains connected to the original block holder via a cervical bridge with sufficient strength and is thus fixed in the transfer device with fixing compound on the transfer holder with unambiguous assignment and the bridge is removed manually or in the grinding machine before the final grinding of the semi-finished product, wherein the Z-coordinate can be detected by contacting the restoration with a grinder or milling cutter at a defined point on the semi-finished product.

9. Transfer holder for force-fit mounting or form-fit enclosure of the semi-finished product, characterized in that the transfer holder consists of a fixing plate and an adapter, and the fixing plate has a marking or a shape with which a unique position determination between the semi-finished product and the fixing plate for force-fit mounting or form-fit enclosure of the semi-finished product is possible on the A fixing plate is manufactured, and the adapter has a holder for clamping the holder into a grinding machine or a CMU.

10. Method according to any one of the preceding claims 1 to 8, wherein a prospective preparation interface is generated on the basis of a database or AI-supported from the preparation scans of the dental practice or several dental practices, or can be freely drawn on the basis of the assessment of the practice or the manufacturing laboratory, or can be derived from the superposition of the scanned tooth with an intraoral radiograph, a panoramic radiograph, a CBCT scan, an MRI scan or diaphanoscopy image, which lies outside the actual preparation interface captured in the treatment session and reduces the processing time for the semi-finished product in the treatment session.

11. Method according to any one of the preceding claims 1 to 8 and 10, wherein a software plug-in or direct programming in the dental CAD software superimposes the CAD restoration data with the preparation scan based on the adjacent teeth and / or the opposing dentition, which must be included in the preparation scan, and enables the display of the expected and actual preparation interface as well as the penetration of the two interfaces.

12. Method according to any one of the preceding claims 1 to 8, 10 and 11, wherein the laboratory's restoration design is adapted to the preparation scan.

13. Transfer holder according to claim 9, characterized in that this automatically links the scanned preparation surface and the surface of the semi-finished product to a restoration, either proprietary or cloud-based in standalone software or as a plug-in, visualizes the restoration and / or semi-finished product and / or preparation scan and adjusts it interactively.

14. Method according to any one of the preceding claims 1 to 8 and 10 to 12, wherein the grinding of the preparation interface in the dental practice is carried out with a simplified Chairside Milling Unit in the smallest possible design, the The technical design takes into account the reduced grinding forces, can process all common restorative materials, and the block holder and transfer holder provide a large contact area to minimize bending forces on the holder.

15. A method according to any one of the preceding claims 1 to 8, 10 to 12 and 14, wherein markings are provided in the grinding machine that enable unambiguous referencing of the transfer holder and / or semi-finished product in relation to the grinding machine.

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