Computerized methods and CAD systems for prosthetic dental procedures.

Abstract

This application provides a computer-aided method (100) and a CAD system (200) for prosthetic dental restoration. The inventors propose a method that reverses the conventional process of first forming a tooth for prosthetic dental restoration and then detecting the formation limit surface using CAD software. In particular, this application defines the formation limit surface and tooth formation in advance, that is, prior to physically forming the tooth for prosthetic dental restoration. Specifically, this novel process includes first detecting the formation limit surface using CAD software and finally digitally forming the tooth for prosthetic dental restoration.

Description

Technical Field

[0001] The present application relates to a computer-implemented method and a CAD system for prosthetic dental treatment. Similar methods and systems are known from WO 2021 / 262336 A1.

Background Art

[0002] Prosthetic dentistry is a known technique for restoring the shape and function of defective teeth. However, when performing such known restorations, there are constantly problems until a preparation margin (edge, preparation limit line) is created and the prosthetic dental restoration is finally placed.

[0003] In current practice, the dentist processes the shape of the tooth to create a preparation margin and then creates a digital model using a dental 3D scanner. This model is sent to a dental laboratory, which provides a suitable prosthetic dental restoration. The dental technician uses CAD software and a specific algorithm to accurately detect the preparation margin.

[0004] However, even with such advanced technology, problems can occur where the preparation margin is insufficient or excessive. If a problem is discovered during the design process, the dentist may have to start over from the tooth preparation, which may cause a delay in progress.

[0005] Also, if a deficiency in the preparation margin is discovered after the final placement of the prosthetic dental restoration, it can be a serious problem for the patient. That is, problems such as bacteria growing in hard-to-reach areas around the prosthetic dental restoration area and causing cavities, or discomfort and pain due to restoration incompatibility can be considered.

[0006] To treat such problems, additional appointments, time, and costs are often required. Although the dentist may sometimes try to adjust the prosthetic dental restoration without completely removing it, this is not always possible.

[0007] Therefore, the main objective of this application is to introduce a novel process that can eliminate the risk of delayed detection of defects in the preparation of teeth for prosthetic dental restorations. [Overview of the Initiative]

[0008] As described in the attached claims, this application provides a system and method that can enhance the precision, efficiency, and individualization in the preparation of dental restorations, thereby improving patient outcomes and making the dental restoration process smoother and more successful.

[0009] The dependent claims describe specific embodiments relating to this application.

[0010] These other embodiments relating to this application will be understood based on the embodiments described below. [Brief explanation of the drawing]

[0011] Further details, aspects, and embodiments of this application are described for illustrative purposes only, with reference to the drawings. Similar reference numerals in the drawings are used to identify similar or functionally similar elements. It should be noted that elements in the drawings are shown for brevity and clarity and are not necessarily drawn to scale. Elements shown with solid lines are mandatory, while those shown with dotted lines are optional.

[0012] [Figure 1] A schematic flowchart of the method relating to this application is shown. [Figure 2] This shows a front view of the dental 3D digital model related to this application. [Figure 3] Another front view of the dental 3D digital model relating to this application is shown. [Figure 4] Figure 1 shows some of the steps in the method. [Figure 5] This is a block diagram of the system related to this application. [Modes for carrying out the invention]

[0013] The embodiments described in this application may largely consist of elements already known to those skilled in the art. Therefore, in order to avoid obscuring the teachings of this application, explanations beyond what is considered necessary for understanding and recognizing the fundamental concepts of this application will not be provided.

[0014] [Problems to be solved by this application]

[0015] The inventors have devised a method to prevent the discovery of improper tooth preparation for prosthetic dental restorations from occurring at too late.

[0016] The technical problem addressed by this application is the lack of precision, efficiency, and individualization in conventional processes for preparing dental prosthetics. Conventional methods often rely on manual processes, which can lead to problems such as errors, patient discomfort, and suboptimal results.

[0017] [Solution of this application]

[0018] In contrast, this application utilizes advanced technology that can automate and streamline the process. By generating and manipulating 3D models, highly accurate and individualized dental prosthetic plans can be realized. Furthermore, because the area to be restored can be precisely identified and formed, perfect placement can be ensured, leading to successful treatment.

[0019] In particular, this application provides a highly accurate and efficient method for preparing dental restoratives.

[0020] In this application, the system can automatically determine the areas where planned prosthetic dental restorations should be performed on a 3D model that digitally represents a patient's natural teeth and gums. This process of demarcating the restoration area from the non-restoration area is extremely important in order to ensure that the prosthetic dental restoration is perfectly fitted without affecting the areas that should be left untouched.

[0021] In the present application, a pre-formed dental model is generated by improving the recognition of non-restored areas on the initial dental model. This makes it easier to distinguish between the areas where prosthetic dental restoration should be performed and the areas where it should not be performed.

[0022] Next, in the present application, a wax-up model, that is, a model that digitally represents the proposed changes to the patient's teeth in 3D, is obtained. This enables the final result prediction of the dental restoration process to be visually indicated.

[0023] Furthermore, in the present application, the pre-formed dental model or the initial dental model is aligned with the wax-up model to further improve the accuracy and correctness. This alignment makes it easier to identify the areas where the planned restoration does not match the current condition of the patient's teeth.

[0024] Furthermore, in the present application, an offset depression area is created inside the pre-formed dental model or the initial dental model by offsetting from the surface of the wax-up model in the inward direction. This offset depression area represents the area where the inward offset penetrates into the patient's natural teeth.

[0025] Finally, the present application generates a final dental formation model by forming the surface of the pre-formed dental model or the initial dental model that matches the offset depression area. This emphasizes the exact area where prosthetic dental restoration will be performed, thereby ensuring a perfect fit and enabling the success of the dental restoration procedure.

[0026] Overall, the present application can achieve the technical effect of a highly accurate and efficiently individualized dental restoration plan. That is, by automating the process group that was previously manual, the risk of errors can be reduced and the patient's outcome can be improved.

[0027] [First Aspect According to the Present Application: Computer-Implemented Method (100)]

[0028] As shown in Figure 1, the first aspect of this application relates to a computer implementation method (100) using a computer-aided design (CAD) system.

[0029] In other words, this application relates to a method implemented on a computer using a CAD system.

[0030] As is commonly known in the field of prosthodontics and dental restoration, CAD systems allow dental professionals to digitally create precisely tailored designs. They can also be used to manufacture physical dental prosthetics through methods such as 3D printing and 3D milling.

[0031] The computer-aided method (100) in this application is designed to accept or fit a specific type of prosthetic dental restoration by digitally shaping one or more natural teeth.

[0032] In this specification, "natural teeth" refers to the original teeth that humans have grown naturally, and is contrasted with artificial teeth or teeth restored by prosthetic dentistry. Examples of natural teeth include incisors, canines, premolars, and molars.

[0033] Furthermore, in this specification, "receive or fit" means that by shaping a natural tooth, it becomes possible to enable that natural tooth to accept or securely hold a prosthetic dental restoration.

[0034] In this specification, "intended prosthetic dental restoration" refers to a future plan to use artificial replacements to restore the function and aesthetics of one or more damaged or lost teeth. Such artificial replacements include crowns, bridges, dentures, inlays, onlays, or veneers. These prosthetic dental procedures usually involve attachments to the teeth (fillings, crowns, veneers, etc.), so the total volume of the restored tooth may increase.

[0035] In other words, the computer-aided method (100) is specifically designed to digitally shape natural teeth for a certain type of dental restoration.

[0036] In this specification, dental restoration refers to procedures for restoring the function and integrity of teeth damaged by caries or trauma, or procedures performed for aesthetic reasons.

[0037] In particular, the computer-aided method (100) includes preparing a digital model of the patient's natural teeth. The purpose of this preparation is to prepare the teeth to accept or adapt to a specific type of dental restoration.

[0038] The type of dental restoration can be specified or selected in advance. The type of dental restoration may be arbitrary, depending on the patient's needs, and can range from crowns to veneers and fillings.

[0039] This allows dentists who plan dental procedures in advance to perform them as effectively and accurately as possible.

[0040] Figure 2 shows an example of using veneered (10) as a planned prosthetic dental restoration.

[0041] The first step (110) of the computerized method (100) includes obtaining a first 3D dental model known as an initial tooth model. This initial tooth model digitally represents one or more natural teeth of the patient, along with the associated gingiva. At this stage, each natural tooth is not yet formed to accept or accommodate a prosthetic dental restoration.

[0042] In this specification, "3D dental model" refers to a three-dimensional digital representation of a patient's teeth and gums. This 3D dental model will be generated or acquired.

[0043] In the first example, the geometry of a 3D dental object is represented as a collection of interconnected triangles or facets. This is the case for design file formats such as STL, PLY, VRML, X3D, and Collada.

[0044] In the second example, the geometry of a 3D dental object is represented as a collection of control points and weights. This is the case for design file formats such as IGES, IGS, STEP, and SAT.

[0045] In this specification, "initial tooth model" refers to a model showing the current state of a patient's natural teeth and gums before any dental treatment is performed.

[0046] Furthermore, the "initial tooth model" may reflect changes resulting from procedures already performed on the gingiva (such as repositioning of the gingival margin or gingival grafting).

[0047] In other words, an "initial tooth model" can be considered a starting point for planning subsequent dental restorative work.

[0048] Figure 2 shows an early tooth model (20).

[0049] In a step (110) according to a particular embodiment, an initial tooth model can be obtained by an intraoral dental 3D scanner configured to 3D scan and record the 3D shape of at least a portion of the patient's oral cavity.

[0050] In other words, in this embodiment, the design of the intraoral dental 3D scanner is such that it can capture the three-dimensional shape of the patient's teeth and gums in order to perform a 3D scan of the oral cavity.

[0051] The resulting output (i.e., the initial tooth model) provides a highly detailed 3D representation of the patient's oral cavity. This initial tooth model serves as a reference line or starting point for dental procedures and is therefore extremely important.

[0052] By obtaining initial tooth models, dentists can gain a comprehensive understanding of the patient's current dental condition. This knowledge allows for more accurate and efficient planning and execution of dental procedures, ultimately leading to better patient outcomes.

[0053] Next, in step (120), the computer implementation method (100) automatically determines one or more shaping limit lines for one or more natural teeth.

[0054] In other words, the process after the initial tooth model is created or acquired includes accurately identifying the areas that require dental restoration for each tooth in need of treatment. This process is also referred to as the determination of "preparation margin lines."

[0055] The preservation boundary line refers to the individual boundary lines on an initial tooth model. In other words, the preservation boundary line allows one or more restored areas to be distinguished from one or more unrestored areas.

[0056] The term "individual" here emphasizes that each formation boundary line represents a separate and independent boundary. In other words, there can be multiple formation boundary lines, and each of these multiple formation boundary lines can play its own unique role in distinguishing between the repaired area and the unrepaired area.

[0057] In other words, you can think of the formation limit line as a blueprint or map that separates two types of areas.

[0058] In other words, the restoration area refers to the area on the surface of the initial tooth model where prosthetic dental restoration should be performed.

[0059] In other words, the preparation limit line specifies which area of ​​the tooth will be treated with the dental restoration (crown, denture, implant, etc.). The area marked in this way is called the "restoration zone."

[0060] In contrast, the non-restorative zone refers to the surface area on the initial tooth model that should be left as is without prosthetic dental restoration.

[0061] In other words, non-restoration zones are the parts of a tooth that do not undergo dental restoration. These areas are called "non-restoration zones."

[0062] Furthermore, the determination of the preparation limit line is based on the initial tooth model and the corresponding type of planned prosthetic dental restoration.

[0063] In other words, the determination of the preparation limit is influenced by both the initial tooth model and the type of dental restoration planned.

[0064] The determination of the formation limit line in a particular case may be performed according to various algorithms.

[0065] In particular, edge detection algorithms can be used. These algorithms analyze an image to identify the ends of one element and the beginnings of another. Known algorithms of this type include, for example, Sobel, Prewitt, Roberts, and Canny.

[0066] Contour detection algorithms are another useful tool. These algorithms can trace the boundaries of objects within an image in a manner similar to how a painter sketches outlines. Active Contour algorithms are particularly well-known.

[0067] Machine learning algorithms are also useful. These algorithms learn from a series of examples and apply that knowledge to new data. Support vector machines (SVMs), decision trees, and deep learning neural networks are particularly noteworthy examples of this type of algorithm.

[0068] Furthermore, "segmentation algorithms" can be used to divide an image into multiple segments. These algorithms can be thought of as dividing a dental model into separate sections. Commonly used algorithms for this purpose include the Watershed algorithm and the k-means algorithm.

[0069] In certain embodiments, the formation limit line is defined with respect to a reference point. This reference point can be of several options, such as the gingival margin, the interdental contact point where the restoration will come into contact with an adjacent tooth, or the overall anatomical structure of the tooth to be restored.

[0070] In other words, this particular embodiment concerns how to determine the preparation limit line as an essential guideline to use in setting the area to be restored by dental restoration.

[0071] These formation limits are defined with respect to reference points. These reference points refer to specific areas within the mouth that help in setting these guidelines.

[0072] Note that this reference point is not fixed, and other options may be used.

[0073] For example, the gingival margin, that is, the periphery of the gingival tissue surrounding the tooth, could be selected as the reference point.

[0074] In this case, as shown in Figure 2, the following three types of formation limits can be considered. • The subgingival formation limit line (21). This is the line formed closer to the tooth root, and it lies behind the gingival tissue, i.e., below the gingival line (30). • The formation boundary line (22) of the gingival margin. That is, the line formed at the same location where the tooth is in contact with the gingiva, which is the gingival line (31). • The supragingival formation limit line (23). This is a line formed closer to the occlusal surface of the tooth and further away from the tooth root, meaning it lies above the gingival line (32). Here, "above" refers to the side of the tooth that is close to the occlusal surface and farther from the root. "Below" refers to the side of the tooth that is close to the root and farther from the occlusal surface.

[0075] Another option is the interdental contact point. This refers to the area where the restoration contacts the adjacent tooth. Also known as the interproximal preparation boundary surface, this allows for the design of a prosthetic dental restoration that can be naturally fitted to the existing dentition.

[0076] As a final option, the overall anatomical structure of the tooth to be restored can be considered. This refers to the general shape and structure of the tooth. In this case, the preparation boundary can be defined based on the shape, size, and condition of the tooth to be restored. This is a customized method that dentists may use when specific requirements are imposed on the tooth and the restoration, and they determine the preparation boundary based on those requirements. Such a preparation boundary may include a combination of supragingual, subgingival, intragingival, and interdental preparation boundary planes, depending on the needs of the tooth.

[0077] In step (130), the computer-aided method (100) forms the surface of the initial tooth model that matches the unrestored area. This action improves its recognition. As a result, one or more formation limit surfaces are obtained, and a second 3D dental model, i.e., a prepared anterior tooth model, is generated.

[0078] In other words, in process (130), the computer-aided procedure (100) works on the surface of the initial tooth model. However, this work does not extend to the entire initial tooth model, but only to the areas designated as non-restorative zones. The non-restorative zones, in this context, refer to the parts of the tooth that do not undergo dental treatment.

[0079] By creating unrepaired areas in this way, they become more noticeable and their recognition improves. This process may involve various tasks, such as changing the color or texture of the unrepaired areas in the initial tooth model.

[0080] After this editing process, "preparation margins" are obtained. Essentially, these preparation margins refer to the boundary between the non-restorative area and the area where dental treatment will be performed.

[0081] After these steps are completed, a second 3D model of the tooth is generated. This model is called the prepared anterior tooth model. It is like an updated map, clearly distinguishing not only the areas where dental treatment will be performed, but also the areas that will remain untouched.

[0082] This allows for more detailed and accurate planning of dental procedures. The clearer each area becomes, the easier it is to plan and execute dental restorations.

[0083] Figure 3 shows the subgingival grafting limit surface (24).

[0084] In certain embodiments, the process of forming the surface of the initial tooth model (130) includes a digital carving process (131). This digital carving process (131) is performed through the surface of the initial tooth model.

[0085] In other words, this particular example relating to the computer-aided method (100) concerns how to form the surface of an initial tooth model through a process known as digital engraving.

[0086] In this context, digital engraving refers to the process of adjusting or modifying an initial tooth model. Specifically, this engraving is performed on the surface of the initial tooth model. The result is a prepared pre-tooth model, a model that more accurately represents the current state of the patient's teeth. The prepared pre-tooth model includes markings indicating the areas where dental procedures will be performed.

[0087] In digital engraving for specific examples, various tools may be used. These tools include, for example, push / pull tools for manipulating the shape and size of the initial tooth model, smoothing tools for softening or harmonizing rough edges, and texture brushes for adding precise surfaces or patterns. These tools also include those for scaling, rotating, and moving the initial tooth model or parts thereof. Advanced techniques can also be utilized in digital engraving, such as mesh editing for generating complex geometry and Boolean operations for adding, subtracting, or intersecting shapes. To further improve accuracy, cutting or slicing tools can be used to segment the initial tooth model into manageable smaller pieces. Finally, layering tools allow for independent work on different parts of the initial tooth model, and these parts can be merged to obtain the final engraving.

[0088] To make the above easier to understand, imagine an artist working with clay models, adding and removing clay to create the final sculptural form. Digital sculpting is very similar, except that it is done on a computer using a digital model of a tooth.

[0089] This helps in shaping the teeth in the initial tooth model for the planned dental restoration.

[0090] In an example of a particular embodiment, the digital engraving process (131) includes the process of engraving (carving) the surface of the initial tooth model. In particular, this engraving process includes the application of margin design. There are various options for margin design. Such options include chamfer type, deep chamfer type, shoulder type, rounded shoulder type, modified shoulder type, shoulder bevel type, feather edge type, beveled type, knife edge type, etc. Alternatively, an appropriate combination of any of these designs may be selected.

[0091] In other words, an example of this particular embodiment includes a digital carving process that allows a specific design pattern to be applied to an initial tooth model. This pattern design (i.e., the design of the formation limit surface) can essentially be thought of as a blueprint used to shape the tooth for prosthetic dental restoration.

[0092] Depending on the type of dental restoration required, a vast number of marginal surface designs can be selected. For example, a chamfer can be used for crowns or veneers. In this case, the marginal surface design can be such that an inclined edge is provided on the tooth so that the crown or veneer fits snugly.

[0093] Similarly, a shoulder-type shaping limit surface may be designed for dental implants, in which case a flat horizontal edge can be provided to securely position the implant. In the shoulder-bevel type (a variation of the shoulder type), a bevel is added to the flat edge to enable a more precise fit.

[0094] Other designs include deep chamfer, rounded shoulder, modified shoulder, feather edge, beveled, and knife edge types. Each of these designs corresponds to different types of dental restorations that meet specific treatment requirements.

[0095] Depending on what is best suited to the patient's specific dental situation, the computer-aided method (100) may select any of these designs, or any appropriate combination thereof.

[0096] Furthermore, in step (140) of the computer-aided method (100), a wax model can be obtained as a third 3D dental model. This model digitally represents the planned changes and / or improvements to the natural tooth. In other words, it can show a predicted final result of the prosthetic dental restoration.

[0097] In other words, in process (140), a third 3D dental model is generated or acquired. This model is called a "wax-up model." The term "wax-up" is traditionally used in the field of prosthodontics, stemming from the practice of using wax models to show patients proposed modifications to their teeth.

[0098] Digitally speaking, a wax model is a computer-generated model used to show proposed changes or improvements to a patient's natural teeth. These changes represent what the dentist intends to do in a dental restorative procedure.

[0099] This is somewhat similar to before-and-after photographs. "Before" refers to the patient's original tooth, while "after" refers to the expected appearance after the prosthetic dental restoration is completed. In a wax model, the "after" area represents the final result that the dentist aims to achieve through prosthetic dental restoration.

[0100] This allows for the visualization of expected outcomes before actual dental procedures are performed, which is helpful for both dentists and patients.

[0101] In step (150), the computer-aided method (100) aligns the prepared anterior tooth model or initial tooth model with the wax model.

[0102] In other words, step (150) involves superimposing (aligning) two digital 3D models of the patient's teeth.

[0103] The first model referred to here is the prepared anterior tooth model. The prepared anterior tooth model shows the current state of the patient's teeth, but it is designed so that the areas where dental work will be performed and the areas that will not are clearly distinguishable. Alternatively, the initial tooth model mentioned above may be used as the first model.

[0104] Figure 4(a) shows a lateral view of one tooth (40) from a prepared anterior tooth model or an early tooth model.

[0105] The second type of model is a wax model. A wax model shows a predicted appearance of the patient's teeth after dental restoration.

[0106] As is well known in the field of prosthodontic restoration, a wax model represents the patient's teeth after restoration, and therefore includes pre-prepared tooth models. This is because in dental restoration procedures, materials (fillings, crowns, veneers, etc.) are often added to the teeth, increasing their overall volume.

[0107] Furthermore, the wax model may be positioned (penetrated) inside the prepared anterior tooth model. This is particularly common in dental restorative procedures that primarily involve removing material from the tooth. In cases of jaws where teeth tend to protrude outward, it may be necessary to deliberately position the wax model inside the initial tooth model. In such cases, a two-step process may be required: first, the tooth structure is trimmed, the offset intrusion area is carved, and then the veneer or other restoration is placed. This technique is generally called subtractive restoration (cutting restoration), and as a result, the overall volume of the tooth structure may be reduced.

[0108] In other words, the computer-aided procedure (100) allows for a comparison between the current state of the patient's teeth and the planned final result by aligning these two types of models. This is somewhat similar to the act of superimposing two photographs to see the changes from one state to the next.

[0109] This allows the dentist to visualize how the tooth needs to be modified to achieve the desired result. In other words, it provides a roadmap for dental treatment.

[0110] In certain cases, this alignment process may be performed according to various algorithms. Such algorithms include iterative nearest neighbor (ICP), thin plate spline function (TPS), robust point cloud alignment method (RPM), Gaussian mixture model (GMM), normal distribution transformation, robust point cloud alignment method (RPM), and coherent point drift method (CPD).

[0111] Figure 4(b) shows a lateral view of one tooth (40) from a prepared anterior tooth model or an early tooth model, aligned with the wax (50) of the associated wax model.

[0112] Furthermore, in step (160), the computer-aided method (100) offsets the wax model inward from its surface. This offset corresponds to one or more predetermined offsets associated with the type of prosthetic dental restoration to be intended. This offset process generates one or more offset indentation zones within the prepared anterior tooth model or the initial tooth model. Each offset indentation zone represents the area in which the inward offset penetrates into the prepared anterior tooth model or the initial tooth model.

[0113] In other words, step (160) involves a process such as creating small depressions by pressing down inwards in specific areas of the surface of the wax model. Such adjustments are carefully calculated and performed depending on the type of dental restorative work to be performed.

[0114] This inward adjustment, or "offset," allows for the creation of what are called "offset intrusion zones" in the prepared anterior tooth model or initial tooth model. These offset intrusion zones refer to areas in the prepared anterior tooth model or initial tooth model where adjustments are made inward.

[0115] In other words, the offset in this context can be thought of as a buffer zone or gap etched into the surface of the wax model. This offset "cancels out" or extends inward from the surface of the wax model toward the surface of the prepared anterior tooth model or the initial tooth model. This extension occurs along a given plane.

[0116] By applying this offset, the computer-aided method (100) can generate an "offset intrusion area" within the prepared anterior tooth model or initial tooth model. This offset intrusion area refers to the region in which the offset intrudes (moves into) the interior of the prepared anterior tooth model or initial tooth model.

[0117] These offsets may include one or more predetermined offsets, which are pre-determined measurements depending on the type of dental restoration to be planned and the corresponding given position on the wax model.

[0118] The information described above will help dentists plan dental restorations in a way that is accurate and safe for the rest of the patient's teeth.

[0119] Figure 4(c) corresponds to Figure 4(b) and further shows the offset (60) and the offset reduction area (70).

[0120] As an example, imagine a first given point P1 set on the surface of a wax model. A second given point P2 is set on the surface of the prepared anterior tooth model, on the same plane (90) as the first given point P1. The length of the surface gap (80) between the first given point P1 and the second given point P2 is recorded as 0.3 mm. Now, let's consider the case where veneering is planned, and assume an offset of 0.5 mm. In this case, a third given point P3 on the plane (90) is set on the surface of the prepared anterior tooth model after it has been prepared to create an indentation area (70). The thickness of the offset indentation area (70) inside the prepared anterior tooth model, that is, the distance between the second given point P2 and the third given point P3, will be 0.2 mm (i.e., 0.5 mm minus 0.3 mm).

[0121] Finally, in step (170), the computer-aided method (100) forms the surface of the prepared anterior tooth model or the surface of the initial tooth model that matches the offset intrusion area. This formation improves recognition and allows for the creation of one or more tooth preparation areas. Then, a fourth 3D dental model, called the final prepared tooth model, can be generated.

[0122] In other words, step (170) involves forming the surface of the prepared anterior tooth model or the initial tooth model, more specifically, forming the area adjacent to the offset indentation area. As mentioned above, the offset indentation area refers to the area to which offset or excess spacing was added in the preceding step (160).

[0123] By creating these areas, they become more eye-catching and recognizable. This process may involve various techniques; for example, the area may be emphasized in some way on a model of prepared anterior teeth.

[0124] This process produces what are called "tooth-prepared zones." These tooth-prepared zones essentially refer to areas of the tooth that have been prepared and ready for dental restoration.

[0125] In this way, a fourth 3D model of the tooth is generated. This model is called the final tooth preparation model. It is like an updated blueprint, and it clearly distinguishes not only the areas where dental procedures will be performed, but also the areas that are ready for dental restoration.

[0126] This allows for a more detailed and precise approach to planning dental procedures.

[0127] The clearer each area becomes, the easier it becomes to plan and execute dental restorations.

[0128] Furthermore, the prepared teeth within the final tooth preparation model can be used to digitally design the planned dental restorations corresponding to the prepared tooth area.

[0129] Figure 3 shows the tooth preparation area (25).

[0130] In certain embodiments, the formation (170) of the surface of the prepared anterior tooth model or the surface of the initial tooth model includes a digital carving step (171). This digital carving step (171) is performed through the surface of the prepared anterior tooth model or the surface of the initial tooth model.

[0131] In other words, this particular embodiment relates to a specific method for forming a pre-formed tooth model or an early tooth model, primarily through a process called digital carving.

[0132] In this context, digital engraving refers to the process of adjusting or modifying a prepared anterior tooth model or an initial tooth model. Specifically, this engraving is performed on the surface of the prepared anterior tooth model or the initial tooth model. These models represent the current state of the patient's teeth, but also clearly indicate the areas where dental procedures will be performed.

[0133] The features described above assist in shaping the teeth in the model for the intended dental restoration.

[0134] In digital engraving for specific examples, various tools may be used. These tools include, for example, push / pull tools for manipulating the shape and size of the prepared anterior tooth model or initial tooth model, smoothing tools for softening or harmonizing rough edges, and texture brushes for adding refined surfaces or patterns. These tools also include those for scaling, rotating, and moving the prepared anterior tooth model or parts thereof. Advanced techniques can also be utilized in digital engraving, such as mesh editing for generating complex geometries and Boolean operations for adding, subtracting, or crossing shapes. To further improve accuracy, cutting or slicing tools can be used to segment the prepared anterior tooth model or initial tooth model into manageable smaller pieces. Finally, layering tools allow for independent work on different parts of the prepared anterior tooth model, and these parts can be merged to obtain the final engraving.

[0135] To make the above easier to understand, imagine an artist working with clay models, adding and removing clay to create the final sculptural form. Digital sculpting is very similar, except that it is done on a computer using a digital model of a tooth.

[0136] This helps in shaping the teeth that will be used in the model for the planned dental restoration.

[0137] In an example of a particular embodiment, the digital carving step (171) includes carving the surface of a prepared anterior tooth model or the surface of an initial tooth model. In particular, this carving step includes applying a preparation design. There may be various options for the preparation design. Such options include a box cavity shape for an inlay, a pile shape for abutment buildup, an undercut design for a crown, a groove design for an onlay, a slot design for an veneered tooth, and a cavity design for a filling material. Alternatively, an appropriate combination of these designs may be selected.

[0138] In other words, an example of this particular embodiment includes a digital carving process that allows a specific design pattern to be applied to a tooth in a prepared anterior tooth model. This pattern design is called a prepared design and refers to a shape or pattern used to prepare a tooth for prosthetic dental restoration.

[0139] There are various designs for tooth preparation, and the appropriate one can be selected depending on the type of dental restoration being performed.

[0140] For example, a box-shaped cavity can be used for inlays. An inlay is a type of dental restoration that fits into a cavity in a tooth. You can imagine a box-shaped cavity as a cavity made to fit an inlay.

[0141] A peg shape could be used for post and core restoration. Post and core restoration is a type of dental restoration used when a large portion of the tooth is lost. The peg shape refers to the post that will be inserted into the tooth.

[0142] Other design elements include undercut designs for crowns, groove designs for onlays, slot designs for veneered restorations, and cavity designs for fillings. Each of these designs corresponds to a specific type of dental restoration.

[0143] Depending on what is best for the patient's specific situation, the computer-aided procedure (100) may select any of these designs or use a combination thereof.

[0144] [First embodiment relating to the first aspect of this application: Obtain an offset from the database]

[0145] In a first aspect of this application, the computer implementation method (100) may additionally include a step (180) of providing an offset database. This database associates the type of prosthetic dental restoration to be intended with one or more predetermined offsets. The computer implementation method (100) may also include a step (181) of automatically determining one or more predetermined offsets from the offset database. This determination step is based on the type of prosthetic dental restoration to be intended.

[0146] In this specification, “database” is defined as any suitable data storage system, such as relational databases (object relational databases, etc.), triple stores, hierarchical storage, or a suitable combination thereof.

[0147] In other words, the first aspect of this application relates to an additional step of providing an offset database.

[0148] In particular, an offset database can be thought of as a collection of information that links each type of dental restoration to one or more predetermined offsets according to a given location.

[0149] For example, the offset database can provide information such as whether the offset for crown treatment should be 0.5 mm at a given position on a digital model of the patient's tooth, or whether the offset for veneering treatment should be 0.2 mm.

[0150] The computer-aided procedure (100) also includes another step of automatically determining the offset. This means that the computer-aided procedure (100) can determine how the offset should be set for each dental restoration.

[0151] This automated decision is based on the type of dental restoration being performed and the given position of the patient's teeth in a digital model.

[0152] For example, suppose a dentist is planning a crown procedure. The computer implementation method (100) can refer to an offset database to determine that the offset for the crown is 0.5 mm, and then automatically apply that offset to a digital model representing the patient's tooth at a given position on the digital model.

[0153] This helps dentists plan dental restorations in a way that is accurate and safe for the rest of the patient's teeth.

[0154] [Second embodiment relating to the first aspect of this application: Allows manual adjustment on the user interface]

[0155] A computerized method (100) according to a second aspect of this application also includes a step (182) of preparing a user interface for a CAD system. The design of this user interface allows a user to manually modify the output from one or more automatically performed steps.

[0156] In this specification, “user interface” is defined as any suitable software rendering system for providing information to and / or receiving information from a user who uses the user interface via a display device. A user interface may be based on one or more of the following types of interactions: visual, graphic, tactile, auditory, perceptual, etc.

[0157] In other words, the second aspect of this application relates to another feature of the computer implementation method (100), namely the provision of a user interface for a CAD system.

[0158] One example of what such a user interface would enable users to do is to manually modify some of the results of automatically performed processes. Dentists or dental technicians are the most likely users of such interfaces, and if they are not satisfied with the results of the automated process, they can interfere with the results and make adjustments themselves.

[0159] This method allows dentists to have greater control over the process and tailor dental restorations to the patient's specific needs and preferences.

[0160] [Second aspect of this application: Computer-readable media]

[0161] This application also relates to a computer-readable medium which stores computer instructions that, when executed by a processor, enable the computer implementation method (100) described above.

[0162] [Third aspect of this application: CAD system]

[0163] As shown in Figure 5, this application also relates to a 3D computer-aided design (CAD) system (200).

[0164] The 3D-CAD system (200) includes one or more memory modules (210), one or more user interfaces (220), and one or more processors (230).

[0165] The memory (210) is configured to store the offset database (211) as described above.

[0166] The memory (210) is also configured to store executable instructions (212) for carrying out the computer implementation method (100), as described above.

[0167] The user interface (220) is of the known type as described above.

[0168] The processor (230) is coupled with memory (210) and a user interface (220).

[0169] The processor (230) is configured to execute an executable instruction (213).

[0170] The detailed description of the invention in this application is provided solely for illustrative and explanatory purposes and is not intended to be exhaustive or to limit this application to only the disclosed embodiments. The selected embodiments described are intended to clearly illustrate the principles and practical applications of this application, and those skilled in the art will be able to understand this application through various embodiments with various modifications suitable for specific uses.

Claims

1. A computer-aided design (CAD) system for digitally shaping one or more natural teeth in order to receive or be fitted with a given type of prosthetic dental restoration, (100) Step (110) of obtaining a first 3D dental model, called an initial tooth model, which digitally represents one or more natural teeth of the patient along with the associated gums, and in which each of the natural teeth is in a state where it has not yet undergone or been prepared to be fitted with a prosthetic dental restoration. Step (120) of automatically determining, with respect to one or more natural teeth, one or more restoration lines that represent boundaries that distinguish one or more restoration areas representing one or more surface areas on the initial tooth model where prosthetic dental restoration is to be performed from one or more unrestored areas representing one or more surface areas on the initial tooth model where prosthetic dental restoration is to be performed, based on the initial tooth model and the corresponding type of prosthetic dental restoration to be performed, Step (130) is to improve the recognizability of the initial tooth model by forming a surface that matches one or more unrestored areas, thereby obtaining one or more formation limit surfaces, and generating a second 3D dental model called a formed pre-tooth model. Step (140): Obtain a third 3D dental model, called a wax model, which explains the final outcome expected from the prosthetic dental restoration, by digitally representing the proposed changes and / or improvements to one or more natural teeth. The steps include aligning the prepared anterior tooth model or the initial tooth model with the wax model (150), Step (160): Create one or more offset indentation areas within the prepared anterior tooth model or the initial tooth model by offsetting inward from the surface of the wax model according to one or more predetermined offsets associated with the planned type of prosthetic dental restoration, wherein each offset indentation area represents a region into which the inward offset penetrates the prepared anterior tooth model or the initial tooth model. Step (170): To improve the recognizability by forming the surface of the prepared anterior tooth model or the surface of the initial tooth model that matches one or more offset indentation areas, thereby obtaining one or more tooth preparation areas and generating a fourth 3D digital dental model called the final prepared tooth model. Methods that include...

2. The steps of forming the surface of the initial tooth model (130) and / or forming the surface of the formed pre-tooth model (170) are respectively The steps of digitally engraving the surface of the initial tooth model (131), and / or Step (171) of digitally carving the surface of the prepared anterior tooth model. A computer implementation method (100) according to claim 1, including the method described in claim 1.

3. The step (131) of digitally carving the surface of the initial tooth model is Steps to digitally apply a margin design selected from chamfer type, deep chamfer type formation, shoulder type formation, rounded shoulder type formation, modified shoulder type formation, shoulder bevel type formation, feather edge type formation, beveled type formation, knife edge type formation, or any appropriate combination thereof. The computer implementation method (100) according to claim 2, including the method described in claim 2.

4. The step (171) of digitally carving the surface of the prepared anterior tooth model or the surface of the initial tooth model, Steps to digitally apply a preparation design selected from a box cavity shape for inlays, a pile shape for core buildup, an undercut design for crowns, a groove design for onlays, a slot design for veneers, a cavity design for fillings, or any appropriate combination thereof. The computer implementation method (100) according to claim 2, including the method described in claim 2.

5. The computer-aided method (100) according to claim 1 or 2, wherein one or more formation limit lines are defined with respect to the gingival margin, an interdental contact point where the restoration will come into contact with an adjacent tooth, or a reference point selected from the overall anatomical structure of the tooth to be restored.

6. moreover (180) A step of providing an offset database for associating a planned type of prosthetic dental restoration with one or more predetermined offsets, Step (181) of automatically determining one or more predetermined offsets based on the planned type of prosthetic dental restoration A computer implementation method (100) according to claim 1 or 2, including the method described in claim 1 or 2.

7. moreover (182) A user interface is provided to the CAD system, and the user interface is configured such that the user of the user interface can manually modify the result of one or more automatically performed steps. A computer implementation method (100) according to claim 1 or 2, including the method described in claim 1 or 2.

8. A computer-readable medium that stores computer instructions that, when executed by a processor, perform the computer implementation method (100) described in claim 1 or 2.

9. A 3D computer-aided design (CAD) system (200), The following An offset database (211) that associates planned types of prosthetic dental restorations with one or more predetermined offsets, and An executable instruction (212) for performing the computer implementation method (100) described in claim 1 or 2. One or more memory (210) for storing, One or more user interfaces (220), One or more processors (230) are coupled to the memory (210) and the user interface (220) and configured to execute the executable instructions (212). A system that includes this.

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