Method and device for orienting a prosthetic crown model, electronic device and storage medium

Abstract

The application is suitable for the field of 3D printing technology, and provides a method and device for directional orientation of a repaired dental crown model, electronic equipment and a storage medium, wherein the method comprises the following steps: acquiring triangular mesh model data; traversing the triangular mesh; screening the first N groups of triangular mesh groups with the largest included angle values of triangular mesh normal vectors from all the triangular meshes by taking two adjacent triangular meshes as a group; taking the triangular meshes in the screened groups as base meshes one by one and calculating the dot product values of the normal vectors of the base meshes with the normal vectors in other screened groups one by one to obtain (N-1) groups of dot product values corresponding to the base meshes; adding and summing the larger dot product values in the (N-1) groups corresponding to any base mesh, and taking the normal vector direction of the base mesh corresponding to the largest sum dot product value from 2N sum results as the reference direction of the model groove surface and vertically upward to the xy plane; and storing three-dimensional data. The application can automatically orient the groove surface of the repaired dental crown model upward.

Description

Technical Field

[0001] This application relates to the field of 3D printing technology, specifically to methods, devices, electronic devices, and storage media for orienting dental crown models. Background Technology

[0002] Currently, with the rapid development of oral medicine and digital technology, 3D printing technology is widely used in the field of oral medicine, enabling cosmetic dental crown restoration to evolve from simple restoration to digital restoration applied in clinical practice. However, current customized fabrication of dental crowns mainly employs SLA point light source curing technology, DLP surface light source curing technology, and LCD surface light source curing technology. All three technologies require the addition of support units to the model during the printing and fabrication of dental crowns. Considering that the surface of the dental crown will have structural residue after printing and removal of the support units, and that the groove of the dental crown needs to be fitted onto the dental post of the patient's living tooth, to avoid discomfort, the addition of supports to the groove of the 3D model should be avoided during model preprocessing. Therefore, in the current model preprocessing process, each dental crown model needs to be manually oriented to keep the groove facing upwards. To improve the batch processing efficiency of 3D models, it is necessary to automatically orient multiple identical or different 3D models, ensuring the groove faces upwards, so that supports can be added to the tooth surface on top of this.

[0003] Therefore, a method for orienting dental crown models is needed to automatically orient the groove surfaces of the 3D model of the dental crown upwards, so as to avoid adding supports to the groove surfaces of the 3D model of the dental crown, and at the same time realize the batch automatic orientation of the 3D model of the dental crown, thereby improving the model preprocessing efficiency. Summary of the Invention

[0004] This application provides a method, apparatus, electronic device, and storage medium for orienting a dental crown model. The purpose is to enable the 3D model of the dental crown to be automatically oriented with the groove surface facing upwards during the model preprocessing process, thereby avoiding the need to add support to the groove surface of the 3D model of the dental crown and improving the efficiency of model preprocessing.

[0005] The first aspect of this application provides a method for orienting a dental crown model, including:

[0006] Obtain triangular mesh model data for the 3D model of the restored dental crown;

[0007] Traverse all the triangular meshes that are pieced together to form the 3D model of the restorative crown;

[0008] For all triangular meshes, filter the N groups with the largest included angle between the normal vectors of the adjacent triangular meshes.

[0009] Each triangular mesh in the filtering group is obtained as the base mesh, and its normal vector is used to calculate the dot product of the normal vectors in other filtering groups to obtain (N-1) sets of dot product values ​​corresponding to the base mesh.

[0010] The larger dot product values ​​in the (N-1) groups corresponding to any basic grid are summed, and the normal vector direction of the basic grid corresponding to the largest summed dot product value among the 2N summation results is used as the reference direction of the model slot surface.

[0011] The 3D model data of the restored crown was processed by angle and coordinate transformation so that the 3D model is perpendicular to the xy plane with the reference direction upward.

[0012] The three-dimensional data of the completed 3D model of the restored crown is stored in the storage unit.

[0013] Furthermore, the step of filtering all triangular meshes by grouping them into pairs of adjacent triangular meshes and selecting the top N groups with the largest included angle values ​​between their triangular mesh normals, includes:

[0014] For all triangular meshes, group them into pairs of adjacent triangular meshes and calculate the angle between the normal vectors of the two triangular meshes within each group. Then, use the angle values ​​of all groups as the set of angles.

[0015] Sort the included angle values ​​in the included angle set by size;

[0016] Obtain the normal vectors of the 2N triangular grids in the top N filtering groups with the largest included angle values ​​in the sorting queue.

[0017] Further, the step of summing up the larger dot product values ​​within (N-1) groups corresponding to any basic grid and using the normal vector direction of the basic grid corresponding to the largest summed dot product value among the 2N summations as the reference direction for the model slot surface includes:

[0018] Obtain the dot product values ​​of (N-1) groups corresponding to each basic grid in the filtered group and compare them to obtain the larger dot product value in each group;

[0019] For any given base grid, sum the (N-1) largest dot product values ​​to obtain the summation dot product value;

[0020] The maximum summation dot product value and the direction of the normal vector corresponding to the basic mesh are determined as the reference direction for the groove surface of the 3D model of the restored crown.

[0021] Furthermore, after storing the processed 3D data of the restored crown 3D model in the storage unit, the method for orienting the restored crown model further includes:

[0022] Add support units to the tooth surface of the 3D model of the restored crown.

[0023] Furthermore, after adding support units to the tooth surface of the 3D model of the restorative crown, the method for orienting the restorative crown model further includes:

[0024] The overall three-dimensional data of the 3D model of the restored crown and the supporting unit were sliced ​​and slice image data were obtained.

[0025] Furthermore, after slicing the overall three-dimensional data of the restored crown 3D model and the support unit and obtaining slice image data, the method for orienting the restored crown model further includes:

[0026] The sliced ​​image data is imported into the 3D printing equipment for 3D exposure printing.

[0027] A second aspect of this application provides a directional device for a dental crown model, comprising:

[0028] The model data acquisition module is used to acquire triangular mesh model data of the 3D model of the restored dental crown;

[0029] The model mesh traversal module is used to traverse all the triangular meshes that are pieced together to form the 3D model of the restorative crown.

[0030] The angle and normal vector filtering module is used to filter all triangular meshes by grouping them into pairs of adjacent triangular meshes and selecting the top N groups with the largest included angle values ​​of the triangular mesh normal vectors.

[0031] The basic grid dot product value calculation module is used to obtain the triangular grids in the filtering groups one by one as the basic grids and calculate the dot product value of their normal vectors with the normal vectors in other filtering groups to obtain (N-1) groups of dot product values ​​corresponding to the basic grid.

[0032] The dot product accumulation and reference direction determination module is used to accumulate and sum the larger dot product values ​​in (N-1) groups corresponding to any base grid, and use the normal vector direction of the base grid corresponding to the largest summed dot product value among the 2N summed results as the reference direction of the model slot surface;

[0033] The model data conversion module is used to perform angle and coordinate transformation on the 3D model data of the restored crown so that the 3D model is perpendicular to the xy plane with the reference direction upward.

[0034] The three-dimensional data storage module is used to store the three-dimensional data of the processed 3D model of the restorative crown in the storage unit.

[0035] Furthermore, the included angle and normal vector filtering module includes:

[0036] The adjacent angle calculation module is used to calculate the angle between the normal vectors of two triangular meshes within each group of all triangular meshes, and to collect the angle values ​​of all groups as the angle set.

[0037] The sorting module is used to sort the angle values ​​in the angle set by size.

[0038] The normal vector filtering module is used to obtain the normal vectors of the 2N triangular grids in the top N filtering groups with the largest included angle values ​​in the sorting queue.

[0039] Furthermore, the dot product accumulation and reference direction determination module includes:

[0040] The larger dot product value acquisition module is used to acquire the (N-1) groups of dot product values ​​corresponding to each basic grid in the filtering group and compare them to obtain the larger dot product value in each group.

[0041] The dot product summation module is used to sum the (N-1) largest dot product values ​​corresponding to any base grid to obtain the summation dot product value.

[0042] The reference direction determination module is used to determine the maximum summation dot product value and the direction of the normal vector corresponding to the basic mesh for all the basic meshes, which serve as the reference direction for the groove surface of the 3D model of the restored crown.

[0043] Furthermore, the orientation device for the dental crown model also includes:

[0044] The support unit addition module is used to add support units to the tooth surface of the 3D model of the restorative crown.

[0045] Furthermore, the orientation device for the dental crown model also includes:

[0046] The slicing module is used to slice the overall three-dimensional data of the 3D model of the restorative crown and the supporting unit and obtain slice image data.

[0047] Furthermore, the orientation device for the dental crown model also includes:

[0048] 3D printing equipment is used to import sliced ​​image data into the 3D printing equipment for 3D exposure printing.

[0049] A third aspect of this application provides an electronic device, including:

[0050] At least one processor; and a storage unit communicatively connected to said at least one processor;

[0051] The storage module stores instructions that can be executed by the at least one processor, and when the at least one processor executes the instructions, it implements the steps of the orientation method for the dental crown model as described above.

[0052] A fourth aspect of this application provides a non-transitory computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the orientation method for a dental crown model as described above.

[0053] A fifth aspect of this application provides a computer program product comprising computer instructions that, when executed by a computer, implement the steps of the orientation method for a dental crown model as described above.

[0054] Compared with the prior art, the beneficial effects of this application are:

[0055] 1. The method for orienting a dental crown model provided in the first aspect of this application allows the dental crown model to be positioned with the groove surface facing upwards during the model preprocessing stage, and enables the support unit to be added to the lower tooth surface of the dental crown model, thus avoiding discomfort caused by the support residue on the groove surface of the dental crown model coming into contact with the living tooth of the dental patient after subsequent printing.

[0056] 2. The method for orienting dental crown models provided in the first aspect of this application can automatically orient multiple dental crown models of different shapes in batches. While ensuring that the groove surface of the dental crown model faces upward and avoiding discomfort to dental patients, it can also avoid manually adjusting the orientation of each 3D model of the dental crown, thereby improving the model processing efficiency.

[0057] 3. The orientation method for the restorative crown model provided in the first aspect of the present application can achieve the optimal orientation for a bridge-type restorative crown model with multiple grooves, even if the grooves of the two surfaces are facing different directions. This avoids printing in an inclined state as much as possible, thereby reducing the required support units and support residues.

[0058] 4. The orientation method for the dental crown model provided in the first aspect of this application, based on the structural characteristics of the dental crown model, finds the upper toroidal surface and the outer polished surface contour of the groove surface feature of the dental crown model, and selects the normal vector direction of the triangular mesh with the highest co-directional integration degree of the upper toroidal surface as the overall optimal orientation of the dental crown model. The method is ingenious and has high orientation accuracy. Attached Figure Description

[0059] Figure 1 The flowchart of the orientation method for the dental crown model in this application embodiment Figure 1;

[0060] Figure 2 The flowchart of the orientation method for the dental crown model in this application embodiment Figure 2 ;

[0061] Figure 3 The structure of the orientation device for the dental crown model according to an embodiment of this application. Figure 1 ;

[0062] Figure 4 The structure of the orientation device for the dental crown model according to an embodiment of this application. Figure 2 ;

[0063] Figure 5A -B is a schematic diagram of the installation of the restorative dental crown in an embodiment of this application;

[0064] Figure 6A -B is a schematic diagram of adding support units to the dental crown model in an embodiment of this application;

[0065] Figure 7A -C is a triangular mesh diagram of the dental crown model in the embodiment of this application;

[0066] Figure 8A -B is a schematic diagram of the filtering and extraction of adjacent group angles and normal vectors of the model mesh in the embodiment of this application;

[0067] Figure 8C This is a schematic diagram illustrating the process of obtaining the dot product value of the basic grid in the model orientation method of this application embodiment;

[0068] Figure 9A The electronic device structure diagram for implementing the orientation method of the dental crown model in the embodiments of this application is shown below;

[0069] Figure 9B This is a schematic diagram of the electronic device performing preprocessing slicing on a 3D model according to an embodiment of this application;

[0070] Figure 10A A structural block diagram of a 3D printing device for implementing the orientation method of the dental crown model for restoration according to this application;

[0071] Figure 10B This is a schematic diagram illustrating the import of image data obtained by slicing after implementation of the method described in this application into a 3D printing device.

[0072] Label Explanation:

[0073] Electronic device 9; Computer program 90; Processing unit 91; Storage unit 92; 3D printing equipment 10; Controller 101; Memory 102; Printing control program 103; Mobile storage device 11; Dental cavity 501; Restorative crown 502; Tooth surface 503; Groove surface 504; Mounting post 505; Normal tooth 506; Support unit 601; Support base 602; Triangular mesh 603;

[0074] Model data acquisition module 100; Model data acquisition module 200; Angle and normal vector filtering module 300; Basic mesh dot product value calculation module 400; Dot product value accumulation and reference direction determination module 500; Model data conversion module 600; 3D data storage module 700; Support element addition module 800; Slicing module 900; Adjacent angle calculation module 320; Sorting module 340; Normal vector filtering and acquisition module 360; Larger dot product value acquisition module 520; Dot product value accumulation and summation module 540; Reference direction determination module 560. Detailed Implementation

[0075] To make the inventive objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0076] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of a described feature, integral, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0077] Figure 1 The flowchart of the orientation method for the dental crown model in this application embodiment Figure 1 As shown in the figure, the orientation method for restoring a dental crown model includes the following basic steps:

[0078] S100, Obtain the triangular mesh model data of the 3D model of the restored crown;

[0079] S200, traverse and assemble all the triangular meshes that form the 3D model of the restorative crown;

[0080] S300. For all triangular meshes, filter the N groups with the largest included angle between the normal vectors of the triangular meshes by grouping two adjacent triangular meshes.

[0081] S400. Obtain the triangular meshes in the filtering groups one by one as the base meshes and calculate the dot product of their normal vectors with the normal vectors in other filtering groups to obtain (N-1) sets of dot product values ​​corresponding to the base mesh.

[0082] S500, sum the larger dot product values ​​in the (N-1) groups corresponding to any basic grid, and take the normal vector direction of the basic grid corresponding to the largest summation dot product value among the 2N summation results as the reference direction of the model slot surface;

[0083] S600: Perform angle and coordinate transformation on the 3D model data of the restored crown so that the 3D model is perpendicular to the xy plane with the reference direction upward.

[0084] S700 stores the three-dimensional data of the processed 3D model of the restored crown in the storage unit.

[0085] In addition, the following optional steps are also included:

[0086] S800, add support units to the tooth surface of the 3D model of the restored crown;

[0087] S900: The overall three-dimensional data of the 3D model of the restored crown and the supporting unit are sliced ​​and sliced ​​image data is obtained.

[0088] S950: Import the sliced ​​image data into the 3D printing equipment for 3D exposure printing.

[0089] Specifically, in the flowchart above, N is a preset value and is a positive integer; for example, when N is set to 300, step S300 above will filter out the normal vectors of the triangular meshes in the top 300 groups with the largest included angle values.

[0090] Figure 2 The flowchart of the orientation method for the dental crown model in this application embodiment Figure 2 As shown in the figure, the orientation method for the dental crown restoration model includes the following specific steps:

[0091] S100, Obtain the triangular mesh model data of the 3D model of the restored crown;

[0092] S200, traverse and assemble all the triangular meshes that form the 3D model of the restorative crown;

[0093] S320. For all triangular meshes, group them into two adjacent triangular meshes and calculate the angle between the normal vectors of the two triangular meshes within each group. Then, use the angle values ​​of all groups as the set of angles.

[0094] S340. Sort the included angle values ​​in the included angle set by size;

[0095] S360. Obtain the normal vectors of the 2N triangular grids in the top N filtering groups with the largest included angle values ​​in the sorting queue;

[0096] S400. Obtain the triangular meshes in the filtering groups one by one as the base meshes and calculate the dot product of their normal vectors with the normal vectors in other filtering groups to obtain (N-1) sets of dot product values ​​corresponding to the base mesh.

[0097] S520. Obtain the dot product values ​​of each basic grid in the filtered group (N-1) groups one by one and compare them to obtain the larger dot product value in each group.

[0098] S540. For any basic grid, sum the (N-1) largest dot product values ​​corresponding to it to obtain the summation dot product value;

[0099] S560. Determine the maximum summation dot product value and the direction of the normal vector corresponding to the basic mesh for all basic meshes as the reference direction for the groove surface of the 3D model of the restored crown;

[0100] S600: Perform angle and coordinate transformation on the 3D model data of the restored crown so that the 3D model is perpendicular to the xy plane with the reference direction upward.

[0101] S700 stores the three-dimensional data of the processed 3D model of the restored crown in the storage unit.

[0102] In addition, the following optional steps are also included:

[0103] S800, add support units to the tooth surface of the 3D model of the restored crown;

[0104] S900: The overall three-dimensional data of the 3D model of the restored crown and the supporting unit are sliced ​​and sliced ​​image data is obtained.

[0105] S950: Import the sliced ​​image data into the 3D printing equipment for 3D exposure printing.

[0106] Specifically, in the flowchart above, N is a preset value and is a positive integer; for example, when N is set to 300, step S300 above will filter out the normal vectors of the triangular meshes in the top 300 groups with the largest included angle values.

[0107] Figure 3The structure of the orientation device for the dental crown model according to an embodiment of this application. Figure 1 As shown in the figure, the orientation device for the dental crown model includes:

[0108] The model data acquisition module 100 is used to acquire the triangular mesh model data of the 3D model of the restored dental crown;

[0109] Model mesh traversal module 200 is used to traverse all the triangular meshes that are pieced together to form the 3D model of the restorative crown.

[0110] The angle and normal vector filtering module 300 is used to filter the N groups with the largest included angle values ​​of the normal vectors of all triangular meshes by grouping them into two adjacent triangular meshes.

[0111] The basic grid dot product value calculation module 400 is used to obtain the triangular grids in the filtering group one by one as the basic grid and calculate the dot product value of its normal vector with the normal vectors in other filtering groups to obtain (N-1) groups of dot product values ​​corresponding to the basic grid.

[0112] The dot product accumulation and reference direction determination module 500 is used to accumulate and sum the larger dot product values ​​in (N-1) groups corresponding to any basic grid and use the normal vector direction of the basic grid corresponding to the largest summed dot product value among the 2N summed results as the reference direction of the model slot surface.

[0113] The model data conversion module 600 is used to perform angle and coordinate transformation on the 3D model data of the restored crown so that the 3D model is perpendicular to the xy plane with the reference direction upward.

[0114] The 3D data storage module 700 is used to store the 3D data of the processed 3D model of the restorative crown in the storage unit.

[0115] In addition, the following optional modules are also included:

[0116] Support unit addition module 800 is used to add support units to the tooth surface of the 3D model of the restorative crown;

[0117] The slicing module 900 is used to slice the overall three-dimensional data of the 3D model of the restored crown and the supporting unit and obtain slice image data.

[0118] 3D printing equipment 10 is used to import sliced ​​image data into the 3D printing equipment for 3D exposure printing.

[0119] Figure 4 The structure of the orientation device for the dental crown model according to an embodiment of this application. Figure 2 As shown in the figure, the orientation device for the dental crown restoration model, more specifically, includes:

[0120] The model data acquisition module 100 is used to acquire the triangular mesh model data of the 3D model of the restored dental crown;

[0121] Model mesh traversal module 200 is used to traverse all the triangular meshes that are pieced together to form the 3D model of the restorative crown.

[0122] The adjacent angle calculation module 320 is used to calculate the angle between the normal vectors of two triangular meshes in each group of all triangular meshes, and to use the angle values ​​of all groups as the angle set.

[0123] The sorting module 340 is used to sort the angle values ​​in the angle set by size.

[0124] The normal vector filtering and acquisition module 360 ​​is used to obtain the normal vectors of the 2N triangular grids in the top N filtering groups with the largest included angle values ​​in the sorting queue;

[0125] The basic grid dot product value calculation module 400 is used to obtain the triangular grids in the filtering group one by one as the basic grid and calculate the dot product value of its normal vector with the normal vectors in other filtering groups to obtain (N-1) groups of dot product values ​​corresponding to the basic grid.

[0126] The larger dot product value acquisition module 520 is used to acquire (N-1) groups of dot product values ​​corresponding to each basic grid in the filtering group and compare them to obtain the larger dot product value in each group.

[0127] The dot product summation module 540 is used to sum the (N-1) largest dot product values ​​corresponding to any basic grid to obtain the summation dot product value.

[0128] The reference direction determination module 560 is used to determine the maximum summation dot product value and the normal vector direction of the basic mesh as the reference direction for the groove surface of the 3D model of the restored crown.

[0129] The model data conversion module 600 is used to perform angle and coordinate transformation on the 3D model data of the restored crown so that the 3D model is perpendicular to the xy plane with the reference direction upward.

[0130] The 3D data storage module 700 is used to store the 3D data of the processed 3D model of the restorative crown in the storage unit.

[0131] In addition, the following optional modules are also included:

[0132] Support unit addition module 800 is used to add support units to the tooth surface of the 3D model of the restorative crown;

[0133] The slicing module 900 is used to slice the overall three-dimensional data of the 3D model of the restored crown and the supporting unit and obtain slice image data.

[0134] 3D printing equipment 10 is used to import sliced ​​image data into the 3D printing equipment for 3D exposure printing.

[0135] Figure 5A -B is a schematic diagram of the installation of the restorative dental crown according to an embodiment of this application. As shown in the figure... Figure 5A and Figure 5B The illustrations depict the process in current oral medicine or cosmetic dentistry where a restorative crown 502 is fitted onto a dental post 505 with a groove surface 504. Both the two adjacent normal teeth 506 and the dental post 505 are fixed to the jawbone 501. Both the two adjacent normal teeth 506 and the restorative crown 502 have tooth surfaces 503, but only the restorative crown 502 has a groove surface 504.

[0136] Figure 6A -B is a schematic diagram of adding support units to the dental crown model according to an embodiment of this application. As shown in the figure... Figure 5A This illustration shows a schematic diagram of adding a support unit 601 to the restorative crown 502 during the computer preprocessing stage of the restorative crown model; specifically, the support unit 601 in the figure has a support base 602. Furthermore, considering that the surface of the restorative crown 502 will have structural residue after printing and the support unit 601 is removed, and that the groove surface 504 of the restorative crown 502 needs to be fitted onto the dental post 505 for the dental patient, to avoid discomfort, adding support to the groove surface 504 of the restorative crown 502 should be avoided during model preprocessing; therefore, in the existing model preprocessing technology, the restorative crown 502 needs to be oriented; and as shown in the figure, the restorative crown 502 needs to be oriented with the groove surface 504 upwards. Specifically, for a single 3D model of a restorative crown 502, manual orientation can be used, but for 3D models of multiple restorative crowns 502, manual orientation is inefficient. Therefore, automatic orientation using the method described in this application is necessary to improve model processing efficiency.

[0137] Figure 6B exist Figure 6ABased on the illustration, the triangular mesh 603 of the 3D model that assembles the restorative crown 502 is shown. In particular, it can be observed that the entire restorative crown 502 resembles a bowl, with a mountain-like structural feature forming around the "rim". Specifically, for example, at the circled area in the figure, the included angle between two adjacent triangular meshes 603 with the "mountain-like line" as the boundary is significantly smaller than the included angle between two adjacent triangular meshes 603 on the relatively flat side of the model. In particular, the mountain-like structural feature on the model in the figure is actually the structural feature that the restorative crown 502 fits with after the tooth post 505 is polished. Therefore, almost every restorative crown 502 has this structural feature, and the restorative crown model orientation method described in this application will also be implemented around this structural feature.

[0138] Figure 7A -C represents a triangular mesh diagram of the dental crown model in this embodiment of the application. As shown in the figure... Figure 7A exist Figure 6B Based on this, the 3D model of the restored crown 502 is further enlarged and displayed, along with all the triangular meshes 603 that make up the restored crown 502 model. Figure 7B Taking the triangular mesh 603 located at the mountain peak line on the 3D model taken from the restored crown 502 as an example, that is, obtaining the triangular mesh 603 corresponding to M1-M10. Figure 7C For corresponding Figure 7B The normal vectors m1-m10 of the triangular mesh 603.

[0139] Figure 8A -B is a schematic diagram illustrating the extraction of adjacent group angles and normal vectors in the model mesh of this application embodiment. As shown in the figure... Figure 8A This indicates that the information is taken from... Figure 7C Find the angle between the normal vectors m2 and m3 of two adjacent triangular meshes M2 and M3, where the angle between the normal vectors m2 and m3 is 5 degrees. Figure 8B This indicates that the information is taken from... Figure 7C Find the angle between the normal vectors m3 and m8 of two adjacent triangular meshes M3 and M8, and the angle between the normal vectors m3 and m8 is 60 degrees.

[0140] According to Figure 7A Observing adjacent triangular grids along the Zhongshan Peak line, it can be seen that within one group, adjacent triangular grids M2 and M3 tend to lie on the same plane, therefore the angle between their normal vectors m2 and m3 is small; while within another group, adjacent triangular grids M3 and M8 do not tend to lie on the same plane, therefore the angle between their normal vectors m3 and m8 is large; similarly, located at... Figure 7A In the model, adjacent triangular meshes on the side tend to converge to the same plane, and the angle between their corresponding normal vectors is also relatively small; therefore, using methods such as... Figure 1In step S300, all triangular meshes are grouped by adjacent triangular meshes, and the top N groups with the largest included angle between their triangular mesh normals are selected. If N is set to 300, then 300 groups of adjacent triangular meshes can be selected. Specifically, it is possible to select, for example... Figure 7A In the model, adjacent triangular meshes are grouped along the mountain peak line; it may also filter to other locations, such as... Figure 5A The larger angle between the normal vectors at point 503 on the tooth surface corresponds to the grouping of two adjacent triangular meshes.

[0141] Figure 8C This is a schematic diagram illustrating the process of obtaining the dot product value of the basic grid in the model orientation method of this application embodiment. According to... Figure 1 In step S300, all triangular meshes are grouped by adjacent triangular meshes, and the top N groups with the largest included angle between their triangular mesh normals are selected; after selecting such groups... Figure 8B As illustrated, after grouping the 300 adjacent triangular meshes with the largest included angle of their normal vectors; according to Figure 1 In step S400, the triangular meshes in the filtering groups are obtained one by one as the base meshes, and the normal vectors of the base meshes are calculated to obtain the dot product of the normal vectors of the other filtering groups to obtain (N-1) sets of dot product values ​​corresponding to the base meshes.

[0142] Specifically, as shown in the figure, by Figure 7C Taking the grouping of adjacent triangular meshes selected in the three groups as an example, if triangular meshes M1 and M10 are in the first group, triangular meshes M3 and M8 are in the second group, and triangular meshes M5 and M6 are in the third group, then the triangular mesh normal vectors m1 and m10 are in the first group, triangular meshes m3 and m8 are in the second group, and triangular meshes m5 and m6 are in the third group; since the result of the dot product of two vectors such as m1 and m3 reflects the similarity of m1 and m3 in direction in geometry, the larger the result, the more similar they are;

[0143] Therefore, to select the normal vector with the highest similarity to the triangular mesh normal vector m1 in the first group from the remaining two groups of the above three groups, it is necessary to calculate the dot product value k13 of m1 multiplied by m3, the dot product value k18 of m1 multiplied by m8, the dot product value k15 of m1 multiplied by m5, and the dot product value k16 of m1 multiplied by m6 respectively; where the triangular mesh M1 is the base mesh;

[0144] Similarly, from the remaining two groups of the above three groups, to select the normal vector with the highest similarity to the triangular mesh normal vector m10 in the first group, it is necessary to calculate the dot product value k103 of m10 multiplied by m3, the dot product value k108 of m10 multiplied by m8, the dot product value k105 of m10 multiplied by m5, and the dot product value k106 of m10 multiplied by m6; where the triangular mesh M10 is the other corresponding basic mesh;

[0145] Based on obtaining the dot product values ​​of the normal vector m1 and the normal vectors in the other two groups, according to Figure 1 In step S500, the larger dot product values ​​within the (N-1) groups corresponding to any base mesh are summed, and the normal vector direction of the base mesh corresponding to the largest summed dot product value among the 2N summations is used as the reference direction for the model groove surface; then... Figure 7A It can be seen that, since the planes of triangular meshes M1, M3, and M5 are located at the upward position of the "bowl" of the restored crown 502, the orientation of the planes of triangular meshes M1, M3, and M5 tends to be upward together, and the corresponding normal vectors m1, m3, and m5 have a higher similarity in direction; therefore, it can be seen that the dot product value k13 is greater than the dot product value k18, and the dot product value k15 is greater than the dot product value k16.

[0146] Specifically, according to Figure 2 In step S520, the dot product values ​​of (N-1) groups corresponding to each basic grid in the filtering group are obtained one by one and compared to obtain the larger dot product value in each group; the larger dot product values ​​k13 and k15 corresponding to the basic grid M1 can be obtained by filtering.

[0147] Specifically, based on Figure 2 In step S540, for any basic grid, the corresponding (N-1) larger dot product values ​​are summed to obtain the summed dot product value; the summed dot product value SM1 = k13 + k15 for basic grid M1 can be obtained; correspondingly, the summed dot product value SM10 = k106 + k108 for basic grid M10 can be obtained; correspondingly, the summed dot product values ​​for basic grids M3, M5, M6, and M8 can also be obtained.

[0148] Specifically, based on Figure 2 In step S560, the maximum summation dot product value and the normal vector direction of the basic mesh are determined as the reference direction for the groove surface of the 3D model of the restored crown. When SM1 is greater than SM10 and other summation dot product values, the normal vector direction of the basic mesh M1 is the reference direction for the groove surface of the 3D model of the restored crown.

[0149] Unlike other methods, because the planes of triangular meshes M10, M8, and M6 are located outwards from the "bowl" of the restored crown 502, the orientation of these planes tends to diverge more outwards, resulting in greater differences in orientation among the three triangular mesh planes. Therefore, when comparing the maximum summation dot product value, following the conclusion that the greater the similarity between two vectors in direction, the larger the dot product value, this should be extended to multiple vectors. Thus, the greater the similarity between multiple vectors in direction, the larger the summation dot product value. Consequently, the summation dot product value corresponding to any basic mesh in triangular meshes M10, M8, and M6 is less than that of the basic mesh M1. Therefore, the crown model orientation method of this application, by means of... Figure 7A The planar convergence of the triangular meshes at the mountain peak line of the upper model is used to select the normal vector of the basic mesh with the greatest coplanarity as the final reference direction for the groove surface of the 3D model of the restored crown. The method is ingenious and has high accuracy.

[0150] Based on this, the angle and coordinate transformation of the 3D model data of the restored crown is performed, and the three-dimensional data of the processed restored crown model is stored, thus completing the orientation of the restored crown model.

[0151] Figure 9A The electronic device structure diagram for implementing the orientation method of the dental crown model in this application is shown in the figure. As shown, the electronic device 9 in this figure is exemplified by having a processing unit 91. As shown, an electronic device 9 includes a processing unit 91 and a storage unit 92; wherein the storage unit 92 stores a computer program 90 or instructions executable by the processing unit 91, and the computer program 90 or instructions are executed by the processing unit 91 to enable the processing unit 91 to perform actions such as... Figure 1 Steps S100-S700 in the above steps, or perform as follows: Figure 1 Steps S100-S900 in the process.

[0152] Storage unit 92, which is the third aspect of this application, provides a non-transitory computer-readable storage medium. Storage unit 92 stores instructions executable by at least one processing unit 91, causing the at least one processing unit 91 to perform, as follows: Figure 1 Steps S100-S700 in the above, or implemented as follows: Figure 1 Steps S100-S900 in the process.

[0153] Storage unit 92, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as those implemented during execution. Figure 1 The program instructions / modules corresponding to steps S100-S700, or implementations such as... Figure 1The program instructions / modules corresponding to steps S100-S900 are described above. Processing unit 91 executes various server functions and data processing by running the non-transient computer program 90, instructions, and modules stored in storage unit 92, thereby achieving the aforementioned... Figure 1 The corresponding embodiments involve steps involving a computer and a processor.

[0154] Storage unit 92 may include a stored program area and a stored data area. The stored program area may store the operating system and applications required for at least one function; the stored data area may store data created during the use of electronic device 9. Furthermore, storage unit 92 may include a high-speed random access memory module and may also include a non-transient storage module, such as at least one disk storage module, flash memory device, or other non-transient solid-state storage module. In some embodiments, storage unit 92 may optionally include storage modules remotely disposed relative to processing unit 91. These remote storage modules can be connected to the electronic device generated by the support structure via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0155] Various implementations of the systems and techniques described herein can be implemented in digital electronic circuit systems, integrated circuit systems, application-specific integrated circuits (ASICs), computer hardware, firmware, software, and / or combinations thereof. These various implementations may include: implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input unit, and at least one output device, and transmitting data and instructions to the storage system, the at least one input unit, and the at least one output device.

[0156] These computer programs 90 (also referred to as programs, software, software applications, or code) include machine instructions for a programmable processor and can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. As used herein, the terms “machine-readable medium” and “computer-readable medium” refer to any computer program product, device, and / or apparatus (e.g., disk, optical disk, storage module, programmable logic device (PLD)) used to provide machine instructions and / or data to a programmable processor, including machine-readable media that receive machine instructions as machine-readable signals. The term “machine-readable signal” refers to any signal used to provide machine instructions and / or data to a programmable processor.

[0157] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this application can be achieved, and this is not limited herein.

[0158] Figure 9B This is a schematic diagram of the electronic device performing preprocessing slicing on a 3D model according to an embodiment of this application. As shown in the figure, the user runs 3D slicing software through the electronic device 9 and uses the orientation method for a dental crown model provided in the first aspect of this application to orient and place the 3D model of the dental crown. Then, in step S800, a support unit is added to the lower part of the 3D model of the dental crown. Then, in step S900, the overall three-dimensional data of the 3D model of the dental crown and the support unit are sliced ​​and sliced ​​to obtain slice image data.

[0159] Figure 10A The structural block diagram of the 3D printing device for implementing the orientation method of the dental crown model in this application is shown in the figure. As shown, a 3D printing device 10 includes a controller 101 and a memory 102; wherein the memory 102 stores a printing control program 103 or instructions that can be executed by the controller 101. The printing control program 103 or instructions are executed by the controller 101 to enable the controller 101 to perform actions such as... Figure 1 In step S950, the overall printed part of the restorative crown 3D model with support units added to the lower tooth surface is obtained.

[0160] Figure 10B This diagram illustrates the import of image data obtained by slicing after implementation of the method described in this application into a 3D printing device. As shown, the user uses a mobile storage device 11 to import the sliced ​​image data and / or printing parameters of the 3D model of the restorative crown with support units added to the lower tooth surface, obtained by the electronic device 9, into the 3D printing device 10 for 3D exposure printing, thereby obtaining the overall printed part of the 3D model of the restorative crown with support units added to the lower tooth surface.

[0161] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for orienting a dental crown model, characterized in that, include: Obtain triangular mesh model data for the 3D model of the restored dental crown; Traverse all the triangular meshes that are pieced together to form the 3D model of the restorative crown; For all triangular meshes, filter the N groups with the largest included angle between the normal vectors of the adjacent triangular meshes. Each triangular mesh in the filtering group is obtained as the base mesh, and its normal vector is used to calculate the dot product of the normal vectors in other filtering groups to obtain (N-1) sets of dot product values ​​corresponding to the base mesh. The maximum dot product values ​​in each of the (N-1) groups corresponding to any base grid are summed, and the normal vector direction of the base grid corresponding to the largest summed dot product value among the 2N summation results is used as the reference direction of the model slot surface. The 3D model data of the restored crown was processed by angle and coordinate transformation so that the 3D model is perpendicular to the xy plane with the reference direction upward. The three-dimensional data of the completed 3D model of the restored crown is stored in the storage unit.

2. The method for orienting a dental crown model according to claim 1, characterized in that, The process of filtering all triangular meshes by grouping them into pairs of adjacent triangular meshes and selecting the top N groups with the largest included: For all triangular meshes, group them into pairs of adjacent triangular meshes and calculate the angle between the normal vectors of the two triangular meshes within each group. Then, use the angle values ​​of all groups as the set of angles. Sort the included angle values ​​in the included angle set by size; Obtain the normal vectors of the 2N triangular grids in the top N filtering groups with the largest included angle values ​​in the sorting queue.

3. The method for orienting a dental crown model according to claim 1, characterized in that, The step of summing the maximum dot product values ​​within each of the (N-1) groups corresponding to any basic mesh and using the normal vector direction of the basic mesh corresponding to the largest summed dot product value among the 2N summations as the reference direction for the model slot surface includes: Obtain the dot product values ​​of each basic grid in the filtered group (N-1) groups one by one, and compare them to obtain the maximum dot product value in each group; For any given base grid, sum the (N-1) largest dot product values ​​to obtain the summation dot product value; The maximum summation dot product value and the direction of the normal vector corresponding to the basic mesh are determined as the reference direction for the groove surface of the 3D model of the restored crown.

4. The method for orienting a dental crown model according to claim 1, characterized in that, Also includes: Add support units to the tooth surface of the 3D model of the restored crown; The overall three-dimensional data of the 3D model of the restored crown and the supporting unit were sliced ​​and slice image data were obtained. The sliced ​​image data is imported into the 3D printing equipment for 3D exposure printing.

5. A directional device for a dental crown model, characterized in that, include: The model data acquisition module is used to acquire triangular mesh model data of the 3D model of the restored dental crown; The model mesh traversal module is used to traverse all the triangular meshes that are pieced together to form the 3D model of the restorative crown. The angle and normal vector filtering module is used to filter all triangular meshes by grouping them into pairs of adjacent triangular meshes and selecting the top N groups with the largest included angle values ​​of the triangular mesh normal vectors. The basic grid dot product value calculation module is used to obtain the triangular grids in the filtering group one by one as the basic grid and calculate the dot product value of its normal vector with the normal vectors in other filtering groups to obtain (N-1) groups of dot product values ​​corresponding to the basic grid. The dot product accumulation and reference direction determination module is used to accumulate and sum the maximum dot product values ​​in each of the (N-1) groups corresponding to any base grid, and use the normal vector direction of the base grid corresponding to the largest summed dot product value among the 2N summation results as the reference direction of the model slot surface. The model data conversion module is used to perform angle and coordinate transformation on the 3D model data of the restored crown so that the 3D model is perpendicular to the xy plane with the reference direction upward. The three-dimensional data storage module is used to store the three-dimensional data of the processed 3D model of the restorative crown in the storage unit.

6. The orientation device for a dental crown model according to claim 5, characterized in that, The included angle and normal vector filtering module includes: The adjacent angle calculation module is used to calculate the angle between the normal vectors of two triangular meshes within each group of all triangular meshes, and to collect the angle values ​​of all groups as the angle set. The sorting module is used to sort the angle values ​​in the angle set by size. The normal vector filtering module is used to obtain the normal vectors of the 2N triangular grids in the top N filtering groups with the largest included angle values ​​in the sorting queue.

7. The orientation device for a dental crown model according to claim 5, characterized in that, The dot product accumulation and reference direction determination module includes: The maximum dot product value acquisition module is used to obtain the (N-1) groups of dot product values ​​corresponding to each basic grid in the filtering group and compare them to obtain the maximum dot product value in each group. The dot product summation module is used to sum the (N-1) largest dot product values ​​corresponding to any base grid to obtain the summation dot product value. The reference direction determination module is used to determine the maximum summation dot product value and the direction of the normal vector corresponding to the basic mesh for all the basic meshes, which serve as the reference direction for the groove surface of the 3D model of the restored crown.

8. An electronic device, characterized in that, include: At least one processor; and a storage unit communicatively connected to the at least one processor; The storage unit stores instructions that can be executed by the at least one processor, and when the at least one processor executes the instructions, it implements the steps of the orientation method for the restorative crown model as described in any one of claims 1 to 4.

9. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the orientation method for the restorative crown model as described in any one of claims 1 to 4.

10. A computer program product, characterized in that, The computer program product includes computer instructions that, when executed by a computer, implement the steps of the orientation method for the restorative crown model as described in any one of claims 1 to 4.

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