Design method and preparation method of a dental implant system

Abstract

The application provides a design method and a preparation method of a dental root implant system. The three-dimensional model of a tooth is used as a design basis, which is close to a real tooth and realizes the force transmission characteristics and stress distribution characteristics of a natural molar. When the three-dimensional model does not meet the requirements, the application also performs straightening treatment on the tooth root of the three-dimensional model and / or processes the bifurcation angle, so that the designed tooth root is more easily positioned in the tooth socket, avoids too large or too small bifurcation angle, and reduces the difficulty of implantation. In addition, the application also designs a coating model and a bone grafting warehouse model. The coating model is connected with the tooth socket in interference, and the bone grafting warehouse model can accommodate anti-inflammatory and growth-promoting drugs, which are helpful to the short-term and long-term stability after implantation. The coating model and the bone grafting warehouse model are both subjected to porous treatment, which is beneficial to drug diffusion and bone tissue growth. Therefore, the implant formed according to the application can not only improve the stability of implantation, but also reduce the difficulty of implantation.

Description

Technical Field

[0001] This invention relates to the field of dental implant technology, and in particular to a design and preparation method for a simulated dental implant system. Background Technology

[0002] Currently, the clinical treatment of edentulism mainly utilizes cylindrical implants, which are screwed into the alveolar bone using surface threads to achieve initial and long-term stability. However, due to the complex masticatory mechanics of teeth, especially in the posterior region, cylindrical implants often do not fit the extraction socket, easily forming a cantilever structure and leading to failure. In recent years, research on root-like implants has improved the fit between implants and sockets, making them more physiologically compatible and beneficial for stress transmission and stability. However, problems still exist; some roots are irregular and have undercuts or outward expansion, making implantation more difficult and increasing the risk of inflammation at root bifurcation points.

[0003] While advancements in clinical knowledge and digital technology have enabled the simulation of natural tooth root geometry and the application of specific modifications based on computer-aided design / manufacturing (CAD / CAM) and computed tomography (CT) to address issues associated with traditional cylindrical or tapered threaded implants, traditional design and fabrication methods struggle to meet the individualized needs of patients, particularly given the irregular curved surfaces of teeth and significant individual, locational, and structural variations.

[0004] Therefore, a new design and fabrication method for pseudo-root implant systems is needed to create new pseudo-root implant systems that can meet patients' personalized implant needs, reduce implantation difficulty, and ensure the initial and long-term stability of the implants. Summary of the Invention

[0005] The purpose of this invention is to provide a design method and a preparation method for a pseudo-dental root implant system, so as to solve at least one of the problems of difficult implantation of pseudo-dental root implants, poor initial and long-term stability after implantation, and inability to meet the personalized implantation needs of patients.

[0006] To address the aforementioned technical problems, this invention provides a design method for a simulated tooth implant system, wherein the simulated tooth implant system is used for implantation at the site of a diseased tooth; the design method includes:

[0007] Collect oral cavity data to obtain a three-dimensional model of the affected tooth;

[0008] Determine whether the three-dimensional model meets the set requirements. If yes, use the three-dimensional model as the reference model. If no, straighten the tooth roots in the three-dimensional model and / or process the bifurcation angle, and use the processed three-dimensional model as the reference model.

[0009] At least based on the tooth root in the reference model, a coating model is obtained that is fitted onto the outer surface of the tooth root; and a bone graft chamber model is obtained based on part or all of a single tooth root in the reference model, or based on a three-dimensional region between two or more tooth roots in the coating model, to form a pseudo-tooth root implant system having a coating and a bone graft chamber on the pseudo-tooth root.

[0010] Optionally, in the design method of the simulated tooth implant system, the process of collecting oral data and obtaining a three-dimensional model of the affected tooth includes:

[0011] CBCT scans were used to collect dentition data, alveolar bone data, and gingival tissue data, in order to obtain at least a tissue model of the affected tooth, as well as an alveolar bone model and a gingival tissue model at the affected tooth.

[0012] The tooth tissue model and the alveolar bone model are subjected to a Boolean intersection operation to obtain the tooth root in the three-dimensional model of the affected tooth;

[0013] Perform a Boolean intersection operation between the affected tooth tissue model and the gingival tissue model to obtain the perforated portion in the three-dimensional model of the affected tooth;

[0014] The affected tooth tissue model is subjected to Boolean subtraction with the gingival tissue model and the alveolar bone model to obtain the crown of the affected tooth in the three-dimensional model;

[0015] The three-dimensional model of the affected tooth consists of the crown, the perforated portion, and the root connected sequentially along the crown-root direction.

[0016] Optionally, in the design method of the simulated tooth implant system, when the crown of the affected tooth is missing or damaged, the corresponding tooth is obtained based on the dentition data. The crown of a tooth or a symmetrical tooth serves as the crown of the three-dimensional model.

[0017] Optionally, in the design method of the simulated tooth implant system, multiple cross-sectional images of the affected tooth are obtained by CBCT scanning; and along the coronal-root direction, each cross-sectional image corresponds to a planar image of the corresponding layer in the three-dimensional model;

[0018] The process of determining whether the 3D model meets the set requirements includes:

[0019] Based on the three-dimensional model and multiple cross-sectional images, starting from the layer closest to the crown in the root, the projection lines of the central connecting lines of each two adjacent layers are obtained sequentially in the coronal and sagittal planes, respectively, and the angle between the projection lines of the first two layers in the coronal or sagittal plane and the projection lines of the last two layers in the corresponding planes is calculated in each consecutive three layers.

[0020] When the included angle is greater than or equal to 5°, the tooth root does not meet the set requirements;

[0021] When all the included angles are less than 5°, the tooth root meets the set requirements;

[0022] Optionally, in the design method of the simulated tooth root implant system, the three-dimensional model of the affected tooth includes at least two roots;

[0023] The process of determining whether the 3D model meets the set requirements also includes:

[0024] Obtain the projection lines of the central axis of each tooth root in the coronal and sagittal planes in the three-dimensional model, and calculate the angle between the projection lines of the central axes of every two tooth roots in the coronal or sagittal planes to obtain the bifurcation angle;

[0025] When the bifurcation angle is less than 5° or greater than 15°, the bifurcation angle does not meet the set requirements;

[0026] When the bifurcation angle is greater than or equal to 5° and less than or equal to 15°, the bifurcation angle meets the set requirements.

[0027] Optionally, in the design method of the simulated tooth root implant system, the method for straightening the tooth root in the three-dimensional model includes:

[0028] The middle layer of every three consecutive layers with an included angle greater than or equal to 5° is taken as the inflection point layer;

[0029] Extract the cross-sectional image corresponding to the inflection point layer, and use the radial contour line of the tooth root in the cross-sectional image as the starting contour line;

[0030] Based on the initial contour line, with the center connecting line of the inflection point layer and the layer adjacent to the inflection point layer and close to the crown direction as the reference axis, equidistant processing is performed in the direction pointing towards the tooth root to obtain at least one equidistant contour line.

[0031] Perform a lofting basic operation on the initial contour line and all the equidistant contour lines to obtain a straightened tooth root.

[0032] Optionally, in the design method of the simulated tooth root implant system, during the equidistant processing, all the equidistant contour lines are sequentially reduced radially at equal intervals; wherein, the size range of each reduction is 0.1 mm to 0.8 mm, and the minimum diameter of the last equidistant contour line is greater than or equal to 0.3 mm; the axial distance between the starting contour line and the last equidistant contour line ranges from 0.1 mm to 8 mm.

[0033] Optionally, in the design method of the simulated tooth root implant system, the bifurcation angle is further processed by:

[0034] Obtain a reference axis and a target axis, wherein the reference axis is the central axis of the tooth root that meets the set requirements or the central axis of the tooth root after straightening treatment, and the target axis is the central axis of the target tooth root to be treated;

[0035] The reference axis and the target axis are both projected onto the coronal and sagittal planes, and an intersection point is formed between the projection lines of the reference axis and the target axis on the coronal or sagittal plane;

[0036] Rotate the projection line of the target axis around the intersection point until the angle between the projection line of the target axis and the projection line of the reference axis meets the set requirements; and use the rotated target axis as the central axis of the tooth root after the bifurcation angle is processed.

[0037] Optionally, in the design method of the simulated tooth root implant system, the process of forming the bone graft chamber model based on a portion of the tooth root in the reference model includes:

[0038] When the reference model has a single tooth root, the placement area of ​​the bone graft chamber model is selected;

[0039] Using the outer surface of the tooth root corresponding to the placement area as a reference plane, the reference plane is stretched along the radial direction of the tooth root and toward the side away from the tooth root to obtain a solid model of the bone graft chamber.

[0040] Alternatively, a portion of the single tooth root in the baseline model can be extracted and used as the solid model of the bone graft chamber.

[0041] The bone graft chamber solid model is subjected to inward shelling to obtain a bone graft chamber shell with a set thickness.

[0042] The bone graft chamber shell is subjected to a porous treatment to obtain the bone graft chamber model that is disposed on the outer surface of the tooth root or replaces part of the tooth root.

[0043] Optionally, in the design method of the simulated tooth root implant system, the process of obtaining a coating model that is applied to the outer surface of the tooth root, based at least on the tooth root in the reference model, includes:

[0044] When the reference model has a single tooth root and the bone graft chamber model is disposed on the outer surface of the tooth root, the tooth root in the reference model is cut off;

[0045] A Boolean joint operation is performed between the solid model of the bone graft chamber located on the outer surface of the tooth root and the excised tooth root to obtain the solid model of the coating.

[0046] The coated solid model is subjected to outward shelling to obtain a coated shell with a set thickness;

[0047] The coated housing is subjected to a porousing process to obtain the coating model.

[0048] Optionally, in the design method of the simulated tooth root implant system, the process of obtaining a coating model that is applied to the outer surface of the tooth root, based at least on the tooth root in the reference model, includes:

[0049] When the reference model has a single tooth root and the bone graft chamber model is obtained based on a portion of the single tooth root, or when the reference model has two or more tooth roots, the tooth root in the reference model is cut off to serve as the coating solid model;

[0050] The coated solid model is subjected to outward shelling to obtain a coated shell with a set thickness;

[0051] The coated housing is subjected to a porousing process to obtain the coating model.

[0052] Optionally, in the design method of the simulated tooth root implant system, the process of obtaining a bone graft chamber model based on the three-dimensional region between two or more tooth roots in the coating model includes:

[0053] The tooth root of the reference model is nested into the coating model;

[0054] The baseline model and the coating model are converted into point cloud format, and all points are connected to each other to obtain the minimum envelope surface;

[0055] Perform a Boolean subtraction operation between the minimum envelope surface and the reference model overlaid with the coating model, and the remaining minimum envelope surface is the solid model of the bone graft chamber;

[0056] The bone graft chamber solid model is subjected to inward shelling to obtain a bone graft chamber shell with a set thickness.

[0057] The shell of the bone graft chamber is subjected to a porous treatment to obtain the bone graft chamber model.

[0058] Optionally, in the design method of the simulated tooth root implant system, the porousing process includes:

[0059] Multiple support units are selected, and all the support units are arranged in an infinite array in three-dimensional space; wherein, the support units are porous structures.

[0060] The coated shell or the bone graft chamber shell is subjected to a Boolean intersection operation with the plurality of support units to form a porous structure.

[0061] Optionally, in the design method of the simulated tooth root implant system, the coronal plane of the coating model is located on the side away from the crown of the coronal plane of the tooth root in the reference model, and the axial distance between the coronal plane of the coating model and the coronal plane of the tooth root in the reference model is 0.1 mm to 1 mm.

[0062] Optionally, in the design method of the simulated tooth root implant system, when the reference model has a single tooth root, an opening is formed on the coating model, the opening being used to expose at least a portion of the bone graft chamber model when the reference model and the bone graft chamber model are nested within the coating model.

[0063] Optionally, in the design method of the simulated tooth root implant system, the porosity of the coating model ranges from 30% to 80%, and the pore size ranges from 100 micrometers to 1000 micrometers.

[0064] Optionally, in the design method of the simulated tooth root implant system, the set thickness of the coating shell is in the range of 0.2 mm to 2 mm.

[0065] Optionally, in the design method of the simulated tooth root implant system, the porosity of the bone graft chamber model ranges from 80% to 90%, and the pore size ranges from 1000 micrometers to 1400 micrometers.

[0066] Optionally, in the design method of the simulated tooth root implant system, the set thickness range of the bone graft chamber shell is 0.3 mm to 0.7 mm.

[0067] Optionally, in the design method of the simulated tooth implant system, the design method further includes:

[0068] Obtain the crown from the reference model and shell the crown inward to obtain the second crown; wherein, the crownmost surface of the second crown is the crownmost surface of the abutment;

[0069] Select a plane that is perpendicular to the central axis of the second crown;

[0070] Along the direction of the central axis of the second crown, the plane intersects with the second crown to obtain the minimum intersection profile and the maximum intersection profile;

[0071] Using the plane where the minimum intersection contour line is located as the reference plane, stretch along the central axis toward the root side until it intersects with the coronal surface where the transgingival portion is located in the reference model to form an abutment;

[0072] Alternatively, using the minimum intersecting contour line as the starting contour line and the maximum intersecting contour line as the ending contour line, perform the basic lofting operation to form the base.

[0073] Optionally, in the design method of the simulated tooth implant system, the design method further includes:

[0074] Remove the crowns from the reference model to form an implant platform on the crown side of the remaining reference model;

[0075] A region is selected at the center of the implant platform, and the surface of the region is stretched toward the crown side to form an abutment protruding from the implant platform;

[0076] Adjust the shape of the side wall of the base so that the angle between the side wall of the base and the planting platform meets the set requirements;

[0077] Adjust the coronal surface of the abutment so that the coronal surface of the abutment has the same surface profile as the coronal surface of the crown in the reference model;

[0078] The abutment and the remaining reference model together form a pseudo-dental implant body model.

[0079] Optionally, in the design method of the simulated tooth root implant system, the axial length of the abutment is less than the axial length of the crown; the radial length of the abutment is less than the radial length of the crown; and the angle between the projection line of the abutment's sidewall in the coronal or sagittal plane and the cross section is required to be within the range of 90°-150°.

[0080] Optionally, in the design method of the simulated tooth implant system, the design method further includes:

[0081] The crown in the reference model is shelled inward; wherein, in executing the shelling command, it is set to retain the crown in the reference model to obtain a first porcelain model; or it is set not to retain the crown in the reference model to obtain a first base crown model.

[0082] Perform a Boolean subtraction operation between the first basal crown model and the abutment to obtain the second basal crown model;

[0083] Using the bottom surface of the first decorative porcelain model as a reference plane, a portion of the first decorative porcelain model with a set thickness is cut off towards the crown to serve as a neck ring model;

[0084] Perform a Boolean subtraction operation between the neck ring model and the first decorative porcelain model to obtain the second decorative porcelain model;

[0085] The neck ring model and the second basal crown model are combined using a Boolean addition operation to obtain the third basal crown model;

[0086] The crown model includes a second base crown model, a second porcelain model, and a cervical ring model; the second porcelain model and the cervical ring model are both fitted onto the outer surface of the second base crown model, and the cervical ring model is in contact with the bottom surface of the second porcelain model.

[0087] Alternatively, the crown model may include a third base crown model and a second porcelain veneer model; the second porcelain veneer model is fitted onto the outer surface of the third base crown model.

[0088] Optionally, in the design method of the simulated tooth root implant system, the thickness range of the neck ring model is set to 0.3 mm to 3 mm.

[0089] Optionally, in the design method of the simulated tooth root implant system, the design method further includes: selecting a Maryland bridge model or clasp model connected to the second porcelain model based on the oral data.

[0090] Optionally, in the design method of the simulated tooth implant system, the design method further includes:

[0091] A simulated screw model is selected; and the shank of the simulated screw model is a hollow cylinder.

[0092] The root of the simulated tooth implant body model is nested into the coating model, and the bone graft chamber model is placed in the three-dimensional region;

[0093] The simulated screw model is placed in the simulated tooth root implant body model along the crown-root direction, so that the simulated screw model coincides with the central axis of the simulated tooth root implant body model, the top of the simulated screw model is located inside the abutment, and the shank of the simulated screw model penetrates the coating model and the bone graft chamber model; or, the simulated screw model is placed through the bone graft chamber model along the buccal-lingual direction.

[0094] When the simulated screw model is set along the crown-root direction, the simulated screw model is subjected to Boolean intersection with the simulated tooth root implant body model, the coating model and the bone graft chamber model, so that a screw channel is formed in the simulated tooth root implant body model, a through hole is formed in the coating model and two guide ring models opposite to each other along the crown-root direction are formed in the bone graft chamber model.

[0095] When the simulated screw model is set along the buccal-tongue direction, the simulated screw model and the bone graft chamber model are subjected to a Boolean intersection operation, so that two guide ring models opposite each other along the buccal-tongue direction are formed in the bone graft chamber model.

[0096] Optionally, in the design method of the simulated tooth root implant system, the design method further includes: designing a screw model arranged along the coronal root direction and a screw model arranged along the buccal-lingual direction; wherein, the shank of the screw model is provided with a self-tapping thread, and the maximum diameter of the shank of the screw model is equal to the inner diameter of the shank of the simulated screw model;

[0097] The screw model, arranged along the buccal-lingual direction, is also equipped with a nut model and a washer model; the washer model is fitted onto the shank of the screw model and connected to the head end of the screw model; the side of the washer model away from the head end of the screw model and the side of the nut model near the head end of the screw model are fitted with a portion of the side of the alveolar bone at the affected tooth.

[0098] Based on the same inventive concept, the present invention also provides a method for preparing a pseudo-dental root implant system, which uses 3D printing technology and / or CNC technology to prepare the pseudo-dental root implant system designed by the design method of the pseudo-dental root implant system.

[0099] Optionally, in the preparation method of the simulated tooth root implant system, the coating and the bone graft chamber are made of titanium alloy or shape memory material independently.

[0100] In summary, this invention provides a design and fabrication method for a simulated tooth root implant system. The design method uses a three-dimensional model of the affected tooth obtained through scanning as the basis for the design, more closely resembling a real tooth. This simulates the force transmission characteristics and stress distribution characteristics of a natural molar. By using multiple roots, the occlusal stress is dispersed, resulting in strong anti-rotation performance. Furthermore, when the three-dimensional model does not meet the set requirements, this invention straightens the roots and / or adjusts the bifurcation angle, making the designed roots easier to position in the extraction socket, avoiding excessively large or small bifurcation angles, and reducing implantation difficulties. In addition, this invention also designs a coating model and a bone graft chamber model. The coating model is fitted onto the outer surface of the root of the reference model, allowing for an interference fit with the extraction socket during implantation, contributing to short-term and long-term post-implantation stability. The bone graft chamber model is a shell model that can accommodate anti-inflammatory and growth-promoting drugs, further contributing to short-term and long-term post-implantation stability. Furthermore, both the coating model and the bone graft chamber model are porous, which facilitates drug diffusion and bone tissue ingrowth. Therefore, the simulated tooth root implant system formed by this invention not only simulates the force characteristics of natural molars, dispersing occlusal stress and improving the short-term and long-term stability of the implant, but also reduces implantation difficulties by straightening the tooth root and / or adjusting the bifurcation angle. Attached Figure Description

[0101] Figure 1 This is a flowchart of the design method of the pseudo-dental implant system in the embodiments of the present invention;

[0102] Figure 2 This is a schematic diagram of a tooth tissue model in an embodiment of the present invention;

[0103] Figure 3 This is a schematic diagram of the tooth crown in the three-dimensional model of an embodiment of the present invention;

[0104] Figure 4 This is a schematic diagram of the transgingival portion and tooth root in the three-dimensional model of an embodiment of the present invention;

[0105] Figure 5 This is a schematic diagram of the tooth root in the three-dimensional model of an embodiment of the present invention;

[0106] Figure 6 This is a schematic diagram of a three-dimensional model in an embodiment of the present invention;

[0107] Figure 7 This is a schematic diagram of the inflection point layer location in an embodiment of the present invention;

[0108] Figure 8 This is a schematic diagram of the flattening process in an embodiment of the present invention;

[0109] Figure 9 This is a schematic diagram of the equidistant processing in an embodiment of the present invention;

[0110] Figure 10 This is a schematic diagram of the basic layout operation in an embodiment of the present invention;

[0111] Figure 11 This is a schematic diagram of the baseline model in an embodiment of the present invention;

[0112] Figure 12 This is a schematic diagram of obtaining the bifurcation angle in a coronal view according to an embodiment of the present invention;

[0113] Figure 13-16 This is a schematic diagram showing the location of the bone graft chamber model in the baseline model with a single tooth root in an embodiment of the present invention.

[0114] Figure 17 This is a schematic diagram of a coated shell with a single tooth root in an embodiment of the present invention;

[0115] Figure 18 This is a schematic diagram of a coated shell with two tooth roots according to an embodiment of the present invention;

[0116] Figure 19 This is a schematic diagram of the arrangement of the support unit bodies in an embodiment of the present invention;

[0117] Figure 20 This is a schematic diagram of the coating model in an embodiment of the present invention;

[0118] Figure 21 This is a schematic diagram of the coated housing in an embodiment of the present invention;

[0119] Figure 22 This is a schematic diagram of the combination of the coating model and the reference model in an embodiment of the present invention;

[0120] Figure 23 This is a schematic diagram of the minimum envelope surface in an embodiment of the present invention;

[0121] Figure 24 This is a schematic diagram of the physical model of the bone graft chamber in an embodiment of the present invention;

[0122] Figure 25 This is a cross-sectional view of the bone graft chamber model in an embodiment of the present invention;

[0123] Figure 26 This is a schematic diagram of the pseudo-dental implant body model in an embodiment of the present invention;

[0124] Figure 27 This is a schematic diagram of the basic model after the removal of the tooth crown in an embodiment of the present invention;

[0125] Figure 28 This is a schematic diagram of the tooth crown in the basic model of this invention embodiment;

[0126] Figure 29 This is a schematic diagram of the second crown in an embodiment of the present invention;

[0127] Figure 30 This is a schematic diagram of the minimum and maximum intersecting contour lines in an embodiment of the present invention;

[0128] Figure 31 This is a schematic diagram of a base formed by stretching based on the minimum intersecting contour line in an embodiment of the present invention;

[0129] Figure 32 This is a schematic diagram of the base in an embodiment of the present invention;

[0130] Figure 33 This is a schematic diagram of the pseudo-dental implant body model in an embodiment of the present invention;

[0131] Figure 34 This is a schematic diagram of the first basal crown model in an embodiment of the present invention;

[0132] Figure 35 This is a cross-sectional view of the second base crown model, the second porcelain ornament model, and the neck ring model in an embodiment of the present invention;

[0133] Figure 36 This is a cross-sectional view of the second decorative porcelain model in an embodiment of the present invention;

[0134] Figure 37 This is a cross-sectional view of the third basal crown model in an embodiment of the present invention;

[0135] Figure 38 This is a schematic diagram of the pseudo-dental implant system model in an embodiment of the present invention;

[0136] Figure 39 This is a schematic diagram of the position of the crown root-oriented simulated screw model in an embodiment of the present invention;

[0137] Figure 40 This is a schematic diagram showing the position of the snout-tongue simulated screw model in an embodiment of the present invention;

[0138] Figure 41 This is a schematic diagram of a screw-like model arranged in the crown root direction in an embodiment of the present invention;

[0139] Figure 42 This is a schematic diagram of the crown-root screw penetrating the pseudo-dental root implant body model in an embodiment of the present invention;

[0140] Figure 43 This is a schematic diagram of the crown-root screw penetrating the pseudo-dental root implant body model in an embodiment of the present invention;

[0141] Figure 44 This is a schematic diagram showing the location of the screw channel in an embodiment of the present invention;

[0142] Figure 45 This is a schematic diagram of a simulated screw model with a buccal tongue orientation in an embodiment of the present invention;

[0143] Figure 46 This is a schematic diagram of the buccal-lingual screw penetrating the pseudo-root implant body model in an embodiment of the present invention;

[0144] Figure 47 This is a cross-sectional view of the bone graft chamber model in an embodiment of the present invention;

[0145] Figure 48 This is a schematic diagram of the crown root screw model in an embodiment of the present invention;

[0146] Figure 49 This is a schematic diagram of the cheek-tongue screw model, nut model, and washer model in an embodiment of the present invention;

[0147] The attached figures are labeled as follows:

[0148] M0 - Diseased tooth tissue model; M1 - 3D model; M2 - Baseline model; M3 - Coated shell; M4 - Coated model; M5 - Bone graft chamber solid model; M6 - Bone graft chamber model; M7 - Prototype implant body model; M8 - First abutment crown model; M9 - Cervical ring model; M10 - Second porcelain ornament model; M11 - Second abutment crown model; M12 - Third abutment crown model; M13 - Guide ring model; M14 - Coronal root-oriented simulated screw model; M15 - Buccal-lingual simulated screw model; M16 - Coronal root-oriented screw model; M17 - Buccal-lingual screw model; M18 - Nut model; M19 - Washer model;

[0149] 101-Crown; 1011-Second crown; 102-Perforated portion; 103-Root; 104-Gingival tissue; 105-Alveolar bone; 106-Abutment;

[0150] A - Irregularly tilted structure; B - Support unit; C - Minimum envelope surface; D - Screw channel; E - Position of the simulated screw model placed along the coronal root direction; F - Position of the simulated screw model placed along the buccal tongue direction. Detailed Implementation

[0151] To make the objectives, advantages, and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clarify the explanation of the embodiments of the present invention. Furthermore, the structures shown in the drawings are often part of the actual structure. In particular, different figures may have different focuses and sometimes use different scales. It should also be understood that, unless specifically stated or indicated, the terms "first," "second," "third," etc., in the specification are only used to distinguish the various components, elements, steps, etc., in the specification, and are not used to indicate the logical or sequential relationships between the various components, elements, steps, etc. In this specification, "crown" refers to the portion above the gingival tissue; "perforated portion" is the portion covered by the gingival tissue; and "root" is the portion below the gingival tissue.

[0152] This embodiment provides a design method for a simulated dental implant system. Please refer to [link to relevant documentation]. Figure 1 ,include:

[0153] Step 1 S10: Collect oral data and obtain a 3D model of the affected tooth;

[0154] Step 2 S20: Determine whether the three-dimensional model meets the set requirements. If yes, use the three-dimensional model as the reference model. If no, straighten the tooth roots in the three-dimensional model and / or process the bifurcation angle, and use the processed three-dimensional model as the reference model.

[0155] Step 3S30: Obtain a coating model covering the outer surface of the tooth root based at least on the tooth root in the reference model; and obtain a bone graft chamber model based on part or all of a single tooth root in the reference model, or based on the three-dimensional region between two or more tooth roots in the coating model, to form a pseudo-tooth root implant system with a coating and a bone graft chamber on the pseudo-tooth root.

[0156] As can be seen, the design method of the simulated tooth root implant system provided in this embodiment is based on the three-dimensional model of the affected tooth obtained by scanning, which is closer to a real tooth and realizes the simulation of the force transmission characteristics and stress distribution characteristics of natural teeth and roots. Especially for molars with multiple roots, the simulation of multiple roots disperses the occlusal stress, thereby having strong anti-rotation performance. Furthermore, when the three-dimensional model does not meet the set requirements, this embodiment will straighten the roots of the three-dimensional model and / or adjust the bifurcation angle, making the designed roots easier to position in the extraction socket, avoiding excessively large or small bifurcation angles, and reducing the difficulty of implantation. In addition, this embodiment also designs a coating model and a bone graft chamber model. The coating model is fitted onto the outer surface of the root of the reference model, and can be tightly connected to the extraction socket during implantation, which helps with short-term and long-term stability after implantation. The bone graft chamber model is a shell model that can contain anti-inflammatory and growth-promoting drugs, which also helps with short-term and long-term stability after implantation. Both the coating model and the bone graft chamber model are porous, which facilitates drug diffusion and bone ingrowth. Therefore, the pseudo-root implant system formed using the design method of the pseudo-root implant system provided in this embodiment not only simulates the force characteristics of natural teeth, dispersing occlusal stress and improving the short-term and long-term stability of the implant, but also reduces implantation difficulties through straightening the root and / or adjusting the bifurcation angle.

[0157] The following is in conjunction with the appendix Figure 1-49 The design method of the simulated tooth root implant system is described in detail.

[0158] Step 1 S10: Please refer to Figure 2-6 We collect oral cavity data and obtain a three-dimensional model of the affected tooth.

[0159] Converting the actual morphology of the dental arch into a digital model via optical scanning is fundamental for personalized dental design. Methods for acquiring oral data include, but are not limited to, cone-beam computed tomography (CBCT) and 3D intraoral scanning. CBCT is used to scan the patient's oral cavity to obtain complete 3D data of the maxilla and teeth. The scanning range is parallel to the mandibular plane, starting from the highest point of the mandibular condyle and extending to the lower border of the mandible, scanning transversely from top to bottom. 3D intraoral scanning obtains 3D data of the dental arch and soft tissues within the oral cavity. Therefore, through intraoral data acquisition, at least dentition data, alveolar bone data, and gingival tissue data are obtained. To improve the accuracy of the data, techniques known to those skilled in the art can be used to process the acquired data, such as: filtering noise, setting slice thickness, selecting image thresholds, masking, morphological processing, smoothing, region growing, mask filling, and calculating three-dimensional models for CBCT data; and performing scanning calibration, scanning accuracy adjustment, noise removal, trimming of the oral scan model area, repair of broken surfaces, and processing of occlusal relationships for oral scan data.

[0160] Please see Figure 2 Based on the acquired dentition data, alveolar bone data, and gingival tissue data, at least a affected tooth tissue model M0, an alveolar bone model, and a gingival tissue model at the affected tooth are obtained. The gingival tissue 104 covers the transgingival portion 102 of the tooth, and the alveolar bone 105 surrounds the tooth root 103. The alveolar bone model and gingival tissue model are then solid models of the gingival tissue 104 and alveolar bone 105 at the affected tooth. Next, a Boolean subtraction operation is performed between the affected tooth tissue model M0 and the gingival tissue model and alveolar bone model to obtain... Figure 3 The crown 101 in the three-dimensional model M1 of the affected tooth is shown. A Boolean intersection operation is performed between the affected tooth tissue model M0 and the gingival tissue model to obtain the following... Figure 4 The perforated portion 102 in the three-dimensional model M1 of the affected tooth is shown. A Boolean intersection operation is performed between the tissue model M0 of the affected tooth and the alveolar bone model to obtain the following... Figure 5 The root 103 in the three-dimensional model M1 of the affected tooth is shown. Finally, as... Figure 6 As shown, the obtained three-dimensional model M1 of the affected tooth includes a crown 101, a transgingival portion 102, and a root 103 connected sequentially along the crown-root direction.

[0161] Furthermore, when the crown 101 of the affected tooth is missing or damaged, the corresponding tooth is obtained based on the dentition data. The crown 101 of a tooth or a symmetrical tooth serves as the crown 101 of the three-dimensional model M1. Specifically, for... A tooth is the opposing tooth that occludes with the affected tooth, and a symmetrical tooth is the tooth that is symmetrical to the affected tooth along the midsagittal plane. When the crown 101 of the affected tooth is missing or damaged, the crown 101 of the three-dimensional model M1 is preferably the crown 101 of the symmetrical tooth. Furthermore, considering the design effect and subsequent cavity preparation and implantation, when acquiring the oral data, as much periodontal ligament, adjacent teeth, and opposing teeth as possible will be obtained. Data related to teeth, etc., are collected as design references and for subsequent implantation needs.

[0162] Step 2 S20: Please refer to Figure 6-12 Determine whether the three-dimensional model M1 meets the set requirements. If yes, use the three-dimensional model M1 as the reference model M2. If no, straighten the tooth root 103 in the three-dimensional model M1 and / or process the bifurcation angle, and use the processed three-dimensional model M1 as the reference model M2.

[0163] Because oral mastication is complex, the teeth and their supporting tissues are subjected to dynamic impact loads during this process. Their deformation and stress distribution are related to the movement process and time, with the load duration having a greater impact than the load intensity. The periodontal ligament exists between the natural tooth root and alveolar bone. This ligament can sense external forces and make corresponding feedback adjustments, providing good protection and preventing trauma from excessive lateral forces. However, the implant-like tooth root is rigidly connected to the bone tissue and has no regulatory function. Therefore, when implanting the implant-like tooth root, it is important to ensure that there is no significant or minor bifurcation between the roots, and that the roots are not concave or flared. This avoids excessive lateral forces causing uneven stress distribution in the surrounding bone tissue, leading to complications such as implant loosening and loss. Therefore, this embodiment requires the assessment and correction of the bifurcation between the roots and the degree of concavity or flaring of the roots in the obtained three-dimensional model M1.

[0164] Anterior teeth with single roots typically have a more standardized shape, often straight or slightly inclined, making them easier to implant and avoiding the implantation difficulties associated with molars. However, molars with two or more roots are more prone to irregular root shapes and excessively large or small bifurcation between roots. Figure 6 As shown, molars typically have two, three, or four roots 103, resulting in a complex chewing mechanics pattern and a tendency for irregular tilting structures A. For example, the root 103 may bend to one side, either inward or outward, making implantation difficult. Therefore, after obtaining the three-dimensional model, it is necessary to analyze the roots of the affected tooth to determine whether irregular tilting structures A exist.

[0165] Please see Figure 7 CBCT scanning can obtain multiple two-dimensional images (i.e., cross-sectional images) of the affected tooth. Each two-dimensional image corresponds to a planar image of a corresponding layer in the three-dimensional model along the crown-root direction. By overlaying a certain number of these two-dimensional images in Mimics software, the three-dimensional model M1 can be reconstructed. It can be understood that during CBCT scanning, the affected tooth is automatically layered, and the planar information of each layer is scanned layer by layer and stored as two-dimensional images. The three-dimensional model M1 of the affected tooth can be reconstructed from multiple two-dimensional images. Therefore, the multiple two-dimensional images obtained by CBCT scanning can be understood as dividing the three-dimensional model M1 of the affected tooth into multiple layers along the z-axis.

[0166] Furthermore, based on the three-dimensional model M1, the multiple layers of two-dimensional images, and the positional relationships between the various two-dimensional images, starting from the layer closest to the crown in the root, the projection lines of the center connecting lines of each adjacent two layers are calculated sequentially on the coronal and sagittal planes, respectively. The angles between the projection lines of the first two layers on the coronal or sagittal plane and the projection lines of the last two layers on the corresponding planes are also calculated for each consecutive three layers. When the angle is greater than or equal to 5°, the root does not meet the set requirements; when all angles are less than 5°, the root meets the set requirements. The center connecting line between adjacent layers is obtained by connecting the center points of the contours of adjacent two-dimensional images, using the centroid of a single two-dimensional image as the center point and obtaining the coordinates of the center point. Calculating each adjacent two layers sequentially means starting from the layer closest to the crown in the root and moving away from the crown, first calculating the first and second layers, then the second and third layers, then the third and fourth layers, and so on. When the three-dimensional model M1 has multiple tooth roots 103, it is necessary to judge each tooth root 103.

[0167] When the included angle is greater than or equal to 5°, the root 103 needs to be straightened. The middle layer of three consecutive layers with an included angle greater than or equal to 5° is taken as the inflection point layer O. Specifically, when judging whether the root 103 of the affected tooth meets the set requirements layer by layer along the crown-root direction, the judgment can stop when the first inflection point layer O appears, regardless of whether other inflection point layers O exist in the remaining portion of the root 103. Since other inflection point layers O have no reference value, only the two-dimensional image corresponding to the first inflection point layer O needs to be obtained. Taking coronal projection as an example, in this embodiment... Figure 7The diagram shows an inflection point layer O, with this inflection point layer O as the boundary layer. The projection line of the central connection line between this boundary layer and the adjacent layer near the gingival portion 102 on the coronal plane is projection line a. The projection line of the central connection line between this boundary layer and the adjacent layer away from the gingival portion 102 on the coronal plane is projection line b. It can be seen that the projection line of the central axis of the tooth root after passing through the inflection point layer O along the coronal root direction changes from a to b on the coronal plane, causing the tooth root 103 to have an undercut shape, which is unfavorable for stress bearing. The angle α formed by projection lines a and b is the angle that needs to be determined. The sagittal projection is similar to the coronal projection and will not be described further here.

[0168] Please see Figure 8 After extracting the two-dimensional image corresponding to the inflection point layer O, the radial contour line of the tooth root 103 in the two-dimensional image is used as the starting contour line S0. Based on the starting contour line S0, with the center connecting line of the inflection point layer O and the layer adjacent to the inflection point layer O and close to the crown 101 as the reference axis a, isometric processing is performed in the direction pointing towards the tooth root to obtain at least one isometric contour line. Figure 8 and 9 As shown, during equidistant processing, the initial contour line S0 is used as a reference, and at least one equidistant contour line is formed at equal intervals towards the negative half-axis of the reference axis a. Wherein, Figure 8 The image shows an equidistant contour line S1. Figure 9 The diagram shows four equidistant contour lines. The specific number of these equidistant contour lines can be determined based on the length of the tooth root. That is, when the inflection point layer O is located in the middle of the tooth root 103 and is relatively far from the lowest point of other tooth roots 103, multiple equidistant contour lines can be set at equal intervals. When the inflection point layer is close to the tip of the tooth root 103, only one equidistant contour line can be set. The last equidistant contour line is designated as the termination contour line S1.

[0169] Furthermore, such as Figure 9As shown, during the equidistant processing, all the equidistant contour lines are sequentially reduced at equal intervals along the radial direction. The size range of each reduction is 0.1 mm to 0.8 mm, optionally 0.1 mm, 0.5 mm, or 0.8 mm. Furthermore, the minimum diameter of the last equidistant contour line, i.e., the terminating contour line S1, is greater than or equal to 0.3 mm. Typically, the equidistant contour line is an irregular planar closed curve. All points on the curve can be simultaneously moved inward by the same distance to proportionally reduce the planar closed curve. Alternatively, it can be fitted into an ellipse, in which case the minor diameter of the elliptical terminating contour line S1 is greater than or equal to 0.3 mm, so that the bottom of the straightened root 103 becomes a curved surface, rather than a contact point, which is beneficial for bearing occlusal forces. Further, the axial distance between the starting contour line S0 and the terminating contour line S1 ranges from 0.1 mm to 8 mm. Preferably, the position of the terminating contour line S1 is flush with the lowest point of the other roots 103 in the affected tooth.

[0170] Please see Figure 10 After completing the isometric processing, a basic lofting operation is performed on the initial contour line S0 and all the isometric contour lines, that is, all contour lines are connected sequentially to form a solid model, thereby completing the straightening process of the tooth root 103. Then, as... Figure 11 As shown, the straightened root 103 replaces the original root 103 with the irregular inclined structure A. The straightened root 103 does not have undercuts or outward expansion, which reduces the difficulty of implantation and makes the stress distribution of the implant-prototype even, which helps to improve the initial and long-term stability of the implant.

[0171] Furthermore, in determining whether the three-dimensional model M1 meets the set requirements, the method also includes: Figure 12 As shown, the bifurcation angle β between two or more tooth roots 103 is calculated using the three-dimensional model M1. The bifurcation angle β is obtained by: obtaining the projection lines of the central axis of each tooth root in the three-dimensional model onto the coronal and sagittal planes, and calculating the angle between the projection lines of the central axes of every two tooth roots onto the coronal or sagittal planes; this angle is the bifurcation angle β. When the bifurcation angle β is less than 5° or greater than 15°, the bifurcation angle β does not meet the set requirements. When the bifurcation angle is greater than or equal to 5° and less than or equal to 15°, the bifurcation angle β meets the set requirements. Because the bifurcation angle β directly affects the uniformity of stress distribution, and when the bifurcation angle β is too large, it will affect the implantation of the implant-like tooth root, and when the bifurcation angle β is too small, it is not conducive to the initial stability of the implantation, therefore, when the bifurcation angle β of the three-dimensional model M1 does not meet the set requirements, the bifurcation angle β needs to be adjusted.

[0172] The method for adjusting the bifurcation angle β provided in this embodiment is as follows: using the central axis of the tooth root 103 that meets the set requirements, or the central axis of the tooth root 103 after straightening treatment, as the reference axis, and the central axis of the target tooth root to be treated as the target axis, both the reference axis and the target axis are projected onto the coronal and sagittal planes. Taking the coronal plane projection as an example, refer to... Figure 12 The reference axis and the target axis are projected onto the coronal plane to obtain projection lines c and d, which intersect at point e. Projection line d is rotated around intersection point e until the angle β between projection line d and projection line c meets the set requirements. The rotated projection line is then used as the processed target axis, and the tooth root 103 is set according to the processed target axis. It is understood that adjusting the bifurcation angle β involves reducing or increasing the bifurcation angle β (which is too large or too small) using intersection point e as the rotation reference point, so that the bifurcation angle β meets the requirement of 5°-15°.

[0173] After straightening the tooth root 103 in the three-dimensional model M1 and / or processing the bifurcation angle β, the following is obtained: Figure 11 The reference model M2 of the simulated tooth root implant system shown is used as the standard reference for all subsequent designs.

[0174] Furthermore, when straightening the root 103 and adjusting the bifurcation angle β, the thickness of the bone wall surrounding the affected tooth needs to be considered. Because the distance between the root and the bone wall is very small, excessively large angles or adjustments during bifurcation angle β adjustment or straightening may cause bone opening. Therefore, during cavity preparation, it is generally necessary to ensure at least 2mm of labial bone wall in the anterior region, at least 1mm of buccal bone wall in the posterior region, and 1–1.5mm of bone wall on the palatal side. The distance from adjacent natural teeth should be 1.5–2mm, and the distance from similar-type implants or other types of implants should be at least 3mm.

[0175] Step 3 S30: Please refer to Figure 13-49 At least based on the tooth root 103 in the reference model M2, a coating model M4 is obtained, which is fitted onto the outer surface of the tooth root 103; and a bone graft chamber model M6 is obtained based on part or all of a single tooth root 102 in the reference model M2, or based on the three-dimensional region between two or more tooth roots in the coating model M4, to form a pseudo-tooth root implant system having a coating and a bone graft chamber on the pseudo-tooth root.

[0176] Because natural anterior teeth generally have a single root and are flattened, while molars generally have two or three roots to distribute occlusal stress, this embodiment requires separate design for single-root and multi-root implant systems. Specifically, when the reference model M2 has a single root 103, the bone graft chamber model M6 needs to be designed first, followed by the coating model M4. This is because the coating model M4 needs to cover part of the root 103 and the bone graft chamber model M6, so it is designed later. When the reference model M2 has two or more roots 103, the coating model M4 needs to be designed first, followed by the bone graft chamber model M6. This is because the coating model M4 only needs to cover part of the root 103, and the bone graft chamber model M6 is located outside the coating model M4, so it is designed later.

[0177] like Figure 13-14 As shown, when the reference model M2 has a single tooth root, the bone graft chamber model M6 can be located on opposite sides of the tooth root 103. Since a single tooth root is typically flat, the thickness of the tooth root 103 along the X direction is greater than the thickness along the Y direction. Therefore, to ensure sufficient connection area and stable connection, the bone graft chamber is generally located in the plane along the X direction. Furthermore, the number of bone graft chambers can be one, two, or three on each side. Alternatively, the number of bone graft chambers on each side can be unequal; for example, one on one side and two on the other. Correspondingly, when the reference model M2 has a single tooth root, this embodiment does not limit the number of bone graft chamber models M6. In addition, when the reference model M2 has a single tooth root, the bone graft chamber model M6 can also replace part of the tooth root 103. Figure 15-16 As shown, the bone graft chamber model M6 is part of the tooth root 103.

[0178] Please see Figure 13-14 When the reference model M2 has a single tooth root 103, the placement area of ​​the bone graft chamber model M6 is first selected. This area can be located on the outer surface of the tooth root 103, or it can be connected to a portion of the tooth root 103, thus serving as part of the tooth root 103. For example... Figure 13-14As shown, when the bone graft chamber model M6 is positioned on the outer surface of the tooth root 103, the outer surface of the tooth root 103 corresponding to the placement area is used as a reference plane. The reference plane is stretched radially along the tooth root 103 and towards the side away from the tooth root 103 to obtain the solid model of the bone graft chamber. It is understood that the designed bone graft chamber needs to be attached to the outer surface of the tooth root. Therefore, when designing the bone graft chamber model M6, the attachment surface, i.e., the reference plane, needs to be selected first, and then the solid model of the bone graft chamber is obtained through stretching. The surface of the solid model of the bone graft chamber in contact with the tooth root 103 is still the selected reference plane.

[0179] like Figure 15-16 As shown, when the bone graft chamber model M6 replaces a portion of a single tooth root 103, a portion of the tooth root 103 in the reference model M2 is first cut off, and this portion of the tooth root 103 is used as the solid model of the bone graft chamber. Using a portion of the tooth root 103 as the solid model of the bone graft chamber ensures that the subsequently designed bone graft chamber model M6 connects well with the remaining portion of the tooth root without any gaps, thus guaranteeing the integrity of the tooth root 103.

[0180] After obtaining the solid model of the bone graft chamber, an inward shelling process is performed on the solid model to obtain a bone graft chamber shell with a set thickness. During the inward shelling command, the original shape needs to be preserved; therefore, the shelled bone graft chamber shell retains its outermost contour dimensions, but the middle portion is hollowed out, becoming a cavity. Finally, a porous treatment is performed on the bone graft chamber shell (see the process of porous coating shell treatment) to obtain the bone graft chamber model M6, which is disposed on the outer surface of the tooth root 103 or replaces a portion of the tooth root 103.

[0181] After designing the bone graft chamber model M6, the coating model M4 needs to be designed. When the reference model M2 has a single tooth root 103, and the bone graft chamber model M6 is placed on the outer surface of the tooth root 103, the tooth root 103 in the reference model M2 is first cut off. Then, the bone graft chamber solid model located on the outer surface of the tooth root 103 and the cut-off tooth root 103 are combined into a single entity, which serves as the coating solid model. Next, as... Figure 17 As shown, an outward shelling process is performed on the coated solid model to obtain a coated shell M3 with a set thickness. When executing the outward shelling command, the original shape of the coated solid model must be preserved so that the inner surface of the obtained coated shell M3 matches the outer surface of the coated solid model. Finally, a porousing process is performed on the coated shell M3 to obtain the coated model M4.

[0182] Where the reference model M2 has a single tooth root 103, and the bone graft chamber model M6 replaces part of the tooth root 103, since it has no impact on the outer surface of the tooth root 103, the bone graft chamber model M6 can be designed first, or the coating model M4 can be designed first. Furthermore, the design method for the coating model M4 is the same as the design method for the coating model M4 when there are two or more tooth roots 103, as detailed below:

[0183] First, the tooth root 103 in the reference model M2 is extracted as the coating solid model. Then, as... Figure 17 As shown in Figure 18, an outward shelling process is performed on the coated solid model to obtain a coated shell M3 with a set thickness. Similarly, when executing the outward shelling command, the original shape of the coated solid model must be preserved so that the inner surface of the obtained coated shell M3 matches the outer surface of the coated solid model. In other words, outward shelling means that the cut-off root 103 is left with only the outer surface intact, while the interior remains empty. The outer surface of the root 103 is then extended a certain thickness towards the outside of the root 103. Finally, as... Figure 20 As shown, the coated housing M3 is subjected to a porous treatment to obtain the coated model M4.

[0184] The processes for porousification of the coated shell M3 and the bone graft chamber shell are the same, differing only in porosity and pore size range. Therefore, the porousification process for the coated shell M3 is as follows:

[0185] like Figure 19 As shown, multiple scaffold units B are selected and arranged in an infinite array in three-dimensional space. Further, the shape of the scaffold units B includes, but is not limited to, rhombic dodecahedrons, regular hexahedrons, or honeycomb structures. Multiple scaffold units B are connected and arranged in an infinite array in three-dimensional space, creating a porous structure in the coating or bone graft chamber. Further, the array can be ordered or disordered, mimicking the trabecular bone structure. The porosity and pore size range can be set by adjusting the size and shape of the scaffold units B. Further, the scaffold unit B consists of multiple rods forming a scaffold structure, and the surface of the rods can be formed with micropores through micro-arc oxidation to increase the surface area of ​​the coating or bone graft chamber, thereby improving drug loading capacity.

[0186] Please see Figure 20The multiple scaffold units B are superimposed on the coating shell M3 (e.g., through Boolean intersection) to form a porous structure, thus obtaining the coating model M4. Similarly, the bone graft chamber model M6 also uses the above method to form a porous structure. The porous structure facilitates bone tissue ingrowth from the implant site to the implant body, forming long-term bio-fixation. Furthermore, the porous design of the bone graft chamber also facilitates drug diffusion within the chamber and promotes bone tissue ingrowth from the implant site to the implant site using autologous tooth tissue, providing short-term and long-term implant stability. The porosity of the coating model M4 ranges from 30% to 80%, and the pore size ranges from 100 micrometers to 1000 micrometers. Preferably, the porosity is 67% and the pore size is 650 micrometers. The porosity of the bone graft chamber model M6 ranges from 80% to 90%, and the pore size ranges from 1000 micrometers to 1400 micrometers. Preferably, the porosity is 85% and the pore size is 1200 micrometers.

[0187] Furthermore, such as Figure 21-22 As shown, the axial distance h between the plane containing the crown of the root 103 in the reference model M2, which is cut out during the design of the coating model M4, and the plane containing the crown of the root 103 in the reference model M2, is 0.1 mm to 1 mm. It can be understood that the axial length of the obtained coating model M4 is less than the axial length of the root 103. The purpose is to create a "platform transfer" similar to that of a traditional implant by forming the coating with the top surface of the root, making the top surface of the coating lower than the top surface of the root. After implantation, bone resorption occurs in the alveolar bone, eventually making the top surface of the coating flush with the top surface of the alveolar bone. Furthermore, after implantation, the gingival tissue adheres to the platform transfer, forming a soft tissue seal, preventing food debris and bacteria from entering the root through gaps, making the implant-like system more stable, and also reducing butterfly-shaped bone resorption of the alveolar bone around the implant platform.

[0188] Furthermore, the thickness of the coating shell M3 is determined by the periodontal ligament of the affected tooth. The thickness of the periodontal ligament on the buccal, lingual, mesial, and distal sides of the affected tooth is obtained based on oral data, and the average value is calculated as a reference thickness for the coating shell M3. When setting the thickness of the coating shell M3, the stress effect of the thickness (interference allowance) on the alveolar bone during implantation must be considered. Only when the stress is within a certain range will bone remodeling occur in the alveolar bone. Therefore, the thickness of the coating shell M3 is slightly greater than the average value. For example, if the average value of the periodontal ligament of the affected tooth is 0.34 mm, the thickness of the coating shell M3 can be selected as 0.5 mm or 0.75 mm. Preferably, to ensure the bonding between the coating and the implant, a 0.5 mm outward peel can be made to form an outer coating shell, and then a 0.25 mm inward peel can be made to form an inner bonding layer. The inner bonding layer is used to bond with the implant, increasing the bonding strength, ultimately resulting in a coating shell with a wall thickness of 0.75 mm. Figure 21 As shown, g represents the outline of the outer coating shell, i represents the outer outline of the tooth root, and f represents the outline of the inner coating shell. The thickness of the coating shell M3 is the thickness between outline g and outline f. To avoid damage to the extraction socket due to excessive coating thickness during implantation, or poor initial stability due to excessively thin coating, the preferred range for the thickness of the coating shell is 0.2 mm to 2 mm.

[0189] The theoretical method for stress analysis in the design process of the coating model M4 is finite element analysis. While alveolar bone stress can be assessed through animal experiments or clinical trials, in actual customized design and manufacturing processes, due to time constraints, finite element calculations are generally used to obtain the impact of the interference fit on alveolar bone stress during implantation. Designing the coating to have an interference fit with the extraction socket contributes to initial post-implantation stability.

[0190] Furthermore, for the coating model M4 having a single tooth root, an opening (not shown) needs to be provided on the coating model M4. This opening is used to expose at least a portion of the bone graft chamber model M6 when the reference model M2 and the bone graft chamber model M6 are nested within the coating model M4, facilitating the placement and diffusion of medication within the designed bone graft chamber. This embodiment does not limit the number of openings; it can be one, two, or three, etc.

[0191] Please see Figure 22-25 For the reference model M4 having two or more tooth roots 103, after obtaining the coated shell M3, the bone graft chamber model M6 needs to be designed. Specifically:

[0192] like Figure 22 As shown, the tooth root 103 of the reference model M2 is first nested into the coating model M4. Then, as... Figure 23 As shown, the convex hull algorithm is used to convert the baseline model M2 and the coating model M4 into point cloud format, and all points are connected to each other to obtain the minimum envelope surface C. Secondly, as... Figure 24 As shown, a Boolean subtraction operation is performed between the minimum envelope surface C and the reference model M2, which is fitted with the coating model M4. The remaining minimum envelope surface is the bone graft chamber solid model M5. Then, an inward shelling process is performed on the bone graft chamber solid model M5 to obtain a bone graft chamber shell with a set thickness. That is, the outer surface of the bone graft chamber solid model M5 is retained, the interior of the bone graft chamber solid model M5 is empty, and then the outer surface of the bone graft chamber solid model M5 is extended inward to a certain thickness to form the bone graft chamber shell with a set thickness. The set thickness of the bone graft chamber shell ranges from 0.3 mm to 0.7 mm, preferably 0.5 mm. Finally, as... Figure 25 As shown, the same porousing treatment method used to form the coating model M4 is employed to porousen the shell of the bone graft chamber to obtain the bone graft chamber model M6. Wherein, Figure 25 for Figure 24 The cross-sectional view along D-D' shows that the outer shell of the bone graft chamber model M6 is porous, with an internal cavity. The purpose is to break down the extracted tooth, after enamel removal, cleaning, and disinfection, along with the alveolar bone removed during cavity preparation. This mixture is then combined with dental bone powder or some growth-promoting and anti-inflammatory drugs and inserted into the designed cavity of the bone graft chamber. This promotes bone tissue growth after implantation, and the autologous bone implantation reduces rejection and improves initial post-implantation stability.

[0193] After the coating model M4 and the bone graft chamber model M6 are prepared, the design method also includes designing a dental crown model.

[0194] Please see Figure 26 To ensure a stable connection of the crown model, the abutment 106 in the simulated root implant body model M7 needs to be designed first to connect with the crown model. This embodiment provides three abutment design schemes for this purpose.

[0195] The first design method for the base is as follows: Figure 27 As shown, the crown of the reference model M2 is removed so that the crown of the remaining reference model M2 forms an implant platform. The remaining reference model M2, i.e., the combined model of the transgingival portion 102 and the root portion 103, can be obtained using the method in step S10. Figure 27As shown, a region is selected at the center of the implant platform, and the surface containing this region is stretched towards the crown side to form an abutment 106 protruding from the implant platform. It can be understood that on the surface of the implant platform, a small section of the surface is selected as a reference plane, centered on the center point of the implant platform's outline, and stretched towards the crown side to obtain... Figure 22 The abutment 106 is shown. Further, the axial length of the abutment 106 is less than the axial length of the crown. Preferably, the coronal distance of the abutment 106 from the coronal axial length of the crown is 2 mm. The radial length of the abutment 106 is less than the radial length of the crown. Preferably, the radial length of the abutment 106 is 2 mm smaller than the radial length of the crown. Further, the shape of the abutment 106 needs to be adjusted so that the angle between the projection line of the abutment's sidewall in the coronal or sagittal plane and the cross-section meets the set requirements, optionally 90°-150°. Thus, the abutment 106 and the remaining reference model M2 form a pseudo-dental implant body model M7.

[0196] The second method for designing the base is as follows: Figure 28-32 As shown, the crown 101 in the reference model M2 is obtained using the method in step S10. The crown 101 is then shelled inwards by 2mm to obtain a scaled-down second crown 1011. The crown's outermost surface is the same as the outermost surface of the abutment 106. Because the sidewalls of the crown 101 are arc-shaped or irregularly curved, if the second crown 1011 is directly used as the abutment 106, the sidewalls of the abutment 106 will also be arc-shaped or irregularly curved, which is not conducive to the subsequent fitting of the crown model onto the abutment 106. Therefore, the sidewalls of the second crown 1011 need to be adjusted. Specifically, the crown axis, i.e., the central axis of the second crown, is obtained by fitting the obtained second crown 1011. For example... Figure 30 As shown, a plane perpendicular to the crown axis is drawn, intersecting with the second crown 1011, thereby obtaining the minimum intersection profile L1 and the maximum intersection profile L2. Please refer to [link / reference]. Figure 31 Using the minimum intersection contour line L1 as the reference plane, the coronal axis is stretched towards the root, and at the intersection of the coronal planes where the transgingival portion 102 is located, the intersection contour line L3 is obtained, thus obtaining the... Figure 31 and 32 The base 106 shown.

[0197] The third method for designing the base is based on the minimum intersecting contour line L1 and the maximum intersecting contour line L2 obtained in the second method. Specifically, it uses the minimum intersecting contour line L1 as the starting contour line and the maximum intersecting contour line L2 as the ending contour line, and performs basic lofting operations, such as... Figure 30As shown. After the layout base is processed, the following can be obtained. Figure 33 The base 106 shown.

[0198] In the second abutment design method, the sidewall of the abutment 106 is perpendicular to the surface of the implant platform (the coronal surface of the transgingival portion). In the third abutment design method, the angle between the projection line of the sidewall of the abutment in the coronal or sagittal plane and the cross-section must meet the set requirements, which can be 90°-150°. Therefore, through the above three schemes, the body model M7 of the simulated root implant with abutment 106 can be obtained.

[0199] Please see Figure 34 After obtaining the simulated implant body model M7, the crown in the reference model M2 is shelled inward. During the shelling command, the outer contour of the crown 101 (i.e., the crown in the reference model) is retained to obtain a first porcelain veneer model (not shown). That is, the outer surface of the crown 101 is retained, the interior of the crown 101 is hollow, and a certain thickness is extended inward from the outer surface of the crown 101 to form the first porcelain veneer model with a set thickness. The design of the porcelain veneer aims to achieve a better aesthetic effect for the crown. Specifically, to avoid an overly abrupt color difference in the base crown, the porcelain veneer is fitted onto the base crown to correct color variations. Furthermore, the thickness of each area of ​​the first porcelain veneer model is equal to ensure balanced stress on the porcelain veneer and the base crown, preventing cracking due to uneven stress. During the shelling command, the outer contour of the crown 101 is not retained to obtain a first base crown model M8. That is, the dimensions of the outer surface of the crown 101 are not retained, and the outer surface of the crown 101 is reduced inward as a whole, and the thickness of the reduction is equal to the thickness of the first porcelain model, so that the first porcelain model can be fitted onto the outer surface of the first base crown model M8.

[0200] A Boolean subtraction operation is performed between the first base crown model M8 and the abutment 106 to obtain a second base crown model. That is, through the Boolean subtraction operation, a groove is formed in the first base crown model M8, and the outline of the groove is the same as the outer outline of the abutment 106.

[0201] Please read Figures 35-37Using the bottom surface of the first porcelain model as a reference plane, a portion of the first porcelain model with a predetermined thickness is cut towards the crown to serve as the cervical ring model M9. The cervical ring is designed to support the porcelain and improve the crown's resistance to pressure. The predetermined thickness of the cervical ring model M9 ranges from 0.3 mm to 3 mm. Preferably, the thickness of the cervical ring located at the molar is 2 mm. After obtaining the cervical ring model M9, a Boolean subtraction operation is performed between the cervical ring model M9 and the first porcelain model to obtain the second porcelain model M10. This yields the crown model, which includes a second base crown model M11, a second porcelain model M10, and a cervical ring model M9. Both the second porcelain model M10 and the cervical ring model M9 are fitted onto the outer surface of the second base crown model M11, and the cervical ring model M9 is in contact with the bottom surface of the second porcelain model M10. For easier later preparation, a Boolean addition operation can also be performed between the cervical ring model M9 and the second base crown model M11 to obtain a third base crown model M12. That is, by combining the cervical ring model M9 and the second abutment crown model M11 into a whole, the crown model includes a third abutment crown model M12 and a second porcelain veneer model M10. The second porcelain veneer model M10 is fitted onto the outer surface of the third abutment crown model M12.

[0202] After the design of the crown model was completed, the following was accomplished: Figure 25 The model of the simulated tooth root implant shown includes: the second porcelain model M10, the second abutment crown model M11, the cervical ring model M9, the simulated tooth root implant body model M7, the coating model M4, and the bone graft chamber model M6. However, in actual implantation, the implant needs to be fixed, so the simulated tooth root implant system also includes a fixation structure.

[0203] Furthermore, depending on the patient's age, oral condition, and bone quality, screw fixation, Maryland bridge fixation, or clasp fixation can be selected. Therefore, based on the patient's dentition data, a Maryland bridge model, clasp model, or screw model connected to the second porcelain ornament model M10 needs to be designed. The Maryland bridge model and clasp model are conventional model designs; existing models can be selected and adapted accordingly, which will not be elaborated upon in this embodiment.

[0204] The design process of the screw model is described in detail below. Screws are often used as fixing structures in older patients or those with poor bone quality. Therefore, it is necessary to obtain the specific location of the affected tooth based on the patient's dental data to determine the axial length and placement of the screw, as well as whether to design it as a buccal-lingual screw or a crown-root screw. This embodiment uses a reference model M2 with two or more tooth roots as an example to illustrate the screw model; the reference model M2 with a single tooth root can refer to the same method.

[0205] When designing screws placed along the buccal-lingual direction or along the coronal root direction, it is necessary to use a screw-like model to obtain the screw channel formed in the designed implant model. For example... Figures 39-40 As shown, first determine the position E of the simulated screw model placed along the coronal root direction or the position F of the simulated screw model placed along the buccal-lingual direction. To ensure the stability of the connection and the balance of forces at each point, the position E of the simulated screw model placed along the coronal root direction can be selected as the position along the central axis of the implant from the coronal root direction, and the position F of the simulated screw model placed along the buccal-lingual direction can be selected as the position along the central axis of the bone graft chamber from the buccal-lingual direction.

[0206] For further details, please refer to Figure 41 After selecting the position E of the simulated screw model placed along the crown-root direction, the simulated screw model M14, also placed along the crown-root direction, is selected. The shank of the simulated screw model M14 is a hollow cylinder, meaning it lacks threads. This is to allow for the subsequent formation of a larger screw channel, facilitating the screw, as designed, to be screwed into the channel. Then, as... Figure 38 and 41 As shown in Figure -44, the root of the simulated root implant body model M7 is nested into the coating model M4, and the bone graft chamber model M6 is placed between the corresponding roots of the coating model M4. Next, the simulated screw model M14 is placed in the simulated root implant body model M7 along the coronal-root direction, so that the simulated screw model M14 coincides with the central axis L0 of the simulated root implant body model M7. The top of the simulated screw model M14 is located inside the abutment 106, and the shank of the simulated screw model M14 penetrates through the coating model M4 and the bone graft chamber model M6. A Boolean intersection operation is performed on the simulated screw model M14, the simulated root implant body model M7, the coating model M4, and the bone graft chamber model M6, resulting in a screw channel D forming in the simulated root implant body model M7, a through hole forming in the coating model M4, and two guide ring models M13 forming in the bone graft chamber model M6 along the coronal-root direction. The thickness of the guide ring model M13 is the same as the wall thickness of the hollow cylinder of the screw-like model M14. Preferably, the thickness of the guide ring model M13 is 0.3 mm. Figure 25As shown, this is a cross-sectional view of the bone graft chamber model M6 along D-D', with the two guide ring models M13 facing each other along the coronal root direction.

[0207] like Figures 45-47 As shown, when designing a screw positioned in the buccal-tongue direction, the simulated screw model M15 is inserted through the bone graft chamber model M6 along the buccal-tongue direction. Then, a Boolean intersection operation is performed between the simulated screw model M14 and the bone graft chamber model M6, resulting in two guide ring models M13 facing each other along the buccal-tongue direction within the bone graft chamber model M6. The guide rings designed based on the guide ring models M13 aim to guide the extension position of the screw and also provide fixation. Furthermore, the guide ring models M13 and the screw channel D can be designed with threads on their inner walls as needed to improve the screw's retention effect.

[0208] After forming the guide ring model M13, the design method further includes designing a screw model M16 disposed along the coronal root direction and a screw model M17 disposed along the buccal tongue direction. See also... Figures 48-49 The screw models M16 and M17 have self-tapping threads on their shanks, and the maximum diameter of the shanks of the screw models M16 and M17 is equal to the inner diameter of the shank of the imitation screw model, so as to ensure that the screws formed according to the screw models M16 and M17 can be screwed into the corresponding screw channels, through holes and guide rings.

[0209] like Figure 49 As shown, the screw model M17, positioned along the buccal-lingual direction, is also fitted with a nut model M18 and a washer model M19. The washer model M19 is fitted onto the shank of the screw model M17 and connects to the head end of the screw model M17. The head contour of the screw model M17 is arc-shaped. The designed screw penetrates the alveolar bone and extends through the soft tissue outside the alveolar bone at both ends to fix the implant and facilitate nut installation. Simultaneously, the arc-shaped head contour of the screw reduces friction from the soft tissue and minimizes food impaction. Since the side of the screw model M17 that connects to the washer model M19 is circular, the side of the washer model M19 closest to the head end of the screw model M17 is also circular. Because the spacer prepared according to the spacer model M19 is used to connect the screw head and the alveolar bone sidewall, in order to avoid a foreign body sensation after implantation, the side of the spacer model M19 away from the head end of the screw model M17 needs to fit the sidewall of the alveolar bone. This ensures that the side of the spacer model M19 away from the head end of the screw model M17 conforms to the sidewall of the alveolar bone, avoiding protrusion or depression, similar to... Figure 49The anatomical shape is shown. The head contour of the nut model M18 is arc-shaped, and its side near the head end of the screw model M18 is also fitted with a portion of the alveolar bone at the affected tooth to conform to the sidewall of the alveolar bone and avoid protrusion or depression.

[0210] In summary, the design of the simulated tooth root implant system is complete. The design model of the simulated tooth root implant system includes: the second porcelain model M10, the second abutment crown model M11, the cervical ring model M9, the simulated tooth root implant body model M7, the coating model M4, the bone graft chamber model M6, and a model of the fixation structure. The fixation structure model includes: a crown-to-root screw model M16 or a buccal-lingual screw model M17, a nut model M18, and a washer model M19, or a Maryland bridge model, or a clasp model. Furthermore, the simulated tooth root implant body model M7 is designed based on a three-dimensional model of the affected tooth. By simulating the stress transmission characteristics of a natural molar and the stress distribution characteristics of the tooth root, the simulated tooth root implant body has strong anti-rotation properties. Moreover, the tooth roots in the simulated tooth root implant body model M7 are all straight, reducing the difficulty of implantation. The coating formed according to the coating model M4 helps to form a stable interference connection between the implant and the extraction socket. Furthermore, both the bone graft chamber model M6 and the coating model M4 are porous structures, which facilitates drug diffusion within the bone graft chamber and promotes bone growth after implantation. In addition, this embodiment provides multiple fixation structure models: the coronal root screw model M16, the buccal-lingual screw model M17, the nut model M18, the washer model M19, the Maryland bridge model, and the clasp model, to meet the personalized fixation needs of patients.

[0211] Furthermore, the computer-aided programs used in the above design methods include, but are not limited to: computer-aided design / manufacturing (CAD / CAM), computed tomography (CT), finite element analysis (FEA), and Materialise's interactive medical image control system (mimics).

[0212] Based on the same inventive concept, this embodiment also provides a method for preparing a pseudo-dental root implant system, including: preparing the pseudo-dental root implant system designed by the design method of the pseudo-dental root implant system using 3D printing technology.

[0213] Furthermore, the simulated tooth root implant body model M7, the coating model M4, and the bone graft chamber model M6 are integrally printed using titanium alloy material. Since 3D printing technology makes intermediate material changes inconvenient, the coating model M4 can also be printed separately using shape memory material, while the simulated tooth root implant body model M7 and the bone graft chamber model M6 can be printed separately using titanium alloy material. The resulting coating model M4 is an elastic coating. This elastic coating has deformation capabilities, reducing the difficulty of the simulated tooth root implant body entering the extraction socket during implantation and avoiding damage to the extraction socket caused by traditional interference connections. Furthermore, after the simulated tooth root implant body reaches the target position, the elastic coating recovers its elastic deformation and abuts against the extraction socket, improving initial implantation stability. After printing separately, the simulated tooth root implant body model M7, the coating model M4, and the bone graft chamber model M6 are combined into one unit through welding, bonding, or other methods. There are two suitable welding methods: the first is laser welding, which only welds the contact surface area, without requiring internal treatment; the second is resistance welding, which uses electric current to heat up and melt all contact parts together. The simulated dental implant body model M7 and the coating model are preferably welded using resistance welding.

[0214] Furthermore, the simulated dental implant body model M7, the coating model M4, and the bone graft chamber model M6 can be printed using metal additive manufacturing technology (AM). Specifically, selective laser melting (SLM) or electron beam melting (EBM) can be selected.

[0215] Since the second base crown and the cervical ring are preferably made of zirconium oxide, and the second veneer is preferably made of feldspar glass ceramic, lithium disilicate glass ceramic, or lithium disilicate glass ceramic, the second base crown model M11, the second veneer model M10, and the cervical ring model M9 can be printed separately using 3D printing technology with different materials. Alternatively, CAD / CAM technology can be used to cut pre-made ceramic blocks into base crowns and cervical rings according to the second base crown model M11 and the cervical ring model M9, and then low-melting-point porcelain powder is attached to the base crowns and cervical rings, which are then sintered to form the veneer. Furthermore, resin cement can be used to bond the veneer, cervical ring, and base crown to form a dental crown.

[0216] After the simulated tooth root implant body, the coating, and the bone graft chamber are printed, they are subjected to heat treatment. After heat treatment, the internal residual stress is reduced, and the sample exhibits high strength and plasticity. Then, the support components from the molding process are removed, and the bottom of the support is smoothed using files and sandpaper until it meets the requirements. Subsequently, after sandblasting, cleaning, and sterilization, the simulated tooth root implant system is complete.

[0217] Furthermore, crown root screws, cheek tongue screws, nuts, washers, Maryland bridges, and clasps can be manufactured using 3D printing technology, CNC (Computerized Numerical Control, i.e., machining using a CNC lathe), or a combination of both.

[0218] In summary, the design and fabrication methods of the simulated tooth root implant system provided in this embodiment are based on the three-dimensional model M1 of the affected tooth obtained by scanning. This model more closely resembles a real tooth, simulating the force transmission characteristics and stress distribution characteristics of a natural molar. By using multiple roots, the occlusal stress is dispersed, resulting in strong anti-rotation performance. Furthermore, when the three-dimensional model M1 does not meet the set requirements, this embodiment will straighten the tooth root 103 of the three-dimensional model M1 and / or adjust the bifurcation angle, making it easier for the designed tooth root 103 to be positioned in the extraction socket, avoiding excessively large or small bifurcation angles, and reducing the difficulty of implantation. In addition, this embodiment also designs a coating model M4 and a bone graft chamber model M6. The coating model M4 is fitted onto the outer surface of the tooth root 103 of the reference model M2, and during implantation, it can be press-fitted into the extraction socket, contributing to initial post-implantation stability. The bone graft chamber model M6 is a shell model that can hold anti-inflammatory and growth-promoting drugs, contributing to short-term and long-term post-implantation stability. Both the coating model M4 and the bone graft chamber model M6 are porous, facilitating drug diffusion. Therefore, the simulated tooth root implant system formed using this embodiment not only simulates the force characteristics of a natural molar, dispersing occlusal stress and improving implant stability, but also reduces implantation difficulties through straightening and bifurcation angle treatment of the tooth root 103.

[0219] Furthermore, it should be understood that although the present invention has been disclosed above with reference to preferred embodiments, these embodiments are not intended to limit the present invention. For any person skilled in the art, many possible variations and modifications can be made to the technical solutions of the present invention based on the disclosed technical content, or equivalent embodiments can be modified accordingly, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, shall still fall within the scope of protection of the present invention.

Claims

1. A design method for a root-like implant system, characterized in that, The simulated tooth implant system is used for implantation at the site of a diseased tooth; the design method includes: Collect oral cavity data to obtain a three-dimensional model of the affected tooth; Determine whether the three-dimensional model meets the set requirements. If yes, use the three-dimensional model as the reference model. If no, straighten the tooth roots in the three-dimensional model and / or process the bifurcation angle, and use the processed three-dimensional model as the reference model. At least based on the tooth root in the reference model, a coating model is obtained that is fitted onto the outer surface of the tooth root; and a bone graft chamber model is obtained based on part or all of a single tooth root in the reference model, or based on a three-dimensional region between two or more tooth roots in the coating model, to form a pseudo-tooth root implant system with a coating and a bone graft chamber on the pseudo-tooth root. The method for obtaining the bifurcation angle includes: obtaining the projection lines of the central axis of each tooth root in the three-dimensional model on the coronal and sagittal planes, and calculating the angle between the projection lines of the central axes of every two tooth roots on the coronal or sagittal planes to obtain the bifurcation angle; and, The process of processing the bifurcation angle includes: Obtain a reference axis and a target axis, wherein the reference axis is the central axis of the tooth root that meets the set requirements or the central axis of the tooth root after straightening treatment, and the target axis is the central axis of the target tooth root to be treated; The reference axis and the target axis are both projected onto the coronal and sagittal planes, and an intersection point is formed between the projection lines of the reference axis and the target axis on the coronal or sagittal plane; Rotate the projection line of the target axis around the intersection point until the angle between the projection line of the target axis and the projection line of the reference axis meets the set requirements; and use the rotated target axis as the central axis of the tooth root after the bifurcation angle is processed.

2. The design method of the pseudo-dental implant system according to claim 1, characterized in that, The process of collecting oral data and obtaining a 3D model of the affected tooth includes: CBCT scans were used to collect dentition data, alveolar bone data, and gingival tissue data, in order to obtain at least a tissue model of the affected tooth, as well as an alveolar bone model and a gingival tissue model at the affected tooth. The tooth tissue model and the alveolar bone model are subjected to a Boolean intersection operation to obtain the tooth root in the three-dimensional model of the affected tooth; Perform a Boolean intersection operation between the affected tooth tissue model and the gingival tissue model to obtain the perforated portion in the three-dimensional model of the affected tooth; The affected tooth tissue model is subjected to Boolean subtraction with the gingival tissue model and the alveolar bone model to obtain the crown of the affected tooth in the three-dimensional model; The three-dimensional model of the affected tooth consists of the crown, the perforated portion, and the root connected sequentially along the crown-root direction.

3. The design method of the pseudo-dental implant system according to claim 2, characterized in that, When the crown of the affected tooth is missing or damaged, the crown of the opposite or symmetrical tooth of the affected tooth is obtained as the crown of the three-dimensional model of the affected tooth based on the dental arch data.

4. The design method of the pseudo-dental implant system according to claim 2, characterized in that, Multiple cross-sectional images of the affected tooth were obtained by CBCT scanning; and along the crown-root direction, each cross-sectional image corresponds to a planar image of the corresponding layer in the three-dimensional model. The process of determining whether the 3D model meets the set requirements includes: Based on the three-dimensional model and multiple cross-sectional images, starting from the layer closest to the crown in the root, the projection lines of the central connecting lines of each two adjacent layers are obtained sequentially in the coronal and sagittal planes, respectively, and the angle between the projection lines of the first two layers in the coronal or sagittal plane and the projection lines of the last two layers in the corresponding planes is calculated in each consecutive three layers. When the included angle is greater than or equal to 5°, the tooth root does not meet the set requirements; When all the included angles are less than 5°, the tooth root meets the set requirements.

5. The design method of the pseudo-dental implant system according to claim 4, characterized in that, The three-dimensional model of the affected tooth includes at least two roots; The process of determining whether the 3D model meets the set requirements also includes: When the bifurcation angle is less than 5° or greater than 15°, the bifurcation angle does not meet the set requirements; When the bifurcation angle is greater than or equal to 5° and less than or equal to 15°, the bifurcation angle meets the set requirements.

6. The design method of the pseudo-dental implant system according to claim 4, characterized in that, The method for straightening the tooth roots in the three-dimensional model includes: The middle layer of every three consecutive layers with an included angle greater than or equal to 5° is taken as the inflection point layer; Extract the cross-sectional image corresponding to the inflection point layer, and use the radial contour line of the tooth root in the cross-sectional image as the starting contour line; Based on the initial contour line, with the center connecting line of the inflection point layer and the layer adjacent to the inflection point layer and close to the crown direction as the reference axis, equidistant processing is performed in the direction pointing towards the tooth root to obtain at least one equidistant contour line. Perform a lofting basic operation on the initial contour line and all the equidistant contour lines to obtain a straightened tooth root.

7. The design method of the pseudo-dental implant system according to claim 6, characterized in that, During the equidistant processing, all the equidistant contour lines are sequentially reduced radially at equal intervals; wherein the size of each reduction ranges from 0.1 mm to 0.8 mm, and the minimum diameter of the last equidistant contour line is greater than or equal to 0.3 mm; the axial distance between the starting contour line and the last equidistant contour line ranges from 0.1 mm to 8 mm.

8. The design method of the pseudo-dental implant system according to claim 1, characterized in that, The process of forming the bone graft chamber model based on a portion of the tooth root in the reference model includes: When the reference model has a single tooth root, the placement area of ​​the bone graft chamber model is selected; Using the outer surface of the tooth root corresponding to the placement area as a reference plane, the reference plane is stretched along the radial direction of the tooth root and toward the side away from the tooth root to obtain a solid model of the bone graft chamber. Alternatively, a portion of a single tooth root can be extracted from the baseline model and used as the physical model of the bone graft chamber; The bone graft chamber solid model is subjected to inward shelling to obtain a bone graft chamber shell with a set thickness. The bone graft chamber shell is subjected to a porous treatment to obtain the bone graft chamber model that is disposed on the outer surface of the tooth root or replaces part of the tooth root.

9. The design method of the pseudo-dental implant system according to claim 8, characterized in that, The process of obtaining a coating model applied to the outer surface of the tooth root, based at least on the tooth root in the reference model, includes: When the reference model has a single tooth root and the bone graft chamber model is disposed on the outer surface of the tooth root, the tooth root in the reference model is cut off; A Boolean joint operation is performed between the solid model of the bone graft chamber located on the outer surface of the tooth root and the excised tooth root to obtain the solid model of the coating. The coated solid model is subjected to outward shelling to obtain a coated shell with a set thickness; The coated housing is subjected to a porousing process to obtain the coating model.

10. The design method of the pseudo-dental implant system according to claim 8, characterized in that, The process of obtaining a coating model applied to the outer surface of the tooth root, based at least on the tooth root in the reference model, includes: When the reference model has a single tooth root and the bone graft chamber model is obtained based on a portion of the single tooth root, or when the reference model has two or more tooth roots, the tooth root in the reference model is cut off to serve as the coating solid model; The coated solid model is subjected to outward shelling to obtain a coated shell with a set thickness; The coated housing is subjected to a porousing process to obtain the coating model.

11. The design method of the pseudo-dental implant system according to claim 10, characterized in that, The process of obtaining a bone graft chamber model based on the three-dimensional region between two or more tooth roots in the coating model includes: The tooth root of the reference model is nested into the coating model; The baseline model and the coating model are converted into point cloud format, and all points are connected to each other to obtain the minimum envelope surface; Perform a Boolean subtraction operation between the minimum envelope surface and the reference model overlaid with the coating model, and the remaining minimum envelope surface is the solid model of the bone graft chamber; The bone graft chamber solid model is subjected to inward shelling to obtain a bone graft chamber shell with a set thickness. The shell of the bone graft chamber is subjected to a porous treatment to obtain the bone graft chamber model.

12. The design method of the pseudo-dental implant system according to any one of claims 8 to 11, characterized in that, The porosification process includes: Multiple support units are selected, and all the support units are arranged in an infinite array in three-dimensional space; wherein, the support units are porous structures. The coated shell or the bone graft chamber shell is subjected to a Boolean intersection operation with the plurality of support units to form a porous structure.

13. The design method of the pseudo-dental implant system according to claim 9 or 10, characterized in that, The plane containing the crown of the coating model is located on the side of the plane containing the crown of the tooth root in the reference model that is away from the crown, and the axial distance between the plane containing the crown of the coating model and the plane containing the crown of the tooth root in the reference model is 0.1 mm to 1 mm.

14. The design method of the pseudo-dental implant system according to claim 9 or 10, characterized in that, When the reference model has a single tooth root, an opening is formed in the coating model to expose at least a portion of the bone graft chamber model when the reference model and the bone graft chamber model are nested within the coating model.

15. The design method of the pseudo-dental implant system according to claim 9 or 10, characterized in that, The porosity of the coating model ranges from 30% to 80%, and the pore size ranges from 100 micrometers to 1000 micrometers.

16. The design method of the pseudo-dental implant system according to claim 9 or 10, characterized in that, The set thickness of the coating shell is in the range of 0.2 mm to 2 mm.

17. The design method of the pseudo-dental implant system according to claim 8 or 11, characterized in that, The porosity of the bone graft chamber model ranges from 80% to 90%, and the pore size ranges from 1000 micrometers to 1400 micrometers.

18. The design method of the pseudo-dental implant system according to claim 8 or 11, characterized in that, The thickness of the bone graft chamber shell is set to be between 0.3 mm and 0.7 mm.

19. The design method of the pseudo-dental implant system according to claim 1, characterized in that, The design method further includes: Obtain the crown from the reference model and shell the crown inward to obtain the second crown; wherein, the crownmost surface of the second crown is the crownmost surface of the abutment; Select a plane that is perpendicular to the central axis of the second crown; Along the direction of the central axis of the second crown, the plane intersects with the second crown to obtain the minimum intersection profile and the maximum intersection profile; Using the plane where the minimum intersection contour line is located as the reference plane, stretch along the central axis toward the root side until it intersects with the coronal surface where the transgingival portion is located in the reference model to form an abutment; Alternatively, using the minimum intersecting contour line as the starting contour line and the maximum intersecting contour line as the ending contour line, perform the basic lofting operation to form the base.

20. The design method of the pseudo-dental implant system according to claim 1, characterized in that, The design method further includes: Remove the crowns from the reference model to form an implant platform on the crown side of the remaining reference model; A region is selected at the center of the implant platform, and the surface of the region is stretched toward the crown side to form an abutment protruding from the implant platform; Adjust the shape of the side wall of the base so that the angle between the side wall of the base and the planting platform meets the set requirements; Adjust the coronal surface of the abutment so that the coronal surface of the abutment has the same surface profile as the coronal surface of the crown in the reference model; The abutment and the remaining reference model together form a pseudo-dental implant body model.

21. The design method of the pseudo-dental implant system according to claim 19 or 20, characterized in that, The axial length of the abutment is less than the axial length of the crown; the radial length of the abutment is less than the radial length of the crown; and the angle between the projection line of the abutment's sidewall in the coronal or sagittal plane and the cross-section is required to be within the range of 90°-150°.

22. The design method of the pseudo-dental implant system according to claim 19 or 20, characterized in that, The design method further includes: The crown in the reference model is shelled inward; wherein, in executing the shelling command, it is set to retain the crown in the reference model to obtain a first porcelain model; or it is set not to retain the crown in the reference model to obtain a first base crown model. Perform a Boolean subtraction operation between the first basal crown model and the abutment to obtain the second basal crown model; Using the bottom surface of the first decorative porcelain model as a reference plane, a portion of the first decorative porcelain model with a set thickness is cut off towards the crown to serve as a neck ring model; Perform a Boolean subtraction operation between the neck ring model and the first decorative porcelain model to obtain the second decorative porcelain model; The neck ring model and the second basal crown model are combined using a Boolean addition operation to obtain the third basal crown model; The crown model includes a second base crown model, a second porcelain model, and a cervical ring model; the second porcelain model and the cervical ring model are both fitted onto the outer surface of the second base crown model, and the cervical ring model is in contact with the bottom surface of the second porcelain model. Alternatively, the crown model may include a third base crown model and a second porcelain veneer model; the second porcelain veneer model is fitted onto the outer surface of the third base crown model.

23. The design method of the pseudo-dental implant system according to claim 22, characterized in that, The thickness of the neck ring model is set to be between 0.3 mm and 3 mm.

24. The design method of the pseudo-dental implant system according to claim 22, characterized in that, The design method further includes: selecting a Maryland bridge model or a clasp model connected to the second porcelain model based on the oral cavity data.

25. The design method of the pseudo-dental implant system according to claim 21, characterized in that, The design method further includes: A simulated screw model is selected; and the shank of the simulated screw model is a hollow cylinder. The root of the simulated tooth implant body model is nested into the coating model, and the bone graft chamber model is placed in the three-dimensional region; The simulated screw model is placed in the simulated tooth root implant body model along the crown-root direction, so that the simulated screw model coincides with the central axis of the simulated tooth root implant body model, the top of the simulated screw model is located inside the abutment, and the shank of the simulated screw model penetrates the coating model and the bone graft chamber model; or, the simulated screw model is placed through the bone graft chamber model along the buccal-lingual direction. When the simulated screw model is set along the crown root direction, the simulated screw model is subjected to Boolean subtraction with the simulated tooth root implant body model and the coating model, and Boolean intersection with the bone graft chamber model, so that a screw channel is formed in the simulated tooth root implant body model, a through hole is formed in the coating model, and two guide ring models opposite to each other along the crown root direction are formed in the bone graft chamber model. When the simulated screw model is set along the buccal-tongue direction, the simulated screw model and the bone graft chamber model are subjected to a Boolean intersection operation, so that two guide ring models opposite each other along the buccal-tongue direction are formed in the bone graft chamber model.

26. The design method of the pseudo-dental implant system according to claim 25, characterized in that, The design method further includes: designing a screw model arranged along the crown root direction and a screw model arranged along the cheek tongue direction; wherein, the shank of the screw model is provided with a self-tapping thread, and the maximum diameter of the shank of the screw model is equal to the inner diameter of the shank of the imitation screw model; The screw model, arranged along the buccal-lingual direction, is also equipped with a nut model and a washer model; the washer model is fitted onto the shank of the screw model and connected to the head end of the screw model; the side of the washer model away from the head end of the screw model and the side of the nut model near the head end of the screw model are fitted with a portion of the side of the alveolar bone at the affected tooth.

27. A method for preparing a root-like implant system, characterized in that, The simulated tooth root implant system designed by the design method of the simulated tooth root implant system as described in any one of claims 1 to 26 is prepared using 3D printing technology and / or CNC technology.

28. The method for preparing the pseudo-dental implant system according to claim 27, characterized in that, The coating and the bone graft chamber are made of titanium alloy or shape memory material, respectively.

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