Manufacturing method of cavity preparation guide plate for autologous tooth transplantation operation

Abstract

The invention discloses a manufacturing method of an autologous tooth transplantation operation cavity preparation guide plate. The manufacturing method comprises the following steps: S1, obtaining digital models of a transplanted tooth donor, a transplanted tooth and an alveolar bone, and respectively printing solid models; s2, preparing a hole in the alveolar bone entity model to simulate transplantation; s3, scanning the alveolar bone solid model after hole preparation to obtain an alveolar bone digital model after hole preparation; s4, registering and overlapping the two alveolar bone digital models before and after hole preparation to obtain the difference of the states of the alveolar bone before and after hole preparation, and modeling according to the amount of the ground bone during hole preparation to obtain a bone grinding amount digital model; s5, designing a bone grinding guide plate model through the prismoid and the cone; s6, simulating placement of the bone grinding guide plate model, and trimming the position, shielded by the alveolar fossa, of the bone grinding guide plate model; and S7, designing side wings and combining the side wings with the bone grinding guide plate model. Compared with the prior art, the method has the advantages that the fitting rate of the transplanted tooth donor and the alveolar socket and the success rate of one-time implantation and in-place of the transplanted tooth donor are improved.

Description

Technical Field

[0001] This invention relates to the field of dental transplantation technology, and in particular to a method for fabricating a surgical guide for preparing a cavity in autologous tooth transplantation. Background Technology

[0002] Autologous tooth transplantation is a technique that involves transplanting a donor tooth to a recipient site within the same body. Clinically, autologous tooth transplantation is commonly used to treat tooth loss caused by caries, periodontitis, pulpitis, or trauma. The recipient site can be an alveolar socket that is immediately extracted or one that has been surgically prepared. In recent years, digital surgical guides have been widely used in autologous tooth transplantation. Patent CN110236712B discloses a surgical guide for preparing an alveolar socket for autologous tooth transplantation and its manufacturing method. It uses computer-generated virtual design of the donor tooth position to design the surgical guide or surgical guide assembly to guide the preparation of the recipient alveolar socket. However, some uncertainties still exist in this procedure. This includes difficulties for surgeons in determining the optimal position and occlusion of the donor tooth during surgery, which prolongs the operation time; secondly, the fit between the donor tooth and the recipient tooth socket is not high enough, there is a lack of placement simulation process, the cylindrical channel combination covers the neck and root of the tooth but does not take into account tolerance issues, and cannot guarantee that the transplant tooth donor model can be implanted in one go; the designed guide plate does not involve limiting the working depth of the drill bit, and there is a risk of preparing too deep during the preparation of the transplant socket, which reduces the accuracy. Summary of the Invention

[0003] This invention provides a method for fabricating a surgical guide for preparing the alveolar socket during autogenous tooth transplantation, which solves the problems of poor fit with the alveolar socket and low feasibility of single-stage implantation during existing autogenous tooth transplantation procedures.

[0004] This invention provides a method for fabricating a surgical cavity preparation guide for autologous tooth transplantation, comprising the following steps:

[0005] S1: Digital models of the transplant donor, transplanted tooth, and alveolar bone are obtained through scanning, and physical models of the transplant donor, transplanted tooth, and alveolar bone are made according to the digital models; data on the patient's open-mouth gingiva and crowns are collected using an optical intraoral scanner, and occlusal data are obtained by scanning.

[0006] S2: Simulate transplantation on a solid alveolar bone model, prepare the cavity step by step, and obtain the alveolar socket of the recipient area in the solid alveolar bone model.

[0007] S3: Obtain a solid model of the alveolar bone after successful cavity preparation by scanning with CBCT, and then create a digital model of the alveolar bone after cavity preparation.

[0008] S4: Register and overlap the two alveolar bone digital models before and after cavity preparation to obtain data on the difference in state of alveolar bone before and after cavity preparation. Then, model the amount of bone removed during cavity preparation based on the alveolar bone solid model to obtain a digital model of bone removal amount.

[0009] S5: Fit the bone grinding straight drill with a prism of the same diameter, place the prism according to the wall thickness of the bone grinding digital model, fit the diameter and working depth of the straight drill, fit the inner surface of the alveolar socket in front of the bone grinding cavity with a cone, and design a bone grinding guide plate model for alveolar bone preparation.

[0010] S6: Place the simulated bone guide plate model into the alveolar socket of the implant area, and subtract the parts of the bone guide plate model whose bottom and side walls are covered by the alveolar socket of the implant area along the placement direction.

[0011] S7: Design a wing for fixing to a tooth adjacent to the transplanted tooth, and incorporate the wing into the bone guide plate model in step S6.

[0012] Preferably, in step S7, the donor physical model of the transplant tooth is transplanted onto the prepared alveolar bone physical model and scanned together with it using CBCT. Then, a digital model of the alveolar bone after the transplant tooth donor is in place is created. The digital model of the alveolar bone after the transplant tooth donor is in place is registered and overlapped with the digital model of the alveolar bone before the preparation of the cavity to obtain the digital model A of the alveolar bone after the transplant tooth donor is in place. Then, the digital model of the transplant tooth donor is registered and overlapped with the transplant tooth donor on the digital model A of the alveolar bone to obtain the digital model B of the alveolar bone after the transplant tooth donor is in place. Then, the digital model of the maxilla and mandible in occlusion state acquired by the intraoral optical scanner is registered and overlapped with the digital model B of the alveolar bone after the transplant tooth donor is in place to obtain the digital model C of the alveolar bone. A wing for fixing to the tooth adjacent to the transplant tooth donor is designed on the digital model C of the alveolar bone.

[0013] Preferably, in step S7, the bone guide plate model obtained in step 6 is placed on the transplanted tooth donor on the alveolar bone digital model C, and the fixation reference area is selected according to the bone guide plate model and the alveolar bone digital model C to obtain the wing model.

[0014] Preferably, after step S7, the following steps are also included: finding the spatial positional relationship of the transplant tooth donor through the alveolar bone digital model C, obtaining preoperative occlusal status data, and then designing a repositioning occlusal guide model based on the preoperative occlusal status data.

[0015] Preferably, the spatial relationships of the transplant tooth donor include: the relationship between the transplant tooth donor and the mucosa, the relationship between the transplant tooth donor and adjacent teeth, the relationship between the transplant tooth donor and the alveolar bone, and the relationship between the transplant tooth donor and the opposing tooth.

[0016] Preferably, after step S7, the following steps are also included: on the digital model of alveolar bone C, the intersection boundary between the digital model of the transplanted tooth donor and the mucosa is found, the intersection boundary is fitted with a circular arc, and a mucosal trephine drill of the corresponding diameter is selected by measuring the diameter of the intersection boundary; then the axial direction of the neck and root of the transplanted tooth donor after re-registration and overlap is fitted as the direction of the mucosal trephine drill cutting, the fixation point of the mucosal trephine drill guide plate is determined, and then the mucosal trephine drill guide plate model is designed according to the fixation point and the direction of the mucosal trephine drill cutting.

[0017] Preferably, in step S2, the occlusal surface of the transplant tooth donor model is adjusted according to the occlusal state data obtained in step S1 and the cavity preparation process of the alveolar bone solid model in step S2, so that it meets the needs of clinical occlusal reconstruction, and the cavity preparation is completed.

[0018] Preferably, in step S2, the transplanted tooth donor model is implanted into the prepared cavity of the alveolar bone model based on the buccal and lingual directions of the transplanted tooth donor model.

[0019] Preferably, in step S4, the digital model of the alveolar bone after cavity preparation is registered and overlapped with the digital model of the alveolar bone before cavity preparation, and then the difference in the state of the alveolar bone before and after cavity preparation is solved by Boolean subtraction.

[0020] Preferably, in step S6, when the simulated bone guide plate model is placed into the alveolar socket of the implantation area, the direction in which the bone guide plate model is placed is perpendicular to the bottom of the alveolar socket of the implantation area before the cavity is prepared or parallel to the side wall of the alveolar socket.

[0021] Compared with the prior art, in this invention, a solid model of alveolar bone, a solid model of transplanted tooth donor, and a solid model of transplanted tooth are printed separately. Then, a cavity is prepared on the solid model for simulated transplantation, so that it meets the requirements of clinical occlusal reconstruction. Then, modeling was performed again. By registering and overlapping the digital model of the alveolar bone after cavity preparation and the digital model of the alveolar bone before cavity preparation, the difference in the state of the alveolar bone before and after cavity preparation was analyzed, and the amount of bone removed during cavity preparation was obtained. Based on the amount of bone removed, a digital model of the bone removal volume was obtained. Then, based on the wall thickness of the digital model of the bone removal volume, a prism was used to fit the bone grinding straight drill, and a cone was used to fit the inner surface of the alveolar socket of the recipient area before cavity preparation. Finally, it was merged with the lateral wings fixed on the adjacent teeth of the transplanted tooth to obtain the bone grinding guide model. This design achieved feature matching and curvature matching between the bone grinding guide model and the alveolar socket, improved the fit between the cavity opening and the neck of the transplanted tooth, improved the fit rate between the transplanted tooth donor and the alveolar socket, and increased the success rate of transplantation in one attempt. The cavity preparation and transplantation time was shortened to 5-8 minutes, the waiting time after transplanted tooth donor removal was reduced, and the survival rate and long-term efficacy of autologous tooth transplantation were improved. The entire process of autologous tooth transplantation was basically digitized. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a flowchart of the process of the present invention;

[0024] Figure 2 This is a schematic diagram of a CBCT scan of the oral cavity according to the present invention;

[0025] Figure 3 This is a distribution diagram of the transplanted teeth and the transplanted tooth donors in this invention;

[0026] Figure 4 This is a digital model diagram of the alveolar bone, the transplanted tooth, and the transplanted tooth donor of the present invention.

[0027] Figure 5 This is a solid model diagram of the alveolar bone, the transplanted tooth, and the transplanted tooth donor according to the present invention.

[0028] Figure 6 This is a schematic diagram of the alveolar bone solid model during cavity preparation and transplantation according to the present invention.

[0029] Figure 7 This is a schematic diagram of the structure of the transplanted tooth donor physical model after the occlusal surface has been adjusted and positioned according to the present invention.

[0030] Figure 8 This is a digital model of the alveolar bone after the cavity has been prepared according to the present invention;

[0031] Figure 9 A schematic diagram of the registration and overlapping of digital models of alveolar bone before and after cavity preparation in this invention;

[0032] Figure 10 A schematic diagram of the structure established by the digital model of bone grinding volume of the present invention;

[0033] Figure 11 This is a structural schematic diagram of the wall thickness of the digital model for bone grinding volume in this invention;

[0034] Figure 12 This is a schematic diagram of the structure of the present invention simulating the placement of a bone-grinding straight drill;

[0035] Figure 13 This is a schematic diagram of the structure of the proximal control type guide plate adjusting prism holder of the present invention;

[0036] Figure 14 This is a schematic diagram of the structure of fitting an alveolar socket with a cone according to the present invention;

[0037] Figure 15 This is a schematic diagram illustrating the relationship between the prism and adjacent teeth in this invention.

[0038] Figure 16 This is a schematic diagram of the side wing model design of the present invention;

[0039] Figure 17 This is a schematic diagram of the structure of the digital model of the bone grinding guide plate of the present invention;

[0040] Figure 18 This is a schematic diagram of the structure of the digital model of the alveolar bone after the removal of the transplanted tooth donor according to the present invention.

[0041] Figure 19 This is a schematic diagram of the structure of the alveolar bone digital model after the transplanted tooth donor is in place according to the present invention.

[0042] Figure 20 This is a schematic diagram of the structure of the alveolar bone digital model A obtained by registering and overlapping the overall model after the transplanted tooth donor is in place according to the present invention.

[0043] Figure 21 A schematic diagram of the structure of the digital alveolar bone model B obtained by registration and overlap of the transplanted tooth donor in this invention;

[0044] Figure 22 This is a schematic diagram of the structure of the digital alveolar bone model C of the present invention;

[0045] Figure 23 This is a schematic diagram of the resetting engagement guide plate design of the present invention;

[0046] Figure 24 This is a schematic diagram of the position of the transplanted tooth donor and the mucosa in this invention;

[0047] Figure 25 This is a schematic diagram of the axial structure of the transplant tooth donor of the present invention;

[0048] Figure 26 This is a schematic diagram of the structure of the guide plate design for the mucosal circumferential drilling of the present invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0050] See attached document Figure 1 This embodiment provides a method for fabricating a surgical cavity preparation guide for autologous tooth transplantation, comprising the following steps:

[0051] S1: The patient's oral cavity data was acquired using CBCT (cone-beam computed tomography) and then exported in DICOM format with a slice thickness of 0.13–0.25 mm. The DICOM data was imported into medical image processing software, which was used to segment the proposed third molar or impacted tooth (i.e., the donor tooth, selected through morphological comparison), the transplanted tooth, and the alveolar bone (recipient). The resulting data was then exported in STL format, which included digital models of the donor tooth, the transplanted tooth, and the alveolar bone. The STL data was then output to a 3D printer to create physical models of the donor tooth, the transplanted tooth, and the alveolar bone. An optical intraoral scanner was used to acquire data on the patient's open-mouth gingiva and crowns (clinically measuring mouth opening), and occlusal data was obtained. This design allowed for the acquisition of occlusal data, which, after registration and overlap, enabled adjustments to the occlusal gap height and occlusal position. Secondly, after processing the intraoral data obtained by using an optical scanner into a high-precision model, the guide plate is then tested, which can more realistically reflect the intraoral condition and the degree of guide plate placement and fit.

[0052] Specifically, solid models of the transplant tooth donor, the transplanted tooth, and local alveolar bone are fabricated using a light-cured resin 3D printing (Digital Light Processing) device.

[0053] S2: Simulate transplantation on a solid alveolar bone model, preparing the cavity step by step (shaping the alveolar socket of the transplanted tooth). While maintaining the original buccal and lingual orientation of the donor tooth model as much as possible, implant it into the alveolar socket (recipient alveolar socket) after preparation in the solid alveolar socket model. Based on the occlusal data obtained in step S1, ensure that the crown height of the donor tooth model is close to that of the adjacent teeth and the transplanted tooth, and that the neck height of the donor tooth model is as close as possible to the oral height of the recipient alveolar socket in the solid alveolar bone model. That is, adjust the occlusal surface of the donor tooth model. This process requires slow and repeated trial implantation until the donor tooth model can be quickly positioned, does not spontaneously fall out of the prepared cavity when inverted, and meets the clinical requirements for occlusal reconstruction. This completes the cavity preparation. Confirming the occlusal degree during the simulated transplantation means that no adjustment of the occlusion is needed during the subsequent surgical transplantation, which helps to reduce the operation time and increase the success rate of the first transplant.

[0054] S3: After successful cavity preparation, the alveolar bone solid model is scanned by CBCT, and then the DIOCM data is exported. The digital model of the alveolar bone after cavity preparation is obtained by modeling based on the DIOCM data.

[0055] S4: Register and overlap the digital model of alveolar bone after cavity preparation (moving side) with the digital model of alveolar bone before cavity preparation (fixed side) (register according to anatomical feature points and global surface features, with an error of less than 0.1mm). Then, solve the data of the difference between the state of alveolar bone before and after cavity preparation by Boolean subtraction. Based on the data of the difference between the state of alveolar bone before and after cavity preparation, obtain the amount of bone removed during cavity preparation of the alveolar bone solid model. Then, model the amount of bone removed during cavity preparation of the alveolar bone solid model to obtain the digital model of bone removal. Analyze the wall thickness of the digital model of bone removal through the digital model of bone removal.

[0056] S5: Fit the bone-grinding straight drill using prisms of the same diameter. Place the prisms one by one according to the wall thickness of the digital model of bone grinding volume, and then fit them according to the diameter and working depth of the straight drill. Fit the inner surface of the alveolar socket before bone grinding with a cone. Design a bone grinding guide plate model for alveolar bone preparation. The bone grinding guide plate model is divided into proximal control of the depth of the bone grinding straight drill and distal control of the depth of the bone grinding straight drill. Generally, the distal control of the bone grinding guide plate has a lower requirement for mouth opening, while the proximal control of the bone grinding guide plate has a higher requirement for mouth opening. The mouth opening can be calculated and designed based on the mouth opening measured in step S1.

[0057] S6: When designing the bone resurfacing guide model, a simulation of its placement is required. The bone resurfacing guide model should be placed perpendicular to the bottom of the alveolar socket in the implantation area or parallel to the sidewall of the alveolar socket. This design involves subtracting the portion of the bone resurfacing guide model whose bottom and sidewalls are obscured by the alveolar socket along the placement direction. This is because the sidewalls and bottom of the alveolar socket are uneven. This structural design ensures that the 3D-printed bone resurfacing guide model can be smoothly positioned at the bottom of the alveolar socket, ensuring a good fit between the bone resurfacing guide model and the alveolar socket. If the sidewalls of the cavity preparation and the mouth are relatively straight, the simulation of the placement of the bone resurfacing guide model can be placed as the last step in designing the bone resurfacing guide model. If the sidewalls of the cavity preparation and the mouth have a large curvature and significant bending, the simulation of the placement of the bone resurfacing guide model should be performed first to ensure that the bottom of the designed bone resurfacing guide model is not too small. When it is not possible to design a distally controlled bone resurfacing guide model, and only a proximal controlled bone resurfacing guide model can be designed, this is disadvantageous for patients with poor mouth opening.

[0058] Among them, if the wall thickness of the digital model for bone grinding is less than 0.2mm and the upper and lower ranges are missing, it is advisable to not place or place fewer prisms.

[0059] S7: Design a wing for fixing to teeth adjacent to the transplanted tooth, incorporate the wing into the bone reshaping guide model from step S6, and then fabricate the bone reshaping guide based on the model. One implementation: Design a wing on the alveolar bone before cavity preparation. Through this structural design, the bone reshaping guide model includes a prism, a cone, and a wing. The cone is fixed within the alveolar socket, and the wing is fixed to the adjacent tooth. This double fixation ensures good stability of the fabricated bone reshaping guide during bone reshaping, facilitating rapid and precise cavity preparation in the recipient area.

[0060] Another implementation of the wing design: In step S7, the donor tooth model is transferred to the prepared alveolar bone model and scanned together using CBCT. The DIOCM data is then exported, and a digital model of the alveolar bone after donor tooth placement is obtained using medical image processing software. This digital model is then registered and overlapped with the pre-prepared alveolar bone digital model (fixed side) to obtain digital model A of the alveolar bone after donor tooth placement. Next, the donor tooth digital model is registered and overlapped with the donor tooth on alveolar bone digital model A to obtain digital model B of the alveolar bone after donor tooth placement, thus obtaining data on the donor tooth's post-placement state. Then, the digital models of the maxilla and mandible in occlusal state acquired by an intraoral optical scanner are registered and overlapped with digital model B (fixed side) of the alveolar bone after donor tooth placement to obtain digital model C of the alveolar bone. A wing for fixing to adjacent teeth of the donor tooth is designed on alveolar bone digital model C. In this structural design, the digital models of the maxilla and mandible in occlusal state acquired by the intraoral optical scanner can be registered and overlapped with the digital model of the alveolar bone before the cavity preparation to obtain a digital model of the alveolar bone with less error. Then, the digital model of the alveolar bone after the transplant tooth donor is in place is registered and overlapped with the digital model of the alveolar bone with less error, and the subsequent registration and overlap remain unchanged.

[0061] Specifically, in step S7, the bone guide model obtained in step 6 is placed on the transplanted tooth donor on the alveolar bone digital model C. A retention reference area is selected based on the bone guide model and the alveolar bone digital model C to obtain the wing model. In step S7, the designed wing is fixed to the lateral surface of the adjacent tooth crown and the occlusal surface, but it does not completely cover the tooth to avoid situations where installation is not possible.

[0062] In another embodiment of the present invention, after step S7, the following steps are also included: finding the spatial positional relationship of the transplant tooth donor through the alveolar bone digital model C to obtain preoperative occlusal state data; then designing a repositioning occlusal guide model based on the preoperative occlusal state data; and fabricating the repositioning occlusal guide model. In actual surgery, after the transplant tooth donor model or the transplant tooth donor is positioned in the alveolar socket, the repositioning occlusal guide is used to fine-tune the height difference between the transplant tooth donor and adjacent teeth, and the micro-rotation of the buccal and lingual surfaces, to ensure that the state of the transplant tooth donor after positioning during actual operation is consistent with the state designed in the computer and during surgical simulation.

[0063] By repositioning the occlusal guide, it is convenient to fine-tune the occlusion and spatial position of the transplant tooth donor during the operation to keep it consistent with the virtual design.

[0064] Specifically, the spatial relationships of transplant tooth donors include: the relationship between the transplant tooth donor and the mucosa, the relationship between the transplant tooth donor and adjacent teeth, the relationship between the transplant tooth donor and the alveolar bone, and the relationship between the transplant tooth donor and the opposing tooth.

[0065] In another embodiment of the present invention, after step S7, the following steps are also included: On the digital model of alveolar bone C, the intersection boundary between the digital model of the transplant tooth donor and the mucosa is found, and the intersection boundary is fitted with a circular arc. A mucosal circumferential cutting drill of the appropriate diameter is selected by measuring the diameter of the intersection boundary. Then, the axial direction of the neck and root of the transplant tooth donor after re-registration and overlap is fitted as the direction of the mucosal circumferential cutting drill, and the fixation point of the mucosal circumferential cutting drill guide is determined. Then, the mucosal circumferential cutting drill guide model is designed according to the fixation point and the direction of the mucosal circumferential cutting drill, and the mucosal circumferential cutting drill guide model is used to fabricate the mucosal circumferential cutting drill guide. The mucosa is circumferentially cut using the mucosal circumferential cutting drill guide. This design facilitates soft tissue cuff formation and fits the neck of the transplant tooth donor.

[0066] During surgery, based on the preoperative assessment, if the minimally invasive extraction of the donor tooth is simple, the cavity is prepared before extraction. That is, the transplanted tooth and its remaining roots are extracted first (minimally invasive extraction) to reduce scraping, compression, and deformation of the alveolar socket, facilitating the placement of the bone guide plate. The main goal is precise and rapid cavity preparation, using the bone guide plate to gradually prepare the cavity (making it fresh), and using a physical model of the transplanted tooth for trial implantation (minimizing the use of the transplanted tooth for testing to reduce the impact on the periodontal ligament and mucosa). If the minimally invasive extraction of the donor tooth is more difficult, or if it is the only transplanted tooth donor, or if there are important blood vessels and nerves nearby, the tooth is extracted first, followed by cavity preparation. The main goal is to ensure the integrity of the transplanted tooth donor and precise and rapid cavity preparation (reducing the time the transplanted tooth donor is removed from the body); and to improve the success rate of single-time implantation of the transplanted tooth donor.

[0067] The donor tooth for transplantation is obtained through minimally invasive tooth extraction (temporarily stored in saline solution). After testing that the tooth is fully in place, a repositioning guide is used, with the adjacent tooth as a fixation point, to finely adjust the buccal and lingual surfaces of the donor tooth for transplantation and the depth of transplantation.

[0068] The mucosa is sutured elastically to fix the transplanted tooth donor and maintain immediate stability. Postoperative follow-up is conducted at least once a month, including pulp vitality testing, and small dental X-rays and CBCT to monitor osseointegration.

[0069] In this invention, a solid model of alveolar bone, a solid model of the transplanted tooth donor, and a solid model of the transplanted tooth are printed respectively. Then, a cavity is prepared on the solid model for simulated transplantation to make it meet the requirements of clinical occlusal reconstruction. Then, modeling was performed again. By registering and overlapping the digital model of the alveolar bone after cavity preparation and the digital model of the alveolar bone before cavity preparation, the difference in the state of the alveolar bone before and after cavity preparation was analyzed, and the amount of bone removed during cavity preparation was obtained. Based on the amount of bone removed, a digital model of the bone removal volume was obtained. Then, based on the wall thickness of the digital model of the bone removal volume, a prism was used to fit the bone grinding straight drill, and a cone was used to fit the inner surface of the alveolar socket of the recipient area before cavity preparation. Finally, it was merged with the lateral wings fixed on the adjacent teeth of the transplanted tooth to obtain the bone grinding guide model. This design achieved feature matching and curvature matching between the bone grinding guide model and the alveolar socket, improved the fit between the cavity opening and the neck of the transplanted tooth, improved the fit rate between the transplanted tooth donor and the alveolar socket, and increased the success rate of transplantation in one attempt. The cavity preparation and transplantation time was shortened to 5-8 minutes, the waiting time after transplanted tooth donor removal was reduced, and the survival rate and long-term efficacy of autologous tooth transplantation were improved. The entire process of autologous tooth transplantation was basically digitized.

[0070] Case study of bone grinding guide plate fabrication:

[0071] CBCT was used to collect the patient's oral cavity data, as shown in the appendix. Figure 2 View CBCT images using Onis 2.5 Free Edition. (See attached document.) Figure 3 The patient's tooth 47 has a distal buccal crown defect and a fractured mesial crown, requiring transplantation. Tooth 48 is essentially normal and can be used as a transplant donor.

[0072] See attached document Figure 4 CBCT data is imported into MIMICS for reconstruction, resulting in a digital model of the alveolar bone, a digital model of the transplanted tooth, and a digital model of the transplanted tooth donor. The digital model of the alveolar bone includes digital models of the maxilla and mandible.

[0073] See attached document Figure 5 Based on the digital model of alveolar bone, the digital model of the transplanted tooth, and the digital model of the transplanted tooth donor, solid models of the transplanted tooth donor, the transplanted tooth, and the alveolar bone are respectively processed using 3D printing equipment. The material of the solid models is resin.

[0074] See attached document Figure 6 A cavity was prepared in the alveolar bone model of the recipient area (the alveolar socket of tooth 47) to allow for the implantation of the donor tooth model (tooth 48). During the implantation process, the donor tooth model was implanted according to its original buccal and lingual surfaces.

[0075] See attached document Figure 7 The base of the jawbone of the donor tooth model is adjusted using occlusal data collected by an intraoral optical scanner. The occlusal surface of the donor tooth model is made close to that of the adjacent teeth to meet the needs of clinical occlusal reconstruction, thus completing the cavity preparation.

[0076] See attached document Figure 8 A solid model of the alveolar bone after successful cavity preparation was obtained by using CBCT scanning, and then modeling was performed to obtain a digital model of the alveolar bone after cavity preparation.

[0077] See attached document Figure 9 The alveolar bone digital model after cavity preparation (moving side) is registered and overlapped with the alveolar bone digital model before cavity preparation (fixed side). That is, the alveolar bone digital model before cavity preparation is used as the reference, and the alveolar bone digital model after cavity preparation is moved for registration and overlap. Then, Boolean calculation is used to obtain the data on the difference in state of the alveolar bone solid model before and after cavity preparation.

[0078] See attached document Figure 10 Boolean subtraction is used to solve the difference in the state of alveolar bone before and after cavity preparation, and the amount of bone removed during cavity preparation is obtained. A digital model of the amount of bone removed during cavity preparation is then created based on the amount of bone removed during cavity preparation.

[0079] See attached document Figure 11 The wall thickness of the digital model of bone grinding is analyzed to visualize the specific wall thickness and distribution, thus providing an intuitive basis for whether or not to place a prism to fit the bone grinding straight drill.

[0080] See attached document Figure 12 Based on the wall thickness of the digital model of bone grinding, a prism is used to simulate the position of the straight drill, so that the prism completely occupies the wall thickness of the digital model of bone grinding.

[0081] The digital model of the bone grinding guide is adjusted by changing the position of the prism, ensuring that the distal end of the digital model controls the working depth while the proximal end remains roughly flush. (See attached image) Figure 13 The digital model of the bone grinding guide plate is a proximal control type guide plate. In this model, the length of the prism in the guide plate is consistent with the actual working depth of the straight drill. After the bone grinding straight drill is inserted into place, it will be held in place by the proximal end of the guide plate.

[0082] See attached document Figure 14The transplanted tooth is virtually removed, and then the inner wall of the alveolar socket where the transplanted tooth is located is extracted. The inner surface of the alveolar socket (where the transplanted tooth is located) before the bone preparation is fitted with a cone. The digital model of the bone guide plate includes a cone and a prism, with the prism distributed on the outside of the cone.

[0083] See attached document Figure 18 The donor tooth to be transplanted is removed from the digital model of the alveolar bone before the cavity is prepared.

[0084] See attached document Figure 19 After transplanting the donor tooth model onto the alveolar bone model, CBCT scanning was performed, followed by modeling to obtain a digital model of the alveolar bone after the donor tooth was in place. (See attached figure.) Figure 20 The alveolar bone digital model after the transplant tooth donor is in place is registered and overlapped with the alveolar bone digital model (fixed side) reconstructed from the patient's oral cavity data acquired by CBCT. This yields alveolar bone digital model A after the transplant tooth donor is in place. At this point, alveolar bone digital model A is a single entity, and the transplant tooth donor within alveolar bone digital model A cannot be adjusted individually.

[0085] See attached document Figure 21 Then, the digital model of the transplant donor tooth (moving side) reconstructed from the patient's oral cavity data acquired by CBCT is registered and overlapped with the transplant donor tooth on the alveolar bone digital model A to obtain the alveolar bone digital model B after the transplant donor tooth is in place. At this time, the transplant donor tooth on the alveolar bone digital model B can be freely adjusted along its axis. See Appendix Figure 22 The digital models of the maxilla and mandible in occlusal state, acquired by an intraoral optical scanner, were registered and overlapped with the digital model B of the alveolar bone after the transplant tooth donor was in place, to obtain the alveolar bone digital model C. Specifically, the digital models of the gingiva and crowns in the patient's occlusal state, acquired by the intraoral optical scanner, were registered and overlapped with the mandibular digital model in the alveolar bone digital model B after the transplant tooth donor was in place. The occlusal gap of the transplant tooth donor digital model was measured to be 0.96-1.33 mm. Since the data acquired by the intraoral optical scanner is more accurate than the data acquired by CBCT, the re-alignment and overlap of the two can reduce the errors introduced by the CBCT scan.

[0086] See attached document Figure 15 The digital model of the bone guide was placed on the alveolar bone digital model C, the donor tooth, and the positional relationship between each prism of the bone guide digital model and adjacent teeth, as well as the positional relationship between each prism and opposing teeth, was observed to prevent interference. (See attached...) Figure 16 Then, a retention reference area is selected on the mandibular tooth to obtain the flank model. The retention reference area is generally selected as a portion of the tooth, rather than completely covering it, to avoid situations where installation is not possible. (See attached diagram.) Figure 17 Then, the flank model and the digital model of the bone grinding guide are combined to obtain a digital model of the bone grinding guide with flanks.

[0087] See attached document Figure 23 The spatial positional relationship of the transplant tooth donor is found through the digital model C of the alveolar bone, and the preoperative occlusal state data is obtained. Then, a repositioning occlusal guide model is designed based on the preoperative occlusal state data. That is, the preoperative occlusal state is fixed by repositioning the occlusal guide. The spatial positional relationship of the transplant tooth donor includes: the relationship between the transplant tooth donor and the mucosa, the relationship between the transplant tooth donor and the adjacent teeth, the relationship between the transplant tooth donor and the alveolar bone, and the relationship between the transplant tooth donor and the opposing teeth.

[0088] See attached document Figure 24 On the digital model C of the alveolar bone, find the intersection boundary between the digital model of the transplant tooth donor and the mucosa, referring to the attached diagram. Figure 25 Then, the axial direction of the donor tooth neck and root after re-registration and overlap is used as the direction for drilling and cutting the mucosal circumferential bur, as shown in the attached figure. Figure 26 First, determine the fixation point of the guide plate of the mucosal girder, and then design the guide plate model of the mucosal girder based on the fixation point and the direction of the mucosal girder's drilling.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for fabricating a surgical guide for preparing a cavity in autologous tooth transplantation, characterized in that, Includes the following steps: S1: Digital models of the transplant donor, transplanted tooth, and alveolar bone are obtained through scanning, and physical models of the transplant donor, transplanted tooth, and alveolar bone are made according to the digital models; data on the patient's open-mouth gingiva and crowns are collected using an optical intraoral scanner, and occlusal data are obtained by scanning. S2: Simulate transplantation on a solid alveolar bone model, prepare the cavity step by step, and obtain the alveolar socket of the recipient area in the solid alveolar bone model. S3: Obtain a solid model of the alveolar bone after successful cavity preparation by scanning with CBCT, and then create a digital model of the alveolar bone after cavity preparation. S4: Register and overlap the two alveolar bone digital models before and after cavity preparation to obtain data on the difference in state of alveolar bone before and after cavity preparation. Then, model the amount of bone removed during cavity preparation based on the alveolar bone solid model to obtain a digital model of bone removal amount. S5: Fit the bone grinding straight drill with a prism of the same diameter, place the prism according to the wall thickness of the bone grinding digital model, fit the diameter and working depth of the straight drill, fit the inner surface of the alveolar socket in front of the bone grinding cavity with a cone, and design a bone grinding guide plate model for alveolar bone preparation. S6: Place the simulated bone-grinding guide plate model into the alveolar socket of the implantation area, and subtract the bottom and sidewalls of the bone-grinding guide plate model from the alveolar socket of the implantation area along the placement direction. S7: Design a wing for fixing to a tooth adjacent to the transplanted tooth, and incorporate the wing into the bone guide plate model in step S6.

2. The method for fabricating the surgical cavity preparation guide for autologous tooth transplantation according to claim 1, characterized in that, In step S7, the donor physical model of the transplant tooth is transferred onto the prepared alveolar bone physical model and scanned together with it using CBCT. Then, a digital model of the alveolar bone after the transplant tooth donor is in place is created. The digital model of the alveolar bone after the transplant tooth donor is in place is registered and overlapped with the digital model of the alveolar bone before the preparation of the cavity to obtain the digital model A of the alveolar bone after the transplant tooth donor is in place. Then, the digital model of the transplant tooth donor is registered and overlapped with the transplant tooth donor on the digital model A of the alveolar bone to obtain the digital model B of the alveolar bone after the transplant tooth donor is in place. Then, the digital model of the maxilla and mandible in occlusion state acquired by the intraoral optical scanner is registered and overlapped with the digital model B of the alveolar bone after the transplant tooth donor is in place to obtain the digital model C of the alveolar bone. A wing for fixing to the tooth adjacent to the transplant tooth donor is designed on the digital model C of the alveolar bone.

3. The method for fabricating a surgical cavity preparation guide for autologous tooth transplantation according to claim 2, characterized in that, In step S7, the bone guide plate model obtained in step 6 is placed on the transplanted tooth donor on the alveolar bone digital model C. The fixation reference area is selected according to the bone guide plate model and the alveolar bone digital model C to obtain the wing model.

4. The method for fabricating the surgical cavity preparation guide plate for autologous tooth transplantation according to claim 3, characterized in that, The steps following step S7 include: finding the spatial positional relationship of the transplant tooth donor through the alveolar bone digital model C, obtaining preoperative occlusal status data, and then designing a repositioning occlusal guide model based on the preoperative occlusal status data.

5. The method for fabricating the surgical cavity preparation guide for autologous tooth transplantation according to claim 4, characterized in that, The spatial relationships of the transplanted tooth donors include: the relationship between the transplanted tooth donor and the mucosa, the relationship between the transplanted tooth donor and adjacent teeth, the relationship between the transplanted tooth donor and the alveolar bone, and the relationship between the transplanted tooth donor and the opposing tooth.

6. The method for fabricating a surgical cavity preparation guide for autologous tooth transplantation according to claim 3, characterized in that, The steps following step S7 are as follows: On the digital model of alveolar bone C, the intersection boundary between the digital model of the transplanted tooth donor and the mucosa is found, and the intersection boundary is fitted with a circular arc. The diameter of the intersection boundary is measured to select a mucosal trephine drill of the appropriate diameter. Then, the axial direction of the neck and root of the transplanted tooth donor after re-registration and overlap is fitted as the direction of the mucosal trephine drill cutting. The fixation point of the mucosal trephine drill guide plate is determined. Then, the mucosal trephine drill guide plate model is designed according to the fixation point and the direction of the mucosal trephine drill cutting.

7. The method for fabricating a surgical cavity preparation guide for autologous tooth transplantation according to claim 1, characterized in that, In step S2, the occlusal surface of the transplant tooth donor model is adjusted according to the occlusal state data obtained in step S1 and the cavity preparation process of the alveolar bone solid model in step S2, so that it meets the needs of clinical occlusal reconstruction, and the cavity preparation is completed.

8. The method for fabricating a surgical cavity preparation guide for autologous tooth transplantation according to claim 7, characterized in that, In step S2, the transplanted tooth donor model is implanted into the prepared cavity of the alveolar bone model based on the buccal and lingual directions of the transplanted tooth donor model.

9. The method for fabricating a surgical cavity preparation guide for autologous tooth transplantation according to claim 1, characterized in that, In step S4, the digital model of alveolar bone after cavity preparation is registered and overlapped with the digital model of alveolar bone before cavity preparation, and then the difference in state of alveolar bone before and after cavity preparation is solved by Boolean subtraction.

10. The method for fabricating a surgical cavity preparation guide for autologous tooth transplantation according to claim 1, characterized in that, In step S6, when the simulated bone guide plate model is placed into the alveolar socket of the implantation area, the direction in which the bone guide plate model is placed is perpendicular to the bottom of the alveolar socket of the implantation area before the cavity is prepared or parallel to the side wall of the alveolar socket.

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