Pallate-side retention subperiosteal implant stent and manufacturing method thereof

Abstract

The invention discloses a palatal-side retention subperiosteal implant stent and a manufacturing method thereof. The implant stent comprises a palatal-side connecting plate, a screw hole is formed in one side of the palatal-side connecting plate, a screw fixed to the palatal side is arranged in the screw hole, and a plurality of implant bases are arranged on the other side of the palatal-side connecting plate; the lip-buccal side connecting plate reconstructs a complete jaw bone structure of a patient through scanning data, the lip-buccal side bone surface contour is extracted, a basic support model is obtained after the contour line of the lip-buccal side connecting plate is designed in a three-dimensional model, then through three-dimensional finite element analysis, the layout of the implant abutment is optimized in combination with a stress distribution result and a screw hole site of the lip-buccal side, and the implant abutment is constructed. And then manufacturing the implant stent through 3D printing by adopting a topological optimization method. The device has good mechanical stability and biological adaptability, the minimally invasive concealment of the palatal access is realized, and the device is particularly suitable for the repair requirements of aesthetic areas and complex bone defect cases.

Description

Technical Field

[0001] The present invention relates to a palatal-retained subperiosteal implant bracket and a manufacturing method, and in particular to a palatal-retained subperiosteal implant bracket and a manufacturing method based on three-dimensional finite element analysis and 3D printing, belonging to the field of oral restoration and reconstruction. Background Art

[0002] With the development of oral implant technology, implant dentures have been widely used in clinical practice as an important means of restoring missing teeth. However, successful implant treatment depends on good bone volume, especially in the maxillary area. Severe alveolar ridge absorption, insufficient bone height, and missing bone walls limit the successful implantation of conventional implants. In order to overcome the limitations brought about by insufficient bone volume, clinical attention has gradually begun to focus on the application of subperiosteal implants. As a structure that does not rely on drilling holes in the implant socket to achieve retention, subperiosteal implants are particularly suitable for patients with severe bone height deficiency. Traditional subperiosteal implants are mostly formed by empirical design and manual bending of titanium plates. The structure and force lack scientific support. In clinical use, problems such as poor implant stability, poor fit with the bone surface, and stress concentration leading to implant breakage or loosening often occur. In addition, the surgical process is complicated and traumatic, which is not conducive to promotion.

[0003] In cases where the buccal and labial bone walls are weak or even absent, traditional designs that rely on the buccal and labial fulcrums as the primary fulcrum for fixation have significant limitations, making stable fixation difficult and increasing the risk of postoperative failure. The palate, however, as an area with relatively intact anatomical structure and dense bone, offers superior bone support and can serve as a stable and reliable scaffold retention area. Therefore, the development of a subperiosteal implant with the palate as the primary fulcrum for retention has important clinical significance and potential for widespread adoption. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: how to provide good retention support for the implant scaffold for patients with insufficient bone volume or thin or missing labial and buccal bone walls.

[0005] In order to solve the above technical problems, the technical solution of the present invention is to provide a palatal-retained subperiosteal implant bracket, which is characterized by comprising a palatal connecting plate, a screw hole is provided on one side of the palatal connecting plate, a screw fixed to the palate is provided in the screw hole, and a plurality of implant abutments are provided on the other side of the palatal connecting plate;

[0006] The palatal connecting plate obtains imaging data of the patient's maxillary palatal area through scanning data, reconstructs the three-dimensional structure of the palatal process bone surface, designs the outline of the palatal connecting plate in the three-dimensional model, and obtains the basic bracket model. Then, through three-dimensional finite element analysis, the layout of the implant base is combined with the stress distribution results and the screw hole position on the palatal side to optimize. Then, the topological optimization method is used to obtain the optimal implant bracket shape, and the implant bracket is manufactured by 3D printing.

[0007] Preferably, the palatal connecting plate is a fitting structure designed according to the residual palatal bone surface morphology of the patient, and one edge of the palatal connecting plate is provided with multiple screw holes for easy fixation to the palatal bone surface; the other side of the palatal connecting plate is bent at the labial and buccal side.

[0008] Preferably, the palatal connecting plate is an integrally formed structure, and the palatal connecting plate includes a connecting plate body. The overall structure of the connecting plate body is a field-shaped structure, and the outer contour of the connecting plate body is a triangle. A support rod is provided at one corner of the triangle, and a planting base is provided at the end of the support rod and on one side of the connecting plate body on the same side as the support rod. The support rod is an extension of one side of the triangular connecting plate body, and a plurality of screw holes are provided on one side of the extending support rod on the connecting plate body; a plurality of small holes are provided on the side of the connecting plate body close to the planting base and between any two adjacent planting bases, and the plurality of small holes form a mesh structure.

[0009] Preferably, the steps of obtaining the basic scaffold model are as follows:

[0010] Using CBCT technology to obtain imaging data of the patient's maxillary palatal area, the palatal connection plate outline was designed in the 3D model, and the 3D structure of the palatal process bone surface was reconstructed as the basis for the design of the palatal connection plate.

[0011] The shape of the palatal connecting plate with high fitting degree is drawn according to the anatomical surface of the palatine process, and multiple screw holes and reserved holes of the implant base are reasonably arranged to obtain the model structure of the basic bracket.

[0012] Preferably, the three-dimensional finite element analysis is as follows: applying multi-directional simulated bite loads, analyzing stress concentration in different areas, optimizing the plate thickness and connection form according to the direction of the force line, and ensuring uniform force. The specific steps are as follows:

[0013] Step 1: Import the model structure of the basic bracket into the finite element platform to obtain the oral implant bracket model; perform finite element meshing on the oral implant bracket model;

[0014] Step 2: Perform physical field modeling on the oral implant bracket model and assign material properties to the implant and maxillary bone;

[0015] Step 3: Obtain the pressure exerted on the oral implant bracket during chewing in the oral cavity;

[0016] Step 4: Determine the boundary conditions and loads of the system: Since the upper surface of the human maxillary bone is completely fixed, the vertical load is directly applied to the oral implant bracket.

[0017] Step 5: Analyze the simulation results: including pressure distribution, Mises stress distribution and displacement distribution.

[0018] Preferably, in step 1, when dividing the finite element mesh, small mesh units are used in the contact area between the screw and the human maxillary bone and the oral implant bracket on the oral implant bracket model, and large mesh units are used in the remaining areas on the oral implant bracket model, so as to achieve a balance between accuracy and computational efficiency.

[0019] Preferably, it is characterized in that the topology optimization method is used to obtain the optimal implant support shape with the goal of minimizing and maximizing Mises stress; the specific method is:

[0020] S31, initializing design variables;

[0021] S32, establishing an objective function, wherein the objective function is to minimize the maximum Mises stress of the oral implant bracket;

[0022] S33. Use numerical methods to calculate the sensitivity of objective functions and constraints to design variables;

[0023] S34, updating the design variables according to the sensitivity;

[0024] S35. updating the material properties of the finite element model according to the updated design variables;

[0025] S36. Determine the stopping condition and check whether the current number of iterations or volume fraction meets the stopping condition; if so, stop the iteration and output the current optimal design variable distribution, that is, the optimal implant shape; otherwise, return to step S33 and continue iteration.

[0026] Preferably, in step S31, the design variable is the unit density, which represents the relative content of the material in each finite element unit; in step S35, the SIMP interpolation model is used to associate the unit density with the material elastic modulus, and the updated finite element model is solved to calculate the design response of the stress and displacement of the implant.

[0027] Preferably, the surface of the palatal connecting plate located on the bone contact side is provided with a rough mesh structure; the surface of the palatal connecting plate located on the soft tissue contact side is subjected to a high polishing treatment.

[0028] A method for manufacturing a palatal-retained subperiosteal implant scaffold, characterized by comprising the following steps:

[0029] Step 1: Image acquisition and 3D reconstruction

[0030] CBCT technology is used to obtain high-resolution imaging data of the patient's maxillary palatal area, and professional modeling software is used to reconstruct the three-dimensional structure of the palatine bone surface as the basis for subsequent stent design;

[0031] Step 2: Preliminary modeling and design of the palatal connection plate

[0032] On the digital design platform, a connection plate shape with high fit was drawn according to the anatomical surface of the palatine process, and multiple screw holes and reserved holes for the implant abutment were rationally arranged to ensure the unity of structural stability and functional requirements, thus obtaining a model of the basic bracket.

[0033] Step 3: 3D finite element analysis and topology optimization

[0034] The preliminarily designed basic bracket model was imported into the finite element analysis system, and a simulated occlusal load was applied to dynamically evaluate the stress distribution of the palatal connecting plate under load. This allowed the spatial arrangement of the implant abutment and the plate geometry to be optimized, thereby improving mechanical safety.

[0035] Step 4: Bracket molding and surface treatment

[0036] After completing the optimized design of the oral implant bracket, the implant bracket is manufactured using the preferred titanium alloy powder material through metal 3D printing technology. After printing, heat treatment, mechanical polishing and surface roughening are performed to improve the structural strength and bone integration performance.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] Concealed surgery: The palatal approach avoids excessive labial flap;

[0039] Stable retention: The palatine process has high bone density, the screw retention is more secure, and the shear resistance is better than the labial side;

[0040] Improved aesthetics: The implant structure is located inside the mouth and does not affect the lip contour;

[0041] Widely applicable to the population: especially suitable for repairing edentulous areas with severe bone resorption on the lip and cheek sides or with high aesthetic requirements.

[0042] Subperiosteal implant designs based on 3D finite element analysis demonstrate superior mechanical optimization and structural adaptability compared to traditional approaches. Through digital modeling and occlusal mechanics simulation, the stress distribution of the implant under varying occlusal forces can be accurately simulated during the design phase, allowing targeted optimization of critical stress-bearing areas and effectively improving the mechanical stability and long-term lifespan of the restoration. Finite element analysis also accurately assesses the stress conditions in the subperiosteal implant's contact areas with the bone surface and soft tissue, providing a scientific basis for the implant's biomechanical performance. Modeling based on patient CT data, combined with finite element analysis optimization, and then directly 3D printing allows the implant's morphology to closely match the individual's bone anatomy, avoiding the large errors and poor fit associated with traditional manual shaping. This technology not only simulates the fatigue performance of the implant over long-term use and predicts potential mechanical risks, but also effectively reduces the incidence of localized mechanical stress concentrations and biocompatibility issues. The overall design better meets the individual patient's needs, significantly improving postoperative comfort and clinical success rates. This type of technology-driven innovation provides solid support for the development of subperiosteal implants, demonstrating enhanced performance advantages and broad clinical application prospects.

[0043] The present invention can realize customized design of oral implant brackets, construct a three-dimensional model of the oral implant bracket based on the obtained human maxillary model, use finite element simulation technology to simulate the implant, obtain the Mises stress distribution, and then based on the topology optimization method, with the purpose of reducing the maximum Mises stress, make the Mises stress distribution more uniform. While ensuring rigidity and durability, the overall structure is lighter and uses fewer screws, which can better adapt to the patient's oral physiological condition, thereby reducing the pressure on the patient when wearing it, significantly improving the service life of the bracket, and reducing the risk of pressure damage.

[0044] The present invention is based on three-dimensional finite element analysis and 3D printing technology, combined with the patient's individualized CBCT data, to accurately design and optimize the palatal retention structure. Under the premise of ensuring mechanical properties and biological compatibility, the surgical operation process is effectively simplified, and the safety and feasibility of clinical application are improved. This solution is particularly suitable for patients with insufficient labial and buccal bone volume or thin or missing labial and buccal bone walls, and conventional implants cannot provide good retention support. It provides a new path for efficient, minimally invasive and stable implant restoration. This solution has both good mechanical stability and biological adaptability, and the palatal approach is minimally invasive and concealed, which is particularly suitable for the repair needs of aesthetic areas and complex bone defect cases. Its digital design and production process is efficient and controllable, which is convenient for clinical promotion and application, and has significant practical value and broad development prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Schematic diagram of a palatally retained subperiosteal implant scaffold;

[0046] Figure 2 Schematic diagram of finite element meshing for the human maxillary model;

[0047] Figure 3 Comparison diagram of Mises stress before and after stent optimization; (a) is the Mises stress diagram before stent optimization; (b) is the Mises stress diagram after stent optimization;

[0048] Figure 4 Schematic diagram of the installation and use of a palatal-retained subperiosteal implant bracket.

[0049] Among them, 1 is the palatal connection plate; 2 is the implant base; 3 is the screw;

[0050] 11 is the connecting plate body; 12 is the support rod; 13 is the screw hole; 14 is the small hole. DETAILED DESCRIPTION

[0051] To make the present invention more clearly understood, preferred embodiments are described in detail below with reference to the accompanying drawings.

[0052] The present invention provides a palatal-retained subperiosteal implant scaffold based on three-dimensional finite element analysis and 3D printing technology. Figure 1 As shown, it includes a palatal connecting plate 1, a screw hole 13 is provided on one side of the palatal connecting plate 1, a screw 3 fixed to the palate is provided in the screw hole 13, and a plurality of implant bases 2 are provided on the other side of the palatal connecting plate 1;

[0053] The palatal connecting plate 1 obtains the imaging data of the patient's maxillary palatal area through scanning data, reconstructs the three-dimensional structure of the palatal process bone surface, designs the contour line of the palatal connecting plate 1 in the three-dimensional model, and obtains the basic bracket model. Then, through three-dimensional finite element analysis, the layout of the implant base 2 is combined with the stress distribution results and the screw hole position on the palatal side to be optimized. Then, the topological optimization method is used to obtain the optimal implant bracket shape, and the implant bracket is manufactured by 3D printing.

[0054] The palatal connecting plate 1 is a fitting structure designed according to the residual bone surface morphology of the patient's palate. One edge of the palatal connecting plate 1 is provided with multiple screw holes 13 for easy fixation to the palatal bone surface; the other side of the palatal connecting plate 1 is bent at the labial and buccal side.

[0055] The palatal connecting plate 1 is an integrally formed structure, and the palatal connecting plate 1 includes a connecting plate body 11. The overall structure of the connecting plate body 11 is a field-shaped structure. The outer contour of the connecting plate body 11 is a triangle, and a support rod 12 is provided at one corner of the triangle. The end of the support rod 12 and the side of the connecting plate body 11 on the same side as the support rod 12 are provided with a planting base 2. The support rod 12 is an extension of one side of the triangular connecting plate body 11, and a plurality of screw holes 13 are provided on one side of the extending support rod 12 on the connecting plate body 11; a plurality of small holes 14 are provided on the side of the connecting plate body 11 close to the planting base 2 and located between any two adjacent planting bases 2, and the plurality of small holes 14 form a mesh structure.

[0056] The palatal connecting plate 1 reconstructs the patient's complete three-dimensional jaw structure through CBCT scanning data, extracts the palatal bone surface contour, and designs the outline of the palatal connecting plate 1 in the three-dimensional model to obtain the basic bracket model. Then, the occlusal force and multi-directional stress distribution are simulated through three-dimensional finite element analysis. The structure of the palatal connecting plate 1, the layout of the implant base 2, combined with the stress distribution results and the screw hole position on the labial side are optimized to achieve the best match in terms of mechanical properties, bone surface fit and postoperative stability. Then, the topological optimization method is used to obtain the optimal implant bracket shape, and the implant bracket is manufactured by 3D printing.

[0057] Among them, the palatal connecting plate 1 is designed according to the shape of the palatine process, adopts a curved three-dimensional fitting structure, and has screw holes on the edge for fixing to the palatine process and the adjacent bone surface;

[0058] Mid-palatal abutment: Multiple abutments (i.e., implant abutments 2) extend from the center of the palatal connecting plate 1. The abutments penetrate the soft tissue and emerge from the oral cavity for connection to the upper restoration.

[0059] Surface treatment: The bone contact side of the palatal connection plate 1 is designed with a mesh-like rough surface to provide a good bone-bonding interface and promote bone integration. The soft tissue contact surface is highly polished to reduce the risk of soft tissue exposure.

[0060] Mechanical simulation: Finite element analysis was used to optimize the structure of the palatally retained subperiosteal implant, using forces simulating the patient's occlusal orientation. This ensured optimal abutment placement and sufficient strength at the connection point, meeting functional requirements and effectively avoiding localized stress concentration. The palatal framework was implanted approximately 0.5–1 mm into the bone, with the alveolar crest region extending 1–2 mm deeper into the bone. This enhanced initial mechanical stability, promoted new bone growth around the framework surface, and reduced soft tissue exposure and the risk of complications.

[0061] A specific optimized manufacturing method for a palatal-retained subperiosteal implant scaffold is as follows:

[0062] Step 1: Image acquisition and 3D reconstruction

[0063] CBCT technology is used to obtain high-resolution imaging data of the patient's maxillary palatal area, and professional modeling software is used to reconstruct the three-dimensional structure of the palatine bone surface as the basis for subsequent stent design.

[0064] Step 2: Preliminary modeling and design of palatal connection plate 1

[0065] In the digital design platform, the shape of the connecting plate with high fitting degree is drawn according to the anatomical surface of the palatine process, and multiple screw holes 13 and reserved holes of the implant base 2 are reasonably arranged to ensure the unity of structural stability and functional requirements, and obtain the model of the basic bracket.

[0066] Step 3: Finite element simulation (3D finite element analysis optimization) and structural parameter optimization (using topology optimization method)

[0067] The preliminarily designed basic bracket model was imported into the finite element analysis system, and a simulated occlusal load was applied to dynamically evaluate the stress distribution of the palatal connecting plate 1 under the load state, thereby optimizing the spatial layout and plate geometric parameters of the implant base 2 and improving mechanical safety.

[0068] Three-dimensional finite element analysis uses finite element simulation technology to simulate the oral implant bracket, simulate and analyze the constructed oral implant bracket model, and obtain its Mises stress distribution. The specific steps are as follows:

[0069] S21. Import the model structure of the basic bracket into the finite element platform to obtain the oral implant bracket model; the three-dimensional model of the oral implant bracket can be created using a computer-aided design tool (nTop, New York, USA). Perform finite element meshing on the oral implant bracket model: the smaller the unit of the finite element mesh, the higher the accuracy of the calculation, but the greater the amount of calculation. In order to strike a balance between accuracy and computational efficiency, smaller mesh units can be used in the contact area between the screw and the human maxillary bone and bracket as needed. The schematic diagram of finite element meshing is shown in the figure below. Figure 2 As shown;

[0070] S22. Perform physical field modeling on the oral implant scaffold model: assign material properties to the implant and maxillary bone; the material properties of the oral implant scaffold need to consider its mechanical properties, such as elastic modulus and Poisson's ratio; the material properties of the human maxillary bone model refer to the mechanical properties of human cortical bone.

[0071] S23. Obtain the pressure exerted on the oral implant bracket during chewing in the mouth by reviewing literature and conducting clinical research.

[0072] S24. Determine the boundary conditions and loads of the system: the upper surface of the human maxillary bone is completely fixed, and a vertical load is directly applied to the oral implant bracket model.

[0073] S25. Analyze simulation results: including pressure distribution, Mises stress distribution and displacement distribution.

[0074] The calculation formula of Mises stress is:

[0075]

[0076] Among them, σ1, σ2, and σ3 are three principal stresses. The principal stresses of each unit are calculated by finite element method, and then the Mises stress of each unit is obtained as the basic data of the design response.

[0077] The above simulation process using finite element analysis (FEA) is performed by using specialized finite element analysis software Abaqus.

[0078] S3. Use topology optimization to minimize the maximum Mises stress (Mises stress is a yield criterion, and its value is usually called equivalent stress) to obtain the optimal implant scaffold shape. The specific method is as follows:

[0079] S31, initializing design variables. In this embodiment, the design variable is unit density;

[0080] Element density is a core design variable that represents the relative amount of material in each finite element. Its value range is usually from 0 (no material) to 1 (solid material). In this example, the density of all elements in the design domain is initially set to 0.5 (indicating medium density).

[0081] S32. Establish an objective function. The objective function is typically to minimize or maximize a scalar quantity extracted from the design response. In this embodiment, the objective function is to minimize the maximum Mises stress of the implant.

[0082] The objective function can be expressed as

[0083] J=min(max(σ vM,i ))

[0084] Among them, J is the objective function, σ vM,i represents the Mises stress of the i-th unit, max(σ vM,i ) represents the maximum value of the Mises stress of all elements, and the optimization process aims to make this maximum value as small as possible by changing the design variables.

[0085] S33. Calculate sensitivity: Use numerical methods to calculate the sensitivity of the objective function and constraints to the design variables;

[0086] Sensitivity analysis is to calculate the derivatives of the objective function and constraints with respect to the unit density, which is used to guide the updating direction of the design variables. The calculation formula of the objective function sensitivity is:

[0087]

[0088] in, represents the sensitivity of Mises stress to element density, x_i represents element density, represents the principal stress components (j = 1, 2, 3);

[0089] S34: Update the design variables according to the sensitivity calculated in step S33. This is achieved through the optimization criterion method. The specific formula of the optimization criterion method is:

[0090]

[0091] in, represents the density of unit i at the k+1th iteration, c i represents the sensitivity of the objective function to the density of unit i, λ represents the Lagrange multiplier, m represents the maximum change in each iteration, x min and x max Indicates the lower and upper limits of density, usually 0.001 and 1;

[0092] S35. Update the material properties of the finite element model based on the updated cell density value. Use the SIMP (Solid Isotropic Material with Penalization) interpolation model to relate the cell density to the material elastic modulus, solve the updated finite element model, and calculate the design response of the implant, such as stress and displacement;

[0093] The SIMP interpolation formula is as follows:

[0094]

[0095] Among them, E0 is the elastic modulus of the solid material, E min is the elastic modulus of the cavity area (usually a very small value, such as E min =10 -9 E0), p is a penalty factor (generally p≥3), which is used to penalize the intermediate density units and promote the design to develop towards 0-1 discretization.

[0096] S36: Determine the stopping condition and check whether the current number of iterations or volume fraction meets the stopping condition. If so, stop the iteration and output the current optimal cell density distribution, i.e., the optimal implant shape. Otherwise, return to step S33 and continue the iteration.

[0097] The stopping condition can be expressed as

[0098]

[0099] Among them, V current is the implant volume of the current iteration step, V initial is the volume of the initial implant, f is the designed volume fraction, n is the current iteration number, N max is the maximum number of iterations, and ∨ represents a logical OR operation.

[0100] With material design strength as the goal, geometric models of implants with varying dimensions (e.g., implant thickness, typically the thickness of the rod near the implant abutment 2) and configurations (changing the internal structure while the implant outline is fixed) are established. Finite element analysis is then used to determine the size range and different structural configurations that meet the material design strength target. Alternatively, if the implant outline and internal structure are fixed, only geometric parameters such as thickness need to be varied when performing multiple finite element analyses.

[0101] Step 4: Bracket molding and surface treatment

[0102] After completing the optimized design of the oral implant bracket, the implant bracket is manufactured using the preferred titanium alloy powder material through metal 3D printing technology. After printing, heat treatment, mechanical polishing and surface roughening are performed to improve the structural strength and bone integration performance.

[0103] The specific steps are as follows:

[0104] Generate 3D printing files: First, export the optimized oral implant framework design from the finite element simulation software and convert it into the STL file format suitable for 3D printing.

[0105] Prepare a 3D printer: Based on the design requirements and usage characteristics of the oral implant scaffold, select an appropriate 3D printer and choose the appropriate printing material. Since the oral implant scaffold needs to be implanted in the human oral environment, the material must be safe, non-toxic, comfortable, and possess sufficient strength and elasticity. Possible materials include plastics (such as PLA and ABS), elastomers (such as TPU), or specialized biomedical 3D printing materials.

[0106] Set 3D printing parameters: Based on the performance of the selected 3D printer and the characteristics of the printing material, reasonably set the 3D printing parameters, mainly including but not limited to parameters such as printing speed, layer thickness, filling density, printing temperature, etc., to ensure printing quality.

[0107] Start 3D printing: Load the generated 3D print file into the 3D printer and start the printing process after confirming that it is correct. During the printing process, the 3D printer will add printing material layer by layer according to the design of the 3D model, and finally form a three-dimensional oral implant framework.

[0108] Post-processing: After printing, a series of post-processing operations may be required to ensure the safety and comfort of the oral implant scaffold. These include removing support structures used during printing, smoothing the surface, and performing rigorous disinfection. Surface treatment includes roughening (sandblasting, acid etching, etc.) the bone-contacting surface of the scaffold to promote osseointegration. The soft-tissue contacting surface of the scaffold is highly polished to reduce the risk of soft-tissue exposure.

[0109] Step 5: Preoperative preparation and precise implantation

[0110] After completing preoperative suitability assessment and strict sterilization, the bone surface is exposed through the oral palatal flap during the operation, and the customized stent is accurately implanted, such as Figure 4 As shown, the fixation operation was completed using 13 preset screw holes, and the soft tissue was subsequently sutured.

[0111] Step 6: Postoperative management and functional recovery

[0112] After the operation, a temporary restoration was installed according to the clinical plan and the healing process was observed. About 4 months later, a permanent restoration was installed after the bone integration was completed to restore the patient's chewing function and aesthetic effect.

[0113] The invention has achieved a breakthrough in optimizing 3D-printed stents. Using a 70% volume fraction as the core constraint, the invention's implementation method successfully achieved a significant improvement in stent performance.

[0114] Before the adoption of the present invention, the maximum stress the stent could withstand under the same working conditions was 2581 MPa, which severely impacted the stent's service life and brought potential risks to clinical applications. However, after the adoption of the present invention, the maximum stress was significantly reduced to 1,389 MPa, a decrease of 46.2%. Figure 3 As shown, it is far lower than the tensile strength of titanium alloy.

[0115] The stent of the present invention has achieved a qualitative leap in mechanical properties while maintaining the original load-bearing capacity, which not only greatly enhances the structural stability and durability of the stent, but also provides more reliable protection for patient safety.

Claims

1. A palatal-retained subperiosteal implant scaffold, characterized in that: The invention comprises a palatal connecting plate (1), wherein a screw hole (13) is provided on one side of the palatal connecting plate (1), a screw (3) fixed to the palatal side is provided in the screw hole (13), and a plurality of implant bases (2) are provided on the other side of the palatal connecting plate (1); The palatal connecting plate (1) obtains the imaging data of the patient's maxillary palatal area through scanning data, reconstructs the three-dimensional structure of the palatal process bone surface, designs the outline of the palatal connecting plate (1) in the three-dimensional model, and obtains the basic bracket model. Then, through three-dimensional finite element analysis, the layout of the implant base (2) is combined with the stress distribution results and the screw hole position on the palatal side to optimize. Then, the topological optimization method is used to obtain the optimal implant bracket shape, and the implant bracket is manufactured by 3D printing.

2. The palatal-retained subperiosteal implant scaffold according to claim 1, characterized in that: The palatal connecting plate (1) is a fitting structure designed according to the residual bone surface morphology of the patient's palate. A plurality of screw holes (13) are provided on one edge of the palatal connecting plate (1) for easy fixation to the palatal bone surface; the other side of the palatal connecting plate (1) is bent at the labial and buccal side.

3. The palatal-retained subperiosteal implant scaffold according to claim 1, characterized in that: The palatal connecting plate (1) is an integrally formed structure. The palatal connecting plate (1) includes a connecting plate body (11). The overall structure of the connecting plate body (11) is a field-shaped structure. The outer contour of the connecting plate body (11) is a triangle. A support rod (12) is provided at one corner of the triangle. The end of the support rod (12) and one side of the connecting plate body (11) on the same side as the support rod (12) are provided with a planting base (2). The support rod (12) is an extension of one side of the triangular connecting plate body (11). A plurality of screw holes (13) are provided on one side of the connecting plate body (11) where the support rod (12) is extended. A plurality of small holes (14) are provided on the connecting plate body (11) on one side close to the planting base (2) and between any two adjacent planting bases (2). The plurality of small holes (14) form a mesh structure.

4. The palatal-retained subperiosteal implant scaffold according to claim 1, characterized in that: The steps for obtaining the basic support model are as follows: Based on CBCT technology, imaging data of the patient's maxillary palatal area is obtained, the outline of the palatal connecting plate (1) is designed in the three-dimensional model, and the three-dimensional structure of the palatal process bone surface is reconstructed as the design basis of the palatal connecting plate (1); the shape of the palatal connecting plate (1) with high fitting degree is drawn according to the anatomical surface of the palatal process, and multiple screw holes (13) and reserved holes of the implant base (2) are reasonably arranged to obtain the model structure of the basic bracket.

5. The palatal-retained subperiosteal implant scaffold according to claim 1, characterized in that: The three-dimensional finite element analysis involves applying multi-directional simulated bite loads, analyzing stress concentration in different areas, and optimizing the plate thickness and connection configuration based on the force line direction to ensure uniform stress distribution. The specific steps are as follows: Step 1: Import the model structure of the basic bracket into the finite element platform to obtain the oral implant bracket model; perform finite element meshing on the oral implant bracket model; Step 2: Perform physical field modeling on the oral implant bracket model and assign material properties to the implant and maxillary bone; Step 3: Obtain the pressure exerted on the oral implant bracket during chewing in the oral cavity; Step 4: Determine the boundary conditions and loads of the system: Since the upper surface of the human maxillary bone is completely fixed, the vertical load is directly applied to the oral implant bracket. Step 5: Analyze the simulation results: including pressure distribution, Mises stress distribution and displacement distribution.

6. The palatal-retained subperiosteal implant scaffold according to claim 5, characterized in that: In step 1, when dividing the finite element mesh, small mesh units are used in the contact area between the screw and the human maxillary bone and the oral implant bracket on the oral implant bracket model, and large mesh units are used in the remaining areas on the oral implant bracket model, so as to achieve a balance between accuracy and computational efficiency.

7. The palatal-retained subperiosteal implant scaffold according to claim 1, characterized in that: The topology optimization method is used to obtain the optimal implant scaffold shape with the goal of minimizing and maximizing Mises stress; the specific method is as follows: S31, initializing design variables; S32, establishing an objective function, wherein the objective function is to minimize the maximum Mises stress of the oral implant bracket; S33. Use numerical methods to calculate the sensitivity of objective functions and constraints to design variables; S34, updating the design variables according to the sensitivity; S35. updating the material properties of the finite element model according to the updated design variables; S36. Determine the stopping condition and check whether the current number of iterations or volume fraction meets the stopping condition; if so, stop the iteration and output the current optimal design variable distribution, that is, the optimal implant shape; otherwise, return to step S33 and continue iteration.

8. The palatal-retained subperiosteal implant scaffold according to claim 7, characterized in that: In step S31, the design variable is the unit density, which represents the relative content of the material in each finite element unit; in step S35, the SIMP interpolation model is used to associate the unit density with the material elastic modulus, and the updated finite element model is solved to calculate the design response of the stress and displacement of the implant.

9. The palatal-retained subperiosteal implant scaffold according to claim 1, characterized in that: The palatal connecting plate (1) is located on the bone contact side and is provided with a rough mesh structure; the palatal connecting plate (1) is located on the soft tissue contact side and is subjected to a high polishing treatment.

10. A method for manufacturing a palatal-retained subperiosteal implant scaffold according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: Image acquisition and 3D reconstruction CBCT technology is used to obtain high-resolution imaging data of the patient's maxillary palatal area, and professional modeling software is used to reconstruct the three-dimensional structure of the palatine bone surface as the basis for subsequent stent design; Step 2: Preliminary modeling and design of the palatal connection plate (1) In the digital design platform, a connection plate shape with high fitting degree is drawn according to the anatomical surface of the palatine process, and multiple screw holes (13) and reserved holes of the implant base (2) are reasonably arranged to ensure the unity of structural stability and functional requirements, thereby obtaining a model of the basic bracket; Step 3: 3D finite element analysis and topology optimization The preliminarily designed basic bracket model is imported into the finite element analysis system, and a simulated occlusal load is applied to dynamically evaluate the stress distribution of the palatal connecting plate (1) under the load state, thereby optimizing the spatial arrangement and plate geometric parameters of the implant base (2) and improving mechanical safety; Step 4: Bracket molding and surface treatment After completing the optimized design of the oral implant bracket, the implant bracket is manufactured using the preferred titanium alloy powder material through metal 3D printing technology. After printing, heat treatment, mechanical polishing and surface roughening are performed to improve the structural strength and bone integration performance.

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