Preparation method of 3D printing porous degradable metal GBR membrane

Abstract

This invention relates to a method for preparing a 3D-printed porous biodegradable metal GBR membrane, belonging to the field of biomaterial additive manufacturing. The method includes the following steps: S1, performing a CT scan of the alveolar bone of the patient undergoing bone defect repair, and using reverse engineering technology to obtain a scanned prototype of the personalized GBR membrane; S2, selecting a lattice structure with node connections and symmetry as the basic filling unit for constructing the porous GBR membrane; S3, performing a single-cell adaptive filling design on the scanned prototype of the personalized GBR membrane to form a porous GBR membrane model; S4, using post-printing processing software to correct the mesh of the porous GBR membrane model; S5, using biodegradable biometal powder, and preparing the porous biodegradable metal GBR membrane through 3D printing technology. Providing a personalized GBR membrane allows for better adaptation to the patient's oral structure. The porous GBR membrane promotes bone cell migration and growth, accelerating the bone defect repair process.

Description

Technical Field

[0001] This invention relates to the field of biomaterial additive manufacturing, specifically to a method for preparing a 3D printed porous biodegradable metal GBR membrane. Background Technology

[0002] Dental implants have revolutionized overall dental rehabilitation, significantly improving the quality of life. Guided bone regeneration (GBR) is commonly used to repair alveolar bone loss or insufficiency at implant sites. GBR membranes are frequently used in dental and maxillofacial surgery to guide and promote bone regeneration. However, GBR membranes made from biodegradable polymers lack rigidity, limiting their applicability to small alveolar bone defects that do not require additional fixation and stability. GBR membranes made from biodegradable metallic materials, including zinc-based, magnesium-based, and iron-based metals, are typically used to provide excellent mechanical support for severe and complex bone defect areas. Furthermore, the biocompatibility and degradability of biodegradable metallic GBR membranes reduce the need for secondary surgeries and lower the risk of infection. Simultaneously, they promote healing through biocompatibility and the release of potential growth factors, providing spatial support for severe and complex bone defect areas and offering an ideal solution for bone regeneration, thus improving treatment outcomes and patient experience.

[0003] Existing GBR membranes often lack personalized shapes and contours, leading to poor therapeutic effects. Integrating porous designs into the curved surfaces of 3D-printed metal-based GBR membranes presents significant challenges in handling irregular boundaries and achieving uniform stress distribution. In conventional unit cell array filling design methods, the center points of the units are distributed along a straight line, while the boundary lines of the GBR model are curved. When constructing models with irregular boundaries, some units in the array may extend beyond the GBR model boundaries, resulting in incomplete units and poor connectivity between unit supports. Therefore, to address the challenges of integrating porous designs into curved membranes, it is necessary to develop special porous design techniques to avoid the problems of units extending beyond the boundaries and poor connectivity between unit supports when constructing models with irregular boundaries, ensuring the mechanical properties required for spatial support.

[0004] Traditional GBR membrane manufacturing methods primarily rely on mold casting and machining processes. These methods are insufficient to meet the needs of personalized treatment and have low production efficiency. 3D printing technology, however, can achieve complex porous structures and personalized designs, providing sufficient mechanical support and offering great potential for porous biodegradable metal GBRs. Therefore, to address the aforementioned issues, it is necessary to propose a design and manufacturing method for porous biodegradable metal GBR membranes based on 3D printing technology. This method should be adapted to address different personalized GBR membrane shapes and treatment requirements, improve the mechanical properties of GBR membranes, and provide a more ideal solution for the treatment of bone defects. Summary of the Invention

[0005] Therefore, it is necessary to provide a 3D printing method for preparing porous biodegradable metal GBR membranes, which addresses the problems that traditional GBR membrane manufacturing methods cannot meet the needs of personalized treatment and have low production efficiency.

[0006] The purpose of this invention is to provide a method for preparing a 3D-printed porous biodegradable metal GBR membrane, which is biodegradable and can be precisely customized according to the specific needs of patients. At the same time, it adopts a single-cell adaptive filling strategy to maintain sufficient mechanical integrity during bone regeneration and has excellent mechanical properties.

[0007] A method for preparing a 3D-printed porous biodegradable metal GBR film includes the following steps:

[0008] S1. Perform CT scans on the alveolar bone of the recipient of the bone defect repair procedure, and use reverse engineering technology to obtain a scanned physical prototype of the personalized GBR membrane.

[0009] S2. Select a lattice structure with node connections and symmetry as the basic filling unit for constructing a porous GBR membrane;

[0010] S3. Perform single-cell adaptive filling design on the scanned physical prototype of the personalized GBR membrane to form a porous GBR membrane model.

[0011] S4. Use post-printing processing software to correct the mesh of the porous GBR membrane model, remove excess shells and repair misaligned meshes.

[0012] S5. Using biodegradable biometal powder, a porous biodegradable metal GBR membrane was prepared by 3D printing technology and combined with optimized process parameters.

[0013] This application discloses a method for preparing a 3D-printed porous biodegradable metal GBR membrane. Utilizing CT scanning and reverse engineering techniques, it enables the provision of personalized GBR membranes to patients, ensuring precise matching between the GBR membrane and the patient's alveolar bone and improving restorative outcomes. A lattice structure with node connections and symmetry is used as the basic filling unit. This structure offers advantages in mechanical properties and space utilization, providing better support and stability. Adaptive single-cell filling design is employed for the personalized GBR membrane to obtain a porous GBR membrane model, ensuring the uniformity and consistency of the porous GBR membrane, which is crucial for uniform growth and healing of bone defects. Post-printing processing software is used to correct the mesh of the porous GBR membrane model, eliminating potential errors during printing and improving product accuracy and quality. The porous biodegradable metal GBR membrane is prepared using biodegradable biometal powder. This material not only promotes bone tissue growth but also gradually degrades after fulfilling its function, reducing long-term impacts on the human body. Combining optimized process parameters for 3D printing improves printing efficiency, reduces material waste, and ensures the mechanical properties and biocompatibility of the final product. Personalized GBR membranes can better adapt to the patient's oral structure, improving postoperative comfort. The porous structure of the GBR membrane facilitates bone cell migration and growth, promotes bone integration, and accelerates the repair process of bone defects.

[0014] In any of the above technical solutions, in step S1, the position, size, edge shape, and contour of the personalized GBR membrane are matched with the bone defect area.

[0015] By precisely matching the position, size, edge shape, and contour of a personalized GBR membrane to the bone defect area, a perfect fit can be ensured, improving surgical precision and repair outcomes. A precisely matched GBR membrane can reduce complications caused by mismatch with the bone defect area, such as infection, inflammation, or poor healing.

[0016] In any of the above technical solutions, in step S1, the radius of curvature, bending angle, and thickness of the personalized GBR membrane obtained by reverse engineering technology are matched with the shape and size characteristics of the bone defect site.

[0017] The radius of curvature, bending angle, and thickness of the personalized GBR membrane obtained through reverse engineering are adapted to and matched with the shape and size characteristics of the bone defect site. This allows the personalized GBR membrane to better fit the irregular shape of the bone defect area, improving the stability of the alveolar bone and the repair effect.

[0018] In any of the above technical solutions, in step S2, the shape of the basic filling unit is one or more of the following: body-centered cubic, octahedral cubic, face-centered cubic, regular hexahedron, cubic octahedron, truncated octahedron, regular dodecahedron, rhombic dodecahedron, regular icosahedron, diamond, truncated hexagonal tessellation, small rhombic truncated cube, honeycomb, and foam.

[0019] By selecting different basic filling unit shapes such as body-centered cubic, octahedral cubic, and face-centered cubic, diverse porous structures can be designed to meet the specific needs of different bone defect areas. Different lattice structures possess different mechanical properties. For example, the face-centered cubic structure exhibits high strength and stiffness due to its close-packed characteristics, which is particularly important for repairing bone defects subjected to significant mechanical loads. By selecting specific lattice structures, the porosity and pore size of porous GBR membranes can be controlled, thereby influencing their biocompatibility and osteogenic capacity. Different lattice structures can provide different attachment and growth spaces for osteoblasts, promoting osteoblast migration and growth, and accelerating the healing of bone defect areas.

[0020] In any of the above technical solutions, the step S3 of performing unit cell adaptive filling design on the scanning prototype of the personalized GBR film is as follows:

[0021] S31. Select and calculate the normal reference vector a of the center point of the lattice on the surface model of the personalized GBR film, and the tangential reference filling vector b that is perpendicular to the normal reference vector a.

[0022] S32. Based on the filling requirements, select and calculate two mutually perpendicular target vectors a1 and b1 of the lattice.

[0023] S33. Using the geometric center as the center of rotation, calculate the angle α1 between the corresponding normal reference vectors a and a1.

[0024] S34. According to the vector formula a n =a-a1, calculate the rotation direction vector a n The rotation of the lattice is achieved by calculating the rotation angle and rotation direction of the lattice using a rotation matrix.

[0025] S35. Repeat steps S33 and S34 for the tangential reference filling vector b to obtain a conformally filled porous GBR membrane model.

[0026] By calculating the normal reference vector 'a' of the lattice center point on the curved surface model of the personalized GBR film, and the tangential reference filling vector 'b' perpendicular to 'a', the normal reference vector 'a' and the tangential reference filling vector 'b' coincide with the corresponding vectors of the filling nodes of the personalized GBR film. This allows the lattice arrangement to precisely adapt to the three-dimensional shape of the personalized GBR film, whether it be a straight line, a curve, or a complex surface morphology. By calculating parameters such as the target vector, included angle, rotation angle, and rotation direction, a single-cell adaptive filling design for the scanned solid prototype of the personalized GBR film was achieved. This design method ensures filling accuracy, avoids material waste, and improves the mechanical properties of the GBR film. The porous GBR film using the single-cell adaptive filling design exhibits uniform stress distribution, no significant deformation under load, reduces local stress concentration points, and lowers the risk of GBR film structural damage.

[0027] In any of the above technical solutions, the unit cell maintains structural integrity during the adaptive filling design process.

[0028] By employing structurally intact single cells as the basic filling unit in a single-cell adaptive filling design to prepare porous GBR membranes, the mechanical stability of the porous GBR membranes is improved, enabling them to withstand the stress and pressure in the oral environment. Simultaneously, the durability of the porous GBR membranes is enhanced, extending their in vivo lifespan and reducing the need for replacement or repair.

[0029] In any of the above technical solutions, the porous GBR membrane model obtained through the single-cell adaptive filling design process is subjected to uniform load distribution.

[0030] The porous GBR membrane model obtained through the single-cell adaptive filling design process has a uniform load distribution, which reduces local stress concentration and lowers the risk of deformation or breakage of the porous GBR membrane under stress.

[0031] In any of the above technical solutions, during the unit cell adaptive filling design process, the unit cells are arranged smoothly and continuously, precisely and completely adapting to the three-dimensional shape of the personalized GBR membrane.

[0032] The smooth and continuous arrangement of individual cells allows for precise and complete adaptation to the three-dimensional shape of a personalized GBR membrane. This characteristic enables the fabricated porous GBR membrane to exhibit high adaptability and flexibility, allowing it to conform to complex tissue surfaces and improve implantation outcomes.

[0033] In any of the above technical solutions, during step S4, the process of deleting redundant shells includes interfering shells and shells with a volume of 0.

[0034] Removing excess shells reduces unnecessary material waste and simplifies the printing process, making it more efficient. It also helps eliminate potential defects and flaws, resulting in a more uniform and consistent GBR film and reducing the difficulty and cost of post-processing.

[0035] In any of the above technical solutions, step S4, repairing the misaligned mesh includes correcting bad edges, overlapping and intersecting triangular facets.

[0036] By repairing misaligned meshes, especially correcting bad edges, overlaps, and intersecting triangular facets, the accuracy of 3D printing can be significantly improved, ensuring that the printed membrane structure is precise and error-free. Repairing misaligned meshes can prevent defects in the printed membrane structure, enhancing its integrity and durability.

[0037] In any of the above technical solutions, in step S5, the biodegradable biometal powder includes one of zinc, zinc-based alloy, magnesium, magnesium-based alloy, iron, and iron-based alloy.

[0038] The use of biodegradable metal powder offers significant advantages in GBR membrane applications. Biodegradable metal GBR membranes naturally degrade after use, eliminating the need for secondary surgery, greatly reducing patient discomfort, and lowering medical risks. The selected metal powder possesses antibacterial properties, which is crucial for preventing postoperative infections. Utilizing 3D printing technology to fabricate porous GBR membranes allows for customization of membrane structure and properties to meet specific needs.

[0039] In any of the above technical solutions, in step S4, the 3D printing technology includes one of laser selective melting technology and electron beam selective melting technology.

[0040] In summary, this invention enables the customization of GBR membranes according to the patient's specific anatomical structure, precisely adapting to the patient's specific bone defect condition. The 3D-printed porous biodegradable metal GBR membrane proposed in this invention, compared to traditional GBR membranes, ensures unit cell integrity and reduces stress concentration, providing sufficient mechanical support. Especially in areas of severe and complex bone defects, it ensures the stability of spatial support during bone regeneration, while simultaneously promoting vascularization and cell attachment, accelerating the bone regeneration process. Its biodegradable nature avoids secondary surgery, reducing patient discomfort and recovery time, and bringing a more efficient, precise, and patient-friendly solution to the field of bone regeneration. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the preparation method of the present invention;

[0042] Figure 2This invention, in embodiment 1, is a personalized GBR membrane designed using reverse engineering techniques to meet the patient's bone needs.

[0043] Figure 3 This is the process of a porous GBR membrane designed with BCC single-cell adaptive filling in Embodiment 1 of the present invention;

[0044] Figure 4 This is a porous GBR membrane designed with BCC single-cell adaptive filling in Embodiment 1 of the present invention;

[0045] Figure 5 The porous biodegradable GBR membrane of Embodiment 1 of the present invention is formed by SLM;

[0046] Figure 6 A comparison diagram of the adaptive porous GBR membrane and the array porous GBR membrane designed in Embodiment 1 of the present invention;

[0047] Figure 7 Finite element analysis of the porous GBR model designed using conventional unit cell array filling method and adaptive unit cell arrangement filling method in Embodiment 1 of the present invention;

[0048] Figure 8 The corrosion surface morphology of the porous biodegradable GBR membrane of Example 1 of the present invention after immersion in simulated body fluid for 28 days and 60 days;

[0049] Figure 9 The pH change trend of the porous biodegradable GBR membrane in simulated body fluid with immersion time in Example 1 of the present invention;

[0050] Figure 10 SEM images of the antibacterial bands of the porous biodegradable GBR membrane and the comparative titanium membrane of Example 1 of the present invention;

[0051] Figure 11 This is a bar chart showing the diameter data of the antibacterial band of the porous biodegradable GBR membrane and the control group titanium membrane in Example 1 of the present invention. Detailed Implementation

[0052] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0053] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0054] The following describes, with reference to the accompanying drawings, some embodiments of the present invention for the preparation of 3D-printed porous biodegradable metal GBR membranes.

[0055] Example 1

[0056] like Figure 1 As shown, a method for preparing a 3D-printed porous biodegradable metal GBR membrane includes the following steps:

[0057] S1. Perform CT scans on the alveolar bone of the recipient of the bone defect repair procedure, and use reverse engineering technology to obtain a scanned physical prototype of the personalized GBR membrane.

[0058] S2. Select a lattice structure with node connections and symmetry as the basic filling unit for constructing a porous GBR membrane;

[0059] S3. Perform single-cell adaptive filling design on the scanned physical prototype of the personalized GBR membrane to form a porous GBR membrane model.

[0060] S4. Use post-printing processing software to correct the mesh of the porous GBR membrane model, remove excess shells and repair misaligned meshes.

[0061] S5. Using biodegradable biometal powder, a porous biodegradable metal GBR membrane was prepared by 3D printing technology and combined with optimized process parameters.

[0062] In step S1, the radius of curvature, bending angle, and thickness of the personalized GBR membrane obtained using reverse engineering technology are matched to the shape and size characteristics of the bone defect site. Personalized GBR membranes designed using reverse engineering technology, such as... Figure 2 As shown.

[0063] In step S2, the porous GBR membrane uses a body-centered cubic (BCC) lattice as the filling unit cell and constructs a parameterized model of the BCC filling unit cell. The body-centered cubic boundary size is 1.2mm × 1.2mm × 1.5mm and the diameter of the support pillar is 0.2mm.

[0064] In step S3, such as Figure 3 As shown, the unit cell adaptive filling design for the scanned physical prototype of the personalized GBR film includes a lattice filling process. During lattice filling, the geometric center of the lattice is located on the curved surface of the GBR film. The steps for conformal filling of the lattice according to the curved surface angle of the GBR film model are as follows:

[0065] S31. Select and calculate the normal reference vector a of the center point of the lattice on the surface model of the personalized GBR film, and the tangential reference filling vector b that is perpendicular to the normal reference vector a.

[0066] S32. Based on the filling requirements, select and calculate two mutually perpendicular target vectors a1 and b1 of the lattice.

[0067] S33. Using the geometric center as the center of rotation, calculate the angle α1 between the corresponding normal reference vectors a and a1. S34. According to the vector formula a... n =a-a1, calculate the rotation direction vector a n The rotation of the lattice is achieved by calculating the rotation angle and rotation direction of the lattice using a rotation matrix.

[0068] S35. Repeat steps S33 and S34 for the tangential reference filling vector b to obtain a conformally filled porous GBR membrane model.

[0069] In step S3, the porous GBR membrane designed with BCC unit cell adaptive filling is as follows: Figure 4 As shown.

[0070] In step S5, the biodegradable biometal powder is made of pure zinc.

[0071] In step S5, the 3D printing method uses laser selective melting technology and a laser powder bed fusion machine (Laseradd, China) with a maximum laser power of 500W to prepare a BCC adaptive filled porous biodegradable metal GBR film.

[0072] In step S5, the optimized process parameters are used to print porous biodegradable metal GBR films with a scanning speed of 600 mm / s, a scanning spacing of 80 μm, a layer thickness of 30 μm, and a scanning direction of 45°.

[0073] Porous biodegradable pure zinc GBR membranes formed by SLM, such as Figure 5 As shown, the support geometry is evenly distributed and fully interconnected, providing stable and consistent support in different areas, creating a favorable mechanical environment for bone tissue regeneration.

[0074] The mechanical properties, degradation performance and antibacterial effect of the 3D printed porous biodegradable metal GBR membrane selected in Example 1 were tested according to the following standard procedure.

[0075] (1) Conformal structure

[0076] like Figure 6As shown, the left figure is the porous GBR model obtained after Boolean calculations of the lattice unit array and the GBR prototype model, while the right figure is the adaptive porous GBR model with conformal lattice filling. In the array method, the centers of the BCC unit cells are distributed along a straight line, while the boundary lines of the GBR model are curved. This causes some structures of the BCC unit cells in that row to extend beyond the GBR boundary, resulting in incomplete BCC lattices and poor connectivity between BCC support rods. In the adaptive method, the center and angle of each BCC lattice are adaptively adjusted for filling, ensuring that the boundary lines of that row of BCCs are consistent with the trajectory of the GBR boundary lines. The BCC lattice is completely preserved within the GBR boundary lines, giving the GBR porous model a complete lattice morphology.

[0077] (2) Mechanical properties

[0078] Static simulations of porous GBR membranes were performed using ABAQUS software (Dassault Systèmes, France) to compare the mechanical properties of conventional array-filled and adaptive unit-cell-filled GBR membranes under the same loading conditions. In the simulation, the upper surface of the GBR membrane model was subjected to a uniform load perpendicular to the membrane surface, while the lower surface was completely fixed.

[0079] like Figure 7 As shown, finite element analysis reveals that under the same load perpendicular to the surface, the stress distribution of the adaptively filled porous structure is more uniform than that of the conventional array-filled structure. Under the same load perpendicular to the surface, the incomplete struts of the conventional array-filled GBR membrane model lead to stress concentration and severe deformation. This could affect the mechanical properties of the spatial support in GBR applications. In contrast, the porous GBR adaptively filled membrane exhibits a more uniform stress distribution without significant deformation, providing a more stable and reliable mechanical environment for bone regeneration.

[0080] (3) Biodegradation

[0081] A 3D-printed porous biodegradable metal GBR membrane was immersed in simulated body fluid (China Yuanye) at 37°C for up to 60 days. According to ASTM G31-72 standard, the solution volume to sample surface area ratio was 20 ml / cm². 2 The surface morphology of the samples was observed using a digital camera and scanning electron microscope after immersion in SBF for 28 and 60 days. The biodegradation of the 3D-printed porous biodegradable metal GBR membrane was evaluated by immersion in simulated body fluid for 60 days, during which Zn content was monitored. 2+ The time evolution of concentration.

[0082] After 60 days of immersion, the pH change trend of the 3D-printed porous biodegradable GBR membrane in simulated body fluid with immersion time is as follows: Figure 8 As shown, the pH trend is weakly alkaline. In the early stages of degradation, on day 7, the Zn content of the 3D-printed porous biodegradable GBR membrane...2+ The release concentration was 10.29 ± 0.45 μg / ml. With increasing soaking time, Zn... 2+ The release rate has increased.

[0083] The corrosion surface morphology of 3D-printed porous biodegradable metal GBR membranes after immersion in simulated body fluid for 28 and 60 days is shown below. Figure 9 As shown, after 28 days, the edge of the 3D-printed porous biodegradable GBR membrane fractured, and the supporting structure was damaged; at 60 days, the integrity of the porous biodegradable GBR membrane was further compromised. The white biodegradable products were spherical in shape, with gradually increasing particle size; the particulate degradation products almost completely covered and blocked all the pores in the porous matrix.

[0084] (4) Antibacterial properties

[0085] The antibacterial properties of 3D-printed porous biodegradable metal GBR membranes were evaluated using the disk diffusion method. The 3D-printed porous biodegradable metal GBR membranes were sterilized by irradiation under ultraviolet light for 2 hours. A pure titanium membrane of the same size served as a control group. The samples were placed on a culture medium inoculated with Staphylococcus aureus and incubated at 37°C for 24 hours. The diameter of the inhibition zone was then observed and measured.

[0086] In the antibacterial zone experiment, after immersing the 3D-printed porous biodegradable metal GBR membrane in simulated body fluid for 60 days, it was co-cultured with Staphylococcus aureus for 24 hours. Transparent bacterial inhibition rings of varying sizes formed around the membrane, such as... Figure 10 As shown in the figure. This phenomenon was not observed around the titanium membrane in the control group, indicating that the 3D-printed pure zinc porous biodegradable GBR membrane possesses durable antibacterial capabilities. Scanning electron microscopy images show that live Staphylococcus aureus are scattered in a spherical form on the surface of the titanium membrane, while amorphous dead bacteria aggregates were observed around the 3D-printed porous biodegradable metal GBR membrane, indicating that the membrane has good antibacterial effects. The bar chart of the diameter data of the antibacterial zone is shown below. Figure 11 As shown, the larger the diameter of the inhibition zone, the better the antibacterial performance of the sample. The 3D-printed porous biodegradable metal GBR membrane exhibits good antibacterial performance.

[0087] Example 2

[0088] like Figure 1 As shown, a method for preparing a 3D-printed porous biodegradable metal GBR membrane includes the following steps:

[0089] S1. Perform CT scans on the alveolar bone of the recipient of the bone defect repair procedure, and use reverse engineering technology to obtain a scanned physical prototype of the personalized GBR membrane.

[0090] S2. Select a lattice structure with node connections and symmetry as the basic filling unit for constructing a porous GBR membrane;

[0091] S3. Perform single-cell adaptive filling design on the scanned physical prototype of the personalized GBR membrane to form a porous GBR membrane model.

[0092] S4. Use post-printing processing software to correct the mesh of the porous GBR membrane model, remove excess shells and repair misaligned meshes.

[0093] S5. Using biodegradable biometal powder, a porous biodegradable metal GBR membrane was prepared by 3D printing technology and combined with optimized process parameters.

[0094] This application discloses a method for preparing a 3D-printed porous biodegradable metal GBR membrane. Utilizing CT scanning and reverse engineering techniques, it enables the provision of personalized GBR membranes to patients, ensuring precise matching between the GBR membrane and the patient's alveolar bone and improving restorative outcomes. A lattice structure with node connections and symmetry is used as the basic filling unit. This structure offers advantages in mechanical properties and space utilization, providing better support and stability. Adaptive single-cell filling design is employed for the personalized GBR membrane to obtain a porous GBR membrane model, ensuring the uniformity and consistency of the porous GBR membrane, which is crucial for uniform growth and healing of bone defects. Post-printing processing software is used to correct the mesh of the porous GBR membrane model, eliminating potential errors during printing and improving product accuracy and quality. The porous biodegradable metal GBR membrane is prepared using biodegradable biometal powder. This material not only promotes bone tissue growth but also gradually degrades after fulfilling its function, reducing long-term impacts on the human body. Combining optimized process parameters for 3D printing improves printing efficiency, reduces material waste, and ensures the mechanical properties and biocompatibility of the final product. Personalized GBR membranes can better adapt to the patient's oral structure, improving postoperative comfort. The porous structure of the GBR membrane facilitates bone cell migration and growth, promotes bone integration, and accelerates the repair process of bone defects.

[0095] In any of the above technical solutions, in step S1, the position, size, edge shape, and contour of the personalized GBR membrane are matched with the bone defect area.

[0096] By precisely matching the position, size, edge shape, and contour of a personalized GBR membrane to the bone defect area, a perfect fit can be ensured, improving surgical precision and repair outcomes. A precisely matched GBR membrane can reduce complications caused by mismatch with the bone defect area, such as infection, inflammation, or poor healing.

[0097] In any of the above technical solutions, in step S1, the radius of curvature, bending angle and thickness of the personalized GBR membrane obtained by reverse engineering technology are matched with the shape and size characteristics of the bone defect site.

[0098] The radius of curvature, bending angle, and thickness of the personalized GBR membrane obtained through reverse engineering are adapted to and matched with the shape and size characteristics of the bone defect site. This allows the personalized GBR membrane to better fit the irregular shape of the bone defect area, improving the stability of the alveolar bone and the repair effect.

[0099] In any of the above technical solutions, in step S2, the shape of the basic filling unit is one or more of the following: body-centered cubic, octahedral cubic, face-centered cubic, regular hexahedron, cubic octahedron, truncated octahedron, regular dodecahedron, rhombic dodecahedron, regular icosahedron, diamond, truncated hexagonal tessellation, small rhombic truncated cube, honeycomb, and foam.

[0100] By selecting different basic filling unit shapes such as body-centered cubic, octahedral cubic, and face-centered cubic, diverse porous structures can be designed to meet the specific needs of different bone defect areas. Different lattice structures possess different mechanical properties. For example, the face-centered cubic structure exhibits high strength and stiffness due to its close-packed characteristics, which is particularly important for repairing bone defects subjected to significant mechanical loads. By selecting specific lattice structures, the porosity and pore size of porous GBR membranes can be controlled, thereby influencing their biocompatibility and osteogenic capacity. Different lattice structures can provide different attachment and growth spaces for osteoblasts, promoting osteoblast migration and growth, and accelerating the healing of bone defect areas.

[0101] In any of the above technical solutions, step S3, which involves performing a single-cell adaptive filling design on the scanned prototype of the personalized GBR membrane, is as follows:

[0102] S31. Select and calculate the normal reference vector a of the center point of the lattice on the surface model of the personalized GBR film, and the tangential reference filling vector b that is perpendicular to the normal reference vector a.

[0103] S32. Based on the filling requirements, select and calculate two mutually perpendicular target vectors a1 and b1 of the lattice.

[0104] S33. Using the geometric center as the center of rotation, calculate the angle α1 between the corresponding normal reference vectors a and a1. S34. According to the vector formula a... n =a-a1, calculate the rotation direction vector a n The rotation of the lattice is achieved by calculating the rotation angle and rotation direction of the lattice using a rotation matrix.

[0105] S35. Repeat steps S33 and S34 for the tangential reference filling vector b to obtain a conformally filled porous GBR membrane model.

[0106] By calculating the normal reference vector 'a' of the lattice center point on the curved surface model of the personalized GBR membrane, and the tangential reference filling vector 'b' perpendicular to 'a', the normal reference vector 'a' and the tangential reference filling vector 'b' coincide with the corresponding vectors of the filling nodes of the personalized GBR membrane. This allows the lattice arrangement to precisely adapt to the three-dimensional shape of the personalized GBR membrane, whether it be a straight line, a curve, or a complex surface morphology. By calculating parameters such as the target vector, included angle, rotation angle, and rotation direction, a single-cell adaptive filling design for the scanned prototype of the personalized GBR membrane was achieved. This design method ensures filling accuracy, avoids material waste, and improves the mechanical properties of the GBR membrane. The porous GBR membrane with the single-cell adaptive filling design exhibits uniform stress distribution, no significant deformation under load, reduces local stress concentration points, and lowers the risk of GBR membrane structural damage.

[0107] In any of the above technical solutions, the unit cell maintains structural integrity during the adaptive filling design process.

[0108] By employing structurally intact single cells as the basic filling unit in a single-cell adaptive filling design to prepare porous GBR membranes, the mechanical stability of the porous GBR membranes is improved, enabling them to withstand the stress and pressure in the oral environment. Simultaneously, the durability of the porous GBR membranes is enhanced, extending their in vivo lifespan and reducing the need for replacement or repair.

[0109] In any of the above technical solutions, the porous GBR membrane model obtained through the single-cell adaptive filling design process is subjected to uniform load distribution.

[0110] The porous GBR membrane model obtained through the single-cell adaptive filling design process has a uniform load distribution, which reduces local stress concentration and lowers the risk of deformation or breakage of the porous GBR membrane under stress.

[0111] In any of the above technical solutions, during the unit cell adaptive filling design process, the unit cells are arranged smoothly and continuously, precisely and completely adapting to the three-dimensional shape of the personalized GBR membrane.

[0112] The smooth and continuous arrangement of individual cells allows for precise and complete adaptation to the three-dimensional shape of a personalized GBR membrane. This characteristic enables the fabricated porous GBR membrane to exhibit high adaptability and flexibility, allowing it to conform to complex tissue surfaces and improve implantation outcomes.

[0113] In any of the above technical solutions, during step S4, the process of deleting redundant shells includes interfering shells and shells with a volume of 0.

[0114] Removing excess shells reduces unnecessary material waste and simplifies the printing process, making it more efficient. It also helps eliminate potential defects and flaws, resulting in a more uniform and consistent GBR film and reducing the difficulty and cost of post-processing.

[0115] In any of the above technical solutions, step S4, repairing the misaligned mesh includes correcting bad edges, overlapping and intersecting triangular facets.

[0116] By repairing misaligned meshes, especially correcting bad edges, overlaps, and intersecting triangular facets, the accuracy of 3D printing can be significantly improved, ensuring that the printed membrane structure is precise and error-free. Repairing misaligned meshes can prevent defects in the printed membrane structure, enhancing its integrity and durability.

[0117] In any of the above technical solutions, in step S5, the biodegradable biometal powder includes one of zinc, zinc-based alloy, magnesium, magnesium-based alloy, iron, and iron-based alloy.

[0118] The use of biodegradable metal powder offers significant advantages in GBR membrane applications. Biodegradable metal GBR membranes naturally degrade after use, eliminating the need for secondary surgery, greatly reducing patient discomfort, and lowering medical risks. The selected metal powder possesses antibacterial properties, which is crucial for preventing postoperative infections. Utilizing 3D printing technology to fabricate porous GBR membranes allows for customization of membrane structure and properties to meet specific needs.

[0119] In any of the above technical solutions, in step S4, the 3D printing technology includes one of laser selective melting technology and electron beam selective melting technology.

[0120] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0121] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing a 3D-printed porous biodegradable metal GBR film, characterized in that, Includes the following steps: S1. Perform CT scans on the alveolar bone of the recipient of the bone defect repair procedure, and use reverse engineering technology to obtain a scanned physical prototype of the personalized GBR membrane. S2. Select a lattice structure with node connections and symmetry as the basic filling unit for constructing a porous GBR membrane; S3. Perform single-cell adaptive filling design on the scanned physical prototype of the personalized GBR membrane to form a porous GBR membrane model. S4. Use post-printing processing software to correct the mesh of the porous GBR membrane model, remove excess shells and repair misaligned meshes. S5. Using biodegradable biometal powder, a porous biodegradable metal GBR membrane was prepared through 3D printing technology and optimized process parameters. In step S3, the steps for performing unit cell adaptive filling design on the scanned prototype of the personalized GBR membrane are as follows: S31. Select and calculate the normal reference vector a of the center point of the lattice on the surface model of the personalized GBR film, and the tangential reference filling vector b that is perpendicular to the normal reference vector a. S32. Based on the filling requirements, select and calculate two mutually perpendicular target vectors a1 and b1 of the lattice; S33. Using the geometric center as the center of rotation, calculate the angle between the corresponding normal reference vectors a and a1. ; S34. According to the vector formula Calculate the rotation direction vector The rotation angle and direction of the lattice are calculated using a rotation matrix to achieve lattice rotation. S35. Repeat steps S33 and S34 for the tangential reference filling vector b to obtain a conformally filled porous GBR membrane model.

2. The method for preparing a 3D-printed porous biodegradable metal GBR film according to claim 1, characterized in that, In step S1, the position, size, edge shape, and contour of the personalized GBR membrane are matched to the bone defect area.

3. The method for preparing a 3D-printed porous biodegradable metal GBR film according to claim 1, characterized in that, In step S1, the radius of curvature, bending angle, and thickness of the personalized GBR membrane obtained by reverse engineering are matched with the shape and size characteristics of the bone defect site.

4. The method for preparing a 3D-printed porous biodegradable metal GBR film according to claim 1, characterized in that, In step S2, the basic filling unit is one or more of the following shapes: body-centered cubic, face-centered cubic, regular hexahedron, cubic octahedron, truncated octahedron, regular dodecahedron, rhombic dodecahedron, regular icosahedron, diamond, truncated hexagonal tessellation, small rhombic truncated cube, honeycomb, and foam.

5. The method for preparing a 3D-printed porous biodegradable metal GBR film according to claim 1, characterized in that, In the process of adaptive filling design of unit cells, the unit cell maintains structural integrity; And / or the porous GBR membrane model obtained through a single-cell adaptive filling design process is subject to uniform load distribution; In the process of adaptive cell filling design, the cells are arranged smoothly and continuously to precisely and completely adapt to the three-dimensional shape of the personalized GBR membrane.

6. The method for preparing a 3D-printed porous biodegradable metal GBR film according to claim 1, characterized in that, In step S4, during the process of deleting redundant shells, the redundant shells include interfering shells and shells with a volume of 0.

7. The method for preparing a 3D-printed porous biodegradable metal GBR film according to claim 1, characterized in that, In step S4, repairing misaligned meshes includes correcting bad edges, overlaps, and intersecting triangular facets.

8. The method for preparing a 3D-printed porous biodegradable metal GBR film according to claim 1, characterized in that, In step S5, the biodegradable biometal powder includes one of zinc, zinc-based alloys, magnesium, magnesium-based alloys, iron, and iron-based alloys.

9. The method for preparing a 3D-printed porous biodegradable metal GBR film according to claim 1, characterized in that, In step S5, the 3D printing technology includes one of laser selective melting and electron beam selective melting.

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