Preparation method of 3D printing porous degradable metal GBR film

Abstract

The invention relates to a preparation method of a 3D printing porous degradable metal GBR film, and belongs to the field of biological material additive manufacturing. A preparation method of a 3D printing porous degradable metal GBR film comprises the following steps that S1, CT scanning is conducted on an alveolar bone of a bone defect repair implementation object, and a scanning entity prototype of the personalized GBR film is obtained through a reverse engineering technology; s2, selecting a lattice structure which is connected with nodes and has a symmetrical property as a basic filling unit for constructing the porous GBR membrane; s3, performing unit cell self-adaptive filling design on the scanning entity prototype of the personalized GBR membrane to form a porous GBR membrane model; s4, correcting the grids of the porous GBR membrane model by using printing post-processing software; and S5, preparing the porous degradable metal GBR film by adopting degradable biological metal powder through a 3D printing technology. By providing the personalized GBR film, the oral cavity structure of a patient can be better adapted. The porous GBR membrane is beneficial to migration and growth of bone cells and accelerates the repair process of bone defects.

Description

Technical Field

[0001] The present invention relates to the field of biomaterial additive manufacturing, and in particular to a method for preparing a 3D printed porous degradable metal GBR membrane. Background Art

[0002] Dental implants have revolutionized the rehabilitation of all teeth and significantly improved the quality of human life. Guided bone regeneration (GBR) is often used to repair alveolar bone loss or deficiency at the implant site. GBR membranes are often used to guide and promote bone tissue regeneration in dental and maxillofacial surgery. The lack of rigidity of GBR membranes made of biodegradable polymers limits their applicability to small alveolar bone defects that do not require additional fixation and stability. GBR membranes made of degradable metal materials, including zinc-based metals, magnesium-based metals, and iron-based metals, are often used to provide excellent mechanical support for severe and complex bone defect areas. In addition, the biocompatibility and degradability of degradable metal GBR membranes can reduce the need for secondary surgery and reduce the risk of infection. At the same time, they promote healing through biocompatibility and potential growth factor release, provide spatial support for severe and complex bone defect areas, and provide an ideal solution for bone tissue regeneration, improving treatment outcomes and patient experience.

[0003] Existing GBR membranes often lack personalized shapes and contours, resulting in poor treatment effects. Incorporating porous design into the curved surface of 3D printed metal-based GBR membranes also presents significant challenges in dealing with irregular boundaries and achieving uniform stress distribution. In the conventional unit cell array filling design method, the center points of the unit cells are distributed along a straight line, and the boundary lines of the GBR model are distributed in a curved line. When constructing a model with an irregular boundary, some unit cells in the array may exceed the boundary of the GBR model, resulting in incomplete unit cells and poor connectivity between unit pillars. Therefore, in response to the challenge of incorporating porous design into curved membranes, it is necessary to develop special porous design technology to avoid the problem of unit cells exceeding the boundary and poor connectivity of unit pillars when constructing irregular boundary models, and ensure the mechanical properties required for its spatial support.

[0004] Traditional GBR membrane manufacturing methods mainly rely on mold casting, mechanical processing and other processes. These methods are difficult to meet the needs of personalized treatment and have low production efficiency. 3D printing technology can achieve complex porous structures and personalized designs, provide sufficient mechanical support, and bring great potential to porous degradable metal GBR. Therefore, in order to solve the above problems, it is necessary to propose a porous degradable metal GBR membrane design and manufacturing method based on 3D printing technology to cope with different personalized GBR membrane shapes and treatment needs, improve the mechanical properties of GBR membranes, and provide a more ideal solution for the treatment of bone defects. Summary of the invention

[0005] Based on this, it is necessary to provide a 3D printed porous degradable metal GBR membrane preparation method to address the problem that the traditional GBR membrane manufacturing method is difficult to meet the needs of personalized treatment and has low production efficiency.

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

[0007] A method for preparing a 3D printed porous degradable metal GBR membrane comprises the following steps:

[0008] S1. Perform CT scanning on the alveolar bone of the subject to be repaired, and use reverse engineering technology to obtain the scanned entity prototype of the personalized GBR membrane;

[0009] S2, selecting a lattice structure with node connection and symmetry as a basic filling unit for constructing a porous GBR membrane;

[0010] S3, performing unit cell adaptive filling design on the scanned physical prototype of the personalized GBR membrane to form a porous GBR membrane model;

[0011] S4. Use the post-printing processing software to correct the mesh of the porous GBR membrane model, delete the redundant shells and repair the misplaced mesh;

[0012] S5. Use biodegradable biometal powder, through 3D printing technology, and combine with optimized process parameters to prepare porous biodegradable metal GBR membrane.

[0013] The present application discloses a method for preparing a 3D printed porous degradable metal GBR membrane. Through CT scanning technology and reverse engineering technology, it can provide patients with personalized GBR membranes, ensure the precise matching of the GBR membrane with the patient's alveolar bone, and improve the repair effect. A lattice structure with node connection and symmetrical properties is used as the basic filling unit. This structure has advantages in mechanical properties and space utilization, and can provide better support and stability. The personalized GBR membrane is adaptively filled with a single cell to obtain a porous GBR membrane model, which can ensure the uniformity and consistency of the porous GBR membrane, which is crucial for the uniform growth and healing of bone defect repair. Correcting the grid of the porous GBR membrane model using post-printing processing software can eliminate errors that may occur during the printing process and improve the accuracy and quality of the product. A porous degradable metal GBR membrane is prepared using degradable biometal powder. This material can not only promote the growth of bone tissue, but also gradually degrade after completing its function, reducing the long-term impact on the human body. 3D printing combined with optimized process parameters can improve printing efficiency, reduce material waste, and ensure the mechanical properties and biocompatibility of the final product. Personalized GBR membranes can better adapt to the patient's oral structure and improve the patient's postoperative comfort. The porous GBR membrane structure is conducive to the migration and growth of bone cells, 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 all match the bone defect area.

[0015] By precisely matching the position, size, edge shape and contour of the personalized GBR membrane with the bone defect area, it can be ensured that the personalized GBR membrane fits the bone defect area perfectly, improving the accuracy of the surgery and the repair effect. The 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 curvature radius, bending angle and thickness of the personalized GBR membrane obtained by reverse engineering technology match the shape and size characteristics of the bone defect site.

[0017] The curvature radius, bending angle and thickness of the personalized GBR membrane obtained through reverse engineering technology are adapted and matched to the shape and size characteristics of the bone defect area, so that the personalized GBR membrane can better fit the irregular shape of the bone defect area and improve the stability and repair effect of the alveolar bone.

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

[0019] By selecting different basic filling unit shapes such as body-centered cubic, regular octahedral cubic, face-centered cubic, etc., a variety of porous structures can be designed to meet the specific needs of different bone defect areas. Different lattice structures have different mechanical properties. For example, the face-centered cubic structure has higher strength and stiffness due to its densest packing characteristics, which is especially important for repairing bone defects that bear large mechanical loads. By selecting a specific lattice structure, the porosity and pore size of the porous GBR membrane can be regulated, thereby affecting its biocompatibility and osteogenic ability. Different lattice structures can provide different attachment and growth spaces for bone cells, promote the migration and growth of bone cells, and accelerate the healing of bone defect areas.

[0020] In any of the above technical solutions, in step S3, the steps of performing unit cell adaptive filling design on the scanned entity prototype of the personalized GBR membrane are as follows:

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

[0022] S32. According to the filling requirements, two mutually perpendicular target vectors a1 and b1 of the lattice are selected and calculated.

[0023] S33. Taking the geometric center as the rotation center, 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 , and calculate the rotation angle and direction of the lattice through the rotation matrix to realize the rotation of the lattice.

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

[0026] By calculating the normal reference vector a of the center point of the lattice on the surface model of the personalized GBR membrane, and the tangential reference filling vector b perpendicular to the normal reference vector a, the normal reference vector a and the tangential reference filling vector b coincide with the corresponding vectors of the personalized GBR membrane filling nodes, so that the arrangement of the lattice can accurately adapt to the three-dimensional shape of the personalized GBR membrane, whether it is a straight line, a curve or a complex surface morphology. By calculating parameters such as the target vector, angle, rotation angle and rotation direction, the single cell adaptive filling design of the scanned entity prototype of the personalized GBR membrane is realized. This design method can ensure the accuracy of filling, avoid material waste, and improve the mechanical properties of the GBR membrane. The porous GBR membrane with single cell adaptive filling design has uniform stress distribution and no obvious deformation when loaded, which reduces local stress concentration points and reduces the risk of damage to the GBR membrane structure.

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

[0028] By using a unit cell with structural integrity as the basic filling unit of the unit cell adaptive filling design to prepare a porous GBR membrane, the mechanical stability of the porous GBR membrane is improved, enabling it to withstand the stress and pressure in the oral environment. At the same time, the durability of the porous GBR membrane is enhanced, its action time in the body is extended, and the need for replacement or repair is reduced.

[0029] In any of the above technical solutions, the porous GBR membrane model obtained through the unit cell adaptive filling design process is evenly distributed under load.

[0030] The porous GBR membrane model obtained through the unit cell adaptive filling design process is evenly distributed under load, which reduces local stress concentration and reduces the risk of deformation or fracture of the porous GBR membrane when subjected to 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 to accurately and completely adapt to the three-dimensional shape of the personalized GBR membrane.

[0032] The smooth and continuous arrangement of the unit cells can accurately and completely adapt to the three-dimensional shape of the personalized GBR membrane. This feature makes the prepared porous GBR membrane highly adaptable and flexible, able to fit complex tissue surfaces and improve implantation effects.

[0033] In any of the above technical solutions, in the step S4, in the process of deleting redundant shells, the redundant shells include interfering shells and shells with a volume of zero.

[0034] By removing the extra shell, unnecessary material waste can be reduced, and at the same time, the complexity of the printing process can be reduced, making the printing process more efficient. Removing the extra shell helps eliminate potential defects and flaws, thereby producing a more uniform and consistent GBR membrane and reducing the difficulty and cost of post-processing.

[0035] In any of the above technical solutions, in step S4, repairing the misaligned mesh includes correcting bad edges, overlapping and crossing triangles.

[0036] By repairing the misaligned mesh, especially correcting bad edges, overlapping and intersecting triangles, the accuracy of 3D printing can be significantly improved, ensuring that the printed membrane structure is accurate. Repairing the misaligned mesh can avoid defects in the printed membrane structure and enhance the integrity and durability of the structure.

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

[0038] The metal powder used is degradable, which has significant advantages in the use of GBR membranes. After completing its mission, the degradable metal GBR membrane can naturally degrade, avoiding the need for secondary surgery, greatly alleviating the patient's pain, and reducing medical risks. The selected metal powder has antibacterial properties, which plays an important role in preventing postoperative infections. The porous GBR membrane is prepared using 3D printing technology, and the structure and properties of the membrane can be customized according to 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, the present invention can customize the GBR membrane according to the patient's specific anatomical structure and accurately adapt to the patient's specific bone defect condition; the 3D printed porous degradable metal GBR membrane proposed in the present invention can ensure the integrity of the single cells and reduce stress concentration, and provide sufficient mechanical support, especially in severe and complex bone defect areas, to ensure the stability of spatial support during bone regeneration, while promoting vascularization and cell attachment, and accelerating the bone regeneration process; the biodegradable property avoids secondary surgery, reduces the patient's discomfort and recovery time, and brings a more efficient, accurate and patient-friendly solution to the field of bone regeneration. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0042] Figure 2The personalized GBR membrane designed by reverse engineering technology in Embodiment 1 of the present invention in combination with the patient's bone needs;

[0043] Figure 3 The porous GBR membrane process designed by adaptive filling of BCC cells in Example 1 of the present invention;

[0044] Figure 4 The porous GBR membrane designed by adaptive filling of BCC cells in Example 1 of the present invention;

[0045] Figure 5 The porous degradable GBR membrane formed by SLM in Example 1 of the present invention;

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

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

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

[0049] Fig. 9 The pH variation trend of the porous degradable GBR membrane in simulated body fluid with immersion time in Example 1 of the present invention;

[0050] Fig.10 The SEM images of the antibacterial zones of the porous degradable GBR membrane of Example 1 of the present invention and the titanium membrane of the comparative example;

[0051] Fig.11 It is a bar graph of the diameter data of the antibacterial zone of the porous degradable GBR membrane of Example 1 of the present invention and the titanium membrane of the control group. DETAILED DESCRIPTION

[0052] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0053] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0054] The following describes the method for preparing the 3D printed porous degradable metal GBR membrane according to some embodiments of the present invention with reference to the accompanying drawings.

[0055] Example 1

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

[0057] S1. Perform CT scanning on the alveolar bone of the subject to be repaired, and use reverse engineering technology to obtain the scanned entity prototype of the personalized GBR membrane;

[0058] S2, selecting a lattice structure with node connection and symmetry as a basic filling unit for constructing a porous GBR membrane;

[0059] S3, performing unit cell adaptive filling design on the scanned physical prototype of the personalized GBR membrane to form a porous GBR membrane model;

[0060] S4. Use the post-printing processing software to correct the mesh of the porous GBR membrane model, delete the redundant shells and repair the misplaced mesh;

[0061] S5. Use biodegradable biometal powder, through 3D printing technology, and combine with optimized process parameters to prepare porous biodegradable metal GBR membrane.

[0062] In step S1, the curvature radius, bending angle and thickness of the personalized GBR membrane obtained by reverse engineering technology match the shape and size characteristics of the bone defect. Figure 2 shown.

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

[0064] In step S3, Figure 3 As shown, the unit cell adaptive filling design of the scanned entity prototype of the personalized GBR membrane includes the process of lattice filling. When the lattice is filled, the geometric center of the lattice is located on the surface of the GBR membrane. The steps of conformal filling of the lattice according to the surface angle of the GBR membrane model are as follows:

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

[0066] S32. According to the filling requirements, two mutually perpendicular target vectors a1 and b1 of the lattice are selected and calculated.

[0067] S33, taking the geometric center as the rotation center, calculate the angle α1 between the corresponding normal reference vector a and a1. S34, according to the vector formula a n =a-a1, calculate the rotation direction vector a n , and calculate the rotation angle and direction of the lattice through the rotation matrix to realize the rotation of the lattice.

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

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

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

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

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

[0073] The porous degradable pure zinc GBR membrane formed by SLM Figure 5 As shown, the support geometry is evenly distributed and fully interconnected, and different areas can provide stable and consistent support forces, creating a good mechanical environment for the regeneration of bone tissue.

[0074] The mechanical properties, degradation properties and antibacterial effects of the 3D printed porous degradable metal GBR membrane selected in this Example 1 were tested according to the following standard procedures.

[0075] (1) Structural conformity

[0076] like Figure 6As shown in the figure, the left figure is a porous GBR model obtained after lattice unit array processing and Boolean calculation of the GBR prototype model, and the right figure is an adaptive porous GBR model with lattice conformal filling. In the array method, the center of the BCC unit cell is distributed along a straight line, while the boundary line of the GBR model is a curve, which makes part of the structure of the BCC unit cell in this column exceed the GBR boundary, resulting in incomplete BCC lattice and poor connectivity between BCC support rods. In the adaptive method, the center and angle of each BCC lattice are filled with angle adaptive adjustment, so that the boundary line of the row of BCC is consistent with the GBR boundary line trajectory, and the BCC lattice is completely retained within the boundary line of the GBR, so that the GBR porous model has a complete lattice morphology.

[0077] (2) Mechanical properties

[0078] The static simulation of the porous GBR membrane was carried out using ABAQUS software (Dassault, France) to compare the mechanical properties of the GBR membrane with conventional array filling and adaptive unit cell filling 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 in the figure, finite element analysis shows that under the same load perpendicular to the surface, the stress distribution of the adaptive filling porous structure is more uniform than that of the conventional array filling. Under the same load perpendicular to the surface, the incomplete struts of the GBR membrane model filled with conventional arrays lead to stress concentration and severe deformation of the struts. This may affect the mechanical properties of the spatial support in GBR applications. In contrast, the stress distribution of the porous GBR adaptive filling membrane is more uniform, without obvious deformation, and can provide a more stable and reliable mechanical environment for bone regeneration.

[0080] (3) Biodegradation

[0081] The 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 ratio of solution volume to sample surface area was 20 ml / cm 2 The surface morphology of the samples was observed by digital camera and scanning electron microscope after immersion in SBF for 28 and 60 days. The biodegradation of the 3D printed porous degradable metal GBR membrane was evaluated by immersion in simulated body fluid for 60 days. During the immersion process, the Zn 2+ Time evolution of concentration.

[0082] After immersion for 60 days, the pH change trend of the 3D printed porous degradable GBR membrane in simulated body fluid with immersion time is as follows Figure 8 As shown in the figure, the pH change trend is weakly alkaline. In the early stage of degradation, the Zn content of the 3D printed porous degradable GBR membrane on the 7th day2+ The release concentration was 10.29±0.45μg / ml. With the increase of immersion time, Zn 2+ The release rate increased.

[0083] The corrosion surface morphology of the 3D printed porous biodegradable metal GBR membrane after immersion in simulated body fluid for 28 days and 60 days is shown in Figure 2. Fig. 9 As shown in Figure 2, the edges of the 3D printed porous degradable GBR membrane were broken and the supporting structure was damaged after 28 days; at 60 days, the integrity of the porous degradable GBR membrane was further damaged. The white biodegradable products were spherical in shape and gradually increased in size; the granular degradation products almost completely covered and blocked all the pores within the porous matrix.

[0084] (4) Antibacterial properties

[0085] The antibacterial properties of 3D printed porous degradable metal GBR membranes were evaluated by disk diffusion method. The 3D printed porous degradable metal GBR membranes were sterilized by irradiation with ultraviolet light for 2 hours. A pure titanium membrane of the same size was used as the control group. The samples were placed on a culture medium inoculated with Staphylococcus aureus and cultured at 37°C for 24 hours before observing and measuring the inhibition zone diameter value.

[0086] In the inhibition zone test, the 3D printed porous biodegradable metal GBR membrane was immersed in simulated body fluid for 60 days and co-cultured with Staphylococcus aureus for 24 hours, and transparent bacterial inhibition rings of different sizes were formed around it, such as Fig.10 As shown. This phenomenon was not observed around the titanium film in the control group, indicating that the 3D printed pure zinc porous degradable GBR membrane has a long-lasting antibacterial ability. Scanning electron microscope images show that live Staphylococcus aureus is scattered on the surface of the titanium film in a spherical form, while amorphous dead bacteria are observed around the 3D printed porous degradable metal GBR membrane, indicating that the membrane has a good antibacterial effect. The data bar graph of the diameter of the inhibition zone is shown in Fig.11 As shown, the larger the inhibition zone diameter, the better the antibacterial property of the sample, and the 3D printed porous degradable metal GBR membrane exhibits good antibacterial property.

[0087] Example 2

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

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

[0090] S2, selecting a lattice structure with node connection and symmetry as a basic filling unit for constructing a porous GBR membrane;

[0091] S3, performing unit cell adaptive filling design on the scanned physical prototype of the personalized GBR membrane to form a porous GBR membrane model;

[0092] S4. Use the post-printing processing software to correct the mesh of the porous GBR membrane model, delete the redundant shells and repair the misplaced mesh;

[0093] S5. Use biodegradable biometal powder, through 3D printing technology, and combine with optimized process parameters to prepare porous biodegradable metal GBR membrane.

[0094] The present application discloses a method for preparing a 3D printed porous degradable metal GBR membrane. Through CT scanning technology and reverse engineering technology, it can provide patients with personalized GBR membranes, ensure the precise matching of the GBR membrane with the patient's alveolar bone, and improve the repair effect. A lattice structure with node connection and symmetrical properties is used as the basic filling unit. This structure has advantages in mechanical properties and space utilization, and can provide better support and stability. The personalized GBR membrane is adaptively filled with a single cell to obtain a porous GBR membrane model, which can ensure the uniformity and consistency of the porous GBR membrane, which is crucial for the uniform growth and healing of bone defect repair. Correcting the grid of the porous GBR membrane model using post-printing processing software can eliminate errors that may occur during the printing process and improve the accuracy and quality of the product. A porous degradable metal GBR membrane is prepared using degradable biometal powder. This material can not only promote the growth of bone tissue, but also gradually degrade after completing its function, reducing the long-term impact on the human body. 3D printing combined with optimized process parameters can improve printing efficiency, reduce material waste, and ensure the mechanical properties and biocompatibility of the final product. Personalized GBR membranes can better adapt to the patient's oral structure and improve the patient's postoperative comfort. The porous GBR membrane structure is conducive to the migration and growth of bone cells, 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 the personalized GBR membrane with the bone defect area, it can be ensured that the personalized GBR membrane fits the bone defect area perfectly, improving the accuracy of the surgery and the repair effect. The 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 curvature radius, bending angle and thickness of the personalized GBR membrane obtained by reverse engineering technology match the shape and size characteristics of the bone defect site.

[0098] The curvature radius, bending angle and thickness of the personalized GBR membrane obtained through reverse engineering technology are adapted and matched to the shape and size characteristics of the bone defect area, so that the personalized GBR membrane can better fit the irregular shape of the bone defect area and improve the stability and repair effect of the alveolar bone.

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

[0100] By selecting different basic filling unit shapes such as body-centered cubic, regular octahedral cubic, face-centered cubic, etc., a variety of porous structures can be designed to meet the specific needs of different bone defect areas. Different lattice structures have different mechanical properties. For example, the face-centered cubic structure has higher strength and stiffness due to its densest packing characteristics, which is especially important for repairing bone defects that bear large mechanical loads. By selecting a specific lattice structure, the porosity and pore size of the porous GBR membrane can be regulated, thereby affecting its biocompatibility and osteogenic ability. Different lattice structures can provide different attachment and growth spaces for bone cells, promote the migration and growth of bone cells, and accelerate the healing of bone defect areas.

[0101] In any of the above technical solutions, in step S3, the steps of performing unit cell adaptive filling design on the scanned physical prototype of the personalized GBR membrane are as follows:

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

[0103] S32. According to the filling requirements, two mutually perpendicular target vectors a1 and b1 of the lattice are selected and calculated.

[0104] S33, taking the geometric center as the rotation center, calculate the angle α1 between the corresponding normal reference vector a and a1. S34, according to the vector formula a n =a-a1, calculate the rotation direction vector a n , and calculate the rotation angle and direction of the lattice through the rotation matrix to realize the rotation of the lattice.

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

[0106] By calculating the normal reference vector a of the center point of the lattice on the surface model of the personalized GBR membrane, and the tangential reference filling vector b perpendicular to the normal reference vector a, the normal reference vector a and the tangential reference filling vector b coincide with the corresponding vectors of the personalized GBR membrane filling nodes, so that the arrangement of the lattice can accurately adapt to the three-dimensional shape of the personalized GBR membrane, whether it is a straight line, a curve or a complex surface morphology. By calculating parameters such as the target vector, angle, rotation angle and rotation direction, the single cell adaptive filling design of the scanned prototype of the personalized GBR membrane is realized. This design method can ensure the accuracy of the filling, avoid material waste, and improve the mechanical properties of the GBR membrane. The porous GBR membrane with single cell adaptive filling design has uniform stress distribution and no obvious deformation when loaded, which reduces local stress concentration points and reduces the risk of damage to the GBR membrane structure.

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

[0108] By using a unit cell with structural integrity as the basic filling unit of the unit cell adaptive filling design to prepare a porous GBR membrane, the mechanical stability of the porous GBR membrane is improved, enabling it to withstand the stress and pressure in the oral environment. At the same time, the durability of the porous GBR membrane is enhanced, its action time in the body is extended, and the need for replacement or repair is reduced.

[0109] In any of the above technical solutions, the porous GBR membrane model obtained through the unit cell adaptive filling design process is evenly distributed under load.

[0110] The porous GBR membrane model obtained through the unit cell adaptive filling design process is evenly distributed under load, which reduces local stress concentration and reduces the risk of deformation or fracture of the porous GBR membrane when subjected to 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 to accurately and completely adapt to the three-dimensional shape of the personalized GBR membrane.

[0112] The smooth and continuous arrangement of the unit cells can accurately and completely adapt to the three-dimensional shape of the personalized GBR membrane. This feature makes the prepared porous GBR membrane highly adaptable and flexible, able to fit complex tissue surfaces and improve implantation effects.

[0113] In any of the above technical solutions, in step S4, in the process of deleting redundant shells, the redundant shells include interfering shells and shells with a volume of zero.

[0114] By removing the extra shell, unnecessary material waste can be reduced, and at the same time, the complexity of the printing process can be reduced, making the printing process more efficient. Removing the extra shell helps eliminate potential defects and flaws, thereby producing a more uniform and consistent GBR membrane and reducing the difficulty and cost of post-processing.

[0115] In any of the above technical solutions, in step S4, repairing the misaligned mesh includes correcting bad edges, overlapping and crossing triangles.

[0116] By repairing the misaligned mesh, especially correcting bad edges, overlapping and intersecting triangles, the accuracy of 3D printing can be significantly improved, ensuring that the printed membrane structure is accurate. Repairing the misaligned mesh can avoid defects in the printed membrane structure and enhance the integrity and durability of the structure.

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

[0118] The metal powder used is degradable, which has significant advantages in the use of GBR membranes. After completing its mission, the degradable metal GBR membrane can naturally degrade, avoiding the need for secondary surgery, greatly alleviating the patient's pain, and reducing medical risks. The selected metal powder has antibacterial properties, which plays an important role in preventing postoperative infections. The porous GBR membrane is prepared using 3D printing technology, and the structure and properties of the membrane can be customized according to needs.

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

[0120] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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 above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a 3D printed porous degradable metal GBR membrane, characterized in that: The steps include: S1. Perform CT scanning on the alveolar bone of the subject undergoing bone defect repair, and use reverse engineering technology to obtain a scanned physical prototype of the personalized GBR membrane; S2, selecting a lattice structure with node connection and symmetry as a basic filling unit for constructing a porous GBR membrane; S3, performing unit cell adaptive filling design on the scanned physical prototype of the personalized GBR membrane to form a porous GBR membrane model; S4. Use the post-printing processing software to correct the mesh of the porous GBR membrane model, delete the redundant shells and repair the misplaced mesh; S5. Use biodegradable biometal powder, through 3D printing technology, and combine with optimized process parameters to prepare porous biodegradable metal GBR membrane.

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

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

4. The method for preparing a 3D printed porous degradable metal GBR membrane according to claim 1, characterized in that: In step S2, the shape of the basic filling unit is one or more of body-centered cube, octahedron cube, face-centered cube, hexahedron, cuboctahedron, truncated octahedron, dodecahedron, rhombic dodecahedron, icosahedron, diamond, truncated hexagonal mosaic, rhombic truncated cube, honeycomb, and foam.

5. The method for preparing a 3D printed porous degradable metal GBR membrane according to claim 1, characterized in that: In step S3, the steps of performing unit cell adaptive filling design on the scanned entity prototype of the personalized GBR membrane are as follows: S31, selecting and calculating a normal reference vector a of the center point of the lattice on the surface model of the personalized GBR film, and a tangential reference filling vector b perpendicular to the normal reference vector a; S32, according to the filling requirement, select and calculate two mutually perpendicular target vectors a1 and b1 of the lattice; S33, taking the geometric center as the rotation center, calculating 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 , and calculate the rotation angle and rotation direction of the lattice through the rotation matrix to realize the rotation of the lattice; S35. Repeat steps S33 and S34 for the tangential reference filling vector b to obtain a porous GBR membrane model with conformal filling.

6. The method for preparing a 3D printed porous degradable metal GBR membrane according to claim 1, characterized in that: During the unit cell adaptive filling design process, the unit cell has structural integrity; and / or the porous GBR membrane model obtained through the unit cell adaptive packing design process is uniformly distributed under load; And / or during the unit cell adaptive filling design process, the unit cells are arranged smoothly and continuously, accurately and completely adapting to the three-dimensional shape of the personalized GBR membrane.

7. The method for preparing a 3D printed porous degradable metal GBR membrane according to claim 1, characterized in that: In the process of deleting redundant shells in step S4, the redundant shells include interfering shells and shells with a volume of zero.

8. The method for preparing a 3D printed porous degradable metal GBR membrane according to claim 1, characterized in that: In step S4, repairing the misaligned mesh includes correcting bad edges, overlapping and crossing triangles.

9. The method for preparing a 3D printed porous degradable metal GBR membrane according to claim 1, characterized in that: In the step S5, the biodegradable metal powder includes one of zinc, zinc-based alloy, magnesium, magnesium-based alloy, iron, and iron-based alloy.

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

Images