Preparation method for TPMS gradient structure of 3d-printed personalized implant root

Abstract

Disclosed in the present invention is a preparation method for a TPMS gradient structure of a 3D-printed personalized implant root. The method comprises: constructing a plurality of different types of implant root structure models; performing finite element simulation analysis on the implant root structure models; selecting an implant root structure model corresponding to a Gyroid structure; determining the porosity range of the Gyroid structure; designing the Gyroid structure as a gradient porosity Gyroid structure; and on the basis of the gradient porosity Gyroid structure, using a 3D printer to prepare a TPMS gradient structure of an implant root. The present invention combines a TPMS gradient structure with a 3D printing technique, such that the biocompatibility, mechanical property and personalization adaptability of an implant are improved, thereby promoting the effective integration of the implant with host tissue, and achieving a better functional reconstruction effect.

Description

3D printing personalized implant root TPMS gradient structure preparation method TECHNICAL FIELD

[0001] The application belongs to the technical field of porous implant root structure preparation, and particularly relates to a 3D printing personalized implant root TPMS gradient structure preparation method. BACKGROUND

[0002] Traditional porous implant root structures usually adopt uniform pore structures, which to some extent limit tissue growth and intravascular biological adaptability, and can lead to loose bonding between the implant and the host tissue, in addition, stress concentration phenomenon is prone to occur, and there are challenges for long-term functional reconstruction. In addition, the implant preparation of the traditional method is usually universalized, and lacks personalized design, so that the patient-specific anatomical structure and physiological characteristics cannot be fully considered.

[0003] SUMMARY

[0004] The purpose of the present application is to solve the problems of large structural stiffness, poor biocompatibility, high elastic modulus and stress concentration prone to occur in traditional implant root structures.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is:

[0006] A 3D printing personalized implant root TPMS gradient structure preparation method, comprising the following steps:

[0007] S1, constructing a plurality of different types of implant root structure models based on ANSYS finite element software;

[0008] S2, performing finite element simulation analysis on a plurality of implant root structure models;

[0009] S3, selecting the implant root structure model corresponding to the Gyroid structure according to the finite element simulation analysis result;

[0010] S4, determining the porosity range of the Gyroid structure according to the relative elastic modulus of the implant root structure;

[0011] S5, combining the porosity range and implicit function of the Gyroid structure, and designing the Gyroid structure as a gradient porosity Gyroid structure in the xy plane;

[0012] S6, based on the gradient porosity Gyroid structure, using a 3D printer to prepare an implant root TPMS gradient structure.

[0013] Further, the plurality of different types of implant root structure models in step S1 include Schwarz structure, Diamond structure, Gyroid structure and SplitP structure.

[0014] Further, step S2 includes: respectively performing finite element simulation analysis on the implant root structure models corresponding to the Schwarz structure, Diamond structure, Gyroid structure and SplitP structure, and respectively comparing the stress and deformation of each structure.

[0015] Further, step S3 includes: according to the finite element simulation analysis results of the stress and deformation of the implant root structure models corresponding to the Schwarz structure, Diamond structure, Gyroid structure and SplitP structure, selecting the implant root structure model corresponding to the Gyroid structure.

[0016] Further, step S4 includes:

[0017] Calculate the relative elastic modulus of the implant root structure:

[0018] Where E* is the relative elastic modulus of the implant structure unit, E is the elastic modulus of the material, and the porosity is

[0019] Based on the calculated value of the porosity and the compression test, it is determined that the porosity range is 20% to 50%.

[0020] Further, step S5 includes:

[0021] Based on the porosity range, the Gyroid structure is designed as a gradient porosity Gyroid structure with the porosity gradually increasing from the inner diameter to the outer diameter in the xy plane;

[0022] And the value of the gradient porosity Gyroid structure at different radius positions is controlled by the implicit function of the Gyroid structure, so as to control the gradient change of the porosity gradually increasing from the inner diameter to the outer diameter by 20% to 50%.

[0023] Further, the expression of the implicit function f(x, y, z) of the Gyroid structure is: f(x, y, z)=sin(k1x)cos(k2y)+sin(k2y)cos(k3z)+sin(k3z)cos(k1x)+d0-m(r cyl )

[0024] Where k1, k2, k3 are constants; d0 is a constant offset; x, y, z are spatial variables; m(r cyl) is a mapping function defined according to the shape of the implant root.

[0025] Further, the mapping function m(r cyl ) is expressed as:

[0026] where p min is the porosity of r min ; p max is the porosity of r max ; r min and r max are the minimum and maximum distance values corresponding to the innermost diameter and the outermost diameter of the implant root, respectively; and r is the actual distance from a specific point to the center of the implant root.

[0027] The 3D printing personalized implant root TPMS gradient structure preparation method provided by the application has the following beneficial effects:

[0028] 1. The application combines TPMS gradient structure and 3D printing technology to improve the biocompatibility, mechanical properties and personalized adaptability of the implant, thereby promoting the effective combination of the implant and the host tissue and achieving better functional reconstruction effect.

[0029] 2. The TPMS gradient porous structure can better simulate the characteristics of biological tissues, such as the multi-level pore distribution and mechanical properties of bone structure; compared with the traditional porous structure, the smooth joint and gradually porous design of the application make the TPMS gradient structure have higher surface area, better intravascular biological adaptability and better extracellular matrix support, which can promote cell migration and tissue regeneration, and is expected to achieve better tissue growth and functional reconstruction effect.

[0030] 3. Improve the bonding force of the implant and the host tissue: the design of the TPMS gradient structure with suitable pore distribution and shape is beneficial to promote cell migration and tissue growth, and enhances the bonding force of the implant and the host tissue to achieve long-term stability.

[0031] 4. Improve biocompatibility and mechanical properties: using biocompatible materials for printing, and adjusting the pore size and shape of the TPMS gradient structure, ensures that the implant has good biocompatibility and mechanical properties, and avoids rejection reaction and structural failure.

[0032] 5. Realize personalized design: using 3D printing technology, personalized design is carried out according to the specific conditions of the patient, considering different anatomical structures and physiological characteristics, so that the implant better adapts to the needs of the patient, improves the treatment effect and the quality of life of the patient.

[0033] 6. The gradient change of the TPMS structure is accurately controlled through the implicit function and mapping function expression, so as to be suitable for various implant root morphologies and improve the individualization of the implant. BRIEF DESCRIPTION OF DRAWINGS

[0034] Fig. 1 is a schematic diagram of a 3D-printed individualized implant structure according to Embodiment 2 of the present application.

[0035] Fig. 2 is a diagram of an individualized root structure according to Embodiment 2 of the present application.

[0036] Fig. 3 is a cross-sectional view of a gradient porosity Gyroid structure according to Embodiment 2 of the present application.

[0037] Fig. 4 is a flowchart of a method according to Embodiment 1 of the present application.

[0038] wherein 1, abutment; 2, porous root; 3, implant bottom; 4, 20% porosity range; 5, 35% porosity range; 6, 50% porosity range; 7, Gyroid structure; 8, 20% porosity pore size of the Gyroid structure; 9, 35% porosity pore size of the Gyroid structure; 10, 50% porosity pore size of the Gyroid structure. DETAILED DESCRIPTION

[0039] The specific embodiments of the present application are described below to facilitate the understanding of the present application for those skilled in the art, but it should be clear that the present application is not limited to the scope of the specific embodiments, and for those skilled in the art, any changes that are obvious within the spirit and scope of the present application as defined and determined by the appended claims are obvious, and all inventions utilizing the concept of the present application are within the scope of protection.

[0040] Embodiment 1

[0041] The present embodiment provides a method for preparing a 3D-printed individualized implant root TPMS gradient structure. The present embodiment obtains a gradient porosity Gyroid structure with a porosity of 20%-50% through finite element analysis, which has better biomechanical properties. The porosity gradient is accurately controlled through a mapping function and an implicit function expression. Compared with traditional porous structures, the present embodiment overcomes the limitations of traditional implant root structures. The smooth joints and gradually porous design of the present embodiment make the TPMS gradient structure have a higher surface area, better intravascular biological adaptability, and better extracellular matrix support, which can promote cell migration and tissue regeneration, and is expected to achieve better tissue growth and functional reconstruction effects. Referring to Fig. 4, the method specifically includes the following steps:

[0042] Step S1, constructing a plurality of different types of implant root structure models based on ANSYS finite element software;

[0043] Four structures were selected in this embodiment: Schwarz structure, Diamond structure, Gyroid structure and SplitP structure, and the implicit function expressions of each structure are shown in Table 1:

[0044] Table 1 Implicit function expression

[0045] Step S2, finite element simulation analysis is performed on the plurality of implant root structure models;

[0046] The finite element simulation analysis is performed on the different four structures in step S1 by ANSYS, and the selection of each structure comprehensively considers the mechanical properties and the interaction with the bone tissue; specifically, the implant root structure models corresponding to the Schwarz structure, the Diamond structure, the Gyroid structure and the SplitP structure are respectively subjected to finite element simulation analysis, and the stress and deformation of each structure are compared.

[0047] Through the finite element analysis, it can be known that the Gyroid structure is about 14% lower in the maximum stress value, reducing the potential risk of stress concentration.

[0048] The maximum stress value of the SplitP structure is 214.287 MPa, which is the highest among the four structures, but its maximum deformation is slightly lower than that of the Gyroid. Compared with the Gyroid structure, the SplitP structure may be more prone to stress concentration in the local area, which may lead to local fatigue in implant applications.

[0049] The maximum stress distribution value of the Diamond structure is 57.776 MPa, and the maximum deformation is 1.511e-03 mm, which indicates that this structure may exhibit a better balance between strength and rigidity when subjected to compression. However, the lower stress distribution may also mean that its carrying capacity is limited in actual application.

[0050] The Schwarz structure shows moderate performance in deformation and stress distribution, with a maximum stress value of 109.862 MPa and a maximum deformation of 1.802e-03 mm. This moderate response indicates that it may provide a compromise between mechanical properties and flexibility.

[0051] Step S3, according to the results of the finite element simulation analysis in step S2, the implant root structure model corresponding to the Gyroid structure is selected;

[0052] According to the results of the finite element simulation analysis of the stress and deformation of the implant root structure models corresponding to the Schwarz structure, the Diamond structure, the Gyroid structure and the SplitP structure, the implant root structure model corresponding to the Gyroid structure is selected;

[0053] From the finite element simulation analysis results in step S2, the Gyroid structure shows potential application value for dental implants due to its more uniform stress distribution and moderate elastic modulus, so the Gyroid structure will be adopted in this embodiment and the gradient will be adjusted as needed, and the specific gradient adjustment is shown in steps S4 and S5.

[0054] Step S4, according to the relative elastic modulus of the implant root structure, the porosity range of the Gyroid structure is determined;

[0055] The relative elastic modulus of the implant root structure is calculated as follows:

[0056] Where E* is the relative elastic modulus of the implant structure unit, E is the elastic modulus of the material, and the porosity is

[0057] By calculating and analyzing the elastic modulus in the design stage, when the porosity is 50%, the elastic modulus is close to the elastic modulus of human bone 10-30 GPa, which further optimizes the selection of materials and the design of gradient structure, and through compression test, as shown in Table 2, to realize the stability and reliability of the implant after implantation, greatly reducing the stress concentration phenomenon. Realize the optimization matching of material and structure, so as to improve the functional performance of the implant.

[0058] Table 2-

[0059] Based on the calculation value of the porosity and the compression test, it can be determined that the porosity range is 20%-50%, which can realize the optimization matching of material and structure, so as to improve the functional performance of the implant.

[0060] Step S5, combining the porosity range of the Gyroid structure and the implicit function, the Gyroid structure is designed as a gradient porosity Gyroid structure in the xy plane;

[0061] Based on the porosity range, the Gyroid structure is designed as a gradient porosity Gyroid structure with increasing porosity from the inner diameter to the outer diameter in the xy plane;

[0062] Specifically, the gradient structure has small porosity at the inner diameter and large porosity at the outer diameter, and the porosity gradually increases from 20% to 50% from the inner diameter to the outer diameter, forming a porosity gradient from the inner diameter to the outer diameter. In addition, the parameters of the Gyroid structure are adjusted to control the porosity, and the change of the porosity can be realized by adjusting the density of the Gyroid, that is, adjusting the "thickness" of the contour line on the surface.

[0063] This embodiment controls the value of the gradient porosity Gyroid structure at different radius positions through the implicit function of the Gyroid structure, to control the gradient change of the porosity gradually increasing from 20% to 50% from the inner radius to the outer radius, which is as follows:

[0064] For the convenience of calculation, the implant root of this embodiment is assumed to be a cylinder; the center line of the cylinder is defined as the Z axis, the center point of the bottom surface of the cylinder is defined as the coordinate origin, and the distance (in the xy plane) of an arbitrary point to the center line of the cylinder can be represented by r According to the mapping function m(r cyl ) defined according to the shape of the implant root, the distance r cyl from the center line is mapped to the porosity, and the distance from 0 to R corresponds to the porosity change from 20% to 50%.

[0065] where p min is the porosity of the inner radius r min , which is 20% here;

[0066] p max is the porosity of the outermost radius r max , which is 50% here;

[0067] r min and r max are the minimum and maximum distance values corresponding to the innermost and outermost radii of the implant root, respectively; r is the actual distance of a specific point to the center of the implant root.

[0068] In this way, the porosity can be adjusted according to the distance of each point to the center, so as to realize the gradient change of the porosity; based on this, according to the mapping function m(r cyl ), the expression of the Gyroid implicit function is modified as: f(x,y,z)=sin(k1x)cos(k2y)+sin(k2y)cos(k3z)+sin(k3z)cos(k1x)+d0-m(r cyl )

[0069] where k1, k2, and k3 are constants; d0 is a constant offset; x, y, and z are spatial variables; and m(r cyl ) is a mapping function defined according to the shape of the implant root.

[0070] This embodiment realizes the gradient change of the porosity by controlling the value at different radius positions of the cylinder, to ensure the accurate control of the porosity and the mechanical stability of the structure.

[0071] The gradient porosity Gyroid structure of the present embodiment, i.e. the implant root TPMS gradient structure, has a design scheme of small inner diameter porosity and large outer diameter porosity, which helps to improve the biocompatibility and bioactivity of the implant. The lower porosity at the inner diameter can provide more mechanical support and stability, which is beneficial for the initial implantation and healing of the implant; while the higher porosity at the outer diameter provides more cell attachment points and growth space, promoting the regeneration and growth of the surrounding tissue.

[0072] Step S6, based on the gradient porosity Gyroid structure, a 3D printer is used to prepare the implant root TPMS gradient structure.

[0073] The implant root TPMS gradient structure of the present embodiment can be customized according to specific clinical needs. By adjusting the slope and range of the gradient, the porosity distribution of different parts can be realized to meet the physiological and functional needs of different tissues. It can be customized according to the individual differences and specific needs of patients. By adjusting the parameters of the pores, such as size, shape and distribution, personalized implant design can be achieved, thereby improving the adaptability and acceptability of the implant. This personalized design helps to improve the adaptability and stability of the implant, and reduces post-implantation complications and rejection reactions.

[0074] The present application gradually increases the inner diameter to outer diameter porosity from 20% to 50%, forming a porosity gradient from the inner diameter to the outer diameter. This gradient design can better simulate the structural characteristics of natural tissues, providing a suitable environment for the repair and regeneration of surrounding tissues; the design of gradient porosity can also optimize the mechanical properties of the implant. The lower porosity region at the inner diameter provides higher strength and stiffness, while the higher porosity region at the outer diameter can reduce the weight and pressure of the implant. The gradient porosity structure can better simulate the microenvironment of natural biological tissues, providing more cell attachment points and growth space, thereby promoting the regeneration and growth of surrounding tissues, as shown by the bone mineral density (BMD) and bone volume / total volume value (BV / TV) of the TPMS structure implant in rats. This helps to reduce foreign body reactions and rejection reactions, and improve the compatibility of the implant with the host tissue. It can promote cell migration and blood vessel neogenesis. By creating pores of different sizes and shapes in the implant, better migration channels can be provided for cells and more growth space can be provided for blood vessels, thereby accelerating the tissue repair and regeneration process. The mechanical properties of different regions are optimized. By adjusting the density and distribution of the pores, the mechanical properties of the implant, such as strength, stiffness and toughness, can be precisely controlled to meet the needs of different clinical applications.

[0075] Table 3 Bone mineral density (BMD) and bone volume / total volume value (BV / TV) of TPMS structure implant in rats

[0076] One application of the present application is to implant 3D-printed personalized implant root TPMS gradient structures into animals for biomedical research and therapeutic experiments. The implant adopts a Gyroid structure and designs a porosity gradient increasing from 20% to 50%. This structure design can optimize the biocompatibility and mechanical properties of the implant, promote effective bonding with host tissues and tissue regeneration. The implantation process follows strict aseptic surgical techniques. First, a suitable animal model and implantation site are selected, usually areas that are easy to operate and can provide necessary biological feedback. Before implantation, the relevant surgical tools and implantation area need to be thoroughly disinfected to prevent infection and rejection. During the operation, the implant is precisely placed in the predetermined position and the appropriate fixation method is used to ensure its stability. After implantation, the animal will be closely monitored for recovery, monitoring the stability of the implant and the response of the host tissue. Subsequently, the bonding of the implant is evaluated through regular medical imaging and biomechanical testing. The results show that the implant structure reduces foreign body reactions and rejection reactions, improves compatibility with host tissues and osteogenic ability. The creation of pores of different sizes and shapes in the implant can provide better migration channels for cells and more growth space for blood vessels. At the same time, it also promotes cell migration and blood vessel neogenesis. The implantation of such implants not only provides a new tool for scientific research, but also has the potential to be applied in clinical implant therapy that requires high personalization and biocompatibility, thereby improving treatment effectiveness and patient quality of life.

[0077] In addition, the gradient porosity structure of the present application can be used to control drug release and biomolecule delivery. By adjusting the size, shape and distribution of the pores, precise control of drug release rate and biomolecule delivery can be achieved, thereby improving treatment effectiveness and reducing side effects.

[0078] Example 2

[0079] This example is based on the preparation method in Example 1 and gives a specific implementation of a 3D-printed personalized implant root TPMS gradient structure.

[0080] This example does not limit the specific shape and size of the implant root TPMS gradient structure, which can be a cuboid, a cube, a cylinder or other regular or irregular shapes.

[0081] As a preferred embodiment of this example, as shown in Figures 1-3, the preferred implant root TPMS gradient structure of this example is a cylinder.

[0082] Specifically, referring to Figure 1, it includes a porous root 2, at the upper end of the porous root 2 is an abutment 1, and at the lower end is an implant bottom 3.

[0083] Referring to FIG. 2, the porous root 2 selects a Gyroid structure 7 and gradient designs the Gyroid structure 7, that is, a gradient porosity Gyroid structure with a gradient change of 20% to 50% from the inner diameter to the outer diameter. Three specific ranges are given in this embodiment, including a 20% porosity range 4, a 35% porosity range 5, and a 50% porosity range 6.

[0084] Referring to FIG. 3, the gradient porosity Gyroid structure of this embodiment has a gradually increasing porosity pore size as the porosity range increases. Three specific pore size changes are given in this embodiment, in order from the inner diameter to the outer diameter: a Gyroid structure 20% porosity pore size 8, a Gyroid structure 35% porosity pore size 9, and a Gyroid structure 50% porosity pore size 10.

[0085] Although the specific embodiments of the application are described in detail with reference to the accompanying drawings, it should not be understood as limiting the scope of protection of the patent. Various modifications and variations that can be made by those skilled in the art within the scope described in the claims are still within the scope of protection of the patent.

Claims

1. A method for preparing a 3D printed personalized implant root (TPMS) gradient structure, characterized in that, The method comprises the following steps: S1, constructing a plurality of different types of implant root structure models based on ANSYS finite element software; S2, performing finite element simulation analysis on the plurality of implant root structure models; S3, selecting the implant root structure model corresponding to the Gyroid structure according to the finite element simulation analysis results; S4, determining the porosity range of the Gyroid structure according to the relative elastic modulus of the implant root structure; S5, combining the porosity range of the Gyroid structure and the implicit function, and designing the Gyroid structure as a gradient porosity Gyroid structure in the xy plane; S6, based on the gradient porosity Gyroid structure, using a 3D printer to prepare the implant root TPMS gradient structure.

2. The method of claim 1, wherein the 3D printed personalized implant root (TPMS) gradient structure is prepared by, The plurality of different types of implant root structure models in the step S1 include Schwarz structure, Diamond structure, Gyroid structure and SplitP structure.

3. The method of claim 2, wherein the 3D printed personalized implant root (TPMS) gradient structure is prepared by, The step S2 includes: performing finite element simulation analysis on the implant root structure models corresponding to the Schwarz structure, Diamond structure, Gyroid structure and SplitP structure respectively, and comparing the stress and deformation of each structure respectively.

4. The method of claim 3, wherein the 3D printed personalized implant root (TPMS) gradient structure is prepared by, The step S3 includes: selecting the implant root structure model corresponding to the Gyroid structure according to the finite element simulation analysis results of the stress and deformation of the implant root structure models corresponding to the Schwarz structure, Diamond structure, Gyroid structure and SplitP structure.

5. The method for preparing a 3D printed personalized implant root (TPMS) gradient structure according to claim 1, characterized in that, The step S4 includes: calculating the relative modulus of elasticity of the implant root structure: where E* is the relative modulus of elasticity of the implant structural unit, E is the modulus of elasticity of the material, and porosity is Based on porosity The calculation value and compression test of determine the porosity range of 20% to 50%.

6. The method for preparing a 3D printed personalized implant root (TPMS) gradient structure according to claim 5, characterized in that, The step S5 includes: Based on the porosity range, the Gyroid structure is designed as a gradient porosity Gyroid structure with the porosity gradually increasing from the inner diameter to the outer diameter in the xy plane; And the value of the gradient porosity Gyroid structure at different radius positions is controlled through the implicit function of the Gyroid structure, so as to control the gradient change of the porosity gradually increasing from the inner diameter to the outer diameter by 20% to 50%.

7. The method according to claim 6, wherein the method further comprises the step of: The implicit function f(x,y,z) of the Gyroid structure is expressed as: f(x,y,z) = sin(klx)cos(k2y) + sin(k2y)cos(k3z) + sin(k3z)cos(klx) + d0 - m(r cyl ) where k1, k2, k3 are constants; d0 is a constant offset; x, y, z are spatial variables; m(r cyl ) is a mapping function defined according to the implant root shape.

8. The method of claim 5, wherein the 3D printed personalized implant root (TPMS) gradient structure is prepared by, The mapping function m(r cyl ) is expressed as: where p min is the porosity of the inner diameter r min ; p max is the porosity of the outer diameter r max ; r min and r max are the minimum and maximum distance values corresponding to the innermost and outermost diameters of the implant root, respectively; and r is the actual distance from a specific point to the center of the implant root.

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