Bionic implant with stress self-buffering effect and preparation method thereof

Abstract

The application discloses a kind of bionic implants with stress self-buffering effect, including implant core components, implant intermediate layer structure and implant outer layer structure, the implant core components material is TA4 titanium bar, implant outer layer structure is made of polyether ether ketone resin and ceramic composite material, form the elastic modulus gradient change between different materials.New stress self-buffering bionic implant adopts metal additive manufacturing technology, uses additive manufacturing technology to replace subtractive manufacturing technology, gives the unique mechanical properties and biological properties of implant, so that implant has good biomechanical properties, is conducive to the long-term stability of implant-bone interface.The application also discloses a kind of preparation method of bionic implant with stress self-buffering effect and performance detection method of new stress self-buffering bionic implant, including biocompatibility research and the method for analyzing the biomechanical properties of the new implant by three-dimensional finite element, has greater development space.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of bionic implant, more particularly, relates to a bionic implant with stress self-buffering effect; in particular to a bionic implant with stress self-buffering effect and a preparation method thereof. BACKGROUND

[0002] With the continuous development and progress of oral material science, computer science, oral implantology and other disciplines, the research and development and improvement of oral implants are also new and promising. Oral implants need to have good mechanical properties, as well as good biocompatibility, biomechanical compatibility, bone bonding properties and other properties to function stably in the oral cavity for a long time.

[0003] Since the 1960s, when the "osseointegration" theory was proposed, in addition to pure titanium and its alloys, scholars have successively tried to use ceramic, high polymer, and tantalum-based metal materials for the production of oral implants. The success of implant denture repair is affected by factors such as implant timing, initial stability, implant torque, and other implant surgery-related factors; bone mass in the implant area; occlusal design of implant denture; implant macrostructure and surface treatment process; clinical experience and technology of implant doctors; overall health status of patients; patient compliance and other implant-related factors. The above factors are interrelated and influence each other. Occlusal overload is considered to be one of the main reasons for the failure of implant denture repair, and many factors of oral biomechanics should be considered when designing and producing implants, and the balance between implant strength and elastic modulus should be considered. The design of the implant itself should simulate the morphology and functional characteristics of natural teeth to establish a dynamic balance that meets the physiological functional requirements of the oral cavity, which is conducive to the long-term stable function of implant dentures. Current research and development of implants mainly focuses on the following aspects:

[0004] 1. Implant Materials: Titanium and titanium alloys remain the most widely used dental implant materials. Their good osseointegration with bone tissue is one of the important criteria for evaluating implant material performance. In addition, the mechanical, chemical, and biological properties of the material must also be evaluated. Pure titanium implants, with an elastic modulus approximately 8-10 times that of human bone, can cause stress shielding and peri-implant bone resorption under occlusal load. Reducing the elastic modulus of the implant to a certain extent helps transfer stress at the implant-bone interface to the surrounding bone tissue, which is beneficial for improving the success rate of immediate loading and the long-term effects of implant-supported prostheses. Porous tantalum materials can have their elastic modulus and other mechanical properties altered by adjusting their porosity. This material also has good osteoconductivity and osteoinductive properties, making it a promising implant material. Current research shows that it can achieve better immediate implant restoration results than titanium implants. Clinical studies have shown that porous tantalum implants, when subjected to occlusal loading within two weeks after implantation, achieved good short-term restorative results. Zirconia implants possess excellent aesthetic properties and biocompatibility, but they also suffer from issues such as hydrothermal aging, low-temperature degradation, and easy wear, leading to ongoing controversy regarding their clinical application. Ceria-stabilized tetragonal zirconia polycrystals (Ce-TZP) overcome the drawback of easy low-temperature degradation, and cerium-stabilized zirconia-alumina composites exhibit good bone integration and soft tissue compatibility. However, the results of numerous studies are inconsistent.

[0005] Clinical studies by Cannizzaro G et al. found that immediate loading of posterior zirconia implants with single crowns carried a higher risk of failure than immediate restorations. Spies, BC et al. and Balmer, M. et al., however, believed that zirconia implants could achieve ideal implant success rates, stable marginal bone volume, and good soft tissue health. A bibliometric study by Lorusso F et al. showed that zirconia implants are an important method for reconstructing oral function, achieving similar results to titanium implants in terms of marginal bone resorption and implant survival rates. A 5-year clinical study involving 17 patients and 32 implants showed that the 1-year success rate of immediately loaded one-piece zirconia implants was 96.9%, and the 5-year success rate was 96.8%, demonstrating good marginal bone resorption control and acceptable soft tissue health. A prospective randomized controlled clinical trial involving 22 patients and including 16 zirconia implants and 15 titanium implants, after 80 months of follow-up, found no significant difference in clinical outcomes between the two methods.

[0006] 2. Macroscopic Morphology of Implants: Appropriate macroscopic morphology and structure of implants are another important factor affecting immediate loading and the long-term effectiveness of implant-supported prostheses. When bone volume at the implantation site allows, implants with a relatively large diameter and a length greater than 10mm are more likely to achieve good initial stability. Implants longer than 13mm achieve a higher success rate for immediate loading, while implants shorter than or equal to 10mm have a significantly lower success rate. In recent years, with advancements in implant technology, there have been reports of short implants being used in immediate loading techniques.

[0007] Current research indicates that altering the material properties and geometry of implants can guide bone remodeling to better adapt to their biomechanical environment. Three-dimensional finite element analysis of implants of different shapes shows that tapered implants have advantages over cylindrical implants in immediate loading, performing better under both compressive and shear stresses. Immediately loading implants can achieve ideal initial stability by increasing the contact area between the implant surface and bone tissue. Studies have also confirmed that threaded implants with roughened surfaces can enhance the mechanical interlocking effect with bone tissue, reduce implant micromovement, and promote implant-osseointegration.

[0008] 3. Implant Surface Treatment: Implant surface modification is an effective method to improve the biomechanical properties and osseointegration performance of implants. Its main purpose is to improve osseointegration, enhance biomechanical properties, and improve antibacterial properties. It has been confirmed that implant surface micro-features are related to early osseointegration and can promote rapid osteoblast differentiation and bone mineralization. Implant surface modification mainly includes three methods: physical, chemical, and biological modification. Methods such as sandblasting, acid etching, and electrochemical modification can roughen the implant surface, enhance hydrophilicity and surface energy, and accelerate bone healing. The combination or combined application of these methods is one of the trends in implant surface modification. The multi-level roughened structure obtained through acid etching and sandblasting can produce a synergistic effect that promotes osseointegration. Nagay BE et al. compared the 5-year success rates of immediate and delayed loading of anodized implant crowns, finding them to be 95.18% (95% CI: 93.76%–96.63%) and 97.10% (95% CI: 95.77%–98.45%), respectively, with no statistically significant difference between the two. Mangano FG et al.'s research showed that double-etched titanium implant surfaces were beneficial for osseointegration in areas with low bone density (Class IV bone). Liu P et al. constructed a zinc-ion-containing chitosan / gelatin bioactive polyelectrolyte multilayer coating that inhibited bacterial adhesion and promoted osteoblast growth.

[0009] 4. Implant bionics research: The scope of implant bionics research is broad, including bionic research on components such as implants, abutments, and implant crowns, as well as the treatment of peri-implant hard and soft tissues, so as to simulate the morphology and functional characteristics of natural tissues and organs to the greatest extent possible, achieving a near-natural, physiologically compatible aesthetic effect and good function.

[0010] Biomimetic research on implants mainly focuses on mimicking the morphology of natural tooth roots, the natural periodontal ligament, and the structure of natural teeth. 3D-printed personalized root-analogue implants (RAIs) have achieved promising clinical results. By micronizing or nano-sizing the implant surface, a more bioactive surface can be created, enhancing the implant's compatibility with bone tissue and facilitating osseointegration. The concept of peri-implant ligaments (PILs) is also based on biomimetic research, aiming to mimic the buffering effect of natural teeth on excessive occlusal forces.

[0011] Dental implants need to possess good mechanical strength to meet the requirements of the complex biomechanical environment of the oral cavity. Simultaneously, they should have an elastic modulus similar to that of natural tooth roots, closely matching the elastic modulus of the surrounding bone tissue to avoid stress shielding effects that could lead to peri-implant bone damage and resorption. Current research has confirmed that the implant neck is a stress concentration point during the functional process of implant prostheses. Even if the maximum stress generated by the loading is far below the bone's strength limit, irreversible bone fatigue damage can still occur. Implant loosening caused by cortical bone resorption at the implant neck is a major reason affecting the long-term restorative effect of implant prostheses. Summary of the Invention

[0012] The purpose of this invention is to overcome the shortcomings of existing technologies. By combining metal additive manufacturing technology and implant surface treatment technology, materials with different elastic moduli are sequentially bonded to the surface of the implant core structural material. This creates a stress self-buffering effect due to the different elastic moduli between the internal materials of the implant, allowing occlusal forces to be evenly transmitted to the surrounding bone tissue and preventing stress concentration. The outermost layer of the implant undergoes a specific surface treatment technique to form an amorphous titanium dioxide nanotube array topology, mimicking the periodontal ligament of natural teeth, further improving biomechanical properties. This invention presents a biomimetic implant with a stress self-buffering effect.

[0013] To achieve the above objectives, the present invention provides the following technical solution:

[0014] A bionic implant with stress self-buffering effect includes an implant core component, an implant intermediate layer structure, and an implant outer layer structure. The implant intermediate layer structure is disposed between the implant core component and the implant outer layer structure. The implant core component is a TA4 titanium rod structure, and the implant core component includes an implant anti-rotation structure, a screw channel, and an internal thread.

[0015] The biomimetic implant, formed by the implant core component, the implant intermediate layer structure, and the implant outer layer structure, has an elastic modulus gradient change due to the performance differences of different materials, which provides better buffering of occlusal stress.

[0016] The implant core component is made of pure titanium or titanium alloy with an elastic modulus of approximately 80-110 GPa, and the implant core component and the implant intermediate layer structure are joined by laser welding or sintering.

[0017] The implant intermediate layer structure is made of high-strength ceramic, which mainly contains 20nm prepolymerized silica nanoparticles and 4-11nm prepolymerized zirconia nanoparticles. The elastic modulus of this material is 20-50GPa. The surface of the implant intermediate layer structure is etched with hydrofluoric acid and then coated with a coupling agent to fuse the implant outer layer structure.

[0018] The outer layer structure of the implant is made of a composite material of polyetheretherketone resin and ceramic, with an elastic modulus of 8-20 GPa.

[0019] This invention also provides a method for preparing a biomimetic implant with a stress self-buffering effect, comprising the following steps:

[0020] S1. Select a suitable TA4 titanium rod and manufacture the core structural components of the implant through cutting and other methods. The core structural components of the implant include the implant anti-rotation structure, screw channel, and internal thread.

[0021] S2. After grinding, polishing, sandblasting, and acid etching on the surface of the core implant component, the intermediate layer structure material of the implant is deposited through welding or electrodeposition. After grinding, polishing, sandblasting, and acid etching again, the outer layer structure of the implant is firmly bonded to the intermediate layer structure of the implant through welding, electrodeposition, or sintering.

[0022] S3. The outer layer of the implant is processed by micronization or nano-sizing to simulate the microstructure of bone tissue and enhance the bone integration ability. By forming a polymer-infiltrated amorphous array of titanium dioxide nanotubes on the implant surface, the biomechanical properties and bone induction properties of the implant are synergistically improved.

[0023] S4. Mechanical performance analysis of novel stress-buffered bionic implants:

[0024] S4.1 Preparation of novel stress-self-buffered bionic implant specimens: The novel stress-self-buffered bionic implant specimens were prepared using the metal additive manufacturing method and processing technology described above.

[0025] S4.2 Analysis of the mechanical properties of novel stress-buffered bionic implants;

[0026] ① X-ray diffraction (XRD) detection: scanning speed 4°min -1 Quantitative chemical composition analysis was performed on an X-ray energy dispersive spectroscopy analyzer with a scanning angle of 30°-90°.

[0027] ② Observe the microstructure of the specimen using a metallographic microscope;

[0028] ③ Microhardness tester to determine the Vickers hardness of the specimen: hardness load 200g, loading time 10s, 10 points are randomly measured for each specimen, and the hardness range of the specimen is calculated.

[0029] ④ Tensile test: Ten tensile specimens were placed on a computer-controlled electronic universal testing machine for tensile testing. Displacement control was used during the tensile test, and the loading speed was 1 mm·min. -1 The tensile strength, yield strength, and elongation of the specimen are calculated according to the following formulas: tensile strength (σb) = Fb / So, yield strength (Re) = Fe / So, elongation (δ) = ΔL / L × 100% (Fb: maximum tensile stress; So: original cross-sectional area; Fe: stress at the yield point; L: original gauge length; ΔL: total deformation length);

[0030] ⑤ Observe the cross-sectional morphology of the specimen using a scanning electron microscope.

[0031] S5. Biocompatibility Study of Novel Stress-Cushioning Bionic Implants:

[0032] S5.1 and CCK8 cell proliferation:

[0033] Cell proliferation capacity was tested using Straumann zirconium titanium-zirconium alloy implants and novel stress-buffered biomimetic implants. Four parallel samples were prepared for each implant group. Mouse embryonic osteoblast precursor cells MC3T3-E1 were formulated to a concentration of 2×10⁻⁶. 4Cell suspension of cells / mL; four parallel samples each of Straumann zirconium titanium-zirconium alloy implants and novel stress-buffered biomimetic implant specimens were placed in 48-well plates; after thoroughly washing and discarding the samples with PBS, 500 μL / well of cell suspension was evenly dropped onto the surface of the plates; the plates were cultured at 37°C and 5% CO2 in a constant temperature incubator for 1 day, 4 days and 7 days respectively; after reaching the time point, the culture medium was discarded and the sample surface was thoroughly rinsed with PBS; 300 μL of serum-free αMEM medium containing 10% CCK-8 was added to each well, and the plates were incubated at 37°C in the dark for 4 hours; then 100 μL of the solution from each well was taken and the optical density at 450 nm was measured using an ELISA reader, and the relative cell proliferation rate was calculated and the cytotoxicity level was evaluated;

[0034] S5.2 Detection of apoptosis;

[0035] S5.3, Cell adhesion ability test:

[0036] The cell adhesion ability of the implant samples was observed using scanning electron microscopy. The experimental seeding method and sample setup were the same as in S5.1. After seeding the cells on the sample surface under the same conditions, the samples were cultured in a cell culture incubator for 168 h. Then, the culture medium in the well plate was discarded and the samples were thoroughly washed with PBS. 4% paraformaldehyde was added to cover the samples in the well plate, and the samples were fixed in a refrigerator at 4°C for 4 h. The paraformaldehyde was discarded and the samples were thoroughly washed with PBS. Then, the samples were dehydrated using an ethanol gradient. After completion, the samples were air-dried overnight in a cool place, sputter-coated with gold, and the cell adhesion was observed using scanning electron microscopy.

[0037] S6. Biomechanical properties of the novel implant were analyzed using three-dimensional finite element method:

[0038] DICOM data of the mandible of patients with missing or damaged teeth were obtained by cone-beam computed tomography (CBCT). The mandible and implant specimen models were then created using software to simulate the stress environment of the implant in the oral cavity and to analyze its biomechanical properties.

[0039] The bionic implant is constructed by welding an intermediate layer and an outer layer structure with gradually decreasing elastic modulus onto the core components of the implant.

[0040] The bionic implant utilizes two manufacturing processes: metal powder and fused wire. Additive manufacturing technologies using metal powder include four methods: selective laser melting, electron beam melting, laser powder deposition, and binder spraying. Additive manufacturing technologies using fused wire include arc fused wire additive manufacturing, laser fused wire deposition, and electron beam fused wire additive manufacturing. These methods and processes are compared and selected based on factors such as manufacturing flow and bonding strength. A suitable metal additive manufacturing method and process are then chosen. After the core components and intermediate layer structure of the implant are bonded together using metal additive manufacturing, and after the intermediate layer structure is bonded together with the outer layer structure, a universal testing machine is used to simulate the oral cavity stress environment. The compressive strength, tensile strength, and flexural strength of each internal structure are tested, and the mechanical properties are compared with those of current mainstream implants to obtain research data on the bonding performance between the internal structures of this novel stress-buffered bionic implant.

[0041] The analysis of the mechanical properties of the stress-buffered bionic implant will be carried out from the following aspects:

[0042] ① X-ray diffraction (XRD) detection: scanning speed 4°min -1 Quantitative chemical composition analysis was performed on an X-ray energy dispersive spectroscopy analyzer with a scanning angle of 30°-90°.

[0043] ② Observe the microstructure of the specimen using a metallographic microscope;

[0044] ③ Microhardness tester to determine the Vickers hardness of the specimen: hardness load 200g, loading time 10s, 10 points are randomly measured for each specimen, and the hardness range of the specimen is calculated.

[0045] ④ Tensile test: Ten tensile specimens were placed on a computer-controlled electronic universal testing machine for tensile testing. Displacement control was used during the tensile test, and the loading speed was 1 mm·min. -1 The tensile strength, yield strength, and elongation of the specimen are calculated according to the following formulas: tensile strength (σb) = Fb / So, yield strength (Re) = Fe / So, elongation (δ) = ΔL / L × 100% (Fb: maximum tensile stress; So: original cross-sectional area; Fe: stress at the yield point; L: original gauge length; ΔL: total deformation length).

[0046] ⑤ Observe the cross-sectional morphology of the specimen using a scanning electron microscope.

[0047] Specifically, step S5.2, the method for detecting apoptosis, includes:

[0048] Apoptosis was determined by flow cytometry using the FITC / PI double staining method; at a concentration of 1×10⁻⁶ cells / mL. 4Cells were seeded at a density of cells / cm² on the surface of Straumann zirconium titanium-zirconium alloy implants and novel stress-buffered biomimetic implant specimens, and then cultured in a cell culture incubator for 72 h. At the time point, cells were digested with EDTA-free trypsin and collected. After resuspending the cells gently with cold PBS buffer, they were centrifuged at 1000 r / min for 5 min at below 4°C and the liquid was discarded. This process was repeated twice. 100 μL of Binding Buffer was added to each tube and the cells were gently resuspended. Then, 5 μL each of Annexin V-FITC and PI were added to each tube for staining. After reacting in the dark for 15 min, 400 μL of Binding Buffer was added to each tube, and the cells were gently resuspended. Cell apoptosis was detected within 1 h.

[0049] The technical effects and advantages of this invention are as follows:

[0050] 1. The present invention provides a bionic implant with stress self-buffering effect, which is used for the application of novel stress self-buffering bionic implant metal additive manufacturing technology. It innovates the traditional implant manufacturing process, uses metal additive manufacturing technology to replace metal subtractive manufacturing technology, and endows the implant with unique mechanical and biological properties.

[0051] 2. The present invention provides the research and development and preparation of a novel stress-buffering bionic implant internal stress-buffering component; by further improving the bionic nature of the implant, it promotes its good osseointegration performance;

[0052] 3. This invention further improves the biomimicry of implants by imparting different elastic moduli to different internal structures, thereby enhancing osseointegration performance and promoting long-term stability of implants in a functional state;

[0053] 4. This invention integrates the design of biomimetic characteristics such as mechanical and biological properties of implants into the research and development and preparation process of implants, providing a new approach to ensure the long-term stable function of implants;

[0054] 5. The present invention provides a metal additive manufacturing process for a bionic implant with stress self-buffering effect. The process includes the following steps: mechanical property analysis of the novel stress self-buffering bionic implant; preparation of the novel stress self-buffering bionic implant specimen; analysis of the mechanical properties of the novel stress self-buffering bionic implant; biocompatibility study of the novel stress self-buffering bionic implant; and biomechanical performance analysis of the novel implant using three-dimensional finite element method. The invention has significant potential for further development. Attached Figure Description

[0055] Figure 1 This is a cross-sectional structural diagram of the bionic implant with stress self-buffering effect of the present invention;

[0056] Figure 2 This is a flowchart of the preparation method of the bionic implant of the present invention.

[0057] In the diagram: 1. Core component of the implant; 2. Middle layer structure of the implant; 3. Outer layer structure of the implant. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] In the description of this invention, it should be understood that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing the invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0060] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific context of the specification.

[0061] This invention provides, for example Figure 1 A bionic implant with stress self-buffering effect includes an implant core component 1, an implant intermediate layer structure 2 and an implant outer layer structure 3. The implant intermediate layer structure 2 is disposed between the implant core component 1 and the implant outer layer structure 3. The implant core component 1 is a TA4 titanium rod structure, and the implant core component 1 includes an implant anti-rotation structure, a screw channel and an internal thread.

[0062] The outer layer structure 3 of the implant is micronized or nanonized to simulate the microstructure of bone tissue. By forming a polymer-infiltrated amorphous array of titanium dioxide nanotubes on the implant surface, the implant's biomechanical properties and osteoinductive properties can be synergistically improved.

[0063] The biomimetic implant, formed by the implant core component 1, the implant intermediate layer structure 2, and the implant outer layer structure 3, has a gradient change in elastic modulus due to the performance differences of different materials, which provides better buffering of occlusal stress.

[0064] Specifically, the implant core component 1 is made of pure titanium or titanium alloy with an elastic modulus of approximately 80-110 GPa, and the implant core component 1 and the implant intermediate layer structure 2 are joined by laser welding or sintering.

[0065] Specifically, the implant intermediate layer structure 2 is made of high-toughness ceramic nanocomposite ceramic, which mainly contains 20nm prepolymerized silica nanoparticles and 4-11nm prepolymerized zirconia nanoparticles. The elastic modulus of this material is similar to that of dentin, about 20-50GPa. After hydrofluoric acid etching, a coupling agent is applied to the surface of the implant intermediate layer structure 2 to fuse the implant outer layer structure 3 into shape.

[0066] Specifically, the outer layer structure 3 of the implant is a composite material made of polyetheretherketone resin and ceramic, with an elastic modulus of 8-20 GPa.

[0067] like Figure 2 As shown, the present invention also provides a method for preparing a biomimetic implant with stress self-buffering effect, comprising the following steps:

[0068] S1. Select a suitable TA4 titanium rod and manufacture the core structural component of the implant through cutting and other methods. The core component 1 of the implant includes an anti-rotation structure, screw channel, and internal thread.

[0069] S2. After grinding, polishing, sandblasting, and acid etching on the surface of the implant core component 1, the implant intermediate layer structure 2 material is deposited by welding or electrodeposition. After grinding, polishing, sandblasting, and acid etching again, the implant outer layer structure 3 is firmly bonded to the implant intermediate layer structure 2 by welding, electrodeposition, or sintering.

[0070] S3, the outer layer structure of the implant is simulated by micronization or nano-sizing to enhance the bone integration ability. By forming a polymer-infiltrated amorphous array of titanium dioxide nanotubes on the implant surface, the biomechanical properties and bone induction properties of the implant are synergistically improved.

[0071] S4. Mechanical Performance Analysis of the Novel Stress-Cushioning Bionic Implant: The mechanical performance analysis of the stress-cushioning bionic implant will be conducted from the following aspects:

[0072] ① X-ray diffraction (XRD) detection: scanning speed 4°min -1 Quantitative chemical composition analysis was performed on an X-ray energy dispersive spectroscopy analyzer with a scanning angle of 30°-90°.

[0073] ② Observe the microstructure of the specimen using a metallographic microscope;

[0074] ③ Microhardness tester to determine the Vickers hardness of the specimen: hardness load 200g, loading time 10s, 10 points are randomly measured for each specimen, and the hardness range of the specimen is calculated.

[0075] ④ Tensile test: Ten tensile specimens were placed on a computer-controlled electronic universal testing machine for tensile testing. Displacement control was used during the tensile test, and the loading speed was 1 mm·min. -1 The tensile strength, yield strength, and elongation of the specimen are calculated according to the following formulas: tensile strength (σb) = Fb / So, yield strength (Re) = Fe / So, elongation (δ) = ΔL / L × 100% (Fb: maximum tensile stress; So: original cross-sectional area; Fe: stress at the yield point; L: original gauge length; ΔL: total deformation length).

[0076] ⑤ Observe the cross-sectional morphology of the specimen using a scanning electron microscope.

[0077] S4.1 Preparation of novel stress-self-buffered bionic implant specimens: The novel stress-self-buffered bionic implant specimens were prepared using the metal additive manufacturing method and processing technology described above.

[0078] S4.2 Analysis of the mechanical properties of novel stress-buffered bionic implants;

[0079] S5. Biocompatibility Study of Novel Stress-Cushioning Bionic Implants:

[0080] S5.1 and CCK8 cell proliferation:

[0081] Cell proliferation capacity was tested using Straumann zirconium titanium-zirconium alloy implants and novel stress-buffered biomimetic implants. Four parallel samples were prepared for each implant group. Mouse embryonic osteoblast precursor cells MC3T3-E1 were formulated to a concentration of 2×10⁻⁶. 4Cell suspension of cells / mL; four parallel samples each of Straumann zirconium titanium-zirconium alloy implants and novel stress-buffered biomimetic implant specimens were placed in 48-well plates; after thoroughly washing and discarding the samples with PBS, 500 μL / well of cell suspension was evenly dropped onto the surface of the plates; the plates were cultured at 37°C and 5% CO2 in a constant temperature incubator for 1 day, 4 days and 7 days respectively; after reaching the time point, the culture medium was discarded and the sample surface was thoroughly rinsed with PBS; 300 μL of serum-free αMEM medium containing 10% CCK-8 was added to each well, and the plates were incubated at 37°C in the dark for 4 hours; then 100 μL of the solution from each well was taken and the optical density at 450 nm was measured using an ELISA reader, and the relative cell proliferation rate was calculated and the cytotoxicity level was evaluated;

[0082] S5.2 Detection of apoptosis, specifically including: using flow cytometry with FITC / PI double staining to determine apoptosis; according to l×10 4 Cells were seeded at a density of cells / cm² on the surface of Straumann zirconium titanium-zirconium alloy implants and novel stress-buffered biomimetic implant specimens, and then cultured in a cell culture incubator for 72 h. At the time point, cells were digested with EDTA-free trypsin and collected. Cells were resuspended gently with cold PBS buffer and centrifuged at 1000 r / min for 5 min at below 4 °C, and the centrifuge solution was discarded. This process was repeated twice. 100 μL of Binding Buffer was added to each tube for resuscitation. Then, 5 μL each of Annexin V-FITC and PI were added to each tube for staining. After reacting in the dark for 15 min, 400 μL of Binding Buffer was added to each tube for resuscitation. Cell apoptosis was detected within 1 h.

[0083] S5.3, Cell adhesion ability test:

[0084] Cell adhesion ability of implant samples was observed using scanning electron microscopy. The experimental seeding method and sample setup were the same as in S5.2. After seeding cells onto the sample surface under the same conditions, the samples were cultured in a cell culture incubator for 168 h. Then, the culture medium in the well plate was discarded and the samples were thoroughly washed with PBS. 4% paraformaldehyde was added to cover the samples in the well plate, and the samples were fixed in a refrigerator at 4°C for 4 h. The paraformaldehyde was discarded and the samples were thoroughly washed with PBS. Then, the samples were dehydrated using an ethanol gradient. After completion, the samples were air-dried overnight in a cool place, sputter-coated with gold, and the cell adhesion was observed using scanning electron microscopy.

[0085] S6. Biomechanical properties of the novel implant were analyzed using three-dimensional finite element method:

[0086] DICOM data of the mandible of patients with missing or damaged teeth were obtained by cone-beam computed tomography (CBCT). The mandible and implant specimen models were then created using software to simulate the stress environment of the implant in the oral cavity and to analyze its biomechanical properties.

[0087] Specifically, the bionic implant does not change the macroscopic shape and surface structure of the current mainstream implants. Instead, it mainly welds and stacks intermediate and outer layers with gradually decreasing elastic modulus on the core components of the implant, thereby giving the implant a certain stress self-buffering effect and obtaining more ideal biomechanical properties. Furthermore, it improves its osseointegration performance through implant surface treatment technology.

[0088] Specifically, the bionic implant utilizes two processes: metal powder and fused wire. Additive manufacturing technologies using metal powder include four methods: selective laser melting, electron beam melting, laser powder deposition, and binder spraying. Additive manufacturing technologies using fused wire include arc fused wire additive manufacturing, laser fused wire deposition, and electron beam fused wire additive manufacturing. These methods and processes are compared and selected based on factors such as manufacturing flow and bonding strength, ultimately choosing the most suitable metal additive manufacturing method and process. After the core components of the implant are bonded to the intermediate layer structure, and the intermediate layer structure is bonded to the outer layer structure, a universal testing machine is used to simulate the oral cavity stress environment. The compressive strength, tensile strength, and flexural strength of each internal structure are tested, and the mechanical properties are compared with those of current mainstream implants to obtain research data on the bonding performance between the internal structures of this novel stress-buffered bionic implant.

[0089] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0090] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

Claims

1. A biomimetic implant with stress self-buffering effect, characterized in that: It includes an implant core component (1), an implant intermediate layer structure (2) and an implant outer layer structure (3). The implant intermediate layer structure (2) is disposed between the implant core component (1) and the implant outer layer structure (3). The implant core component (1) is a TA4 titanium rod structure, and the implant core component (1) includes an implant anti-rotation structure, a screw channel and an internal thread structure. The implant core component (1), the implant intermediate layer structure (2), and the implant outer layer structure (3) have elastic modulus gradient changes due to the performance differences of different materials, which can better buffer the occlusal stress. Wherein: the implant core component (1) is made of pure titanium or titanium alloy with an elastic modulus of 80-110 GPa, and the implant core component (1) and the implant intermediate layer structure (2) are joined by laser welding or sintering. The implant intermediate layer structure (2) is made of high-toughness ceramic, which contains mainly 20nm prepolymerized silica nanoparticles and 4-11nm prepolymerized zirconium oxide nanoparticles. The elastic modulus of the implant intermediate layer structure (2) is 20-50 GPa. The surface of the implant intermediate layer structure (2) is acid-etched with hydrofluoric acid and then coated with a coupling agent to form the implant outer layer structure (3). The implant outer layer structure (3) is made of a composite material of polyether ether ketone resin and ceramic with an elastic modulus of 8-20 GPa.

2. A method for preparing a biomimetic implant with stress self-buffering effect according to claim 1, characterized in that: Includes the following steps: S1. Select a suitable TA4 titanium rod and use a cutting method to make the implant core structure component. The implant core component (1) includes an implant anti-rotation structure, screw channel, and internal thread. S2. After grinding, polishing, sandblasting and acid etching on the surface of the implant core component (1), the implant intermediate layer structure (2) material is stacked by welding or electrodeposition. After grinding, polishing, sandblasting and acid etching again, the implant outer layer structure (3) is firmly bonded to the implant intermediate layer structure (2) by welding, electrodeposition or sintering. S3, outer layer structure of implant (3) Through micronization or nano-processing, the macro and micro structure of bone tissue is simulated. By forming a polymer-infiltrated titanium dioxide nanotube amorphous array on the implant surface, the biomechanical properties and bone-inducing properties of the implant are synergistically improved, the bone integration ability of the implant is improved, and the bone integration time is shortened. The bionic implant is constructed by welding an intermediate and an outer layer structure with gradually decreasing elastic modulus onto the core components of the implant. The bionic implant utilizes two processes: metal powder and fused wire. The additive manufacturing technologies using metal powder include four types: selective laser melting, electron beam melting, laser powder deposition, and binder spraying. The additive manufacturing technologies using fused wire include arc fused wire additive manufacturing, laser fused wire deposition, and electron beam fused wire additive manufacturing.

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