Method for preparing bionic multilevel structure on surface of pure titanium implant material

Abstract

The invention relates to the technical field of pure titanium implant surface modification, in particular to a method for preparing a bionic multilevel structure on the surface of a pure titanium implant material. The method specifically comprises the following steps that the pure titanium implant material is subjected to sand blasting treatment, ultrasonic cleaning, first-time acid etching treatment, ultrasonic cleaning, second-time acid etching treatment, ultrasonic cleaning and drying; in the sand blasting treatment, aluminum oxide particles are used for carrying out sand blasting treatment on the pure titanium implant material; in the first time of acid etching treatment, hydrofluoric acid is used for carrying out acid etching treatment on the pure titanium implant material treated in the previous step; and in the second acid etching treatment, the pure titanium implant material treated in the previous step is subjected to acid etching treatment by using a mixed solution of hydrochloric acid and sulfuric acid. The bionic multi-stage pore structure is constructed through the sand blasting coarsening-gradient acid etching process, the natural bone matrix microenvironment is simulated, more bioactive molecules are adsorbed, and the biological activity of bone cells is promoted.

Description

Technical Field

[0001] The present application relates to the technical field of surface modification of pure titanium implants, and in particular to a method for preparing a bionic multi-level structure on the surface of a pure titanium implant material. Background Art

[0002] Bone implant materials play a key role in repairing bone defects and replacing diseased bones. Currently, the commonly used materials in this field mainly cover three categories: metals, ceramics and polymer materials. Among them, metal materials are represented by titanium alloys and stainless steel. With their high strength and excellent mechanical properties, they occupy an important position in load-bearing implants. However, there is a significant difference between their elastic modulus and that of natural bone tissue. For example, the elastic modulus of titanium alloy is about 110GPa, which far exceeds the 10-30GPa of natural bone tissue. This difference can easily cause a stress shielding effect. This effect will cause the bone tissue around the implant to gradually atrophy and absorb due to insufficient force, seriously affecting the long-term stability and service life of the implant, and becoming a core problem in the clinical application of metal materials.

[0003] Overall, the common challenge facing existing bone implant materials is their difficulty in mimicking natural bone tissue. Ideal bone implant materials must simultaneously meet dual requirements: an elastic modulus that matches bone tissue to avoid stress shielding, while also possessing a pore size of 300-500μm to promote bone cell adhesion, proliferation, and vascularization.

[0004] However, the current technological system has obvious limitations: the process of reducing the elastic modulus of the material often comes at the expense of mechanical strength, making it difficult to strike a balance between modulus regulation and strength maintenance; at the same time, the means of pore size regulation are limited, and precise control of pore size and distribution cannot be achieved, resulting in difficulty in improving the integration efficiency of bone implants and host bone tissue.

[0005] In related technologies, although a single rough surface can increase the bone-implant contact area, it lacks nanoscale topological structure and mechanical matching, resulting in: (1) insufficient "contact guidance" effect in the early stage of osteoblast adhesion; (2) ineffective activation of the cytoskeleton tension signal transduction pathway; and (3) the stress shielding effect caused by elastic modulus mismatch still exists.

[0006] Therefore, constructing a bionic multi-level structure that combines micron-level mechanical anchoring, submicron-level material transmission and nanometer-level biological signals has become a key technical bottleneck in improving the efficiency of implant bone integration. Summary of the Invention

[0007] The present application provides a method for preparing a bionic multi-level structure on the surface of a pure titanium implant material.

[0008] With the aging population, the clinical demand for edentulous and missing teeth is growing. Dental implants have become an effective alternative to natural teeth. Titanium-based implants are widely used due to their excellent biocompatibility and mechanical properties. Surface treatment is crucial for improving implant osseointegration and promoting osteoblast adhesion and growth.

[0009] The study found that the surface of the implant is mainly rough at the macro level, which can expand the bone-implant contact area, improve biological activity, and promote the deposition of new bone on the implant surface; the implant surface constructs a bionic multi-level structure similar to bone tissue at the micro level, achieving multi-level conforming pore scales at the micron and nano levels, forming a biological effect of mechanical support, biological signal optimization, and directional regulation, which can improve the efficiency of osteogenic differentiation and the speed of mineralization formation, and fully demonstrate the excellent implant bone integration ability.

[0010] Traditional surface treatment techniques (such as single sandblasting or acid etching) can only achieve micron-scale roughening and are unable to simulate the multi-level pore structure of natural bone tissue. Natural bone tissue has a highly ordered hierarchical structure, which is the basis for its diverse physiological functions. Constructing this ordered biomimetic multi-level structure facilitates direct contact between the implant surface and bone, establishing initial implant stability. Furthermore, as the implant heals, the biomimetic multi-level structure promotes contact between new bone and secondary bone on the implant surface, improving secondary stability.

[0011] The surface treatment method of pure titanium implant material provided in this application optimizes the surface treatment process of pure titanium implant material, obtains a bionic multi-level structure surface with three-level pores and simulates natural bone matrix, solves the existing single "roughening" problem, brings a bionic surface structure, realizes the "contact-tension-signal" chain reaction, promotes osteogenesis, and provides a better choice for the manufacture and clinical application of oral dental implants.

[0012] This application uses a "sandblasting-gradient acid etching" process to construct a biomimetic multi-level pore structure (primary micropores 20-50μm, secondary micropores 1-10μm, and tertiary micropores 50-300nm) to simulate the natural bone matrix microenvironment, adsorb more bioactive molecules, and promote the biological activity of bone cells. At the same time, the elastic modulus of the treated pure titanium implant material can match that of bone tissue, achieving uniform stress distribution, promoting implant osseointegration, and maintaining the overall stability of the implant.

[0013] In a first aspect, the present application provides a method for preparing a bionic multi-level structure on the surface of a pure titanium implant material, using the following technical solution:

[0014] A method for preparing a bionic multi-level structure on the surface of a pure titanium implant material, the method specifically comprising the following steps:

[0015] The pure titanium implant material was subjected to sandblasting, ultrasonic cleaning, first acid etching, ultrasonic cleaning, second acid etching, ultrasonic cleaning and drying;

[0016] In the first acid etching treatment, the pure titanium implant material treated in the previous step is subjected to acid etching treatment using hydrofluoric acid; the concentration of the hydrofluoric acid is 1-5%; the treatment temperature of the first acid etching treatment is 25-35° C., and the treatment time is 10-30 seconds;

[0017] In the second acid etching treatment, the pure titanium implant material treated in the previous step is acid-etched using a mixture of hydrochloric acid and sulfuric acid; the hydrochloric acid and the sulfuric acid are mixed in a volume ratio of 1:1 to obtain a mixed solution; the concentration of the hydrochloric acid is 10-20%, and the concentration of the sulfuric acid is 5-15%; the treatment temperature of the second acid etching treatment is 90-120°C, and the treatment time is 5-10 minutes.

[0018] The method provided in this application mainly includes "sandblasting roughening-gradient acid etching". After the pure titanium implant material is treated with the surface treatment method provided in this application, a biomimetic multi-level structure is formed on the surface of the pure titanium implant material. In this application, the conditions of the first acid etching treatment are controlled as follows: the acid used is hydrofluoric acid with a concentration of 1-5% and the treatment time is 10-30 seconds; the conditions of the second acid etching treatment are controlled as follows: the treatment temperature is 90-120°C, the treatment time is 5-10 minutes, and the acid used is a mixture of hydrochloric acid with a concentration of 10-20% and sulfuric acid with a concentration of 5-15% in a volume ratio of 1:1.

[0019] Through experimental exploration, it was found that the first hydrofluoric acid etching at low temperature and short time accurately removed the sandblasting defects and formed a transition interface; the second strong acid high temperature and long time treatment constructed nanopores on the titanium surface. The problem of uneven pore size distribution caused by single acid etching is avoided by synergistic two-stage acid etching. This application controls the concentration and temperature of the etching solution to achieve a pore size of 0.05-5μm accounting for ≥80%, and the micropore elastic modulus reaches 15.4GPa (close to natural bone), effectively reducing the stress shielding effect. Only by controlling the influencing parameters in the surface treatment within the above range can a suitable bionic multi-level structure be formed on the surface of the implant, while meeting the efficiency requirements of industrial production.

[0020] Optionally, in the sandblasting process, the pure titanium implant material is sandblasted using aluminum oxide particles; the particle size of the aluminum oxide particles is 60-100 mesh.

[0021] Optionally, the sandblasting treatment conditions are: the pressure is controlled at 0.2-0.4 MPa, the time is controlled at 15-60 s, and the distance between the pure titanium implant material and the nozzle for sandblasting is 50-100 mm.

[0022] Through experimental research, it was found that the mesh size of the particles determines the diameter of the micron pit (a decrease in mesh size leads to an increase in diameter), the pressure affects the depth of the pit (an increase in pressure leads to an increase in depth), and the distance and time jointly control the uniformity of the surface roughness.

[0023] In this application, sandblasting uses high-speed particles to impact and roughen the surface of titanium (pure titanium implant material), forming a primary structure (20-50 μm), i.e., micron-level roughness; two acid etching treatments remove the sharp ridges of the sandblasted surface and selectively corrode the surface, further forming a secondary structure (1-10 μm) and a tertiary structure (50-300 nm), i.e., a nanoscale microporous structure.

[0024] In a specific embodiment, in the first acid etching treatment, the concentration of hydrofluoric acid is 1%, 3%, or 5%.

[0025] In some specific embodiments, in the first acid etching treatment, the concentration of hydrofluoric acid is 1-3% or 3-5%.

[0026] In a specific embodiment, the treatment temperature of the first acid etching treatment is 25°C, 30°C, or 35°C.

[0027] In some specific embodiments, the treatment temperature of the first acid etching treatment is 25-30°C or 30-35°C.

[0028] In a specific embodiment, the treatment time of the first acid etching treatment is 10s, 20s, or 30s.

[0029] In some specific embodiments, the treatment time of the first acid etching treatment is 10-20 seconds or 20-30 seconds.

[0030] In a specific embodiment, the concentration of hydrochloric acid in the second acid etching treatment is 10%, 15%, or 20%.

[0031] In some specific embodiments, the concentration of hydrochloric acid in the second acid etching treatment is 10-15% or 15-20%.

[0032] In a specific embodiment, the concentration of sulfuric acid in the second acid etching treatment is 5%, 10%, or 15%.

[0033] In some specific embodiments, the concentration of sulfuric acid in the second acid etching treatment is 5-10% or 10-15%.

[0034] In a specific embodiment, the treatment temperature of the second acid etching treatment is 90°C, 100°C, or 120°C.

[0035] In some specific embodiments, the treatment temperature of the second acid etching treatment is 90-100°C or 100-120°C.

[0036] In a specific embodiment, the treatment time of the second acid etching treatment is 5 minutes, 7 minutes, or 10 minutes.

[0037] In some specific embodiments, the second acid etching treatment lasts for 5-8 minutes or 7-10 minutes.

[0038] In a specific embodiment, the particle size of the aluminum chloride particles is 60 mesh, 80 mesh, or 100 mesh.

[0039] In some specific embodiments, the particle size of the aluminum chloride particles is 60-80 mesh or 80-100 mesh.

[0040] In a specific embodiment, the pressure of the sandblasting treatment is 0.2 MPa, 0.3 MPa, or 0.4 MPa.

[0041] In some specific embodiments, the pressure of the sandblasting treatment is 0.2-0.3 MPa or 0.3-0.4 MPa.

[0042] In a specific embodiment, the sandblasting time is 15s, 30s, or 60s.

[0043] In some specific embodiments, the sandblasting treatment lasts for 15-30 seconds or 30-60 seconds.

[0044] In a specific embodiment, the distance between the pure titanium implant material and the nozzle for sandblasting is 50 mm, 80 mm, or 100 mm.

[0045] In some specific embodiments, the distance between the pure titanium implant material and the nozzle for sandblasting is 50-80 mm or 80-100 mm.

[0046] Optionally, the process parameters of the method are as follows: the first acid etching is carried out with a hydrofluoric acid concentration of 3%, a temperature of 30°C, and a time of 20 seconds; the second acid etching is carried out with a concentration of 15% hydrochloric acid and 10% sulfuric acid mixed in a volume ratio of 1:1, a temperature of 100°C, and a time of 7 minutes.

[0047] Through experimental analysis, it was found that by further controlling the surface treatment process parameters within the above range, the pore size of 0.05-5μm in the obtained bionic multi-level structure accounted for 90.54%, the micropore elastic modulus was 15.4GPa, the roughness Ra=1.30±0.073μm, and the contact angle was 69.01°.

[0048] Optionally, before sandblasting, the pure titanium implant material is cleaned and dried; the specific operation of the cleaning is: placing the pure titanium implant material in cleaning liquid and deionized water respectively and cleaning under ultrasonic conditions for 5-10 minutes, and repeating the above operation twice.

[0049] Optionally, before sandblasting, the temperature of ultrasound during cleaning of the pure titanium implant material is 25-50°C.

[0050] Optionally, before sandblasting, the cleaned pure titanium implant material is dried at 60-80° C. for 10-20 minutes.

[0051] Optionally, the pure titanium implant material is cleaned using Fiber 191, Micro-90, or KKS surfactant cleaning agents.

[0052] In one embodiment, the cleaning solution is Fiber 191 at a concentration of 10%.

[0053] In a specific embodiment, the cleaning solution is Micro-90 at a concentration of 10%.

[0054] In a specific embodiment, the cleaning solution is a KKS surfactant cleaning agent with a concentration of 5%.

[0055] Optionally, the ultrasonic cleaning is as follows: the pure titanium implant material treated in the previous step is placed under ultrasonic conditions and cleaned with deionized water for 10-20 minutes.

[0056] Optionally, the temperature condition of the ultrasonic cleaning is 25-50°C.

[0057] Optionally, in the drying process, the pure titanium implant material treated in the previous step is dried at a temperature of 90-120° C. for 10-20 minutes.

[0058] In summary, this application includes at least one of the following beneficial technical effects:

[0059] This application provides a method for preparing a biomimetic multi-level structure on the surface of a pure titanium implant material. The method uses a combination of alumina particle sandblasting and two acid etching treatments to prepare the biomimetic multi-level structure. The process parameters are as follows: the first acid etching is performed with a hydrofluoric acid concentration of 1-5%, a temperature of 25-35°C, and a duration of 10-30 seconds; the second acid etching is performed with a 1:1 volume mixture of hydrochloric acid (concentration of 10-20%) and sulfuric acid (concentration of 5-15%), a temperature of 90-120°C, and a duration of 5-10 minutes.

[0060] In this application, a bionic multi-level pore structure is constructed on the surface of pure titanium implant materials through the synergistic effect of "mechanical roughening-chemical etching". In the sandblasting pre-treatment step, the pure titanium implant material is ultrasonically cleaned and dried multiple times to effectively remove impurities on the surface of the material, ensuring that the rough morphology formed in the subsequent sandblasting process is of higher quality. In the sandblasting step, by adjusting key parameters such as alumina particles, sandblasting machine pressure, the distance between the nozzle and the material, and sandblasting time, a primary structure (20-50μm) is formed on the surface of pure titanium, i.e., micron-level roughness. In the acid etching step, by adjusting key parameters such as the concentration of the etching solution, the etching temperature, and the etching time, a selective corrosion surface is achieved, further forming secondary (1-10μm) and tertiary pore structures (50-300nm), i.e., nanoscale microporous structures.

[0061] The optimized surface treatment process achieves ideal porosity, micropore elastic modulus, surface roughness, and contact angle, meeting standard requirements for medical implants and mimicking the natural bone matrix nanotopology. The primary pore structure provides more surface binding sites for cell adhesion, accelerating vascularization and new bone formation. The secondary pore structure increases the specific surface area, promoting protein adhesion and enhancing osteogenic activity. The tertiary pore structure regulates cytoskeletal tension, matching the elastic modulus of bone tissue, and reducing stress shielding. The synergistic effect of this multi-level structure shortens the bone healing cycle and improves bone bond strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is a flow chart of a method for preparing a bionic multi-level structure on the surface of a pure titanium implant material provided in this application.

[0063] Figure 2 This is the test result of the pure titanium implant material after treatment in Example 2 under an electron microscope (A is the primary structure (20-50 μm); B is the secondary structure (1-10 μm); C is the tertiary structure (50-300 nm)).

[0064] Figure 3 This is the test result of the pure titanium implant material after treatment in Example 2 under an atomic force microscope (A is a 3D topography image; B is a force spectrum measurement curve).

[0065] Figure 4 This is the test result of the pure titanium implant material after treatment in Example 2 under the 3D profilometer (A is the 3D profilometer diagram; B is the roughness curve). DETAILED DESCRIPTION

[0066] Before describing the embodiments of the present application in detail, it should be understood that the terminology used herein is only for the purpose of describing particular embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the term belongs.

[0067] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. Furthermore, in the description of this application, unless otherwise specified, "plurality" means two or more.

[0068] The endpoints of the ranges and any values ​​disclosed in this application are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed herein.

[0069] In this application, the term "comprise" or "include" is an open expression, that is, it includes the content specified in this application, but does not exclude other aspects of the content.

[0070] The present application provides a method for preparing a bionic multi-level structure on the surface of a pure titanium implant material, such as Figure 1 As shown, the specific steps include:

[0071] (1) Cleaning before sandblasting: Use finished cleaning fluid to clean the pure titanium implant material.

[0072] Prepare the cleaning solution according to the instructions of the finished cleaning solution, place the pure titanium implant material to be sandblasted in the prepared cleaning solution, place it in an ultrasonic cleaner at 25-50℃ and clean it for 5-10 minutes, then place it in an ultrasonic cleaner at 25-50℃ and clean it with deionized water for 5-10 minutes: repeat the above steps twice.

[0073] The cleaned pure titanium implant material is placed in a dryer at 60-80°C and dried for 10-20 minutes.

[0074] (2) Sandblasting: inject alumina particles (particle size of 60-100 mesh) into the sandblasting machine, open the air compressor valve, adjust the sandblasting machine pressure gauge (pressure 0.2-0.4 MPa), adjust the distance between the pure titanium implant material to be sandblasted and the nozzle (distance 50-100 mm), start sandblasting and time it for 15-60 seconds.

[0075] (3) Ultrasonic cleaning: Place the sandblasted pure titanium implant material in an ultrasonic cleaning machine at 25-50°C and clean it with deionized water for 10-20 minutes. Remove the residual sand and metal debris on the surface of the pure titanium implant material to ensure the uniformity of the subsequent acid etching reaction.

[0076] (4) First acid etching treatment: The pure titanium implant material treated in the previous step is subjected to acid etching treatment using hydrofluoric acid with a concentration of 1-5%, the treatment temperature being 25-35° C. and the treatment time being 10-30 seconds.

[0077] (5) Ultrasonic cleaning: Place the pure titanium implant material after the first acid etching treatment in an ultrasonic cleaning machine at 25-50°C and clean it with deionized water for 10-20 minutes.

[0078] (6) Second acid etching treatment: A mixture of 10-20% hydrochloric acid and 5-15% sulfuric acid in a volume ratio of 1:1 is used to acid-etch the pure titanium implant material after the previous step. The treatment temperature is 90-120° C. and the treatment time is 5-10 minutes.

[0079] (7) Ultrasonic cleaning: The pure titanium implant material after the second acid etching treatment is placed in an ultrasonic cleaning machine at 25-50°C and cleaned with deionized water for 10-20 minutes.

[0080] (8) Drying: The pure titanium implant material treated in the previous step is placed in a temperature condition of 90-120° C. and dried for 10-20 minutes to obtain a pure titanium implant material with a bionic multi-level structure.

[0081] To make the purpose, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be understood as limiting this application.

[0082] If no specific techniques or conditions are specified in the examples, the experiments were carried out according to the techniques or conditions described in the literature in the field or according to the product instructions. All reagents or instruments used without specifying the manufacturer are commercially available conventional products.

[0083] In the following examples, the pure titanium implant material is TA4 pure titanium rod purchased from Zapp in Germany; alumina particles are purchased from Henan Tengfei Environmental Protection Technology Co., Ltd.; and chemicals are purchased from Beijing Huateng Chemical Co., Ltd. The raw materials, equipment, etc. used in this application can all be obtained commercially.

[0084] The present application is further described in detail below in conjunction with the examples and test results.

[0085] Example

[0086] Example 1

[0087] This embodiment provides a method for preparing a bionic multi-level structure on the surface of a pure titanium implant material.

[0088] The steps of the above method are as follows:

[0089] (1) Cleaning before sandblasting: Prepare the cleaning solution according to the instructions of the finished cleaning solution, place the pure titanium implant material to be sandblasted in the prepared cleaning solution (10% concentration of Micro-90), place it in an ultrasonic cleaning machine at 25-50°C for 5 minutes, and then place it in an ultrasonic cleaning machine at 25-50°C for 5 minutes using deionized water: repeat the above operation twice.

[0090] The cleaned pure titanium implant material was placed in a dryer at 60-80°C and dried for 15 minutes.

[0091] (2) Sandblasting: Inject alumina particles (particle size of 80 mesh) into the sandblasting machine, open the air compressor valve, adjust the sandblasting machine pressure gauge (pressure 0.3 MPa), adjust the distance between the pure titanium implant material to be sandblasted and the nozzle (distance 80 mm), start sandblasting and time for 30 seconds.

[0092] (3) Ultrasonic cleaning: Place the sandblasted pure titanium implant material in an ultrasonic cleaning machine at 25-50°C and clean it with deionized water for 20 minutes. Remove the residual sand and metal debris on the surface of the pure titanium implant material to ensure the uniformity of the subsequent acid etching reaction.

[0093] (4) First acid etching treatment: The pure titanium implant material treated in the previous step was subjected to acid etching treatment using 1% hydrofluoric acid at a temperature of 30° C. for 20 seconds.

[0094] (5) Ultrasonic cleaning: The pure titanium implant material after the first acid etching treatment is placed in an ultrasonic cleaning machine at 25-50°C and cleaned with deionized water for 10 minutes.

[0095] (6) Second acid etching treatment: A mixture of 15% hydrochloric acid and 10% sulfuric acid in a volume ratio of 1:1 was used to acid-etch the pure titanium implant material after the previous step. The treatment temperature was 100° C. and the treatment time was 7 min.

[0096] (7) Ultrasonic cleaning: The pure titanium implant material after the second acid etching treatment is placed in an ultrasonic cleaning machine at 25-50°C and cleaned with deionized water for 10 minutes.

[0097] (8) Drying: The pure titanium implant material treated in the previous step is placed in a temperature condition of 90-120°C and dried for 15 minutes to obtain a pure titanium implant material with a bionic multi-level structure.

[0098] Example 2-19

[0099] Examples 2-19 each provide a method for preparing a biomimetic multi-level structure on the surface of a pure titanium implant material. The above examples differ from Example 1 in that the process parameters in the above methods are specifically shown in Table 1. The remaining steps remain the same as in Example 1.

[0100] Specifically, the differences between Examples 1-19 are as follows:

[0101] The difference between Examples 1-3 lies in the concentration of hydrofluoric acid in the first acid etching treatment.

[0102] The difference between Examples 2 and 4-5 lies in the treatment temperature of the first acid etching treatment.

[0103] The difference between Examples 2 and 6-7 lies in the treatment time of the first acid etching treatment.

[0104] The difference between Examples 2 and 8-15 lies in the concentration of hydrochloric acid or sulfuric acid in the second acid etching treatment.

[0105] The difference between Examples 2 and 16-17 lies in the treatment temperature of the second acid etching treatment.

[0106] The difference between Examples 2 and 18-19 lies in the treatment time of the second acid etching treatment.

[0107] Table 1 Parameters involved in some steps of the method provided in the above embodiment

[0108]

[0109]

[0110] Comparative Example

[0111] Comparative Example 1

[0112] This comparative example provides a method for preparing a biomimetic hierarchical structure on the surface of a pure titanium implant. This method differs from Example 2 in that the sandblasting process uses diamond abrasive particles of the same size. The remaining steps remain the same as in Example 2.

[0113] Comparative Example 2

[0114] This comparative example provides a surface treatment method for an implant. The difference from Example 2 is that the treatment target is replaced by a titanium-zirconium alloy containing 12-17 wt% zirconium instead of pure titanium implant material. The remaining steps are consistent with Example 2.

[0115] Comparative Example 3

[0116] This comparative example provides a method for forming a biomimetic hierarchical structure on the surface of a pure titanium implant. This method differs from Example 2 in that the first acid etching treatment uses a solution of 0.1% hydrofluoric acid and 0.15% HNO₃ in a 1:1 volume ratio. The remaining steps remain the same as in Example 2.

[0117] Comparative Example 4

[0118] This comparative example provides a method for preparing a biomimetic hierarchical structure on the surface of a pure titanium implant. This method differs from Example 2 in that the first acid etching treatment lasts for 20 minutes. The remaining steps remain the same as in Example 2.

[0119] Comparative Example 5

[0120] This comparative example provides a method for forming a biomimetic hierarchical structure on the surface of a pure titanium implant. This method differs from Example 2 in that the second acid etching treatment uses a solution of 8% hydrochloric acid and 20% sulfuric acid in a 1:1 volume ratio. The remaining steps remain the same as in Example 2.

[0121] Comparative Example 6

[0122] This comparative example provides a method for preparing a biomimetic hierarchical structure on the surface of a pure titanium implant material. The difference from Example 2 is that the second acid etching treatment is performed at a temperature of 70° C. The remaining steps are consistent with those of Example 2.

[0123] Comparative Example 7

[0124] This comparative example provides a method for preparing a biomimetic hierarchical structure on the surface of a pure titanium implant. This method differs from Example 2 in that the second acid etching treatment lasts for 120 minutes. The remaining steps remain the same as in Example 2.

[0125] Performance testing

[0126] The implants provided in the above embodiments and comparative examples were tested respectively. The test items specifically included the following:

[0127] (1) Surface state-pore size distribution detection

[0128] The surface condition after surface treatment was observed using an electron microscope at 5000x magnification. The proportion of pores with a diameter of 0.05-5 μm was statistically analyzed using Image J software. The results are shown in Table 2.

[0129] The results of the electron microscope test on the pure titanium implant material after treatment in Example 2 are as follows: Figure 2 shown.

[0130] (2) Surface morphology and nanomechanical testing

[0131] Atomic force microscopy (AFM) was used to examine surface morphology and perform nanomechanical measurements, obtaining two-dimensional and three-dimensional topography and force spectroscopy curves. The scanning range was 4000 nm x 4000 nm, and the image size was 2561 x 256 pixels. The micropore elastic modulus was analyzed, and the test results are shown in Table 2.

[0132] The test results of the pure titanium implant material treated in Example 2 under an atomic force microscope are as follows: Figure 3 As shown (probe radius R = 38 nm, Poisson's ratio ν = 0.33, elastic modulus 15.4 GPa).

[0133] (3) Roughness detection

[0134] The surface roughness of the treated implant material was measured using a 3D profilometer to obtain the roughness value Ra. Five random locations were tested and the average value was calculated. The test results are shown in Table 2.

[0135] The test results of the pure titanium implant material after treatment in Example 2 under the 3D profilometer are as follows: Figure 4 As shown, Ra is 1.3 μm.

[0136] (4) Contact angle detection

[0137] The contact angle of the treated implant surface was measured using a contact angle analyzer (CAT), using the ellipse fitting method. The test results are shown in Table 2.

[0138] Table 2 Test results of the pure titanium implant material with bionic multi-level structure provided in the above embodiment

[0139]

[0140]

[0141] It can be seen from Table 2 that the surface pore size of the pure titanium plant material after treatment provided by Examples 1-19 accounts for 72.65-90.54%, the micropore elastic modulus is 15.4-29.89Gpa, the surface roughness Ra is 1.3-1.935μm, and the contact angle is 69.01-74.45°. As can be seen from the above, the bionic multi-level structure of the treated pure titanium implant material of the present application fully simulates the porosity and mechanical properties of the bone structure, and meets the requirements of bone integration. The bionic multi-level structure matches the porosity of cancellous bone of 50-90% and the elastic modulus of bone tissue of 10-30Gpa, simulating the geometric morphology of the porous bone structure. The multi-level composite structure can synergistically improve the rate of osteogenic differentiation and mineralization formation, which helps to obtain better initial stability of implant implantation, thereby promoting the bone integration process.

[0142] In addition, the test results of Example 2 are compared with those of Comparative Examples 1-7, and the specific analysis is as follows:

[0143] By comparing the solutions of Example 2 and Comparative Example 1, it can be seen that the sandblasting particles used in Comparative Example 1 are diamond particles. Due to the high hardness of the diamond particles, the porosity of the treated pure titanium implant material is reduced and the elastic modulus is increased, which is far from the porosity of cancellous bone (50-90%) and the elastic modulus of bone tissue (10-30 GPa).

[0144] By comparing the solutions of Example 2 and Comparative Example 2, it can be seen that the implant used in Comparative Example 2 is a titanium-zirconium alloy containing 12-17wt% zirconium. Since the titanium-zirconium alloy containing 12-17wt% zirconium itself has a high elastic modulus, even after treatment, the improvement on its surface is small, and its elastic modulus is also greater than the elastic modulus of bone tissue.

[0145] By comparing the solutions of Example 2 and Comparative Example 3, it can be seen that the acid used for the first acid etching treatment in Comparative Example 3 is a mixture of hydrofluoric acid and nitric acid. Since the acid concentration used is low, the porosity of the treated pure titanium implant material is low, so its elastic modulus is still high, much greater than the elastic modulus of bone tissue.

[0146] By comparing the solutions of Example 2 and Comparative Example 4, it can be seen that the time for the first acid etching treatment in Comparative Example 4 is 20 minutes. Compared with Example 2, the reaction time is increased, the porosity of the treated pure titanium implant material is reduced, the etching degree is increased, the substrate may be exposed, and the elastic modulus is high, which is much greater than the elastic modulus of bone tissue.

[0147] By comparing the solutions of Example 2 and Comparative Example 5, it can be seen that the acid used for the second acid etching treatment in Comparative Example 5 is a solution of 8% hydrochloric acid and 20% sulfuric acid mixed in a volume ratio of 1:1. Due to the increase in the concentration of sulfuric acid, oxidation occurs, and the porosity of the treated pure titanium implant material decreases and the elastic model increases.

[0148] By comparing the solutions of Example 2 and Comparative Example 6, it can be seen that the temperature of the second acid etching treatment in Comparative Example 6 is 70°C. Due to the lower treatment temperature, the roughness of the treated pure titanium implant is reduced, which cannot meet the roughness requirement of bone implant materials in the prior art (1-2μm).

[0149] By comparing the solutions of Example 2 and Comparative Example 7, it can be seen that the time for the second acid etching treatment in Comparative Example 7 is 120 minutes. Due to the prolonged acid etching treatment time, excessive corrosion and destruction of the pore structure, the roughness and elastic modulus of the treated pure titanium implant material are increased.

[0150] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a bionic multi-level structure on the surface of a pure titanium implant material, characterized in that: The method specifically comprises the following steps: The pure titanium implant material was subjected to sandblasting, ultrasonic cleaning, first acid etching, ultrasonic cleaning, second acid etching, ultrasonic cleaning and drying; In the first acid etching treatment, hydrofluoric acid is used to perform acid etching on the pure titanium implant material treated in the previous step; The concentration of the hydrofluoric acid is 1-5%; the treatment temperature of the first acid etching treatment is 25-35° C., and the treatment time is 10-30 seconds; In the second acid etching treatment, the pure titanium implant material treated in the previous step is acid-etched using a mixture of hydrochloric acid and sulfuric acid; the hydrochloric acid and the sulfuric acid are mixed in a volume ratio of 1:1 to obtain a mixed solution; the concentration of the hydrochloric acid is 10-20%, and the concentration of the sulfuric acid is 5-15%; the treatment temperature of the second acid etching treatment is 90-120°C, and the treatment time is 5-10 minutes.

2. The method according to claim 1, characterized in that Before sandblasting, the pure titanium implant material was cleaned and dried. The specific operation of the cleaning was as follows: the pure titanium implant material was placed in a cleaning solution and deionized water and cleaned under ultrasonic conditions for 5-10 minutes, and the above operation was repeated twice.

3. The method according to claim 2, wherein The pure titanium implant material was cleaned using Fiber 191, Micro-90, and KKS surfactant cleaning agents.

4. The method according to claim 2, characterized in that The temperature of the ultrasound is 25-50°C.

5. The method according to claim 2, characterized in that The cleaned pure titanium implant material is placed at 60-80° C. and dried for 10-20 minutes.

6. The method according to claim 1, characterized in that In the sandblasting process, the pure titanium implant material is sandblasted using aluminum oxide particles; the particle size of the aluminum oxide particles is 60-100 meshes.

7. The method according to claim 1, characterized in that The sandblasting treatment conditions are as follows: the pressure is controlled at 0.2-0.4 MPa, the time is controlled at 15-60 s, and the distance between the pure titanium implant material and the nozzle used for sandblasting is 50-100 mm.

8. The method according to claim 1, characterized in that The ultrasonic cleaning is as follows: the pure titanium implant material treated in the previous step is placed under ultrasonic conditions and cleaned with deionized water for 10-20 minutes.

9. The method according to claim 8, characterized in that The temperature condition of the ultrasonic cleaning is 25-50°C.

10. The method according to claim 1, characterized in that In the drying process, the pure titanium implant material treated in the previous step is placed under a temperature condition of 90-120° C. and dried for 10-20 minutes.

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