A method for preparing a titanium dental implant surface coating with antibacterial and osteoinductive properties

Abstract

The present application relates to a kind of preparation method of titanium dental implant surface coating with antibacterial and bone formation performance, belong to dental implant material technical field.The method is through titanium substrate pretreatment, inner layer hydroxyapatite, chitosan composite coating preparation, outer layer zinc-loaded mesoporous silane coating preparation three-step composite process, constructs double-layer function synergic coating on titanium substrate surface.Inner layer utilizes the osteogenic activity of hydroxyapatite and the natural antibacterial property of chitosan to form basic function layer, outer layer is loaded with zinc ion through the slow-release structure of mesoporous silane, realizes the long-acting controllable release of antibacterial component, while zinc ion and mesoporous silane synergistically improve the proliferation and differentiation ability of osteoblasts.The present application solves the technical problems of single function, poor antibacterial durability, insufficient bone formation effect, weak coating and substrate bonding force and complex preparation process of existing titanium dental implant coating.The prepared coating is firmly combined with titanium substrate, has high biological safety, simple and controllable process, is suitable for industrial production, and has important application value in the field of dental implant.

Description

Technical Field

[0001] This invention relates to the field of titanium dental implant technology, and more specifically to a method for preparing a titanium dental implant surface coating that has both antibacterial and osteogenic properties. Background Technology

[0002] Titanium and titanium alloys have become the mainstream material for dental implants due to their excellent biocompatibility, mechanical properties, and corrosion resistance. However, pure titanium has insufficient surface bioactivity, making it prone to bacterial infection and inflammatory reactions after implantation. At the same time, the adhesion, proliferation, and differentiation capacity of osteoblasts on its surface are limited, resulting in insufficient bonding strength between the implant and bone tissue, which affects the success rate and long-term stability of the implant.

[0003] To address the aforementioned issues, existing technologies primarily employ modification by preparing coatings on the surface of titanium implants. Some technologies introduce antibacterial components such as silver and copper ions to create antibacterial coatings. While these can inhibit bacterial growth in the short term, the rapid release of these antibacterial components leads to poor durability, and high concentrations of metal ions may be toxic to osteoblasts. Other technologies prepare bioceramic coatings such as hydroxyapatite and tricalcium phosphate to enhance osteogenic properties; however, these coatings lack antibacterial functionality and cannot address the risk of bacterial infection around the implant. Some composite coatings attempt to simply mix antibacterial and osteogenic components, but these suffer from uneven component distribution, weak adhesion between the coating and the substrate, and poor synergy between antibacterial and osteogenic properties. Furthermore, the preparation processes for existing composite coatings are often complex, involving specialized equipment such as high-temperature sintering and plasma spraying, resulting in high production costs and hindering large-scale application.

[0004] Therefore, developing a simple process for preparing a titanium dental implant surface coating that achieves both long-lasting antibacterial properties and excellent osteogenic properties has become a pressing technical problem in the field of dental implant materials. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a titanium dental implant surface coating that has both antibacterial and osteogenic properties, in order to overcome the defects of the above-mentioned coatings, such as lack of antibacterial function, inability to cope with the risk of bacterial infection around the implant, and poor synergy between antibacterial and osteogenic properties.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a method for preparing a titanium dental implant surface coating that possesses both antibacterial and osteogenic properties, comprising the following steps:

[0007] Titanium matrix pretreatment: The titanium dental implant matrix is ​​sequentially subjected to gradient sandpaper polishing, ultrasonic cleaning, alkali treatment, and acid etching to obtain a titanium matrix with a rough surface and rich in hydroxyl groups. The gradient sandpaper polishing uses 400 grit → 800 grit → 1200 grit → 2000 grit sandpaper to remove the oxide layer and processing defects on the surface of the titanium matrix, gradually building a micron-level rough surface (roughness Ra increased to 1.5-2.0 μm).

[0008] Preparation of inner hydroxyapatite-chitosan composite coating: hydroxyapatite powder is dispersed in a 1-3 wt% chitosan acetic acid solution and ultrasonically dispersed to obtain a uniform coating slurry; wherein the mass ratio of hydroxyapatite to chitosan is 3-5:1.

[0009] A rough titanium substrate rich in hydroxyl groups is immersed in a coating slurry and coated at a pulling speed of 5-10 mm / s. The substrate is then placed in a hydrothermal reactor and reacted at 120-150℃ for 4-6 hours. After cooling, the substrate is washed and dried to obtain a titanium substrate with an inner coating layer.

[0010] Preparation of outer zinc-loaded mesoporous silane coating: The mesoporous silane precursor and zinc nitrate are dissolved in a mixed solvent of ethanol and deionized water, the pH is adjusted to 3-5, and the mixture is stirred and hydrolyzed at 25-30℃ for 2-4h to obtain a sol; the molar ratio of zinc nitrate to mesoporous silane precursor is 0.05-0.1:1, and the volume ratio of ethanol to deionized water in the mixed solvent is 3-5:1; the titanium substrate with the inner coating is immersed in the sol, coated at a pulling speed of 3-8mm / s, sintered at 300-400℃ for 1-2h, and the target product is obtained after cooling.

[0011] Existing composite coatings often involve a physical mixture of antibacterial components (such as silver ions) and osteogenic components (such as hydroxyapatite), which can lead to the contradiction of "antibacterial components inhibiting osteoogenesis while osteogenic components weaken antibacterial activity." This solution innovatively designs a two-layer structure: an inner layer with basic function and an outer layer with long-term regulation. The inner layer uses hydroxyapatite (osteogenic matrix) and chitosan (natural antibacterial) to form an "osteogenic-initial antibacterial" foundation, avoiding the toxicity of metal ions to osteogenic cells. The outer layer uses a porous structure of mesoporous silanes to load zinc ions, achieving long-term sustained release of zinc ions through mesoporous structures. Furthermore, the synergistic antibacterial effect of zinc ions and chitosan (zinc ions disrupt bacterial cell membranes, chitosan adsorbs bacteria) and the synergistic osteogenic effect of zinc ions and mesoporous silanes (mesoporous structures facilitate nutrient exchange, zinc ions promote osteoblast differentiation) achieve a functional synergy of "1+1>2." This structural design is unprecedented in existing titanium implant coating technologies and is highly innovative.

[0012] Existing technologies for pretreatment of titanium substrates often involve simple grinding or acid / alkali cleaning, achieving only surface cleaning or preliminary roughening, resulting in weak adhesion between the coating and the substrate. This invention innovatively employs a four-step pretreatment process: gradient sanding → ultrasonic cleaning → alkali treatment → acid etching. Gradient sanding constructs a gradient micron-level rough structure, laying the foundation for mechanical interlocking; ultrasonic cleaning removes impurities; alkali treatment forms a sodium titanate gel layer on the substrate surface, introducing a large number of hydroxyl groups; acid etching further optimizes the porous morphology, removes alkali residue, and enhances hydroxyl density. This pretreatment not only achieves "physical roughening" but also introduces hydroxyl active sites through chemical modification, enabling the inner coating to form "mechanical interlocking + hydrogen bonding" (coordination of hydroxyl groups with Ca²⁺ in hydroxyapatite). The final coating adhesion reaches level 1 in the cross-cut adhesion test, solving the technical challenge of existing pretreatments failing to simultaneously achieve "morphological roughness" and "chemical activity," demonstrating originality.

[0013] Meanwhile, existing composite coatings mostly rely on specialized equipment such as high-temperature sintering (>500℃) and plasma spraying, which are complex and costly, making large-scale production difficult. This invention employs a combined process of "coiling pull-out method + hydrothermal reaction + low-temperature sintering": the lifting pull-out method allows for precise control of coating thickness, avoiding the uneven thickness of spraying; the 120-150℃ hydrothermal reaction promotes densification of the inner coating layer, preventing high temperatures from damaging the biocompatibility of chitosan; and the 300-400℃ low-temperature sintering achieves the shaping of the outer mesoporous structure, eliminating the need for energy-intensive equipment. Furthermore, all process parameters (such as the inner layer hydroxyapatite-chitosan mass ratio of 3-5:1 and the outer layer zinc nitrate-mesoporous silane molar ratio of 0.05-0.1:1) have been precisely optimized, ensuring both functionality and process adaptability, achieving a balance between "process simplification" and "functional efficiency," meeting the needs of large-scale industrial production. Its process design is innovative.

[0014] Furthermore, the ultrasonic cleaning involves using deionized water at a power of 200-400W for 15-20 minutes.

[0015] Compared with existing technologies, the power range of 200-400W is a safe and efficient range for titanium substrates. It can remove fine impurities through ultrasonic cavitation effect while avoiding impact damage to the titanium substrate caused by excessive power. The cleaning time of 15-20 minutes balances "thoroughness of decontamination" and "efficiency", avoiding incomplete decontamination if the cleaning time is less than 15 minutes and oxidation of the substrate surface if the cleaning time is more than 20 minutes.

[0016] Furthermore, the alkaline treatment involves soaking the affected area in a 5-10 mol / L sodium hydroxide solution at 60-80°C for 2-3 hours.

[0017] Compared with existing technologies, a concentration of 5-10 mol / L can form a uniform sodium titanate gel layer of 1-2 μm thickness on the substrate surface, which ensures hydroxyl density and avoids excessive corrosion; a temperature of 60-80℃ accelerates the reaction between NaOH and the titanium substrate (TiO2 + 2NaOH → Na2TiO3 + H2O), shortening the treatment time; a soaking time of 2-3 hours ensures sufficient reaction, avoiding incomplete reaction in less than 2 hours and gel layer detachment in more than 3 hours.

[0018] Furthermore, the acid etching treatment involves immersing the sample in a 1-2 mol / L hydrochloric acid solution at room temperature for 30-60 minutes.

[0019] Compared with existing technologies, a concentration of 1-2 mol / L provides a mild corrosion range, which can slowly dissolve the sodium titanate gel layer formed by alkali treatment, while further refining the surface porous structure and avoiding excessive coarseness; no heating equipment is required at room temperature, reducing energy consumption and ensuring uniform corrosion; a duration of 30-60 minutes ensures the removal of residual Na from the gel layer. + At the same time, it enhances the density of hydroxyl groups.

[0020] Furthermore, the ultrasonic dispersion time is 30-40 min, and the power is 300-400 W; after reacting at 120-150℃ for 4-6 h, the washing and drying process involves rinsing with deionized water for 2-3 min, and then drying at 60-80℃ for 2-3 h.

[0021] Compared with existing technologies, 300-400W power can break the van der Waals aggregation of hydroxyapatite, while avoiding the chitosan chain breakage caused by high power; 30-40min duration ensures uniform dispersion (slurry particle size ≤1μm), avoiding incomplete dispersion in less than 30min and energy waste in more than 40min.

[0022] Furthermore, the mesoporous silane precursor includes at least one of tetraethyl orthosilicate or γ-aminopropyltriethoxysilane.

[0023] Furthermore, the mesoporous silane precursor comprises tetraethyl orthosilicate and γ-aminopropyltriethoxysilane, with a mass ratio of tetraethyl orthosilicate to γ-aminopropyltriethoxysilane of 3:1.

[0024] Compared to existing technologies, the mesoporous silane precursors in current technologies mostly use a single tetraethyl orthosilicate. While this can form a mesoporous structure, it suffers from insufficient biocompatibility. If other precursors (such as aminosilanes) are used, the mesoporous structure is prone to instability due to low reactivity. In the above-mentioned technical solution, tetraethyl orthosilicate exhibits high reactivity and easily forms a regular mesoporous structure (pore size 2-5 nm), making it suitable for zinc ion slow release. γ-aminopropyltriethoxysilane contains an amino group (-NH2), which enhances the hydrophilicity of the coating (reducing the contact angle to below 30°), promotes osteoblast adhesion, and its amino group can form hydrogen bonds with the hydroxyl groups of the inner chitosan, enhancing interlayer bonding. The choice of these two precursors covers both the requirements of "structural stability" (tetraethyl orthosilicate) and "biocompatibility" (γ-aminopropyltriethoxysilane), and can achieve functional complementarity through compounding (regular mesoporous structure and excellent hydrophilicity), solving the problem of existing precursors being unable to simultaneously achieve both "structure and biocompatibility."

[0025] Secondly, the present invention provides a titanium dental implant, which is prepared by the method described above during the preparation of a surface coating.

[0026] Compared with existing technologies, this invention directly and continuously prepares inner and outer coatings after titanium substrate pretreatment, without the need for intermediate storage or transfer. This avoids interface contamination and ensures coating uniformity through precise control of the dip-coating method.

[0027] Furthermore, the surface of the titanium dental implant has a double-layer composite coating, with the inner layer being a hydroxyapatite-chitosan composite layer with a thickness of 50-100 μm; and the outer layer being a zinc-loaded mesoporous silane layer with a thickness of 20-50 μm.

[0028] Compared with existing technologies, the inner layer with a thickness of 50-100μm can provide sufficient hydroxyapatite osteogenic matrix to support the complete process of osteoblasts from adhesion to differentiation; the outer layer with a thickness of 0-50μm can load sufficient zinc ions, which are released slowly through the mesoporous structure, while avoiding mechanical embrittlement caused by excessive thickness. Detailed Implementation

[0029] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention is further described below with reference to specific embodiments. It should be understood that, unless otherwise stated, all raw materials used in this invention are commercially available.

[0030] Example 1

[0031] A method for preparing a titanium dental implant surface coating with both antibacterial and osteogenic properties includes the following steps:

[0032] Titanium matrix pretreatment: The titanium dental implant matrix was sequentially subjected to gradient sandpaper polishing, deionized water cleaning at 200W for 15 min, immersion in 5mol / L sodium hydroxide solution at 60℃ for 2 h, and immersion in 1mol / L hydrochloric acid solution at room temperature for 30 min, resulting in a titanium matrix with a rough surface and rich in hydroxyl groups. The gradient sandpaper polishing was carried out using 400 grit → 800 grit → 1200 grit → 2000 grit sandpaper to remove the oxide layer and processing defects on the surface of the titanium matrix, gradually building a micron-level rough surface (roughness Ra increased to 1.5 μm).

[0033] Preparation of inner hydroxyapatite-chitosan composite coating: Hydroxyapatite powder was dispersed in a 1 wt% chitosan acetic acid solution and ultrasonically dispersed for 30 min at a power of 300 W to obtain a uniform coating slurry; wherein, the mass ratio of hydroxyapatite to chitosan was 3:1.

[0034] A rough titanium substrate rich in hydroxyl groups was immersed in a coating slurry and coated at a pulling speed of 5 mm / s. The substrate was then placed in a hydrothermal reactor and reacted at 120°C for 4 h. After cooling, the substrate was rinsed with deionized water for 2 min and then dried at 60°C for 2 h to obtain a titanium substrate with an inner coating layer.

[0035] Preparation of the outer zinc-loaded mesoporous silane coating: A mesoporous silane precursor composed of tetraethyl orthosilicate and γ-aminopropyltriethoxysilane in a mass ratio of 3:1, and zinc nitrate were dissolved in a mixed solvent of ethanol and deionized water. The pH was adjusted to 3, and the mixture was stirred and hydrolyzed at 25°C for 2 hours to obtain a sol. The molar ratio of zinc nitrate to the mesoporous silane precursor was 0.05:1, the volume ratio of ethanol to deionized water in the mixed solvent was 3:1, and the mass-volume ratio of zinc nitrate to the mixed solvent was 1 g: 100 ml. The titanium substrate with the inner coating was immersed in the sol, coated at a pulling speed of 3 mm / s, sintered at 300°C for 1 hour, and the target product was obtained after cooling.

[0036] Example 2

[0037] A method for preparing a titanium dental implant surface coating with both antibacterial and osteogenic properties includes the following steps:

[0038] Titanium matrix pretreatment: The titanium dental implant matrix was sequentially subjected to gradient sandpaper polishing, deionized water cleaning at 400W for 20 min, immersion in 10mol / L sodium hydroxide solution at 80℃ for 3 h, and immersion in 2mol / L hydrochloric acid solution at room temperature for 60 min, resulting in a titanium matrix with a rough surface and rich in hydroxyl groups. The gradient sandpaper polishing was carried out using 400 grit → 800 grit → 1200 grit → 2000 grit sandpaper to remove the oxide layer and processing defects on the surface of the titanium matrix, gradually building a micron-level rough surface (roughness Ra increased to 2.0 μm).

[0039] Preparation of inner hydroxyapatite-chitosan composite coating: Hydroxyapatite powder was dispersed in a 3wt% chitosan acetic acid solution and ultrasonically dispersed at 400W for 40min to obtain a uniform coating slurry; wherein, the mass ratio of hydroxyapatite to chitosan was 5:1.

[0040] A rough titanium substrate rich in hydroxyl groups was immersed in a coating slurry and coated at a pulling speed of 10 mm / s. The substrate was then placed in a hydrothermal reactor and reacted at 150°C for 6 h. After cooling, the substrate was rinsed with deionized water for 3 min and then dried at 80°C for 3 h to obtain a titanium substrate with an inner coating layer.

[0041] Preparation of the outer zinc-loaded mesoporous silane coating: A mesoporous silane precursor composed of tetraethyl orthosilicate and γ-aminopropyltriethoxysilane in a mass ratio of 3:1 and zinc nitrate were dissolved in a mixed solvent of ethanol and deionized water. The pH was adjusted to 5, and the mixture was stirred and hydrolyzed at 30°C for 4 hours to obtain a sol. The molar ratio of zinc nitrate to mesoporous silane precursor was 0.1:1, the volume ratio of ethanol to deionized water in the mixed solvent was 5:1, and the mass-volume ratio of zinc nitrate to the mixed solvent was 1g:100ml. The titanium substrate with the inner coating was immersed in the sol, coated at a pulling speed of 3-8mm / s, sintered at 400°C for 2 hours, and cooled to obtain the target product.

[0042] Example 3

[0043] A method for preparing a titanium dental implant surface coating with both antibacterial and osteogenic properties includes the following steps:

[0044] Titanium matrix pretreatment: The titanium dental implant matrix was sequentially subjected to gradient sandpaper polishing, deionized water cleaning at 300W for 18 min, immersion in 7.5mol / L sodium hydroxide solution at 70℃ for 2.5 h, and immersion in 1.5mol / L hydrochloric acid solution at room temperature for 45 min, resulting in a titanium matrix with a rough surface and rich in hydroxyl groups. The gradient sandpaper polishing was carried out using 400 grit → 800 grit → 1200 grit → 2000 grit sandpaper to remove the oxide layer and processing defects on the surface of the titanium matrix, gradually building a micron-level rough surface (roughness Ra increased to 1.8 μm).

[0045] Preparation of inner hydroxyapatite-chitosan composite coating: Hydroxyapatite powder was dispersed in a 2wt% chitosan acetic acid solution and ultrasonically dispersed for 350W for 35min to obtain a uniform coating slurry; wherein, the mass ratio of hydroxyapatite to chitosan was 4:1.

[0046] A rough titanium substrate rich in hydroxyl groups was immersed in a coating slurry and coated at a pulling speed of 8 mm / s. The substrate was then placed in a hydrothermal reactor and reacted at 130°C for 5 h. After cooling, the substrate was rinsed with deionized water for 2.5 min and then dried at 70°C for 2.5 h to obtain a titanium substrate with an inner coating layer.

[0047] Preparation of the outer zinc-loaded mesoporous silane coating: A mesoporous silane precursor composed of tetraethyl orthosilicate and γ-aminopropyltriethoxysilane in a mass ratio of 3:1 and zinc nitrate were dissolved in a mixed solvent of ethanol and deionized water. The pH was adjusted to 4, and the mixture was stirred and hydrolyzed at 28°C for 3 hours to obtain a sol. The molar ratio of zinc nitrate to the mesoporous silane precursor was 0.07:1, the volume ratio of ethanol to deionized water in the mixed solvent was 4:1, and the mass-volume ratio of zinc nitrate to the mixed solvent was 1 g: 100 ml. The titanium substrate with the inner coating was immersed in the sol, coated at a pulling speed of 5 mm / s, sintered at 350°C for 1.5 hours, and cooled to obtain the target product.

[0048] It should be understood that in Examples 1-3 above, the amount of sodium hydroxide solution and hydrochloric acid solution used should be just enough to submerge the titanium dental implant matrix.

[0049] Comparative Example 1 (Hydroxyapatite Single-Layer Coating)

[0050] Titanium matrix pretreatment: Same as in Example 3.

[0051] Coating preparation: Hydroxyapatite powder was dispersed in deionized water and ultrasonically dispersed at 350W for 35min; the remaining steps are described in Example 3.

[0052] Comparative Example 2 (Hydroxyapatite-silver ion composite coating)

[0053] Titanium matrix pretreatment: Same as in Example 3.

[0054] Coating preparation: Hydroxyapatite powder and silver nitrate (mass ratio 10:0.5) were dispersed in deionized water and ultrasonically dispersed at 350W for 35min to obtain a slurry. The remaining steps were the same as in Example 3.

[0055] Comparative Example 3 (Hydroxyapatite-chitosan monolayer coating)

[0056] Titanium matrix pretreatment: Same as in Example 1.

[0057] Coating preparation: The preparation of the inner coating is the same as in Example 3, but the preparation of the outer coating is omitted, that is, the process of preparing the outer zinc-loaded mesoporous silane coating is omitted, and the product is obtained directly.

[0058] Comparative Example 4 (Pure Titanium Matrix Blank Control Group)

[0059] Pure titanium dental implant matrix without any coating treatment.

[0060] Performance testing experiment

[0061] 1. Antibacterial performance test

[0062] Test strains: Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Candida albicans (ATCC 10231)

[0063] Test method: The plate count method was used. Implant samples (size: φ4mm×10mm) from each example, comparative example, and blank control group were immersed in 1×10⁻⁶ slabs. 6 After incubating the bacterial suspension at 37°C for 24 h, 72 h, and 168 h with CFU / mL of solution, the samples were removed and the suspension was thoroughly shaken before being diluted 10⁻⁶. 3 Take 100 μL of the sample and spread it on an LB agar plate. Incubate at 37°C for 18-24 h, then count the bacteria and calculate the inhibition rate.

[0064] Antibacterial rate = (number of colonies in blank control group - number of colonies in experimental group) / number of colonies in blank control group × 100%. The results are shown in Table 1.

[0065] Table 1. Antibacterial performance test results (inhibition rate %)

[0066] sample Staphylococcus aureus (24h) Staphylococcus aureus (72h) Staphylococcus aureus (168h) Escherichia coli (24h) Escherichia coli (72h) Escherichia coli (168h) Candida albicans (24h) Candida albicans (72h) Candida albicans (168h) Example 1 95.3 92.1 89.7 94.7 91.5 88.9 93.5 90.2 87.6 Example 2 93.8 90.5 87.3 93.2 89.8 86.5 91.8 88.4 85.1 Example 3 96.1 93.4 90.5 95.5 92.8 89.6 94.2 91.3 88.2 Comparative Example 1 12.5 8.3 5.1 10.7 7.2 4.8 9.3 6.5 3.2 Comparative Example 2 97.2 75.3 52.8 96.8 73.5 50.3 95.6 72.4 48.7 Comparative Example 3 82.4 70.6 58.9 81.8 68.9 56.4 80.5 67.3 54.2 Comparative Example 4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

[0067] 2. Promotes bone performance testing

[0068] Test cells: Osteoblasts MC3T3-E1 (purchased from the Cell Bank of the Chinese Academy of Sciences)

[0069] Test method:

[0070] (1) Cell proliferation rate: The CCK-8 assay was used to inoculate cells at a rate of 5 × 10⁻⁶ cells / year. 3 The samples were seeded at a density of 1000 cells / well and cultured for 1 day, 3 days, 7 days and 14 days respectively. Then, 10 μL of CCK-8 reagent was added and incubated at 37℃ for 4 hours. The absorbance value (OD value) at 450 nm was measured using an ELISA reader, and the proliferation rate was calculated.

[0071] Proliferation rate = (OD value of experimental group / OD value of blank control group) × 100%

[0072] (2) Alkaline phosphatase (ALP) activity: Cells were inoculated at 1×10 4 ALP cells were seeded onto the sample surface at a density of cells / well. After 7 and 14 days of culture, the activity was measured using an ALP detection kit (Beyotime Biotechnology). The relative activity was calculated based on the activity of the blank control group.

[0073] (3) Formation of mineralized nodules: Cells were seeded on the sample surface and cultured for 21 days. The formation of mineralized nodules was observed under a microscope using Alizarin Red S staining, and the proportion of mineralized area was calculated using ImageJ software.

[0074] The results are shown in Table 2.

[0075] Table 2 Results of bone performance tests

[0076] sample Cell proliferation rate (1 day) / % Cell proliferation rate (3d) / % Cell proliferation rate (7d) / % Cell proliferation rate (14d) / % ALP relative activity (7d) / % ALP relative activity (14d) / % Mineralized area percentage (21d) / % Example 1 125.5 142.7 168.3 205.6 156.2 189.4 28.7 Example 2 115.3 128.4 162.5 198.4 148.7 176.3 25.3 Example 3 124.2 135.1 172.6 212.8 161.5 195.7 30.5 Comparative Example 1 100.0 112.3 135.8 156.4 120.5 145.2 18.6 Comparative Example 2 102.4 88.7 85.3 79.6 95.8 88.4 12.3 Comparative Example 3 100.6 108.5 142.7 168.9 128.3 156.7 20.4 Comparative Example 4 100.0 100.0 100.0 100.0 100.0 100.0 10.0

[0077] 3. Coating adhesion test

[0078] Test method: The cross-cut test (GB / T 9286-1998) is used. A 1mm×1mm grid (100 grids) is drawn on the coating surface using a cross-cut tester. 3M tape is applied and then quickly peeled off. The coating peeling in the grid area is observed and rated (Grade 1: no peeling; Grade 2: ≤5% peeling; Grade 3: 5%-15% peeling; Grade 4: 15%-35% peeling; Grade 5: >35% peeling).

[0079] The results are shown in Table 3.

[0080] Table 3. Coating adhesion test results

[0081] sample Grading method Number of missing squares ( / 100) Coating adhesion evaluation Example 1 Level 1 0 excellent Example 2 Level 1 1 excellent Example 3 Level 1 0 excellent Comparative Example 1 Level 2 3 good Comparative Example 2 Level 2 4 good Comparative Example 3 Level 1 2 excellent Comparative Example 4 Uncoated Uncoated Uncoated

[0082] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a titanium dental implant surface coating with both antibacterial and osteogenic properties, characterized in that, Includes the following steps: Titanium matrix pretreatment: The titanium dental implant matrix is ​​sequentially subjected to gradient sandpaper polishing, ultrasonic cleaning, alkali treatment and acid etching treatment to obtain a titanium matrix with a rough surface and rich in hydroxyl groups; Preparation of inner hydroxyapatite-chitosan composite coating: hydroxyapatite powder is dispersed in a 1-3 wt% chitosan acetic acid solution and ultrasonically dispersed to obtain a uniform coating slurry; wherein the mass ratio of hydroxyapatite to chitosan is 3-5:

1. A rough titanium substrate rich in hydroxyl groups is immersed in a coating slurry and coated at a pulling speed of 5-10 mm / s. After coating, it is reacted at 120-150℃ for 4-6 hours, cooled, washed and dried to obtain a titanium substrate with an inner coating layer. Preparation of outer zinc-loaded mesoporous silane coating: The mesoporous silane precursor and zinc nitrate are dissolved in a mixed solvent of ethanol and deionized water, the pH is adjusted to 3-5, and the mixture is stirred and hydrolyzed at 25-30℃ for 2-4h to obtain a sol; the molar ratio of zinc nitrate to mesoporous silane precursor is 0.05-0.1:1, and the volume ratio of ethanol to deionized water in the mixed solvent is 3-5:1; the titanium substrate with the inner coating is immersed in the sol, coated at a pulling speed of 3-8mm / s, sintered at 300-400℃ for 1-2h, and the target product is obtained after cooling.

2. The preparation method according to claim 1, characterized in that, The ultrasonic cleaning process involves using deionized water at a power of 200-400W for 15-20 minutes.

3. The preparation method according to claim 1, characterized in that, The alkaline treatment involves soaking the patient in a 5-10 mol / L sodium hydroxide solution at 60-80°C for 2-3 hours.

4. The preparation method according to claim 1, characterized in that, The acid etching treatment involves immersing the sample in a 1-2 mol / L hydrochloric acid solution at room temperature for 30-60 minutes.

5. The preparation method according to claim 1, characterized in that, The ultrasonic dispersion time is 30-40 min, and the power is 300-400 W. After reacting at 120-150℃ for 4-6 h, the washing and drying process involves rinsing with deionized water for 2-3 min and then drying at 60-80℃ for 2-3 h.

6. The preparation method according to claim 1, characterized in that, The mesoporous silane precursor includes at least one of tetraethyl orthosilicate or γ-aminopropyltriethoxysilane.

7. A titanium dental implant, characterized in that, The titanium dental implant is prepared by the method described in any one of claims 1-6 during the preparation of the surface coating.

8. A titanium dental implant according to claim 7, characterized in that, The surface of the titanium dental implant has a double-layer composite coating. The inner layer is a hydroxyapatite-chitosan composite layer with a thickness of 50-100μm; the outer layer is a zinc-loaded mesoporous silane layer with a thickness of 20-50μm.