Sand blasting and acid etching surface treatment process method for zirconia ceramic dental implant

Abstract

The invention relates to a zirconia ceramic dental implant sand blasting and acid etching surface treatment process method, which is characterized in that through two-step core treatment of sand blasting and acid etching, the surface appearance of a zirconia ceramic dental implant is improved, the surface roughness and biological activity of the zirconia ceramic dental implant are improved, and the binding capacity of the implant and bone tissue is enhanced. The long-term stability and the success rate of the implant are further improved. Wherein a hydrothermal aging pretreatment step is added between a sand blasting procedure and an acid etching procedure, so that zirconium oxide is promoted to be converted into a monoclinic phase from a tetragonal phase, the symmetry of a crystal structure is reduced, atomic arrangement is more disordered, the surface energy is obviously improved, and meanwhile, a large number of active sites are formed; in the subsequent sand blasting process, the alumina particles moving at a high speed are used for impacting the surface of the zirconia ceramic, and an initial microscopic rough structure is constructed; the acid etching process further enlarges the surface pores, optimizes the surface characteristics, and creates more favorable conditions for bone tissue growth.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of dental implant surface treatment process, and particularly relates to a zirconia ceramic dental implant sandblasting and acid-etching surface treatment process method. BACKGROUND

[0002] With the rapid development of oral implantology, zirconia ceramic has become an ideal substitute material for metal implants due to its excellent biocompatibility, good mechanical strength and aesthetic effect comparable to natural teeth, and its application in clinical practice is becoming more and more widespread. However, as a biologically inert material, the chemical inertness and smooth microstructure of zirconia limit its ability to bond with the surrounding bone tissue, i.e., osseointegration. Poor osseointegration ability can lead to prolonged healing period, insufficient implant stability, and even long-term failure. Therefore, how to construct a microtopography on the surface of zirconia implants that can promote the adhesion, proliferation and differentiation of osteoblasts through surface modification technology has become a research hotspot and a key technical challenge in this field.

[0003] Currently, the mainstream surface modification techniques include sandblasting, acid etching and their combination process. Sandblasting treatment can effectively increase the surface roughness and expand the bone tissue contact area; while acid etching can further create complex micro-nano pore structures on the basis of roughening, not only increasing the specific surface area, but also being beneficial to protein adsorption and cell behavior regulation. Simple sandblasting treatment may introduce residual stress and cause particle residues; while simple acid etching has limited effect on dense zirconia. Therefore, the "sandblasting and acid etching" technique combining sandblasting and acid etching has been proven to be an effective strategy for creating an ideal osseointegration surface.

[0004] However, the existing technology faces significant challenges when acid-etching zirconia. Zirconia has extremely high chemical stability, and traditional strong acids (such as hydrochloric acid, sulfuric acid) used for acid-etching of titanium implants have little effect on it. Although hydrofluoric acid can effectively etch zirconia, its reactivity is still limited, making it difficult to form an ideal and uniform microstructure. In addition, the connection between sandblasting and acid etching processes, the precise control of process parameters, and the thorough cleaning of the treated surface all directly affect the final treatment effect and the long-term stability of the implant. If not properly handled, it may lead to surface contamination, uneven structure or residual harmful substances, which in turn negatively affect osseointegration. SUMMARY

[0005] Technical problems to be solved: The application provides a systematic sandblasting and acid-etching surface treatment process for a zirconia ceramic dental implant. The core innovation of the method is the introduction of a key hydrothermal aging pretreatment step. This step promotes the controllable transformation of zirconia from metastable tetragonal phase to monoclinic phase under high temperature and high pressure environment. This phase transition not only increases the surface microcracks and active sites, but also greatly improves the reactivity and uniformity of subsequent hydrofluoric acid etching, so as to prepare an ideal composite morphology combining micron-level roughness and nanometer-level pores.

[0006] Technical scheme: A sandblasting and acid-etching surface treatment process method for a zirconia ceramic dental implant, comprising the following steps: S1. Implant pretreatment: placing the zirconia ceramic dental implant to be treated into an ultrasonic cleaner, cleaning with deionized water, and then drying the implant in a drying box; S2. Two-stage variable parameter composite sandblasting treatment: fixing the zirconia ceramic dental implant on a sandblasting operation table, and using a sandblasting device to spray aluminum oxide particles and zirconia-aluminum oxide composite particles to the surface of the implant in stages; S3. Cleaning and inspection: after sandblasting, placing the implant into an ultrasonic cleaner and cleaning with deionized water, and then performing surface inspection; S4. Hydrothermal aging pretreatment: placing the implant treated in step S3 into a high-temperature and high-pressure reaction kettle for two-stage hydrothermal aging treatment in a reaction medium; S5. Acid etching treatment: immersing the implant treated by the hydrothermal aging pretreatment into a hydrofluoric acid solution for acid etching; S6. Termination and cleaning: after acid etching, immediately immersing the implant into a sodium bicarbonate-boric acid buffer solution, then rinsing with deionized water, and then placing it into an ultrasonic cleaner for further cleaning; S7. Immersing and coating a polydopamine coating: immersing the implant cleaned in step S6 into a dopamine hydrochloride solution modified with Tris-HCl buffer solution, and then placing it under constant temperature conditions for reaction, rinsing the implant with a large amount of deionized water to remove physically adsorbed particles, and then drying at low temperature to obtain the implant.

[0007] Preferably, the cleaning time in step S1 is 15-20 min, the drying box temperature is set to 60-80 DEG C, and the time is 1-2 h.

[0008] Preferably, the parameters of the sandblasting treatment in step S2 are: the sandblasting equipment pressure of the first stage is 0.3-0.6 Mpa, the spraying angle is 50-60°, the distance between the sandblasting gun and the surface of the implant is 1-5 mm, the particle size of the alumina particles is 110-130 µm, and the sandblasting time is 30-40 s; the sandblasting pressure of the second stage is 0.2-0.4 MPa, the spraying angle is 30-40°, the distance between the sandblasting gun and the surface of the implant is 10-15 mm, the particle size of the zirconium oxide-alumina composite particles with a mass ratio of 1:3 is 60-80 µm, and the sandblasting time is 50-60 s.

[0009] Preferably, the cleaning time in step S3 is 10-15 min, and after cleaning, the surface of the implant is checked to be free of residual particles and the rough structure is uniform.

[0010] Preferably, the parameters of the hydrothermal aging pretreatment in step S4 are: the reaction medium is a calcium phosphate source buffer solution, the calcium source of the calcium phosphate source buffer solution is calcium nitrate, the phosphorus source is ammonium dihydrogen phosphate, and the calcium to phosphorus molar ratio is controlled to be 1.6; first, the temperature is raised to 160-180 °C at a rate of 3-5 °C / min, and the temperature is maintained for 2 h; then, the temperature is raised to 220-260 °C, and the temperature is maintained for 1 h; then, the temperature is lowered to 80 °C at a rate of 3 °C / min, and the temperature is naturally cooled to room temperature.

[0011] Preferably, the parameters of the acid etching treatment in step S5 are: the solution temperature is 40-60 °C, a constant temperature stirrer is used to stir the solution at a speed of 50-100 r / min, and the acid etching time is 30-40 min.

[0012] Preferably, the concentration of the hydrofluoric acid solution in step S5 is 30%-40% by mass fraction.

[0013] Preferably, the pH value of the sodium bicarbonate-boric acid buffer solution in step S6 is 7.2-7.4, the soaking time is 5-10 min, the rinsing time is 15-20 min, the implant is constantly turned over during the rinsing process, and the ultrasonic cleaning time is 10-15 min.

[0014] Preferably, in the Tris-HCl buffer modified dopamine hydrochloride composite solution in step S7, the concentration of the dopamine hydrochloride solution is 1-2 mg / mL, the mass fraction of the nano-hydroxyapatite particles is 0.5-0.8%, and the mass fraction of the chitosan is 0.1-0.3%; the pH value of the Tris-HCl buffer is 7.5-8.5, the solution temperature is controlled at 37-50 °C, the constant temperature condition is 25-37 °C, the reaction time is 12-24 h, the low temperature drying temperature is 30-50 °C, and the time is 6-8 h.

[0015] Advantages: The sandblasting and acid etching surface treatment process method for the zirconia ceramic dental implant has the following advantages: 1. In the sandblasting process of the present application, 110-130 µm alumina particles impact the surface of zirconia ceramic implants under the action of 0.6 MPa pressure, achieving a suitable blasting speed by setting the pressure and distance. The impact force of the particles causes local crushing and plastic deformation of the implant surface material, forming tiny pits and protrusions and increasing the surface roughness. This preliminary rough structure not only increases the surface area of the implant, but also provides more reaction sites for the subsequent acid etching process, facilitating the full contact between hydrofluoric acid and zirconia during the acid etching process and improving the acid etching effect; 2. In the hydrothermal aging pretreatment of the present application, zirconia changes from tetragonal phase to monoclinic phase, the symmetry of the crystal structure decreases, the atomic arrangement becomes more disordered, the surface energy increases significantly, and the active sites increase substantially. These active sites make it easier for F⁻ ions in hydrofluoric acid to attack Zr-O bonds in the zirconia lattice, accelerating the chemical reaction; 3. The F⁻ ions in hydrofluoric acid have strong complexing ability and can react with zirconia to form zirconium tetrafluoride and water. Based on the rough surface formed by sandblasting, hydrofluoric acid further corrodes the implant surface, preferentially attacking weak spots and defects on the surface, continuously expanding surface pores, and making the surface microstructure more complex. As the reaction proceeds, the protruding parts of the surface are gradually corroded, the pits are further deepened and expanded, and finally a rough surface that is conducive to bone tissue ingrowth is formed. At the same time, by controlling the concentration, temperature, and acid etching time of hydrofluoric acid, the surface roughness and pore structure can be precisely adjusted to meet the different needs of implant and bone tissue combination; 4. The process of the present application can effectively optimize the surface of zirconia ceramic dental implant and improve the bone bonding effect after implantation through the synergistic effect of sandblasting and acid etching; 5. The polydopamine coating of the present application can significantly promote protein adsorption and cell adhesion, especially for gingival fibroblasts, which is conducive to the soft tissue sealing of the neck of the implant. At the same time, it has certain antibacterial performance and can inhibit the initial adhesion of bacteria. The polydopamine coating is a low-temperature wet chemical process that does not affect the micro-roughness formed by the previous process and the phase stability of the zirconia substrate, and has excellent compatibility with the previous process; 6. The introduction of zirconia-alumina composite particles in the present application can avoid the residual of surface impurities caused by single alumina particle sandblasting, and at the same time, the hardness difference between the two particles forms a multi-level rough structure of "micron protrusions + nanometer pits" on the surface of the implant, providing an excellent surface morphology basis for subsequent cell adhesion; 7. In the high-temperature and high-pressure hydrothermal environment of the present application, calcium and phosphorus ions in the reaction medium will undergo heterogeneous nucleation and growth on the surface of the zirconia implant. Combined with the precise regulation of the gradient temperature change process, a uniform thickness of hydroxyapatite precursor film can be generated on the surface of the implant, avoiding performance fluctuations caused by direct conversion of the zirconia matrix. At the same time, the process can induce a suitable amount of monoclinic phase transformation on the surface of the zirconia, improving the surface activity and mechanical compatibility of the implant, effectively solving the problem of uneven thickness and insufficient activity of the surface film caused by traditional single-temperature hydrothermal aging. 8. The introduction of nano-hydroxyapatite particles in the present application can enhance the bioactivity of the coating, and chitosan can improve the antibacterial performance and biocompatibility of the coating, solving the problems of insufficient antibacterial performance and slow bone bonding rate of traditional single-polydopamine coating. Under constant temperature conditions, the reaction is static, ensuring uniform deposition of the coating. After the reaction is completed, the implant is rinsed with a large amount of deionized water for 3 times to remove the physically adsorbed particles and unreacted substances. DETAILED DESCRIPTION

[0016] The present application will be further described in conjunction with the following examples, which are an explanation of the present application and the present application is not limited to the following examples: Example 1

[0017] A sandblasting and acid etching surface treatment process for a zirconia ceramic dental implant, comprising the following steps: S1. Implant pretreatment: Place the zirconia ceramic dental implant to be treated into an ultrasonic cleaner, wash with deionized water for 15 min, and then dry the implant in a dry box at 60°C for 1 h; S2. Sandblasting treatment: Fix the dried zirconia ceramic dental implant on a sandblasting operation table, first uniformly spray the surface of the implant with aluminum oxide particles with a particle size of 110 µm under the conditions of a sandblasting equipment pressure of 0.6 MPa, a spraying angle of 60°, and a distance between the sandblasting gun and the surface of the implant of 3 mm for 30 s; then uniformly spray the surface of the implant with zirconia-alumina composite particles with a particle size of 80 µm at a mass ratio of 1:3 under the conditions of a sandblasting pressure of 0.4 MPa, a spraying angle of 40°, and a distance between the sandblasting gun and the surface of the implant of 15 mm for 60 s.

[0018] S3. Cleaning and inspection: After sandblasting, place the implant in an ultrasonic cleaner and wash with deionized water for 10 min, then inspect the surface of the implant for no residual particles and uniform rough structure; S4. Hydrothermal aging pretreatment: the implant treated in step S3 is placed in a reaction medium calcium phosphate source buffer solution, wherein the calcium source of the calcium phosphate source buffer solution is calcium nitrate, the phosphorus source is ammonium dihydrogen phosphate, and the calcium-phosphorus molar ratio is controlled to be 1.6; in a high-temperature and high-pressure reaction kettle, first heated to 180℃ at a rate of 5℃ / min, and kept for 2h; then heated to 220℃, and kept for 1h; then cooled to 80℃ at a rate of 3℃ / min, and naturally cooled to room temperature; S5. Acid etching treatment: the implant treated by hydrothermal aging pretreatment is immersed in a 30% hydrofluoric acid solution, and acid etched for 30min under the condition of constant speed stirring at 40℃ and 50r / min; S6. Termination and cleaning: after acid etching, the implant is immediately taken out, immersed in a sodium bicarbonate-boric acid buffer solution with a pH value of 7.2 for 10min, then washed with flowing deionized water for 15min (the implant is constantly turned over during the washing process), and then placed in an ultrasonic cleaning machine and cleaned with deionized water for 10min to completely remove the residual acid.

[0019] S7. Immersion coating of polydopamine coating: the implant cleaned in step S6 is immersed in a dopamine hydrochloride solution with a concentration of 1mg / mL prepared by Tris-HCl buffer solution with a pH value of 8 (the solution temperature is controlled at 40℃), the mass fraction of nano-hydroxyapatite particles is 0.5%, and the mass fraction of chitosan is 0.1%, and the reaction is carried out at 25℃ for 12h, then the implant is washed with a large amount of deionized water and dried at 30℃ for 6h to obtain the implant.

[0020] Example 2

[0021] The difference between Example 2 and Example 1 is that in step S1, the zirconia ceramic dental implant to be treated is placed in an ultrasonic cleaning machine, and after being cleaned with deionized water for 20min, the implant is placed in a drying box at 70℃ and dried for 1.5h.

[0022] Example 3

[0023] The difference between Example 3 and Example 1 is that in step S1, the zirconia ceramic dental implant to be treated is placed in an ultrasonic cleaning machine, and after being cleaned with deionized water for 20min, the implant is placed in a drying box at 80℃ and dried for 2h.

[0024] Example 4

[0025] Example 4 differs from Example 1 in that in the sandblasting treatment of Step S2, the dried zirconia ceramic dental implant is fixed on the sandblasting operation table, first the surface of the implant is uniformly sprayed with aluminum oxide particles with a particle size of 120 pm under the conditions of a sandblasting equipment pressure of 0.4 MPa, a spraying angle of 60°, and a distance between the sandblasting gun and the surface of the implant of 5 mm for 30 s; then zirconia-alumina composite particles with a mass ratio of 1:3 and a particle size of 70 pm are used for uniform spraying at a sandblasting pressure of 0.2 MPa, a spraying angle of 50°, and a distance between the sandblasting gun and the surface of the implant of 10 mm for 60 s.

[0026] Example 5

[0027] Example 5 differs from Example 1 in that in the sandblasting treatment of Step S2, the dried zirconia ceramic dental implant is fixed on the sandblasting operation table, first the surface of the implant is uniformly sprayed with aluminum oxide particles with a particle size of 130 pm under the conditions of a sandblasting equipment pressure of 0.3 MPa, a spraying angle of 60°, and a distance between the sandblasting gun and the surface of the implant of 1 mm for 30 s; then zirconia-alumina composite particles with a mass ratio of 1:3 and a particle size of 60 pm are used for uniform spraying at a sandblasting pressure of 0.3 MPa, a spraying angle of 50°, and a distance between the sandblasting gun and the surface of the implant of 12 mm for 60 s.

[0028] Example 6

[0029] Example 6 differs from Example 1 in that after the sandblasting in Step S3, the implant is placed in an ultrasonic cleaner and washed with deionized water for 15 min, and then the implant surface is checked for no residual particles and uniform and consistent rough structure.

[0030] Example 7

[0031] Example 7 differs from Example 1 in that in Step S4, the parameters of the hydrothermal aging pretreatment are as follows: the reaction medium is a calcium phosphate source buffer solution, the calcium source in the calcium phosphate source buffer solution is calcium nitrate, the phosphorus source is ammonium dihydrogen phosphate, and the calcium to phosphorus molar ratio is controlled at 1.6; first, the temperature is increased to 160 °C at a rate of 3-5 °C / min, and held for 2 h; then the temperature is increased to 240 °C, and held for 1 h; then the temperature is decreased to 80 °C at a rate of 3 °C / min, and naturally cooled to room temperature.

[0032] Example 8

[0033] Example 8 differs from Example 1 in that the parameters of the hydrothermal aging pretreatment in step S4 are as follows: the reaction medium is a calcium phosphate source buffer solution, the calcium source in the calcium phosphate source buffer solution is calcium nitrate, the phosphate source is ammonium dihydrogen phosphate, and the calcium to phosphate molar ratio is controlled to be 1.6; the temperature is first increased to 170°C at a rate of 3-5°C / min, and the temperature is maintained for 2 h; then the temperature is increased to 260°C, and the temperature is maintained for 1 h; then the temperature is decreased to 80°C at a rate of 3°C / min, and the temperature is naturally cooled to room temperature.

[0034] Example 9

[0035] Example 9 differs from Example 1 in that the hydrothermally aged pretreated implant is immersed in a hydrofluoric acid solution with a mass fraction of 35% in step S5, and the acid etching is performed at 50°C under constant speed stirring at 80 r / min for 35 min.

[0036] Example 10

[0037] Example 10 differs from Example 1 in that the hydrothermally aged pretreated implant is immersed in a hydrofluoric acid solution with a mass fraction of 40% in step S5, and the acid etching is performed at 60°C under constant speed stirring at 100 r / min for 40 min.

[0038] Example 11

[0039] Example 11 differs from Example 1 in that after the acid etching in step S6 is completed, the implant is immediately taken out, immersed in a sodium bicarbonate-boric acid buffer solution with a pH value of 7.0 for 10 min, and then washed with flowing deionized water for 20 min (the implant is constantly turned over during the washing process), and then the implant is placed in an ultrasonic cleaning machine and washed with deionized water again for 15 min to completely remove the residual acid solution.

[0040] Example 12

[0041] Example 12 differs from Example 1 in that the implant washed in step S6 is immersed in a dopamine hydrochloride solution with a concentration of 1 mg / mL prepared using a Tris-HCl buffer solution with a pH value of 8 (the solution temperature is controlled at 40°C) in step S7, the mass fraction of the nano-hydroxyapatite particles is 0.8%, and the mass fraction of chitosan is 0.3%, and the reaction is performed at a constant temperature of 25°C for 12 h, then the implant is washed with a large amount of deionized water and dried at a low temperature of 30°C for 6 h to obtain the implant.

[0042] Comparative Example 1 Comparative Example 1 differs from Example 1 in that the zirconia ceramic dental implant to be treated is placed in an ultrasonic cleaning machine and washed with deionized water in step S1, and then the implant is placed in a dry box at 40°C and dried for 0.5 h after 5 min.

[0043] Comparative Example 2 Comparative Example 2 differs from Example 1 in that the zirconia ceramic dental implant after drying is fixed on the sandblasting operation table in the sandblasting treatment of step S2, and the surface of the implant is uniformly sprayed with 200 pm diameter aluminum oxide particles under the conditions of a sandblasting equipment pressure of 1.0 MPa and a distance of 10 mm between the sandblasting gun and the surface of the implant for 10 s.

[0044] Comparative Example 3 Comparative Example 3 differs from Example 1 in that after the sandblasting in step S3 is completed, the implant is placed in an ultrasonic cleaner and washed with deionized water for 5 min, and then the implant surface is checked for no residual particles and uniform and consistent rough structure.

[0045] Comparative Example 4 Comparative Example 4 differs from Example 1 in that the implant after step S3 is placed in a high-temperature and high-pressure reaction kettle for hydrothermal aging treatment at 400°C for 1 h in step S4.

[0046] Comparative Example 5 Comparative Example 5 differs from Example 1 in that the implant after hydrothermal aging pretreatment is immersed in a 10% by mass fraction hydrofluoric acid solution in step S5, and etched in acid for 10 min under the conditions of 30°C and 20 r / min stirring.

[0047] Comparative Example 6 Comparative Example 6 differs from Example 1 in that after the acid etching in step S6 is completed, the implant is immediately removed and washed with flowing deionized water for 5 min (the implant is constantly turned over during the washing process), and then it is placed in an ultrasonic cleaner and washed again with deionized water for 5 min to completely remove the residual acid.

[0048] Comparative Example 7 Comparative Example 7 differs from Example 1 in that the hydrothermal aging treatment of step S4 is not performed.

[0049] Comparative Example 8 Comparative Example 8 differs from Example 1 in that the step S7 of immersing and coating the polydopamine coating is not performed.

[0050] Performance test: Test Example 1 Surface topography analysis: 3D optical profilometer was used to measure the surface roughness parameters (Sa, Sz).

[0051] Wettability test: a contact angle measuring instrument was used to measure the static contact angle of deionized water on the surface, the droplet volume was 2 pL, and 5 points were measured for each sample to take the average value.

[0052] Table 1: Surface topography and wettability test results Sample Sa (pm) Sz (pm) Contact angle (°) Example 1 1.52 12.3 28.5 Example 2 1.48 11.8 29.1 Example 3 1.55 12.5 27.8 Example 4 1.45 11.5 30.2 Example 5 1.50 12.0 29.5 Example 6 1.53 12.4 28.9 Example 7 1.60 13.0 26.5 Example 8 1.65 13.5 25.0 Example 9 1.58 12.8 27.2 Example 10 1.62 13.2 26.0 Example 11 1.51 12.2 28.0 Example 12 1.54 12.4 20.5 Comparative Example 1 0.85 6.2 65.0 Comparative Example 2 2.10 18.5 45.3 Comparative Example 3 1.50 12.1 60.5 Comparative Example 4 1.70 14.0 35.2 Comparative Example 5 1.20 9.5 50.1 Comparative Example 6 1.53 12.3 55.8 Comparative Example 7 1.25 10.0 48.5 Comparative Example 8 1.52 12.3 75.2 All example samples showed uniform "micro-nano" composite rough structure, with Sa values between 1.45-1.65 pm and Sz values between 11.5-13.5 pm, indicating good synergy between sandblasting and acid etching process. Example 8 (staged highest temperature control at 260°C hydrothermal aging) had the densest surface nanopores, but slightly increased microcracks. Comparative Example 2 (over- aggressive sandblasting parameters) had the highest roughness (Sa = 2.10 pm), but the structure was not uniform, which could affect mechanical stability. Comparative Example 7 (no hydrothermal aging) had only micron structure from sandblasting, lacking nanopores, indicating that hydrothermal aging was critical for subsequent acid etching.

[0053] Example samples all had contact angles below 30°, showing good hydrophilicity, which was beneficial for protein adsorption and early cell adhesion. Example 12 (with PDA coating) had the lowest contact angle (20.5°), indicating that PDA further improved surface hydrophilicity and bioactivity. Comparative Example 8 (without PDA) had a contact angle as high as 75.2°, which was significantly hydrophobic.

[0054] Test Example 2 Bioactivity Test: Soak samples in simulated body fluid (SBF, pH = 7.4) at 37°C for 7 days, observe surface apatite deposition by SEM, and analyze Ca / P ratio by EDS. Replace SBF every 24 hours.

[0055] Table 2: Surface Ca / P ratio after 7 days of SBF soaking Sample Ca / P ratio Proportion of apatite coverage Example 1 1.68 85% Example 12 1.70 90% Comparative Example 7 1.55 40% Comparative Example 8 1.60 60% From Table 2 above, it can be seen that example samples formed a uniform bone-like apatite layer on the surface after 7 days of SBF soaking, with a Ca / P ratio close to the theoretical value of hydroxyapatite (1.67), and a coverage area of 85-90%. Comparative Example 7 had only 40% apatite coverage, indicating that the surface without hydrothermal aging had significantly reduced bioactivity.

[0056] Test Example 3 Cell Response Test: Use MC3T3-E1 osteoblast cell line, cell adhesion: observe cell morphology by SEM after 4 hours of culture; cell proliferation: measure OD450 value by CCK-8 method after 1, 3, and 7 days of culture; cell differentiation: measure alkaline phosphatase (ALP) activity after 7 days of culture.

[0057] Table 3: Cell response test results (7 days of culture) Sample Cell adhesion number (x 10 3 / cm 2 )]]> CCK-8 (OD450) ALP activity (U / mg) Example 1 12.5 1.85 0.45 Example 12 14.2 2.10 0.52 Comparative Example 7 8.5 1.20 0.25 Comparative Example 8 10.0 1.50 0.30 As shown in Table 3, the sample of the embodiment significantly promotes the adhesion, proliferation and differentiation of osteoblasts. The cell adhesion number and ALP activity of Example 12 are the highest due to the PDA coating. The cell indicators of Comparative Example 7 and Comparative Example 8 are significantly lower than those of the embodiment, further confirming the key role of hydrothermal aging and PDA coating in promoting osseointegration.

[0058] The surface treatment process of sand blasting and acid etching combined with hydrothermal aging and PDA coating can systematically optimize the surface performance of zirconia implants, achieving: uniform micron-nanometer composite rough structure; controllable phase transformation to improve the acid etching effect; excellent hydrophilicity and bioactivity; significantly enhanced osteoblast response. All the comparative examples show performance degradation when deviating or missing a process step, which reversely verifies the necessity of the process steps and the rationality of the parameter settings of the present application.

[0059] Obviously, the above examples are only examples for the sake of clarity, and are not limitations on the embodiments. Based on the above description, those skilled in the art can also make other different forms of changes or variations. It is not necessary and impossible to exhaust all the embodiments here. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for surface treatment of zirconia ceramic dental implants by sandblasting and acid etching, characterized in that, Includes the following steps: S1. Implant pretreatment: The zirconia ceramic dental implant to be treated is placed in an ultrasonic cleaner, cleaned with deionized water, and then placed in a drying oven to dry. S2 Two-Stage Variable Parameter Composite Sandblasting Treatment: The zirconia ceramic dental implant is fixed on the sandblasting table, and the alumina particles and zirconia-alumina composite particles are sprayed onto the implant surface in stages using sandblasting equipment. S3 Cleaning and Inspection: After sandblasting, the implant is placed in an ultrasonic cleaner and cleaned with deionized water, followed by a surface inspection. S4. Hydrothermal aging pretreatment: The implants treated in step S3 are placed in a high-temperature and high-pressure reactor and subjected to staged hydrothermal aging treatment in the reaction medium. S5. Acid etching treatment: The implants, which have undergone hydrothermal aging pretreatment, are immersed in hydrofluoric acid solution for acid etching. S6. Termination and Cleaning: After acid etching is completed, the implant is removed and immediately immersed in sodium bicarbonate-boric acid buffer solution, then rinsed with deionized water, and then placed in an ultrasonic cleaner for cleaning again. S7. Impregnation and coating with polydopamine: The implants cleaned in step S6 are immersed in a dopamine hydrochloride solution modified with Tris-HCl buffer. After static reaction under constant temperature conditions, the implants are rinsed with a large amount of deionized water to remove physically adsorbed particles, and then dried at low temperature to obtain the implants.

2. The surface treatment method for zirconia ceramic dental implants by sandblasting and acid etching according to claim 1, characterized in that, The pretreatment and cleaning time for the implant in step S1 is 15-20 minutes, and the temperature of the drying oven is set to 60-80℃ for 1-2 hours.

3. The surface treatment method for zirconia ceramic dental implants by sandblasting and acid etching according to claim 1, characterized in that, The parameters for the sandblasting treatment in step S2 are as follows: For the first stage, the sandblasting equipment pressure is 0.3-0.6 MPa, the spray angle is 50-60°, the distance between the sandblasting gun and the implant surface is 1-5 mm, the alumina particle size is 110-130 µm, and the sandblasting time is 30-40 s; for the second stage, the sandblasting pressure is 0.2-0.4 MPa, the spray angle is 30-40°, the distance between the sandblasting gun and the implant surface is 10-15 mm, the zirconium oxide-alumina composite particles with a mass ratio of 1:3 have a particle size of 60-80 µm, and the sandblasting time is 50-60 s.

4. The surface treatment method for zirconia ceramic dental implants by sandblasting and acid etching according to claim 1, characterized in that, The cleaning time in step S3 is 10-15 minutes. After cleaning, the implant surface is checked and found to have no residual particles and a uniform rough structure.

5. The surface treatment method for zirconia ceramic dental implants by sandblasting and acid etching according to claim 1, characterized in that, The parameters for the hydrothermal aging pretreatment in step S4 are as follows: the reaction medium is a calcium-phosphorus source buffer solution, wherein the calcium source of the calcium-phosphorus source buffer solution is calcium nitrate and the phosphorus source is ammonium dihydrogen phosphate, and the calcium-phosphorus molar ratio is controlled at 1.6; first, the temperature is raised to 160-180℃ at a rate of 3-5℃ / min and held for 2 hours; then the temperature is raised to 220-260℃ and held for 1 hour; subsequently, the temperature is lowered to 80℃ at a rate of 3℃ / min and allowed to cool naturally to room temperature.

6. The surface treatment method for zirconia ceramic dental implants by sandblasting and acid etching according to claim 1, characterized in that, The parameters for the acid etching process in step S5 are: solution temperature 40-60℃, stirring the solution at a speed of 50-100r / min using a constant temperature stirrer, and acid etching time 30-40min.

7. The surface treatment method for zirconia ceramic dental implants by sandblasting and acid etching according to claim 1, characterized in that, The concentration of the hydrofluoric acid solution in step S5 is 30%-40% by mass.

8. The surface treatment method for zirconia ceramic dental implants by sandblasting and acid etching according to claim 1, characterized in that, In step S6, the pH value of the sodium bicarbonate-boric acid buffer solution is 7.2-7.4, the rinsing time is 15-20 minutes, the implant is constantly turned over during the rinsing process, and the ultrasonic cleaning time is 10-15 minutes.

9. The surface treatment method for zirconia ceramic dental implants by sandblasting and acid etching according to claim 1, characterized in that, In step S7, the concentration of dopamine hydrochloride in the Tris-HCl buffer-modified dopamine hydrochloride composite solution is 1-2 mg / mL, the mass fraction of nano-hydroxyapatite particles is 0.5-0.8%, and the mass fraction of chitosan is 0.1-0.3%. The pH value of the Tris-HCl buffer is 7.5-8.5, the solution temperature is controlled at 37-50℃, the isothermal condition is 25-37℃, the reaction time is 12-24 h, the low-temperature drying temperature is 30-50℃, and the time is 6-8 h.