Surface Treatment Method for Titanium Alloy Implants and Titanium Alloy Implants Processed by The Method

Abstract

The present invention relates to a surface treatment method for a titanium alloy implant without using acid and a titanium alloy implant surface-treated by the same method. More specifically, the invention relates to a surface treatment method for a titanium alloy implant capable of modifying the pores of an oxide film formed on the surface using a chloride electrolyte so that they are uniformly distributed into completely open pores, and a titanium alloy implant surface-treated by the same method.

Description

Technology Field

[0001] The present invention relates to a surface treatment method for a titanium alloy implant without using acid and a titanium alloy implant surface-treated by the same method. More specifically, the invention relates to a surface treatment method for a titanium alloy implant capable of modifying the pores of an oxide film formed on the surface using a chloride electrolyte so that they are uniformly distributed into completely open pores, and a titanium alloy implant surface-treated by the same method. Background Technology

[0003] Titanium is the most widely used material for dental implants due to its excellent corrosion resistance, mechanical properties, biocompatibility, and osteointegration characteristics. However, as titanium is a bio-inert material that does not directly induce bone formation, its slow bone development necessitates surface modification. To date, various physicochemical methods have been used to modify the surface of titanium implants, with the most representative method being the application of appropriate surface roughness.

[0004] Furthermore, in the field of dental treatment, there is a growing need for narrow-diameter implants applicable to patients for whom implant placement is difficult, such as the elderly and children, as well as to cases involving narrow bone widths and anterior extraction sites. Currently, the most commonly used titanium metal for dental implant fixtures is pure titanium (CP-Ti); however, due to its low strength and resulting fracture hazards, it is necessary to use titanium alloys such as Ti6Al4V:ELI for narrow-diameter implants. While CP-Ti is primarily surface-treated using the SLA method, it is difficult to modify the surface of Ti6Al4V alloys using this method due to their high surface hardness and differences in crystallographic structure.

[0005] The method of surface treatment by immersing titanium metal in an electrolyte and applying electricity has economic advantages as it does not depend on the shape of the implant, does not apply mechanical stress, and does not incur high treatment costs. Micro Arc Oxidation (MAO), a representative electrochemical treatment method, can provide roughness by applying a high anode voltage to titanium metal, causing dielectric breakdown of the TiO2 oxide film formed on the surface to form a porous surface. However, it is difficult to provide appropriate roughness depending on the size of the pores formed on the surface, and in particular, as shown in FIG. 1, pores are formed in a closed shape (11a) in the oxide film (11) on the surface of titanium metal (10), so acids or salts are trapped inside the pores, making cleaning difficult.

[0006] Meanwhile, as shown in FIG. 2, when a pure titanium metal is surface-treated using an electric pulse in a chloride electrolyte, a surface etching effect occurs due to chloride ions, and the surface of the titanium metal (20) can be provided with a porous surface consisting of open pores (20a) and sufficient roughness. However, in the case of a Ti6Al4V alloy implant, it is difficult to achieve a uniform surface using this method due to the surface structure being different from CP-Ti. The problem to be solved

[0008] The present invention has been devised to solve the aforementioned problems, and the objective of the present invention is to provide an acid-free surface treatment method for titanium alloy implants capable of forming a porous surface with uniformly distributed open pores on the surface of titanium alloy implants, such as Ti6Al4V:ELI, which have excellent mechanical properties such as strength and are applicable to patients for whom implant placement is difficult, such as the elderly and children, as well as in cases involving narrow bone widths and anterior extraction sites, and to provide a titanium alloy implant surface-treated by the same method. means of solving the problem

[0010] To achieve the above objective, the present invention provides a surface treatment method for a titanium alloy implant characterized by comprising: a step of forming an oxide film on the surface of a titanium alloy implant; a step of placing the titanium alloy implant with the formed oxide film into a chloride electrolyte and performing electrochemical etching treatment to surface treat the oxide film so that the closed pores become fully open pores; and a step of washing the surface-treated titanium alloy implant to remove residues.

[0011] In a preferred embodiment, the method further includes a step of performing hydrothermal treatment after the residue removal to modify the surface so that a nanostructure is formed.

[0012] In a preferred embodiment, the titanium alloy implant is a Ti6Al4V alloy implant.

[0013] In a preferred embodiment, the oxide film is formed through micro arc oxidation (MAO).

[0014] In a preferred embodiment, the electrolyte used for the micro-arc oxidation is an alkaline electrolyte obtained by mixing potassium hydroxide (KOH) or sodium hydroxide (NaOH) with potassium phosphate (K3PO4) or sodium phosphate (Na3PO4).

[0015] In a preferred embodiment, the chloride electrolyte used for the electrochemical etching treatment is a calcium chloride (CaCl2) electrolyte.

[0016] In a preferred embodiment, the hydrothermal treatment is performed by immersing the titanium alloy implant in an alkaline aqueous solution at a temperature of 180°C for 4 hours.

[0017] In addition, the present invention further provides a titanium alloy implant surface-treated by the above surface treatment method, wherein the titanium alloy implant has a surface roughness (Ra) of 2.5 μm to 3.2 μm and a contact angle of 5° to 5.5°. Effects of the invention

[0019] The present invention has the following excellent effects.

[0020] According to the surface treatment method for a titanium alloy implant of the present invention and the titanium alloy implant surface-treated by the method, a porous surface with open pores uniformly distributed on the implant surface can be formed through micro-arc oxidation, electrochemical etching treatment, and hydrothermal treatment, which has the advantage of being very advantageous for osseointegration. Brief explanation of the drawing

[0022] FIG. 1 is a drawing illustrating a micro-arc oxidation treated titanium implant surface, FIG. 2 is a drawing illustrating the surface of a titanium implant after electrochemical surface treatment in a chloride electrolyte. FIG. 3 is a diagram showing an overview of a surface treatment system for performing a surface treatment method for a titanium alloy implant according to an embodiment of the present invention. FIG. 4 is a drawing illustrating a concept for commercially performing a surface treatment method for a titanium alloy implant according to an embodiment of the present invention. FIG. 5 is a flowchart of a surface treatment method for a titanium alloy implant according to one embodiment of the present invention, Figure 6 is an SEM image showing the surface of an implant treated with Ti-MAO, Figure 7 is an SEM image showing the surface of an implant treated with Ti-MAO-ECE, Figure 8 is an SEM image showing the surface of an implant treated with Ti-MAO-ECE-HT, Figure 9 shows surface roughness data of the implant surface treated with Ti-MAO-ECE-HT, FIG. 10 is a diagram illustrating the contact angle of an implant surface treated with Ti-MAO-ECE-HT. Figure 11 is an SEM image showing the surface of an implant treated with Ti-ECE. Specific details for implementing the invention

[0023] The terms used in this invention have been selected to be as widely used as possible; however, in specific cases, terms have been arbitrarily selected by the applicant. In such cases, the meaning should be understood by considering the meaning described or used in the detailed description of the invention, rather than merely the name of the term.

[0024] Hereinafter, the technical configuration of the present invention will be described in detail with reference to preferred embodiments illustrated in the attached drawings.

[0025] However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Throughout the specification, the same reference numerals indicate the same components.

[0027] FIG. 3 is a diagram showing an overview of a surface treatment system for performing a surface treatment method for a titanium alloy implant according to one embodiment of the present invention.

[0028] Referring to FIG. 3, a surface treatment method for a titanium alloy implant according to one embodiment of the present invention is performed by placing a titanium alloy implant (100) into a tank (30) filled with a chloride electrolyte (31) and applying an electrical pulse while stirring with a stirrer (40).

[0029] Additionally, the surface treatment system includes a power supply unit (60) for supplying power to an electrode connected to a titanium alloy implant (100) and a controller (50) for controlling the current density, period, and duty ratio of the power supply unit.

[0030] Additionally, FIG. 4 is a drawing for explaining the concept of commercially performing a surface treatment method for titanium alloy implants according to an embodiment of the present invention. Referring to FIG. 4, in order to increase the yield commercially, a plurality of titanium alloy implants (100) can be immersed in a single tank to perform surface treatment. Instead of supplying current to all titanium alloy implants (100) simultaneously, a plurality of titanium alloy implants (100) are sequentially surface treated by applying a pulse waveform (51) independently while alternately turning on / off the relays connected to each titanium alloy implant (100).

[0031] This is because supplying current to all titanium alloy implants (100) simultaneously for surface treatment results in a non-uniform current distribution compared to treating a single titanium alloy implant (100), making it difficult to obtain a uniform surface shape.

[0032] FIG. 5 is a flowchart of a surface treatment method for a titanium alloy implant according to an embodiment of the present invention. Referring to FIG. 5, the surface treatment method for a titanium alloy implant according to an embodiment of the present invention first prepares a titanium alloy implant and forms an oxide film on the surface of the titanium alloy implant (S1000).

[0033] Here, oxide film formation occurs through micro arc oxidation (MAO).

[0034] In addition, the titanium alloy implant is a Ti6Al4V alloy implant, and more specifically, a dental implant made of Ti6Al4V:ELI alloy with a diameter of 2.8 mmΦ.

[0035] In addition, compared to pure titanium (CP-Ti) having a single crystal structure (hexagonal close packed; HCP, α-phase), the titanium alloy implant is an α+β-phase alloy that possesses the characteristics of α-type Ti-alloys and intermediate properties of β-type Ti-alloys, and because it has α-phase (HCP) and β-phase (body centered cubic; BCC) crystal structures, the surface structure of the metal is more complex and non-uniform compared to CP-Ti.

[0036] Due to these characteristics, when an anode is applied to the titanium alloy implant, the distribution of current flow is non-uniform, so certain tissues are significantly etched, whereas certain tissues are relatively difficult to etch, resulting in a very non-uniform surface treatment.

[0037] Therefore, in the present invention, it is necessary to form an insulating film to compensate for the non-uniformity of current flow in a heterogeneous structure, and as a solution to this, a method of forming a secondary TiO2 anodic oxide film through micro-arc oxidation was utilized.

[0038] In addition, in the case of the above micro-arc oxidation, rather than etching the surface of the titanium alloy implant, it is expected that an insulating oxide film will be formed that is firmly bonded to the base metal, and a thicker oxide film will be formed in areas with a high current flow.

[0039] That is, it is expected that a more uniform porous surface can be obtained by forming a TiO2 oxide film of about 10㎛ or less through the above-described micro-arc oxidation and then performing the electrochemical etching surface treatment described below, thereby compensating for the shielding of the preceding titanium oxide film.

[0040] In addition, the electrolyte used for the micro-arc oxidation may be an alkaline electrolyte mixed with potassium hydroxide (KOH) or sodium hydroxide (NaOH) in potassium phosphate (K3PO4) or sodium phosphate (Na3PO4), and the potassium phosphate (K3PO4) or sodium phosphate (Na3PO4) may have a concentration of 0.02 mol, and the potassium hydroxide (KOH) or sodium hydroxide (NaOH) may have a concentration of 0.1 mol.

[0041] Next, the titanium alloy implant with the formed oxide film is placed in a chloride electrolyte and electrochemical etching (ECE) is performed to surface treat the oxide film so that the closed pores become fully open pores (S2000).

[0042] In addition, the electrochemical etching treatment can convert closed pores formed by micro-arc oxidation (see '11a' in FIG. 1) into completely open pores (see '20a' in FIG. 2) through surface etching by chloride ions, and can form a sufficient porous surface and roughness.

[0043] In addition, the chloride electrolyte used in the above electrochemical etching treatment may be a calcium chloride (CaCl2) electrolyte.

[0044] Next, the surface-treated titanium alloy implant is washed to remove residue (S3000).

[0045] In addition, in the present invention, residues were removed through ultrasonic cleaning.

[0046] Next, the cleaned titanium alloy implant is modified by hydrothermal treatment (HT) to form a nanostructure on the surface (S4000).

[0047] In addition, the above hydrothermal treatment is performed at 180°C for 4 hours in an alkaline aqueous solution (pH=11).

[0048] In addition, the above hydrothermal treatment can form a nanostructure on the surface and significantly increase the hydrophilicity of the surface.

[0049] The experimental results of the surface treatment method of the present invention will be described in detail below.

[0050] This experiment analyzed changes in surface roughness and structure by applying electrochemical surface treatment technology to dental implants fabricated from Ti6Al4V alloy, and was conducted in three stages: Ti-MAO treatment, Ti-MAO-ECE treatment, and Ti-MAO-ECE-HT treatment.

[0051] The processing conditions are as shown in Table 1 below.

[0052] MAO ECE Maximum applied voltage [V] 10~220 70 Maximum applied current [mA] - 9000 Pulse period [msec] 2000~5000 3000 duty rate[%] 30 10 Number of pulse applications [count] Increase from 10 to 220V and apply 50 times, then apply at 220V again 20 times. 30

[0053] Ti -MAO

[0054] Ti-MAO treatment was performed using a K3PO4 and KOH solution, providing an etched porous structure along with the formation of a surface oxide film. The treatment results are illustrated in Fig. 6, where Fig. 6(a) and (b) are SEM images obtained from different parts of the implant surface treated with Ti-MAO. As can be seen in Fig. 6, porosity was observed on the implant surface, but the formed pores were of non-uniform size and unevenly distributed. Additionally, closed pores were observed, confirming structural features that could potentially reduce the efficiency of cleaning and subsequent treatments.

[0055] Ti -MAO- ECE

[0056] After MAO treatment, an additional ECE treatment was applied to form a uniform porous structure on the surface. Through this process, a structure with uniformly distributed pores of approximately 20–30 µm in size was formed on the implant surface, and the problem of surface non-uniformity observed in the conventional Ti-ECE treatment was improved.

[0057] In addition, Figure 7 is an SEM image showing the surface of an implant treated with Ti-MAO-ECE, where (a) is a low-magnification image and (b) is a high-magnification image, and it was confirmed that the structure changed to one with uniformly distributed pores after MAO treatment.

[0058] Ti -MAO- ECE -HT

[0059] For the Ti-MAO-ECE-HT treatment, the surface of the Ti-MAO-ECE-treated implant was further modified by immersing it in an alkaline solution (pH=11) and performing hydrothermal treatment (HT) at 180°C for 6 hours. Figure 8 is an SEM image showing the surface of the implant treated with Ti-MAO-ECE-HT, in which nanostructures of approximately 30 nm in size were formed on the surface and the hydrophilicity of the surface increased significantly. Figure 9 shows the surface roughness data of the implant surface treated with Ti-MAO-ECE-HT, and the measured surface roughness (Ra) was confirmed to be 2.5–3.2 μm. Figure 10 is intended to explain the contact angle of the implant surface treated with Ti-MAO-ECE-HT, where (a) shows the contact angle of pure titanium metal, (b) shows the contact angle of the titanium alloy implant treated with Ti-MAO, and (c) shows the contact angle of the titanium alloy implant treated with Ti-MAO-ECE-HT. The contact angle of the titanium alloy implant treated with Ti-MAO-ECE-HT is 5.2°, which is 65°, and the contact angle of pure titanium metal is 65°, thus securing a superhydrophilic surface.

[0060] As a comparative example, the surface of an implant treated only with Ti-ECE without MAO treatment and HT treatment was observed.

[0061] Ti - ECE

[0062] Ti-ECE treatment was performed by applying electrical pulses in a constant current manner with adjustable cycle, intensity, and duty ratio while the implant was immersed in a CaCl2 electrolyte solution. Figure 11 is an SEM image showing the surface of the implant treated with Ti-ECE. Referring to Figure 11, non-uniformly distributed etching pores were formed on the implant surface. The pore sizes varied in diameter, and while etching proceeded excessively in some areas, pore formation was insufficient in others, resulting in a non-uniform pore distribution. These results are interpreted as being due to the non-uniformity of current distribution caused by the complex α+β phase crystal structure of the Ti6Al4V alloy.

[0063] The following describes in detail the methods for measuring pore shape, surface roughness, and contact angle.

[0064] Pore ​​shape measurement

[0065] Pore ​​morphology was measured using a scanning electron microscope (SEM), and specimens prepared under each treatment condition (Ti-ECE, Ti-MAO-ECE, Ti-MAO-ECE-HT) were kept on clean and dry surfaces suitable for SEM observation.

[0066] For the SEM observation setup, the acceleration voltage was set in the range of 15 to 20 kV to clearly analyze the detailed structure of the surface, and the size and distribution of pores were captured using various magnifications (x50, x500, x1000).

[0067] Pore ​​analysis was conducted as follows. First, pore diameters were measured under each treatment condition using SEM software, and the average size of the various pores was calculated. The average pore size was found to be approximately 20–30 µm for Ti-MAO-ECE treatment, while the diameter of the nanostructures was approximately 30 nm for Ti-MAO-ECE-HT treatment. Second, the uniformity of the surface treatment was evaluated by analyzing the pore distribution. In the case of Ti-ECE treatment, the pore sizes varied and the distribution was non-uniform, whereas a uniform pore distribution was confirmed in Ti-MAO-ECE treatment. Third, the pore morphology was observed to analyze whether the pores were open or closed structures. In Ti-MAO-ECE and Ti-MAO-ECE-HT treatments, open pore structures were formed, exhibiting characteristics favorable for washing and osteosynthesis.

[0068] Surface roughness measurement

[0069] Surface roughness measurements were performed to quantitatively evaluate the micro-morphology of the implant surface, and a 3D Optical Profiler NV-E1000 (Nanosystem, Korea) was used in this experiment.

[0070] Implant specimens with surface treatments completed according to each treatment condition (Ti-ECE, Ti-MAO-ECE, Ti-MAO-ECE-HT) were mounted on a surface roughness measuring device, and the surface was scanned in a non-contact manner. Laser technology was used to generate a 3D image of the fine features of the surface, and the centerline mean roughness (Ra) was calculated.

[0071] As a result of measurement, the Ti-MAO-ECE treated specimens formed a structure containing uniform pores of approximately 20–30 µm, and the surface roughness (Ra) was measured to be 2.5–3.0 µm. The Ti-MAO-ECE-HT treatment formed a nanostructure of approximately 30 nm in size, and the average roughness value was measured to be 2.5–3.2 µm.

[0072] contact angle measurement

[0073] Contact angle measurements were performed using the sessile drop method to evaluate the hydrophilicity of the implant surface. A drop of distilled water was placed on the surface of a dental Ti6Al4V alloy implant, and the contact angle was measured; the measurement procedure is as follows.

[0074] First, an implant specimen was prepared and secured to the sample holder of the equipment, and the surface was set to remain perfectly horizontal. Subsequently, distilled water was accurately dropped onto the implant surface in the form of a drop using a fixed injector. After the droplet had stably formed on the surface, an image of the droplet was captured after 5 seconds had elapsed. The captured image was analyzed using the equipment's software, and the contact angle between the surface and the droplet was automatically calculated based on the contour of the droplet.

[0075] In this experiment, contact angles were repeatedly measured under Ti-ECE, Ti-MAO-ECE, and Ti-MAO-ECE-HT treatment conditions, and changes in hydrophilicity according to the treatment stage were confirmed. The implant treated with Ti-MAO-ECE showed high hydrophilicity with a contact angle of approximately 10°, while the implant treated with Ti-MAO-ECE-HT exhibited superhydrophilicity with a contact angle of approximately 5.2°.

[0076] In addition, to evaluate the biocompatibility and safety of the Ti-MAO-ECE-HT-treated implants and to determine whether they induce potential adverse reactions, cytotoxicity tests, microbial reversion mutation tests, and pyrogen tests were performed as follows.

[0077] cytotoxicity test

[0078] To evaluate the cytotoxicity of Ti6Al4V alloy implants with a diameter of 2.8 mm, test materials were prepared based on the direct or indirect contact sites of the implant, and extracts were prepared in a sterile environment. Extraction conditions were set at a ratio of 3 cm² / mL based on the surface area of ​​the test material, and extraction was performed at 37°C ± 1°C for 72 ± 2 hours. For the control group, an untreated control, a negative control (0.74 g / mL), and a positive control (1.06 g / mL) were established to conduct the test. An untreated Ti6Al4V alloy was used as the untreated control material, a high-density polyethylene film was used as the negative control material, and a 0.1% ZDEC (Zinc Diethyldithiocarbamate) polyurethane film was used as the positive control material.

[0079] The test is performed on 1×10⁻⁶ in a 6-well plate 5 After inoculating the cells, the procedure was carried out by culturing them in MEM medium for 24 hours. Subsequently, 2 mL each of the test substance extract of the present invention, a negative control, a positive control, and an untreated control were applied three times, and the treated cells were further cultured at 37°C ± 1°C for 48 ± 2 hours. After culture, morphological changes in the cells were observed using a microscope (LEICA, DMI3000B).

[0080] Table 2 below shows the response grade results from the cytotoxicity test (exposure time: 48 ± 2 hours).

[0081] Exposure time Test substance extract (present invention) control group A B C Untreated Negative Positive A B C A B C A B C 48±2hrs 0 0 0 0 0 0 0 0 0 4 4 4

[0082] A, B, and C represent replicates performed independently under identical conditions, and are groups of repeated measurements established to verify the reliability of the experimental results.

[0083] As a result of observation, the test substance extract, the negative control, and the untreated control were all rated as Grade 0, indicating no cytotoxicity. This means that no inhibition of cell growth or morphological changes were observed. On the other hand, the positive control was rated as Grade 4, indicating almost complete destruction of the cell layer. These results indicate that the test substance, the Ti6Al4V alloy implant, does not induce cytotoxicity and provides a safe environment for cell survival.

[0084] Table 3 below contains the qualitative morphological grades of cytotoxicity and is for reference.

[0085] rating Reactivity All culture conditions 0 doesn't exist Cytoplasmic granules appear sporadically, no cell lysis, no decrease in cell growth 1 a little Less than 20% of cells are rounded or loosely attached, lack of cytoplasmic granules, and morphological changes; intermittent cell lysis observed, slight growth inhibition 2 minor Less than 50% of cells are round, lack cytoplasmic granules, no extensive cell lysis; growth inhibition of less than 50% 3 middle Less than 70% of the cell layer is rounded or dissolved; growth inhibition of more than 50% although the cell layer is not completely destroyed 4 seriousness Nearly complete or complete destruction of the cell layer

[0087] Microbial reverse mutation test

[0088] About 10 for the test 9 Salmonella typhimurium (TA98, TA100, TA1535, TA1537) and Escherichia coli (WP2uvrA) strains prepared at viable bacterial concentrations of CFU / mL were used. Ti-MAO-ECE-HT treated implant samples were extracted using sterile physiological saline (0.9% NaCl, polar solvent) and dimethyl sulfoxide (DMSO, non-polar solvent) at a surface area-to-solvent ratio of 3 cm² / mL, and maintained at 121 ± 2°C for 1 hour for extraction. The control group consisted of a positive control and a negative control (solvent only), and both the test group and the control group were incubated at 37 ± 1°C for 20 minutes during the pretreatment step. The samples were mixed with top agar and applied to glucose agar plates, and the coated culture dishes were further incubated at 37°C for 48–72 hours. The test results were evaluated based on whether there was a twofold or greater increase in the number of revertant colonies compared to the negative control group.

[0089] The positive control substances and solvents used in the test are as follows.

[0090] Positive control substance

[0091] NaN3: Sodium azide, 9-AA: 9-Aminoacridine, AF-2: 2-(2-Furyl)-3-(5-nitro-2-furyl) acrylamide, 2-AA: 2-Aminoanthracene, BP: 3,4-Benzopyrene, 4-NQO: 4-nitroquinoline 1-oxide

[0093] <Solvent>

[0094] Dimethyl sulfoxide

[0095] As a result of the test, it was confirmed that the test sample does not induce microbial reverse mutations, as no increase in the number of reverse mutant colonies was observed under conditions with or without a metabolic activation system, and in both polar solvents (sterile physiological saline) and non-polar solvents (dimethyl sulfoxide, DMSO), resulting in no findings that could be judged as positive.

[0096] Table 4 below shows the results of the number of reverse mutation colonies in a polar solvent (sterile physiological saline).

[0097] Table 5 below shows the results of the number of reverse mutation colonies in a polar solvent (sterile physiological saline).

[0098] Metabolic activation Dose (100 µl / plate) Revertant(colony / plate) Base substitution type frameshift type TA100 TA1535 WP2uvrA TA98 TA1537 S9Mix(-) Extract of negative control 93 9 66 11 4 87 10 61 21 6 100 11 64 15 6 Mean±SD 93±6.5 10±1.0 64±2.5 16±5.0 5±1.2 Extract of test article 96 10 71 21 5 99 6 68 17 7 113 13 61 15 5 Mean±SD 103±9.1 10±3.5 67±5.1 18±3.1 6±1.2 S9Mix(+) Extract of negative control 117 13 70 29 12 123 12 64 19 13 123 16 66 19 17 Mean±SD 121±3.5 14±2.1 67±3.1 22±5.8 14±2.6 Extract of test article 106 10 59 24 11 101 13 73 23 10 119 12 60 22 12 Mean±SD 109±9.3 12±1.5 64±7.8 23±1.0 11±1.0 Positive control S9Mix (-) Reagent AF-2 NaN3 4-NQO AF-2 9-AA Dose(μg / plate) 0.01 0.5 0.25 0.1 80.0 colony / plate 312 344 295 420 1600 424 240 252 436 1518 280 268 243 396 1476 Mean±SD 339±75.6 284±53.8 263±27.8 417±20.1 1531±63.1 S9Mix (+) Reagent 2-AA 2-AA 2-AA BP 2-AA Dose(μg / plate) 1.0 2.0 10.0 10.0 2.0 colony / plate 568 254 290 256 138 636 260 227 260 164 588 246 213 256 162 Mean±SD 597±34.9 253±7.0 243±41.0 257±2.3 155±14.5

[0100] S9Mix(+) means the state in which the metabolic activation system (S9Mix) is present, and S9Mix(-) means the state in which the metabolic activation system (S9Mix) is absent.

[0101] Metabolic activation Dose (100 µl / plate) Revertant(colony / plate) Base substitution type frameshift type TA00 TA1535 WP2uvrA TA98 TA1537 S9Mix(-) Extract of negative control 98 12 68 13 6 106 8 62 11 8 110 19 62 14 6 Mean±SD 105±6.1 13±5.6 64±3.5 13±1.5 7±1.2 Extract of test article 107 7 58 10 6 95 11 70 13 5 100 15 65 15 3 Mean±SD 101±6.0 11±4.0 64±6.0 13±2.5 5±1.5 S9Mix(+) Extract of negative control 104 10 61 20 12 114 11 72 13 19 106 12 68 20 15 Mean±SD 108±5.3 11±1.0 67±5.6 18±4.0 15±3.5 Extract of test article 93 11 57 25 9 78 14 65 26 14 94 18 58 20 10 Mean±SD 88±9.0 14±3.5 60±4.4 24±3.2 11±2.6 Positive control S9Mix (-) Reagent AF-2 NaN3 4-NQO AF-2 9-AA Dose(μg / plate) 0.01 0.5 0.25 0.1 80.0 colony / plate 312 344 295 420 1600 424 240 252 436 1518 280 268 243 396 1476 Mean±SD 339±75.6 284±53.8 263±27.8 417±20.1 1531±63.1 S9Mix (+) Reagent 2-AA 2-AA 2-AA BP 2-AA Dose(μg / plate) 1.0 2.0 10.0 10.0 2.0 colony / plate 568 254 290 256 138 636 260 227 260 164 588 246 213 256 162 Mean±SD 597±34.9 253±7.0 243±41.0 257±2.3 155±14.5

[0102] S9Mix(+) means the state in which the metabolic activation system (S9Mix) is present, and S9Mix(-) means the state in which the metabolic activation system (S9Mix) is absent.

[0103] 발열성물질 시험

[0104] The extraction solution of the test specimen was prepared under sterile conditions for 1 hour at an extraction temperature of 121 ± 2°C, based on a direct human contact area of ​​1.31 cm² / mL. The prepared extraction solution was heated to body temperature (37 ± 2°C), and after confirming body temperature stabilization using a temperature probe inserted into the anus of the experimental animal, New Zealand white rabbit, it was administered intravenously at a dose of 10 mL / kg. Subsequently, rectal temperature was measured at 30-minute intervals for 3 hours, and the pattern of temperature change and whether the temperature rose by more than 0.5°C relative to the reference temperature were recorded. For the determination of a febrile response, if the maximum increase in body temperature was 0.5°C or less, it was considered that there were no pyrogens; the test was evaluated as suitable if the total increase in body temperature in all 8 test specimens did not exceed 3.3°C.

[0105] (1) As a result of observing clinical signs and mortality, no significant clinical signs or mortality were observed in any of the experimental animals during the test period, which means that the test specimens and the extract solution did not impair the physiological safety of the experimental animals.

[0106] (2) As a result of measuring changes in body temperature and maximum body temperature, the reference body temperatures of the test animals were measured as 38.9°C, 39.3°C, and 39.2°C, and the maximum body temperatures were observed as 38.7°C, 39.4°C, and 39.2°C, respectively. The difference between the reference body temperature and the maximum body temperature was 0.0°C, 0.1°C, and 0.0°C, respectively. The total sum of the changes in body temperature was only 0.1°C, confirming that there was no increase in body temperature due to the pyrogen.

[0107] Table 6 below shows the results of mortality rates and clinical signs.

[0108] Table 7 below shows the results of individual body temperature measurements.

[0109] (SEX:MALE) No. of animals Mortality (%) Clinical signs 3 0 No clinical signs

[0111] (SEX:MALE) Animal No. 1 2 3 Body Weight (kg) 1.7945 1.8673 1.8151 Dose Volume (㎖) 17 18 18 Baseline Temp (℃) 38.9 39.3 39.2 1.0 hr Temp (℃) 38.7 39.2 39.2 1.5 hr Temp (℃) 38.6 39.2 39.1 2.0 hr Temp (℃) 38.6 39.1 39.1 2.5 hr Temp (℃) 38.7 39.4 39.1 3.0 hr Temp (℃) 38.7 39.4 39.2 Maximum Rise (℃) 0.0 0.1 0.0 Total Rise (℃) 0.1

[0113] As described above, the present invention has been illustrated and explained with reference to preferred embodiments, but it is not limited to the aforementioned embodiments, and various changes and modifications may be made by those skilled in the art within the scope of the invention without departing from the spirit of the invention. Explanation of the symbols

[0115] 10,20: Titanium implant 11: Oxide film 30: Aquarium 31: Electrolyte 40: Stirrer 50: Controller 60: Power supply 100: Titanium alloy implant

Claims

Claim 1 A method for surface treatment of a titanium alloy implant characterized by comprising: a step of forming an oxide film on the surface of a titanium alloy implant; a step of placing the titanium alloy implant with the formed oxide film into a chloride electrolyte and performing electrochemical etching treatment to surface treat the oxide film so that the closed pores become fully open pores; and a step of washing the surface-treated titanium alloy implant to remove residues. Claim 2 A surface treatment method for a titanium alloy implant according to claim 1, further comprising the step of performing hydrothermal treatment after the removal of the residue to modify the surface so that a nanostructure is formed. Claim 3 A surface treatment method for a titanium alloy implant according to claim 1, characterized in that the titanium alloy implant is a Ti6Al4V alloy implant. Claim 4 A surface treatment method for a titanium alloy implant according to claim 3, characterized in that the oxide film is formed through micro arc oxidation (MAO). Claim 5 A surface treatment method for a titanium alloy implant according to claim 4, characterized in that the electrolyte used for the micro-arc oxidation is an alkaline electrolyte mixed with potassium hydroxide (KOH) or sodium hydroxide (NaOH) in potassium phosphate (K3PO4) or sodium phosphate (Na3PO4). Claim 6 A surface treatment method for a titanium alloy implant according to claim 5, characterized in that the chloride electrolyte used in the electrochemical etching treatment is a calcium chloride (CaCl2) electrolyte. Claim 7 A surface treatment method for a titanium alloy implant according to claim 2, characterized in that the hydrothermal treatment is performed by immersing the titanium alloy implant in an alkaline aqueous solution at a temperature of 180°C for 4 hours. Claim 8 A titanium alloy implant surface-treated by any one of the surface treatment methods of claims 1 to 7, characterized in that the surface roughness (Ra) is 2.5 μm to 3.2 μm and the contact angle is 5° to 5.5°.

Images