A medical tantalum coating and a method of making and using the same

Abstract

This invention discloses a medical tantalum coating, its preparation method, and its application, belonging to the field of medical device coatings. The preparation method of this medical tantalum coating involves a multi-arc ion plating deposition method, combined with dynamic magnetic confinement arc spot control of the target surface. Under low vacuum deposition conditions protected by inert gas, the arc is stably ignited at a low operating current below 200A, continuously depositing the tantalum target onto the surface of a medical substrate to form a medical tantalum coating. The tantalum target can be a pure tantalum target or a tantalum alloy target, and the tantalum coating can be a pure tantalum coating or a tantalum alloy coating. The body-centered cubic α-Ta phase content in this medical tantalum coating is ≥95%. This invention overcomes the technical bottleneck of conventional multi-arc tantalum plating, solving the industry problem that high-melting-point tantalum metal requires a current above 200A to stably ignite in conventional multi-arc ion plating processes. It achieves stable arc ignition and continuous deposition at low currents of 100A to 170A, fundamentally suppressing large particle defects and balancing excellent plating properties with controllable phase structure.

Description

Technical Field

[0001] This invention belongs to the field of medical device coating technology, specifically relating to a medical tantalum coating, its preparation method, and its application. Background Technology

[0002] With the rapid development of minimally invasive implantable medical technologies such as orthopedics and dentistry, surface modification of medical metal implants has become a core element in improving implant biocompatibility, osseointegration, and long-term clinical lifespan. Tantalum, as a high-performance medical bioinert metal, possesses excellent osteogenic activity in its surface coating, effectively promoting osteoblast adhesion, proliferation, and differentiation, rapidly achieving osseointegration between the implant and human bone tissue. It also exhibits excellent resistance to corrosion from human body fluids and tissue compatibility, with no significant cytotoxicity or rejection reactions. It is now widely used in the surface modification of various complex medical implants, such as dental implants, orthopedic bone defect repairs, spinal fixation devices, and porous bone implants, and is currently recognized in the medical field as an ideal bone implant interface coating material.

[0003] Currently, the industrial preparation of medical tantalum coatings mainly relies on magnetron sputtering technology. However, this process has inherent technical limitations, the core issue being extremely poor coating performance. Conventional magnetron sputtering, based on the principle of linear particle deposition, can only achieve effective coating deposition on a single planar area of ​​the implant facing the target. For the numerous personalized and complex implants used in clinical practice, including irregular curved surfaces, deep cavities, micropores, blind holes, interconnected porous structures, and hidden areas such as corners and crevices, it cannot achieve comprehensive, uniform coverage without blind spots. This easily leads to large areas of missing coatings and uneven thickness in dead zones. After implantation, these incompletely coated implants not only lose the osteogenic modification advantages of tantalum coatings but are also prone to substrate corrosion and local tissue inflammation, directly affecting bone integration efficiency and long-term implant stability. This makes it difficult to meet the stringent requirements for coating integrity in medical implants with complex anatomical structures.

[0004] To compensate for the poor plating properties of magnetron sputtering, the industry has gradually explored the use of multi-arc ion plating technology to prepare tantalum coatings. However, existing conventional multi-arc tantalum plating processes have significant parameter limitations. To ensure coating deposition efficiency and substrate bonding strength, these processes generally employ a high-current operating mode. This high current directly leads to excessive melting of the tantalum target and a large amount of metal droplet splashing, ultimately forming numerous micron-sized large particle defects on the implant surface. These large particles not only damage the density and surface smoothness of the tantalum coating and reduce the bonding force between the coating and the substrate, but also cause particle shedding and interface wear during long-term service in the implant, thereby inducing local aseptic inflammation, aggravating tissue damage at the implantation site, and significantly shortening the clinical lifespan of medical implants. Furthermore, they fail to leverage the uniform and delicate osteogenic interface advantages of tantalum coatings, violating the core purpose of surface modification for medical implants.

[0005] In summary, existing mainstream technologies for preparing medical tantalum coatings all suffer from irreconcilable technical contradictions: while conventional magnetron sputtering can produce high-purity tantalum coatings, its insufficient plating flexibility prevents full-surface coverage of complex implants; traditional multi-arc plating processes, while improving coating coverage, generate numerous large-particle defects due to the high-current process, failing to balance coating purity with clinical safety. Currently, no tantalum coating preparation technology exists that can simultaneously achieve stable low-current deposition, full-surface coverage of complex structures without dead zones, and a coating free of large-particle defects. This makes it difficult to meet the core clinical demand for high-performance medical tantalum coatings, severely limiting the large-scale promotion and application of tantalum coatings in complex medical implants. Therefore, it is urgent to develop new preparation processes to overcome these technical bottlenecks. Summary of the Invention

[0006] Addressing the industry pain points of conventional multi-arc ion plating processes for high-melting-point tantalum metal requiring a current of over 200A to stably initiate the arc and resulting in large particle defects in the coating, this invention aims to provide a method for preparing a medical tantalum coating. This method achieves stable deposition of the tantalum coating using a low-current multi-arc ion plating process, while also ensuring excellent plating properties and high surface quality without large particles. This medical tantalum coating is suitable for the surface modification needs of complex medical implants, further expanding its industrial application scenarios.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] In a first aspect, the present invention provides a method for preparing a medical tantalum coating, which employs a multi-arc ion plating deposition method, in conjunction with dynamic magnetic confinement arc spot control of the target surface, and under low vacuum deposition conditions protected by inert gas, stably initiates the arc with a low operating current of less than 200A, and continuously deposits the tantalum target material onto the surface of the medical substrate to form a medical tantalum coating.

[0009] Furthermore, the tantalum target material is a pure tantalum target or a tantalum alloy target, and the tantalum coating is a pure tantalum coating or a tantalum alloy coating, wherein the tantalum alloy coating is obtained by any of the following methods:

[0010] First, the tantalum target material uses a tantalum alloy, which is continuously deposited onto the surface of the medical substrate. The tantalum alloy is composed of tantalum and functional alloying elements.

[0011] Secondly, the tantalum target material uses a pure tantalum target, which is co-deposited onto the surface of the medical substrate in conjunction with functional metal targets.

[0012] Furthermore, the functional alloying element is Cu or Ag, forming TaCu or TaAg alloys.

[0013] Furthermore, the low operating current used in multi-arc ion plating is 100A to 170A, the substrate negative bias voltage is -30V to -80V, and the pulse duty cycle is 20% to 40%.

[0014] Furthermore, the magnetic field strength for dynamic magnetic confinement arc spot modulation is 3000 Gs to 7000 Gs.

[0015] Furthermore, high-purity argon gas is introduced during the deposition process to maintain a vacuum level of 1.0 Pa to 10 Pa inside the furnace.

[0016] Furthermore, the dynamic magnetic field is a pulsed dynamic magnetic field.

[0017] Secondly, the present invention provides a medical tantalum coating, which is deposited on a medical implant using the above-mentioned method for preparing a medical tantalum coating.

[0018] Furthermore, the thickness of the medical tantalum coating is controlled to be 10 nm to 10 μm, and the content of the body-centered cubic α-Ta phase in the coating is ≥95%.

[0019] Thirdly, the application of a medical tantalum coating for surface modification of various complex medical implants such as dental implants, orthopedic bone defect repairs, spinal fixation devices, and porous bone implants.

[0020] Advantages and effects of the present invention:

[0021] 1. Breakthrough in conventional multi-arc tantalum plating technology bottleneck: This invention, through dynamic magnetic confinement control, solves the industry problem that high-melting-point tantalum metal requires a current of over 200A to stably initiate an arc in conventional multi-arc ion plating processes. It achieves stable arc initiation and continuous deposition at low currents of 100A to 170A, significantly reducing process energy consumption and equipment requirements, and laying the foundation for the industrial-scale production of tantalum coatings.

[0022] 2. Suppresses large particle defects at the source: This invention effectively avoids the problems of excessive melting of tantalum targets and droplet splashing in traditional high-current processes by using low-current deposition combined with dynamic magnetic confinement arc spot control. It eliminates micron-sized large particle defects in the coating at the source, significantly improves the coating density, surface smoothness, interfacial adhesion and performance consistency, and avoids clinical risks such as aseptic inflammation caused by large particle shedding.

[0023] 3. It combines excellent coating performance with controllable phase structure: This invention retains the excellent coating performance of multi-arc ion plating technology, which can achieve uniform coating coverage on the entire surface of implants with complex structures such as irregular curved surfaces, porous structures, and blind holes. At the same time, the coating thickness can be precisely controlled within the range of 10nm to 10μm, ensuring that the α-Ta phase content in the coating is not less than 95%, and giving full play to the excellent osteogenic activity and corrosion resistance of the α-Ta phase.

[0024] 4. Strong process compatibility and wide range of applications: This invention can flexibly introduce functional alloying elements such as Cu and Ag through alloy target or multi-target co-deposition to meet the functional requirements of different clinical scenarios; the process is compatible with a variety of mainstream implant substrates such as medical TC4 titanium alloy and PEEK, and can be widely used in the surface modification of various complex medical implants, with extremely high clinical application value and industrialization prospects. Attached Figure Description

[0025] Figure 1 The image shows the grazing incidence X-ray diffraction (GIXRD) pattern of the pure Ta coating on the surface of the TC4 titanium alloy used in traditional Chinese medicine in Example 1.

[0026] Figure 2 This is a scanning electron microscope (SEM) image of the pure Ta coating on the surface of TC4 titanium alloy used in traditional Chinese medicine, as shown in Example 1.

[0027] Figure 3 This is a comparison of the osteogenic properties of a pure tantalum coating with α-Ta phase as the main component prepared in Example 1, a pure tantalum coating with β-Ta phase as the main component, and a TC4 titanium alloy substrate in animal experiments. Detailed Implementation

[0028] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0029] A method for preparing a medical tantalum coating employs a multi-arc ion plating deposition method, combined with dynamic magnetic confinement arc spot control on the target surface. The dynamic magnetic confinement arc spot control utilizes a pulsed dynamic magnetic field, with the following core process parameters: operating current: 100A~170A; substrate negative bias voltage: -30V~-80V; pulse duty cycle: 20%~40%; dynamic magnetic field strength: 3000Gs~7000Gs; high-purity argon gas is introduced during deposition to maintain a furnace vacuum of 1.0Pa~10Pa; a low operating current below 200A is used for stable arc initiation; and tantalum target material is continuously deposited onto the surface of a medical substrate to form a medical tantalum coating. The tantalum target material can be a pure tantalum target or a tantalum alloy target; the tantalum coating can be a pure tantalum coating or a tantalum alloy coating; and the tantalum alloy coating can be obtained through any of the following methods:

[0030] First, the tantalum target material uses a tantalum alloy, which is continuously deposited onto the surface of the medical substrate. It consists of a TaCu alloy or a TaAg alloy composed of tantalum and functional metal elements Cu or Ag.

[0031] Second, the tantalum target material uses a pure tantalum target, which is co-deposited onto the surface of the medical substrate in conjunction with functional metal targets.

[0032] A medical tantalum coating is obtained by deposition in a medical implant using the above-mentioned method for preparing a medical tantalum coating; the thickness of the medical tantalum coating can be controlled between 10 nm and 10 μm, and the content of the body-centered cubic α-Ta phase in the coating is ≥95%.

[0033] An application of a medical tantalum coating for surface modification of various complex medical implants, such as dental implants, orthopedic bone defect repairs, spinal fixation devices, and porous bone implants.

[0034] Example 1

[0035] A method for preparing a medical tantalum coating includes the following steps:

[0036] Substrate pretreatment: The substrate is a medical-grade TC4 titanium alloy sample with a sample size of Φ15mm×5mm. After sandblasting, the substrate is ultrasonically cleaned with acetone and anhydrous ethanol for 15 minutes each, and then dried with nitrogen before being placed into the working chamber of the multi-arc ion plating equipment.

[0037] Multi-arc ion plating deposition: Evacuate the working chamber to 1×10 -2 Below Pa, turn on the heater to heat the temperature around the sample to 200℃, then continue evacuating to a background vacuum of 2×10⁻⁶. -3Pa; Deposition was performed using a multi-arc ion plating process, with a distance of 70 mm between the substrate and the pure tantalum target. High-purity argon gas was introduced to maintain a vacuum of 1.5 Pa in the working chamber. The working current of the tantalum target was controlled at 100 A, the pulsed dynamic magnetic field strength on the target surface was 3000 Gs-4500 Gs, the negative bias voltage of the substrate was -50 V, the pulse duty cycle was 20%, the deposition time was 2 min, and the coating thickness was 200 nm. After deposition, the argon gas supply and the power supply to the target were stopped, the heater was turned off, and the sample was cooled to room temperature in a vacuum environment before being removed from the furnace.

[0038] Using the preparation method in Example 1, a pure tantalum coating was formed on medical-grade TC4 titanium alloy, and its properties were characterized: the phase structure of the coating was detected using grazing incidence X-ray diffraction (GIXRD), and the results are as follows. Figure 1 As shown, the phase structure of the tantalum coating is dominated by the α-Ta phase, with a small amount of β-Ta phase, of which the α-Ta phase content is approximately 96%. Scanning electron microscopy (SEM) was used to observe the cross-section of the coating, and the results are as follows: Figure 2 As shown, the coating structure is dense and uniform, and the tantalum coating has a good interface with the TC4 titanium alloy substrate, with no obvious pores, cracks and large particles.

[0039] Osteogenic performance analysis:

[0040] The osteogenic properties of the medical tantalum coating of this invention were verified through animal experiments. Medical implant samples were prepared using a pure tantalum coating dominated by the α-Ta phase (hereinafter referred to as α-Ta coating), a pure tantalum coating dominated by the β-Ta phase (hereinafter referred to as β-Ta coating), and TC4 titanium alloy (hereinafter referred to as TC4). The α-Ta coating samples, α-Ta coating samples, and TC4 samples were then implanted into healthy adult experimental mice. The volume fraction of newly formed bone was measured at 4, 6, 8, and 10 weeks post-implantation. Figure 3 As shown, with the extension of in vivo implantation time, the new bone volume fraction of the three groups of samples, namely α-Ta coating, β-Ta coating and TC4, showed a continuous upward trend. At all observation time points, the bone volume fraction of α-Ta coating was always the highest. Moreover, as the test cycle progressed, the difference in bone formation between α-Ta coating and β-Ta coating and TC4 continued to widen. This indicates that the pure tantalum coating with α-Ta phase as the main component in Example 1 can effectively promote in vivo new bone formation and has excellent osteogenic performance. Its osteogenic effect is significantly better than that of the pure tantalum coating with β-Ta phase as the main component.

[0041] Example 2

[0042] A method for preparing a medical tantalum coating includes the following steps:

[0043] Substrate pretreatment: The substrate is a medical-grade TC4 titanium alloy sample with a sample size of Φ15mm×5mm. After sandblasting, the substrate is ultrasonically cleaned with acetone and anhydrous ethanol for 15 minutes each, and then dried with nitrogen before being placed into the working chamber of the multi-arc ion plating equipment.

[0044] Multi-arc ion plating deposition: Evacuate the working chamber to 1×10 -2 Below Pa, turn on the heater to heat the temperature around the sample to 200℃, then continue evacuating to a background vacuum of 3×10⁻⁶. -3 The deposition was performed using a multi-arc ion plating process. The distance between the substrate and the TaAg alloy (Ag: 1.5 at.%) target was 70 mm. High-purity argon gas was introduced to maintain a vacuum of 1.0 Pa in the working chamber. The working current of the tantalum target was controlled at 120 A, the pulsed dynamic magnetic field strength on the target surface was 5000 Gs-6000 Gs, the substrate negative bias voltage was -30 V, the pulse duty cycle was 40%, the deposition time was 2 min, and the coating thickness was approximately 230 nm. After deposition, the argon gas supply and target power supply were stopped, the heater was turned off, and the sample was cooled to room temperature in a vacuum environment before being removed from the furnace.

[0045] Using the preparation method in Example 2, a TaAg alloy coating was formed on medical TC4 titanium alloy, and its performance was characterized: the phase structure of the coating was detected by GIXRD. The phase structure of the TaAg alloy coating was mainly α-Ta phase, with a small amount of β-Ta phase. The α-Ta phase content was about 98%. Due to the low Ag content, no characteristic diffraction peaks of Ag were detected. The cross-section of the coating was observed by SEM. The coating structure was dense and uniform. The TaAg alloy coating and the TC4 titanium alloy substrate had good interfacial bonding and no obvious pores or large particle defects.

[0046] Animal experiments have verified that the TaAg alloy coating prepared in Example 2 exhibits excellent osteogenic and antibacterial properties in mice.

[0047] Example 3

[0048] A method for preparing a medical tantalum coating includes the following steps:

[0049] Substrate pretreatment: The substrate used is medical PEEK sample with a sample size of Φ15mm×5mm. After sandblasting, the substrate is ultrasonically cleaned with acetone for 15 min, dried with nitrogen, and then placed into the working chamber of the multi-arc ion plating equipment.

[0050] Multi-arc ion plating deposition: Evacuate the working chamber to 1×10 -2 Below Pa, turn on the heater and heat the ambient temperature of the sample to 100℃, then stop heating. After cooling to room temperature, continue evacuating to a background vacuum of 2.3 × 10⁻⁶. -3Pa; Multi-target deposition was performed using a multi-arc ion plating process, employing two pure tantalum targets and one pure copper target. The distance between the substrate and the targets was 90 mm. High-purity argon gas was introduced to maintain a vacuum level of 1.5 Pa in the working chamber. The operating current of the tantalum targets was controlled at 150 A, the pulsed dynamic magnetic field strength on the target surface was 5000 Gs-7000 Gs, the operating current of the copper target was controlled at 40 A, the substrate negative bias voltage was -40 V, the pulse duty cycle was 20%, the deposition time was 1.2 h, and the layer thickness was approximately 10 μm. After deposition, the argon gas supply and target power supply were stopped, and the sample was cooled to room temperature in a vacuum environment before being removed from the furnace.

[0051] Using the preparation method in Example 3, a TaCu alloy coating was formed on medical PEEK, and its performance was characterized: the phase structure of the coating was detected by GIXRD. The phase structure of the TaCu alloy coating was mainly α-Ta phase, with a small amount of β-Ta phase. The α-Ta phase content was about 99%. Due to the low Cu content, no characteristic diffraction peaks of Cu were detected. The cross-section of the coating was observed by SEM. The coating structure was dense and uniform. The TaCu alloy coating and the TC4 titanium alloy substrate had good interfacial bonding with no obvious pores or large particle defects.

[0052] Animal experiments have verified that the TaCu alloy coating prepared in Example 3 exhibits excellent osteogenic and antibacterial properties in mice.

[0053] Example 4

[0054] A method for preparing a medical tantalum coating includes the following steps:

[0055] Substrate pretreatment: The substrate is a medical pure titanium alloy sample with a sample size of Φ15mm×5mm. After sandblasting, the substrate is ultrasonically cleaned with acetone and anhydrous ethanol for 10 minutes each. After being dried with nitrogen, it is placed into the working chamber of the multi-arc ion plating equipment.

[0056] Multi-arc ion plating deposition: Evacuate the working chamber to 1×10 -2 Below Pa, turn on the heater to heat the temperature around the sample to 200℃, then continue evacuating to a background vacuum of 6×10⁻⁶. -3 The deposition was performed using a multi-arc ion plating process. The distance between the substrate and the TaAg alloy (Ag: 1.5 at.%) target was 70 mm. High-purity argon gas was introduced to maintain a vacuum of 10 Pa in the working chamber. The target working current was controlled at 170 A, the pulsed dynamic magnetic field strength on the target surface was 4000 Gs-5500 Gs, the substrate negative bias voltage was -80 V, the pulse duty cycle was 40%, the deposition time was 2 min, and the coating thickness was approximately 230 nm. After deposition, the argon gas supply and target power supply were stopped, the heater was turned off, and the sample was cooled to room temperature in a vacuum environment before being removed from the furnace.

[0057] Using the preparation method in Example 2, a TaAg alloy coating was formed on medical TC4 titanium alloy, and its performance was characterized: the phase structure of the coating was detected by GIXRD. The phase structure of the TaAg alloy coating was mainly α-Ta phase, with a small amount of β-Ta phase. The α-Ta phase content was about 98%. Due to the low Ag content, no characteristic diffraction peaks of Ag were detected. The cross-section of the coating was observed by SEM. The coating structure was dense and uniform. The TaAg alloy coating and the TC4 titanium alloy substrate had good interfacial bonding and no obvious pores or large particle defects.

[0058] Animal experiments have verified that the TaAg alloy coating prepared in Example 4 exhibits excellent osteogenic and antibacterial properties in mice.

[0059] Example 5

[0060] A method for preparing a medical tantalum coating includes the following steps:

[0061] Substrate pretreatment: The substrate is a medical TC4 alloy sample with a sample size of Φ10mm×5mm. After sandblasting, the substrate is ultrasonically cleaned with acetone and anhydrous ethanol for 10 minutes each. After being dried with nitrogen, it is placed into the working chamber of the multi-arc ion plating equipment.

[0062] Multi-arc ion plating deposition: Evacuate the working chamber to 1×10 -2 Below Pa, turn on the heater to heat the temperature around the sample to 200℃, then continue evacuating to a background vacuum of 6×10⁻⁶. -3 The deposition was performed using a multi-arc ion plating process. The distance between the substrate and the Ta (Ag: 1.5 at.%) target was 70 mm. High-purity argon gas was introduced to maintain a vacuum of 5 Pa in the working chamber. The target operating current was controlled at 110 A, the pulsed dynamic magnetic field strength on the target surface was 4000 Gs-5500 Gs, the substrate negative bias voltage was -30 V, the pulse duty cycle was 20%, the deposition time was 5 s, and the coating thickness was approximately 10 nm. After deposition, the argon gas supply and target power supply were stopped, the heater was turned off, and the sample was cooled to room temperature in a vacuum environment before being removed from the furnace.

[0063] Using the preparation method in Example 2, a Ta coating was formed on medical TC4 titanium alloy, and its performance was characterized: the phase structure of the coating was detected by GIXRD, and the phase structure of the Ta coating was mainly α-Ta phase with a small amount of β-Ta phase, of which the α-Ta phase content was about 95%; the coating cross section was observed by TEM, and the coating structure was dense and uniform, and the interface between the Ta coating and the TC4 titanium alloy substrate was well bonded, with no obvious pores or large particle defects.

[0064] Animal experiments have verified that the TaAg alloy coating prepared in Example 5 exhibits excellent osteogenic and antibacterial properties in mice.

Claims

1. A method for preparing a medical tantalum coating, characterized in that, A multi-arc ion plating deposition method is adopted, which is coordinated with dynamic magnetic confinement arc spot control of the target surface. Under low vacuum deposition conditions protected by inert gas, the arc is stably ignited with a low working current of less than 200A, and the tantalum target material is continuously deposited onto the surface of the medical substrate to form a medical tantalum coating.

2. The method for preparing a medical tantalum coating as described in claim 1, characterized in that, The tantalum target material is a pure tantalum target or a tantalum alloy target, and the tantalum coating is a pure tantalum coating or a tantalum alloy coating. The tantalum alloy coating is obtained through any of the following methods: First, the tantalum target material uses a tantalum alloy, which is continuously deposited onto the surface of the medical substrate. The tantalum alloy is composed of tantalum and functional alloying elements. Secondly, the tantalum target material uses a pure tantalum target, which is co-deposited onto the surface of the medical substrate in conjunction with functional metal targets.

3. The method for preparing a medical tantalum coating as described in claim 2, characterized in that, The functional alloying elements are Cu or Ag, forming TaCu or TaAg alloys.

4. The method for preparing a medical tantalum coating as described in claim 1, characterized in that, Multi-arc ion plating uses a low operating current of 100A to 170A, a substrate negative bias voltage of -30V to -80V, and a pulse duty cycle of 20% to 40%.

5. The method for preparing a medical tantalum coating as described in claim 1, characterized in that, The magnetic field strength for dynamic magnetic confinement arc spot modulation is 3000 Gs to 7000 Gs.

6. The method for preparing a medical tantalum coating as described in claim 1, characterized in that, High-purity argon gas is introduced during the deposition process to maintain a vacuum of 1.0 Pa to 10 Pa inside the furnace.

7. The method for preparing a medical tantalum coating as described in claim 1, characterized in that, The dynamic magnetic field is a pulsed dynamic magnetic field.

8. A medical tantalum coating, characterized in that, The tantalum coating is deposited on a medical implant using the method described in any one of claims 1-7.

9. A medical tantalum coating as described in claim 8, characterized in that, The thickness of the medical tantalum coating is controlled at 10 nm to 10 μm, and the content of the body-centered cubic α-Ta phase in the coating is ≥95%.

10. An application of the medical tantalum coating as described in claim 8, characterized in that, Surface modification of various complex medical implants, including dental implants, orthopedic bone defect repairs, spinal fixation devices, and porous bone implants.

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