TWI853755B - Method for surface treatment of medical implant and medical implant treated by the same - Google Patents

Abstract

A method for surface treatment of a medical implant is used for solving the problem of the surface coating of the medical implant being unable to have both high density and high porosity. The method comprises: spraying a base layer coating onto the surface of a medical implant at a substrate bonding temperature, solidifying the base layer coating on the surface of the medical implant at a cooling temperature to form a base layer. A surface layer coating is sprayed onto the surface of the base layer at the substrate bonding temperature, and the surface layer coating is solidified on the surface of the base layer at the cooling temperature to form a surface layer. The base layer and the surface layer together form a tantalum coating layer. With such performance, the surface of the medical implant can simultaneously achieve both high density and high porosity. The medical implant which is treated according to the method is also disclosed.

Description

Surface treatment method of medical implant and medical implant obtained by treatment

The present invention relates to a surface treatment method, in particular to a surface treatment method for a medical implant. The present invention also relates to a medical implant treated by the surface treatment method for a medical implant.

Tantalum is a metal with high ductility, high toughness, high corrosion resistance and high electrical conductivity. It can be used as a corrosion-resistant and wear-resistant coating material and is widely used in aerospace, electronics and communications. The low thermal conductivity of tantalum also makes it widely used in metal surface treatment. By compounding a dense tantalum coating on the metal surface, the composite material of the metal and the tantalum coating can have a good thermal insulation effect.

In addition to its application in industrial thermal insulation processes, tantalum can also promote the proliferation and differentiation of cartilage cells and exhibit good osteogenic activity in the human body, so tantalum is an emerging coating material for medical implants. However, the porosity of the tantalum coating formed by the surface treatment method of spraying tantalum thermal insulation coating in industry is extremely low, which conflicts with the requirement of the coating on medical implants to have appropriate porosity to increase the biocompatibility of the medical implants. Therefore, the tantalum coating forming method used in industry cannot be applied to the surface treatment of medical implants.

In view of this, there is still a need to provide a surface treatment method for medical implants to solve the above problems.

To solve the above problems, the object of the present invention is to provide a surface treatment method for a medical implant, which is used to form a tantalum coating having good density and appropriate porosity on the medical implant.

A second object of the present invention is to provide a surface treatment method for a medical implant, which is capable of improving the bonding strength and uniformity between the formed tantalum coating and the surface of the medical implant.

Another object of the present invention is to provide a medical implant obtained by treating the surface of the medical implant using the above-mentioned surface treatment method of the medical implant.

The directions or similar terms described throughout the present invention, such as "front", "rear", "left", "right", "upper (top)", "lower (bottom)", "inside", "outside", "side", etc., are mainly with reference to the directions of the attached drawings. Each direction or similar terms are only used to assist in the description and understanding of the various embodiments of the present invention, and are not used to limit the present invention.

The quantifiers "a" or "an" used in the elements and components described throughout the present invention are only for convenience of use and to provide a general meaning of the scope of the present invention; they should be interpreted in the present invention as including one or at least one, and the single concept also includes the plural case unless it is obvious that it means otherwise.

The surface treatment method of the medical implant of the present invention comprises: spraying a base coating material onto the surface of the medical implant at a substrate bonding temperature, and solidifying the base coating material on the surface of the medical implant at a cooling temperature to form a base layer; and spraying a surface coating material onto the base layer at the substrate bonding temperature, and solidifying the surface coating material on the base layer at the cooling temperature to form a surface layer, wherein the base coating material The bottom layer and the surface layer together form a tantalum coating layer; wherein the bottom layer coating is composed of a first tantalum metal particle, and the first tantalum metal particle is in a completely molten state at the substrate bonding temperature, and the surface layer coating includes the first tantalum metal particle and a second tantalum metal particle, the particle size of the first tantalum metal particle is smaller than the particle size of the second tantalum metal particle, and the second tantalum metal particle is in a partially molten state at the substrate bonding temperature.

Accordingly, the surface treatment method of the medical implant of the present invention forms the base layer using a base coating composed of first tantalum metal particles with a smaller particle size, and forms the surface layer using a surface coating containing first tantalum metal particles with a smaller particle size and second tantalum metal particles with a larger particle size, so that the medical implant can have good density and porosity at the same time, thereby achieving the effect of improving the implantation effect of the medical implant.

Furthermore, by controlling the surface temperature of the medical implant, the surface of the bottom layer and/or the surface of the middle layer to maintain a certain value in the bottom layer forming step, the surface layer forming step and the middle layer forming step, the bottom layer, the surface layer and the middle layer can be uniformly formed, so that the tantalum metal coating can be effectively formed on the surface of the medical implant.

When spraying the bottom layer coating, the temperature difference between the highest temperature and the lowest temperature of the surface temperature of the medical implant can be controlled to be no more than ±5%, and when spraying the surface layer coating, the temperature difference between the highest temperature and the lowest temperature of the surface temperature of the bottom layer can be controlled to be no more than ±5%. In this way, the bottom layer surface can have a relatively uniform temperature distribution, which has the effect of improving the uniformity of the formation of the surface layer.

The surface coating may contain more than 10% by weight of the first tantalum metal particles and less than 90% by weight of the second tantalum metal particles. In this way, it can be ensured that the surface coating contains enough first tantalum metal particles to be sprayed onto the base layer in a molten state, which has the effect of ensuring that the surface layer and the base layer have sufficient bonding strength and that the base layer has sufficient density.

The surface coating may further include a third tantalum metal particle, the particle size of the third tantalum metal particle may be between the particle size of the first tantalum metal particle and the particle size of the second tantalum metal particle, and the total weight of the second tantalum metal particle and the third tantalum metal particle accounts for less than 90% of the surface coating. In this way, the third tantalum metal particle of the surface coating can be sprayed onto the bottom layer in a partially molten state, which has the effect of increasing the porosity of the surface layer.

The surface treatment method of the medical implant of the present invention may further include: after forming the base layer, spraying an intermediate layer coating containing the first tantalum metal particles onto the base layer at the substrate bonding temperature, and forming an intermediate layer on the base layer with the intermediate layer coating at the cooling temperature, and then forming the surface layer with the surface layer coating on the intermediate layer, and the base layer, the intermediate layer and the surface layer together form the tantalum metal coating. In this way, the intermediate layer can be uniformly formed between the base layer and the surface layer, and the first tantalum metal particles of the intermediate layer can be sprayed onto the base layer in a molten state, which has the effect of increasing the bonding strength between the intermediate layer and the base layer and improving the density of the base layer.

When spraying the intermediate layer coating, the temperature difference between the highest temperature and the lowest temperature of the surface temperature of the bottom layer can be controlled to be no more than ±5%. In this way, the bottom layer surface can have a relatively uniform temperature distribution, which has the effect of improving the uniformity of the formation of the intermediate layer.

The intermediate layer coating may further include a third tantalum metal particle, and the particle size of the third tantalum metal particle is between the particle size of the first tantalum metal particle and the particle size of the second tantalum metal particle. Thus, the third tantalum metal particle can further increase the porosity of the intermediate layer, and has the effect of further improving the medical effect of the tantalum metal coating after implantation into the human body.

The intermediate layer coating may contain more than 10% of the first tantalum metal particles and less than 90% of the third tantalum metal particles by weight. In this way, the intermediate layer coating can be ensured to have sufficient first tantalum metal particles sprayed onto the bottom layer in a molten state, which can ensure that the intermediate layer and the bottom layer have sufficient bonding strength and that the bottom layer has sufficient density.

The intermediate layer coating may further include the second tantalum metal particles. Thus, the second tantalum metal particles can increase the surface roughness of the intermediate layer, thereby enhancing the bonding effect between the intermediate layer and the surface layer.

The intermediate layer coating may contain more than 10% of the first tantalum metal particles by weight, and the total weight of the second tantalum metal particles and the third tantalum metal particles accounts for less than 90% of the intermediate layer coating. In this way, it can be ensured that the intermediate layer coating has sufficient first tantalum metal particles sprayed onto the bottom layer in a molten state, which has the effect of ensuring that the intermediate layer and the bottom layer have sufficient bonding strength and ensuring that the bottom layer has sufficient density.

The particle sizes of the first tantalum metal particles and the second tantalum metal particles may be between 5 and 75 μm. In this way, the tantalum metal coating layer may have a micron-level particle size close to that of human tissue, thereby improving the biocompatibility of the tantalum metal coating layer.

The particle size of the first tantalum metal particles may be between 5 and 15 μm, and the particle size of the second tantalum metal particles may be between 55 and 75 μm. In this way, the bottom layer can have good density, and the surface layer can have appropriate pore structure and surface roughness, which can enhance the bonding strength between the tantalum metal coating and the medical implant, and increase the contact surface area between the tantalum metal coating and human tissue.

The particle size of the third tantalum metal particle may be between 5 and 75 μm. In this way, the tantalum metal coating layer may have a micron-level particle size close to that of human body tissue, thereby improving the biocompatibility of the tantalum metal coating layer.

The particle size of the third tantalum metal particles can be between 45 and 55 μm. In this way, the intermediate layer can have a good pore structure, and the third tantalum metal particles can support the pores in the tantalum metal coating, which has the effect of improving the medical effect of the tantalum metal coating after implantation into the human body.

The thickness of the bottom layer does not exceed one third of the total thickness of the tantalum coating layer. In this way, the spraying time of the bottom layer can be reduced, which has the effect of improving the efficiency of the spraying process.

The substrate bonding temperature may be between 2900 and 3100° C. In this way, the temperature of the medical implant can be maintained at the melting point of the tantalum coating, so that the tantalum coating is evenly distributed on the surface of the medical implant, which has the effect of improving the bonding strength between the tantalum coating and the medical implant.

The cooling temperature may be between 50 and 300° C. In this way, the bottom layer, the middle layer and the surface layer can maintain an ideal solidification rate, which has the effect of preventing the temperature of the medical implant from dissipating too quickly and causing the bottom layer, the middle layer and the surface layer to deform and crack.

The medical implant of the present invention is obtained by treating the surface of the medical implant as described above, wherein the surface of the medical implant has the tantalum metal coating.

Accordingly, the medical implant of the present invention, through the tantalum metal coating, can promote cell attachment to the medical implant when implanted in the human body, improve cell proliferation and differentiation capabilities, and achieve the effect of improving the biocompatibility and therapeutic effect of the medical implant.

In order to make the above and other purposes, features and advantages of the present invention more clearly understood, the following specifically describes the preferred embodiments of the present invention in detail with reference to the accompanying drawings.

Please refer to FIG. 1 , which is a first embodiment of the surface treatment method of the medical implant of the present invention, which may include an implant providing step S1, a base layer forming step S2 and a surface layer forming step S3, thereby being able to form a tantalum metal coating 2 having both density and porosity on a medical implant 1 (as shown in FIG. 2 ).

Specifically, in the implant providing step S1, the medical implant 1 can be provided. The "medical implant" described in the present invention refers to a biomedical material that can be implanted in the human body and provide medical effects. For example, the medical implant 1 can be made of materials such as metal, polymer or ceramic, and can be formed into a bone nail, a bone plate, an intervertebral fusion device, a tooth root, a metal bone repair, etc. This is understandable to those with ordinary knowledge in the technical field to which the present invention belongs, and is not limited here. In this embodiment, a titanium alloy is used as the medical implant 1.

Preferably, the medical implant 1 may have a surface roughness of 10-40 μm, for example, formed by an etching process or a sandblasting process, thereby increasing the bonding strength between the subsequently formed tantalum metal coating 2 and the surface of the medical implant 1.

Next, please refer to FIGS. 1 and 2 , in the bottom layer forming step S2, the worker may spray a bottom layer coating onto the surface of the medical implant 1, thereby forming a bottom layer 21. Specifically, the bottom layer coating may be composed of a first tantalum metal particle, and the particle size of the first tantalum metal particle may be in the micrometer range, for example, in the particle size range of 5 to 75 μm, so that the bottom layer coating may have good biocompatibility and stability in the human body.

The worker may raise the temperature of the medical implant 1 to a substrate bonding temperature, then spray the bottom coating onto the surface of the medical implant 1, and then lower the temperature of the medical implant 1 to a cooling temperature, so that the bottom coating sprayed onto the surface of the medical implant 1 may cool and solidify to form the bottom layer 21. For example, the substrate bonding temperature may be between 2900 and 3100°C. In this embodiment, in order to enhance the bonding strength between the bottom layer 21 and the surface of the medical implant 1, the first tantalum metal particles in the bottom layer coating are first completely molten, and then the bottom layer coating is sprayed onto the surface of the medical implant 1. At this time, the medical implant 1 is maintained at the substrate bonding temperature that can make the first tantalum metal particles molten. After the spraying operation is completed, the medical implant 1 is cooled to the cooling temperature, and the bottom layer coating can solidify to form the bottom layer 21 and bond to the surface of the medical implant 1.

It is worth noting that the worker can preferably control the surface temperature of the medical implant 1 to maintain a certain value, for example, the temperature difference between the highest temperature and the lowest temperature of the surface temperature of the medical implant 1 does not exceed ±5% (for example, when the substrate bonding temperature is set to 3000°C, the highest temperature of the surface temperature of the medical implant 1 does not exceed 3150°C, and the lowest temperature is not lower than 2850°C). In this way, the surface of the medical implant 1 can have a relatively uniform temperature distribution, so that the bottom layer coating can be evenly sprayed onto the surface of the medical implant 1, which has the effect of improving the uniformity of the formation of the bottom layer 21.

In addition, the worker can set the cooling temperature to between 50 and 300°C. After completing the spraying operation, by maintaining the base coating at the cooling temperature, the base coating can maintain an ideal solidification speed, avoiding the medical implant 1 from losing temperature too quickly, which may cause deformation and cracking of the medical implant 1 and the base coating, and helping to improve the uniformity of the base layer 21 during solidification.

Please refer to FIGS. 1 and 2 , in the surface layer forming step S3 , the worker may spray a surface layer coating onto the base layer 21 , thereby forming a surface layer 22 . In addition to the first tantalum metal particles mentioned above, the surface layer coating may also include a second tantalum metal particle. The particle size of the second tantalum metal particle may also be in the micrometer range. However, it should be noted that the particle size of the second tantalum metal particle is larger than the particle size of the first tantalum metal particle, so that when the surface layer coating is heated to the substrate bonding temperature at which the first tantalum metal particle is in a molten state, the second tantalum metal particle in the surface layer coating is only partially molten, thereby making the surface layer 22 formed by the surface layer coating have a different porosity from the bottom layer 21 formed by the bottom layer coating. In this embodiment, the surface layer coating contains more than 10% by weight of the first tantalum metal particles (that is, when the surface layer coating is composed of the first tantalum metal particles and the second tantalum metal particles, the surface layer coating contains less than 90% by weight of the second tantalum metal particles, and when the surface layer coating contains other tantalum metal particles, the total weight of the second tantalum metal particles and the other tantalum metal particles is less than 90% of the surface layer coating).

In order to form the surface layer 22, after forming the bottom layer 21, the worker can raise the temperature of the bottom layer 21 to the substrate bonding temperature, then spray the surface layer coating onto the surface of the bottom layer 21, and finally cool and solidify the surface layer coating at the cooling temperature to form the surface layer 22. Similarly, the worker can control the surface temperature of the bottom layer 21 to maintain a certain value, for example, the temperature difference between the highest temperature and the lowest temperature of the surface temperature of the bottom layer 21 does not exceed ±5%, thereby making the surface of the bottom layer 21 have a relatively uniform temperature distribution, so that the surface layer coating can be uniformly sprayed onto the surface of the bottom layer 21, which has the effect of improving the uniformity of the formation of the surface layer 22.

It is particularly important to explain that, since the bottom coating used to form the bottom layer 21 is composed of first tantalum metal particles with a smaller particle size, the first tantalum metal particles in the bottom coating can be in a completely molten state at the substrate bonding temperature; and since the surface coating used to form the surface layer 22 also includes second tantalum metal particles with a larger particle size, the second tantalum metal particles with a larger particle size in the surface coating can be in a completely molten state at the substrate bonding temperature. The metal particles will be in a partially molten state, and the bottom layer 21 formed in this way can have a smaller porosity and a higher density, so it has a good bonding strength with the surface of the medical implant 1. The surface layer 22 formed will have a larger porosity and a larger surface roughness due to the presence of the second tantalum metal particles, which can allow bone cells to climb on it, thereby improving the implantation effect of the medical implant 1. Furthermore, since the surface layer coating used to form the surface layer 22 still contains first tantalum metal particles with a smaller particle size, at the substrate bonding temperature, the first tantalum metal particles in a completely molten state sprayed onto the base layer 21 can penetrate into the base layer 21 to fill the pores of the base layer 21, which can not only further improve the density of the base layer 21, but also make the boundary between the base layer 21 and the surface layer 22 disappear, thereby jointly forming the tantalum metal coating 2.

Preferably, in the base layer forming step S2 and/or the surface layer forming step S3, the worker can spray the base layer coating onto the surface of the medical implant 1 and/or spray the surface layer coating onto the surface of the base layer 21 by atmospheric plasma spray. In this way, the base layer 21 and/or the surface layer 22 can be formed in an atmospheric environment without the need to additionally create a vacuum environment or inject expensive inert gas, thereby reducing the operating cost of surface treatment of the medical implant 1.

In addition, please refer to FIG. 3 , in order to further adjust the porosity of the formed tantalum metal coating 2, in the second embodiment of the surface treatment method of the medical implant of the present invention, an intermediate layer spraying step S4 may be included between the aforementioned bottom layer spraying step S2 and the surface layer spraying step S3, and the worker may spray an intermediate layer coating onto the surface of the bottom layer 21 to form an intermediate layer 23, and then perform the surface layer spraying step S3 to form the surface layer 22 on the intermediate layer 23 (as shown in FIG. 4 ). The worker may also perform the intermediate layer spraying step S4 several times according to the needs to form a plurality of intermediate layers 23 between the bottom layer 21 and the surface layer 22. This is something that can be adjusted by a person having ordinary knowledge in the technical field to which the present invention belongs and is not limited here.

The intermediate layer coating at least includes the first tantalum metal particles, and may also include a third tantalum metal particle. The particle size of the third tantalum metal particle should also be larger than the particle size of the first tantalum metal particle, and the proportion of the first tantalum metal particle is preferably more than 10%, so that when the intermediate layer coating is heated to the substrate bonding temperature at which the first tantalum metal particle is in a molten state, the third tantalum metal particle in the intermediate layer coating is only partially molten, so that the intermediate layer 23 formed by the intermediate layer coating can also have a different porosity from the bottom layer 21 formed by the bottom layer coating. Furthermore, in order to make the intermediate layer 23 and the surface layer 22 formed by the surface layer coating have different porosities, the particle size of the third tantalum metal particles can be between the particle size of the first tantalum metal particles and the particle size of the second tantalum metal particles. In this embodiment, the surface layer coating includes the third tantalum metal particles in addition to the first tantalum metal particles and the second tantalum metal particles.

In addition, in order to improve the forming uniformity of the middle layer 23, the worker can also control the surface temperature of the bottom layer 21 to maintain a certain value, for example, the temperature difference between the highest temperature and the lowest temperature of the surface temperature of the bottom layer 21 does not exceed ±5%, thereby making the surface of the bottom layer 21 have a relatively uniform temperature distribution, so that the middle layer coating can be evenly sprayed onto the surface of the bottom layer 21.

In order to verify that the surface treatment method of the medical implant can indeed form a stable tantalum coating 2 on the medical implant 1, tantalum metal particles with particle sizes of 5-15 μm, 55-75 μm and 45-55 μm are used as the first tantalum metal particles, the second tantalum metal particles and the third tantalum metal particles, and the bottom coating, the surface coating and the middle coating are formed respectively according to the proportions shown in Table 1.

Table 1. Particle size ratio of tantalum metal particles in each tantalum metal coating in this test Proportion (weight percentage) First, tantalum metal particles (5-15 μm) Second tantalum metal particles (55-75 μm) Third tantalum metal particles (45-55 μm) Base coating 100 0 0 Intermediate coating 50 0 50 Surface coating 10 40 50

Next, after performing atmospheric plasma spraying to sequentially form a bottom layer 21 with a thickness of 150 μm, a middle layer 23 with a thickness of 150 μm, and a surface layer 22 with a thickness of 200 μm using the bottom layer coating, the middle layer coating, and the surface layer coating, the surface roughness, porosity, and coating cross-sectional morphology of the medical implant 1 subjected to the surface treatment are analyzed.

This test is to compare the effect of temperature control (during spraying, the temperature difference between the highest and lowest temperature points of the surface is controlled to be no more than ±5%, and after spraying, the surface temperature is controlled to be the cooling temperature) on the formed tantalum coating 2 under the same tantalum coating material and the same thickness of each layer.

The results show that under the condition of temperature control, the surface roughness of the medical implant 1 after the surface treatment is 113 μm and the porosity is 26%. Compared with the surface roughness (198 μm) and porosity (30%) of the medical implant 1 after the surface treatment under the condition of no temperature control, both meet the standards (the surface roughness is between 50 and 200 μm, and the porosity is between 10 and 35%).

However, please refer to FIG. 5 , in the cross-sectional morphology of the medical implant 1 subjected to the surface treatment under the condition of temperature control, the tantalum metal coating 2 formed on the medical implant 1 can be observed, but in FIG. 6 , the tantalum metal layer 2 cannot be observed on the medical implant 1 subjected to the surface treatment under the condition of not performing temperature control, indicating that the tantalum metal coating 2 cannot be effectively formed on the surface of the medical implant 1 when temperature control is not performed.

In addition, in order to verify that the tantalum coating 2 can be effectively formed by spraying multiple passes of the intermediate layer coating, multiple tantalum coatings are formed according to the proportions shown in Table 2, including a bottom layer coating for forming the bottom layer 21 and a surface layer coating for forming the surface layer 22. For the convenience of subsequent understanding, the remaining intermediate layer coatings for forming the multiple intermediate layers 23 are respectively referred to as "first intermediate layer coating", "second intermediate layer coating", "third intermediate layer coating" and "fourth intermediate layer coating".

Table 2. Particle size ratio of tantalum metal particles in each tantalum metal coating in this test Proportion (weight percentage) First, tantalum metal particles (5-15 μm) Second tantalum metal particles (55-75 μm) Third tantalum metal particles (45-55 μm) Base coating 100 0 0 First intermediate coating 50 0 50 Second intermediate coating 10 40 50 Third intermediate coating 100 0 0 Fourth intermediate coating 50 0 50 Surface coating 10 40 50

Next, atmospheric plasma spraying is performed to form a bottom layer 21 with a thickness of 150 μm with the bottom layer coating, and then the first intermediate layer coating, the second intermediate layer coating, the third intermediate layer coating and the fourth intermediate layer coating are respectively formed to form an intermediate layer 23 with a total thickness of 250 μm (the thicknesses formed by each tantalum metal coating are 50 μm, 50 μm, 50 μm and 100 μm, respectively), and finally the surface layer coating is used to form a surface layer 22 with a thickness of 100 μm, and the surface roughness, porosity and coating cross-sectional morphology of the medical implant 1 subjected to the surface treatment are similarly analyzed.

The results show that the bottom layer 21 formed by the bottom layer coating, the middle layer 23 formed by the first middle layer coating, the second middle layer coating, the third middle layer coating and the fourth middle layer coating, and the surface layer 22 formed by the surface layer coating can also together constitute the tantalum coating 2 located on the surface of the medical implant 1, and the surface roughness of the medical implant 1 after the above-mentioned surface treatment is 72 μm and the porosity is 18%, which also meets the specifications (surface roughness is between 50 and 200 μm, and the porosity is between 10 and 35%).

Furthermore, please refer to FIG. 7 , which is similar to the above results. In the cross-sectional morphology of the medical implant 1 subjected to the surface treatment under temperature control, a tantalum metal coating 2 formed on the surface of the medical implant 1 can be observed.

In summary, the surface treatment method of the medical implant of the present invention forms the base layer using a base coating composed of first tantalum metal particles with a smaller particle size, and forms the surface layer using a surface coating containing first tantalum metal particles with a smaller particle size and second tantalum metal particles with a larger particle size, so that the medical implant can have good density and porosity at the same time, thereby achieving the effect of improving the implantation effect of the medical implant.

Furthermore, by controlling the surface temperature of the medical implant 1, the surface of the bottom layer 21 and/or the surface of the middle layer 23 to maintain a certain value in the bottom layer forming step S2, the surface layer forming step S3 and the middle layer forming step S4, the bottom layer 21, the surface layer 22 and the middle layer 23 can be uniformly formed, so that the tantalum coating 2 can be effectively formed on the surface of the medical implant 1.

In addition, the medical implant of the present invention is obtained by treating the surface of the medical implant as described above. Thus, the tantalum metal coating can promote cell attachment to the medical implant when implanted in the human body, thereby improving the proliferation and differentiation ability of cells, thereby achieving the effect of enhancing the biocompatibility and therapeutic effect of the medical implant.

Although the present invention has been disclosed using the above preferred embodiments, they are not intended to limit the present invention. Any person skilled in the art can make various changes and modifications to the above embodiments without departing from the spirit and scope of the present invention, and the scope of protection of the present invention includes all changes within the meaning and equivalent scope of the attached patent application. In addition, when the above several embodiments can be combined, the present invention includes any combination of implementations.

[The present invention] 1: Medical implant 2: Titanium coating 21: Base layer 22: Surface layer 23: Intermediate layer S1: Implant providing step S2: Base layer forming step S3: Surface layer forming step S4: Intermediate layer forming step

[Figure 1] A method flow chart of the first embodiment of the surface treatment method of the medical implant of the present invention. [Figure 2] A schematic diagram of the medical implant obtained by the first embodiment of the surface treatment method of the medical implant of the present invention. [Figure 3] A method flow chart of the second embodiment of the surface treatment method of the medical implant of the present invention. [Figure 4] A schematic diagram of the medical implant obtained by the second embodiment of the surface treatment method of the medical implant of the present invention. [Figure 5] A cross-sectional morphology of the coating of the medical implant of the present invention that has been surface treated under temperature control. [Figure 6] A cross-sectional morphology of the coating of the medical implant of the present invention that has been surface treated without temperature control. [Figure 7] A cross-sectional morphology of the coating layer of the present invention after multiple passes of intermediate layer coating spraying under temperature control.

S1: Implant provision step

S2: Bottom layer formation step

S3: Surface layer formation step

Claims (19)

A surface treatment method for a medical implant comprises: At a substrate bonding temperature, spraying a base coating onto the surface of a medical implant, and solidifying the base coating on the surface of the medical implant at a cooling temperature to form a base layer; and At the substrate bonding temperature, spraying a surface coating onto the base layer, and solidifying the surface coating on the base layer at the cooling temperature to form a surface layer, wherein the base layer and the surface layer together form a tantalum coating; The bottom coating is composed of a first tantalum metal particle, and the first tantalum metal particle is in a completely molten state at the substrate bonding temperature. The surface coating includes the first tantalum metal particle and a second tantalum metal particle. The particle size of the first tantalum metal particle is smaller than that of the second tantalum metal particle, and the second tantalum metal particle is in a partially molten state at the substrate bonding temperature. A surface treatment method for a medical implant as claimed in claim 1, wherein, when spraying the base coating, the temperature difference between the highest temperature and the lowest temperature of the surface of the medical implant is controlled to be no more than ±5%, and when spraying the surface layer coating, the temperature difference between the highest temperature and the lowest temperature of the surface of the base layer is controlled to be no more than ±5%. A surface treatment method for a medical implant as claimed in claim 1, wherein the surface layer coating contains more than 10% by weight of the first tantalum metal particles. A surface treatment method for a medical implant as claimed in claim 3, wherein the surface layer coating contains less than 90% by weight of the second tantalum metal particles. A surface treatment method for a medical implant as claimed in claim 3, wherein the surface coating further comprises a third tantalum metal particle, the particle size of the third tantalum metal particle is between the particle size of the first tantalum metal particle and the particle size of the second tantalum metal particle, and the total weight of the second tantalum metal particle and the third tantalum metal particle accounts for less than 90% of the surface coating. The surface treatment method of the medical implant as claimed in claim 1 further comprises: After forming the base layer, spraying an intermediate layer coating containing the first tantalum metal particles onto the base layer at the substrate bonding temperature, and forming an intermediate layer on the base layer with the intermediate layer coating at the cooling temperature, and then forming the surface layer with the surface layer coating on the intermediate layer, and the base layer, the intermediate layer and the surface layer together form the tantalum metal coating. A surface treatment method for a medical implant as claimed in claim 6, wherein, when spraying the intermediate layer coating, the temperature difference between the highest temperature and the lowest temperature of the surface of the bottom layer is controlled to not exceed ±5%. A surface treatment method for a medical implant as claimed in claim 6, wherein the intermediate layer coating further comprises a third tantalum metal particle, and the particle size of the third tantalum metal particle is between the particle size of the first tantalum metal particle and the particle size of the second tantalum metal particle. A surface treatment method for a medical implant as claimed in claim 8, wherein the intermediate layer coating contains more than 10% by weight of the first tantalum metal particles and less than 90% by weight of the third tantalum metal particles. A surface treatment method for a medical implant as claimed in claim 8, wherein the intermediate layer coating further comprises the second tantalum metal particles. A surface treatment method for a medical implant as claimed in claim 10, wherein the intermediate layer coating contains more than 10% by weight of the first tantalum metal particles, and the total weight of the second tantalum metal particles and the third tantalum metal particles accounts for less than 90% of the intermediate layer coating. A surface treatment method for a medical implant as claimed in any one of claims 1 to 11, wherein the particle size of the first tantalum metal particles and the second tantalum metal particles is between 5 and 75 μm. A surface treatment method for a medical implant as claimed in claim 12, wherein the particle size of the first titanium metal particles is between 5 and 15 μm, and the particle size of the second titanium metal particles is between 55 and 75 μm. A surface treatment method for a medical implant as claimed in any one of claims 5 and 8 to 11, wherein the particle size of the third tantalum metal particles is between 5 and 75 μm. A surface treatment method for a medical implant as claimed in claim 14, wherein the particle size of the third tantalum metal particles is between 45 and 55 μm. A surface treatment method for a medical implant as claimed in any one of claims 1 to 11, wherein the thickness of the base layer does not exceed one third of the total thickness of the tantalum metal coating. A surface treatment method for a medical implant as claimed in any one of claims 1 to 11, wherein the substrate bonding temperature is between 2900 and 3100°C. A surface treatment method for a medical implant as claimed in any one of claims 1 to 11, wherein the cooling temperature is between 50 and 300°C. A medical implant is obtained by treating the surface of the medical implant according to any one of claims 1 to 18, wherein the surface of the medical implant has the tantalum metal coating.