阅读说明：本技术 用于植入物组件的延性涂层 (Ductile coatings for implant components ) 是由 H·D·林克 理查德·卡萨扎尔 于 2020-04-24 设计创作，主要内容包括：本发明涉及一种用于植入物组件的涂层、一种用于生产具有所述涂层的植入物组件的方法、以及所述涂层在植入物组件上的用途。该涂层旨在用于植入物组件,特别是脊椎植入物组件,并且该涂层是一种TiNb涂层,该TiNb涂层除了具有Ti的原子％比例和Nb的原子％比例之外,Ag的原子％比例为5-30原子％。(The present invention relates to a coating for an implant component, a method for producing an implant component having said coating, and the use of said coating on an implant component. The coating is intended for implant components, in particular spinal implant components, and is a TiNb coating having an atomic% proportion of Ag of 5-30 atomic% in addition to an atomic% proportion of Ti and an atomic% proportion of Nb.)

1. An implant component at least partially coated with a coating, wherein the coating is a TiNb coating having an atomic% proportion of Ti and an atomic% proportion of Nb, wherein the coating additionally has an atomic% proportion of Ag of 1-25 at% and the implant component with the coating is plastically deformable.

2. The implant component of claim 1, wherein the coating has 1.5-15 at% Ag, 1.5-5 at% Ag, or about 2 at% Ag.

3. The implant component of claim 1 or 2, wherein the coating has 5-40 at% Nb, 10-30 at% Nb, 15-25 at% Nb, or about 18 at% Nb.

4. The implant assembly of one of claims 1 to 3, wherein Ag and TiNb are formed on the coating surface in close proximity to each other.

5. The implant assembly of one of the preceding claims, wherein the coating has a thickness of 2.5-6 μ ι η, 3.5-5.5 μ ι η, or about 4.5 μ ι η.

6. The implant component of one of the previous claims, wherein the TiNb coating is present substantially as a non-stoichiometric TiNb layer.

7. Implant assembly according to one of the preceding claims, wherein the implant assembly is a bone plate or a spinal implant assembly, in particular a component of a spinal fusion implant and/or a linkage of a spinal fusion implant.

8. The implant assembly according to one of the preceding claims, wherein the surface of the coated portion has TiNb in which Ag islands are embedded.

9. Implant assembly according to one of the preceding claims, wherein the implant assembly to be coated has a titanium alloy, and preferably consists of a titanium alloy.

10. A method for producing an implant assembly according to one of the preceding claims, wherein the method comprises the following steps:

-providing an implant component to be coated in a coating chamber;

-providing at least one target such that a predetermined atomic% ratio of titanium, niobium and silver is produced upon evaporation;

-providing an inert atmosphere;

-evaporating the at least one target; and

-simultaneously coating the implant assembly with the evaporated metal of the at least one target; and

-plastically deforming the coated implant component prior to implantation.

11. The method for applying an implant coating according to claim 10, wherein the at least one target is evaporated by means of arc evaporation and in the process the voltage applied to the target is 15-30V or 20-25V and the current applied is 40-70A.

12. The method according to claim 10 or 11, wherein after providing the implant to be coated in the coating chamber, the implant surface to be coated is purged by glow discharge under a hydrogen atmosphere.

13. Method according to one of claims 10 to 12, wherein the implant surface to be coated is cleaned by bombarding the implant surface with ions under an inert atmosphere after introducing the implant to be coated into the coating chamber.

14. Use of an implant assembly according to one of claims 1 to 9, wherein the use comprises plastic deformation of the implant assembly coated with the coating prior to implantation.

Technical Field

The present invention relates to an implant component with a TiNb-Ag coating, to a method for the application of such a coating and to the use of such a coating on an implant.

Background

One reason for implant failure in situ (in situ) is pathogen infection. This pathogen is primarily Staphylococci (staphylocci), such as Staphylococcus epidermidis (staphyloccus epidermidis), which are parasitic on the skin and mucous membranes of humans. Furthermore, pathogens such as staphylococcus epidermidis, among others, can colonize the implant surface with a biofilm. Thus, this biofilm protects pathogens from antibiotics, phagocytes and other immune responses of the body.

Studies have shown that, for example, staphylococcus epidermidis is a common cause of postoperative infection after implantation of an implant. In diagnosing post-operative infections, it is often the first attempt to inhibit the infection with an active substance (e.g., an antibiotic). If this is not successful, the implant may need to be removed. Removing the implant will remove the source of infection as much as possible. While this may result in a more effective treatment for the infection, there are also consequences of a reduced mobility of the patient.

An additional difficulty in the case of S.epidermidis infections is that this microorganism is often antibiotic-resistant (80% according to Takizawa et al in SPINE Vol.42, No. 7, p.525-530). According to Takizawa, in the field of spinal surgery, there is evidence that a pathogen called Methicillin-resistant Staphylococcus epidermidis (MRSE) presents a risk that is only detected at a later stage because it is inherently low-toxic, initially showing fewer signs of infection. In the worst case, this may lead to a higher incidence of the patient post-surgery than before surgery, especially if the infection prevents further use of the implant.

To avoid these complications, it is therefore desirable to resist actual colonization by pathogens. Thus, US2009/0198343a1 suggests providing a coating for an artificial joint, intended for a metal-paired working surface, with an antibacterial effect. To achieve this, in US2009/0198343a1, the chromium nitride coating is supplemented with silver by alternately coating the friction surface of the implant with chromium nitride and silver. However, chromium nitride is classified as an sensitizer, and thus there is a risk that an allergic reaction may occur after implantation. Furthermore, the coating disclosed in US2009/0198343a1 is only effective to a very limited extent against colonization by staphylococcus epidermidis. In a review of the literature, Lin Xiao et al ("Orthopaedic animal biological with bone antibiotic and anti-infection peptides and associated in vivo evaluation methods. Nanomedicine: NBM 2017, Vol.13, pages 123. sup. -, 142, ISSN 1549. sup. -, 9634) compared the antibacterial and osteogenic properties of various biomaterials. WO 2015/150186a1 relates to an implant assembly with a connection part which is at least partially coated with a TiNb coating.

In addition to this, in fact, for most implant components, it is desirable to be able to accommodate the implant component by bending before introduction into the patient. In other words, these implant components are designed to be plastically deformable so that they can adapt to the environment of the implant component or the position of other implant components. These properties are particularly advantageous for rods in the spinal region and bone plates used to treat bone fractures. However, nitride coatings in particular can only be used for this purpose to a limited extent, since nitride coatings are not only relatively hard but also relatively brittle. As a result, plastic deformation of the implant components provided with nitride coatings can lead to damage of the coatings. As a result, increased amounts of metal ions, metal oxides, organo-metal phosphates and small metal particles may be released and may cause pain, aseptic loosening of the implant components, or negative effects on surrounding tissue. This may also lead to allergic reactions, which may also require the repair of the implant.

Disclosure of Invention

It is therefore an object of the present invention to provide a coating for an implant surface that prevents infection in situ. In particular, it is an object of the present invention to provide a coating for an implant surface that is resistant to colonization by pathogens, in particular staphylococcus epidermidis. Another object is that the coated implant surface does not cause any allergic or hypersensitivity reactions in the patient. Furthermore, the coated implant surface should be able to withstand any mechanical influences, in particular mechanical influences caused by plastic deformation of the implant component, so that an implant component with such a coating can adapt to the anatomical environment of the implantation site.

In view of these objects, the claims define a coating for an implant component, a method for producing an implant component with said coating, and the use of said coating on an implant component.

The coating is intended for implant components, in particular spinal implant components, and is a TiNb coating having, in addition to an atomic% proportion of Ti and an atomic% proportion of Nb, an atomic% proportion of Ag of 1-25 at%.

The proportion of Ag present in such a coating prevents infection by pathogens. In this respect, antimicrobial action against Staphylococcus epidermidis has been demonstrated in particular. The person skilled in the art will understand that the present coating is a coating applied by a technical, machine-based method, wherein the coating is produced during the production of the implant.

Furthermore, the proportion of atomic% of Ag (i.e. the proportion of silver) within the above-defined range does not lead to any significant reduction in the mechanical resistance of the coating, so that the coating is sufficient to withstand the mechanical contact forces occurring during implantation. It is believed that the mechanical resistance remains at such a level, since the proportion of silver has a limited effect on ductility. This prevents the implant material or the base material of the implant, which is located below the coating, from coming into contact with the body tissue of the patient and possibly causing hypersensitivity reactions.

Because of the resistance and ductility of silver, titanium-niobium coatings with a proportion of silver (i.e., TiNb-Ag coatings) are particularly suitable for structural implants that support or replace portions of bone when introduced into a patient. An example of such a structural implant is a rod-like connecting element that is used in spinal fusion (spinal fusion) for the spinal column (spinal column) region in order to fix two vertebrae with respect to each other. Such connecting elements are generally plastically deformed prior to fixation in the body in order to fix the vertebrae in a particular position relative to one another. Due to ductility, the coating remains intact during plastic deformation; this may therefore prevent the release of alloy constituents into the patient which may otherwise lead to hypersensitivity. In other words, substantially no tearing or chipping occurs during coating due to plastic deformation, i.e. the coating is substantially plastic at least to a certain extent even in the deformed state, such that the coating material of the implant component is sealed in the coating area.

The implant component is plastically deformable with the coating. Thus, the ductility of the coating is preferably the same as or greater than the ductility of the material of the implant component. The coating had the following properties: the coating substantially only plastically deforms so long as the implant component is plastic to the deformation of the anatomical environment of the implantation site. This means that the seal of the implant component by the coating remains intact by plastic deformation (without breakage).

It would be advantageous if the coated implant component could not be exposed to rubbing against another implant component in the patient's body due to alternating or expansive loading of the implant components. In other words, there should be substantially no relative movement between the coated implant component and the adjacent implant component, such as is the case in the articular surface of an articular replacement.

It should be noted, however, that the coating may also be advantageously used in other implant components that are exposed to strong elastic or plastic bending. This includes, for example, bone plates for healing bone fractures, and which, like the rod-shaped connecting elements described above in the spinal column (spinal column) region, adapt to the anatomical environment by plastic deformation directly prior to their final implantation. A particularly advantageous, further embodiment of the present coating is a flexible tab, for example for a partial pelvic prosthesis. These implant components all share the common feature that they can adapt to the anatomical environment of the implantation site by plastic deformation (i.e., permanent, substantially failure-free deformation). This improves the functionality of the implant assembly without increasing the cost of the implant assembly in the process.

In a preferred embodiment, the coating has 1.5 to 15 atomic% Ag, 1.5 to 5 atomic% Ag, or about 2 atomic% Ag.

These preferred proportions of silver in the coating satisfy the above requirements. In terms of hardness, the lower the proportion of silver, the greater the hardness. However, as mentioned above, the reduction in hardness does not substantially affect the resistance and ductility of the coating.

In a further preferred embodiment, the coating has 5-40 at% Nb, 10-30 at% Nb, 15-25 at% Nb, or about 18 at% Nb.

These preferred ratios of niobium prevent hypersensitivity reactions in the patient and additionally provide the necessary ductility so as not to be substantially damaged by plastic deformation that occurs during intervention.

As described above, the remaining proportion other than the Ag proportion and the Nb proportion is substantially occupied by Ti. In this context, essentially means that production-related impurities from other compounds may be present, but not exceeding a proportion of 3%, 2% or 1% by atomic%. In the present coating, Ti preferably has the highest atomic% proportion. In particular, the atomic% proportion of titanium is preferably 65 to 90 atomic%, 75 to 85 atomic%, or about 80 atomic%.

In one embodiment, Ag and TiNb are formed adjacent to each other on the coating surface.

In this way, the proportion of Ag can better exert the anti-infection effect of Ag. In order to achieve such surface juxtaposition of the coating and thus direct contact with the patient's tissue or fluid, it is preferred to apply both coating components simultaneously. Such simultaneous application also means that the coating components are additionally, substantially homogeneously distributed over the implant surface.

In preferred embodiments, the coating has a thickness of 2.5-6 μm, 3.5-5.5 μm, or about 4.5 μm.

It has been determined that these coating thicknesses prevent at least continuous damage to the coating. Here, thicker coatings tend to be advantageous. On the other hand, thicknesses exceeding these values do not provide any particular improvement, but may promote non-uniformity and delamination of the coating. It is believed that the mechanical resistance of the coating at a given thickness is also due to the fact that there are no continuous portions of silver in the thickness direction. In other words, the three-dimensional heterogeneous structure of the TiNb-Ag coating means that in principle a continuous TiNb coating is present.

In one embodiment, the TiNb coating exists substantially as a non-stoichiometric TiNb layer.

Such a layer forms together with the proportion of silver a particularly homogeneous inert layer with antimicrobial action, effectively acting against hypersensitivity and infections after implant implantation.

Furthermore, an implant assembly, in particular a spinal implant, is provided, which is at least partially coated with a coating according to one of the above embodiments.

As mentioned above, infections may occur, in particular, due to exposure of the implant to the environment prior to implantation. In this regard, it has been determined (particularly in the area of the spinal column) that such infections are commonly caused by the pathogen staphylococcus epidermidis. As a result, the preventive action of the coating according to the invention is particularly effective here.

It is emphasized that the displacement of the coating structure caused by the bending has substantially no effect on the infection-inhibiting effect of the coating.

In a preferred embodiment, the implant component is a component of a spinal fusion implant, and in particular a linkage rod of such a spinal fusion implant.

In the case of spinal fusion implants, the connecting rod connecting at least two vertebrae for reinforcement is particularly preferably provided with a coating according to the invention.

In a particularly preferred embodiment, the surface of the coated portion has TiNb with Ag islands (Ag island) embedded therein.

As mentioned above, this distribution of TiNb and silver in the coating makes it possible to produce a substantially continuous TiNb coating, since the embedded Ag islands typically do not extend through the entire coating thickness. This achieves sufficient mechanical resistance or hardness of such a coating, since TiNb has a greater hardness than Ag in the coating.

In a further preferred embodiment, the implant component to be coated has a titanium alloy and preferably consists of said titanium alloy.

First, because of the proportion of TiNb, the TiNb-Ag coating adheres particularly well to the titanium alloy of such implant components, thereby preventing detachment of the coating. Second, the implant component to be coated, which is made of a titanium alloy, further reduces the risk of hypersensitivity, since such hypersensitivity is unlikely to occur even in case the coating is damaged, due to the biocompatibility of titanium. In this embodiment, the adhesion of the coating can be further improved by applying a coating comprising substantially only Ti as an adhesion promoting coating before the TiNb-Ag coating.

There is also provided a method for producing an implant component having a coating as described above, the method comprising the steps of: providing an implant component to be coated, in particular for a spinal implant, in a coating chamber; providing at least one target such that a predetermined atomic percent ratio of titanium, niobium, and silver is produced upon evaporation; providing an inert atmosphere; evaporating the at least one target; and simultaneously coating the implant assembly with the evaporated metal of the at least one target.

The method enables simultaneous coating with titanium, niobium and silver to form a TiNb-Ag coating. While the coating ensures that the silver is exposed at the surface of the coating, the implant component can thus exert an infection-inhibiting effect of the coating in the implanted state. Furthermore, by selecting the number of individual targets of the coating assembly, the atomic% proportion of the coating composition can be adjusted to the desired composition of the coating, at least on the order of magnitude of the targets. Here, the atomic% ratio of the coating components produced during evaporation substantially corresponds to the desired atomic% ratio of the coating applied to the implant component.

Alternatively or in addition to the composition of the coating being adjusted by the number of individual targets, at least one target having a specific ratio of titanium and silver may be provided. Preferably, however, only one or more targets are used, which have a specific atomic% proportion of titanium, niobium and preferably silver, corresponding to the desired composition of the coating.

In a preferred embodiment, the at least one target is evaporated by means of arc evaporation. In this process, the voltage applied to the target is 15-30V or 20-25V and the current applied is 40-70A.

These set ranges of voltage and current make it possible to adjust the coating composition just like the number of targets for each coating composition described above. In particular, the ratio obtained by selecting the number of targets can be more finely adjusted.

In a further embodiment, after providing the implant to be coated in the coating chamber, the implant surface to be coated is purged by glow discharge under a hydrogen atmosphere.

This purification step has the advantage of removing any organic residues that may be present on the surface of the implant to be coated, thereby improving the adhesion of the coating to the implant.

In one embodiment, after the implant to be coated is introduced into the coating chamber, the implant surface to be coated is decontaminated by bombarding the implant surface with high energy ions under an inert atmosphere.

As a result, the oxide layer present on the surface of the implant is removed, which otherwise reduces the adhesion of the coating to the implant.

For example, such an oxide layer is formed on an implant made of a titanium alloy and can be removed in particular by bombardment with argon ions and titanium ions by the method steps of the present embodiment. Here, the titanium ions may be preferably generated from a Ti target for coating. The inert atmosphere (e.g., argon atmosphere) here resists the reformation of the oxide layer.

In a particular embodiment of the production method, the method further comprises the step of plastically deforming the coated implant component prior to implantation.

This plastic deformation makes it possible to prepare the shape of the now coated implant component to the shape in the patient's body at the time of introduction into the patient's body or before.

Furthermore, the use of the above-mentioned coating for preventing biofilm on implants, in particular spinal implants, is provided.

As mentioned above, this use of the coating is particularly advantageous.

Detailed Description

As mentioned above, a coating in the context of the present invention is understood to mean a coating which is used by technical methods. Examples of such technical processes are Chemical Vapor Deposition (CVD), Physical Vapor Deposition (PVD) or galvanic coating processes.

As mentioned above, the coating according to the invention comprises a mixture of titanium-niobium coatings doped with silver (TiNb-Ag coating). In other words, the coating has at least one monolayer of a titanium niobium coating in which silver is embedded. Here, silver is present in particular in the form of silver islands, i.e. silver or silver atoms are arranged in the immediate vicinity of the TiNb lattice.

Due to the size of the silver atoms, it is assumed that only a small portion of the silver (if any) is disposed in interstitial spaces within the TiNb lattice. Instead, silver was observed to be present in the TiNb-Ag coating in the form of silver agglomerates. In other words, silver is not substantially integrated into the TiNb lattice. The silver agglomerates are preferably present in a size in the range of 1 μm to 50 μm, and more preferably in a size in the range of 5 μm to 30 μm.

Furthermore, it is assumed that the efficacy of silver comes in particular from the following facts: in the implanted state of the implant component, silver is converted into an ionic state by local elemental formation when it comes into contact with body fluids, and thus exerts the antibacterial effect of silver. Such local element formation is made possible by the above-described arrangement of silver islands (Ag islands) on the coating surface. This arrangement is achieved by coating the implant with titanium, niobium and silver simultaneously.

Due to the antibacterial properties of the coating, the coating has an infection-inhibiting effect, which is particularly relevant to staphylococcus epidermidis. It is believed that the proportion of silver of the coating present in the TiNb matrix disrupts the formation of biofilms grown by these bacteria. Due to this disruption, the protective mechanism of the bacteria against antibiotics by such biofilms is at least no longer fully functional, and the bacteria can thus be inhibited.

Further, it was observed that silver could be dissolved from the coating in ionic form. It is assumed that these silver particles ionized at the surface of the coating form an active zone (inhibition zone) in the immediate environment of the implant, where the silver particles exert an antibacterial effect. Thus, the coating may serve not only to prevent infection spreading directly from the implant surface, but also to prevent infection occurring in the surroundings of the implant assembly.

The TiNb-Ag coating with silver content of 5-30 atom% has antibacterial effect. This is particularly effective against Staphylococcus epidermidis. As mentioned above, such pathogens are commonly found on human skin and may therefore be a common cause of infection after implantation. Studies have shown that this pathogen causes an increased risk of serious infection after implantation, especially in the spinal region. This may be due to the fact that staphylococcus epidermidis has relatively low toxicity among staphylococci. This results in signs of infection appearing only in late stages and may be overlooked in early stages. Since the coating has a particularly inhibitory effect on this pathogen, it is possible to prevent infections which are detected only at a late stage, in particular for the reasons mentioned above.

Preferably, the atomic% proportion of silver and/or the atomic% proportion of niobium is less than the atomic% proportion of titanium. In other words, there is no need for a stoichiometric distribution. The distribution of the coating components may be superstoichiometric or substoichiometric. Overall, the coating has a proportion of TiNb of at least 80 atomic%, in particular a proportion of TiNb of at least 90 atomic%. The atomic% proportion of titanium is preferably 65 to 90 atomic%, 75 to 85 atomic% or about 80 atomic%.

A maximum proportion of Ag of 25 at% ensures that TiNb has silver deposits or islands, but not the opposite. This has the advantage of providing TiNb as a substantially continuous coating in which the silver is embedded. As a result, as described above, there are preferably no areas on the coating where the silver islands extend completely through the thickness of the coating. Thus, the dissolution of silver does not substantially adversely affect the functionality and integrity of the coating.

Other preferred silver proportions for the present coating, for example a proportion of silver of 1.5 to 15 atomic%, 1.5 to 5 atomic% or about 2 atomic%, also have this advantage. This structure of the coating results in particular in the presence of at least a proportion of silver in the immediate vicinity of the proportion of TiNb on the surface of the coating, in particular in the coating process described below.

In addition to the above-mentioned antibacterial effect, the proportion of silver together with the proportion of TiNb as a TiNb-Ag coating does not cause substantial changes in the mechanical properties associated with pure TiNb coatings. Thus, it still has a sufficiently high hardness to prevent damage during handling of the implant during implantation, while having sufficient ductility that it does not substantially compromise the integrity of the coating upon elastic or plastic deformation of the implant. As a result, the TiNb-Ag coating can prevent both infection and at least excessive release of alloy components that might otherwise cause hypersensitivity in the patient.

It is believed that not only the hardness but also the ductility supports the mechanical resistance or strength of the coating, so that it can withstand the mechanical influences that occur during implantation of the implant assembly. Such mechanical influence occurs, for example, when the implant component produces a press fit in the bone tissue, by contact of the implant component with a fastening element (for example when screwing in a bone screw for fastening a plate or a clamp), or in particular plastic deformation of the implant component. Such loading can occur in spinal regions, for example, during assembly of implant components (e.g., to construct a spinal fusion). Also in the treatment of bone fractures, such loads on the implant assembly occur during implantation.

For these reasons, the present coatings are particularly useful for implant components that support a patient's bone or replace portions of the bone after implantation. For such implant components, mechanical loading of the coating typically occurs during implantation and assembly of the implant. After implantation, stresses and strains can occur in the coating of the implant components, particularly as a result of the daily loading of the implant within the patient. The present coating can also withstand such stresses and strains.

In other words, the coating is firstly suitable for implant components, wherein the friction mainly occurs during implantation and/or assembly of the implant and the coating in the implanted state is substantially not subject to functionally induced friction. For this purpose, it has been established that a coating thickness of less than 10 μm, in particular from 2.5 to 6 μm, preferably from 3.5 to 5.5 μm, more preferably about 4.5 μm, is sufficient. Nevertheless, it is also conceivable to use such a coating with a greater layer thickness.

Furthermore, in the present coating, the difference in material properties (in particular elasticity) from the underlying substrate of the implant can be partially reduced by the proportion of silver. This also provides sufficient mechanical resistance and adhesion of the coating. Furthermore, especially for this reason, the coating can be applied to a variety of different implant materials, including not only metal alloys, but also polymers, such as polyethylene or PEEK. Thus, the present coating may particularly improve the resistance of implant components made of polymers.

Overall, the TiNb-Ag coating thus exhibits advantageous antimicrobial properties and advantageous mechanical properties, which are very useful for patients of implants or implant components at least partially coated with the coating.

As already discussed above, such coatings are produced in particular by using a physical vapor deposition method (PVD method).

For this purpose, the implant component to be provided with the coating is purged, preferably with water, before being introduced into the coating chamber.

The implant is placed in a coating chamber that is subsequently evacuated. For subsequent processes, the implant is preferably heated to 400 to 600 ℃ in order to improve the ion mobility at the surface of the implant and to achieve better adhesion of the coating on the implant.

The surface of the implant component is preferably decontaminated in a coating chamber prior to application of the coating. For example, purging by glow discharge may be performed under a hydrogen atmosphere in order to remove any organic residues on the uncoated implant surface.

Furthermore, the surface of the implant component can be cleaned by means of ion etching. The implant component is bombarded with ions (for example, titanium ions or argon ions) in an inert atmosphere, in particular an argon atmosphere, in order to remove an oxide layer present at the surface of the uncoated implant material. This also achieves better adhesion of the coating to the surface of the implant.

Each of the above purification steps is superiorIs selected at 10^-1To 10^-4Under a negative pressure mbar.

After optional purging by at least one of the above-mentioned purging steps, the coating is also applied to the implant component under an inert atmosphere, in particular under an argon atmosphere.

As already described, the coating can be produced with at least one silver target, at least one niobium target and at least one titanium target, depending on the desired composition of the coating. One or more targets having atomic% proportions of titanium, niobium and/or silver for the coating may likewise be used. In other words, a target consisting of at least two coating components, in particular a target consisting of the desired atomic% proportions of titanium and silver, can be used. Thus, the composition of the coating is at least partially determined by the composition of the target.

In order to keep the evaporated target material scattered on the gas particles in the coating chamber and thus to minimize the loss of target material, the coating 10^-2To 10^-3Under reduced pressure of mbar.

Once the desired atmosphere is set, the process of evaporating at least one target is started. Particularly preferably, for this purpose, an arc is used which dissolves the material from the target and moves it into the gas phase by means of a strong current through the discharge. For this discharge, in particular a voltage in the range of 15-30V, and preferably a voltage in the range of 20-25V, and a current in the range of 40-70A are used. However, it will be appreciated by those skilled in the art that other processes may be used to evaporate the target, such as thermal evaporation, electron beam evaporation or laser beam evaporation.

At least during part of the coating, even if a plurality of targets made of different materials are used, the coating with these targets is performed simultaneously so as to form the island-like structure of the above-described TiNb-Ag coating.

Depending on the substrate of the implant to be coated, a negative voltage of 100V to 1500V may also be applied to the substrate in order to improve adhesion and layer uniformity. The target and the implant can also be moved relative to each other during the coating process in order to achieve a coating that is as uniform as possible.

After the coating and cooling stages, the coating chamber is again vented and one or more coated implants may be removed. Cooling is preferably performed with the support of a gas atmosphere (e.g., nitrogen or inert gas) to improve heat dissipation, thus speeding up the cooling process.