JPH01299562A - Composite implant member - Google Patents

Abstract

PURPOSE:To provide an implant member which improves mechanical performance, affinity for an organism, and safety and bas excellent rapid tendency of sticking to a bone tissue, by a method wherein spattering is made on a specified composition form forming a glass serving as a target to form a glass- covered layer on a metallic base material surface. CONSTITUTION:In an implant member, spattering is effected a composition for forming a glass, serving as a target for spattering, in which a composition (100% in total) consisting of 42-53% CaO, 22-41% P2O2, and 10-27% P2O5 amounts for at least 90% of a total component. After an amorphous glass- covered layer is formed on a metallic material surface, an apatite phase [Ca10(PO4)6O] and a wollastonite phase (CaO.SiO2) are deposited in a well balanced manner in a crystallized glass-covered layer by heat treatment. In this case, it is desirable that heat treatment is effected at 900-1200 deg.C.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a composite implant member that can be widely used for artificial bones, 9 artificial interstices, 0 artificial tooth roots, etc., and specifically, has high mechanical performance and The present invention relates to a composite implant member that does not elute harmful substances and has excellent affinity with living tissue, particularly bonding with bone tissue.

[Prior Art] Implant members such as artificial bones, artificial joints, and artificial tooth roots are in practical use as prosthetics or replacements for teeth, joints, bones, etc. that are damaged or missing due to complex fractures or diseases such as bone tumors or hypoxia. has been made into Such implant materials include cobalt-chromium alloy, stainless steel,
Metal materials such as titanium, titanium alloys, and tantalum, ceramic materials such as alumina and apatite, and polymer materials such as high-density polyethylene have been widely used.

However, while metal materials have excellent toughness and impact resistance, they have poor compatibility with living tissues.
Furthermore, if it is implanted into the human body for a long period of time, trace amounts of metal ions may gradually elute and have an adverse effect on living tissue.

Furthermore, among ceramic materials, alumina has a relatively high mechanical strength but has poor affinity with living tissues, and conversely, apatite has good affinity with living tissues but has low mechanical strength. This problem has been pointed out.

Furthermore, although polymeric materials do not seem to have any harmful effects on living organisms, problems remain in terms of mechanical strength.

In this way, conventional implant materials have advantages and disadvantages.
It cannot be said that it satisfies all of the performance requirements such as mechanical strength, compatibility with living tissue, and no adverse effects on living organisms, and this has been a major bottleneck in promoting generalization.

On the other hand, no single material has been found that satisfies all of the above required properties. Therefore, various studies are being conducted in the direction of satisfying these required properties by combining known materials.For example, ceramics (which have excellent affinity with living tissues) are added to the surface of a metal base material with excellent mechanical strength. apatites)
A technique has been proposed to cover the
49° Special Publication No. 58-39533, etc.).

[Problems to be Solved by the Invention] However, in the composite imbrite member obtained by the above-mentioned technique, it takes 4 hours to complete the fixation of the apatites and bone tissue.
The drawback is that it requires a long period of time, up to 8 weeks. Therefore, during treatment, it is necessary to keep the implant member fixed until the above-mentioned fixation is completed, resulting in a long resting period for the patient and causing great pain to the patient.

The present invention has been made with attention to these circumstances, and is an implant member that not only has good mechanical performance, biocompatibility, safety, etc., but also has excellent quick fixation with bone tissue. The purpose is to provide the following.

[Means for Solving the Problems] The implant member of the present invention that achieves the above objects contains CaO: 42-53%, 5i02: 22-41%, P
2O5: Composition consisting of 10-27% (100% in total)
The gist of this method is that a glass-forming composition having 90% or more of the total components is used as a sputtering target, and sputtering is performed to form a glass coating layer on the surface of a metal substrate.

[Effect] The reason why apatites have a slow rate of fixation with living tissue, especially bone tissue, despite their excellent biocompatibility, is that the elution of apatites from biological fluids is delayed more than expected. It is believed that this is because

Therefore, the present inventors discovered that the fixation speed with bone tissue is faster,
Moreover, as a result of various studies on coating materials with high adhesion strength after completion of adhesion, we found that CaO: 4
2-53%, 5i02:22-41%, P2O5:10
We have found a composition in which the composition consisting of ~27% accounts for more than 90% of the components. That is, the composition has a high elution rate in biological fluids, and the eluted substance forms a biological apatite layer on the surface of the composition, which quickly adheres to bone tissue.

In the implant material of the present invention, a glass coating layer of the above-mentioned composition is formed on the surface of the metal base material, but the means for forming the layer is not particularly limited. However, since a high level of surface strength is naturally required for the implant material, it is desirable that the composition be made of crystallized glass, although an amorphous glass layer may be used in the present invention. In the present invention, a method of heat treatment after sputtering is recommended as a means for forming crystallized glass. That is, in the present invention, when forming an implant material coated with crystallized glass, a coating composition having the above composition is used as a sputtering target, and an amorphous coating composition having the above composition is applied to the surface of a metal base material through a sputtering method. After forming the crystallized glass coating layer, heat treatment can be performed to form a crystallized glass layer. Since a high-strength coating layer is formed on the surface of the metal base material, excellent mechanical performance can be obtained. The rate of elution into biological fluids is fast, and the coating layer having the above-mentioned component composition is quickly fixed to bone tissue with good bonding strength.

Therefore, bone tissue prosthesis or alternative treatment can be performed quickly. In addition, an apatite phase [cato(po4)6o] is formed in the crystallized glass coating layer by heat treatment after sputtering.
] and the wollastonite phase (CaO.5i02) can be precipitated in a well-balanced manner, and heat treatment at 900 to 1200°C is desirable.

To explain the composition (expressed as a proportion in the main component composition) of the composition (hereinafter particularly referred to as the main component composition) that accounts for 90% or more of the composition for forming the coating layer of the implant material of the present invention, first, the amount of CaO If the amount of CaO is less than 42%, an apatite phase having excellent biocompatibility and a wollastonite phase effective for improving strength cannot be efficiently precipitated. On the other hand, if the amount of CaO exceeds 53%, the melting point of the composition becomes too high and crystallization progresses too much during the cooling process, making it difficult to obtain a glass body. In addition, the amount of 5i02 is 22 to 41%, P2O,
The amount needs to be 10 to 27%; if the amount is less than the respective lower limit, the wollastonite crystal phase, which is important for increasing the strength of the coating film, cannot be efficiently precipitated. On the other hand, if the upper limit is exceeded, it becomes difficult to efficiently (precipitate) an apatite phase that is effective for improving biocompatibility during the crystallization process.

Components other than the above main component composition include alkali metal oxides and alkaline earth metal oxides.

A1203, ZrO2, etc. are exemplified, and the content thereof needs to be suppressed to less than 10% of the total components.

Further, the metal base material in the present invention is not particularly limited, but may include Co-Cr alloy, stainless steel, Ti,
Examples include metal materials such as Ti alloy and Ta.

The basic structure of the present invention is as described above, but the method for preparing the target material used for sputtering in the present invention is, for example, by mixing and melting the glass forming composition having the above composition, sufficiently removing the gas component, and then Alternatively, the molten material may be injected into a mold to form a plate, or the molten material may be rapidly cooled and vitrified, and then ground to a specified particle size, which is used as a raw material for sintering, and a molding binder is added. Examples include a method of mixing, molding, and sintering to obtain a target material.

[Example] Main component composition 93% M g O4,
3% A120.・2%Ca
F, 0.4% unavoidable impurities: The remaining composition raw materials were melted at 1500°C. The melt was then dropped into water to produce a glass caret. The caret was ground in an alumina ball to a particle size of 30μ.
Adjusted to below m. Add 3% PVA to the obtained powder,
Press molded to a diameter of 125mff1. A molded body with a height of 10 mm was manufactured. After removing PVA by heating under atmospheric pressure, the temperature was increased at a rate of 100°C/hr, and the temperature was increased to 1100°C for 4 hours.
A target was manufactured by sintering by holding for a period of time.

After sintering, it was processed to have a diameter of 100 mm and a height of 3 am, and was fixed to a cooling base material made of copper via In.

Pure Ti and Ti-6AI- as implant metal substrates
Sputtering was performed using the above target using a round bar made of 4V plywood. The sputtering conditions are: high frequency power source, output 300W, Ar gas pressure 5 x 10-3To
rr, sputtering speed was 200 A/min, and sputtering time was about 3 hours.

The resulting sputtered coating was subjected to X-ray photoelectron spectroscopy (E
When the components were analyzed by SCA), almost the same analysis results as the target material were obtained.

Further, when the crystal phase was identified by thin film X-ray analysis, it was confirmed that it was in a glass state as shown in FIG. On the other hand, the sample obtained by the above sputtering process was
When the coating layer on the surface of the sample was subjected to X-ray diffraction after heat treatment at t for 2 hours, remarkable peaks of apatite, wallasnite and β-TCP were observed as shown in FIG. The heat treatment progressed crystallization and further improved the membrane strength, making it possible to obtain an implant material that could withstand long-term use.

Diameter 3mm, length 5no manufactured by the above method
When the sample n was implanted into the rabbit's femur bone and the adhesion between the bone and the sample was examined two weeks later, the rabbit was able to walk freely and there was a gap between the rabbit's living bone and the coating film. It was possible to confirm a good adhesion condition without any problems.

[Effects of the Invention] The present invention is constructed as described above, and has excellent mechanical strength, biocompatibility, and safety (no elution of harmful substances), and has high fixation speed and fixation strength with bone tissue. A composite implant material could be obtained.

[Brief explanation of the drawing]

Figure 1 shows the thin film X of the heat-treated coating film after sputtering.
Graph showing the results of line diffraction. FIG. 2 is a graph showing the results of thin film X-ray diffraction of the sputtered coating film in the example.

Claims (1)

[Claims] CaO: 42 to 53% (meaning of weight %, same below),
SiO_2: 22-41%, P_2O_5: 10-27
% (total 100%) accounts for 90% or more of the total components as a sputtering target, and sputtering is performed to form a glass coating layer on the surface of the metal substrate. Composite implant component.