JPH072170B2 - Composite implant member and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composite implant member such as an artificial bone, an artificial joint, and an artificial tooth root, and a method for producing the same, and more specifically, to enhance the integrity with living bone tissue. The present invention relates to a composite implant member in which a surface layer having a high porosity in terms of material and structure is formed outside a base material layer, and a method for manufacturing the same.

[Prior Art] Implant members such as artificial bones, artificial joints and artificial tooth roots are used for the purpose of repairing damaged or missing human bones, joints, teeth and the like. It is necessary for the implant member to have excellent compatibility with the living body and to secure strong adhesion to the living bone tissue. To satisfy these requirements, the surface of the implant member base material is coated with another metal material or a ceramic material. Composite implant members are used.

2 (a) to 2 (c) are sectional explanatory views showing enlarged surface layers of a composite implant member provided with various surface structures, and in FIG. 2 (a), fine-grained powder is formed on the base material layer 1. 2 into (b)
In the figure, the bead-shaped particles 3 are joined together, and in the figure (c), the filaments 4 are joined together to form a surface layer. With respect to these surface structures, for example, referring to FIG. 2 (a), the pores 5 are formed between the base material layer 1 and the fine-granular powder 2 and between the fine-granular powders 2, and the composite implant member is formed. A fine uneven structure is formed on the surface of. As a result, new bone tissue easily invades and grows in the hole portion 5, and both of them form a strong fixed state.

In the production of the above composite implant member, fine powder 2, bead-shaped particles 3, and filaments 4 are diffusion-bonded to the surface of the base material layer 1 by a sintering method or a thermal spraying method, and then the surface layer is formed. The general manufacturing method is to finish by polishing.

[Problems to be Solved by the Invention] Generally, the fine powder 2 and the beaded particles 3 have a particle diameter of 200 to 700 μm, and the filaments 4 have a diameter of 200 to 300 μm. And thereby the pores 5 having a diameter of about 20 to 400 μm on the surface of the composite implant member.
To form. However, these holes 5 are formed, for example, between the base material layer 1 and the fine grain powder 2 and between the fine grain powders 2 as shown in FIG. a) ~
In any of (c), the porosity is at most 30-50.
It was about%. If an attempt is made to increase the porosity further, the binding force between the fine-grain powder 2 and the like and the base material layer 1 or the fine-grain powder 2 and the like will decrease, and the fine-grain powder 2 and the like will easily peel off. .

By the way, when a composite implant member having a porosity within the above numerical range is embedded in a living body, the living bone tissue has pores 5
As described above, it penetrates and grows inside to form a strong adherence state with the composite implant member, but in actual clinical practice, it exerts a predetermined strength (expected for the composite implant member. It usually requires a long time of 4 to 8 weeks to reach the maximum strength), and the ultimate strength of fixation with living bone can be sufficiently satisfied in supporting the weight of the human body and the load applied to daily life. Not up to.

Therefore, the inventors of the present invention provide a composite implant member and a method for producing the same, which can eliminate the above-mentioned drawbacks by forming a surface layer having high porosity and not easily peeled from the base material itself. The present invention has been completed through repeated research for the purpose of providing it.

[Means for Solving the Problems] The composite implant member of the present invention which achieves the above object,
The particles or filaments that form the surface layer are themselves 10 ~
The gist is that it is formed of an inorganic porous material having 100 μm pores, and a method for producing the composite implant member is described below, wherein the inorganic porous material having 10-100 μm pores is used as asymmetric particles. The gist is to pulverize and spray the particles onto the surface of the base material layer to diffusely bond the base material layer and the particles and the particles together.

[Operations and Examples] In the composite implant member of the present invention, a metal or ceramic porous body is used as the surface layer forming material. The porous body contains a large number of pores of 10 to 100 μm,
Also, select a material that is highly compatible with the living body. As a typical example thereof, there can be mentioned open-cell type sponge titanium.

In forming the surface layer of the composite implant member, the porous body is pulverized into asymmetric particles of about 100 to 400 μm, and the particles are sprayed onto the surface of the base material layer by a plasma spray method to form a base material. Diffusion bonding between particles or particles is performed. At this time, the surface of the base layer is subjected to mechanical surface roughening treatment such as sandblasting in advance or chemical surface roughening treatment such as etching to improve the adhesion between the surface layer and the base layer. Also, it is preferable in terms of easiness of forming the holes. At this time, the particles do not completely melt and lose the pores, and only the surface portion is softened and melted and bonded to the surface of the base material layer. On the surface of the composite implant member manufactured in this manner, the pores 5 are formed between the base material and the particles and between the particles.
And the porous particles themselves have fine pores, the porosity of the surface layer of the composite implant member can be in the high range of 50 to 80%. Therefore, the stable strength is reached early by the invasion and growth of new bone. Also, since the pores 5 and pores are formed in a complicated direction in a random direction, invasion of new bone tissue
The growth eventually leads to a very strong sticking force.

Further, the bonding force between the base material and the particles or between the particles is not deteriorated as compared with the case where a conventional simple fine powder is used, and the particles themselves are not easily peeled off. Further, even if the amount of particles sprayed is smaller than that when the conventional fine powder is used, fine irregularities can be effectively formed. As a result, when the composite implant member of the present invention is embedded in a living body, it integrates with the living bone in a short period of time to exhibit the required fixing force, and the final reaching fixing force is sufficiently strong to support the human body. You can secure the quality.

Next, the porosity of the surface layer will be described.

FIG. 3 is a graph showing changes in the porosity as seen in the thickness direction of the surface layer when spongy Ti powder particles are plasma sprayed. As can be seen from this figure, the porosity of the outermost surface side of the surface layer is higher than the porosity of the base material layer side. It is considered that this is because the initial thermal spray particles in the thermal spraying method are crushed by the large collision energy with the base material and become denser on the base material side. In this structure, the porosity of the base material layer has a great influence on the adhesion between the base material layer and the surface layer. Therefore, it is preferable that the porosity is low as described above, while the porosity of the outermost surface side is the biological bone. The porosity is preferably high as described above, since it has a great influence on the integration with the above and the formation of apatites. Therefore, it can be said that the surface layer formed by this thermal spraying method exhibits a suitable porosity distribution.

Ti is often used as the material of the base material layer of the composite implant member, and considering the aspects such as improving the adhesion and adhesion strength with this Ti, the material of the surface layer is Ti of the same quality as the base material layer.
Base materials are preferred. On the other hand, from the viewpoint of integration with living bone, it is recommended to use an apatite-based material such as a calcium phosphate-based compound as the material of the surface layer.

Therefore, from the above viewpoints, the preferred embodiments of the material and structure of the surface layer are roughly classified into the following two.

Select foamed Ti as the same material as the base material, for example, the Ti base material, or select a porous material that does not form apatite, such as porous alumina material, zirconia material, titania material, etc. as the base material on the ceramic base material. If. In this case, the porous surface layer may be further coated with a calcium phosphate-based compound or a glassy material containing the calcium phosphate-based compound.

When selecting apatites that have previously produced apatites such as porous granules of hydroxyapatites or a glassy substance containing a calcium phosphate compound, or a porous body that produces apatites in a living body. The calcium phosphate compounds include hydroxyapatite, carbonate apatite, fluoroapatite, chlorine apatite, Ca ₃ (PO ₄ )
₂ , Ca ₃ P ₂ O _{7 and the} like are exemplified.

In the case of, there is no problem, but in the case of, the difference in the coefficient of thermal expansion and the coefficient of thermal expansion between the metal such as Ti selected for the base material and the surface layer material may be large, and the problem of the adhesion of the surface layer may occur. In such a case, it is preferable to coat a thin film (intermediate layer) such as alumina, zirconia, or titanium having a thermal expansion coefficient close to that of the base material as the underlayer.

A sponge-like material is first used as a typical material for the porous particles.
Although Ti was mentioned, the spongy Ti is generally produced by dropping Ti chloride onto molten Na or molten Mg and performing reduction treatment. Then, it is recommended to grind this with a press or the like, if necessary, to classify particles having a particle size of about 100 to 400 μm, and use the particles for the thermal spraying.

<Experimental Example> FIG. 1 is a graph showing changes over time (adhesion strength improvement rate) in the adhesive force when the composite implant member of the present invention is used and when the conventional composite implant member is used. The solid line shows the embodiment of the present invention, and the broken line shows the conventional example. In the examples of the present invention, Ti-6A1 was used as the base material layer.
A −4V alloy was used, and the surface layer was formed by plasma spraying pure Ti particles having pores with a particle size of 10 to 100 μm.
On the other hand, as a conventional product, a particle size of 400
Sintered bead-shaped particles made of Ti having a size of ˜700 μm were used. Then, these composite implant members were embedded in the tibia of a dog under the same conditions, and changes in pull-out strength after a predetermined period were measured.

As a result, in the example of the present invention, after 2 weeks, it was already 10 kg / c.
While the drawing strength of m ² or more was reached, in the conventional example it was 10
It took 4 weeks to exceed kg / cm ² . Further, in any measurement, the embodiment of the present invention can exhibit a pulling strength of 1.5 to 2 times as compared with the conventional example, and the strength at the time of relatively stable after the 8th week is about 1.5: 1. It turned out to be a difference.

The present invention is not particularly limited as to the material of the composite implant substrate, Ti, Ti alloy, Zr, Zr alloy that is usually used as a material that has excellent mechanical strength and does not adversely affect the living body , Co-Cr-Mo alloy, Co-Cr-W
-Metal materials such as Ni alloy, Ta, and stainless steel can be used, as well as ceramics such as hydroxyapatite and alumina.

EFFECTS OF THE INVENTION Since the composite implant member of the present invention is configured as described above and has a high porosity in its surface layer, it is firmly integrated with living tissue within a short period of time and stable. In addition, it becomes possible to exert strong adhesiveness for a long period of time. Further, the manufacturing method of the present invention has made it possible to reliably manufacture a composite implant member having a surface layer with a high porosity.

[Brief description of drawings]

FIG. 1 is a graph in which a composite implant member of the present invention and a conventional composite implant member are each embedded in a living bone and the pull-out strengths after that are compared, and FIGS. 2 (a) to (c) are surface layers of the conventional composite implant member. FIG. 3 is an enlarged cross-sectional explanatory view showing a portion, and FIG. 3 is a graph showing a change in porosity in a surface layer portion in a thickness direction when diffusion bonding is performed on a base material layer by spongy Ti particles. 1 ... Base material layer, 2 ... Fine powder 3 ... Bead-like particles, 4 ... Striatum

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Doi 6-4-1 Suganodai, Suma-ku, Kobe City, Hyogo Prefecture (56) References JP-A-63-160646 (JP, A) JP-A-63-59950 (JP) , A) JP 63-210079 (JP, A) JP 62-503011 (JP, A)

Claims (5)

[Claims] 1. A composite implant member comprising a porous surface layer formed by adhering powder or particles to the surface of a base material layer, wherein the powder or particles have a diameter of 10 to 100 μm. A composite implant member comprising an inorganic porous material having pores. 2. The composite implant member according to claim 1, wherein the inorganic porous body is spongy Ti. 3. The composite implant member according to claim 2, wherein the surface of spongy Ti is coated with apatites or an apatite-forming compound. 4. The porosity of the surface layer is so formed that the outermost surface side porosity is higher than the base material layer side porosity when viewed in the thickness direction. The composite implant member according to any one of claims. 5. An inorganic porous material having pores of 10 to 100 μm is crushed into asymmetric particles, and the particles are sprayed onto the surface of the base material layer,
A method for producing a composite implant member, which comprises diffusion-bonding a base material layer, particles, and particles to each other.