JPH042341A - Implant member and manufacture thereof - Google Patents

Abstract

PURPOSE:To achieve a remarkable anchoring effect by forming a biologically active material layer on a deep inner surface of a recess in a base material surface using a slurry liquid in which a powder of a biologically active material is scattered. CONSTITUTION:When an artificial bone A which has a surface layer formed having protrusions 4a and recesses 4b measuring about 100-400mum is immersed into a slurry liquid 12 in which a biologically active material such as apatite, bioglass, beta-bone tri-calcium phosphate lime, 'ceravital' (phonetic) or the like is crushed into fine powder to be scattered in a medium, the liquid is attached entirely to a surface layer 2 by a surface tension. Then, air is sent against the artificial bone A to blow off the slurry liquid 12 on the side of external surfaces of the protrusions of the surface layer 2 and then, the medium of the slurry liquid is evaporated dry by adding heat or heating. Thereafter, the bone is heated up to a high temperature exceeding 900 deg.C to bake the biologically active material attached in the recess 4b and a biologically active material layer 3 is formed. This facilitates the infiltration of a new biological tissue deep into the recesses 4b thereby enabling the fastening of the artificial bone firmly on an organic bone.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to living body implant members, such as artificial bones and artificial tooth roots, and methods for manufacturing the same, and more specifically, to implant members that can be firmly bonded to living tissue. The present invention relates to an implant member and a method for manufacturing the same.

[Prior Art] When repairing damaged or missing bones, joints, tooth roots, etc., biological implant members such as an artificial bone 2, an artificial intersection, and 2 artificial tooth roots are sometimes used.

The implant member has excellent strength and compatibility with the living body, and the new living bone tissue (hereinafter sometimes referred to as new living tissue) that grows after surgery has a high resistance to the implant member. Another important requirement is that it be structured in a way that shows strong unity. One way to achieve this is to roughen the surface of the implant member to form irregularities.
One way to do this is to allow new biological tissue to invade and grow within the recess formed there to exert an anchor effect and increase the strength against extraction.

Methods for roughening the surface of the implant member include thermal spraying or pressure welding of fine particles or filaments on the base material surface of the implant member, or pasting a mesh or wire. Alternatively, there is a method of roughening the surface of the base material by shot blasting.

Metal materials such as stainless steel and titanium alloy with high mechanical strength are often used as the base material of implant components, and the same type of metal material as the base material is used for the powder particles and filament bodies. There is. However, metal materials have low affinity with living tissue, and it is difficult to ensure sufficient adhesion simply by roughening the surface of the implant member and expecting a mechanical anchoring effect. Therefore, as an alternative method, bioactive materials such as apatite and bioglass, which have a high affinity for living tissues, can be added by thermal spraying on the outermost layer of the implant component, or by applying powder coating and then firing. It is being set up.

[Problems to be Solved by the Invention] FIG. 4 is an enlarged partial cross-sectional view of an implant member, in which a surface layer 2 having irregularities is formed by spraying or diffusion bonding fine metal powder onto a base material 1. Furthermore, a bioactive material layer 3 typified by a calcium phosphate compound such as hydroxyapatite, bioactive glass, etc. is applied over the entire outer surface of the surface layer 2 by the firing method described above.

However, when formed by such a method, the bioactive material layer 3 is formed so as to considerably fill the recesses 4b of the surface layer 2, so that the irregularities are smoothed out. The anchoring effect due to the invasion of new living tissue cannot be expected, and the bondability with the remaining living bone becomes low.

In the above figure 344, the bioactive material layer 3 is located in the recess 4 of the surface layer.
Although it is shown as if it penetrates deep into the inner part of b, in reality, it does not reach the inner part sufficiently, and in many cases, the bioactive material is coated only on the surface area centered on the convex part 4a. Even if the new biological tissue were to penetrate deep into the recess 4b, chemical bonding with the biological bone would be insufficient, and in the end, the bonding force could not be dramatically improved.

Therefore, the present inventors have developed a new biological tissue that can penetrate deep into the recesses of the surface layer without smoothing the uneven parts of the surface layer, thereby forming strong chemical bonds and exerting a strong anchoring effect. The first objective is to provide a sophisticated implant component that can be manufactured with ease, and the second objective is to develop a method that can easily manufacture such an implant component. Completed the invention.

[Means for Solving the Problems] The implant member of the present invention that achieves the above object has a gist in that a bioactive material layer is formed on the inner surface of the recesses of the fine irregularities formed on the surface of the base material. Furthermore, in the manufacturing method of the present invention, after applying a slurry liquid in which powder of a bioactive material is dispersed to the surface of an implant member having fine irregularities formed therein, The gist of the method is to include the steps of removing the slurry liquid, further drying, and firing the bioactive material.

[Function and Examples] An example of a method for forming a bioactive material layer on a metal artificial bone A will be described in detail below with reference to FIGS. 1 and 2. The artificial bone A is made by thermally spraying or diffusion bonding the same type of metal powder onto the surface of the base material 1, as shown as the downward left hatching part 2 in FIGS. , 4b is formed. Up to this point, all conventional methods can be employed. FIG. 1(a) is an explanatory diagram showing a state in which an artificial bone A is immersed in a slurry liquid 12 in a closed container 10, and a vacuum pump 13 and an inert gas supply source 14 are connected to the closed container 12. Ru. The slurry liquid 12 is made by pulverizing a bioactive material such as apatite, bioglass, β-tricalcium phosphate, ceravital, or crystallized glass into a fine powder of several micrometers or less to several hundred micrometers, and dispersing it in a medium such as water or alcohol. Therefore, it is desirable that the slurry concentration is 10% or less.

First, the artificial bone A is held in a space above the slurry liquid 12 (indicated by the broken line A') while suspended from the lifting arm 11.
The vacuum pump 13 is driven to evacuate the upper space and expose the artificial bone A to a vacuum environment. By degassing the air in the recess 4b in this manner, air pockets are prevented from remaining in the recess 4b when immersed in the slurry liquid 12. Then, the lifting arm 11 is lowered to immerse the artificial bone A into the slurry liquid 12. Next, it is preferable to introduce air, N2 gas, or the like from a gas tank into the space above the slurry liquid 12 to pressurize it, thereby making it possible to reliably push the slurry liquid deep into the surface layer recess 4b. If necessary, vibration or shock may be applied to release residual air bubbles.

The artificial bone A that has been immersed in the slurry liquid 12 is taken out from the sealed container 10. At this time, the adhering state of the slurry liquid 12 is as shown in FIG. 2(a).
2 continuously covers the adjacent convex portions 4a by surface tension and is adhered over the entire surface of the surface layer 2.

Next, as shown in FIG. 1(b), the artificial bone A that has been soaked is
Air is blown by the blower 15 toward the surface of the surface layer 2, and the slurry liquid 12 adhering to the outer surface of the convex portion of the surface layer 2 is blown away as shown in FIG. (so that the top surface of the convex portion 4a is not covered by the slurry liquid 12). Then, by warming or heating this artificial bone A, the medium of the slurry liquid is evaporated and dried. After that 9
By heating to a high temperature of 00° C. or higher, the bioactive material adhering to the recess 4b is fired to form the bioactive material layer 3. In this way, as shown in FIG. 2(C), the bioactive material layer 3 is formed only on the inner surface of the recess 4b in the surface layer 2, making it easier for new biological tissues to invade the inner depth of the recess 4b. The lid allows for a strong bond between living bone and artificial bone. It should be noted that since it is said that biological new tissues do not invade microscopic areas of 40 μm or less, even if they are filled with the bioactive material layer 3, the bondability will not be significantly affected.

(Example 1) Crystallized glass powder of 10 μm or less was made into a 10% slurry liquid, and the slurry liquid was adhered to the surface concavities of a Ti artificial bone through the steps shown in Fig. 1 (a) and (b). .

Incidentally, evacuation was performed at 10'' Torr, and pressurization of inert gas was performed at 5 Kg/cm2. The extracted artificial bone was dried at 110°C and then heat treated at 1050°C to obtain the artificial bone as shown in Fig. 2(c).

(Example 2) A mixture of pre-crystallized glass ceramics and this raw glass powder at a ratio of 1=1 is dispersed to form a slurry liquid, and this slurry liquid is applied to the surface of an artificial bone under the same conditions as Example 1. After adhering and drying, the artificial bone was heat-treated at 900°C to form a crystallized glass layer in the concave portions.

(Example 3) Fine hydroxyapatite powder that has been heat-treated at 1000°C or higher is dispersed in a water-insoluble solvent, and Si
An alkoxide (eg, ethyl silicate) and acetic acid were added, followed by water to form a sol-gel slurry. This was impregnated into an artificial bone, followed by drying and heat treatment through the steps shown in FIG. 1(b) to form a bioactive material layer as shown in FIG. 2(C).

The artificial bone manufactured according to Example 1.2.3 above was implanted into the knee joint of an adult, and a pullout test was conducted at predetermined intervals, and the results shown in the solid line (A) in FIG. 3 were obtained. In addition(
The comparative examples shown in (b) to (f) have the following surface shapes.

(b) An asymmetric surface layer 2 having fine irregularities is formed, and a crystallized glass layer is formed so as to completely cover the entire surface layer.

(A) Forming an asymmetrical surface layer 2 in the same manner as above, but not forming a bioactive material layer.

(:) Only bead-shaped particles are attached to the base material 1.

(e) A flat base material surface coated uniformly with crystallized glass.

(f) Only a flat base material (made of alumina).

As is clear from FIG. 3, the artificial bone of the example of the present invention has improved pull-out strength compared to the conventional product shown in the comparative example.
(A) showed a value higher than (8) by more than 10 g/cm''.

The method for coating the surface layer 2 with a bioactive material is not limited to the above example, but a sol-gel method using an alkoxide can be used to coat the surface layer with crystallized glass, bioactive glass mainly composed of Na, hydroxyapatite, etc. A method of attaching it to the recess 4b of No. 2 may also be used.

On the other hand, as a method for removing the slurry liquid 12 on the surface layer 2 and changing the state from the state shown in FIG. 2(a) to the state shown in FIG. 2(b), instead of the air blowing method described above, a brush It may also be removed by rubbing it off with a cloth or the like.

[Effects of the Invention] Since the implant member of the present invention is configured as described above, it is chemically firmly bonded to the new biological tissue and also exhibits an anchoring effect, so it can be used as a stable artificial bone over a long period of time. Now I can do it. Furthermore, the present invention allows the implant member to be manufactured easily.

Drawing 0 simple cage

[Brief explanation of drawings]

FIG. 1 (δ), fb) is an explanatory diagram showing an example of the process of the method of the present invention, and FIGS. 2 (a) to (c) are enlarged views showing the cross-sectional shape of the artificial bone manufactured by the method of the present invention at each step. Explanatory diagram,
Figure 3 is a graph showing the difference in pull-out strength between the example of the present invention and the comparative example, and Figure 4 is a graph showing the 2... surface layer of the conventional artificial bone.
3... Bioactive material layer 4a... Convex portion
4b--Recessed portion 10... Sealed container 11...
Lifting arm 12...Slurry liquid 13...Vacuum pump 14...Inert gas supply source 15...Blower

Claims (2)

[Claims] (1) An implant member in which a bioactive material having high affinity with living tissue is adhered to the surface of a base material, wherein the bioactive material is attached to the inner surface of a concave part with fine irregularities formed on the surface of the base material. An implant member characterized by forming layers. (2) In manufacturing the implant member according to claim (1), after applying a slurry liquid in which bioactive material powder is dispersed to the surface of the implant member on which fine irregularities are formed, the implant member is A method for manufacturing an implant member, comprising the steps of removing the slurry liquid adhering to the convex portions, drying the slurry liquid, and firing the bioactive material.