JPS63240854A - Composite member for prosthesis of living body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a bioprosthetic composite member used in medical fields such as orthopedics, neurosurgery, oral surgery, and dentistry.

[Prior art and its problems]

Conventionally used composite members for bioprosthetics include metal,
There are various types in which a biocompatible material is adhered to the surface of a high-strength substrate such as ceramic.

For example, ceramic porous layer - ceramic base, ceramic bead layer - ceramic base, ceramic porous layer - glass adhesive layer - ceramic base, metal bead layer -
Materials that are a combination of metal base, metal fiber metal-metal base, etc. are used.

However, all of these bioprosthetic composite members are ceramic-ceramic, ceramic-glass, or metal-metal bonded materials. Therefore, when these bioprosthetic composite members are subjected to an external force, the biocompatible material layer first breaks down, and the generated crank passes through the joint interface with almost no resistance, leading to catastrophic destruction of the base. In fact, the strength of this bioprosthetic composite member to which the biocompatible material layer is bonded is 30 to 70x lower than that of a base body alone.

Furthermore, these bioprosthetic composite members require high-temperature heat treatment at about 800° C. to 1700° C. for bonding the biocompatible material layer and the base body. For this reason, the high-temperature heat treatment during bonding causes deterioration of the underlying material (for example, a decrease in strength and corrosion resistance, dimensional changes, etc.).

Due to these drawbacks, conventional composite members for bioprosthesis have insufficient strength, the base material does not exhibit its original characteristics, and the areas where it can be applied to living organisms are extremely limited.

[Means for solving problems]

In view of the above, a composite member for bioprosthesis is constructed by attaching a biocompatible material via an organic polymer layer so as to have high strength and prevent material deterioration of the base material.

〔Example〕

Hereinafter, the present invention will be specifically explained in detail with reference to Examples.

(Example 1) Naphthalene or graphite particles classified to have an average particle size of 150 μm are mixed with alumina green granules that have been granulated and classified to have an average particle size of 300 μm, and the mixture is filled into a mold and pressure-molded. Sinter this at 1400-1700"C and
A porous alumina sheet of xlOx 0.8t is produced.

On the other hand, the base is made of rubber press-molded alumina molded body, and is machined to a diameter of approximately 1.2 mm from the surface.
, a large number of holes with a depth of about 1 and 2 mm are drilled at intervals of about 5 mm. This is sintered at 1,400 to 1,700°C to form countless holes H on the surface as shown in Figure 1 (a) and (b).
An alumina ceramic +ffA having the following properties is obtained.

This is called base type 1.

At the same time, a flat plate with the same dimensions and no holes was fabricated using the same method. This is called base type 2.

Next, between the porous alumina sheet and the base type 1,
Evenly sandwich 0.05g of polyethylene powder per cm and apply a load of several g per 1c to 100
The polyethylene was melted by heat treatment at ~200° C., and the porous alumina sheet P was adhered to the alumina ceramic plate A of substrate type 1.

A cross section of this composite member is shown in FIG. As can be seen, the composite member is maintained by the penetration of the molten polyethylene into the pores of the porous alumina and the holes 11 in the substrate. This is called a composite member with an organic polymer layer made of polyethylene interposed therebetween.

As a comparison sample, SiO
Apply glass powder G containing 203 as the main component and heat to 1100℃
heat-treated and coated. A cross section of the composite member thus obtained through the glass layer is shown in FIG.

Dimensions obtained in this way: 10X15X 2~3t■
Strength evaluation by three-point bending test and adhesive strength of the porous alumina layer to the substrate were performed on substrate type 1, (i) substrate type 2, (i) composite member using polyethylene, and (ii) composite member using glass.

The three-point bending test was carried out under the conditions of a span of 10 mm and an upper punch lowering speed of 0.5 mm/min as shown in FIG.

Furthermore, the adhesion strength of the porous alumina layer to the substrate was evaluated in the vertical direction and in the shear direction. The method is to fix the porous alumina layer with polymethyl methacrylate,
Each test was conducted as a vertically upward tensile test and a push-out test. Adhesion strength was evaluated as the value obtained by dividing the breaking load at the bonding interface by the area where the porous layer is present. These results are collectively shown in Table 1. However, the three-point bending strength is the span 10n+lI+ for the fracture load value, and the cross section is all constant 2.
It is calculated as a rectangular cross section of mm x 10-.

As can be seen from this, the strength of the composite member using polyethylene is approximately 70x stronger than that of the joined body using glass. In addition, it can be said that the two are almost equivalent in terms of adhesive strength.

Next, in order to evaluate biocompatibility, a composite member made with polyethylene and a composite member made with glass as a comparison sample were implanted as test pieces into the femoral condyle of an adult mongrel. After 4 weeks, 8 weeks, and 12 weeks after implantation, after tetracycline labeling, delayering, and fresh bone containing the test piece were taken out, fixed in formalin, made into a non-decalcified specimen, and examined using an optical microscope, etc. The bonding state with the bone was observed.

According to this, no difference was observed between the two after 4 weeks of implantation, and bone intrusion into the porous alumina layer was observed in both materials. Even after 8 weeks, no difference was observed between the two, indicating that bone invasion had progressed further. At 12 weeks, the invading bone tissue filled the porous alumina layer.

There was no difference between the two here as well.

(Example 2) A 10 x 15 x 0.8 t fiber metal porous sheet was produced by pressure forming a wire titanium wire with a wire diameter of 250 μm and vacuum sintering. On the other hand, as a base, a hole with a diameter of about 0.3 mm, a depth of about 0, and 5 mm was made.
Example 1: x15 x 2t zirconia ceramic plate
It was made in the same way as that of . Then, add 1 cm of urethane monomer to form an organic polymer layer between the porous layer and the substrate.
Approximately 0.05 g of each sheet was applied and bonded, and ultraviolet rays were irradiated from the fiber metal porous sheet side to polymerize.

The strength and adhesive force of the porous layer of the thus obtained composite member using the urethane resin were evaluated in the same manner as in Example 1.

The results are shown in Table 1. It was equivalent to that of a composite member using polyethylene.

(Left below) (Example 3) Average particle size 600. +1m a? 1 Remina Green Granules
Alumina particles with an average grain size of 500 μm obtained by firing at 500° C. and classification are prepared. 10x15x 2t in parallel
A titanium alloy plate was prepared, a silicone resin adhesive was applied to the surface, alumina beads were sown on it, and the silicone resin was then cured to bond the alumina beads to the titanium alloy base.

This is called a composite member with an organic polymer layer made of silicone resin interposed therebetween.

As a comparison sample, titanium alloy spherical beads with an average particle diameter of about 500 μm were prepared, sown on a 10 x 15 x 2 t titanium alloy plate, and placed under a vacuum of 10-'torr at 130 m.
The beads were sintered at 0° C. and adhered to the surface of the titanium alloy plate. This is called a titanium alloy bead sintered composite member. The strength of both of these and the titanium alloy plate of the substrate (the shape is the same as substrate type 2) and the adhesion force between the bead layer and the substrate in the titanium alloy bead sintered composite member and the composite member via silicone resin were measured. However, the strength is different from that of ceramics, and a de-fatigue test (3-point bending type oscillation bending with a span of 10 mm) was carried out at room temperature at a frequency of 20 Hz, and the rupture stress after 107 repetitions was determined to be 3-point bending fatigue. strength. At this time, the zygote is
It was placed in a 3-point bending jig so that tensile stress was generated on the bead coat side. (The dimensions of the jig are the same as those shown in Figure 4.) The stress is the same as in the case of 3-point bending strength, with a span of 10 mm and a folded surface of 2 m x 5 m for the load value.
Calculated as a rectangular cross section.

The results are shown in Table 2. The adhesion strength of the porous layer of titanium beads is compared to that of the bonded body using silicone resin6.
~7 times stronger, but on the other hand, the strength is less than half.

(Left below) (Example 4) Hydroxylated apatite powder was molded at a pressure of 100,100 O/cm"
After dry press molding, it is sintered at 1300 degrees in the atmosphere to obtain dense hydroxide apatite. This is ground with a diamond grindstone to produce a 10x15x 0.5t apatite thin plate. On the other hand, a dense hydroxyapatite thin plate of 10 x 15 x 005t was adhered to the alumina plate of substrate type 2 described in Example 1 using an α-cyanoacrylate adhesive forming an organic polymer layer. The strength of the thus obtained composite member using the α-cyanoacrylate adhesive was evaluated in the same manner as in Example 1, and the adhesive force of the apatite layer to the substrate was evaluated. The results are shown in Table 1.

Compared to the alumina strength of substrate type 2, the strength does not decrease, and on the contrary, it becomes stronger as the thickness increases.

〔Effect of the invention〕

By applying a biocompatible material to the surface of a base made of a high-strength material such as metal, ceramic, etc. through an organic polymer layer, as in the case of ridges, a biocompatible and high-strength material can be created. A prosthetic composite component can be provided.

[Brief explanation of the drawing]

FIG. 1(a) is a plan view of only the base for constructing the composite member for bioprosthesis according to the present invention, FIG. 1(b) is a sectional view taken along the line X-X in FIG. is a sectional view of a composite material for bioprosthesis according to an embodiment of the present invention, FIG. 3 is a sectional view of a conventional composite member for bioprosthesis, and FIG. 4 is a cross-sectional view of a composite material for bioprosthesis at three points for measuring the strength of the composite member for bioprosthesis. FIG. 2 is a perspective view of an apparatus for explaining a bending strength testing method. A: Alumina ceramic plate B: Organic polymer layer p: Bolus alumina sheet

Claims (1)

[Claims] A composite member for bioprosthesis, characterized in that a biocompatible material is adhered to the surface of a base made of a high-strength material such as metal or ceramic via an organic polymer layer.