JPH09122223A - Organism implant material and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organism implant material having high mechanical strength and excellent in the bonding property to a bone by ion-implanting the constituent element of an organism activating inorganic material to the surface layer of a film mainly made of titanium silicide and formed on the surface of a metal body mainly made of Ti. SOLUTION: A film mainly made of titanium silicide is formed on the surface of a metal body mainly made of Ti, and the constituent element of an organism activating inorganic material is ion-implanted to the surface layer of the film to form an organism implant material. When this organism implant is buried into an organism, the surface of the film is oxidized to generate a thin oxide film containing SiO2 , it is further hydrated into silica gel, and it is bonded to a bone in a short period. The titanium silicide layer on the surface of the metal body exerts the role of an intermediate layer, and high bonding force is obtained between the generated silica gel and the organism implant. The constituent element of the organism activating inorganic material is ion- implanted to the film, the organism activating inorganic constituent is increased toward the surface of the surface layer portion, and the bonding property to the bone is further improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an artificial bone, an artificial hip joint,
The present invention relates to a bioimplant material useful as a biosubstitute material such as an artificial tooth root and a method for producing the bioimplant material.

[0002]

2. Description of the Related Art Conventionally, as a bioimplant material for repairing a bone defect or the like, one made of titanium metal or titanium alloy has been known. Since such an implant material has biocompatibility and high mechanical strength, it is used in a portion to which a large load is applied, such as a femur or a hip joint.

[0003]

However, since the above-mentioned implant material has a weak force for guiding the bone, it takes time to bond the bone after reaching the surface of the implant material. For this reason, there is a problem that the patient cannot leave the bed for a long period of time, and the physical and mental burden on the patient is large.

In addition, bioactive inorganic materials such as crystallized glass that precipitates apatite or apatite are known to react with surrounding bone tissue in the living body and chemically bond with the bone. It has the drawback of low mechanical strength.

An object of the present invention is to provide a bioimplant material having high mechanical strength and excellent bondability with bone, and a method for producing the same.

[0006]

Means for Solving the Problems As a result of various studies to achieve the above object, the inventors of the present invention have found that silica gel is generated in a short period of time when a bioimplant material is implanted in a living body. It binds to bone, and such silica gel is produced by forming a titanium silicide layer on the surface of a metal body, and when the surface layer is ion-implanted with a component element of a bioactive inorganic material, it becomes bone. The present invention has been found to further improve the bondability of the above and is proposed as the present invention.

That is, the bioimplant material of the present invention is
A coating film containing titanium silicide as a main component is formed on the surface of a metal body containing i as a main component, and a constituent element of a bioactive inorganic material is ion-implanted into the surface layer of the coating film.

Further, in the method for producing a bioimplant material of the present invention, a compound containing Si is applied to the surface of a metal body containing Ti as a main component, heat treatment is performed, and then a component element of the bioactive inorganic material is ion-implanted. It is characterized by

The metal body containing Ti as a main component in the present invention means titanium metal and titanium alloy. As a titanium alloy, Ti, as a main component, Al, Sn, Cr, Z
Alloys containing r, Mo, Ni, Pd, Ta, Nb, V, Pt, etc. can be used. Among them, Ti-6Al
It is preferable to use a -4V alloy.

The titanium silicide contained as the main component in the film may have any ratio of Ti to Si, and for example, Ti ₅ Si ₃ can be used. Further, the film may be formed such that the Ti content ratio of titanium silicide is smaller as the surface becomes closer, that is, the Si content ratio is increased.
It should be noted that the film may contain other compounds such as Al-P, Ti-B, and Ti-P as long as it is not harmful to the living body. The thickness of this coating is preferably 50 μm or less, and if it is larger than this, breakage easily occurs in the coating, which is not preferable.

The constituent element of the bioactive inorganic material is ion-implanted into the surface layer of the coating film containing titanium silicide as a main component. This surface layer has a low concentration of the above components in the deeper part,
The concentration increases toward the surface portion, and since the surface portion is closer to the bone tissue than titanium silicide, it is possible to shorten the period of bonding with bone by forming this layer.

Examples of the constituent elements of the bioactive inorganic material include Ca, P, O and H. However, other constituents that are not harmful to the living body, such as Na, K and Si, are required. Ions can be implanted accordingly.

Next, a method for producing the bioimplant material of the present invention will be described.

First, a titanium metal formed into a desired shape,
A metal body containing Ti as a main component such as a titanium alloy is prepared.
As the titanium alloy, for example, Ti such as Ti-6Al-4V is used as a main component, and Al, Sn, Cr, Zr, and M are used.
Alloys containing o, Ni, Pd, Ta, Nb, V, Pt and the like can be used. Further, it is desirable that the surface of the metal body is made uneven by a known method such as sandblasting or plasma spraying. By providing the surface of the metal body with irregularities in this way, it is possible to obtain a bioimplant material having irregularities on the surface, and it is possible to increase the binding force with bone.

Then, a compound containing Si is applied to the surface of the metal body. As a compound containing Si, SiO ₂ −
_{P 2 O 5 -CaO-MgO-} B 2 O 3 system Si such as glass
O ₂ -containing glass, silica gel, water glass or the like can be used.

As a coating method, when SiO ₂ -containing glass is used, the glass is made into a powder having a particle size of 45 μm or less, and this is kneaded with a binder and a solvent to form a slurry, and then a metal body is added to the slurry. Is applied by a method such as dipping. When silica gel is used, a metal alkoxide containing Si such as tetramethoxysilane,
It may be applied by mixing water, alcohol, hydrochloric acid or the like to prepare a silica sol solution, and then immersing the metal body in the solution. When water glass is used, it may be applied directly to the surface of the metal body.

Thereafter, the metal body is heat-treated to react Si in the applied compound with Ti in the metal body to form a coating film containing titanium silicide as a main component.
The film thus formed has a thermal expansion coefficient similar to that of a metal body, and Ti in the metal body is diffused in the film, so that peeling at the interface between the two hardly occurs.
The heat treatment is preferably performed at 600 to 950 ° C. This is because if it is lower than 600 ° C, Ti and Si do not react, and
This is because when the temperature exceeds 50 ° C., Ti is transferred and the metal body becomes brittle. The heat treatment is preferably performed in vacuum or in an inert gas so that a thick oxide film cannot be formed on the surface of titanium metal or titanium alloy.

Next, the constituent elements of the bioactive inorganic material are ion-implanted into the surface layer of the coating. The feature of the ion implantation method is that it can be added at room temperature and that the implantation amount and the addition depth can be adjusted by controlling the ion current and time. That is, the total amount of ion implantation is determined as current × time = electricity, and the concentration distribution and depth change depending on the implantation energy (implantation voltage) and the type of material to be implanted. Therefore, it is necessary to set the injection conditions for each element so that the desired amount of bioactive inorganic component is injected.

[0019]

When the biological implant material of the present invention is embedded in a living body, the surface of the coating film containing titanium silicide as the main component is oxidized to form a very thin oxide film containing SiO ₂ . It is then further hydrated to silica gel, which binds to bone in a short period of time. In addition, since the titanium silicide layer on the surface of the metal body plays a role of an intermediate layer, a high bonding force can be obtained between the generated silica gel and the bioimplant material.

Further, the constituent element of the bioactive inorganic material is ion-implanted into the coating, and the surface active portion of the coating has the bioactive inorganic component increasing in an inclined manner toward the surface. It will be further improved.

[0021]

EXAMPLES Hereinafter, the bioimplant material of the present invention will be described in detail based on examples.

[0022]

[Table 1]

Table 1 shows examples of the present invention (Sample No. 1).
And the peel strength of the comparative examples (Sample Nos. 2 to 4).

The example No. The sample No. 1 was prepared as follows.

First, a Ti-6Al-4V alloy having a size of 10 × 15 × 2 ^t mm was prepared as a base material, and the surface was sandblasted so that the surface roughness of the base material was about 10 μm at R _max. The unevenness was formed on the surface. Further, tetramethoxysilane, water, methanol, dimethylformamide, and ammonia are used in a molar ratio of 1: 10: 2.2: 1: 3.
A silica sol solution was prepared by mixing at a ratio of 7 × 10 ⁴ .

Next, the substrate is dipped in this silica sol solution,
Silica gel is attached to the surface of the substrate by drying, and then 900 ° C. in a vacuum of 2 × 10 ⁻⁶ Torr.
It heat-processed on the condition of 1 hour.

[0027] The surface portion of the resulting material was thus identified by X-ray diffraction analysis, Ti ₅ to both surfaces
It was confirmed that Si ₃ was generated. Cross section SE
When the thickness was measured by M observation, it was 1-2 μm.
Met.

Further, an injection energy of 100 k is applied to this material.
eV: Ca, P, O, H in order of 1.9 × 10 ¹⁷ ions
/ Cm ² , 1.1 × 10 ¹⁷ ions / cm ² , 5.0 ×
10 ¹⁷ ions / cm ² , 38 × 10 ¹⁷ ions / cm
Ion implantation was performed under each condition of ² .

No. 1 which is a comparative example. Sample No. 2 uses the same Ti-6Al-4V alloy as in the example,
No. Sample No. 3 is Ti-6Al-4V as in the example.
After the surface of the alloy was sandblasted, it was immersed in a silica sol solution under the same conditions as in Example, dried, and then heat treated. Furthermore, No. Sample No. 4 has the same T
After sandblasting the surface of the i-6Al-4V alloy,
Ion implantation was performed under the same conditions as in the example.

Each sample thus prepared was used as a rabbit (16 animals)
The specimens were placed in the tibia of No. 1, and 8 weeks and 24 weeks later, 8 animals were sacrificed, the peel strength between each sample and the bone was measured, and the average value thereof is shown in Table 1.

As is apparent from Table 1, No. The peel strength of the sample No. 1 was 4.0 ± 1.0 kg after 8 weeks,
It was 4.5 ± 0.9 kg after 24 weeks, which was higher than that of each sample of Comparative Example. This indicates that the bioimplant material of the present invention firmly binds to bone in a short period of time.

[0032]

As described above, the bioimplant material of the present invention has excellent biocompatibility and high mechanical strength. Therefore, it is firmly bonded to the bone in a short period of time. It can be placed for a long time,
Even if a large external force is applied, it is difficult for the coating to peel from the base material. Therefore, it is suitable as a biosubstitute material for artificial bones, artificial hip joints, artificial tooth roots and the like.

Claims (2)

[Claims] 1. A coating containing titanium silicide as a main component is formed on the surface of a metal body containing Ti as a main component, and the surface element of the coating is ion-implanted with a component element of a bioactive inorganic material. A bioimplant material characterized by: 2. S is formed on the surface of a metal body containing Ti as a main component.
A method for producing a bioimplant material, which comprises applying a compound containing i, heat-treating it, and then ion-implanting a component element of the bioactive inorganic material.