JP2956318B2 - Implant made of Ti or Ti alloy coated with calcium phosphate-based ceramic layer and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a calcium phosphate-based ceramic layer-coated Ti or Ti alloy implant having excellent biocompatibility and used in the fields of dentistry and orthopedics, and a method for producing the same.

[0002]

2. Description of the Related Art In general, implants to be embedded in living bodies such as artificial joints and artificial roots are, for example, stainless steel,
It is made of a metal or alloy having excellent corrosion resistance, such as a Co-Cr alloy, Ti or a Ti alloy.

[0003] Among them, Ti or Ti alloy is light in weight, has excellent corrosion resistance to human body tissues and body fluids, and does not cause inflammation, hypersensitivity, allergy or the like to human body tissues. It is also known to be particularly suitable as

However, Ti or Ti alloy implants, like other metal or alloy implants, have poor biocompatibility. Therefore, a coated implant made of Ti or Ti alloy in which a calcium phosphate-based ceramic coating layer such as hydroxyapatite or tricalcium phosphate excellent in biocompatibility is formed on the surface of the implant body made of Ti or Ti alloy by thermal spraying or sintering is also provided. (See the public relations of Japanese Patent Publication No. 58-39533).

[0005] The calcium phosphate-based ceramic coating layer has poor adhesion to the surface of a Ti or Ti alloy implant body, and various measures have been devised for that. For example, JP-A-63-160666 discloses a method of preparing ceramic particles coated with a metal such as W, Mo, and Ge, and welding the metal-coated ceramic particles to the surface of a Ti or Ti alloy implant body. The surface of the deposited metal-coated ceramic particles is polished to expose the ceramics therein, and a calcium phosphate-based ceramic coating layer such as hydroxyapatite or tricalcium phosphate is formed on the exposed ceramic surface.
An i or Ti alloy coated implant is described.

[0006]

The above-mentioned Ti or Ti alloy implant coated with a calcium phosphate-based ceramic layer comprises a metal such as W, Mo or Ge between the calcium phosphate-based ceramic coating layer and the Ti or Ti alloy implant. Although the adhesion greatly improved the adhesion of the calcium phosphate-based ceramic coating layer to the Ti or Ti alloy implant, the manufacturing process was complicated and costly.

[0007]

Means for Solving the Problems Accordingly, the present inventors have:
As a result of research to develop a low-cost Ti or Ti alloy coated implant in which a calcium phosphate-based ceramic coating layer is firmly adhered to the surface of the Ti or Ti alloy implant body, a calcium phosphate-based ceramic coarse powder or granule was obtained. Embedded in the surface of the implant body made of Ti or Ti alloy, which is manufactured by casting a molten Ti or Ti alloy into a mold projecting from the inner surface of the mold so that the calcium phosphate-based ceramic particles or granules are partially exposed. The implants used are Ti
Alternatively, a calcium titanate intermediate layer is formed at the boundary between the Ti alloy and the calcium phosphate-based ceramic coarse powder or granule, and together with the anchor effect, the bonding between the Ti or Ti alloy implant body and the calcium phosphate-based ceramic coarse powder or granule is performed. The calcium phosphate-based ceramics layer-coated Ti or Ti alloy implant obtained by forming a calcium phosphate-based ceramics coating layer on the surface of the implant is excellent in peeling resistance and biocompatibility. That's the finding.

The present invention has been made based on this finding, and (1) a part of a calcium phosphate-based ceramic coating layer coated on the surface of an implant body made of Ti or Ti alloy is made of Ti or Ti alloy. A calcium phosphate-based ceramic layer-coated Ti or Ti alloy implant embedded in the surface of the implant body, (2)
A calcium titanate intermediate layer is formed at an interface between a part of the calcium phosphate-based ceramic coating layer embedded in the surface of the Ti or Ti alloy implant body and the Ti or Ti alloy implant body (1). ) Described calcium phosphate based ceramic layer coating Ti
Or (3) the calcium phosphate-based ceramic coating layer described above in (1) or (2), wherein the calcium phosphate-based ceramic coating layer is a hydroxyapatite coating layer or a tricalcium phosphate coating layer. Implant, (4) Ti or Ti alloy is cast into a mold in which coarse particles or granules of calcium phosphate ceramics are embedded so as to partially protrude and expose inside the cavity of the mold. A composite implant made of Ti or Ti alloy in which a coarse powder or granules of calcium phosphate ceramic is partially exposed is produced, and a calcium phosphate ceramic coating layer is formed on the surface of the composite implant made of Ti or Ti alloy. Calcium phosphate ceramic Scan layer coated Ti or preparation of Ti alloy coated implants, and it has the characteristics to.

[0009] The calcium phosphate-based ceramic coarse powder or granules have a particle size of 1 mm or more, preferably 1 mm or more.
Hydroxyapatite or tricalcium phosphate particles or granules having a predetermined particle size in the range of 2.5 mm are preferred.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an implant made of Ti or Ti alloy coated with a calcium phosphate-based ceramic layer according to the present invention and a method for producing the implant will be described with reference to the drawings.

Example 1 First, a wax mold 1 having the same shape as a Ti alloy artificial hip joint as shown in FIG. 1 was produced. On the other hand, calcium phosphate powder synthesized wet as tricalcium phosphate coarse powder was 800
After calcining at about 3 hours for about 3 hours, pulverizing for about 10 hours with a wet ball mill, adding a binder, dispersing in a slurry, and spray-drying the obtained powder to granulate or press-mold the powder. By calcining at 800 ° C. and then at 1200 ° C., a tricalcium phosphate coarse powder having a rounded particle size of 1 to 2.5 mm was prepared.

The above-mentioned tricalcium phosphate coarse powder is heated, and the above-mentioned heated tricalcium phosphate coarse powder 2 is sprinkled on the surface of the above-mentioned wax mold 1. Then, the coarse calcium triphosphate phosphate 2 adhering to the surface of the wax mold 1 is pressed. Or add the above phosphoric acid 3
A holding tool having a concave portion for holding the calcium coarse powder in a geometrical arrangement is prepared, and the holding tool is heated and pressed against the surface of the wax mold 1 to obtain the III-II of FIGS.
As shown in FIG. 3 which is a cross-sectional view of I, a composite wax 3 was produced in which the calcium tricalcium phosphate powder 2 was partially projected and exposed and partially embedded in the wax 1.

This composite wax 3 is immersed in a coating material which is prepared by mixing silica and flower with an aqueous solution of ethyl silicate, and is immersed in a coating material which is dried.
0%, balance: Cover with a zirconia mold agent, pour back-up filler, solidify the filler, and then heat to dissolve the wax of wax type 1. As shown in the cross-sectional view of FIG. Then, there is obtained a precision casting mold 4 in which tricalcium phosphate coarse powder 2 is partially exposed and partially embedded in the inner surface of the cavity 5 of the mold.

When a Ti-6% Al-4% V Ti alloy melt at a temperature of 1800 ° C. is cast into the precision casting mold 4 from the direction A, the Ti alloy artificial hip joint body 6 as shown in FIG. A composite hip prosthesis made of a Ti alloy in which tricalcium phosphate coarse powder 2 is partially exposed and partially embedded on the surface can be manufactured.

In the case where the tricalcium phosphate coarse powder has a small particle size, the tricalcium phosphate coarse powder 2 is directly sprayed onto the surface of the composite artificial hip joint made of a Ti alloy in which a part of the tricalcium phosphate coarse powder protrudes and is exposed and partly embedded. By forming the tricalcium phosphate coating layer 9, a coated artificial hip joint made of Ti alloy can be manufactured. However, when the particle size of the tricalcium phosphate coarse powder 2 is large, as shown in FIG. Polish and T
The surface of the i-alloy artificial hip joint body 6 is made flush with the surface thereof, and the surface of the polished Ti alloy composite artificial hip joint is sprayed with tricalcium phosphate to form a tricalcium phosphate coating layer 9 of the present invention. It is preferable to produce a hip joint made of a coated Ti alloy.

In the Ti alloy precision casting, the boundary between the Ti alloy and tricalcium phosphate is shown in the sectional view of FIG. 7 until the molten Ti alloy contacts the tricalcium phosphate coarse powder 2 until the molten Ti alloy solidifies. Thus, the calcium titanate intermediate layer 7 is formed, and the calcium titanate intermediate layer 7 further strengthens the bond between the Ti alloy implant body 6 and the tricalcium phosphate coarse powder 2.
Therefore, the Ti alloy artificial hip joint body 6 used in the present invention needs to be a Ti alloy cast.

The phosphoric acid 3 of the present invention thus obtained
Bending the artificial hip joint made of calcium layer coated Ti alloy,
When the tricalcium phosphate coating layer 9 was examined for detachment, cracks were found in the tricalcium phosphate coating layer 9, but no detachment was observed.

Example 2 Calcium phosphate-based ceramics coarse powder:
A hydroxyapatite granule of 0 to 2.5 mm is prepared, and a precision casting mold in which the hydroxyapatite granule is partially projected and exposed in the mold is produced in the same manner as in Example 1. The precision casting mold has a temperature of 1800 ° C. By casting a pure Ti melt, a pure Ti composite hip prosthesis in which hydroxyapatite granules are partially projected and partially embedded on the surface of a pure Ti artificial hip joint body having the same shape as in FIG. 5 is manufactured. Sprayed with hydroxyapatite on the surface of a composite hip prosthesis made of a synthetic hip joint, and having a hydroxyapatite coating layer according to the present invention.
An i-alloy hip prosthesis was produced. This Ti alloy-coated artificial hip joint was subjected to bending, and the hydroxyapatite coating layer was examined for detachment. Cracks were found in the hydroxyapatite coating layer, but no detachment was observed.

Example 3 An artificial tooth root having the same shape as that of an artificial tooth made of Ti alloy was prepared. Further, as a coarse powder of calcium phosphate ceramics, the particle size was 1 mm to 1.5 mm in the same manner as in Example 1.
A tricalcium phosphate coarse powder in the range of was prepared.

In the same manner as in Example 1, the above-described tricalcium phosphate coarse powder was used to produce an artificial root composite wax mold in which the tricalcium phosphate coarse powder was embedded so as to be partially exposed.

Using this artificial root composite wax mold, a precision casting mold is obtained in the same manner as in Example 1, in which tricalcium phosphate coarse powder is partially projected and exposed and partially embedded inside the mold.

The precision casting mold has a T of 1800 ° C.
When the molten Ti alloy of i-6% Al-4% V is cast, Ti
A composite artificial dental implant made of Ti alloy in which tricalcium phosphate coarse powder partially protrudes and partially embeds on the surface of the alloy artificial dental implant body, and the protruding portion is polished, is flush with the surface of the Ti alloy artificial dental implant body. A composite dental implant made of a Ti alloy can be produced.

At the time of the above-mentioned precision casting, the calcium titanate intermediate layer 7 is formed on the boundary between the Ti alloy and the tricalcium phosphate until the molten Ti alloy comes into contact with the tricalcium phosphate coarse powder and the molten Ti alloy solidifies. As in the first embodiment, the bond between the Ti alloy artificial tooth root body 8 and the tricalcium phosphate coarse powder 2 is further strengthened.

A tricalcium phosphate coating layer 9 is formed on the surface of the Ti alloy composite artificial tooth obtained as described above, and as shown in FIG. Was manufactured. Bending the tricalcium phosphate layer-coated Ti alloy artificial tooth of the present invention,
When the falling of the tricalcium phosphate coating layer 9 was examined, no falling was found.

[0025]

According to the present invention, Ti or Ti alloy is cast into a mold in which calcium phosphate-based ceramic coarse powder or granules are embedded and held so that a part of the powder or granules protrudes and is exposed from the inner surface of the cavity of the mold. A composite implant made of Ti or Ti alloy is firmly embedded in the surface of the implant body of Ti or Ti alloy so that coarse powder or granules of calcium phosphate ceramics are partially exposed, and the exposed portion is manufactured. By forming a calcium phosphate-based ceramic coating layer on the substrate, it is possible to manufacture a calcium phosphate-based ceramic layer-coated Ti or Ti alloy implant having a calcium phosphate-based ceramic coating layer with excellent adhesion, which is excellent in the medical industry. It has the effect that it has.

[Brief description of the drawings]

FIG. 1 is a side view of a wax type artificial hip joint.

FIG. 2 is a side view of a composite wax mold in which tricalcium phosphate coarse powder is partially projected and exposed and partially embedded in a wax mold.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a cross-sectional view of a precision casting mold in which tricalcium phosphate coarse powder is partially exposed and partially embedded in the cavity inner surface of the mold.

FIG. 5 is a side view of a Ti alloy composite artificial hip joint in which tricalcium phosphate coarse powder is partially projected and exposed and partially embedded in the surface of the Ti alloy artificial hip joint body.

FIG. 6 is a side view of a Ti alloy composite artificial hip joint in which tricalcium phosphate coarse powder is partially exposed and partially embedded in the surface of the Ti alloy artificial hip joint body.

FIG. 7 is a longitudinal sectional view of a Ti alloy artificial hip joint coated with a tricalcium phosphate layer according to the present invention.

FIG. 8 is a longitudinal sectional view of an artificial dental implant made of a Ti alloy coated with a tricalcium phosphate layer according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 wax type, 2 calcium phosphate coarse powder, 3 composite wax type, 4 precision casting mold, 5 cavity, 6 Ti alloy artificial hip joint body, 7 calcium titanate intermediate layer, 8 Ti alloy composite artificial tooth body, 9 phosphoric acid 3 Calcium coating layer

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) A61L 27/00 A61C 8/00 A61F 2/28

Claims (4)

(57) [Claims] 1. A calcium phosphate, characterized in that a part of a calcium phosphate-based ceramic coating layer coated on a surface of a Ti or Ti alloy implant body is embedded in a surface of the Ti or Ti alloy implant body. An implant made of Ti or Ti alloy coated with a ceramics layer. 2. A calcium titanate intermediate layer is formed at an interface between a part of the calcium phosphate-based ceramic coating layer embedded in the surface of the Ti or Ti alloy implant main body and the Ti or Ti alloy implant main body. The implant made of Ti or Ti alloy coated with a calcium phosphate-based ceramics layer according to claim 1, wherein the implant is made of Ti or Ti alloy. 3. The calcium phosphate-based ceramic coating layer is a hydroxyapatite coating layer or a tricalcium phosphate coating layer.
The implant made of Ti or Ti alloy coated with the calcium phosphate-based ceramic layer described in the above. 4. An implant body made of Ti or Ti alloy by casting Ti or Ti alloy into a mold in which coarse particles or granules of calcium phosphate ceramics are embedded so as to protrude and partially expose inside the cavity of the mold. Ti or Ti embedded such that the calcium phosphate-based ceramic coarse powder or granules are partially exposed on the surface of
An alloy composite implant is made and the Ti or T
A method for producing a Ti or Ti alloy implant coated with a calcium phosphate-based ceramic layer, comprising forming a calcium phosphate-based ceramic coating layer on the surface of an i-alloy composite implant.