JPH0622566B2 - Artificial bone for implant - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an artificial bone for implants, and more particularly to an artificial bone for implants that has good compatibility with living organisms and excellent mechanical strength.

[Prior Art] Artificial bones for implants such as artificial bone prosthesis materials, bone relay materials, artificial joints and artificial tooth roots are already clinically used in orthopedics, dentistry and the like.

Conventionally, most artificial bones for implants have been made of metal, but in recent years, various ceramics artificial bones have been developed and used as excellent artificial bones instead of metal.

For example, as artificial bone for implants for tooth roots, metal Ti, Co-Cr alloys or Fe-Ni- are generally used.
A Cr-based alloy or the like is used. However, these artificial bones for metal-based implants have the disadvantage that they are not compatible with living tissue and may harm the living body depending on the metal. Therefore, as an alternative to artificial bones for metal implants, ceramic artificial bones such as alumina and zirconia have been developed in recent years and are being used in dental clinics (for example, Journal of Japan Dental Implant Society, 181 (1978)). ). Since the artificial bone made of ceramic is chemically stable, it has no effect on the living body, has excellent wear resistance, and has good processability.

[Problems to be Solved by the Invention] Artificial bones made of ceramics have advantages such as good compatibility with living bodies, but ceramics are inherently brittle materials, so that there is a problem that they lack reliability in terms of mechanical properties. there were.

In particular, the implant artificial bone is usually a porous body so as to be fixed to the bone and meat of the living body as naturally as possible,
Moreover, in order to obtain a sufficient fixing effect as a porous body, it is necessary to use a porous body having a large pore size, for example, a pore size of 0.1 mm or more, and having continuous pores, so that the mechanical strength Is significantly reduced, cracks and pinholes are likely to be formed, and in extreme cases, artificial bone may be damaged.

[Means for Solving Problems] The present invention solves the above-mentioned conventional problems and provides an artificial bone for implants that is well compatible with living bodies and excellent in mechanical strength. In an artificial bone for implants made of a porous body having pores, a coating film is formed on the inner walls of continuous pores by a CVD reaction, and a porous body or a dense body having independent pores. The artificial bone for implants, which comprises a joined body with a porous body having continuous pores, is characterized in that a coating film is formed on the inner walls of the continuous pores by a CVD reaction.

Hereinafter, the present invention will be described in detail with reference to the drawings.

The artificial bone for implants of the present invention has a coating film 3 formed by a CVD reaction on the inner wall of continuous pores 1 of a porous body 2 having continuous pores 1 as shown in the enlarged view of its cross section in FIG. Is. The porous body 2 usually has small pores 7 in the skeleton forming the porous body 2, which also contributes to the decrease in the strength of the porous body 2.

As a material of the coating film formed by the CVD reaction, ceramics are preferable in consideration of the compatibility with living bodies and the influence on living bodies. Among the ceramics, zirconia is most preferable in terms of strength and the like.

The thickness of the coating film 3 is not particularly limited, but if the film thickness is too thin, a sufficient strength improving effect due to the coating film cannot be obtained, and conversely, if it is too thick, the problem of peeling of the coating film may occur. Therefore, it is preferable to form them to an appropriate thickness in consideration of these.

In the present invention, the porosity, pore diameter, etc. of the porous body 2 are appropriately determined according to the purpose of use and the required characteristics of the artificial bone. Also,
As the material of the porous body 2, a metal or ceramics sintered body which has been conventionally used as an artificial bone can be used. When a zirconia film is formed as the coating film 3, the material of the porous body 2 is preferably a zirconia sintered body from the viewpoint of its adhesiveness.

The artificial bone for implant of the present invention may be wholly constituted by a porous body having a CVD coating film formed on the inner walls of continuous pores as shown in FIG. The bone fixing portion may be formed of a film-forming porous body, and the other portion may be a porous body having independent pores or a dense body to improve strength.

That is, the artificial bone for implants according to the second aspect of the present invention has continuous pores 1 as shown in the enlarged view of its cross section in FIG. 2, and the coating film 3 by the CVD reaction is formed on the inner walls of the pores. The porous body 2 and the porous body 5 having the independent pores 4 or the dense body are joined together via the joint surface 6.

In this case, the porosity of the porous body 5 having the independent pores 4 and the material of the porous body 5 or the material of the dense body are appropriately selected according to the purpose of use and the required characteristics of the artificial bone. Body 5
Alternatively, the material of the dense body is preferably a ceramic-based sintered body such as zirconia as described above.

The porous body 5 or the dense body and the porous body 2 having continuous pores can be joined by using an inorganic or organic adhesive, a brazing agent, or the like. It is preferable to join by the CVD reaction deposit.

The method for producing the artificial bone for implant of the present invention will be described below.

In the present invention, the porous body 2 having the continuous pores 1 serving as the substrate is heated to the deposition temperature range of the CVD reaction, and the CVD reaction gas is supplied through the continuous pores 1 as shown in FIG. A CVD reaction deposit is deposited as shown in FIG. 3 (b).

The heating method is not particularly limited as long as it can partially heat the porous body, but high frequency induction heating or the like is advantageous. When the high frequency induction heating is adopted, if the porous body is a conductive member, it is sufficient to shift the heating points by sequentially applying the magnetic field in that state. When the porous body is non-conductive, the porous body is coated with a conductive substance such as carbon in advance to perform a conductive treatment, and then an alternating magnetic field is applied by a high frequency coil. Similarly, it is advantageous to perform high frequency induction heating.

The thickness of the CVD coating film thus formed is C
It can be arbitrarily adjusted by adjusting the supply amount of VD reaction gas or the heating time.

Further, an artificial bone for implant according to the second invention of the present invention is manufactured by joining a porous body having such a CVD coating film formed thereon and a porous body or a dense body having independent pores. In FIG. 4, the product manufactured by the procedure of FIGS. 3 (a) to (c) may be adhered to the counterpart member with an adhesive or the like.
It is preferable to join by a CVD reaction deposit by the method as shown in (a) to (c).

That is, first, as shown in FIG. 4 (a), a mating member (a porous body or a dense body having independent pores) 6 to be joined and a porous body 2 having continuous pores 1 are superposed, and then the porous body is formed. A CVD reaction is generated by heating the vicinity of the joint between 2 and the counterpart member 6 to the deposition temperature range of the CVD reaction and supplying the CVD reaction gas to the joint surface via the continuous pores 1 of the porous body 2. Let

As a result of the CVD reaction, CVD reaction deposits 7 are deposited in the continuous pores in the portion of the porous body 2 that is to be joined to the counterpart member 6, as shown in FIG. 4 (b), and a solid phase is formed. Due to this CVD reaction deposit 7, the porous body 2 and the counterpart member 6 are bonded very strongly.

After joining in this way, the CVD coating film 3 is formed on the inner walls of the continuous pores 1 of the porous body 2 by sequentially causing the CVD reaction while shifting the heating portion as described above.

In the above description, the method of forming the coating film after joining the porous body and the counterpart member has been described, but the reverse is the case, that is, the porous body on which the coating film is previously formed is the counterpart member. You may make it join to.

[Operation] Since the CVD reaction deposit is extremely dense and has excellent mechanical strength such as strength, by forming a CVD coating film on the inner walls of the continuous pores of the porous body as in the present invention, bonding with a living body is achieved. It is possible to significantly improve the strength of the artificial bone without impairing the sex.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to the following examples unless it exceeds the gist.

Example 1 By the method shown in FIGS. 3 (a) and 3 (b), continuous porosity (porosity 8
A CVD reaction gas is fed to the zirconia ceramic porous body 2 having 0% and an average pore diameter of 150 μm) to form a zirconia CVD coating film having an average film thickness of 10 μm on the inner walls of the continuous pores to obtain the implant artificial bone of the present invention. Was manufactured.

This artificial bone was cut into a predetermined size to form a sample, and a bending strength measurement test was performed. The results are shown in Table 1.

As a comparative example, an artificial bone for implants made of a zirconia porous sintered body not subjected to the CVD treatment was similarly tested, and the results are also shown in Table 1.

From Table 1, it is clear that the artificial bone for implants of the present invention has remarkably higher strength than conventional ones.

[Effects of the Invention] As described in detail above, the artificial bone for implant of the present invention is
Since it is composed of a porous body having continuous pores and a CVD coating film is formed on the inner walls of the continuous pores, the continuous pores can be extremely naturally and satisfactorily fixed to the bone and meat of the living body.

Since the porous body is reinforced by the CVD coating film, the mechanical strength is extremely high.

And so on. Therefore, the artificial bone for implant of the present invention is stably fixed without adversely affecting the living body,
Moreover, damage such as cracks hardly occurs, and the reliability is extremely high.

[Brief description of drawings]

1 is an enlarged view of a cross section according to an embodiment of the artificial bone for implant of the present invention, FIG. 2 is an enlarged view of a cross section according to another embodiment of the artificial bone for implant of the present invention, FIG. 3 (a) , (B) is a cross-sectional view showing a production example of the artificial bone for implant of the present invention, and FIGS. 4 (a) to (c) are cross-sectional views showing another production example of the artificial bone for implant of the present invention. 1 ... continuous pores, 2 ... porous body, 3 ... CVD coating film, 4 ... independent pores, 5 ... porous body.

Claims (3)

[Claims] 1. An artificial bone for implant, which comprises a porous body having continuous pores, wherein a coating film is formed on the inner walls of the continuous pores by a CVD reaction. 2. An artificial bone for implant comprising a porous body having independent pores or a joined body of a dense body and a porous body having continuous pores, wherein a coating film is formed on the inner wall of the continuous pores by a CVD reaction. An artificial bone for implants characterized by: 3. A porous body or a dense body having independent pores and a porous body having continuous pores are joined by a CVD reaction deposit.
The artificial bone for implant according to the item.