JPH0657244B2 - Biomedical implant - Google Patents

Description

TECHNICAL FIELD The present invention relates to a biomedical implant applied to the fields of dentistry and dentistry.

[Conventional technology]

2. Description of the Related Art In recent years, biomaterials used in the field of dentistry and medicine, especially in the field of orthopedics, have made remarkable progress, and various new materials have been developed and put into practical use.

It is important for the implant material as such a biomaterial to have low biotoxicity and good compatibility with the living body (affinity), high mechanical strength, corrosion resistance, and wear resistance. Excellent characteristics are required. Of these, Ni-Cr alloy and Co- are mainly used as dental materials.
Cr-Mo alloys, metals such as titanium, and ceramic materials use sintered bodies such as alumina, apatite, and zirconia, while dental materials often include ceramics, stainless steel, cobalt-chromium alloys, titanium, and titanium alloys. It is used.

However, when the implant made of the above-mentioned material is embedded in a living body and is used for a long period of time, the joint with the bone of the living body is likely to loosen.

To prevent such loosening, artificial roots and bones,
In order to fix and hold various implants such as artificial joints to the bone, the implant is brought into close contact with the bone tissue in a sufficiently engaged state.

Screws and spikes are formed on the implant itself, and these are mechanically fixed with great strength.

Glue cement is filled between the implant and the bone and adhesively fixed.

Such measures have been taken.

Of these, the most desirable implant for the living body is to join the bone tissue shown in the above in a sufficiently engaged state. For that purpose, it has been considered to allow the infiltration of bone cells into the part that joins with the bone and strengthen the mechanical engagement force between the bone and the implant. In order to enable the infiltration of bone cells in this way, the pore size of the receiving pore is 150-200 μm.
It is said that more than m is required. Therefore, the current implants are used in which the surface is provided with indentations or projections, metal particles or ceramic particles are attached, or a porous layer is formed.

[Problems to be solved by the invention]

However, in the case where a large number of fine receiving holes are provided for bone penetration by adhering metal particles or ceramic particles or forming a porous layer, the structure of the receiving holes is not uniform. However, it is difficult to arrange regularly because the distribution tends to vary greatly, and therefore there is no one in which a porous layer having a uniform and desired pore size is formed.

As a result, a sufficiently large bond strength with the bone due to the invasion of the bone could not be obtained, and despite the porous structure, it could not be bonded to the bone with a sufficient bond strength.

[Means for solving problems]

As described above, in order to prevent loosening, falling out, sedimentation, etc. due to long-term use of the implant, on the surface of the implant, a fibrous state made of a non-biologically harmful material such as metal, ceramic, or polymer material, or It is characterized by attaching a reticulate body and aligning and orienting the bone receiving holes having a substantially uniform pore size so as to evenly grow and invade the bones, and thereby bring about the maximum binding force. .

〔Example〕

Next, an embodiment of the biomedical implant according to the present invention will be specifically described with reference to the drawings.

FIG. 1 (a) shows a partial fractured cross-sectional view of a biomedical implant P1. This implant P1 has a body B made of ceramic, metal or the like on the outer surface thereof. A linear body W having a small number of windings is wound in a state in which the pitch is narrowed. As the wire diameter of the wound linear body W, various ones are used depending on the required size of the bone receiving space S formed between the wound wires, but it is possible to increase the penetration of bone. The range is from 150 to
Since it is 200 μm or more, a linear body W having a wire diameter of about 50 to 500 μm is used.

Further, as in the implant P2 shown in FIG. 6B, a spring-formed linear body W ₁ having a plurality of thin wires may be wound at a required pitch, and a base body on which such a linear body W ₁ is wound. B ₁ may be tubular.

Next, as shown in FIG. 3C, the reticulate body N may be attached to the surface of the base B. Further, as shown in the partial surface views of FIGS. 2 (a) and 2 (b), in FIG. 2 (a), a titanium plate is provided with a mesh body N _{1 in} which a large number of holes H are regularly formed. , (B), a net-like body N ₂ formed by arranging linear bodies radially from two directions is attached.

Thus, Fig. 1 (a) (b) (c) and Fig. 2 (a)
As shown in (b), the linear bodies W, W ₁ , the nets N, N ₁ , N ₂
By adhering to the outer surfaces of the substrates B and B ₁ , a regular array structure having a constant direction is formed and adjacent linear W,
A uniform space S can be created between W _{1 s} , and this space S serves as a hole for bone penetration. It is also possible to form a three-dimensional mesh structure by stacking the mesh bodies N, N ₁ and N ₂ in multiple stages.

The materials of the bases B and B ₁ and the linear bodies W and W ₁ and the reticulate bodies N, N ₁ and N ₂ attached to them are preferably ceramics or metal, but metal-ceramics, metal-polymer materials , Different materials such as ceramic-polymer materials can also be used. As a method for adhering the material for forming the bone receiving hole on the surface of the substrate as described above, a general sintering method may be used, but in order to achieve higher bonding strength and uniform bonding, the pressure cutting by high temperature and high pressure is performed. Contact method, for example hot isostatic pressing
(HIP) method is recommended.

Further, in the implants P ₁ and P ₂ shown in the examples of the present invention, the corrosion area such as contact corrosion and gap corrosion is increased due to the increase in the contact area with the living body, and at the same time, the corrosion rate is also expected to increase, A linear body forming a porous bone receiving hole,
The surface of the mesh is coated with a material having excellent wear resistance and corrosion resistance such as oxides, carbides, nitrides, and carbonitrides by a known method such as an ion plating method and a radiation method. Good.

〔The invention's effect〕

As described above, according to the present invention, a metal ceramics composed of a linear body and a net body on the outer surface as a biomedical implant,
Since the aligned and oriented bone receptive holes were formed using a material such as a polymer material that is less harmful to living organisms, the average hole diameter, porosity, etc. were almost uniform, and the bone receptive holes had a regular shape. As described above, the proliferation and invasion of bone cells can be obtained, and the maximum mechanical engagement force between the implant and the bone can be expected.As a result, it is possible to prevent loosening, loosening, and sedimentation of the implant, and for a long period of time. It is possible to provide a biomedical implant capable of obtaining stable and strong holding performance.

[Brief description of drawings]

1 (a), (b), and (c) are partial cross-sectional views of a biomedical implant according to an embodiment of the present invention, and FIG. 2 (a).
(B) is a partial plan view of another embodiment of the biomedical implant according to the present invention. B, B ₁ : substrate W, W ₁ : linear body N, N ₁ , N ₂ : mesh body

Claims (1)

[Claims] 1. A living body characterized in that a linear body or a reticulate body made of a material having a low biotoxicity such as metal, ceramics, and plastic is adhered to a surface of a base body forming a biomedical implant that comes into contact with bone. Implant.