JPS61284253A - Implant material - 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 is applicable to artificial bones, artificial joints, artificial tooth roots, etc.
Pertains to implant materials intended to substitute or replace bones in various parts of the human body.

[Background of technology] With the development of bioengineering, recently, artificial materials processed into the shape of joints or tooth roots are inserted (implanted) into the bone tissue of the human body to restore lost biological functions. Implant surgery for this purpose is in the spotlight.

Traditionally, artificial materials used in this implant procedure include
Metal materials such as cobalt-chromium alloy, titanium, and tantalum, and ceramic materials such as hydroxyapatite, zirconia, alumina, and glassy carbon are known. However, although metal materials have excellent mechanical strength, they have poor affinity for living organisms, and some of them are harmful due to elution of metal ions. On the other hand, although ceramic materials have excellent affinity for living organisms, they remain unsatisfactory in terms of mechanical properties.

That is, conventional artificial materials each have advantages and disadvantages in terms of toxicity to living organisms, compatibility with bones, durability, etc., and it is difficult to say that they are necessarily satisfactory implant materials.

[Object of the Invention] In view of the above-mentioned circumstances, the present invention aims to provide a practically reliable implant material that is excellent in biocompatibility, biostability, mechanical properties, etc.

[Summary of the Invention] According to the present invention, the above object is achieved by a composite integrated implant material formed by forming a layer of a composition consisting of hydroxyapatite/thermosetting resin on the outer periphery of a metal substrate. .

[Effect of the invention J: As an implant material that is a composite and integrated combination of a metal material and other materials, JP-A-53-28997 discloses an implant material in which a sprayed layer of ceramic powder and hydroxyapatite powder is formed on the outer periphery of a metal base material. do. The implant material has biocompatible properties of hydroxyapatite,
It is expected that the mechanical properties of the metal base material can be mutually utilized, but due to the difference in thermal expansion between the metal base material and the sprayed layer material, cracks are likely to occur in the sprayed layer, and metal ions can be leached from the cracks. There are concerns.

Furthermore, in JP-A No. 57-156757, the outer surface of a metal base material is coated with thermoplastic polymer such as polysulfone, high-density polyethylene, polymethyl methacrylate, calcium phosphate, etc.
An implant material coated with a composition containing 20 to 30% of an inorganic substance such as hydroxyapatite is disclosed. However, since thermoplastic polymers have poor adhesion to metal substrates, the implant material tends to peel off at the interface, and is therefore difficult to say is practically reliable. The implant material tends to be easy to insert in implant surgery, and the implant material is characterized in that it does not come out or fall out when inserted,
It is difficult to find an implant material that takes advantage of the biocompatibility properties of minerals, especially human oxyapatite, and has poor compatibility with bone.

The implant material of the present invention integrates hydroxyapatite and gold H base material into one body through a thermosetting resin that has an excellent retention rate of hydroxyapatite and has excellent adhesion to metal base materials, and takes advantage of the characteristics of each. It has excellent biocompatibility, biostability, mechanical properties, etc., and is reliable in practice. Furthermore, when the implant material of the present invention is used as an artificial tooth root, it is characterized by the fact that it does not cause any discomfort to the living body due to the appropriate elastic modulus and hardness of the thermosetting resin.

[Summary of the Invention] The hydroxyapatite according to the present invention is a synthetic or natural hydroxyapatite, a calcined product thereof, or a mixture thereof.

Synthetic hydroxyapatite may be obtained by a known production method, for example, Ceramics Vol. 10 (7) 461
900-1 as described in p. 900-1 (1975).
Ca3 (PO
4) A dry synthesis method in which 2 is reacted with excess CaCO3, or a method in which a fine particulate calcium hydroxide emulsion is reacted with an aqueous phosphoric acid solution under high-speed stirring (JP-A-56-45814), C
a(NO3)2 aqueous solution and NH4H2PO4 aqueous solution with N1
-1408 Method of reaction under alkalinity (Anaew
, Chea+, 67327 (1955)) and their sintered bodies.

Natural hydroxyapatite is made from natural bone, and can be produced by, for example, calcining the back of a cow at around 800°C to remove organic matter. The hydroxyapatite may contain light ivy or a different element such as fluorine or iron, if necessary.

The particle size of hydroxyapatite is 1000 μm or less, preferably 1 μm, from the viewpoint of moldability, ease of handling, mechanical strength, etc.
00μ to 0.01μ. Since thermosetting resins are implanted in living organisms for a long period of time, it is necessary that there is no deterioration of the resin or destruction of living cells. The latter is particularly preferred. The thermosetting resins may be used alone or in a mixture.

The thermosetting resin has superior bonding properties with metal substrates, as well as superior adhesion to hydroxyapatite and neonatal tissue and epithelial adhesion, compared to thermoplastic resins such as polymethacrylate.

The mixing ratio of hydroxyapatite and thermosetting resin is 35/
65-85/15 (weight ratio) preferably 50/50-
It is in the range of 80/20. The mixing ratio is arbitrarily selected in consideration of adhesion to bone, bone formation rate, or mechanical properties.

Note that the resin composition does not necessarily have to be uniform; for example, when used as an artificial tooth root, the portion located near the inner edge epithelium is rich in resin phase, and the portion located near the alveolar bone portion is rich in hydroxyl. The composition ratio may be such that it is rich in apatite phase.

The metal base material according to the present invention includes all known metals and alloys, including Co-Cr-Ni alloy, Co-Cr-M
o series alloy, stainless steel 18-8.316L, titanium,
Dense or porous materials, such as tantalum, which have extremely little harmful effect on living tissues, have sufficient mechanical strength, and have been conventionally used as artificial materials are preferred.

The metal base material may be provided with independent and/or continuous grooves on its outer periphery for anchoring effect with the resin composition and dispersion of external force after implantation. The shape and size of the metal base material is not particularly limited, and may be a bottle type, slurry type, blade type, anchor type, plate type, mesh type, etc.
Its cross section may also be square, circular, oval, etc.

The method for obtaining the implant material of the present invention is not particularly limited, but for example, the metal material may be molded, sintered, cast, or cut, and the resulting core material may be optimally polished and set in a mold. It can be manufactured by pouring the resin composition blended in advance and cutting and polishing the surface of the resin composition depending on the thermosetting resin.

The outer surface of the resin composition may be smooth or have an uneven shape such as a screw shape. Although the application site of the implant material of the present invention is not particularly limited, it goes without saying that it can be used in the gingiva, bone tissue, subperiosteal area, intramucosal area, etc.

In addition, when the implant material of the present invention is used as an artificial tooth root, an M4 structure made of hydroxyapatite alone may be disposed around the outer periphery of the resin composition in a portion located near the inner edge epithelium. Furthermore, the shape of the resin composition in the vicinity of the epithelium may be made into a brim shape to improve epithelial adhesion.

Hereinafter, the implant material of the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view of an artificial tooth root made of the implant material of the present invention, and FIG. 2 is a cross-sectional view showing its internal structure. That is, for example, titanium or cobalt-based alloy is used to constitute the core body 3 of the implant body 1, and its outer surface is coated with 1 to 30,000 parts of a condensable resin of triethylene glycol dimethacrylate and 70 parts of hydroxyapatite added thereto. The core body 3 is coated using a resin silicate obtained by coating the core body 3.
A screw-shaped groove 4 is provided in the groove.

A standard Iu artificial tooth crown can be freely selected and adhesively fixed to the upper part.

A crystal was inserted into the jawbone of an adult, and X-ray observation was performed after 12 months had elapsed. Good bone formation was observed, and no abnormalities such as inflammation were observed.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the implant material of the present invention, and FIG. 2 is a cross-sectional view. DESCRIPTION OF SYMBOLS 1... Implant material main body, 2... Resin composition part, 3... Metal core, 4... Screw-shaped groove.

Claims (3)

[Claims] (1) An implant material formed by forming a layer of a composition made of hydroxyapatite and a thermosetting resin on the outer periphery of a metal base material. (2) Claim 1 characterized in that the composition ratio of hydroxyapatite and thermosetting resin composition is 35/65 to 85/15 (hydroxyapatite/thermosetting resin, weight ratio). Implant materials listed. (3) The implant material according to claim 1, wherein the thermosetting resin is a triethylene glycol dimethacrylate polycondensation resin.