JPS6365870A - Implant - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in implants. The present invention can be generally applied to bones in various parts of the human body. In recent years, implants, which restore lost parts and functions of the living body by inserting and replacing artificial materials such as artificial organs, artificial blood vessels, artificial joints, artificial bones, and artificial tooth roots, have been in the spotlight. In particular, implants for bones and tooth roots have had a great effect on treatment and functional recovery. There is no artificial bone, artificial joint, or artificial tooth root that satisfies these conditions.

Artificial materials that have traditionally been mainly used for bones and teeth include metal materials such as Co-Cr alloys, stainless steel, titanium, and tantalum, and ceramics (materials include Ti0z,
A(LO3, Ca0-AQtO3, AQ203-S1
02 series glass, 5iOt-NazO-CaO-P205
Although there are other types of ceramics such as glass (bioglass) and carbon, bioceramics based on phosphate-based materials are attracting attention.

Although metal materials have excellent mechanical strength, particularly impact strength, they often have problems with their affinity for living tissues.

For example, metal ions are eluted and act as cytotoxic agents for bone cells surrounding the implant. In addition, there is an obstacle to the functioning of cremated remains, which is thought to be due to too good heat conduction. Implants made of ceramics generally have good affinity with bone, do not react with tissue, and are highly durable, but they have a problem with fixation with bone tissue. In addition, these artificial materials have a completely different composition from the hard tissues of bones and teeth, and although they are not toxic, they are nothing more than dead materials in living organisms.

Among calcium phosphate materials, tricalcium phosphate and/or tetracalcium phosphate are materials that have a composition similar to that of bones and teeth. Tricalcium phosphate and/or tetracalcium phosphate are hydroxyapatite precursors that are similar to the inorganic components of bones and teeth, and dissolve in tissues. Since it is absorbed and incorporated into the body's metabolism, and hard tissue induction is replaced by new bone, it has particularly excellent biocompatibility and bioactivity.

The present invention has been improved in consideration of the above-mentioned drawbacks.
What is needed is an implant that provides even stronger fixation without losing the advantages of ceramics.

The implant of the present invention has a core material made of dense ceramics, and on all surfaces in contact with tissue, ■) tricalcium phosphate powder and/or tetracarunium phosphate powder, 2) ceramic powder and tricalcium phosphate powder. and/or mixed powder of tetracarnoum phosphate powder, or 3) ceramic powder and then thermal spray coating with tricalcium phosphate powder and/or tetracalcium phosphate powder. The sprayed layer of ceramic powder has some pores and has good affinity with living organisms, and new bone cells enter the pores on the surface of the layer and are firmly fixed. The sprayed layer of tricalcium phosphate powder and/or tetracalcium phosphate powder is the outermost layer of the implant and is in contact with the living tissue, and is absorbed by the body and replaced by new bone, just like the ceramic sprayed layer. It has pores and intrusion of bone tissue.

The ceramic powder and the tricalcium phosphate powder and/or the tetracalcium phosphate powder are thermally sprayed to form a coating, and the thermally sprayed coating has excellent mechanical strength and adhesive strength. The implant not only has ceramics and tricalcium phosphate and/or tetracalcium phosphate that have a very good affinity with living tissue, but also has an uneven surface of the sprayed layer, which prevents bone tissue from growing on the uneven areas. To show the anchor effect,
It does not require the bone cement traditionally used for artificial tooth roots, artificial bones, and artificial joints.

Next, the present invention will be explained according to the drawings.

Figures 1 and 2 show examples of implants according to the present invention, where Figure 1 shows a dental implant and Figure 2 shows an artificial joint, which differs in shape from conventional metal implants. The difference is that a ceramic sintered body is used for the core material 1. Ceramic sintered bodies can withstand excellent mechanical properties such as compression, bending, tension, and impact using conventional processing techniques, and can sufficiently withstand various external forces required for implants.

The ceramic core material 1 has a thermally sprayed layer 2 of ceramic powder and a thermally sprayed layer 3 of tricalcium phosphate powder and/or tetracalcium phosphate powder on its outer periphery in FIG. 1 and in FIG. A sprayed layer 4 of tricalcium phosphate powder and/or tetracalcium phosphate powder is provided, and bone cells enter the pores of the sprayed layer to provide firm fixation.

As the ceramics used in the present invention, metal oxides conventionally used for corrosion resistance, wear resistance, and surface treatment of metals can be used as they are or as a mixture. For example, as metal oxides, A(hoz, Trot, 2nOt
, 5ift, 5nOt, P, Os, Cab.

B, 0. Examples include. In addition, the tricalcium phosphate in the present invention includes CaCO3, CaCO3,
Cab, Ca(Off) =, P- as phosphate source
Os.

+1. PO,,N1. lI*PQ,, (N)1. ),
llPO4 and qC containing both calcium and phosphate
aHPOi, Ca(HtPOJ*, etc.), prepared by a conventional method and expressed as Caz(PO4)t. In addition, tricalcium phosphate in the present invention may be α-type, β-type, or α-type,
A β-mixture may also be used, but the following manufacturing method is preferable, especially under conditions such as in vivo activity and thermal spraying.The manufacturing method is not particularly limited, but α-type tricalcium phosphate synthesized by dry heat method etc. was crushed. Preferably, a powder of 70 μm or less is used as a starting material, and this is usually mixed with water of 117 to 8. Fl! 'J under pressure of about 1 to IO atmosphere,
A powder formed by compression molding and firing at 800 to 1300° C. for 1 to 10 hours, preferably adjusted to a particle size of about 100 μm or less, may be suitably used.

In order to control the porosity of the tricalcium phosphate sprayed layer, ceramic powders and the like can be mixed with the tricalcium phosphate powder. In addition, tetracarunium phosphate in the present invention can be used as a calcium source such as CaC0, Cab, C
a(Ofl)! , PfO,, Hjf as phosphoric acid source
'O,,NH,H2PO,,(N11.)tHPo,,
and CaHPO containing both calcium and phosphoric acid,
, Ca(nfPo, ), etc., and adjusted by a conventional method.

(PO,), represented by O. In addition, the method for producing tetracarunium phosphate in the present invention is as follows: ■ carunium hydrogen phosphate (C
allPO, ) or γ-calcium birophosphate (
After mixing calcium carbonate (CaCOl) with calcium carbonate (CaCOl), it is fired at 1000 to 1500°C and is represented by the chemical formula below, but it is preferable to rapidly cool it in air or to fire it in a nitrogen gas atmosphere.

■2CaCoff + 2Ca11POa→Ca4(P
O4) 20-1-11tO+ 2CO2■ 7 Cat
PtOt+ 2CaCOt→Ca4(PO4)to+
The manufacturing method for 2COp is not particularly limited, but synthetic tetracarunium phosphate was pulverized by a dry heat method or the like. Preferably, a powder prepared by F1 adjustment to a particle size of about 100 μm or less may be suitably used.

In order to control the porosity of the tetracalcium phosphate sprayed layer, the above-mentioned ceramic powder etc. can also be mixed with the tetracalcium phosphate powder.

It goes without saying that the implant of the present invention may be used in a captive, intraosseous, subperiosteal, intramucosal, etc. area, although there is no particular limitation. The shape of the ceramic core material in the implant is not particularly limited, and includes pin-type, scrico-type, blade-type, anchor-type, plate-type, mesh-type, and the like.

In order to obtain the implant of the present invention, a core material is created by sintering a ceramic material using conventional techniques. For example, after molding by isostatic pressure compression or mud casting, 10
Sintering is carried out at a temperature of 00-2000°C for about 5 minutes. If it is necessary to make the surface of the core material uneven, the surface roughening is performed by machining such as cutting or grid blasting before, during, or after sintering. Further, when creating a core material having a complicated shape, the shape can be adjusted by machining as described above. ■) on the outer periphery of the core material you created.
tricalcium phosphate powder and/or tetracalcium phosphate powder, 2) ceramic powder and tricalcium phosphate powder and/or tetracalcium phosphate powder, 3) ceramic powder and then tricalcium phosphate powder and/or tetracalcium phosphate The powders are each sprayed using commercially available thermal spray equipment, preferably plasma spray equipment. Areas that do not require thermal spraying are masked before Grid Plast. The sprayed ceramic and tricalcium phosphate and/or tetracalcium phosphate coatings can be used as they are, but depending on the location, the surface may be polished before use. or,
800 in air, vacuum, or inert gas
It is sometimes used by performing firing at a temperature of ~1700°C.

The present invention will be explained in detail below with reference to Examples, but the present invention is not limited thereto.

Example 1 An implant core (O) was created using aluminum oxide. Tricalcium phosphate powder was sprayed onto the ceramic implant core material using a plasma spraying device.
/1 m of tricalcium phosphate powder was obtained. The main island was implanted into the tibia of a domestic rabbit, and X-ray fluoroscopic observation was performed after 2 months had passed.
As a result, a tube-forming effect of the phlegmon was observed around the imblat.

Example 2 The procedure was the same as in Example 1, and the second layer was made of 50% by weight of tricarnoum phosphate and 50% of alumina (Meteco powder number 105).
The implant was obtained by thermal spraying the mixed powder of % by weight. After 2 months had elapsed since the ice crystals were buried in the goat's mandible, X-ray fluoroscopic observation revealed a cremation effect around the implant.

Furthermore, macroscopic observation revealed that no abnormality had occurred in the periodontal tissues.

Example 3 Except for using high-purity alumina as the implant core material,
An artificial bone head circumference for an artificial joint was prepared in the same manner as in Example I. No abnormalities were observed after 3 months had passed since ice crystals were implanted in the dog's hip.

Example 4 Co-Cr-Ni alloy (Nobilium Co., Ltd. Nob
The cast body obtained by performing high frequency melting using ilium and centrifugal casting was polished to obtain an implant core material (1 g).

This metal core material is grisot blasted (
The blasting material is Methycolyte vF.

The pressure was 30 psi). Next, argon, hydrogen, and plasma jet flame (ARC
A current of 5 QOAmp) was generated, and nickel-aluminum alloy powder (Meteco powder number 450), which was a self-bonding bonding agent, was dissolved as a first layer to form a film with a thickness of about 80 μm over the entire surface of the core material. The second layer contains tetracalcium phosphate powder (particle size 10 synthesized by the production method described in -1-).
A white powder of 0 μm or less was sprayed to an average thickness of 200 μm.

The ice crystals obtained by baking the implant at 1200'C in a vacuum electric furnace for 10 minutes were implanted into the tibia of a domestic rabbit, and 2 months later, X-ray observation was performed.As a result, the implant was observed. Dense skeletal remains were observed around the area.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment in which the present invention is used as a dental implant. FIG. 2 is a perspective view showing an embodiment in which the present invention is used as an artificial hip joint. ■ ・・・・・・・・・・・・・・・・・・ Core part 2
・・・・・・・・・・・・・・・・・・ Ceramic layer 3.4 ・・・・・・・・・・・・Tricarnoum phosphate support/or tetracalcium phosphate layer Radiation patent applicant: Advance Development Institute Co., Ltd. Figure 1 Figure 2

Claims (3)

[Claims] (1) An implant characterized by having a sprayed layer of tricalcium phosphate powder and/or tetracalcium phosphate powder on the outer periphery of a ceramic implant core material. (2) An implant characterized by having a sprayed layer of a mixed powder of ceramic powder and tricalcium phosphate powder and/or tetracalcium phosphate powder on the outer periphery of a ceramic implant core material. (3) An implant characterized by having a sprayed layer of ceramic powder formed on the outer periphery of a ceramic implant core material, followed by a sprayed layer of tricalcium phosphate powder and/or tetracalcium phosphate powder.