JPH05154191A - Bioactive implant and production thereof - Google Patents

Abstract

PURPOSE:To prevent the deformation of a metallic base body at the time of firing ceramics and to improve the density and strength of the ceramics by enhancing the bioactivity of the ceramics and attaining the lower-temp. firing of the material. CONSTITUTION:A bioactive ceramic material which has a non-calcium phosphate type compsn. consisting essentially of at least one kind of an alkaline earth metal oxide or alkaline metal oxide and SiO2 and can form HAP in an aq. soln. contg. P ions and Ca ions is used as the ceramic material of the bioimplant formed by laminating a ceramic layer on the metallic base body. In addition, the bioactive ceramic power is formed as fine powder having >=10m<2>/g BET value. As a result, the ceramic layer having the properties of <=1200 deg.C firing temp. and >=30MPa peeling strength is obtd.

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to bioactive implants applicable to artificial bones, artificial tooth roots, artificial joints and the like. It is an implant that combines this with a substrate such as a metal.

[0002]

2. Description of the Related Art Until now, bioactive implants used for artificial bones, artificial tooth roots, artificial joints, etc. have been made of metals such as stainless steel, metallic titanium, nickel-cobalt alloys, and ceramics such as alumina and zircon. It has been

[0003] However, since these materials do not have the property (bioactivity) to directly bond with living tissues such as bones and integrate homogeneously with them, after the implantation surgery, when time passes under conditions where stress is applied repeatedly, A gap may occur at the interface between the bone and the implant, which may reduce the fixation force and cause wobble. Furthermore, this may cause bone resorption, damage to the bone, and the risk of falling off.

[0004] On the other hand, calcium phosphate-based materials, which have a composition similar to that of bones and teeth, have bioactivity and are homogeneously integrated with bones in the living body over time to directly bond with them. Has stability.

For this reason, recently, hydroxyapatite (HA
P), tricalcium phosphate (TCP), bioglass, and other calcium phosphate-based ceramics are attracting attention.

[0006]

However, although the calcium phosphate-based ceramics such as HAP described above also have the characteristic of directly bonding with new bone, these materials still do not support the growth and maturation of new bone, and the bonding with other materials. However, it was not enough for early cure.

[0007] In addition, since the mechanical strength is lower than that of metals, alumina, zirconia, and other metal oxide ceramics, there is a drawback that the range of application as a single ceramic is extremely limited.

[0008] In order to supplement strength, an implant made by laminating calcium phosphate ceramics on a high-strength material such as metal has also been proposed in Japanese Patent Publication No. 58-39533, etc., but the strength of the calcium phosphate ceramics is weak. Therefore, there were problems of peeling and chipping.

Furthermore, conventionally, it has been believed that a ceramic material exhibiting bioactivity must have a composition based on the same calcium phosphate compound as that used in living tissue. Couldn't improve.

In view of the above problems, the inventors of the present invention conducted extensive research on bioceramics materials, and found that CaO,
We have found that ceramics containing _SiO2 , although non-calcium phosphate ceramics, exhibit unexpectedly good bioactivity, and have previously filed a patent application (Japanese Unexamined Patent Application Publication No. 3-901).
52, Japanese Patent Application No. 2-131191).

[0011] However, in the method of forming an implant by coating a ceramic material paste on a metal substrate such as titanium and firing it, if the firing temperature of the ceramic material exceeds the melting point of the metal substrate, deformation of the substrate, reduction in strength, etc. occur. There was also the problem of causing the problem of

In order to impart high mechanical strength to the non-calcium phosphate ceramic material, generally 1
1000°C because it has a firing temperature of over 000°C
In order to bake on a metal material having a melting point near C,
It was also difficult.

[0013] That is, sintering below the melting point of the metal substrate does not increase the density of the ceramics and does not provide the strength of the material itself. rice field.

[0014] An object of the present invention is to overcome the drawbacks of the conventional implants described above and to provide an implant having excellent bioactivity and strength.

[0015]

Means for Solving the Problems That is, the present invention provides a biological implant comprising ceramics laminated on the surface of a substrate such as a metal, in which the ceramics constituting the outer surface are alkaline earth metal oxides and alkali metal oxides. At least one metal oxide selected from the group consisting of
A bioactive ceramic material having a non-calcium phosphate composition containing SiO ₂ as an essential component and capable of depositing a calcium phosphate compound on the surface in an aqueous solution containing Ca ions and P ions, and a firing temperature of the ceramic material. is 500° C. or higher and lower than the softening point of the metal substrate, and the peel strength of the ceramic material is 30 MPa or higher.

[0016] The implant of the present invention may particularly have the following configuration as preferred features. That is, the firing temperature of the ceramic material is 800°C to 1
Must be 200°C. Crystal grain size of ceramics is 0.0
1 to 2 μm.

[0017] The composition of the ceramic should be substantially free of phosphorus. Further, the alkaline earth metal oxide has a composition containing CaO as an essential component, or contains at least one of BaO, MgO and SrO and does not substantially contain CaO.

[0018] The present invention also provides a method for producing the above implant, wherein the surface of a substrate such as a metal is coated with at least one metal oxide selected from alkaline earth metal oxides and alkali metal oxides, and SiO ₂ as essential components. Applying a ceramic material powder paste composed of a non-calcium phosphate composition,
It includes a method for producing a bioactive ceramic implant characterized by firing at a temperature range of 500° C. or higher and below the softening point of the metal substrate, and in particular, the BET value of the ceramic material powder is 10 m ² /g or higher. , and the ceramic material powder is preferably produced by a liquid phase synthesis method.

[0019]

In the present invention, instead of using conventional calcium phosphate sintered ceramics, ceramics composed of a composition containing at least one of alkaline earth metal oxides or alkali metal oxides and SiO ₂ are used as the ceramic material. Further, by miniaturizing the ceramic raw material powder, the activity is enhanced and the firing temperature is lowered below the melting point of the metal substrate.

[0020] As a result, baking or the like can be performed without deforming the metal substrate.

[0021] Further, the low-temperature sintering reduces the crystal grain size and crystallinity of the ceramic layer and enhances the compatibility with living bones.

[Concrete Construction] The concrete construction of the present invention will be described below.

[Substrate Material] The implant of the present invention has a structure in which ceramics forming the outer surface of the implant are laminated and combined on a substrate such as a rod.

The substrate material used here is not particularly limited as long as it is harmless to living organisms and has a certain level of strength (usually 500 MPa or more). , cobalt-chromium alloy, pure tantalum, and the like are used.

From the viewpoint of biocompatibility, titanium metal and titanium alloys are preferable.
Those having a high melting point are more preferable.

[Ceramic Material] The ceramic material used in the present invention is a ceramic material comprising a composition containing at least one of alkaline earth metal oxides or alkali metal oxides and SiO ₂ , and containing phosphorus as a basic component. is a non-calcium phosphate ceramic material that does not substantially contain

[0027] The present material exhibits bioactivity in spite of being non-calcium phosphate, and when it comes into contact with an aqueous solution containing Ca ions and P ions (for example, body fluids, simulated body fluids), the calcium phosphate-based compound For example, it is characterized by producing hydroxyapatite (HAP).

[0028] Thus, when implanted in vivo, the HA having good biocompatibility reacts with body fluids to the contact surface with living bones.
P precipitates rapidly and uniformly, promoting new bone formation.

[0029] In particular, the HAP produced here has an extremely low degree of crystallinity, unlike HAP obtained by a conventional sintering method, and has a structure resembling that of living bone, so that the formation and maturation of new bone are facilitated. Faster and quicker connection with the implant.

[0030] Moreover, the components in the composition form a concentration gradient in the joint portion with the living bone thus formed, and the implant and the living bone are continuous in terms of crystallinity. , resulting in a very strong bond.

In contrast, conventional implants made of sintered HAP do not deposit a calcium phosphate compound on the surface, and the degree of crystallinity is different from that of bone. Early fixation becomes weak.

[Low-Temperature Firing of Ceramics] In the present invention, since ceramics are laminated on a substrate such as a metal by baking or the like, it is important to suppress the firing temperature of the ceramics below the melting point of the substrate material.

For example, the melting temperatures of major metal materials are 1668° C. for titanium metal, 1650° C. for Ti-6Al-4V alloy, 1400° C. for stainless steel, and 1300° C. for nickel alloy.

Therefore, the sintering temperature of ceramics is 120°C.
It is preferable to set the temperature to 0°C or less, preferably 1000°C or less.

As a method for low-temperature firing, in addition to the method of adjusting the composition described later, there is a method of increasing the activity of the ceramics by making the raw material powder finer, etc. is effective.

[0036] These can be used separately, but they are preferably used in combination with each other.

[0037] As a method for increasing the activity of ceramics, there are a method of refining the raw material powder, a method of acid-treating the surface of the ceramic raw material powder for activation, and the like.

For the refinement of the raw material powder, the powder size of the ceramic raw material powder is preferably 5 m ² /g in terms of BET value particle size.
As mentioned above, it is more preferably in the range of 10 to 200 m ² /g.

Here, the BET having a particle size larger than the above range
This is because when the value is low, it is difficult to achieve low-temperature firing, and on the contrary, when the particle size is smaller than the above range and the BET value is high, production usually becomes difficult.

[0040] In order to enhance the activity, it is more preferable that the ceramic material powder is fine and uniform.

[0041] The material powder as described above may be acid-treated with hydrochloric acid or the like before firing to increase surface activity.

Another effective method is to mix a low-melting-point glass frit with ceramic powder to form a matrix, and lower the firing temperature.

In this method, ceramic powder and low-melting-point glass frit are mixed with a solvent such as water to form a paste, which is then applied to a substrate and fired to weld.

However, although the addition of glass is effective in lowering the firing temperature, it tends to lower the bioactivity. Therefore, from the viewpoint of bioactivity, the method of increasing the activity of the ceramics is more preferable.

The firing temperature is usually 400 to 1000° C., which is higher than the softening temperature of the glass.

Examples of the glass include silica-based, borate-based, silicate-based, borosilicate-based, and phosphate-based glasses. preferable.

The amount of glass to be blended is usually 5-80% by weight, preferably 15-60% by weight, based on the total amount of the coating material. If the blending amount is less than the above range, the adhesiveness is lowered, and if it exceeds the range, the bioactivity is lowered.

[Method for Synthesizing Ceramic Material] The ceramic material powder used in the present invention can be synthesized by a dry synthesis method, a wet synthesis method, or the like. , a liquid phase synthesis method such as a coprecipitation method or a precipitation method, an alkoxide method, a sol-gel method, or the like is preferably used.

That is, in the spray pyrolysis method, an aqueous solution containing ceramic component ions adjusted to a desired composition is atomized by gas or an ultrasonic vibrator, and this is heated to synthesize fine spherical, hollow particles. can be obtained.
It is also preferable to further pulverize the obtained hollow particles to increase the BET value.

The coprecipitation method involves uniformly mixing ceramic component ions in an aqueous solution and then chemically depositing the mixed components simultaneously as a solid phase by utilizing differences in solubility. Fine particles of ² /g or more can be obtained.

In the alkoxide method, Ca alkoxide, Si alkoxide, etc. are mixed, an alkoxide solution containing each ceramic component is prepared, and this is hydrolyzed to synthesize fine particles of high purity and large BET value. can be obtained.

In the sol-gel method, desired components are mixed in an aqueous solution to form a sol, dehydrated to gel, and calcined to form an oxide.

[Ceramic Material Composition] A representative ceramic composition of the ceramic material used in the present invention is at least one of alkaline earth metal oxides or alkali metal oxides and SiO ₂ at a weight ratio of 1:4 to 6. :1, preferably 1:3 to 2:1. This is because biocompatibility or strength decreases outside this range.

In this composition, the coefficient of thermal expansion can be increased by increasing the amount of SiO ₂ added. It is preferable to achieve matching with the thermal expansion coefficient of the metal base.

When the ceramic material is laminated on the metal substrate, the content of SiO ₂ is in the range of 30 to 75% by weight, preferably in the range of 35 to 70% by weight, based on the total ceramic composition. The expansion coefficient ratio is set to 0.0.
It can be controlled in the range of 5 to 1.5.

As alkaline earth metal oxides, C
One or more of aO, MgO, SrO, BaO and the like are selected, preferably CaO and MaO.

{Essential composition of CaO} Among the alkaline earth metal oxides, those containing CaO containing the HAP component that precipitates as an essential component are preferred from the standpoints of bioactivity, strength, and ease of production.

In particular, 20% CaO is added to the ceramic composition.
Those containing ∼90% by weight, particularly 30 to 70% by weight, are preferred.

CaO is an essential component, part of which is M
Other alkaline earth metal oxides such as gO, SrO, and BaO can also be used, and inclusion of MgO is particularly preferable because it contributes to low-temperature firing and adjustment of the coefficient of thermal expansion.

(1-x)CaO.xMgO.2S
In compositions denoted by iO ₂ , increasing x decreases the coefficient of thermal expansion, and decreasing x increases the coefficient of thermal expansion.

The content of MgO is preferably in the range of 0.1 to 60% by weight in the ceramic composition.

0.1 to 3, especially when low-temperature firing is desired.
A range of 5% by weight is preferable.
2-35% by weight, _SiO2 = 10-80% by weight, preferably CaO = 18-47% by weight, MgO = 10-25% by weight, _SiO2 = 37-68% by weight.

{CaO-Free Composition System} Initially, the presence of CaO containing HAP components was considered essential for the formation of HAP on ceramics. However, in subsequent research, it was unexpectedly discovered that even a composition system containing no CaO has the ability to generate HAP. In addition, it was found that this composition system also exhibited bioactivity higher than that of conventional calcium phosphate-based ceramics.

MgO, SrO,
It is also possible to use at least one or more metal oxides of other alkaline earth metal oxides such as BaO and/or alkali metal oxides, and in this case, it is possible to have a composition that does not substantially contain CaO. is.

When other alkaline earth metal oxides such as MgO, SrO and BaO are used, their content is in the range of 0.1 to 90% by weight in the ceramic composition, and the total amount is It is preferable to contain 20 to 90% by weight, particularly 30 to 70% by weight in the ceramic composition.

Alkali metal oxides may be used in place of or as part of the alkaline earth metal oxides.

In this case, mainly Na ₂ O, K ₂ O,
One or more of Li ₂ O is selected and preferably used as an additive composition to CaO and MgO.

In this case, the content of the alkaline earth metal oxide is in the range of 0.1 to 90% by weight in the ceramic composition, and the total amount in the ceramic composition is 0.1%.
A range of up to 70% by weight, particularly 50% by weight or less is preferable from the viewpoint of strength and bioactivity.

{Example of composition region} The ceramic composition used in the present invention is, for example, Diopside (C
a, Mg)O-MgO- _2SiO2 , especially 2SIO2 _- C
aO-MgO), wollastonite (Wollaston
ite: β-(Ca, Mg)O- _SiO2 , especially CaO-
_SiO2 ), alite (3CaO-Si
O), belite (2CaO-Si
O ₂ ), Akermanite: 2
CaO-MgO- _2SiO2 ), monticelite (Mo
nticellite: CaO-MgO- _SiO2 ),
Forsterite: 2 (Mg, C
a) O-- _SiO2 ), protoenstatite (Prot
oenstatite: ((Mg, Ca) O—Si
O ₂ )), Tridymite: SiO
₂ ) and other ceramics materials belonging to the area.

Among the material systems essentially containing CaO, preferred are those in the regions of diopsite, woratonite, alite, bellite, arkermanite and monticerite, among which sinterability is possible at relatively low temperatures. Ceramics mainly composed of a diopsite region or a woratonite region are preferable because of their high strength.

[0071] In the material system containing no CaO, those in the forsterite region are preferred.

[0072] In addition to the ceramic materials in the preferred composition range described above, mixtures with other compounds described above can also be used.

Materials containing alkali metal oxides include SiO ₂ --K ₂ O, SiO ₂ --Li ₂ O--MgO,
_SiO2 -Li2O- _TiO2 , _{SiO2 - TiO2-}
There are compositions based on CaO, _SiO2 - _Na2O , and the like.

SiO ₂ -K ₂ can be particularly fired at a low temperature.
O, _SiO2 - _Na2O system.

In addition to the above components, the ceramics used in the present invention may contain optional components such as TiO ₂ , ZnO, B ₂ O ₃ , FeO, ZrO ₂ and the like can be blended.

In particular, by incorporating an oxide of a metal base material such as TiO ₂ into the ceramic, it is possible to improve the bonding strength between the metal base and the intermediate layer.

However, the inclusion of Al ₂ O ₃ tends to lower the bioactivity, so it is not very preferable.

[Lamination Method] As a method for laminating ceramics on a metal substrate, for example, a baking method or the like is preferably used.

That is, the ceramic material powder is mixed with a binder component such as an organic resin and a solvent component such as an alcohol to form a paste. I do. This enables strong bonding.

The firing temperature in this case is 500° C. or higher and lower than the melting temperature of the metal substrate, preferably 800 to 1200° C.
°C, more preferably 1000°C or less.

[0081] In addition, it is also possible to laminate by a thermal spraying method or a vapor phase film forming method such as a sputtering method.

When thermal spraying is used, the HAP material is likely to be converted to TCP when heated to a high temperature.

In the case of the sputtering method, heat treatment is usually performed after sputtering.
Temperatures below 0° C. are possible and there is no risk of deformation of the substrate.

[Thickness of ceramic coating layer] The thickness of the ceramic coating layer provided on the metal substrate is 1 to 5000 µm.
m, preferably 10-2000 μm, more preferably 50-10
00 μm is preferred.

[0085] Below this range, formation of new bone tends to be insufficient, and above this range, the peel strength tends to decrease.

[Surface Roughness of Ceramic Coating Layer] The surface roughness of the ceramic layer is preferably 1 to 200 μm, more preferably 5 to 100 μm.

If the amount is less than this range, the surface becomes slippery and the anchoring effect is difficult to obtain.

[Porosity] Part or all of the ceramic layer can be made porous with independent pores and continuous pores within the range that does not impair the strength. In this case, a porous layer may be formed on the pre-baked dense ceramic layer.

Retention of osteoblasts and osteoblasts,
Circulation of blood and the like can be promoted, and formation and bonding of new bone can be promoted.

This porous layer generally has a pore diameter of 5 to 2000 μm, preferably 10 to 100 μm, from the viewpoint of biocompatibility.
μm, porosity 10-80%, preferably 20-70
%, more preferably in the range of 25-60%.

This porous layer can be produced by mixing thermally decomposable material particles such as crystalline cellulose with a desired size and amount into ceramic raw material powder and baking the mixture on a substrate.

[0092] As the thermally decomposable substance particles, those having an average particle size of 5 to 2,000 µm, preferably 10 to 100 µm are used.
Mix in the range of 0 to 200 parts by weight, preferably 20 to 100 parts by weight.

[Ceramic Grain Size of Ceramics] Ceramics fired on a metal substrate usually have an average crystal grain size of 0.5.
It is preferable to make it into the range of 001-100 micrometers.

[0094] For materials having a firing temperature of 1000°C or more, the range of 0.01 to 50 µm is preferable.
A range of 0.1 to 20 µm is more preferred.

On the other hand, the low-temperature firing material preferably has a thickness of 1 μm or less, more preferably 0.1 μm or less.

[0096] If the crystal grain size is less than this range, the production is difficult, while if it exceeds this range, the strength decreases.

[0097] The crystal grain size was measured by a scanning electron microscope (SE).
Assuming that this is a circle from the crystal grain area measured by M), the average diameter can be determined and measured.

[Peeling strength of ceramic layer] It is preferable that the peeling strength of the ceramics baked on the metal substrate is as high as possible. and at least 30M
Pa or more, more preferably 40 MPa or more, still more preferably 50 MPa or more.

[0099]

EXAMPLES The present invention will now be described with reference to examples.

[Material Examples A to C] Ca(C ₂ H ₅ O) ₂ and Si(C ₂ H ₅ O) ₄ were mixed at a predetermined ratio to obtain an alkoxide solution. Dilute this 10 times with alcohol,
Water was added with stirring at 0°C and pH 9-10 to form a precipitate. This precipitate is separated by filtration and dried to obtain a ceramic material, which is calcined at 800°C,
It was pulverized to obtain a ceramic material powder.

Table 1 shows the composition and BET value of the ceramic material powder obtained here.

[Material Examples D to I] Ceramic material powders shown in Table 1 were obtained by the alkoxide method in the same manner as above.
Table 1 also shows the compositions and BET values of these ceramic material powders.

[Material Examples J and K] Ca with an average particle size of 5 μm
Powders of O, MgO and SiO ₂ were mixed in a predetermined ratio and 80
After drying at °C for 5 minutes, it was calcined at 950°C for 5 hours. Next, this calcined product was pulverized to obtain a ceramic material powder (material example J).

Similarly, the HAP material obtained by the dry synthesis method was pulverized to obtain ceramic material powder (material example K).

The composition of these ceramic material powders, BE
T values are also shown in Table 1.

[Examples 1 to 10, Comparative Example 11] The ceramic material powder described above was mixed with an alcohol solvent to form a coating solution, which was coated on a metal substrate shown in Table 2, fired and baked. and various samples were obtained. Table 2 shows the substrate material and firing temperature of each sample.

Each sample was also examined for the peel strength of the ceramic layer, deformation of the substrate due to firing, and bioactivity.

[0108] The peel strength of the ceramic layer was measured by the following method.

A cylindrical metal substrate having a length of 18 mm and a diameter of 3 mm was blasted, and a ceramic layer having a thickness of 200 μm was formed on the surface of the substrate to obtain a sample. The sample was fixed by embedding and hardening, and an extrusion test was performed by pushing the exposed upper surface portion of the sample with a rod-shaped metal piston. The peel strength was evaluated by the pressure when the sample was extruded from the epoxy resin body. The head speed at this time was 0.5 mm/min.

[0110] Deformation of the substrate was carried out by measuring the external dimensions of the sample.

Biological activity is Na ⁺ 142.0mmo
l, K ⁺ 5.0 mmol, Mg ²⁺ 1.5 mmol, Ca
²⁺ 2.5 mmol, Cl ⁻ 148.8 mmol, HCO
₃ ^- 4.2 mmol, and HPO ₄ ² - 150 ml of a simulated body fluid consisting of an aqueous solution containing 1.0 mmol at 37°C.
, and each sample was immersed in this and SEM after 14 days
The presence or absence of the HAP precipitate phase was measured. Here, depending on the degree of precipitation, HAP was uniformly precipitated over the entire surface with ⊙, and partially precipitated with ◯.

The components of the precipitated phase were confirmed by electron beam diffraction.

Each result is shown in Table 2.

[0114]

[Table 1]

[0115]

[Table 2]

[Comparative Example 12] 73.7% by weight of CaO powder having an average particle size of 5 μm and 26.3% by weight of SiO ₂ powder were mixed, dried at 80°C for 5 minutes, and then dried at 950°C for 5 hours. calcined. Next, this calcined product was pulverized to obtain a BET value of 3
of ceramic material powder (material example L) was obtained.

This ceramic material powder was mixed with an alcoholic solvent to form a coating solution, which was then mixed with a Ni alloy (melting point 130
0° C.) was coated on a substrate, and baked and baked to obtain a sample.

As a result, the ceramic coating layer of the obtained sample had high strength, but the metal substrate was distorted.

As described above, when the raw material powder of the comparative example having a small BET value and a large particle size was used, the density was not obtained by low-temperature firing, and the peel strength was lowered.

[0120] Further, when the ceramics were fired at a high temperature in order to increase the density of the ceramics, the metal substrate was deformed.

On the other hand, in the implant of the present invention, the raw material powder was uniform and fine, the activity was high, the density was obtained even when fired at a low temperature, and the peel strength was improved.

[0122]

Effect of the Invention In the present invention, as a ceramic material,
By using ceramics composed of a composition containing at least one of alkaline earth metal oxides or alkali metal oxides and SiO ₂ without using conventional calcium phosphate-based sintered ceramics, and by refining the ceramic raw material powder, etc. By increasing the activity and setting the firing temperature to the melting point of the metal substrate or lower, even when the ceramic is fired onto the metal substrate, the firing density and strength can be improved without causing deformation of the substrate.

[0123] Further, by reducing the crystal grain size and the degree of crystallinity, the affinity with living bones can be enhanced.

──────────────────────────────────────────────────── ────

[Written Amendment]

[Submission date] July 14, 1992

[Procedural amendment 1]

[Name of document to be amended] Description

[Correction target item name] 0001

[Correction method] Change

[Correction details]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to bioactive implants applicable to artificial bones, artificial tooth roots, artificial joints and the like. The present invention relates to an implant obtained by combining this with a substrate such as a metal.

[Procedural amendment 2]

[Name of document to be amended] Description

[Correction target item name] 0002

[Correction method] Change

[Correction details]

[0002]

2. Description of the Related Art Until now, bioimplants used for artificial bones, artificial tooth roots, artificial joints, etc. have been made of metals such as stainless steel, metallic titanium, nickel-cobalt alloys, and ceramics such as alumina and zirconia . It has been

[Procedural amendment 3]

[Name of document to be amended] Description

[Correction target item name] 0054

[Correction method] Change

[Correction details]

In this composition, the coefficient of thermal expansion can be lowered by increasing the amount of SiO ₂ added. It is preferable to achieve matching with the thermal expansion coefficient of the metal base.

[Procedural amendment 4]

[Name of document to be amended] Description

[Correction target item name] 0060

[Correction method] Change

[Correction details]

That is, in the composition represented by x CaO.y MgO.2SiO ₂ , the thermal expansion coefficient increases as x increases.
and increasing y decreases the coefficient of thermal expansion. example
For example , CaO.2SiO ₂ , 1/2CaO.1/ 2MgO
・Thermal expansion of each composition of 2SiO ₂ and MgO.2SiO ₂
The coefficients are respectively 10.0×10 ⁻⁶ , 9.5×10 ⁻⁶ ,
7.5×10 ⁻⁶ . This allows adjustment of the coefficient of thermal expansion.
It is possible.

Claims (9)

[Claims] 1. A biological implant comprising ceramics laminated on the surface of a substrate, wherein the ceramics constituting the outer surface is oxidized with at least one metal selected from the group consisting of alkaline earth metal oxides and alkali metal oxides. and a bioactive ceramic material having a non-calcium phosphate composition containing SiO ₂ as an essential component and capable of depositing a calcium phosphate compound on the surface in an aqueous solution containing Ca ions and P ions, said ceramic material is sintered at a temperature of 500° C. or higher and lower than the softening point of the substrate, and the peel strength of the ceramic material is 30 MPa
A bioactive ceramic implant characterized by the above. 2. The firing temperature of said ceramic material is 800.
A bioactive ceramic implant according to claim 1, characterized in that the temperature is between °C and 1200 °C. 3. The crystal grain size of said ceramics is from 0.01 to 0.01.
A bioactive ceramic implant according to any of the preceding claims, characterized in that it is 2 µm. 4. A bioactive ceramic implant according to any one of claims 1 to 3, characterized in that said ceramic is substantially free of phosphorus. 5. A bioactive ceramic implant according to any one of claims 1 to 4, wherein said alkaline earth metal oxide has a composition containing CaO as an essential component. 6. The alkaline earth metal oxide is BaO, M
Claim 1, characterized in that the composition is at least one of gO and SrO and does not substantially contain CaO.
6. A bioactive ceramic implant according to any one of paragraphs 1 through 5. 7. A ceramic material powder paste having a non-calcium phosphate composition containing at least one or more metal oxides selected from alkaline earth metal oxides and alkali metal oxides and SiO ₂ as essential components is applied to the substrate surface. and 500
A method for producing a bioactive ceramic implant, characterized in that the implant is baked at a temperature above 0°C and below the softening point of the metal-metal substrate. 8. The ceramic material powder has a BET value of 10.
8. A method for producing a bioactive ceramic implant according to claim 7, characterized in that it is m ² /g or more. 9. The method for producing a bioactive ceramic implant according to claim 7, wherein said ceramic material powder is produced by a liquid phase synthesis method.