KR830001541B1 - Method of manufacturing hydroxyapatite - Google Patents

Abstract

No content.

Description

Method of manufacturing pure oxidized apatite

The present invention relates to a hydroxyapatite, a ceramic material and a manufacturing method comprising a ceramic hydroxyapatite.

In more detail, the present invention relates to a colorless transparent ceramic material of hydroxyapatite having a high density, high purity and high thermal stability, a method for preparing the material, and a method for preparing a composition useful as an implant comprising a ceramic material and an organic binder. It is about.

Hydroxyapatite is represented by the general formula Ca ₁₀ (PO ₄ ) ₆ (OH) ₂ or Ca ₅ (PO ₄ ) ₃ (OH), and is one of the inorganic components of solid tissues of living bodies such as bones, teeth and the like.

Simulated materials of synthetic hydroxyapatite (hereinafter referred to as "ceramic material of hydroxyapatite") are useful as implants such as artificial roots or artificial bones, which are very similar to living bodies, as reported in the literature. And Kato, "Ceramic", 10 (7): 469 (1975), especially in recent years.

Naturally, the synthetic ceramic material of hydroxyapatite preferably has physical characteristics similar to those of hydroxyapatite present in nature. That is, the ceramic material of hydroxyapatite used in the living body should be colorless and dense and be safe for the living body.

The above-mentioned safety-related purity means physicochemical purity. In other words, the purity of the ceramic material is that the foreign material does not contain as much as possible elements other than Ca, P or PO ₄ , which are essential elements of hydroxyapatite, and the Ca / P atomic ratio is close to the theoretical value of hydroxyapatite, and the physical structure is pure. Determined by the closest possible formation of the structure of hydroxyapatite.

Among these factors, certain defects of the physical structure are detected by X-ray analysis, and if potential defects cannot be detected, they can be clearly detected after treatment at a high temperature of about 1350 ° C. Impurities commonly contained in hydroxyapatite are whitl ockite, which has a low Ca / P ratio, a different physical structure, and dissolves very well in an aqueous solvent.

These impurities are present in the ceramic material and are colored if there are structural defects, and dissolve to the site where the material is applied in vivo. Accelerated substitution by the aforementioned elution of biological tissues may be desirable, but from a safety point of view, the living body may be harmed by local electrolyte imbalances due to elution and the detrimental action of the eluted material itself.

Therefore, the ceramic material of hydroxyapatite is almost colorless and must be high in density, and must be high in purity, and it is very important to provide an industrial manufacturing method of such an ideal ceramic material. As described below, however, no ceramic material has been produced that satisfies the above conditions.

Many synthetic methods of hydroxyapatite have been proposed. [Reference: R.W. Chem, Mooney et al. Rev. 61: 433 (1961) and kanazawa "kagaku no Ryolki" 27: 622 (1973).

However, there have been few cases where the method of producing a ceramic material characterized by the combustion of the above-mentioned hydroxyapatite has been described. Among them, Morere reported that compression-molding powdered hydroxyapatite and burning the molding at 1300 ° C. under normal pressure yielded a ceramic material (see J. Dent-Res 50,860 (1971)). The ceramic material described by Leo contains up to 30% (weight) of Wheat Trokit (alpha-calcium triphosphate), making it a highly pure hydroxyapatite ceramic material.

The reason why the ceramic material of highly pure hydroxyapatite could not be obtained until now is due to the structural defect that the composition of the hydroxyapatite used does not have an accurate stoichiometric composition or produces a by-product of the phytokit of different structure upon combustion. In view of this, there have been attempts to synthesize hydroxyapatite having an accurate stoichiometric composition and to phosphorus the hydroxyapatite. However, the conventional hydroxyapatite obtained by the conventional synthesis method is low in sinterability and thermal stability because of purity, crystalline structure problems and morphological problems of crystal grains. Therefore, ceramic materials that are safe against heat with high density and high purity have not been obtained. For example, Japanese Patent Laid-Open Publication No. 64199/77 provides a method of adding a foreign material such as MgO to improve the insufficient sintering property of a ceramic material precursor having a stoichiometric composition of hydroxyapatite by conventional synthesis. Since it is based on the introduction of an ellipsoid for the purpose of improving the sintering property, the present invention is completely different from that in view of the present invention.

On the other hand, M. Jarcho is described in Haek method [see Angew. Chem. 67: 327 (1995) and Inorg Synt 7: 63 (1963)], which adjust the pH of the reaction system to 10-12 by addition of ammonia and react calcium nitrate with diammonium hydrogen phosphate Based on the following reaction to synthesize apatite.

5Ca (NO ₃ ) ₂ +3 (NH ₄ ) ₂ HPO ₄ + 4NH ₃ + H ₂ O → Ca ₅ (OH) (PO ₄ ) ₃ + 10NH ₄ NO ₃

The cake-like hydroxyapatite obtained by filtration is burned at 110 to 1200 ° C.

It has been reported that this method yields a ceramic material of hydroxyapatite having an average size of crystals of about 0.2 to 3 microns and a density of 3.10 to 3.14 g / cm 3. US Patent No. 4,097,935, Japanese Patent Application Nos. 40400/76, 94309/77 and J. Material Sci 11: 2027 (1976).

However, it is described in the above reference that the ceramic material of hydroxyapatite is partially decomposed into by-products, butotrophic, when treated at temperatures above 1250 ° C. for at least 1 hour. That is, the ceramic material of hydroxyapatite obtained by the above method still has a structurally unstable factor and thus has low thermal stability. It is also difficult to remove ammonium nitrate produced as a byproduct.

As another method of synthesizing hydroxyapatite, a method of utilizing the reaction of calcium hydroxide and phosphoric acid has been proposed.

5Ca (OH) ₂ + 3H ₃ PO ₄ → Ca ₅ (PO ₄ ) ₃ (OH) + 9H ₂ O

The reaction is thought to be an industrial method for preparing hydroxyapatite of the correct stoichiometric composition, in that (1) it does not contain other elements and (2) the by-product is water, but Money [Chem. Rev "61, 433 (1961)], it is difficult to obtain hydroxyapatite (theoretical Ca / P atomic ratio: 1.67) of stoichiometric composition by the reaction, and only hydroxyapatite corresponding to calcium triphosphate having a Ca / P of 1.50 is obtained. It is stated that it is obtained.

Meanwhile, al. Wellew (R. Wallaey), Angew Chem paris 7,808 (19521), described above completes the reaction with Ca / P by boiling the reaction mixture mentioned above to complete the reaction or by boiling to the phenolphthalein neutralization point. A hydroxyapatite having an atomic ratio of 1.61 to 1.67 was obtained.

However, according to the Walley's trace-experiment results by the inventors, the sinterability of the dried filter cake of hydroxyapatite obtained by the Wallaey method is weak, and the hotpress method at a high temperature. Also gives only a ceramic material having a density of about 3.11 g / cm 3, and the obtained product is colored blue after sintering. The cause of the coloring is not yet known, but it is considered to be due to some structural defects as a ceramic material in addition to the presence of trace impurities. As mentioned above, it is apparent that the Wallaey burr cannot satisfy the object of the present invention.

As described above, ceramic materials of hydroxyapatite known so far contain external components to enhance the sinterability of synthetic hydroxyapatite, have structural defects that cause low thermal stability, or are colored during sintering. In other words, at present, it has not been completed in a highly pure and highly stable ceramic material of high density hydroxyapatite suitable for in vivo application and its effective preparation.

In view of the above-mentioned circumstances, the relationship between the sinterability or thermal stability of ceramic materials and the crystal form, form and structure of synthetic hydroxyapatite is excellent in thermal stability, colorlessness, no structural defects, highly pure and high strength. The present invention has been found to be obtained by heating a dry cake after filtering a synthetic hydroxyapatite having a stoichiometric composition, which does not decompose even after heating for 1 hour at 1350 ° C. to produce a kit.

An object of the present invention is to provide a filtered and dried cake of hydroxyapatite having a three-dimensional structure having an average radius of 50 to 150 mm 3 and a volume of 0.2 to 0.8 cm 3 / g. The atomic ratio of phosphorus is 1.67 to 1.69, the length is 150 to 1200Å, the width is 50 to 400Å, and the ratio of the width is made of hydroxyapatite of 3 to 10.

Another object of the present invention is that the atomic ratio of calcium to phosphorus is 1.67 to 1.69, the average crystal size is 4 to 20 mu, the density is 3.14 to 3.16 g / cm 3, and no phytokit is found even when heated at 1350 ° C. for at least 1 hour. To provide a colorless or translucent ceramic material consisting of ceramic hydroxyapatite having thermal stability.

Another object of the present invention is to provide a plant comprising a ceramic material of hydroxyapatite and a binding material which is biologically nontoxic to a living body. A special object of the present invention

(a) converting calcium carbonate powder into calcium oxide by pyrolysis in an inert atmosphere at 800 to 1300 ° C. for 0.5 to 10 hours;

(b) converting calcium oxide to less than 500 ° C. in an inert atmosphere to obtain extremely porous, highly reactive calcium oxide;

(c) the cooled calcium oxide is digested with water while stirring under turbulent flow to obtain very fine calcium hydroxide milk;

and (d) reacting the obtained calcium hydroxide with an aqueous solution of phosphate in an inert atmosphere under turbulent flow to obtain a hydroxyapatite.

According to the present invention, when an aqueous emulsion of calcium hydroxide fine particles produced by reacting an almost pure calcium oxide porous particle with an excess of water is reacted with an aqueous solution of phosphate in an inert atmosphere, a milky containing hydroxyapatite as a reaction product is obtained. The reaction is obtained.

After filtering the oil phase reaction mixture, the separation cake is washed with water and dried to produce an aggregate of hydroxyapatite having the following characteristics.

Ca / p atomic ratio analysis: 1.67 to 1.69 Average value of dimension of hydroxyapatite

Length: 150 to 1200Å. Width: 50 to 400 mm Length / Width: 3 to 10. Void: 0.2 to 0.8 cm 3 / g

Average radius of the hole: 50 to 150

The filter cake, hydroxyapatite aggregate, described above is combusted to obtain a ceramic material of hydroxyapatite having the following physical characteristics.

Analysis of Ca / p: 1.67 to 1.69 Average crystal size: 4 to 20 microns, Density: 3.14 to 3.16 cm 3 / g

The fact that the average crystal size of the material thus obtained is larger than that of the conventional synthetic ceramic material of hydroxyapatite means that the ceramic material of the present invention is made from a purer material than the raw material used to prepare the material. In addition, even after burning the hydroxyapatite aggregates for 1 hour at 1350 ° C., the production of phytoxykittes, which are decomposition products of hydroxyapatite, does not occur, which means that there is no structural defect including decomposition and the thermal stability of the aggregates is excellent.

The following is a more detailed description of the present invention.

Porous fine particles of calcium oxide used in the present invention can be obtained by thermal decomposition of powdered calcium carbonate. As a raw material, calcium carbonate having a purity of 99.0% or more, preferably 99.8% and a micro-fine state is preferable. Pyrolysis conditions are: inert atmosphere, 800 to 1300 ° C., preferably 950 to 1200 ° C., 0.5 to 10 to 10 hours, preferably 1 to 5 hours. Calcium carbonate is highly porous and highly reactive calcium oxide. It is converted into fine powder and carbon phosphate is liberated.

In pyrolysis, undecomposed calcium carbonate remains in the calcium oxide produced under mild conditions. Residual calcium carbonate, one of the final products of the present invention, is not only difficult to remove, but also causes structural defects and reduced thermal stability of the ceramic material of hydroxyapatite. The porosity and reactivity of the resulting calcium oxide is also impaired if the pyrolysis conditions are stronger or if the product of pyrolysis is not cooled in an inert atmosphere until the temperature of the product drops to 500 ° C., preferably 200 ° C. In this respect, the above-mentioned inert atmosphere means an atmosphere which does not contain components such as gaseous carbon dioxide and ammonia, which cause a secondary reaction of the resulting calcium oxide and calcium hydroxide.

It is effective to blow inert gas such as nitrogen, helium and argon into the pyrolysis system for the inert atmosphere because carbon dioxide gas generated in this way is continuously removed from the system.

The aqueous emulsion of the fine particle calcium hydroxide of the present invention can be prepared by adding calcium oxide to a large amount of water in a state of stirring at high speed to form a turbulent flow under an inert atmosphere as mentioned above. In this case, the amount of water mixed with 1 part by weight of calcium oxide is not limited, but is usually 10 to 100 parts by weight.

The reaction mentioned above is carried out under high speed stirring for a relatively long time, preferably at a relatively low temperature, usually at 0 to 80 ° C., preferably at 0.5 to 96 hours at 0 to 50 ° C., preferably for 1 to 24 hours. .

The end point of the reaction mentioned above is determined by X-ray diffraction analysis, part of the reaction product is recovered into the sample and the disappearance of d200 in the sample's X-ray diffraction pattern is taken as a signal of reaction completion.

In addition, the average particle size of calcium hydroxide produced by the process of the present invention is 0.05 to 0.1 micron and much smaller than calcium hydroxide having an average particle size of 1 to 10 microns obtained by dispersing commercial calcium hydroxide in water.

The emulsion of calcium hydroxide of the fine particles mentioned above is an important factor for obtaining the sinterable hydroxyapatite having the sinterability described above.

The hydroxyapatite according to the present invention is formed in an emulsified state by adding an aqueous solution of phosphoric acid in an amount corresponding to 1.6 to 1.69 of Ca / P to an aqueous emulsion of calcium hydroxide of fine particles in an inert atmosphere under high speed stirring.

In the preparation of hydroxyapatite, it is preferable to continue stirring even after the above-mentioned emulsion formation of calcium hydroxide is completed, and the aqueous solution of phosphoric acid is continuously added to the reaction system with stirring. Phosphoric acid is usually prepared in a 1 to 10 weight percent solution, which is slowly added to the above mentioned emulsions. High-speed stirring in this context means stirring to bring the liquid in the reaction system into the turbulent state.

Reaction temperature is 0-50 degreeC. At lower temperatures, the viscosity of the emulsion is high, making homogeneous reaction difficult, and at higher temperatures the sinterability of the aggregates of hydroxyapatite mentioned above is impaired. Therefore, the reaction temperature is an extremely important factor that affects the size of crystals related to sinterability or the easy settling properties described later. The reaction is usually carried out for 0.5 to 280 hours, preferably for 5 to 100 hours. The reaction mixture is considerably analytical at pH 13 at initial stage and alkalinity gradually decreases to pH 8-9 at reaction completion stage. Microscopic size of hydroxyapatite in the reaction system ranges from 50 to 400 mm long and 150 to 1200 mm long and the ratio of length to butterfly is 3 to 10.

These dimensions are apparently different from the dimensions of the butterfly crystals of 200 microseconds and 200 microns in length obtained by the reaction between calcium nitrate and diammonium hydrogen phosphate. The easy settling force of the hydroxyapatite obtained by the manufacturing method of the present invention is believed to be attributable to the size, shape, and shape of the crystal and also to the charge on the surface of the crystal. Moreover, these factors probably contribute to the formation of agglomerates of the hydroxyapatite of the present invention with advantageous sinterability.

Aggregates of hydroxyapatite according to the present invention can be obtained by filtration of hydroxyapatite obtained by the above-mentioned method with an accompanying content of about 0 to 2% by weight. The cake of hydroxyapatite aggregates thus obtained has the following physical properties. The cake has a pore ratio of 0.2 to 0.8 cm 3 / g and a pore radius of 50 to 150 ° C., and the hydroxyapatite has a Ca / P atomic ratio of 1.67 to 1.69, a butterfly of 50 to 400 Å, a length of 150 to 1200 Å, and a butterfly: length of 3 to It has a crystal size of 10, and these properties are specific to the ceramic material of hydroxyapatite, which will be described later.

Conventional methods of casting and burning agglomerates can be applied in the manufacture of ceramic materials according to the invention. For example, the agglomerates may be given after casting using a metal or rubber mold or the agglomerates may be cast and burned by thermal pressure or the casting cake may be burned under reduced pressure.

Other semitransparent, highly pure, highly dense, and highly stable ceramide materials may also be used by pressure casting the agglomerates of hydroxyapatite of the present invention followed by combustion under reduced pressure. Baking conditions are as follows. Bake at a temperature of 850 to 1400 ° C., preferably at 1250 to 1400 ° C. for 0.5 to 5 hours and preferably 1 to 3 hours. Furthermore, it should be noted that the growth of crystals during sintering by combustion of the hydroxyapatite of the present invention is significantly larger than that of conventional hydroxyapatite. Such properties are probably hydroxyapatite aggregates

The ceramic material of hydroxyapatite prepared according to the present invention has the following properties.

a) Analytical Ca / P: 1.67 to 1.69

b) average size of crystals: 4 to 20 microns

c) Density: 3.14 to 3.16 g / cm 3 and

d) Thermal stability: After heating at 1350 ° C. for 1 hour, notice no kit formation with any wheat.

Known ceramic materials of hydroxyapatite form a whittrokit when heated at temperatures above 1200 ° C. or 1300 ° C. while the ceramic material of the invention is extremely stable at temperatures above 1300 ° C. and the crystal size of the material of the invention is hydroxylated. It is larger than that of the known ceramic material of apatite and the former is distinctly different from the latter.

The ceramic material of the present invention has excellent stability in vivo without structural defects. In addition, the ceramic material of the present invention is prepared in a sequence of successive steps of drying and burning the cake obtained by filtration of the reaction solution mentioned above.

The thermal stability of the above-mentioned ceramic material is determined by the X-ray diffraction pattern after sintering the material at 1350 ° C. for 1 hour.

As described in accordance with the present invention, hydroxyapatite having good sinterability and high molecular weight in composition can be readily used by reacting calcium hydroxide with phosphoric acid under moderate conditions, and thus the method of the present invention is extremely effective as an industrial method.

Moreover, the ceramic material of hydroxyapatite obtained by the present invention is chemically and physically pure, stable enough for use in vivo, and useful as an implant material such as an artificial root and artificial bone.

In practical application as grafting material of hydroxyapatite ceramic material, especially as artificial root material, the foreign material can be applied by the following method. Ceramic materials can only be used as implants.

The implantable material of the present invention can be prepared by casting a mixture of hydroxyapatite and organic substrates having a particle size of 1000 microns in a known manner, or considering the manufacturability, ease of handling, and mechanical strength of the ceramics having pores of the present invention. It is prepared by saturation into the material. In the preparation method of the implant, the ratio of the surface area of the hydroxyapatite to the bone-to-bone organic substrate of the implant is 5:95 to 70:30, preferably 10:90 to 60:40. Table of fixation surfaces where the hydroxyapatite phase is mentioned above

Organic polymerization binder refers to an organic medium. Bisphenol A, glycidyl methacrylate, poly (methyl methacrylate), poly (2- Hydroxyethyl methacrylate), poly (triethyleneglycol dimethacrylate), polyethylene, polysulfone resin, polyamide resin, polyester resin, poly (tetrafluoroethylene), poly (vinylidene fluoride) and poly Line from group consisting of carbonate resin

In addition, the ceramic material of the present invention is a composition prepared by impregnating a material useful in vivo, such as sintered material with organic materials such as cellulose and collagen, impregnating an organic resin, or impregnating and polymerizing an organic monomer with a porous material. It is used as a component in a porous material produced by boring, a powdered ceramic material composition with organic or herd matrix, or a combination thereof.

Furthermore, the hydroxyapatite according to the invention is used as a packing material for chromatographic columns or as other baked material.

The invention is described in more detail in the following examples, which are not intended to limit the embodiments.

Example 1

600 g of reagent (G. R.) powdered calcium carbonate was added to an electric furnace under a gaseous nitrogen stream having a flow rate of 1 L / min and heated to 1000 ° C. at a rate of 30 ° C./min. After heating for 3 hours to decompose the material and cooling to 200 ° C. under a nitrogen stream of 1 L / min gas phase outflow rate, 335 g of calcal oxygen was obtained at a yield of 99.7%. Thus, the obtained calcium oxide was confirmed to be free of calcium carbonate by x-ray diffraction analysis.

The purity of the product measured by the EDTA method is 90.8%. According to the microscopic observation, the crystal form of the obtained calcium oxide is similar to that of the raw material calcium carbonate and the crystal of calcium oxide is porous.

6 liters of degassed distilled water was added to a 17 liter three-neck magnetic enameled tank equipped with a heater, a thermostat and a thermometer, and replaced with nitrogen while rotating the air in the tank at 350 rpm. 280 g (5 mol) of the above-mentioned calcium oxide was slowly added within 10 minutes, and then reacted under a gaseous nitrogen atmosphere at 50 ° C. for 15 hours at 50 ° C. for 5 hours to a calcium hydroxy emulsion having an average particle diameter of 0.075 microns. Obtained.

Therefore, 3 mol of a 3.5% phosphoric acid aqueous solution prepared with 85% diacid was added to the emulsion within 30 minutes while vigorously shaking the resulting emulsion at 3000 rpm, and the solution was continued for 48 hours at a temperature of 20 ° C. After completion of the reaction, the resulting suspension is filtered under pressure and the residue is washed with water and dried at 150 ° C. for 16 hours.

Thus, 497 g of dried hydroxyapatite filter cake was obtained, which was referred to as sample No1 and the properties of the dried, ie, hydroxyapatite collection of the present invention are shown in Table 1.

Example 2

In Example 1, another hydroxyapatite collection of the present invention was prepared by the same method as in Example 1 except that the reaction conditions of reacting for 48 hours at 20 ℃ temperature for 24 hours here. Name it Sample No2. The prepared sample Table 2 shows the same properties as in Table 1.

Control Example 1

A dispersed aqueous solution prepared by adding 5 mol of reagent (GR) powdered calcium hydroxy to 6 liters of degassed distilled water was placed in a magnetic enamel tank used in Example 1 and subjected to 3.5% phosphoric acid with vigorous shaking at 3000 rpm under nitrogen atmosphere substituted with gaseous nitrogen. 3 moles of aqueous solution is slowly added to the dispersion. After reacting at a temperature of 70 ° C. for 24 hours, hydroxyapatite obtained by performing the same method as in Example 1 was designated as sample No. 3, and the properties of sample No. 3 are shown in Table 1.

Control Example 2

A sample No. 4 hydroxyapatite collection was prepared by the following known method and its properties are shown in Table 1.

Diammonium hydrogen phosphate (160 g) is dissolved in distillation (3 L) and 28% ammonium solution (1700 ml) is added to the solution to adjust to pH 11-12. Distilled water is added thereto to dissolve the precipitated diammonium hydrogen phosphate.

The solution was added to a solution prepared by dissolving 477 g of calcium nitrate in 188 ml of distilled water. The solution was adjusted to pH 12 by adding 60 ml of aqueous ammonia solution and stirred at 20 ° C. for 30 minutes at high speed. The mixture is diluted with distilled water to a total volume of 7.0 liters. The resulting dilution is boiled for 10 minutes and then left at room temperature for 20 hours.

The resulting gelatinous material is filtered with a funnel under slight pressure reduction, washed with water on a filter, and subjected to high vacuum for 2 hours when cracks appear on the surface of the filter cake. Drying the filter cake at 150 ° C. for 15 hours yielded 197 g of hydroxyapatite.

Example 3

Each sample of the hydroxyapatite collections obtained in Examples 1 and 2 and Controls is placed in an electric furnace and heated to a temperature of 1350 ° C. at a rate of 30 ° C./min. It is left at this temperature for 1 hour and then taken out of the electric furnace and cooled to room temperature. The resulting ceramic materials have specific properties, as shown in Table 2.

Each ceramic material is pressed into pieces of about 5 mm in size, soaked in 0.1% neutral red water solution for 15 hours at room temperature, washed with water, dried and tested for coloring of each pressed surface. As a result, no pigmentation was observed in Example 1 and its sample No. 1 and No. 2, but the sample No. In 4, coloring was observed.

Sample No. 3 could not be compared because it appeared blue prior to soaking in the dye solution. As a result, it is evident that the ceramic material of the present invention is different from known ceramic materials.

Example 4

Hydroxyapatite collection of the present invention obtained in Example 1, Sample No. 1, 20 g is heated at 1250 ° C. for 1 hour under reduced pressure of 10 ⁻² mmHg and then cooled to 200 ° C. under reduced pressure to prepare a ceramic material. The ceramic material thus produced is white and transparent and has a density of 3.16 g / cm 3 in theory.

Example 5

Sample No. of Example 1 1 and Control Example Sample No. Sintering test was done about the hydroxyapatite collection of 4.

Each 20 g of the sample was baked at 1200, 1250, 1300 and 1350 ° C. for 1 hour to determine the amount of Whittrokit produced in the sintered material by x-ray diffraction analysis. The results are shown in Table 3. As can be seen from Table 3 the difference between the ceramic material according to the invention and the known ceramic material is evident.

Example 6

Sample No. The ceramic material prepared from 1 was pulverized to collect a fraction passed through a 200 mesh sieve. The powdered material was mixed with a 1: 1 volume ratio (calculated weight and density of two components) of bisphenol, glycidyl methacrylate copolymer and monomeric methyl methacrylate in a weight of 6: 4, and then used as a polymerization initiator. 0.05% by weight of benzoyl peroxide was added to uniformly mix the mixture to polymerize the mixture at 80 ° C. for 2 hours to obtain a hydroxyapatite composition. The composition is placed in a cylinder of 4.5 mm in diameter and 10 mm in length and placed in the perforated hole of the dog's jawbone immediately after extraction. The injected material is not removed naturally after 3 months of injection. Six months after the injection, the dog's jaw was cut and examined with light microscopy and x-rays. The injection site was restored normally and new bone tissue was found between the injection composition and the jawbone.

TABLE 1

Properties of Hydroxyapatite Aggregates

Note 1) and 2) are measured with POROSIMETRO Model 70 (manufactured by Acom Co.).

TABLE 2

Properties of Hydroxyapatite Ceramic Material

1) Attention: 1) Evaluate the presence of whittrokit in sample when heated at 1,350 ℃ for 1 hour.

TABLE 3

Sintered Test Results

Claims (1)

The calcium carbonate powder is pyrolyzed at 800 to 1300 ° C. for 0.5 to 10 hours in an inert atmosphere, converted to calcium oxide, the converted calcium oxide is cooled to less than 500 ° C. in an inert atmosphere, and the cooled calcium oxide is stirred under turbulence, A method for producing hydroxyapatite, which is obtained by slaking with water to obtain calcium hydroxide, and reacting the obtained calcium hydroxide with an aqueous solution of phosphoric acid in a turbulent inert atmosphere.