JPS6171059A - Composition for filling bone and tooth and its production - 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 Field of the Invention The present invention relates to a novel bone and tooth filling composition and a method for producing the same. More specifically, medical and dental materials are used to fill defects and voids in bones and teeth caused by pathological and external reasons, to facilitate the generation of new bone and teeth in those areas, and to later A bone or tooth filling composition that is an inorganic material or a composite of an inorganic material and an organic material that is integrated with the bone tissue or tooth tissue of a living body, and a method for producing the same.

BACKGROUND TECHNOLOGY Conventionally, methods for filling bone defects and voids in cases such as compound fractures and bone tumor resection include autologous bone grafting,
Allogeneic bone grafting, xenogeneic bone grafting, and the like are known and used, but both methods tend to cause biological rejection and have many problems that need to be improved.

Therefore, there is a need for the development of an artificial material that has excellent biocompatibility, promotes the function of ashes in the area where it is used and its surrounding areas, and allows the structure and function of damaged and void areas to be repaired and restored.

Conventionally, Ni-Cr based materials,
Alloy materials such as Go-Cr and Ti-based materials and plastic materials are used, but these materials tend to undergo changes such as dissolution and deterioration in the harsh environment of living organisms.
In addition, since there is a risk of reactions that form toxins or foreign substances, ceramic materials that have good affinity with living organisms have recently been attracting attention.

For example, artificial bones, artificial joints, and artificial tooth roots made of single crystal or polycrystalline Al2O3, and artificial bones and artificial tooth roots made of sintered bodies of calcium phosphate and hydroxyapatite have been proposed.

However, these implant materials have the same drawbacks as ceramics, such as being hard and brittle, and many issues remain before they can be used as artificial bones and artificial tooth roots, such as improving toughness and impact resistance. There is.

Additionally, a method has been proposed in which hydroxyapatite-type calcium phosphate powder is mixed with physiological saline and filled into bone defects and voids in living organisms, but this method has no strength at all immediately after filling, so there are many limitations in its use. .

Problems to be Solved by the Invention As detailed above, various materials such as alloys, plastics, and ceramics have been proposed and attempted to be used as filling materials for bone defects and voids, but To date, no material has been developed that has excellent compatibility, promotes cremation function at the site of use and its surroundings, and is capable of repairing and restoring the structure and function of damaged and void sites.

Therefore, the purpose of the present invention is to create an ideal bone and tooth defect with high compressive pressure resistance that does not cause foreign body formation reactions, has excellent biocompatibility, and can be used even when high strength is required immediately after salt addition. An object of the present invention is to provide a composition that can be used as a filler for spaces and voids, and a method for producing the same.

Means for Solving the Problems The present inventor has developed a new filling material in view of the above-mentioned current state of filling materials for bones, teeth, etc., which have excellent biocompatibility and excellent strength immediately after filling. As a result of various studies and studies, it was discovered that a composition whose main component is α-tricalcium phosphate or a fired product of its raw material and aluminum phosphate provides a filler that satisfies the above conditions, and the present invention was completed. did.

That is, the composition of the present invention has a ratio Ca/Al of 2 to 120.
A fluid or plastic bone or tooth filling composition characterized by containing α-tricalcium phosphate or its raw material within the range of 0, aluminum phosphate, a fired product thereof, and a kneading liquid. .

The filler composition of the present invention is prepared by mixing fine powder of α-tricalcium phosphate produced by the specific method described below with a saline solution or an aqueous solution of an organic acid to form a fluid or plastic state. Prepared by

The method for producing a fired product of α-tricalcium phosphate or its raw material and aluminum phosphate used in the composition of the present invention is as follows.

That is, calcium T-pyrophosphate and calcium carbonate are uniformly mixed in equimolar amounts, 0.1 to 30% by weight of aluminum phosphate is added to the mixture, and after thorough drying, the temperature is preferably 1000 to 1300°C. is calcined at around 1200℃ for about 1 hour, and the resulting product is finely ground to a particle size of 100℃.
It can be obtained by making it into a fine powder of μm or less.

Further, the fired product obtained as described above is compressed under pressure using a rubber press method, etc., and then fired again at a temperature of 1200 to 1500°C, preferably 1250 to 1350°C for 2 hours or more, and similarly pulverized. It can also be made into a fine powder with a particle size of about 0.5 to 20 μm. It is also possible to add aluminum phosphate before carrying out this second firing step. In the above pressure compression process, the higher the pressure, the better.
0 kg/c111"- or more is preferable.

Performing firing and pulverization treatment twice in this way
First, a fired product or α-tricalcium phosphate is formed in the first operation, and the density is improved by the second operation, and in some cases, a fired product of α-tricalcium phosphate and aluminum phosphate is formed. This is intended to increase the compressive strength. However, it goes without saying that the product obtained by the first firing and pulverization can also function satisfactorily as a component of the filler composition.

By adding the aluminum phosphate component in an amount of 0.1 to 30% by weight, the strength of the composition can be improved. This aluminum phosphate is added before the first or second firing and pulverization operation, and the firing produces Al2
Since O3 is formed, AI□03 particles are dispersed in the product. If the amount added is outside the above range, it is critical because the product becomes unsuitable as a biological material, and it also becomes hard and brittle.

This Al2O3 is a ceramic material that is inert to living organisms, and its inclusion has no adverse effects on living organisms.

The kneading liquid added to impart fluidity and plasticity to the baked product thus obtained and to harden it includes physiological saline, aqueous sodium sulfate solution, glycolic acid, malic acid, lactic acid, and pantothenic acid. , aqueous solutions of organic acids such as glutamic acid, acrylic acid, maleic acid, fumaric acid,
Aqueous solutions of organic acids such as itaconic acid or aqueous solutions of polymers (including copolymers) of unsaturated organic acids such as acrylic acid, maleic acid, fumaric acid, and itaconic acid have been used in the field of dental cement. It can be whatever is used. These can be used alone or in a mixture of two or more.

The kneading liquid (curing agent) other than the polymer is generally used as a 0 to 30% by weight solution, and has a concentration of 0 to I based on the total weight of the composition.
O weight% (in terms of solute) is added.

This range is a necessary condition for achieving a predetermined curing speed and compressive strength of the composition.

Further, the unsaturated carboxylic acid polymer can be produced by any known method, and is used as an aqueous solution with a concentration of 10 to 60% by weight, and the amount used is 15 to 60% by weight based on the total weight of the composition.
It is within the range of 60% by weight (in terms of solid matter), which is a preferable condition for the same reason as above.

The kneading operation method does not need to be particularly limited, and any method conventionally used in the field of dental cement may be used, for example, the method specified in JTS-6602 can be used.

Effect The composition for filling defects and voids in bones and teeth of the present invention is composed of α-tricalcium phosphate or its raw material having a Ca/Al ratio in the range of 2 to 1200, that is, T=calcium pyrophosphate and carbonate. It is characterized by the use of a calcined product of calcium and aluminum phosphate, and when used in combination with the kneading liquid as described above, it brings about various advantages as described below.

One of the important physical properties that a bone or tooth substitute material should have is compressive pressure strength. It is said that this pressure resistance strength is preferably 1000 kg/cr& or more, but it is recommended that α-tricalcium phosphate produced by conventional technology be kneaded with physiological saline, an aqueous solution of acrylic acid polymer, etc. The compressive pressure strength achieved when used is at best about 300 kg/cot. Surprisingly, with the present invention, the compressive strength can be increased to approximately 1500
It became possible to increase the weight to around 1800kg/cnl.

In general, the compressive pressure strength of a powder material that has been kneaded with a liquid to make it fluid or plastic and hardened within a short period of time has a strong correlation with the powder-liquid ratio (weight ratio of powder to liquid), making it easier to use. When the consistency is within the allowable range, the higher the powder-liquid ratio, the higher the compressive pressure strength. Therefore, also in the composition of the present invention, the higher the density of the powder, the better.

In the second method of the present invention, the firing and pulverizing treatment is performed twice, and the powder density can be improved by the second firing and pulverizing treatment, thereby increasing the compressive strength of the composition to 180%.
It is now possible to increase the weight from 0 to 2200 kg/cr&.

EXAMPLES The present invention will be explained in more detail with reference to Examples and Production Examples.

Production example 1 Calcium hydrogen phosphate trihydrate, Ca HP 04.
Put 2H20 (2 mol) in a magnetic crucible and heat 2H20 at 500℃.
The product obtained was subjected to X-ray diffraction and T-
Conversion to calcium pyrophosphate (γ-Ca2P207) was confirmed. Next, the 1:1 mixture of γ-calcium pyrophosphate and dry calcium carbonate thus obtained was thoroughly stirred to make it homogeneous, and then the mixture ratio as shown in Table 1 was added to increase the compressive pressure strength. Aluminum phosphate (AI P'' 04) was added thereto, and the mixture was fired under various temperature conditions, and after being allowed to cool in the air, it was made into powder particles with a size of 50 to 50 μm.

Production Example 2 Among the fired products shown in Table 1, the product of sample number I-5 was compressed and pressurized by a rubber press method under the conditions shown in Table 2 below, sintered for 2 hours, and then 50 people It was made into powder and granules with a diameter of 50 μm.

Table 2 Example 1 The granules of the fired products obtained in Production Examples 1 and 2 were kneaded with any of the following kneading liquids.

■, Glycolic acid 20% aqueous solution 2, Tetrahydrofuran tetracarboxylic acid 50% aqueous solution 3, Polyacrylic acid aqueous solution (concentration -45%) (Product name G
, C, carbonate liquid) Z The compressive compressive strength of the composition of the present invention thus prepared was measured.

The results are shown in Table 3. Note that the kneading operation method and testing method were based on the method described in J I 5-T-6602 (for dental cement).

Effects of the Invention The novel composition of the present invention, unlike conventional hydroxyapatite-type calcium phosphate compositions, has excellent initial strength immediately after insertion, high compressive pressure strength, extremely good tissue compatibility with living organisms, and is easy to use. It is ideal for bone and tooth defects, as it can be supplied in large quantities, is easy to use, and has the synergistic effect of compensating for the lack of autologous bone and significantly promoting bone tissue repair and healing. It is highly promising as a filling material for voids.

Claims (9)

[Claims] (1) α- whose ratio Ca/Al is within the range of 2 to 1200
1. A fluid or plastic bone or tooth filling composition comprising a fired product of tricalcium phosphate or its raw material and aluminum phosphate, and a kneading solution. (2) Claims characterized in that the kneading liquid is selected from the group consisting of physiological saline, sodium sulfate aqueous solution, organic acid aqueous solution, unsaturated carboxylic acid polymer aqueous solution, or a mixture thereof. Composition according to item 1. (3) the organic acid is glycolic acid, malic acid, lactic acid, pantothenic acid, glutamic acid, acrylic acid, maleic acid,
The composition according to claim 2, characterized in that the composition is selected from the group consisting of fumaric acid and itaconic acid. (4) The concentration of the aqueous solution of the organic acid is 0 to 30% by weight, and the amount of the organic acid used is 0 to 10% by weight based on the total weight of the composition. The composition according to any one of item 3. (5) The unsaturated carboxylic acid polymer is a polymer or copolymer having a repeating unit of at least one member selected from the group consisting of acrylic acid, maleic acid, fumaric acid, and itaconic acid. A composition according to claim 4. (6) The concentration of the unsaturated carboxylic acid polymer aqueous solution is 10
60% by weight, and the amount used is 15 to 60% by weight of the total weight of the composition in terms of solids. (7) Mix γ-calcium pyrophosphate and calcium carbonate in equimolar amounts, add 0.1 to 30% by weight of aluminum phosphate to the mixture, and after drying,
The powder obtained by calcining at ℃ and pulverizing the resulting product is
Ca/Al ratio of 2 to 1200, characterized by kneading with at least one kneading liquid selected from the group consisting of physiological saline, sodium sulfate aqueous solution, organic acid aqueous solution, or unsaturated carboxylic acid polymer aqueous solution. α− within the range of
A method for producing a fluid or plastic bone or tooth filling composition comprising a fired product of tricalcium phosphate or its raw material and aluminum phosphate, and a kneading solution. (8) The fired and pulverized powder is pressurized and compressed again at 120°C.
7. The method according to claim 6, comprising a second firing step of firing at a temperature of 0 to 1500°C for 2 hours or more. (9) The method according to claim 7, characterized in that the aluminum phosphate is added before the second firing step.