JPH03184554A - Medical or dental curable composition - Google Patents

Abstract

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

Description

Detailed Description of the Invention [Industrial Application Field] The present invention cures biological hard tissue by mixing a powder mainly composed of calcium phosphate and a liquid agent mainly composed of an organic acid or an inorganic acid. Regarding a medical or dental composition that provides a cured product that is homogenized.

More specifically, the present invention relates to a medical or dental curable composition that is implanted as a bone filling material into bone defects, tooth extraction sockets, periodontal tissue defects, etc. of living bodies to promote the bone-increasing action of new bone.

[Problems to be solved by conventional techniques and inventions] Conventionally,
Bone cement, zinc phosphate cement, glass ionomer, amalgam, carboxylate cement, etc. are used as medical and dental curable compositions.

However, these compositions cannot be expected to integrate with living hard tissue even if they remain in the living body for a long period of time.

Recently, calcium phosphate, which is the same as or similar to the components of bones and teeth, has attracted attention, and medical and dental clinics are using this as the main component of powders and bio-derived organic acids, such as malic acid and citric acid, as hardening liquids. Curable compositions have been proposed for
No. 48, No. 62-182146, No. 63-11556
No. 8.

No. 64-61407, Japanese Unexamined Patent Publication No. 1-121059, etc.). However, these compositions themselves cannot be expected to integrate with biological hard tissues.

On the other hand, in order to integrate with biological hard tissue, it is desirable that the curable composition forms a porous cured body, particularly a porous cured body in which capillary-like three-dimensional communicating pores are formed. . Conventionally, the following methods are known as methods for obtaining porous bodies intended for integration with biological hard tissues, but each method has various problems that need to be solved.

■ Obtaining a porous body using a powdered filling material
1-9075).

In this method, since the filling is performed using a powdered filling material, the filling material tends to scatter during the operation and cannot be molded, resulting in poor handling properties.

(2) Calcium phosphate compound powder is sintered under specific conditions to obtain a porous body in which needle-shaped calcium phosphate compound crystals are cross-connected to each other (Japanese Patent Application Laid-Open No. 60-90880).

■ Adding a foaming agent to amorphous calcium phosphate slurry and heating and decomposing it after one foaming to obtain a porous body (Japanese Patent Application Laid-open No. 1983-
16879).

■ Mixing organic fibers, resin and slurry or powder,
A porous body is obtained by removing organic fibers during heating and sintering (JP-A-60-18174 and JP-A-62-158175).

■ Immerse the organic porous material in calcium phosphate slurry,
A porous body of calcium phosphate is obtained by sintering an organic porous body to eliminate it by heating (Japanese Unexamined Patent Publication No. 166843/1984).

In all of the above methods, the porous body is a sintered body,
It is difficult to process because it forms a porous body through sintering.
and poor filling compatibility.

(2) A porous body is obtained by wet-mixing silicon nitride and a calcium phosphate compound and sintering the mixture under pressure using a hot press (Japanese Unexamined Patent Publication No. 197066/1986).

Although this method also forms a porous body by sintering, the processability is improved. However, there is still a problem with filling compatibility, and it is necessary to process and fit the filling at the time of filling.

The present invention has been made to solve the problems of the prior art described above, and is a medical or dental curable composition that provides a porous cured product with excellent operability and filling compatibility, and which can be integrated with biological hard tissue. The purpose is to provide something.

[Means and effects for solving the problem] The present inventors,
As a result of intensive studies to achieve the above objectives, we have developed a self-curing filling composition consisting of a powder agent mainly composed of calcium phosphate and a liquid agent mainly composed of organic or inorganic acids. When the fibers are uniformly mixed into a paste made by kneading the above-mentioned powder and liquid and filled into bone defects, tooth extraction sockets, and periodontal tissue defects in the living body, self-hardening occurs. At the same time, the fibers of the bioabsorbable material uniformly dispersed in this hardened material are absorbed by the living body and disappear, making the hardened material porous and inhibiting new bone formation and integration with new bone. It was discovered that effective pores are generated.

Therefore, according to the medical or dental curable composition of the present invention, the filling operation is carried out in the form of a paste, and the porous body is formed not by sintering but by bioabsorption from the hardened body after filling. Because it is based on bioabsorption and disappearance of bioactive fibers, it has excellent operability and filling compatibility, and has excellent properties as a bone grafting material for living bodies.

The present invention will be explained in more detail below.

The medical or dental curable composition of the present invention comprises a powder containing calcium phosphate as a main component, a liquid containing an organic or inorganic acid as a main component, and fibers of a bioabsorbable material.

Calcium phosphate, which is the main component of the powder, includes α-tricalcium phosphate, β-tricalcium phosphate, calcium phosphate, tetracalcium phosphate, calcium hydrogen phosphate, calcium hydrogen phosphate dihydrate, and water. Examples include acid apatite, fluoroapatite, etc., and one or two of these
More than one species can be used in combination. In addition to calcium phosphate, the powder may contain calcium carbonate, calcium hydroxide, alumina, zirconia, silica, aluminosilicate, zinc oxide, barium sulfate,
One type or two or more types of calcium fluoride or the like may be used in combination, but the amount thereof is preferably 40 parts by weight or less per 100 parts by weight of calcium phosphate.

On the other hand, as a liquid agent, citric acid, d
- Organic acids such as malic acid, lactic acid, glycolic acid, and tartaric acid, and their salts, as well as inorganic acids such as nitric acid, phosphoric acid, and hydrochloric acid.
Although one species or two or more species can be used as the main component, d-malic acid and citric acid are preferred from the viewpoint of increasing the strength of the cured product. Note that the liquid agent can be prepared by dissolving the above-mentioned curable component in a solvent such as water.

The amounts of the powder and liquid used may be the usual amounts, and generally 0.1 to 2 parts by weight of the liquid may be used for 1 part by weight of the powder.

The bioabsorbable material used in the present invention may be any material as long as it can be absorbed by the living body and disappear from the cured product, and examples include mucopolysaccharide, collagen, fibrin, polylactic acid, polydioxanone, and polyglycol. Examples include acids, chitin, and copolymers of polylactic acid and polyglycolic acid, and one type of these can be used alone or two or more types can be used in combination. The present invention uses fibers made of these materials, and the diameter of the fibers is 20 to 2.
00-, and the length is preferably selected so that one through pore is formed when the fiber disappears from the cured product.

The blending amount of the fibers in the bioabsorbable material can be selected from various methods, but is preferably 10 to 50% by weight, especially 25 to 40% by weight of the total composition.
It is preferable to set it as weight%.

In addition, the composition of the present invention may contain a bone growth promoting component such as Bonmorpho Genetec protein, and the combination of this component imparts osteoinductive ability and rapidly generates new bone. preferable.

The composition of the present invention is used by kneading a powder and a liquid, uniformly mixing fibers of a bioabsorbable material, and filling the application site with a paste in which the fibers are dispersed. As a result, the paste self-cures and a cured body in which the fibers are dispersed is obtained, and the fibers dispersed in this cured body are absorbed by the living body and disappear over time.
The fiber dispersed portion becomes pores and the cured product becomes porous.

New bone grows in the pores of such a porous hardened body, and the porous hardened body is integrated with the generated hard tissue.

〔Effect of the invention〕

As explained above, according to the present invention, since it is paste-like and self-curing during the filling operation, it is easy to operate, and there is no scattering of powder, making it easy to handle.
Furthermore, since the bone defect is filled as a paste, it can easily adapt to the shape of the defect. Furthermore, the formation of pores is caused by the fibers of the bioabsorbable material filling the defect and being absorbed into the body and disappearing in a hardened state, so there is no need for disadvantageous operations such as sintering, and new bone formation occurs. The formation of porosity, which is effective for the production and incorporation of pores, is easily, reliably, and stably carried out.

Therefore, the composition of the present invention can be used to treat periodontal diseases, intramaxillary cysts, tooth extraction sockets, maxillary resorption, combined artificial tooth roots, the posterior wall of the external auditory canal, the frontal sinus,
Effectively used for bone replacement, etc.

EXAMPLES The present invention will be specifically explained below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example 1] 0.952 g of α-tricalcium phosphate (α-TCP) and 0.048 g of calcium fluoride were placed on kneaded Japanese paper, and
After initial kneading with 0.270 g of diammonium citrate aqueous solution, 0.270 g of chitin fiber with a diameter of 50 mm was added to this.
500 g was added and final kneaded to obtain a paste composition (Example).

For comparison, a comparative paste composition was prepared in the same manner except that chitin fiber was not added.

Next, these compositions were applied to two artificially formed cavities (2 mm in diameter) in the femurs of Peagle dogs.

It was filled to a depth of 1 mm). In addition, each composition self-cured within 2 to 5 minutes after filling.

When we observed the passage of two months after filling, we found that in the case of the composition of Example, the chitin fibers were bioabsorbed and disappeared from the hardened body, making it porous, and new bone was generated within this porous body. As a result, the hardened material (filling material) and bone tissue were integrated. However, in the case of the comparative composition, the hardened material has no pores and does not become porous, so new bone was generated around the hardened material, but the hardened material and bone tissue become integrated. It had not reached that point.

[Example 2] α-TCP 0.900g and tetracalcium phosphate 0.10
Neutralize the mixed powder with 0g with sodium hydroxide to adjust the pH.
Add 0.300 g of 30% α-malic acid solution prepared as 5 and knead, and then add polylactic acid fibers with a diameter of 50/Jl.
．． 720 g was added and kneaded to prepare a paste composition.

When this was filled into the cavity of a peagle dog in the same manner as in Example 1, it self-hardened in 3 to 5 minutes.

As a result of observing the progress two months after the filling, the polylactic acid fibers in the hardened body disappeared and became porous, new bone was generated within this porous body, and the hardened body (filling material) and bone tissue were integrated. was.

[Example 3] α-TCP 0.814g and hydroxyapatite 0.286g
Neutralize the mixed powder with ammonium hydroxide to pH 5.
A mixed solution of 0.260 g of 18% citric acid and 0.001 g of ammonium fluoride O, 5, was added and kneaded, and then 0.600 g of polyglycolic acid fiber with a diameter of 150μ was added.
g was added and kneaded to prepare a paste composition.

When this was filled into the cavity of a peagle dog in the same manner as in Example 1, it self-hardened in 3 to 5 minutes.

As a result of observing the progress two months after the filling, the polyglycolic acid fibers in the hardened body disappeared and became porous, new bone grew within this porous body, and the hardened body (filling material) and bone tissue were separated. It was integrated.

Claims (1)

[Claims] 1. A medical or dental curable composition comprising a powder containing calcium phosphate as a main component, a liquid containing an organic or inorganic acid as a main component, and fibers of a bioabsorbable material.