JP2609909B2 - Medical or dental curable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a curable composition for medical or dental use, particularly as a material to be used in direct contact with dental pulp such as covering material and root canal filling material. It relates to a suitable curable composition.

[Conventional technology and problems to be solved]

The use of α-tricalcium phosphate having biocompatibility as a powder as a medical or dental curable composition has been attracting attention, and such curable compositions include:
An aqueous solution of an acid such as polyacrylic acid, citric acid and tartaric acid is mainly used as a curing liquid.

However, when these acid aqueous solutions are used as a curing liquid, the pH of the curable composition is lowered, and thus there is a problem that the composition has irritation to living bodies. Therefore, there is a problem in using it as a covering material, a root canal filling material, etc., which is used by directly contacting the pulp.

Further, in order to solve the problem of the pH of the curing liquid, those obtained by adding a neutral salt or the like to an acid such as polyacrylic acid, citric acid, and tartaric acid have been developed. The curable composition using is disadvantageous in that the disintegration rate is high.

In view of this situation, the present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have biocompatibility, have no irritating property to a living body, and have a low disintegration rate for medical or dental purposes. The present invention has found a curable composition for use in the present invention.

[Means for solving the problem]

That is, the present invention provides a composition comprising a powder comprising α-tricalcium phosphate powder and a curing liquid, wherein the curing liquid is selected from the group consisting of diammonium phosphate, ammonium oxalate, ammonium acetate and sodium hydrogen tartrate. The present invention also relates to a curable medical or dental composition, which is an aqueous solution of at least one salt.

Further, in the present invention, when X-ray contrast is required, 100 parts by weight of α-tricalcium phosphate powder and 5 to 3 parts of iodoform powder are used.
The present invention relates to the curable medical or dental composition using 0 parts by weight of a powder.

 Hereinafter, the present invention will be described in detail.

The powder [P] constituting the curable composition of the present invention is composed of α-tricalcium phosphate powder alone or, when X-ray contrast property is required, it and iodoform powder.

The α-tricalcium phosphate can be produced by a known method, for example, the following method.

That is, γ-calcium pyrophosphate and calcium carbonate are uniformly mixed in an equimolar amount, and after sufficient drying, 1000 to
It can be obtained by calcining at 1400 ° C., preferably around 1250 ° C. for about 1 hour, and pulverizing the obtained product into a fine powder having a particle size of 100 μm or less. Alternatively,
It can also be obtained by uniformly mixing calcium hydrogen phosphate dihydrate and calcium carbonate in a molar ratio of 2: 1 and then calcining and pulverizing under substantially the same conditions as in the above method.

 The particle size of the powder is preferably 20 μm or less.

Further, as the above-mentioned iodoform powder, those conventionally used for this kind of application can be used, and the particle size of the powder is preferably 10 μm or less.

The amount of the iodoform powder is 5 to 30 parts by weight, particularly preferably 15 to 25 parts by weight, per 100 parts by weight of α-tricalcium phosphate.

If the amount of iodoform powder is less than the above range, the X-ray contrast of the curable composition will be insufficient, which is not preferable. It is not preferable because it becomes worse.

The powder [P] used in the present invention has α
-It is composed of tricalcium phosphate powder or iodoform powder, but may further contain barium sulfate powder, basic bismuth carbonate powder, silica powder, alumina powder, apatite powder and the like, if necessary.

The curing liquid [L] constituting the curable composition of the present invention is an aqueous solution of at least one salt selected from the group consisting of diammonium phosphate, ammonium oxalate, ammonium acetate and sodium hydrogen tartrate.

The concentration of these salts in aqueous solution is diammonium phosphate
10-40 wt%, preferably 10-20 wt%; ammonium oxalate 3-5 wt%, preferably 4-5 wt%; ammonium acetate 20-60 wt%, preferably 30-50 wt%;
Sodium bitartrate 3-5% by weight, preferably 4-
5% by weight is suitable. When the concentration of the aqueous solution is less than the above range, the curability and workability of the curable composition tend to be poor. On the other hand, if it exceeds the above range, the solubility of the kneaded and cured product tends to increase.

In the present invention, an aqueous solution of a polyalkylene glycol such as polyethylene glycol and polypropylene glycol (aqueous solution concentration of 5 to 15% by weight) can be used in combination as the curing liquid in order to improve the kneadability and the like. Further, if necessary, various additives such as a thickener and a surfactant can be added in a small amount.

The curable composition of the present invention comprises the powder [P] and the curing liquid [L] described above, and preferably has a weight ratio [P] / [L] of [P] / [L] of 1.0 to 2.0. The mixture is kneaded immediately before use and used for use.

〔The invention's effect〕

The curable composition of the present invention is chemically close to the components of the teeth,
Since α-tricalcium phosphate is used, it has biocompatibility, the pH of the kneaded product is near neutral, it is not irritating to the living body, and the disintegration rate is small. Therefore, it is suitable as a capping material and a root canal filling material, and it satisfies the properties such as moderate kinematic viscosity, operability, curability, and sealing property of the kneaded material required as a capping material and a root canal filling material. It can be said that this is an epoch-making curable composition.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to examples.

Examples 1 to 6 and Comparative Examples 1 to 3 γ-calcium pyrophosphate and calcium carbonate were equimolarly mixed by a known method, calcined to synthesize α-tricalcium phosphate, pulverized and passed through a 300-mesh sieve. Thus, α-tricalcium phosphate powder having a predetermined particle size was obtained.

The thus obtained α-tricalcium phosphate powder (referred to as α-TCP) was used and mixed with other powder components [P] shown in Table 1 according to the method of JIS-T-6602. And kneaded with the curing liquid [L] shown in Table 1. (Numerical values in the table indicate parts by weight.) The disintegration rate, surface pH and X-ray contrast of the kneaded mixture thus prepared were examined, and the results are shown in the lower part of Table 1.

As is clear from the test results in Table 1, the curable composition of the present invention has a cured product having a surface pH near neutrality, and therefore has very low irritation to the living body and a small disintegration rate. It was

On the other hand, Comparative Example 1 using an aqueous solution of triammonium phosphate as a curing liquid and Comparative Example 2 using an aqueous solution of sodium polyacrylate have a high disintegration rate, and Comparative Example 3 using an aqueous solution of polyacrylic acid shows that the surface of the cured product It was unsuitable due to low pH and irritation to living organisms.

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Claims (2)

(57) [Claims] 1. A neutral medical or dental curable composition comprising a powder of α-tricalcium phosphate powder and a curing liquid, wherein the curing liquid is diammonium phosphate, ammonium oxalate, acetic acid A curable medical or dental composition which is an aqueous solution of at least one salt selected from the group consisting of ammonium and sodium bitartrate. 2. A neutral curable composition for medical or dental use, which comprises a powder comprising 100 parts by weight of α-tricalcium phosphate powder and 5 to 30 parts by weight of iodoform powder, and a curing liquid. A curable composition for medical or dental use, wherein the curing liquid is an aqueous solution of at least one salt selected from the group consisting of diammonium phosphate, ammonium oxalate, ammonium acetate and sodium hydrogen tartrate.