JPH078548A - Hardenable powder for living body - Google Patents

Abstract

PURPOSE:To provide a hardenable powder for living bodies which hardly deteriorates even by the contact with the moisture in the air for a long period, stabilized in quality when formed into cement, and excellent in storing stability by incorporating a magnesium compound in a specified ratio to a self-hardening type potassium phosphate. CONSTITUTION:To a self hardening type potassium phosphate, 0.5-15wt.% of a magnesium compound is included. Otherwise, a hardly soluble fluoride is included in the self-hardening type potassium phosphate, and 0.5-15wt.% of the magnesium compound is further included. The self-hardening type potassium phosphate is alpha-type tricalcium phosphate. The hardenable biological powder material contains as an X-ray contrast medium one kind or more selected from the group consisting of barium sulfate, basic bismuth carbonate, and iodoform, and the hardly soluble fluoride is a fluoride of alkaline earth metal. Thus, the deterioration at storing can be suppressed, and the powder material can be stored for a long period even when the X-ray contrast medium is mixed thereto.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a curable biomaterial. More specifically, the present invention relates to a powder material which is a mixture of a calcium phosphate powder and a magnesium compound and is used for a curable living body and has excellent storage stability.

[0002]

2. Description of the Related Art Self-hardening calcium phosphate refers to one that hardens by reacting with water. Of these, those that produce hydroxyapatite (hereinafter, abbreviated as HAP) after being hardened particularly have recently been used as medical cements for teeth, bone filling agents, etc. because HAP approximates to the main components of teeth and bones in vivo. Attention has been paid.

The self-hardening calcium phosphate is kneaded with a liquid agent such as water to form a cement, which is crushed by a ball mill or the like to improve the operability at that time. Since self-curing calcium phosphate is active in water as it is hardened by reacting with water, it may change over time due to adsorption of water in the air. For example, α-type tricalcium phosphate, which is attracting attention as a self-hardening calcium phosphate, when stored under high temperature and high humidity,
In a short time, a part of α-tricalcium phosphate gradually changes into massive HAP. Therefore, it takes time to knead with the liquid agent to form a paste at the time of use, and it becomes difficult to perform the operation even if it is inserted, filled or poured into the application site. Further, even if the ingredients are kneaded, there may occur a phenomenon that the variation does not disappear and a good paste is not formed.

As described above, when a cement is prepared by kneading with a liquid agent by adsorbing water in the air, there are problems such as variations in curing time and deterioration of kneading property. ) Is not stable. Therefore, in order to prevent the time-dependent change of the self-hardening calcium phosphate, the packaging may be filled in a water-impermeable container such as glass, but even in that case, once opened, the self-hardening calcium phosphate powder is used every time. There is a problem in storage stability such that moisture in the air is adsorbed to cause a change over time and the operability gradually deteriorates.

The present inventors have also confirmed that the addition of basic bismuth carbonate, which is an X-ray contrast agent, tends to accelerate the change with time of self-curing calcium phosphate. For this reason, the development of a hardenable biomaterial made of self-curing calcium phosphate, which does not easily change even if it comes into contact with moisture in the air for a long period of time, has stable quality when used as cement, and has excellent storage stability. It was strongly desired.

[0006]

In view of the above situation, the present inventors have diligently studied a curable biological powder material containing calcium phosphate, which does not easily deteriorate due to adsorption of moisture in the air over time and is excellent in storage stability. As a result, when mixed with a specific proportion of a magnesium compound, which has a reaction-inhibiting effect on α-type tribasic calcium phosphate, it has excellent storage stability, and the quality of the hardenable biomedical powder when used as cement The inventors have found that a material can be obtained and completed the present invention.

That is, (1) self-hardening calcium phosphate, and a hardenable biomaterial characterized by containing 0.5 to 15% by weight of magnesium compound, and (2) self-hardening calcium phosphate. Contains a sparingly soluble fluoride and further contains a magnesium compound 0.5 to 1
The present invention provides a curable biomedical powder material containing 5% by weight.

The present invention will be described in more detail below. The self-curing calcium phosphate referred to in the present invention is one that exhibits curability by hydration when kneaded with water or water containing a curing accelerator such as an acid, and is exemplified by α-type tricalcium phosphate and phosphorus. Self-hardening calcium phosphate such as tetracalcium acid or a mixture of α-type tricalcium phosphate and tetracalcium phosphate or non-self-hardening calcium phosphate such as octacalcium phosphate, β-type tricalcium phosphate, calcium hydrogen phosphate Is a mixture of.

In the self-hardening calcium phosphate, the atomic ratio of calcium to phosphorus is 1.3 to 2.0 (Ca / P).
Is preferable, and more preferably 1.4 to 1.8. If the composition is out of this range, the difference between the theoretical composition of HAP and the Ca / P ratio is too large. Therefore, even if calcium phosphate is kneaded with water containing a curing accelerator such as an acid, it is hardened and converted into a HAP structure. It is difficult to obtain a good cured product.

The method for preparing this self-hardening calcium phosphate is not particularly limited. For example, in the case of α-type tricalcium phosphate, γ-type obtained by heating dicalcium phosphate at about 550 ° C. for about 2 hours. It is particularly preferable that calcium pyrophosphate is mixed with calcium carbonate and calcined at about 1200 ° C. and pulverized, and the particle size is 100 μm or less, preferably 2 μm.
Those having a thickness of 0 μm or less can be preferably used. In the present invention, a self-curing calcium phosphate is mixed with a magnesium compound at 0.5
-15% by weight (hereinafter,% by weight is represented by% unless otherwise specified), and more preferably 5-10%. If the addition amount of the magnesium compound is less than 0.5%, the storage stability of the self-curing calcium phosphate will not be sufficiently improved.
Further, if it exceeds 15%, the storage stability is improved, but the fluidity is lowered after mixing with a solvent to form a paste, and the operability and workability are deteriorated in use, which is not preferable.

Specific examples of the magnesium compound used in the present invention include inorganic compounds such as magnesium silicate, magnesium silicide, magnesium calcium silicate, magnesium calcium metasilicate, magnesium oxide, magnesium hydroxide and carbonic acid. magnesium,
Examples thereof include basic magnesium carbonate and magnesium phosphate, phosphates such as magnesium phosphate, borates such as magnesium borate, sulfates such as magnesium sulfate, and the like. Organic compounds include citric acid. Examples thereof include fatty acid salts such as magnesium, magnesium malate, magnesium stearate, magnesium benzoate, and magnesium formate, which may be used alone or as a mixture of two or more.

If desired, the mixture of the self-curing calcium phosphate and magnesium compound of the present invention may further contain a poorly soluble fluoride.
It has been confirmed that when a poorly soluble fluoride is added to the mixture, it becomes fluorapatite when it is used as a cement.
This fluorapatite is known as a particularly stable form among apatites, and it can be easily understood that this cement exhibits excellent stability in the living body or the oral cavity.

The amount of the sparingly soluble fluoride is such that Ca / F (gram atom ratio) is at least 4.2 in order for fluorine to be incorporated into apatite, and Ca / F is required for curing time within several hours. Is preferably 60 or less. Specific examples of the poorly soluble fluoride include calcium fluoride, magnesium fluoride, strontium fluoride, an alkaline earth metal fluoride of barium fluoride, lithium fluoride, chromium fluoride, lead fluoride, nickel fluoride, Examples thereof include metal fluorides such as iron fluoride and aluminum fluoride, sodium silicofluoride, potassium silicofluoride, calcium silicofluoride, and barium silicofluoride, which may be used alone or as a mixture of a plurality thereof.

The self-curing calcium phosphate of the present invention may further contain an X-ray contrast agent, if desired. As the X-ray contrast agent, one or more kinds can be selected from the group consisting of barium sulfate, basic barium carbonate and iodoform. The amount of the X-ray contrast agent added is not particularly limited, but it is preferably 0.1 to 30% in the powder material.

[0015]

The present invention will be described in more detail with reference to the following examples. Example 1 100 g of α-type tricalcium phosphate (α-TCP) powder and 1 g of magnesium oxide were dry-mixed for 2 minutes using a mixer to obtain a mixture. The mixture was subjected to an acceleration test for 2 weeks in a thermo-hygrostat at a temperature of 60 ° C. and a relative humidity of 70%. After the acceleration test, the hydration rate of α-TCP was measured.

The hydration rate of α-TCP was measured by a powder X-ray diffractometer. A mixture of α-type tricalcium phosphate and magnesium oxide before and after the hydration test was added with Ti.
O ₂ (rutile type) was added as an internal standard at 20%, and α-
From 30.8 °, which is the main peak of TCP, and 27.5 °, which is the main peak of TiO ₂ (rutile type),
The hydration rate of α-TCP was calculated by the following formula.

[0017]

[Equation 1]

The consistency used in the present invention refers to a powdery agent comprising a mixture of α-type tricalcium phosphate and magnesium oxide subjected to an accelerated test and a citric acid solution (provided that the pH is adjusted to 3.0 with ammonia water). Liquid is JIST6602
Knead according to the above, and take the kneaded product on a glass plate. Then, a glass plate was placed on the kneaded product, and a weight was placed on the glass plate so that the total amount became 120 g. At 10 minutes after the kneading was started, the weight and the glass plate were removed, and the dimension (mm) of the maximum part and the minimum part between the parallel lines of the spread kneading was measured, and the average value was taken as the consistency. It was used as an index for evaluating the miscibility of cement. As a result of measurement, α-TCP
Has a low hydration rate of 20% and the cement consistency is 35m.
m was also well kneaded. The results are shown in Table 1.

Examples 2 to 4 The same conditions as in Example 1 were carried out except that the amount of magnesium oxide in Example 1 was changed to 5, 10, 13 g. The results are shown in Table 1.
Shown in.

Example 5 The same conditions as in Example 1 were carried out except that the magnesium oxide was changed to 10 g of magnesium hydroxide. As a result of the measurement,
The hydration rate of α-TCP is low, and the consistency of cement is 34
mm and kneadability was also good. The results are shown in Table 1.

Example 6 The same conditions as in Example 1 were carried out except that 100 g of α-TCP powder, 10 g of magnesium oxide, and 2.5 g of calcium fluoride which was a poorly soluble fluoride were dry-mixed for 2 minutes with a mixer. As a result of the measurement, the hydration rate of α-TCP was low, and the consistency of the cement was 33 mm, indicating good mixing.
The results are shown in Table 1.

Example 72 100 g of α-TCP powder, 10 g of magnesium oxide, 2.5 g of calcium fluoride which is a sparingly soluble fluoride, and 10 g of basic bismuth carbonate which is an X-ray contrast agent were mixed in a mixer for 2 minutes. It carried out on the same conditions as Example 1. As a result of the measurement, the hydration ratio of α-TCP was low, and the cement had a good consistency of 34 mm with a kneading property. The results are shown in Table 1.

Comparative Example 1 The same conditions as in Example 1 were used except that the amount of magnesium oxide was changed to 0.3 g. As a result of the measurement, the hydration rate of α-TCP was high, and further, the cement had a consistency of 17 mm and was poor in miscibility. The results are shown in Table 1.

Comparative Example 2 Example 1 except that magnesium oxide was changed to 20 g.
The same conditions were used. As a result of the measurement, the hydration rate of α-TCP was low, but the cement had a consistency of 21 mm, which showed a decrease in miscibility. The results are shown in Table 1.

Comparative Example 3 The procedure of Example 6 was repeated except that the amount of magnesium oxide was changed to 0.3 g. As a result of the measurement, the hydration rate of α-TCP was high, and the cement had a consistency of 15 mm, which showed a decrease in the miscibility. The results are shown in Table 1.

Comparative Example 4 Example 6 except that the amount of magnesium oxide was changed to 20 g.
The same conditions were used. As a result of the measurement, the hydration rate of α-TCP was low, but the consistency of the cement was 20 mm and the miscibility was low.

[0027]

[Table 1]

[0028]

EFFECTS OF THE INVENTION According to the present invention, it is possible to suppress deterioration of self-curing calcium phosphate during storage, which has not been achieved by the prior art. That is, it is difficult to prevent alteration of the conventional powder material made of self-curing calcium phosphate during storage, and the operability is poor when it is used as cement. In contrast,
The material of the present invention is not deteriorated by moisture and is good without impairing operability. Further, even if an X-ray contrast agent, which has conventionally been accelerated in deterioration due to water, is mixed, it can be stored for a long period of time, and the operability when used as a cement is also good.

Front page continued (72) Inventor Toshihiko Nishitsuji 7-1, 1-1 Hikoshimasako-cho, Shimonoseki-shi, Yamaguchi Prefecture Mitsui Toatsu Chemical Co., Ltd. (72) Yoshihito Ochiai 3-3-7 Fujisawa, Kanagawa Prefecture ( 72) Inventor Koichi Saito 457 Yamanishi, Ninomiya-cho, Naka-gun, Kanagawa Prefecture Ninomiya Dormitory (72) Inventor Fumio Osato 457 Yamanishi, Ninomiya-cho, Naka-gun, Kanagawa Prefecture Nyomiya Dormitory, Ltd.

Claims (5)

[Claims] 1. A curable biomaterial, which comprises self-curing calcium phosphate and 0.5 to 15% by weight of a magnesium compound. 2. A self-curing calcium phosphate and a sparingly soluble fluoride are contained, and a magnesium compound 0.5 to 1 is further contained.
A curable biomedical powder comprising 5% by weight. 3. The curable biomedical powder material according to claim 1, wherein the self-curing calcium phosphate is α-type tricalcium phosphate. 4. The curable biomedical material according to claim 1, wherein the curable biomedical powder material contains at least one selected from the group consisting of barium sulfate, basic bismuth carbonate and iodoform as an X-ray contrast agent. Powder material. 5. The curable biomedical powder material according to claim 2, wherein the poorly soluble fluoride is a fluoride of an alkaline earth metal.