JP4111421B2 - Calcium phosphate cement for living bone reinforcement treatment capable of forming a high-strength hardened body - Google Patents

Description

【００１４】
【発明の効果】
表１に示される結果から、従来セメントを構成する混合組成物に硫酸マグネシウムを配合した本発明セメント１〜１５は、これより成形された硬化体が前記硫酸マグネシウムの配合がない従来セメント１〜１１より形成された硬化体に比して一段と高い強度をもつことが明らかである。
上述の通り、本発明セメントは、高強度を有する硬化体の成形を可能とするものであり、治療補強骨の強度向上に大いに寄与するほか、硬化体使用量の低減を図ることができるなど工業上有用な特性を有するものである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a calcium phosphate cement used for living bone reinforcement treatment in the medical field including oral surgery, and capable of forming a high-strength hardened body.
[0002]
[Prior art]
In general, the cement for living bone reinforcement treatment
(1) Coagulation property that a slurry formed by adding an aqueous solution for curing solidifies;
(2) Curability in which the solidified body is cured in the presence of moisture,
(3) Hardened body strength sufficient to allow movement of the treatment-reinforcing bone,
(4) Absorption and replacement properties for the cured body to regenerate into living bone,
However, various types of cement for living bone reinforcing treatment have been proposed as cements having these characteristics.
[0003]
[Problems to be solved by the invention]
On the other hand, since the cured body is a foreign body for a living body, it is desirable that a predetermined amount of strength is obtained in the treatment reinforcing bone with as little cured body usage as possible, but in the conventionally proposed living bone reinforcing treatment cement, Since sufficient strength cannot be obtained in the cured body, it is not possible to satisfactorily reduce the amount of the cured body used as a treatment reinforcing bone, and thus a living bone that can further improve the strength of the cured body There is a strong demand for the development of cement for reinforcement treatment.
[0004]
[Means for Solving the Problems]
In view of the above, the present inventors have conducted research to develop a living bone reinforcing treatment cement capable of improving the strength of a cured body, and as a result, various conventionally proposed living bone reinforcing treatment cements have been proposed. Of which, calcium phosphate cement, that is, by mass% (hereinafter,% represents mass%),
Dicalcium phosphate: 3-10%,
Tetracalcium phosphate: 10-25%
α-type tricalcium phosphate and inevitable impurities: the rest,
Calcium phosphate cement composed of a mixed composition having a blend composition consisting of the above, and a mixed composition comprising 0.03 to 0.5% of magnesium sulfate in this calcium phosphate cement is used as the calcium phosphate cement. And, in applying this, the fluidity of the paste formed by adding a curable aqueous solution to this is further improved by the action of the magnesium sulfate, and as a result, the entrainment of bubbles is significantly reduced, Research results have been obtained that a dense cured body can be formed, and the strength of the formed cured body is significantly improved.
[0005]
This invention was made based on the above research results,
Magnesium sulfate: 0.03-0.5%,
Dicalcium phosphate: 3-10%,
Tetracalcium phosphate: 10-25%
α-type tricalcium phosphate and inevitable impurities: the rest,
It is characterized by a calcium phosphate cement for living bone reinforcement treatment that can be formed into a high-strength hardened body, which is composed of a mixed composition having a blend composition comprising:
[0006]
Next, the reason why the composition of the calcium phosphate cement for living bone reinforcement treatment of the present invention (hereinafter simply referred to as the present invention cement) is limited as described above will be described.
(A) Magnesium sulfate In this component, as described above, when applying cement, the fluidity of the paste is improved, so that entrainment of bubbles is remarkably suppressed, and a dense hardened body can be formed. In order to fully exhibit this effect, the fourth component which is the remaining component in the state of being kneaded in advance with the second calcium phosphate which is the component in the production of the cement of the present invention. It is necessary to blend with calcium phosphate and α-type tricalcium phosphate, but if the ratio is less than 0.03%, the desired effect cannot be obtained, whereas if the ratio exceeds 0.5%, the cured body is cured. Therefore, the ratio is set to 0.03 to 0.5%, preferably 0.1 to 0.3%.
[0007]
(B) Dicalcium phosphate This component has an action of promoting the setting of the paste to the cured body, but if the ratio is less than 3%, the desired setting acceleration action cannot be secured, while the ratio is If it exceeds 10%, the curing time becomes too short, and the workability is inevitably deteriorated. Therefore, the ratio is set to 3 to 10%, preferably 4 to 8%.
[0008]
(C) Calcium quaternary phosphate This component has an action of promoting the absorption and replacement property of the cured body to regenerate into living bone, but if the ratio is less than 10%, the desired improvement effect cannot be obtained for the action. If the proportion exceeds 25%, the strength of the cured product will decrease, so the proportion was determined to be 10 to 25%, preferably 12 to 20%.
Examples of the curable aqueous solution of the cement of the present invention include curable aqueous solutions that are usually used in practice, such as disodium succinate and sodium chondroitin sulfate, sodium lactate, sodium phosphate, sodium chloride, sodium bisulfite, and pyrophosphate. An aqueous solution containing a predetermined amount of one or more of sodium sulfite and the like, and distilled water can be applied.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, the cement of the present invention will be specifically described with reference to examples.
First, α-type tricalcium phosphate and tetracalcium phosphate, which are constituents of the cement of the present invention, were prepared as follows, and commercially available magnesium sulfate and dicalcium phosphate were used.
(1) α-type tricalcium phosphate calcium hydroxide: 3 mol of water is suspended in 10 liters of water, and phosphoric acid: 2 mol of phosphoric acid: 2 mol diluted with water is slowly added dropwise with stirring. After completion of the dripping, the mixture is allowed to stand at room temperature for 1 day, and then dried to form an agglomerate under a condition of holding at 110 ° C. for 24 hours. Then, the fired product was pulverized, and α-type tribasic calcium phosphate having a purity of 99.9% was produced by sieving to a particle size of 88 μm or less (average particle size: 6.5 μm).
[0010]
(2) Quaternary calcium phosphate: 4 mol of calcium hydroxide suspended in 10 liters of water, and 40% phosphoric acid aqueous solution prepared by diluting 2 mol of phosphoric acid with water was slowly added dropwise with stirring. After the completion, it is allowed to stand at room temperature for 1 day, and then dried to form an aggregate by holding it at 110 ° C. for 24 hours, and this aggregate is first pre-sintered at 900 ° C. for 3 hours. Subsequently, in a state of uniform pulverization, calcination is performed at 1400 ° C. for 3 hours, the baked product is pulverized, and sieved to a particle size of 88 μm or less (average particle size: 6.5 μm). As a result, a mixed product was produced in which the content ratio of the quaternary calcium phosphate was 90.5% and the remainder was substantially composed of hydroxyapatite as an inevitable impurity.
In this example, the above mixed product was used as tetracalcium phosphate.
[0011]
Next, α-type tribasic calcium phosphate and quaternary calcium phosphate obtained in (1) and (2) above as the raw material powder, and commercially available magnesium sulfate and dicalcium phosphate are used. And the second calcium phosphate are sufficiently kneaded in advance in a kneader for 30 minutes in a proportion corresponding to the total proportion shown in Table 1, and this kneaded powder and other raw material powders are blended in the blending proportions shown in Table 1. The cements 1 to 15 of the present invention and conventional cements 1 to 11 containing no magnesium sulfate were produced by mixing to obtain a mixed composition having substantially the same composition as the blending ratio.
[0012]
Furthermore, for the purpose of evaluating the strength of the cured bodies formed from the above-mentioned cements 1 to 15 of the present invention and the conventional cements 1 to 11, these cements were respectively mixed with sodium chondroitin sulfate: 5% and disodium succinate hexahydrate. : A curing aqueous solution containing 15% and sodium bisulfite: 0.3%, with the balance being water, is added at a mass ratio of cement: curing aqueous solution = 3: 1 and kneaded to a slurry. The slurry was condensed to form a cylindrical solid body having a diameter of 6 mm × height: 12 mm. The solid body was Na ⁺ : 142.0 mM, K ⁺ : 5.0 mM, Mg ²⁺ : 1. Immerse in an aqueous solution (pseudo body fluid) containing 5 mM, Ca ²⁺ : 2.5 mM, Cl ⁻ : 148.8 mM, HCO ₃ ⁻ : 4.2 mM, HPO ₄ ^{2 −} : 1.0 mM for 5 days to cure. ,this The compressive strength of the cured product after the curing process of the day was measured. The measurement results are also shown in Table 1.
[0013]
[Table 1]

[0014]
【The invention's effect】
From the results shown in Table 1, according to the present invention cements 1 to 15 in which magnesium sulfate is blended with the mixed composition constituting the conventional cement, the cements 1 to 11 in which the hardened body formed from this has no blend of the magnesium sulfate. It is clear that it has a much higher strength than a more formed cured body.
As described above, the cement of the present invention enables molding of a cured body having high strength, greatly contributes to the improvement of the strength of the treatment-reinforced bone, and can reduce the amount of the cured body used. It has the above useful characteristics.

Claims (1)

% By mass
Magnesium sulfate: 0.03-0.5%,
Dicalcium phosphate: 3-10%,
Tetracalcium phosphate: 10-25%
α-type tricalcium phosphate and inevitable impurities: the rest,
A calcium phosphate cement for living bone reinforcement treatment capable of forming a high-strength hardened body, characterized by comprising a mixed composition having a composition comprising: