JP2877840B2 - Cement material for living hard tissue - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder-liquid type cement material for living hard tissue which is excellent in curability and biocompatibility and can be satisfied in operability. .

[Prior art] Dental cement was first commercialized as a cement for living hard tissue, and zinc phosphate cement, zinc oxide-polycarboxylate cement, glass ionomer cement and the like have been used for a long time, and then methacrylate-based polymers have been used. Resin cement was also developed. However, since these cement materials are chemically different from the components of teeth and bones, there is a problem that the affinity for the living body is insufficient and the bonding strength with the living body is insufficient.

Therefore, research has been conducted on a new material exhibiting good affinity for living hard tissues such as teeth and bones, and α-tricalcium phosphate (hereinafter abbreviated as α-TCP) having a composition close to the main components of living hard tissues. Do) or hydroxyapatite (HAP)
And a number of inventions have been proposed.
However, all of them are powdery and have low chemical activity, and when applied to the human body by a usual method, for example, in combination with a reactive curable resin material such as polyfunctional methacrylate, the biocompatibility of the combined material is not sufficient. Because it is sufficient, it cannot be said that the intended purpose has been achieved, and there are still problems in terms of strength and shrinkage upon curing. Is central.

On the other hand, attention was paid to the fact that α-TCP is converted into HAP having better biocompatibility by hydration reaction, and it was kneaded with a small amount of an organic acid aqueous solution or an inorganic acid aqueous solution and repaired for living hard tissue. Has been proposed. However, even in these methods, the curing time is long, the compressive strength is low,
There are various drawbacks such as poor workability during kneading, and it is desired to provide a cement material for living hard tissue that does not have these drawbacks.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned drawbacks of the prior art, and does not have these drawbacks. The purpose of the present invention is to provide a cement material for living hard tissue which is excellent in applicability to such materials.

[Means for Solving the Problems] The cement material for living hard tissue of the present invention, which can achieve the above object, is a powder component consisting essentially of α-TCP or, if necessary, HAP and / or The gist consists of a powder component containing calcium monophosphate and a kneading liquid containing sodium carboxymethylcellulose (hereinafter abbreviated as CMC) as essential components.

[Function] The most typical point in the present invention is that CM is used as a kneading liquid.
The point of using C is that the kneading operability is improved, and the effect of reducing the amount of kneading liquid used (increasing the powder-liquid ratio) is obtained, improving the clinical technique and reducing the contraction rate. It has become possible to lay the foundation for reducing and increasing the mechanical strength.

A second feature of the present invention is that α-TCP is a main component,
In this respect, a powder component obtained by blending HAP and / or calcium monophosphate is used, whereby the effects of shortening the curing time (improving curability) and increasing the compressive strength are achieved. When used in combination, the biocompatibility is further improved.

The α-TCP used in the present invention is generally manufactured by a dry method, but does not matter what manufacturing means. Although the powder component in the present invention can be composed of α-TCP alone, the present invention also relates to a case where the powder component is used in combination with HAP and / or calcium monophosphate, or a case where calcium hydroxide is further used as necessary. include. When such combined use is carried out, it is desired that the blending amount of α-TCP is 60% by weight (hereinafter simply abbreviated as “%”) or more.

Next, the compounding amounts of these concomitant agents when HAP or calcium phosphate monobasic is used in combination are not particularly limited, as can be understood from the gist of the present invention. However, when it is desired to exhibit these combined effects more clearly, HAP can be set to 2% or more, preferably 5% or more, and calcium monophosphate to 0.1% or more, preferably 0.5% or more. Incidentally, the upper limit of the combination of these concomitant agents is the α-TC
From the viewpoint of securing the lower limit of P (60%), it is desired to be 40% or less. Particularly, in the case of HAP, it is 30% or less because HAP has a high bulk density and acts to lower the powder-liquid ratio. In the case of monobasic calcium phosphate, from the point that too much curing time will be too short and clinical workability will deteriorate.
It is recommended that each be less than 10%.

CMC, which is the main component of the kneading solution, is prepared as an aqueous solution, and the CMC concentration in the aqueous solution is 0.05 to 10%, preferably 0.1 to 5%.
% Is good. If it is less than 0.05%, the viscosity at the time of kneading is insufficient, and if it exceeds 10%, the viscosity may be too high and uneven kneading may occur. The degree of etherification of CMC is not particularly limited, but generally the degree of etherification is in the range of 0.6 to 1.2.

Example A powder component and a kneading solution having the compositions shown in Table 1 were prepared,
The test was performed according to ST 6602, and the results shown in Table 1 were obtained.

As is clear from the results in Table 1, in the examples satisfying the requirements of the present invention, the operable time was an appropriate length, the kneading operability was good, and the cured state after 24 hours was good. And showed satisfactory results in terms of strength.

FIG. 1 shows No. 5 (Example) and No. 9 used in the above experiment.
For each of Comparative Examples, the conversion rate of α-TCP after kneading to HAP was measured, and the amount of α-TCP at 0 minutes was 1
The figure shows the amount of change over time in the α-TCP amount and the HAP amount when the HAP amount is set to 0. As can be seen in Figure 1, CMC
In the example using, the conversion of α-TCP to HAP progressed very quickly, and a favorable effect on the expression of biocompatibility can be expected.

[Effect of the Invention] Since the present invention is configured as described above, the kneading operability is improved, and the powder-liquid ratio is increased by reducing the amount of the kneading liquid, thereby improving the mechanical strength. It is now possible to contribute. In addition, various hardenings such as an improvement in curability and an increase in compressive strength can be obtained by improving the powder component.

[Brief description of the drawings]

 FIG. 1 is a graph showing the conversion rate of α-TCP to HAP.

Claims (2)

(57) [Claims] 1. A cement material for living hard tissue, comprising a kneading solution containing a powder component consisting essentially of α-tricalcium phosphate and sodium carboxymethylcellulose as essential components. 2. A kneading solution containing α-tricalcium phosphate as a main component, a powder component obtained by mixing hydroxyapatite and / or calcium monophosphate, and sodium carboxymethylcellulose as an essential component. A cement material for living hard tissue, characterized in that: