JPH06321515A - High-strength hardenable material - Google Patents

Abstract

PURPOSE:To obtain a high-strength hardenable material capable of controlling the hardening reaction by blending a hardenable material containing tetracalcium phosphate powder with an inorganic or an organic hardening modifier and forming a surface coating layer. CONSTITUTION:The hardenable material is obtained by adding and blending an inorganic hardening modifier and/or an organic hardening modifier with a hardenable material containing power, having a surface coating layer and consisting essentially of tetracalcium phosphate. Respective oxides, hydroxides, fluorides, chlorides, carbonates, phosphates, sulfates, silicates, etc., of lithium, sodium, potassium, magnesium, calcium, aluminum, zinc, bismuth or tin are cited as the inorganic hardening modifier used. Collagen, chitosan, tannic acid, ethanol, propylene glycol, etc., are cited as the organic hardening modifier.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical and dental high strength curable material useful as a bone filling material, bone cement, dental cement and the like.

[0002]

2. Description of the Related Art Tetracalcium phosphate has the composition formula Ca ₄ (PO ₄ ) ₂ O.
In the presence of water, acid, etc., it has the property of being easily converted into a compound that is extremely similar to the inorganic component that is the main component of bones and teeth in the living body, and thus has attracted attention as a biomaterial. ing.

A curable material for use in artificial bones, bone filling materials, dental cements, etc., containing a powder containing tetracalcium phosphate as a main component, which has such a high chemical activity that it hardens easily at room temperature. As a method of obtaining, (1) citric acid,
A method of obtaining a curable material by mixing with an aqueous solution of a TCA cycle organic acid such as malonic acid, (2) mixing with an aqueous solution having a composition similar to that of the interstitial fluid in the body in addition to physiological saline, phosphate buffer, etc. To obtain a curable material, (3) a method of mixing with a polysaccharide aqueous solution to obtain a curable material, and (4) a method of mixing with an aqueous solution of a homopolymer or copolymer of an unsaturated organic acid, Method for obtaining curable material, (5) above (1) to (4)
A method of obtaining a curable material by appropriately combining the above methods has been proposed.

The curable material obtained by these methods is usually provided to clinicians in the form of a powder liquid type in which a powder material and a liquid agent are combined. In general, a curable material for living body needs to be used in a desired form after a clinician kneads and mixes a powder material and a liquid agent at the time of treatment to form a paste or clay, and after the treatment, It is required to cure rapidly and to be firmly fixed to the affected area, and to exhibit excellent biocompatibility.

[0005]

However, since the tetracalcium phosphate powder, which is the main component of the powder material, has a very high chemical activity and is an alkaline substance, it reacts violently when mixed with an acidic aqueous solution, and it is a contaminant. It is difficult to obtain a uniform composition that retains an appropriate softness for a certain period of time, and a curable material having satisfactory performance can be obtained by any of the methods (1) to (5) above. I can't.

Therefore, conventionally, in order to improve the physical properties of the composition until it is cured or to delay the curing time of the composition, the acid concentration of the liquid agent is decreased or the water content of the composition is increased. For example, a method has been proposed that secures a treatment operation time and improves operability during treatment. Also in powder materials, apatite, calcium phosphate, calcium monohydrogen phosphate, alkaline phosphate,
Attempts have been made to suppress the high reaction activity of tetracalcium phosphate by adding citrate or the like.

However, although the curable composition obtained by these methods remarkably deteriorates the properties as a tetracalcium phosphate-based curable composition, it is recognized that the curing reaction property is improved to the extent of compensating for it. At present, no tetracalcium phosphate-based curable material having satisfactory properties has been put into practical use. The present invention has been made in view of the above circumstances, and an object thereof is to provide a high-strength curable material capable of controlling a curing reaction.

[0008]

[Means for Solving the Problems] In order to achieve the above-mentioned objects, the present inventors have succeeded in achieving various curing reaction characteristics without impairing the characteristics of a tetracalcium phosphate-based composition as a biomaterial. As a result of earnestly examining the material, it was obtained by adding an inorganic curing modifier and / or an organic curing modifier to a curable material containing tetracalcium phosphate powder having a double structure as an essential component. When using different materials,
It has been found that the problems of the prior art are substantially eliminated or significantly reduced. Here, the “double structure” means that the surface of the tetracalcium phosphate particles is a substance having an affinity for the living body or a substance harmless to the living body such as hydroxyapatite, fluorinated apatite, carbonate apatite, octaphosphate. It means a structure coated with calcium.

That is, the present invention has a surface coating layer,
And high-strength curability for medical and dentistry characterized by adding an inorganic curing modifier and / or an organic curing modifier to a curable material containing a powder containing tetracalcium phosphate as a main component. It depends on the material.

The present invention will be described in detail below based on the structure. The medical and dental curable material according to the present invention,
A curable material and a curing control agent having a dual structure tetracalcium phosphate powder as an essential component, having a surface coating layer on the surface of at least a powder containing tetracalcium phosphate as a main component (referred to as tetracalcium phosphate powder) It is a combination of

The tetracalcium phosphate powder used in the present invention may be produced by any method,
A high-purity product in which the purity of tetracalcium phosphate is 98% or more is desirable. Such high-purity powder is obtained, for example, by mixing CaCO ₃ powder and CaHPO ₄ .2H ₂ O powder,
It can be produced by the solid-state reaction method of the following chemical formula 1, which is fired as described above.

[0012]

[Chemical 1]

In order to increase the purity of the obtained tetracalcium phosphate powder, when carrying out the solid-state reaction method of the above chemical formula 1, CaCO ₃ powder, CaHPO ₄ .2H ₂ O powder, and further alumina powder (Al ₂ O ₃ ) is added and the produced tetracalcium phosphate is made into a sintered body, whereby a powder containing tetracalcium phosphate in high purity can be obtained (JP-A-2-180705). Further, by coating the particle surface of the tetracalcium phosphate powder with a substance having biocompatibility, for example, apatite,
Further, high quality tetracalcium phosphate powder can be obtained (JP-A-4-89307 and JP-A-4-139050).

The coating substance may be any substance having a property of softening the reaction between tetracalcium phosphate and a strongly acidic aqueous solution, and examples thereof include hydroxyapatite, fluorapatite and carbonate apatite. The particle size of the tetracalcium phosphate powder coated with this coating substance varies depending on the use of the hardened product and is not necessarily limited, but it is usually 20 μm or less, and an average of about 5 μm is used. preferable.

The composition of the curable material used in the present invention is, in addition to the above-mentioned tetracalcium phosphate powder, hydroxyapatite powder, carbonate apatite powder, fluorapatite powder, tricalcium phosphate powder, calcium monohydrogen phosphate. Powders and the like may be contained, but the amount of these powders is preferably 50% by weight or less. If the content of the tetracalcium phosphate powder is less than 50% by weight, the physical strength of the cured product after kneading may be extremely lowered, or a curing failure may occur, which is not preferable. As the additive powder other than the tetracalcium phosphate powder, bone powder and the like can be used in addition to those obtained by a known or known method.

The curing solution used in the present invention contains a TCA cycle type organic acid as a main component, and a high molecular weight organic acid or an inorganic acid may be added. TCA cycle organic acids include citric acid, tartaric acid, malic acid, malonic acid, itaconic acid, fumaric acid, maleic acid, succinic acid, etc., one kind selected from these groups, or two kinds The above is mixed and used. The high molecular weight organic acid includes, for example, a homopolymer of acrylic acid, a copolymer of acrylic acid and itaconic acid, a copolymer of acrylic acid and fumaric acid, and the inorganic acid includes, for example, phosphoric acid, nitric acid, Hydrochloric acid, sulfuric acid, etc. are included.

A hardened product can be obtained by kneading and mixing such an acid with a powder material in the form of an aqueous solution containing usually 30 to 70% pure water as a solvent. The reaction activity and the curing time can be freely controlled by further adding a curing modifier during the kneading and mixing.

Further, the curing modifier used in the present invention is roughly classified into an inorganic substance and an organic substance. As the inorganic curing modifier, lithium carbonate, sodium oxide, sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, sodium chloride, sodium fluoride, sodium phosphate,
Sodium hydrogen phosphate, sodium sulfate, potassium hydroxide, potassium carbonate, potassium chloride, potassium hydrogen phosphate, magnesium oxide, magnesium carbonate, magnesium phosphate, magnesium sulfate, calcium oxide, calcium hydroxide, calcium carbonate, calcium chloride, phosphorus Calcium dihydrogen acid, calcium sulfate, calcium pyrophosphate, barium oxide, barium carbonate, barium chloride, aluminum hydroxide, aluminum chloride, aluminum phosphate, zinc oxide, zinc chloride, zinc phosphate, bismuth oxychloride, basic bismuth nitrate, Tin chloride, tin fluoride,
Sodium silicate, sodium silicofluoride, calcium silicate, aluminosilicate, silica gel, sodium borate, etc. are exemplified, and at least one selected from these groups is used. Although the compound is not particularly limited, it is relatively easily dissolved in water or an acidic aqueous solution, and lithium ion, sodium ion, potassium ion, magnesium ion, calcium ion, barium ion, aluminum ion, zinc ion, bismuth ion, tin ion, fluorine ion Chloride ion, chloride ion, carbonic acid (hydrogen)
Ions, phosphate (hydrogen) ions, sulfate ions, hydroxide ions, hydrated silicate ions, and various ions such as borate ions can be used, as long as they are substances or compounds that elute various ions such as oxide glass. It may be a complex containing.

As the organic curing modifier, water-soluble alcohols such as ethanol and propylene glycol, collagen, chitosan, tannic acid and their derivatives, as well as various metals such as sodium citrate and calcium lactate and other carboxylic acids. Examples of the salt include at least one selected from these groups.

These curing modifiers can be added to the powder material and / or the curing solution in advance in the form of being mixed with the powder material in the form of powder and / or dissolved in the curing solution. The addition amount is preferably in the range of 0.01 to 10% by weight when added to either the powder material side or the curing solution side, and when added to both sides, the total amount should be in the range of 0.01 to 10% by weight. To If it is less than these ranges, the curing preparation effect may not be exhibited, and if it exceeds these ranges, the physical properties of the cured product may deteriorate, which is not preferable.

The total acid concentration of the curing solution is not particularly limited, but is preferably in the range of 10 to 80% by weight. If the amount is out of these ranges, the curing time may not be controlled even if the curing modifier is added.

The high-strength curable material according to the present invention can be obtained by kneading and mixing a powder material and a curing solution to which a curing modifier is appropriately added as described above. The mixing ratio of the powder and the liquid is preferably 5 to 80 parts by weight of the curing solution as an acid with respect to 100 parts by weight of the powder in order to obtain a cured product having high strength. It should be noted that materials other than those described above, which are commonly used by those skilled in the art, may be included as long as the object of the present invention is not hindered.

[0023]

The present invention will be further clarified by the following examples and comparative examples. The present invention is not limited to the following examples.

Example 1 A powder material and a curing solution were prepared using the respective materials in the proportions shown in Table 1. However, in producing the powder material, a composition obtained by mixing tetracalcium phosphate powder, hydroxyapatite powder, tricalcium phosphate powder, and calcium monohydrogen phosphate powder in the ratio shown in Table 1 was used.
The powder material and the curing solution are kneaded and mixed at a powder / liquid ratio of 2.5 g / ml,
The curing time, compressive strength and consistency were measured. The results are also shown in Table 1. However, the surface of the tetracalcium phosphate powder
Covered with hydroxyapatite.

[0025]

[Table 1]

Example 2 A powder comprising a mixture of tetracalcium phosphate powder 88% by weight, hydroxyapatite powder 10% by weight and calcium fluoride powder 2% by weight, citric acid 40% by weight, polyacrylic acid 2% by weight, Hardening solution of 18% phosphoric acid (total amount of acid 60% by weight
The mixed acid) was prepared, and the curing regulator was added in the proportions shown in Table 2. Both were kneaded and mixed at a powder / liquid ratio of 2.5 g / ml, and the curing time, compression strength and consistency were measured. The results are also shown in Table 2. However, the surface of the tetracalcium phosphate powder was coated with hydroxyapatite.

[0027]

[Table 2]

Comparative Example 1 The measurement was carried out under the same conditions as in Examples 1 and 2 except that no curing modifier was used. Table 3 shows the compounding conditions and the measurement results.

[0029]

[Table 3]

Comparative Example 2 Measurement was carried out under the same conditions as in Examples 1 and 2 except that the conventional tetracalcium phosphate powder having no surface coating layer was used. The compounding conditions and the measurement results are shown in Tables 4 and 5.

[0031]

[Table 4]

[0032]

[Table 5]

..

According to the present invention, since the curing reaction can be controlled by adding a small amount of the curing modifier, the added curing modifier adversely affects the physical properties of tetracalcium phosphate itself. It is possible to knead and mix with good operability even in a compounding region where it was not practically possible to knead and mix the tetracalcium phosphate powder without affecting, and further, in the tetracalcium phosphate powder having a double structure. Even if it is present, the kneading and mixing becomes easy even in a compounding area where it is difficult to practically use it and a cured product having high strength can be obtained. In addition, the powder / liquid ratio and the acid concentration of the curing solution can be made higher than before, and a curable material having higher strength can be obtained.

Furthermore, the curing time can be freely set without sacrificing the performance of the material depending on the purpose of use or the purpose of treatment, and the remarkable effect that the range of application as a biomaterial is expanded is obtained.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location C04B 28/34

Claims (3)

[Claims] 1. An inorganic curing regulator and / or an organic curing regulator is added to a curable material having a surface coating layer and containing a powder containing tetracalcium phosphate as a main component. A high-strength curable material for medical and dental purposes. 2. As an inorganic curing modifier, oxides, hydroxides, fluorides, chlorides, carbonates of lithium, sodium, potassium, magnesium, calcium, potassium, aluminum, zinc, bismuth and tin, The high strength curable material according to claim 1, wherein at least one selected from the group consisting of phosphate, sulfate and silicate is used. 3. An organic curing regulator, collagen,
The high-strength curable material according to claim 1, wherein at least one of chitosan, tannic acid, ethanol, propylene glycol, sodium citrate, calcium citrate, potassium citrate, and calcium lactate is used.