JPH0523389A - Medical or dental curable composition - Google Patents

Abstract

PURPOSE:To obtain the title curable composition having sufficient curability and strength required as a prosthetic material or a filling material and excellent in biocompatibility and X-ray image forming properties. CONSTITUTION:A medical or dental curb composition consists of a strontium phosphate or strontium calcium phosphate type devitrified glass powder containing a strontium apatite crystal and/or strontium calcium phosphate crystal and a kneading liquid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curable composition for medical or dental use, and more particularly, as a medical or dental material having an X-ray contrast property, which has been produced especially for pathological or external reasons. Used as a bone cement or dental cement for filling a defect or void of bone or tooth or mounting an artificial prosthesis, to facilitate the generation of new bone or tooth newly at the location, and later the bone of the living body. Bone, which is an inorganic material or a composite of an inorganic material and an organic material, which is integrated with tissues and tooth tissues, and can be easily and accurately observed after surgery.
The present invention relates to a curable composition for filling teeth.

[0002]

2. Description of the Related Art Defects or voids in bones and teeth due to traffic accidents, bone tumor resection, etc. in the field of surgery and orthopedics, or alveolar pyorrhea, alveolar bone resorption, tooth extraction and carious tooth deletion in the field of dentistry. Occurs. Filling of such bone defects or voids, autologous bone, polymer for prosthesis,
Various materials such as metals and ceramics are used. Among them, autologous bone is excellent in that it has excellent bone-forming ability and few rejection reactions. However, since the autologous bone must be collected from the normal tissue of the person himself, it is not only accompanied by great pain due to the operation, but also a sufficient amount cannot be secured in many cases. Therefore, in recent years, hydroxyapatite has begun to be used as a material to replace autogenous bone. Hydroxyapatite can be obtained by, for example, synthesizing or burning animal bones to remove organic components, and is known to have very good biocompatibility. However, it has been pointed out that when hydroxyapatite is used as a filler in the form of fine powder or granules, it leaks as blood or body fluid or leaks as foreign matter even after suturing.

Further, when the artificial prosthesis is attached to a living body hard tissue, it is joined and attached using bone cement. So-called medical polymers mainly composed of PMMA (polymethyl methacrylate) are often used for this bone cement, but this material not only has insufficient biocompatibility, but is also generated by the reaction heat generated during the curing reaction. The pain in the affected area and the biohazard of unreacted monomers pose problems.

On the other hand, the dental cement material is used not only as a bonding material for prostheses but also as a filling material and a lining material, and various dental cement materials are used as restoration materials in the dental field. Is being developed. Among them, as described in Japanese Patent Publication No. 50-23050, glass ionomer cement is a curing agent composed of a glass powder obtained by melting alumina and silica at a high temperature with a fluxing agent such as fluoride, polyacrylic acid, and a copolymer of unsaturated carboxylic acid. It is also composed of a liquid, has a large crushing resistance after hardening, is relatively excellent in adhesiveness to the tooth substance, and has little harm because it is against dental pulp. However, it has a drawback that biocompatibility is insufficient.

For these reasons, a new dental cement consisting of an inorganic component which constitutes the hard tissue of the living body has been attracting attention in recent years, and a cement based on a crystalline powder of calcium phosphate or apatite is being developed. These main components are similar to bones and have extremely excellent biocompatibility. However, such a crystalline powder has a drawback that it is extremely inferior in the reaction with the organic curing liquid. This is because the reaction components with the curing liquid are very limited. Therefore, the crushing resistance of the hardened cement is extremely low, which is not practical.

As described above, the dental cement materials that have been developed have advantages and disadvantages, and it is necessary to use the dental cement materials properly according to their uses. However, the dental cement materials have sufficient hardening characteristics and biocompatibility. Having properties is a common required property, and it is desired to satisfy both of them.

[0007] Further, at the present time, none of the various medical / dental materials described above has been found to have both biocompatibility and X-ray contrast at the same time. Needless to say, biocompatibility is extremely important as a biomaterial, but in the case of an artificial material that is implanted in some form in the body, it is possible to accurately grasp the state when implanted and the secular change after implantation. It is important to do so. That is, the X-ray contrast property is also an important property. Generally, as a means for imparting X-ray contrast, strontium, barium,
A method of blending a metal oxide such as lanthanum or a metal salt as an X-ray contrast agent is often adopted. However, these contrast components not only have no biocompatibility, but also have high in vivo solubility, or have a problem of harmful effects due to allergies and the like. For these reasons, there has been a strong demand in recent years for a material that has a contrasting component itself with biocompatibility and can exist stably in a living body.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned technical problems, and the purpose thereof is, as is clear from the above point, a prosthetic material and a filling material. The object of the present invention is to provide a curable composition for medical or dental use which has sufficient curability and strength required as described above, is excellent in biocompatibility, and has X-ray contrast.

[0009]

Means for Solving the Problems The medical or dental curable composition of the present invention capable of achieving the above object is a strontium phosphate devitrified glass containing strontium apatite crystals and / or strontium phosphate crystals. Powder,
Alternatively, the gist is that it is composed of a strontium calcium phosphate-based devitrifying glass powder containing strontium solid solution apatite crystals and a kneading solution. The inventors of the present invention aim to develop a curable composition for medical or dental use which satisfies the above-mentioned requirements, and as a result of various studies, a strontium phosphate devitrified glass containing a strontium apatite crystal and / or a strontium phosphate crystal. Powder or strontium calcium phosphate-based devitrifying glass powder containing strontium solid solution apatite crystals, and various kneading liquids are mixed and kneaded to obtain any of curability, biocompatibility, and X-ray contrast property. However, they have found that an excellent curable composition can be obtained, and completed the present invention.

[0010]

The present invention will be described in detail below. The strontium phosphate devitrified glass powder or strontium calcium phosphate devitrified glass powder of the present invention must contain strontium apatite crystals and / or strontium phosphate crystals or strontium solid solution apatite crystals. These crystals are very close to the main components of bone and promote the formation of bone. This must be a so-called devitrified glass in which a crystal-stabilized crystal phase is dispersed in the glass, not simply a glass obtained by adding and mixing the above crystals. This crystalline phase is indispensable for imparting biocompatibility and X-ray contrast. Further, coexistence of glass in the above crystal phase is also an essential condition. This glass is indispensable for providing excellent curability, and is a so-called devitrified glass in which the above crystal phase and glass phase coexist, in terms of biocompatibility, X-ray contrast, and curability. It is an excellent curable composition. In order to generate these crystal phases, it is essential that the raw material contains an appropriate amount of a strontium salt or calcium salt, which is a main component, or a phosphoric acid chloride. In particular, the material of the present invention does not reheat the molten glass to crystallize it or slowly cool the molten glass to crystallize it, but rather quench the molten glass product and There is a feature in obtaining devitrified glass by crystallizing, and selection and preparation of raw materials for devitrification are extremely important. In the case of producing a so-called crystallized glass in which a crystal phase and a glass phase coexist, in the conventional method, the generated glass is heat-treated again, or the glass in a molten state is gradually cooled to obtain a crystallized glass. Since the devitrified glass used in the present invention is rapidly cooled to devitrify the glass in a molten state, a devitrified glass having a high activity can be obtained. The activity means that the reaction components are easily provided to various kneading liquids described later, and thus a curable composition having excellent physical properties can be obtained. The physical properties mentioned here include curing time, strength and dissolution stability of the cured product.

The raw material composition of the devitrified glass of the present invention can be expressed, for example, as follows: SrO: 3 to 55% by weight CaO: 0 to 40% by weight P ₂ O ₅ : _{5 to} 32% by weight SiO ₂ : 15-30 wt% Al ₂ O _3: 3~37 wt% F _2: 1 to 10% by weight MgO: 0 to 2 wt%

SrO is indispensable as a component for imparting X-ray contrast, but it is not a mixture of so-called contrast components such as SrO for the purpose of imparting contrast. Not only do these contrast agents have low affinity for living organisms,
This is because it has a high solubility in vivo or has a problem of harm due to allergies and the like. The feature of the present invention is that strontium, which is effective as a component that imparts an X-ray contrast property, is not in the form of strontium oxide (SrO) as described above, but strontium apatite [Sr ₁₀ (PO ₄ ) ₆ (OH) ₂ ] or strontium phosphate crystal or strontium solid solution apatite [Sr _x Ca _10-x (PO ₄ ) ₆ (OH) ₂ ] having the same structure as the main components of the bones and teeth of the living body Is characterized in that

The reasons for limiting the composition will be described below. First, if SrO is less than 3% by weight, it is insufficient to impart X-ray contrast. On the contrary, when SrO exceeds 55% by weight, the glass component occupying the whole becomes small. That is, the components that are involved in the curing reaction are reduced, so that the curing characteristics are inferior.

The CaO content is preferably 0 to 40% by weight, and when it is 0% by weight, the crystal phase produced in the devitrified glass is pure strontium apatite or strontium phosphate crystal. When CaO is added, strontium solid solution apatite crystals are generated. In this case, it is a solid solution and gives an apatite type crystal phase whose structure is continuously changed depending on the amount ratio of SrO and CaO. The compounding ratio of both can be arbitrarily changed depending on the target crystal phase or the target contrast of X-ray, but the total amount of both is preferably 60% by weight or less. When it exceeds 60% by weight, the glass component occupying the whole is reduced. That is, the components that are involved in the curing reaction are reduced, and the curing properties are inferior. It should be noted that although various crystals are formed depending on the content of CaO, they all have a structure that closely resembles the hard tissue of the living body, and the biocompatibility is extremely good in any case.

[0015] In the P ₂ O ₅ is less than 5 wt%, not give out strontium phosphate-based crystals or strontium phosphate calcium-based crystals are crystals, no affinity with the living body, is P ₂ O ₅ in the opposite 32 If it exceeds 5% by weight, the chemical durability is poor and erosion in the living body is observed, which is unsuitable.

On the other hand, if SiO ₂ is less than 15% by weight, the glass component occupying the whole is small and the transparency is lowered. On the contrary, if SiO ₂ exceeds 30% by weight, calcium phosphate crystals in the glass powder are contained. The proportion of the phase or strontium calcium phosphate crystal phase is relatively small, and the biocompatibility is also reduced.

Further, when Al ₂ O ₃ is less than 3% by weight, the glass strength is lowered, and conversely, when Al ₂ O ₃ exceeds 37% by weight, biocompatibility is lowered like SiO _2. Invite.

F ₂ has an effect as a fluxing agent, and when applied in the dental field, a sustained release effect of fluorine can be seen by adding 1 to 10% by weight, but when it exceeds 10% by weight, devitrified glass is used. The original mechanical strength and chemical durability are reduced.

Further, one or more kinds of components selected from the group consisting of MgO, Na ₂ O and B ₂ O ₃ may be added for the purpose of controlling the glass melting temperature and the amount of crystals formed. However, when added in a large amount, crystallization of strontium phosphate crystals or strontium calcium phosphate crystals is extremely suppressed, resulting in a decrease in biocompatibility. Therefore,
The addition amount of these components is 2% by weight or less.

Next, as the kneading liquid, physiological saline, a water-soluble polymer solution, an aqueous solution of an inorganic acid, an aqueous solution of an organic acid, an aqueous solution of a polymer of an unsaturated carboxylic acid, or a mixture of these is used as a kneading solution. One selected from the group consisting of
For example, when the application to dental cement is assumed, strength development in a short time is required, so an aqueous solution of an unsaturated carboxylic acid polymer having a concentration of 20 to 80% is preferable, and more preferably 40%. An inorganic or organic acid having a concentration of 20% or less is added to an aqueous solution having a concentration of -60% for the purpose of adjusting the curing characteristics.

On the other hand, when it is used as a filling material for a bone defect portion or a tooth root canal portion, physiological saline is recommended as a material which is not stimulated by acid or alkali, but an appropriate amount for imparting fluidity and viscosity. It is also effective to add a water-soluble polymer such as CMC (sodium carboxymethyl cellulose) or polyethylene glycol.

In addition to the strontium apatite, the strontium phosphate crystal, or the strontium solid solution apatite crystal, the wollastonite crystal is contained in the resulting crystal.
(CaO ・ SiO ₂ ), diopsite crystal (MgO ・ CaO
・ 2SiO ₂ ), forsterite crystal (2MgO ・ Si
Although it may contain a small amount of an alkaline earth metal silicate crystal such as O ₂ ), both are included in the devitrified glass in the present invention.

[0023]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but it goes without saying that the present invention is not limited thereby.

Example 1 SrO: 36.2% by weight, P ₂ O ₅ : 12.2% by weight, Si
O ₂ : 23.4% by weight, Al ₂ O ₃ : 22.7% by weight, Mg
Glass raw materials were prepared so that O: 0.5% by weight and F ₂ : 5% by weight, melted at 1600 ° C. for 2 hours, and then rapidly cooled in water to obtain a devitrified glass. When this was identified by an X-ray diffraction method, a strontium apatite crystal, a tristrontium phosphate crystal and an amorphous phase were confirmed. The result is shown in FIG.

Next, the devitrified glass powder thus obtained was finely pulverized to obtain a powder having an average particle size of 10 μm, which was then added to a physiological saline solution.
% (2) (powder) by weight of the kneading solution added with CMC
It was 8 hours when the setting time was examined by adding in the ratio of (liquid). The X-ray contrast was equivalent to a pure aluminum plate of 6 mm.

Further, this was filled in a bone marrow cavity perforated in two femurs of a mongrel dog and subjected to X-ray photography, whereby the filling was clearly photographed. Three months later, the sliced pieces were cut out to prepare a polished thin piece in accordance with a conventional method, and when examined under a microscope, it was confirmed that new bone had entered the periphery of the glass powder so as to surround it and firmly bonded.

A mixture of an aluminosilicate glass powder having an average particle size of 10 μm and a hydroxyapatite crystal powder having an average particle size of 10 μm in a weight ratio of 1: 1 in place of the strontium phosphate devitrified glass having an average particle size of 10 μm. Similarly to Example 1, the bone marrow cavities perforated in two femurs of a mongrel dog were filled and confirmed by X-ray, but no clear difference from the surroundings was observed. Three months later, the sliced pieces were cut out to prepare polished slices according to a conventional method and examined under a microscope. As a result, more new bone was found around the filling site.

Example 2 SrO: 27.8% by weight, CaO: 12.0% by weight, P ₂
O ₃ : 7.0% by weight, SiO ₂ : 22.0% by weight, Al
₂ O ₃ : 26.4 wt%, MgO: 0.5 wt%, F ₂ : 4:
Glass raw material is mixed so as to be 4% by weight, and the temperature is 1600 ° C.
After melting for 2 hours, it was rapidly cooled in the air to obtain a devitrified glass. This was finely pulverized with a pot mill so that the average particle diameter was 3 μm. According to the X-ray diffraction method, the obtained devitrified glass powder had a glass phase and a crystal phase coexistent, the crystal was strontium solid solution apatite, and the glass phase and the crystal phase were 7: 3. The result is shown in FIG.

Next, 40% by weight of a polycarboxylic acid having an average molecular weight of about 15,000 prepared from itaconic acid (40% by weight) and acrylic acid (60% by weight) was added to the obtained devitrified glass powder.
A kneading solution consisting of 10% by weight of tartaric acid and 50% by weight of water was added at a weight ratio of 1.2 (powder): 1 (liquid), and added to "JIS T-6.
Tested according to “602”, curing time about 6 minutes, 24
Compressive strength after 1240 kg / cm ² , and 24
A hardened cement product having a time disintegration rate of 0.28% was obtained. When the powder and the kneading liquid were added at a weight ratio of 1.8 (powder): 1 (liquid), the curing time was about 5 minutes and the cement strength after 16 hours had a compressive strength of 1630 kg / cm ² . The thing was obtained. The X-ray contrast was equivalent to a pure aluminum plate of 5 mm.

Example 3 A glass raw material was prepared so as to have the chemical composition shown in Table 1 below, melted at 1400 to 1650 ° C., and then rapidly cooled in water to obtain a devitrified glass (trial No. 1 to 3). . These were pulverized with a pot mill so that the average particle diameter was 2 to 5 μm. 40 parts of polyacrylic acid to 1.6 parts by weight of devitrified glass powder
1.0 part by weight of a kneading liquid containing 10 wt% of tartaric acid and 50 wt% of water was added and kneaded, and the properties of the obtained cured product were investigated. In the table, the identification result of the crystallized phase by the X-ray diffraction method, the curing time, the compressive strength after 24 hours and the X-ray contrast property are described. As a comparative example, prototype Nos. 4 to 7
The same investigations as above were carried out for the glass raw material prepared in (1) and prepared by a known method for producing crystallized glass, and for the hydroxyapatite crystal powder (trial No. 8). In particular, regarding the compressive strength, the product of the present invention is 1040 to 1680 kg /
While it was cm ^2, and the sample No.4~8 of comparative product 5
The value was as low as 0 to 400 kg / cm ² .

[0031]

[Table 1]

As is clear from the above results, it is understood that the medical or dental curable composition of the present invention exhibits good curing characteristics and has good biocompatibility.

[0033]

According to the present invention, by adopting the constitution described above, the curability is excellent and the cured product has sufficient strength,
Further, it is possible to provide a new medical or dental curable composition having excellent biocompatibility.

[Brief description of drawings]

1 is an X-ray diffraction diagram of a strontium phosphate-based devitrification glass powder obtained in Example 1. FIG.

FIG. 2 is an X-ray diffraction diagram of the strontium calcium phosphate-based devitrified glass powder obtained in Example 2.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Sadayuki Yuda             6 120 120 Kamo, Kawanishi City, Hyogo Prefecture             Central Research Institute of Industry Co., Ltd. (72) Inventor Masahiko Ueda             6 120 120 Kamo, Kawanishi City, Hyogo Prefecture             Central Research Institute of Industry Co., Ltd.

Claims (5)

[Claims] 1. A curable composition for medical or dental use comprising a strontium phosphate-based devitrifying glass powder containing strontium apatite crystals and / or strontium phosphate crystals, and a kneading solution. 2. The strontium phosphate devitrifying glass powder is an essential component consisting of SrO, P ₂ O ₅ , Al ₂ O ₃ , SiO ₂ and F ₂ or the essential component, and MgO, Na ₂ O and B ₂ The composition according to claim 1, which is obtained by melting one or more components selected from the group consisting of O ₃ and quenching them to devitrify. 3. A medical or dental curable composition comprising a strontium calcium phosphate devitrified glass powder containing strontium solid solution apatite crystals and a kneading solution. 4. The strontium calcium phosphate devitrified glass powder comprises an essential component consisting of SrO, CaO, P ₂ O ₅ , Al ₂ O ₃ , SiO ₂ and F ₂ or the essential component and MgO, Na ₂ O.
And one or more components selected from the group consisting of B ₂ O ₃ and B ₂ O ₃ are melted and rapidly cooled to devitrify.
The composition as described. 5. The kneading solution is one selected from the group consisting of physiological saline, a water-soluble polymer solution, an inorganic acid aqueous solution, an organic acid aqueous solution, an unsaturated carboxylic acid polymer aqueous solution, and a mixture thereof. The composition according to claim 1 or 3, characterized in that: