JPH08245331A - Dental curable composition - Google Patents

Abstract

PURPOSE: To obtain a hardenable composition for dentistry useful as a filler of a paste root canal and a root canal filling sealer by mixing a water- hardenable composition containing a calcium phosphate compound and an acid with a crosslinkable polymer of an unsaturated carboxylic acids. CONSTITUTION: A calcium phosphate-based hardenable composition for dentistry comprising a calcium phosphate compound as a principal component mixed with an acid and water is incorporated with a crosslinkable polymer of an unsaturated carboxylic acid having (500-000)×10<4> weight-average molecular weight, especially acrylic acid in an amount of 0.005-5wt.% to whole composition. A mixing amount of the calcium phosphate compound is 20-95wt.% based on total powdery agent and the acid (e.g. citric acid) is 3-60wt./vol% as a concentration in a liquid agent in the case of mixing into a liquid agent. The objective hardenable composition for dentistry gives a mixed slurry having glossy and smooth surface nature and has an excellent fluidity, hardening time, adhesivity and a film thickness as a paste root canal filler or a root canal filling sealer and is especially useful as a material of a paste root canal filler or a root canal filling sealer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dental curable composition used as a root canal filling material or a root canal filling sealer.

[0002]

2. Description of the Related Art Root canal filling is the final treatment of root canal treatment in the dental preservation area.
The purpose is to seal the root canal by airtightly filling the root canal cavity with a root canal filling material after demyelination or after treatment of infected root canal.
It is an important therapeutic action that influences the prognosis, by blocking the oral cavity, the periodontal ligament, and the root canal, preventing reinfection, promoting the healing of the apical part, and protecting the apical wound.

Root canal fillers are roughly classified into solid root canal fillers and paste root canal fillers. The former uses gutta-percha points, metal points, etc. for the purpose of physically closing the root canal, but since the solid root canal filling material alone is not sufficient for sealing, the glue root canal filling material is used. The root canal filling method, which is also used as a tube filling sealer, is currently a general treatment method. On the other hand, the paste root canal filler is a material for filling only the paste (slurry). A zinc oxide-eugenol system is a typical preparation for such a root canal filling material or a root canal filling sealer, but this preparation has the following problems.

That is, since the root canal filling material and the root canal filling sealer are in contact with the periodontal ligament tissue, there should be absolutely no tissue irritation, but the eugenol contained in the zinc oxide-eugenol system preparation is eluted into the periodontal ligament tissue. However, the problem is that it exhibits irritation. Moreover, as long as it is adapted to the living body, biocompatibility is required, but the above-mentioned preparation is a material that is far from the biocomponents and has no biocompatibility at all.

In order to solve such a problem, a paste root canal filler or a root canal sealer containing calcium phosphate as a main component, which is excellent in biocompatibility, has been proposed in recent years. These are preparations containing hydroxyapatite which is an inorganic component of teeth and bones or α-tricalcium phosphate which is a hydroxyapatite precursor.

However, for example, in the former case, hydroxyapatite itself has biocompatibility, but since a large amount of non-biocompatible components such as guaiacol and rosin which have no biocompatibility are added to this, the characteristics of using hydroxyapatite are reduced. , Substantially eliminates biocompatibility. On the other hand, the formulation containing α-tricalcium phosphate is an acidic kneading solution containing a high concentration of a linear polymer of an unsaturated carboxylic acid such as polyacrylic acid in order to improve its operability and curability. Used and irritating due to low pH. Further, even if the pH is neutral, since the linear polymer of unsaturated carboxylic acid is blended at a high concentration, there is a problem of tissue damage due to elution into the living body.
It causes a problem of inhibiting the conversion of calcium phosphate into the only stable apatite in the living body.

Apart from that, there have been proposed some calcium phosphate-based water-curable compositions having excellent biocompatibility, which are used as dental or medical compositions not limited to paste root canal fillers (Japanese Patent Publication No. 61-9265, Japanese Examined Patent Publication No. 3-41423, JP-A-5-839, etc.). For example, in JP-A-5-839, a water-soluble fluoride, a neutralizing agent, an acid and water are specified for a system consisting of a specific hydrated self-hardening calcium phosphate, water and a poorly water-soluble fluoride. Characterized by containing in a range, it becomes a cured product having an appropriate curing time and an appropriate hardness, and does not contain a polymer compound which is a non-biological component, and the pH of the kneaded slurry is neutral. Therefore, a curable composition having excellent biocompatibility and not having tissue irritation is disclosed.

When such a composition is applied to a paste root canal filler, it is possible to improve the fluidity of the slurry and to fill the root canal with each component of the above composition. When kneading the prepared liquid agent and powder agent, it is necessary to increase the liquid agent / powder agent ratio. However, a paste filler (Renturo) generally used for adhering the slurry on the kneading board or kneading paper, transporting the slurry to the root canal position, and tightly filling the root canal. In addition, since the slurry having improved fluidity of the above composition is water-like, it is difficult to adhere, and it is impossible to fill a sufficient amount in one transportation, and transportation and filling operation must be repeated several times. I have to. In fact, it is desired that the above-mentioned transportation and filling operations be performed only once in a clinical setting. Therefore, it is necessary to improve the adhesiveness of the slurry to the paste filling device.

On the other hand, as a means for improving the adhesion of the slurry of the composition to the paste filling machine, there is a method of blending a water-soluble polymer compound into the composition. The calcium phosphate-based hydraulic composition proposed in Japanese Patent No. 839 etc. generally contains an acid, a halide, a neutralizing agent and the like in order to accelerate the curing of the composition. Therefore, the water-soluble polymer compound that can be added to such a composition needs to be a water-soluble polymer compound that can be sufficiently dissolved even when slurried in the presence of these electrolytes.

However, among the water-soluble polymer compounds known as additives to be incorporated in the calcium phosphate hydraulic composition, for example, nonionic water-soluble compounds such as hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose and polyvinylpyrrolidone. Polymeric compounds are hydrated and dissolved by the Lone-Pair electron of the oxygen atom in the molecule.However, in the presence of other electrolytes, the hydration of ionizing groups in the electrolyte takes precedence over the dissolution of these polymer compounds. Therefore, it is expected that the dissolution of the polymer compound is suppressed. In fact, when the nonionic water-soluble polymer compound is blended in the calcium phosphate-based hydraulic composition containing the above electrolyte, the polymer compound becomes insoluble in the slurry and adheres to the paste filler. The effect of improving the property cannot be obtained, and the insoluble matter results in a slurry having a rough texture and rough skin.

On the other hand, anionic water-soluble polymer compounds of natural or semi-synthetic polysaccharides such as sodium carboxymethylcellulose, carrageenan, xanthan gum and alginic acid have an ionizing group (carboxyl group), and therefore, in the presence of another electrolyte. The hydration solubility of is higher than that of the above nonionic polymer compounds. However, when these are actually blended in a calcium phosphate-based hydraulic composition in the same manner as described above, these polymer compounds are slightly dissolved in the slurry and the adhesiveness is slightly improved, but the paste material is sufficiently filled in operation. No adherence to vessels is obtained. It can be said that this is because the number of ionizing groups in the polymer compound is insufficient for the anionic polymer compound to be hydrated and dissolved in the calcium phosphate-based hydraulic composition.

Acrylic acid and methacrylic acid, which have been conventionally compounded with calcium phosphate-based water-curable compounds,
Itaconic acid, maleic acid, glutaconic acid, aconitic acid, linear homopolymers or linear copolymers of unsaturated carboxylic acids such as citraconic acid and mesaconic acid, since the number of ionizing groups in the molecule is large, Even when the calcium phosphate-based water-curable composition is blended in the same manner as described above, it is sufficiently hydrated and dissolved in the slurry, and the adherence of the slurry to the paste filler is significantly improved. However, in the slurry,
For example, when the Ca ion in the calcium phosphate compound is dissolved by the acid which is the curing agent, the carboxyl group in the polymer and the Ca ion react with each other and bond to form an insoluble precipitate. Therefore, lumps that can be clearly recognized with the naked eye are generated in the slurry, and the adhesion to the paste filling device becomes uneven. Moreover, when used together with a solid root canal filling material represented by gutta-percha points as a root canal filling sealer, the sealer part becomes a thin film and a solid root canal filling material of the same size as the root canal reaches the apex. However, in the above case, the lumps in the slurry are prevented from forming a thin film, so that the solid root canal filling material cannot sufficiently reach the apex.

That is, the required properties of the paste root canal filling material or the root canal filling sealer are that they have no biostimulation, are excellent in biocompatibility, and harden in a proper time, and in addition, they are easy to operate. Is not only high in fluidity but also adheres to the paste filling machine in a sufficient amount. However, the paste root canal filler and the root canal sealer that have been conventionally proposed have all of these performances. There is no combination of these, and therefore, a paste root canal filling material or a root canal filling sealer having such performance is desired.

The present invention has been made in view of the above circumstances, and the above paste material is prepared by blending a cross-linkable polymer of unsaturated carboxylic acids with a water-curable composition containing a calcium phosphate compound and an acid. It is an object of the present invention to provide a dental curable composition having all the required properties of a root canal filling material or a root canal filling sealer.

[0015]

Means and Actions for Solving the Problems As a result of intensive studies for achieving the above object, the present inventor has found that a calcium phosphate-based dental curable composition containing a calcium phosphate compound as a main component and containing an acid and water. In addition, by blending a cross-linking polymer of unsaturated carboxylic acids having a molecular weight in a certain predetermined range as an adhesion improver, while the slurry of the dental curable composition maintains high fluidity, a paste material is filled. It has been found that the container can meet the property of adhering sufficiently uniformly.

That is, as described above, when a dental curable composition containing a calcium phosphate compound as a main component is blended with a linear homopolymer or a linear copolymer of unsaturated carboxylic acids for the purpose of promoting curing, It is necessary to contain such a polymer, which is a biological component, at a high concentration. On the other hand, if an acid is further added as a curing accelerator to reduce the blending amount of the polymer, the liberation of Ca ions may be promoted to bond with the polymer and become insoluble.

However, the inventor of the present invention, by using a cross-linking type polymer in the above composition in place of the linear unsaturated carboxylic acid polymer, is insoluble even if an acid is blended as a curing accelerator. No precipitates are generated and the blending amount of high molecular compounds (polymers of unsaturated carboxylic acids), which are non-biological components, can be reduced, and the adhesiveness to the paste filling machine is sufficient for operability. The present invention has been completed based on the finding that Incidentally, the above phenomenon, when comparing the reactivity of the carboxyl group in the polymer of unsaturated carboxylic acids when the polymer has a cross-linked structure and when it is a linear structure, the case of a cross-linked structure The reactivity becomes low due to steric hindrance, and even if the dissolution of Ca ion in the calcium phosphate compound progresses, the carboxyl group and Ca
It is considered that this is because the reaction with the ions and the bond are less likely to occur and a new insoluble precipitate is not generated.

Therefore, the present invention is characterized in that it contains a calcium phosphate compound, an acid and water, and is blended with a cross-linking polymer of unsaturated carboxylic acids having a weight average molecular weight of 500,000 to 10,000,000. A dental curable composition is provided.

The present invention will be described in more detail below. The dental curable composition of the present invention comprises a calcium phosphate compound,
It contains a cross-linking polymer of acid, water and unsaturated carboxylic acid as an essential component. In this case, a high-molecular compound (a cross-linked polymer of unsaturated carboxylic acids) that is a non-biological component is not blended in a high concentration for the purpose of promoting curing, but is formulated for the purpose of improving the adhesiveness of the slurry and curing is accelerated. It is characterized by containing an acid as an essential component. Here, the composition of the present invention can be mixed with these components at the time of use to form an aqueous slurry, but an embodiment in which a powder and a liquid are prepared in advance and the powder and the liquid are mixed at the time of use Is preferable in terms of usability. In this case, as the powder, the calcium phosphate compound,
It can be prepared by mixing other water-insoluble or sparingly soluble components, and the liquid preparation can be prepared by dissolving the above-mentioned acid and other water-soluble components in water. In addition, the trace components are appropriately mixed with the powder or liquid.

The calcium phosphate compound used in the present invention is curable by hydration when it is slurried with water or a curing accelerator such as an inorganic acid, an organic acid or an organic acid salt and water. As such a calcium phosphate compound, known compounds can be used, for example, α-tricalcium phosphate (α-TCP), tetracalcium phosphate (4CP), dicalcium phosphate dihydrate (DCPD), Dicalcium phosphate anhydrous (DCP
A), octacalcium phosphate (OCP), primary calcium phosphate monohydrate (MCPM), primary calcium phosphate anhydrous salt (MCPA), etc., and one of them may be used alone or two of them may be used. The above can be used in combination.

The method for producing the above-mentioned calcium phosphate compound is not particularly limited, and a known method can be adopted. For example, in the case of α-TCP, γ-calcium phosphate is produced from dibasic calcium phosphate, and α-TCP is produced from this γ-calcium pyrophosphate and calcium carbonate.
May be produced, or the above reaction may be carried out in one step. Further, the particle size is not particularly limited, and can be appropriately selected depending on the purpose of use of the composition and the like.
For example, when used as a root canal filling sealer that is used in combination with a solid root canal filling material such as gutta-percha points, the film thickness when the above composition is slurried is the same as the root canal diameter as described above. A smaller particle size of the calcium phosphate compound is inevitably required because a thinner thickness is desired for the filler to reach the apex. Therefore, when used as a root canal filling sealer,
The average particle size is preferably 0.5 to 10 μm, particularly 1 to 6 μm, and the maximum particle size is 50 μm or less, especially 20 μm.
The following is preferred. If the average particle size is less than 0.5 μm, the surface area becomes large, so the dissolution reaction may be too fast and the curing time may become too short. If it exceeds 10 μm, the surface area may become too small and the dissolution reaction may be too slow to cure. The time may become longer than necessary and the film thickness may become thick. Further, if the maximum particle size exceeds 50 μm, the film thickness when slurried may become thick.

The amount of the calcium phosphate compound compounded in the dental curable composition of the present invention is not particularly limited, but it is preferably 20 to 95% (% by weight, the same applies hereinafter), particularly 50 to 80% of the total powder. preferable. 20%
If it is less than the above range, the continuous layer of apatite produced from calcium phosphate may be too small to be cured, and if it exceeds 95%, a contrast agent that imparts sufficient contrast power may not be blended.

The acid blended in the dental curable composition of the present invention is blended as a hardening accelerator, and as such an acid, known acids such as organic acids and inorganic acids should be used. For example, organic acids such as monobasic acids such as formic acid, acetic acid and propionic acid; hydroxycarboxylic acids such as citric acid, malic acid, glycolic acid, sugar acid, ascorbic acid and lactic acid; acidic amino acids such as glutamic acid and aspartic acid; Oxalic acid, malonic acid, succinic acid, glutaric acid,
Dibasic acids such as adipic acid and itaconic acid; pyruvic acid,
Keto acids such as acetoacetic acid and levulinic acid; organic acids such as aromatic carboxylic acids and polycarboxylic acids and their derivatives; and inorganic acids such as phosphoric acid, hydrochloric acid, sulfuric acid and nitric acid. Among them, it is preferable to use an organic acid. Further, in consideration of biocompatibility, among organic acids, those contained in a biological component are preferable. Therefore, it is more preferable to use citric acid among organic acids. These acids may be used alone or in combination of two or more.

The amount of the above-mentioned acid to be mixed in the dental curable composition of the present invention is not particularly limited, but when it is mixed in the above-mentioned liquid agent, for example, the concentration in the liquid agent is 3 to 6.
It is preferably 0% by weight / volume, particularly 25 to 45% by weight / volume. If it is less than 3% by weight, the calcium phosphate compound may not be sufficiently dissolved in the slurry and curing may be significantly slowed down. If it exceeds 60% by weight, the curing of the slurry may be too fast to obtain sufficient fluidity. It may not be possible.

As the cross-linking polymer of unsaturated carboxylic acids used in the present invention, known ones can be used, for example, acrylic acid, methacrylic acid, itaconic acid, maleic acid, glutaconic acid, aconitic acid, citraconic acid and Examples thereof include cross-linked polymers containing one kind or two or more kinds of unsaturated carboxylic acids such as mesaconic acid. Among them, cross-linked polymers of acrylic acid are used alone or mainly acrylic acid. Of the unsaturated carboxylic acid are particularly preferable, and particularly when combined with other unsaturated carboxylic acid, acrylic acid / other unsaturated carboxylic acid (molar ratio) ≧
A value of 2 is more preferable.

When a low molecular weight cross-linking polymer of unsaturated carboxylic acids used in the present invention is used, it is necessary to increase the viscosity of the slurry in order to impart the adhesiveness to the slurry, so that it is blended in a relatively high concentration. It is necessary to produce a large amount of insoluble matter. Therefore, the crosslinked polymer of unsaturated carboxylic acids of the present invention has a weight average molecular weight of 5
It is necessary to be 0 to 10,000,000, especially 100
It is more preferable that it is from 10 to 5 million. If it is less than 500,000, the necessary amount of compounding for imparting sufficient adhesion exceeds 5% by weight with respect to the entire composition, and it is clearly recognized for the reaction, bonding and insolubilization of the carboxyl group and Ca ion. It is difficult to secure a thin film because of possible lumps, and when it exceeds 10 million, the slurry viscosity becomes extremely high and the usable fluidity cannot be maintained.

The method for producing the crosslinked polymer of unsaturated carboxylic acids is not particularly limited, and a known method can be adopted. For example, an alkenyl group is added to the unsaturated carboxylic acid monomer of 2 A method in which a cross-linking agent having at least one is added and polymerized is included.

The method of blending the crosslinked polymer of unsaturated carboxylic acids is not particularly limited, and may be blended in either the powder or liquid formulation, or both.

The amount of the crosslinkable polymer of the unsaturated carboxylic acids in the dental curable composition of the present invention is not particularly limited, but 0.005 to 5%, particularly 0.05 to 5% with respect to the entire composition. It is preferably 2%. 0.005%
If it is less than 5%, the effect of improving the adhesiveness of the composition may be insufficient, and if it exceeds 5%, the effect of reducing the blending amount of the non-biological component may be insufficient.

In addition to the above-mentioned components, the dental curable composition of the present invention may further contain the following components within a range not impairing the effects of the present invention.

That is, hydroxyapatite (HA
P), fluoroapatite (FAP), fluorinated apatite, etc .; alkaline earth fluorides such as calcium fluoride, magnesium fluoride; metal fluorides such as lithium fluoride, iron fluoride; sodium silicofluoride, potassium silicofluoride, etc. Silicofluoride; CaCO ₃ , MgO, CaO, Ca
(OH) ₂ etc .; Bismuth subcarbonate, barium sulfate, iodoform, and other X-ray contrast agents, etc., which are poorly water-soluble, may be used alone or in combination of two or more to form the compounding ingredient in the powder, calcium phosphate. As a root canal filling sealer, KF, NaF, KFHF, NaFHF, water-soluble fluorides such as monofluorophosphate and the like are appropriately blended alone or in combination of two or more for the purpose of accelerating the hydraulic reaction of When used, one polyhydric alcohol such as glycerin, ethylene glycol, propylene glycol, sorbitol, polyethylene glycol, polypropylene glycol, polyvinyl alcohol, etc. is used alone for the purpose of imparting wettability to the gutta-percha point of the solid root canal filling material. Or, use in combination of two or more kinds, and sodium hydroxide, hydroxide Potassium, ammonium hydroxide, hydrochloric acid, can such be formulated as a component of pH adjusting agent singly or in combination the liquid or in powder of two or more of nitric acid, and the like. When the above components are blended in the powder, the average particle size is preferably 0.5 to 5 μm and the maximum particle size is preferably 20 μm or less for the same reason as the particle size of the calcium phosphate compound.

The dental curable composition of the present invention may be prepared by separately preparing each of the above-mentioned components and mixing and kneading all the components at the time of use, or, as described above, each of the above-mentioned components may be mixed. The poorly water-soluble or water-insoluble components may be prepared in advance as powders mixed and stirred, and the water-soluble components may be prepared in advance as liquids dissolved in water, and these powders and liquids may be kneaded at the time of use. Here, it is preferable that the liquid agent is adjusted to pH 5 to around neutral, particularly pH = 5.5 to 6.5 by the pH adjusting agent. If the pH is low, the curing may be too fast and the operating time may be insufficient. On the other hand, p
When H is high, the pH buffering effect in the slurry decreases, and it becomes difficult to maintain suitable fluidity and curing time, and particularly when an organic acid is used, it becomes remarkable.

The dental curable composition of the present invention can be used according to a known method, and the obtained slurry is mixed with a paste filling machine such as a lenturo or together with a solid root canal filling material. Although it is filled in a tube, by blending a cross-linking polymer of unsaturated carboxylic acid having a molecular weight in a predetermined range, the slurry adheres to a paste filling machine sufficiently uniformly without lumps, As it has excellent filling properties and contains an acid as a curing agent, the slurry is completely cured by a hydraulic reaction in a reasonable time after being filled into the living body, and calcium phosphate is converted into apatite in the living body. In addition to being extremely stable, it has excellent biocompatibility and does not have tissue irritation because the blending amount of the polymer compound, which is a non-biological component, is particularly reduced. This excellent biocompatibility is
It does not impair wound healing at the apex, promotes calcification, and seals biological tissue.

[0034]

EXAMPLES The present invention will be specifically described below by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples. (1) Production of α-TCP γ-Ca ₂ P ₂ O ₇ and CaCO ₃ were mixed, heated at 1250 ° C. for 4 hours, and then cooled to obtain α-TCP. This α
-TCP was crushed and classified to have an average particle diameter of 5 µm and a maximum particle diameter of 20 µm. (2) Preparation of Dust Formulation Based on the above α-TCP as a base material, an X-ray contrast agent and other additives are added as shown in Table 1, and further a cross-linked polymer of unsaturated carboxylic acids shown in Table 1 or other water-soluble materials. Polymer compound was added, and these were mixed with stirring to obtain a dust. The X-ray contrast agent, other additives, and the polymer compound are also α-T.
Similar to CP, it was crushed and classified in advance. In addition, the blending amount of each component in Table 1 shows the ratio with respect to the whole powder by weight%. (3) Preparation of liquid agent The acid and other additives shown in Table 2 were dissolved in water, and the pH was adjusted as shown in Table 2 to obtain a liquid agent. In addition, the blending amounts of glycerin and ethylene glycol in Table 2 are ratios based on the whole liquid agent in terms of weight / volume%. (4) Preparation of Dental Curable Composition The above powder and liquid are shown in Table 3 as liquid / powder ratio (ml /
g) and kneaded to give Examples 1 to 8 and Comparative Examples 1 to 1.
A dental curable composition (mixing slurry) 6 was obtained.

(5) Evaluation The performance of each kneading slurry was evaluated according to the following test method. The results are shown in Table 4. <Flowability test method: ADA for root canal filling materials
Standard No. 57> 0.5 ml of the kneading slurry was taken and placed on a glass plate of about 20 g. Three minutes after the kneading was started, another glass plate similar to the above was placed on the slurry, and immediately, a 100 g weight was gently placed. Ten minutes after the start of kneading, the weight was removed and the spread of the slurry was calculated as the average value (mm) of the maximum and minimum diameters, which was taken as the flow value.
This flow value is specified as 25 mm or more in the standard.

<Method of Testing Adhesion to Paste for Filling Material> Easiness of adhesion when the kneading slurry was transported by a lenturo was sensory-evaluated according to the following evaluation criteria. [Evaluation Criteria] ◯: Adhesive amount is evenly attached Δ: Adhesion is present but non-uniform x: No attachment

<Curing time: ISO 6876-1986
(E) Dental root canal sea
ring material> kneading slurry has a diameter of 1
Time until the ring of 0 mm and height of 2 mm is filled, and 2 minutes after kneading, the temperature is 37 ° C, the relative humidity is 95% or more, the load is 100 g, and the Gilmore needle with a diameter of 2 mm does not become indented. Was measured and the time was defined as the curing time. Note that the ISO standard does not specify a particularly appropriate curing time, but for example, Endodontics,
3rd edition (Ingle, J.I. and
Taintor, J .; F. Lea & Febig
er, 1985.226-231) describes only slow curing. Considering the actual clinical situation, it is usual to directly implant and attach prostheses etc. into the root canal filling site after the root canal filling, so it is necessary to complete the operation 24 hours after the root canal filling. It is considered necessary to be cured.

<Film thickness: ADA standard No. 1 for root canal filling material 57> Kneading slurry is sandwiched between two glass plates having an area of 200 mm ² , and 15 kg after 3 minutes from the start of kneading.
10 minutes after the start of kneading, the thickness of the slurry was measured with a micrometer. This test is a standard test for a root canal filling sealer (type II), and the standard specifies that the film thickness is 50 μm or less.

<Slurry Property Confirmation Test Method> The degree of smoothness of the surface properties of the kneading slurry was sensory evaluated according to the following evaluation criteria. [Evaluation Criteria] ○: Smooth and smooth △: Smooth but lumps are observed ×: Coarse texture and rough skin

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

[Table 3]

[0043]

[Table 4]

From the results of Table 4, the dental curable composition of the present invention has a smooth and smooth surface property of the kneading slurry, and has a good flowability as a paste root canal filler and a root canal sealer. Since it has the following properties, curing time, adhesion and film thickness,
In particular, it was found to be useful as a material for a glue root canal filler and a root canal sealer.

On the other hand, when a linear polymer was used as the polymer of unsaturated carboxylic acids (Comparative Example 1), the linear polymer of unsaturated carboxylic acids was used in combination with other water-soluble polymer compounds. In the case (Comparative Example 4), it was confirmed that lumps were generated in the kneading slurry and a good film thickness could not be obtained as a root canal filling sealer. When other water-soluble polymer compounds were used in place of the cross-linked polymer of unsaturated carboxylic acids (Comparative Examples 2 and 3), the kneading slurries had coarse texture and rough skin, resulting in poor adhesion. Not only was it found that a good coating thickness could not be obtained as a root canal filling sealer, and when no polymer compound was added (Comparative Example 5), the surface properties of the kneading slurry were good. However, it was confirmed that the adhesion was poor.

Further, even a cross-linked polymer of unsaturated carboxylic acids has a molecular weight outside the range of the present invention (low molecular weight).
(Comparative Example 6), the kneaded slurry was lumpy and could not have a sufficiently uniform adhesiveness, and a good film thickness as a root canal filling sealer could not be obtained. Was confirmed.

[0047]

EFFECTS OF THE INVENTION The dental curable composition of the present invention forms a smooth slurry which has a smooth surface property and is free from lumps, and can be uniformly adhered to a filling device and can secure a thin film. It is possible, and completely hardened in a living body by a hydraulic reaction in a suitable time, and is not only extremely stable in a living body because calcium phosphate is converted to apatite with hardening, there is no particular biostimulation at all. A paste root canal filling material and a root canal filling sealer having excellent biocompatibility.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yoshihito Ochiai 1-3-7 Honjo, Sumida-ku, Tokyo Lion Corporation (72) Inventor Takao Tanaka 7-1, 1-1 Hikoshimasako-cho, Shimonoseki-shi, Yamaguchi Prefecture No. Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Hiroko Wachi 7-1-1 Hikoshimasako-cho, Shimonoseki-shi, Yamaguchi Prefecture Mitsui Toatsu Chemicals Co., Ltd. Machi 7-1, 1-1 Mitsui Toatsu Chemical Co., Ltd.

Claims (5)

[Claims] 1. Dental hardening comprising a calcium phosphate compound, an acid and water, and a cross-linked polymer of unsaturated carboxylic acids having a weight average molecular weight of 500,000 to 10,000,000. Sex composition. 2. The dental curable composition according to claim 1, wherein the blending amount of the crosslinked polymer of unsaturated carboxylic acids is 0.005 to 5% by weight based on the whole composition. 3. The cross-linked polymer of unsaturated carboxylic acids contains a cross-linked polymer of acrylic acid.
The dental curable composition described. 4. The dental curable composition according to claim 1, 2 or 3, wherein the acid is an organic acid. 5. The dental curable composition according to claim 4, wherein the acid is citric acid.