JPH07101817A - Curable composition for dental use - Google Patents

Abstract

PURPOSE:To provide a curable composition for dental use, having excellent fluidity in the form of paste and enabling the filling to a narrow or complicate- formed part such as root canal. CONSTITUTION:This curable composition for dental use contains calcium phosphate and a fluorine compound in combination with fine particles of a polymer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a dental composition. More specifically, the present invention relates to a self-hardening dental composition having excellent biocompatibility and capable of filling root canal portions of teeth, other bone defects and bone voids.

[0002]

2. Description of the Related Art Conventional dental compositions include, for example,
Zinc phosphate cement, oxidized zinc-eugenol system, iodoform system, polymer system and the like are used. However, these dental compositions are composed of materials that are essentially different from the living tissues of teeth and bones. Therefore, it is only chemically or physically adhered to the living tissue, and the adhesive strength is decreased with time in the oral cavity or in the living body, and many dead spaces in the filling part due to peeling or breakage may occur. is there. Further, in the case of a dental root canal filling material, it is a problem that substances such as eugenol and iodoform which are mixed therein are eluted to show irritation.

On the other hand, the self-hardening calcium phosphate is converted into apatite which is a main component of bones and teeth by mixing with water or acid, and simultaneously hardens. Due to this property, it has excellent biocompatibility and easily assimilates with living tissue, and therefore various attempts have been made to use it as a dental biomaterial.

[0004]

However, the self-hardening calcium phosphate has a drawback that the workability is poor as compared with the above-mentioned polymer type. That is, since the kneaded product with water or acid is in the form of wet sand with low fluidity, it is difficult to fill a narrow portion such as a bone defect portion or a root canal or a place having a complicated shape. In addition, the poor sealability may cause reinfection of the treatment site. In addition, the curing time is about 10 minutes, and there is a problem that the filling workable time is short when used for dentistry.

The characteristics of the required dental composition are:
Workability, especially fluidity and kneading properties are good, biocompatibility is excellent, it is a curable type, and it can be filled for a long time, but at present, dentistry that satisfies all these characteristics There is no composition for use. A mixture of calcium phosphate and a fluorine compound, which is kneaded with water or an acid, becomes apatite after filling and has excellent biocompatibility. However, since this product has a setting time of 30 minutes or less (Japanese Patent Laid-Open No. 63-252913), it has poor workability and fluidity, and has a shortcoming that the workable time is short.

[0006]

Means for Solving the Problems As a result of intensive studies to overcome such difficulties of the dental composition, the present inventors have mixed calcium phosphate with a fluorine compound, and further added polymer fine particles. It was found that by doing so, a composition having good workability, fluidity and filling work can be provided by eliminating these drawbacks. That is, the present invention provides a dental curable composition characterized by containing calcium phosphate and a fluorine compound, and further containing polymer fine particles.

The composition of the present invention is a hardened dental composition exhibiting excellent operability. After being filled with a root canal, it hardens and transforms into apatite, has no irritation, and has excellent biocompatibility. Can be used as a filler.

The present invention will be described in more detail below. Examples of calcium phosphate used in the present invention include α-tricalcium phosphate (α-TCP), tetracalcium phosphate (4 CP), dicalcium phosphate dihydrate (DCPD), hydroxyapatite (HAP), and fluoroapatite. (FAP), β-tricalcium phosphate (β-TC
P), dicalcium phosphate anhydrous salt (DCPA), octacalcium phosphate (OCP), monocalcium phosphate
There are anhydrous salts (MCPA), monocalcium phosphate monohydrate (MCPM) and the like. Of these calcium phosphates, one kind or a mixture of two or more kinds is used. The atomic ratio of phosphorus to calcium in the calcium phosphate is 1.3 to
2.0 (Ca / P) is preferable, and 1.4 is more preferable.
The range of to 1.8 is preferable. The calcium phosphate used in the present invention is usually a powder, which is not particularly different from that used conventionally for dentistry, but usually has an average particle size of 0.5 to 20 μm, preferably 1 to 10 μm.

Next, as the fluorine compound, CaF ₂ , MgF ₂ , NaPO ₃ F, BeF ₂ and SrF which are poorly soluble in water are used.
₂ , BaF ₂ , SnF ₂ , AlF ₃ , water-soluble KF, N
Examples include aF, KFHF, NaFHF, NH ₄ FHF and the like. These fluorine compounds may be used alone or in combination of two or more, and CaF ₂ is particularly preferable. The compounding amount is preferably Ca / F (gram atom ratio) of 1.0 to 60 with respect to calcium phosphate. When the fluorine compound is a powder that is poorly soluble in water, it is usually used having an average particle size of 0.5 to 20 μm, preferably 1 to 10 μm. When the dental curing composition of the present invention comprises a liquid material and a powder material, this fluorine compound may be mixed with either the liquid material or the powder material.

As the polymer fine particles used in the present invention, an insoluble organic polymer is used, and the production method is not particularly limited, but in general, one or several vinyl monomers, It is a spherical polymer obtained by emulsion-polymerizing a crosslinkable monomer by a conventional method, and a commercially available product can also be used.

The average particle diameter of the polymer fine particles used in the present invention is preferably 0.1 to 10 μm, more preferably 0.5 to 5.0 μm, and most preferably 1.0 to 3.0.
μm is preferred. If the particle size is less than 0.1 μm, sufficient effect for improving fluidity cannot be exhibited. On the other hand, when it exceeds 10 μm, the kneaded product with water or acid is rough and the spreadability is reduced, so that the fluidity is lowered.

The amount of polymer fine particles added to the total amount of calcium phosphate and fluorine compound powder is 0.1 in the powder.
-20% by weight (hereinafter,% by weight is represented by% unless otherwise specified) is preferable, and more preferably 1-15%. When the amount of the polymer fine particles added is less than 0.1%, the fluidity is not sufficiently improved, and the time during which the filling operation can be performed cannot be extended, which is not preferable. If the addition amount exceeds 20%, the hardening of calcium phosphate is inhibited and the performance as a dental composition is not sufficiently exhibited, which is not preferable.

Vinyl monomers used in the production of the above polymers include styrene, α-methylstyrene, acrylic acid,
Examples thereof include alkyl acrylate, methacrylic acid, alkyl methacrylate, vinyl ester, vinyl cyanide and vinyl halide.

Examples of the crosslinkable monomer include monomers having two or more unsaturated bonds in one molecule, such as divinylbenzene, ethylene glycol (meth) acrylate, and trimethylolpropane trimethacrylate.

Further, the dental curing composition of the present invention may further contain an X-ray contrast agent, if desired. As the X-ray contrast agent, one or more kinds can be selected from the group consisting of barium salt, bismuth salt, aluminum salt and iodoform. The addition amount of the X-ray contrast agent is not particularly limited, but is preferably 0.1 to 50% with respect to the calcium phosphate powder.

Further, the dental curing composition powder 10 of the present invention
The amount of water or acid with respect to 0 part is preferably 10 to 200 parts, and more preferably 25 to 200 parts.
If the amount is less than 10 parts, the paste viscosity is too high, the clinical operability is poor, and the curing time is short, which is not preferable. Further, when it exceeds 200 parts, the paste viscosity becomes low and the filling operation becomes difficult, which is not preferable.

In addition to the above-mentioned components, the dental curing composition of the present invention further comprises an organic acid such as malic acid or citric acid or a salt thereof, a pH adjusting agent, alumina, zirconia, etc. It is possible to add various fillers, polycarboxylic acids or derivatives thereof and salts thereof, polyhydric alcohols, surfactants, water-soluble polymer substances such as CMC-Na, etc. within a range that does not impair the effects of the present invention.

The dental hardening composition of the present invention may be prepared by dissolving and suspending a mixture of the above components in water at the time of use, or a liquid prepared by previously dissolving a powder material and a water-soluble component in water. Alternatively, the powder material and the liquid material may be kneaded when used.

[0019]

EXAMPLES The present invention will be specifically described below by showing Examples and Comparative Examples, but the invention is not limited to the following Examples. Hereinafter, parts and% indicating the composition represent parts by weight and% by weight, unless otherwise specified. Example 1 A separable flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 20 parts of water and 0.01 part of sodium lauryl sulfate, and the temperature was raised to 70 ° C. under nitrogen with stirring. The internal temperature was maintained at 70 ° C., 2 parts of potassium persulfate was added as a polymerization initiator, and after dissolution, a mixed monomer of 2 parts of styrene, 0.01 parts of methyl methacrylate and 0.01 part of divinylbenzene was charged and reacted for 3 hours. . After completion of the reaction, 200 parts of water and 1.5 parts of sodium lauryl sulfate were previously prepared.
297 parts of styrene, 3 parts of methyl methacrylate, and 12 parts of divinylbenzene were added under stirring to the emulsion to prepare a monomer mixture, which was continuously added for 4 hours to carry out the reaction. It was After the addition was completed, aging was performed for 4 hours to obtain an emulsion. The emulsion was cooled to room temperature, neutralized with 8% ammonium water, and adjusted to pH 8.5.
Adjusted to. 220 parts of the emulsion thus obtained,
300 parts of styrene and 12 parts of divinylbenzene were emulsified and polymerized with 200 parts of water in the presence of 270 parts of water and 2 g of ammonium persulfate. Then, it was dried with a spray dryer to obtain polymer fine particles having an average particle diameter of 1.0 μm.

The following tests were carried out using the polymer fine particles thus obtained. α-TCP (average particle size 3.5
0.1 mol of CaF ₂ (average particle size 2 μm)
The polymer fine particles obtained above were stirred and mixed by 10% into the mixture added at a ratio of / mol α-TCP to obtain a dental composition. To 1 g of the dental composition, 0.40 ml of a 0.2 M citric acid solution having a pH of 5.0 (pH was adjusted with a mixed solution of NaOH and KOH) was added and kneaded to obtain a paste.
The following tests were performed on this paste. The results are shown in Table 1.

The paste was evaluated according to the following test methods. Kneadability evaluation A paste-like product that was formed in 1 minute after the start of kneading was judged to have good kneadability. In addition, those requiring kneading for more than 1 minute in order to obtain the paste were regarded as defective. Fluidity (flow) test ADA No. 57 0.5 ml of the kneading paste was taken and placed on a glass plate of about 20 g. After 3 minutes from the start of kneading, another glass plate as above was placed on the paste, and a weight of 100 g was gently placed. Ten minutes after the start of kneading, the weight was removed, and the spread of the paste was calculated as the average value of the maximum and minimum diameters, which was taken as the flow value. The larger the value, the better the fluidity. Flowability-After 10 minutes 0.5 ml of the kneading paste was taken and placed on a glass plate of about 20 g. Ten minutes after the start of kneading, put another glass plate as above on the paste, and gently quietly 100 g.
I put the weight of. The weight was removed 17 minutes after the start of kneading, and the spread of the paste was calculated as the average value of the maximum and minimum diameters. The larger the value, the better the fluidity. Curing test 2 minutes after the start of kneading, paste with an inner diameter of 10 mm and a height of 2 mm
Was filled in a constant temperature bath at 37 ° C. and a relative humidity of 95% or more, and then the time when the indentation of a Gilmore needle having a load of 100 g and a diameter of 2 mm was not formed was defined as the curing time. It was judged that the one having a curing time in the range of 30 to 240 minutes was suitable for the operable time. Apatite-forming test The specimen evaluated for curability was immersed in water at 37 ° C for one week. The sample was taken out, dried, and then crushed in an agate mortar.
Furthermore, as an internal standard, 20% by weight titanium oxide was thoroughly mixed in an agate mortar, and from the ratio of the diffraction intensity of α-TCP2θ30.7 ° and the peak intensity of titanium oxide 2θ27.5 °, α-T
The amount of conversion of apatite (degree of HA conversion) was calculated back from the amount of residual CP. Sealing test The crowns and root canals of the extracted teeth were excised, and the roots were sealed using a temporary sealing material. The root canal portion of the extracted tooth was filled with paste and hardened, and then only the root apex was immersed in ink. After this was stored at 37 ° C. for 24 hours, it was cut into the dentinal tubules using a sharp blade, and the penetration ratio of ink from the apex was measured. This invasion ratio was expressed by the ratio of the length of the invading part to the length of the root canal, and the smaller the value, the better the sealing performance.

Example 2 According to the production method of Example 1, polymer fine particles having an average particle diameter of 1.8 μm were produced. The same procedure as in Example 1 was carried out using the polymer fine particles. The results are shown in Table 1.

Example 3 The polymer fine particles of Example 1 were mixed with commercially available Techpolymer MB-
4C (polymethylmethacrylate true spherical particles, average particle size 4 μm, manufactured by Sekisui Plastics Co., Ltd.), and the same conditions as in Example 1 were used. The results are shown in Table 1.

Example 4 The same procedure as in Example 1 was carried out by replacing α-TCP of Example 1 with an equimolar mixture of α-TCP and dicalcium phosphate dihydrate (DCPD, average particle size 6 μm). It was
The results are shown in Table 1.

Example 5 The α-TCP of Example 1 was mixed with tetracalcium phosphate (tetra-C).
P, average particle size 5 μm), and the same conditions as in Example 1 were used. The results are shown in Table 1.

Example 6 α-TCP of Example 1 was replaced with dicalcium phosphate dihydrate (DCPD, average particle size 6 μm), and the same conditions as in Example 1 were used. The results are shown in Table 1.

Example 7 A test was conducted by replacing CaF ₂ of Example 1 with a mixture of CaF ₂ and NH ₄ F.HF. CaF ₂ 0.13mo
1 / mol α-TCP, NH ₄ F · HF 0.2 mol /
It was added in the proportion of mol α-TCP. The following was performed under the same conditions as in Example 1. The results are shown in Table 1.

Example 8 CaF ₂ of Example 1 was replaced with KF by replacing a 0.2M citric acid solution with a 1.2M citric acid solution, and carrying out the same conditions as in Example 1. The results are shown in Table 1.

Example 9 CaF ₂ of Example 1 was mixed with SrF ₂ (average particle size 2 μm).
A 0.2M citric acid solution was replaced with a 1.2M citric acid solution in an equimolar mixture of NaF and NaF, and the same conditions as in Example 1 were used. The results are shown in Table 1.

Example 10 The α-TCP of Example 1 was replaced with an equimolar mixture of α-TCP and dicalcium phosphate dihydrate (DCPD (, average particle size 3 μm)), and used in Example 3. The commercially available techpolymer MB-4C (average particle size: 4 μm, manufactured by Sekisui Plastics Co., Ltd.) was used, and the same conditions as in Example 1 were used. The results are shown in Table 1.

Example 11 The procedure was carried out under the same conditions as in Example 1 except that CaF ₂ in Example 1 was removed and the 0.2 M citric acid solution was replaced with a solution containing 1.0 M citric acid solution and 1.5 KF. The results are shown in Table 1.

Example 12 α-TCP with CaF ₂ 0.1 mol / mol α-TC
To 70 parts of the mixture added in the proportion of P, 15 parts of barium sulfate (average particle size 1.5 μm), 20 parts of bismuth subcarbonate (average particle size 1.1 μm), and 10 parts of the polymer fine particles of Example 1 were stirred and mixed. Then, a dental composition was obtained. 1 g of this dental composition was added to a 1.2 M citric acid solution having a pH of 6.0 (NaO 2).
The pH was adjusted with a mixed solution of H and KOH. ) 0.4m
l was added and kneaded to obtain a paste. This paste was applied under the same conditions as in Example 1. The results are shown in Table 1.

Comparative Example 1 The same conditions as in Example 1 were used except that the polymer fine particles were removed. The results are shown in Table 1.

Comparative Example 2 α-TCP of Example 1 was prepared by converting α-TCP and dicalcium phosphate dihydrate (DCPD (, average particle size 3.5 μm
m)) was replaced with an equimolar mixture and the polymer fine particles were removed, and the same conditions as in Example 1 were used. The results are shown in Table 1.
Shown in.

Comparative Example 3 CaF ₂ of Example 1 was replaced with a mixture of CaF ₂ and NH ₄ F.HF, and polymer fine particles were removed, and a test was conducted.
CaF ₂ 0.13 mol / mol α-TCP, NH ₄ F
-HF was added at a ratio of 0.2 mol / mol α-TCP. The following was performed under the same conditions as in Example 1. The result is
It shows in Table 1.

Comparative Example 4 The same conditions as in Example 1 were used except that CaF ₂ in Example 1 was omitted. The results are shown in Table 1.

[0036]

[Table 1]

[0037]

EFFECT OF THE INVENTION The dental curable composition of the present invention has sufficient fluidity to be added to a narrow portion such as a root canal or a portion having a complicated shape by adding polymer fine particles, The operation time has also been extended. Further, the composition is completely hardened in a suitable time in a living body, and since calcium phosphate is further converted into fluorinated apatite, it is extremely stable in a living body, has no irritation, and has excellent biocompatibility. It is also suitable as a biomaterial such as a dental root canal filling material and a bone filling material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshihiko Nishitsuji 7-1, 1-1 Hikoshimasako-cho, Shimonoseki-shi, Yamaguchi Mitsui Toatsu Chemical Co., Ltd. (72) Inhito Yoshihito 3-3 Motofujisawa, Fujisawa-shi, Kanagawa -7 (72) Inventor Koichi Saito 457 Yamanishi, Ninomiya-cho, Naka-gun, Kanagawa Lion Ninomiya Dormitory (72) Inventor Fumio Osato 457 Yamanishi, Ninomiya-cho, Naka-gun Kanagawa Prefecture Ninomiya Dormitory, Ltd.

Claims (4)

[Claims] 1. A dental curable composition comprising calcium phosphate and a fluorine compound, and further containing polymer fine particles. 2. The polymer fine particles have an average particle size of 0.1 to 1.
The composition according to claim 1, which is 0 μm. 3. Atomic ratio of calcium phosphate (Ca / P)
Is 1.3 to 2.0. 4. The composition according to claim 1, wherein the calcium phosphate contains α-tricalcium phosphate.