JPH0782114A - Dental hardening composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition showing fluidity by possession of silica particles, capable of being filled into a narrow part such as root canal and a part of a complicated shape. CONSTITUTION:This dental hardening composition comprises calcium phosphate, a fluorine compound and silica particles having 0.5-20mum particle diameter.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a curable composition used for dental treatment. More specifically, the present invention relates to a self-hardening dental composition that is kneaded with water or acid to give a paste having excellent biocompatibility and capable of filling a root canal part of teeth, other bone defects and bone voids. .

[0002]

2. Description of the Related Art Heretofore, as dental hardenable compositions, for example, zinc phosphate cement, oxidized zinc-eugenol type, iodoform type and polymer type have been used. However, these dental curable compositions are made of a material which is essentially different from the living tissues of teeth and bones. Therefore, the adhesion of the cured product to the biological tissue is a chemical or physical adhesion, does not permanently assimilate with the biological body, and the adhesive force decreases with time in the oral cavity or in the living body, causing peeling. There are many cases where death in the filling section is caused by breakage. 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 and exhibit irritation.

On the other hand, self-hardening calcium phosphates such as α-tricalcium phosphate, tetracalcium phosphate, dicalcium phosphate / dihydrate, etc. are converted into apatite which is the main component of bones and teeth by mixing with water or acid. And cure at the same time. Due to this property, it has excellent biocompatibility and is easily assimilated with living tissue, and therefore it has been attempted to be used as a dental biomaterial.

[0004]

However, the self-hardening calcium phosphate has a drawback that it is poor in workability as compared with polymer-based ones which are widely used. 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 causes reinfection of the treatment area. Moreover,
The curing time is about 10 minutes, the kneaded product is cured during the filling operation, and there is a problem that the filling operation time is short when used for dentistry.

The characteristics of the required dental composition are:
It has good workability, especially fluidity and kneading property, is excellent in biocompatibility, is an easily curable type, and has a sufficiently long filling work time. No satisfactory dental composition is available. On the other hand, a mixture of calcium phosphate and a fluorine compound, which is kneaded with water or an acid, becomes apatite after filling and is excellent in biocompatibility. However, this product has poor workability and fluidity, and has a shortcoming that the filling work time is short.

[0006]

Means for Solving the Problems As a result of intensive studies to overcome the drawbacks of the conventional dental hardenable composition, the present inventors have made calcium phosphate contain a fluorine compound and further By mixing silica particles having a particle size, the property of being apatite by kneading with water or an acid is not impaired, the workability and fluidity of the kneaded product are improved, and the time during which the filling work can be further performed The present invention has been completed based on this finding. This composition is a dental hardenable material that exhibits excellent operability, and a paste-like material is used after root canal filling.
It is a root canal filling material that hardens and converts to apatite, has no irritation, and has excellent biocompatibility.

That is, the present invention relates to a dental curable composition characterized by containing calcium phosphate and a fluorine compound, and further containing silica particles having a particle size of 0.5 to 20 μm.

The present invention will be described in more detail below. Examples of the calcium phosphate used in the present invention include α-tricalcium phosphate (α-TCP) and tetracalcium phosphate (tetra-C).
P), dibasic calcium phosphate dihydrate (DCPD), hydroxyapatite (HAP), 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.

Next, as a fluorine compound, a sparingly soluble Ca
F ₂ , NaPO ₃ F, MgF ₂ , BeF ₂ , SrF ₂ ,
BaF ₂ , SnF ₂ , AlF ₃ , water-soluble KF, Na
F, KF · HF, NaF · HF, NH ₄ F · HF and the like can be mentioned. These fluorine compounds may be used either individually or in combination of two or more, but in particular CaF ₂
Is preferred. The compounding amount is Ca / F (gram atom ratio) 1.
0-60 are preferable.

Examples of the silica particles used in the present invention include spherical porous, melt-crush type or crush type porous SiO ₂ . Of these silica particles, one kind or a mixture of two or more kinds may be used. The particle size of the silica particles is preferably 0.5 to 20 μm, more preferably 1.0 to 10 μm. If the particle size is less than 0.5 μm,
It is not possible to exert sufficient effect for improving the fluidity. Also, 20μ
If it exceeds m, the kneaded product with water or acid will be rough and the spreadability will be reduced, and the fluidity will be reduced.

The amount of silica particles used in the calcium phosphate powder is preferably 0.1 to 15% by weight (hereinafter,% means% by weight unless otherwise specified) in the powder, and more preferably 1 to 10%. Is. If the amount of silica particles added is too small, the fluidity is not improved, and the time during which the filling operation is possible cannot be extended, which is not preferable. If the added amount is too large, the curing of calcium phosphate will be inhibited, the performance as a dental treatment composition will not be exhibited, and the kneaded product will have a dry and kneadability.

In the present invention, the form of the calcium phosphate component and the fluorine compound component in use is not particularly limited, but it is usually used as a powder having a particle size of 100 μm or less, preferably a particle size of 20 μm or less.
Further, the dental curable composition of the present invention may further contain an X-ray contrast agent, if desired. X
As the line 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 0.1 to 30% with respect to the calcium phosphate powder.
Is preferred. In order to cure the composition of the present invention, water or acid is added and kneaded to form a paste. The amount of water or acid at this time is not particularly limited, but relative to 1 part by weight of the curable composition,
Preferably 0.1 to 2 parts by weight, more preferably 0.2 to
0.7 parts by weight.

[0013]

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% are parts by weight and% by weight unless otherwise specified.
Represents The pastes obtained in Examples and Comparative Examples were evaluated according to the test methods below.

Evaluation of Kneadability When the kneading was started, a paste was formed within 1 minute, and the paste was not rough and was glossy. In addition, it was judged that the kneading time was one minute or more to obtain the paste, or that the paste had a rough texture was not kneadable. Flowability test (according to 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, the paste has an inner diameter of 10 mm and a height of 2 mm.
The ring was filled in, and placed in a constant temperature bath at 37 ° C. and a relative humidity of 95% or more and left for 2 hours. After that, it was determined that the curability was good when the indentation of the Gilmore needle with a load of 100 g and a diameter of 2 mm was not made, and the curability was good. In addition, those having even slight indentations were judged to be poor in curability. 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 crown and root canal portion of the extracted tooth were excised and subjected to root canal treatment. After filling the root canal with a paste and hardening the paste, only the tooth root portion was dipped in India ink. This was stored at 37 ° C. for 24 hours, then cut in the longitudinal direction, and the penetration ratio of the India ink from the apex was measured. This penetration ratio was expressed by the ratio of the penetration distance to the length of the root canal, and the smaller this value was, the better the sealing performance was.

Example 1 CaF ₂ was added to α-TCP at 0.1 mol / mol α-TC
To the mixture added in the proportion of P, commercially available silica particles FB-5
S (fused type, spherical silica, average particle size 5.3 μm, manufactured by Denki Kagaku Co., Ltd.) was mixed with stirring by 10% to obtain a dental composition. To 1 g of the dental composition, 0.40 ml of a 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 paste was tested for fluidity, curability and apatitization. The results are shown in Table 1.

Example 2 The silica particles of Example 1 were replaced with commercially available silica particles Admafine SO-C5 (trade name, spherical silica, porous, average particle size 1.4 μm, manufactured by Admatex Co., Ltd.). A paste was prepared and tested in exactly the same manner as in Example 1. The results are shown in Table 1.

Example 3 The silica particles of Example 1 were replaced with commercially available silica particle trefil E.
-501 (trade name, spherical silica, porous, average particle size 1
2.6 μm, manufactured by Toray Dow Corning Silicone Co., Ltd.), and a paste was prepared and tested in exactly the same manner as in Example 1. The results are shown in Table 1.

Example 4 The silica particles of Example 1 were used as commercially available silica particles FS-30.
A paste was prepared and tested in exactly the same manner as in Example 1 except that (trade name, fused crushed silica, average particle size 6.4 μm, manufactured by Denki Kagaku Co., Ltd.) was used. The results are shown in Table 1.

Example 5 A paste was prepared and tested in exactly the same manner as in Example 1 except that the α-TCP of Example 1 was replaced with a mixture of α-TCP and DCPD in equimolar amounts. . The results are shown in Table 1.

Example 6 Except that the α-TCP of Example 1 was replaced with four CPs,
A paste was prepared and tested in exactly the same manner as in Example 1. The results are shown in Table 1.

Example 7 A paste was prepared and tested in exactly the same manner as in Example 1 except that the α-TCP of Example 1 was replaced with DCPD. The results are shown in Table 1.

Example 8 CaF ₂ of Example 1 was replaced with a mixture of NH ₄ F.HF, and CaF ₂ 0.13 mol / mol TCP, NH
_A paste was prepared and tested in exactly the same manner as in Example 1 except that ₄ F · HF was added at a ratio of 0.2 mol / mol TCP. The results are shown in Table 1.

Example 9 A paste was prepared and tested in exactly the same manner as in Example 1, except that CaF ₂ in Example 1 was replaced with KF. The results are shown in Table 1.

Example 10 Four CP of α-TCP of Example 1 and silica particles FB-5 were used.
Commercial Admafine SO-C5 with S used in Example 2
(Trade name, spherical silica, porous, average particle size 1.4 μm,
A paste was prepared and tested in exactly the same manner as in Example 1 except that it was replaced with Admatex Co., Ltd.). The results are shown in Table 1.

Example 11 α-TCP of Example 1 was mixed with equimolar mixture of α-TCP and DCPD, and silica particles FB-5S were used as commercially available silica particles FS-15 (trade name, fused crushed silica, average). A paste was prepared and tested in exactly the same manner as in Example 1, except that the particle size was 3.3 μm, manufactured by Denki Kagaku Co., Ltd.). The results are shown in Table 1.

Comparative Example 1 Except that the commercial silica particles FB-5S of Example 1 were omitted.
A paste was prepared and tested in exactly the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 The α-TCP of Example 1 was prepared by adding tetracalcium phosphate (4 CP).
Was replaced with and the silica particles were removed, and a paste was prepared and tested in exactly the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 3 A paste was prepared and tested in the same manner as in Example 1 except that CaF ₂ in Example 1 was replaced with KF and silica particles were removed. The results are shown in Table 1.

Comparative Example 4 Silica particles FB-5S of Example 1 were mixed with Nipsil E-22.
0 (trade name, spherical silica, porous, average particle size 28 μm,
(Manufactured by Nihon Silica Co., Ltd.) and the same conditions as in Example 1 were applied. However, when the kneadability was evaluated, the kneaded product was dry and did not form a paste even when a kneading time of 1 minute or more was required, and other operability could not be evaluated.

Comparative Example 5 Silica particles FB-5S of Example 1 were treated with Trefil R-90.
No. 0 (trade name, crushed type, porous, average particle size 26 μm, manufactured by Toray Dow Corning Silicone Co., Ltd.) and other conditions were the same as in Example 1. As a result, similarly to Comparative Example 4, the kneaded product did not form a paste, and other operability could not be evaluated.

Comparative Example 6 Except that CaF ₂ was omitted, the procedure of Example 1 was repeated.
Pastes were prepared and tested. The results are shown in Table 1.

[0032]

[Table 1]

[0033]

EFFECTS OF THE INVENTION The dental curable composition of the present invention has sufficient fluidity so that it can be filled in a narrow portion such as a root canal or a portion having a complicated shape, and the operable time is 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 can also be used as a biomaterial such as a dental root canal filling material and a bone filling material.

Front page continued (72) Inventor Toshihiko Nishitsuji 7-1, 1-1 Hikoshimasako-cho, Shimonoseki-shi, Yamaguchi Prefecture Mitsui Toatsu Chemical Co., Ltd. (72) Yoshihito Ochiai 3-3-7 Fujisawa, Kanagawa Prefecture ( 72) Inventor Koichi Saito 457 Yamanishi, Ninomiya-cho, Naka-gun, Kanagawa Prefecture Ninomiya Dormitory (72) Inventor Fumio Osato 457 Yamanishi, Ninomiya-cho, Naka-gun, Kanagawa Prefecture Nyomiya Dormitory, Ltd.

Claims (3)

[Claims] 1. A dental curable composition comprising calcium phosphate and a fluorine compound, and further containing silica particles having a particle diameter of 0.5 to 20 μm. 2. Atomic ratio of calcium phosphate (Ca / P)
Is 1.3 to 2.0. The composition according to claim 1, wherein 3. The composition according to claim 1, wherein the calcium phosphate contains α-tricalcium phosphate.