JP2007302631A - Dental curable composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dental curable composition suitably used for a composite resin or the like which has moderate translucency as dental curable composition and is desired to show reduced change in visuality before and after curing resulting from small change in transparency and color tone before and after curing. <P>SOLUTION: The dental curable composition comprises (A) a polymerizable vinyl monomer, (B) a filler component substantially comprising (b1) a filler with a high refractive index, (b2) a filler with a middle refractive index and (b3) a filler with a low refractive index, respectively within a range of a specific refractive index and (C) a radical polymerization initiator. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dental curable composition that initiates polymerization by radical polymerization.

  In recent years, esthetics have been emphasized in the restoration treatment of medical care, and restoration closer to natural teeth has been demanded. On the other hand, with the development of various adhesive monomers, the concept of MI (minimum intervention) is becoming widespread for the restoration of carious teeth. According to this concept, caries teeth are treated by minimizing the removal of carious sites, applying an adhesive called a bonding agent to the cavity formed by cutting, curing, and then filling a composite resin. After the restoration agent is filled, it is cured by polymerization and cured. In order to perform treatment with emphasis on aesthetics by using a restoration material that directly fills the teeth and polymerizes and cures them, a method that reproduces the delicate color tone of natural teeth by preparing materials with different colors and transparency in advance. Is taken.

  There are individual differences in natural teeth, and the color tone of each tooth part is also different, so the dentist selects the color tone of the restoration material with reference to the shade guide that simulates the color tone of the material, and the material of that color tone Is filled into the repair site and polymerized and cured. Whether the color of the restoration material used matches the color of the natural teeth is determined by comparing the material after polymerization and the surrounding natural teeth, and it is natural if the color of the restoration material is closer to the natural teeth. It can be said that it is a restoration.

  Color and transparency are important to satisfy aesthetic restoration. For example, it can be said that the cut end portion of natural teeth is a portion having a thin color and high transparency, and the tooth neck portion and the root portion are portions having a dark color and low transparency. In order to aesthetically restore such natural teeth, it is necessary to control the color tone and transparency of the filling restorative material. In general, additives such as pigments are used to adjust the color tone and transparency of filling restoration materials, and various color tones are created by adjusting the amount of these additives.

  When an dentist performs an aesthetic restoration using such a filling restorative material, he selects the color of the restorative material with reference to a shade guide that simulates the color of the material, and fills the restoration site with the material of that color. To polymerize and cure. At this time, there is no problem if the color tone of the selected material matches the color tone of the surrounding teeth, but in the unlikely event that the color tone of the restoration material and the natural tooth is different, the restoration site will become noticeable and unnatural. If it cannot be obtained, the restoration is removed and then refilled and the repair treatment is repeated. The cured restoration material is difficult to remove because it is firmly bonded to the tooth by the bonding agent, which requires a lot of labor and time for the dentist, and also causes great pain for the patient. .

In order to alleviate such problems, not only the restoration material color selection depends on the shade guide and experience, but also whether the restoration material and the teeth around the cavity are compatible in the state before polymerization hardening. It is effective to be able to judge whether or not. In the state before polymerization curing, the filling and restorative material is not adhered to the tooth, so it can be easily removed and re-restored.This problem is caused by the refractive index of the vinyl monomer used in the polymerizing and curing restoration material. Is caused by change before and after polymerization. Generally, the polymer after polymerization has a higher refractive index than the vinyl monomer before polymerization, and this causes the transparency and color tone of the material to change. In order to suppress the change in transparency before and after curing, various refractive indexes of fillers used for filling and restoration materials have been studied (for example, see Patent Documents 1 and 2).

JP 63-218703 A Japanese Patent Laid-Open No. 01-186807

  According to the above prior art, by combining a filler with a higher refractive index and a filler with a lower refractive index than the average refractive index of the monomer and the polymer, it is cured while having translucency similar to natural teeth. The change in transparency before and after is reduced. As described above, the combination of two kinds of fillers having different specific refractive indexes is suitable because the change in transparency can be considerably reduced. For example, Patent Document 1 evaluates the difference in transparency before and after curing using the contrast ratio (Yb / Yw), and Patent Document 2 evaluates using the difference in lightness (L value). It can be seen that the change in transparency is small because the difference between before and after curing is small.

However, in order to perform more sophisticated aesthetic restoration, it is necessary not only to suppress the change in transparency but also to reduce the change in color tone. For example, according to the L ^* a ^* b ^* color system standardized by the International Commission on Illumination (CIE), the color tone is represented by lightness L ^* and chromaticity a ^* , b ^* . The change in color tone due to this display is represented by [(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ] ^1/2 , and the evaluation of only the L value as in Patent Document 2 is sufficient to change the color tone. It cannot be expressed, and the suppression of color change is insufficient. As described above, further improvement has been demanded regarding the change in color tone before and after curing.

  The present inventors have continued intensive studies to solve the above problems. As a result, three types of fillers with different refractive indexes, that is, fillers near the refractive index of the monomer, fillers between the refractive index of the monomer and the polymer, and fillers near the refractive index of the polymer can be combined to further change the transparency. It has been found that the change in color tone is suppressed and the present invention has been completed.

That is, the present invention
(A) Polymerizable vinyl monomer (B) Filler component consisting essentially of b1) to b3) shown below b1) High refractive index filler having a refractive index (n _D ^F1 ) satisfying the following formula

b2) the refractive index filler in having a refractive index satisfying the following formula ^{_(n D F2)}

b3) Low refractive index filler having a refractive index (n _D ^F2 ) satisfying the following formula

[However, n _D ^M is the refractive index of the polymerizable vinyl monomer, n _D ^P is the refractive index of the polymer obtained by polymerizing the vinyl monomer. ]
(C) A dental curable composition comprising a radical polymerization initiator.

  Furthermore, this invention also provides the dental filling restoration material which consists of said dental photocurable composition.

  The dental curable composition of the present invention has little change in color tone and transparency before and after curing, and can determine whether the color tone of the material matches the color tone of teeth around the cavity before polymerization curing. .

  Therefore, the dental curable composition of the present invention can be suitably used in applications such as a dental filling restorative material, a dental crown material, a dental sealant, a dental cement, a dental adhesive, and a dental repair material using the above properties. . In particular, it is most suitable for dental filling restorative materials called compositoresins.

  The dental curable composition of the present invention is characterized in that three kinds of fillers each having a different refractive index and having a specific range of refractive index are used in combination.

The filler having a refractive index represented by n _D ^F1 has the highest refractive index among the three types of fillers and is close to the refractive index of the vinyl polymer. Although the said filler is also described below as a high refractive index filler, the refractive index of this filler needs to satisfy the following formula | equation.

When the refractive index (n _D ^F1 ) of the high refractive index filler is larger than n _D ^P +0.030, the paste before curing becomes opaque and the change in transparency before and after curing becomes large. In addition, when n _D ^F1 is (n _D ^P + n _D ^M ) /2+0.005 or less, a change in color tone before and after curing becomes large. From the viewpoint of reducing the transparency change and color tone change before and after curing, the refractive index of the high refractive index filler is:

More preferably,

It is more preferable that

  The high refractive index filler of the present invention may be one type of filler represented by the same composition, and two or more types of fillers may be mixed and used as long as the above mathematical formula is satisfied.

The filler having a refractive index represented by n _D ^F2 has an intermediate refractive index among the three types of fillers, and has a refractive index between the vinyl monomer and the vinyl polymer. Although the said filler is also described below as a medium refractive index filler, the refractive index of this filler needs to satisfy the following formula | equation.

When such a medium refractive index filler is not contained, the color change before and after curing of the curable composition becomes large. From the viewpoint of reducing the color tone change before and after curing, the refractive index of the medium refractive index filler is:

More preferably,

It is more preferable that

  The medium refractive index filler of the present invention may be one kind of filler represented by the same composition, and two or more kinds of fillers may be mixed and used as long as the above mathematical formula is satisfied.

The filler having a refractive index represented by n _D ^F3 has the lowest refractive index among the three types of fillers and is close to the refractive index of the vinyl monomer. Hereinafter, the filler is also referred to as a low refractive index filler, but the refractive index of the filler needs to satisfy the following formula.

When the refractive index (n _D ^F3 ) of the low refractive index filler is larger than (n _D ^P + n _D ^M ) /2−0.015, the color tone change before curing becomes large. Further, when n _D ^F3 is smaller than n _D ^M −0.050, the cured product after curing becomes opaque, and the change in transparency before and after curing becomes large. From the viewpoint of making the change in transparency and color change before and after curing smaller, the refractive index of the low refractive index filler is:

More preferably,

It is more preferable that

  The low refractive index filler of the present invention may be one type of filler represented by the same composition, and two or more types of fillers may be mixed and used as long as the above mathematical formula is satisfied.

  Although the mechanism which can suppress the color tone change before and after hardening by mix | blending the high refractive index filler which has specific refractive index like this invention, a medium refractive index filler, and a low refractive index filler is not clear, three types of fillers It is considered that not only is ΔL * suppressed as in Patent Document 2, but also has an effect of suppressing Δa * and Δb *.

  In the filler component, the blending ratio of each refractive index filler is not particularly limited, but the blending amount of the high refractive index filler is from the viewpoint of improving the transparency change and color change before and after curing. It is 20 to 90% by mass, the compounding amount of the medium refractive index filler is preferably 5 to 70% by mass, and the compounding amount of the low refractive index filler is preferably 1 to 20% by mass. In order to particularly reduce the change in transparency and color tone before and after curing, the blending amount of the high refractive index filler is 30 to 80% by mass, the blending amount of the medium refractive index filler is 10 to 60% by mass, and low The blending amount of the refractive index filler is more preferably 2 to 15% by mass.

  In the present invention, these filler components are substantially constituted by the above b1) to b3), and those consisting of only these three kinds of fillers are usually used. As long as the effect of the present invention is not greatly reduced, a small amount of filler other than the components b1) to b3) is allowed to be mixed, but the amount is usually within 3% by mass, particularly preferably 1. It is within mass%.

As n _D ^F1 , n _D ^F2 , and n _D ^F3 , a known filler is used without any limitation as long as the above refractive index is satisfied. Generally as this filler, the organic inorganic composite filler which added the inorganic filler to the inorganic filler, the organic polymer, and the organic polymer is mentioned. The type of filler used as each refractive index filler is determined by the refractive index required for each of these fillers in relation to each refractive index of the polymerizable vinyl monomer to be combined, and the filler used is also a composite In this case, since the refractive index varies depending on the composition ratio of the constituent components, the refractive index is not generally distributed, and if it is appropriately selected based on the relationship between the required refractive index and the refractive index of each filler. Good.

Specific examples of inorganic fillers used as the respective refractive index fillers include, for example, amorphous silica; natural minerals such as quartz, cristobalite, eucryptite, sppositumene, carneget, orthofeldspar, anorthite, anorthite, and the like. ; silica - alumina - calcia - sodium oxide - potassium oxide, silica - alumina - boron oxide - potassium oxide - barium oxide, silica - calcia - boron oxide - sodium oxide - potassium oxide - zinc oxide, silica - sodium oxide - potassium oxide - A glass mainly composed of lead oxide and the like; at least one metal oxide selected from the group consisting of Group I, Group II, Group III and Group IV of the periodic table capable of binding to silica and silica Inorganic oxides as main constituents such as silica-zirconia, silica-titania, silica-chi Near - it can be mentioned zirconia. Here, the refractive index of each of the above inorganic fillers is about 1.46 for amorphous silica, and natural minerals are very wide, usually in the range of 1.4 to 1.7. The refractive index of the object is in the range of about 1.47 to 1.58 depending on the composition ratio of silica and other components.

  The organic filler may be any filler that does not dissolve in the vinyl monomer and can act as a filler. Specific examples thereof include polymethyl methacrylate, polyethyl methacrylate, polymethyl acrylate, polyethyl acrylate, poly n -Monofunctional methacrylate or acrylate polymer such as butyl acrylate; ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,6-hexanediol dimethacrylate, 2,2-bis [ 4- (3-Methacryloxy) -2-hydroxypropoxyphenyl 9] bifunctional methacrylate polymers such as propane or their methacrylic groups substituted with acrylic groups Type acrylate polymer; trifunctional or tetrafunctional methacrylate polymer such as trimethylol propane trimethacrylate, tetramethylol methane trimethacrylate, tetramethylol methane tetramethacrylate, or acrylate polymer in which these methacrylic groups are substituted with acrylic groups Etc. It is also possible to use a copolymer of each of the above monomers. In addition, polycarbonate, polystyrene, polydiallyl phthalate, polydiethylene glycol bisallyl carbonate, and the like can be used. Here, the refractive index of each of the organic fillers is usually in the range of about 1.45 to 1.60, and among these, about 1.54 to 1 for the polymer of the monomer having an aromatic ring. Usually, it is in the range of 65.

  Further, in order to reinforce the polymer, it is possible to fill with an inorganic filler to form an organic-inorganic composite filler. As the organic-inorganic composite filler, those having a structure in which the inorganic filler used in the present invention is uniformly dispersed in the polymer are suitable. Since this organic-inorganic composite filler needs to have light transmittance, the difference in refractive index between the inorganic filler and the polymer is preferably within 0.02. Furthermore, considering that the dental curable composition of the present invention is polished after curing, the average particle size of the inorganic filler is preferably 3 μm or less.

  These fillers used in the present invention are preferably inorganic fillers or organic-inorganic composite fillers rather than organic fillers from the viewpoint of the reinforcing effect. Furthermore, in the present invention, the following fillers are preferably used as the high refractive index filler, medium refractive index filler and low refractive index filler. The high refractive index filler has high aesthetics, suppression of color change before and after curing, and addition of X-ray contrast, silica-zirconia, silica-titania-zirconia, silica-alumina-boron oxide-potassium oxide- A glass containing barium oxide as a main component is suitable. In addition, the medium refractive index filler has high aesthetics, small color change, improved operability, and imparted X-ray contrast properties, such as silica-zirconia, silica-titania-zirconia, silica-titania, etc., and their inorganic oxidation Organic-inorganic composite fillers containing substances are preferred. The low refractive index filler is preferably amorphous silica, silica-titania or the like from the viewpoint of suppressing change in color tone before and after curing, improving storage stability and operability, and improving surface smoothness.

  The particle size and shape of the high refractive index filler, medium refractive index filler and low refractive index filler used in the present invention are not particularly limited. However, if the particle size is too small, when the filler and the vinyl monomer are mixed, the area of the interface becomes large and it becomes difficult to fill the vinyl monomer with a large amount of the filler. As a result, the strength of the cured product obtained by polymerizing the curable composition is lowered. Therefore, the average particle size of the filler used in the present invention is preferably 0.02 μm or more. On the other hand, when a filler having a large particle size is used, the surface of the cured product obtained by polymerizing the curable composition is generally rough, so the average particle size of the filler is in the range of 0.02 to 100 μm. It is preferable. In particular, when the filler is an inorganic substance, if the particle size is large, not only the surface of the cured body becomes rough, but it is difficult to obtain a smooth surface even by polishing. Is preferably in the range of 0.02 to 10 μm, more preferably in the range of 0.05 to 3 μm. Furthermore, if the shape of the filler is spherical, a smoother surface can be easily obtained, which is very preferable. On the other hand, when the filler is an organic material or an organic-inorganic composite filler, the average particle size is preferably in the range of 1 to 100 μm from the viewpoint of ease of production and the like because it is difficult to be affected by the particle size on the polished surface.

  When an inorganic oxide containing silica is used for the filler of the present invention, it is preferable to reduce surface silanol groups in order to maintain the surface stability. For this purpose, a means for drying the inorganic oxide and firing it at a temperature of 500 to 1000 ° C. is often suitably employed. In general, the baked inorganic oxide is most preferably used after surface treatment with an organosilicon compound in order to maintain stability. The surface treatment method is not particularly limited, and a known method, for example, an inorganic oxide and a known organosilicon compound such as γ-methacryloxypropyltrimethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane, alcohol, etc. A method of removing the solvent after contacting in a solvent for a certain time is employed.

Next, the polymerizable vinyl monomer in the present invention will be described. The vinyl monomer is not particularly limited, and generally known monomers having a vinyl group, an allyl group, an acrylic group, a methacryl group or the like as a polymerizable group can be used. Examples of typical monomers used in the present invention are polymerizable monomers having an acrylic group and / or a methacryl group. In addition, the polymerizable vinyl monomer is a bifunctional or more functional monomer, more preferably a bifunctional to tetrafunctional polymerizable monomer, for reasons such as polymerizability of the monomer and mechanical properties of the obtained cured product. Is preferred. A specific example is as follows.
(I) Bifunctional polymerizable monomer (i) Aromatic compound type 2,2-bis [4- (3-methacryloyloxy-2-hydroxypropoxy) phenyl] propane, 2,2-bis (4- Methacryloyloxyphenyl) propane, 2,2-bis (4-methacryloyloxypolyethoxyphenyl) propane, 2,2-bis (4-methacryloyloxydiethoxyphenyl) propane, 2,2-bis (4-methacryloyloxytetraethoxy) Phenyl) propane, 2,2-bis (4-methacryloyloxypentaethoxyphenyl) propane, 2,2-bis (4-methacryloyloxydipropoxyphenyl) propane, 2 (4-methacryloyloxydiethoxyphenyl) -2 (4 -Methacryloyloxytriethoxyphenyl) propane, 2 4-methacryloyloxydipropoxyphenyl) -2- (4-methacryloyloxytriethoxyphenyl) propane, 2,2-bis (4-methacryloyloxypropoxyphenyl) propane, 2,2-bis (4-methacryloyloxyisopropoxyphenyl) ) Propane; acrylates corresponding to the above-mentioned various methacrylates; and diaducts obtained from addition of OH group-containing vinyl monomers and diisocyanate compounds having an aromatic group.

  (Examples of the OH group-containing vinyl monomer include methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 3-chloro-2-hydroxypropyl methacrylate, or acrylates corresponding to these methacrylates. Examples of the diisocyanate include diisocyanate methylbenzene and 4,4′-diphenylmethane diisocyanate.

(Ii) Aliphatic compounds 1,2-bis (3-methacryloyloxy-2-hydroxypropoxy) ethane, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, neopentyl Glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexamethylenediol dimethacrylate and acrylates corresponding to these methacrylates; and OH group-containing vinyl monomers and aliphatic Diaducts obtained from addition with diisocyanate compounds.
(Examples of the OH group-containing vinyl monomer include the same as those exemplified above, and examples of the aliphatic diisocyanate compound include hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diisocyanate methylcyclohexane, isophorone diisocyanate, And methylene bis (4-cyclohexyl isocyanate).
(II) Trifunctional polymerizable monomers: methacrylates such as trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, pentaerythritol trimethacrylate, trimethylolmethane trimethacrylate; and acrylates corresponding to these methacrylates.

(III) tetrafunctional polymerizable monomer pentaerythritol tetramethacrylate, pentaerythritol tetraacrylate; and a diadduct obtained from an adduct of a diisocyanate compound and glycidol dimethacrylate;
(Examples of the diisocyanate compound include diisocyanate methylbenzene, diisocyanate methylcyclohexane, isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, methylenebis (4-cyclohexylisocyanate), 4,4-diphenylmethane diisocyanate, and tolylene-2,4- A diisocyanate etc. can be mentioned.

Further, among these monomers, those particularly preferably used are as follows.
(I) Bifunctional polymerizable monomer (i) Aromatic compound type 2,2-bis [4- (3-methacryloyloxy-2-hydroxypropoxy) phenyl] propane, 2,2-bis (4- Methacryloyloxypolyethoxyphenyl) propane, 2,2-bis (4-methacryloyloxydiethoxyphenyl) propane, 2,2-bis (4-methacryloyloxytriethoxyphenyl) propane, 2,2-bis (4-methacryloyloxy) Pentaethoxyphenyl) propane, 2 (4-methacryloyloxydiethoxyphenyl) -2 (4-methacryloyloxytriethoxyphenyl) propane, 2 (4-methacryloyloxydipropoxyphenyl) -2- (4-methacryloyloxytriethoxyphenyl) ) Propane etc.

(Ii) Aliphatic compound-based ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,6-hexamethylenediol dimethacrylate and acrylates corresponding to these methacrylates; OH group Diaducts obtained from the addition of a vinyl monomer and an aliphatic diisocyanate compound.

(II) Trifunctional polymerizable monomer Trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate and the like.

(III) Tetrafunctional polymerizable monomer Pentaerythritol tetramethacrylate and the like.

  The polyfunctional (meth) acrylate monomer described above may be used in combination of a plurality of types as required.

  Furthermore, you may use polymerizable monomers other than a monofunctional (meth) acrylate type monomer and said polyfunctional (meth) acrylate type monomer as needed. Monofunctional (meth) acrylate monomers include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, hydroxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and glycidyl. A (meth) acrylate etc. can be mentioned.

  The polymerizable vinyl monomer in the present invention includes not only a single component but also a vinyl monomer mixture composed of a plurality of vinyl monomers. When a plurality of types of polymerizable vinyl monomers are used, when these vinyl monomers have a very high viscosity at room temperature or are solid, it is preferably used in combination with a low viscosity polymerizable vinyl monomer. This combination is not limited to two types, and may be three or more types.

The composition ratio in the combination of the vinyl monomers may be determined as necessary, but generally indicates a composition ratio that is preferably employed.
(1) The aromatic compound of the bifunctional vinyl monomer is 30 to 80% by mass, and the aliphatic compound is 70 to 20% by mass.
(2) 30 to 100% by mass of trifunctional vinyl monomer and 0 to 70% by mass of tetrafunctional vinyl monomer
(3) The aromatic compound of the bifunctional vinyl monomer is 10 to 60% by mass, the aliphatic compound is 5 to 30% by mass, the trifunctional vinyl monomer is 10 to 80% by mass, and the tetrafunctional vinyl monomer is 0 to 0% by mass. A composition ratio such as 50% by mass is preferred.

  The refractive index of the polymerizable vinyl monomer suitably used in the curable composition of the present invention is in the range of 1.45 to 1.55, and the refractive index of the vinyl polymer obtained by polymerizing the vinyl monomer is 1. It is in the range of 50 to 1.60. More preferably, the refractive index of the vinyl monomer is in the range of 1.48 to 1.53, and the refractive index of the vinyl polymer obtained by polymerizing the vinyl monomer is in the range of 1.52 to 1.58. Furthermore, the difference in refractive index between the polymerizable vinyl monomer used in the curable composition of the present invention and the vinyl polymer obtained by polymerizing the vinyl monomer is preferably within 0.04.

  Next, the radical polymerization initiator used in the present invention will be described. A known radical polymerization initiator that is generally used as a dental curable composition is used without limitation, but is a photopolymerization initiator, peroxide / polymerization that can be excited by irradiation with visible light at 390 to 700 nm to start polymerization. Examples thereof include a chemical polymerization initiator composed of an accelerator and a thermal polymerization initiator capable of initiating polymerization by overheating. A photopolymerization initiator or a chemical polymerization initiator is preferable, and a photopolymerization initiator is more preferable.

  As the photopolymerization initiator used in the present invention, a photopolymerization initiator that is excited by irradiation with visible light of 390 to 700 nm and can start polymerization is selected, and preferably polymerization that initiates polymerization with visible light of 400 to 600 nm. It is an initiator. In general, it is preferable to use a photosensitizer and a photopolymerization accelerator in combination as a photopolymerization initiator. Examples of those suitably used as photosensitizers include benzyl, camphorquinone, α-naphthyl, acetonaphthene, p, p′-dimethoxybenzyl, p, p′-dichlorobenzyldiacetyl, pentanedione, 1,2- Examples include α-diketones such as phenanthrenequinone, 1,4-phenanthrenequinone, 3,4-phenanthrenequinone, 9,10-phenanthrenequinone, and naphthoquinone. In the present invention, the α-diketone can be used by selecting at least one of known α-diketones, and can also be used by mixing two or more. Camphor quinone can be most preferably used.

  Examples of the photopolymerization accelerator include N, N-dimethylaniline, N, N-diethylaniline, N, N-dimethyl-p-toluidine, N, N-diethyl-p-toluidine, N, N-dimethyl-m-. Toluidine, m-chloro-N, N-dimethylaniline, p-dimethylaminoacetophenone, p-dimethylaminobenzoic acid, ethyl p-dimethylaminobenzoate, N, N-dihydroxyethylaniline, N, N-dihydroxyethyl-p -Toluidine, p-dimethylaminophenethyl alcohol, N, N-dimethyl-3,5-xylidine, 4-dimethylaminopyridine, N, N-dimethyl-α-naphthylamine, triethylamine, tributylamine, N, N-dimethylaminoethyl Methacrylate, N, N-diethylaminoethyl methacrylate, tri Tertiary amines such as tanolamine, N-methyldiethanolamine and N-ethyldiethanolamine; Barbituric acids such as 5-butyl barbituric acid and 1-benzyl-5-phenylbarbituric acid; Benzoyl peroxide, di-t Organic peroxides such as butyl peroxide and t-butyl perbenzoate; diphenyliodonium, bis (p-chlorophenyl) iodonium, ditolyliodonium, bis (p-methoxyphenyl) iodonium, bis (p-tert-butylphenyl) ) Iodonium, p-isopropylphenyl-p-methylphenyliodonium, bis (m-nitrophenyl) iodonium, p-tert-butylphenylphenyliodonium, p-methoxyphenylphenyliodonium, p-octylo Cations such as xylphenylphenyliodonium, p-phenoxyphenylphenyliodonium, chloride, bromide, benzenesulfonate, p-toluenesulfonate, trifluoromethanesulfonate, tetrafluoroborate, tetrakis (pentafluorophenyl) borate, tetrakis (penta Fluorophenyl) gallate, hexafluorophosphate, hexafluoroarsenate, iodonium salts such as salts composed of anions such as hexafluoroantimonate; 2,4,6-tris (trichloromethyl) -s-triazine, 2-phenyl- 4,6-bis (trichloromethyl) -s-triazine, 2- (p-chlorophenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-biphenylyl) -4, - bis triazines such as (trichloromethyl) -s-triazine can be suitably used. Among these photopolymerization accelerators, at least one kind can be selected and used, and two or more kinds can also be mixed and used.

  In addition, when tertiary amines are used as accelerators, tertiary amines in which a nitrogen atom is directly bonded to an aromatic group are more preferably used. Furthermore, in order to improve the polymerization promoting ability, in addition to tertiary amines, addition of oxycarboxylic acids such as citric acid, malic acid, tartaric acid, glycolic acid, gluconic acid, α-oxyisobutyric acid, 2-hydroxypropanoic acid, etc. It is effective.

  In addition, as the chemical polymerization initiator used in the present invention, a peroxide and a polymerization accelerator are used in combination. Examples of the peroxide include the organic peroxides described above, and examples of the polymerization accelerator include the tertiary amines and barbituric acids described above.

  Examples of the thermal polymerization initiator used in the present invention include the above organic peroxides; azo compounds such as azobisisobutyronitrile.

  When the suitable mixing ratio of the curable composition of this invention is shown, the compounding quantity of (B) filler component is 50-900 mass parts with respect to 100 mass parts of (A) polymerizable vinyl monomers, (C ) The blending amount of the radical polymerization initiator is 0.001 to 10 parts by mass. More preferably, the blending amount of the filler component (B) is 100 to 870 parts by weight with respect to 100 parts by weight of the polymerizable vinyl monomer (A), and the blending amount of the (C) radical polymerization initiator is 0.00. 0 to 1 part by mass.

  When the curable composition of the present invention is polymerized, the polymerization method varies depending on the type of radical polymerization initiator. In the case of a photopolymerization initiator, the light wavelength is 390 to 700 nm, preferably 400 to 600 nm. When using for the dental curable composition applied to a human body, it is important that the wavelength of the light to irradiate is harmless to a human body. As the light in the wavelength range, light such as a halogen lamp, a xenon lamp, a laser, a fluorescent lamp, and sunlight can be used. Moreover, although the temperature and irradiation time in the case of irradiating the said light and superposing | polymerizing a vinyl monomer differ with intensity | strengths of irradiation light, generally it should just determine suitably according to desired polymerization time. It is sufficient to perform irradiation for about 3 seconds to several minutes, preferably in the range of 0 to 60 ° C.

  In the case of a chemical polymerization initiator, the chemical reaction starts by mixing the peroxide and the polymerization accelerator immediately before use, leading to polymerization and curing. In order to perform this mixing operation sufficiently uniformly, it is necessary to secure a time from curing several tens of seconds to 10 minutes until curing. For this reason, it is necessary to select suitably the quantity of a polymerization initiator and a polymerization inhibitor.

  In the case of a thermal polymerization initiator, the heating temperature varies depending on the type of polymerization initiator used, but is generally in the range of 30 to 200 ° C, preferably 50 to 150 ° C.

  Furthermore, ultraviolet absorbers such as 2-hydroxy-4-methylbenzophenone; polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, 2,5-di-t-butyl-4-methylphenol; 2,5-dihydroxyterephthale Fluorescent agents such as diethyl acid; components such as pigments can also be added to the curable composition of the present invention.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. First, abbreviations of compounds such as fillers, polymerizable monomers, polymerization catalysts and the like used in the examples are shown below.
(1) Abbreviations / abbreviations / CQ: camphorquinone / DMBE: N, N-dimethyl p-ethyl benzoate / 3G: triethylene glycol dimethacrylate / GMA: 2,2-bis [(3-methacryloyloxy-2-hydroxy Propyloxy) phenyl] propane / D-2.6E: 2,2-bis (4-methacryloyloxypolyethoxyphenyl) propane (having an average of 2.6 repeating units of ethylene oxide in one molecule)
D-6E: 2,2-bis (4-methacryloyloxypolyethoxyphenyl) propane (having an average of 6 repeating units of ethylene oxide in one molecule)
UDMA: 1,6-bis (methacrylethyloxycarbonylamino) trimethyloxane HD: hexamethylenediol dimethacrylate F-11: spherical silica-zirconia with an average primary particle size of 0.2 μm (refractive index 1.542) )
F-12: Spherical silica-titania with an average primary particle size of 0.2 μm (refractive index: 1.544)
F-21: Spherical silica-zirconia with an average primary particle size of 0.2 μm (refractive index 1.522)
F-22: Organic inorganic composite filler having an average particle size of 40 μm composed of spherical silica-zirconia having an average particle size of 0.2 μm and 3G / GMA / HD = 25/35/40 (refractive index of 1.524)
F-23: Amorphous silica-zirconia with an average primary particle size of 3 μm (refractive index 1.531)
F-31: Spherical silica-titania with an average primary particle size of 0.2 μm (refractive index: 1.504)
F-32: Spherical silica-titania with an average primary particle size of 0.08 μm (refractive index of 1.506)
The following methods were used as the refractive index measurement method, paste preparation method, transparency and color tone measurement method shown in the following Examples and Comparative Examples.

(1) Measuring method of refractive index of filler A solvent having the same refractive index as that of the inorganic filler of the sample was prepared, and the refractive index of the solvent was used as the refractive index of the sample. As a method for preparing the solvent, the sample was suspended in the solvent, and the composition of the solvent that was most transparent by visual observation was prepared at 23 ° C. The solvents used were pentane, hexane, cyclohexane, toluene, styrene, aniline, methylene iodide, and the like, and the refractive index of the solvent was measured with an Abbe refractometer.

(2) Polymerizable vinyl monomer and method for measuring refractive index of vinyl polymer obtained by polymerizing vinyl monomer The refractive index of vinyl monomer and polymer was measured at 23 ° C. directly using an Abbe refractometer.

(3) Measuring method of transparency The paste-like curable composition was filled in a mold made of tetrafluoroethylene having a hole having a diameter of 7 mm and a thickness of 1 mm, and pressed with a polypropylene film. In this state, the Y value which is one of the tristimulus values was measured with a color difference meter (TC-1500MK-II, manufactured by Tokyo Denshoku Co., Ltd.). At this time, Y. According to the method described in Miyagawa et al., “Journal of Rental Research”, 60 (5), 890-894, 1981, a standard white plate (X = 81.2, Y = 82.7, Z = 93) .8) and Y value (hereinafter referred to as Yw) when a standard black plate (X = 0.1, Y = 0.1, Z = 0.2) is placed on the back side of the sample. The Y value (hereinafter referred to as Yb) was measured, and the contrast ratio indicating the opacity of the cured product was calculated by the following equation.

Contrast ratio = Yb / Yw
The transparency was calculated by the following formula using the contrast ratio.

Transparency = 1−Contrast ratio = 1−Yb / Yw
The transparency varies in the range from 0 to 1, and the larger the value, the higher the transparency.

  Next, a light guide of a visible light irradiator (Optilax LC-T, manufactured by Cybron Dental Co., Ltd.) was closely attached to the polypropylene film of the sample, and light irradiation was performed for 30 seconds. With the polypropylene film attached, the transparency was measured in the same manner as above to obtain the transparency of the cured product.

(4) Color tone measurement method The paste-like curable composition was filled in a tetrafluoroethylene mold having a diameter of 7 mm and a thickness of 1 mm, and was press-contacted with a polypropylene film. In this state, using the same color difference meter as in (3), a standard black plate was placed on the back side of the sample, and the color tone (L *, a *, b *) was measured.

  Next, a light guide of a visible light irradiator (Optilax LC-T, manufactured by Cybron Dental Co., Ltd.) was closely attached to the polypropylene film of the sample, and light irradiation was performed for 30 seconds. The color tone of the cured product was measured in the same manner as above.

  The change in color tone before and after curing was calculated by the following formula.

ΔE * = [(ΔL *) ² + (Δa *) ² + (Δb *) ² ] ^1/2
ΔL * = L * after curing−L * before curing
Δa * = a * after curing−a * before curing
Δb * = b * after curing−b * before curing
(5) Evaluation of change in color tone by visual inspection before and after curing The paste-like curable composition was inserted into a tetrafluoroethylene mold having a diameter of 1 cm and a thickness of 3 mm, and pressed with a polypropylene film, and then the same as (4) Light was irradiated by the method to obtain a disk-shaped cured body. A hole with a diameter of 5 mm was made in the center of the cured body, the paste used for the production of the cured body was inserted, and the color tone of the cured body in the peripheral portion and the paste in the central portion were visually compared. ◎ when there is no difference in the color tone of the cured product and the paste, ○ a slight change in color tone is observed, ○ when it is almost unknown, △ when there is a slight difference in color tone, a clear difference is seen The case is represented by x.

(6) Preparation method of paste-like composition A predetermined amount of filler is blended in an organic matrix consisting of a predetermined amount of a polymerizable vinyl monomer and a photopolymerization initiator, and the mixture is uniformly stirred and removed using a mortar under red light. Prepared by foaming.

Example 1, Comparative Examples 1 and 2
A paste-like curable composition was prepared by blending the filler shown in Table 1 with an organic matrix in which CMA 0.3 parts by mass and DMBE 0.5 parts by mass were dissolved in 60 parts by mass GMA, 40 parts by mass 3G, and transparent before and after curing. The color change before and after curing was measured by matching the change in sex.

  As a result, as shown in Example 1, when three types of fillers having different refractive indexes are used, the change in color tone before and after curing is smaller than when only two types are used as in Comparative Examples 1 and 2. I understood.

Generally, when ΔE ^* exceeds 2, the change in color tone can be visually confirmed gradually, and if it is less than that, it is said that it can hardly be confirmed. Since the color tone change in Example 1 was 2.2, there was almost no difference in color tone between the cured product and the paste, but it was obvious that Comparative Examples 1 and 2 were 4.8 and 3.3. Changes were observed. Thus, when ΔE ^* was increased, a clear difference could be observed visually.

Examples 2-5
A paste was prepared in the same manner as in Example 1 except that the composition shown in Table 1 was used, and the change in color tone before and after curing was measured. The results are shown in Table 2.

Example 6 and Comparative Example 3
Evaluation was performed in the same manner as in Example 1 except that F-22 was used as the medium refractive index filler and the amount of the filler was increased. The results are shown in Table 2. In Example 6, the change in color tone before and after curing was smaller than that in Comparative Example 3, and it was difficult to confirm the change in color tone visually.

Example 7
A paste was prepared in the same manner as in Example 6 except that the composition shown in Table 1 was used, and the change in color tone before and after curing was measured. The results are shown in Table 2.

Claims (3)

(A) Polymerizable vinyl monomer (B) Filler component consisting essentially of b1) to b3) shown below b1) High refractive index filler having a refractive index (n _D ^F1 ) satisfying the following formula

b2) the refractive index filler in having a refractive index satisfying the following formula ^{_(n D F2)}

b3) Low refractive index filler having a refractive index (n _D ^F3 ) satisfying the following formula

[However, n _D ^M is the refractive index of the (A) polymerizable vinyl monomers, n _D ^P is the refractive index of the polymer obtained by polymerizing the vinyl monomer. ]
(C) A dental curable composition comprising a radical polymerization initiator. (A) The blending amount of the filler component is 50 to 900 parts by weight with respect to 100 parts by weight of the polymerizable vinyl monomer, and (C) the blending amount of the radical polymerization initiator is 0.001 to 10 parts by weight. In the filler component (B), the blending amount of b1) high refractive index filler is 20 to 90% by mass, b2) the blending amount of medium refractive index filler is 5 to 70% by mass, and b3) The dental curable composition according to claim 1, wherein the amount of the low refractive index filler is 1 to 20% by mass. A dental filling / restoration material comprising the dental curable composition according to claim 1.