JP5154809B2 - Dental restoration material - Google Patents

Description

  The present invention relates to a dental restoration material used by mixing a powder material and a liquid material.

  In recent years, as the demand for dental restoration has changed from functionality to aesthetics, the color of dental restoration materials has become increasingly important. The color tone of the dental restorative material is expressed by adding an organic substance or an inorganic substance such as titania as a pigment, and various color tones are expressed by adjusting the addition amount of the pigment.

  However, if the pigment is not uniformly dispersed, a desired color tone cannot be obtained, and if the dispersibility is poor, color unevenness occurs. In particular, since a dental restorative material composed of a powder material and a liquid material mixes the powder material and the liquid material when used, it is necessary to uniformly disperse the pigment during mixing.

  Dental restoration materials consisting of powder and liquid materials are used for dental denture repair, dental room-temperature polymerization resin used for temporary teeth, etc., dental cement used for temporary fixation of swing teeth, and denture repair It is used as a rebase material that is a material, or as a temporary sealing material that is temporarily packed in teeth between treatments. The method of using a dental restorative material composed of these powder material and liquid material can be roughly classified into a kneading method and a writing method. The kneading method is a method in which a certain amount of powder material and liquid material are taken and kneaded using a spatula or the like. The brush stacking method is a method in which the liquid material is sufficiently immersed in the tip of a brush made of animal hair such as pig hair or a synthetic fiber brush, and the tip of the brush is brought into contact with the powder material and mixed. It is. In the brush stacking method, the liquid material contained in the brush enters the gap between the powder materials by capillary action, so that the liquid material and the powder material are mixed.

  In both the kneading method and the writing method, it is required that the pigment is uniformly dispersed when the liquid material and the powder material are mixed. In particular, in the writing method, it is difficult to uniformly disperse the pigment. . This is because in the brush writing method, external force is hardly applied when the powder material and the liquid material contact each other. For this reason, in particular, in the writing method, the dispersibility of the pigment is insufficient and color unevenness occurs. In order to solve such problems, for example, a method has been proposed in which a pigment is coated on the surface of organic polymer particles, which are the main constituent material of a powder material, and the distribution of the organic polymer and the pigment is made uniform (non-patent document). Reference 1).

GC Unident Three's introduction page (URL: http://www.gcdental.co.jp/unifast3/) on the dental care website (URL: http://www.gcdental.co.jp) Search February 23, 19 "

  However, the above prior art has the following problems. Even if the distribution of the organic polymer and the pigment in the powder material can be made uniform, the pigment will not be uniformly dispersed in the dental restorative material unless the organic polymer is sufficiently dissolved in the liquid material.

  An object of the present invention is to solve the above problems, that is, to provide a dental restorative material comprising a powder material and a liquid material with improved pigment dispersibility.

  As a result of diligent research to solve the above problems, the present inventor uses a powder material that contains a pigment-supporting organic polymer that supports a pigment and has a solubility in a liquid material of a specific speed or higher. As a result, it was found that the pigment was uniformly dispersed and a dental restoration material having no color unevenness was obtained, and the present invention was completed.

  That is, the present invention comprises (A) a liquid material containing a polymerizable monomer, (A) a powder material (B) containing an organic polymer (b) dissolved in the liquid material, and (A) the liquid material or In the dental restorative material containing the polymerization initiator (c) contained in at least one of the (B) powder material, (b) at least a part of the organic polymer carries a pigment, and a polymerizable monomer After adding 2 parts by mass to 100 parts by mass of the body and stirring for 3 minutes at a rotation speed of 300 rpm and a liquid temperature of 23 ° C., the dissolution rate in the polymerizable monomer is 40% by weight or more (b1 ) Dental restorative material with organic polymer for pigment support.

Here, when the polymerizable monomer is methyl methacrylate, the pigment-supporting organic polymer is polyethyl (meth) acrylate, a copolymer of methyl (meth) acrylate and ethyl (meth) acrylate (however, Only when the molar ratio of ethyl (meth) acrylate occupies 60% or more) and a copolymer of methyl (meth) acrylate and ethyl (meth) acrylate (provided that the molar ratio of ethyl (meth) acrylate is 50) % And less than 60%, and the average particle diameter is 30 μm or less).

Further, when the polymerizable monomer is acetoacetoxyethyl methacrylate, the pigment-supporting organic polymer is selected from the group consisting of polybutyl (meth) acrylate and polyethyl (meth) acrylate having an average particle size of 10 μm or less. Selected. Further, when the polymerizable monomer is a combination of propionoxyethyl methacrylate and triethylene glycol dimethacrylate, the pigment-supporting organic polymer is a group consisting of polybutyl (meth) acrylate and polyethyl (meth) acrylate. More selected.

  When the dental restorative material of the present invention is used, when the powder material and the liquid material come into contact with each other, the organic polymer supporting the pigment in the powder material quickly dissolves in the liquid material, and the pigment is uniformly in the liquid material. scatter.

  According to the present invention, the dispersibility of the pigment in the dental restorative material can be further improved, and color unevenness can be prevented.

  Hereinafter, embodiments of the dental restoration material according to the present invention will be described.

  A dental restorative material according to an embodiment of the present invention is a restorative material that is divided into a powder material and a liquid material and packaged and stored, and is used as a paste in which both materials are mixed. The powder material mainly contains an organic polymer and a pigment. The pigment functions to impart aesthetics to the dental restorative material and needs to be uniformly dispersed in the restorative material. The pigment is supported on at least a part of the organic polymer. The organic polymer is an organic polymer for supporting a pigment, and may be only a pigment-supporting organic polymer that is easily dissolved in a polymerizable monomer constituting a liquid material. You may use together. Such an organic polymer not supporting a pigment may be an organic polymer having the same solubility as the organic polymer for pigment support, but has a higher solubility in polymerizable monomers than the organic polymer for pigment support. It is preferably a low organic polymer (this is referred to as a low solubility organic polymer).

  By blending the low-solubility organic polymer into the powder material in this way, good initial fluidity can be imparted to the paste obtained by mixing and kneading the powder material and the liquid material. That is, when the powder material and the liquid material are mixed and kneaded, the organic polymer for pigment support dissolves in the liquid material component and the viscosity increases. Here, the low-solubility organic polymer also swells with the liquid material component to increase the viscosity, but the viscosity increase rate is slower than the pigment-supporting organic polymer. Therefore, if both the powdery low-solubility organic polymer and the pigment-supporting organic polymer are blended so that the final viscosity is appropriate, the viscosity is lower than the final viscosity and becomes fluid. It becomes an excellent paste, and thus can be a restoration material excellent in operability such as shaping.

  In addition to the organic polymer (including at least the pigment-supporting organic polymer) and the pigment, an inorganic filler may be added to the powder material. By adding an inorganic filler, the hardness of the final composition can be adjusted. That is, by adding an inorganic filler to the dental restorative material according to the present embodiment, the final hardness of the pasted restorative material is increased. Therefore, other compounding components (the above organic polymer, pigment, polymerizable monomer constituting the liquid material described later) determined from the viewpoints of storage stability, kneadability, economy and the like are mixed at a predetermined ratio. In the case where the hardness of the composition obtained is too soft, an inorganic filler can be added to the powder material to function as a hardness adjusting material. The inorganic filler may be added to either the powder material or the liquid material, but is preferably blended into the powder material from the viewpoints of storage stability, kneadability and the like.

  The liquid material contains a polymerizable monomer as a main component. As the polymerizable monomer, a radical polymerizable monomer can be particularly preferably used. Moreover, a polymerization initiator is mix | blended with at least any one of a powder material or a liquid material.

  Next, the organic polymer, the pigment and the inorganic filler contained in the powder material, the polymerizable monomer that is the main component of the liquid material, and the polymerization initiator contained in at least one of the powder material or the liquid material will be described in detail. .

(1) Organic polymer As an organic polymer, polymethyl (meth) acrylate, polyethyl (meth) acrylate, methyl (meth) acrylate-ethyl (meth) acrylate copolymer, cross-linked polymethyl (meth) acrylate, cross-linked polyethyl (meth) Acrylate, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, acrylonitrile-styrene copolymer, acrylonitrile-styrene-butadiene copolymer, etc. can be mentioned, and as one or a mixture of two or more thereof Can be used.

  Among these organic polymers, those that can be used as a pigment-supporting organic polymer for supporting a pigment have a solubility of 40% by weight when the pigment-supporting organic polymer is dissolved in a polymerizable monomer by the following method. Above, preferably 60% by weight or more, particularly preferably 80% by weight or more. The method is that 2 parts by mass of an organic polymer for pigment support is added to 100 parts by mass of a polymerizable monomer, stirred for 3 minutes at a liquid temperature of 23 ° C. at a rotational speed of 300 rpm, and then into the polymerizable monomer. In this method, the amount of the pigment-supporting organic polymer that has not been dissolved is measured to determine the amount of the pigment-supporting organic polymer that has been dissolved.

  As a more preferable method, 200 mg of a pigment-supporting organic polymer is added to 10 g of a polymerizable monomer, stirred for 3 minutes at a liquid temperature of 23 ° C. at a rotation speed of 300 rpm, and then used for supporting the polymerizable monomer and the pigment. In this method, 1 g is taken out from the mixture with the organic polymer, centrifuged, and the amount of the precipitated pigment-supporting organic polymer is measured. In this case, the dissolution rate (% by weight) is calculated by the formula of (200 mg-precipitate) × 100/200 mg. Centrifugation is performed at a rotational speed of 15000 rpm for 10 minutes.

  Among the above organic polymers for supporting pigments, polymethyl (meth) acrylate, polyethyl (meth) acrylate, polypropyl (meth) acrylate, poly n-butyl (meth) are easily dissolved and handled easily. A monomer unit based on a (meth) acrylic acid ester of an alcohol having 1 to 20 carbon atoms (more preferably 1 to 10) such as an acrylate is 50 to 100 mol% (more preferably 80 to 100 mol%). Homopolymers or copolymers are preferred.

  The size of the organic polymer for pigment support is not limited as long as it is in powder form, but it is volume average from the viewpoint of ease of handling as a powder material (fluidity and cohesiveness) and easy solubility in liquid materials. The powder preferably has a particle size of 0.1 to 100 μm, more preferably 1 to 80 μm, and even more preferably 5 to 50 μm.

  Further, the mass average molecular weight and molecular weight distribution of the organic polymer including the pigment-supporting organic polymer are not particularly limited, but if the mass average molecular weight is too small, the paste obtained by contacting with the liquid material In some cases, the operability is poor, the Tg is less than 0 ° C., or in an extreme case, it becomes liquid. On the other hand, those having an extremely large mass average molecular weight are not only difficult to synthesize and obtain, but also sometimes difficult to improve the operability of the paste. Therefore, as an organic polymer mix | blended with the powder material of the dental restoration material which concerns on this Embodiment, a thing with a mass mean molecular weight of 20,000-5 million is suitable, and a thing with 50,000-1 million is more preferable. .

  In addition, the mass average molecular weight in polymers, such as the said organic polymer, is a standard polystyrene conversion molecular weight measured by gel permeation chromatography (henceforth GPC).

  As the pigment-supporting organic polymer, the mass-average molecular weight, molecular weight distribution, average particle diameter, etc., depending on the type and ratio of the monomer, so as to be easily soluble in the polymerizable monomer constituting the liquid material One or more different organic polymers can be selected.

  The powdery low-solubility organic polymer can be used without particular limitation as long as it does not interfere with the effects of the present invention. Among these, (meth) acrylic polymers are preferably used because they do not significantly affect physical properties. Specific examples of such low solubility organic polymers include polymethyl (meth) acrylate, polyethyl (meth) acrylate, polypropyl (meth) acrylate, polyisopropyl (meth) acrylate, polybutyl (meth) acrylate, polyisobutyl ( Two or more different ones of the polymerizable monomers constituting these polymers, such as (meth) acrylate, polyhexyl (meth) acrylate, poly-2-ethylhexyl (meth) acrylate, polycyclohexyl (meth) acrylate, etc. Examples include poly (meth) acrylate-based organic polymers made of a copolymer. As this organic polymer, it may be used independently or may use 2 or more types together. These low-solubility organic polymers are prepared by adding 2 parts by weight of the organic polymer to 100 parts by weight of the polymerizable monomer described above, and stirring for 3 minutes at a liquid temperature of 23 ° C. at a rotational speed of 300 rpm. When the dissolution rate is evaluated by a method of measuring the amount of the organic polymer not dissolved in the monomer, it has 0.5% by weight or more, especially 1-10% by weight Is preferred.

  The particle diameter of the low-solubility organic polymer is not particularly limited, but from the viewpoint of maintaining the good feeling of kneading at the time of kneading and better maintaining the feel of the composition after kneading, the volume average particle diameter Is preferably a powder of 0.1 to 200 μm, more preferably a powder of 1 to 150 μm. As said low solubility organic polymer, you may use together 2 or more types of organic polymers which differ in the kind and ratio of the monomer unit which comprises this polymer, a mass average molecular weight, molecular weight distribution, an average particle diameter, etc.

  In the present invention, the blending amount of the organic polymer is not particularly limited as long as it does not interfere with the effects of the present invention, but the feeling of kneading between the prepared powder material and the liquid material and the softness of the final composition are good. Therefore, it is preferably used in the range of 5 to 400 parts by mass, more preferably in the range of 50 to 300 parts by mass, and in the range of 80 to 250 parts by mass with respect to 100 parts by mass of the polymerizable monomer. Is particularly preferred. In the present invention, at least a part of the organic polymer is the above-described (b1) pigment-supporting organic polymer. The amount of the organic polymer is not limited to the viewpoint of blending the necessary amount of pigment into the dental restorative material, From the viewpoint of imparting appropriate initial fluidity when the material and the liquid material are mixed and kneaded, the weight of the organic polymer is 0.05 to 400 parts by weight with respect to 100 parts by weight of the polymerizable monomer. It is preferably used in a range, more preferably in a range of 0.1 to 250 parts by mass, and particularly preferably in a range of 0.5 to 100 parts by mass.

(2) Pigment The pigment can be used alone or in combination as appropriate so as to obtain a desired color tone from known pigments such as organic pigments and inorganic pigments. Specifically, inorganic pigments such as black iron oxide, yellow iron oxide, dial, titanium oxide, zirconium oxide, and organic pigments such as phthalocyanine-based polycyclic pigments or azo pigments can be used.

  For supporting the pigment on the organic polymer, the pigment may be attached to the surface of the organic polymer, or the pigment may be contained inside the particles of the organic polymer. Since the organic polymer is dissolved in the liquid from the surface, it is more preferable to carry out the method by attaching the pigment to the surface of the organic polymer from the viewpoint of dispersibility of the pigment. Here, as a method of attaching the pigment to the surface of the organic polymer, the organic polymer and the pigment may be mechanically mixed using a ball mill, a Henschel mixer or the like. As a method for incorporating a pigment into the organic polymer particles, the organic polymer is thermally melted or dissolved in an organic solvent, and the resulting organic polymer solution is mixed with the pigment, and then cooled, or The organic solvent may be removed and the solidified organic polymer may be pulverized. Further, when the organic polymer is polymerized, it may be obtained by mixing a pigment with a raw material polymerizable monomer and polymerizing the polymerizable monomer composition. The amount of the pigment supported on the organic polymer is not particularly limited, but if the amount supported is too small, an excessive amount of the pigment-supporting organic polymer must be blended to impart the desired color tone to the dental restorative material. In the case of an inorganic pigment, the amount is preferably 1% by weight or more, more preferably 5% by weight or more, and in the case of an organic pigment, the amount is preferably 1% by weight or more. It is preferably 0.1% by weight or more, and more preferably 0.5% by weight or more. On the other hand, if the amount of the pigment supported on the organic polymer is too large, it becomes difficult to uniformly support the pigment on the particles of the pigment-supported organic polymer. The organic pigment is preferably 10% by weight or less, more preferably 5% by weight or less.

(3) Inorganic filler Moreover, an inorganic filler can also be added to a powder material. Thereby, the intensity | strength of a hardening body can be improved. Specific examples of typical inorganic fillers include quartz, silica, alumina, silica titania, silica zirconia, lanthanum glass, barium glass, and strontium glass. Further, among the inorganic fillers, examples of the cation-eluting filler include hydroxides such as calcium hydroxide and strontium hydroxide, and oxides such as zinc oxide, silicate glass, and fluoroaluminosilicate glass. These may be used alone or in combination of two or more.

  In some cases, a particulate organic-inorganic composite filler obtained by adding a polymerizable monomer to these inorganic fillers in advance, forming a paste, polymerizing, and pulverizing may be used. The particle size of these fillers is not particularly limited, and fillers having an average particle size of 0.01 to 100 μm that are generally used as dental materials can be appropriately used according to the purpose. Moreover, the refractive index of a filler is not specifically limited, The thing of the range of 1.4-1.7 which a general dental filler has can be used without a restriction | limiting.

(4) Polymerizable monomer The main component of the liquid material of the dental restorative material according to the present embodiment is a polymerizable monomer. Examples of the polymerizable monomer include a radical polymerizable monomer and a cationic polymerizable monomer. Here, a radical polymerizable monomer is preferably used. The radical polymerizable monomer is not particularly limited as long as it has a polymerizable unsaturated bond such as a vinyl group, and examples thereof include aromatic compounds such as (meth) acrylates and divinylbenzene, alkyls Ether-based polymerizable monomers such as vinyl ether can be used. Among them, a (meth) acrylate monomer is preferably used because of its good polymerizability. Specific examples of the (meth) acrylate polymerizable monomer include the following.

(4.1) Monofunctional radically polymerizable monomer Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, n -Alkyl esters of (meth) acrylic acid such as lauryl (meth) acrylate, tridecyl (meth) acrylate, n-stearyl (meth) acrylate; cyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, Isobornyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, glycidyl (meth) acrylate, aceto Acetoxyethyl (meth) acrylate, propionoxyethyl (meth) acrylate, butanoneoxyethyl (meth) acrylate; 1H, 1H, 3H-hexafluorobutyl methacrylate, 1H, 1H, 5H-octafluoropentyl methacrylate, 1H, 1H, 6H -Fluorine-containing (meth) acrylates such as decafluorohexyl methacrylate and 1H, 1H, 7H-dodecafluoroheptyl methacrylate.

(4.2) Bifunctional radical polymerizable monomer Ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butanediol Dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, 2,2-bis (methacryloxyphenyl) propane 2,2-bis [4- (3-methacryloxy) -2-hydroxypropoxyphenyl] propane, 2,2-bis (4-methacryloxyethoxyphenyl) propane, 2, 2-bis (4-methacryloxydiethoxyphenyl) propane, 2,2-bis (4-methacryloxytetraethoxyphenyl) propane, 2,2-bis (4-methacryloxypentaethoxyphenyl) propane, 2,2- Bis (4-methacryloxydipropoxyphenylpropane, 2- (4-methacryloxyethoxyphenyl) -2- (4-methacryloxydiethoxyphenyl) propane, 2- (4-methacryloxydiethoxyphenyl) -2- ( 4-methacryloxytriethoxyphenyl) propane, 2- (4-methacryloxydipropoxyphenyl-2- (4-methacryloxytriethoxyphenyl) propane, 2,2-bis (4-methacryloxypropoxyphenyl) propane, 2 , 2-bis (4-methacryloxyisopropoxyphe Trimethylolpropane, and these acrylate.

(4.3) Trifunctional radical polymerizable monomer Trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolmethane tri (meth) acrylate, etc. It is done.

(4.4) Tetrafunctional radically polymerizable monomer Examples include pentaerythritol tetramethacrylate and pentaerythritol tetraacrylate.

  Considering the solubility of organic polymers among these monomers, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, acetoxyethyl (meth) acrylate, propionoxyethyl (meth) acrylate, butanoneoxyethyl (Meth) acrylate; 1H, 1H, 3H-hexafluorobutyl methacrylate, 1H, 1H, 5H-octafluoropentyl methacrylate, 1H, 1H, 6H-decafluorohexyl methacrylate, 1H, 1H, 7H-dodecafluoroheptyl methacrylate, etc. Fluorine-containing (meth) acrylate can be suitably used, and it is also preferable to use these monomers in combination with other monomers.

  Further, in addition to the (meth) acrylate polymerizable monomer, other polymerizable monomers may be mixed and polymerized. Examples of these other polymerizable monomers include fumaric acid ester compounds such as monomethyl fumarate, diethyl fumarate and diphenyl fumarate; styrene derivatives such as styrene, divinylbenzene and α-methylstyrene; diallyl phthalate and diallyl terephthalate And allyl compounds such as diallyl carbonate and allyl diglycol carbonate. These other polymerizable monomers can be used alone or in combination of two or more.

(5) Polymerization initiator (polymerization catalyst)
The dental restorative material according to the embodiment of the present invention is blended with a polymerization initiator for polymerizing the radical polymerizable monomer. As the polymerization initiator, a known polymerization initiator can be used. As polymerization initiators used in the dental field, there are chemical polymerization initiators (room temperature redox initiators), photopolymerization initiators, thermal polymerization initiators, etc., but taking into account curing in the oral cavity, chemical polymerization initiators And / or a photoinitiator is preferable.

  The chemical polymerization initiator is a polymerization initiator that is composed of two or more components and generates polymerization active species near room temperature by mixing all the components immediately before use. Such chemical polymerization initiators are typically amine compound / organic peroxide type. Specific examples of the amine compound include aromatic amine compounds such as N, N-dimethyl-p-toluidine, N, N-dimethylaniline, and N, N-diethanol-p-toluidine.

  As typical organic peroxides, organic peroxides classified into known ketone peroxides, peroxyketals, hydroperoxides, diaryl peroxides, peroxyesters, diacyl peroxides, and peroxydicarbonates are preferable. . The organic peroxide to be used may be appropriately selected and used, and it may be used alone or in combination of two or more. Among them, hydroperoxides, ketone peroxides, peroxyesters and diacyl Peroxides are particularly preferred from the viewpoint of polymerization activity. Furthermore, among these, it is preferable to use an organic peroxide having a 10-hour half-life temperature of 60 ° C. or higher from the viewpoint of storage stability when a curable composition is used.

  An aryl borate compound / acidic compound polymerization initiator that utilizes the fact that an aryl borate compound is decomposed by an acid to generate a radical can also be used. The aryl borate compound is not particularly limited as long as it is a compound having at least one boron-aryl bond in the molecule, and known compounds can be used, but among them, three in one molecule are considered in view of storage stability. Alternatively, an aryl borate compound having four boron-aryl bonds is preferably used, and an aryl borate compound having four boron-aryl bonds is more preferable from the viewpoint of easy handling, synthesis, and availability. Two or more of these aryl borate compounds may be used in combination.

As the acidic compound, an acidic group-containing radical polymerizable monomer can be preferably used, and at least one acidic group in one molecule, or an acid anhydride structure in which two of the acidic groups are condensed by dehydration, or an acidic group Any known compound can be used as long as it is a compound having an acid halide group in which the hydroxyl group is substituted with halogen and at least one radically polymerizable unsaturated group. Here, the acidic group is a group in which an aqueous solution or a suspension of a radical polymerizable monomer having the group exhibits acidity. Examples of the acidic group include a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phosphinico group {═P (═O) OH}, a phosphono group {—P (═O) (OH) ₂ }, and the like. In addition, examples in which these groups are acid anhydrides or acid halides are exemplified. Specific examples of such an acidic group-containing radical polymerizable monomer are as exemplified in the radical polymerizable monomer.

  Further, it is also preferable to use a combination of an organic peroxide and / or a transition metal compound in addition to such an aryl borate compound / acidic compound polymerization initiator. The organic peroxide is as described above. The transition metal compound is preferably a + IV and / or + V vanadium compound.

  Furthermore, examples of preferred chemical polymerization initiators include (x) pyrimidinetrione derivatives (for example, 1-cyclohexyl-5-methylpyrimidinetrione, 1-cyclohexyl-5-ethylpyrimidinetrione, etc.), (y) halogen ions Forming compounds (eg dilauryldimethylammonium chloride, lauryldimethylbenzylammonium chloride, benzyltrimethylammonium chloride, etc.) and (z) cupric or ferric ion forming compounds (eg acetylacetone copper, cupric acetate, olein) And a combination thereof (such as acid copper and iron acetylacetone). This chemical polymerization initiator system is less likely to cause discoloration after curing, and is particularly preferable as a catalyst system when the curable composition of the present invention is used for the purpose of a dental restoration material.

  As the photopolymerization initiator, α-diketones are preferable from the viewpoints of good polymerization activity and low harm to the living body. When α-diketone is used, it is preferably used in combination with a tertiary amine compound. These photopolymerization initiators may be used alone or in combination of two or more. Each of the above polymerization initiators can be used not only alone but also in combination of a plurality of types as required.

  When the polymerizable monomer and the organic polymer for supporting a pigment are combined as follows, the dispersibility of the pigment is improved when the powder material and the liquid material are mixed. The polymerizable monomer is mainly composed of methyl (meth) acrylate, and the pigment-supporting organic polymer is polyethyl (meth) acrylate. Disperse more uniformly. Here, the polymerizable monomer having methyl (meth) acrylate as a main component is one that occupies at least 50 mol% of the polymerizable monomer and contains methyl (meth) acrylate, and further polymerizes. It is preferable that methyl (meth) acrylate is contained in at least 80 mol% of the polymerizable monomer, and it is most preferable that substantially all of the polymerizable monomer is methyl (meth) acrylate. Similarly, in the case where the polymerizable monomer is mainly composed of methyl (meth) acrylate, the organic polymer for pigment support is a copolymer of methyl (meth) acrylate and ethyl (meth) acrylate. , A copolymer having a higher molar ratio of ethyl (meth) acrylate, more preferably a copolymer in which the molar ratio of ethyl (meth) acrylate accounts for 60% or more, particularly preferably ethyl (meth) acrylate. The dissolution rate of the organic polymer for pigment support, which is a copolymer having a molar ratio of 80% or more, becomes higher, and the pigment is more uniformly dispersed.

(6) Others (6.1) Plasticizer The plasticizer is not particularly limited, and those usually used in the dental field can be used. Typical examples are dimethyl phthalate, diethyl phthalate, dibudyl phthalate, diheptyl phthalate, dioctyl phthalate, diisodecyl phthalate, butyl benzyl phthalate, diisononyl phthalate, ethyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, etc. Phthalate esters, dibutyl adipate, dibutyl diglycol adipate, dibutyl sebacate, dioctyl sebacate, dibutyl maleate, dibutyl fumarate and other dibasic acid esters, glycerol triacetate and other glycerin esters, tributyl phosphate, tributyl phosphate And phosphate esters such as octyl phosphate and triphenyl phosphate. Among the above esters, the aliphatic esters are preferably those having 1 to 12 carbon atoms, and more preferably 1 to 8 carbon atoms. In particular, among the plasticizers described above, phthalate esters are preferred. These plasticizers can be used alone or in combination of two or more as required.

(6.2) Ultraviolet Absorber / Polymerization Inhibitor A known ultraviolet absorber may be further added to the dental restorative material according to the embodiment of the present invention to prevent discoloration with respect to ultraviolet rays. In order to improve storage stability, it is also preferable to add a known polymerization inhibitor.

  Next, examples of the present invention will be described in comparison with comparative examples. However, the present invention is not limited to the following examples.

  Various materials used in the following examples and comparative examples, and evaluation methods of solubility of the organic polymer supporting the pigment in the polymerizable monomer and pigment dispersibility are as follows.

1. 1. Powder Material 1.1 Organic Polymer Organic polymers include ethyl (meth) acrylate (EMA) and methyl (meth) acrylate (MMA) copolymer (referred to as EMA-MMA copolymer), polyethyl (meth) acrylate ( PEMA) and polybutyl (meth) acrylate (PBMA) were used. A total of nine types of EMA-MMA copolymers, PEMA and PBMA shown below were used.

(1) ME10-110L
EMA-MMA copolymer having a mass average molecular weight of 250,000, an average particle size of 110 μm, and an EMA / MMA ratio of 10/90 (2) ME50-80
EMA-MMA copolymer having a mass average molecular weight of 500,000, an average particle size of 80 μm, and an EMA / MMA ratio of 50/50 (3) ME50-30
EMA-MMA copolymer having a mass average molecular weight of 500,000, an average particle size of 30 μm, and an EMA / MMA ratio of 50/50 (4) ME60-45L
EMA-MMA copolymer having a mass average molecular weight of 250,000, an average particle diameter of 45 μm, and an EMA / MMA ratio of 60/40 (5) ME80-45LL
EMA-MMA copolymer having a mass average molecular weight of 125,000, an average particle diameter of 45 μm, and an EMA / MMA ratio of 80/20 (6) E70
PEMA having a mass average molecular weight of 500,000 and an average particle size of 70 μm
(7) E35
PEMA having a mass average molecular weight of 500,000 and an average particle size of 35 μm
(8) E10
PEMA having a mass average molecular weight of 500,000 and an average particle size of 10 μm
(9) B30
PBMA having a mass average molecular weight of 500,000 and an average particle size of 30 μm

1.2 Pigment Master A total of four types of pigment masters, the following white pigment master, red pigment master, yellow pigment master, and blue pigment master, were prepared and used as part of the constituent material of the powder material.
(1) White pigment master One type of the above-mentioned organic polymer (this organic polymer is referred to as “organic pigment-supporting polymer” because it supports a pigment on it) and titania (Ishihara Sangyo Co., Ltd.) which is a pigment. Product name: CR-50) 5 g and silica filler (0.15 g, manufactured by Tokuyama Co., Ltd., 0.15 g) together with 500 g of alumina balls having a diameter of about 10 mm and an alumina pot with an internal volume of 400 ml And mixed for 6 hours in a dry manner to prepare a white pigment master.
(2) Red pigment master 49.5 g of pigment-supporting organic polymer, 0.5 g of pigment chromoftal red BRN (manufactured by Nagase Sangyo Co., Ltd.) and silica (manufactured by Tokuyama Co., Ltd., trade name: DM) as an inorganic filler -30) 0.15 g was put together with 500 g of alumina balls having a diameter of about 10 mm into an alumina pot having an internal volume of 400 ml and mixed in a dry manner for 6 hours to prepare a red pigment master.
(3) Yellow Pigment Master 49.5 g of pigment-supporting organic polymer, 0.5 g of pigment chromophthal yellow GR (manufactured by Nagase Sangyo Co., Ltd.), and silica as an inorganic filler (manufactured by Tokuyama Co., Ltd., trade name: DM) -30) 0.15 g was put together with 500 g of alumina balls having a diameter of about 10 mm into an alumina pot having an internal volume of 400 ml and mixed in a dry method for 6 hours to prepare a yellow pigment master.
(4) Blue pigment master 49.5 g of pigment-supporting organic polymer, 0.5 g of pigment chromophthal blue A3R (manufactured by Nagase Sangyo Co., Ltd.), and silica as an inorganic filler (manufactured by Tokuyama Co., Ltd., trade name: DM) -30) 0.15 g was placed in an alumina pot having an internal volume of 400 ml together with 500 g of alumina balls having a diameter of about 10 mm and mixed in a dry method for 6 hours to prepare a blue pigment master.

1.3 Inorganic filler Silica (trade name: DM-30, manufactured by Tokuyama Corporation) was used as the inorganic filler.

1.4 Polymerization initiator As a polymerization initiator put into the powder material side, benzoyl peroxide, 1-cyclohexyl-5-methylpyrimidinetrione, and acetylacetone copper were used.

1.5 Production method of powder material Plural types of organic polymers (total 100 g), pigment master (in the case of white pigment master 5 g, and four types of pigment master (the total of four types may be 12 g)), Silica (0.1 g or 0.3 g) and one or two kinds of polymerization initiators (total of about 2 g) were mixed in a rocking mixer to prepare a powder material.

2. 2. Liquid Material 2.1 Polymerizable Monomer Three types of methyl (meth) acrylate (MMA), acetoacetoxyethyl methacrylate, and a combination of propionoxyethyl methacrylate and triethylene glycol dimethacrylate were used.

2.2 Polymerization initiator As a polymerization initiator put on the liquid material side, N, N-dimethyl-p-toluidine, N, N-diethanol-p-toluidine, and dilauryldimethylammonium chloride were used.

2.3 Production method of liquid material 1 or 2 kinds of polymerizable monomers (100 g in total) and a polymerization initiator (0.3 g or 1.5 g) are put in a container, and 1 using a stirrer stirrer. The liquid material was produced by stirring for a time.

3. Method for evaluating solubility of organic polymer for pigment support Into a glass sample tube with an internal volume of 20 mm of φ27 mm × 55 mm, 10 g of a polymerizable monomer and 200 mg of an organic polymer for pigment support were placed, and at a liquid temperature of about 23 ° C., The mixture was stirred for 3 minutes at a rotation speed of 300 rpm. Subsequently, 1 g was taken out from the mixed solution after stirring, and centrifuged at a rotational speed of 15000 rpm for 10 minutes. The mass of the precipitate after centrifugation was measured, and the proportion of the pigment-supporting organic polymer dissolved in the polymerizable monomer was determined. Specifically, the dissolution rate (% by weight) was determined by the formula of (200 mg-precipitate) × 100/200 mg.

4). Pigment dispersibility evaluation method A brush tip containing a liquid material was brought into contact with a powder material by a writing method to prepare a resin mud, and the resin mud was pressed with a polypropylene sheet. The weight ratio (powder-liquid ratio) between the liquid material and the powder material constituting the resin mud was determined from the respective reduced amounts of the liquid material and the powder material by the implementation of the writing method. After the resin pressure-contacted with the polypropylene sheet was cured, the thickness of the cured resin was measured with a micrometer. The thickness of the cured body of each resin was set to 0.3 mm. The dispersibility of the pigment in the cured resin was measured at four points using a color difference meter (trade name: TC-1800MKII, manufactured by Tokyo Denshoku Co., Ltd.), and the degree of color variation between the points (standard deviation) Value). When only a white pigment was used, the standard deviation value of Yb / Yw (described later) was determined to be 0.080 or less. Further, when a white pigment and a pigment of other colors were mixed and used, the standard deviation value of ΔE * (described later) was 2 or less.

  Next, the evaluation results of each example will be described in comparison with a comparative example.

1. Examples 1 to 5, Comparative Examples 1 and 2
Table 1 shows each constituent material constituting the powder material and liquid material of the dental restoration material in Examples 1 to 5 and Comparative Examples 1 and 2. Table 2 shows the characteristics of the pigment-supporting organic polymers used in Examples 1 to 5 and Comparative Examples 1 and 2, and the pigment dispersion characteristics of the cured resin using each of the pigment-supporting organic polymers.

  EMA / MMA in Table 2 indicates the molar ratio of EMA and MMA constituting the polymer. In Table 2, Mw and Dav. Indicates mass average molecular weight and average particle diameter, respectively. Yb in Table 2 is a parameter that determines the relative luminance of the background in a color appearance model called CIECAM97s, which is a standard of the International Commission on Illumination (CIE). Yw in Table 2 is one of the parameters for determining the adaptive white stimulus value in the model. Therefore, Yb / Yw is a parameter indicating the color tone of white. The average value and standard deviation in Table 2 indicate the average value of Yb / Yw and the degree of variation thereof at the four measurement points, respectively.

  As shown in Table 1, in Examples 1 to 5 and Comparative Examples 1 and 2, a mixture of ME10-110L, ME50-80, and ME60-45L was used as the organic polymer not carrying the pigment in the powder material. . As shown in Table 2, the pigment-supporting organic polymer in Table 1 includes E10 (Example 1), E35 (Example 2), ME80-45LL (Example 3), and ME60-45L (Example 4). ME50-30 (Example 5), ME50-80 (Comparative Example 1) and ME10-110L (Comparative Example 2) were used. MMA was used for the polymerizable monomer which is the main component of the liquid material. Other constituent materials are as shown in Table 1.

  As is clear from the relationship between the respective dissolution rates of Examples 1 to 5 and the respective standard deviations, when the dissolution rate of each pigment-supporting organic polymer is 43.2% by weight or more, the standard deviation is 0.042 or less, It was found that a resin cured body with extremely low color unevenness can be obtained. On the other hand, in the case of Comparative Example 1 and Comparative Example 2, ME50-80 and ME10-110L, which are difficult to dissolve in MMA constituting the liquid material, were used as the pigment-supporting organic polymers, respectively, so that the standard deviation was 0.098 or more. As a result, only a cured resin having uneven color was obtained. Here, ME50-30 and ME50-80 are EMA / MMA copolymers of EMA / MMA = 50/50 that differ only in the average particle diameter. Although the resin cured product using ME50-30 has a significantly lower color unevenness than that using ME50-80, the MMA having a smaller average particle diameter is the same type of copolymer. It is considered that the solubility in water is high and the color unevenness is low.

  Moreover, in Table 2, the tendency for the dissolution rate (% by weight) to decrease from Example 1 to Comparative Example 2 was observed as the ratio of EMA from Example 1 to Comparative Example 2 decreased. From this result, when MMA is used as the polymerizable monomer, it is considered that the use of a pigment-supporting organic polymer having a large EMA ratio increases the solubility and improves the dispersibility of the pigment.

2. Examples 6 to 10 and Comparative Examples 3 and 4
In Table 3, each constituent material which comprises the powder material and liquid material of the dental restoration material in Examples 6-10 and Comparative Examples 3 and 4 is shown. Table 4 shows the characteristics of the pigment-supporting organic polymers used in Examples 6 to 10 and Comparative Examples 3 and 4, and the pigment dispersion characteristics of the cured resin bodies using the pigment-supporting organic polymers.

  L *, a * and b * in Table 4 are each an L * a * b * color system that is one of the uniform color spaces defined by CIE (in Japan, it is standardized by JIS Z8729). These parameters. L * is the brightness index. a * and b * are chromaticness indices (chromaticity coordinates) that determine hue and saturation, respectively. ΔE * and standard deviation in Table 4 indicate the color difference and the degree of variation of the color difference, respectively.

  As shown in Table 3, in Examples 6 to 10 and Comparative Examples 3 and 4, a mixture of ME10-110L, ME50-80, and ME60-45L was used as the organic polymer not supporting the pigment in the powder material. . As the pigment master, four types of white pigment master, red pigment master, yellow pigment master and blue pigment master shown in Table 3 were mixed and used. In addition, as shown in Table 4, E10 (Example 6), E35 (Example 7), ME80-45LL (Example 8), and ME60 are included in the pigment-supporting organic polymer in each pigment master in Table 3. -45L (Example 9), ME50-30 (Example 10), ME50-80 (Comparative Example 3) and ME10-110L (Comparative Example 4) were used. MMA was used for the polymerizable monomer which is the main component of the liquid material. Other constituent materials are as shown in Table 3.

  As is clear from the relationship between each dissolution rate of Examples 6 to 10 and each standard deviation, when the dissolution rate of each pigment-supporting organic polymer is 43.2% by weight or more, the standard deviation is 1.063 or less. It was found that a resin cured body with low color unevenness can be obtained. On the other hand, in the case of Comparative Example 3 and Comparative Example 4, ME50-80 and ME10-110L, which are difficult to dissolve in MMA constituting the liquid material, were used as the pigment-supporting organic polymers, respectively, so that the standard deviation was 2.665 or more. As a result, only a cured resin having uneven color was obtained. Here, although ME50-30 and ME50-80 are the same type of copolymer, the resin cured product using ME50-30 has a significantly lower color unevenness than that using ME50-80. From this, it can be considered that the smaller the average particle diameter, the higher the solubility in MMA, and the lower the color unevenness.

  Moreover, in Table 4, the tendency for the dissolution rate (% by weight) to decrease from Example 6 to Comparative Example 4 was observed as the ratio of EMA from Example 6 to Comparative Example 4 decreased. From this result, when MMA is used as the polymerizable monomer, it is considered that the use of a pigment-supporting organic polymer having a large EMA ratio increases the solubility and improves the dispersibility of the pigment.

3. Examples 11 and 12, Comparative Examples 5 and 6
Table 5 shows each constituent material constituting the powder material and liquid material of the dental restoration material in Examples 11 and 12 and Comparative Examples 5 and 6. Table 6 shows the characteristics of the pigment-supporting organic polymers used in Examples 11 and 12 and Comparative Examples 5 and 6, and the pigment dispersion characteristics of the cured resin using each of the pigment-supporting organic polymers. In Example 11 in Table 6, BMA = 100 indicates that the pigment-supporting organic polymer is an organic polymer composed only of butyl (meth) acrylate (BMA).

  As shown in Table 5, in Examples 11 and 12 and Comparative Examples 5 and 6, a mixture of E70 and E35 was used as the organic polymer not supporting the pigment in the powder material. As shown in Table 6, B30 (Example 11), E10 (Example 12), E35 (Comparative Example 5), and ME80-45LL (Comparative Example 6) are used for the pigment-supporting organic polymers in Table 5. It was. As a polymerizable monomer constituting the liquid material, acetoacetoxyethyl methacrylate (AAEM) was used. Other constituent materials are as shown in Table 5.

  As is clear from the relationship between the respective dissolution rates of Examples 11 and 12 and the respective standard deviations, the standard deviation is 0.021 or less when the solubility rate of each pigment-supporting organic polymer is 63.2% by weight or more. Thus, it was found that a resin cured body with extremely low color unevenness can be obtained. On the other hand, in the case of Comparative Example 5 and Comparative Example 6, since E35 and ME80-45LL, which are difficult to dissolve in AAEM as the main component of the liquid material, were used as the pigment-supporting organic polymers, the standard deviation was 0.083 or more. As a result, only a cured resin having uneven color was obtained. Here, E10 and E35 are PEMA which differ only in average particle diameter. Although the resin cured body using E10 has a significantly lower color unevenness than that using E35, although it is the same type of organic polymer, the smaller the average particle diameter, the more soluble in AAEM. It is considered that the color unevenness has decreased due to the increase.

4). Examples 13 to 15 and Comparative Example 7
In Table 7, each constituent material of the powder material and liquid material of the dental restorative material in Examples 13 to 15 and Comparative Example 7 is shown. Table 8 shows the characteristics of the pigment-supporting organic polymers used in Examples 13 to 15 and Comparative Example 7, and the pigment dispersion characteristics of the cured resin using each of the pigment-supporting organic polymers.

  As shown in Table 7, in Examples 13 to 15 and Comparative Example 7, a mixture of E70 and E35 was used for the organic polymer not supporting the pigment in the powder material. As shown in Table 8, B30 (Example 13), E10 (Example 14), E35 (Example 15) and ME80-45LL (Comparative Example 7) are used for the organic polymer for pigment support in Table 7. It was. A mixture of propionoxyethyl methacrylate and triethylene glycol dimethacrylate was used as the polymerizable monomer as the main component of the liquid material. Other constituent materials are as shown in Table 7.

  As is clear from the relationship between each dissolution rate of Examples 13 to 15 and each standard deviation, when the dissolution rate of each pigment-supporting organic polymer is 62.1% by weight or more, the standard deviation is 0.055 or less. It was found that a resin cured body with low color unevenness can be obtained. On the other hand, in the case of Comparative Example 7, ME80-45LL, which is difficult to dissolve in the mixed monomer of propionoxyethyl methacrylate and triethylene glycol dimethacrylate, which are the main components of the liquid material, was used as the pigment-supporting organic polymer. The standard deviation was 0.095, and only a cured resin product having color unevenness was obtained. Here, E10 and E35 are PEMA which differ only in average particle diameter. Although the resin cured product using E10 has a relatively lower color unevenness than that using E35, the smaller the average particle diameter, the smaller the average particle size and propionoxyethyl methacrylate. It is considered that the color unevenness was lowered because the solubility in the mixed monomer with triethylene glycol dimethacrylate was increased.

  As is clear from the above examples, even when the pigment-supporting organic polymer was the same, the solubility changed and the dispersibility of the pigment changed when the polymerizable monomer constituting the liquid material changed. It was found that when the dissolution rate of the pigment-supporting organic polymer in the polymerizable monomer was 40% by weight or more, the color unevenness in the cured resin was low, and a good dental restoration material was obtained.

  The dental restorative material according to the present invention is a dental normal temperature polymerization resin used for denture repair, temporary teeth, etc., dental cement used for temporary fixation of swing teeth, etc., and rebase that is a denture repair material It can be used as a material, or a temporary sealing material temporarily packed in teeth between treatments.

Claims (3)

(A) liquid material containing methyl (meth) acrylate,
(B) a powder material containing (B) an organic polymer that dissolves in the liquid material (A), and
A polymerization initiator (c) contained in at least one of the liquid material (A) or the powder material (B);
In dental restorative materials including
(B) at least a part of the organic polymer,
Carrying pigments,
After adding 2 parts by mass to 100 parts by mass of the methyl (meth) acrylate and stirring for 3 minutes at a liquid temperature of 23 ° C. at a rotation speed of 300 rpm, the dissolution rate in the polymerizable monomer is 40% by weight. (B1) an organic polymer for supporting a pigment,
(B1) The pigment-supporting organic polymer is polyethyl (meth) acrylate, a copolymer of methyl (meth) acrylate and ethyl (meth) acrylate (provided that the molar ratio of ethyl (meth) acrylate is 60% or more) And a copolymer of methyl (meth) acrylate and ethyl (meth) acrylate (provided that the molar ratio of ethyl (meth) acrylate occupies 50% or more and less than 60%, and the average particle size is A dental restorative material, characterized in that it is a material selected from the group consisting of: (A) liquid material containing acetoacetoxyethyl methacrylate;
(B) a powder material containing (B) an organic polymer that dissolves in the liquid material (A), and
A polymerization initiator (c) contained in at least one of the liquid material (A) or the powder material (B);
In dental restorative materials including
(B) at least a part of the organic polymer,
Carrying pigments,
After adding 2 parts by mass with respect to 100 parts by mass of the acetoacetoxyethyl methacrylate and stirring for 3 minutes at a rotation speed of 300 rpm and a liquid temperature of 23 ° C., the dissolution rate in the polymerizable monomer is 40% by weight or more. (B1) an organic polymer for supporting a pigment,
The dental restoration characterized in that the organic polymer for pigment support (b1) is a material selected from the group consisting of polybutyl (meth) acrylate and polyethyl (meth) acrylate having an average particle diameter of 10 μm or less. Wood. (A) a liquid material containing propionoxyethyl methacrylate and triethylene glycol dimethacrylate,
(B) a powder material containing (B) an organic polymer that dissolves in the liquid material (A), and
A polymerization initiator (c) contained in at least one of the liquid material (A) or the powder material (B);
In dental restorative materials including
(B) at least a part of the organic polymer,
Carrying pigments,
2 parts by mass are added to 100 parts by mass of the total amount of propionoxyethyl methacrylate and triethylene glycol dimethacrylate, and the mixture is stirred for 3 minutes at a liquid temperature of 23 ° C. at a rotation speed of 300 rpm. (B1) an organic polymer for supporting a pigment having a solubility in a polymer of 40% by weight or more,
(B1) A dental restorative material, wherein the pigment-supporting organic polymer is a material selected from the group consisting of polybutyl (meth) acrylate and polyethyl (meth) acrylate.