Dental hardening composition

Abstract

To provide a dental curable composition applicable to natural teeth in a variety of tones only with a single-colored filling and restorative material, in the restoration of various parts of teeth such as cavities and incisal angles.SOLUTION: Provided is a dental curable composition comprising: (A) an amorphous composite metal oxide filler containing SiO2, ZrO2 and Al2O3; (B) a spherical SiO2 filler with an average particle diameter of 50 nm or less; (C) a (meth)acrylate polymerizable monomer; and (D) a coloring material, a blending ratio (mass ratio) of the SiO2 filler (B) and the composite metal oxide filler (A) being 1: 0.8 to 1: 8, the transmittance (Tt) of a cured body with a thickness of 1 mm after polymerization and curing of the curable composition being 52 or more and 66 or less, the turbidity (haze value) being 85 or more and 98 or less, and in a L*a*b* color system, the L* value being 70 or more and 77 or less, a* value being -0.5 or more and 1.5 or less, and b* value being 11 or more and 19 or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a dental curable composition.

Background Art

[0002] Conventionally, as a curable composition used for repairing teeth damaged by dental caries, fracture, etc., there is known one using a structural color exhibited by interference, diffraction, refraction, scattering, etc. of light of spherical fillers to be blended (for example, Patent Document 1 and Patent Document 2). Patent Document 1 discloses a curable composition containing a polymerizable monomer component (A), a spherical filler (B) having an average particle diameter in the range of 230 nm to 1000 nm, and a polymerization initiator (C). In a state where a cured body having a thickness of 1 mm is formed, the lightness (V) of the measured value in the Munsell color system of the colored light under a black background, measured using a color difference meter, is less than 5, the chroma (C) is 0.05 or more, and the lightness (V) of the measured value in the Munsell color system under a white background is 6 or more, and the chroma (C) is less than 2. A curable composition is described.

[0003] Patent Document 2 discloses a dental curable composition comprising a polymerizable monomer component (A), an inorganic spherical filler (B) having an average primary particle diameter in the range of 100 nm or more and 1000 nm or less, and in which 90% or more of the total number of particles in the number-based particle size distribution is present in the range of ±5% of the average primary particle diameter, an amorphous inorganic filler (C) having an average particle diameter in the range of 100 nm or more and 1000 nm or less, and a polymerization initiator (D), wherein the refractive index of the inorganic spherical filler (B) at 25°C: n FB is greater than the refractive index of the polymer obtained by polymerizing the polymerizable monomer component (A) at 25°C: n p is described.

[0004] Since the curable compositions described in Patent Documents 1 and 2 utilize light colored by structural color, they can harmonize with the shades of natural teeth without using coloring substances such as pigments and enable restoration that continues to harmonize with natural teeth over a long period. Furthermore, since the curable composition described in Patent Document 2 has appropriate opacity, in the restoration of anterior tooth defects, particularly Class III cavities (adjacent surface cavities of anterior teeth that do not include the incisal corner) or Class IV cavities (adjacent surface cavities of anterior teeth that include the incisal corner) that do not contain dentin in the deeper layer, high color tone compatibility can be obtained without using a composite resin (CR) for the base.

[0005] However, the curable compositions described in Patent Documents 1 and 2 need to exhibit structural color, and since the particle size, refractive index, shape, and blending ratio of spherical and amorphous inorganic fillers are limited, the degree of freedom in composition design is low and composition design is difficult. For this reason, there is a need for a technique that can harmonize with the shades of natural teeth using only a single-color filling restoration material through color tone design using coloring materials such as pigments without using the technique of exhibiting structural color and can harmonize with natural teeth in the restoration of Class III or Class IV cavities without using a CR for the base.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide a dental curable composition that can be made compatible with natural teeth of various color tones using only a single-color filling restoration material in the restoration of various parts of teeth such as cavities and incisal corners.

Means for Solving the Problems

[0008] As a result of intensive studies to solve the above problems, the present inventors have found that the dental curable composition shown below can achieve the above object, and have completed the present invention.

[0009] That is, the present invention is as follows. Item 1. (A) An amorphous composite metal oxide filler containing SiO2, ZrO2 and Al2O3, (B) A spherical SiO2 filler having an average particle diameter of 50 nm or less, (C) A (meth)acrylate-based polymerizable monomer, and (D) A colorant A dental curable composition containing: The mixing ratio (mass ratio) of the (B) SiO2 filler and the (A) composite metal oxide filler is 1:0.8 to 1:8, The transmittance (Tt) of a cured body having a thickness of 1 mm after polymerization curing of the curable composition is 52 or more and 66 or less, The haze value is 85 or more and 98 or less, L * a * b * In the color system The L * value (lightness) is 70 or more and 77 or less, The a * value (chromaticity) is -0.5 or more and 1.5 or less, and The b * value (chromaticity) is 11 or more and 19 or less, a dental curable composition. Item 2. The dental curable composition according to Item 1, wherein the (D) colorant contains at least one selected from the group consisting of a red pigment, a yellow pigment, a black pigment, and a white pigment. Item 3. As the (D) colorant, a red pigment, a yellow pigment, a black pigment, and a white pigment are included, and their contents are The amorphous composite metal oxide filler containing the (A) SiO2, ZrO2 and Al2O3, the spherical SiO2 filler with an average particle diameter of 50 nm or less for (B), and with respect to 100 parts by mass in total of the (meth)acrylate polymerizable monomer for (C), the red pigment is 0.0003 to 0.0009 parts by mass, the yellow pigment is 0.0004 to 0.0011 parts by mass, the black pigment is 0.0003 to 0.003 parts by mass, and the white pigment is 0.05 to 0.18 parts by mass, the dental curable composition according to item 1 or 2. Item 4. The opal value of the cured body with a thickness of 1 mm after polymerization curing of the dental curable composition is 10 or more and 23 or less, the dental curable composition according to any one of items 1 to 3. Item 5. The color tone of the tooth color reference pellet with a diameter of 15 mm and a thickness of 1 mm corresponding to the color tones from A1 to A4 of the shade guide used as the tooth color standard, and The color tone of the cured body with a diameter of 15 mm and a thickness of 1 mm after polymerization curing of the dental curable composition and the color tone of the cured body when the cured body is overlaid on the tooth color reference pellet, The color difference (ΔE) is 10.5 or less, the dental curable composition according to any one of items 1 to 4. Item 6. The ratio (Y W / Y B : contrast ratio) of the Y value (Y B ) of the cured body with a thickness of 1 mm after polymerization curing of the dental curable composition on a white background to the Y value (Y W ) on a black background is 0.43 or more and 0.58 or less, the dental curable composition according to any one of items 1 to 5. Item 7. The dental curable composition is formed into a disc shape with a diameter of 12 mm and a thickness of 1 mm, and a cut is made with a metal plate with a thickness of 1 mm to divide the dental curable composition into two halves, When left standing at 37°C, the divided dental curable composition is deformed, and the time until the divided dental curable compositions come into contact with each other is 300 seconds or more, the dental curable composition according to any one of items 1 to 6. Item 8. The dental curable composition according to any one of items 1 to 7, wherein 0.65 g of the dental curable composition is formed into a sphere, a weight of 3.25 kg is placed thereon, and the elongation rate (consistency) when allowed to stand for 60 seconds is 160% or more. Item 9. The dental curable composition according to any one of items 1 to 8, which is a paste. Item 10. The dental curable composition according to any one of items 1 to 9, wherein the (A) composite metal oxide filler is a filler comprising secondary particles having an average particle size of 2 to 8 μm in which primary particles having an average particle size of 0.1 to 0.9 μm are partially bonded by sintering. Item 11. A cured body obtained by polymerizing and curing the dental curable composition according to any one of items 1 to 10. Item 12. A dental material obtained by polymerizing and curing the dental curable composition according to any one of items 1 to 10.

Advantages of the Invention

[0010] According to the present invention, it is possible to provide a dental curable composition that can be matched with natural teeth of various color tones using only a single-color filling and restorative material in the restoration of various parts of teeth such as cavities and incisal corners. Further, the dental curable composition of the present invention is excellent in the shape retention of the crown form, has high operability, and can easily form the crown shape of anterior tooth defects, posterior teeth, etc.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

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Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0012] The dental curable composition of the present invention will be described in detail below.

[0013] 1. Dental curable composition The dental curable composition of the present invention contains (A) an amorphous composite metal oxide filler containing SiO2, ZrO2, and Al2O3, (B) a spherical SiO2 filler having an average particle diameter of 50 nm or less, (C) a (meth)acrylate-based polymerizable monomer, and (D) a coloring material. The blending ratio (mass ratio) of the (B) SiO2 filler to the (A) composite metal oxide filler is 1:0.8 to 1:8. The transmittance (Tt) after polymerization curing of the curable composition is 52 or more and 66 or less. The haze value is 85 or more and 98 or less. L * a * b * In the color system, the L * value is 70 or more and 77 or less, the a * value is -0.5 or more and 1.5 or less, and the b * value is 11 or more and 19 or less. Thus, the dental curable composition of the present invention can be made compatible with natural teeth of various color tones using only a single-color filling and restorative material in the restoration of various parts of teeth such as cavities and incisal corners.

[0014] The dental curable composition of the present invention can also be referred to as a dental filling material, a dental filling and restorative material, a dental composite resin, etc. Further, the material can also be referred to as an agent.

[0015] Each component incorporated into the dental curable composition of the present invention will be described below.

[0016] (A) Amorphous composite metal oxide filler containing SiO 2 , ZrO 2 and Al2 O 3 Method for producing the composite metal oxide filler The dental curable composition of the present invention contains, as an essential component, an amorphous composite metal oxide filler (hereinafter sometimes referred to as "component A" or "composite metal oxide filler") containing SiO2, ZrO2 and Al2O3.

[0017] The composite metal oxide filler is preferably a filler that is secondary particles with an average particle size of 2 to 8 μm in which primary particles with an average particle size of 0.1 to 0.9 μm are partially bonded by sintering. Note that amorphous means that the shape of the primary particles observed by SEM (Scanning Electron Microscope) has a large number of irregular corners and surfaces. Also, the amorphous composite metal oxide filler means a filler composed of particles obtained by crushing or pulverizing.

[0018] The content of the composite metal oxide filler in the dental curable composition is usually 10 to 80% by mass, preferably 20 to 75% by mass, and more preferably 25 to 70% by mass. Only one type of the composite metal oxide filler can be used, or two or more different composite metal oxide fillers can be mixed.

[0019] The composite metal oxide filler, that is, the aggregated secondary particles in which the sintered primary particles are bonded, is produced through a process of finely pulverizing particles composed of a porous SiO2 - Al2O3 - ZrO2 amorphous body prepared by the sol - gel method to obtain gel fine particles, a process of aggregating the gel fine particles, and a process of firing the aggregate. By this firing, the primary particles are sufficiently sintered, but secondary particles with weak bonding between the sintered primary particles are formed, and this is the composite metal oxide filler used in the present invention. The dental curable composition of the present invention is imparted with great flexural strength by containing a filler (secondary particles, average particle size = 2 to 8 μm) in which primary particles having an average particle size of about 0.1 to 0.9 μm are bonded. The surface of the filler (secondary particles) has irregularities, and a polymerization monomer enters and cures in these irregularities, resulting in a fitting effect (also referred to as an anchor effect), which is considered to increase the mechanical strength.

[0020] The filler used in the present invention is SiO2 - Al2O3 - ZrO2 - based gel fine powder particles (primary particles after sintering). After drying, it is fired at a high temperature, so the surface of the primary particles is sufficiently sintered. For this reason, its specific surface area is small, and the dental curable composition using this filler has a small water absorption rate and excellent durability under wet conditions such as in the oral cavity.

[0021] (B) Spherical SiO with an average particle diameter of 50 nm or less The composite metal oxide filler used in the present invention comprises a step (A1 step) of coprecipitating and drying a mixture of an alkoxysilane, a hydrolyzable zirconium compound, and a hydrolyzable aluminum compound by the sol - gel method to form a gel body, a step (A2 step) of pulverizing the gel body into fine particles (primary particles), and a step (A3 step) of forming secondary particles by firing the primary particles. Optionally, it can be produced by a method comprising a step (A4 step) of surface - treating with a silane coupling agent.

[0022] Specifically, in the A1 step, an alkoxysilane, a hydrolyzable aluminum compound, and a hydrolyzable zirconium compound are uniformly mixed in a solvent to prepare a solution containing 50 to 95% by mass of SiO2 (preferably 60 to 85% by mass), 0.1 to 30% by mass of ZrO2 (preferably 10 to 20% by mass), and 0.1 to 30% by mass of Al2O3 (preferably 0.3 to 10% by mass). An alkaline solution is mixed to simultaneously hydrolyze each component, and gel particles of the reaction product are precipitated.

[0023] Among the compositions of the composite metal oxide filler in the present invention, the refractive index (nD) of SiO2 is 1.46, that of ZrO2 is 2.2, and that of Al2O3 is 1.76. Depending on the content of each component, the refractive index (nD) of the composite metal oxide filler changes substantially according to the additive rule. Further, in order to impart X-ray contrast in dental materials, a ZrO2 component can be contained. In addition, although it is possible to introduce components such as TiO2, CeO2, and Y2O3 that increase the refractive index (nD) of the composite metal oxide filler, it is desirable to keep the amount to 3% by mass or less with respect to the total weight of the final filler.

[0024] Here, the alkoxysilane is not particularly limited. For example, a tetraalkoxysilane compound represented by the general formula: Si(OR)4 (R represents an alkyl group, preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, etc.); a partial hydrolysis oligomer of tetraalkoxysilane, etc. can be mentioned. Among them, as the alkoxysilane, ethoxysilane, methoxysilane, methyl silicate oligomer (SiO2 content = 52 wt%, (CH3O) 10 Si4 = about tetramer, MS51 manufactured by Mitsubishi Chemical Corporation) is preferable, and methyl silicate oligomer is more preferable in terms of being inexpensive and easy to handle.

[0025] The hydrolyzable aluminum compound is not particularly limited. For example, aluminum salts such as inexpensive and easily thermally decomposed Al nitrate (Al(NO3)3), Al acetate (Al(OAc)3), and Al acetylacetonate salt; trialkoxyaluminum compounds represented by Al(OR)3 (R represents an alkyl group, preferably an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, etc.) can be mentioned. The aluminum salt can usually be used as an aqueous solution.

[0026] Examples of hydrolyzable zirconium compounds include tetrazirconium compounds represented by the general formula: Zr(OR')4 (where R' represents an alkyl group, preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, etc.); ZrO(NO3)2·nH2O; ZrOCl2·nH2O, etc. Among them, ZrO(NO3)2·nH2O or ZrOCl2·nH2O and ZrO(NO3)2·nH2O are preferred. n represents an integer from 1 to 10.

[0027] As a specific production method of the composite metal oxide filler, aluminum nitrate (Al(NO3)3·9H2O) is dissolved in water or alcohol, and a zirconium compound (for example, an aqueous solution of ZrO(NO3)2) is added to this solution and mixed well. To the mixed solution, an alkoxysilane, for example, methyl silicate oligomer, is added to obtain a homogeneous and transparent raw material mixed solution. The inorganic oxide content in the obtained raw material mixed solution ranges from about 1 to 35% by mass, preferably from about 3 to 10% by mass. This is because if the content of a solvent such as water or alcohol is high, it takes time for drying and is uneconomical, and if the solvent is less, the next neutralization stirring operation becomes difficult.

[0028] The raw material mixed solution (sol) prepared as above can be gelled by hydrolysis and coprecipitation reactions by adding an alkaline solution. The alkaline solution is not particularly limited. For example, ammonia water is preferred in that it dissolves the above raw material mixed solution, can be dissolved in water at an arbitrary ratio, and does not remain in the filler after drying and heat treatment. The amount of ammonia water needs to show basicity when mixed with the raw material mixed solution. Generally, an amount that results in a pH of about 7 to 9, preferably about pH 8, is a guideline. For example, about twice the dilution of commercially available ammonia water (content: 35 wt%) can be adopted.

[0029] The method for mixing the above raw material mixed solution and the alkaline solution is not particularly limited. For example, in order to prevent the deviation of components in the coprecipitate caused by the different hydrolysis conditions of each raw material component by alkali, it is desirable to add them all at once. There are also no particular limitations on the stirring speed, reaction temperature, and time. For the purpose of a uniform reaction, vigorous stirring is carried out for rapid neutralization to obtain an aggregate of coprecipitated fine particles (jelly-like gel body), thereby preventing the deviation of components. The sol-gel body obtained by the above operation is subjected to evaporation removal and drying of the solvent, excess ammonia, water, etc. using a normal evaporator or dryer. There is no particular limitation on the drying temperature. For example, it is in the range of 40 to 150 °C, preferably 70 to 120 °C.

[0030] Next, the dried gel body is washed with water to remove by-products such as ammonium nitrate. For example, after sufficiently drying the gel body with a forced-air dryer or the like, ethanol is added to the dried product, and it is wet-milled into gel fine particles with an average particle diameter of 0.1 to 0.9 μm using a planetary mill, bead mill, etc., and the ethanol is evaporated and removed and dried to obtain a gel fine particle powder. This fine particle powder is made into particles with an average particle diameter of 3 to 20 μm using a pneumatic mill such as a jet mill and fired in an electric furnace.

[0031] In the firing of the particles, the sintering of the primary particles and the formation of secondary particles (average particle diameter 3 to 10 μm) in which the primary particles are combined are important. The optimum heat treatment conditions (temperature, time, etc.) are appropriately selected according to the content rates of the SiO2, ZrO2, and Al2O3 components. For example, the heating rate is desirably about 20 °C per minute at the fastest, usually about 3 to 10 °C per minute. The firing temperature is about 800 to 1200 °C, preferably about 1000 to 1190 °C, more preferably 1050 to 1150 °C.

[0032] The secondary particles produced by the above method are adjusted to have an appropriate particle size distribution by methods such as crushing and blending. The inorganic filler of the secondary particles is amorphous particles (particle size = 1 to 50 μm) in which sintered primary particles with an average particle size of about 0.1 to 0.9 μm are mutually bonded by neck formation, having no sharp edges, a broad particle size distribution, uneven particle sizes, and a rough surface. These fired secondary particles can be crushed by an air-flow mill as needed and adjusted to an average particle size of 2 to 8 μm.

[0033] The measurement of the average particle size and particle size distribution in the present invention is performed, for example, by a laser diffraction particle size distribution measuring device (SALD-2200, manufactured by Shimadzu Corporation). Since the average particle size measures the particle size distribution obtained by the laser diffraction / scattering method on a volume basis, it means the volume average particle size. The particle sizes of the gel fine particles (primary particles) and particles (secondary particles) before firing were measured after charging the powder into a particle size distribution measuring device with distilled water as a solvent, setting the refractive index to 1.45 ± 0.10, and subjecting it to ultrasonic dispersion for 5 minutes. Also, the particle size of the particles (secondary particles) after firing was measured under the condition of a refractive index of 1.50 ± 0.10.

[0034] Filler 2 (C) (Meth)acrylate polymerizable monomer The dental curable composition of the present invention needs to contain spherical SiO2 fillers with an average particle size of 50 nm or less (hereinafter, sometimes referred to as "Component B" or "ultrafine SiO2 fillers"). Note that the spherical shape includes not only a perfect sphere but also a substantially spherical shape. The ultrafine SiO2 fillers are not particularly limited as long as they are known SiO2 fillers with an average particle size of the primary particles of 50 nm or less, and examples include colloidal silica and fumed silica. The average particle size of the ultrafine SiO2 fillers may be 50 nm or less, and a range of 10 to 50 nm is preferable. Only one type of the ultrafine SiO2 filler can be used, or two or more different ultrafine SiO2 fillers can be mixed.

[0035] The content of the ultrafine SiO2 filler contained in the dental curable composition is usually 5 to 45% by mass, preferably 7 to 30% by mass, and more preferably 9 to 20% by mass. The compounding ratio (mass ratio) of the (B) ultrafine SiO2 filler to the (A) composite metal oxide filler is 1:0.8 to 1:8, preferably 1:0.9 to 1:8, and more preferably 1:1 to 1:7.

[0036] The ultrafine SiO2 filler of the B component is a SiO2 filler that does not contain ZrO2 and Al2O3. In contrast, the A component is a composite metal oxide filler containing SiO2, ZrO2, and Al2O3, and necessarily contains SiO2, ZrO2, and Al2O3. Therefore, the A component and the B component can be clearly distinguished. Also, the A component and the B component are not coloring materials and can be clearly distinguished from the D component.

[0037] (D) Colorant The dental curable composition of the present invention needs to be blended with a (meth)acrylate-based polymerizable monomer (hereinafter sometimes referred to as "C component", "polymerizable monomer", or "monomer"). Note that (meth)acrylate means acrylate or methacrylate.

[0038] As the polymerizable monomer, any (meth)acrylate-based polymerizable monomer (monomer) that can be used for dental applications can be used without particular limitation. For example, monofunctional (meth)acrylates such as (meth)acrylic acid esters (for example, in the case of alkyl esters, the alkyl group has 1 to 12 carbon atoms; in the case of esters containing an aromatic group, it has 6 to 12 carbon atoms. In addition, those containing a substituent such as a polyethylene glycol chain in these groups also include their carbon atoms); polyalkylene glycol di(meth)acrylates (the alkylene group has 2 to 20 carbon atoms), ethylene glycol oligomer di(meth)acrylates (2 to 10 mers), di(meth)acrylates containing bisphenol A, urethane (meth)acrylates which are reaction products of 2 moles of (meth)acrylate having a hydroxyl group and 1 mole of diisocyanate, etc., di(meth)acrylates; tri(meth)acrylates such as trimethylolpropane tri(meth)acrylate; tetra(meth)acrylates such as pentaerythritol tetra(meth)acrylate and other polyfunctional (meth)acrylates. Specifically, monomers disclosed in JP-A-50-042696 or JP-A-56-152408 are preferable.

[0039] Examples of the monofunctional (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, allyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxytetraethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxyhexaethylene glycol (meth)acrylate, glycerol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, phenyl (meth)acrylate, pentaerythritol mono(meth)acrylate, dipentaerythritol mono(meth)acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, caprolactone-modified dipentaerythritol (meth)acrylate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, and the like.

[0040] Examples of the polyfunctional (meth)acrylate include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, glycerol di(meth)acrylate, bisphenol A di(meth)acrylate, ethylene oxide-modified bisphenol A di(meth)acrylate, ethylene oxide-modified bisphenol A glycidyl di(meth)acrylate, 2,2-bis(4-methacryloxypropoxyphenyl)propane, 7,7,9-trimethyl-4,13-dioxa-3,14-dioxo-5,12-diazahexadecane-1,16-diol di(meth)acrylate, neopentyl glycol hydroxypivalate di(meth)acrylate, caprolactone-modified hydroxypivalic acid neopentyl glycol ester di(meth)acrylate, trimethylolethane di(meth)acrylate, trimethylolpropane di(meth)acrylate, urethane di(meth)acrylate (1,6-bis((meth)acryloyloxy-2-ethoxycarbonylamino)-2,4,4-trimethylhexane), reaction product of 3-chloro-2-hydroxypropyl (meth)acrylate and methylcyclohexane diisocyanate, reaction product of 2-hydroxypropyl (meth)acrylate and methylcyclohexane diisocyanate, reaction product of 2-hydroxypropyl (meth)acrylate and methylene bis(4-cyclohexyl isocyanate), reaction product of 2-hydroxypropyl (meth)acrylate and trimethylhexamethylene diisocyanate, reaction product of 2-hydroxyethyl (meth)acrylate and isophorone diisocyanate, reaction product of 3-chloro-2-hydroxypropyl (meth)acrylate and isophorone diisocyanate, and other di(meth)acrylates;Trimethylolmethane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate and other tri(meth)acrylates; pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate and other tetra(meth)acrylates.

[0041] The (meth)acrylate-based polymerizable monomer is preferably a polyfunctional (meth)acrylate, more preferably ethylene glycol dimethacrylate, diethylene glycol dimethacrylate (DEGDMA), triethylene glycol dimethacrylate (TEGDMA), trimethylolpropane di(meth)acrylate, urethane dimethacrylate (UDMA) and bisphenol A glycidyl dimethacrylate (Bis-GMA), and particularly preferably DEGDMA, TEGDMA, UDMA and Bis-GMA.

[0042] These (meth)acrylate-based polymerizable monomers can be used alone, but it is preferably to mix and use two or more kinds of polymerizable monomers, more preferably to mix and use two or more kinds of polyfunctional (meth)acrylates, and particularly preferably to mix and use two or more kinds of di(meth)acrylates to adjust the viscosity.

[0043] The content of the polymerizable monomer contained in the dental curable composition is usually 10 to 35% by mass, preferably 15 to 30% by mass, and more preferably 20 to 25% by mass.

[0044] In addition to the (meth)acrylate-based polymerizable monomer, the dental curable composition of the present invention can also be polymerized by mixing other polymerizable monomers other than the (meth)acrylate-based polymerizable monomer for the ease of polymerization, viscosity adjustment, or adjustment of other physical properties.

[0045] (E) Optional component The dental curable composition of the present invention needs to contain a coloring agent (hereinafter, also referred to as "Component D"). As the coloring agent (coloring pigment), known pigments used in general dental treatment applications can be used without particular limitation. The coloring agent may be either an inorganic pigment or an organic pigment. Examples of the inorganic pigment include iron oxide-based coloring pigments, aluminum oxide-based coloring pigments, titanium oxide-based coloring pigments, zirconium oxide pigments, and the like. Examples of the organic pigment include isoindolinone, pigment red, and the like.

[0046] The (D) coloring agent preferably contains at least one selected from the group consisting of a red pigment, a yellow pigment, a black pigment, and a white pigment, and more preferably contains a red pigment, a yellow pigment, a black pigment, and a white pigment. Specific examples of the red pigment include ferric oxide (iron(III) oxide), pigment red, and the like. Specific examples of the yellow pigment include isoindolinone, nickel titanium yellow, chromium oxide, and the like. Specific examples of the black pigment include magnetite (iron(II,III) oxide), amorphous carbon (carbon black), and the like. Specific examples of the white pigment include zirconium oxide, titanium white (titanium dioxide), zinc oxide, and the like. The white pigment is sometimes referred to as an opacifier.

[0047] When the coloring material contains a red pigment, a yellow pigment, a black pigment, and a white pigment, the content of the D component is preferably 0.0003 to 0.0009 parts by mass of the red pigment, 0.0004 to 0.0011 parts by mass of the yellow pigment, 0.0003 to 0.003 parts by mass of the black pigment, and 0.05 to 0.18 parts by mass of the white pigment with respect to a total of 100 parts by mass of the A component, the B component, and the C component. More preferably, the red pigment is 0.0004 to 0.0008 parts by mass, the yellow pigment is 0.0005 to 0.001 parts by mass, the black pigment is 0.0004 to 0.002 parts by mass, and the white pigment is 0.07 to 0.15 parts by mass. Further, the blending ratio of the red pigment, the yellow pigment, the black pigment, and the white pigment is preferably 0.3 to 1% by mass of the red pigment, 0.2 to 1.6% by mass of the yellow pigment, and 0.3 to 4% by mass of the black pigment with respect to 100% by mass of the white pigment. More preferably, the red pigment is 0.5 to 0.8% by mass, the yellow pigment is 0.4 to 1.1% by mass, and the black pigment is 0.4 to 3% by mass.

[0048] 2. Method for producing a dental curable composition The dental curable composition of the present invention may further contain optional components other than the above components, if necessary. The optional components can be blended within a range that does not impair the effects of the dental curable composition of the present invention. Examples of the optional components include known additives such as a polymerization initiator, a polymerization accelerator, a fluorescent material, a polymerization inhibitor, an antioxidant, an antibacterial agent, an X-ray contrast agent, a stabilizer, an ultraviolet absorber, and a discoloration inhibitor. These can be used alone or in appropriate combination of two or more.

[0049] When blending the optional components, they can be added usually in a proportion of 0.001 to 10% by mass, preferably 0.01 to 5% by mass, more preferably 0.1 to 3% by mass with respect to 100% by mass of the dental curable composition.

[0050] The dental curable composition is excellent in shape retention. Specifically, when the dental curable composition is formed into a disk shape with a diameter of 12 mm and a thickness of 1 mm, and a cut is made with a metal plate having a thickness of 1 mm to divide it in half and it is allowed to stand at 37°C, the time until the divided dental curable composition deforms until the dental curable compositions come into contact is preferably 300 seconds or more, more preferably 360 seconds or more, and even more preferably 420 seconds or more.

[0051] The dental curable composition is excellent in consistency (elongation rate). Specifically, when 0.65 g of the dental curable composition is formed into a sphere, and a weight of 3.25 kg is gently placed thereon from above and allowed to stand for 60 seconds, the elongation rate (consistency) is preferably 160% or more, more preferably 180% or more, and even more preferably 200% or more. The sphere includes not only a perfect sphere but also a substantially spherical shape.

[0052] 3. Method for curing a dental curable composition The dental curable composition of the present invention can be produced by blending (A) an amorphous composite metal oxide filler containing SiO2, ZrO2, and Al2O3, (B) an SiO2 filler having an average particle diameter of 50 nm or less, (C) a (meth)acrylate-based polymerizable monomer, and (D) a coloring material in the specific ratios described above.

[0053] The mixing ratio (mixing ratio) of each component in the above dental curable composition can be appropriately adjusted according to viscosity and the purpose of use. For example, with respect to 100 parts by mass of the (C) (meth)acrylate-based polymerizable monomer, the total amount of the (A) composite metal oxide filler and the (B) SiO2 filler is 300 to 650 parts by mass, preferably 350 to 600 parts by mass, more preferably 400 to 550 parts by mass, and the (D) coloring material is blended, and further, if necessary, a polymerization initiator, a polymerization accelerator, a coloring pigment, an opacifying agent, an opalizing agent, a fluorescent material, a polymerization inhibitor, an antioxidant, an antibacterial agent, an X-ray contrast agent, a stabilizer, an ultraviolet absorber, a discoloration inhibitor, and other additives can be appropriately blended. When the dental curable composition contains a polymerization initiator, care must be taken in its handling, and storage in a sealed container in the dark and at low temperature is essential.

[0054] The manufacturing method of the dental curable composition preferably includes a step of taking predetermined amounts of the above components into a container, sufficiently kneading and dispersing them to obtain a paste, and a step of kneading the paste under reduced pressure or stirring it in a vacuum. By using such a method, a uniform clay-like or paste-like dental curable composition with air bubbles removed can be obtained. The dental curable composition can be polymerized according to a known polymerization (light and heating) method to obtain a cured product.

[0055] 4. Use The dental curable composition of the present invention can be polymerized and cured by light irradiation. The method of polymerizing and curing by light irradiation varies depending on the type of photoinitiator, and although the wavelength of ultraviolet light can also be used, it is usually polymerized and cured by irradiating light with a wavelength of visible light that is harmless to the human body. As the wavelength of the light, for example, the range of 250 to 700 nm is preferable, 300 to 500 nm is more preferable, and 350 to 490 nm is even more preferable.

[0056] There is no particular limitation on the light source in the above wavelength range, and for example, light such as an LED lamp, a halogen lamp, a xenon lamp, a metal halide lamp, a laser, a fluorescent lamp, or sunlight can be used.

[0057] Also, the irradiation time of the light varies depending on the thickness, transparency, color tone of dental prostheses and the like obtained from the dental curable composition, and the amount of light of the irradiation light, but generally it may be appropriately determined according to the desired polymerization time. Preferably, light irradiation is performed for about 5 seconds to 3 minutes, more preferably 10 seconds to 120 seconds, and even more preferably 20 seconds to 60 seconds.

[0058] The dental curable composition includes not only the state before curing but also the meaning of the cured body (cured product or cured film) obtained by irradiating the dental curable composition with light. Since it is impossible to completely specify the structure of this cured body at present or it is difficult to an extent that is approximately impractical, the cured body is described by a product-by-process claim.

[0059] The transmittance (Tt) of the cured body with a thickness of 1 ± 0.05 mm after polymerizing and curing the dental curable composition is 52 or more and 66 or less, preferably 53 or more and 62 or less, and more preferably 53 or more and 60 or less.

[0060] The haze value of the cured body with a thickness of 1 ± 0.05 mm after polymerizing and curing the dental curable composition is 85 or more and 98 or less, preferably 88 or more and 98 or less, and more preferably 92 or more and 98 or less.

[0061] The L * a * b * In the L value in the color system * is 70 or more and 77 or less, preferably 71 or more and 76 or less, and more preferably 72 or more and 75 or less, and the a * value is -0.5 or more and 1.5 or less, preferably -0.2 or more and 1.2 or less, and more preferably 0.1 or more and 0.9 or less, and the b * value is 11 or more and 19 or less, preferably 13 or more and 18 or less, and more preferably 14 or more and 18 or less. Also, from the a * value and the b * value, the following formula Formula A: C * = {(a * ) 2 + (b * ) 2} 1 / 2 is used to calculate the C * value representing the chroma. The C * value of the cured body with a thickness of 1 ± 0.05 mm after polymerizing and curing the dental curable composition is 11 or more and 20 or less, preferably 13 or more and 19 or less, and more preferably 14 or more and 18 or less. Generally, the chromaticity of the material used as a dental crown has a larger b * value compared to the a * value, and the C * value is often approximated to the b * value.

[0062] The transmittance, turbidity, and L of the cured body after polymerizing and curing the dental curable composition * a * b * in the L value in the color system * value, a * value, and b * value satisfy the above numerical range, so that the dental curable composition can be of one type (single composition) and the color tone of the restored part can be made to match the color tone of natural teeth.

[0063] The opalescence of the dental curable composition can be calculated as the opalescence value from the a value and b value in the L value in the color system of the cured body with a thickness of 1 ± 0.05 mm after polymerizing and curing the dental curable composition by the following formula 1. * a * b * a in the color system * value and b * value. Formula 1: (Opalescence value) = {(a w * - a * B ) 2 +(b W * - b * B ) 2} 1 / 2 In Formula 1, a w * : a value of the cured body of the dental curable composition on a white background * value a B * : a value of the cured body of the dental curable composition on a black background * value b w * : b value of the cured body of the dental curable composition on a white background * value b B * : b value of the cured body of the dental curable composition on a black background * value

[0064] Note that the opalescence means having an opal effect, and the opal effect means the same specific visible light scattering effect as that of opal. More specifically, it means that there are particles having a size approximate to the wavelength of light in a substance, and when the particles scatter the short wavelength region of visible light, the transmitted light of the substance has a yellowish tint and the scattered light has a bluish tint. Regarding the opal value of natural teeth, when the thickness of natural teeth is 0.7 to 1.3 mm, it is known that the opal value is about 10 to 23. From this, the opal value of a cured body with a thickness of 1 ± 0.05 mm after polymerizing and curing the dental curable composition is preferably 10 or more and 23 or less, more preferably 11 or more and 20 or less, and even more preferably 12 or more and 19 or less. Therefore, by setting the opal value of the cured body after polymerization curing of the dental curable composition to 10 or more and 23 or less, a color tone close to that of natural teeth can be obtained.

[0065] The cured body after polymerization curing of the dental curable composition of the present invention is excellent in color tone compatibility. The color tone compatibility is evaluated by the color difference (ΔE) between the color tone of the cured body of the dental curable composition of the present invention when overlaid on a tooth color standard pellet and the color tone of the tooth color standard pellet. Here, as the tooth color standard (tooth color sample), the shade guide "VITA (registered trademark) PAN classical" of VITA is often used. The shade guide is divided into A type, B type, C type, and D type, each having a different color tone. Since many Japanese people fall into the A type, the color tone compatibility was evaluated using a tooth color standard pellet corresponding to the A type shade. Specifically, a tooth color standard pellet with a diameter of 15 ± 0.5 mm and a thickness of 1 ± 0.05 mm having a color tone corresponding to the A type shade of the shade guide used as the tooth color standard (for example, color tones corresponding to A1, A2, A3, A3.5, and A4 shades, etc.) is used, and by a spectrophotometer, L2 * , a2 * , and b2 *Measure it. Also, after polymerizing and curing the dental curable composition, a cured body (evaluation pellet) with a diameter of 15 ± 0.5 mm and a thickness of 1 ± 0.05 mm is overlaid on the tooth color reference pellet, and for the evaluation pellet in this state, L1 is measured with a spectrophotometer. * , a1 * , and b1 * Measure them, and calculate the color difference (ΔE) between the color tone of the evaluation pellet overlaid on the tooth color reference pellet and the color tone of the tooth color reference pellet according to the following formula 2. Note that Δ is read as delta and means "difference".

[0066] Formula 2: ΔE = {(ΔL * ) 2 + (Δa * ) 2 + (Δb * ) 2}} 1 / 2 ΔL * = L1 * - L2 * Δa * = a1 * - a2 * Δb * = b1 * - b2 * Here, L1 * : Brightness of the evaluation pellet overlaid on the tooth color reference pellet a1 * , b1 * : Chromaticity of the evaluation pellet overlaid on the tooth color reference pellet L2 * : Brightness of the tooth color reference pellet a2 * , b2 * : Chromaticity of the tooth color reference pellet

[0067] The color difference (ΔE) between the color tone of the evaluation pellet overlaid on the tooth color reference pellet and the color tone of the tooth color reference pellet is preferably 10.5 or less, more preferably 10.3 or less, and even more preferably 10.1 or less.

[0068] Generally, the color difference (ΔE) recognized as the same color is said to be 3.2 or less, which is within the A-class tolerance range (1.6 - 3.2). When ΔE is 10.5, it is within the C-class tolerance range (6.5 - 13.0), which corresponds to the color difference of one step adjacent to one of the Munsell color chips. Clinically, a dental curable composition is filled in a part of the tooth crown, and visual confirmation is made as to whether the color tone is compatible. However, in colorimetry, when the dental curable composition is filled only in a part, the color difference before and after filling becomes small, so there is also a measurement error during colorimetry, and it is difficult to evaluate the color tone compatibility due to a slight difference in composition. Therefore, in the evaluation of color tone compatibility, in order to increase the color difference obtained by colorimetry, colorimetry was performed by overlapping an evaluation pellet so as to cover the entire upper surface of the tooth color reference pellet, and evaluation was performed under harsher conditions compared to the clinical usage method. For example, when the color difference when filling 25% of the colorimetric range is set to ΔE = 1, the color difference tends to change according to the filling ratio per colorimetric range so that the color difference becomes ΔE = 2 when filling 50% of the range. From the above, the conditions for evaluating color tone compatibility are harsh, and the value of the obtained color difference is not a value indicating color tone compatibility in clinical practice. It is merely a condition for relative evaluation in the evaluation of color tone compatibility. Considering these facts, in the evaluation of color tone compatibility, the reference for the color difference is not 3.2 or less, but 10.5 or less. In the evaluation of color tone compatibility, if the color difference is 10.5 or less, when the filling range is about 25%, the color difference becomes 3.2 or less, which is within the A-class tolerance, and the color tone of the filled part can be well blended with the surrounding teeth. That is, if the ΔE is 10.5 or less, it is considered that the color tone compatibility is high and sufficient color tone compatibility can be obtained using the dental curable composition.

[0069] The dental curable composition of the present invention has appropriate shielding properties. The shielding property of the dental curable composition of the present invention is the Y value (Y on a white background obtained when color difference measurement is performed in the XYZ display system using a spectrocolorimeter for a cured body having a thickness of 1 ± 0.05 mm after polymerizing and curing the dental curable composition.W ) with respect to the black background, the ratio of the Y value (Y B ) (Y B / Y W ) was used as an index for the contrast ratio determined as such. In addition, according to previous basic research, when the contrast ratio is 0.42 or less, if the color of the base of the filled area has changed color, the color cannot be sufficiently shielded. On the other hand, when the contrast ratio is 0.59 or more, the transparency of the filled area becomes insufficient, and it has been found that it becomes difficult to reproduce the texture of the tooth. That is, it is preferable to set the contrast ratio that affects the shielding property and transparency to a value that is neither too high nor too low. Therefore, the contrast ratio is preferably 0.43 or more and 0.58 or less, and more preferably 0.45 or more and 0.55 or less.

[0070] It can be said that the closer the contrast ratio is to 0, the smaller the shielding property (the higher the transparency), and the closer it is to 1, the greater the shielding property (the lower the transparency). Therefore, since the contrast ratio of the cured body of the dental curable composition is 0.43 or more and 0.58 or less, and the repaired portion has an appropriate shielding property, it is possible to harmonize without a sense of incongruity with the surrounding teeth.

[0071] Production Example 1 The dental curable composition of the present invention can be suitably used as a dental filling and repair material, but is not limited thereto, and can also be suitably used for other uses. Examples of other uses include, for example, dental cement, repair materials for abutment construction, and the like.

Examples

[0072] Hereinafter, the present invention will be described more specifically by way of examples, but the technical scope of the present invention is not limited to these examples.

[0073] The raw materials used in the examples and comparative examples are shown below.

[0074] [(A) Amorphous composite metal oxide filler containing SiO2, ZrO2 and Al2O3] As the A component, the one produced according to Production Example 1 below was used. Photoinitiator 10 parts by mass of aluminum nitrate (Al(NO3)3·9H2O, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) and 15 parts by mass of AP-1 (modified ethanol, manufactured by Nippon Alcohol Sales Co., Ltd., 87% ethanol, 13% isopropyl alcohol) were mixed and dissolved. Next, 118 parts by mass of Zircozol ZN (aqueous zirconium nitrate solution, manufactured by Daiichi Rare Element Chemical Industry Co., Ltd., ZrO2 content = 25 wt%) was added to the obtained solution, and further, 280 parts by mass of MS51 (methyl silicate oligomer, manufactured by Mitsubishi Chemical Corporation, SiO2 content = 52 wt%) and 430 parts by mass of distilled water were added. Then, the obtained mixture was mixed with a stirrer for 60 minutes to prepare a transparent and uniform raw material mixture solution. Next, when 127 parts by mass of a two-fold diluted solution of aqueous ammonia solution (for example, manufactured by Nacalai Tesque, Inc., NH3 = 28%) was added to the previously prepared raw material mixture solution while stirring, coprecipitation gelation occurred and it became jelly-like. This gelled product was taken out and dried at 100 °C to remove excess ammonia, water and solvent, and a dried gel was obtained. By washing and filtering this dried gel, ammonium nitrate by-produced was removed and dried again. Note that if a large amount of ammonium nitrate remains, gas will be generated during firing and there is a risk of explosion, so it is necessary to wash it sufficiently.

[0075] 100 parts by mass of this dried gel was dispersed in 250 parts by mass of AP-1, and it was pulverized for 4 hours using a bead mill (manufactured by Simar Enterprises Co., Ltd., MULUTI-LABO) filled with a specified amount of zirconia balls with a diameter of 0.65 mm to obtain a slurry. When the particle size and particle size distribution of this slurry were measured, the average particle size was 0.6 μm, and it was not pulverized to less than 0.2 μm. The slurry was recovered and dried to remove the solvent. The particles at this stage correspond to the primary particles of the finished filler. Next, this pulverized and dried gel was treated with a jet mill (manufactured by Hosokawa Micron Corporation, 100AFG / 50ATP) to obtain an average particle size of about 20 μm for the gel powder. This aggregated gel was placed in an alumina dish, heated to 1100 °C (270 °C per hour) in an electric furnace, held at the same temperature for 3.5 hours, then taken out of the furnace and allowed to cool, obtaining a white powder.

[0076] This fired gel was pulverized with the above jet mill to obtain an amorphous composite metal oxide filler containing SiO2, ZrO2, and Al2O3. The average particle size of the composite metal oxide filler was 5.5 μm (10%D: 0.4 μm, 50%D: 10.1 μm, 90%D: 26.9 μm), and it was recognized to be a polydisperse system widely distributed in the range of about 0.5 to about 50 μm. 100 parts by mass of this composite metal oxide filler was suspended in 200 parts by mass of an alcohol solvent (AP-1), 9 parts by mass of γ-MPTS (TSL-8370, manufactured by Momentive Performance Materials Japan) was added, and ultrasonic dispersion was carried out for more than 1 hour. Then, after removing the solvent with an evaporator, drying was performed at 80 °C for 2 hours under reduced pressure and at 110 °C for 1 hour under reduced pressure to obtain a composite metal oxide filler surface-treated with a silane coupling agent.

[0077] [(B) Spherical SiO2 filler with an average particle size of 50 nm or less] SiO2 filler with an average particle size of 50 nm (AdmaNano (registered trademark) YA050C, manufactured by Admatechs Co., Ltd.) SiO2 filler with an average particle size of 15 nm (MEK-ST, manufactured by Nissan Chemical Industries, Ltd.)

[0078] [(C) (Meth)acrylate-based polymerizable monomer] UDMA: 2,2,4-Trimethylhexamethylene bis(2-carbamoyloxyethyl) dimethacrylate (NF-501 urethane dimethacrylate, manufactured by Mitsubishi Chemical Corporation) TEGDMA: Triethylene glycol dimethacrylate (NK Ester 3G, manufactured by Shin-Nakamura Chemical Co., Ltd.) Bis-GMA: Bisphenol A glycidyl di(meth)acrylate (D-GMAP, manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0079] [(D) Colorant] Ferric oxide: Red pigment (manufactured by Dainichi Seika Kogyo Co., Ltd.) Isoindolinone: Yellow pigment (manufactured by Dainichi Seika Kogyo Co., Ltd.) Magnetite: Black pigment (manufactured by Dainichi Seika Kogyo Co., Ltd.) Zirconium oxide: White pigment (SPZ Zirconium Oxide, manufactured by Daiichi Rare Element Chemical Industry Co., Ltd.)

[0080] [(E) Optional component] Polymerization accelerator CQ: Camphorquinone (Camphorquinone, manufactured by Tokyo Chemical Industry Co., Ltd.) Evaluation of the cured body of the dental curable composition DMABE: Ethyl p-dimethylaminobenzoate (Ethyl p-dimethylaminobenzoate, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0081] (Example 1) 85 parts by mass of UDMA, 10 parts by mass of TEGDMA, 5 parts by mass of Bis-GMA, 0.3 parts by mass of CQ, and 0.6 parts by mass of DMABE were mixed in a mass ratio to prepare a polymerizable monomer mixture (M1). To 22.0 parts by mass of the obtained polymerizable monomer mixture (M1), 39.0 parts by mass of Component A obtained in Production Example 1 and 39.0 parts by mass of an SiO2 filler having an average particle diameter of 50 nm as Component B were added. To 100 parts by mass of the obtained mixture, 0.00075 parts by mass of ferric oxide (red) as a colorant, 0.0006 parts by mass of isoindolinone (yellow), 0.002 parts by mass of magnetite (black), and 0.1 parts by mass of zirconium oxide (white) were added, and the mixture was mixed and defoamed under light shielding to obtain a dental curable composition.

[0082] (Examples 2 to 3 and 6 to 12) Each dental curable composition was produced in the same manner as in Example 1, except that the blending ratios described in Tables 1 to 4 below were used.

[0083] (Example 4) UDMA was mixed at a mass ratio of 45 parts by mass, TEGDMA at 10 parts by mass, Bis-GMA at 45 parts by mass, CQ at 0.3 parts by mass, and DMABE at 0.6 parts by mass to prepare a polymerizable monomer mixture (M2). To 23.5 parts by mass of the obtained polymerizable monomer mixture (M2), 65.6 parts by mass of Component A obtained in Production Example 1 and 10.9 parts by mass of an SiO2 filler having an average particle diameter of 50 nm as Component B were added. To 100 parts by mass of the obtained mixture, 0.00075 parts by mass of ferric oxide (red) as a coloring agent, 0.0006 parts by mass of isoindolinone (yellow), 0.002 parts by mass of magnetite (black), and 0.1 parts by mass of zirconium oxide (white) were added, and the mixture was mixed and degassed under light shielding to obtain a dental curable composition.

[0084] (Example 5) UDMA was mixed at a mass ratio of 85 parts by mass, TEGDMA at 10 parts by mass, Bis-GMA at 5 parts by mass, CQ at 0.3 parts by mass, and DMABE at 0.6 parts by mass to prepare a polymerizable monomer mixture (M1). To 30.0 parts by mass of the obtained polymerizable monomer mixture (M1), 60.0 parts by mass of Component A obtained in Production Example 1 and 10.0 parts by mass of an SiO2 filler having an average particle diameter of 15 nm as Component B were added. To 100 parts by mass of the obtained mixture, 0.00075 parts by mass of ferric oxide (red) as a coloring agent, 0.0006 parts by mass of isoindolinone (yellow), 0.002 parts by mass of magnetite (black), and 0.1 parts by mass of zirconium oxide (white) were added, and the mixture was mixed and degassed under light shielding to obtain a dental curable composition.

[0085] (Comparative Examples 1 to 10) Each comparative composition was produced in the same manner as in Example 1, except that the blending ratios described in Tables 1 to 4 below were used.

[0086] (Reference Examples 1 to 3) Dental filling and restorative materials that are commercially available, boasting harmony with multiple shades of color in a single color, were used as Reference Examples 1 to 3.

[0087] Acceptance criteria For the cured bodies after polymerization and curing of the dental curable compositions of Examples 1 to 12 and Comparative Examples 1 to 10, transmittance, haze, color tone, opalescence, color tone compatibility, and hiding power were measured or evaluated by the following methods. Also, for the dental filling and restorative materials of Reference Examples 1 to 3, the color tone compatibility and hiding power of the cured bodies were measured by the following methods.

[0088] [Transmittance and Haze] The dental curable compositions of Examples 1 to 12 and Comparative Examples 1 to 10 were each filled into a mold (inner diameter 15 mm, thickness 1 mm), and both sides were irradiated with light of a wavelength of 460 nm from a light polymerizer (LED CURE Master, manufactured by Dentsply Sirona) for 15 seconds for polymerization and curing to produce cured bodies (test pieces) with a diameter of 15 ± 0.5 mm and a thickness of 1 ± 0.05 mm. The transmittance and haze of this test piece were measured with a haze meter (NDH4000, manufactured by Nippon Denshoku Industries Co., Ltd.). The results are shown in Tables 1 to 4.

[0089] Acceptance criteria If the transmittance was 52 - 66%, it was considered qualified (〇), and if it was less than 52% or more than 66%, it was considered unqualified (×). If the haze was 85 - 98, it was considered qualified (〇), and if it was less than 85 or more than 98, it was considered unqualified (×).

[0090] [Color Tone] Regarding the color tone of the cured bodies with a thickness of 1 ± 0.05 mm after polymerization and curing of the dental curable compositions of Examples 1 to 12 and Comparative Examples 1 to 10, the L * a * b * values in the L * value, a * value, b *The values were measured with a spectrocolorimeter (CM3610A, manufactured by Konica Minolta, Inc.). The color measurement conditions were: light source: D65 light source, viewing angle: 2° (degrees). Color measurements were performed on white and black backgrounds respectively, and the average values were calculated. The results are shown in Tables 1 to 4.

[0091] Acceptance criteria If the lightness (L * ) is between 70 and 77, it is considered qualified (〇), and if it is less than 70 or more than 77, it is considered unqualified (×). If the chromaticity (a * ) is between -0.5 and 1.5, it is considered qualified (〇), and if it is less than -0.5 or more than 1.5, it is considered unqualified (×). If the chromaticity (b * ) is between 11 and 19, it is considered qualified (〇), and if it is less than 11 or more than 19, it is considered unqualified (×).

[0092] [Opalescence] Regarding the opalescence of the cured bodies after polymerization and curing of the dental curable compositions of Examples 1 to 12 and Comparative Examples 1 to 10, an index (opale value) indicating the opalescence of test pieces with a disk shape and a thickness of 1 ± 0.05 mm, which is the same as the measurement of transmittance and turbidity, was measured with a spectrocolorimeter (CM3610A, manufactured by Konica Minolta, Inc.). The color measurement conditions were: light source: D65 light source, viewing angle: 2° (degrees), background color: white and black. The results are shown in Tables 1 to 4.

[0093] Acceptance criteria If the opale value is between 10 and 23, it is considered qualified (〇), and if it is less than 10 or more than 23, it is considered unqualified (×).

[0094] [Color tone compatibility] Figure 1 shows a schematic diagram explaining the evaluation method of color tone compatibility. Hereinafter, the evaluation method of color tone compatibility will be explained with reference to Figure 1. The color tone of tooth color standard pellets (TMR-Zetafil 10. Universal, manufactured by YAMAKIN Co., Ltd.) with a diameter of 15 ± 0.5 mm and a thickness of 1 ± 0.05 mm, having color tones corresponding to A1, A3, and A4 shades of the VITA shade guide "VITA (registered trademark) PAN classical" used as a tooth color standard, was measured by the same method as the measurement of the color tone. Next, the dental curable compositions of Examples 1 to 12, Comparative Examples 1 to 10, and Reference Examples 1 to 3 were polymerized and cured, and three evaluation pellets each with a diameter of 15 ± 0.5 mm and a thickness of 1 ± 0.05 mm were prepared. The evaluation pellets were stacked on top of each tooth color standard pellet, and in that state, the color tone of the evaluation pellets was measured by the same method as the measurement of the color tone. Note that glycerin was applied between the pellets to prevent the presence of an air layer. The color difference (ΔE) between the tooth color standard pellet and the evaluation pellet was Equation 1: ΔE = {(ΔL * ) 2 +(Δa * ) 2 +(Δb * ) 2} 1 / 2 ΔL * = L1 * - L2 * Δa * = a1 * - a2 * Δb * = b1 * - b2 * (L1 * : Brightness of the evaluation pellet stacked on the tooth color standard pellet a1 * , b1 * : Chromaticity of the evaluation pellet stacked on the tooth color standard pellet L2 * : Brightness of the tooth color standard pellet a2 * , b2 * : Chromaticity of the tooth color standard pellet) It was determined from . The results are shown in Tables 1 to 5. In the tables, for example, "vs. A1" indicates that the pellet placed under the evaluation pellet is a tooth color standard pellet having a color tone corresponding to the A1 shade.

[0095] Acceptance criteria If ΔE was 10.5 or less, it was judged as pass (〇), and if it exceeded 10.5, it was judged as fail (×).

[0096] Fig. 2 shows a schematic diagram for explaining the sensory evaluation of color tone compatibility. Hereinafter, the sensory evaluation method of color tone compatibility will be described with reference to Fig. 2. Class I cavities were formed in artificial teeth (molars) having color tones corresponding to the A1, A3, and A4 shades of the VITA shade guide "VITA (registered trademark) PAN classical" used as tooth color standards. The dental curable compositions of Example 2, Example 11, Example 12, Comparative Example 9, and Comparative Example 10 were filled into the cavities of the artificial teeth and photocured. Each artificial tooth was observed by three persons with normal color vision under daylight white fluorescent lamps, and scored according to the following evaluation criteria. 5 points: The color tone of the artificial tooth and the color tone of the filled part are completely compatible, and the boundary cannot be distinguished at all. 4 points: The color tone of the artificial tooth and the color tone of the filled part are compatible, and the boundary cannot be distinguished. 3 points: The color tone of the artificial tooth and the color tone of the filled part are almost compatible, and the boundary can hardly be distinguished. 2 points: The color tone of the artificial tooth and the color tone of the filled part are not compatible, and the boundary can be partially distinguished. 1 point: The color tone of the artificial tooth and the color tone of the filled part are not compatible at all, and the boundary can be easily distinguished.

[0097] Acceptance criteria For each of the three artificial teeth, the average score of three persons was calculated. If the average score of all three was 3 or more, it was judged as pass (〇), and if the average score of even one was less than 3, it was judged as fail (×). Note that the A type of the shade guide is numbered by color brightness (the smaller the number, the brighter the color), and they are arranged in the order of A1, A2, A3, A3.5, and A4. Therefore, if the evaluation results at A1 and A3 are qualified, it can be inferred that the evaluation result at A2 is also qualified. If the evaluation results at A3 and A4 are qualified, it can be inferred that the evaluation result at A3.5 is also qualified. Also, Example 11 has the largest addition amount of Component D (coloring agent) among Examples 1 to 12, and Example 12 has the smallest addition amount of Component D (coloring agent) among Examples 1 to 12. Therefore, if the results of the sensory evaluation of color tone compatibility for Examples 11 and 12 are qualified, it can be inferred that the results of the sensory evaluation of color tone compatibility for Examples 1 to 10 are also qualified.

[0098] [Light-shielding property] Fig. 3 shows a schematic diagram for explaining the evaluation method of the light-shielding property (contrast ratio). Hereinafter, the evaluation method of the light-shielding property (contrast ratio) will be explained with reference to Fig. 3. The evaluation pellets of Examples 1 to 12, Comparative Examples 1 to 10, and Reference Examples 1 to 3 prepared in the evaluation of the color tone compatibility were placed on a white plate and a black plate, and their respective color tones were measured by the same method as the measurement of the color tone. The ratio of the Y value (Y W ) on the black background to the Y value (Y B ) on the white background (Y B / Y W : contrast ratio) was obtained. The results are shown in Tables 1 to 5.

[0099] Acceptance criteria Y B / Y W If it is within the range of 0.43 to 0.58, it is judged as qualified (〇), and if it is less than 0.43 or more than 0.58, it is judged as unqualified (×).

[0100] Fig. 4 shows a schematic diagram for explaining the sensory evaluation of the light-shielding property. Hereinafter, the sensory evaluation method of the light-shielding property will be explained with reference to Fig. 4. The sensory evaluation of the shielding property was evaluated based on the transparency. When the shielding property is small, that is, when the transparency is too high, the background of the filled area can be seen through. On the other hand, when the shielding property is large, that is, when the transparency is too low, the background of the filled area cannot be seen at all. In either case, it causes a sense of discomfort when compared with the surrounding teeth of the filled area, so it is not preferable. An artificial tooth (incisor) having a color tone corresponding to A2 of the shade guide "VITA (registered trademark) PAN classical" of VITA used as a tooth color standard was formed with a Class IV cavity. The dental curable compositions of Example 2, Example 11, Example 12, Comparative Example 9, and Comparative Example 10 were filled (tamped) into the cavities of the artificial teeth and photopolymerized. Each artificial tooth was placed on a black background and observed by three persons with normal color vision under daylight white fluorescent lamps, and scored according to the following evaluation criteria. 4 points: The transparency of the artificial tooth and the transparency of the filled area are very close, and the boundary cannot be distinguished at all. 3 points: The transparency of the artificial tooth and the transparency of the filled area are close, and the boundary can hardly be distinguished. 2 points: The transparency of the artificial tooth and the transparency of the filled area are different, and the boundary can be partially distinguished. 1 point: The transparency of the artificial tooth and the transparency of the filled area are very different, and the boundary can be easily distinguished.

[0101] Evaluation of the dental curable composition If the average score of the three persons is 3 points or more, it is judged as pass (〇), and if it is less than 3 points, it is judged as fail (×). Note that Example 11 has the lowest transmittance and the highest turbidity among Examples 1 to 12, and Example 12 has the highest transmittance and the lowest turbidity among Examples 1 to 12. Therefore, if the results of the sensory evaluation of the shielding property of Example 11 and Example 12 are qualified, it can be estimated that the results of the sensory evaluation of the shielding property of Examples 1 to 10 are also qualified.

[0102] Acceptance criteria Regarding the dental curable compositions of Examples 1 to 5 and 11 to 12, and Comparative Examples 1 to 2 and 9 to 10, the shape retention and consistency were measured or evaluated by the following method.

[0103] [Shape retention property] Fig. 5 shows a schematic diagram for explaining the method for evaluating the shape retention property. Hereinafter, the method for evaluating the shape retention property will be described with reference to Fig. 5. The dental curable compositions of Examples 1 to 5 and 11 to 12, and Comparative Examples 1 to 2 and 9 to 10 were allowed to stand in an incubator set at 37°C for 60 minutes, and then filled into a mold (inner diameter 12 mm, thickness 1 mm) on a flat table (black) to form a disc shape as an evaluation sample. Three evaluation samples were prepared for each. The evaluation sample was vertically cut from above so as to be divided into two by a metal plate (thickness 1 mm), and then allowed to stand in the incubator. At 180 seconds, 240 seconds, and 300 seconds after the evaluation sample was divided, it was visually confirmed whether the divided evaluation sample was deformed and adhered (the evaluation sample could not be seen covering the underlying black color), and evaluated as follows. The results are shown in Tables 1 to 4. 1 point: Less than 180 seconds 2 points: Less than 240 seconds 3 points: Less than 300 seconds 4 points: 300 seconds or more

[0104] Acceptance criteria The average score of the three scores was taken as the score of the evaluation sample. If the average score was 4 points, it was judged as qualified (〇), and if the average score was less than 4 points, it was judged as unqualified (×).

[0105] [Consistency] Fig. 6 shows a schematic diagram for explaining the method for evaluating the consistency. Hereinafter, the method for evaluating the consistency will be described with reference to Fig. 6. 0.65 g of the dental curable compositions of Examples 1 to 5 and 11 to 12, and Comparative Examples 1 to 2 and 9 to 10 were weighed with an electronic balance and formed into a spherical shape to obtain a sample for evaluation. The sample for evaluation was placed on a polyester film, another polyester film was placed on the sample for evaluation, and it was placed at the center of the bottom surface of an instrument provided with a guide so that a vertical force was applied. A 3.25 kg weight was gently placed along the guide thereon and compressed for 60 seconds. The diameter of the sample for evaluation after removing the weight was measured at 45-degree intervals (4 locations), and the elongation rate obtained from the following formula was used as the value of consistency, and the average value thereof was used as the consistency of the sample for evaluation. Since the diameter of the sample before compression was about 8 mm, the elongation rate was obtained with the diameter of the sample before compression being 8 mm (fixed value) for all samples. The measurement was carried out in an environment at 25°C. L X =(L1 - L0) / L0×100 L X : Elongation rate [%] = Consistency [%] L0: Sample diameter before compression [mm] L1: Sample diameter after compression [mm] Note that the shape retention and consistency vary depending on the composition ratios of the A component, B component, C component, and D component. However, since the content of the D component in the dental curable composition is extremely small compared to other components, it is expected that there is almost no influence on the shape retention and consistency. Therefore, for Examples 6 to 10 and Comparative Examples 3 to 8, which differ only in the D component compared to Example 2, it is considered that they exhibit the same shape retention and consistency as Example 2.

[0106] ​ If the elongation rate was 160% or more, it was judged as qualified (〇), and if it was less than 160%, it was judged as unqualified (×).

[0107] As a comprehensive judgment, if all items were qualified, it was judged as "〇", and if there was even one unqualified item, it was judged as "×". These results are shown in Tables 1 to 5.

[0108]

Table 1

[0109]

Table 2

[0110]

Table 3

[0111]

Table 4

[0112]

Table 5

[0113] <Result> From the test results of Tables 1 to 4, all the dental curable compositions of Examples 1 to 12 passed all the evaluation items, and the comprehensive judgment was also qualified. The curable composition of Comparative Example 1 had an unqualified consistency (elongation rate) because the mixing ratio of Component B to Component A was 1:10 and the ratio of Component A was too high. The curable composition of Comparative Example 2 had an unqualified shape retention because the mixing ratio of Component B to Component A was 1:0.75 and the ratio of Component A was too low. The curable compositions of Comparative Examples 3 to 6 had an unqualified color tone compatibility because the chromaticity (a * and / or b * ) of the cured body was out of the numerical range. The curable compositions of Comparative Examples 7 to 8 had an unqualified color tone compatibility because the lightness (L * ) and / or chromaticity (a * ) of the cured body was out of the numerical range. The curable composition of Comparative Example 9 had unqualified color tone compatibility and shielding property because the transmittance of the cured body was lower than 52. The curable composition of Comparative Example 10 had an unqualified transmittance, turbidity, and lightness (L* ) was out of the predetermined numerical range, resulting in non-compliance with color tone compatibility and shielding properties. From Table 5, the composite resins of Reference Examples 1 and 2 were both out of the predetermined numerical range in terms of color tone compatibility with the A4 shade of the cured body, and were non-compliant with color tone compatibility and shielding properties compared to the dental curable composition of the present invention. Reference Example 3 passed the color tone compatibility test but failed the shielding property test.

Claims

1. (A) SiO ２ , ZrO ２ and Al ２ O ３ and an amorphous composite metal oxide filler containing the same (B) Spherical SiO with an average particle diameter of 50 nm or less ２ filler A dental curable composition containing (C) a (meth)acrylate polymerizable monomer and (D) a coloring agent, wherein the (D) coloring agent includes a red pigment, a yellow pigment, a black pigment, and a white pigment, The above-mentioned (B) SiO ２ The mixing ratio (mass ratio) of the filler and the above-mentioned (A) composite metal oxide filler is 1:0.8 to 1:8, and their contents are based on 100 parts by mass in total of the (A) amorphous composite metal oxide filler containing SiO₂, ZrO₂, and Al₂O₃, the (B) spherical SiO₂ filler with an average particle diameter of 50 nm or less, and the (C) (meth)acrylate polymerizable monomer, the red pigment is 0.0003 to 0.0009 parts by mass, the yellow pigment is 0.0004 to 0.0011 parts by mass, the black pigment is 0.0003 to 0.002 parts by mass, and the white pigment is 0.05 to 0.18 parts by mass, and the color difference (ΔE) between the color tone of a 15 mm diameter and 1 mm thick tooth color standard pellet corresponding to the color tones from A1 to A4 of the shade guide used as the tooth color standard and the color tone of a cured body with a diameter of 15 mm and a thickness of 1 mm after polymerization curing of the dental curable composition when the cured body is overlaid on the tooth color standard pellet is 10.5 or less. A dental curable composition.

2. The dental curable composition according to claim 1, wherein the (A) composite metal oxide filler is a filler composed of secondary particles with an average particle diameter of 2 to 8 μm in which primary particles with an average particle diameter of 0.1 to 0.9 μm are partially bonded by sintering.

3. The dental curable composition according to claim 1, wherein the opal value of a cured body with a thickness of 1 mm after polymerization curing of the dental curable composition is 10 or more and 23 or less.

4.

5. The dental curable composition according to claim 1, wherein the dental curable composition is formed into a disk shape with a diameter of 12 mm and a thickness of 1 mm, and a cut is made with a metal plate with a thickness of 1 mm to divide the dental curable composition into two halves. The ratio (Y Ｗ / Y Ｂ : contrast ratio) of the Y value (Y Ｂ ) of the cured body with a thickness of 1 mm after polymerization curing of the dental curable composition on a black background to the Y value (Y Ｗ ) on a white background is 0.43 or more and 0.58 or less. The dental curable composition according to claim 1. When left standing at 37°C, the divided dental curable compositions are deformed, and the time until the divided dental curable compositions come into contact with each other is 300 seconds or more. The dental curable composition according to claim 1.

6. The dental curable composition according to claim 1, wherein 0.65 g of the dental curable composition is formed into a spherical shape, and when a 3.25 kg weight is placed on it from above and left standing for 60 seconds, the elongation rate (consistency) is 160% or more.

7. The dental curable composition according to claim 1, which is a paste.

8. A cured body obtained by polymerizing and curing the dental curable composition according to claim 1.

9. ​ ​ A dental material obtained by polymerizing and curing the dental curable composition according to claim 1.

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