JP2012153640A - Complex restorative material for dental use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a complex restorative material for dental use that has high operability and high mechanical strength of paste, has high transparency, has an opal effect, and keeps the opal effect at a high degree even when the paste is stored in a long time.SOLUTION: The complex restorative material for dental use includes: (A) 100 pts.mass of a polymerizable monomer; (B) spherical silica-titanium-group-oxide-based composite oxide particles [I-1] where the average primary particle diameter is in the range of 0.15-0.50 μm and the standard deviation of particle diameter is within 1.30; (C) organic/inorganic composite filler where silica-titanium-group-oxide-based composite oxide fine particles [II-1] having an average primary particle diameter of 0.01-0.10 μm are dispersed in an organic resin matrix by 50-75 mass% and the refractive index difference from a cured body of the polymerizable monomer (A) is 0.10 or lower; and (D) an effective amount of polymerization initiator.

Description

  The present invention relates to a dental composite restorative material. More specifically, the present invention relates to a dental composite restorative material having good transparency and an opal effect and excellent in aesthetics.

  Dental composite restorative materials have rapidly spread as a material for restoring treated teeth because they can provide the same color tone as natural tooth colors and are easy to operate.In recent years, most of the treatment of front teeth Is being used not only with composite restorative materials, but also for the restoration of molars and the like that are subject to high occlusal pressure.

  In recent years, not only restoration of occlusion but also demand for aesthetic restoration that looks like natural teeth is increasing, and restoration materials that can reproduce not only the equivalent color tone but also the transparency and color tone of each part of the tooth Is required.

  Natural teeth consist of dentin and enamel, and their color or shade is mostly from dentin and is transmitted through the enamel, which is almost transparent and colorless, to the tooth surface. In particular, since the incisal portion of the front tooth is a portion containing a large amount of enamel, it is known that it has higher transparency than other portions and emits milky light peculiar to enamel.

  Milky white light is a light scattering phenomenon in a transparent material that is described as an “opal effect” typified by the mineral opal, in which the light reflected by the scattering of short wavelength light is blue and the transmitted light is orange. . In order to perform aesthetic restoration, it is necessary to reproduce such a delicate color tone. As a composite restoration material, a material having high transparency and an opal effect has been demanded.

  The dental composite restorative material is generally composed mainly of a polymerizable monomer (monomer), a filler, and a polymerization catalyst, but the operability of the paste before curing, the aesthetics and mechanical strength of the cured body, This greatly depends on the type, shape, particle diameter, filling amount, etc. of the filler used. For example, in order to make the composite restorative material into a paste property with good operability and sufficient mechanical strength of the cured body, the filler is preferably blended in an equivalent amount with respect to the polymerizable monomer exhibiting a liquid state. It will be necessary. In order to increase the mechanical strength of the cured body, an amorphous filler obtained by pulverization is effective. However, the blending of the amorphous filler deteriorates the polishing properties and wear resistance, and causes a problem that a glossy finished surface similar to natural teeth cannot be obtained clinically. Further, the particle size distribution is wide, and the above opal effect is hardly obtained.

  In order to solve this problem, various proposals have been made to use an inorganic filler having a relatively small particle diameter, particularly an inorganic filler composed of spherical inorganic particles and / or aggregates thereof. Among these, as examples having an opal effect, examples using an inorganic filler having a particle size range of 0.2 to 0.6 μm (Patent Document 1, Claims), and an average particle size of 0.18 to 0.28 μm Examples using inorganic fillers (Patent Document 2,

Column) and the like (hereinafter, these inorganic fillers are referred to as “opal imparting fillers”). These opal imparting fillers are more advantageous because the opal effect becomes clearer as the particle size distribution becomes sharper in addition to the spherical shape. In addition, in these blending examples of the opal property-imparting filler, in addition to the opal property-imparting filler, the average primary particle size is further increased in order to increase the filler filling amount and to obtain a paste property and high mechanical strength with good operability. Is also blended with a fine inorganic filler of 0.1 μm or less.

  In these dental composite filler materials, silica-based particles are suitable because the inorganic filler has a small difference in refractive index from the polymerizable monomer, the cured product is transparent, and the opal effect is easily exhibited. Among these, since the refractive index can be finely adjusted by changing the composite ratio, it is advantageous to use silica-based composite oxide particles composed of silica and other metal oxides. Since it is particularly small and can impart radiopacity, composite oxide particles of silica and titanium group oxide (silica / titanium group oxide composite oxide particles) such as silica / zirconia particles and silica / titania particles Is optimal.

  In addition, in patent document 2, the organic inorganic composite filler is described as one of arbitrary additives other than the said opal provision filler and a fine inorganic filler (

Column). However, as for the inorganic filler dispersed in the filler, various types such as pulverized glass and silica are shown, and there is no specific explanation for the particle size.

Special table 2003-511400 gazette Special table 2007-532518

  The present inventors have made various additional trials for the dental composite filling material in which the above-mentioned opalizing filler and the fine inorganic filler are combined, when the silica / titanium group oxide composite oxide particles are used as these fillers. . Then, if the average primary particle size of the fine inorganic filler is 0.10 μm or less, the filler filling amount can be increased as described above, and the operability and mechanical strength of the paste are good, and the particle size is sufficiently larger than the visible light wavelength. Therefore, the transparency of the cured product was kept high, and the opal effect was obtained very well.

  However, this composite filling material has insufficient storage stability of the color tone, and when the paste is stored for a long period of time, the color changes and the above-mentioned opal effect imparted with a corner is greatly reduced. This is because the surface acid point of the silica-titanium group oxide-based composite oxide particles is a particularly strong acid point, and the minute inorganic filler has a large specific surface area, so that the polymerizable monomer component and the polymerization initiator component This is thought to be due to the loss of stability. Since the opal effect is caused by the delicate light scattering phenomenon, the occurrence of slight discoloration is greatly reduced.

  From the above, in the dental composite restorative material having good operability and mechanical strength of the paste, excellent transparency, and also having an opal effect, the opal effect is highly maintained even if the paste is stored for a long period of time. Developing was a major challenge.

  In view of the above problems, the present inventors have continued intensive research. As a result, by using at least a part of silica-titanium group oxide composite oxide fine particles having an average primary particle diameter of 0.01 to 0.10 μm in an organic-inorganic composite filler, the above-mentioned problems are solved. The present inventors have found that this can be done and have completed the present invention.

That is, the present invention includes (A) 100 parts by mass of a polymerizable monomer,
(B) Spherical silica / titanium group oxide-based composite oxide particles [I−] having an average primary particle size in the range of 0.15 to 0.50 μm and a standard deviation of the particle size distribution within 1.30. 1] 40-200 parts by weight,
(C) Silica / titanium group oxide composite oxide fine particles [II-1] having an average primary particle diameter in the range of 0.01 to 0.10 μm are dispersed in an organic resin matrix by 40 to 75 mass%. (A) 90 mass parts or more of the organic-inorganic composite filler having a refractive index difference of 0.1 or less with respect to the cured product of the polymerizable monomer, and (B) silica / titanium group oxide composite oxide particles A dental composite restorative material comprising a blending amount of [I-1] not exceeding 550 parts by mass and (D) an effective amount of a polymerization initiator.

  The dental composite restorative material of the present invention not only has good operability and mechanical strength of the paste, but also has high transparency and an opal effect, and allows natural restoration of teeth. Further, these excellent aesthetic properties are also excellent in storage stability, and in particular, the disappearance of the opal effect can be highly suppressed even when the composite restoration material is stored for a long period of time.

  The dental composite restorative material of the present invention comprises (A) a polymerizable monomer, (B) silica / titanium group oxide composite oxide particles [I-1], (C) an organic-inorganic composite filler, (D) It contains a polymerization initiator. Here, the organic-inorganic composite filler means a composite filler of a polymer and composite oxide fine particles.

  The greatest feature of the present invention is that the silica-titanium group oxide composite oxide fine particles having an average primary particle size of 0.01 to 0.10 μm are blended to improve the operability and mechanical strength of the paste. About [II], it exists in the point which included at least one part ([II-1]) in the (C) organic inorganic composite filler. As a result, a large number of strong acid points existing on the particle surface are included in the organic resin matrix and do not come into direct contact with the (A) polymerizable monomer component or (D) polymerization initiator component. . As a result, alteration of (A) the polymerizable monomer component and (D) the polymerization initiator component is suppressed, and the color tone is maintained at a high level even when the composite restoration material is stored for a long period of time. It will not do. In addition, blending the (C) organic-inorganic composite filler in this manner is also effective in reducing polymerization shrinkage when the composite restorative material is cured.

Hereinafter, each component of the dental curable material of the present invention will be described.

<(A) Polymerizable monomer>
In the dental composite restorative material of the present invention, known polymerizable monomers are not particularly limited, and radical polymerizable monomers and cationic polymerizable monomers can be used. When viewed as a dental use, from the viewpoint of polymerization rate, it is preferable to use a radical polymerizable monomer, and more preferably a polyfunctional one. Particularly preferred radical polymerizable monomers are polyfunctional (meth) acrylate polymerizable monomers. Examples of polyfunctional (meth) acrylate polymerizable monomers include those shown in the following (a) to (c).

(I) Bifunctional polymerizable monomer (i) Aromatic compound-based 2,2-bis (methacryloyloxyphenyl) propane,
2,2-bis [4- (3-methacryloyloxy) -2-hydroxypropoxyphenyl] propane,
2,2-bis (4-methacryloyloxyphenyl) propane,
2,2-bis (4-methacryloyloxypolyethoxyphenyl) propane,
2,2-bis (4-methacryloyloxydiethoxyphenyl) propane,
2,2-bis (4-methacryloyloxytetraethoxyphenyl) propane,
2,2-bis (4-methacryloyloxypentaethoxyphenyl) propane,
2,2-bis (4-methacryloyloxydipropoxyphenyl) propane,
2 (4-methacryloyloxydiethoxyphenyl) -2 (4-methacryloyloxytriethoxyphenyl) propane,
2 (4-methacryloyloxydipropoxyphenyl) -2- (4-methacryloyloxytriethoxyphenyl) propane,
2,2-bis (4-methacryloyloxypropoxyphenyl) propane,
2,2-bis (4-methacryloyloxyisopropoxyphenyl) propane and acrylates corresponding to these methacrylates;
Methacrylates having —OH groups such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, etc., or acrylates having —OH groups corresponding to these methacrylates, diisocyanate methylbenzene, 4, 4 Diadduct obtained by addition with a diisocyanate compound having an aromatic group such as' -diphenylmethane diisocyanate.

(Ii) aliphatic compound-based ethylene glycol dimethacrylate,
Diethylene glycol dimethacrylate,
Triethylene glycol dimethacrylate,
Tetraethylene glycol dimethacrylate,
Neopentyl glycol dimethacrylate,
1,3-butanediol dimethacrylate,
1,4-butanediol dimethacrylate,
1,6-hexanediol dimethacrylate,
1,2-bis (3-methacryloyloxy-2-hydroxypropoxy) ethyl and acrylates corresponding to these methacrylates;
Methacrylates having —OH groups such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, etc., or acrylates having —OH groups corresponding to these methacrylates, hexamethylene diisocyanate, trimethylhexamethylene Diaducts obtained from adducts with diisocyanate compounds such as diisocyanate, diisocyanate methylcyclohexane, isophorone diisocyanate, and methylenebis (4-cyclohexylisocyanate).

(B) Trifunctional polymerizable monomer trimethylolpropane trimethacrylate,
Trimethylolethane trimethacrylate,
Pentaerythritol trimethacrylate,
Trimethylol methane trimethacrylate and acrylates corresponding to these methacrylates.

(C) tetrafunctional polymerizable monomer pentaerythritol tetramethacrylate,
Pentaerythritol tetraacrylate;
Diisocyanate compounds and glycidol such as diisocyanate methylbenzene, diisocyanate methylcyclohexane, isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, methylenebis (4-cyclohexylisocyanate), 4,4-diphenylmethane diisocyanate, tolylene-2,4-diisocyanate Diaducts obtained from adducts with dimethacrylate or glycidol diacrylate.

  These polyfunctional (meth) acrylate-based polymerizable monomers usually have a cured product having a refractive index (25 ° C.) of 1.45 to 1.60, more preferably 1.52 to 1.56. It is. Among these, it is preferable to select and use such that the difference becomes small according to the refractive index (25 ° C.) of the (C) organic-inorganic composite filler to be used (specific values of the refractive index difference will be described later). To do). Two or more kinds of polymerizable monomers may be combined and adjusted to a desired refractive index as a whole. In general, many aromatic polymerizable monomers exhibit a high refractive index, and many aliphatic polymerizable monomers exhibit a low refractive index. Usually, it is preferable to adjust by adding 20% by mass or more of the aromatic polymerizable monomer with respect to the total amount of the polymerizable monomer.

Furthermore, if necessary, the polymerizable monomer includes
Methyl methacrylate,
Ethyl methacrylate,
Isopropyl methacrylate,
Hydroxyethyl methacrylate,
Tetrahydrofurfuryl methacrylate,
Methacrylates such as glycidyl methacrylate,
In addition, monofunctional (meth) acrylate monomers such as acrylates corresponding to these methacrylates, or radical polymerizable monomers other than the (meth) acrylate monomers may be used.

<(B) Spherical silica / titanium group oxide-based composite oxide particles having an average primary particle size in the range of 0.15 to 0.50 μm and a standard deviation of the particle size distribution within 1.30 [I -1]>
The dental composite restorative material of the present invention contains silica / titanium group oxide composite oxide particles [I-1] having an average primary particle size of 0.15 to 0.50 μm for the purpose of giving an opal effect. Is done. Here, for the expression of the opal effect, it is important that the average primary particle diameter of the composite oxide particles [I-1] is 0.15 to 0.50 μm. In other words, the expression of the opal effect is due to diffraction interference occurring in accordance with the Bragg condition and the enhancement of light of a specific wavelength. Will develop the aesthetic properties. From the viewpoint of further enhancing the opal effect, the average primary particle diameter of the silica / titanium group oxide-based composite oxide is more preferably 0.15 to 0.30 μm, and particularly preferably 0.18 to 0.28 μm. .

  In addition, it is important that the silica-titanium group oxide-based composite oxide particles [I-1] have a primary particle diameter in the above average value range. If the particles satisfy this requirement, each of the primary particles is It may exist as some aggregated particles. However, it is preferable to exist as independent particles as much as possible. Specifically, it is preferable that aggregated particles of 10 μm or more are less than 10% by volume.

  In the present invention, the average primary particle size of the particles is obtained by taking a photograph of the powder with a scanning electron microscope, selecting 30 or more of the particles observed within the unit field of view of the photograph, (Mean diameter) is the average value.

  Further, the shape of the silica / titanium group oxide composite oxide particles [I-1] needs to be spherical because scattered light becomes uniform and vivid color appears. Furthermore, since the uniformity of the scattered light increases when the particle size is uniform, the standard deviation of the primary particle size distribution is within 1.30, preferably within 1.20.

  Here, the particles are spherical as long as they are substantially spherical, and are not necessarily perfect spheres. In general, a photograph of particles is taken with a scanning electron microscope, and for each particle (30 or more) in the unit field of view, the average uniformity in which the particle diameter in the direction perpendicular to the maximum diameter is gradually reduced by the maximum diameter. Is 0.6 or more, more preferably 0.8 or more.

  On the other hand, the particle size distribution of the particles is a value obtained from the following calculation formula by taking a photograph of the powder with a scanning electron microscope, selecting 30 or more particles observed in the unit field of view of the photograph. .

  In the present invention, the silica-titanium group oxide-based composite oxide is a composite oxide of silica and a titanium group (group IV element of the periodic table), such as silica-titania, silica-zirconia, silica-titania. -Zirconia etc. are mentioned. Among these, silica / zirconia is preferred because it has a strong acid strength at the surface acid point and a remarkable effect of reducing the disappearance of the opal effect, and can also impart high radiopacity. The composite ratio is not particularly limited, but the content of silica is 70 to 95 mol% from the viewpoint of imparting sufficient radiopacity and making the refractive index in a suitable range described later, and the titanium group The thing whose content of an oxide is 5-30 mol% is preferable. In the case of silica zirconia, the refractive index can be freely changed in the range of 1.48 to 1.56 by changing the composite ratios in this way.

  These silica / titanium group oxide-based composite oxides are allowed to be combined with metal oxides other than silica and titanium group oxides, as long as the amount is small. Specifically, an alkali metal oxide such as sodium oxide or lithium oxide may be contained within 10 mol%.

  The method for producing such silica / titanium group oxide composite oxide particles is not particularly limited. For example, a mixed solution containing a hydrolyzable organosilicon compound and a hydrolyzable organotitanium group metal compound is used as an alkaline solvent. A so-called sol-gel method is preferably employed in which the reaction product is precipitated by addition into the product and hydrolysis.

  These silica / titanium group oxide composite oxide particles may be surface-treated with a silane coupling agent. By the surface treatment with the silane coupling agent, the (A) polymerizable monomer is excellent in interfacial strength with the cured body portion. Examples of typical silane coupling agents include organosilicon compounds such as γ-methacryloyloxyalkyltrimethoxysilane and hexamethyldisilazane. There is no particular limitation on the surface treatment amount of these silane coupling agents, and it is sufficient to determine the optimum value after confirming in advance the mechanical properties and the like of the resulting composite restoration material, but if a suitable range is exemplified, The range is 1 to 10 parts by weight with respect to 100 parts by weight of the particles.

  As described above, the opal effect appears more clearly when the cured product is highly transparent. Therefore, the silica / titanium group oxide composite oxide particles [I-1] have a refractive index difference of 0.10 or less, more preferably 0.05 or less, from the cured product of the polymerizable monomer (A). Therefore, it is preferable to select and use one that does not impair the transparency as much as possible.

  The blending amount of (B) silica-titanium group oxide composite oxide particles [I-1] in the present invention is 40 to 200 parts by mass with respect to 100 parts by mass of (A) polymerizable monomer. By blending 40 parts by mass or more of silica / titanium group oxide-based composite oxide [I-1], the opal effect is favorably expressed. On the other hand, it is generally difficult to blend a large amount of particles having an average primary particle size of 0.15 to 0.5 μm exceeding 200 parts by mass. In addition, as the composite oxide particles [I-1], when the difference in refractive index from the cured product of the polymerizable monomer (A) exceeds 0.10, the transparency of the cured product is reduced. As a result, the opal effect may not be sufficiently exhibited. Considering these, the blending amount of (B) silica / titanium group oxide composite oxide particles [I-1] is preferably 60 to 180 parts by mass with respect to 100 parts by mass of (A) polymerizable monomer. 70 to 160 parts by mass is particularly preferable.

<(C) Silica / titanium group oxide composite fine particles [II-1] having an average primary particle size in the range of 0.01 to 0.10 μm are dispersed in an organic resin matrix in an amount of 40 to 75% by mass. (A) Organic-inorganic composite filler having a refractive index difference of 0.10 or less from the cured product of the polymerizable monomer>
The greatest feature of the present invention is that at least part of the silica / titanium group oxide-based composite oxide fine particles [II-1] having an average primary particle diameter in the range of 0.01 to 0.10 μm is used as the organic / inorganic composite filler. It is in the point made to contain. As a result, the strong acid point present on the particle surface does not come into direct contact with the (A) polymerizable monomer component or (D) polymerization initiator component, and the transparency of the cured product is maintained even after long-term storage. The problem of a decrease in the opal effect is greatly improved.

  Here, the average primary particle diameter of the silica / titanium group oxide composite fine particles [II-1] needs to be in the range of 0.01 to 0.10 μm. That is, since this particle size is sufficiently smaller than the visible light wavelength, light scattering is unlikely to occur, and the filler filling amount can be increased while maintaining the transparency of the cured body high, and the cured body of the composite repair material can be increased. It becomes possible to increase the mechanical strength. Note that particles having an average primary particle diameter of less than 0.01 μm have a high viscosity and are difficult to handle. The average primary particle diameter of the silica / titanium group oxide composite oxide fine particles [II-1] is more preferably 0.01 to 0.08 μm, and 0.05 to 0.08 μm. Particularly preferred.

  The silica / titanium group oxide composite oxide fine particles [II-1] may have some aggregated particles as in the composite oxide particles [I-1]. Moreover, since the shape is a sufficiently small particle diameter, it can be used in a spherical shape or an indefinite shape. Further, the primary particle size distribution is not particularly limited, but the standard deviation is preferably within 1.30, particularly preferably within 1.20 so as not to inhibit the light scattering effect.

  As the silica-titanium group oxide composite oxide constituting the composite oxide fine particles [II-1], the same one as described in the composite oxide particles [I-1] is used. Of course, it may be surface-treated with a silane coupling agent.

  The content of silica / titanium group oxide composite fine particles [II-1] in the organic-inorganic composite filler (filling ratio with respect to the organic-inorganic composite filler) is 40 to 75% by mass. When the content in the organic-inorganic composite filler is less than 40% by mass, it is difficult to sufficiently increase the mechanical strength of the cured body of the composite restorative material. In addition, it is difficult in terms of operation to make the composite oxide fine particles [II-1] more than 75 mass% contained in the organic-inorganic composite filler, or it becomes difficult to obtain a homogeneous product. A more preferable content of the composite oxide fine particles [II-1] in the organic-inorganic composite filler is 45 to 75% by mass.

  (C) In the organic-inorganic composite filler, the organic resin matrix is not limited to a homopolymer or a plurality of copolymers of the same polymerizable monomer as that described as the (A) polymerizable monomer. Can be adopted.

  The (C) organic-inorganic composite filler does not lower the transparency of the composite restorative material due to its blending, so that the refractive index difference from the cured product of the (A) polymerizable monomer is 0.10 or less, more preferably It is necessary to use those having the same refractive index difference adjusted to 0.05 or less. As a result, the opal effect of (B) silica / titanium group oxide-based composite oxide particles [I-1] can be favorably expressed. Such adjustment of the refractive index of the (C) organic-inorganic composite filler may be carried out by appropriately selecting the type and blending ratio of the composite oxide fine particles [II-1] to be used and the organic resin matrix.

  In the present invention, (C) the organic-inorganic composite filler is a method of mixing predetermined amounts of each component of the composite oxide fine particles [II-1], the polymerizable monomer, and the polymerization initiator, and heating or light irradiation. The polymer may be produced according to a general production method of an organic-inorganic composite filler that is polymerized and then pulverized. As the polymerization initiator, a known polymerization initiator is used without particular limitation. However, since a cured product having a lower yellowness can be obtained, it is preferable to use a thermal polymerization initiator, and further, an aromatic substance is included in the structure. It is more preferable to use a compound made of a compound having no group ring.

  In the present invention, the average particle diameter of the organic-inorganic composite filler (C) is not particularly limited, but is preferably 2 to 100 μm from the viewpoint of improving the mechanical strength of the cured body and the operability of the curable paste. Furthermore, 5-50 micrometers is more preferable, and it is especially preferable that it is 15-30 micrometers.

  (C) In addition to silica / titanium group oxide composite oxide particles [II-1], the organic / inorganic composite filler has the same category as silica / titanium group oxide composite oxide particles [I-1]. It is effective to contain particles ([I-2]). The opal effect is better exhibited in the composite restorative material as the opal imparting filler is more uniformly dispersed. Therefore, the composite oxide particle [I-2] is also contained in the organic-inorganic composite filler. Therefore, it is possible to further enhance the aesthetic properties.

  (C) When the organic-inorganic composite filler contains silica / titanium group oxide composite oxide particles [I-2], the content is 5% by mass or more in the organic resin matrix, and (A) polymerization The amount by which the difference in refractive index from the cured monomer is maintained at 0.10 or less is preferred. In addition, when [I-2] and [II-1] of the silica-titanium group oxide-based composite oxide particles are used in combination, due to the effect of improving the filling property due to the difference in the particle diameter of each other, The total content can be increased as compared with the case where [II-1] is contained alone. For this reason, the compounding amount of the composite oxide particles [I-2] to the organic-inorganic composite filler is such that the total amount with the silica / titanium group oxide composite oxide fine particles [II-1] does not exceed 85% by mass. Is preferred.

  Furthermore, in consideration of the expression of a more uniform opal effect, the content of the composite oxide particles [I-2] in the organic-inorganic composite filler is (B) the composite oxide with respect to (A) the polymerizable monomer. It is preferable that the blending amount of the particles [I-1] is not so different (within a range of 0.5 to 2.0 mass times).

  The composite oxide particles [I-2] to be contained in the organic-inorganic composite filler are preferably the same type of silica / titanium group oxide composite oxide as the composite oxide fine particles [II-1] Different types may be used.

  (C) A well-known additive can be mix | blended with the organic inorganic composite filler in the range which does not inhibit the effect. Specific examples include pigments, polymerization inhibitors, and fluorescent brighteners. In addition, the organic-inorganic composite filler may be further subjected to a surface treatment with a cleaning agent, a silane coupling agent or the like before being used as a dental composite restorative material.

  The blending amount of the (C) organic-inorganic composite filler in the present invention is 90 parts by mass or more with respect to (A) 100 parts by mass of the polymerizable monomer, and (B) silica / titanium group oxide composite oxide particles. The total amount with [I-1] does not exceed 550 parts by mass. That is, in order to improve the operability of the composite restoration material paste and the mechanical strength of the cured body by blending the organic-inorganic composite filler, the organic-inorganic composite filler is 120 parts by mass or more, more preferably 140 parts by mass. The above needs to be blended.

  In addition, it is difficult in terms of operation to add a large amount of (C) organic-inorganic composite filler in excess of 550 parts by mass in total with (B) silica / titanium group oxide-based composite oxide particles [I-1]. It is difficult to obtain a homogeneous composite repair material. Furthermore, the transparency of the cured body of the composite restorative material is lowered, and the opal effect may not be sufficiently exhibited. Considering these, the blending amount of (C) the organic-inorganic composite filler is such that the total amount with (B) silica / titanium group oxide composite oxide particles [I-1] does not exceed 470 parts by mass. More preferably.

<(D) Polymerization initiator>
The polymerization initiator used in the present invention is blended for the purpose of polymerizing and curing the present composition, and any known polymerization initiator is used without particular limitation.

  Among them, a photopolymerization initiator (composition) or a chemical polymerization initiator composition is preferable for dental direct filling and restoration use, which is often cured in the oral cavity, and there is no need for a mixing operation. Composition) is preferred.

  Polymerization initiators used for photopolymerization include benzoin alkyl ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether, benzyl ketals such as benzyldimethyl ketal and benzyl diethyl ketal, benzophenone, and 4,4′-dimethylbenzophenone. Benzophenones such as 4-methacryloxybenzophenone, diacetyl, 2,3-pentadionebenzyl, camphorquinone, 9,10-phenanthraquinone, α-diketones such as 9,10-anthraquinone, 2,4-dike Thioxanthone compounds such as ethoxythioxanthone, 2-chlorothioxanthone, methylthioxanthone, bis- (2,6-dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzene) Zoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis (2 , 4,6-Trimethylbenzoyl) -phenylphosphine oxide, etc. can be used.

  Incidentally, a reducing agent is often added to the photopolymerization initiator. Examples thereof include tertiary amines such as 2- (dimethylamino) ethyl methacrylate, ethyl 4-dimethylaminobenzoate, and N-methyldiethanolamine. Aldehydes such as lauryl aldehyde, dimethylaminobenzaldehyde and terephthalaldehyde, and sulfur-containing compounds such as 2-mercaptobenzoxazole, 1-decanethiol, thiosalicylic acid and thiobenzoic acid.

  Furthermore, there are many cases where a photoacid generator is used in addition to the photopolymerization initiator and the reducing compound. Examples of such a photoacid generator include diaryl iodonium salt compounds, sulfonium salt compounds, sulfonate ester compounds, halomethyl-substituted S-triazine conductors, pyridinium salt compounds, and the like.

  In the present invention, the change in color tone of the composite restorative material due to the silica / titanium group oxide composite oxide fine particles [II-1] occurs remarkably when amines are contained as a reducing agent in the polymerization initiator. In the present invention, it is particularly effective to apply to a polymerization initiator containing an amine as a component.

  These polymerization initiators may be used alone or in combination of two or more. The blending amount of the polymerization initiator may be an effective amount depending on the purpose, but is usually 0.01 to 10 parts by weight, more preferably 0.1 to 100 parts by weight of the polymerizable monomer. Used in a proportion of ˜5 parts by weight.

<(E) Silica-titanium group oxide composite oxide fine particles having an average primary particle size in the range of 0.01 to 0.10 μm and a standard deviation of the particle size distribution within 1.30 [II-2 ]>
In the dental composite restorative material of the present invention, silica / titanium group oxide composite oxide fine particles [II] having an average primary particle diameter in the range of 0.01 to 0.10 μm are used. In addition to what is added to (II-1), it may be added as a separate component [II-2]. That is, in order to impart sufficient mechanical strength to the cured body of the composite restorative material, (B) silica / titanium group oxide composite oxide particles [I-1] and (C) an organic-inorganic composite filler are blended. As the mechanical strength increases as the filler filling amount of the composite restorative material increases, as a separate component, (A) silica / titanium with respect to the polymerizable monomer It is preferable to add group oxide composite oxide fine particles [II-2].

  As described above, silica-titanium group oxide composite oxide fine particles [II] are blended in the composite restorative material as they are without being included in the organic-inorganic composite filler, and the opal effect is obtained when the paste is stored for a long period of time. Go down. However, in the present invention, since it is only blended ([II-2]) as a part of the silica / titanium group oxide composite oxide fine particles [II], it is blended with the organic-inorganic composite filler ([II-1] ) The effect of preventing the reduction of the opal property is exhibited only by the amount obtained.

  (E) The silica / titanium group oxide composite oxide fine particles [II-2] do not inhibit the light scattering effect, and (B) the primary particles of the silica / titanium group oxide composite oxide particles [I-1]. In order to clearly distinguish the particle size from the particle size range, the standard deviation of the primary particle size distribution is within 1.30, and further within 1.20. The detailed particle properties of the other (E) silica / titanium group oxide composite fine particles [II-2] are as follows: (C) silica / titanium group oxide composite oxide mixed with the organic / inorganic composite filler This is the same as the fine particle [II-1].

  In the present invention, the blending amount of the (E) silica / titanium group oxide composite oxide fine particles [II-2] is the same as the reason for blending the (C) organic-inorganic composite filler. The total amount of (B) silica / titanium group oxide composite oxide particles [I-1] and (C) organic-inorganic composite filler does not exceed 550 parts by mass with respect to 100 parts by weight of the monomer. is there. Further, from the viewpoint of preventing a decrease in the opal effect, the amount of the silica / titanium group oxide composite oxide fine particles [II-2] is 120 with respect to 100 parts by weight of the polymerizable monomer (A). It is preferable to keep it below mass parts, more preferably below 100 mass parts.

  Furthermore, from the viewpoint of sufficiently exerting the blending effect of the (E) silica / titanium group oxide composite fine particles [II-2], 50 masses per 100 mass parts of the polymerizable monomer (A). It is desirable to blend at least 70 parts by weight, more preferably at least 70 parts by weight.

<Other additives>
In the dental composite restorative material of the present invention, other known additives can be blended in addition to the components (A) to (E) as long as the effect is not impaired. Specific examples include a polymerization inhibitor, a pigment, and an ultraviolet absorber.

<Opal properties of cured composite restoration materials>
The cured product of the dental composite restorative material of the present invention has excellent transparency and good opal properties. That is, the contrast ratio of a 1 mm-thick test piece, which is an index indicating transparency, in the cured body at the time of manufacturing the composite restoration material is usually an excellent value of 0.30 or less, more preferably 0.25 or less. Things are also obtained. Here, the contrast ratio is a value obtained by measuring the Y values of the tristimulus values with the background colors black and white using a color difference meter, and based on the following equation.

Contrast ratio = Y value in the case of black background color / Y value in the case of white background The test piece with the thickness of 1 mm is an index showing the opal effect, and ΔC * is usually an excellent value of 18 or more. More preferably, 20 or more are also obtained. Here, ΔC * is obtained by the following equation. The orange color of transmitted light is represented by a ^* representing red-green, and the blue color of reflected light is represented by b ^* representing blue-yellow.

ΔC * = √ (a ^* _b− a ^* _w ) ² + (b ^* _b− b ^* _w ) ²
(A ^* _b , b ^* _b : Color quality index with black background, a ^* _w , b ^* _w : Color quality index with white background)
Furthermore, the spectral reflectance when the test piece having the same thickness of 1 mm is a black background color is maximized at a wavelength of 420 to 470 nm. The condition of the black background color means measurement of light reflected from the test piece, and the hardened body of the dental composite restorative material of the present invention shows blue light due to excellent transparency and opal properties, 420 to 470 nm. The maximum is shown at the wavelength of.

  In the dental composite restorative material of the present invention, the properties of the cured body exhibiting such excellent transparency and opal properties are well maintained even when the composite restorative material is stored for a long period of time.

  In general, the dental composite restorative material of the present invention is sufficiently kneaded by taking a predetermined amount of each of the essential components and, if necessary, each optional component, and if necessary, defoaming the paste under reduced pressure to remove bubbles. It can be obtained by removing.

The dental composite restorative material of the present invention may be used in accordance with a general method for using a filling composite resin. Specifically, if (D) the polymerization initiator is a photopolymerization initiator, the cavity of the tooth to be restored is treated with an appropriate pretreatment material or adhesive, and then directly filled with the tooth cavity. Examples thereof include a method of irradiating with strong light with a dedicated light irradiator and then curing by polymerization after forming into a shape.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Various physical property measuring methods in the present invention are as follows.
(1) Average primary particle size and standard deviation of particle size distribution of composite oxide fine particles Take a picture of the powder with a scanning electron microscope (manufactured by JEOL Ltd., “T-330A”), and within the unit field of view of the photograph The number of particles to be observed (30 or more) and the particle diameter were measured, and the average particle diameter and standard deviation were calculated from the following formula based on the measured values.

(2) Average asymmetry of composite oxide fine particles Take a picture of the powder with a scanning electron microscope, and the number of particles observed in the unit field of view (n: 30 or more), the maximum diameter of the particles The major axis (Li) and the minor axis (Bi) were calculated from the diameter in the direction perpendicular to the major axis, and calculated according to the following formula.

(3) Specific Surface Area Measurement of Composite Oxide Fine Particles A specific surface area measurement apparatus “Flowsorb II2300” (manufactured by Shimadzu Corporation) was used for measurement by the BET method. Note that a mixture of 30% nitrogen and 70% helium was used, and liquid nitrogen was used as the refrigerant.

(4) Measurement of refractive index In a thermostatic chamber at 23 ° C., 1 g of composite oxide fine particles are dispersed in 50 ml of anhydrous toluene in a 100 ml sample bottle. While stirring this dispersion with a stirrer, 1-bromotoluene was dropped little by little, and the refractive index of the dispersion when the dispersion became the most transparent was measured with an Abbe refractometer, and the obtained value was combined. The refractive index of the oxide fine particles was used.

(5) Evaluation of opal effect The paste of the dental composite restorative material was put into a mold having a hole of 7 mmφ × 1 mm, and both sides were pressed with a polyester film. After irradiating and curing both sides with a visible light irradiator (Tokuyama, Powerlight) for 30 seconds each, remove it from the mold, and use a color difference meter (“TC-1800MKII”, manufactured by Tokyo Denshoku) Measurement was performed in black and white, and ΔC ^* was calculated based on the following formula, which was used as an index of the opal effect. Here, the orange color of transmitted light, which is a feature of the opal effect, is represented by a ^* representing red-green, and the blue color of reflected light is represented by b ^* representing blue-yellow.

ΔC ^* = √ (a ^* _b− a ^* _w ) ² + (b ^* _b− b ^* _w ) ²
(A ^* _b , b ^* _b : Color quality index with black background, a ^* _w , b ^* _w : Color quality index with white background)
Moreover, visual evaluation was performed based on the following parameter | index.

    4: A very vivid pale white color is seen in the background color black.

    3: A bright blue color is seen in the background color black.

    2: A blue color is seen in the black background.

    1: Blue color is not seen in the background color black or yellow.

(6) Storage stability evaluation of opal effect of cured body A paste of a dental composite restorative material was stored at 50 ° C. After 4 weeks, 6 weeks, and 8 weeks from the start of storage, a cured product was prepared in the same manner as in (5), and visual evaluation was performed based on the same index.

(7) Evaluation of transparency Using the color difference meter in the same manner as in (5), the Y values of the tristimulus values were measured with the background color black and white. The contrast ratio was calculated based on the following formula and used as an index of transparency.

      Contrast ratio = Y value when the background color is black / Y value when the background color is white

The polymerizable monomers, polymerization initiators, etc. used in the examples and comparative examples are as follows.
[Polymerizable monomer]
2,2-bis [(3-methacryloyloxy-2-hydroxypropyloxy) phenyl] propane (hereinafter abbreviated as “bis-GMA”)
Triethylene glycol dimethacrylate (hereinafter abbreviated as “3G”)
2,2-bis (4-methacryloyloxypolyethoxyphenyl) propane (hereinafter abbreviated as “D-2.6E”)
1,6-bis (methacrylethyloxycarbonylamino) trimethyloxane (hereinafter abbreviated as “UDMA”)
[Polymerization initiator]
Azobisisobutyronitrile (hereinafter abbreviated as “AIBN”)
Camphorquinone (hereinafter abbreviated as “CQ”).
N, N-dimethyl p-ethyl benzoate (hereinafter abbreviated as “DMBE”).
[Polymerization inhibitor]
Hydroquinone monomethyl ether (hereinafter abbreviated as “HQME”)
Dibutylhydroxytoluene (hereinafter abbreviated as “BHT”)
[Ultraviolet absorber]
2-hydroxy-4-methoxybenzophenone (hereinafter abbreviated as “BS110”)

Production Example 1 [Adjustment of organic resin matrix]
Polymerizable monomers as shown in Table 1 were mixed to prepare matrices M-1 to M-4.

The method for producing the particles used in the present invention is shown below.
Production Example 2 [Production of Silica / Titanium Group Oxide Composite Oxide Particles [I] and Fine Particles [II]]
The silica / titanium group oxide-based composite oxide particles used in Examples and Comparative Examples were produced by the following methods.
2-1) [Synthesis of spherical silica-titania particles having an average primary particle diameter of 0.25 μm]
170 g of tetraethyl silicate (manufactured by Colcoat, product name: ethyl silicate 28) was mixed with 400 g of methanol, 5 g of a 0.04 mass% hydrochloric acid aqueous solution was added, and the mixture was hydrolyzed while stirring at a temperature of 30 ° C. for about 1 hour. Thereafter, a solution prepared by dissolving 27 g of tetrabutyl titanate and 10 g of a sodium methylate methanol solution (concentration 30% by mass) in 200 g of isopropyl alcohol was mixed with this solution while stirring to prepare a mixed solution of tetraethyl silicate and tetrabutyl titanate. . Next, 1000 g of methanol was introduced into a glass container having an internal volume of 3 liters equipped with a stirrer, and 250 g of a 25% by mass aqueous ammonia solution was added thereto to prepare an ammoniacal alcohol solution. To this was added 2 g of tetraethyl silicate for producing silica seed particles, and after stirring for 30 minutes, the mixed solution of tetraethyl silicate and tetrabutyl titanate was added dropwise over about 5 hours.

  During the reaction, the temperature of the reaction vessel was kept at 40 ° C. After completion of the reaction, the solvent was distilled off from the clouded reaction vessel liquid, dried and baked at 950 ° C. for 1 hour to obtain silica-titania particles (PF-1). The silica-titania particles had a particle size distribution of 0.23 to 0.27 μm and an average primary particle size of 0.25 μm, and the shape thereof was spherical from SEM observation. The obtained particles were further surface-treated with γ-methacryloyloxypropylmethoxysilane. Various physical properties of the obtained particles are shown in Table 2.

2-2) [Synthesis of spherical silica-zirconia particles having an average primary particle diameter of 0.19 μm]
120 g of tetraethyl silicate (manufactured by Colcoat, product name: ethyl silicate 28) is mixed with 400 g of isobutyl alcohol (manufactured by Tosho Petrochemical), 5 g of 0.05% dilute sulfuric acid aqueous solution is added, and the mixture is stirred at 40 ° C. for about 1 hour. While hydrolyzing. Thereafter, a solution prepared by dissolving 25 g of tetrabutyl zirconate (manufactured by Nippon Soda Co., Ltd.) and 10 g of sodium methylate methanol solution (concentration: 28% by mass) in 200 g of isobutyl alcohol was mixed with stirring, and tetraethyl silicate and tetrabutyl were mixed. A mixed solution of zirconate was prepared. Next, 4 g of tetraethyl silicate was added while stirring in an ammoniacal alcohol solution into which 1000 g of methanol and 250 g of 25% aqueous ammonia were introduced into a 3 l glass container with a stirrer and stirred for 30 minutes, and then the tetraethyl silicate and tetrabutyl zirco were added. The mixed solution of nate was added dropwise over about 6 hours.

  During the reaction, the temperature of the reaction vessel was kept at 40 ° C. After completion of the reaction, the solvent was distilled off from the cloudy reaction vessel liquid, dried, and calcined at 950 ° C. for 1 hour to obtain silica-zirconia particles (PF-2). The silica-zirconia particles had a particle size distribution of 0.16 to 0.20 μm, an average primary particle size of 0.19 μm, and a spherical shape. The obtained particles were further surface-treated with γ-methacryloyloxypropylmethoxysilane. Various physical properties of the obtained particles are shown in Table 2.

2-3) [Synthesis of spherical silica-titania fine particles having an average primary particle diameter of 0.08 μm]
170 g of tetraethyl silicate (manufactured by Colcoat, product name: ethyl silicate 28) was mixed with 400 g of methanol, 5 g of a 0.04 mass% hydrochloric acid aqueous solution was added, and the mixture was hydrolyzed while stirring at a temperature of 30 ° C. for about 1 hour. Thereafter, a solution prepared by dissolving 26 g of tetrabutyl titanate (manufactured by Nippon Soda Co., Ltd.) and 10 g of sodium methylate methanol solution (concentration 28% by mass) in 200 g of isopropyl alcohol was mixed with stirring, and tetraethyl silicate and tetrabutyl titanate were mixed. The mixed solution was prepared. Next, 1000 g of methanol was introduced into a glass container with an internal volume of 3 liters equipped with a stirrer, and 250 g of 25% aqueous ammonia solution was added thereto to prepare an ammoniacal alcohol solution. To this was added 2 g of tetraethyl silicate for producing silica seed particles, and after stirring for 30 minutes, the mixed solution of tetraethyl silicate and tetrabutyl titanate was added dropwise over about 5 hours.

  During the reaction, the temperature of the reaction vessel was kept at 40 ° C. After completion of the reaction, the solvent was retained from the cloudy reaction vessel liquid, dried and fired at 1000 ° C. for 1 hour to obtain silica-titania particles (PF-3). The silica-titania particles had a particle size distribution of 0.072 to 0.095 μm, an average primary particle size of 0.079 μm, and a spherical shape from SEM observation. The obtained fine particles were further surface-treated with γ-methacryloyloxypropylmethoxysilane. Various physical properties of the obtained particles are shown in Table 2.

2-4) [Synthesis of spherical silica-zirconia fine particles having an average primary particle diameter of 0.06 μm]
80 g of tetraethyl silicate (manufactured by Colcoat, product name: ethyl silicate 28) is mixed with 400 g of isobutyl alcohol (manufactured by Tosho Petrochemical), 5 g of 0.05% dilute sulfuric acid aqueous solution is added, and the mixture is stirred at 40 ° C. for about 1 hour. While hydrolyzing. Thereafter, a solution obtained by dissolving 21 g of tetrabutyl zirconate (manufactured by Nippon Soda Co., Ltd.) and 13 g of sodium methylate methanol solution (concentration 28% by mass) in 200 g of isobutyl alcohol was mixed with stirring, and tetraethyl silicate and tetrabutyl were mixed. A mixed solution of zirconate was prepared. Next, the mixed solution of tetraethyl silicate and tetrabutyl zirconate was dropped over about 3 hours while stirring in an ammoniacal alcohol solution into which 1000 g of methanol and 200 g of 25% ammonia water were introduced into a 3 l glass container with a stirrer. did.

  During the reaction, the temperature of the reaction vessel was kept at 40 ° C. After completion of the reaction, the solvent was distilled off from the cloudy reaction vessel liquid, dried, and calcined at 950 ° C. for 1 hour to obtain silica-zirconia particles (PF-4). The silica-zirconia particles had a particle size distribution of 0.04 to 0.08 μm, an average primary particle size of 0.064 μm, and a spherical shape. The obtained fine particles were further surface-treated with γ-methacryloyloxypropylmethoxysilane. Various physical properties of the obtained particles are shown in Table 2.

2-5) [Synthesis of spherical silica-zirconia particles having an average primary particle size of 0.40 μm]
120 g of tetraethyl silicate (manufactured by Colcoat, product name: ethyl silicate 28) is mixed with 400 g of isobutyl alcohol (manufactured by Tosho Petrochemical Co., Ltd.), 5 g of 0.05% by weight dilute sulfuric acid aqueous solution is added, and the mixture is stirred at 40 ° C. for about 1 hour. Hydrolysis. Thereafter, a solution prepared by dissolving 24 g of tetrabutyl zirconate (manufactured by Nippon Soda Co., Ltd.) and 10 g of sodium methylate methanol solution (concentration 28% by mass) in 200 g of isobutyl alcohol was mixed with stirring, and tetraethyl silicate and tetrabutyl were mixed. A mixed solution of zirconate was prepared. Next, 4 g of tetraethyl silicate was added while stirring in an ammoniacal alcohol solution into which 1000 g of methanol and 250 g of 25% aqueous ammonia were introduced into a 3 l glass container with a stirrer and stirred for 30 minutes, and then the tetraethyl silicate and tetrabutyl zirco were added. The mixed solution of nate was added dropwise over about 6 hours.

  During the reaction, the temperature of the reaction vessel was kept at 40 ° C. After completion of the reaction, the solvent was distilled off from the cloudy reaction vessel liquid, dried, and calcined at 950 ° C. for 1 hour to obtain silica-zirconia particles (PF-5). The silica-zirconia particles had a particle size distribution of 0.36 to 0.43 μm, an average primary particle size of 0.40 μm, and a spherical shape. The obtained particles were further surface-treated with γ-methacryloyloxypropylmethoxysilane. Various physical properties of the obtained particles are shown in Table 2.

2-6) [Synthesis of spherical silica-titania particles having an average primary particle diameter of 0.61 μm]
120 g of tetraethyl silicate (manufactured by Colcoat, product name: ethyl silicate 28) was mixed with 400 g of methanol, 5 g of 0.04 mass% hydrochloric acid aqueous solution was added, and the mixture was hydrolyzed while stirring at 30 ° C. for about 1 hour. Thereafter, a solution prepared by dissolving 20 g of tetrabutyl titanate and 10 g of sodium methylate methanol solution (concentration 30% by mass) in 100 g of isopropyl alcohol was mixed with this solution while stirring to prepare a mixed solution of tetraethyl silicate and tetrabutyl titanate. . Next, 1000 g of methanol was introduced into a glass container having an internal volume of 3 liters equipped with a stirrer, and 250 g of a 25% by mass aqueous ammonia solution was added thereto to prepare an ammoniacal alcohol solution. To this was added 2 g of tetraethyl silicate for producing silica seed particles, and after stirring for 30 minutes, the mixed solution of tetraethyl silicate and tetrabutyl titanate was added dropwise over about 5 hours.

  During the reaction, the temperature of the reaction vessel was kept at 40 ° C. After completion of the reaction, the solvent was distilled off from the cloudy reaction vessel liquid, dried, and calcined at 950 ° C. for 1 hour to obtain silica-titania particles (PF-6). The silica-titania particles had a particle size distribution of 0.56 to 0.64 μm and an average primary particle size of 0.61 μm, and the shape was spherical from SEM observation. The obtained particles were further surface-treated with γ-methacryloyloxypropylmethoxysilane. Various physical properties of the obtained particles are shown in Table 2.

Production Example 3 [Production of organic-inorganic composite filler]
In the mortar, each composite oxide particle shown in Table 3 was weighed in an amount corresponding to the filling rate shown in Table 3 in the organic-inorganic composite filler to be produced. To this composite oxide particle, a matrix shown in Table 3 in which 0.5% by mass of a polymerization initiator AIBN was previously dissolved was gradually added and mixed to form pastes. The paste was polymerized at 95 ° C. in a nitrogen atmosphere for 1 hour. The polymer obtained was pulverized with a roll crusher, and then pulverized for 30 minutes in a vibration ball mill (New Light Mill, manufactured by Chuo Kako Co., Ltd.) under the condition that 10 φ25 mm zirconia balls were put in a 400 ml pot. An inorganic composite filler raw material was obtained.

50 g of each organic / inorganic composite filler material was added to a mixed solution of 75 ml of ethanol and 6.6 ml of 30% hydrogen peroxide solution, refluxed at 80 ° C., and then decolorized by filtration, washing and drying. A composite filler was obtained. Each obtained organic-inorganic composite filler was further surface-treated with γ-methacryloyloxypropylmethoxysilane.
Various physical properties of the obtained organic-inorganic composite filler are shown in Table 3, respectively.

Example 1
(A) 0.2% by mass of CQ, 0.3% by mass of DMBE, 0.15% by mass of HQME, 0.02% by mass of BHT, and 0.5% by mass of BS110 with respect to matrix M-1. In addition, mixing was performed to prepare a uniform polymerizable monomer composition. Next, (B) silica / titanium group oxide composite oxide particles [I-1] and (C) organic-inorganic composite filler CF-1 were weighed in a mortar and prepared from the matrix M-1. 100 parts by mass of the curable monomer composition was gradually added under red light and sufficiently kneaded in a dark place to obtain a uniform curable paste. Further, this paste was degassed under reduced pressure to remove bubbles to produce a dental composite restorative material. About the obtained composite restoration material, each physical property was evaluated based on said method. The composition and results are shown in Table 4.

Examples 2-8
In the same composite restorative material composition as in Example 1, (C) the organic-inorganic composite filler CF-1 was changed to the type (CF-1 or CF-2) and blending amount shown in Table 4, and (E) Silica The paste was prepared in the same manner as in Example 1 except that PF-3 of the titanium group oxide composite oxide fine particles [II-2] was also used in the blending amounts shown in Table 4 (unblended in Example 5). Prepared and manufactured dental composite restorative material. Each physical property of the obtained composite restorative material was evaluated. The results are shown in Table 4.

Examples 9-10
Table 4 shows PF-2 or PF-5 instead of PF-1 in (B) silica / titanium group oxide-based composite oxide particles [I-1] in the same composite restorative material composition as in Example 3. A paste was prepared in the same manner as in Example 3 except that it was used in a different blending amount to produce a dental composite restorative material. Each physical property of the obtained composite restorative material was evaluated. The results are shown in Table 4.

Example 11
In the same composite restorative material composition as in Example 3, (A) Instead of the matrix M-1, a paste was prepared using a matrix M-3 to produce a dental composite restorative material. Each physical property of the obtained composite restorative material was evaluated. The results are shown in Table 4.

Example 12
In the same composite restorative material composition as in Example 11, instead of (C) the organic / inorganic composite filler CF-1, a paste was prepared using an organic / inorganic composite filler CF-2 to produce a dental composite restorative material. Each physical property of the obtained composite restorative material was evaluated. The results are shown in Table 4.

Example 13
In the same composite restorative material composition as in Example 3, instead of PF-3 of (E) silica-titanium group oxide composite oxide fine particles [II-2], a paste was prepared using PF-4, and dental A composite restorative material was produced. Each physical property of the obtained composite restorative material was evaluated. The results are shown in Table 4.

Example 14
In the same composite restorative material composition as in Example 9, (A) Matrix M-1, (C) Organic-inorganic composite filler CF-1, (E) Silica-titanium group oxide composite oxide fine particles [II-2] A dental composite restorative material was prepared in the same manner as in Example 9 except that M-4, CF-3, and PF-4 were used in the blending amounts shown in Table 4 instead of PF-3. Manufactured. Each physical property of the obtained composite restorative material was evaluated. The results are shown in Table 4.

  In all of Examples 1 to 14, a dental composite restorative material is obtained in which the operability of the paste is good, the contrast ratio is small, the opal effect is strong, and the spectral reflectance when the background color is black is maximum near 440 nm. It was. Furthermore, the storage stability of the color tone is also stable for a long period of time. In particular, the amount of the (E) component silica / titanium group oxide composite oxide fine particles is large [(A) 100 parts by weight of the polymerizable monomer. Except for Examples 4, 8, and 14 in which the amount exceeds 100 parts by mass, very good storage stability was exhibited.

Comparative Example 1
(A) 0.2% by mass of CQ, 0.3% by mass of DMBE, 0.15% by mass of HQME, 0.02% by mass of BHT, and 0.5% by mass of BS110 with respect to matrix M-3 In addition, mixing was performed to prepare a uniform polymerizable monomer composition. Next, (B) silica / titanium group oxide composite oxide particles [I-1] and (E) silica / titanium group oxide composite oxide particles [II-2] shown in Table 5 in a mortar. Weighed and 100 parts by weight of the polymerizable monomer composition prepared from the matrix M-3 was gradually added under red light, and was sufficiently kneaded in a dark place to obtain a uniform curable paste. Further, this paste was degassed under reduced pressure to remove bubbles to produce a dental composite restorative material. About the obtained composite restoration material, each physical property was evaluated based on said method. The composition and results are shown in Table 5.

  In Comparative Example 1, (C) the organic-inorganic composite filler, which is an essential component of the present invention, is not blended, and the operability of the paste is very sticky. (E) Silica / titanium group oxide Since the compounding amount of the system composite oxide fine particles [II-2] is large, the storage stability of the opal effect is very low.

Comparative Example 2
In the same composite restorative material composition as in Example 11, except that (C) organic-inorganic composite filler and (E) silica / titanium group oxide composite fine particles [II-2] were used in the blending amounts shown in Table 5. A paste was prepared in the same manner as in Example 11 to produce a dental composite restorative material. Each physical property of the obtained composite restorative material was evaluated. The results are shown in Table 5.

  In Comparative Example 2, the amount of (C) the organic / inorganic composite filler is small, and the amount of (E) silica / titanium group oxide composite oxide fine particles [II-2] is large, so that the opal effect is preserved. The stability was low.

Comparative Example 3
In the same composite restorative material composition as in Example 1, instead of (A) the matrix M-1 and (C) the organic-inorganic composite filler CF-1, the paste was prepared using the matrix M-3 and the organic-inorganic composite filler CF-4. Prepared and manufactured dental composite restorative material. Each physical property of the obtained composite restorative material was evaluated. The results are shown in Table 5.

  The comparative example 3 mix | blended the organic filler as (C) organic inorganic composite filler which is an essential component of this invention, and the opal effect hardly expressed.

Comparative Example 4
In the same composite restorative material composition as in Example 11, instead of PF-1, which is (B) silica-titanium group oxide composite oxide particles [I-1], a paste was prepared using PF-6 and dental A composite restorative material was manufactured. Each physical property of the obtained composite restorative material was evaluated. The results are shown in Table 5.

  In Comparative Example 4, the particle size of (B) silica / titanium group oxide composite oxide particles [I-1] is outside the range of the present invention, and good operability of the paste can be obtained. Further, ΔC * was small and the opal effect was hardly exhibited.

Claims (6)

(A) 100 parts by mass of a polymerizable monomer,
(B) Spherical silica / titanium group oxide-based composite oxide particles [I−] having an average primary particle size in the range of 0.15 to 0.50 μm and a standard deviation of the particle size distribution within 1.30. 1] 40-200 parts by weight,
(C) Silica / titanium group oxide composite oxide fine particles [II-1] having an average primary particle diameter in the range of 0.01 to 0.10 μm are dispersed in an organic resin matrix by 40 to 75 mass%. (A) 90 mass parts or more of the organic-inorganic composite filler having a refractive index difference of 0.10 or less with respect to the cured product of the polymerizable monomer, and (B) silica / titanium group oxide composite oxide particles A dental composite restorative material comprising a blending amount of [I-1] not exceeding 550 parts by mass and (D) an effective amount of a polymerization initiator. further,
(E) Silica / titanium group oxide composite oxide fine particles [II-2] having an average primary particle size in the range of 0.01 to 0.10 μm and a standard deviation of the particle size distribution within 1.30. The total amount of (B) silica / titanium group oxide composite oxide particles [I-1] and (C) the organic-inorganic composite filler does not exceed 550 parts by mass. The dental composite restorative material described in 1. (C) The organic-inorganic composite filler is further
Spherical silica / titanium group oxide composite oxide particles [I-2] having an average primary particle diameter in the range of 0.15 to 0.50 μm and a standard deviation of the particle diameter distribution within 1.30. The organic resin matrix is dispersed in an amount of 5% by mass or more and (A) a polymerizable monomer is maintained in a blending amount so that the difference in refractive index from the cured product is maintained at 0.10 or less. The dental composite restorative material according to claim 1 or 2. The dental composite restorative material according to any one of claims 1 to 3, wherein the polymerizable monomer (A) has a cured product having a refractive index of 1.45 to 1.60. In the cured product at the time of manufacturing the composite restoration material, the contrast ratio is 0.30 or less, ΔC ^* is 18 or more, and has an opal property that provides a maximum spectral reflectance at a wavelength of 420 to 470 nm when the color is a black background color. The dental composite restorative material according to any one of claims 1 to 4, wherein the dental composite restorative material is. At least (A) 100 parts by mass of a polymerizable monomer,
(B) Spherical silica / titanium group oxide-based composite oxide particles [I−] having an average primary particle size in the range of 0.15 to 0.50 μm and a standard deviation of the particle size distribution within 1.30. 1] 40-200 parts by weight,
(C) Silica / titanium group oxide composite oxide fine particles [II-1] having an average primary particle diameter in the range of 0.01 to 0.10 μm are dispersed in an organic resin matrix by 40 to 75 mass%. (A) 90 mass parts or more of the organic-inorganic composite filler having a refractive index difference of 0.10 or less with respect to the cured product of the polymerizable monomer, and (B) silica / titanium group oxide composite oxide particles The manufacturing method of the dental composite restorative material which mixes the compounding quantity whose total amount with [I-1] does not exceed 550 mass parts, and each component of the polymerization initiator of (D) effective amount.