Dental curable composition, two-component dental curable composition, one-component dental curable composition, dental cement, dental abutment construction material, dental filling repair material, dental double syringe, and dental single syringe

Abstract

The present invention achieves exceptional mechanical strength in a cured product, makes it possible to achieve both exceptional dischargeability and exceptional sagging properties even without using fumed silica, and achieves exceptional sagging properties even after long-term storage. This dental curable composition contains 100 parts by mass of a polymerizable monomer (A), 0.2-25 parts by mass of a polyoxyethylene sorbitan ester (B), an inorganic filler (C), and a polymerization initiator (D) containing at least one selected from the group consisting of chemical polymerization initiators (D1) and photopolymerization initiators (D2).

Description

Dental hardenable compositions, two-component dental hardenable compositions, one-component dental hardenable compositions, dental cements, dental core building materials, dental filling and restorative materials, dental double syringes, and dental single syringes

[0001] The present invention relates to a dental hardenable composition, a two-component dental hardenable composition, a one-component dental hardenable composition, a dental cement, a dental core build-up material, a dental filling and restorative material, a dental double syringe, and a dental single syringe.

[0002] Various dental hardenable compositions are used depending on the intended purpose and application (see, for example, Patent Documents 1 to 6). For example, dental resin cements (hereinafter simply referred to as "dental cements") are used to bond crown restorative materials such as inlays, onlays, laminate veneers, and crowns in dental treatment. Dental cements consist of a highly fluid, paste-like hardenable composition containing a polymerizable monomer, an inorganic filler, and a chemical polymerization initiator and / or a photopolymerization initiator. When using dental cement to bond a tooth structure to a crown restorative material, an excess amount of dental cement is applied to the crown restorative material and the crown restorative material is pressed against the tooth structure.

[0003] During this process, it is necessary to remove excess dental cement (also referred to as "excess cement") that spills out from the junction between the tooth substance and the crown restorative material, known as the margin, during the pressure application. From the standpoint of ease of use, this excess cement is typically removed by scraping it off with a dental probe or similar tool after the excess cement has reached a semi-hardened state (a state in which it has hardened to a certain extent and lost its fluidity). Therefore, from the standpoint of ease of removal of excess cement, appropriate sagging is desirable. Here, "sagging" is evaluated by the flow distance caused by the weight of a given amount of paste placed on a vertical surface. If sagging is excessive, the resulting excess cement will spread over a wide area, making removal difficult. Furthermore, removing the excess cement before it sags and spreads requires rapid removal, making the process more difficult.

[0004] Patent Document 7 discloses a dental cement that can meet these demands, namely, a dental cement that remains in a semi-cured state after photopolymerization for a sufficiently long period of time, has good removability of excess cement, and is excellent in both the strength of the cement itself and its adhesive strength to tooth structure. The dental cement contains (i) a polymerizable monomer, (ii) an α-diketone compound, (iii) a tertiary aromatic amine composition consisting of three types of compounds each represented by a specific general formula, such as i) ethyl 4-dimethylaminobenzoate, ii) N,N-di(2-hydroxyethyl)-p-toluidine, and iii) N,N-dimethyl-p-toluidine, and (iv) a filler, and may optionally contain (e) a peroxide.

[0005] When using a dental curable composition such as a dental cement, it is sometimes applied to a predetermined location using a syringe. For this reason, the dental curable composition is stored in a sealed state in a cylindrical barrel constituting a syringe, and when used, it is often provided to a predetermined location by extruding the composition from the cylindrical barrel using a needle tip attached to the tip of the cylindrical barrel. The shape of such a syringe varies depending on the type of polymerization initiator blended in the dental curable composition. For example, in the case of (i) a photocurable dental curable composition (single-component dental curable composition) containing only a photopolymerization initiator as the polymerization initiator, a previously prepared dental curable composition is sealed and filled in a syringe (single syringe) equipped with a single cylindrical barrel.

[0006] In addition, in the case of (iia) a chemical polymerization-curable dental hardenable composition using only a chemical polymerization initiator as the polymerization initiator, or (iib) a dual-cure dental hardenable composition containing both a photopolymerization initiator and a chemical polymerization initiator as the polymerization initiator, i.e., a two-component dental hardenable composition consisting of a first component and a second component that exhibits polymerization activity upon contact and mixing with the first component, a pre-prepared dental hardenable composition is sealed and filled in a syringe (double syringe) equipped with two cylindrical barrels. In this case, the first component is sealed and filled in one cylindrical barrel, and the second component is sealed and filled in the other cylindrical barrel. When using a double syringe, the double syringe is set in a dispenser as needed, and then a mixing tip (a needle tip having the function of mixing the two components inside and then discharging the mixture from its tip) is attached to the outlet of each cylindrical barrel. Next, the two plungers are pushed into each cylindrical barrel in conjunction with one another either directly with fingers or via a dispenser, whereby the mixture (dental curable composition) prepared by mixing the first and second agents in the mixing tip is ejected from the ejection port of the mixing tip and supplied to a predetermined location.

[0007] In such single syringes and double syringes, if the force required to discharge the dental curable composition from the syringe (also referred to as "discharge pressure") is large, a larger force is required in clinical work, which may make delicate work difficult or cause stress to the user.

[0008] For this reason, in a paste-like dental curable composition containing an inorganic filler, such as a dental cement provided to a user in a sealed syringe, it is preferable to adjust the sagging property and discharge pressure to be within an appropriate range by adjusting the type and amount of the inorganic filler or by adding a thickener. As a method for adjusting the sagging property and discharge pressure, a common method is to add 10 to 17 parts by mass of fumed silica, which acts as a thickener and thixotropy imparting agent, to 100 parts by mass of the polymerizable monomer (see Patent Documents 8 and 9).

[0009] Fumed silica is a powder or granule consisting of agglomerated (secondary) particles or their aggregates (tertiary particles) formed by agglomeration of fine silica (silicon dioxide) primary particles of approximately 7 to 50 nm, obtained by burning silicon tetrachloride in an oxyhydrogen flame. When fumed silica is blended into a dental hardenable composition containing a polymerizable monomer, such as dental cement, a three-dimensional network structure is formed by hydrogen bonding between hydroxyl groups on the silica surface when a dispersant penetrates and disperses the gaps between the agglomerated secondary particles or aggregates. This is known to result in thickening and thixotropy-imparting effects.

[0010] As described above, fumed silica not only thickens the paste properties of dental hardenable compositions such as dental cements, but also has the effect of imparting thixotropy. Therefore, by incorporating fumed silica into dental hardenable compositions, it is possible to reduce sagging without increasing the discharge pressure. However, it is known that these effects are affected by the powder properties of fumed silica. Specifically, if the fumed silica is insufficiently dispersed, the discharge pressure becomes excessively high. Conversely, if the fumed silica is excessively dispersed, the thickening effect of the fumed silica is not fully exerted, and sagging cannot be suppressed.

[0011] In this regard, Patent Document 10 proposes a dental pretreatment agent consisting of an aqueous paste-like composition in which the dispersion state of agglomerated secondary particles of fumed silica is controlled within a predetermined range. The dental pretreatment agent described in Patent Document 10 can achieve both excellent dischargeability and excellent dripping properties when applied using a syringe. To achieve this effect, it is necessary to mix the components under strict condition control using a planetary centrifugal mixer during preparation of the dental pretreatment agent in order to control the dispersion state of the agglomerated secondary particles of fumed silica within a predetermined range. In addition, it is necessary to confirm using a particle size distribution analyzer or the like whether the dental pretreatment agent has been properly prepared, in other words, whether the dispersion state of the agglomerated secondary particles of fumed silica is within the desired range.

[0012] Japanese Patent Application Laid-Open No. 2023-107373 Japanese Patent Application Laid-Open No. 2020-040937 Japanese Patent Application Laid-Open No. 2009-19108 Japanese Patent Application Laid-Open No. 2008-37776 Japanese Patent Application Laid-Open No. 2002-530308 Japanese Patent Application Laid-Open No. 5-255035 Japanese Patent Application Laid-Open No. 2012-162490 Japanese Patent Application Laid-Open No. 2022-187437 International Publication No. 2008 / 068862 Pamphlet Japanese Patent Application Laid-Open No. 2015-63489

[0013] However, in dental curable compositions that further contain an inorganic filler in addition to fumed silica used as a thickener, it is difficult to distinguish the particle size of the fumed silica from the particle size of the inorganic filler in the composition using a particle size distribution analyzer or the like. In this case, it is not easy to confirm the dispersion state of the agglomerated secondary particles of fumed silica. This means that it is difficult to use an inorganic filler other than fumed silica in combination with the technology described in Patent Document 10. As described above, the technology described in Patent Document 10, which uses fumed silica to ensure excellent dischargeability and excellent sagging properties, has problems such as an extremely complicated preparation process in order to achieve a dispersion state of fumed silica within a predetermined range, and it is difficult to use an inorganic filler other than fumed silica in combination, which imposes limitations on composition design.

[0014] On the other hand, for dental curable compositions used in various applications such as dental cement, it is generally important that the cured product has excellent mechanical strength, regardless of the application. Furthermore, as described above, when a dental curable composition is used as dental cement, excellent dischargeability and sagging property are required, but these properties may also be important in applications other than dental cement.

[0015] For example, dental filling and restorative materials are used to treat teeth by filling cavities formed in the teeth and then hardening them. Recently, due to their excellent convenience, dental filling and restorative materials (so-called flowable composite resins) that are provided to users in a syringe equipped with a needle tip at the time of use have become increasingly popular in clinical settings. Users are provided with a variety of flowable composite resins with different fluidities depending on the case. In particular, low-flow flowable composite resins that use dental filling and restorative materials with low fluidity require not only excellent ejection properties but also excellent dripping properties.

[0016] Furthermore, when a crown restoration is performed after root canal treatment of a tooth, a dental core construction material is used in the treatment process described below. First, a post hole formed by removing caries is cleaned and pretreated. Next, a post is inserted into the cleaned and pretreated post hole as needed, and a dental hardenable composition is injected and hardened to form a post. Subsequently, the dental hardenable composition is further built up on the post, roughly shaped, and then hardened. After hardening, the post is ground to form a post. In this treatment process, a dental core construction material is used at least as the dental hardenable composition for the construction of the post. Furthermore, from the viewpoint of facilitating the construction of the post, excellent dripping properties are required for the dental core construction material. Therefore, even when the dental core construction material is provided to a user in a state filled in a syringe to which a needle tip is attached at the time of use, not only excellent dischargeability but also excellent dripping properties are required. Note that the dental core construction material can be used for the construction of a post in addition to the construction of an abutment.

[0017] Furthermore, dental hardenable compositions that are provided to users in a state filled in a syringe to which a needle tip is attached at the time of use are extremely convenient for users. Therefore, with future advances in dental treatment technology and changes in user needs, dental hardenable compositions filled in a syringe to which a needle tip is attached at the time of use are expected to be widely used in the future for applications other than the above-mentioned dental cements, dental filling and restorative materials, and dental core build-up materials.

[0018] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a dental hardenable composition that has excellent mechanical strength after curing, that can easily achieve both excellent dischargeability and excellent sagging properties even without using fumed silica, and that has excellent sagging properties even after long-term storage; a two-component dental hardenable composition, a one-component dental hardenable composition, a dental cement, a dental core build-up material, and a dental filling and restorative material each composed of the dental hardenable composition; and a dental double syringe and a dental single syringe each using the dental hardenable composition.

[0019] The above object can be achieved by the present invention, which is as follows: The dental curable composition of the present invention comprises 100 parts by mass of a polymerizable monomer (A), 0.2 to 25 parts by mass of a polyoxyethylene sorbitan ester (B), an inorganic filler (C), and a polymerization initiator (D) containing at least one selected from the group consisting of a chemical polymerization initiator (D1) and a photopolymerization initiator (D2).

[0020] In one embodiment of the dental curable composition of the present invention, the polyoxyethylene sorbitan ester (B) is preferably a compound represented by the following general formula (1):

[0021]

[0022] (In the general formula (1), R represents a hydrocarbon group having 5 to 30 carbon atoms in its main chain, which may have at least one substituent selected from the group consisting of an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, an alkynyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, a nitro group, a cyano group, a phenyl group, and a halogen atom; w, x, y, and z each independently represent an integer of 0 to 30, and the sum of w, x, y, and z is 10 to 30.)

[0023] Another embodiment of the dental curable composition of the present invention preferably contains 150 to 270 parts by mass of the inorganic filler (C) relative to 100 parts by mass of the polymerizable monomer (A).

[0024] Another embodiment of the dental curable composition of the present invention preferably contains 0.1 to 20 parts by mass of a prepolymerization initiator (D) relative to 100 parts by mass of the polymerizable monomer (A).

[0025] The two-part dental hardenable composition of the present invention is composed of all components of the dental hardenable composition of the present invention, and is composed of a first partial composition consisting of a portion of all the components, and a second partial composition consisting of the remainder of all the components, the polymerization initiator (D) includes at least the chemical polymerization initiator (D1), and the chemical polymerization initiator (D1) includes a first partial chemically polymerizable component and a second partial chemically polymerizable component that exhibits polymerization activity upon contact with the first partial chemically polymerizable component, the first partial composition includes the entire amount of the first partial chemically polymerizable component, and the second partial composition includes the entire amount of the second partial chemically polymerizable component.

[0026] In one embodiment of the two-component dental hardenable composition of the present invention, it is preferable that the first partially chemically polymerized component comprises a hydroperoxide, and the second partially chemically polymerized component comprises a thiourea compound and a copper compound.

[0027] The dental cement of the present invention comprises the two-component dental hardenable composition of the present invention.

[0028] The dental core build-up material of the present invention comprises the two-component dental hardenable composition of the present invention.

[0029] The one-component dental hardenable composition of the present invention is composed entirely of the dental hardenable composition of the present invention, and all of the components are contained in one composition.

[0030] The dental cement of the present invention comprises the one-component dental hardenable composition of the present invention.

[0031] The dental filling and restorative material of the present invention comprises the one-component dental hardenable composition of the present invention.

[0032] The dental double syringe of the present invention includes a cylindrical barrel having openings at its front and rear ends, a plunger slidably inserted into the cylindrical barrel from the opening at the rear end, and a cap that seals the opening at the front end of the cylindrical barrel and is detachably attached to the opening at the front end, and is equipped with a first syringe and a second syringe having an enclosed space formed inside the cylindrical barrel by sealing the openings at both ends of the cylindrical barrel with the plunger and the cap, the first syringe and the second syringe being arranged adjacent to each other so that their openings at their front ends are flush with each other and their axial directions are parallel, the enclosed space of the first syringe is filled with a first partial composition that constitutes the two-component dental hardenable composition according to claim 5, and the enclosed space of the second syringe is filled with a second partial composition that constitutes the two-component dental hardenable composition according to claim 5.

[0033] The dental single syringe of the present invention comprises a cylindrical barrel having openings at a front end and a rear end, a plunger slidably inserted into the cylindrical barrel from the opening at the rear end, a cap that seals the opening at the front end of the cylindrical barrel and is detachably attached to the opening at the front end, and the one-component dental curable composition according to claim 9 that is filled into an airtight space formed inside the cylindrical barrel by sealing both end openings with the plunger and the cap.

[0034] As described above, according to the present invention, it is possible to provide a dental hardenable composition that has excellent mechanical strength after curing, that can easily achieve both excellent dischargeability and excellent sagging properties even without using fumed silica, and that has excellent sagging properties even after long-term storage; a two-component dental hardenable composition, a one-component dental hardenable composition, a dental cement, a dental core build-up material, and a dental filling and restorative material each composed of the dental hardenable composition; and a dental double syringe and a dental single syringe each using the dental hardenable composition.

[0035] 1A and 1B are schematic diagrams showing an example of a dental double syringe and a mixing tip used in combination with the dental single syringe of the present embodiment, and a needle tip used in combination with the dental single syringe of the present embodiment.

[0036] In the description of this specification, unless otherwise specified, the expression "x to y" using numerical values ​​x and y means "greater than or equal to x and less than or equal to y." In such an expression, when a unit is assigned only to the numerical value y, the unit also applies to the numerical value x. Furthermore, in this specification, the term "(meth)acrylic" means both "acrylic" and "methacrylic." Similarly, the term "(meth)acrylate" means both "acrylate" and "methacrylate," and the term "(meth)acryloyl" means both "acryloyl" and "methacryloyl."

[0037] <Dental Curable Composition> The dental curable composition of this embodiment contains 100 parts by mass of a polymerizable monomer (A), 0.2 to 25 parts by mass of a polyoxyethylene sorbitan ester (B), an inorganic filler (C), and a polymerization initiator (D) containing at least one selected from the group consisting of a chemical polymerization initiator (D1) and a photopolymerization initiator (D2). This allows the dental curable composition of this embodiment to have excellent mechanical strength in the cured product. It is easy to achieve both excellent dischargeability and excellent sagging properties without the use of fumed silica, and it also maintains excellent sagging properties even after long-term storage. Therefore, when the dental curable composition of this embodiment filled in a syringe is discharged from the outlet of a needle tip attached to the syringe, the discharge pressure is not too high, resulting in good operability. Furthermore, the dental curable composition of this embodiment, once dispensed and applied to the desired location, is less likely to sagging, reducing stress for the user during application and facilitating removal of excess dental curable composition that extends beyond the intended application site. Furthermore, since there is little change in dripping properties over time, whether the user uses the syringe immediately after purchase or a long time after purchase, there is no significant difference in operability during dispensing work, and the feeling of use is consistent.

[0038] Each component contained in the dental curable composition of this embodiment will be described in detail below.

[0039] 1-1. Polymerizable Monomer (A) As the polymerizable monomer (A), any polymerizable monomer that can be used in a dental curable composition can be used without any particular limitation, but it is preferable to use a radically polymerizable monomer. The radically polymerizable monomer is not particularly limited, and any known radically polymerizable monomer can be used. Furthermore, the radically polymerizable unsaturated group contained in the radically polymerizable monomer is also not particularly limited, and any known group can be used. Specific examples of the radically polymerizable unsaturated group include a (meth)acryloyl group, a (meth)acryloyloxy group, a (meth)acryloylamino group, a (meth)acryloylthio group or other (meth)acryloyl derivative group, a vinyl group, an allyl group, or a styryl group. Among these, from the viewpoint of polymerizability, the radically polymerizable unsaturated group is preferably a (meth)acryloyl group, a (meth)acryloyloxy group, or a (meth)acryloylamino group, and more preferably a (meth)acryloyloxy group.

[0040] Specific examples of such (meth)acrylate polymerizable monomers having a (meth)acryloyloxy group include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, glycidyl (meth)acrylate, benzyl (meth)acrylate, allyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-(meth)acryloxyethyl propionate, and 2-methacryloxyethyl acetoacetate. water-insoluble polymerizable monomers having one polymerizable unsaturated group such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, glyceryl mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, or ethoxylated undecenol (meth)acrylate; water-soluble polymerizable monomers such as nonaethylene glycol di(meth)acrylate, decaethylene glycol di(meth)acrylate, dodecaethylene glycol di(meth)acrylate, tetradecaethylene glycol di(meth)acrylate; water-soluble polymerizable monomers such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate or 1,aliphatic polymerizable monomers having a plurality of polymerizable unsaturated groups, such as 6-bis(methacrylethyloxycarbonylamino)-2,2-4-trimethylhexane; 2,2-bis((meth)acryloxyphenyl)propane, 2,2-bis[4-(2-hydroxy-3-(meth)acryloxypropoxy)phenyl]propane, 2,2-bis(4-(meth)acryloxyethoxyphenyl)propane, 2,2-bis(4-(meth)acryloxypolyethoxyphenyl)propane, or 2,2-bis(4-(meth)acryloxypropoxyphenyl)propane; Examples of the polymerizable monomer include aromatic monomers having a plurality of polymerizable unsaturated groups, and polymerizable monomers containing an acidic group, such as 2-methacryloyloxyethyl dihydrogen phosphate, bis(2-methacryloyloxyethyl)hydrogen phosphate, 10-methacryloyloxydecyl dihydrogen phosphate, 11-methacryloyloxy-1,1-undecanedicarboxylic acid, 4-methacryloxyethyl trimellitic anhydride, 6-methacryloxyhexyl-3-phosphonopropionate, and 3-sulfopropane(meth)acrylate.

[0041] Among the above-mentioned radical polymerizable monomers, it is preferable to include a di- or higher functional polymerizable monomer from the viewpoint of the mechanical strength of the cured product.

[0042] In the dental curable composition of this embodiment, the above-mentioned radical polymerizable monomer may be used alone, or two or more types of radical polymerizable monomers may be used in combination. Furthermore, multiple types of radical polymerizable monomers having different numbers of functional groups may be used in combination.

[0043] In particular, from the viewpoint of aesthetics such as color resistance, it is preferable to use a polymerizable monomer (A) that does not contain an acidic group. The polymerizable monomer (A) that does not contain an acidic group can be any compound that does not have an acidic group in the molecule of the above-mentioned polymerizable monomer. Examples of the acidic group include a carboxyl group, a sulfo group, a phosphonic group, a phosphate monoester group, and a phosphate diester group.

[0044] 1-2. Polyoxyethylene sorbitan ester (B) The dental curable composition of this embodiment contains a polyoxyethylene sorbitan ester (B) primarily for the purpose of controlling sagging and ejection properties. This allows the dental curable composition of this embodiment to easily achieve both excellent ejection properties and excellent sagging properties, and to maintain excellent sagging properties even after long-term storage, compared to dental curable compositions containing surfactants other than polyoxyethylene sorbitan ester. To reliably achieve this effect, the polyoxyethylene sorbitan ester (B) is added in an amount of 0.2 to 25 parts by mass, preferably 0.4 to 18 parts by mass, per 100 parts by mass of the polymerizable monomer (A). Furthermore, when the polyoxyethylene sorbitan ester (B) is added in an amount of 0.2 parts by mass or more, the increase in ejection pressure tends to saturate even when the amount is increased. Therefore, good ejection properties can be easily maintained over a wide range of amounts, including amounts of 0.2 parts by mass or more. On the other hand, sagging resistance, particularly after long-term storage, is significantly worsened when the blending amount is less than 0.2 parts by mass or more than 25 parts by mass. However, good sagging resistance can be ensured both initially and after long-term storage when the blending amount is within the range of 0.2 to 25 parts by mass. Therefore, excellent dischargeability and excellent sagging resistance can be easily achieved when the blending amount is within the range of 0.2 to 25 parts by mass. Furthermore, when a large amount of polyoxyethylene sorbitan ester is blended into the dental hardenable composition, the proportion of polymerizable monomer in the dental hardenable composition decreases relatively, resulting in a significant decrease in the mechanical strength of the cured product. However, when the blending amount is 25 parts by mass or less, the mechanical strength of the cured product can be ensured.

[0045] In the dental curable composition of this embodiment, the polyoxyethylene sorbitan ester blended in the above blending amount range means a polyoxyethylene sorbitan ester that is uniformly dispersed in the components other than the inorganic filler in the dental curable composition. Therefore, for example, a polyoxyethylene sorbitan ester used as a surface treatment agent for an inorganic filler (i.e., a polyoxyethylene sorbitan ester that is unevenly distributed only on the surfaces of filler particles that constitute the inorganic filler) is not counted in the blending amount.

[0046] Furthermore, when preparing the dental curable composition of this embodiment by mixing and stirring the raw material components, any conventionally known mixing and stirring method and conditions can be used to easily uniformly disperse the polyoxyethylene sorbitan ester in the dental curable composition. In other words, with the dental curable composition of this embodiment, there is no need to be limited to a specific mixing and stirring method and conditions in order to uniformly disperse the polyoxyethylene sorbitan ester in the dental curable composition. Therefore, there is no need to check the dispersion state of the polyoxyethylene sorbitan ester in the dental curable composition. In addition, because the change in the ejection and sagging properties relative to the amount of polyoxyethylene sorbitan ester tends to be extremely gradual, excellent ejection and sagging properties can be achieved over a wide range of amounts. Furthermore, the polyoxyethylene sorbitan ester also has the effect of suppressing changes in sagging properties over time. In these respects, the dental curable composition of this embodiment is superior to conventional dental curable compositions containing fumed silica.

[0047] The polyoxyethylene sorbitan ester (B) means a compound having a structure in which a polyoxyethylene chain is added to a sorbitan ester, and any available nonionic surfactant can be used without any particular limitation, but a compound represented by the following general formula (1) is preferred.

[0048]

[0049] In general formula (1), R represents a hydrocarbon group having 5 to 30 carbon atoms in its main chain, and preferably a hydrocarbon group having 10 to 20 carbon atoms, which may have at least one substituent selected from the group consisting of an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, an alkynyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, a nitro group, a cyano group, a phenyl group, and a halogen atom. Furthermore, w, x, y, and z are each independently integers of 0 to 30, and the sum of w, x, y, and z is 10 to 30. R is more preferably an alkyl group or alkenyl group having 5 to 30 carbon atoms in its main chain, and even more preferably an alkyl group or alkenyl group having 10 to 20 carbon atoms.

[0050] As the polyoxyethylene sorbitan ester (B), polyoxyethylene sorbitan fatty acid esters are particularly preferably used. Examples of fatty acids include capric acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, arachidic acid, behenic acid, palmitoleic acid, oleic acid, erucic acid, and isostearic acid.

[0051] Specific examples of the polyoxyethylene sorbitan ester (B) that can be suitably used in the dental curable composition of this embodiment include polyoxyethylene sorbitan monolaurate (Tween 20), polyoxyethylene sorbitan monopalmitate (Tween 40), polyoxyethylene sorbitan monostearate (Tween 60), polyoxyethylene sorbitan monooleate (Tween 80), and polyoxyethylene sorbitan trioleate (Tween 85).

[0052] 1-3. Inorganic Filler (C) In the dental curable composition of this embodiment, an inorganic filler (C) is blended for the purposes of (i) improving the mechanical strength of the cured product, (ii) suppressing shrinkage during polymerization, and (iii) adjusting the viscosity (operability) of the dental curable composition. The amount of inorganic filler (C) blended is not particularly limited, but is preferably 150 to 270 parts by mass, and more preferably 210 to 250 parts by mass, per 100 parts by mass of polymerizable monomer (A). By blending an amount of 150 parts by mass or more, it becomes easy to obtain a cured product with sufficient mechanical strength and also to obtain better sagging properties. Furthermore, by blending an amount of 270 parts by mass or less, it becomes easy to obtain better discharge properties.

[0053] Here, inorganic filler refers to (a) a filler made of inorganic powder or (b) a filler containing inorganic powder. (a) Fillers made of inorganic powder include silica-based inorganic fillers (excluding fumed silica) and ion-eluting fillers, while (b) fillers containing inorganic powder include organic-inorganic composite fillers. However, in this specification, fumed silica is not classified as an inorganic filler but as a thickener, as described below. This is because, in the field of dental materials, fumed silica is generally used only for the purpose of (iii) adjusting the viscosity (operability) of dental curable compositions, and therefore does not functionally fall under the category of inorganic fillers.

[0054] Examples of silica-based inorganic fillers include (i) silica or (ii) composite oxide particles containing silica and a metal oxide of Groups 2 to 14 of the periodic table that can bond to the silica. The content of the silica component in the composite oxide particles is at least 10 mol% or more, and preferably 50 mol% or more. Specific examples of silica-based inorganic fillers include quartz, silica (excluding fumed silica), silica alumina, silica titania, and silica zirconia. Examples of ion-eluting fillers include hydroxides such as calcium hydroxide and strontium hydroxide, zinc oxide, silicate glass, fluoroaluminosilicate glass, barium glass, and ytterbium fluoride.

[0055] The organic-inorganic composite filler can be any filler that combines an inorganic powder and a resin component. Examples of such fillers include (i) fillers obtained by polymerizing a mixture of an inorganic powder and a polymerizable monomer and a polymerization initiator, followed by pulverizing the cured product to form particles, and (ii) microporous fillers obtained by immersing aggregated particles of primary particles constituting the inorganic powder and a polymerizable monomer in a polymerizable composition containing a polymerizable monomer, a polymerization initiator, and an organic solvent, removing the organic solvent, and then polymerizing and curing the polymerizable monomer. Furthermore, silica-based inorganic fillers or ion-eluting fillers can be used as the inorganic powder and a filler contained in the organic-inorganic composite filler. The inorganic powder and a filler typically account for 60% to 90% by mass of the organic-inorganic composite filler.

[0056] The inorganic filler (C) may be surface-treated with a surface treatment agent, typically a silane coupling agent. Use of a surface-treated inorganic filler can improve affinity with the polymerizable monomer, dispersibility in the polymerizable monomer, and the mechanical strength and water resistance of the cured product. While there are no particular limitations on the surface treatment agent, it is preferable to use at least one surface treatment agent selected from the group consisting of vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloyloxypropyltrimethoxysilane, κ-methacryloyloxydodecyltrimethoxysilane, β-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, and methyltriethoxysilane. The surface treatment method using these may also be in accordance with a known method.

[0057] The particle size and shape of the inorganic filler (C) can be appropriately selected, but the average particle size is usually preferably 0.1 μm to 50 μm. The average particle size refers to the average particle size of the primary particles constituting the inorganic filler. Specifically, the average particle size is determined by the following procedure. First, a photograph of the inorganic filler (powder / granule) is taken using a scanning electron microscope, and 100 or more particles observed within a unit field of view of the photograph are selected. Next, the primary particle diameter (maximum diameter) of each selected particle is measured, and the average value of the measured primary particle diameters (maximum diameters) is determined as the average particle size. The average particle size of the inorganic filler can be determined, for example, by taking a photograph of the powder / granule with a scanning electron microscope (manufactured by JEOL Ltd., "JSM-7800F Prime") at a magnification of 5,000 to 100,000 times, measuring the number of particles (100 or more) and the primary particle diameter (maximum diameter) observed within a unit field of view of the photograph, and calculating the number average primary particle diameter based on these measurements using the following formula:

[0058]

[0059] 1-4. Polymerization Initiator (D) The dental curable composition of this embodiment contains a chemical polymerization initiator (D1) and / or a photopolymerization initiator (D2) as the polymerization initiator (D). The amount of the polymerization initiator (D) is not particularly limited, but is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 15 parts by mass, per 100 parts by mass of the polymerizable monomer (A). When both a chemical polymerization initiator (D1) and a photopolymerization initiator (D2) are contained as the polymerization initiator (D), the amount of (D1) per 100 parts by mass of the polymerizable monomer (A) is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 7.5 parts by mass, provided that the total amount of both is within the above-mentioned range. In this case, the remaining amount corresponds to the amount of the photopolymerization initiator (D2).

[0060] <Chemical Polymerization Initiator (D1)> The chemical polymerization initiator used in the dental curable composition of this embodiment may be any chemical polymerization initiator (redox-based polymerization initiator including a combination of an oxidizing agent and a reducing agent) used in known dental curable compositions, without any particular limitations. Known examples of such chemical polymerization initiators include those consisting of a combination of an oxidizing agent made of an organic peroxide and a reducing agent made of an amine, a sulfinic acid compound, a thiourea compound, an oxime compound, a transition metal compound, or the like. The compounds listed above as reducing agents may function as reducing agents alone or in combination, and are sometimes collectively referred to as polymerization accelerators. The chemical polymerization initiator may be any combination of an oxidizing agent and a reducing agent, without any particular limitations. From the viewpoints of storage stability and chemical polymerization activity, chemical polymerization initiators consisting of a hydroperoxide, a thiourea compound, and a copper compound are preferably used.

[0061] Examples of hydroperoxides include p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-hexyl hydroperoxide, and t-butyl hydroperoxide. Two or more of these compounds can also be used in combination.

[0062] Preferred thiourea derivatives are ethylenethiourea, N,N'-dimethylthiourea, 1-(2-pyridyl)-2-thiourea, and 1-(2-tetrahydrofurfuryl)-2-thiourea. Two or more of these compounds can also be used in combination.

[0063] The copper compound is blended to promote the redox reaction between the organic peroxide and the reducing agent, and at least one selected from the group consisting of copper(I) chloride, copper(I) bromide, copper(II) chloride, copper(II) acetate, copper(II) sulfate, copper(II) acetylacetonate, zinc(II) chloride, and zinc(II) acetate can be used. Among these, it is particularly preferable to use a divalent copper compound from the viewpoints of storage stability and chemical polymerization activity.

[0064] <Photopolymerization initiator (D2)> As the photopolymerization initiator, photopolymerization initiators used in dental curable compositions, such as combinations of α-diketones and tertiary amines, combinations of acylphosphine oxides and tertiary amines, combinations of thioxanthones and tertiary amines, and combinations of α-aminoacetophenones and tertiary amines, can be used without any particular limitation.

[0065] Examples of α-diketones include camphorquinone, benzil, α-naphthyl, acetonaphthene, naphthoquinone, p,p'-dimethoxybenzyl, p,p'-dichlorobenzylacetyl, 1,2-phenanthrenequinone, 1,4-phenanthrenequinone, 3,4-phenanthrenequinone, and 9,10-phenanthrenequinone.

[0066] Examples of tertiary amines include 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, methyl 3-(dimethylamino)benzoate, 4-dimethylaminoacetophenone, etc. Among these, it is preferable to use ethyl 4-dimethylaminobenzoate or methyl 4-dimethylaminobenzoate because they are easily available or synthesized, and have excellent chemical stability and solubility in polymerizable monomers.

[0067] Examples of acylphosphine oxides include benzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, and 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide.

[0068] Examples of thioxanthones include 2-chlorothioxanthone and 2,4-diethylthioxanthone.

[0069] Examples of α-aminoacetophenones include 2-benzyl-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-benzyl-diethylamino-1-(4-morpholinophenyl)-butanone-1, 2-benzyl-dimethylamino-1-(4-morpholinophenyl)-propanone-1, 2-benzyl-diethylamino-1-(4-morpholinophenyl)-propanone-1, 2-benzyl-dimethylamino-1-(4-morpholinophenyl)-pentanone-1, and 2-benzyl-diethylamino-1-(4-morpholinophenyl)-pentanone-1.

[0070] The photopolymerization initiators may be used alone or in combination of two or more.

[0071] 1-5. Other Components The dental curable composition of this embodiment may contain optional components other than components (A) to (D), as needed. Examples of other components include polymerization inhibitors such as dibutylhydroxytoluene and hydroquinone monomethyl ether, chain transfer agents, antioxidants, pigments, dyes, ultraviolet absorbers, and thickeners.

[0072] In the dental curable composition of this embodiment, polyoxyethylene sorbitan ester (B) and inorganic filler (C) are used as essential components for viscosity adjustment, but a thickener may also be used as needed to fine-tune the viscosity. For example, when fumed silica is used as a thickener, the amount of fumed silica per 100 parts by mass of polymerizable monomer (A) is preferably 3.0 parts by mass or less, more preferably less than 2.5 parts by mass. In addition, if the desired viscosity can be obtained by appropriately selecting the type and amount of polyoxyethylene sorbitan ester (B) and / or inorganic filler (C), fumed silica may not be used.

[0073] In general, a dental curable composition may contain a solvent component such as water or an organic solvent (ethanol, acetone, etc.) depending on its intended use. However, from the viewpoint of increasing the mechanical strength of the cured product, the dental curable composition of this embodiment preferably does not contain water or an organic solvent, and more preferably does not contain both water and an organic solvent.

[0074] <Two-component dental hardenable composition, one-component dental hardenable composition, dental cement, dental core build-up material, dental filling and restorative material> The dental hardenable composition of this embodiment can be used in either the one-component form shown in (i) below or the two-component form shown in (ii) below. (i) A one-component dental hardenable composition in which all components constituting the dental hardenable composition are contained in one composition. (ii) A two-component dental hardenable composition composed of a first partial composition consisting of a part of all components constituting the dental hardenable composition and a second partial composition consisting of the remaining part of all components.

[0075] When the dental curable composition of this embodiment is used as a one-component dental curable composition, it is usually preferred to use only the photopolymerization initiator (D2) as the polymerization initiator (D). In other words, when the dental curable composition of this embodiment is a one-component dental curable composition, it is preferred to use it as a photopolymerization-curable dental curable composition.

[0076] Furthermore, when the dental curable composition of this embodiment is used as a two-component dental curable composition, there are two embodiments: one in which only the chemical polymerization initiator (D1) is used as the polymerization initiator (D), and one in which the chemical polymerization initiator (D1) is used in combination with a photopolymerization initiator (D2). In other words, when the dental curable composition of this embodiment is a two-component dental curable composition, in the former embodiment it can be used as a chemical polymerization curable dental curable composition, and in the latter embodiment it can be used as a dual-cure dental curable composition.

[0077] Photopolymerization-curable dental hardenable compositions can be hardened in a short time by light irradiation. In contrast, chemical polymerization-curable or dual-cure dental hardenable compositions can sufficiently harden the entire layer even when the layer made of the dental hardenable composition applied to the desired position is thick and external irradiation light has difficulty reaching the depth of the layer. Furthermore, dual-cure dental hardenable compositions can achieve a higher degree of hardening because they use photopolymerization in addition to chemical polymerization. Therefore, the hardening type of the dental hardenable composition can be appropriately selected based on the hardening characteristics of each hardening type of the dental hardenable composition described above and the content and case of dental treatment.

[0078]

[0023] When the two-part dental hardenable composition is not in use, such as during storage or transportation, the first and second partial compositions are physically separated so that they cannot come into contact with each other, and when in use, the first and second partial compositions are mixed to form a mixture, which is then supplied to a desired location. The formulations of the first and second partial compositions are not particularly limited as long as they are within the range of the formulation of the dental hardenable composition of this embodiment in their mixed state, but it is usually particularly preferable that they have at least the formulation described below.

[0079] That is, when at least a chemical polymerization initiator (D1) is used as the polymerization initiator (D), and the chemical polymerization initiator (D1) contains a first partial chemical polymerization component and a second partial chemical polymerization component that exhibits polymerization activity upon contact with the first partial chemical polymerization component, it is preferable that (i) the first partial composition contains the entire amount of the first partial chemical polymerization component, and (ii) the second partial composition contains the entire amount of the second partial chemical polymerization component. In this case, the first partial composition does not contain any of the second partial chemical polymerization component, and the second partial composition does not contain any of the first partial chemical polymerization component.

[0080] In the combination of the first and second partial compositions described above, a curing reaction by chemical polymerization begins immediately after mixing the first and second partial compositions. Examples of combinations of the first and second partial chemically polymerizable components include a combination of (a) an oxidizing agent and (b) a reducing agent, and a particularly preferred combination is a combination of (a) a hydroperoxide as the oxidizing agent and (b) a thiourea compound and a copper compound as the reducing agents.

[0081] It is particularly preferable that the compositions of the first and second partial compositions are determined so that, when mixed in equal amounts, they essentially correspond to the composition of the dental hardenable composition of this embodiment. Here, "mixed in equal amounts" means that the mixing ratio of the first and second partial compositions (volume of first partial composition:volume of second partial composition) is within the range of 95:105 to 105:95, with 100:100 being particularly preferred. However, the mixing ratio (volume ratio) of the first and second partial compositions may be outside this range. In this case, the mixing ratio (volume ratio) is preferably within the range of 33:167 to 167:33, and more preferably within the range of 50:150 to 150:50.

[0082] Each component constituting the dental curable composition of this embodiment can be blended into the first partial composition and / or the second partial composition in any of the following modes (i) to (iii). However, it is particularly preferable that the polymerizable monomer (A), polyoxyethylene sorbitan ester (B), and inorganic filler (C), which are the main components constituting the dental curable composition of this embodiment, are blended into the first partial composition and / or the second partial composition in terms of the amount in terms of the mode (i) below. (i) A mode in which the entire amount of the component is divided equally into two, and one of the two divided components is blended into the first partial composition, and the other is blended into the second partial composition. (ii) A mode in which the entire amount of the component is divided unequal into two, and one of the two divided components is blended into the first partial composition, and the other is blended into the second partial composition. (iii) A mode in which the entire amount of the component is blended into only one of the first partial composition and the second partial composition.

[0083] The first and second partial compositions can be easily prepared by weighing and mixing the components according to the determined composition. In this case, the first and second partial compositions can be prepared by kneading them uniformly under light-shielded conditions using a known kneading method that uses a mixer such as a mechanical stirrer, a mortar, or a planetary mixer. Similarly, one-component dental curable compositions can be prepared by kneading the raw material components uniformly using a known kneading method.

[0084] Specific uses of the dental hardenable composition of this embodiment as a dental material are not particularly limited, but when the dental hardenable composition of this embodiment is a two-component dental hardenable composition, examples of the uses include chemical polymerization-hardening or dual-cure dental cements and dental core-building materials, and when the dental hardenable composition of this embodiment is a one-component dental hardenable composition, examples of the uses include photopolymerization-hardening dental cements and dental filling and restorative materials.

[0085] When the dental curable composition of the present embodiment is used as a dental cement, regardless of whether it is a one-component type or a two-component type, the average particle size of the inorganic filler (C) used is more preferably 0.12 μm to 10 μm, and even more preferably 0.12 μm to 5 μm, from the viewpoint of compatibility with prostheses.

[0086] <Dental double syringe> When the dental hardenable composition of the present embodiment is a two-component dental hardenable composition, the dental hardenable composition of the present embodiment is provided to the user as a dental double syringe. The dental double syringe of the present embodiment can use any conventional double syringe for the container part as long as the two types of paste-like compositions filled in the two cylindrical barrels are each composed of the two-component dental hardenable composition of the present embodiment. However, it is preferable that the dental double syringe have, for example, the following structure.

[0087] That is, the dental double syringe of this embodiment includes a cylindrical barrel having openings at the distal end and the rear end, a plunger slidably inserted into the cylindrical barrel from the rear end opening, and a cap sealing the distal end opening of the cylindrical barrel and detachably attached to the distal end opening, and is provided with a first syringe and a second syringe having a sealed space formed inside the cylindrical barrel by sealing the openings at both ends of the cylindrical barrel with the plunger and the cap. Here, the first syringe and the second syringe are arranged adjacent to each other so that their distal end openings are flush with each other and their axial directions are parallel. The sealed space of the first syringe is filled with a first partial composition constituting the two-component dental hardenable composition of this embodiment, and the sealed space of the second syringe is filled with a second partial composition constituting the two-component dental hardenable composition of this embodiment.

[0088] When using the dental double syringe of this embodiment, first, the caps sealing the openings at the tip ends of the two cylindrical barrels are removed, and then mixing tips are attached to the tips of the two cylindrical barrels. The mixing tip is a needle tip that mixes the first fluid filled in the first syringe and the second fluid filled in the second syringe to form a mixed fluid, and then discharges the mixed fluid from a discharge port provided at the tip end.

[0089] Next, the two plungers are simultaneously pushed toward the tip of the cylindrical barrel. This forces the first and second partial compositions, respectively, filled in the two cylindrical barrels, into the mixing tip, where they are mixed. The mixture of the first and second partial compositions is then dispensed from the dispensing port provided at the tip of the mixing tip. This mixture is then supplied to the user's desired location during dental treatment.

[0090] The composition and / or filling amount of the first partial composition and the second partial composition filled in each of the two syringes are appropriately set so that the composition of the mixture discharged from the discharge port of the mixing tip falls within the composition range of the dental hardenable composition of this embodiment.

[0091] The dental double syringe of this embodiment may be provided to the user as a single dental double syringe, or may be provided to the user as a dental syringe kit that combines at least (i) the dental double syringe and (ii) a mixing tip and / or a spare cap.

[0092] 1 is a schematic diagram showing an example of a dental double syringe according to this embodiment and a mixing tip used in combination therewith. The X-axis direction in FIG. 1 refers to the direction parallel to the axial direction of the two cylindrical barrels, the X1 direction refers to the tip end side of the two cylindrical barrels, and the X2 direction refers to the rear end side of the two cylindrical barrels. The dental double syringe 100 shown in FIG. 1 has two cylindrical barrels 10A and 10B each having the same outer diameter, inner diameter, and length, two plungers 20A and 20B each having the same shape and size, and a cap 30. One half of the cylindrical barrel 10A, plunger 20A, and cap 30 constitutes a first syringe, and the other half of the cylindrical barrel 10B, plunger 20B, and cap 30 constitutes a second syringe.

[0093] The two cylindrical barrels 10A, 10B are integrally molded to form a single resin member (composite barrel 10C), with the openings 12A, 12B at the front ends thereof flush with each other, and the openings 14A, 14B at the rear ends thereof flush with each other and arranged adjacent to each other with their axial directions parallel to each other. A flange portion 16 is provided at the rear end of the composite barrel 10C. The flange portion 16 is provided so as to extend in a direction perpendicular to the arrangement direction of the two cylindrical barrels 10A, 10B (a direction parallel to the paper surface in the drawing).

[0094] Plungers 20A, 20B are disposed inside each cylindrical barrel 10A, 10B and slidably inserted through openings 14A, 14B at the rear end. In the example shown in FIG. 1 , the tip end portions (not shown) of the plungers 20A, 20B are located near the rear end portions of the cylindrical barrels 10A, 10B. The rear end portions of the plungers 20A, 20B are provided with plunger head portions 22, which also function as connecting portions connecting the plungers 20A and 20B. Therefore, when the plunger head portions 22 are pushed toward the composite barrel 10C, the two plungers 20A, 20B can be simultaneously pushed from the rear end portions toward the tip ends of the two cylindrical barrels 10A, 10B. Furthermore, the tip portions of plungers 20A, 20B are made of a material that allows these tip portions to fit tightly against the inner wall surfaces of cylindrical barrels 10A, 10B without any gaps. Examples of such a material include sealing members such as removable gaskets.

[0095] A cap 30 that simultaneously seals the two openings 12A and 12B is detachably attached to the tip end of the composite barrel 10C. In the example shown in Fig. 1 , one half of the cap 30 seals the opening 12A, and the other half of the cap 30 seals the opening 12B. The openings 12A and 14A at both ends of the cylindrical barrel 10A are sealed with the plunger 20A and the cap 30 to form a sealed space (first sealed space) inside the cylindrical barrel 10A. The first partial composition (not shown in the figure) constituting the two-component dental hardenable composition of this embodiment is filled into the sealed space. The second partial composition (not shown in the figure) constituting the two-component dental hardenable composition of this embodiment is filled into the sealed space (second sealed space) inside the cylindrical barrel 10B. The openings 12B and 14B at both ends of the cylindrical barrel 10B are sealed with the plunger 20B and the cap 30 to form a sealed space. The volume of the first sealed space is the same as the volume of the second sealed space.

[0096] The amount (volume) of the first partial composition and the amount (volume) of the second partial composition filled into the dental double syringe 100 are the same. The compositions of the first partial composition and the second partial composition filled into the dental double syringe 100 are prepared so that the composition of a mixture obtained by mixing the respective compositions in a volume ratio of 1:1 falls within the composition range of the dental hardenable composition of this embodiment.

[0097] When using the dental double syringe 100, the cap 30 is removed from the composite barrel 10C, the mixing tip 110 is attached to the tip of the composite barrel 10C, and the two plungers 20A, 20B are then pushed into the two cylindrical barrels 10A, 10B via the plunger heads 22. This causes a mixture of the first partial composition and the second partial composition in a volumetric ratio of 1:1 to be ejected from the ejection port 112 provided at the tip of the mixing tip 110.

[0098] The mixing tip 110 has a Y-shaped flow path (not shown in the figure), two inlet ports 114A and 114B provided adjacent to each other at two ends upstream of the confluence of the Y-shaped flow path, and one outlet port 112 provided at one end downstream of the confluence of the Y-shaped flow path. A mixing means (not shown in the figure) composed of a stirring plate or the like is provided in the flow path between the outlet port 112 and the confluence of the Y-shaped flow path to thoroughly mix the two types of fluids flowing through the flow path from upstream to downstream. When the mixing tip is attached to the tips of the two cylindrical barrels 10A and 10B, the two openings 12A and 12B provided at the tips of the two cylindrical barrels 10A and 10B are joined without any gaps to the two inlet ports 114A and 114B provided in the mixing tip 110.

[0099] <Dental Single Syringe> When the dental hardenable composition of the present embodiment is a one-component dental hardenable composition, the dental hardenable composition of the present embodiment is provided to the user as a dental single syringe. As long as the paste-like composition filled in one cylindrical barrel is composed of the one-component dental hardenable composition of the present embodiment, the dental single syringe of the present embodiment can use any conventional single syringe for the container part, but it is preferable that the dental single syringe have, for example, the following structure.

[0100] That is, the dental double syringe of this embodiment has a cylindrical barrel having openings at the front and rear ends, a plunger slidably inserted into the cylindrical barrel from the opening on the rear end side, a cap that seals the opening on the front end side of the cylindrical barrel and is detachably attached to the opening on the front end side, and the one-component dental curable composition of this embodiment filled in an airtight space formed inside the cylindrical barrel by sealing both end openings with the plunger and the cap.

[0101] When using the dental single syringe of this embodiment, first, the cap sealing the opening at the tip end of the cylindrical barrel is removed, and then a needle tip is attached to the tip end of the cylindrical barrel. Next, the plunger is pushed toward the tip end of the cylindrical barrel. This causes the one-component dental curable composition of this embodiment, which is filled in each cylindrical barrel, to be discharged from the discharge port of the needle tip via the flow path within the needle tip. The one-component dental curable composition of this embodiment discharged from the needle tip is then supplied to the desired location of the user during dental treatment.

[0102] The dental single syringe of this embodiment may be provided to the user as a single dental syringe, or may be provided to the user as a dental syringe kit that combines at least (i) the dental single syringe and (ii) a needle tip and / or a spare cap.

[0103] Figure 2 is a schematic diagram showing an example of a dental single syringe of this embodiment and a needle tip used in combination with it. The X-axis direction in Figure 2 refers to the direction parallel to the axial direction of the cylindrical barrel, the X1 direction side refers to the tip end side of the cylindrical barrel, and the X2 direction side refers to the rear end side of the cylindrical barrel.

[0104] The dental single syringe 102 shown in FIG. 2 includes a cylindrical barrel 10, a plunger 20, and a cap 32. A flange 18 is provided at the rear end of the cylindrical barrel 10. A plunger 20 is slidably inserted into the cylindrical barrel 10 through an opening 14 at the rear end. In the example shown in FIG. 2, the tip of the plunger 20 (not shown) is located near the rear end of the cylindrical barrel 10. The tip of the plunger 20 is made of a material that allows it to tightly contact the inner wall surface of the cylindrical barrel 10. Examples of such a material include a sealing material such as a removable gasket. A plunger head 24 is provided at the rear end of the plunger 20.

[0105] A cap 32 that seals the opening 12 on the tip side is detachably attached to the tip side of the cylindrical barrel 10. The openings 12, 14 at both ends of the cylindrical barrel 10 are sealed with the plunger 20 and the cap 32, and an airtight space formed inside the cylindrical barrel 10 is filled with the one-component dental curable composition of this embodiment.

[0106] When using the dental single syringe 102, the cap 32 is removed from the cylindrical barrel 10, the needle tip 120 is attached to the distal end of the cylindrical barrel 10, and the plunger 20 is then pushed into the cylindrical barrel 10 via the plunger head 24. This causes the one-component dental curable composition of this embodiment to be ejected from the ejection port 122 provided at the distal end of the needle tip 120. The needle tip 120 includes the ejection port 122 provided at the distal end, an inlet 124 provided at the rear end, and a single flow path (not shown in the figure) connecting the ejection port 122 and the inlet 124. When the needle tip 120 is attached to the distal end of the cylindrical barrel 10, the opening 12 provided at the distal end of the cylindrical barrel 10 is joined to the inlet 124 of the needle tip 120 without any gaps.

[0107] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0108] 1. Raw Material Components The names of the raw material components used in preparing the dental curable compositions of each Example and Comparative Example and their abbreviations are described below.

[0109] <Polymerizable Monomer (A)> Bis-GMA: 2,2-bis[4-(3-methacryloyloxy)-2-hydroxypropoxyphenyl]propane 3G: triethylene glycol dimethacrylate D-2.6E: 2,2'-bis(4-methacryloxypolyethoxyphenyl)propane UDMA: 1,6-bis(methacrylethyloxycarbonylamino)-2,2-4-trimethylhexane

[0110] <Polyoxyethylene sorbitan esters (B)> Tween 20: polyoxyethylene sorbitan monolaurate Tween 40: polyoxyethylene sorbitan monopalmitate Tween 80: polyoxyethylene sorbitan monooleate.

[0111] <Inorganic Filler (C)> F1: A filler made of silica zirconia powder particles having an average particle size of 3 μm, surface-treated with gamma-methacryloyloxypropyltrimethoxysilane. F2: A filler made of silica zirconia powder particles having an average particle size of 4 μm, surface-treated with gamma-methacryloyloxypropyltrimethoxysilane. F3: A filler made of silica zirconia powder particles having an average particle size of 0.15 μm, surface-treated with gamma-methacryloyloxypropyltrimethoxysilane.

[0112] <Polymerization initiator (D)> <Chemical polymerization initiator (D1)> Oxidizing agent: organic peroxide (hydroperoxide) PO1: 1,1,3,3-tetramethylbutyl hydroperoxide PO2: cumene hydroperoxide Reducing agent (thiourea compound and copper compound) BzTU: N-benzoylthiourea PyTU: 2-pyridylthiourea Cu1: copper (II) acetylacetonate Cu2: copper (II) acetate dihydrate.

[0113] <Photopolymerization initiator (D2)> CQ: camphorquinone DMBE: ethyl 4-dimethylaminobenzoate

[0114] <Other Components> Surfactants other than component (B) SA1: Polyethylene glycol monolaurate SA2: Sorbitan monolaurate (Span 20) SA3: Polyethylene glycol mono-4-octylphenyl ether SA4: Nonaethylene glycol monododecyl ether Polymerization inhibitor BHT: Dibutylhydroxytoluene.

[0115] 2. Preparation of Base Compositions Base composition 1 and base composition 2 having the following compositions were prepared as mixed compositions of multiple types of polymerizable monomers (A): <Base composition 1> A mixed composition consisting of 6% by mass of Bis-GMA, 34% by mass of 3G, and 60% by mass of D-2.6E <Base composition 2> A mixed composition consisting of 40% by mass of Bis-GMA, 20% by mass of 3G, and 40% by mass of UDMA

[0116] 3. Preparation and evaluation of two-component dental hardenable composition (1) Preparation of first partial composition and second partial composition <Example A1> (A) component: 50 mass parts of base composition 1, (B) component: 1 mass part of Tween 20, (D1) component: 1.5 mass parts of oxidizing agent PO1, and other components: 0.165 mass parts of polymerization inhibitor BHT were dissolved to prepare a mixture. Next, this mixture was mixed with (C) component: 117 mass parts consisting of F1: 70 mass parts and F3: 47 mass parts, to prepare a first partial composition (first agent).

[0117] In addition, a mixture was prepared by dissolving 50 parts by weight of the base composition 1 (A) as the component, 1 part by weight of Tween 20 (B) as the component, 0.75 parts by weight of BzTU and 0.005 parts by weight of Cu1 as the reducing agent constituting the remainder of the (D1) component, 0.4 parts by weight of CQ and 0.425 parts by weight of DMBE as the (D2) component, and 0.085 parts by weight of a polymerization inhibitor as another component. Next, 117 parts by weight of the (C) component consisting of 70 parts by weight of F1 and 47 parts by weight of F3 was mixed with this mixture to prepare a second partial composition (second part). This resulted in a two-part dental hardenable composition consisting of a first part and a second part.

[0118] Examples A2 to A17 and Comparative Examples A1 to A7 Two-component dental curable compositions consisting of a first component and a second component were obtained in the same manner as in Example A1, except that the compositions of the first component and the second component were changed as shown in Tables 1 and 2. Here, in Examples A1 to A16 and Comparative Examples A1 to A7, Base Composition 1 was used as the component (A) of the first component and the second component, but in Example A17, 50 parts by mass of Base Composition 2 (100 parts by mass in total for the two components) was used as the component (A) of the first component and the second component instead of 50 parts by mass of Base Composition 1 (100 parts by mass in total for the two components).

[0119] The parts by weight (numbers in parentheses) of each component shown in Tables 1 and 2 represent parts by weight relative to 50 parts by weight of the base composition, which is a mixed composition of two or more polymerizable monomers (A). For example, in the first part of Example A1, the blending amounts of the (B), (C), and part of the (D1) components, as well as the other components, relative to 50 parts by weight of the (A) component are, as shown in Table 1, 1 part by weight of Tween 20, 70 parts by weight of F1, and 47 parts by weight of F3 (total: 117 parts by weight), 1.5 parts by weight of PO1, and 0.165 parts by weight of BHT, respectively. The "↑" symbol in the table indicates the same as above. The two-part dental curable compositions of each Example can be used as dental cements or dental core construction materials.

[0120] (2) Evaluation Method and Results The two-component dental curable compositions of each Example and Comparative Example were filled into a double syringe, and then a mixing tip was attached to the double syringe to evaluate dischargeability and sagging. The mixed composition was discharged from the tip of the mixing tip and cured, and the cured product was evaluated for bending strength. The methods for evaluating dischargeability, sagging, and bending strength are as follows. The evaluation results for dischargeability, sagging, and bending strength for each Example and Comparative Example are shown in Tables 1 and 2.

[0121] <Dischargeability (Discharge Pressure)> A double syringe (Two-Component Systems 5 mL cartridge (ratio 1:1) manufactured by Medmix) filled with equal amounts of the first and second agents immediately after preparation was attached to a mixing tip (Medmix Mixing Tip T-Mixer (Outlet S)). This was then fixed to a compression tester (Autograph AG5000D, manufactured by Shimadzu Corporation) with the outlet of the mixing tip facing downwards. Using a compression jig (maximum load capacity 5 t), a force in the compression direction was applied to the plunger of the double syringe at a test speed of 5 mm / min, and the test force (N) detected at this time (i.e., the force required to discharge a mixture obtained by mixing the first agent and the second agent at a volume ratio of 1:1 from the outlet) was measured as "discharge pressure / N". The discharge pressure was rated as good when it was 30N or less.

[0122] <Flexural Strength> A mixing tip (medmix T-Mixer (Outlet S) mixing tip) was attached to a double syringe (medmix TWO-COMPONENT SYSTEMS 5 mL cartridge (Ratio 1:1)) filled with equal amounts of the first and second agents immediately after preparation. Next, the plunger was pushed in, and the paste-like mixture (mixing ratio (volume ratio) of the first agent to the second agent = 1:1) was discharged from the outlet of the mixing tip, and the mixture was filled into a prismatic through-hole (opening size: length 25 mm × width 2 mm, hole depth: 2 mm) provided in a mold. Next, both openings of the through-hole were pressed with polyester film, and then the film was sandwiched between glass slides and pressed with a clip. Thereafter, the opening on one side of the through-hole was irradiated with light through the film and glass slide at five equally spaced positions along the longitudinal direction of the opening. At this time, the light irradiation time per location was 20 seconds, and the irradiation intensity was 500 mW / cm ２ The distance from the opening of the through-hole to the tip of the light irradiator was adjusted so that the light irradiation was performed on the opening on the other side of the through-hole. This cured the mixture in the through-hole to form a cured body.

[0123] Next, the cured product removed from the mold was polished with P320 waterproof abrasive paper and then immersed in 37°C water overnight to obtain a test specimen. The three-point bending fracture strength of this test specimen was measured using a universal testing machine (AG-I type, manufactured by Shimadzu Corporation) at a crosshead speed of 1.0 mm / min. Five test specimens were prepared, and the average value of the three-point bending fracture strength of each test specimen was calculated as the bending strength. A bending strength of 120 MPa or more was considered good.

[0124] <Dripping property (dripping length)> A mixing tip (medmix mixing tip T-Mixer (Outlet S)) was attached to a double syringe (medmix TWO-COMPONENT SYSTEMS 5 mL cartridge (Ratio 1:1)) filled with equal amounts of the first and second agents immediately after preparation. Subsequently, the plunger was pressed to eject approximately 0.1 g of a paste-like mixture (mixing ratio (volume ratio) of the first agent to the second agent = 1:1) from the ejection port of the mixing tip. The mixture was then placed on a glass slide and left to stand for 1 minute. During this time, a mark was made with a marker on the edge of the paste-like mixture placed on the glass slide. The glass slide was then placed vertically with the mark facing downwards, and allowed to stand in an incubator at 23°C for 3 minutes. After 3 minutes, the distance traveled by the paste mixture (movement distance), i.e., the length from the mark (initial value: 0 mm) to the bottom end of the paste mixture, was measured with a caliper as "drooping length / mm." From this value, the "initial" drooping properties shown in Tables 1 and 2 were evaluated.

[0125] Furthermore, a double syringe (Two-Component Systems 5 mL cartridge (1:1 ratio) manufactured by Medmix) filled with equal amounts of the first and second components immediately after preparation was left in an incubator at 65°C for 35 days with both end openings sealed. Thereafter, the double syringe was removed from the incubator and the "dripping length / mm" was measured using the same procedure as in the evaluation of "initial" drooping. The drooping properties "after 35 days at 65°C" shown in Tables 1 and 2 were then evaluated from this value.

[0126] The sagging length was evaluated as good when it was 4 mm or less in both the "initial" and "after 35 days at 65°C" cases.

[0127]

[0128]

[0129] Examples A1 to A17 exhibited good dischargeability, bending strength, and sagging properties. In contrast, Comparative Example A1, which did not use component (B), and Comparative Example A2, in which the total content of component (B) in the two components was less than 0.2 parts by mass, exhibited poor sagging properties after 35 days at 65°C. Comparative Example A3, in which the total content of component (B) in the two components exceeded 25 parts by mass, exhibited poor sagging properties after 35 days at 65°C. Comparative Examples A4 to A7, in which a surfactant other than component (B) was used instead of component (B), exhibited poor sagging properties after 35 days at 65°C in Comparative Examples A4, A5, and A7, and Comparative Example A6 exhibited poor sagging properties both initially and after 35 days at 65°C.

[0130] 4. Preparation and evaluation of one-pack dental hardening composition (1) Preparation of one-pack dental hardening composition <Example B1> As (A) component, base composition 1:100 mass parts, as (B) component, Tween20:1 mass parts, as (D2) component, CQ:0.8 mass parts and DMBE:0.85 mass parts, and as other components, BHT:0.17 mass parts of polymerization inhibitor are dissolved to prepare a mixture.Then, with this mixture, by mixing (C) component:245 mass parts, which consists of F1:147 mass parts and F2:98 mass parts, prepare one-pack dental hardening composition.

[0131] Examples B2 to B5 and Comparative Examples B1 to B5 As shown in Tables 3 and 4, one-pack dental curable compositions were prepared in the same manner as in Example B1, except that the compositions were changed.

[0132] The parts by mass (numbers in parentheses) of each component shown in Tables 3 and 4 represent parts by mass relative to 100 parts by mass of the base composition, which is a mixed composition of two or more types of polymerizable monomers (A). The "↑" symbol in the tables indicates the same as above. The one-component dental curable compositions of each Example can be used as dental cements or dental filling and restorative materials.

[0133] (2) Evaluation Method and Results The one-component dental curable compositions of each Example and Comparative Example were filled into a single syringe, and then a needle tip was attached to the single syringe to evaluate dischargeability and sagging. The mixed composition was discharged from the tip of the needle tip and cured, and the cured product was evaluated for bending strength. The methods for evaluating dischargeability, sagging, and bending strength are as follows. The evaluation results of dischargeability, sagging, and bending strength for each Example and Comparative Example are shown in Tables 3 and 4.

[0134] <Dischargeability (Discharge Pressure)> A needle tip (Tokuyama Dental Palfique Esthelite LV syringe tip) was attached to a single syringe (Tokuyama Dental Esthelite Universal Flow syringe 1.8 mL cartridge) filled with the single-component dental curable composition immediately after preparation. The syringe was then fixed to a compression tester ("Autograph AG5000D" manufactured by Shimadzu Corporation) with the discharge port of the needle tip facing downward. Using a compression tool (maximum load capacity 5 t), a compressive force was applied to the plunger of the single syringe at a test speed of 5 mm / min. The test force (N) detected at this time (i.e., the force required to discharge the single-component dental curable composition from the discharge port) was measured as "discharge pressure / N." A discharge pressure of 30 N or less was considered good.

[0135] <Flexural Strength> A needle tip (Tokuyama Dental Palfique Esthelite LV syringe tip) was attached to a single syringe (Tokuyama Dental Esthelite Universal Flow syringe 1.8 mL cartridge) filled with the immediately prepared one-component dental curable composition. The plunger was then pushed in, ejecting the paste-like one-component curable composition from the needle tip outlet and filling it into a prismatic through-hole (opening size: length 25 mm x width 2 mm, hole depth: 2 mm) provided in a mold. The bending strength was then determined using the same procedure as in the evaluation of the bending strength of the two-component dental curable composition. A bending strength of 120 MPa or more was considered good.

[0136] <Dragging (Dragging Length)> A needle tip (Palfique Esthelite LV syringe tip, manufactured by Tokuyama Dental Co., Ltd.) was attached to a single syringe (1.8 mL cartridge for Esthelite Universal Flow syringe, manufactured by Tokuyama Dental Co., Ltd.) filled with the one-component dental curable composition immediately after preparation. Thereafter, the "initial" dragging shown in Tables 3 and 4 was evaluated using the same procedure as in the evaluation of the dragging of the two-component dental curable composition.

[0137] In addition, a single syringe (Tokuyama Dental Co., Ltd., Esthelite Universal Flow syringe 1.8 mL cartridge) filled with the one-component dental curable composition immediately after preparation was left in an incubator at 65°C for 35 days with both end openings sealed. Thereafter, the single syringe was removed from the incubator and the "dripping length / mm" was measured using the same procedure as in the evaluation of "initial" drooping. Then, the drooping "after 35 days at 65°C" shown in Tables 3 and 4 was evaluated from this value.

[0138] The sagging length was evaluated as good when it was 4 mm or less in both the "initial" and "after 35 days at 65°C" cases.

[0139]

[0140]

[0141] Examples B1 to B5 exhibited good dischargeability, bending strength, and sagging properties. In contrast, Comparative Example B1, which did not use component (B), and Comparative Example B2, which contained less than 0.2 parts by mass of component (B), exhibited poor sagging properties after 35 days at 65°C. Comparative Example B3, which contained more than 25 parts by mass of component (B), exhibited poor sagging properties after 35 days at 65°C. Comparative Examples B4 and B5, which used a surfactant other than component (B) instead of component (B), exhibited poor sagging properties after 35 days at 65°C.

[0142] 10, 10A, 10B Cylindrical barrel 10C Composite barrel 12, 12A, 12B Opening 14, 14A, 14B Opening 16 Flange 18 Flange 20, 20A, 20B Plunger 22 Plunger head 24 Plunger head 30 Cap 32 Cap 100 Dental double syringe 102 Dental single syringe 110 Mixing tip 112 Discharge outlet 114A, 114B Inlet 120 Needle tip 122 Discharge outlet 124 Inlet

Claims

1. A dental curable composition comprising: 100 parts by mass of a polymerizable monomer (A); 0.2 to 25 parts by mass of a polyoxyethylene sorbitan ester (B); an inorganic filler (C); and a polymerization initiator (D) comprising at least one selected from the group consisting of a chemical polymerization initiator (D1) and a photopolymerization initiator (D2).

2. The dental hardenable composition according to claim 1, wherein the polyoxyethylene sorbitan ester (B) is a compound represented by the following general formula (1): (In the general formula (1), R represents a hydrocarbon group having 5 to 30 carbon atoms in its main chain, which may have at least one substituent selected from the group consisting of an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, an alkynyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, a nitro group, a cyano group, a phenyl group, and a halogen atom; w, x, y, and z each independently represent an integer of 0 to 30, and the sum of w, x, y, and z is 10 to 30.) 3. The dental curable composition according to claim 1, comprising 150 to 270 parts by mass of the inorganic filler (C) relative to 100 parts by mass of the polymerizable monomer (A).

4. The dental curable composition according to claim 1, comprising 0.1 to 20 parts by mass of a prepolymerization initiator (D) relative to 100 parts by mass of the polymerizable monomer (A).

5. A two-component dental hardenable composition, all of whose components are the dental hardenable composition according to any one of claims 1 to 4, comprising a first partial composition consisting of a portion of all of said components, and a second partial composition consisting of the remainder of all of said components, wherein said polymerization initiator (D) comprises at least said chemical polymerization initiator (D1), and said chemical polymerization initiator (D1) comprises a first partial chemically polymerizable component and a second partial chemically polymerizable component that exhibits polymerization activity upon contact with said first partial chemically polymerizable component, wherein said first partial composition comprises the entire amount of said first partial chemically polymerizable component, and said second partial composition comprises the entire amount of said second partial chemically polymerizable component.

6. The two-component dental hardenable composition according to claim 5, wherein the first partial chemically polymerizable component comprises a hydroperoxide, and the second partial chemically polymerizable component comprises a thiourea compound and a copper compound.

7. A dental cement comprising the two-component dental hardenable composition according to claim 5.

8. A dental core construction material comprising the two-component dental hardenable composition according to claim 5.

9. A one-component dental hardenable composition, all of which is composed of the dental hardenable composition according to any one of claims 1 to 4, and all of which are contained in a single composition.

10. A dental cement comprising the one-component dental hardenable composition according to claim 9.

11. A dental filling and restorative material comprising the one-component dental hardenable composition according to claim 9.

12. A dental double syringe comprising: a cylindrical barrel having openings at the front and rear ends; a plunger slidably inserted into the cylindrical barrel from the opening at the rear end; and a cap sealing the opening at the front end of the cylindrical barrel and removably attached to the opening at the front end, wherein the dental double syringe comprises a first syringe and a second syringe having an airtight space formed inside the cylindrical barrel by sealing the openings at both ends of the cylindrical barrel with the plunger and the cap, wherein the first syringe and the second syringe are arranged adjacent to each other so that their openings at the front ends are flush with each other and their axial directions are parallel, and the airtight space of the first syringe is filled with a first partial composition that constitutes the two-part dental hardenable composition according to claim 5, and the airtight space of the second syringe is filled with a second partial composition that constitutes the two-part dental hardenable composition according to claim 5.

13. A dental single syringe comprising: a cylindrical barrel having openings at the front and rear ends; a plunger slidably inserted into the cylindrical barrel from the opening at the rear end; a cap that seals the opening at the front end of the cylindrical barrel and is detachably attached to the opening at the front end; and the one-component dental curable composition according to claim 9, filled into an airtight space formed inside the cylindrical barrel by sealing both end openings with the plunger and the cap.

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