Dental attachment composition

Abstract

The present invention provides a dental attachment composition which is excellent in adhesion to uncutdental enamel even without pretreatment using a dental adhesive or the like after etching using phosphoric acid or the like, has mechanical properties of 1 or more, and can simplify the adhesion operation of a dental attachment. The present invention relates to a dental attachment composition comprising a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C), the aforementioned polymerizable monomer (A) comprising a polymerizable monomer (A-1) having an acidic group and a polymerizable monomer (A-2) not having an acidic group, the content of the polymerizable monomer (A-1) having an acidic group being 1 to 40 parts by mass in 100 parts by mass of the total amount of the aforementioned polymerizable monomer (A), and the content of the filler (C) being 50 to 90 parts by mass in 100 parts by mass of the total amount of the composition.

Description

Technical Field

[0001] This invention relates to compositions for dental attachments. More specifically, the compositions for dental attachments of this invention relate to compositions for dental attachments that exhibit excellent adhesion to uncut enamel and possess certain or more mechanical properties even after etching with phosphoric acid or the like, without pretreatment using dental adhesives or the like. Background Technology

[0002] In traditional orthodontic treatment, brackets have been the mainstream method. However, in recent years, due to concerns about their aesthetic appearance, treatment using clear, colorless dental aligners (sometimes simply called "aligners") has become increasingly popular. In bracket-based treatment, a mechanical load (sometimes referred to as "orthodontic force") is applied to the teeth by attaching a bracket shaped to hold a wire to the tooth surface and then attaching the wire to it, thus guiding the teeth into the desired position. Orthodontic adhesives are typically used to attach the bracket to the tooth surface. On the other hand, in aligner-based treatment, an aligner with a aligner shaped like a dental aligner is installed. A method is known where a protrusion called an attachment is also formed on the tooth surface, and the aligner is attached to this protrusion, thereby applying a more appropriate mechanical load and more effectively guiding the teeth into the desired position. Dental materials used as adhesives and attachments for these orthodontic treatments are typically formed from curable compositions containing polymeric monomers such as (meth)acrylates, polymerization initiators, and fillers. In particular, dental composite resins are typically used as attachment materials.

[0003] The following method is used to form the attachment, employing a dental pad, known as a dental mold, that reflects the position of the teeth before orthodontic treatment. The general method for forming the attachment using a dental mold is described below. The dental mold has recesses with attachment shapes at positions corresponding to the tooth surfaces. First, these recesses are filled with dental composite resin. After selectively surface-treating (etching) the attachment-forming portion of the tooth surface using phosphoric acid or the like, a dental orthodontic adhesive is applied to this portion. Solvent removal is performed using air jetting as needed, and the dental orthodontic adhesive is cured using light irradiation or the like. After the aforementioned dental mold, with the recesses filled with dental composite resin, is installed in the tooth row, the dental composite resin filling the recesses with attachment shapes is cured by light irradiation or the like, thereby forming an attachment at the desired position on the tooth surface (the position where the dental adhesive is applied). As a method for forming attachments for orthodontic appliances, it is well known to use dental adhesive materials to bond dental composite resin to uncut enamel after phosphate etching (see, for example, non-patent literature 1, 2, etc.).

[0004] In orthodontic treatment using this type of appliance, the attachment must withstand various loads, including those incurred during appliance installation, during appliance removal, brushing-based loads, and loads from tooth deflection during occlusion, without detaching from the tooth surface. However, in cases where the adhesion to uncut enamel after phosphate etching is low, detachment may occur during treatment. Furthermore, in cases where the cured material has low strength and modulus of elasticity, there is a risk of attachment breakage or poor fit with the appliance during treatment, leading to inappropriate orthodontic care. Therefore, a certain level of strength and modulus of elasticity is required.

[0005] Furthermore, when using orthodontic appliances for treatment, a large number of attachments need to be bonded to the tooth surface. In the method of using the dental adhesive materials disclosed in Non-Patent Documents 1 and 2, not only is phosphoric acid etching required for all tooth surfaces where attachments are to be formed, but also the application of adhesive material and the filling of the dental model with cured dental material, thus complicating the operation. Ideally, the dental adhesive material should be selectively applied only to the bonding portion between the attachment and the tooth surface, but selective application to specific locations is difficult in itself, and when air is sprayed to evaporate the solvent of the dental adhesive material, it is practically impossible to prevent the dental adhesive material from scattering onto the tooth surface beyond the portion where the attachment is mounted. As a result, the portion of the tooth surface with the dental adhesive material attached is prone to staining, bacteria can easily adhere to it, and the treatment time is significantly increased when performing operations to remove the dental adhesive material applied beyond the portion where the attachment is mounted on the tooth surface. As can be seen, the attachment formation process differs significantly from general filling and restoration treatments for dental cavities, and serious adverse effects can result from the combined use of dental adhesive materials.

[0006] Alternatively, the material used as the attachment could be the dental adhesive materials disclosed in Patent Documents 1-4, which are used for the same orthodontic purposes.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: International Publication No. 2015 / 141683

[0010] Patent Document 2: Japanese Patent Application Publication No. 2010-46266

[0011] Patent Document 3: Japanese Patent Application Publication No. 2011-207806

[0012] Patent Document 4: Japanese Patent Application Publication No. 2016-6040

[0013] Non-patent literature

[0014] Non-patent literature 1: ACTA ODONTOLOGICA LATINOAMERICANA, 2017, Vol. 30, Issue 2, pp. 90-95

[0015] Non-patent literature 2: Materials, "Changes in Roughness and Mechanical Properties of Invisalign Appliances after One-and Two-Weeks Use", 2019, Vol.12(15), 2406 Summary of the Invention

[0016] The problem that the invention aims to solve

[0017] Subsequent research by the inventors revealed that the adhesive materials for orthodontic treatment described in Patent Documents 1 and 2 do not contain polymeric monomers with acidic groups, and there is room for improvement in adhesion to uncut enamel after phosphoric acid etching. It has been established that the dental curing compositions described in Patent Documents 3 and 4 are suitable as fixing materials for loose teeth due to the low elastic modulus of their cured products; however, as attachment materials, the orthodontic force applied to the teeth by the orthodontic appliance is significantly reduced due to the attachment, making proper orthodontic treatment impossible.

[0018] The object of the present invention is to provide a dental attachment composition that, even without pretreatment using dental adhesive materials after etching with phosphoric acid or the like, exhibits excellent adhesion to uncut enamel and possesses certain or more mechanical properties, thereby simplifying the bonding operation of dental attachments.

[0019] Solution for solving the problem

[0020] That is, the present invention includes the following inventions.

[0021] [1] A composition for dental attachments comprising a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C),

[0022] The aforementioned polymerizable monomer (A) includes a polymerizable monomer with acidic groups (A-1) and a polymerizable monomer without acidic groups (A-2).

[0023] Of the total amount of the aforementioned polymerizable monomer (A) in 100 parts by mass, the content of the polymerizable monomer (A-1) having an acidic group is 1 to 40 parts by mass, and

[0024] In 100 parts by mass of the composition, the content of filler (C) is 50 to 90 parts by mass;

[0025] [2] According to the dental attachment composition of [1], wherein the aforementioned non-acidic polymeric monomer (A-2) contains a non-acidic hydrophobic polymeric monomer (A-2b) and a non-acidic hydrophilic polymeric monomer (A-2c) as needed, and the mass ratio of the non-acidic hydrophilic polymeric monomer (A-2c) to the non-acidic hydrophobic polymeric monomer (A-2b) is: non-acidic hydrophilic polymeric monomer (A-2c): non-acidic hydrophobic polymeric monomer (A-2b) = 0:10 to 2:1;

[0026] [3] The dental attachment composition according to [1] or [2], wherein the aforementioned dental attachment composition is a single-component type;

[0027] [4] The dental attachment composition according to any one of [1] to [3], wherein the polymerizable monomer (A-1) having an acidic group is a polymerizable monomer having a phosphate group and / or a polymerizable monomer having a carboxylic acid group;

[0028] [5] The dental attachment composition according to any one of [1] to [4], wherein the polymerizable monomer (A-1) having an acidic group is 10-methacryloyloxydecyl dihydrogen phosphate;

[0029] [6] The dental attachment composition according to any one of [2] to [5], wherein the mass ratio of the aforementioned hydrophilic polymeric monomer (A-2c) without acidic groups to the hydrophobic polymeric monomer (A-2b) without acidic groups is: hydrophilic polymeric monomer (A-2c) without acidic groups: hydrophobic polymeric monomer (A-2b) without acidic groups = 0:10 to 1:1;

[0030] [7] The dental attachment composition according to any one of [2] to [5], wherein the mass ratio of the aforementioned hydrophilic polymeric monomer (A-2c) without acidic groups to the hydrophobic polymeric monomer (A-2b) without acidic groups is: hydrophilic polymeric monomer (A-2c) without acidic groups: hydrophobic polymeric monomer (A-2b) without acidic groups = 0:10 to 1:2;

[0031] [8] The dental attachment composition according to any one of [1] to [7], wherein the aforementioned filler (C) comprises at least one combination selected from the following combinations: filler (C-1) with an average particle size of 1 nm or more and less than 0.1 μm and filler (C-2) with an average particle size of 0.1 μm or more and less than 1 μm; filler (C-1) with an average particle size of 1 nm or more and less than 0.1 μm and filler (C-3) with an average particle size of more than 1 μm and less than 10 μm; filler (C-1) with an average particle size of 1 nm or more and less than 0.1 μm and filler (C-2) with an average particle size of 0.1 μm or more and less than 1 μm and filler (C-3) with an average particle size of more than 1 μm and less than 10 μm; and filler (C-2) with an average particle size of 0.1 μm or more and less than 1 μm and filler (C-3) with an average particle size of more than 1 μm and less than 10 μm;

[0032] [9] The dental attachment composition according to [8], wherein the aforementioned filler (C) comprises the aforementioned combination (I) or the aforementioned combination (II);

[0033]

[10] The composition for dental attachments according to any one of [1] to [9] has a flexural modulus of 3 GPa or higher in its cured form;

[0034]

[11] The dental attachment composition according to any one of [1] to

[10] , wherein the aforementioned photopolymerization initiator (B) comprises a water-soluble photopolymerization initiator (B-1);

[0035]

[12] The dental attachment composition according to any one of [1] to

[11] , wherein the aforementioned photopolymerization initiator (B) comprises a non-water-soluble photopolymerization initiator (B-2);

[0036]

[13] The dental attachment composition according to any one of [1] to

[12] , wherein the aforementioned polymeric monomer (A-2) without acidic groups contains an asymmetric acrylamide-methacrylate compound (A-2a) represented by the following general formula (1);

[0037] [Chemistry 1]

[0038]

[0039] [In the formula, Z is an optional C1-C8 straight-chain or branched aliphatic or aromatic group with substituents, wherein the aforementioned aliphatic group is optionally selected from -O-, -S-, -CO-, -CO-O-, -O-CO-, -NR-, -NR-.] 1 -、-CO-NR 1 -、-NR 1 -CO-、-CO-O-NR 1-、-O-CO-NR 1 -and-NR 1 -CO-NR 1 - At least one linking group in - is interrupted. R 1 [This refers to a hydrogen atom or an optional C1-C8 straight-chain or branched aliphatic group with substituents.]

[0040]

[14] The dental attachment composition according to

[13] , wherein Z is optionally a straight-chain or branched aliphatic group of C1 to C4 having a substituent;

[0041]

[15] The dental attachment composition according to

[13] or

[14] , wherein Z is optionally a C1 to C4 linear or branched alkylene group having a substituent;

[0042]

[16] The dental attachment composition according to any one of

[13] to

[15] , wherein the asymmetric acrylamide methacrylate compound (A-2a) of the aforementioned general formula (1) is selected from at least one of N-methacryloyloxyethyl acrylamide, N-methacryloyloxypropyl acrylamide, N-methacryloyloxybutyl acrylamide, N-(1-ethyl-(2-methacryloyloxy)ethyl)acrylamide and N-(2-(2-methacryloyloxyethoxy)ethyl)acrylamide.

[0043] Invention Effects

[0044] According to the present invention, a dental attachment composition is provided that exhibits excellent adhesion to uncut enamel and possesses certain or more mechanical properties even after etching with phosphoric acid or the like, without pretreatment using dental adhesives or the like, thus simplifying the bonding operation of dental attachments. The dental attachment composition of the present invention is suitable for use in dental attachments for orthodontic appliances. Furthermore, the dental attachment composition of the present invention exhibits excellent adhesion even without the use of dental adhesives, thereby simplifying orthodontic treatment operations. Additionally, since dental adhesives are not required, the operation of removing dental adhesives that have spread beyond the target tooth surface is also eliminated. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of a dental attachment according to one embodiment of the present invention. Detailed Implementation

[0046] The dental attachment composition of the present invention comprises a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C). The polymerizable monomer (A) comprises a polymerizable monomer (A-1) having an acidic group and a polymerizable monomer (A-2) not having an acidic group. Of 100 parts by mass of the total polymerizable monomer (A), the content of the polymerizable monomer (A-1) having an acidic group is 1 to 40 parts by mass. And of 100 parts by mass of the total dental attachment composition, the content of the filler (C) is 50 to 90 parts by mass. In this specification, "dental attachment" refers to a dental orthodontic attachment, that is, a dental orthodontic component used in conjunction with a dental orthodontic appliance. Figure 1 A schematic diagram of a "dental attachment" is shown. For example, as... Figure 1 As shown, the dental attachment 1 is formed in the form of a protrusion on the surface of the tooth 2, including uncut natural teeth, etc. By attaching a dental orthodontic appliance to the protrusion, a more suitable mechanical load is applied, which can more effectively guide the teeth to the desired position.

[0047] From the viewpoint of adhesion to the tooth enamel, the light-curing depth of the dental attachment composition of the present invention is preferably 2 mm or more, more preferably 2.5 mm or more. The upper limit of the light-curing depth is not particularly limited and can be, for example, 6 mm or less. To apply appropriate orthodontic force, the dental attachment requires a certain thickness. By having a certain light-curing depth, even with a certain thickness, sufficient curing of the bonding interface between the tooth enamel and the composition is achieved during curing, thus resulting in high adhesion. Furthermore, in the case of light-curing materials, curing is usually insufficient on the depth side where light intensity is weaker, leading to lower mechanical strength. In the case of filling restorations, the deepest part of the light-curing depth is the bottom of the cavity, which is less susceptible to heat load or abrasion load caused by toothbrushes. On the other hand, in the case of dental attachments, this part is exposed to the tooth enamel surface, therefore, the influence of heat load or abrasion load caused by toothbrushes on the part with low mechanical strength becomes significant. Therefore, due to the high light-curing depth, high strength is also required on the depth side. Thus, even when dental attachments are formed on the tooth surface, there are situations where a high light-curing depth is required. The method for measuring the light-curing depth is as described in the examples described later.

[0048] From the viewpoint of the strength of dental attachments, the Vickers hardness of the cured product obtained by curing the dental attachment composition of the present invention by irradiating it with a dental LED irradiator for 10 seconds is preferably 30 Hv or higher, more preferably 33 Hv or higher, and even more preferably 35 Hv or higher. Due to the high Vickers hardness, the dental attachment is less prone to wear due to friction generated during appliance installation and removal, brushing, etc., exhibiting excellent strength and maintaining orthodontic force as a dental attachment. Unlike composite resins for fillings, from the viewpoint of ease of removal of dental attachments, if the upper limit of the Vickers hardness is too high, removal becomes difficult; therefore, it is preferably 70 Hv or lower, more preferably 65 Hv or lower, and even more preferably 60 Hv or lower. The method for measuring the Vickers hardness of the cured product is as described in the examples described later.

[0049] Regarding the dental attachment composition of the present invention, from the viewpoint of the strength of the dental attachment, the flexural modulus of the cured material is preferably 3 GPa or more, more preferably 3.5 GPa or more, and from the viewpoint of being able to exert a stronger corrective force as a dental orthodontic treatment device by being used together with a dental appliance, it is further preferably 4.0 GPa or more. In a suitable embodiment, the flexural modulus of the cured material of the dental attachment composition of the present invention may be 5.0 GPa or more, or 5.5 GPa or more. By making the flexural modulus of elasticity a certain value or higher, the dental attachment is less likely to deform due to the installation and removal of the appliance or brushing. On the other hand, from the viewpoint of the ease of removal of the dental attachment, the flexural modulus of elasticity is preferably less than 10.0 GPa, more preferably less than 9.5 GPa, and even more preferably less than 9.0 GPa. The method for measuring the flexural modulus of elasticity of the cured material is as described in the examples described later.

[0050] Regarding the dental attachment composition of the present invention, from the viewpoint of the strength of the dental attachment, the three-point flexural strength of the cured material is preferably 70 MPa or more, more preferably 75 MPa or more, and from the viewpoint of being integrated with a dental orthodontic appliance to exert a stronger corrective force as a dental orthodontic treatment device, it is further preferably 80 MPa or more. In a suitable embodiment, the three-point flexural strength of the cured material of the dental attachment composition of the present invention may be 85 MPa or more, or 88 MPa or more. By ensuring that the flexural strength is at least a certain level, the dental attachment is less likely to deform due to appliance installation / removal or brushing. On the other hand, from the viewpoint of ease of removal of the dental attachment, the flexural strength is preferably less than 200 MPa, more preferably less than 180 MPa, and even more preferably less than 160 MPa. The method for measuring the three-point flexural strength of the cured material is as described in the examples described later.

[0051] Dental attachments tend to exhibit the following characteristics: the bonding interface is often exposed to the tooth surface, requiring a thickness of approximately 2 mm; furthermore, the outermost surface of the enamel is more acid-resistant than the enamel within the tooth, and is less prone to flaking due to etching; and the bonding strength of the uncut enamel surface is lower than that of the cut enamel surface. Therefore, compared to general filling applications, higher adhesion and bonding durability are sought while ensuring a certain thickness of the cured polymer (e.g., 2 mm or more). Therefore, regarding the initial bonding strength of the dental attachment composition of the present invention, with a cured polymer thickness of 2 mm, the shear bond strength for the uncut enamel after phosphate etching is preferably 15 MPa or more, more preferably 16 MPa or more, and even more preferably 18 MPa or more. The method for measuring the shear bond strength related to the aforementioned initial bonding strength is as described in the examples described later. Furthermore, regarding the adhesive durability of the dental attachment composition of the present invention, when the thickness of the cured product is 2 mm, the shear bond strength for uncut enamel after phosphate etching is preferably 15 MPa or more, more preferably 18 MPa or more, and even more preferably 20 MPa or more after 10,000 thermal cycles under the conditions described in the examples. The method for measuring the shear bond strength related to the aforementioned adhesive durability is as described in the examples below. In addition, the dental attachment composition of the present invention also exhibits high adhesion and adhesive durability to zirconia (zirconia sintered body) or gold-silver-palladium alloy. Regarding the initial adhesive strength of the dental attachment composition of the present invention, the tensile bond strength for zirconia is preferably 15 MPa or more, more preferably 16 MPa or more, and even more preferably 18 MPa or more. Regarding the adhesive durability of the dental attachment composition of the present invention, the tensile bond strength for zirconia is preferably 10 MPa or more, more preferably 12 MPa or more, and even more preferably 14 MPa or more. Regarding the initial bond strength of the dental attachment composition of the present invention, the tensile bond strength for the gold-silver-palladium alloy is preferably 10 MPa or more, more preferably 12 MPa or more, and even more preferably 13 MPa or more. Regarding the bond durability of the dental attachment composition of the present invention, the tensile bond strength for the gold-silver-palladium alloy is preferably 8 MPa or more, more preferably 9 MPa or more, and even more preferably 10 MPa or more.

[0052] For dental attachments, the cured material is often exposed to the tooth surface, making them more susceptible to water absorption compared to general filling applications. On the other hand, the water absorption typically increases when the composition contains polymeric monomers with acidic groups; therefore, even when containing polymeric monomers with acidic groups, low water absorption is desired. Therefore, regarding the water absorption of the dental attachment composition of the present invention, in accordance with the test method of ISO 4049:2009, the water absorption is preferably 40 μg / mm. 3 The following, or more preferably, is 30 μg / mm 3 The following, and more preferably 20 μg / mm 3 the following.

[0053] Polymerizable monomer (A)

[0054] The polymeric monomer (A) used in the dental attachment composition of the present invention can suitably be a free radical polymeric monomer. Specific examples of free radical polymeric monomers in the polymeric monomer (A) include (meth)acrylate polymeric monomers, (meth)acrylamide polymeric monomers; esters of α-cyanoacrylate, (meth)acrylate, α-haloacrylate, crotonic acid, cinnamic acid, sorbic acid, maleic acid, itaconic acid, etc.; vinyl esters, vinyl ethers, mono-N-vinyl derivatives, styrene derivatives, etc. Among these, from the viewpoint of curability, (meth)acrylate polymeric monomers and (meth)acrylamide polymeric monomers are preferred. Furthermore, from the viewpoint of adhesion and elastic modulus to the tooth matrix, in the dental attachment composition of the present invention, the polymeric monomer (A) must include a polymeric monomer (A-1) having an acidic group and a polymeric monomer (A-2) not having an acidic group.

[0055] • Polymerizable monomers with acidic groups (A-1)

[0056] Examples of polymerizable monomers (A-1) having acidic groups used in this invention include those having at least one phosphate group, pyrophosphate group, thiophosphate group, phosphonic acid group, carboxylic acid group, sulfonic acid group, or other acidic groups. One type of polymerizable monomer (A-1) with acidic groups can be used alone or in appropriate combinations of two or more. Specific examples of polymerizable monomers (A-1) with acidic groups are described below.

[0057] Examples of polymerizable monomers containing phosphate groups include 2-(meth)acryloyloxyethyl phosphate, 3-(meth)acryloyloxypropyl phosphate, 4-(meth)acryloyloxybutyl phosphate, 5-(meth)acryloyloxypentyl phosphate, 6-(meth)acryloyloxyhexyl phosphate, 7-(meth)acryloyloxyheptyl phosphate, 8-(meth)acryloyloxyoctyl phosphate, 9-(meth)acryloyloxynonyl phosphate, 10-(meth)acryloyloxydecyl phosphate, 11-(meth)acryloyloxyundecyl phosphate, 12-(meth)acryloyloxydodecyl phosphate, 16-(meth)acryloyloxyhexadecyl phosphate, and 20-(meth)acryloyloxydi Decyl esters, bis[2-(meth)acryloyloxyethyl] esters, bis[4-(meth)acryloyloxybutyl] esters, bis[6-(meth)acryloyloxyhexyl] esters, bis[8-(meth)acryloyloxyoctyl] esters, bis[9-(meth)acryloyloxynonyl] esters, bis[10-(meth)acryloyloxydecyl] esters, 1,3-di(meth)acryloyloxypropyl esters of dihydrogen phosphate, 2-(meth)acryloyloxyethylphenyl esters, 2-(meth)acryloyloxyethyl-(2-bromoethyl) esters, 2-methacryloyloxyethyl-(4-methoxyphenyl) esters, 2-methacryloyloxypropyl-(4-methoxyphenyl) esters, and their acyl chlorides, alkali metal salts, and amine salts.

[0058] Examples of polymerizable monomers with pyrophosphate groups include bis[2-(meth)acryloyloxyethyl] pyrophosphate, bis[4-(meth)acryloyloxybutyl] pyrophosphate, bis[6-(meth)acryloyloxyhexyl] pyrophosphate, bis[8-(meth)acryloyloxyoctyl] pyrophosphate, bis[10-(meth)acryloyloxydecyl] pyrophosphate, as well as their acyl chlorides, alkali metal salts, and amine salts.

[0059] Examples of polymerizable monomers containing a thiophosphate group include 2-(meth)acryloyloxyethyl thiophosphate, 3-(meth)acryloyloxypropyl thiophosphate, 4-(meth)acryloyloxybutyl thiophosphate, 5-(meth)acryloyloxypentyl thiophosphate, 6-(meth)acryloyloxyhexyl thiophosphate, 7-(meth)acryloyloxyheptyl thiophosphate, 8-(meth)acryloyloxyoctyl thiophosphate, 9-(meth)acryloyloxynonyl thiophosphate, 10-(meth)acryloyloxydecyl thiophosphate, 11-(meth)acryloyloxyundecyl thiophosphate, 12-(meth)acryloyloxydodecyl thiophosphate, 16-(meth)acryloyloxyhexadecyl thiophosphate, 20-(meth)acryloyloxyeicosyl thiophosphate, and their acyl chlorides, alkali metal salts, and ammonium salts.

[0060] Examples of polymerizable monomers with phosphonic acid groups include 2-(meth)acryloyloxyethylphenylphosphonate, 5-(meth)acryloyloxypentyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonopropionate, 10-(meth)acryloyloxydecyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonoacetate, 10-(meth)acryloyloxydecyl-3-phosphonoacetate, and their acyl chlorides, alkali metal salts, and ammonium salts.

[0061] Examples of polymerizable monomers containing carboxylic acid groups include monofunctional (meth)acrylates having one carboxyl group or its anhydride group in the molecule, and monofunctional (meth)acrylates having multiple carboxyl groups or their anhydride groups in the molecule.

[0062] Examples of monofunctional polymerizable monomers having one carboxyl group or its anhydride group within the molecule include (meth)acrylic acid, N-(meth)acryloylglycine, N-(meth)acryloylaspartic acid, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl maleate, O-(meth)acryloyltyrosine, N-(meth)acryloyltyrosine, N-(meth)acryloylphenylalanine, N-(meth)acryloylp-aminobenzoic acid, N-(meth)acryloylo-an-aminobenzoic acid, 2-(meth)acryloyloxybenzoic acid, 3-(meth)acryloyloxybenzoic acid, 4-(meth)acryloyloxybenzoic acid, N-(meth)acryloyl-5-aminosalicylic acid, N-(meth)acryloyl-4-aminosalicylic acid, and compounds obtained by anhydridating the carboxyl group of these compounds.

[0063] Examples of monofunctional polymerizable monomers having multiple carboxyl groups or their anhydride groups within the molecule include, for example, 6-(meth)acryloyloxyhexane-1,1-dicarboxylic acid, 9-(meth)acryloyloxynonane-1,1-dicarboxylic acid, 10-(meth)acryloyloxydecane-1,1-dicarboxylic acid, 11-(meth)acryloyloxyundecane-1,1-dicarboxylic acid, 12-(meth)acryloyloxydodecane-1,1-dicarboxylic acid, 13-(meth)acryloyloxytridecane-1,1-dicarboxylic acid, 4-(meth)acryloyloxyethyl trimellitic acid, and anhydrous 4-(meth)acryloyloxyethyl trimellitic acid. The compounds include 4-(meth)acryloyloxybutyl trimellitate, 4-(meth)acryloyloxyhexyl trimellitate, 4-(meth)acryloyloxydecyl trimellitate, 2-(meth)acryloyloxyethyl-3'-(meth)acryloyloxy-2'-(3,4-dicarboxybenzoyloxy)propyl succinate, 6-(meth)acryloyloxyethylnaphthalene-1,2,6-tricarboxylic anhydride, 6-(meth)acryloyloxyethylnaphthalene-2,3,6-tricarboxylic anhydride, 4-(meth)acryloyloxyethyl carbonylpropionyl-1,8-naphthalenedicarboxylic anhydride, and 4-(meth)acryloyloxyethylnaphthalene-1,8-tricarboxylic anhydride.

[0064] Examples of polymerizable monomers with sulfonic acid groups include 2-sulfoethyl (meth)acrylate.

[0065] Among the aforementioned polymerizable monomers (A-1) containing acidic groups, from the viewpoint of good adhesive strength when used in compositions for dental attachments, it is preferable to include polymerizable monomers containing phosphate groups or polymerizable monomers containing carboxylic acid groups, more preferably 2-(meth)acryloyloxyethyl phosphate, 3-(meth)acryloyloxypropyl phosphate, 4-(meth)acryloyloxybutyl phosphate, 5-(meth)acryloyloxypentyl phosphate, 6-(meth)acryloyloxyhexyl phosphate, and diphosphate... 7-(meth)acryloyloxyheptyl ester, 8-(meth)acryloyloxyoctyl ester, 9-(meth)acryloyloxynonyl ester, 10-(meth)acryloyloxydecyl ester, 11-(meth)acryloyloxyundecyl ester, 12-(meth)acryloyloxydodecyl ester, 16-(meth)acryloyloxyhexadecyl ester, 20-(meth)acryloyloxyeicosyl ester, 4-(meth)acryloyloxyethyl trimellitic acid Anhydrous esters, 4-(meth)acryloyloxyethyl trimellitate, 11-(meth)acryloyloxyundecane-1,1-dicarboxylic acid, and a mixture of 2-methacryloyloxyethyl dihydrogen phosphate and bis(2-methacryloyloxyethyl) hydrogen phosphate. Furthermore, for dental attachments, since the bonding interface is often exposed to the tooth surface, the polymeric monomer (A-1) with acidic groups requires even greater water resistance than for general filling and restoration applications. Therefore, 8-methacryloyloxyethyl dihydrogen phosphate is further preferred. From the viewpoint of balancing curability, 10-(meth)acryloyloxyoctyl ester, 9-(meth)acryloyloxynonyl ester, 10-(meth)acryloyloxydecyl ester, 11-(meth)acryloyloxyundecyl ester, 12-(meth)acryloyloxydodecyl ester, 16-(meth)acryloyloxyhexadecyl ester, and 20-(meth)acryloyloxyeicosyl ester are most preferably 10-(meth)acryloyloxydecyl ester.

[0066] From the viewpoint of adhesion to etched, uncut enamel, the content of the polymeric monomer (A-1) having an acidic group in the dental attachment composition of the present invention needs to be 1 to 40 parts by mass, preferably 2.5 to 35 parts by mass, and more preferably 5 to 30 parts by mass, out of a total of 100 parts by mass of polymeric monomer (A).

[0067] • Polymerizable monomers that do not have acidic groups (A-2)

[0068] Examples of polymerizable monomers (A-2) without acidic groups in this invention include asymmetric acrylamide-methacrylate compounds (A-2a), hydrophobic polymerizable monomers (A-2b) without acidic groups with a solubility of less than 10% by mass in water at 25°C, and hydrophilic polymerizable monomers (A-2c) without acidic groups with a solubility of 10% by mass or more in water at 25°C. One type of polymerizable monomer (A-2) without acidic groups can be used alone, or two or more can be used in combination. In this invention, compounds without acidic groups but containing acrylamide and methacryloyloxy groups are considered asymmetric acrylamide-methacrylate compounds (A-2a). Based on the degree of hydrophilicity, compounds without acidic groups and not included in asymmetric acrylamide-methacrylate compounds (A-2a) are classified into hydrophobic polymerizable monomers (A-2b) and hydrophilic polymerizable monomers (A-2c).

[0069] • Asymmetric acrylamide-methacrylate compound (A-2a)

[0070] As a suitable embodiment, a dental attachment composition that further comprises an asymmetric acrylamide-methacrylate compound (A-2a) can be cited. From the viewpoint of improving the adhesion of the dental attachment composition to the tooth matrix, the asymmetric acrylamide-methacrylate compound (A-2a) is preferably a compound represented by the following general formula (1).

[0071] [Chemistry 2]

[0072]

[0073] In the formula, Z is an optional C1-C8 straight-chain or branched aliphatic or aromatic group with substituents, wherein the aforementioned aliphatic group is optionally selected from -O-, -S-, -CO-, -CO-O-, -O-CO-, -NR-, -O-CO-, -NR-. 1 -、-CO-NR 1 -、-NR 1 -CO-、-CO-O-NR 1 -、-O-CO-NR 1 -and-NR 1 -CO-NR 1 - At least one linking group in - is interrupted. R 1 It represents a hydrogen atom or an aliphatic group of C1 to C8 with optional substituents, either linear or branched.

[0074] Z is the site where the hydrophilicity of the asymmetric acrylamide-methacrylate compound (A-2a) is adjusted. The optional C1-C8 aliphatic group represented by Z can be any of a saturated aliphatic group (alkylene, cycloalkylene (e.g., 1,4-cyclohexylene, etc.)) or an unsaturated aliphatic group (alkenylene, ynylene), with a saturated aliphatic group (alkylene) preferred from the viewpoint of ease of acquisition or manufacture and chemical stability. From the viewpoint of adhesion and polymerization curing properties for tooth materials, Z is preferably a C1-C4 aliphatic group of optional substituent, either linear or branched, and more preferably a C2-C4 aliphatic group of optional substituent, either linear or branched. As an aliphatic group, an alkylene group is preferred. Examples of the aforementioned C1-C8 alkylene groups include methylene, ethylene, n-propylene, isopropylene, and n-butylene.

[0075] Examples of optional aromatic groups with substituents, represented by Z, include aryl and aromatic heterocyclic groups. Among the aforementioned aromatic groups, aryl is preferred. The heterocycle of the aromatic heterocyclic group is generally unsaturated. The aromatic heterocycle is preferably a five-membered or six-membered ring. For example, phenyl is preferred as an aryl group. Examples of aromatic heterocyclic groups include furanyl, thiophene, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, furazolyl, triazolyl, pyranyl, pyridinyl, pyrazinyl, pyrazinyl, and 1,3,5-triazinyl. Among the aforementioned aromatic groups, phenyl is particularly preferred.

[0076] As R 1 The aliphatic group in X can be either a saturated aliphatic group (alkyl) or an unsaturated aliphatic group (alkenyl, alkynyl), and a saturated aliphatic group (alkyl) is preferred from the viewpoint of ease of acquisition or manufacture and chemical stability. As the aforementioned alkyl group, the same alkyl group as the alkyl group described as a substituent in X can be listed.

[0077] As R 1 More preferably, it is a hydrogen atom or a straight-chain or branched C1-C4 alkyl group with a substituent, and even more preferably, it is a hydrogen atom or a straight-chain or branched C1-C3 alkyl group with a substituent.

[0078] When the aforementioned aliphatic group of Z is interrupted by the aforementioned linking group, the number of linking groups is not particularly limited and can be about 1 to 10, preferably 1, 2 or 3, more preferably 1 or 2. In addition, in the aforementioned formula (1), the aliphatic group of Z is preferably not interrupted by the aforementioned linking groups in succession. That is, it is preferable that the aforementioned linking groups are not adjacent to each other. As the linking group, it is further preferred to be at least one linking group selected from -O-, -S-, -CO-, -CO-O-, -O-CO-, -NH-, -CO-NH-, -NH-CO-, -CO-O-NH-, -O-CO-NH- and -NH-CO-NH-, and particularly preferably at least one linking group selected from -O-, -S-, -CO-, -NH-, -CO-NH- and -NH-CO-.

[0079] Examples of substituents in Z include halogen atoms (fluorine, chlorine, bromine, iodine), carboxyl groups, C2-C6 straight-chain or branched acyl groups, C1-C6 straight-chain or branched alkyl groups, and C1-C6 straight-chain or branched alkoxy groups.

[0080] As specific examples of asymmetric acrylamide-methacrylate compounds (A-2a), without particular limitation, the following compounds can be listed.

[0081] [Chemistry 3]

[0082]

[0083] From the viewpoint of adhesion and polymerization curing properties to dentin, Z is preferably an asymmetric acrylamide-methacrylate compound with a linear or branched aliphatic group of C2 to C4 optionally having substituents. More preferably, it is N-methacryloyloxyethyl acrylamide (commonly referred to as "MAEA"), N-methacryloyloxypropyl acrylamide, N-methacryloyloxybutyl acrylamide, N-(1-ethyl-(2-methacryloyloxy)ethyl)acrylamide, or N-(2-(2-methacryloyloxyethoxy)ethyl)acrylamide. From the viewpoint of the degree of hydrophilicity related to penetration into the collagen layer of dentin, MAEA and N-methacryloyloxypropyl acrylamide are most preferred.

[0084] The asymmetric acrylamide-methacrylate compound (A-2a) can be formulated alone or in combination with two or more compounds. The content of the asymmetric acrylamide-methacrylate compound (A-2a) is not particularly limited as long as the desired effect of the invention is achieved. In the dental attachment composition of the present invention, the total amount of polymerizable monomer (A) in 100 parts by mass is preferably 1 to 60 parts by mass, more preferably 2 to 45 parts by mass, further preferably 3 to 30 parts by mass, and particularly preferably 5 to 25 parts by mass.

[0085] • Hydrophobic polymerizable monomers without acidic groups (A-2b)

[0086] Hydrophobic polymeric monomers (A-2b) without acidic groups (hereinafter sometimes simply referred to as "hydrophobic polymeric monomers (A-2b)") improve the workability of dental attachment compositions and the mechanical strength of cured products. As hydrophobic polymeric monomers (A-2b), free radical polymeric monomers without acidic groups but possessing polymeric groups are preferred. From the viewpoint of facilitating free radical polymerization, the polymeric groups are preferably (meth)acryloyl and / or (meth)acrylamide groups. Hydrophobic polymeric monomers (A-2b) refer to polymeric monomers that do not possess acidic groups, are not equivalent to asymmetric acrylamide-methacrylate compounds (A-2a), and have a solubility in water at 25°C of less than 10% by mass. Examples of hydrophobic polymeric monomers (A-2b) include, for example, difunctional polymeric monomers of aromatic compounds, difunctional polymeric monomers of aliphatic compounds, and crosslinking polymeric monomers with trifunctionality or higher.

[0087] Examples of difunctional polymerizable monomers in the aromatic compound system include 2,2-bis((meth)acryloyloxyphenyl)propane, 2,2-bis[4-(3-(meth)acryloyloxy-2-hydroxypropoxy)phenyl]propane, 2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxypolyethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytriethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytetraethoxyphenyl)propane, and 2,2-bis(4-(meth)acryloyloxytetraethoxyphenyl)propane. Acryloyloxypentethoxyphenyl)propane, 2,2-bis(4-(methyl)acryloyloxydipropoxyphenyl)propane, 2-(4-(methyl)acryloyloxydiethoxyphenyl)-2-(4-(methyl)acryloyloxyethoxyphenyl)propane, 2-(4-(methyl)acryloyloxydiethoxyphenyl)-2-(4-(methyl)acryloyloxytriethoxyphenyl)propane, 2-(4-(methyl)acryloyloxydipropoxyphenyl)-2-(4-(methyl)acryloyloxytriethoxyphenyl)propane, 2,2-bis(4-(methyl)acryloyloxypropoxyphenyl)propane, 2,2-bis(4-(methyl)acryloyloxyisopropoxyphenyl)propane, etc. Among these, 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane (commonly referred to as "Bis-GMA"), 2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane, 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (average molar addition of ethoxy: 2.6, commonly referred to as "D-2.6E"), 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytriethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytetraethoxyphenyl)propane, and 2,2-bis(4-(meth)acryloyloxypentaethoxyphenyl)propane are preferred.

[0088] Examples of difunctional polymerizable monomers in aliphatic compound systems include glycerol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, and 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl) di(meth)acrylate. Among these, the preferred choices are triethylene glycol diacrylate, triethylene glycol dimethacrylate (commonly referred to as "3G"), neopentyl glycol di(meth)acrylate, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl) dimethacrylate (commonly referred to as "UDMA"), 1,10-decanediol dimethacrylate (commonly referred to as "DD"), and 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl) dimethacrylate.

[0089] Examples of polymerizable monomers with trifunctionality or higher include trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, N,N-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxyl)propane-1,3-diol]tetra(meth)acrylate, and 1,7-diacetoxy-2,2,6,6-tetra(meth)acryloxymethyl-4-oxaheptane. Among these, N,N-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxyl)propane-1,3-diol]tetramethacrylate is preferred.

[0090] Among the aforementioned hydrophobic polymerizable monomers, from the viewpoint of mechanical strength and operability, difunctional polymerizable monomers based on aromatic compounds and aliphatic compounds are preferred. As difunctional polymerizable monomers based on aromatic compounds, Bis-GMA and D-2.6E are preferred. As difunctional polymerizable monomers based on aliphatic compounds, glycerol di(meth)acrylate, 3G, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, DD, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, and UDMA are preferred.

[0091] Among the above-mentioned hydrophobic polymeric monomers (A-2b), from the viewpoint of good adhesion to the tooth matrix when used as a dental attachment composition, Bis-GMA, D-2.6E, 3G, UDMA, and DD are more preferred, and D-2.6E, 3G, and Bis-GMA are even more preferred.

[0092] The hydrophobic polymeric monomer (A-2b) can be formulated alone or in combination of two or more. Regarding the content of the hydrophobic polymeric monomer (A-2b) in the dental attachment composition of the present invention, it is preferably 20 to 99 parts by mass, more preferably 40 to 95 parts by mass, and even more preferably 60 to 95 parts by mass, out of 100 parts by mass of the total polymeric monomer (A). By keeping the content of the hydrophobic polymeric monomer (A-2b) within the aforementioned range, the wettability of the dental attachment composition in the tooth matrix is ​​not reduced, sufficient adhesion is obtained, and sufficient cured strength is also achieved.

[0093] • Hydrophilic polymerizable monomers without acidic groups (A-2c)

[0094] As the dental attachment composition of the present invention, the polymerizable monomer (A) preferably comprises a hydrophilic polymerizable monomer (A-2c) without acidic groups (hereinafter sometimes simply referred to as "hydrophilic polymerizable monomer (A-2c)"). The hydrophilic polymerizable monomer (A-2c) improves the wettability of the dental attachment composition in dental plasm. As the hydrophilic polymerizable monomer (A-2c), it is preferably a free radical polymerizable monomer that does not have acidic groups but has polymerizable groups. From the viewpoint of easy free radical polymerization, the polymerizable groups are preferably (meth)acryloyl and / or (meth)acrylamide groups. The hydrophilic polymerizable monomer (A-2c) refers to a monomer that does not have acidic groups, is not equivalent to an asymmetric acrylamide-methacrylate compound (A-2a), and has a solubility of 10% by mass or more in water at 25°C. This solubility is preferably 30% by mass or more, and more preferably, it can be dissolved in water in any proportion at 25°C. As a hydrophilic polymerizable monomer (A-2c), it is preferable to have hydrophilic groups such as hydroxyl, oxymethylene, oxyethylidene, oxypropylene, and amide groups. Examples of hydrophilic polymerizable monomers (A-2c) include, for instance, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 1,3-dihydroxypropyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, 2-((meth)acryloyloxy)ethyltrimethylammonium chloride, and polyethylene glycol di(meth)acrylate (monomers with 9 or more oxyethylidene groups); N- Hydrophilic monofunctional (meth)acrylamide polymerizable monomers such as hydroxymethyl (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, N,N-bis(2-hydroxyethyl)(meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, diacetone (meth)acrylamide, 4-(meth)acryloylmorpholine, N-trihydroxymethyl-N-methyl (meth)acrylamide, N,N-dimethylacrylamide, and N,N-diethylacrylamide.

[0095] Among these hydrophilic polymerizable monomers (A-2c), from the viewpoint of adhesiveness to tooth material, 2-hydroxyethyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, and hydrophilic monofunctional (meth)acrylamide polymerizable monomers are preferred, and 2-hydroxyethyl (meth)acrylate, N,N-dimethylacrylamide, and N,N-diethylacrylamide are more preferred. One hydrophilic polymerizable monomer (A-2c) may be used alone or in combination of two or more.

[0096] If the content of the hydrophilic polymeric monomer (A-2c) in the dental attachment composition of the present invention is too low, the effect of improving adhesion may not be sufficiently obtained; if it is too high, the mechanical strength of the cured product may sometimes decrease. Therefore, the content of the hydrophilic polymeric monomer (A-2c) in the dental attachment composition of the present invention is preferably in the range of 0 to 50 parts by weight of polymeric monomer (A) per 100 parts by weight, more preferably 0 to 40 parts by weight, and even more preferably 0 to 30 parts by weight. The content of the hydrophilic polymeric monomer (A-2c) may be 0 parts by weight of polymeric monomer (A) per 100 parts by weight.

[0097] The content of the polymeric monomer (A-2) without acidic groups is preferably 50 to 99 parts by mass, more preferably 60 to 97 parts by mass, and even more preferably 70 to 95 parts by mass, out of 100 parts by mass of the total polymeric monomer (A). Furthermore, from the viewpoint of adhesion to the etched, uncut enamel, the mass ratio of hydrophilic polymeric monomer (A-2c) to hydrophobic polymeric monomer (A-2b) is preferably 0:10 to 2:1, more preferably 0:10 to 1:1, and even more preferably 0:10 to 1:2. As one embodiment, in a total of 100 parts by mass of polymerizable monomer (A), it is preferable to include 1 to 40 parts by mass of polymerizable monomer (A-1) having acidic groups and 60 to 99 parts by mass of polymerizable monomer (A-2) without acidic groups; more preferably, it includes 2.5 to 35 parts by mass of polymerizable monomer (A-1) having acidic groups and 65 to 97.5 parts by mass of polymerizable monomer (A-2) without acidic groups; and even more preferably, it includes 5 to 30 parts by mass of polymerizable monomer (A-1) having acidic groups and 70 to 95 parts by mass of polymerizable monomer (A-2) without acidic groups.

[0098] As a suitable embodiment, a dental attachment composition that substantially does not contain difunctional or higher (meth)acrylamide-based polymeric monomers can be listed. As another suitable embodiment, a dental attachment composition that substantially does not contain trifunctional or higher (meth)acrylamide-based polymeric monomers can be listed. As yet another suitable embodiment, a dental attachment composition that substantially does not contain polymeric monomers containing hydrogen phosphate diester groups can be listed. Polymeric monomers containing hydrogen phosphate diester groups have (meth)acryloyloxy and / or (meth)acrylamide groups. In this invention, substantially not containing a certain polymeric compound means that the content of that polymeric compound is less than 0.5 parts by mass, preferably less than 0.1 parts by mass, more preferably less than 0.01 parts by mass, and can be 0 parts by mass, out of 100 parts by mass of the total amount of polymeric monomers contained in the composition. Furthermore, the content of the substantially non-existent polymeric compound in the total composition can be less than 0.5% by mass or less than 0.1% by mass.

[0099] As another suitable embodiment, examples include dental attachment compositions that substantially do not contain (meth)acrylic block copolymers. The molecular weight distribution (weight-average molecular weight / number-average molecular weight) of the aforementioned (meth)acrylic block copolymer can, for example, be 1.02 to 2.00. The molecular weight distribution can be determined using known methods, such as gel permeation chromatography (GPC), and calculated in the form of values ​​converted from standard polystyrene. The aforementioned (meth)acrylic block copolymer can be difunctional or tetrafunctional or more.

[0100] Photopolymerization initiator (B)

[0101] Photopolymerization initiators (B) are classified into water-soluble photopolymerization initiators (B-1) and water-insoluble photopolymerization initiators (B-2). As a photopolymerization initiator (B), only water-soluble photopolymerization initiator (B-1) or only water-insoluble photopolymerization initiator (B-2) may be used, or a combination of both may be used, with a combination being preferred.

[0102] • Water-soluble photopolymerization initiator (B-1)

[0103] The water-soluble photopolymerization initiator (B-1) improves the polymerization and curing properties at the hydrophilic tooth surface interface, enabling high bond strength. The photopolymerization initiator (B), by including the water-soluble photopolymerization initiator (B-1), further improves adhesion to uncut enamel after etching with phosphoric acid or the like. The water-soluble photopolymerization initiator (B-1) has a solubility of 10 g / L or more in water at 25°C, preferably 15 g / L or more, more preferably 20 g / L or more, and even more preferably 25 g / L or more. By achieving a solubility of 10 g / L or more, the water-soluble photopolymerization initiator (B-1) at the bonding interface is fully dissolved in the water within the tooth material, readily exhibiting a polymerization-promoting effect.

[0104] Examples of water-soluble photopolymerization initiators (B-1) include, for example, water-soluble acylphosphine oxides; water-soluble thioxanthones; substances obtained by introducing a (poly) glycol chain into the hydroxyl group of 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one; substances obtained by introducing a (poly) glycol chain into the hydroxyl group and / or phenyl group of 1-hydroxycyclohexylphenyl ketone; and substances obtained by introducing -OCH2COO into the phenyl group of 1-hydroxycyclohexylphenyl ketone. - Na + The obtained substance, the substance obtained by introducing a (poly)ethylene glycol chain into the hydroxyl and / or phenyl group of 2-hydroxy-2-methyl-1-phenylpropane-1-one, and the substance obtained by introducing -OCH2COO into the phenyl group of 2-hydroxy-2-methyl-1-phenylpropane-1-one - Na + The substances obtained include α-hydroxyalkyl acetophenones; substances obtained by quaternizing the amino group with α-aminoalkyl acetophenones such as 2-methyl-1[4-(methylthio)phenyl]-2-morpholinylpropane-1-one and 2-benzyl-2-(dimethylamino)-1-[(4-morpholinyl)phenyl]-1-butanone.

[0105] As the aforementioned water-soluble thioxanthone derivatives, examples such as 2-hydroxy-3-(9-oxo-9H-thioxanth-4-yloxy)-N,N,N-trimethyl-1-propane ammonium chloride, 2-hydroxy-3-(1-methyl-9-oxo-9H-thioxanth-4-yloxy)-N,N,N-trimethyl-1-propane ammonium chloride, and 2-hydroxy-3-(9-oxo-9H-thioxanth-2-yloxy)-N,N,N-trimethyl-1-propane ammonium chloride can be used. 2-Hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthoxy-2-yloxy)-N,N,N-trimethyl-1-propane ammonium chloride, 2-hydroxy-3-(3,4-dimethyl-9H-thioxanthoxy-2-yloxy)-N,N,N-trimethyl-1-propane ammonium chloride, 2-hydroxy-3-(1,3,4-trimethyl-9-oxo-9H-thioxanthoxy-2-yloxy)-N,N,N-trimethyl-1-propane ammonium chloride, etc.

[0106] As examples of the aforementioned water-soluble acylphosphine oxides, acylphosphine oxides represented by the following general formula (2) or (3) can be listed.

[0107] [Chemistry 4]

[0108]

[0109] [Chemistry 5]

[0110]

[0111] In equations (2) and (3), R 2 R 3 R 4 R 5 R 6 and R 7 The alkyl or halogen atoms are independently C1 to C4 straight-chain or branched, and in formula (2), M is a hydrogen ion, an alkali metal ion, an alkaline earth metal ion, a magnesium ion, a pyridinium ion (the pyridine ring may optionally have substituents) or HN. + R 9 R 10 R 11 (where R is in the formula) 9 R 10 and R 11 Ammonium ions (independently organic groups or hydrogen atoms), where n is 1 or 2. In formula (3), X is a C1-C4 straight-chain or branched alkylene group, R... 8 Use -CH(CH3)COO(C2H4O) p CH3 represents, and p represents an integer from 1 to 1000.

[0112] As R 2 R 3 R4 R 5 R 6 and R 7 The alkyl group is not particularly limited as long as it is a C1-C4 straight-chain or branched alkyl group, and examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, 2-methylpropyl, tert-butyl, etc. As R 2 R 3 R 4 R 5 R 6 and R 7 The alkyl group is preferably a C1-C3 straight-chain alkyl group, more preferably methyl or ethyl, and even more preferably methyl. Examples of alkylene groups X include methylene, ethylene, n-propylene, isopropylene, and n-butylene. The alkylene group X is preferably a C1-C3 straight-chain alkylene group, more preferably methylene or ethylene, and even more preferably methylene.

[0113] Substituents for the pyridine ring when M is a pyridinium ion include halogen atoms (fluorine, chlorine, bromine, iodine), carboxyl groups, C2-C6 straight-chain or branched acyl groups, C1-C6 straight-chain or branched alkyl groups, and C1-C6 straight-chain or branched alkoxy groups. Preferably, M is an alkali metal ion, an alkaline earth metal ion, a magnesium ion, a pyridinium ion (the pyridine ring may optionally have substituents), or HN. + R 9 R 10 R 11 (In the formula, the symbols have the same meaning as above) represent ammonium ions. Examples of alkali metal ions include lithium ions, sodium ions, potassium ions, rubidium ions, and cesium ions. Examples of alkaline earth metal ions include calcium ions, strontium ions, barium ions, and radium ions. As R... 9 R 10 and R 11 The organic groups can be listed as substituents (excluding halogen atoms) that are the same as the substituents of the aforementioned pyridine ring.

[0114] Of these, in formulas (2) and (3), from the viewpoint of preservation stability and color stability in the composition, R is particularly preferred. 2 R 3 R 4 R 5 R 6 and R 7 All are methyl compounds. On the other hand, as M n+ Examples can be listed, such as Li + Na + K + Ca 2+ Mg2+ Ammonium ions derived from various amines. Examples of amines include ammonia, trimethylamine, diethylamine, dimethylaniline, ethylenediamine, triethanolamine, N,N-dimethylaminomethacrylate, 4-(N,N-dimethylamino)benzoic acid and its alkyl esters, 4-(N,N-diethylamino)benzoic acid and its alkyl esters, N,N-bis(2-hydroxyethyl)-p-toluidine, etc. As R 8 From the viewpoint of adhesion, p is preferably 1 or more, more preferably 2 or more, further preferably 3 or more, particularly preferably 4 or more, and preferably 1000 or less, more preferably 100 or less, further preferably 75 or less, particularly preferably 50 or less.

[0115] Among these water-soluble acylphosphine oxides, those represented by general formula (2) and M are particularly preferred. n+ For Li + Compounds of general formula (2), and compounds derived from R 8 The groups shown are largely composed of compounds of general formula (3) synthesized from polyethylene glycol methyl ether methacrylate with a molecular weight of 950. In these compounds, R in general formula (2) 2 R 3 and R 4 and R in general formula (3) 2 R 3 R 4 R ５ R 6 and R 7 As stated above.

[0116] Water-soluble acylphosphine oxides with this structure can be synthesized using known methods, and some can also be obtained commercially available. They can be synthesized using methods disclosed, for example, in Japanese Patent Application Publication No. 57-197289 and International Patent Publication No. 2014 / 095724. The water-soluble photopolymerization initiator (B-1) can be used alone or in combination of two or more.

[0117] The water-soluble photopolymerization initiator (B-1) can be dissolved in the composition for dental attachments or dispersed in the composition in powder form.

[0118] When the water-soluble photopolymerization initiator (B-1) is dispersed in powder form, if its average particle size is too large, it is prone to sedimentation. Therefore, it is preferably 500 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less. On the other hand, if the average particle size is too small, the specific surface area of ​​the powder becomes too large, and the amount that can be dispersed in the composition decreases. Therefore, it is preferably 0.01 μm or more. That is, the average particle size of the water-soluble photopolymerization initiator (B-1) is preferably in the range of 0.01 to 500 μm, more preferably in the range of 0.01 to 100 μm, and even more preferably in the range of 0.01 to 50 μm.

[0119] The average particle size of various water-soluble photopolymerization initiators (B-1) powders can be calculated as volume average particle size based on electron microscope images of more than 100 particles, after image analysis using image analysis particle size distribution measurement software (Mac-View; manufactured by Mac-View Co., Ltd.).

[0120] Regarding the shape of the initiator when dispersing the water-soluble photopolymerization initiator (B-1) in powder form, various shapes such as spherical, needle-like, plate-like, and fragmented shapes can be listed, and there is no particular limitation. The water-soluble photopolymerization initiator (B-1) can be produced using existing known methods such as pulverization, freeze-drying, and redeposition. From the viewpoint of the average particle size of the resulting powder, freeze-drying and redeposition are preferred, and freeze-drying is more preferred.

[0121] From the viewpoint of curability of the obtained dental attachment composition, the content of the water-soluble photopolymerization initiator (B-1) is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the total amount of polymerizable monomers (A) in the dental attachment composition of the present invention. From the viewpoint of adhesion to the tooth matrix, it is more preferably 0.05 to 10 parts by mass, and even more preferably 0.1 to 5 parts by mass. When the content of the water-soluble photopolymerization initiator (B-1) is less than 0.01 parts by mass, polymerization at the adhesive interface will not be sufficient, which may lead to a decrease in adhesive strength. On the other hand, when the content of the water-soluble photopolymerization initiator (B-1) exceeds 20 parts by mass, sufficient adhesive strength may not be obtained, and consequently, the dissolution, dispersion, and diffusion in the dental attachment composition may be insufficient.

[0122] • Insoluble photopolymerization initiator (B-2)

[0123] From the viewpoint of curing properties, the dental attachment composition of the present invention preferably contains a non-water-soluble photopolymerization initiator (B-2) with a solubility of less than 10 g / L in water at 25°C (hereinafter sometimes referred to as non-water-soluble photopolymerization initiator (B-2)). The non-water-soluble photopolymerization initiator (B-2) used in the present invention can be a known photopolymerization initiator. The non-water-soluble photopolymerization initiator (B-2) can be formulated alone or in combination with two or more other initiators.

[0124] As a non-water-soluble photopolymerization initiator (B-2), examples include (bis)acylphosphine oxides, thioxanthones, ketals, α-diketones, coumarins, anthraquinones, benzoin alkyl ethers, and α-aminoketone compounds, in addition to the water-soluble photopolymerization initiator (B-1).

[0125] Among the aforementioned (bis)acylphosphine oxides, examples of acylphosphine oxides include 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 2,6-dimethoxybenzoyl diphenylphosphine oxide, 2,6-dichlorobenzoyl diphenylphosphine oxide, 2,4,6-trimethylbenzoyl methoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyl ethoxyphenylphosphine oxide, 2,3,5,6-tetramethylbenzoyl diphenylphosphine oxide, and benzoyl di(2,6-dimethylphenyl)phosphinate. Examples of diacylphosphine oxides include bis(2,6-dichlorobenzoyl)phenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and bis(2,5,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide.

[0126] Examples of the aforementioned thioxanones include thioxanone, 2-chlorothioxan-9-one, etc.

[0127] Examples of the aforementioned ketals include, for example, benzoyl dimethyl ketal and benzoyl diethyl ketal.

[0128] Examples of the aforementioned α-diketones include diacetyl, benzoyl, dl-camphorquinone, 2,3-pentanedione, 2,3-octanedione, 9,10-phenanthroquinone, 4,4'-oxybenzoyl, and acenaphthoquinone. Among these, dl-camphorquinone is particularly preferred from the viewpoint of having a maximum absorption wavelength in the visible light region.

[0129] Examples of the aforementioned coumarins include 3,3'-carbonylbis(7-diethylaminocoumarin), 3-(4-methoxybenzoyl)coumarin, 3-thiophenecarboxylcoumarin, 3-benzoyl-5,7-dimethoxycoumarin, 3-benzoyl-7-methoxycoumarin, 3-benzoyl-6-methoxycoumarin, 3-benzoyl-8-methoxycoumarin, 3-benzoylcoumarin, 7-methoxy-3-(p-nitrobenzoyl)coumarin, 3-(p-nitrobenzoyl)coumarin, 3,5-carbonylbis(7-methoxycoumarin), 3-benzoyl-6-bromocoumarin, 3,3'-carbonylbiscoumarin, and 3-benzoyl-7-dimethylaminocoumarin. 3-Benzoylbenzo[f]coumarin, 3-Carboxycoumarin, 3-Carboxy-7-methoxycoumarin, 3-Ethoxycarbonyl-6-methoxycoumarin, 3-Ethoxycarbonyl-8-methoxycoumarin, 3-Acetylbenzo[f]coumarin, 3-Benzoyl-6-nitrocoumarin, 3-Benzoyl-7-diethylaminocoumarin, 7-Dimethylamino-3-(4-methoxybenzoyl)coumarin, 7-Diethylamino-3-(4-methoxybenzoyl)coumarin, 7-Diethylamino-3-(4-diethylamino)coumarin, 7-Methoxy-3-(4-methoxybenzoyl)coumarin, 3-(4-Nitrobenzoyl)benzo[f]coumarin, 3-(4- Ethoxycinnamoyl)-7-methoxycoumarin, 3-(4-dimethylaminocinnamoyl)coumarin, 3-(4-diphenylaminocinnamoyl)coumarin, 3-[(3-dimethylbenzothiazol-2-yl)acetyl]coumarin, 3-[(1-methylnaphtho[1,2-d]thiazol-2-yl)acetyl]coumarin, 3,3'-carbonylbis(6-methoxycoumarin), 3,3'-carbonylbis(7-acetoxycoumarin), 3,3'-carbonylbis(7-dimethylaminocoumarin), 3-(2-benzothiazolyl)-7-(diethylamino)coumarin, 3-(2-benzothiazolyl)-7-(dibutylamino)coumarin, 3-(2-benzimidazolyl)-7-(diethylamino)coumarin 3-(2-benzothiazolyl)coumarin, 3-acetyl-7-(dimethylamino)coumarin, 3,3'-carbonylbis(7-dibutylaminocoumarin), 3,3'-carbonyl-7-diethylaminocoumarin-7'-bis(butoxyethyl)aminocoumarin, 10-[3-[4-(dimethylamino)phenyl]-1-oxo-2-propenyl]-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-[1]benzopyran[6,7,8-ij]quinazine-11-one, 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,Compounds described in Japanese Patent Application Publication Nos. 9-3109 and 10-245525, including 11H-[1]benzopyran[6,7,8-ij]quinazine-11-one.

[0130] Among the aforementioned coumarins, 3,3'-carbonylbis(7-diethylaminocoumarin) and 3,3'-carbonylbis(7-dibutylaminocoumarin) are particularly suitable.

[0131] Examples of the aforementioned anthraquinones include, for example, anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1-bromoanthraquinone, 1,2-benzoanthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, and 1-hydroxyanthraquinone.

[0132] Examples of the aforementioned benzoin alkyl ether compounds include, for example, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

[0133] Examples of the aforementioned α-aminoketone compounds include, for example, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylpropane-1-one.

[0134] Among these water-insoluble photopolymerization initiators (B-2), at least one selected from (bis)acylphosphine oxides, α-diketones, and coumarins is preferred. This results in a dental attachment composition exhibiting excellent photocurability in the visible and near-ultraviolet regions, demonstrating sufficient photocurability even when using any light source such as halogen lamps, light-emitting diodes (LEDs), or xenon lamps.

[0135] The content of the water-insoluble photopolymerization initiator (B-2) is not particularly limited. From the viewpoint of the curability of the resulting composition, it is preferably 0.01 to 10 parts by mass relative to 100 parts by mass of the total amount of polymerizable monomer (A) in the dental attachment composition of the present invention, more preferably 0.05 to 7 parts by mass, and even more preferably 0.1 to 5 parts by mass. It should be noted that if the content of the water-insoluble photopolymerization initiator (B-2) exceeds 10 parts by mass, sufficient adhesive strength may not be obtained if the polymerization performance of the initiator itself is low, which may lead to precipitation from the dental attachment composition.

[0136] When using a combination of a water-soluble photopolymerization initiator (B-1) and a non-water-soluble photopolymerization initiator (B-2), the mass ratio of the water-soluble photopolymerization initiator (B-1) to the non-water-soluble photopolymerization initiator (B-2) in this invention [(B-1):(B-2)] is preferably 10:1 to 1:10, more preferably 7:1 to 1:7, further preferably 5:1 to 1:5, and most preferably 3:1 to 1:3. If the water-soluble photopolymerization initiator (B-1) is contained in a mass ratio greater than 10:1, the curing properties of the dental attachment composition itself may decrease, resulting in high adhesive strength. On the other hand, if the non-water-soluble photopolymerization initiator (B-2) is contained in a mass ratio greater than 1:10, although the curing properties of the dental attachment composition itself may increase, the polymerization promotion at the adhesive interface may become insufficient, making it difficult to exhibit high adhesive strength.

[0137] Packing material (C)

[0138] To adjust operability or improve the mechanical strength of the cured material, the dental attachment composition of the present invention must contain filler (C). Examples of such fillers include inorganic fillers and organic-inorganic composite fillers. Examples of raw materials for organic fillers include, for example, polymethyl methacrylate, polyethyl methacrylate, methyl methacrylate-ethyl methacrylate copolymer, cross-linked polymethyl methacrylate, cross-linked polyethyl methacrylate, polyamide, polyvinyl chloride, polystyrene, chloroprene rubber, nitrile rubber, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, acrylonitrile-styrene copolymer, acrylonitrile-styrene-butadiene copolymer, etc. These can be used individually or in mixtures of two or more. The shape of the organic filler is not particularly limited; the particle size of the filler can be appropriately selected. From the viewpoint of operability and mechanical strength of the resulting dental attachment composition, the average particle size of the aforementioned organic filler is preferably 0.001 to 50 μm, more preferably 0.001 to 10 μm.

[0139] Raw materials for inorganic fillers include quartz, silica, alumina, silica-titanium dioxide, silica-titanium dioxide-barium oxide, silica-zirconium oxide, silica-alumina, lanthanum glass, borosilicate glass, sodium glass, barium glass, strontium glass, glass ceramics, aluminosilicate glass, barium borosilicate glass, strontium borosilicate glass, fluoroaluminosilicate glass, calcium fluoride aluminosilicate glass, strontium fluoride aluminosilicate glass, barium fluoride aluminosilicate glass, strontium calcium fluoride aluminosilicate glass, ytterbium oxide, and ytterbium fluoride coated with silica. Furthermore, they can be used individually or in combination of two or more. The shape of inorganic fillers is not particularly limited; the particle size of the filler can be appropriately selected for use. Among these, from the viewpoint of excellent mechanical strength and transparency of the resulting dental attachment composition, quartz, silica, silica-zirconia, barium glass, ytterbium oxide, and ytterbium fluoride coated with silica are preferred, and quartz, silica, silica-zirconia, barium glass, and ytterbium fluoride coated with silica are more preferred. From the viewpoint of operability and mechanical strength of the resulting dental attachment composition, the average particle size of the aforementioned inorganic filler is preferably 0.001 to 50 μm, more preferably 0.001 to 10 μm. It should be noted that in this specification, when the inorganic filler is surface-treated as described later, the average particle size of the inorganic filler refers to the average particle size before surface treatment. As a suitable embodiment, a dental attachment composition in which the filler (C) is an inorganic filler can be cited.

[0140] Examples of inorganic filler shapes include irregularly shaped fillers and spherical fillers. From the viewpoint of improving the mechanical strength of the cured composition for dental attachments, spherical fillers are preferred as the aforementioned inorganic filler. Here, spherical filler refers to filler in which, when photographed using an electron microscope, the particles observed per unit field of view have an arc shape, and the uniformity obtained by dividing the particle size in the direction orthogonal to its maximum diameter by its maximum diameter is 0.6 or more. The average particle size of the aforementioned spherical filler is preferably 0.05 to 5 μm. If the average particle size is less than 0.05 μm, the filling rate of the spherical filler in the dental attachment composition may decrease, resulting in lower mechanical strength. On the other hand, if the average particle size exceeds 5 μm, the surface area of ​​the aforementioned spherical filler may decrease, and a cured composition for dental attachments with high mechanical strength may not be obtained.

[0141] To adjust the flowability of the composition for dental attachments, the aforementioned inorganic filler can be pre-treated with a known surface treatment agent such as a silane coupling agent before use, as needed. Examples of such surface treatment agents include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltri(β-methoxyethoxy)silane, γ-methacryloyloxypropyltrimethoxysilane, 8-methacryloyloxyoctyltrimethoxysilane, 11-methacryloyloxyundecyltrimethoxysilane, γ-epoxypropoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

[0142] As a surface treatment method, any known method can be used without particular limitation. Examples include: spraying the surface treatment agent while vigorously stirring the inorganic filler; removing the solvent after dispersing or dissolving the inorganic filler and the surface treatment agent in a suitable solvent; or hydrolyzing the alkoxy group of the surface treatment agent in an aqueous solution using an acid catalyst to convert it into a silanol group, attaching it to the surface of the inorganic filler in the aqueous solution, and then removing the water. In any of these methods, the reaction between the inorganic filler surface and the surface treatment agent is usually completed by heating in the range of 50–150°C. It should be noted that the amount of surface treatment is not particularly limited; for example, 1–10 parts by mass of the surface treatment agent can be used relative to 100 parts by mass of the inorganic filler before treatment.

[0143] The organic-inorganic composite filler used in this invention refers to a filler obtained by pre-adding polymerizable monomers to the aforementioned inorganic filler to form a paste, followed by polymerization and pulverization. Examples of such organic-inorganic composite fillers include TMPT filler (a filler obtained by mixing trimethylolpropane methacrylate with silica filler, polymerizing the mixture, and then pulverizing it). The shape of the aforementioned organic-inorganic composite filler is not particularly limited, and the particle size can be appropriately selected and used. From the viewpoint of the operability and mechanical strength of the resulting composition, the average particle size of the aforementioned organic-inorganic composite filler is preferably 0.001–50 μm, more preferably 0.001–10 μm.

[0144] It should be noted that, in this specification, the average particle size of the filler can be determined using laser diffraction scattering or electron microscopy. Specifically, laser diffraction scattering is a convenient method for determining the particle size of particles larger than 0.1 μm, while electron microscopy is a convenient method for determining the particle size of ultrafine particles smaller than 0.1 μm. 0.1 μm is a value measured using laser diffraction scattering.

[0145] Specifically, the laser diffraction scattering method can be performed using, for example, a laser diffraction particle size distribution measuring device (SALD-2300: manufactured by Shimadzu Corporation), with a 0.2% sodium hexametaphosphate aqueous solution used as the dispersion medium, and the measurement is performed on a volume basis.

[0146] Specifically, electron microscopy observation can be performed by, for example, taking an electron microscope (S-4000 model, manufactured by Hitachi, Ltd.) photograph of the particles, and then measuring the particle size of the particles (more than 200) observed per unit field of view in that photograph using image analysis-based particle size distribution measurement software (Mac-View). In this case, the particle size is calculated as the arithmetic mean of the maximum and minimum lengths of the particles, and the average primary particle size is calculated based on the number of particles and their respective sizes.

[0147] The dental attachment composition of the present invention preferably uses two or more fillers with different materials, particle size distributions, and morphologies in combination or mixed. By combining two or more fillers, the filler is densely packed, and the interaction points between the filler and the polymerizable monomer or between the filler and itself are increased. Therefore, it is possible to obtain the appropriate flexural modulus and hardness required for the dental attachment. In addition, depending on the type of filler, the flowability of the paste can be controlled by the presence or absence of shear force. From the viewpoint of the operability and paste properties of the dental attachment composition of the present invention, the aforementioned filler (C) is preferably a combination (I) of filler (C-1) with an average particle size of 1 nm or more and less than 0.1 μm and filler (C-2) with an average particle size of 0.1 μm or more and less than 1 μm; a combination (II) of filler (C-1) with an average particle size of 1 nm or more and less than 0.1 μm and filler (C-3) with an average particle size of more than 1 μm and less than 10 μm; and a combination (II) of filler (C-1) with an average particle size of 1 nm or more and less than 0.1 μm and filler (C-3) with an average particle size of more than 1 μm and less than 10 μm. The combinations (III) of fillers with an average particle size of more than 1 μm and less than 10 μm (C-2) and fillers with an average particle size of more than 1 μm and less than 10 μm (C-3), and (IV) of fillers with an average particle size of more than 0.1 μm and less than 1 μm (C-2), are preferred among these combinations, with (I), (II), and (III) being even more preferred. This is because: the dental attachment, as a cured material, has a more suitable flexural modulus of elasticity, and the dental attachment, when integrated with the orthodontic appliance, can exert a stronger orthodontic force as a treatment tool for orthodontic treatment. In addition, regarding the operability of the dental attachment, the flowability required when forming the dental attachment is to be easily filled into the attachment mold and the shaping property to prevent positional displacement after the bonding position with respect to the tooth enamel is determined. General dental composite resins require flowability to fill cavities, but the operability required is different in cases where the degree of shaping property required for dental attachments is not required. The combination (IV) of fillers (C-2) with an average particle size of 0.1 μm or more and 1 μm or less refers to an embodiment comprising two fillers (C-2) with different average particle sizes of 0.1 μm or more and 1 μm or less. The average particle size of filler (C-1) is preferably 1 nm or more and 90 nm or less, more preferably 2 nm or more and 80 nm or less, and even more preferably 3 nm or more and 70 nm or less. The average particle size of filler (C-2) is preferably 0.1 μm or more and 0.9 μm or less, more preferably 0.15 μm or more and 0.85 μm or less, and even more preferably 0.2 μm or more and 0.8 μm or less. The average particle size of filler (C-3) is preferably 1.2 μm or more and 9 μm or less, more preferably 1.5 μm or more and 8 μm or less, and even more preferably 2.0 μm or more and 7 μm or less.It should be noted that, in the above combination, the fillers (C) of each particle size can contain different types of fillers. Additionally, particles other than fillers can be included as a framework without compromising the effectiveness of the invention.

[0148] The content of filler (C) is not particularly limited, but from the viewpoint of the mechanical strength of the cured product and its adhesion to uncut enamel, it must be 50 to 90 parts by mass, preferably 55 to 85 parts by mass, and more preferably 60 to 80 parts by mass, out of a total of 100 parts by mass of the composition for dental attachments.

[0149] The method for manufacturing the dental attachment composition of the present invention is not particularly limited as long as it includes a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C). The polymerizable monomer (A) includes a polymerizable monomer (A-1) having an acidic group and a polymerizable monomer (A-2) not having an acidic group. The content of the polymerizable monomer (A-1) having an acidic group is 1 to 40 parts by mass out of 100 parts by mass of the total amount of polymerizable monomer (A), and the content of the filler (C) is 50 to 90 parts by mass out of 100 parts by mass of the total amount of the dental attachment composition. It can be easily manufactured using methods known to those skilled in the art.

[0150] Polymerization accelerator (D)

[0151] The dental attachment composition of the present invention may use a polymerization accelerator (D) in addition to a non-water-soluble photopolymerization initiator (B-2) and / or a chemical polymerization initiator described later. Examples of polymerization accelerators (D) used in the present invention include, for example, amines, sulfinic acids and their salts, borate esters, barbituric acid derivatives, triazine compounds, copper compounds, tin compounds, vanadium compounds, halides, aldehydes, thiols, sulfites, bisulfites, thiourea compounds, etc.

[0152] Amines used as polymerization accelerators (D) are classified into aliphatic amines and aromatic amines. Examples of aliphatic amines include primary aliphatic amines such as n-butylamine, n-hexylamine, and n-octylamine; secondary aliphatic amines such as diisopropylamine, dibutylamine, and N-methylethanolamine; and tertiary aliphatic amines such as N-methyldiethanolamine, N-ethyldiethanolamine, N-n-butyldiethanolamine, N-lauryldiethanolamine, 2-(dimethylamino)ethyl methacrylate, N-methyldiethanolamine dimethacrylate, N-ethyldiethanolamine dimethacrylate, triethanolamine monomethacrylate, triethanolamine dimethacrylate, triethanolamine trimethacrylate, triethanolamine, trimethylamine, triethylamine, and tributylamine. From the viewpoint of the curing properties and storage stability of compositions for dental attachments, tertiary aliphatic amines are preferred, with N-methyldiethanolamine and triethanolamine being more preferred.

[0153] In addition, examples of aromatic amines include, for instance, N,N-bis(2-hydroxyethyl)-3,5-dimethylaniline, N,N-bis(2-hydroxyethyl)-p-toluidine, N,N-bis(2-hydroxyethyl)-3,4-dimethylaniline, N,N-bis(2-hydroxyethyl)-4-ethylaniline, N,N-bis(2-hydroxyethyl)-4-isopropylaniline, N,N-bis(2-hydroxyethyl)-4-tert-butylaniline, N,N-bis(2-hydroxyethyl)-3,5-diisopropylaniline, N,N-bis(2-hydroxyethyl)-3,5-ditert-butylaniline, N,N-dimethylaniline, N,N-dimethyl-p-toluidine, N,N-dimethyl-m-toluidine, N,N-diethyl-p-toluidine, N,N- Dimethyl-3,5-dimethylaniline, N,N-dimethyl-3,4-dimethylaniline, N,N-dimethyl-4-ethylaniline, N,N-dimethyl-4-isopropylaniline, N,N-dimethyl-4-tert-butylaniline, N,N-dimethyl-3,5-di-tert-butylaniline, ethyl 4-(N,N-dimethylamino)benzoate, methyl 4-(N,N-dimethylamino)benzoate, propyl 4-(N,N-dimethylamino)benzoate, n-butoxyethyl 4-(N,N-dimethylamino)benzoate, 2-(methacryloyloxy)ethyl 4-(N,N-dimethylamino)benzoate, benzophenone, butyl 4-(N,N-dimethylamino)benzoate, etc. Among these, from the viewpoint of imparting excellent curing properties to the composition for dental attachments, it is preferred to use at least one selected from N,N-bis(2-hydroxyethyl)-p-toluidine, ethyl 4-(N,N-dimethylamino)benzoate, n-butoxyethyl 4-(N,N-dimethylamino)benzoate, and 4-(N,N-dimethylamino)benzophenone.

[0154] Specific examples of sulfinic acids and their salts, borate esters, barbituric acid derivatives, triazine compounds, copper compounds, tin compounds, vanadium compounds, halides, aldehydes, thiols, sulfites, bisulfites, and thiourea compounds can be listed in International Publication No. 2008 / 087977.

[0155] The polymerization accelerator (D) described above may be contained in a single form or in combination of two or more forms. The content of the polymerization accelerator (D) used in this invention is not particularly limited. From the viewpoint of the curing properties of the resulting dental attachment composition, it is preferably 0.001 to 30 parts by mass relative to 100 parts by mass of the total amount of polymerizable monomers (A) in the dental attachment composition, more preferably 0.01 to 10 parts by mass, and even more preferably 0.1 to 5 parts by mass. If the content of the polymerization accelerator (D) is less than 0.001 parts by mass, polymerization may not be sufficiently carried out, resulting in reduced adhesion; therefore, 0.05 parts by mass or more is more suitable. On the other hand, if the content of the polymerization accelerator (D) exceeds 30 parts by mass, sufficient adhesion may not be obtained, and precipitation from the dental attachment composition may occur; therefore, 20 parts by mass or less is more suitable.

[0156] [Chemical polymerization initiator]

[0157] The dental attachment composition of the present invention may further contain a chemical polymerization initiator. As a chemical polymerization initiator, an organic peroxide is preferred. The organic peroxide used in the above-mentioned chemical polymerization initiator is not particularly limited, and known substances can be used. Representative organic peroxides include, for example, ketone peroxides, hydroperoxides, diacid peroxides, dialkyl peroxides, peroxyketals, peroxide esters, and peroxydicarbonates. Specific examples of these organic peroxides include substances described in International Publication No. 2008 / 087977. One chemical polymerization initiator may be used alone, or two or more may be used in combination.

[0158] [Substances that release fluoride ions]

[0159] The dental attachment composition of the present invention may further contain a fluoride ion-releasing substance. By containing a fluoride ion-releasing substance, a dental attachment composition capable of imparting acid resistance to tooth enamel is obtained. Examples of such fluoride ion-releasing substances include, for instance, metal fluorides such as sodium fluoride, potassium fluoride, sodium monofluorophosphate, lithium fluoride, and ytterbium fluoride. The aforementioned fluoride ion-releasing substance may be contained individually or in combination of two or more.

[0160] Furthermore, the dental attachment composition of the present invention may contain known additives within a range that does not reduce performance. Examples of such additives include polymerization inhibitors, antioxidants, colorants (pigments, dyes), ultraviolet absorbers, solvents such as water and organic solvents, and thickeners. One additive may be used alone, or two or more may be used in combination. In one embodiment, the content of solvents (e.g., water, organic solvents) in the dental attachment composition is preferably less than 1% by mass, more preferably less than 0.1% by mass, and even more preferably less than 0.01% by mass, depending on the total amount of the dental attachment composition.

[0161] Examples of polymerization inhibitors include hydroquinone, hydroquinone monomethyl ether, butylhydroquinone, butylhydroquinone monomethyl ether, tert-butylcatechol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butylphenol, and 3,5-di-tert-butyl-4-hydroxytoluene. The content of the polymerization inhibitor is preferably 0.001 to 1.0 parts by weight relative to 100 parts by weight of the polymerizable monomer (A) in the dental attachment composition.

[0162] The dental attachment composition exhibits excellent adhesion to phosphate-etched enamel even without pretreatment using dental adhesives, after etching with phosphoric acid or the like, simplifying the bonding process. Therefore, it is suitable for use as a dental attachment for orthodontic appliances.

[0163] This illustration shows an example of the compositional proportions suitable for a dental attachment composition used as an orthodontic appliance. When the total amount of polymeric monomer (A) is set to 100 parts by mass, it is preferable that, in 100 parts by mass of polymeric monomer (A), it comprises 1 to 40 parts by mass of polymeric monomer (A-1) having acidic groups and 60 to 99 parts by mass of polymeric monomer (A-2) without acidic groups; relative to 100 parts by mass of polymeric monomer (A), it comprises 0.05 to 10 parts by mass of photopolymerization initiator (B), 100 to 900 parts by mass of filler (C), and 0.001 to 30 parts by mass of polymerization accelerator (D). More preferably, in 100 parts by mass of polymeric monomer (A), it comprises 2.5 to 35 parts by mass of polymeric monomer (A-1) having acidic groups and 60 to 99 parts by mass of polymeric monomer (A-2) without acidic groups. A-2) comprises 65 to 97.5 parts by weight, relative to 100 parts by weight of polymerizable monomer (A), including 0.1 to 5 parts by weight of photopolymerization initiator (B), 120 to 560 parts by weight of filler (C), and 0.01 to 10 parts by weight of polymerization accelerator (D). More preferably, in 100 parts by weight of polymerizable monomer (A), it includes 5 to 30 parts by weight of polymerizable monomer (A-1) having acidic groups and 70 to 95 parts by weight of polymerizable monomer (A-2) without acidic groups. Relative to 100 parts by weight of polymerizable monomer (A), it includes 0.15 to 2.5 parts by weight of photopolymerization initiator (B), 150 to 400 parts by weight of filler (C), and 0.1 to 5 parts by weight of polymerization accelerator (D).

[0164] As other embodiments, examples include dental orthodontic kits comprising the aforementioned dental attachment composition and dental orthodontic appliances. There are no particular limitations on the dental orthodontic appliances; known materials can be used. The dental orthodontic appliances can use, for example, a photocurable composition comprising a polymerizable monomer, a photopolymerization initiator, and, if necessary, a filler. The polymerizable monomer, photopolymerization initiator, and filler can be the aforementioned polymerizable monomer (A), photopolymerization initiator (B), and filler (C).

[0165] The dosage form of the dental attachment composition of the present invention is not particularly limited, and it can be used, for example, in a two-component form (two-paste formulation). From an operability point of view, a one-component form (single-paste formulation) obtained by pre-mixing all components is preferred. The dental attachment composition of the present invention is more preferably filled into a cylindrical syringe container. Regarding the size of the cylindrical portion of the syringe container, a length of 10 cm and an inner diameter of 15 mm or less is preferred, and a length of 7.5 cm and an inner diameter of 10 mm or less is more preferred. Furthermore, to improve operability, a nozzle can be attached to the tip of the syringe. Regarding the size of the nozzle, a length of 25 mm and an inner diameter of the opening of 1.5 mm or less is preferred, and a length of 20 mm and an inner diameter of the opening of 0.75 mm or less is more preferred.

[0166] As one embodiment, examples of uses for dental attachment compositions comprising a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C) can be given.

[0167] The aforementioned polymerizable monomer (A) includes a polymerizable monomer with acidic groups (A-1) and a polymerizable monomer without acidic groups (A-2).

[0168] Of the aforementioned 100 parts by mass of polymerizable monomer (A), the content of polymerizable monomer (A-1) having acidic groups is 1 to 40 parts by mass, and

[0169] In 100 parts by mass of the composition, the content of filler (C) is 50 to 90 parts by mass.

[0170] The aforementioned uses can include forming dental attachments. The aforementioned uses can include fixing orthodontic appliances. The aforementioned uses can be on tooth surfaces. The aforementioned uses can be non-therapeutic. As other embodiments, the use of the aforementioned dental attachment composition for orthodontic treatment can be listed. As yet another embodiment, the use of the aforementioned dental attachment composition for treating dental diseases can be listed. Examples of such dental diseases include malocclusion, malocclusion, and congenital diseases (e.g., cleft lip and palate, clavicle-craniotomy, Pi-Ros syndrome, branchial arch syndrome, etc.).

[0171] As another embodiment, a method for applying a dental attachment composition to a tooth surface to form a dental attachment can be described, wherein...

[0172] The aforementioned composition for dental attachments comprises a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C).

[0173] The aforementioned polymerizable monomer (A) includes a polymerizable monomer with acidic groups (A-1) and a polymerizable monomer without acidic groups (A-2).

[0174] Of the aforementioned 100 parts by mass of polymerizable monomer (A), the content of polymerizable monomer (A-1) having acidic groups is 1 to 40 parts by mass, and

[0175] In 100 parts by mass of the composition, the content of filler (C) is 50 to 90 parts by mass.

[0176] In another embodiment, a method for manufacturing a dental attachment on a tooth surface can be provided, wherein the aforementioned dental attachment is a cured product of a dental attachment composition.

[0177] The aforementioned composition for dental attachments comprises a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C).

[0178] The aforementioned polymerizable monomer (A) includes a polymerizable monomer with acidic groups (A-1) and a polymerizable monomer without acidic groups (A-2).

[0179] Of the aforementioned 100 parts by mass of polymerizable monomer (A), the content of polymerizable monomer (A-1) having acidic groups is 1 to 40 parts by mass, and

[0180] In 100 parts by mass of the composition, the content of filler (C) is 50 to 90 parts by mass.

[0181] The aforementioned method can be a method of using a dental attachment composition on the tooth surface to fix orthodontic appliances.

[0182] Example

[0183] The present invention will now be described in detail with examples and comparative examples, but the present invention is not limited to the examples. It should be noted that, unless otherwise specified, the parts in the examples are parts by weight.

[0184] Next, the components and abbreviations of the dental attachment compositions of the examples and comparative examples are described below.

[0185] [Polymerizable monomers with acidic groups (A-1)]

[0186] MDP: 10-Methacryloyloxydecyl dihydrogen phosphate

[0187] [Polymerizable monomers without acidic groups (A-2)]

[0188] Bis-GMA: 2,2-Bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane

[0189] D-2.6E: 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (average molar number of ethoxy additions: 2.6)

[0190] 3G: Triethylene glycol dimethacrylate

[0191] DD: 1,10-Decanediol dimethacrylate

[0192] MAEA: N-Methylacryloyloxyethylacrylamide

[0193] DEAA: N,N-Diethylacrylamide

[0194] HEMA: 2-Hydroxyethyl methacrylate

[0195] [Photopolymerization Initiator (B)]

[0196] • Water-soluble photopolymerization initiator (B-1)

[0197] Li-TPO: Lithium phenyl(2,4,6-trimethylbenzoyl)phosphine oxide

[0198] • Insoluble photopolymerization initiator (B-2)

[0199] CQ: dl-camphorquinone

[0200] BAPO: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide

[0201] [Packaging (C)]

[0202] Filler 1: Ultrafine silica manufactured by Aerotica Co., Ltd. of Japan, "Aerotica (registered trademark) R972", average particle size: 16nm

[0203] Filler 2: Silane-treated silica

[0204] 100 g of OX50 (manufactured by Aerogel Co., Ltd., Japan, ultrafine silica "Aerogel (registered trademark) OX50", average particle size: 0.04 μm), 7 g of γ-methacryloyloxypropyltrimethoxysilane, and 200 mL of 0.3% acetic acid aqueous solution were added to a three-necked flask and stirred at room temperature for 2 hours. After removing water by freeze-drying, the mixture was heated at 80°C for 5 hours to obtain filler 2.

[0205] Filler 3: Silane-treated silica powder

[0206] Silica powder (manufactured by Nitsuchitsu Co., Ltd., trade name: Hyishirika) was pulverized using a ball mill to obtain pulverized silica powder. The average particle size of the obtained pulverized silica powder was measured using a laser diffraction particle size distribution measuring device (manufactured by Shimadzu Corporation, model "SALD-2300"), and the result was 2.2 μm. Using conventional methods, 100 parts by mass of the pulverized silica powder were surface-treated with 4 parts by mass of γ-methacryloyloxypropyltrimethoxysilane to obtain silane-treated silica powder.

[0207] Filler 4: Silane-treated barium glass powder

[0208] Barium glass (manufactured by Estée Lauder, product code "E-3000") was pulverized using a ball mill to obtain barium glass powder. The average particle size of the obtained barium glass powder was measured using a laser diffraction particle size distribution measuring device (manufactured by Shimadzu Corporation, model "SALD-2300"), and the result was 2.4 μm. Using conventional methods, 100 parts by mass of the barium glass powder were surface-treated with 3 parts by mass of γ-methacryloyloxypropyltrimethoxysilane to obtain silane-treated barium glass powder.

[0209] Filler 5: Silane-treated barium glass powder

[0210] 100 g of GM27884 NF180 grade (barium glass manufactured by SCHOTT, average particle size: 0.18 μm), 13 g of γ-methacryloyloxypropyltrimethoxysilane, and 200 mL of 0.3% acetic acid aqueous solution were added to a three-necked flask and stirred at room temperature for 2 hours. After removing water by freeze-drying, the mixture was heated at 80°C for 5 hours to obtain packing material 5.

[0211] Filler 6: Silane-treated barium glass powder

[0212] 100 g of 8235UF 0.7 grade (barium glass manufactured by SCHOTT, average particle size: 0.7 μm), 6 g of γ-methacryloyloxypropyltrimethoxysilane, and 200 mL of 0.3% acetic acid aqueous solution were added to a three-necked flask and stirred at room temperature for 2 hours. After removing water by freeze-drying, the mixture was heated at 80°C for 5 hours to obtain packing material 6.

[0213] Filler 7: Silane-treated spherical silica-titanium dioxide composite oxide powder

[0214] 100 g of spherical silica-titanium dioxide composite oxide (average particle size: 0.3 μm), 10 g of γ-methacryloxypropyltrimethoxysilane, and 200 mL of 0.3% acetic acid aqueous solution were added to a three-necked flask and stirred at room temperature for 2 hours. After removing water by freeze-drying, the mixture was heated at 80 °C for 5 hours to obtain filler 7.

[0215] Ar380: Ultrafine silica "Arrozia 380" manufactured by Aerozia Corporation of Japan, average particle size: 7nm

[0216] [Polymerization Accelerator (D)]

[0217] DABE: Ethyl 4-(N,N-dimethylamino)benzoate

[0218] [Polymerization inhibitor]

[0219] BHT: 3,5-Di-tert-butyl-4-hydroxytoluene

[0220] Examples 1-20 and Comparative Examples 1-5 (Preparation of compositions for dental attachments)

[0221] The raw materials shown in Tables 1-3 were mixed and kneaded in the dark at room temperature (23°C) to prepare a paste-like composition for dental attachments. The properties were investigated according to the methods described in Test Examples 1-4 below. The results are shown in Tables 1-3.

[0222] Experimental Example 1: Photocuring Depth

[0223] According to JIS T 6514:2015 (Composite Resins for Dental Restoration), the light-curing depth was evaluated. Specifically, the following procedure was performed: The manufactured dental attachment was filled into a stainless steel mold (12 mm thick, 4 mm in diameter) with the composition. The upper and lower surfaces were overlapped and pressed together in the order of film and carrier. Using a dental visible light irradiator "Penki Yua 2000" (manufactured by Morita Co., Ltd.), the film-pressed surface obtained by removing the glass plate from one side was irradiated for 10 seconds to cure the material. After removing the cured material from the mold, the uncured portion was wiped away. The length from the irradiated surface to the tip of the cured material was measured using a micrometer (manufactured by Mitsutyo Co., Ltd.). Half of the measured value was taken as the light-curing depth (n=5), and the average value was calculated.

[0224] Test Example 2 Vickers Hardness

[0225] The paste of the dental attachment composition prepared in each example and comparative example was loaded onto a carrier in appropriate amounts. Using a 1 mm measuring instrument (Mitsutoyo Co., Ltd.), the upper and lower surfaces were pressed together with the carrier. The mixture was then cured by irradiating it with light from the top for 10 seconds using a dental visible light irradiator, "Penki Yur 2000" (Morita Co., Ltd.), to create a disc with a diameter of 10 mm and a thickness of 1 mm. The smooth surface of the disc was polished using #1500 abrasive paper under dry conditions, and finally mirror-polished using diamond paste. The Vickers hardness (Hv) (n=5) was measured by applying a 200 g load to the sample prepared here for 10 seconds using a microhardness tester (HM-221, Mitsutoyo Co., Ltd.), and the average value was calculated.

[0226] Experimental Example 3: Bending Properties (Bending Modulus of Elasticity, Bending Strength)

[0227] According to ISO 4049:2009, the flexural modulus and flexural strength were evaluated using a bending test. Specifically, as follows: The prepared paste (a composition for dental attachments) was filled into an SUS mold (2mm long × 25mm wide × 2mm thick), and the top and bottom (2mm × 25mm) sides of the paste were pressed together using a carrier. Next, using a dental visible light irradiator "Penki Yua 2000" (manufactured by Morita Corporation), the paste was irradiated with light for 10 seconds at five points on each side, through the carrier, to cure the paste. The cured material was then subjected to a bending test using a universal testing machine (Autograph AG-I100kN, manufactured by Shimadzu Corporation) with a support distance of 20mm and a slider speed of 1mm / min. The three-point flexural strength and flexural modulus (n=5) were measured, and the average value was calculated.

[0228] Shear bond strength between test example 4 and tooth material (uncut enamel of human teeth)

[0229] The labial surface of a person whose teeth have been extracted was brushed with a toothbrush under running water, resulting in samples with cleaned tooth surfaces. These samples were then processed using a 15-hole mold (manufactured by Ultradent Co., Ltd.). Apply adhesive tape to the bottom of the mold and secure the toothed sample thereon. Fill the mold with plaster and let it stand for about 30 minutes to allow the plaster to harden. Remove the sample from the mold and brush it under running water with a toothbrush to remove excess plaster, ensuring the bonded surfaces ( (Above), the surfaces to be bonded are washed with water for 5 minutes using ultrasonic waves.

[0230] Using a pen, apply tooth surface treatment material 1 (a mixture prepared by mixing concentrated phosphoric acid: 50 parts by mass, distilled water: 50 parts by mass, and Ar380: 5 parts by mass) to the bonding surface of the above sample. After leaving it for 10 seconds, wash the surface with tap water for 10 seconds and then air dry it.

[0231] Next, we will prepare separately. A CR filling mold (Bonding Mold Insert, manufactured by Ultraden Co., Ltd.) was installed on a special instrument (Bonding Clamp, manufactured by Ultraden Co., Ltd.). Next, the CR filling mold was lowered to fix the sample in place, ensuring close contact between the CR filling mold, which was installed on the special instrument, and the bonding surface treated with the sample's tooth surface treatment material 1. Then, the dental attachment composition of each embodiment and comparative example was thinly filled into the holes of the CR filling mold to a thickness of no more than 1 mm. Afterward, the dental attachment composition was filled into the mold again (to about 2 / 3 of the mold's volume, approximately 2 mm thick), and the mold was irradiated for 10 seconds using a dental visible light irradiator "VALO" (manufactured by Ultraden Jipa). The samples were removed from the mold and used as test samples for the bonding test; a total of 20 samples were prepared. Next, the test samples for the bonding test were immersed in distilled water and placed in a thermostat set to 37°C for 24 hours. Afterward, they were removed. For 10 of the 20 samples, the bonding strength was measured immediately after 24 hours to evaluate the initial bonding strength. The average value of the measured results is shown in Tables 1-3 as "Initial Bonding Strength". For the remaining 10 samples, to evaluate bonding durability, 10,000 thermal cycles were performed, with one cycle consisting of alternating immersion in cold water at 4°C and warm water at 60°C for 1 minute. The average value of the measured results is shown in Tables 1-3 as "Bond Durability". In the determination of shear bond strength, the test samples were mounted on a dedicated support (Test Base Clamp, manufactured by Ultradent Corporation), and a dedicated clamp (Crosshead Assembly, manufactured by Ultradent Corporation) and a universal testing machine (Autograph AG-I 100kN, manufactured by Shimadzu Corporation) were used. The slider speed was set to 1 mm / min, and the measurement was performed. The bond strength value was set as the average of the measured values ​​for 10 test samples. From the viewpoint that the evaluation can be carried out using test pieces with a thickness of approximately 2 mm, which is similar to the thickness of actual dental attachments, and from the viewpoint that the shape of the test piece is similar to that of dental attachments, this test method is preferred.

[0232] Test Example 5: Tensile bond strength between the repair material (zirconia or gold-silver-palladium alloy) and the repair material.

[0233] A cylindrical (12mm inner diameter × 5mm height) sintered zirconia body (obtained by sintering at 1500°C for 2 hours) made from a zirconia disk used in CAD / CAM systems (trade name: "Katana (registered trademark) Zirconia" HT, manufactured by Clarenoritate Dental Co., Ltd.) and a gold-silver-palladium alloy casting (manufactured by Jiichi Co., Ltd., trade name: "Kyastower 0.C. <12% gold>") cast in a 10mm × 10mm × 1mm shape were used as the substrates. The surfaces of the substrates were ground using #1000 silicon carbide paper (manufactured by Nippon Kenshi Co., Ltd.) to create a flat surface, and then dried by air jetting water onto the surface. An adhesive tape with a diameter of 5mm and a thickness of approximately 150μm was then applied to the dried flat surface to limit the bonding area. Next, the dental attachment compositions of each embodiment and comparative example were filled and coated into the circular holes, and covered with a release film (polyester). Then, a carrier sheet was placed on the release film and pressed down, thereby smoothing the coating surface of the aforementioned dental attachment composition. Next, the dental attachment composition was irradiated for 10 seconds using a dental visible light irradiator "VALO" (manufactured by Ultradento Yapan Co., Ltd.) through the aforementioned release film, causing the dental attachment composition to cure and obtain a cured product. For the surface of the obtained cured product, a stainless steel cylindrical rod (7 mm in diameter, 2.5 cm in length) was bonded to one end face (circular cross-section) using commercially available dental resin cement (manufactured by Clarenoritate Dental Co., Ltd., trade name "Panasyl (registered trademark) 21"). After bonding, the sample was left to stand at room temperature for 30 minutes, then immersed in distilled water to obtain the test sample for the bonding test. Twenty test samples were prepared for both zirconia sintered bodies and gold-silver-palladium alloy castings. The test samples were immersed in distilled water and left to stand for 24 hours in a thermostat maintained at 37°C. For 10 of the 20 test samples, the bonding strength was measured immediately after 24 hours to evaluate the initial bonding strength. The average value of the measured results is shown in Tables 1-3 as "Initial Bonding Strength". This tensile bonding strength represents the initial bonding strength. For the remaining 10 samples, to evaluate bonding durability, 10,000 thermal cycles were performed, with one cycle consisting of alternating immersion in cold water at 4°C and warm water at 60°C for 1 minute. The average value of the measured results is shown in Tables 1-3 as "Bonding Durability". Tensile bond strength was measured using a universal testing machine (manufactured by Shimadzu Corporation) with the slider speed set to 2 mm / min. The bond strength value was set as the average of the measured values ​​for 10 bond test samples.

[0234] [Table 1]

[0235]

[0236] [Table 2]

[0237]

[0238] [Table 3]

[0239]

[0240] According to the results in Tables 1 and 2, the light-curing depth of the dental attachment composition in the examples is 2.2 mm or more, the Vickers hardness of the cured product is 32 Hv or more, and the flexural modulus is 5.5 GPa to 9.6 GPa. Therefore, it exhibits excellent mechanical strength, and its initial bond strength (shear bond strength) relative to uncut enamel is also excellent at 18 MPa or more, as is its bond durability at 20 MPa. It can be confirmed that although there is a tendency for the outermost surface of the enamel to have higher acid resistance than the enamel within the tooth matrix, to be less prone to flaking due to etching, and for the bond strength of the uncut enamel surface to be lower than that of the cut enamel surface, the initial bond strength and bond durability relative to uncut enamel remain excellent. Furthermore, it can be seen that the bond strength (tensile bond strength) for zirconium oxide and gold-silver-palladium alloys is also excellent at 13 MPa or more, and the bond durability is also excellent at 9 MPa or more. On the other hand, as shown in Table 3, in the comparative examples of dental attachment compositions, in Comparative Examples 1 and 2 where the filler (C) was not present in the content of the present invention, the flexural modulus was less than 3.0 GPa, and the mechanical strength was insufficient. Furthermore, it was confirmed that in Comparative Example 3 where the filler (C) was not present in the content of the present invention, the shear bond strength relative to uncut enamel was as low as 12 MPa or less, and the bond durability was as low as 11 MPa or less. It was confirmed that in Comparative Examples 4 and 5 where the polymerizable monomers having acidic groups were not in the specific mass ratio of the present invention, the shear bond strength relative to uncut enamel was as low as 12 MPa or less, the bond durability was as low as 11 MPa or less, and the initial bond strength (tensile bond strength) relative to zirconium oxide and gold-silver-palladium alloy was also as low as 12 MPa or less, and the bond durability was as low as 5 MPa or less.

[0241] Industrial utilization

[0242] The dental attachment composition of the present invention can be suitably used for dental attachments for orthodontic appliances.

Claims

1. A composition for dental attachments, comprising a polymerizable monomer A, a photopolymerization initiator B, and a filler C. The polymerizable monomer A comprises polymerizable monomer A-1 having an acidic group and polymerizable monomer A-2 not having an acidic group. The polymerizable monomer A-1 having an acidic group is composed only of at least one selected from the group consisting of 8-(meth)acryloyloxyoctyl phosphate, 9-(meth)acryloyloxynonyl phosphate, 10-(meth)acryloyloxydecyl phosphate, 11-(meth)acryloyloxyundecyl phosphate, 12-(meth)acryloyloxydodecyl phosphate, 16-(meth)acryloyloxyhexadecyl phosphate, and 20-(meth)acryloyloxyeicosyl phosphate. The polymerizable monomer A-2, which does not have acidic groups, contains the asymmetric acrylamide-methacrylate compound A-2a represented by the following general formula (1). In the formula, Z is an optional C1-C8 straight-chain or branched aliphatic or aromatic group with substituents, wherein the aliphatic group is optionally selected from -O-, -S-, -CO-, -CO-O-, -O-CO-, -NR-, -O-CO-, -NR-. 1 -、-CO-NR 1 -、-NR 1 -CO-、-CO-O-NR 1 -、-O-CO-NR 1 -and-NR 1 -CO-NR 1 - At least one linking group in - is interrupted; R 1 Represents a hydrogen atom or an optional C1-C8 straight-chain or branched aliphatic group with substituents. The non-acidic polymerizable monomer A-2 contains a non-acidic hydrophobic polymerizable monomer A-2b and a non-acidic hydrophilic polymerizable monomer A-2c as needed. The mass ratio of the non-acidic hydrophilic polymerizable monomer A-2c to the non-acidic hydrophobic polymerizable monomer A-2b is: non-acidic hydrophilic polymerizable monomer A-2c : non-acidic hydrophobic polymerizable monomer A-2b = 0:10~2:

1. The photopolymerization initiator B includes the water-insoluble photopolymerization initiator B-2. The water-insoluble photopolymerization initiator B-2 contains at least one selected from (bis)acylphosphine oxides and α-diketones. The packing material C is an inorganic packing material. Of the total amount of polymerizable monomer A, 100 parts by mass, the content of polymerizable monomer A-1 having acidic groups is 1 to 30 parts by mass. The content of the polymerizable monomer A-2 is 50-99 parts by mass out of 100 parts by mass of the total polymerizable monomer A. The content of the hydrophobic polymeric monomer A-2b is 20-99 parts by mass out of 100 parts by mass of the total polymeric monomer A. The content of the hydrophilic polymerizable monomer A-2c is 0-50 parts by weight of polymerizable monomer A100 parts by weight. The content of the non-water-soluble photopolymerization initiator B-2 is 0.01 to 10 parts by mass relative to 100 parts by mass of the total amount of polymerizable monomer A, and In a total of 100 parts by mass of the composition, the content of filler C is 50 to 85 parts by mass.

2. The composition for dental attachments according to claim 1, wherein, The composition for dental attachments is a single-component type.

3. The composition for dental attachments according to claim 1 or 2, wherein, The polymerizable monomer A-1, which has an acidic group, is 10-methacryloyloxydecyl phosphate dihydrogen ester.

4. The composition for dental attachments according to claim 1, wherein, The mass ratio of the hydrophilic polymeric monomer A-2c without acidic groups to the hydrophobic polymeric monomer A-2b without acidic groups is: hydrophilic polymeric monomer A-2c without acidic groups : hydrophobic polymeric monomer A-2b without acidic groups = 0:10~1:

1.

5. The composition for dental attachments according to claim 1, wherein, The mass ratio of the hydrophilic polymeric monomer A-2c without acidic groups to the hydrophobic polymeric monomer A-2b without acidic groups is: hydrophilic polymeric monomer A-2c without acidic groups : hydrophobic polymeric monomer A-2b without acidic groups = 0:10~1:

2.

6. The composition for dental attachments according to claim 1 or 2, wherein, The packing material C comprises at least one combination selected from the following: a combination I of packing material C-1 with an average particle size of 1 nm or more and less than 0.1 μm and packing material C-2 with an average particle size of 0.1 μm or more and less than 1 μm; a combination II of packing material C-1 with an average particle size of 1 nm or more and less than 0.1 μm and packing material C-3 with an average particle size of more than 1 μm and less than 10 μm; a combination III of packing material C-1 with an average particle size of 1 nm or more and less than 0.1 μm and packing material C-2 with an average particle size of 0.1 μm or more and less than 1 μm and packing material C-3 with an average particle size of more than 1 μm and less than 10 μm; and a combination IV of packing material C-2 with an average particle size of 0.1 μm or more and less than 1 μm.

7. The composition for dental attachments according to claim 6, wherein, The packing material C comprises either combination I or combination II.

8. The composition for dental attachments according to claim 1 or 2, wherein the flexural modulus of the cured product is 3 GPa or higher.

9. The composition for dental attachments according to claim 1 or 2, wherein, The photopolymerization initiator B comprises water-soluble photopolymerization initiator B-1.

10. The composition for dental attachments according to claim 1 or 2, wherein, Z is an optional C1-C4 straight-chain or branched aliphatic group with substituents.

11. The composition for dental attachments according to claim 1 or 2, wherein, Z is an optional C1-C4 straight-chain or branched alkylene group with substituents.

12. The composition for dental attachments according to claim 1 or 2, wherein, The asymmetric acrylamide-methacrylate compound A-2a represented by general formula (1) is selected from at least one of N-methacryloyloxyethyl acrylamide, N-methacryloyloxypropyl acrylamide, N-methacryloyloxybutyl acrylamide, N-(1-ethyl-(2-methacryloyloxy)ethyl)acrylamide and N-(2-(2-methacryloyloxyethoxy)ethyl)acrylamide.

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