Dental attachment composition

Abstract

The present invention provides a composition for a dental attachment: which exhibits excellent adhesion to unpolished enamel without carrying out a pretreatment involving a dental adhesive or the like after etching with phosphoric acid or the like; which exhibits at least a certain degree of mechanical properties; and which can simplify the adhesion of a dental attachment. The present invention relates to a composition for a dental attachment, which contains a polymerizable monomer (A), a photopolymerization initiator (B) and a filler (C). The polymerizable monomer (A) contains a polymerizable monomer (A-1) having an acidic group and a polymerizable monomer (A-2) not having an acidic group. The polymerizable monomer (A-1) having an acidic group is contained at a quantity of 1-40 parts by mass relative to a total of 100 parts by mass of the polymerizable monomer (A). The filler (C) is contained at a quantity of 50-90 parts by mass relative to a total of 100 parts by mass of the composition.

Description

[Technical Field]

[0001] The present invention relates to a dental attachment composition. More specifically, the present invention relates to a dental attachment composition that has excellent adhesion to uncut enamel without pretreatment with a dental adhesive or the like after etching with phosphoric acid or the like, and also has certain or higher mechanical properties. [Background technology]

[0002] Traditionally, orthodontic treatment has mainly involved brackets. However, in recent years, due to the unnatural appearance of brackets, orthodontic treatment using colorless, transparent mouthpieces called orthodontic aligners (hereinafter sometimes simply referred to as "aligners") has also become popular. In bracket treatment, brackets shaped to hook a wire are attached to the tooth surface, and the wire is hooked onto the brackets to apply a mechanical load (hereinafter sometimes referred to as "orthodontic force"), thereby guiding the teeth to the desired position. Orthodontic adhesives are generally used to attach the brackets to the tooth surface. On the other hand, in aligner orthodontic treatment, an aligner shaped like a mouthpiece is attached, but in this case, a method is known in which protrusions called attachments are formed on the tooth surface, and the aligner is hooked onto these protrusions to apply a more appropriate mechanical load and more efficiently guide the teeth to the desired position. These orthodontic adhesives and attachments generally use dental materials consisting of a hardenable composition containing a polymerizable monomer such as a (meth)acrylic acid ester, a polymerization initiator, and a filler, and dental composite resins are commonly used as attachment materials in particular.

[0003] Attachments are formed using a mouthpiece called a template, which reflects the pre-orthodontic position of the teeth. A typical method for forming attachments using a template is described below. The template has depressions in the shape of the attachments at positions corresponding to the tooth surfaces. These depressions are first filled with dental composite resin. The portions of the tooth surface where the attachments will be formed are selectively surface-treated (etched) with phosphoric acid or other suitable agents. An orthodontic adhesive is then applied to the areas, and, if necessary, the solvent is removed with an air blower and the orthodontic adhesive is cured by light irradiation or other methods. The template with the dental composite resin filled in the depressions is then attached to the teeth. The dental composite resin filled in the depressions in the shape of the attachments is then cured by light irradiation or other methods, forming the attachments at the desired positions on the tooth surfaces (the positions where the dental adhesive was applied). As such, a widely known method for forming attachments for aligners is to adhere dental composite resin to uncut enamel after phosphoric acid etching using a dental adhesive (see, for example, non-patent literature 1 and 2).

[0004] During orthodontic treatment using such aligners, attachments must be able to withstand many stresses, including those caused by wearing and removing the aligners, brushing, and tooth deflection during occlusion, without falling off the tooth surface. However, materials with poor adhesion to uncut enamel after phosphoric acid etching may fall off during treatment. Furthermore, materials with low strength and elastic modulus after curing can cause problems such as attachment breakage during orthodontic treatment or poor fit with the aligners, preventing orthodontic treatment from progressing properly, so a certain level of strength and elastic modulus is required.

[0005] Furthermore, orthodontic treatment using aligners requires bonding a large number of attachments to the teeth. The methods using dental adhesives disclosed in Non-Patent Documents 1 and 2 require not only phosphoric acid etching but also adhesive application and filling of a template with a hardenable dental material for all tooth surfaces on which attachments will be formed, resulting in cumbersome procedures. Furthermore, while it is ideal for dental adhesives to be selectively applied only to areas where attachments will be bonded to the tooth surface, selective application to specified locations is difficult. Furthermore, when air is blown to volatilize the adhesive solvent, it is virtually inevitable that the dental adhesive will splash onto areas of the tooth surface other than those where the attachments will be attached. Areas where the dental adhesive has adhered to the tooth surface are prone to discoloration and bacterial adhesion, and the procedure required to remove the dental adhesive from areas other than those where the attachments will be attached significantly increases treatment time. As such, it was found that the attachment formation procedure is significantly different from general filling and restorative treatment for dental cavities, and that the use of dental adhesives in combination can cause major problems.

[0006] Furthermore, it is also conceivable to use, as a material for attachments, orthodontic adhesives disclosed in Patent Documents 1 to 4 and the like, which are used for the same orthodontic purposes. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2015 / 141683 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-46266 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-207806 [Patent Document 4] Japanese Patent Application Laid-Open No. 2016-6040 [Non-patent literature]

[0008] [Non-Patent Document 1] ACTA ODONTOLOGICA LATINOAMERICANA, 2017, Vol.30, Issue 2, pp90-95 [Non-patent document 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 [Problem to be solved by the invention]

[0009] Subsequent studies by the present inventors revealed that the orthodontic adhesives described in Patent Documents 1 and 2 do not contain polymerizable monomers with acidic groups, and that there is room for improvement in their adhesion to uncut enamel after phosphoric acid etching. The dental curable compositions described in Patent Documents 3 and 4 have a low modulus of elasticity in the cured product, and are therefore suitable as materials for fixing loose teeth. However, as attachment materials, the orthodontic force applied to the teeth from the aligner is significantly reduced by the attachment, making it clear that appropriate orthodontic treatment is not possible.

[0010] The present invention aims to provide a dental attachment composition that has excellent adhesion to uncut enamel and mechanical properties above a certain level, even without pretreatment with a dental adhesive or the like after etching with phosphoric acid or the like, and that can simplify the adhesive procedure for dental attachments. [Means for solving the problem]

[0011] That is, the present invention includes the following inventions. [1] A composition comprising 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, The content of the polymerizable monomer (A-1) having an acidic group is 1 to 40 parts by mass based on 100 parts by mass of the total amount of the polymerizable monomer (A), and A dental attachment composition, in which the content of the filler (C) is 50 to 90 parts by mass per 100 parts by mass of the total amount of the composition; [2] The dental attachment composition according to [1], wherein the polymerizable monomer (A-2) having no acidic group contains a hydrophobic polymerizable monomer (A-2b) having no acidic group and, if necessary, a hydrophilic polymerizable monomer (A-2c) having no acidic group, and the mass ratio of the hydrophilic polymerizable monomer (A-2c) having no acidic group to the hydrophobic polymerizable monomer (A-2b) having no acidic group is hydrophilic polymerizable monomer (A-2c) having no acidic group:hydrophobic polymerizable monomer (A-2b) having no acidic group = 0:10 to 2:1; [3] The dental attachment composition according to [1] or [2], wherein the dental attachment composition is a one-component type; [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 phosphoric acid group and / or a polymerizable monomer having a carboxylic acid group; [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; [6] The dental attachment composition according to any one of [2] to [5], wherein the mass ratio of the hydrophilic polymerizable monomer (A-2c) not having an acidic group to the hydrophobic polymerizable monomer (A-2b) not having an acidic group is hydrophilic polymerizable monomer (A-2c) not having an acidic group:hydrophobic polymerizable monomer (A-2b) not having an acidic group = 0:10 to 1:1; [7] The dental attachment composition according to any one of [2] to [5], wherein the mass ratio of the hydrophilic polymerizable monomer (A-2c) not having an acidic group to the hydrophobic polymerizable monomer (A-2b) not having an acidic group is (hydrophilic polymerizable monomer (A-2c) not having an acidic group): (hydrophobic polymerizable monomer (A-2b) not having an acidic group) = 0:10 to 1:2; [8] The dental attachment composition according to any one of [1] to [7], wherein the filler (C) comprises at least one combination selected from the group consisting of a combination (I) of a filler (C-1) having an average particle size of 1 nm or more and less than 0.1 μm and a filler (C-2) having an average particle size of 0.1 μm or more and 1 μm or less, a combination (II) of a filler (C-1) having an average particle size of 1 nm or more and less than 0.1 μm and a filler (C-3) having an average particle size of more than 1 μm and 10 μm or less, a combination (III) of a filler (C-1) having an average particle size of 1 nm or more and less than 0.1 μm, a filler (C-2) having an average particle size of 0.1 μm or more and 1 μm or less, and a filler (C-3) having an average particle size of more than 1 μm and 10 μm or less, and a combination (IV) of fillers (C-2) having an average particle size of 0.1 μm or more and 1 μm or less; [9] The dental attachment composition according to [8], wherein the filler (C) includes the combination (I) or the combination (II);

[10] The dental attachment composition according to any one of [1] to [9], wherein the cured product has a flexural modulus of 3 GPa or more;

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

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

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

[11] , wherein the photopolymerization initiator (B) contains a water-insoluble photopolymerization initiator (B-2);

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

[12] , wherein the polymerizable monomer (A-2) having no acidic group contains an asymmetric acrylamide-methacrylate ester compound (A-2a) represented by the following general formula (1): [ka] [In the formula, Z represents a C1 to C8 linear or branched aliphatic or aromatic group which may have a substituent, and the aliphatic group is -O-, -S-, -CO-, -CO-O-, -O-CO-, -NR 1 -, -CO-NR 1 -, -NR 1 -CO-, -CO-O-NR1 -, -O-CO-NR 1 - and -NR 1 -CO-NR 1 - may be interrupted by at least one linking group selected from the group consisting of 1 represents a hydrogen atom or a C1 to C8 linear or branched aliphatic group which may have a substituent.]

[14] The dental attachment composition according to

[13] , wherein Z is a C1-C4 linear or branched aliphatic group which may have a substituent;

[15] The dental attachment composition according to

[13] or

[14] , wherein Z is a C1-C4 linear or branched alkylene group which may have a substituent;

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

[13] to

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

[0012] According to the present invention, a dental attachment composition can be provided that has excellent adhesion to uncut enamel and at least certain mechanical properties, even without pretreatment with a dental adhesive or the like after etching with phosphoric acid or the like, and that can simplify the procedure for attaching dental attachments. The dental attachment composition of the present invention can be suitably used for dental attachments for aligner orthodontics. Furthermore, since the dental attachment composition of the present invention has excellent adhesion even without the use of a dental adhesive, it can simplify the procedure for orthodontic treatment. Furthermore, since there is no need to use a dental adhesive, there is also the effect that there is no need to remove dental adhesive that has splattered on areas other than the intended tooth surface. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram of a dental attachment according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] The dental attachment composition of the present invention comprises a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C), wherein 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, wherein the content of the polymerizable monomer (A-1) having an acidic group is 1 to 40 parts by mass per 100 parts by mass of the total polymerizable monomer (A), and the content of the filler (C) is 50 to 90 parts by mass per 100 parts by mass of the total dental attachment composition. In this specification, the term "dental attachment" refers to an orthodontic attachment, i.e., an orthodontic component used together with an orthodontic aligner. Figure 1 shows a schematic diagram of a "dental attachment." For example, as shown in Figure 1, a dental attachment 1 is formed as a protrusion on the surface of a tooth 2, including an uncut natural tooth, and by hooking an orthodontic aligner onto the protrusion, a more appropriate mechanical load can be applied, allowing the teeth to be more efficiently guided into the desired position.

[0015] From the viewpoint of adhesion to tooth structure, the dental attachment composition of the present invention preferably has a photocuring depth of 2 mm or more, more preferably 2.5 mm or more. The upper limit of the photocuring depth is not particularly limited, but can be, for example, 6 mm or less. To appropriately apply orthodontic force, dental attachments require a certain thickness. By having a photocuring depth of a certain thickness or more, when the dental attachment composition is cured, high adhesion can be achieved because sufficient curing of the adhesive interface between the tooth structure and the composition occurs, even if the dental attachment composition has a certain thickness or more. Furthermore, photocurable materials generally tend to have low mechanical strength due to insufficient curing in the depth direction where the light intensity is weak. In the case of restorative filling treatment, the deepest photocuring depth corresponds to the cavity bottom, which is less susceptible to thermal load or toothbrush abrasion load. On the other hand, in the case of dental attachments, this portion is exposed to the tooth surface, so the impact of thermal load or toothbrush abrasion load on the portion with low mechanical strength is extremely large. Therefore, a high photocuring depth is required to ensure high strength in the depth direction as well. Thus, even though dental attachments are formed on the surface of teeth, a high photocuring depth is required. The method for measuring the photocuring depth is as described in the Examples below.

[0016] From the viewpoint of the strength of the dental attachment, the dental attachment composition of the present invention preferably has a Vickers hardness of 30 Hv or more, more preferably 33 Hv or more, and even more preferably 35 Hv or more, of a cured product cured by irradiating light for 10 seconds with a dental LED irradiator. A high Vickers hardness makes the dental attachment less susceptible to wear due to frictional forces generated during aligner insertion and removal, brushing, etc., and provides excellent strength and maintains orthodontic power even as a dental attachment. Unlike filling composite resins, the upper limit of the Vickers hardness is preferably 70 Hv or less, more preferably 65 Hv or less, and even more preferably 60 Hv or less, from the viewpoint of ease of removal of the dental attachment, since too high a value makes removal difficult. The Vickers hardness of the cured product can be measured as described in the Examples below.

[0017] From the viewpoint of the strength of the dental attachment, the dental attachment composition of the present invention preferably has a flexural modulus of 3 GPa or more, more preferably 3.5 GPa or more, of the cured product. Since the dental attachment composition can exert a stronger orthodontic force as an orthodontic treatment device when used together with an orthodontic aligner, the flexural modulus of the cured product of the dental attachment composition of the present invention may be 5.0 GPa or more, or even 5.5 GPa or more. Having a flexural modulus of a certain level or higher makes the dental attachment less susceptible to deformation during attachment and removal of the aligner, brushing, etc. On the other hand, from the viewpoint of ease of removal of the dental attachment, the flexural modulus is preferably less than 10.0 GPa, more preferably less than 9.5 GPa, and even more preferably less than 9.0 GPa. The flexural modulus of the cured product is measured as described in the Examples below.

[0018] From the viewpoint of the strength of the dental attachment, the dental attachment composition of the present invention preferably has a three-point bending strength of 70 MPa or more, more preferably 75 MPa or more, and even more preferably 80 MPa or more, because when used together with an orthodontic aligner, the dental attachment can exert a stronger orthodontic force as an orthodontic treatment device. In a preferred embodiment, the three-point bending strength of the cured product of the dental attachment composition of the present invention may be 85 MPa or more, or even 88 MPa or more. A bending strength of a certain level or higher makes the dental attachment less likely to deform when putting on or taking off an aligner, or when brushing. On the other hand, from the viewpoint of ease of removal of the dental attachment, the bending strength is preferably less than 200 MPa, more preferably less than 180 MPa, and even more preferably less than 160 MPa. The three-point bending strength of the cured product is measured as described in the Examples below.

[0019] In dental attachments, the adhesive interface must always be exposed to the tooth surface, a thickness of approximately 2 mm is required, and the outermost surface of enamel is more acid-resistant and less susceptible to demineralization by etching than the enamel within the tooth. Therefore, compared to general filling applications, high adhesion and durability are required under conditions where a certain thickness of the cured product after polymerization is ensured (e.g., a thickness of 2 mm or more). Therefore, with regard to initial bond strength, the dental attachment composition of the present invention preferably has a shear bond strength to uncut enamel after phosphoric acid etching of a 2 mm thick cured product of 15 MPa or more, more preferably 16 MPa or more, and even more preferably 18 MPa or more. The shear bond strength measurement method for the initial bond strength is as described in the Examples below. Furthermore, with regard to adhesion durability, the dental attachment composition of the present invention, when the cured product has a thickness of 2 mm, exhibits a shear bond strength to uncut enamel after phosphoric acid etching after 10,000 thermal cycles under the conditions described in the Examples, of preferably 15 MPa or more, more preferably 18 MPa or more, and even more preferably 20 MPa or more. The method for measuring shear bond strength, which relates to adhesion durability, is as described in the Examples below. The dental attachment composition of the present invention also exhibits high adhesion and adhesion durability to zirconia (zirconia sintered body) or a gold-silver-palladium alloy. With regard to initial bond strength, the dental attachment composition of the present invention exhibits a tensile bond strength to zirconia of preferably 15 MPa or more, more preferably 16 MPa or more, and even more preferably 18 MPa or more. With regard to adhesion durability, the dental attachment composition of the present invention exhibits a tensile bond strength to zirconia of preferably 10 MPa or more, more preferably 12 MPa or more, and even more preferably 14 MPa or more.Regarding the initial bond strength, the dental attachment composition of the present invention has a tensile bond strength to a gold-silver-palladium alloy of preferably 10 MPa or more, more preferably 12 MPa or more, and even more preferably 13 MPa or more. Regarding the adhesion durability, the dental attachment composition of the present invention has a tensile bond strength to a gold-silver-palladium alloy of preferably 8 MPa or more, more preferably 9 MPa or more, and even more preferably 10 MPa or more.

[0020] In dental attachments, the cured product is always exposed to the tooth surface, so it is more susceptible to water absorption than in general filling applications. On the other hand, when a composition contains a polymerizable monomer with an acidic group, the amount of water absorption generally increases, so a low amount of water absorption is required even if the composition contains a polymerizable monomer with an acidic group. For this reason, the dental attachment composition of the present invention has a water absorption of 40 μg / mm2 or less in a test method conforming to ISO 4049:2009. 3 Preferably, it is 30 μg / mm or less. 3 More preferably, it is 20 μg / mm or less. 3 It is even more preferable that:

[0021] Polymerizable monomer (A) The polymerizable monomer (A) used in the dental attachment composition of the present invention is preferably a radically polymerizable monomer. Specific examples of the radically polymerizable monomer in the polymerizable monomer (A) include (meth)acrylate polymerizable monomers, (meth)acrylamide polymerizable monomers, esters of α-cyanoacrylic acid, (meth)acrylic acid, α-halogenated acrylic acid, crotonic acid, cinnamic acid, sorbic acid, maleic acid, itaconic acid, etc., vinyl esters, vinyl ethers, mono-N-vinyl derivatives, styrene derivatives, etc. Among these, (meth)acrylate polymerizable monomers and (meth)acrylamide polymerizable monomers are preferred from the viewpoint of curability. Furthermore, from the viewpoints of adhesiveness to tooth substrate and elastic modulus, the polymerizable monomer (A) in the dental attachment composition of the present invention must contain a polymerizable monomer (A-1) having an acidic group and a polymerizable monomer (A-2) not having an acidic group.

[0022] Polymerizable monomer having an acidic group (A-1) The polymerizable monomer (A-1) having an acidic group used in the present invention may be, for example, a polymerizable monomer having at least one acidic group such as a phosphoric acid group, a pyrophosphate group, a thiophosphate group, a phosphonic acid group, a carboxylic acid group, or a sulfonic acid group. The polymerizable monomer (A-1) having an acidic group may be used alone or in combination of two or more. Specific examples of the polymerizable monomer (A-1) having an acidic group are shown below.

[0023] Examples of the polymerizable monomer having a phosphoric acid group include 2-(meth)acryloyloxyethyl dihydrogen phosphate, 3-(meth)acryloyloxypropyl dihydrogen phosphate, 4-(meth)acryloyloxybutyl dihydrogen phosphate, 5-(meth)acryloyloxypentyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 7-(meth)acryloyloxyheptyl dihydrogen phosphate, 8-(meth)acryloyloxyhexyl dihydrogen phosphate, 9-(meth)acryloyloxyheptyl dihydrogen phosphate, 10-(meth)acryloyloxyhexyl dihydrogen phosphate, 11-(meth)acryloyloxyhexyl dihydrogen phosphate, 12-(meth)acryloyloxyhexyl dihydrogen phosphate, 13-(meth)acryloyloxyhexyl dihydrogen phosphate, 14-(meth)acryloyloxyhexyl dihydrogen phosphate, 15-(meth)acryloyloxyhexyl dihydrogen phosphate, 16-(meth)acryloyloxyhexyl dihydrogen phosphate, 17-(meth)acryloyloxyheptyl dihydrogen phosphate, 18-(meth)acryloyloxyhexyl dihydrogen phosphate, 19-(meth)acryloyloxyhexyl dihydrogen phosphate, 20-(meth)acryloyloxyhexyl dihydrogen phosphate, 21-(meth)acryloyloxyhexyl dihydrogen phosphate, 22-(meth)acryloyloxyhexyl dihydrogen phosphate, 23-(meth)acryloyloxyhexyl dihydrogen phosphate, 24-(meth)acryloyloxyhexyl dihydrogen phosphate, 25-(meth)acryloyloxyhexyl dihydrogen phosphate, 26-(meth)acryloyloxyhexyl dihydrogen phosphate, 27-(meth Acryloyloxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl dihydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate, 12-(meth)acryloyloxydodecyl dihydrogen phosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen phosphate, 20-(meth)acryloyloxyicosyl dihydrogen Phosphate, bis[2-(meth)acryloyloxyethyl]hydrogenphosphate, bis[4-(meth)acryloyloxybutyl]hydrogenphosphate, bis[6-(meth)acryloyloxyhexyl]hydrogenphosphate, bis[8-(meth)acryloyloxyoctyl]hydrogenphosphate, bis[9-(meth)acryloyloxynonyl]hydrogenphosphate, bis[10-(meth)acryloyloxydecyl]hydrogenphosphate, 1,3 2-(meth)acryloyloxypropyl dihydrogen phosphate, 2-(meth)acryloyloxyethyl phenyl hydrogen phosphate, 2-(meth)acryloyloxyethyl-(2-bromoethyl)hydrogen phosphate, 2-methacryloyloxyethyl-(4-methoxyphenyl)hydrogen phosphate, 2-methacryloyloxypropyl-(4-methoxyphenyl)hydrogen phosphate, and acid chlorides, alkali metal salts, and amine salts thereof.

[0024] Examples of polymerizable monomers having a pyrophosphate group 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, and acid chlorides, alkali metal salts, and amine salts thereof.

[0025] Examples of polymerizable monomers having a thiophosphate group include 2-(meth)acryloyloxyethyl dihydrogen thiophosphate, 3-(meth)acryloyloxypropyl dihydrogen thiophosphate, 4-(meth)acryloyloxybutyl dihydrogen thiophosphate, 5-(meth)acryloyloxypentyl dihydrogen thiophosphate, 6-(meth)acryloyloxyhexyl dihydrogen thiophosphate, 7-(meth)acryloyloxyheptyl dihydrogen thiophosphate, and 8-(meth)acryloyloxyoctyl dihydrogen thiophosphate, 9-(meth)acryloyloxynonyl dihydrogen thiophosphate, 10-(meth)acryloyloxydecyl dihydrogen thiophosphate, 11-(meth)acryloyloxyundecyl dihydrogen thiophosphate, 12-(meth)acryloyloxydodecyl dihydrogen thiophosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen thiophosphate, 20-(meth)acryloyloxyicosyl dihydrogen thiophosphate, and acid chlorides, alkali metal salts, and ammonium salts thereof.

[0026] Examples of the polymerizable monomer having a phosphonic acid group include 2-(meth)acryloyloxyethyl phenylphosphonate, 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 acid chlorides, alkali metal salts, and ammonium salts thereof.

[0027] Examples of the polymerizable monomer having a carboxylic acid group include a monofunctional (meth)acrylic acid ester having one carboxyl group or its acid anhydride group in the molecule, and a monofunctional (meth)acrylic acid ester having multiple carboxyl groups or their acid anhydride groups in the molecule.

[0028] Examples of monofunctional polymerizable monomers having one carboxyl group or an acid anhydride group thereof in the molecule include (meth)acrylic acid, N-(meth)acryloylglycine, N-(meth)acryloylaspartic acid, 2-(meth)acryloyloxyethyl hydrogen succinate, 2-(meth)acryloyloxyethyl hydrogen phthalate, 2-(meth)acryloyloxyethyl hydrogen maleate, O-(meth)acryloyltyrosine, N-(meth)acryloylthio Examples of the acryloyloxybenzoic acid include acryloylphenylalanine, N-(meth)acryloyl-p-aminobenzoic acid, N-(meth)acryloyl-o-aminobenzoic acid, 2-(meth)acryloyloxybenzoic acid, 3-(meth)acryloyloxybenzoic acid, 4-(meth)acryloyloxybenzoic acid, N-(meth)acryloyl-5-aminosalicylic acid, and N-(meth)acryloyl-4-aminosalicylic acid, as well as compounds in which the carboxyl group of these compounds has been converted to an acid anhydride group.

[0029] Examples of monofunctional polymerizable monomers having a plurality of carboxyl groups or acid anhydride groups thereof in the molecule include 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 trimellitate, 4-(meth)acryloyloxyethyl trimellitate anhydride ... Examples of the acryloyloxyethyl methyl acrylate 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)acryloyloxyethylcarbonylpropionoyl-1,8-naphthalic anhydride, and 4-(meth)acryloyloxyethylnaphthalene-1,8-tricarboxylic anhydride.

[0030] Examples of the polymerizable monomer having a sulfonic acid group include 2-sulfoethyl (meth)acrylate.

[0031] Among the above-mentioned polymerizable monomers (A-1) having an acidic group, from the viewpoint of achieving good adhesive strength when used as a dental attachment composition, it is preferable to contain a polymerizable monomer having a phosphoric acid group or a polymerizable monomer having a carboxylic acid group, and examples thereof include 2-(meth)acryloyloxyethyl dihydrogen phosphate, 3-(meth)acryloyloxypropyl dihydrogen phosphate, 4-(meth)acryloyloxybutyl dihydrogen phosphate, 5-(meth)acryloyloxypentyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 7-(meth)acryloyloxyheptyl dihydrogen phosphate, 8-(meth)acryloyloxyethyl dihydrogen phosphate, 9-(meth)acryloyloxypropyl dihydrogen phosphate, 10-(meth)acryloyloxybutyl dihydrogen phosphate, 11-(meth)acryloyloxybutyl dihydrogen phosphate, 12-(meth)acryloyloxybutyl dihydrogen phosphate, 13-(meth)acryloyloxybutyl dihydrogen phosphate, 14-(meth)acryloyloxybutyl dihydrogen phosphate, 15-(meth)acryloyloxypentyl dihydrogen phosphate, 16-(meth)acryloyloxyhexyl dihydrogen phosphate, 17-(meth)acryloyloxyheptyl dihydrogen phosphate, 18-(meth)acryloyloxybutyl dihydrogen phosphate, 19-(meth)acryloyloxybutyl dihydrogen phosphate, 20-(meth)acryloyloxyethyl dihydrogen phosphate, 21-(meth)acryloyloxypropyl dihydrogen phosphate, 22-(meth)acryloyloxybutyl dihydrogen phosphate, 23-(meth)acryloyloxybutyl dihydrogen phosphate, 24-(meth)acryloyloxybutyl dihydrogen phosphate, 25-(meth) Acryloyloxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl dihydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate, 12-(meth)acryloyloxydodecyl dihydrogen phosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen phosphate, 20-(meth)acryloyloxyicosyl dihydrogen phosphate, 4-(meth)acryloyloxyethyl trimellitate anhydride, 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 are more preferred. Furthermore, in dental attachments, the adhesive interface is always exposed to the tooth surface, and therefore, compared to general filling and restorative applications, water resistance is required from the polymerizable monomer (A-1) having an acidic group. Therefore, 8-(meth)acryloyloxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl dihydrogen phosphate, , 10-(meth)acryloyloxydecyl dihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate, 12-(meth)acryloyloxydodecyl dihydrogen phosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen phosphate, and 20-(meth)acryloyloxyicosyl dihydrogen phosphate are more preferred, and from the viewpoint of a balance of curability, 10-(meth)acryloyloxydecyl dihydrogen phosphate is the most preferred.

[0032] From the viewpoint of adhesion to etched uncut enamel, the content of the polymerizable monomer (A-1) having an acidic group in the dental attachment composition of the present invention must be 1 to 40 parts by mass, preferably 2.5 to 35 parts by mass, and more preferably 5 to 30 parts by mass, per 100 parts by mass of the total amount of polymerizable monomer (A).

[0033] Polymerizable monomer without acidic group (A-2) Examples of the polymerizable monomer (A-2) without an acidic group in the present invention include an asymmetric acrylamide-methacrylate ester compound (A-2a); a hydrophobic polymerizable monomer (A-2b) without an acidic group whose solubility in water at 25°C is less than 10% by mass; and a hydrophilic polymerizable monomer (A-2c) without an acidic group whose solubility in water at 25°C is 10% by mass or more. The polymerizable monomer (A-2) without an acidic group may be used alone or in combination. In the present invention, a compound without an acidic group and containing an acrylamide group and a methacryloyloxy group is referred to as an asymmetric acrylamide-methacrylate ester compound (A-2a). Compounds without an acidic group and not included in the asymmetric acrylamide-methacrylate ester compound (A-2a) are classified as hydrophobic polymerizable monomers (A-2b) and hydrophilic polymerizable monomers (A-2c) depending on their degree of hydrophilicity.

[0034] Asymmetric acrylamide-methacrylate compound (A-2a) A preferred embodiment of the present invention is a dental attachment composition further comprising an asymmetric acrylamide-methacrylate compound (A-2a). The asymmetric acrylamide-methacrylate compound (A-2a) is preferably a compound represented by the following general formula (1), since it improves the adhesiveness of the dental attachment composition to tooth structure.

[0035] [ka] In the formula, Z represents a C1 to C8 linear or branched aliphatic or aromatic group which may have a substituent, and the aliphatic group is -O-, -S-, -CO-, -CO-O-, -O-CO-, -NR 1 -, -CO-NR 1 -, -NR 1 -CO-, -CO-O-NR 1 -, -O-CO-NR 1 - and -NR 1 -CO-NR 1 - may be interrupted by at least one linking group selected from the group consisting of1 represents a hydrogen atom or a C1 to C8 linear or branched aliphatic group which may have a substituent.

[0036] Z is a moiety that adjusts the hydrophilicity of the asymmetric acrylamide-methacrylate compound (A-2a). The optionally substituted C1-C8 aliphatic group represented by Z may be either a saturated aliphatic group (an alkylene group or a cycloalkylene group (e.g., a 1,4-cyclohexylene group)) or an unsaturated aliphatic group (an alkenylene group or an alkynylene group). From the viewpoints of availability, ease of production, and chemical stability, a saturated aliphatic group (an alkylene group) is preferred. From the viewpoints of adhesion to tooth substrate and polymerization curing properties, Z is preferably an optionally substituted linear or branched C1-C4 aliphatic group, more preferably an optionally substituted linear or branched C2-C4 aliphatic group. The aliphatic group is preferably an alkylene group. Examples of the C1-C8 alkylene group include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, and an n-butylene group.

[0037] Examples of the aromatic group represented by Z, which may have a substituent, include an aryl group and an aromatic heterocyclic group. The aromatic group is preferably an aryl group. The heterocycle of the aromatic heterocyclic group is generally unsaturated. The aromatic heterocycle is preferably a 5- or 6-membered ring. The aryl group is preferably a phenyl group. Examples of the aromatic heterocyclic group include a furan group, a thiophene group, a pyrrole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an imidazole group, a pyrazole group, a furazan group, a triazole group, a pyran group, a pyridine group, a pyridazine group, a pyrimidine group, a pyrazine group, and a 1,3,5-triazine group. Among the aromatic groups, a phenyl group is particularly preferred.

[0038] R 1The aliphatic group in may be either a saturated aliphatic group (alkyl group) or an unsaturated aliphatic group (alkenyl group, alkynyl group), and from the viewpoints of ease of availability or production and chemical stability, a saturated aliphatic group (alkyl group) is preferred. Examples of the alkyl group include the same as those explained as the substituent for X.

[0039] R 1 As the alkyl group, a hydrogen atom or a linear or branched C1 to C4 alkyl group which may have a substituent is more preferred, and a hydrogen atom or a linear or branched C1 to C3 alkyl group which may have a substituent is even more preferred.

[0040] When the aliphatic group of Z is interrupted by the linking group, the number of linking groups is not particularly limited, but may be about 1 to 10, preferably 1, 2, or 3, and more preferably 1 or 2. Furthermore, in the formula (1), the aliphatic group of Z is preferably not interrupted by consecutive linking groups. That is, it is preferable that the linking groups are not adjacent to each other. The linking group is more preferably at least one linking group selected from the group consisting of -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 the group consisting of -O-, -S-, -CO-, -NH-, -CO-NH-, and -NH-CO-.

[0041] Examples of the substituent in Z include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), a carboxyl group, a C2 to C6 linear or branched acyl group, a C1 to C6 linear or branched alkyl group, and a C1 to C6 linear or branched alkoxy group.

[0042] Specific examples of the asymmetric acrylamide-methacrylate compound (A-2a) include, but are not limited to, the following:

[0043] [ka]

[0044] Among these, from the viewpoints of adhesion to tooth tissue and polymerization curing properties, asymmetric acrylamide-methacrylate compounds in which Z is a C2-C4 linear or branched aliphatic group which may have a substituent are preferred, with N-methacryloyloxyethyl acrylamide (commonly known as "MAEA"), N-methacryloyloxypropyl acrylamide, N-methacryloyloxybutyl acrylamide, N-(1-ethyl-(2-methacryloyloxy)ethyl)acrylamide, and N-(2-(2-methacryloyloxyethoxy)ethyl)acrylamide being more preferred, and MAEA and N-methacryloyloxypropyl acrylamide being the most preferred from the viewpoint of high hydrophilicity which is involved in penetration into the collagen layer of dentin.

[0045] The asymmetric acrylamide-methacrylate compound (A-2a) may be used alone or in combination of two or more. The content of the asymmetric acrylamide-methacrylate compound (A-2a) is not particularly limited as long as the effects of the present invention are achieved, but is preferably 1 to 60 parts by mass, more preferably 2 to 45 parts by mass, even more preferably 3 to 30 parts by mass, and particularly preferably 5 to 25 parts by mass, per 100 parts by mass of the total amount of the polymerizable monomer (A) in the dental attachment composition of the present invention.

[0046] Hydrophobic polymerizable monomers without acidic groups (A-2b) The hydrophobic polymerizable monomer (A-2b) without an acidic group (hereinafter sometimes referred to simply as "hydrophobic polymerizable monomer (A-2b)") improves the handleability of the dental attachment composition and the mechanical strength of the cured product. The hydrophobic polymerizable monomer (A-2b) is preferably a radically polymerizable monomer without an acidic group and with a polymerizable group. From the viewpoint of ease of radical polymerization, the polymerizable group is preferably a (meth)acrylic group and / or a (meth)acrylamide group. The hydrophobic polymerizable monomer (A-2b) refers to a polymerizable monomer that does not have an acidic group, does not correspond to the asymmetric acrylamide-methacrylate ester compound (A-2a), and has a solubility in water at 25°C of less than 10% by mass. Examples of the hydrophobic polymerizable monomer (A-2b) include crosslinkable polymerizable monomers such as aromatic compound-based bifunctional polymerizable monomers, aliphatic compound-based bifunctional polymerizable monomers, and trifunctional or higher functional polymerizable monomers.

[0047] Examples of aromatic compound-based bifunctional polymerizable monomers 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, 2,2-bis(4-(meth)acryloyloxypentaethoxyphenyl)propane, 2-(4-(meth)acryloyloxydipropoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxyethoxyphenyl)propane, 2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane, 2-(4-(meth)acryloyloxydipropoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxypropoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxyisopropoxyphenyl)propane, and the like. Among these, 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane (commonly known as "Bis-GMA"), 2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane, 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (average number of moles of ethoxy groups added: 2.6, commonly known 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.

[0048] Examples of aliphatic compound-based bifunctional polymerizable monomers 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, butylene glycol 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, triethylene glycol diacrylate, triethylene glycol dimethacrylate (commonly known as "3G"), neopentyl glycol di(meth)acrylate, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)dimethacrylate (commonly known as "UDMA"), 1,10-decanediol dimethacrylate (commonly known as "DD"), and 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)dimethacrylate are preferred.

[0049] Examples of trifunctional or higher polymerizable monomers 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-(aminocarboxy)propane-1,3-diol]tetra(meth)acrylate, and 1,7-diacryloyloxy-2,2,6,6-tetra(meth)acryloyloxymethyl-4-oxaheptane. Among these, N,N-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetramethacrylate is preferred.

[0050] Among the above hydrophobic polymerizable monomers, aromatic bifunctional polymerizable monomers and aliphatic bifunctional polymerizable monomers are preferred in terms of mechanical strength and handling. Bis-GMA and D-2.6E are preferred as aromatic bifunctional polymerizable monomers. 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 as aliphatic bifunctional polymerizable monomers.

[0051] Among the above hydrophobic polymerizable monomers (A-2b), Bis-GMA, D-2.6E, 3G, UDMA, and DD are more preferred, and D-2.6E, 3G, and Bis-GMA are even more preferred, from the viewpoint of good adhesion to tooth structure when used as a dental attachment composition.

[0052] The hydrophobic polymerizable monomer (A-2b) may be used alone or in combination of two or more. The content of the hydrophobic polymerizable monomer (A-2b) in the dental attachment composition of the present invention 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, per 100 parts by mass of the total amount of polymerizable monomer (A). When the content of the hydrophobic polymerizable monomer (A-2b) is within the above range, the wettability of the dental attachment composition to tooth tissue is not reduced, sufficient adhesion is obtained, and sufficient strength of the cured product is also obtained.

[0053] Hydrophilic polymerizable monomers without acidic groups (A-2c) In the dental attachment composition of the present invention, the polymerizable monomer (A) preferably contains a hydrophilic polymerizable monomer (A-2c) that does not have an acidic group (hereinafter, simply referred to as "hydrophilic polymerizable monomer (A-2c)"). The hydrophilic polymerizable monomer (A-2c) improves the wettability of the dental attachment composition to tooth structure. The hydrophilic polymerizable monomer (A-2c) is preferably a radically polymerizable monomer that does not have an acidic group but has a polymerizable group. From the viewpoint of ease of radical polymerization, the polymerizable group is preferably a (meth)acrylic group and / or a (meth)acrylamide group. The hydrophilic polymerizable monomer (A-2c) refers to a monomer that does not have an acidic group, does not correspond to the asymmetric acrylamide-methacrylate ester compound (A-2a), and has a solubility in water at 25°C of 10% by mass or more, preferably 30% by mass or more, and more preferably is soluble in water at any ratio at 25°C. The hydrophilic polymerizable monomer (A-2c) is preferably one having a hydrophilic group such as a hydroxyl group, an oxymethylene group, an oxyethylene group, an oxypropylene group, or an amide group. Examples of the hydrophilic polymerizable monomer (A-2c) include hydrophilic monofunctional (meth)acrylate polymerizable monomers such as 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 (having 9 or more oxyethylene groups); and hydrophilic monofunctional (meth)acrylamide polymerizable monomers such as methylol (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.

[0054] Among these hydrophilic polymerizable monomers (A-2c), from the viewpoint of adhesion to tooth structure, 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 type of hydrophilic polymerizable monomer (A-2c) may be blended alone, or two or more types may be blended in combination.

[0055] If the content of the hydrophilic polymerizable monomer (A-2c) in the dental attachment composition of the present invention is too low, the adhesiveness improving effect may not be sufficiently obtained, and if it is too high, the mechanical strength of the cured product may be reduced. Therefore, the content of the hydrophilic polymerizable monomer (A-2c) in the dental attachment composition of the present invention is preferably in the range of 0 to 50 parts by mass, more preferably 0 to 40 parts by mass, and even more preferably 0 to 30 parts by mass, per 100 parts by mass of the polymerizable monomer (A). The content of the hydrophilic polymerizable monomer (A-2c) may be 0 part by mass per 100 parts by mass of the polymerizable monomer (A).

[0056] The content of the polymerizable monomer (A-2) having no acidic group 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, per 100 parts by mass of the total amount of polymerizable monomer (A). From the viewpoint of adhesion to etched, uncut enamel, the mass ratio of the hydrophilic polymerizable monomer (A-2c) to the hydrophobic polymerizable monomer (A-2b) is preferably hydrophilic polymerizable monomer (A-2c):hydrophobic polymerizable monomer (A-2b) = 0:10 to 2:1, more preferably 0:10 to 1:1, and even more preferably 0:10 to 1:2. In one embodiment, the polymerizable monomer (A) preferably contains 1 to 40 parts by mass of a polymerizable monomer (A-1) having an acidic group and 60 to 99 parts by mass of a polymerizable monomer (A-2) not having an acidic group, more preferably 2.5 to 35 parts by mass of a polymerizable monomer (A-1) having an acidic group and 65 to 97.5 parts by mass of a polymerizable monomer (A-2) not having an acidic group, and even more preferably 5 to 30 parts by mass of a polymerizable monomer (A-1) having an acidic group and 70 to 95 parts by mass of a polymerizable monomer (A-2) not having an acidic group, relative to 100 parts by mass of the total amount of polymerizable monomers (A).

[0057] A preferred embodiment of the present invention is a dental attachment composition that is substantially free of difunctional or higher (meth)acrylamide-based polymerizable monomers. Another preferred embodiment of the present invention is a dental attachment composition that is substantially free of trifunctional or higher (meth)acrylamide-based polymerizable monomers. Another preferred embodiment of the present invention is a dental attachment composition that is substantially free of a hydrogen phosphate diester group-containing polymerizable monomer. The hydrogen phosphate diester group-containing polymerizable monomer has a (meth)acryloyloxy group and / or a (meth)acrylamide group. In the present invention, "substantially free of a certain polymerizable compound" means that the content of the polymerizable 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 even 0 parts by mass, per 100 parts by mass of the total amount of polymerizable monomers contained in the composition. The content of the substantially free polymerizable compound may be less than 0.5% by mass or less than 0.1% by mass of the entire composition.

[0058] Another preferred embodiment is a dental attachment composition that is substantially free of a (meth)acrylic block copolymer. The molecular weight distribution (weight average molecular weight / number average molecular weight) of the (meth)acrylic block copolymer may be, for example, 1.02 to 2.00. The molecular weight distribution can be measured by a known method, for example, gel permeation chromatography (GPC), and calculated as a value converted into standard polystyrene. The (meth)acrylic block copolymer may be difunctional or higher, or tetrafunctional or higher.

[0059] Photopolymerization initiator (B) The photopolymerization initiator (B) is classified into a water-soluble photopolymerization initiator (B-1) and a water-insoluble photopolymerization initiator (B-2). As the photopolymerization initiator (B), only the water-soluble photopolymerization initiator (B-1) may be used, only the water-insoluble photopolymerization initiator (B-2) may be used, or the water-soluble photopolymerization initiator (B-1) and the water-insoluble photopolymerization initiator (B-2) may be used in combination, but it is preferable to use them in combination.

[0060] Water-soluble photopolymerization initiator (B-1) The water-soluble photopolymerization initiator (B-1) improves polymerization and curing at the hydrophilic tooth surface interface, enabling high bond strength. When the photopolymerization initiator (B) contains the water-soluble photopolymerization initiator (B-1), adhesion to uncut enamel after etching with phosphoric acid or the like can be further improved. The water-soluble photopolymerization initiator (B-1) has a solubility in water at 25°C of 10 g / L or more, preferably 15 g / L or more, more preferably 20 g / L or more, and even more preferably 25 g / L or more. A solubility of 10 g / L or more allows the water-soluble photopolymerization initiator (B-1) to dissolve sufficiently in the water present in the tooth at the adhesive interface, making it easier for the polymerization-promoting effect to be achieved.

[0061] Examples of the water-soluble photopolymerization initiator (B-1) include water-soluble acylphosphine oxides, water-soluble thioxanthones, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one having a (poly)ethylene glycol chain introduced into the hydroxyl group, 1-hydroxycyclohexyl phenyl ketone having a (poly)ethylene glycol chain introduced into the hydroxyl group and / or phenyl group, and 1-hydroxycyclohexyl phenyl ketone having a -OCHCOO - Na + those in which a (poly)ethylene glycol chain has been introduced into the hydroxyl group and / or phenyl group of 2-hydroxy-2-methyl-1-phenylpropan-1-one; those in which -OCH2COO has been introduced into the phenyl group of 2-hydroxy-2-methyl-1-phenylpropan-1-one - Na + and α-aminoalkylphenones such as 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one and 2-benzyl-2-(dimethylamino)-1-[(4-morpholino)phenyl]-1-butanone in which the amino group is converted into a quaternary ammonium salt.

[0062] Examples of the water-soluble thioxanthones include 2-hydroxy-3-(9-oxo-9H-thioxanthen-4-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, 2-hydroxy-3-(1-methyl-9-oxo-9H-thioxanthen-4-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, 2-hydroxy-3-(9-oxo-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, 2- Hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, 2-hydroxy-3-(3,4-dimethyl-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, 2-hydroxy-3-(1,3,4-trimethyl-9-oxo-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, and the like can be used.

[0063] Examples of the water-soluble acylphosphine oxides include acylphosphine oxides represented by the following general formula (2) or (3).

[0064] [ka]

[0065] [ka]

[0066] In formulas (2) and (3), R 2 , R 3 , R 4 , R 5 , R 6 , and R 7are each independently a C1 to C4 linear or branched alkyl group or a halogen atom, 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 have a substituent), or HN + R 9 R 10 R 11 (In the formula, R 9 , R 10 , and R 11 are each independently an organic group or a hydrogen atom), and n is 1 or 2. In formula (3), X is a C1-C4 linear or branched alkylene group, and R 8 -CH(CH3)COO(C2H4O) p It is represented by CH3, and p represents an integer of 1 to 1000.

[0067] R 2 , R 3 , R 4 , R 5 , R 6 , and R 7 The alkyl group of R is not particularly limited as long as it is a C1 to C4 linear or branched chain group, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a 2-methylpropyl group, and a tert-butyl group. 2 , R 3 , R 4 , R 5 , R 6 , and R 7 The alkyl group of X is preferably a C1 to C3 linear alkyl group, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. Examples of the alkylene group of X include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, and an n-butylene group. The alkylene group of X is preferably a C1 to C3 linear alkylene group, more preferably a methylene group or an ethylene group, and even more preferably a methylene group.

[0068] When M is a pyridinium ion, examples of the substituent on the pyridine ring include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), a carboxyl group, a C2-C6 linear or branched acyl group, a C1-C6 linear or branched alkyl group, a C1-C6 linear or branched alkoxy group, etc. M is an alkali metal ion, an alkaline earth metal ion, a magnesium ion, a pyridinium ion (the pyridine ring may have a substituent), or HN + R 9 R 10 R 11 (wherein the symbols have the same meanings as above) is preferred. Examples of alkali metal ions include lithium ion, sodium ion, potassium ion, rubidium ion, and cesium ion. Examples of alkaline earth metal ions include calcium ion, strontium ion, barium ion, and radium ion. R 9 , R 10 , and R 11 Examples of the organic group include the same groups as the substituents on the pyridine ring (excluding halogen atoms).

[0069] Among these, in formulas (2) and (3), R 2 , R 3 , R 4 , R 5 , R 6 , and R 7 A compound in which all of M are methyl groups is particularly preferred from the viewpoint of storage stability and color stability in the composition. n+ An example of this is Li + , Na + , K. + , Ca 2+ , Mg 2+and ammonium ions derived from various amines. Examples of amines include ammonia, trimethylamine, diethylamine, dimethylaniline, ethylenediamine, triethanolamine, N,N-dimethylamino methacrylate, 4-(N,N-dimethylamino)benzoic acid and its alkyl esters, 4-(N,N-diethylamino)benzoic acid and its alkyl esters, and N,N-bis(2-hydroxyethyl)-p-toluidine. 8 From the viewpoint of adhesiveness, p is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, particularly preferably 4 or more, and is preferably 1000 or less, more preferably 100 or less, even more preferably 75 or less, particularly preferably 50 or less.

[0070] Among these water-soluble acylphosphine oxides, the water-soluble acylphosphine oxide represented by the general formula (2) n+ Li + and a compound of general formula (2) 8 Particularly preferred is a compound represented by general formula (3) synthesized from polyethylene glycol methyl ether methacrylate, the molecular weight of which is 950, in which the moiety corresponding to the group represented by R 2 , R 3 , and R 4 and R in general formula (3) 2 , R 3 , R 4 , R 5 , R 6 , and R 7 is as described above.

[0071] Water-soluble acylphosphine oxides having such a structure can be synthesized according to known methods, and some are commercially available. For example, they can be synthesized by the methods disclosed in JP-A-57-197289 and WO 2014 / 095724. The water-soluble photopolymerization initiator (B-1) may be used alone or in combination of two or more.

[0072] The water-soluble photopolymerization initiator (B-1) may be dissolved in the dental attachment composition or may be dispersed in the composition in the form of a powder.

[0073] When the water-soluble photopolymerization initiator (B-1) is dispersed as a powder, if its average particle size is too large, it tends to settle, so 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, reducing the amount that can be dispersed in the composition, so 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 0.01 to 100 μm, and even more preferably 0.01 to 50 μm.

[0074] The average particle size of each water-soluble photopolymerization initiator (B-1) powder can be calculated as the volume average particle size after performing image analysis using image analysis particle size distribution measurement software (Mac-View; manufactured by Mountec Co., Ltd.) based on electron microscope photographs of 100 or more particles.

[0075] When the water-soluble photopolymerization initiator (B-1) is dispersed in powder form, the shape of the initiator is not particularly limited, and various shapes such as spherical, needle-like, plate-like, crushed, etc. can be mentioned. The water-soluble photopolymerization initiator (B-1) can be prepared by a conventionally known method such as a pulverization method, a freeze-drying method, or a reprecipitation method. From the viewpoint of the average particle size of the obtained powder, the freeze-drying method and the reprecipitation method are preferred, and the freeze-drying method is more preferred.

[0076] The content of the water-soluble photopolymerization initiator (B-1) is preferably 0.01 to 20 parts by mass per 100 parts by mass of the total amount of polymerizable monomer (A) in the dental attachment composition of the present invention, from the viewpoint of the curability of the resulting dental attachment composition. From the viewpoint of adhesion to tooth structure, the content is more preferably 0.05 to 10 parts by mass, and even more preferably 0.1 to 5 parts by mass. If the content of the water-soluble photopolymerization initiator (B-1) is less than 0.01 part by mass, polymerization at the adhesive interface may not proceed sufficiently, resulting in a decrease in adhesive strength. On the other hand, if the content of the water-soluble photopolymerization initiator (B-1) is more than 20 parts by mass, sufficient adhesive strength may not be obtained, and further dissolution, dispersion, and diffusion in the dental attachment composition may be insufficient.

[0077] Non-water-soluble photopolymerization initiator (B-2) From the viewpoint of curability, the dental attachment composition of the present invention preferably contains a water-insoluble photopolymerization initiator (B-2) (hereinafter, sometimes referred to as water-insoluble photopolymerization initiator (B-2)) having a solubility in water at 25°C of less than 10 g / L. The water-insoluble photopolymerization initiator (B-2) used in the present invention can be a known photopolymerization initiator. The water-insoluble photopolymerization initiator (B-2) may be used alone or in combination of two or more.

[0078] Examples of the water-insoluble photopolymerization initiator (B-2) include (bis)acylphosphine oxides, thioxanthones, ketals, α-diketones, coumarins, anthraquinones, benzoin alkyl ether compounds, and α-aminoketone compounds other than the water-soluble photopolymerization initiator (B-1).

[0079] Among the (bis)acylphosphine oxides, examples of the acylphosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide, and benzoyldi(2,6-dimethylphenyl)phosphonate. Examples of bisacylphosphine 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.

[0080] Examples of the thioxanthones include thioxanthone and 2-chlorothioxanthen-9-one.

[0081] Examples of the ketals include benzyl dimethyl ketal and benzyl diethyl ketal.

[0082] Examples of the α-diketones include diacetyl, benzyl, dl-camphorquinone, 2,3-pentadione, 2,3-octadione, 9,10-phenanthrenequinone, 4,4′-oxybenzyl, acenaphthenequinone, etc. Among these, dl-camphorquinone is particularly preferred because it has a maximum absorption wavelength in the visible light region.

[0083] Examples of the coumarins include 3,3'-carbonylbis(7-diethylaminocoumarin), 3-(4-methoxybenzoyl)coumarin, 3-thienoylcoumarin, 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-bromo Coumarin, 3,3'-carbonylbiscoumarin, 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-ylidene)acetyl]coumarin, 3-[(1-methylnaphtho[1,2-d]thiazol-2-ylidene)acetyl]coumarin, 3,3'-carbo Nylbis(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)-7-(dioctylamino)coumarin, 3-acetyl-7-(dimethylamino)coumarin, 3,3'-carbonylbis(7-dibutylaminocoumarin), 3,Examples of compounds include those described in JP-A-9-3109 and JP-A-10-245525, such as 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]benzopyrano[6,7,8-ij]quinolizin-11-one, and 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinolizin-11-one.

[0084] Among the above-mentioned coumarins, 3,3'-carbonylbis(7-diethylaminocoumarin) and 3,3'-carbonylbis(7-dibutylaminocoumarin) are particularly preferred.

[0085] Examples of the anthraquinones include anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1-bromoanthraquinone, 1,2-benzanthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, and 1-hydroxyanthraquinone.

[0086] Examples of the benzoin alkyl ether compounds include benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

[0087] Examples of the α-aminoketone compounds include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one.

[0088] Among these water-insoluble photopolymerization initiators (B-2), it is preferable to use at least one selected from the group consisting of (bis)acylphosphine oxides, α-diketones, and coumarins, which allows for the production of a dental attachment composition that is excellent in photocurability in the visible and near-ultraviolet regions and exhibits sufficient photocurability using any of a halogen lamp, a light-emitting diode (LED), and a xenon lamp.

[0089] The content of the water-insoluble photopolymerization initiator (B-2) is not particularly limited, but from the viewpoint of the curability of the resulting composition, it is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 7 parts by mass, and even more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable monomer (A) in the dental attachment composition of the present invention. 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 polymerization initiator itself is low, and further, precipitation from the dental attachment composition may occur.

[0090] When a water-soluble photopolymerization initiator (B-1) and a water-insoluble photopolymerization initiator (B-2) are used in combination, the mass ratio of the water-soluble photopolymerization initiator (B-1) to the water-insoluble photopolymerization initiator (B-2) [(B-1):(B-2)] in the present invention is preferably 10:1 to 1:10, more preferably 7:1 to 1:7, even more 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 of more than 10:1, the curability of the dental attachment composition itself may be reduced, making it difficult to achieve high bond strength. On the other hand, if the water-insoluble photopolymerization initiator (B-2) is contained in a mass ratio of more than 1:10, although the curability of the dental attachment composition itself is enhanced, the promotion of polymerization at the adhesive interface may be insufficient, making it difficult to achieve high bond strength.

[0091] Filler (C) The dental attachment composition of the present invention must contain a filler (C) to adjust handleability and increase the mechanical strength of the cured product. Examples of such fillers include inorganic fillers and organic-inorganic composite fillers. Examples of organic filler materials include polymethyl methacrylate, polyethyl methacrylate, methyl methacrylate-ethyl methacrylate copolymers, crosslinked polymethyl methacrylate, crosslinked polyethyl methacrylate, polyamide, polyvinyl chloride, polystyrene, chloroprene rubber, nitrile rubber, ethylene-vinyl acetate copolymers, styrene-butadiene copolymers, acrylonitrile-styrene copolymers, and acrylonitrile-styrene-butadiene copolymers. These may be used alone or in combination with two or more. The shape of the organic filler is not particularly limited, and the particle size of the filler can be appropriately selected. From the viewpoint of the handling property and mechanical strength of the resulting dental attachment composition, the average particle size of the organic filler is preferably 0.001 to 50 μm, and more preferably 0.001 to 10 μm.

[0092] Examples of inorganic filler materials include quartz, silica, alumina, silica-titania, silica-titania-barium oxide, silica-zirconia, silica-alumina, lanthanum glass, borosilicate glass, soda glass, barium glass, strontium glass, glass ceramic, aluminosilicate glass, barium boroaluminosilicate glass, strontium boroaluminosilicate glass, fluoroaluminosilicate glass, calcium fluoroaluminosilicate glass, strontium fluoroaluminosilicate glass, barium fluoroaluminosilicate glass, strontium calcium fluoroaluminosilicate glass, ytterbium oxide, and silica-coated ytterbium fluoride. These materials may be used alone or in combination. The shape of the inorganic filler is not particularly limited, and the particle size of the filler can be appropriately selected. Among these, quartz, silica, silica-zirconia, barium glass, ytterbium oxide, and silica-coated ytterbium fluoride are preferably used, and more preferably quartz, silica, silica-zirconia, barium glass, and silica-coated ytterbium fluoride, because they provide excellent mechanical strength and transparency to the resulting dental attachment composition. From the viewpoint of the handleability and mechanical strength of the resulting dental attachment composition, the average particle size of the inorganic filler is preferably 0.001 to 50 μm, and more preferably 0.001 to 10 μm. In this specification, when the inorganic filler has been surface-treated as described below, the average particle size of the inorganic filler refers to the average particle size before the surface treatment. A preferred embodiment of the dental attachment composition is one in which the filler (C) is an inorganic filler.

[0093] Examples of the shape of the inorganic filler include amorphous fillers and spherical fillers. From the viewpoint of improving the mechanical strength of the cured dental attachment composition, it is preferable to use a spherical filler as the inorganic filler. Here, spherical fillers are fillers in which, when photographed with an electron microscope, the particles observed within a unit field of view are rounded and have an average uniformity of 0.6 or more, calculated by dividing the particle diameter in a direction perpendicular to the maximum diameter by the maximum diameter. The average particle diameter of the spherical filler is preferably 0.05 to 5 μm. If the average particle diameter is less than 0.05 μm, the filling rate of the spherical filler in the dental attachment composition may decrease, resulting in reduced mechanical strength. On the other hand, if the average particle diameter exceeds 5 μm, the surface area of ​​the spherical filler may decrease, resulting in a cured dental attachment composition with high mechanical strength.

[0094] In order to adjust the fluidity of the dental attachment composition, the inorganic filler may be surface-treated in advance with a known surface treatment agent such as a silane coupling agent, if necessary. Examples of such surface treatment agents include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltri(β-methoxyethoxy)silane, γ-methacryloyloxypropyltrimethoxysilane, 8-methacryloyloxyoctyltrimethoxysilane, 11-methacryloyloxyundecyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

[0095] The surface treatment method can be any known method, without particular limitation, and includes, for example, spraying the surface treatment agent onto the inorganic filler while vigorously stirring it, dispersing or dissolving the inorganic filler and the surface treatment agent in a suitable solvent and then removing the solvent, or hydrolyzing the alkoxy groups of the surface treatment agent in an aqueous solution with an acid catalyst to convert them to silanol groups, attaching them to the inorganic filler surface 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 completed by heating in the range of 50 to 150°C, and the surface treatment can be performed. The amount of surface treatment is not particularly limited, and for example, 1 to 10 parts by mass of the surface treatment agent can be used per 100 parts by mass of the inorganic filler before treatment.

[0096] The organic-inorganic composite filler used in the present invention is obtained by adding a polymerizable monomer to the inorganic filler described above in advance, forming a paste, polymerizing it, and pulverizing it. Examples of the organic-inorganic composite filler that can be used include TMPT filler (trimethylolpropane methacrylate and silica filler mixed, polymerized, and then pulverized). The shape of the organic-inorganic composite filler is not particularly limited, and the particle size of the filler can be appropriately selected and used. From the viewpoints of the handleability and mechanical strength of the resulting composition, the average particle size of the organic-inorganic composite filler is preferably 0.001 to 50 μm, and more preferably 0.001 to 10 μm.

[0097] In this specification, the average particle size of the filler can be determined by laser diffraction scattering or electron microscope observation of the particles. Specifically, laser diffraction scattering is convenient for measuring the particle size of particles 0.1 μm or larger, while electron microscope observation is convenient for measuring the particle size of ultrafine particles less than 0.1 μm. The value of 0.1 μm is measured by laser diffraction scattering.

[0098] Specifically, the laser diffraction scattering method can be performed by, for example, measuring on a volume basis using a laser diffraction particle size distribution analyzer (SALD-2300, manufactured by Shimadzu Corporation) and a 0.2% aqueous solution of sodium hexametaphosphate as a dispersion medium.

[0099] Specifically, electron microscope observation can be performed by taking a photograph of the particles using an electron microscope (S-4000 model, manufactured by Hitachi, Ltd.) and measuring the particle diameters of the particles (200 or more) observed within a unit field of view of the photograph using image analysis particle size distribution measurement software (Mac-View (Mountec Co., Ltd.)). In this case, the particle diameter is determined as the arithmetic mean value of the longest and shortest lengths of the particles, and the average primary particle diameter is calculated from the number of particles and their particle diameters.

[0100] The dental attachment composition of the present invention preferably uses a mixture or combination of two or more fillers with different materials, particle size distributions, and morphologies. Combining two or more fillers allows the fillers to be densely packed and increases the number of interaction points between the filler and the polymerizable monomer, or between the fillers themselves. This allows for the appropriate flexural modulus and hardness required for dental attachments. Furthermore, the type of filler can be used to control the fluidity of the paste, depending on whether or not it is subjected to shear force. Among these, from the viewpoint of the handling property and paste properties of the dental attachment composition of the present invention, the filler (C) may be a combination (I) of a filler (C-1) having an average particle size of 1 nm or more and less than 0.1 μm and a filler (C-2) having an average particle size of 0.1 μm or more and 1 μm or less, a combination (II) of a filler (C-1) having an average particle size of 1 nm or more and less than 0.1 μm and a filler (C-3) having an average particle size of more than 1 μm and 10 μm or less, a combination (C-1) of a filler (C-1) having an average particle size of 1 nm or more and less than 0.1 μm and a filler (C-4) having an average particle size of 0.1 μm or more and 1 μm or less, or a combination (II) of a filler (C-1) having an average particle size of 1 nm or more and less than 0.1 μm and a filler (C-5) having an average particle size of 0.1 μm or more and 1 μm or less.

[0013] Preferred are (III) a combination of filler (C-2) with filler (C-3) having an average particle size of more than 1 μm and not more than 10 μm, and (IV) a combination of fillers (C-2) with each other having an average particle size of 0.1 μm or more and not more than 1 μm. Among these combinations, (I), (II), and (III) are more preferred, and (I) and (II) are even more preferred, because the dental attachment, which is the cured product, has a more suitable flexural modulus and can be integrated with the orthodontic aligner to exert a stronger orthodontic force as an orthodontic treatment device. Regarding the handleability of dental attachments, when forming a dental attachment, fluidity is required to allow it to be easily filled into an attachment template, and formability is required to prevent it from shifting once the attachment position on the tooth structure is determined. While general dental composite resins require fluidity to fill cavities, they do not require the same formability as dental attachments, and therefore the required handleability properties are different. The combination (IV) of fillers (C-2) having an average particle size of 0.1 μm or more and 1 μm or less means an embodiment including two types of fillers (C-2) having different average particle sizes of 0.1 μm or more and 1 μm or less.The average particle size of the filler (C-1) is preferably 1 nm to 90 nm, more preferably 2 nm to 80 nm, and even more preferably 3 nm to 70 nm. The average particle size of the filler (C-2) is preferably 0.1 μm to 0.9 μm, more preferably 0.15 μm to 0.85 μm, and even more preferably 0.2 μm to 0.8 μm. The average particle size of the filler (C-3) is preferably 1.2 μm to 9 μm, more preferably 1.5 μm to 8 μm, and even more preferably 2.0 μm to 7 μm. Note that, as long as the above combination is used, different types of fillers may be contained in the fillers (C) having each particle size. Furthermore, particles other than the filler may be unintentionally contained as impurities within a range that does not impair the effects of the present invention.

[0101] The content of the filler (C) is not particularly limited, but from the viewpoint of the mechanical strength of the cured product and 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, per 100 parts by mass of the total amount of the dental attachment composition.

[0102] The method for producing the dental attachment composition of the present invention comprises a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C), wherein the polymerizable monomer (A) comprises a polymerizable monomer (A-1) having an acidic group and a polymerizable monomer (A-2) having no acidic group, and the content of the polymerizable monomer (A-1) having an acidic group is 1 to 40 parts by mass in 100 parts by mass of the total amount of the polymerizable monomer (A), and the content of the filler (C) is 50 to 90 parts by mass in 100 parts by mass of the total amount of the dental attachment composition, and the dental attachment composition can be easily produced by a method known to those skilled in the art.

[0103] Polymerization accelerator (D) The dental attachment composition of the present invention can use a polymerization accelerator (D) together with the water-insoluble photopolymerization initiator (B-2) and / or a chemical polymerization initiator described below. Examples of the polymerization accelerator (D) used in the present invention include amines, sulfinic acid and its salts, borate compounds, barbituric acid derivatives, triazine compounds, copper compounds, tin compounds, vanadium compounds, halogen compounds, aldehydes, thiol compounds, sulfites, hydrogen sulfites, and thiourea compounds.

[0104] Amines used as the polymerization accelerator (D) are divided 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, Nn-butyldiethanolamine, N-lauryldiethanolamine, 2-(dimethylamino)ethyl methacrylate, N-methyldiethanolamine dimethacrylate, N-ethyldiethanolamine dimethacrylate, triethanolamine monomethacrylate, triethanolamine dimethacrylate, triethanolamine trimethacrylate, triethanolamine, trimethylamine, triethylamine, and tributylamine. Among these, tertiary aliphatic amines are preferred from the viewpoint of the curability and storage stability of the dental attachment composition, and N-methyldiethanolamine and triethanolamine are more preferably used.

[0105] Examples of aromatic amines include 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-t-butylaniline, N,N-bis(2-hydroxyethyl)-3,5-diisopropylaniline, N,N-bis(2-hydroxyethyl)-3,5-di-t-butylaniline, N,N-dimethylaniline, N,N-dimethyl-p-toluidine, N,N-dimethyl-m-toluidine, and 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-t-butylaniline, N,N-dimethyl-3,5-di-t-butylaniline, 4-(N,N-dimethylamino)ethyl benzoate, 4-(N,N-dimethylamino)methyl benzoate, 4-(N,N-dimethylamino)propyl benzoate, 4-(N,N-dimethylamino)n-butoxyethyl benzoate, 4-(N,N-dimethylamino)2-(methacryloyloxy)ethyl benzoate, 4-(N,N-dimethylamino)benzophenone, 4-(N,N-dimethylamino)butyl benzoate, and the like. Among these, at least one selected from the group consisting of 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 is preferably used, from the viewpoint of being able to impart excellent curing properties to the dental attachment composition.

[0106] Specific examples of sulfinic acids and salts thereof, borate compounds, barbituric acid derivatives, triazine compounds, copper compounds, tin compounds, vanadium compounds, halogen compounds, aldehydes, thiol compounds, sulfites, hydrogen sulfites, and thiourea compounds include those described in WO 2008 / 087977.

[0107] The polymerization accelerator (D) may be used alone or in combination of two or more. The content of the polymerization accelerator (D) used in the present invention is not particularly limited. However, from the viewpoint of the curability of the resulting dental attachment composition, it is preferably 0.001 to 30 parts by mass, more preferably 0.01 to 10 parts by mass, and even more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the total amount of polymerizable monomer (A) in the dental attachment composition. If the content of the polymerization accelerator (D) is less than 0.001 part by mass, polymerization may not proceed sufficiently, resulting in a decrease in adhesiveness. Therefore, the content is more preferably 0.05 parts by mass or more. On the other hand, if the content of the polymerization accelerator (D) exceeds 30 parts by mass, sufficient adhesiveness may not be obtained and further precipitation from the dental attachment composition may occur. Therefore, the content is more preferably 20 parts by mass or less.

[0108] [Chemical polymerization initiator] The dental attachment composition of the present invention may further contain a chemical polymerization initiator. An organic peroxide is preferably used as the chemical polymerization initiator. The organic peroxide used as the chemical polymerization initiator is not particularly limited, and known organic peroxides can be used. Representative organic peroxides include, for example, ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxyketals, peroxyesters, and peroxydicarbonates. Specific examples of these organic peroxides include those described in International Publication No. 2008 / 087977. One type of chemical polymerization initiator may be used alone, or two or more types may be used in combination.

[0109] [Fluoride ion-releasing substance] 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 structure can be obtained. Examples of such fluoride ion-releasing substances include metal fluorides such as sodium fluoride, potassium fluoride, sodium monofluorophosphate, lithium fluoride, and ytterbium fluoride. The above fluoride ion-releasing substances may be contained alone or in combination of two or more.

[0110] The dental attachment composition of the present invention may also contain known additives within a range that does not impair performance. Examples of such additives include polymerization inhibitors, antioxidants, colorants (pigments, dyes), UV absorbers, solvents such as water and organic solvents, and thickeners. One type of additive may be used alone, or two or more types may be used in combination. In one embodiment, the content of solvents (e.g., water and 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, based on the total amount of the dental attachment composition.

[0111] Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, dibutylhydroquinone, dibutylhydroquinone monomethyl ether, t-butylcatechol, 2-t-butyl-4,6-dimethylphenol, 2,6-di-t-butylphenol, 3,5-di-t-butyl-4-hydroxytoluene, etc. The content of the polymerization inhibitor is preferably 0.001 to 1.0 part by mass relative to 100 parts by mass of the polymerizable monomer (A) in the dental attachment composition.

[0112] The dental attachment composition has excellent adhesion to enamel after etching with phosphoric acid, even without pretreatment with a dental adhesive or the like after etching with phosphoric acid or the like, and can simplify the adhesion operation, making it suitable for use in dental attachments for aligner orthodontics.

[0113] The following shows an example of the composition ratio of a dental attachment composition suitable for use as a dental attachment for aligner orthodontics. When the total amount of polymerizable monomer (A) is 100 parts by mass, the composition preferably contains 1 to 40 parts by mass of polymerizable monomer (A-1) having an acidic group and 60 to 99 parts by mass of polymerizable monomer (A-2) not having an acidic group, and 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) relative to 100 parts by mass of polymerizable monomer (A). The composition preferably contains 2.5 to 35 parts by mass of polymerizable monomer (A-1) having an acidic group and 65 to 97 parts by mass of polymerizable monomer (A-2) not having an acidic group relative to 100 parts by mass of polymerizable monomer (A). It is more preferable that the composition contains 0.5 parts by mass of a photopolymerization initiator (B), 120 to 560 parts by mass of a filler (C), and 0.01 to 10 parts by mass of a polymerization accelerator (D) per 100 parts by mass of the polymerizable monomer (A), and it is even more preferable that the composition contains 5 to 30 parts by mass of a polymerizable monomer (A-1) having an acidic group and 70 to 95 parts by mass of a polymerizable monomer (A-2) not having an acidic group per 100 parts by mass of the polymerizable monomer (A), and it contains 0.15 to 2.5 parts by mass of a photopolymerization initiator (B), 150 to 400 parts by mass of a filler (C), and 0.1 to 5 parts by mass of a polymerization accelerator (D) per 100 parts by mass of the polymerizable monomer (A).

[0114] Another embodiment is an orthodontic kit including the dental attachment composition and an orthodontic aligner. The orthodontic aligner is not particularly limited, and any known aligner can be used. The orthodontic aligner can be, for example, a photocurable composition containing a polymerizable monomer, a photopolymerization initiator, and, if necessary, a filler. The polymerizable monomer, photopolymerization initiator, and filler can be the polymerizable monomer (A), photopolymerization initiator (B), and filler (C) described above.

[0115] The form of the dental attachment composition of the present invention is not particularly limited, and may be, for example, a two-component (two-paste) composition. However, from the viewpoint of ease of use, it is preferably a one-component (one-paste) composition in which all components are premixed. It is more preferable that the dental attachment composition of the present invention be filled into a cylindrical syringe container for use. The cylindrical portion of the syringe container preferably has a length of 10 cm and an inner diameter of 15 mm or less, more preferably a length of 7.5 cm and an inner diameter of 10 mm or less. Furthermore, to improve handleability, a nozzle can be attached to the tip of the syringe. The nozzle preferably has a length of 25 mm and an opening inner diameter of 1.5 mm or less, more preferably a length of 20 mm and an opening inner diameter of 0.75 mm or less.

[0116] In one embodiment, the composition includes 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, The content of the polymerizable monomer (A-1) having an acidic group is 1 to 40 parts by mass in 100 parts by mass of the polymerizable monomer (A), and Examples of the present invention include the use of a dental attachment composition, in which the content of the filler (C) is 50 to 90 parts by mass per 100 parts by mass of the total amount of the composition. The use may be for forming a dental attachment. The use may be for fixing an orthodontic aligner. The use may be on the surface of a tooth. The use may be non-therapeutic. Another embodiment includes the use of the dental attachment composition for orthodontic treatment. Another embodiment includes the use of the dental attachment composition for treating a dental disease. Examples of the dental disease include jaw deformities, occlusion abnormalities, and congenital diseases (e.g., cleft lip and palate, cleidocranial dysplasia, Pierre Robin syndrome, branchial arch syndrome, etc.).

[0117] In certain other embodiments, a method of applying a dental attachment composition to a tooth surface to form a dental attachment on the tooth surface includes the steps of: The dental attachment composition 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, The content of the polymerizable monomer (A-1) having an acidic group is 1 to 40 parts by mass in 100 parts by mass of the polymerizable monomer (A), and In another embodiment, the content of the filler (C) is 50 to 90 parts by mass relative to 100 parts by mass of the total amount of the composition. In another embodiment, the method for producing a dental attachment on a tooth surface includes the steps of: The dental attachment composition 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, The content of the polymerizable monomer (A-1) having an acidic group is 1 to 40 parts by mass in 100 parts by mass of the polymerizable monomer (A), and The method may include a method in which the content of the filler (C) is 50 to 90 parts by mass per 100 parts by mass of the total amount of the composition. The method may also be a method in which the dental attachment composition is applied to the surface of teeth to fix an orthodontic aligner. [Example]

[0118] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the examples, parts are by mass unless otherwise specified.

[0119] Next, the components of the dental attachment compositions of the Examples and Comparative Examples are listed below together with their abbreviations.

[0120] [Polymerizable monomer (A-1) having an acidic group] MDP: 10-methacryloyloxydecyl dihydrogen phosphate

[0121] [Polymerizable monomer (A-2) having no acidic group] Bis-GMA: 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane D-2.6E: 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (average number of moles of ethoxy groups added: 2.6) 3G: Triethylene glycol dimethacrylate DD: 1,10-decanediol dimethacrylate MAEA: N-methacryloyloxyethyl acrylamide DEAA: N,N-diethylacrylamide HEMA: 2-hydroxyethyl methacrylate

[0122] [Photopolymerization initiator (B)] Water-soluble photopolymerization initiator (B-1) Li-TPO: Lithium phenyl(2,4,6-trimethylbenzoyl)phosphinate Non-water-soluble photopolymerization initiator (B-2) CQ: dl-camphorquinone BAPO: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide

[0123] Filler Filler 1: Nippon Aerosil Co., Ltd., ultrafine silica particle "Aerosil (registered trademark) R 972", average particle size: 16 nm Filler 2: Silane-treated silica 100 g of OX50 (Nippon Aerosil Co., Ltd., ultrafine silica particle "Aerosil (registered trademark) OX50", average particle size: 0.04 μm), 7 g of γ-methacryloyloxypropyltrimethoxysilane, and 200 mL of 0.3 mass% acetic acid aqueous solution were placed in 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. Filler 3: Silane-treated silica powder Silica powder (manufactured by Nichitsu Corporation, product name: Hi-Silica) was pulverized in 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 analyzer (manufactured by Shimadzu Corporation, model "SALD-2300") and found to be 2.2 μm. 100 parts by mass of this pulverized silica powder was surface-treated with 4 parts by mass of γ-methacryloyloxypropyltrimethoxysilane by a conventional method to obtain silane-treated silica powder. Filler 4: Silane-treated barium glass powder Barium glass (manufactured by Estec Co., Ltd., product code "E-3000") was pulverized in 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 analyzer (manufactured by Shimadzu Corporation, model "SALD-2300") and found to be 2.4 μm. 100 parts by mass of this barium glass powder was surface-treated with 3 parts by mass of γ-methacryloyloxypropyltrimethoxysilane by a conventional method to obtain silane-treated barium glass powder. Filler 5: Silane-treated barium glass powder 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 mass% acetic acid aqueous solution were placed in 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 5. Filler 6: Silane-treated barium glass powder 100 g of 8235 UF0.7 grade (barium glass manufactured by SCHOTT, average particle size: 0.7 μm), 6 g of γ-methacryloyloxypropyltrimethoxysilane, and 200 mL of 0.3 mass% acetic acid aqueous solution were placed in 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 6. Filler 7: Silane-treated spherical silica-titania composite oxide powder 100 g of spherical silica-titania composite oxide (average particle size: 0.3 μm), 10 g of γ-methacryloyloxypropyltrimethoxysilane, and 200 mL of 0.3 mass% acetic acid aqueous solution were placed in 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. Ar380: Nippon Aerosil Co., Ltd., ultrafine silica particle "Aerosil 380", average particle size: 7 nm

[0124] [Polymerization accelerator (D)] DABE: Ethyl 4-(N,N-dimethylamino)benzoate

[0125] [Polymerization inhibitor] BHT: 3,5-di-t-butyl-4-hydroxytoluene

[0126] Examples 1 to 20 and Comparative Examples 1 to 5 (Preparation of Dental Attachment Compositions) The raw materials shown in Tables 1 to 3 were mixed and kneaded in a dark place at room temperature (23°C) to prepare paste-like dental attachment compositions, and their properties were investigated according to the methods of the following Test Examples 1 to 4. The results are shown in Tables 1 to 3.

[0127] Test Example 1 Photocuring depth The photocuring depth was evaluated according to JIS T 6514:2015 (Dental restorative composite resins). Specifically, the procedure was as follows: The prepared dental attachment composition was filled into a stainless steel mold (12 mm thick, 4 mm diameter). A film and a glass slide were placed on the top and bottom surfaces, and the film was pressed against the surface, with the glass plate removed from one side. The pressed surface was then irradiated with light for 10 seconds using a dental visible light irradiator "PenCure 2000" (Morita Corporation) to cure the composition. After removing the cured product from the mold, the uncured portion was wiped off, and the length from the irradiated surface to the tip of the cured product was measured using a micrometer (Mitutoyo Corporation). Half of the measured value was used as the photocuring depth (n = 5), and the average was calculated.

[0128] Test Example 2: Vickers hardness An appropriate amount of the dental attachment composition paste prepared in each Example and Comparative Example was placed on a glass slide, and the top and bottom surfaces were pressed against the glass slide using a 1 mm gauge (manufactured by Mitutoyo Corporation). The top side was irradiated with light for 10 seconds using a dental visible light irradiator "Pencure 2000" (manufactured by Morita Corporation) to harden the composition, producing a disk with a diameter of 10 mm and a thickness of 1 mm. The smooth surface of the disk was polished under dry conditions with #1500 abrasive paper and finally mirror-polished with diamond paste. The Vickers hardness (Hv) of the prepared sample was measured (n = 5) using a microhardness tester (HM-221, manufactured by Mitutoyo Corporation) with a load of 200 g for 10 seconds, and the average value was calculated.

[0129] Test Example 3: Flexural properties (flexural modulus, flexural strength) The flexural modulus and flexural strength were evaluated by a bending test in accordance with ISO 4049:2009. Specifically, the procedure is as follows. The prepared paste (dental attachment composition) was filled into a stainless steel mold (2 mm long x 25 mm wide x 2 mm thick), and the top and bottom of the paste (2 mm x 25 mm surfaces) were pressed against a glass slide. Next, the paste was cured by irradiating the front and back of the paste with light for 10 seconds at five points on each side through the glass slide using a dental visible light irradiator "PenCure 2000" (Morita Corporation). The resulting cured product was subjected to a bending test using a universal testing machine (Autograph AG-I 100kN, Shimadzu Corporation) with a support distance of 20 mm and a crosshead speed of 1 mm / min. The three-point flexural strength and flexural modulus were measured (n = 5), and the average values ​​were calculated.

[0130] Test Example 4: Shear bond strength to tooth structure (uncut human enamel) The labial surfaces of extracted human teeth were brushed with a toothbrush under running water to clean the tooth surface, and samples were obtained. Tape was attached to the bottom of a 15-hole mold (Ultradent, φ35 mm x H25 mm), and the sample teeth were fixed onto the tape. Plaster was filled into the mold and left to harden for approximately 30 minutes. The samples were removed from the mold and brushed with a toothbrush under running water to remove excess plaster, ensuring a surface to be adhered (φ2.38 mm or larger). The surface to be adhered was then ultrasonically rinsed for 5 minutes.

[0131] Tooth surface treatment material 1 (a mixture prepared by mixing 50 parts by weight of concentrated phosphoric acid, 50 parts by weight of distilled water, and 5 parts by weight of Ar380) was applied to the surface of the above sample using a brush and left for 10 seconds.The surface was then washed with tap water for 10 seconds and dried by air blowing.

[0132] Next, a separately prepared φ2.38 mm CR filling mold (Bonding Mold Insert, manufactured by Ultradent) was attached to a dedicated tool (Bonding Clamp, manufactured by Ultradent). Next, the CR filling mold attached to the dedicated tool was lowered to secure the sample so that it was in close contact with the surface of the sample treated with tooth surface treatment material 1. Next, the dental attachment composition of each Example and Comparative Example was thinly filled into the hole of the CR filling mold to a thickness of 1 mm or less. Thereafter, the dental attachment composition was again filled into the mold (about 2 / 3 of the way up the mold, about 2 mm thick) and irradiated with light for 10 seconds using a dental visible light irradiator "VALO" (manufactured by Ultradent Japan Co., Ltd.). The sample was removed from the mold and used as a test sample for the adhesion test. A total of 20 samples were prepared. The adhesive test samples were then immersed in distilled water and placed in an incubator set at 37°C for 24 hours. After the samples were removed, 10 of the 20 samples were immediately measured for initial adhesive strength. The average values ​​of the measurement results are shown in Tables 1-3 as "initial adhesive strength." The remaining 10 samples were subjected to 10,000 thermal cycles, each cycle consisting of alternating immersion in 4°C cold water and 60°C hot water for 1 minute, before their adhesive strengths were measured. The average values ​​of the measurement results are shown in Tables 1-3 as "adhesion durability." Shear adhesive strength was measured by attaching the adhesive test samples to a dedicated holder (Test Base Clamp, Ultradent) and using a dedicated jig (Crosshead Assembly, Ultradent) and a universal testing machine (Autograph AG-I 100kN, Shimadzu Corporation) at a crosshead speed of 1 mm / min. The adhesive strength was calculated as the average of the measurements for 10 adhesive test samples. This test method is preferable because it allows evaluation using test specimens with a thickness of approximately 2 mm, which is close to the thickness of actual dental attachments, and the shape of the test specimens is similar to that of dental attachments.

[0133] Test Example 5 Tensile bond strength with prosthesis (zirconia or gold-silver-palladium alloy)The adherends were cylindrical (12 mm inner diameter x 5 mm height) zirconia sintered bodies (fired at 1500°C for 2 hours) made from zirconia discs for CAD / CAM systems (product name: "Katana (registered trademark) Zirconia" HT, manufactured by Kuraray Noritake Dental Co., Ltd.), and a gold-silver-palladium alloy casting (manufactured by GC Corporation, product name "Castwell MC <12% Gold>") cast to a size of 10 mm x 10 mm x 1 mm. The adherend surfaces were polished to a flat surface with #1000 silicon carbide paper (manufactured by Nihon Kenshi Co., Ltd.), and then air-dried to remove water from the surface. A 150 μm thick adhesive tape with a 5 mm diameter circular hole was attached to the dried flat surface to define the adhesive area. The dental attachment compositions of each Example and Comparative Example were then filled and applied into the circular hole, and the resulting surface was covered with a release film (polyester). Next, a glass slide was placed on the release film and pressed against it to smooth the surface coated with the dental attachment composition. The dental attachment composition was then irradiated with light for 10 seconds through the release film using a dental visible light irradiator "VALO" (manufactured by Ultradent Japan Co., Ltd.) to harden the dental attachment composition and obtain a cured product. One end face (circular cross section) of a stainless steel cylindrical rod (7 mm diameter, 2.5 cm length) was bonded to the surface of the obtained cured product using a commercially available dental resin cement (manufactured by Kuraray Noritake Dental Co., Ltd., product name "Panavia (registered trademark) 21"). After bonding, the sample was left at room temperature for 30 minutes and then immersed in distilled water to obtain a test sample for the adhesion test. Twenty test samples were prepared for each of the zirconia sintered body and the gold-silver-palladium alloy cast body. The test samples were immersed in distilled water and left to stand in an incubator maintained at 37°C for 24 hours. For 10 of the 20 test samples, the adhesive strength was measured immediately after leaving them to stand for 24 hours to evaluate the initial adhesive strength. The average of the measurement results is shown as "initial adhesive strength" in Tables 1 to 3. This tensile adhesive strength indicates the adhesive strength at the initial stage of adhesion. Furthermore, for the remaining 10 samples, to evaluate adhesive durability, the adhesive strength was measured after 10,000 thermal cycles, each cycle consisting of alternating immersion in cold water at 4°C and hot water at 60°C for 1 minute.The average values ​​of the measurement results are shown as "adhesion durability" in Tables 1 to 3. The tensile adhesive strength was measured using a universal testing machine (manufactured by Shimadzu Corporation) with a crosshead speed set to 2 mm / min. The adhesive strength value was the average value of the measurements for 10 adhesive test samples.

[0134] [Table 1]

[0135] [Table 2]

[0136] [Table 3]

[0137] The results in Tables 1 and 2 indicate that the dental attachment compositions of the examples have excellent mechanical strength, with a photocuring depth of 2.2 mm or greater, a Vickers hardness of 32 Hv or greater, and a flexural modulus of 5.5 GPa to 9.6 GPa. They also have excellent initial bond strength (shear bond strength) to uncut enamel of 18 MPa or greater, and excellent bond durability of 20 MPa. The outermost surface of enamel is more acid-resistant than the enamel within the tooth and is less susceptible to demineralization by etching. Although the bond strength of uncut enamel surfaces tends to be lower than that of cut enamel surfaces, these compositions exhibit excellent initial bond strength and bond durability to uncut enamel. Furthermore, the compositions also exhibit excellent bond strength (tensile bond strength) to zirconia and gold-silver-palladium alloys of 13 MPa or greater, and excellent bond durability of 9 MPa or greater. On the other hand, as shown in Table 3, among the dental attachment compositions of the comparative examples, Comparative Examples 1 and 2, in which the filler (C) was not contained in the amount specified in the present invention, had a flexural modulus of less than 3.0 GPa, and thus insufficient mechanical strength. Furthermore, Comparative Example 3, in which the filler (C) was not contained in the amount specified in the present invention, demonstrated low shear bond strength to uncut enamel of 12 MPa or less and low bond durability of 11 MPa or less. Comparative Examples 4 and 5, in which the polymerizable monomer having an acidic group was not contained in the specific mass ratio specified in the present invention, demonstrated low shear bond strength to uncut enamel of 12 MPa or less and low bond durability of 11 MPa or less. Furthermore, the initial bond strength (tensile bond strength) to zirconia and a gold-silver-palladium alloy was also low, at 12 MPa or less and low bond durability of 5 MPa or less. [Industrial Applicability]

[0138] The dental attachment composition of the present invention can be suitably used for dental attachments for aligner orthodontics.

Claims

1. The composition comprises a polymerizable monomer (A), a photopolymerization initiator (B), and a filler (C), the polymerizable monomer (A) contains a polymerizable monomer (A-1) having an acidic group and a polymerizable monomer (A-2) not having an acidic group, the polymerizable monomer (A-1) having an acidic group is a polymerizable monomer having a phosphate group, The polymerizable monomer having a phosphate group is 2-(meth)acryloyloxyethyl dihydrogen phosphate, 3-(meth)acryloyloxypropyl dihydrogen phosphate, 4-(meth)acryloyloxybutyl dihydrogen phosphate, 5-(meth)acryloyloxypentyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 7-(meth)acryloyloxyheptyl dihydrogen phosphate, 8-(meth)acryloyl Oxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl dihydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate, 12-(meth)acryloyloxydodecyl dihydrogen phosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen phosphate, 20-(meth)acryloyloxyicosyl dihydrogen phosphate, Bis[2-(meth)acryloyloxyethyl]hydrogenphosphate, bis[4-(meth)acryloyloxybutyl]hydrogenphosphate, bis[6-(meth)acryloyloxyhexyl]hydrogenphosphate, bis[8-(meth)acryloyloxyoctyl]hydrogenphosphate, bis[9-(meth)acryloyloxynonyl]hydrogenphosphate, bis[10-(meth)acryloyloxydecyl]hydrogenphosphate, 1,3-di(meth)acryloyloxyethyl]hydrogenphosphate, at least one selected from the group consisting of 2-(meth)acryloyloxypropyl dihydrogenphosphate, 2-(meth)acryloyloxyethylphenyl hydrogen phosphate, 2-(meth)acryloyloxyethyl-(2-bromoethyl)hydrogen phosphate, 2-methacryloyloxyethyl-(4-methoxyphenyl)hydrogen phosphate, 2-methacryloyloxypropyl-(4-methoxyphenyl)hydrogen phosphate, and acid chlorides, alkali metal salts, and amine salts thereof; the photopolymerization initiator (B) is a water-insoluble photopolymerization initiator (B-2), The filler (C) contains two or more fillers having different materials, particle size distributions, and / or morphologies, The content of the polymerizable monomer (A-1) having an acidic group is 1 to 40 parts by mass based on 100 parts by mass of the total amount of the polymerizable monomer (A), and A dental attachment composition, wherein the content of the filler (C) is 50 to 90 parts by mass per 100 parts by mass of the total amount of the composition.

2. 2. The dental attachment composition according to claim 1, wherein the polymerizable monomer (A-2) having no acidic group contains a hydrophobic polymerizable monomer (A-2b) having no acidic group and, if necessary, a hydrophilic polymerizable monomer (A-2c) having no acidic group, and the mass ratio of the hydrophilic polymerizable monomer (A-2c) having no acidic group to the hydrophobic polymerizable monomer (A-2b) having no acidic group is hydrophilic polymerizable monomer (A-2c) having no acidic group:hydrophobic polymerizable monomer (A-2b) having no acidic group = 0:10 to 2:

1.

3. 3. The dental attachment composition according to claim 1, wherein the dental attachment composition is a one-component composition.

4. 4. The dental attachment composition according to claim 1, wherein the polymerizable monomer (A-1) having an acidic group is 10-methacryloyloxydecyl dihydrogen phosphate.

5. 3. The dental attachment composition according to claim 2, wherein a mass ratio of the hydrophilic polymerizable monomer (A-2c) not having an acidic group to the hydrophobic polymerizable monomer (A-2b) not having an acidic group is hydrophilic polymerizable monomer (A-2c) not having an acidic group:hydrophobic polymerizable monomer (A-2b) not having an acidic group is 0:10 to 1:

1.

6. 3. The dental attachment composition according to claim 2, wherein a mass ratio of the hydrophilic polymerizable monomer (A-2c) not having an acidic group to the hydrophobic polymerizable monomer (A-2b) not having an acidic group is hydrophilic polymerizable monomer (A-2c) not having an acidic group:hydrophobic polymerizable monomer (A-2b) not having an acidic group is 0:10 to 1:

2.

7. 7. The dental attachment composition according to claim 1, wherein the filler (C) comprises at least one combination selected from the group consisting of a combination (I) of a filler (C-1) having an average particle size of 1 nm or more and less than 0.1 μm and a filler (C-2) having an average particle size of 0.1 μm or more and 1 μm or less, a combination (II) of a filler (C-1) having an average particle size of 1 nm or more and less than 0.1 μm and a filler (C-3) having an average particle size of more than 1 μm and 10 μm or less, a combination (III) of a filler (C-1) having an average particle size of 1 nm or more and less than 0.1 μm, a filler (C-2) having an average particle size of 0.1 μm or more and 1 μm or less, and a filler (C-3) having an average particle size of more than 1 μm and 10 μm or less, and a combination (IV) of fillers (C-2) having an average particle size of 0.1 μm or more and 1 μm or less.

8. The dental attachment composition according to claim 7 , wherein the filler (C) comprises the combination (I) or the combination (II).

9. 9. The dental attachment composition according to claim 1, wherein the cured product has a flexural modulus of 3 GPa or more.

10. The dental attachment composition according to any one of claims 1 to 9, wherein the polymerizable monomer (A-2) having no acidic group contains an asymmetric acrylamide-methacrylate ester compound (A-2a) represented by the following general formula (1): 【Chemistry 1】 wherein Z is a C 1 ~C 8 a linear or branched aliphatic group or aromatic group, wherein the aliphatic group is selected from the group consisting of —O—, —S—, —CO—, —CO—O—, —O—CO—, —NR 1 --CO-NR 1 -, -NR 1 -CO-, -CO-O-NR 1 -, -O-CO-NR 1 - and -NR 1 -CO-NR 1 - may be interrupted by at least one linking group selected from the group consisting of 1 is a hydrogen atom or an optionally substituted C 1 ~C 8 represents a linear or branched aliphatic group of the formula:

11. Z is an optionally substituted C 1 ~C 4 11. The dental attachment composition according to claim 10, wherein the alkyl group is a linear or branched aliphatic group represented by the formula:

12. Z is an optionally substituted C 1 ~C 4 12. The dental attachment composition according to claim 10, wherein the alkylene group is a linear or branched alkylene group represented by the formula:

13. The dental attachment composition according to any one of claims 10 to 12, wherein the asymmetric acrylamide-methacrylic acid ester compound (A-2a) represented by general formula (1) is at least one selected from the group consisting of N-methacryloyloxyethyl acrylamide, N-methacryloyloxypropyl acrylamide, N-methacryloyloxybutyl acrylamide, N-(1-ethyl-(2-methacryloyloxy)ethyl)acrylamide, and N-(2-(2-methacryloyloxyethoxy)ethyl)acrylamide.

14. The dental attachment composition according to any one of claims 1 to 13, wherein the cured product has a Vickers hardness of 30 Hv or more and 70 Hv or less.

15. The dental attachment composition according to any one of claims 1 to 14, wherein the flexural modulus of the cured product measured in a flexural test in accordance with ISO 4049:2009 is 3 GPa or more and less than 10.0 GPa.

16. The dental attachment composition according to any one of claims 1 to 15, wherein the three-point flexural strength of the cured product measured in a flexural test in accordance with ISO 4049:2009 is 70 MPa or more and less than 200 MPa.

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