Dental glass ionomer cement composition suitable for mechanical mixing

Abstract

To provide a dental glass ionomer cement composition which can improve the mixing efficiency of a powder and a liquid to an extent where the powder-to-liquid ratio can be raised in mechanical mixing without reducing the fluoride-release property, and further expresses a high mechanical property.SOLUTION: The present invention provides a dental glass ionomer cement composition in which a powder and a liquid are separately packaged in a dental capsule, and the powder and the liquid are mechanically mixed immediately before their use. The composition comprises (a) a hydrophobized acid reactive glass powder, (b) a polyalkene acid, and (c) water, and does not involve a polymerization reaction upon curing.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a dental glass ionomer cement composition that is used as a dental filling glass ionomer cement, a dental luting glass ionomer cement, etc., and hardens mainly by an acid-base reaction without a polymerization reaction during hardening.

Background Art

[0002] In dental clinics, for teeth whose morphology has been partially damaged due to dental caries, fractures, etc., direct restoration is performed by filling the teeth with a filling material, and indirect restoration is performed by attaching and / or adhering a dental prosthetic device to the teeth using a luting material. Representative filling materials and luting materials include dental glass ionomer cements that harden only by an acid-base reaction, and resin-reinforced dental glass ionomer cements that harden with a polymerization reaction in addition to an acid-base reaction. However, when importance is attached to tooth substance strengthening and suppression of secondary dental caries, a dental glass ionomer cement with a higher fluoride sustained release property is more suitable.

[0003] Dental glass ionomer cement is generally provided in a form divided into a powder material mainly composed of an acid-reactive glass powder and a liquid material mainly composed of a polyalkenoic acid and water, and the powder material and the liquid material are kneaded and used immediately before use.

[0004] As a method for kneading dental glass ionomer cement, manual kneading is performed by taking out the powder material and the liquid material measured by a specified method from containers in which the powder material or the liquid material is packaged onto a kneading paper and kneading them using an instrument such as a spatula, and in a dental capsule designed for single use, the powder material and the liquid material that have been pre-measured in a separated state are brought into contact in the dental capsule by a specified method, and then mechanical kneading is performed by adding fine and strong vibration to the dental capsule using a capsule kneading device.

Prior Art Documents

Patent Documents

[0005] Patent Document 1 Japanese Patent Application Laid-Open No. 1-308853 Summary of the Invention Problems to be Solved by the Invention

[0006] When a dental glass ionomer cement is kneaded by kneading a powder material and a liquid material, an acid-base reaction proceeds and hardens between an acid-reactive glass powder and a polyalkenoic acid in the presence of water. Here, in the dental glass ionomer cement, generally, as the ratio of the acid-reactive glass powder contained in all components increases, the mechanical properties of the hardened body improve. For this reason, it is preferable that the mass ratio of the powder material to the liquid material during kneading, that is, the powder-liquid ratio, is as high as possible. However, as the powder-liquid ratio increases, the viscosity of the kneaded product increases. Therefore, if the powder-liquid ratio is made too high, the kneaded product may not be sufficiently kneaded and may become a non-uniform kneaded product, which may cause a decrease in the mechanical properties of the hardened body. Therefore, there is a certain limit to increasing the powder-liquid ratio.

[0007] So far, a dental glass ionomer cement composition has been proposed that can increase the powder-liquid ratio and the hardened body obtained thereby exhibits high mechanical properties. For example, Patent Document 1 discloses a technique for increasing the powder-liquid ratio by including spherical coarse inorganic oxide particles having a large particle diameter and fine inorganic oxide particles having a small particle diameter in a specific ratio in a dental glass ionomer cement composition.

[0008] When manually kneading the powder material and the liquid material of the dental glass ionomer cement using a spatula or the like, a strong shearing force and compressive force can be applied to the kneaded product. On the other hand, when mechanically kneading the powder material and the liquid material in a dental capsule, the powder material and the liquid material are kneaded by applying fine and strong vibrations to the dental capsule with a capsule kneading device. Generally, it is more difficult to apply a strong force to the kneaded product than in manual kneading. Therefore, it has been difficult to increase the powder-liquid ratio in mechanical kneading compared to manual kneading.

[0009] In addition, for the dental glass ionomer cement composition of Patent Document 1, in addition to the need to separately manufacture spherical coarse inorganic oxide particles and fine inorganic oxide particles, for the spherical coarse inorganic oxide particles, since the inorganic oxide particles are melted in a dispersed state and the particles are spheroidized by surface tension, the manufacturing process is complicated and it is difficult to control the particle size. Furthermore, since fluorine is released from the inorganic oxide particles in the process of melting and spheroidizing, the fluorine sustained release property, which is one of the major features of dental glass ionomer cement, may decrease.

[0010] Therefore, an object of the present invention is to provide a dental glass ionomer cement composition that can improve the kneading efficiency of the powder material and the liquid material to such an extent that the powder-liquid ratio can be increased in mechanical kneading without reducing the fluorine sustained release property, and further exhibits high mechanical properties.

Means for Solving the Problems

[0011] In a dental glass ionomer cement composition containing acid-reactive glass powder, polyalkenoic acid, and water and not involving a polymerization reaction during curing, by appropriately hydrophobizing the surface of the acid-reactive glass powder with a hydrophobizing surface treatment agent, unexpectedly, the kneading efficiency of the powder material and the liquid material is improved to such an extent that the powder-liquid ratio can be increased in mechanical kneading without reducing the fluorine sustained release property, and thereby the mechanical properties are improved. Based on this finding, the present invention has been completed. That is, it has been found that the above problems can be solved by the following configuration.

[0012] The present invention is a dental glass ionomer cement composition that is mechanically kneaded using a kneading device for capsules, and is characterized by containing (a) hydrophobized acid-reactive glass powder, (b) polyalkenoic acid, and (c) water, and not involving a polymerization reaction during curing.

Effects of the Invention

[0013] The glass ionomer cement composition for dentistry of the present invention enables efficient kneading of the powder component and the liquid component in mechanical kneading. Further, since the powder-liquid ratio can be set high thereby, desired high mechanical properties can be exhibited. Moreover, since it has a desired high fluoride sustained release property, it is effective for tooth substance strengthening and suppression of secondary caries.

Embodiments for Carrying Out the Invention

[0014] Hereinafter, the present invention will be described in detail. In this specification, "dental glass ionomer cement" means a powder-liquid type dental glass ionomer cement that is not intended to be compounded with a compound having a polymerizable group such as a polymerizable monomer, an oligomer having a polymerizable group, and / or a polymer having a polymerizable group so as to impart curing by a polymerization reaction, and that cures mainly by an acid-base reaction occurring between an acid-reactive glass powder and a polyalkenoic acid in the presence of water.

[0015] "Dental capsule" means a capsule used for a capsule kneading device and / or for mixing and dispensing dental materials. Also, "mechanical kneading" means kneading a powder component and a liquid component that are pre-packaged in a separated state in a dental capsule, or a powder component and a liquid component filled into a dental capsule immediately before use, by adding fine and strong vibration to the dental capsule with a capsule kneading device. Also, "capsule kneading device" means a device to which a dental capsule can be attached and that kneads the powder component and the liquid component in the dental capsule by adding fine and strong vibration to the dental capsule. Furthermore, "hydrophobic surface treatment agent" means a compound that can surface-treat an acid-reactive glass powder and that can modify the surface of the acid-reactive glass powder to be hydrophobic by surface-treating it with the compound.

[0016] The glass ionomer cement composition for dentistry of the present invention contains (a) a hydrophobized acid-reactive glass powder, (b) a polyalkenoic acid, and (c) water as essential components, and this component composition improves the kneading efficiency of the powder material and the liquid material in mechanical kneading.

[0017] Therefore, the glass ionomer cement composition for dentistry of Patent Document 1 and the glass ionomer cement composition for dentistry of the present invention are essentially completely different in that the former contains spherical coarse inorganic oxide particles with a large particle diameter, while the latter does not contain the spherical coarse inorganic oxide particles. Hereinafter, the above components of the present invention will be described.

[0018] The (a) hydrophobized acid-reactive glass powder that can be used in the glass ionomer cement composition for dentistry of the present invention is an acid-reactive glass powder that is generally used in glass ionomer cement compositions for dentistry and whose surface has been moderately hydrophobized by surface treatment using a known hydrophobizing agent. By using this (a) hydrophobized acid-reactive glass powder in the glass ionomer cement composition for dentistry, the kneading efficiency of the powder material and the liquid material can be improved to such an extent that the powder-liquid ratio can be increased in mechanical kneading without reducing the fluoride sustained release property, and thereby the mechanical properties are improved. The fluoride sustained release property is preferably at the same high level as that of existing glass ionomer cements for dentistry. It should be noted that the improvement in the kneading efficiency of the powder material and the liquid material by hydrophobizing the acid-reactive glass powder is only in mechanical kneading, and there is no change in the kneading efficiency or, on the contrary, the kneading efficiency deteriorates in manual kneading.

[0019] (a) The acid-reactive glass powder that can be used in producing the hydrophobized acid-reactive glass powder needs to contain acid-reactive elements such as metal elements and fluorine elements. The acid-reactive glass powder, by containing acid-reactive elements, (c) in the presence of water, (b) an acid-base reaction with the acidic groups possessed by polyalkenoic acid proceeds. Specific examples of acid-reactive elements include, but are not limited to, sodium, potassium, calcium, strontium, barium, lanthanum, aluminum, zinc, etc. These acid-reactive elements can include one type or two or more types, and their contents are not particularly limited.

[0020] Furthermore, in order to impart X-ray contrast to the dental glass ionomer cement composition of the present invention, it is preferable to include X-ray impermeable elements in the acid-reactive glass powder. Specific examples of X-ray impermeable elements include, but are not limited to, strontium, lanthanum, zirconium, titanium, yttrium, ytterbium, tantalum, tin, tellurium, tungsten, and bismuth, etc. Also, there are no particular restrictions on other elements contained in the acid-reactive glass powder, and the acid-reactive glass powder in the present invention can contain various elements.

[0021] Examples of the acid-reactive glass powder include, but are not limited to, aluminosilicate glass, borosilicate glass, aluminoborate glass, borosilicate glass, phosphate glass, boric acid glass, and silica glass, etc., which contain the above-mentioned acid-reactive elements, fluorine, and X-ray impermeable elements.

[0022] Furthermore, the particle shape of the acid-reactive glass powder is not particularly limited, and those with any particle shape such as spherical, needle-like, plate-like, crushed, scaly, etc. can be used without any restrictions. These acid-reactive glass powders can be used alone or in combination of several types.

[0023] The manufacturing method of these acid-reactive glass powders is not particularly limited, and those manufactured by any manufacturing method such as the melting method, the vapor phase method, and the sol-gel method can be used without problems. Among them, it is preferable to use acid-reactive glass powders manufactured by the melting method or the sol-gel method, in which the types and contents of elements are easy to control.

[0024] The acid-reactive glass powder can be pulverized and used to obtain a desired particle size. The pulverization method is not particularly limited, and those pulverized by any pulverization method of the wet method or the dry method can be used. Specifically, it is pulverized using a high-speed rotation mill such as a hammer mill or a turbo mill, a container-driven mill such as a ball mill, a planetary mill, or a vibration mill, a medium stirring mill such as an attritor or a bead mill, a jet mill, etc., and the particle size can be appropriately adjusted according to the use application or purpose of use of the dental glass ionomer cement composition of the present invention.

[0025] The (a) hydrophobized acid-reactive glass powder of the dental glass ionomer cement composition may be an acid-reactive glass powder having a 50% particle size (D50) in the cumulative particle size distribution based on volume in the range of 0.5 to 15 μm hydrophobized with a hydrophobizing surface treatment agent. In such a case, the kneading efficiency and / or mechanical properties are likely to be improved.

[0026] Thus, the 50% particle size (D50) of the acid-reactive glass powder suitable for the dental glass ionomer cement composition of the present invention is preferably in the range of 0.5 to 15 μm. Here, the "50% particle size (D50)" refers to the particle size at which the integrated value from the small particle size side becomes 50% in the particle size distribution based on volume measured using a laser diffraction / scattering type particle size distribution measuring device or the like.

[0027] When the dental glass ionomer cement composition of the present invention is used as a filling material, in order to increase the powder-liquid ratio and exhibit a high elastic modulus, the 50% particle size (D50) of the acid-reactive glass powder is preferably in the range of 3 to 15 μm. On the other hand, when the dental glass ionomer cement composition of the present invention is used as an attaching material, in order to exhibit a thin film thickness, the 50% particle size (D50) of the acid-reactive glass powder is preferably in the range of 0.5 to 10 μm, and more preferably in the range of 0.5 to 5 μm.

[0028] When the 50% particle size (D50) of the acid-reactive glass powder is less than 0.5 μm, its surface area increases, and it cannot be contained in a large amount in the composition, so the mechanical properties may deteriorate. Also, the operating margin time may be shortened.

[0029] When the 50% particle size (D50) of the acid-reactive glass powder exceeds 15 μm, when used for filling, the surface of the material becomes rough after polishing, and there is a risk of easy coloring in the oral cavity. Also, when used for attachment, the film thickness becomes thick, and the attached and / or adhered prosthetic device may float, and the intended fit of the prosthetic device may not be obtained.

[0030] (a) Known hydrophobic surface treatment agents can be used when producing the hydrophobic acid-reactive glass powder. Specifically, silane coupling agents, organosilazanes, titanate-based coupling agents, zirconium-based coupling agents, and aluminate-based coupling agents, etc. can be mentioned. These hydrophobic surface treatment agents can be used alone or in combination of several kinds. Among these hydrophobic surface treatment agents, it is preferable to use a silane coupling agent or an organosilazane.

[0031] The hydrophobic surface treatment agent is the following general formula (1): R n SiA 4-n (1) (In the formula, R is a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, A is an alkoxy group having 1 to 4 carbon atoms, an alkoxyalkoxy group having 2 to 10 carbon atoms, an acyloxy group having 1 to 6 carbon atoms, an alkenyloxy group having 2 to 6 carbon atoms, a halogen atom, an isocyanate group, a hydroxy group, or a hydrogen atom, and n is an integer of 1 to 3. However, a plurality of Rs and As may be the same as or different from each other.) A silane coupling agent represented by, and The following general formula (2): R 1 R 2 R 3 -Si-NH-Si-R 4 R 5 R 6 (2) (In the formula, R 1 , R 2 , and R 3 are each independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, and at least one of R 1 , R 2 , and R 3 is a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, and R 4 , R 5 and R 6 are each independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, and at least one of R 4 , R 5 , and R 6 is a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent.) It may be at least one hydrophobic surface treatment agent selected from the group consisting of organosilazanes represented by. In such a case, the kneading efficiency and / or mechanical properties are likely to be improved.

[0032] Examples of the silane coupling agent include the following general formula (1) as described above. General formula (1): R n SiA 4-n (1) (In the formula, R is a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, A is an alkoxy group having 1 to 4 carbon atoms, an alkoxyalkoxy group having 2 to 10 carbon atoms, an acyloxy group having 1 to 6 carbon atoms, an alkenyloxy group having 2 to 6 carbon atoms, a halogen atom, an isocyanate group, a hydroxy group, or a hydrogen atom, and n is an integer of 1 to 3. However, a plurality of Rs and As may be the same as or different from each other.)

[0033] Examples of the hydrocarbon group of R include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, etc. Examples of the alkyl group 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 tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, a 2-ethylhexyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tetradecyl group, an n-hexadecyl group, an eicosyl group, etc. Examples of the cycloalkyl group include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, etc. Examples of the alkenyl group include a vinyl group, an allyl group, a 1-propenyl group, a 1-methylethenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 1-pentenyl group, a 2-pentenyl group, a 4-pentenyl group, a 1-hexenyl group, a 1-heptenyl group, a 1-octenyl group, a 1-nonenyl group, a 1-decenyl group, a 1-undecenyl group, a 1-dodecenyl group, etc. Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a biphenyl group, etc. Examples of the substituent of the hydrocarbon group include an acetyl group, an acetoxy group, a methacryloyloxy group, an acryloyloxy group, an alkoxy group having 1 to 6 carbon atoms, a phenoxy group, an alkylamino group having 1 to 6 carbon atoms, a phenylamino group, a halogen atom, etc.)

[0034] Examples of the C1-C4 alkoxy group of A include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, etc. Examples of the C2-C10 alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, a 3-methoxy-n-propoxy group, a 4-methoxyphenoxy group, etc. Examples of the C1-C6 acyloxy group include an acetoxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a benzoyloxy group, etc. Examples of the C2-C6 alkenyloxy group include an isopropenoxy group, a 2-propenoxy group, a 2-butenoxy group, a 3-butenoxy group, etc.

[0035] Specific examples of the silane coupling agent of the general formula (1) are given below. In the following examples, (meth)acryloyl is used to comprehensively represent both acryloyl and methacryloyl. Methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, diethyldiethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, trimethylsilanol, methoxy tripropylsilane, methyltri-n-propoxysilane, dimethoxydiphenylsilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrichlorosilane, diphenyldichlorosilane, diphenyldimethoxysilane, diphenyldiethoxysilane, diethylsilane, methyltris(2-methoxyethoxy)silane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isobutyltrimethoxysilane, n-butyltrimethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, n-decyltriethoxysilane, cyclopentyltrimethoxysilane, cyclohexylethyldimethoxysilane, cyclohexyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltriacetoxysilane, vinyltris(β-methoxyethoxy)silane, p-styryltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, styrylethyltrimethoxysilane, p-tolyltrimethoxysilane, 3-methoxypropyltrimethoxysilane, allyltriethoxysilane, allyltrimethoxysilane, 3-butenyltriethoxysilane, benzyltriethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 6-(meth)acryloyloxyhexyltrimethoxysilane, 6-(meth)acryloyloxyhexyltriethoxysilane, 10-(meth)acryloyloxydecyltrimethoxysilane, 10-(meth)acryloyloxydecyltriethoxysilane, 11-(meth)acryloyloxyundecyltrimethoxysilane, 11-(meth)acryloyloxyundecyltriethoxysilane,3-(Meth)acryloyloxypropylmethyldiethoxysilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, 3-(meth)acryloyloxypropyltris(2-methoxyethoxy)silane, chloromethyltriethoxysilane, chloromethyltrimethoxysilane, chlorophenyltriethoxysilane, 2-chloroethyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, methyl-3,3,3-trifluoropropyldimethoxysilane, 2-chloroethylmethyldimethoxysilane, etc.

[0036] Examples of the organosilazane include the following general formula (2) as described above. General formula (2): R 1 R 2 R 3 -Si-NH-Si-R 4 R 5 R 6 (2) (In the formula, R 1 , R 2 , and R 3 are each independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, and at least one of R 1 , R 2 , and R 3 is a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, and R 4 , R 5 and R 6 are each independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, and at least one of R 4 , R 5 , and R 6 is a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent.)

[0037] R 1 、R 2 、R 3 、R 4 、R 5 、and R 6Examples of the hydrocarbon group having 1 to 6 carbon atoms which may have a substituent include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, vinyl group, allyl group, phenyl group, and the like.

[0038] Specific examples of the organosilazane of the general formula (2) include 1,1,1,3,3,3-hexamethyldisilazane, 1,1,1,3,3,3-hexaethyldisilazane, 1,3-divinyl-1,1,3,3-tetramethyldisilazane, 1,1,1,3,3,3-hexaphenyldisilazane, 1,1,1,3,3,3-hexaisopropyldisilazane, 1,1,1,3,3,3-hexan-propyldisilazane, 1,1,1,3,3,3-hexabutyldisilazane, 1,3-diethyl-1,1,3,3-tetramethyldisilazane, 1,3-diphenyl-1,1,3,3-tetramethyldisilazane, 1,3-dimethyl-1,1,3,3-tetraphenyldisilazane, 1,3-dipropyl-1,1,3,3-tetramethyldisilazane, 1,1,3,3-tetramethyldisilazane, and the like.

[0039] Examples of the titanate coupling agent include tetramethyl titanate, tetraethyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetraisobutyl titanate, butyl titanate dimer, tetra(2-ethylhexyl) titanate, tetraoctyl titanate, tetrastearyl titanate, tetraisostearyl titanate, isopropyltriisostearoyl titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylisostearoyl titanate, isopropylisostearyldiacryl titanate, and the like.

[0040] Examples of zirconium coupling agents include zirconium n-butoxide, zirconium n-propoxide, zirconium isopropoxide, zirconium acetylacetonate, zirconium tributoxystearate, zirconium dibutoxybis(acetylacetonate), zirconium tributoxyethyl acetoacetate, zirconium butoxyacetylacetonate bis(ethyl acetoacetate), and the like.

[0041] Examples of aluminate coupling agents include aluminum acetylacetonate, acetoalkoxyaluminum diisopropylate, diisopropoxyaluminum ethyl acetoacetate, diisopropoxyaluminum alkyl acetoacetate, diisopropoxyaluminum monomethacrylate, and the like.

[0042] The surface treatment method of the acid-reactive glass powder using the hydrophobic surface treatment agent is not particularly limited, and a known method can be used. For example, while stirring the acid-reactive glass powder in a mixing tank, a hydrophobic surface treatment agent diluted with an appropriate solvent is sprayed, mixed in the tank, and then heat-treated; in a slurry in which the acid-reactive glass powder is dispersed in an appropriate solvent, the hydrophobic surface treatment agent is dissolved, mixed, and then the solvent is distilled off and heat-treated, or spray-dried; in a slurry in which the acid-reactive glass powder is dispersed in an appropriate solvent, the hydrophobic surface treatment agent is dissolved, refluxed, and then the solvent is distilled off and heat-treated, and the like. Incidentally, if necessary, the hydrophobic surface treatment agent can also be used after being hydrolyzed in advance in water or a solvent containing water with an acid catalyst or the like added arbitrarily. Also, in any surface treatment method, the temperature during heat treatment is not particularly limited, but a range of 50 to 200°C is preferable, and a range of 100 to 150°C is more preferable.

[0043] The (a) hydrophobic acid-reactive glass powder of the dental glass ionomer cement composition may be hydrophobically treated with 0.05 to 3.0 parts by mass of the hydrophobic surface treatment agent with respect to 100 parts by mass of the acid-reactive glass powder. In such a case, the kneading efficiency and / or mechanical properties are likely to be improved.

[0044] The treatment amount of the hydrophobic surface treatment agent for the acid-reactive glass powder is preferably in the range of 0.05 to 3.0 parts by mass, more preferably in the range of 0.1 to 1.5 parts by mass, and even more preferably in the range of 0.2 to 1.0 parts by mass, based on 100 parts by mass of the acid-reactive glass powder. When the treatment amount of the hydrophobic surface treatment agent is less than 0.05 parts by mass based on 100 parts by mass of the acid-reactive glass powder, the kneading efficiency of the powder material and the liquid material may not be improved in mechanical kneading, resulting in insufficient kneading and a decrease in mechanical properties. On the other hand, when the treatment amount of the hydrophobic surface treatment agent exceeds 3.0 parts by mass, the acid-base reaction with (b) polyalkenoic acid may be inhibited, and the mechanical properties may decrease.

[0045] In addition, in order to adjust the workability, curing characteristics, mechanical properties, etc. of the dental glass ionomer cement composition of the present invention, within a range that does not adversely affect the acid-base reaction with (b) polyalkenoic acid, as an optional treatment for the acid-reactive glass powder, a surface treatment using a surface treatment agent different from that used in the production of the (a) hydrophobic acid-reactive glass powder (hereinafter referred to as other surface treatment agent), heat treatment, or aggregation treatment in a liquid phase or a gas phase, etc., can be carried out in combination with the surface treatment during the production of the (a) hydrophobic acid-reactive glass powder without any problem. These optional treatments can be carried out alone or in combination of several types, and the order of performing each treatment is not particularly limited. Among these, surface treatment or heat treatment using other surface treatment agents is preferred because various properties can be easily controlled and productivity is also excellent.

[0046] Specific examples of any surface treatment of the acid-reactive glass powder using other surface treatment agents include washing with an acid such as phosphoric acid or acetic acid, surface treatment with an acidic compound such as tartaric acid or a polycarboxylic acid, surface treatment with a fluoride such as aluminum fluoride, and surface treatment with a silane compound such as tetramethoxysilane, tetraethoxysilane, a partially hydrolyzed oligomer of tetramethoxysilane, or a partially hydrolyzed oligomer of tetraethoxysilane. The surface treatment methods that can be used in the present invention are not limited to those described above, and these surface treatment methods can be used alone or in combination.

[0047] Specific examples of the heat treatment method of the acid-reactive glass powder include a treatment method of heating at 200°C to 800°C for 1 hour to 72 hours using an electric furnace or the like. The heat treatment method that can be used in the present invention is not limited to those described above, and single treatment or multi-stage treatment is possible for the treatment process.

[0048] The dental glass ionomer cement composition of the present invention (a) Hydrophobized acid-reactive glass powder: 54.5 to 80.0% by mass, (b) Polyalkenoic acid: 5.8 to 27.3% by mass, and (c) Water: 7.6 to 27.3% by mass may be included. In such a case, the kneading efficiency and / or mechanical properties are likely to be improved.

[0049] (a) The hydrophobized acid-reactive glass powder is preferably contained in an amount of 54.5 to 80.0% by mass based on the total amount of the dental glass ionomer cement composition of the present invention. When the content of (a) the hydrophobized acid-reactive glass powder is less than 54.5% by mass, the mechanical properties may deteriorate. Further, when the content of (a) the hydrophobized acid-reactive glass powder exceeds 80.0% by mass, the operating margin time may be shortened, a uniform kneaded product may not be obtained, and the mechanical properties may deteriorate.

[0050] In addition, in the dental glass ionomer cement composition of the present invention, although not essential for the purpose of adjusting mechanical properties and hardening properties, as long as it does not adversely affect the kneading efficiency in mechanical kneading, an acid-reactive glass powder that has not been surface-treated with a hydrophobizing agent can be included. In this case, the blending ratio of (a) hydrophobized acid-reactive glass powder and acid-reactive glass powder contained in the dental glass ionomer cement composition of the present invention is preferably in the range of 70:30 to 99:1 by mass ratio.

[0051] Further, the dental glass ionomer cement composition of the present invention is composed of a powder material and a liquid material, the powder material and the liquid material are separately packaged in a dental capsule, the powder material contains (a) hydrophobized acid-reactive glass powder, the liquid material contains (c) water, and the powder material and / or the liquid material may contain (b) polyalkenoic acid therein. Such a composition not only easily improves the kneading efficiency and / or mechanical properties without reducing the fluoride sustained release property, but also can be more suitable for actual use (especially for use in a mechanical kneading device).

[0052] The (b) polyalkenoic acid that can be used in the dental glass ionomer cement composition of the present invention can be used without any limitation as long as it is a homopolymer or copolymer of an alkenoic acid having at least one or more carboxy groups in the molecule, such as an unsaturated monocarboxylic acid, an unsaturated dicarboxylic acid, and an unsaturated tricarboxylic acid. Further, there is no problem even if the (b) polyalkenoic acid is a copolymer of a polymerizable monomer having no acidic group in the molecule and an alkenoic acid.

[0053] (b) Examples of the alkene acids that can be used to obtain polyalkenoic acids specifically include acrylic acid, methacrylic acid, 2-chloroacrylic acid, 3-chloroacrylic acid, 2-cyanoacrylic acid, aconitic acid, mesaconic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, glutaconic acid, citraconic acid, utraconic acid, 1-butene-1,2,4-tricarboxylic acid, 3-butene-1,2,3-tricarboxylic acid, etc., but are not limited thereto. Among these, the (b) polyalkenoic acid synthesized using only acrylic acid as a starting material, or the (b) polyalkenoic acid synthesized using two or more kinds such as acrylic acid and maleic acid, acrylic acid and maleic anhydride, acrylic acid and itaconic acid, acrylic acid and 3-butene-1,2,3-tricarboxylic acid as starting materials is preferably used.

[0054] The polymerization method used to obtain various (b) polyalkenoic acids is not particularly limited, and those polymerized by any method such as solution polymerization, suspension polymerization, emulsion polymerization, etc. can be used without any limitation. Also, the polymerization initiator and chain transfer agent used during the synthesis of the polymer may be appropriately selected to obtain the desired polymer. The (b) polyalkenoic acid thus obtained can be used alone or in combination of several kinds.

[0055] The (b) polyalkenoic acid preferably has a weight average molecular weight in the range of 30,000 to 300,000. Here, the weight average molecular weight is the average molecular weight calculated based on the molecular weight distribution measured by gel permeation chromatography. When the weight average molecular weight of the (b) polyalkenoic acid is less than 30,000, the mechanical properties may deteriorate. Also, when the weight average molecular weight of the (b) polyalkenoic acid exceeds 300,000, the operating margin time may become short, or a uniform kneaded product may not be obtained, and the mechanical properties may deteriorate.

[0056] (b) The polyalkenoic acid is preferably contained in an amount of 5.8 to 27.3% by mass based on the entire dental glass ionomer cement composition of the present invention. When the content of (b) the polyalkenoic acid is less than 5.8% by mass, the mechanical properties may deteriorate. Further, when the content of (b) the polyalkenoic acid exceeds 27.3% by mass, the working time may be shortened, a uniform kneaded product may not be obtained, and the mechanical properties may deteriorate.

[0057] The (c) water that can be used in the dental glass ionomer cement composition of the present invention functions as a solvent for dissolving (b) the polyalkenoic acid, diffuses metal ions eluted from (a) the hydrophobized acid-reactive glass powder, and is an essential component for inducing a crosslinking reaction with (b) the polyalkenoic acid.

[0058] (c) The water can be used without any limitation as long as it does not contain impurities that adversely affect the curability and mechanical properties of the dental glass ionomer cement composition of the present invention. That is, any water that can initiate the acid-base reaction of the dental glass ionomer cement can be used without any limitation. For example, distilled water or ion-exchanged water can be used.

[0059] (c) The water is preferably contained in an amount of 7.6 to 27.3% by mass based on the entire dental glass ionomer cement composition of the present invention. When the content of (c) the water is less than 7.6% by mass, the working time may be shortened, a uniform kneaded product may not be obtained, and the mechanical properties may deteriorate. Further, when the content of (c) the water exceeds 27.3% by mass, the mechanical properties may deteriorate.

[0060] Although not essential, the dental glass ionomer cement composition of the present invention may optionally contain an acidic compound for the purpose of adjusting the working time and the setting time. There is no particular limitation on the type of the acidic compound as long as it is an acidic compound. Specific examples of these acidic compounds include carboxylic acid compounds such as tartaric acid, citric acid, maleic acid, fumaric acid, malic acid, aconitic acid, tricarballylic acid, itaconic acid, 1-butene-1,2,4-tricarboxylic acid, 3-butene-1,2,3-tricarboxylic acid, etc., phosphoric acid compounds such as phosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, etc., and metal salts of these acidic compounds, etc., but are not limited thereto. Further, these acidic compounds can be used alone or in combination of several kinds. When an acidic compound is included, it is preferably included in the range of 0.1 to 15% by mass based on the whole dental glass ionomer cement composition of the present invention.

[0061] Furthermore, although not essential, the dental glass ionomer cement composition of the present invention may optionally contain a surfactant for the purpose of adjusting the initial compatibility between the powder material and the liquid material and the consistency of the kneaded product as long as it does not affect various properties. The surfactant that can be used in the dental glass ionomer cement composition of the present invention may be either an ionic surfactant or a nonionic surfactant.

[0062] Specific examples of the ionic surfactant include, as an anionic surfactant, aliphatic carboxylic acid metal salts such as sodium stearate, sulfated aliphatic carboxylic acid metal salts such as sodium dioctyl sulfosuccinate, metal salts of higher alcohol sulfates such as sodium stearyl sulfate, etc. Further, as a cationic surfactant, addition products of higher alkylamines and ethylene oxide, amines made from lower amines, alkyltrimethylammonium salts such as lauryltrimethylammonium chloride, etc. are included. Furthermore, as an amphoteric surfactant, metal salts of higher alkylaminopropionic acids such as sodium stearylaminopropionate, betaines such as lauryldimethylbetaine, etc. are included.

[0063] In addition, examples of nonionic surfactants include polyethylene glycol type, polypropylene glycol type, or polyhydric alcohol type in which ethylene oxide or propylene oxide is added to higher alcohols, alkylphenols, fatty acids, higher aliphatic amines, aliphatic amides, etc., or polyhydric alcohol type in which polyhydric alcohols, diethanolamines, or saccharides are ester-bonded to fatty acids.

[0064] The surfactants described above are not limited to these and can be used without any restrictions. These surfactants can be used alone or in combination of several kinds.

[0065] When a surfactant is included in the dental glass ionomer cement composition of the present invention, the surfactant is preferably included in the range of 0.001 to 5% by mass based on the entire composition.

[0066] Furthermore, the dental glass ionomer cement composition of the present invention may optionally contain a non-acid-reactive powder for the purpose of adjusting workability, mechanical properties, or setting properties, although it is not essential, as long as it does not adversely affect various properties.

[0067] The non-acid-reactive powder that can be used in the dental glass ionomer cement composition of the present invention can be used without particular limitation as long as it does not contain an element that reacts with the acidic group of (b) polyalkenoic acid. Examples of the non-acid-reactive powder include those known as dental filling materials, such as inorganic fillers, organic fillers, and organic-inorganic composite fillers, etc., and these can be used alone or in combination of several kinds. Among them, it is particularly preferable to use an inorganic filler. In addition, the shape of these non-acid-reactive powders is not particularly limited, and they may be of any particle shape such as spherical, needle-shaped, plate-shaped, crushed, scaly, etc., or aggregates thereof, and are not limited thereto. Although there is no particular limitation on the average particle diameter of these non-acid-reactive powders, it is preferably in the range of 0.001 to 30 μm.

[0068] Specific examples of the inorganic filler include, but are not limited to, quartz, amorphous silica, ultrafine silica, various glasses containing no elements reactive with acidic groups (including glass by melting method, synthetic glass by sol-gel method, glass produced by gas-phase reaction, etc.), silicon nitride, silicon carbide, boron carbide, and the like.

[0069] When the non-acid-reactive powder is included in the dental glass ionomer cement composition of the present invention, it is preferably included in the range of 0.001 to 20% by mass based on the whole composition.

[0070] In addition, the dental glass ionomer cement composition of the present invention may optionally contain components such as preservatives, antibacterial agents, coloring agents, fluorescent agents, inorganic fiber materials, organic fiber materials, and other conventionally known additives, although not essential.

[0071] The dental glass ionomer cement composition of the present invention can divide each essential component into a powder material and a liquid material in various combinations as long as (a) the hydrophobized acid-reactive glass powder and (b) the polyalkenoic acid do not coexist in the presence of (c) water. Specifically, examples include a combination of a powder material containing (a) the hydrophobized acid-reactive glass powder, a liquid material containing (b) the polyalkenoic acid, and (c) water, a combination of a powder material containing (a) the hydrophobized acid-reactive glass powder and (b) the polyalkenoic acid, and a liquid material containing (c) water, a combination of a powder material containing (a) the hydrophobized acid-reactive glass powder and (b) the polyalkenoic acid, and a liquid material containing (b) the polyalkenoic acid and (c) water, and the like.

[0072] The powder-liquid ratio in the dental glass ionomer cement composition of the present invention refers to the mass ratio of the powder material to the liquid material (powder material mass / liquid material mass), and although there is no particular limitation, it is preferably in the range of 1.0 / 1.0 to 6.0 / 1.0, and more preferably in the range of 1.2 / 1.0 to 4.0 / 1.0.

[0073] The glass ionomer cement composition for dentistry of the present invention can be used in a wide range of applications in dental treatment, such as pit and fissure sealants, liner (lining) materials, abutment construction materials, etc., in addition to its use as a filling material and a luting material.

Examples

[0074] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. The test methods for evaluating the performance of the glass ionomer cement compositions used in the examples and comparative examples are as follows.

[0075] 〔Preparation of kneaded product〕 <Mechanical kneading> Under the environment of 23°C and 50% humidity, a predetermined amount of powder material and liquid material were filled into a dental capsule. The filling amount of the liquid material was unified to 115 mg, and the filling amount of the powder material was determined according to the powder-liquid ratio set for each example and comparative example. After bringing the liquid material into contact in the dental capsule container, the dental capsule was placed in an automatic kneading device for capsules (manufactured by Ultramat2 / SDI Limited, rotation speed 4000 rpm or more) and kneaded for 10 seconds. The kneaded product was discharged from the nozzle of the dental capsule using a capsule applicator and used for each test. <Manual kneading> Under the environment of 23°C and 50% humidity, an appropriate amount of powder material and liquid material were weighed on a kneading paper according to a predetermined powder-liquid ratio, and then kneaded for about 30 seconds using a plastic spatula and used for each test. In addition, both mechanical kneading and manual kneading were tested with a powder-liquid ratio of 2.2 / 1.0 or more as a filling material and a powder-liquid ratio of less than 2.2 / 1.0 as a luting material.

[0076] 〔Kneadability〕 Under the environment of 23°C and 50% humidity, the kneaded product immediately after kneading was visually confirmed, and the kneadability was evaluated according to the following criteria. In this specification, when the evaluation was ◎ or △, it was judged that the kneadability was good. [Evaluation criteria] ◎: No residual powder material is observed in the kneaded product. △: A small amount of powder material remains in the kneaded product (it is observed that the powder material remaining in the kneaded product is 2% or less of the powder filling amount). ×: A large amount of powder material remains in the kneaded product (it is observed that the powder material remaining in the kneaded product exceeds 2% of the powder filling amount). 〔Compressive strength〕 In accordance with ISO 9917-1:2007, the compressive strength was measured as a mechanical property by the following procedure. In an environment of 23°C and 50% humidity, after filling the kneaded product into a stainless steel mold (cylindrical with an inner diameter of 4 mm and a height of 6 mm), it was left standing in a constant temperature and humidity chamber at 37°C and 100% humidity. After standing for 1 hour, the cured product was removed from the mold and used as a test piece. After immersing the test piece in ion-exchanged water at 37°C for 24 hours from the end of kneading, the compressive strength of the test piece was measured using an Instron universal testing machine (model: 5567A) under the condition of a crosshead speed of 1 mm / min. Also, based on the measurement results of the compressive strength, an evaluation regarding the performance was conducted according to the following evaluation criteria. In this specification, it was determined that both the filling material and the adhering material had good compressive strength (i.e., had high mechanical properties) when the evaluation was ◎~▲. 〔Evaluation〕 - Evaluation criteria - 〔Filling material〕 ◎: The compressive strength is 230 MPa or more. 〇: The compressive strength is 220 MPa or more and less than 230 MPa. △: The compressive strength is 210 MPa or more and less than 220 MPa. ▲: The compressive strength is 200 MPa or more and less than 210 MPa. ×: The compressive strength is less than 200 MPa. 〔Adhering material〕 ◎: The compressive strength is 170 MPa or more. 〇: The compressive strength is 160 MPa or more and less than 170 MPa. △: The compressive strength is 150 MPa or more and less than 160 MPa. ▲: The compressive strength is 140 MPa or more and less than 150 MPa. ×: The compressive strength is less than 140 MPa. 〔Fluorine sustained release〕 In an environment of 23°C and 50% humidity, after filling the kneaded mixture into a stainless steel mold (disc-shaped with an inner diameter of 12 mm and a thickness of 1 mm), it was left standing in a constant temperature and humidity chamber at 37°C and 100% humidity. After standing for 1 hour, the cured product was removed from the mold and immersed in distilled water (5 mL) at 37°C. After immersion for 1 week, the cured product was taken out, and the fluoride ion concentration in the fluoride ion eluate was measured using a fluoride ion composite electrode (Mode196-09: Orion Research Inc.) and an ion meter (Mode1720A: Orion Research Inc.). The measurement of the fluoride ion concentration was carried out after adding 0.5 mL of an ion strength adjuster (TISABIII, Orion Research Inc.) to the fluoride ion eluate. Also, from the measurement results of the fluorine sustained release, an evaluation regarding the performance was carried out according to the following evaluation criteria. In this specification, when the evaluation was ◎~△, it was determined that the fluorine sustained release was excellent. 〔Evaluation〕 - Evaluation criteria - ◎: The fluorine sustained release is 25 ppm or more. 〇: The fluorine sustained release is 20 ppm or more and less than 25 ppm. △: The fluorine sustained release is 15 ppm or more and less than 20 ppm. ×: The fluorine sustained release is less than 15 ppm.

[0077] 〔Comprehensive evaluation〕 As a result of evaluating the above performance, those showing good kneadability, high compressive strength, and excellent fluorine sustained release were judged to have desirable characteristics as a dental glass ionomer cement composition. Specifically, from the evaluation or measurement results of kneadability, compressive strength, and fluorine sustained release, scoring was carried out according to the following evaluation criteria, and a comprehensive evaluation regarding the performance was carried out from the total value. - Evaluation criteria - Each score for the evaluation results of kneadability, compressive strength, and fluorine sustained release ◎: 4 points, 〇: 3 points, △: 2 points, ▲: 1 point, ×: 0 point -Classification of Comprehensive Evaluation- A (Very Good): 12 points B: 11 points C: 10 points D (Good): 9 points E: 8 points F: 7 points G: 6 points H (Somewhat Good): 5 points I (Bad): 4 points or less, or including one or more × in the evaluation of each test.

[0078] The manufacturing methods of the dental glass ionomer cement compositions used in the examples and comparative examples are shown below.

[0079] [Manufacture of Acid-Reactive Glass Powder] [Manufacture of Acid-Reactive Glass Powder 1 (G1)] After mixing at a ratio of 23% by mass of silica, 8% by mass of aluminum oxide, 13% by mass of aluminum phosphate, 14% by mass of aluminum fluoride, and 42% by mass of strontium carbonate, it was melted, and the melt was rapidly cooled in water to obtain glass. The obtained glass was pulverized to obtain acid-reactive glass powder 1 (G1). As a result of measuring the 50% particle size (D50) of this acid-reactive glass powder with a laser diffraction particle size analyzer (Microtrac MT3300EXII: manufactured by Microtrac Bell Co., Ltd.), it was 4.7 μm.

[0080] [Manufacture of Acid-Reactive Glass Powders 2 to 8 (G2 to G8)] It was manufactured in the same manner as acid-reactive glass powder 1 (G1), except that the pulverization time was changed to adjust to the 50% particle size (D50) shown in Table 1.

[0081]

Table 1

[0082] [(a) Manufacture of Hydrophobized Acid-Reactive Glass Powder] [Manufacture of Hydrophobized Acid-Reactive Glass Powder 1 (TG1)] 0.3 g of γ-methacryloyloxypropyltrimethoxysilane, 0.1 g of ion-exchanged water, and 8.8 g of absolute ethanol were mixed to prepare a surface treatment liquid (total mass: 9.2 g). After mixing this surface treatment liquid with 100 g of acid-reactive glass powder 1 (G1) in a dry manner, heat treatment was performed at 110 °C for 5 hours using a hot air dryer to obtain hydrophobized acid-reactive glass powder 1 (TG1).

[0083] [Production of Hydrophobized Acid-Reactive Glass Powders 2 to 18 (TG2 to TG18)] Except for changing the acid-reactive glass powder, surface treatment agent, and their treatment amounts shown in Tables 2 and 3, they were produced in the same manner as hydrophobized acid-reactive glass powder 1 (TG1). The surface treatment liquids used for producing each hydrophobized acid-reactive glass powder were prepared as follows. That is, for each amount of the surface treatment agent shown in Tables 2 and 3, ion-exchanged water was added so that the mass ratio of the surface treatment agent to ion-exchanged water was 3:1, and further absolute ethanol was added so that the total mass became 9.2 g in the same manner as the surface treatment liquid used for producing hydrophobized acid-reactive glass powder 1 (TG1), and each surface treatment liquid was prepared by mixing.

[0084]

Table 2

[0085]

Table 3

[0086] [(b) Polyalkenoic Acid] PCA1: Acrylic acid-tricarboxylic acid copolymer powder (weight average molecular weight: 80,000) PCA2: Acrylic acid homopolymer powder (weight average molecular weight: 100,000) [(c) Water] IEW: Ion-exchanged water [Other Components] TA: Tartaric acid

[0087] [Preparation of Powder Materials and Liquid Materials] The compositions of powder materials P1 to P22 are shown in Tables 4 and 5. For powder materials P1 to P14 and P16 to P22, (a) hydrophobic acid-reactive glass powder shown in Tables 4 and 5 was used as is. Powder material P15 was prepared by mixing the components in the proportions shown in Table 5. Liquid materials L1 to L4 were prepared by mixing the components in the proportions shown in Table 6.

[0088] [Table 4]

[0089] [Table 5]

[0090] [Table 6]

[0091] The powder and liquid materials were mixed in the combinations, powder-liquid ratios, and mixing methods shown in the Examples and Comparative Examples in Tables 7 to 10 to produce dental glass ionomer cement compositions (Examples 1 to 28, Comparative Examples 1 to 5). The mixability, compressive strength, and fluoride release were evaluated according to the methods described above. The results are shown in Tables 7 to 10.

[0092] [Table 7]

[0093] [Table 8]

[0094] [Table 9]

[0095] [Table 10]

[0096] <Example 1> Example 1 showed good workability in mechanical kneading and had high compressive strength. Furthermore, it also showed excellent fluoride sustained release property and had desirable properties as a dental glass ionomer cement. <Examples 2 to 28> The outlines of the compositions of Examples 2 to 28 are as follows. Example 2: A composition with a higher powder-liquid ratio than that of Example 1 Examples 3 to 4, 11, 15 to 21, 24, 27 and 28: Compositions in which the particle size of the acid-reactive glass powder, the treatment amount of the hydrophobic surface treatment agent, and the powder-liquid ratio were changed from those of Example 1 Examples 5 to 7: Compositions in which the type of the hydrophobic surface treatment agent was changed from that of Example 1 Examples 8 to 9, 13 to 14, 22 to 23, 25 and 26: Compositions using liquid materials with different polyalkenoic acid concentrations Example 10: A composition in which the type of (b) polyalkenoic acid was changed from that of Example 1 Example 12: A composition in which (b) polyalkenoic acid was blended into the powder material of Example 1 As a result of evaluating Examples 2 to 28, all of them showed good workability in mechanical kneading and had high compressive strength. Furthermore, they also showed excellent fluoride sustained release property and had desirable properties as a dental glass ionomer cement.

[0097] <Comparative Example 1> Comparative Example 1 is a composition in which an acid-reactive glass powder having the same particle size and without surface treatment was blended instead of the (a) hydrophobic acid-reactive glass powder [50% particle size (D50): 4.7 μm, treatment amount: 0.30 parts by mass] of Example 1. As a result of evaluating Comparative Example 1, the workability was poor in mechanical kneading and the compressive strength was low. <Comparative Example 2> Comparative Example 2 is a composition obtained by manually kneading Example 1. As a result of evaluating Comparative Example 2, the powder material and the liquid material were not easily compatible, and the kneading efficiency was poor, so it was not suitable for manual kneading. Furthermore, the compressive strength was low. <Comparative Example 3> Comparative Example 3 is a composition in which, instead of the (a) hydrophobized acid-reactive glass powder [50% particle size (D50): 0.5 μm, treatment amount: 1.00 part by mass] of Example 18, an acid-reactive glass powder having the same particle size and not subjected to surface treatment is blended. As a result of evaluating Comparative Example 3, the kneadability was poor in mechanical kneading and the compressive strength was low. <Comparative Example 4> Comparative Example 4 is a composition in which, instead of the (a) hydrophobized acid-reactive glass powder [50% particle size (D50): 15.0 μm, treatment amount: 0.05 part by mass] of Example 3, an acid-reactive glass powder having the same particle size and not subjected to surface treatment is blended. As a result of evaluating Comparative Example 4, the kneadability was poor in mechanical kneading and the compressive strength was low. <Comparative Example 5> Comparative Example 5 is a composition in which, instead of the (a) hydrophobized acid-reactive glass powder (hydrophobizing surface treatment agent: γ-methacryloyloxypropyltrimethoxysilane) of Example 1, an acid-reactive glass subjected to hydrophilic surface treatment using γ-aminopropyltrimethoxysilane as a surface treatment agent is blended. As a result of evaluating Comparative Example 5, the kneadability was poor in mechanical kneading and the compressive strength was low.

Claims

1. A dental glass ionomer cement composition that is mechanically kneaded using a kneading device for capsules, comprising: (a) a hydrophobized acid-reactive glass powder, (b) a polyalkenoic acid, and (c) water and being a dental glass ionomer cement composition that does not involve a polymerization reaction during curing.

2. The dental glass ionomer cement composition according to Claim 1, wherein the (a) hydrophobized acid-reactive glass powder is obtained by hydrophobizing an acid-reactive glass powder having a 50% particle diameter (D50) of 0.5 to 15 μm in the volume-based cumulative particle size distribution with a hydrophobizing surface treatment agent.

3. The hydrophobizing surface treatment agent is the following general formula (1): R ｎ SiA ４－ｎ (1) (In the formula, R is a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, A is an alkoxy group having 1 to 4 carbon atoms, an alkoxyalkoxy group having 2 to 10 carbon atoms, an acyloxy group having 1 to 6 carbon atoms, an alkenyloxy group having 2 to 6 carbon atoms, a halogen atom, an isocyanate group, a hydroxy group, or a hydrogen atom, and n is an integer of 1 to 3. However, a plurality of Rs and As may be the same as or different from each other.) a silane coupling agent represented by, and the following general formula (2): R １ R ２ R ３ -Si-NH-Si-R ４ R ５ R ６ (2) (wherein R １ , R ２ , and R ３ are each independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, and at least one of R １ , R ２ , and R ３ is a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, and R ４ , R ５ and R ６ are each independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, and at least one of R ４ , R ５ , and R ６ is a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent.) The dental glass ionomer cement composition according to Claim 2, which is at least one hydrophobizing surface treatment agent selected from the group consisting of organosilazanes represented by.

4. (a) 54.5 to 80.0% by mass of hydrophobized acid-reactive glass powder, (b) 5.8 to 27.3% by mass of polyalkenoic acid, and (c) 7.6 to 27.3% by mass of water The dental glass ionomer cement composition according to any one of Claims 1 to 3, comprising.

5. The dental glass ionomer cement composition according to any one of Claims 1 to 4, wherein the (a) hydrophobized acid-reactive glass powder is obtained by hydrophobizing 100 parts by mass of the acid-reactive glass powder with 0.05 to 3.0 parts by mass of the hydrophobizing surface treatment agent.

6. Composed of a powder material and a liquid material, the powder material and the liquid material are separately packaged in a dental capsule, the powder material contains (a) hydrophobized acid-reactive glass powder, the liquid material contains (c) water, and the powder material and / or the liquid material contains (b) polyalkenoic acid The dental glass ionomer cement composition according to any one of Claims 1 to 5, comprising.

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