Dental glass ionomer cement composition containing chitosan and method for producing the same

Abstract

To provide a dental glass ionomer cement composition that stably exhibits high mechanical properties without adversely affecting mixing properties or working time, and to provide a method for producing the same.SOLUTION: A two-component dental glass ionomer cement composition comprises: (a) chitosan 0.01 mass% or more and 1.5 mass% or less, (b) acid-reactive glass powder 30 mass% or more and 75 mass% or less, (c) polyalkenoic acid 5 mass% or more and 30 mass% or less, (d) water 10 mass% or more and 35 mass% or less, (e) tartaric acid, and (f) one or more acidic compounds selected from the group consisting of water-soluble polycarboxylic acid compounds other than tartaric acid and water-soluble ascorbic acid compounds, the total content of (e) tartaric acid and (f) acidic compounds being 1 mass% or more and 10 mass% or less of the total composition, the mass ratio of the content of (e) tartaric acid to the content of (f) acidic compounds ((e) tartaric acid / (f) acidic compounds) being 0.01 or more and 99 or less, and at least one of the two components comprising (a) chitosan, (d) water, and one or more compounds selected from the group consisting of (e) tartaric acid and (f) acidic compounds.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a dental glass ionomer cement composition such as a glass ionomer cement for dental fillings or a glass ionomer cement for dental luting, and a method for producing the same. [Background technology]

[0002] In clinical dentistry, direct restoration, in which filling materials are placed in the teeth, and indirect restoration, in which dental prostheses are attached and / or bonded to the teeth using adhesive materials, are performed to restore the aesthetic and functional appearance of teeth that have been partially damaged by caries, fractures, etc. Dental glass ionomer cement is one of the most common filling and adhesive materials, and its greatest feature is its sustained release of fluoride ions, which strengthens tooth structure and inhibits secondary caries.

[0003] Dental glass ionomer cement is mainly composed of acid-reactive glass powder, such as fluoroaluminosilicate glass powder, polyalkenoic acid, and water. In the presence of water, acidic compounds such as polyalkenoic acid react with the acid-reactive glass powder, converting it into polyvalent metal ions (Al 3+ , Ca 2+ , Sr 2+ The polyalkenoic acid is hardened by ionic bonding between the eluted polyvalent metal ions and the acidic groups of the polyalkenoic acid, forming a crosslinked structure between the polyalkenoic acids via the polyvalent metal ions. Furthermore, a technique for delaying the hardening reaction and increasing the working time by adding tartaric acid to the main components of dental glass ionomer cement is known in the art (Patent Document 1).

[0004] Meanwhile, various studies have been conducted to further improve the mechanical properties of dental glass ionomer cements. For example, Patent Document 2 discloses a technique for improving the mechanical properties by adding polysaccharide nanofibers to the powder or liquid material of a dental glass ionomer cement composition. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. WO2014 / 050924 [Patent Document 1] Japanese Patent Publication No. 2022-018774 Summary of the Invention [Problem to be solved by the invention]

[0006] In general, the mechanical properties of dental glass ionomer cement improve as the proportion of acid-reactive glass powder in the total components increases. Therefore, it is preferable to maintain the mass ratio of powder to liquid during mixing, i.e., the powder-liquid ratio, as high as possible. However, as the powder-liquid ratio increases, the viscosity of the mixture increases, resulting in an insufficient mixture and an inhomogeneous mixture, which may actually lead to a deterioration in the mechanical properties of the set product. Another effect of increasing the powder-liquid ratio is that the working time (the time during which the mixture can undergo plastic deformation) becomes too short. This can lead to the mixture hardening during the process, especially when treating multiple teeth at once, which requires a long treatment time. Because of these adverse effects on mixing and working time, there is a certain limit to how high the powder-liquid ratio can be.

[0007] Furthermore, while the technology disclosed in Patent Document 2 can improve the mechanical properties of dental glass ionomer cement compositions without increasing the powder-liquid ratio, polysaccharide nanofibers have a tendency to aggregate very easily. Therefore, when polysaccharide nanofibers are added to the powder material of dental glass ionomer cement, the nanofibers aggregate over time, and the effect of improving the mechanical properties may gradually be lost. Furthermore, when polysaccharide nanofibers are added to the liquid material of dental glass ionomer cement, the nanofibers settle over time, which requires shaking the liquid material immediately before use, making the process complicated. Furthermore, if the liquid material is not shaken sufficiently, the effect of improving the mechanical properties may not be fully achieved.

[0008] Therefore, an object of the present invention is to provide a dental glass ionomer cement composition that stably exhibits high mechanical properties without adversely affecting mixing properties or working time, and a method for producing the same. [Means for solving the problem]

[0009] As a result of intensive research conducted by the inventors to address these challenges, they discovered that by blending chitosan and a specific acidic compound in addition to the main components of conventional dental glass ionomer cement compositions, namely, acid-reactive glass powder, polyalkenoic acid, water, and tartaric acid, and by incorporating each component in a specific ratio and by blending the chitosan in a state of being pre-dissolved in water, the mechanical properties can be specifically improved without adversely affecting the kneading properties, working time, etc., and have completed the present invention.

[0010] That is, the above problem can be solved by using the following component composition. (a) chitosan 0.01% by mass or more and 1.5% by mass or less; (b) acid-reactive glass powder: 30% by mass or more and 75% by mass or less; (c) polyalkenoic acid 5% by mass or more and 30% by mass or less, (d) Water 10% by mass or more and 35% by mass or less, (e) tartaric acid, and (f) one or more acidic compounds selected from the group consisting of water-soluble polycarboxylic acid compounds other than tartaric acid and water-soluble ascorbic acid compounds; A two-component dental glass ionomer cement composition comprising: the total content of the (e) tartaric acid and the (f) acidic compound is 1% by mass or more and 10% by mass or less based on the total mass of the composition; the mass ratio of the content of the (e) tartaric acid to the content of the (f) acidic compound ((e) tartaric acid / (f) acidic compound) is 0.01 or more and 99 or less, and A dental glass ionomer cement composition, characterized in that at least one of the two components contains (a) chitosan, (d) water, and one or more compounds selected from the group consisting of (e) tartaric acid and (f) acidic compounds.

[0011] The dental glass ionomer cement composition of the present invention can be produced, for example, by the following method. The dental glass ionomer cement composition comprises: a first agent containing the (a) chitosan, the (c) polyalkenoic acid, the (d) water, and at least one of the (e) tartaric acid and the (f) acidic compound; and (b) a second agent containing an acid-reactive glass powder, When the second agent contains the (d) water, it does not contain the (c) polyalkenoic acid, the (e) tartaric acid, or the (f) acidic compound; a step of mixing the (a) chitosan, a part or all of the (d) water, and a part or all of the (e) tartaric acid and / or the (f) acidic compound to produce a mixed solution; A method for producing a dental glass ionomer cement composition, comprising the step of producing the first agent by mixing the mixed liquid with the remaining components of the first agent that were not mixed in the step of producing the mixed liquid. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a dental glass ionomer cement composition that has good mixing properties, sufficient working time, and stably exhibits high mechanical properties. DETAILED DESCRIPTION OF THE INVENTION

[0013] In the present invention, the (f) acidic compound may be one or more selected from the group consisting of citric acid, malic acid, maleic acid, malonic acid, ascorbic acid, isoascorbic acid, fumaric acid, and aconitic acid.

[0014] In the present invention, the (f) acidic compound may be citric acid and / or malic acid.

[0015] In the present invention, the composition may be substantially free of inorganic acids and monocarboxylic acids.

[0016] In the present invention, the dental glass ionomer cement composition comprises: a first agent containing the (a) chitosan, the (c) polyalkenoic acid, the (d) water, and at least one of the (e) tartaric acid and the (f) acidic compound; and (b) a second agent containing an acid-reactive glass powder, When the second agent contains (d) water, it may be free of (c) polyalkenoic acid, (e) tartaric acid, and (f) acidic compound.

[0017] The present invention will be described in detail below. As used herein, the term "dental glass ionomer cement" refers to a dental glass ionomer cement that does not contain compounds having polymerizable groups, such as polymerizable monomers, oligomers having polymerizable groups, and / or polymers having polymerizable groups, for the purpose of imparting hardening properties through a polymerization reaction, and that hardens primarily through an acid-base reaction that occurs between an acid-reactive glass powder and a polyalkenoic acid in the presence of water.

[0018] As used herein, the term "polyalkenoic acid" refers to a polymer containing an ethylenically unsaturated monomer unit having an acidic group. Furthermore, as used herein, "(meth)acrylate" refers to both acrylate and methacrylate, and "(meth)acryloyl" refers to both acryloyl and methacryloyl.

[0019] In this specification, the term "polycarboxylic acid compound" refers to a compound having two or more carboxy groups in the molecule, and includes acid anhydrides. Note that (c) polyalkenoic acids are not included in the polycarboxylic acid compound.

[0020] As used herein, "water-soluble" means that the solubility in water at 20°C is 0.4 g / 100 mL or more.

[0021] In this specification, "a state in which (a) chitosan is pre-dissolved in (d) water" may mean that the dental glass ionomer cement composition of the present invention is provided in a two-component form, such as powder / liquid or paste / paste, and is used by mixing the two components immediately before use, and that (a) chitosan is completely dissolved in (d) water at the stage of the two components before mixing.

[0022] The dental glass ionomer cement composition of the present invention contains (a) chitosan, (b) acid-reactive glass powder, (c) polyalkenoic acid, (d) water, (e) tartaric acid, and (f) an acidic compound selected from the group consisting of water-soluble polycarboxylic acid compounds other than tartaric acid and water-soluble ascorbic acid compounds, in specific proportions. By using this component composition and dissolving (a) chitosan in (d) water in advance, the composition exhibits good kneading properties, sufficient working time, and high mechanical properties. Each component used in the present invention will be described in detail below.

[0023] <(a) Chitosan> (a) Chitosan, which can be used in the dental glass ionomer cement composition of the present invention, is one of the components that contributes to improving mechanical properties, and this effect is achieved by being included in the composition in a state where it is pre-dissolved in (d) water. Note that (a) Chitosan alone does not dissolve in (d) water, but it can be dissolved in (d) water by coexisting with (e) tartaric acid and / or (f) an acidic compound. (a) Chitosan is a polysaccharide whose basic structure is β-1,4-linked D-glucosamine, and it may also contain β-1,4-linked N-acetyl-D-glucosamine.

[0024] The origin of (a) chitosan is not particularly limited, but suitable examples include deacetylated chitin (β-1,4-poly-N-acetyl-D-glucosamine) obtained by removing calcium and proteins from the shells of crustaceans such as shrimp, crab, and krill. The degree of deacetylation from chitin is preferably 60% or higher, more preferably 75% or higher, and most preferably 90% or higher. A higher degree of deacetylation from chitin makes (a) chitosan more soluble in (d) water in the presence of (f) an acidic compound.

[0025] (a) The molecular weight of chitosan is not particularly limited, but the molecular weight is preferably such that the viscosity (20°C) of an aqueous acetic acid solution containing 0.5% by mass of chitosan (acetic acid concentration 0.5% by mass) measured using a B-type viscometer is 1 mPa·s or more and 650 mPa·s or less, more preferably 1 mPa·s or more and 450 mPa·s or less, and even more preferably 1 mPa·s or more and 250 mPa·s or less. If the viscosity is less than 1 mPa·s, the effect of improving mechanical properties may not be obtained. If the viscosity exceeds 650 mPa·s, the viscosity of the kneaded product increases, which may adversely affect operability.

[0026] Furthermore, (a) chitosan may be one in which some of the hydroxyl and / or amino groups contained in the molecule have been modified by carboxylation, tosylation, sulfation, phosphate, etc., or one in which some of the hydroxyl and / or amino groups have been substituted with hydroxyalkyl groups, etc., so long as the effect of improving the mechanical properties of the dental glass ionomer cement composition of the present invention is not impaired. The above-mentioned (a) chitosans may be used alone or in combination of several types.

[0027] The content of (a) chitosan must be between 0.01% and 1.5% by mass based on the total dental glass ionomer cement composition of the present invention. If the content of (a) chitosan is less than 0.01% by mass, the improvement in mechanical properties is not achieved. Furthermore, if the content of (a) chitosan exceeds 1.5% by mass, the mechanical properties are reduced. (d) Chitosan may be present in the dental glass ionomer cement composition of the present invention in a state undissolved in water, provided that it does not adversely affect the properties. In this case, it is not included in the content. (d) The amount of chitosan undissolved in water can be determined by dispersing other solid components, such as acid-reactive glass powder, in water, separating the chitosan from the other solid components using a gravity separation method, and then isolating the chitosan by centrifugation, filtration, and drying. (e) If no other solid components are present, the amount can be determined by isolating the chitosan by centrifugation, filtration, and drying. When dissolved chitosan coexists with solid components, the solid components are removed by centrifugation and filtration, and then the solution containing chitosan is neutralized with an aqueous sodium hydroxide solution or the like to precipitate chitosan, which is then isolated by centrifugation, filtration, and drying, allowing for quantitative determination.

[0028] <(b) Acid-reactive glass powder> The (b) acid-reactive glass powder that can be used in the dental glass ionomer cement composition of the present invention is a component that contributes to the hardening of the composition and must contain an acid-reactive element such as a metal element and fluorine. The (b) acid-reactive glass powder contains an acid-reactive element, which, in the presence of (d) water, undergoes an acid-base reaction with the acidic group of (c) the polyalkenoic acid. Specific examples of acid-reactive elements include, but are not limited to, sodium, potassium, calcium, strontium, barium, lanthanum, aluminum, and zinc. One or more of these acid-reactive elements may be present, and the amount of each element is not particularly limited.

[0029] Furthermore, in order to impart radiopacity to the dental glass ionomer cement composition of the present invention, it is preferable that the (a) acid-reactive glass powder contain a radiopaque element. Specific examples of radiopaque elements include, but are not limited to, strontium, lanthanum, zirconium, titanium, yttrium, ytterbium, tantalum, tin, tellurium, tungsten, and bismuth. Furthermore, there are no particular limitations on the other elements contained in the (b) acid-reactive glass powder, and the (b) acid-reactive glass powder of the present invention can contain a variety of elements.

[0030] (b) Examples of acid-reactive glass powders include, but are not limited to, aluminosilicate glass, borosilicate glass, aluminoborate glass, boroaluminosilicate glass, phosphate glass, borate glass, and silicate glass containing the above-mentioned acid-reactive elements, fluorine, and radiopaque elements.

[0031] Furthermore, the particle shape of the (b) acid-reactive glass powder is not particularly limited, and any particle shape such as spherical, needle-like, plate-like, crushed, scale-like, etc. can be used without any limitation. These (b) acid-reactive glass powders can be used alone or in combination of several kinds.

[0032] The method for producing these (b) acid-reactive glass powders is not particularly limited, and any of the methods such as a melting method, a vapor phase method, and a sol-gel method can be used without any problems. Among these, it is preferable to use the (b) acid-reactive glass powder produced by the melting method or the sol-gel method, which allows for easy control of the type and content of elements.

[0033] (b) The acid-reactive glass powder can be used after being pulverized to a desired particle size. The pulverization method is not particularly limited, and either wet or dry pulverization can be used. Specifically, the raw glass can be pulverized using a high-speed rotary mill such as a hammer mill or turbo mill, a container-driven mill such as a ball mill, planetary mill, or vibration mill, a media-agitating mill such as an attritor or bead mill, or a jet mill, and the particle size can be appropriately adjusted depending on the desired properties to be imparted to the dental glass ionomer cement composition of the present invention.

[0034] The 50% particle size (D50) of the (b) acid-reactive glass powder used in the dental glass ionomer cement composition of the present invention is preferably 0.5 μm or more and 20 μm or less, and more preferably 0.5 μm or more and 10 μm or less. Here, the 50% particle size (D50) refers to the particle size at which the cumulative value from the small particle size side reaches 50% in a volume-based particle size distribution measured using a laser diffraction / scattering particle size distribution analyzer or the like. The dental glass ionomer cement composition of the present invention may contain only acid-reactive glass powder having a 50% particle size (D50) of 0.5 μm or more and 20 μm or less as the (b) acid-reactive glass powder.

[0035] (b) If the 50% particle size (D50) of the acid-reactive glass powder is less than 0.5 μm, its surface area increases, making it impossible to incorporate a large amount into the composition, which may result in reduced mechanical properties. Furthermore, the working time may be significantly shortened. (b) If the 50% particle size (D50) of the acid-reactive glass powder is greater than 20 μm, the mechanical properties may be reduced. Furthermore, when used as a filling material, the material surface may become rough after polishing, which may lead to increased discoloration in the oral cavity. When used as a bonding material, the coating thickness may increase, causing the bonded and / or adhered dental prosthetic device to lift, resulting in the dental prosthetic device not fitting as intended.

[0036] In order to adjust the handling, hardening characteristics, mechanical properties, etc. of the dental glass ionomer cement composition of the present invention, (b) the acid-reactive glass powder can be subjected to various surface treatments, heat treatments, or aggregation treatments in a liquid phase or a gas phase, etc., within a range that does not adversely affect the acid-base reaction with (c) the polyalkenoic acid. These treatments can be performed alone or in combination, and the order in which each treatment is performed is not particularly limited. Among these, surface treatments and heat treatments are preferred because they allow for easy control of various properties and are also highly productive.

[0037] Specific examples of surface treatments for the (b) acid-reactive glass powder 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 (meth)acryloyloxymethyltrimethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 8-(meth)acryloyloxyoctyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, a partially hydrolyzed oligomer of tetramethoxysilane, and a partially hydrolyzed oligomer of tetraethoxysilane. The surface treatments that can be used in the present invention are not limited to those described above, and these surface treatments can be used alone or in combination. Furthermore, the amount of surface treatment agent relative to the (b) acid-reactive glass powder during surface treatment is not particularly limited; it can be appropriately adjusted depending on the particle size and desired properties of the (b) acid-reactive glass powder.

[0038] (b) A specific example of the heat treatment of the acid-reactive glass powder is a treatment method in which the powder is heated at 200°C to 800°C for 1 hour to 72 hours using an electric furnace or the like. The heat treatments that can be used in the present invention are not limited to those described above, and the treatment process can also be a treatment at a single temperature or a multi-stage treatment at multiple temperatures.

[0039] The (b) acid-reactive glass powder must be contained in an amount of 30% by mass to 75% by mass, more preferably 40% by mass to 75% by mass, and even more preferably 50% by mass to 75% by mass, based on the total dental glass ionomer cement composition of the present invention. If the content of (b) acid-reactive glass powder is less than 30% by mass, the mechanical properties will deteriorate. On the other hand, if the content of (b) acid-reactive glass powder exceeds 75% by mass, the working time will be significantly shortened and the viscosity of the mixed product will increase, resulting in poor mixing properties and other adverse effects on workability.

[0040] <(c) Polyalkenoic Acid> The (c) polyalkenoic acid that can be used in the dental glass ionomer cement composition of the present invention is a component that contributes to the hardening of the composition. The (c) polyalkenoic acid can be any homopolymer or copolymer of an ethylenically unsaturated monomer having at least one carboxy group in the molecule, such as an ethylenically unsaturated monocarboxylic acid, an ethylenically unsaturated dicarboxylic acid, or an ethylenically unsaturated tricarboxylic acid. Furthermore, the (c) polyalkenoic acid may be a copolymer of an ethylenically unsaturated monomer that does not have a carboxy group in the molecule and an ethylenically unsaturated monomer that has a carboxy group. Even in such a copolymer, the ethylenically unsaturated monomer unit having a carboxy group preferably accounts for 60% or more, more preferably 70% or more, and most preferably 80% or more.

[0041] Specific examples of ethylenically unsaturated monomers having a carboxy group that can be used to obtain (c) polyalkenoic acid include, but are not limited to, ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, 2-chloroacrylic acid, 3-chloroacrylic acid, and 2-cyanoacrylic acid, ethylenically unsaturated dicarboxylic acids such as mesaconic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, glutaconic acid, and citraconic acid, and ethylenically unsaturated tricarboxylic acids such as aconitic acid, 1-butene-1,2,4-tricarboxylic acid, and 3-butene-1,2,3-tricarboxylic acid. Among these, it is preferable to use (c) polyalkenoic acid synthesized using only acrylic acid as a starting material, or (c) polyalkenoic acid synthesized using two or more starting materials, such as acrylic acid and maleic acid, acrylic acid and maleic anhydride, acrylic acid and itaconic acid, or acrylic acid and 3-butene-1,2,3-tricarboxylic acid.

[0042] The polymerization method used to obtain various (c) polyalkenoic acids is not particularly limited, and any polymerization method such as solution polymerization, suspension polymerization, or emulsion polymerization can be used without any restrictions. Furthermore, known polymerization initiators and chain transfer agents can be used during polymerization, and the amounts added can be adjusted appropriately depending on the desired properties. The (c) polyalkenoic acids thus obtained can be used alone or in combination.

[0043] The weight-average molecular weight of the (c) polyalkenoic acid is preferably 30,000 or more and 300,000 or less. Here, the weight-average molecular weight is the average molecular weight calculated based on the molecular weight distribution measured by gel permeation chromatography. If the weight-average molecular weight of the (c) polyalkenoic acid is less than 30,000, the mechanical properties may be reduced. On the other hand, if the weight-average molecular weight of the (c) polyalkenoic acid is more than 300,000, the working time may be significantly shortened, or the viscosity of the kneaded product may increase, resulting in poor kneading properties, which may adversely affect workability. The dental glass ionomer cement composition of the present invention may also contain only polyalkenoic acids having a weight-average molecular weight of 30,000 or more and 300,000 or less as the (c) polyalkenoic acid.

[0044] Furthermore, (c) polyalkenoic acid can be used after neutralizing some of its carboxyl groups with a basic compound to adjust the acid-base reactivity with (b) acid-reactive glass powder, as long as it does not adversely affect various properties. Examples of basic compounds that can be used for neutralization include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; alkali metal carbonates such as sodium carbonate, potassium carbonate, and lithium carbonate; and alkali metal bicarbonates such as sodium bicarbonate, potassium bicarbonate, and lithium bicarbonate. Various amine compounds, such as primary amines, secondary amines, and tertiary amines, can also be used without any problems. Suitable amine compounds include triethanolamine, diethanolamine, N-methyldiethanolamine, and 2-dimethylaminoethyl (meth)acrylate.

[0045] The (c) polyalkenoic acid must be contained in an amount of 5% by mass to 30% by mass, and more preferably 10% by mass to 20% by mass, based on the total dental glass ionomer cement composition of the present invention. If the (c) polyalkenoic acid content is less than 5% by mass, the mechanical properties will deteriorate. If the (c) polyalkenoic acid content exceeds 30% by mass, the working time will be significantly shortened and the viscosity of the kneaded product will increase, resulting in poor kneading properties and other adverse effects on workability.

[0046] <(d)Water> (d) Water, which can be used in the dental glass ionomer cement composition of the present invention, functions as a solvent for (a) chitosan, (c) polyalkenoic acid, (e) tartaric acid, and (f) acidic compound, and is also a component that diffuses metal ions eluted from (b) acid-reactive glass powder and induces a crosslinking reaction between (c) polyalkenoic acids.

[0047] (d) Water may be used without any restrictions as long as it does not contain impurities that inhibit the acid-base reaction in the dental glass ionomer cement composition of the present invention or that adversely affect the curing properties or mechanical properties. However, it is preferable to use distilled water or ion-exchanged water.

[0048] (d) Water must be contained in an amount of 10% by mass or more and 35% by mass or less of the total dental glass ionomer cement composition of the present invention, more preferably 10% by mass or more and 30% by mass or less, and even more preferably 15% by mass or more and 25% by mass or less. If the (d) water content is less than 10% by mass, the working time will be significantly shortened, and the viscosity of the kneaded product will increase, resulting in poor kneading, which will have a negative impact on workability. If the (d) water content exceeds 35% by mass, the mechanical properties will be reduced.

[0049] <(e)Tartaric acid> (e) Tartaric acid, which can be used in the dental glass ionomer cement composition of the present invention, is a component that contributes to extending the working time. Furthermore, (e) Tartaric acid has the effect of solubilizing (a) Chitosan in (d) Water, and is one of the components that contributes to improving mechanical properties. (e) Tartaric acid may be any of L-tartaric acid, D-tartaric acid, mesotartaric acid, and DL-tartaric acid. (e) Tartaric acid may also be partially neutralized with a basic compound. The basic compound may be the same as the compound that can be used to neutralize (c) Polyalkenoic Acid.

[0050] <(f) Acidic compounds> The (f) acidic compound that can be used in the dental glass ionomer cement composition of the present invention is a compound selected from the group consisting of water-soluble polycarboxylic acid compounds other than tartaric acid and water-soluble ascorbic acid compounds, and has the effect of solubilizing (a) chitosan in (d) water and is one of the components that contributes to improving mechanical properties. It is not a problem if the (f) acidic compound is partially neutralized with a basic compound. The basic compound can be the same as the compound that can be used to neutralize the (c) polyalkenoic acid.

[0051] (f) Acidic compounds include, but are not limited to, oxalic acid, citric acid, malic acid, maleic acid, malonic acid, ascorbic acid, isoascorbic acid, fumaric acid, aconitic acid, tricarballylic acid, mesaconic acid, itaconic acid, glutaric acid, oxaloacetic acid, etc. These (f) acidic compounds may be used alone or in combination.

[0052] Among these, it is preferable to use one or more of the acidic compounds (f) selected from the group consisting of citric acid, malic acid, maleic acid, malonic acid, ascorbic acid, isoascorbic acid, fumaric acid, and aconitic acid, and it is more preferable to use citric acid and / or malic acid.

[0053] The total content of (e) tartaric acid and (f) acidic compound should be 1% by mass or more and 10% by mass or less, and preferably 2% by mass or more and 8% by mass or less, based on the total dental glass ionomer cement composition of the present invention. If the total content is less than 1% by mass, the effect of improving mechanical properties cannot be obtained. On the other hand, if the total content exceeds 10% by mass, the mechanical properties will be reduced.

[0054] Furthermore, the mass ratio of the content of (e) tartaric acid to the content of (f) acidic compound in the dental glass ionomer cement composition of the present invention ((e) tartaric acid / (f) acidic compound) must be between 0.01 and 99. If the mass ratio ((e) tartaric acid / (f) acidic compound) is outside this range, the mechanical improvement effect cannot be sufficiently obtained.

[0055] It is preferable that the dental glass ionomer cement composition of the present invention be substantially free of inorganic acids such as hydrochloric acid and phosphoric acid, and monocarboxylic acids such as acetic acid and lactic acid. In this specification, "substantially free of inorganic acids and monocarboxylic acids" means that inorganic acids and / or monocarboxylic acids are not intentionally incorporated into the composition. This definition also applies to compositions containing small amounts of inorganic acids and / or monocarboxylic acids as impurities or additives. Even in cases where inorganic acids and / or monocarboxylic acids are unintentionally incorporated into the composition, the content of inorganic acids and / or monocarboxylic acids is preferably 0.5% by mass or less relative to the total dental glass ionomer cement composition of the present invention. The inclusion of inorganic acids and / or monocarboxylic acids in the dental glass ionomer cement composition of the present invention may result in reduced mechanical properties.

[0056] <Other ingredients> The dental glass ionomer cement composition of the present invention can optionally contain a surfactant to adjust the initial compatibility of the first and second parts and the properties of the kneaded product, as long as the surfactant does not affect the 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.

[0057] Specific examples of ionic surfactants include anionic surfactants such as metal salts of aliphatic carboxylic acids (e.g., sodium stearate), sulfated metal salts of aliphatic carboxylic acids (e.g., sodium dioctyl sulfosuccinate), and metal salts of higher alcohol sulfates (e.g., sodium stearyl sulfate). Cationic surfactants include adducts of higher alkylamines and ethylene oxide, amines prepared from lower amines, and alkyltrimethylammonium salts (e.g., lauryltrimethylammonium chloride). Amphoteric surfactants include metal salts of higher alkylaminopropionic acids (e.g., sodium stearylaminopropionate), and betaines (e.g., lauryldimethylbetaine).

[0058] Examples of nonionic surfactants include polyethylene glycol-type surfactants or polypropylene glycol-type surfactants in which ethylene oxide or propylene oxide is added to higher alcohols, alkylphenols, fatty acids, higher aliphatic amines, aliphatic amides, etc., and polyhydric alcohol-type surfactants in which polyhydric alcohols, diethanolamines, sugars, and fatty acids are ester-bonded.

[0059] The surfactants described above are not limited to these, and may be used alone or in combination. When a surfactant is contained in the dental glass ionomer cement composition of the present invention, the surfactant is preferably contained in an amount of 0.001% by mass or more and 5% by mass or less based on the total mass of the composition. However, the dental glass ionomer cement composition of the present invention may not contain a surfactant.

[0060] Furthermore, the dental glass ionomer cement composition of the present invention may optionally contain a non-acid-reactive powder for the purpose of adjusting the handling properties, mechanical properties, or hardening properties, as long as the powder does not adversely affect the various properties.

[0061] The non-acid-reactive powder that can be used in the dental glass ionomer cement composition of the present invention is not particularly limited as long as it does not contain an element that reacts with the acidic group of (c) the polyalkenoic acid. Examples of non-acid-reactive powders include those known in the dental field, such as inorganic fillers, organic fillers, and organic-inorganic composite fillers, which can be used alone or in combination. Among these, inorganic fillers are particularly preferred. Furthermore, the shape of these non-acid-reactive powders is not particularly limited, and they may be any particle shape, such as spherical, acicular, plate-like, crushed, or scaly, or aggregates thereof. The 50% particle size (D50) of these non-acid-reactive powders is not particularly limited, but is preferably 0.001 μm or more and 30 μm or less.

[0062] Specific examples of inorganic fillers include, but are not limited to, quartz, amorphous silica, ultrafine silica particles, various glasses that do not contain elements that react with acidic groups (including glasses produced by melting methods, synthetic glasses by the sol-gel method, glasses produced by gas-phase reactions, etc.), silicon nitride, silicon carbide, boron carbide, etc. These inorganic fillers can be used alone or in combination.

[0063] When the dental glass ionomer cement composition of the present invention contains a non-acid-reactive powder, the content of the non-acid-reactive powder is preferably 0.001% by mass or more and 20% by mass or less of the total composition. However, the dental glass ionomer cement composition of the present invention may not contain a non-acid-reactive powder.

[0064] Furthermore, when the dental glass ionomer cement composition of the present invention is in a paste form, a thickener can be optionally added to adjust the paste properties within a range that does not adversely affect various properties.

[0065] The thickener that can be used in the dental glass ionomer cement composition of the present invention may be either an inorganic or organic thickener, such as fumed silica, calcium carbonate, calcium silicate, magnesium silicate, or clay minerals such as saponite, montmorillonite, beidellite, vermiculite, sauconite, stevensite, hectorite, smectite, tietite, and sepiolite.

[0066] Examples of organic thickeners include methyl cellulose, hydroxyethyl cellulose, hydroxymethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, calcium carboxymethyl cellulose, carboxypolymethylene, sodium alginate, propylene glycol alginate, sodium polyacrylate, starch, sodium starch glycolate, starch phosphate ester, polyvinylpyrrolidone, carboxyvinyl polymer, khaya gum, gum arabic, karaya gum, guar gum, and xanthan gum.

[0067] The thickeners listed above are not limited to these, and may be used alone or in combination. When a thickener is contained in the dental glass ionomer cement composition of the present invention, the thickener is preferably contained in an amount of 0.001% by mass to 10% by mass in the paste. However, the dental glass ionomer cement composition of the present invention may not contain a thickener.

[0068] Furthermore, the dental glass ionomer cement composition of the present invention may optionally contain preservatives, antibacterial agents, colorants, fluorescent agents, inorganic fiber materials, organic fiber materials, and other conventionally known additives, as needed.

[0069] The dental glass ionomer cement composition of the present invention is typically provided in two separate parts to prevent the coexistence of (b) acid-reactive glass powder and various acidic components ((c) polyalkenoic acid, (e) tartaric acid, and (f) acidic compounds) when they coexist in the presence of (d) water, because an acid-base reaction occurs between these three components. From the standpoint of storage stability, it is preferable to minimize the amount of various acidic components ((c) polyalkenoic acid, (e) tartaric acid, and (f) acidic compounds) coexisting with (b) acid-reactive glass powder, even in the absence of (d) water. Furthermore, since (a) chitosan can be dissolved in (d) water in the presence of (e) tartaric acid and / or (f) acidic compounds, the coexistence of (a) chitosan, (d) water, and one or both of (e) tartaric acid and (f) acidic compounds is essential.

[0070] Considering the above conditions, it is preferable that the components of the dental glass ionomer cement composition of the present invention are divided into two parts as follows: The first part contains (a) chitosan, (c) polyalkenoic acid, (d) water, and one or both of (e) tartaric acid and (f) acidic compound. The second part contains (b) acid-reactive glass powder, and optionally (c) polyalkenoic acid, (d) water, (e) tartaric acid, and / or (f) acidic compound. However, when the second part contains (d) water, it is preferable that (c) polyalkenoic acid, (e) tartaric acid, and (f) acidic compound are not contained in the second part. Furthermore, even when the second agent does not contain (d) water, it is preferable that the second agent contains small amounts of (c) polyalkenoic acid, (e) tartaric acid, and (f) acidic compound. Specifically, it is preferable that the total content of (c) polyalkenoic acid, (e) tartaric acid, and (f) acidic compound is 0.1 parts by mass or more and 20 parts by mass or less per 100 parts by mass of (b) acid-reactive glass powder contained in the second agent.

[0071] When the dental glass ionomer cement composition of the present invention is divided into two portions in this manner, the composition may be in any of the following forms: liquid / powder, paste / paste, liquid / paste, or paste / powder.

[0072] As mentioned above, (a) chitosan can be dissolved in (d) water by coexisting with (e) tartaric acid and / or (f) an acidic compound. On the other hand, when (c) polyalkenoic acid is coexisted, (a) chitosan does not dissolve in (d) water. Furthermore, even when (c) polyalkenoic acid is coexisted with (e) tartaric acid and / or (f) an acidic compound, (a) chitosan does not dissolve in (d) water. Therefore, (c) polyalkenoic acid must be added after (a) chitosan has been dissolved in (d) water by coexisting with (e) tartaric acid and / or (f) an acidic compound. Considering the above, a preferred method for producing the dental glass ionomer cement composition of the present invention is as follows.

[0073] The dental glass ionomer cement composition comprises a first part containing (a) chitosan, (c) polyalkenoic acid, (d) water, and at least one of (e) tartaric acid and (f) acidic compound, and a second part containing (b) acid-reactive glass powder, and when the second part contains (d) water, it does not contain (c) polyalkenoic acid, (e) tartaric acid, and (f) acidic compound. The first part can be produced by mixing (a) chitosan, some or all of (d) water, and some or all of (e) tartaric acid and / or (f) acidic compound to obtain a mixture in which (a) chitosan is dissolved in (d) water, and then mixing the mixture with the remaining components of the first part that were not mixed in the mixture production step. When dissolving (a) chitosan in (d) water, the ratio of (d) water to (a) chitosan and the ratio of (e) tartaric acid and / or (f) acidic compound to (a) chitosan are not particularly limited, and may be adjusted appropriately so that (a) chitosan is stably dissolved. There are no particular limitations on the method for producing the second agent, but it can be easily produced by mixing all of the components at once.

[0074] The dental glass ionomer cement composition of the present invention can be used for a wide range of purposes in dental treatment, such as as a filling material and a bonding material, as well as a pit and fissure sealant, a lining material, and a core construction material. [Example]

[0075] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The components used in preparing the dental glass ionomer cement compositions of the examples and comparative examples and their abbreviations are shown below.

[0076] [(a) Chitosan] CH1: Koyo Chitosan FL-80 (viscosity of 0.5% by mass chitosan in acetic acid solution [20°C]: 5 mPa·s, manufactured by Koyo Chemical Co., Ltd.) CH2: Koyo Chitosan FH-200 (viscosity of 0.5% by mass chitosan in acetic acid solution [20°C]: 120 mPa·s, manufactured by Koyo Chemical Co., Ltd.) CH3: Daichitosan H (viscosity of 0.5% by mass chitosan in acetic acid solution [20°C]: 610 mPa·s, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) (The acetic acid concentration in each aqueous solution was 0.5% by mass.)

[0077] [(b) Acid-reactive glass powder] G1: Acid-reactive glass powder 1 (fluoroaluminosilicate glass powder, 50% particle size (D50): 3.4 μm) G2: Acid-reactive glass powder 2 (fluoroaluminosilicate glass powder, 50% particle size (D50): 4.7 μm) [Production of Acid-Reactive Glass Powder 1 (G1)] 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 were mixed and melted in a melting furnace at 1400°C. The melt was removed from the furnace and quenched in water to obtain fluorosilicate glass. The resulting glass was crushed to a 50% particle size (D50) of 3.4 μm to obtain acid-reactive glass powder 1 (G1). The 50% particle size was measured using a laser diffraction particle size analyzer (Microtrac MT3300EXII, manufactured by Microtrac-Bell). [Production of Acid-Reactive Glass Powder 2 (G2)] The acid-reactive glass powder was prepared in the same manner as in the acid-reactive glass powder 1, except that the 50% particle size (D50) was adjusted to 4.7 μm by adjusting the grinding time.

[0078] [(c) Polyalkenoic acid] PA1: Acrylic acid homopolymer powder 1 (weight average molecular weight: 50,000) PA2: Acrylic acid-tricarboxylic acid copolymer powder 2 (weight average molecular weight: 140,000) PA3: Acrylic acid-tricarboxylic acid copolymer powder 3 (weight average molecular weight: 250,000)

[0079] [(d)Water] IEW: Ion-exchanged water

[0080] [(e)Tartaric acid] TA: Tartaric acid

[0081] [(f) Acidic compounds] A1: Malic acid A2: Maleic acid A3: Citric acid A4: Malonic acid A5: Ascorbic acid

[0082] [Other acidic ingredients] B1: Acetic acid B2: Hydrochloric acid B3: Lactic acid

[0083] [Preparation of liquid material] Liquid materials were prepared by mixing (a) chitosan, (d) water, and (e) tartaric acid and / or (f) acidic compounds in the proportions shown in Tables 1 to 7 to prepare a chitosan solution in which (a) chitosan was dissolved in (d) water, and then mixing the chitosan solution with (c) polyalkenoic acid. Liquid materials L27, L28, L29, and L38, which do not contain (a) chitosan, were prepared by mixing all components at once. Liquid materials L31, L32, and L42, which contain other acidic components instead of (f) acidic compounds, were prepared by mixing (a) chitosan, (d) water, (e) tartaric acid, and other acidic components to prepare a chitosan solution in which (a) chitosan was dissolved in (d) water, and then mixing the chitosan solution with (c) polyalkenoic acid. Liquid materials L33 and L34, which do not contain (e) tartaric acid and contain other acidic components instead of (f) acidic compounds, were prepared by mixing (a) chitosan, (d) water, and other acidic components to prepare a chitosan solution in which (a) chitosan was dissolved in (d) water, and then mixing the chitosan solution with (c) polyalkenoic acid. Liquid material L37 was prepared by mixing (c) polyalkenoic acid, (d) water, (e) tartaric acid, and (f) acidic compounds, and then mixing the resulting solution with (a) chitosan. Note that in this L37, (a) chitosan did not dissolve in (d) water.

[0084] [Preparation of powder material] Powder materials were prepared by mixing the components in the proportions shown in Table 8. For P1 and P2, acid-reactive glass powder 1 (G1) and acid-reactive glass powder 2 (G2) were used as they were, respectively.

[0085] The test methods used to evaluate the performance of the dental glass ionomer cement compositions of the Examples and Comparative Examples are as follows.

[0086] [Mixability] In an environment of 23±1°C temperature and 50±10% humidity, the powder and liquid materials of the dental glass ionomer cement compositions of the Examples or Comparative Examples were mixed using a plastic spatula in the proportions shown in Tables 9 to 18. The time from the start of mixing was used as the base point, and the time until no remaining powder material was visually detected in the mixed mixture and the mixed mixture became homogeneous was measured. The total amount of powder and liquid was 420 mg. When evaluated according to the following evaluation criteria, a rating of A was determined to indicate good mixability. Three evaluators each performed three measurements, and the average of the measurement results was evaluated according to the following evaluation criteria to determine the evaluation result for the measurement object. [Evaluation criteria] A: The time it takes for the kneaded material to form a lump is less than 40 seconds. B: The time it takes for the kneaded material to form a lump is 40 seconds or more, or the kneaded material does not form a lump.

[0087] [Operational margin time] The powder and liquid materials of the dental glass ionomer cement compositions of the Examples or Comparative Examples were mixed using a plastic spatula in the proportions shown in Tables 9 to 18 in an environment with a temperature of 23±1°C and a humidity of 50±10%. After mixing, the fluidity of the resulting mixture was confirmed using a plastic spatula, and the time from the start of mixing until the mixture lost its fluidity was defined as the working time. The total amount of powder and liquid materials was 420 mg. When evaluated according to the following evaluation criteria, a rating of A was deemed to indicate sufficient working time. Three evaluators each performed three measurements, and the average of the measurement results was evaluated according to the following evaluation criteria to determine the evaluation result of the measurement object. [Evaluation criteria] A: The operating time is more than 3 minutes. B: The operating time is less than 3 minutes.

[0088] [Compression strength] Compressive strength was measured according to ISO 9917-1:2007 using the following procedure. The powder and liquid components of the dental glass ionomer cement compositions of the Examples and Comparative Examples were mixed using a plastic spatula in the proportions shown in Tables 9 to 18 under an environment of 23±1°C temperature and 50±10% humidity. The mixed mixture was filled into a stainless steel mold (cylindrical, inner diameter: 4 mm, height: 6 mm) and then placed in a thermo-hygrostat chamber at 37°C and a humidity of 90% or higher. After standing for 1 hour, the cured product was removed from the mold and used as a test specimen. The test specimen was immersed in 37°C ion-exchanged water for 24 hours after mixing, and then the compressive strength of the test specimen was measured using an Instron universal testing machine (model: 5567A) at a crosshead speed of 1 mm / min. Five measurements were performed for each evaluation, and the average value was calculated.

[0089] The mixing properties, working time, and compressive strength of dental glass ionomer cement compositions (Examples 1 to 34, Comparative Examples 1 to 33) prepared by mixing the liquid material and powder material in the combinations and powder-liquid ratios shown in Tables 9 to 18 were evaluated.

[0090] [Examples 1 to 34] Tables 9 to 18 show the evaluation results of Examples 1 to 34. As a result, Examples 1 to 34 exhibited high compressive strength, good kneading properties, and sufficient working time, demonstrating desirable properties for dental glass ionomer cements.

[0091] [Comparative Examples 1 to 33] Tables 9 to 14 and 16 show the results of Comparative Examples 1 to 33. Comparative Example 1 is a composition in which (a) chitosan was blended in an amount less than the lower limit of Example 1. Evaluation of Comparative Example 1 revealed that the compressive strength was lower than that of Example 1. Comparative Example 2 is a composition that does not contain (a) chitosan and (f) acidic compound, unlike Example 1. Evaluation of Comparative Example 2 revealed that it had a lower compressive strength than Example 1. Comparative Example 3 is a composition that does not contain tartaric acid (e), unlike Example 1. Evaluation of Comparative Example 3 revealed that it had a lower compressive strength than Example 1. In Comparative Example 4, (a) chitosan was added later to a mixed solution of (c) polyalkenoic acid, (d) water, (e) tartaric acid, and (f) acidic compound, as compared to Example 1, and therefore (a) chitosan did not dissolve in (d) water. Evaluation of Comparative Example 4 showed that the compressive strength was lower than that of Example 1. In Comparative Example 5, (a) chitosan was blended with the powder material in Example 1, and therefore (a) chitosan was not dissolved in (d) water. As a result of evaluating Comparative Example 5, the compressive strength was lower than that of Example 1. Comparative Example 6 is a composition in which (a) chitosan is blended in an amount less than the lower limit and (f) no acidic compound is contained, compared to Example 1. Evaluation of Comparative Example 6 showed that the compressive strength was lower than that of Example 1.

[0092] Comparative Example 7 is a composition in which (a) chitosan was blended in an amount less than the lower limit of Example 2. Evaluation of Comparative Example 7 revealed that the compressive strength was lower than that of Example 2. Comparative Example 8 is a composition in which (a) chitosan was blended in an amount less than the lower limit of Example 3. Evaluation of Comparative Example 8 revealed that the compressive strength was lower than that of Example 3. Comparative Example 9 is a composition in which (a) chitosan is blended in an amount greater than the upper limit of the composition in Example 4. Evaluation of Comparative Example 9 revealed that the compressive strength was lower than that of Example 4. Comparative Example 10 is a composition that does not contain (e) tartaric acid and (f) contains hydrochloric acid, an inorganic acid, instead of the acidic compound, as compared to Example 4. Evaluation of Comparative Example 10 showed that the compressive strength was lower than that of Example 4. Comparative Example 11 is a composition in which (a) chitosan was blended in an amount greater than the upper limit of the composition in Example 5. As a result of evaluating Comparative Example 11, it was found that the compressive strength was lower than that of Example 5.

[0093] Comparative Example 12 is a composition that does not contain the acidic compound (f) as compared with Example 6. Evaluation of Comparative Example 12 revealed that it had a lower compressive strength than Example 6. Comparative Example 13 is a composition that does not contain (a) chitosan and (f) acidic compound, unlike Example 6. Evaluation of Comparative Example 13 revealed that it had a lower compressive strength than Example 6. Comparative Example 14 is a composition in which acetic acid, a water-soluble monocarboxylic acid compound, was blended in place of the acidic compound (f) in Example 6. Evaluation of Comparative Example 14 revealed that the compressive strength was lower than that of Example 6. Comparative Example 15 is a composition in which hydrochloric acid, an inorganic acid, is blended in place of the acidic compound (f) of Example 6. As a result of evaluating Comparative Example 15, it was found that the compressive strength was lower than that of Example 6.

[0094] Comparative Example 16 is a composition that does not contain (e) tartaric acid and (f) contains acetic acid, a water-soluble monocarboxylic acid compound, instead of the acidic compound in Example 6. Evaluation of Comparative Example 16 showed that the compressive strength was lower than that of Example 6. Comparative Example 17 is a composition obtained by blending (b) an acid-reactive glass powder in an amount greater than the upper limit and (d) water in an amount less than the lower limit of Example 6. As a result of evaluating Comparative Example 17, the kneaded product did not form a lump, the working time was less than 3 minutes, and the compressive strength was lower than that of Example 6. Comparative Example 18 is a composition obtained by blending (b) an acid-reactive glass powder in an amount less than the lower limit, (c) a polyalkenoic acid in an amount greater than the upper limit, and (d) water in an amount greater than the upper limit, compared to Example 6. Evaluation of Comparative Example 18 showed that the compressive strength was lower than that of Example 6. Comparative Example 19 is a composition in which the total content of (e) tartaric acid and (f) acidic compound is less than the lower limit compared to Example 6. As a result of evaluating Comparative Example 19, it was found that the compressive strength was lower than that of Example 6. Comparative Example 20 is a composition in which lactic acid, a water-soluble monocarboxylic acid compound, was blended in place of the acidic compound (f) in Example 6. Evaluation of Comparative Example 20 revealed that the compressive strength was lower than that of Example 6.

[0095] Comparative Example 21 is a composition that does not contain (a) chitosan and (f) acidic compound, unlike Example 7. Evaluation of Comparative Example 21 revealed that it had a lower compressive strength than Example 7. Comparative Example 22 is a composition that does not contain tartaric acid (e), unlike Example 8. Evaluation of Comparative Example 22 revealed that it had a lower compressive strength than Example 8. In Comparative Example 23, (a) chitosan was blended with the powder material in Example 9, and therefore (a) chitosan was not dissolved in (d) water. As a result of evaluating Comparative Example 23, the compressive strength was lower than that of Example 9.

[0096] Comparative Example 24 is a composition that does not contain (a) chitosan, unlike Example 10. As a result of evaluating Comparative Example 24, it was found that the compressive strength was lower than that of Example 10. Comparative Example 25 is a composition in which the total content of (e) tartaric acid and (f) acidic compound is higher than the upper limit value compared to Example 11. As a result of evaluating Comparative Example 25, it was found that the compressive strength was lower than that of Example 11. Comparative Example 26 is a composition in which the mass ratio of the content of (e) tartaric acid to the content of (f) acidic compound is lower than the lower limit of the content of Example 12. As a result of evaluating Comparative Example 26, the compressive strength was lower than that of Example 12.

[0097] Comparative Example 27 is a composition in which (b) acid-reactive glass powder was blended in an amount less than the lower limit of Example 21. Evaluation of Comparative Example 27 revealed that the compressive strength was lower than that of Example 21. Comparative Example 28 is a composition in which (b) acid-reactive glass powder was blended in an amount greater than the upper limit of the amount used in Example 21. Evaluation of Comparative Example 28 revealed that the working time was short, less than 3 minutes. Comparative Example 29 is a composition in which (c) polyalkenoic acid was blended in an amount less than the lower limit of the amount of Example 21. Evaluation of Comparative Example 29 revealed that the compressive strength was lower than that of Example 21. Comparative Example 30 is a composition in which (c) polyalkenoic acid was blended in an amount greater than the upper limit of the amount of Example 21. Evaluation of Comparative Example 30 revealed that the working time was short, less than 3 minutes. Furthermore, the compressive strength was lower than that of Example 21. Comparative Example 31 is a composition prepared by blending (d) water in an amount less than the lower limit of Example 21. Evaluation of Comparative Example 31 revealed that the working time was short, less than 3 minutes. Comparative Example 32 is a composition in which (d) water was blended in an amount greater than the upper limit of the amount of water in Example 21. As a result of evaluating Comparative Example 32, it was found that the compressive strength was lower than that of Example 21. Comparative Example 33 is a composition in which the mass ratio of the content of (e) tartaric acid to the content of (f) acidic compound is higher than the upper limit value compared to Example 21. As a result of evaluating Comparative Example 33, the compressive strength was lower than that of Example 21.

[0098] [Table 1]

[0099] [Table 2]

[0100] [Table 3]

[0101] [Table 4]

[0102] [Table 5]

[0103] [Table 6]

[0104] [Table 7]

[0105] [Table 8]

[0106] [Table 9]

[0107] [Table 10]

[0108] [Table 11]

[0109] [Table 12]

[0110] [Table 13]

[0111] [Table 14]

[0112] [Table 15]

[0113] [Table 16]

[0114] [Table 17]

[0115] [Table 18] [Industrial Applicability]

[0116] The dental glass ionomer cement composition of the present invention can be suitably used in dental treatments such as filling dental cavities, lining layers or relinings, bonding dental prosthetic devices such as crowns, inlays and bridges to tooth structures, sealing pits and fissures, preventive coating of tooth surfaces, and core construction.

Claims

1. (a) chitosan 0.01% by mass or more and 1.5% by mass or less; (b) acid-reactive glass powder: 30% by mass or more and 75% by mass or less; (c) polyalkenoic acid 5% by mass or more and 30% by mass or less, (d) Water 10% by mass or more and 35% by mass or less, (e) tartaric acid, and (f) one or more acidic compounds selected from the group consisting of water-soluble polycarboxylic acid compounds other than tartaric acid and water-soluble ascorbic acid compounds; A two-part dental glass ionomer cement composition comprising: the total content of the (e) tartaric acid and the (f) acidic compound is 1% by mass or more and 10% by mass or less based on the total mass of the composition; the mass ratio of the content of the (e) tartaric acid to the content of the (f) acidic compound ((e) tartaric acid / (f) acidic compound) is 0.01 or more and 99 or less; and A dental glass ionomer cement composition, characterized in that at least one of the two components contains (a) chitosan, (d) water, and one or more compounds selected from the group consisting of (e) tartaric acid and (f) acidic compounds.

2. 2. The dental glass ionomer cement composition according to claim 1, wherein the acidic compound (f) is one or more selected from the group consisting of citric acid, malic acid, maleic acid, malonic acid, ascorbic acid, isoascorbic acid, fumaric acid, and aconitic acid.

3. 2. The dental glass ionomer cement composition according to claim 1, wherein the acidic compound (f) is citric acid and / or malic acid.

4. 4. The dental glass ionomer cement composition according to claim 1, which is substantially free of inorganic acids and monocarboxylic acids.

5. The dental glass ionomer cement composition comprises: a first agent containing the (a) chitosan, the (c) polyalkenoic acid, the (d) water, and at least one of the (e) tartaric acid and the (f) acidic compound; and (b) a second agent containing an acid-reactive glass powder, 4. The dental glass ionomer cement composition according to claim 1, wherein the second agent, when containing (d) water, does not contain (c) polyalkenoic acid, (e) tartaric acid, or (f) acidic compound.

6. The dental glass ionomer cement composition comprises: a first agent containing the (a) chitosan, the (c) polyalkenoic acid, the (d) water, and at least one of the (e) tartaric acid and the (f) acidic compound; and (b) a second agent containing an acid-reactive glass powder, 5. The dental glass ionomer cement composition according to claim 4, wherein when the second agent contains (d) water, it does not contain (c) polyalkenoic acid, (e) tartaric acid, or (f) acidic compound.

7. 1. A method for producing a dental glass ionomer cement composition, comprising: The dental glass ionomer cement composition comprises: a first agent containing the (a) chitosan, the (c) polyalkenoic acid, the (d) water, and at least one of the (e) tartaric acid and the (f) acidic compound; and (b) a second agent containing an acid-reactive glass powder, When the second agent contains the (d) water, it does not contain the (c) polyalkenoic acid, the (e) tartaric acid, or the (f) acidic compound; a step of mixing the (a) chitosan, a part or all of the (d) water, and a part or all of the (e) tartaric acid and / or the (f) acidic compound to produce a mixed solution; A method for producing a dental glass ionomer cement composition, comprising the step of producing the first agent by mixing the mixed liquid with the remaining components constituting the first agent that were not mixed in the step of producing the mixed liquid.

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