Easily removable glass ionomer cement composition for dental luting

Abstract

To provide a glass ionomer cement composition for dental luting that has less risk of water sensitivity while being excellent in removability of excess cement after hardening because of having shape retention of a kneaded material without dripping by its own weight despite developing a thin coating during luting, and is excellent in operability during luting, such as being able to remove excess cement quickly after applying it in the oral cavity.SOLUTION: Provided is a glass ionomer cement composition for dental luting, containing at least: an acid-reactive glass powder having an average particle size of 4.5 to 7.0 μm as a component (a); a polymer of acidic group-containing polymerizable monomers having a weight average molecular weight of 30,000 to 100,000 as a component (b); a chelating agent as an ingredient (c); and water as a component (d), the glass ionomer cement composition for dental luting having a plastic flow distance of the kneaded product before hardening of 2 mm or less and an excess cement removal time of two minutes and zero seconds or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a glass ionomer cement for bonding or affixing a dental prosthetic device to a tooth. [Background technology]

[0002] In clinical dentistry, cement materials such as dental adhesive resin cements and dental bonding glass ionomer cements are used to adhere or bond dental prosthetic devices such as crowns, inlays, and bridges to teeth that have been partially damaged in shape due to caries, fractures, etc.

[0003] Dental adhesive resin cements are generally composed of matrix resins made of several types of polymerizable monomers, various fillers such as glass fillers, and polymerization catalysts, and are one of the dental materials that have been widely used in recent years due to their high mechanical strength and high adhesive strength. However, many dental adhesive resin cements do not have self-adhesive properties to tooth tissue, and when using such materials, a tooth primer must be used in combination, which makes the operation complicated. In addition, moisture prevention is important when applying a tooth primer, so in cases where moisture prevention is difficult, there is a risk of poor adhesion due to the influence of moisture. Furthermore, the preventive effect of secondary caries by the sustained release of fluoride ions has only been recognized in some commercially available products.

[0004] In contrast, dental glass ionomer cements are generally composed mainly of polycarboxylic acid, water, and acid-reactive glass powder, typically fluoroaluminosilicate glass, and have the advantage that they do not require the use of a tooth primer because the polycarboxylic acid in the composition causes the cement to self-adhere to the tooth. In addition, the composition contains water, so the cement can be used in cases where moisture is difficult to prevent. Furthermore, the hardened material releases fluoride ions continuously, which is expected to prevent secondary caries.

[0005] In order to prevent the dental prosthetic device from floating up and becoming poorly fitted when it is bonded or fused to the tooth, these cement materials are generally designed to have a low viscosity so that the coating thickness is thin. However, if the viscosity of the kneaded material is low, when the dental prosthetic device is attached, the excess cement overflowing from the gap between the tooth, i.e., the excess cement, will drip down under its own weight, causing various problems in clinical practice. Specifically, the excess cement dripping down onto the soft tissue or contacting the tongue not only causes discomfort to the patient, but also makes the removal work after hardening complicated because the excess cement spreads over a wide area. If the excess cement flows under the gum line, the removal of small areas becomes even more complicated, which causes stress for both dentists and patients. In addition, in the case of glass ionomer cement for dental luting, the kneaded material has an acidic taste, so when the dripping excess cement comes into contact with the patient's tongue, it promotes saliva secretion, leading to the cement becoming water-sensitive. This tendency is particularly pronounced in children, who have active saliva secretion. The term "water sensitivity" refers to the phenomenon in which poor hardening occurs at the contact surface when glass ionomer cement comes into contact with water during the initial hardening process.

[0006] Another problem with glass ionomer cement for dental bonding is that it takes a long time from fitting the dental prosthesis in the mouth until the excess cement can be removed. The patient must wait while lightly biting down on the fitted dental prosthesis until the mixed cement has hardened to a certain extent, and the dentist cannot remove the excess cement and cannot proceed to the next step. This is also a source of stress for both the dentist and the patient.

[0007] In light of this background, there has been a demand for a glass ionomer cement for dental bonding that has excellent operability during bonding and has a low risk of water sensitivity, such as being able to maintain its shape so that the mixed material does not drip under its own weight despite producing a thin coating thickness during bonding, and allowing excess cement to be easily removed quickly after application to the oral cavity.

[0008] To date, the following techniques have been proposed with the aim of improving the operability of dental glass ionomer cement for luting.

[0009] Japanese Patent Laid-Open Publication No. 4-173713 proposes a dental glass ionomer cement paste containing glass powder, a water-soluble polymer, and water, and a dental glass ionomer cement preparation kit consisting of said paste and an aqueous polycarboxylic acid solution. This dental glass ionomer cement preparation kit discloses that the glass component, which has been conventionally supplied in powder form, is supplied in paste form, so that a fixed-volume discharge device can be used and the amount can be measured accurately, that mixing with the aqueous polycarboxylic acid solution is very simple and the mixing is completed in a short time, so that sufficient operation time can be obtained, that there is no non-uniformity such as powder aggregation due to moisture absorption, and that glass does not scatter during work, so that the examination room can always be kept clean.

[0010] Japanese Patent Publication No. 6-27049 discloses that by using an aqueous dispersion containing a polymer containing a carboxylic acid group, a graft copolymer containing a carboxylic acid group, and a polybasic acid in a specific ratio as a hardening liquid for a dental cement, it is possible to impart excellent adhesiveness and a low disintegration rate in the oral cavity to the dental cement, and also to significantly improve the kneading properties.

[0011] Japanese Patent Publication No. 7-53645 discloses that a dental cement hardening liquid containing a carboxylic acid group and a partially crosslinked water-soluble star polymer can simultaneously impart excellent kneadability and excellent durability such as crush resistance to a hardened dental cement.

[0012] Japanese Patent Laid-Open Publication No. 9-48702 proposes a powder containing a dental cement powder having an average particle size of 0.01-20 μm and a sphericity (Fx) of 0.50-0.95, and a dental cement composition consisting of the powder and an organic acid aqueous solution. It is disclosed that when the powder containing the dental cement powder is used, air between the fine particles is quickly removed during mixing with the organic acid aqueous solution, and a uniform paste-like cement composition is easily obtained, thereby shortening the working time, and further that the obtained paste-like cement composition is difficult to dissolve in water, making it easy to repair or bond teeth, and has high compressive strength and low disintegration rate.

[0013] Japanese Patent No. 2813906 proposes a dental cement hardener consisting of a polymer-cement complex obtained by polymerizing an unsaturated carboxylic acid monomer or a mixed monomer of said monomer and another copolymerizable unsaturated monomer in an aqueous medium in which dental cement powder is dispersed. It is disclosed that this dental cement hardener is superior to conventional hardeners in operability and kneadability when mixed with dry cement powder components, and therefore can be kneaded sufficiently in a short time without requiring much skill, and that a hardened cement product can be obtained that is excellent in physical strength such as crush resistance and has no variation in final performance.

[0014] Japanese Patent No. 3452379 proposes a method for preparing a dental cement, which comprises preparing a dental cement composition containing fluoroaluminosilicate with a specific ratio of SrO and La2O3 in an average particle size of 0.1-30 μm, filling the composition into a container with an outlet with a diameter of 1.0-4.0 mm, and discharging the granular dental cement composition from the outlet to determine the amount. It is disclosed that the granular dental cement composition is not only excellent in compatibility with an aqueous hardener solution and ease of handling, but also provides good X-ray contrast without the addition of an X-ray contrast agent, and can provide a hardened cement product with consistent final performance, and can easily determine the required amount of the dental cement composition.

[0015] However, none of these disclosed patent documents mentions any improvement in dripping of excess cement, removability after hardening, risk of water sensitivity, time required for removal after application in the oral cavity, etc. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] Japanese Patent Application Publication No. 4-173713 [Patent Document 2] Special Publication No. 6-27049 [Patent Document 3] Special Publication No. 7-53645 [Patent Document 4] Japanese Patent Application Publication No. 9-48702 [Patent Document 5] Patent No. 2813906 [Patent Document 6] Patent No. 3452379 Summary of the Invention [Problem to be solved by the invention]

[0017] Although conventional dental glass ionomer cements for luting have a thin coating thickness, the viscosity of the kneaded material is low, so that when the dental prosthetic device is attached, the excess cement drips under its own weight, which is not only uncomfortable for the patient, but also spreads over a wide area, making the removal work after hardening cumbersome. If the excess cement flows under the gum line, removing small areas becomes even more cumbersome, causing stress for both dentists and patients. In addition, since the kneaded material has a sour taste, when the dripping excess cement comes into contact with the patient's tongue, it promotes saliva secretion, which leads to the cement becoming water-sensitive. Another problem is that it takes a long time from when the dental prosthetic device is attached to the oral cavity until the excess cement can be removed, so the patient has to wait until the kneaded cement has initially hardened to a certain extent while lightly biting the attached dental prosthetic device, and the dentist also has the disadvantage of not being able to remove the excess cement and therefore not being able to proceed to the next step. [Means for solving the problem]

[0018] In order to solve the above problems, the present inventors have conducted extensive research and found that, when a composition in which the average particle size of the acid-reactive glass powder and the weight-average molecular weight of the polymer of the acidic group-containing polymerizable monomer are adjusted within a specific range has a specific plastic flow distance, it is possible to suppress dripping of excess cement even though a thin coating thickness is exhibited during luting. Furthermore, the more the amount of excess cement is, the more likely it is to drip and flow. However, it has been found that, in addition to the above characteristics, by imparting a hardening property that allows the excess cement to be removed early after the dental prosthesis is placed in the oral cavity, dripping can be more effectively suppressed even when the amount of excess cement is large. Based on this knowledge, it has been found that a glass ionomer cement composition for dental luting having the above characteristics can simultaneously solve the problems of dripping of excess cement, the associated cumbersome removal after hardening, the risk of water sensitivity, and the need to wait a long time after the dental prosthesis is placed in the oral cavity before the excess cement can be removed, and thus the present invention has been completed.

[0019] That is, the present invention Component (a) an acid-reactive glass powder having an average particle size of 4.5 to 7.0 μm; Component (b) a polymer of an acidic group-containing polymerizable monomer having a weight average molecular weight of 30,000 to 100,000; Component (c) a chelating agent, and Component (d) water The glass ionomer cement composition for dental bonding contains at least the above-mentioned compound, and is characterized in that the plastic flow distance of the kneaded material before hardening is 2 mm or less, and the time during which excess cement can be removed is 2 minutes 00 seconds or less.

[0020] In the glass ionomer cement composition for dental bonding, it is preferable that the plastic flow distance of the kneaded material before hardening is 1 mm or less, and the time required for removing excess cement is 1 minute 30 seconds or less.

[0021] In addition, in the glass ionomer cement composition for dental luting, Component (a) 30.0 to 75.0 wt % of an acid-reactive glass powder having an average particle size of 4.5 to 7.0 μm; Component (b) 5.0 to 30.0 wt % of a polymer of an acidic group-containing polymerizable monomer having a weight average molecular weight of 30,000 to 100,000; Component (c) chelating agent 1.0 to 10.0 wt %, and Component (d) Water 10.0~35.0wt% It is preferred that the compound contains

[0022] The average particle size of the component (a), the acid-reactive glass powder, is preferably within the range of 5.0 to 6.5 μm.

[0023] Furthermore, the polymer of the acidic group-containing polymerizable monomer (b) is preferably a polymer of an α-β unsaturated carboxylic acid, and more preferably has a weight average molecular weight of 50,000 to 80,000. It is also preferred that the component (c) chelating agent is tartaric acid.

[0024] Also, the component (b) polymer of an acidic group-containing polymerizable monomer is preferably a polymer of acrylic acid and 1-butene-1,2,4-tricarboxylic acid and / or a polymer of acrylic acid and 3-butene-1,2,3-tricarboxylic acid. Effect of the Invention

[0025] The glass ionomer cement composition for dental luting of the present invention has a shape retention property that does not drip under its own weight even though it exhibits a thin coating thickness during luting, and since excess cement can be removed at an early timing after the dental prosthesis is placed in the oral cavity, dripping can be effectively suppressed regardless of the amount of excess cement. This reduces the risk of water sensitivity, eliminates the discomfort of the patient caused by excess cement dripping onto the soft tissue, and improves operability during luting, such as facilitating the removal of excess cement after hardening. In addition, it is no longer necessary to wait a long time after the dental prosthesis is placed in the oral cavity until the excess cement can be removed, reducing stress during treatment for both the dentist and the patient. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Each component of the glass ionomer cement composition for dental luting of the present invention will be described in detail below. The component (a) acid-reactive glass powder of the present invention must contain an acid-reactive element, such as a metal element belonging to Groups 1, 2, and 3 of the periodic table, and a fluorine element. The component (a) acid-reactive glass powder contains an acid-reactive element, and in the presence of water, an acid-base reaction with an acidic group of the polymer of the acidic group-containing polymerizable monomer (b) described below proceeds. Specific examples of the acid-reactive element include, but are not limited to, sodium, potassium, calcium, strontium, barium, lanthanum, aluminum, zinc, etc. These acid-reactive elements may be contained in one or more types, and the content of these elements is not particularly limited. Furthermore, in order to impart X-ray contrast to the dental glass ionomer cement composition of the present invention, it is desirable to include an element that is radiopaque in the component (a) acid-reactive glass powder. Specific examples of the X-opaque element 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 other elements contained in the component (a) acid-reactive glass powder, and the component (a) acid-reactive glass powder in the present invention can contain a variety of elements.

[0027] Examples of component (a) acid-reactive glass powder include aluminosilicate glass, borosilicate glass, aluminoborate glass, boroaluminosilicate glass, phosphate glass, borate glass, and silica glass, which contain the above-mentioned acid-reactive elements, fluorine, and X-ray opaque elements, but are not limited to these. Furthermore, the particle shape of the component (a) 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 restriction. These component (a) acid-reactive glass powders can be used alone or in combination of several kinds. The method for producing these component (a) acid-reactive glass powders is not particularly limited, and any method such as a melting method, a gas phase method, a sol-gel method, etc. can be used without any problem. Among them, it is preferable to use an acid-reactive glass powder produced by a melting method or a sol-gel method, which makes it easy to control the type and content of elements contained in the acid-reactive glass powder.

[0028] The component (a) 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 glass can be pulverized using a high-speed rotating mill such as a hammer mill or turbo mill, a container-driven medium mill such as a ball mill or vibration mill, a medium-agitating mill such as a sand grinder or attritor, a jet mill, or the like.

[0029] The average particle size of the component (a) acid-reactive glass powder must be within the range of 4.5 to 7.0 μm, and is preferably within the range of 5.0 to 6.5 μm. Here, the average particle size is the average particle size calculated based on the volume-based particle size distribution measured by a laser diffraction type particle size distribution measuring device or the like. If the average particle size of the component (a) acid-reactive glass powder is less than 4.5 μm, mixing and kneading may become difficult, the viscosity of the kneaded product may increase, and the operability may decrease. In addition, since it becomes difficult to include a large amount in the composition due to the increase in surface area, there is a risk of causing a decrease in mechanical strength. In addition, the operation time may be shortened. If the average particle size of the component (a) acid-reactive glass powder exceeds 7.0 μm, the coating thickness becomes thick, so that the dental prosthetic device to be bonded may float up and the fit may become poor. In addition, the fluidity of the kneaded product may increase, and the excess cement may drip under its own weight, or the hardening may become slow, and it may be necessary to wait a long time to remove the excess cement.

[0030] In order to adjust the operability, hardening properties, mechanical properties, etc. of the glass ionomer cement composition for dental luting of the present invention, the component (a) acid-reactive glass powder can be subjected to various surface treatments, heat treatments, aggregation treatments in a liquid phase or a gas phase, etc., microencapsulation treatments in which particles are encapsulated with organic substances, or grafting treatments in which the surface is functionalized with organic substances, within the range that does not adversely affect the acid-base reaction with the polymer of the component (b) acidic group-containing polymerizable monomer described below. In addition, there is no problem even if these treatments are performed alone or in combination of several kinds. Among these, surface treatments and heat treatments are preferred because they are easy to control various properties and have excellent productivity.

[0031] Specific examples of surface treatment methods for the component (a) 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 polycarboxylic acid, surface treatment with a fluoride such as aluminum fluoride, surface treatment with a silane compound such as γ-mercaptopropyltrimethoxysilane or tetramethoxysilane, etc. The surface treatment methods that can be used in the present invention are not limited to those mentioned above, and these surface treatment methods can be used alone or in combination.

[0032] A specific example of a method for heat treating the component (a) acid-reactive glass powder is a treatment method in which the powder is heated for 1 to 72 hours at a temperature in the range of 100° C. to 800° C. using an electric furnace, etc. The heat treatment method that can be used in the present invention is not limited to the above, and the treatment process can also be a single treatment or a multi-stage treatment.

[0033] The component (a) acid-reactive glass powder is preferably contained in an amount of 30.0 to 75.0 wt%, more preferably 45.0 to 75.0 wt%, and even more preferably 45.0 to 70.0 wt% based on the total glass ionomer cement composition for dental luting. If the content of the component (a) acid-reactive glass powder is less than 30.0 wt%, the fluidity of the kneaded product will be high, and the hardening will be slow, so that the excess cement may drip under its own weight, or it may take a long time to remove the excess cement. In addition, it may cause a decrease in the mechanical strength of the hardened product. If the content of the component (a) acid-reactive glass powder exceeds 75.0 wt%, it may become difficult to mix and knead the kneaded product, the viscosity of the kneaded product may increase, and the operability may decrease. Furthermore, the operation time may be shortened, or the dental prosthetic device to be bonded may float up due to the thick coating, resulting in poor fit.

[0034] The component (b) polymer of an acidic group-containing polymerizable monomer can be used without any limitation as long as it is a polymer obtained by polymerizing an acidic group-containing polymerizable monomer having at least one acidic group in the molecule.

[0035] The acidic group-containing polymerizable monomer used to obtain a polymer of the component (b) acidic group-containing polymerizable monomer is not particularly limited in the type of acidic group, and any acidic group-containing polymerizable monomer can be used. In addition, the number (monofunctional or polyfunctional) and type of radically polymerizable unsaturated groups that the acidic group-containing polymerizable monomer has can be used without any limitation. Specific examples of the acidic groups that the acidic group-containing polymerizable monomer has include, but are not limited to, a phosphoric acid group, a pyrophosphoric acid group, a phosphonic acid group, a carboxyl group, a sulfonic acid group, and a thiophosphoric acid group. Specific examples of the unsaturated group possessed by the acidic group-containing polymerizable monomer include a (meth)acryloyl group, a styryl group, a vinyl group, an allyl group, etc., and among these unsaturated groups, an acidic group-containing polymerizable monomer having a (meth)acryloyl group is preferred. Furthermore, these acidic group-containing polymerizable monomers may also have other functional groups, such as an alkyl group, a halogen, an amino group, a glycidyl group, and / or a hydroxyl group, in the molecule.

[0036] Specific examples of the acidic group-containing polymerizable monomer having a (meth)acryloyl group as the unsaturated group and which can be used to obtain a polymer of the acidic group-containing polymerizable monomer (b) are given below. Examples of the acidic group-containing polymerizable monomer having a phosphoric acid group include (meth)acryloyloxymethyl dihydrogen phosphate, 2-(meth)acryloyloxyethyl dihydrogen phosphate, 3-(meth)acryloyloxypropyl dihydrogen phosphate, 4-(meth)acryloyloxybutyl dihydrogen phosphate, 5-(meth)acryloyloxypentyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 7- (Meth)acryloyloxyheptyl dihydrogen phosphate, 8-(meth)acryloyloxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl dihydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate, 12-(meth)acryloyloxydodecyl dihydrogen phosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen phosphate, 20-(meth)acryloyloxyeicosyl dihydrogen phosphate, bis[2-(meth)acryloyloxyethyl]hydrogen phosphate, bis[3-(meth)acryloyloxypropyl]hydrogen phosphate, bis[4-(meth)acryloyloxybutyl]hydrogen phosphate, bis[6-(meth)acryloyloxyhexyl]hydrogen phosphate, bis[8-(meth)acryloyloxyoctyl]hydrogen phosphate Examples of the hydrogen phosphate include, but are not limited to, bis[9-(meth)acryloyloxynonyl]hydrogen phosphate, bis[10-(meth)acryloyloxydecyl]hydrogen phosphate, 1,3-di(meth)acryloyloxypropyl-2-dihydrogen phosphate, 2-(meth)acryloyloxyethylphenyl hydrogen phosphate, and 2-(meth)acryloyloxyethyl-2'-bromoethyl hydrogen phosphate.

[0037] Examples of the acidic group-containing polymerizable monomer having a pyrophosphate group include, but are not limited to, bis[2-(meth)acryloyloxyethyl] pyrophosphate, bis[3-(meth)acryloyloxypropyl] pyrophosphate, bis[4-(meth)acryloyloxybutyl] pyrophosphate, bis[5-(meth)acryloyloxypentyl] pyrophosphate, bis[6-(meth)acryloyloxyhexyl] pyrophosphate, bis[7-(meth)acryloyloxyheptyl] pyrophosphate, bis[8-(meth)acryloyloxyoctyl] pyrophosphate, bis[9-(meth)acryloyloxynonyl] pyrophosphate, bis[10-(meth)acryloyloxydecyl] pyrophosphate, bis[12-(meth)acryloyloxydodecyl] pyrophosphate, and tris[2-(meth)acryloyloxyethyl] pyrophosphate.

[0038] In addition, examples of the acidic group-containing polymerizable monomer having a phosphonic acid group include 5-(meth)acryloyloxypentyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonopropionate, 10-(meth)acryloyloxydecyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonoacetate, and 10-(meth)acryloyloxydecyl-3-phosphonoacetate, but are not limited thereto. Examples of the acidic group-containing polymerizable monomer having a carboxyl group include (meth)acrylic acid, 2-chloroacrylic acid, 3-chloro(meth)acrylic acid, 2-cyanoacrylic acid, aconitic acid, mesaconic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, glutaconic acid, citraconic acid, utraconic acid, 1,4-di(meth)acryloyloxyethylpyromellitic acid, and 6-(meth)acryloyloxynaphthalene-1,2,6-tricarboxylic acid. Acid, 1-butene-1,2,4-tricarboxylic acid, 3-butene-1,2,3-tricarboxylic acid, N-(meth)acryloyl-p-aminobenzoic acid, N-(meth)acryloyl-5-aminosalicylic acid, 4-(meth)acryloyloxyethyl trimellitic acid and its anhydride, 4-(meth)acryloyloxybutyl trimellitic acid and its anhydride, 2-(meth)acryloyloxybenzoic acid, β-(meth)acryloyloxyethyl hydrogen succinate, β-(meth)acryloyloxyethyl hydrogen maleate, 11-(meth)acryloyloxy-1,1-undecanedicarboxylic acid, p-vinyl benzoic acid, 4-(meth)acryloyloxyethoxycarbonyl phthalic acid, 4-(meth)acryloyloxybutyloxycarbonyl phthalic acid, 4-(meth)acryloyloxyhexyloxycarbonyl phthalic acid, 4-(meth)acryloyloxyoctyloxycarbonyl phthalic acid, 4-(meth)acryloyloxyethyl Examples of the acryloyloxycarbonyl phthalic acid include, but are not limited to, acryloyloxydecyloxycarbonylphthalic acid and its acid anhydrides, 5-(meth)acryloylaminopentylcarboxylic acid, 6-(meth)acryloyloxy-1,1-hexanedicarboxylic acid, 8-(meth)acryloyloxy-1,1-octanedicarboxylic acid, 10-(meth)acryloyloxy-1,1-decanedicarboxylic acid, and 11-(meth)acryloyloxy-1,1-undecanedicarboxylic acid.

[0039] Examples of the acidic group-containing polymerizable monomer having a sulfonic acid group include, but are not limited to, 2-(meth)acrylamide-2-methylpropanesulfonic acid, styrenesulfonic acid, 2-sulfoethyl(meth)acrylate, 4-(meth)acryloyloxybenzenesulfonic acid, and 3-(meth)acryloyloxypropanesulfonic acid. Examples of the acidic group-containing polymerizable monomer having a thiophosphate group include, but are not limited to, 2-(meth)acryloyloxyethyl dihydrogen thiophosphate, 3-(meth)acryloyloxypropyl dihydrogen thiophosphate, 4-(meth)acryloyloxybutyl dihydrogen thiophosphate, 5-(meth)acryloyloxypentyl dihydrogen thiophosphate, 6-(meth)acryloyloxyhexyl dihydrogen thiophosphate, 7-(meth)acryloyloxyheptyl dihydrogen thiophosphate, 8-(meth)acryloyloxyoctyl dihydrogen thiophosphate, 9-(meth)acryloyloxynonyl dihydrogen thiophosphate, and 10-(meth)acryloyloxydecyl dihydrogen thiophosphate.

[0040] The above-mentioned acidic group-containing polymerizable monomers may be used alone or in combination to synthesize a polymer of the acidic group-containing polymerizable monomer (b) without any problem.Furthermore, an acidic group-containing polymerizable monomer having at least one acidic group in the molecule and a polymerizable monomer having no acidic group may be copolymerized to synthesize a polymer of the acidic group-containing polymerizable monomer (b) without any problem. Among these acidic group-containing polymerizable monomers, it is preferable to use an α-β unsaturated carboxylic acid-based acidic group-containing polymerizable monomer. The α-β unsaturated carboxylic acid-based acidic group-containing polymerizable monomer to be used in this case is not particularly limited, and can be used regardless of the number of carboxyl groups in the molecule or the presence or absence of carboxylic anhydride or other substituents. Specific examples of these α-β unsaturated carboxylic acid-based acidic group-containing polymerizable monomers include (meth)acrylic acid, 2-chloroacrylic acid, 3-chloro(meth)acrylic 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, and 3-butene-1,2,3-tricarboxylic acid. Among these, it is more preferable to use a polymer of component (b) an acidic group-containing polymerizable monomer synthesized using only acrylic acid as a starting material, or a polymer of component (b) an acidic group-containing polymerizable monomer synthesized using two or more kinds of starting materials, such as acrylic acid and maleic acid, acrylic acid and maleic anhydride, acrylic acid and itaconic acid, acrylic acid and 1-butene-1,2,4-tricarboxylic acid, acrylic acid and 3-butene-1,2,3-tricarboxylic acid, etc. From the viewpoint of expressing high shape retention, it is more preferable to use a polymer of component (b) an acidic group-containing polymerizable monomer synthesized using two or more kinds of starting materials, such as acrylic acid and maleic acid, acrylic acid and maleic anhydride, acrylic acid and itaconic acid, acrylic acid and 1-butene-1,2,4-tricarboxylic acid, acrylic acid and 3-butene-1,2,3-tricarboxylic acid, etc. It is more preferable to use a polymer of component (b) an acidic group-containing polymerizable monomer synthesized using as starting materials acrylic acid and an acidic group-containing polymerizable monomer of an α-β unsaturated carboxylic acid type having a large number of carboxyl groups per monomer unit, such as acrylic acid and itaconic acid, acrylic acid and 1-butene-1,2,4-tricarboxylic acid, or acrylic acid and 3-butene-1,2,3-tricarboxylic acid, and it is particularly preferable to use a polymer of acrylic acid and 1-butene-1,2,4-tricarboxylic acid, and / or a polymer of acrylic acid and 3-butene-1,2,3-tricarboxylic acid. The method of polymerizing various polymerizable monomers is not particularly limited, and any method such as solution polymerization, suspension polymerization, emulsion polymerization, etc. can be used without any restrictions. In addition, the polymerization initiator and chain transfer agent used in the synthesis of the polymer may be appropriately selected to obtain a desired polymer. The polymer of the component (b) acidic group-containing polymerizable monomer thus obtained can be used alone or in combination of several kinds.

[0041] The weight-average molecular weight of the polymer of the acidic group-containing polymerizable monomer (b) must be within the range of 30,000 to 100,000, and is preferably within the range of 50,000 to 80,000. 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 polymer of the acidic group-containing polymerizable monomer (b) is less than 30,000, the fluidity of the kneaded product increases, and hardening becomes slow, so that the excess cement may drip under its own weight, or it may take a long time to remove the excess cement. In addition, there is a risk of causing a decrease in mechanical strength. If the weight-average molecular weight of the polymer of the acidic group-containing polymerizable monomer (b) exceeds 100,000, mixing and kneading may become difficult, the viscosity of the kneaded product may increase, and operability may decrease. Furthermore, the operation time may be shortened, or the dental prosthetic device to be bonded may float up due to the thick coating film, resulting in poor fit.

[0042] The polydispersity of the polymer of the acidic group-containing polymerizable monomer (b) is not particularly limited, but is preferably 1.7 or more, and more preferably 2.5 or more. By making the polydispersity of the polymer of the acidic group-containing polymerizable monomer (b) 1.7 or more, the glass ionomer cement composition for dental luting of the present invention has a higher shape retention and is less likely to drip under its own weight. In addition, the time from when the dental prosthetic device is placed in the oral cavity until the excess cement can be removed is shortened. The component (b) polymer of the acidic group-containing polymerizable monomer is preferably contained in an amount of 5.0 to 30.0 wt%, more preferably 10.0 to 25.0 wt%, based on the total glass ionomer cement composition for dental luting. If the content of the component (b) polymer of the acidic group-containing polymerizable monomer is less than 5.0 wt%, the fluidity of the kneaded product will be high, and the hardening will be slow, so that the excess cement may drip under its own weight, or it may take a long time to remove the excess cement. In addition, there is a risk of causing a decrease in mechanical strength. If the content of the component (b) polymer of the acidic group-containing polymerizable monomer exceeds 30.0 wt%, mixing and kneading may become difficult, the viscosity of the kneaded product may increase, and operability may decrease. Furthermore, the operation time may be shortened, or the dental prosthetic device to be bonded may rise up due to the thick coating, resulting in poor fit.

[0043] Any chelating agent as component (c) can be used without any restrictions so long as it can form a coordinate bond with a metal ion and a chelate complex. Specific examples of the component (c) chelating agent include tartaric acid, citric acid, maleic acid, fumaric acid, malic acid, aconitic acid, tricarballylic acid, itaconic acid, salicylic acid, 1-butene-1,2,4-tricarboxylic acid, 3-butene-1,2,3-tricarboxylic acid, ethylenediaminetetraacetic acid, nitrilotriacetic acid, mellitic acid, trimellitic acid, pyromellitic acid, dihydroxybenzoic acid, and other carboxylic acid compounds, phosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, and other phosphoric acid compounds, and metal salts of these basic acids. These basic acids and their metal salts can be used alone or in combination. Among them, it is preferable to use tartaric acid as the component (c) chelating agent.

[0044] The content of the component (c) chelating agent is preferably 1.0 to 10.0 wt%, more preferably 2.0 to 8.0 wt%, based on the total content of the dental glass ionomer cement composition. If the content of the component (c) chelating agent is less than 1.0 wt%, the operation time may be shortened. If the content of the component (c) chelating agent is more than 10.0 wt%, the mechanical strength may be reduced.

[0045] Component (d) water functions as a solvent for dissolving the polymer of component (b) the acidic group-containing polymerizable monomer, and is also an essential component for diffusing metal ions eluted from component (a) the acid-reactive glass powder and inducing a crosslinking reaction with the polymer of component (b) the acidic group-containing polymerizable monomer. The component (d) water can be used without any restrictions as long as it does not contain impurities that adversely affect the hardening and mechanical strength of the dental glass ionomer cement composition. Specifically, it is preferable to use distilled water or ion-exchanged water.

[0046] The content of component (d) water is preferably 10.0 to 35.0 wt%, more preferably 10.0 to 25.0 wt%, and even more preferably 15.0 to 25.0 wt% based on the total glass ionomer cement composition for dental luting. If the content of component (d) water is less than 10.0 wt%, the content of component (a) acid-reactive glass powder and component (b) polymer of acidic group-containing polymerizable monomer increases relatively, making mixing and kneading difficult, increasing the viscosity of the kneaded product, and so on, which may reduce operability. In addition, the operation time may be shortened, or the coating thickness may be thickened, causing the dental prosthetic device to be bonded to float up, resulting in poor fit. If the content of component (d) water exceeds 35.0 wt%, the fluidity of the composition increases, and hardening becomes slow, causing excess cement to drip under its own weight, or requiring a long time to remove the excess cement. Furthermore, there is a risk of causing a decrease in mechanical strength.

[0047] The glass ionomer cement composition for dental luting of the present invention must have a plastic flow distance of 2 mm or less, preferably 1 mm or less, and most preferably 0 mm, before hardening. If the plastic flow distance exceeds 2 mm, the excess cement will drip under its own weight and come into contact with the soft tissue or tongue, causing discomfort to the patient, and the removal work after hardening will become complicated, adversely affecting operability. In addition, it will also lead to an increased risk of water sensitivity. In this specification, the plastic flow distance means the distance that the kneaded material flows down under its own weight when 0.3 g of the kneaded material is placed on a horizontal, smooth glass surface in an environment of room temperature (23±1°C) so that the diameter of the kneaded material is within 10 mm, and then the glass surface is turned vertically and the kneaded material is left to stand until it hardens (the distance from the position of the lowest end of the kneaded material before plastic flow to the position of the lowest end of the kneaded material after hardening).

[0048] The glass ionomer cement composition for dental luting of the present invention must have a time within 2 minutes and 00 seconds for removing excess cement, and preferably within 1 minute and 30 seconds. If the time exceeds 2 minutes and 00 seconds, dripping may not be effectively suppressed when the amount of excess cement is large, even if the plastic flow distance is 2 mm or less. In addition, the patient must wait while lightly biting the dental prosthetic device, and the dentist cannot remove the excess cement, so the patient cannot proceed to the next step for a long time. In this specification, the time during which excess cement can be removed means the time from when the mixture is placed in a constant temperature bath at 37°C-70% humidity 1 minute and 30 seconds after the start of mixing, when 0.3 g of the mixture is sandwiched between the bottom surfaces of two rectangular resin blocks (12 mm long x 16 mm wide x 10 mm high) in an environment at room temperature of 23±1°C, the resin blocks are pressed together firmly to cause the mixture to protrude from the gaps, and the mixture is then placed in a constant temperature bath at 37°C-70% humidity 1 minute and 30 seconds after the start of mixing, until the mixture that has protruded from the gaps between the resin blocks can be removed in one lump.

[0049] In the glass ionomer cement composition for dental luting of the present invention, the content of each of the preferred components exhibiting the above-mentioned characteristics is, relative to the entire composition, Component (a) 30.0 to 75.0 wt % of an acid-reactive glass powder having an average particle size of 4.5 to 7.0 μm; Component (b) 5.0 to 30.0 wt % of a polymer of an acidic group-containing polymerizable monomer having a weight average molecular weight of 30,000 to 100,000; Component (c) chelating agent 1.0 to 10.0 wt %, and Component (d) Water 10.0~35.0wt% In a glass ionomer cement composition for dental bonding comprising such a content range, when the plastic flow distance of the kneaded material before hardening is 2 mm or less and the time during which excess cement can be removed is within 2 minutes and 00 seconds, the kneaded material has shape retention that does not drip under its own weight despite the thin coating thickness that is exhibited during bonding, and therefore the removability of excess cement after hardening is excellent, there is little risk of water sensitivity, and excess cement can be removed at an early timing after application to the oral cavity, making it possible to provide a composition with excellent operability during bonding.

[0050] The more preferred content of each component is, based on the entire glass ionomer cement composition for dental luting, Component (a) 45.0 to 75.0 wt % of an acid-reactive glass powder having an average particle size of 4.5 to 7.0 μm; Component (b) 10.0 to 25.0 wt % of a polymer of an acidic group-containing polymerizable monomer having a weight average molecular weight of 30,000 to 100,000, Component (c) chelating agent 1.0 to 10.0 wt %, and Component (d) Water 10.0~25.0wt% In a glass ionomer cement composition for dental bonding comprising the above content range, when the plastic flow distance of the kneaded material before hardening is 2 mm or less and the time during which excess cement can be removed is within 2 minutes and 00 seconds, the above effects are more significantly exhibited and the physical properties are also excellent. More preferably, the content of each component is, based on the entire glass ionomer cement composition for dental luting, Component (a) 45.0 to 70.0 wt % of an acid-reactive glass powder having an average particle size of 4.5 to 7.0 μm; Component (b) 10.0 to 25.0 wt % of a polymer of an acidic group-containing polymerizable monomer having a weight average molecular weight of 30,000 to 100,000, Component (c) chelating agent 2.0 to 8.0 wt %, and Component (d) Water 15.0~25.0wt% In a glass ionomer cement composition for dental bonding comprised within such a content range, when the plastic flow distance of the kneaded material before hardening is 2 mm or less and the time during which excess cement can be removed is within 2 minutes and 00 seconds, the above-mentioned effects are more significantly exhibited, and the composition has extremely excellent operability and physical properties, making it extremely suitable as a glass ionomer cement for dental bonding.

[0051] Furthermore, the glass ionomer cement composition for dental luting of the present invention may contain a surfactant for the purpose of improving kneadability, so long as the various properties are not adversely affected. The surfactant that can be used in the glass ionomer cement composition for dental luting of the present invention may be either an ionic surfactant or a nonionic surfactant. Specific examples of ionic surfactants include anionic surfactants such as metal salts of aliphatic carboxylic acids, such as sodium stearate, sulfated metal salts of aliphatic carboxylic acids, such as sodium dioctyl sulfosuccinate, and metal salts of higher alcohol sulfates, such as sodium stearyl sulfate. Cationic surfactants include adducts of higher alkylamines and ethylene oxide, amines made from lower amines, and alkyltrimethylammonium salts, such as lauryltrimethylammonium chloride. Amphoteric surfactants include metal salts of higher alkylaminopropionic acids, such as sodium stearylaminopropionate, and betaines, such as lauryldimethylbetaine. Examples of nonionic surfactants include polyethylene glycol-type 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, or the like, and polyhydric alcohol-type surfactants in which polyhydric alcohols, diethanolamines, sugars, and fatty acids are ester-bonded. 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. The surfactant is preferably contained in an amount ranging from 0.001 to 5.0% by weight based on the total weight of the glass ionomer cement composition for dental luting.

[0052] Furthermore, when the glass ionomer cement composition for dental luting of the present invention is in a paste form, a thickener can be added to adjust the paste properties within a range that does not adversely affect various characteristics. In the glass ionomer cement composition for dental luting of the present invention, either an inorganic or an organic thickener can be used. Inorganic thickeners include fumed silica, calcium carbonate, calcium silicate, magnesium silicate, as well as clay minerals such as saponite, montmorillonite, beidellite, vermiculite, sauconite, stevensite, hectorite, smectite, tietite, and sepiolite. 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, polyvinylpyrrolidone, carboxyvinyl polymer, khaya gum, gum arabic, karaya gum, guar gum, etc. These can be used alone or in combination of two or more. The thickener is preferably contained in the paste in an amount of 0.001 to 10.0 wt %.

[0053] The glass ionomer cement composition for dental bonding of the present invention may contain a non-acid-reactive powder for the purpose of adjusting the handling properties, mechanical properties, or hardening properties, so long as the properties are not adversely affected. The non-acid-reactive powder used in the dental glass ionomer cement composition of the present invention can be used without any particular limitation as long as it does not contain an element to which the acidic group of the polymer of the acidic group-containing polymerizable monomer is chelated. Examples of the non-acid-reactive powder include known dental fillers, such as inorganic fillers, organic fillers, and organic-inorganic composite fillers, which can be used alone or in combination of several kinds. Among them, it is particularly preferable to use inorganic fillers. In addition, the shape of these non-acid-reactive powders is not particularly limited, and may be any particle shape such as spherical, needle-like, plate-like, crushed, or scaly, or an aggregate thereof, and is not limited to these. The average particle size of these non-acid-reactive powders is not particularly limited, but is preferably in the range of 0.001 to 30 μm.

[0054] Specific examples of inorganic fillers include quartz, amorphous silica, ultrafine silica particles, various glasses that do not contain elements that are chelated by acidic groups or alkali metal salts of 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., but are not limited to these. The non-acid-reactive powder is preferably contained in an amount of 0.001 to 40 wt % based on the entire glass ionomer cement composition for dental luting. The glass ionomer cement composition for dental luting of the present invention is provided in various forms such as powder / liquid, paste / liquid, paste / paste, etc. From the viewpoint of storage stability, it is preferable that component (a) acid-reactive glass powder and component (b) polymer of acidic group-containing polymerizable monomer, or component (a) acid-reactive glass powder and component (c) chelating agent do not coexist in the presence of component (d) water.

[0055] The powder / liquid form is as follows: A combination of a powder material containing component (a) an acid-reactive glass powder, component (b) a polymer of an acid group-containing polymerizable monomer, component (c) a chelating agent, and component (d) a liquid material containing water; A combination of a powder material containing component (a) an acid-reactive glass powder and component (b) a polymer of an acid group-containing polymerizable monomer with a liquid material containing component (c) a chelating agent and component (d) water; A combination of a powder material containing component (a) an acid-reactive glass powder and (b) a polymer of an acidic group-containing polymerizable monomer with a liquid material containing component (b) a polymer of an acidic group-containing polymerizable monomer, component (c) a chelating agent, and component (d) water; A combination of a powder material containing component (a) an acid-reactive glass powder and component (c) a chelating agent with a liquid material containing component (b) a polymer of an acid group-containing polymerizable monomer and component (d) water; A combination of a powder material containing component (a) an acid-reactive glass powder and component (c) a chelating agent with a liquid material containing component (b) a polymer of an acid group-containing polymerizable monomer, component (c) a chelating agent, and component (d) water; A combination of a powder material containing component (a) an acid-reactive glass powder, component (b) a polymer of an acid group-containing polymerizable monomer, and component (c) a chelating agent, and a liquid material containing component (d) water; A combination of a powder material containing component (a) an acid-reactive glass powder, component (b) a polymer of an acidic group-containing polymerizable monomer, and component (c) a chelating agent, and a liquid material containing component (b) a polymer of an acidic group-containing polymerizable monomer, and component (d) water; A combination of a powder material containing component (a) an acid-reactive glass powder, component (b) a polymer of an acid group-containing polymerizable monomer, and component (c) a chelating agent, and a liquid material containing component (c) the chelating agent and component (d) water; A combination of a powder material containing component (a) an acid-reactive glass powder, component (b) a polymer of an acidic group-containing polymerizable monomer, and component (c) a chelating agent, and a liquid material containing component (b) a polymer of an acidic group-containing polymerizable monomer, component (c) a chelating agent, and component (d) water; The following are provided, but are not limited to these:

[0056] The form of the paste / liquid material may be, but is not limited to, a combination of a paste containing component (a) an acid-reactive glass powder and component (d) water, and a liquid containing component (b) a polymer of an acidic group-containing polymerizable monomer, component (c) a chelating agent, and component (d) water. As the paste / paste form, a combination of a first paste containing (a) an acid-reactive glass powder and component (d) water and a second paste containing component (b) a polymer of an acidic group-containing polymerizable monomer, component (c) a chelating agent, and component (d) water is provided, but is not limited thereto.

[0057] Furthermore, the glass ionomer cement composition for dental luting of the present invention may contain any of a variety of ingredients, such as preservatives, antibacterial agents, coloring pigments, and other conventionally known additives, as necessary. EXAMPLES

[0058] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. (Details of the components used in the preparation of the dental glass ionomer cement composition) Table 1 shows the components (a) to (d) used in the preparation of the glass ionomer cement compositions for dental luting of the Examples and Comparative Examples.

[0059] [Table 1]

[0060] The method for producing fluoroaluminosilicate glass is as follows. (Method of manufacturing fluoroaluminosilicate glass 1) Various raw materials of silicon dioxide, aluminum oxide, sodium fluoride, and strontium carbonate (glass composition: SiO2 23.8% by weight, Al2O3 16.2% by weight, SrO 35.6% by weight, Na2O 2.3% by weight, F 11.6% by weight) were mixed and melted in a melting furnace at 1400°C. The molten liquid was removed from the melting furnace and quenched in water to produce glass. The obtained glass was pulverized to obtain an acid-reactive glass powder. The average particle size of this acid-reactive glass powder was measured using a laser diffraction particle sizer (Microtrac MT3300EXII: manufactured by Nikkiso Co., Ltd.) and found to be 3.4 μm. (Production methods of fluoroaluminosilicate glass 2 to 7) Fluoroaluminosilicate glasses 2 to 7 were all produced in the same manner as fluoroaluminosilicate glass 1, except that the average particle size of each was adjusted by pulverization as shown in Table 1.

[0061] (Production method of acrylic acid-tricarboxylic acid copolymer 1) 70 parts of acrylic acid and 30 parts of 3-butene-1,2,3-tricarboxylic acid were added to 150 mL of water and 150 parts of methanol, and ammonium persulfate was added as a catalyst at a ratio of 2% based on the weight of the monomer. The mixture was heated to 60-70°C and allowed to polymerize for 4 hours while stirring. After the reaction was completed, the resulting solution was dried to obtain a polymer of an acidic group-containing polymerizable monomer (acrylic acid-tricarboxylic acid copolymer 1). The weight average molecular weight and polydispersity of this polymer of an acidic group-containing monomer were measured by gel permeation chromatography (GCP-900: manufactured by JASCO Corporation), and the weight average molecular weight was 23,000 and the polydispersity was 1.64. (Production methods of acrylic acid-tricarboxylic acid copolymers 2 to 7) Acrylic acid-tricarboxylic acid copolymers 2 to 7 were all prepared in the same manner as acrylic acid-tricarboxylic acid copolymer 1, except that the weight average molecular weight and polydispersity were adjusted as shown in Table 1 by appropriately changing the reaction conditions. (Production methods of polyacrylic acids 1 and 2) Polyacrylic acids 1 and 2 were prepared in the same manner as acrylic acid-tricarboxylic acid copolymer 1, except that only acrylic acid was used as the monomer and the weight-average molecular weight and polydispersity were adjusted as shown in Table 1 by appropriately changing the reaction conditions. (Preparation of powder and liquid materials) Powder materials P1 to P7 were prepared as shown in Table 2. Furthermore, liquid materials L1 to L18 were prepared by mixing the components in the ratios shown in Table 3.

[0062] [Table 2]

[0063] [Table 3]

[0064] These powder and liquid materials were mixed in the combinations and powder / liquid ratios shown in Tables 4 to 10 to produce dental glass ionomer cement compositions (Examples 1 to 20, Comparative Examples 1 to 6) that were evaluated. The evaluation methods were as follows. All evaluations were performed in an environment of room temperature of 23±1°C and humidity of 50±10%.

[0065] (Plastic flow distance) 0.3 g of the kneaded material was placed on a horizontal, smooth glass surface so that the diameter of the kneaded material was within 10 mm, and then the glass surface was turned vertically and the kneaded material was left to stand until it hardened. After hardening, the distance that the kneaded material had flowed under its own weight (the distance from the position of the lowest end of the kneaded material before plastic flow to the position of the lowest end of the kneaded material after hardening) was measured in 0.25 mm units. (Time required to remove excess cement) 0.3 g of the kneaded material was sandwiched between the bottoms of two rectangular resin blocks (12 mm long x 16 mm wide x 10 mm high), and the resin blocks were pressed firmly against each other to make the kneaded material protrude from the gap. This was placed in a 37°C-70% thermostatic chamber 1 minute and 30 seconds after the start of kneading, and the protruding kneaded material was touched every 15 seconds with a metal instrument, and the time from when it was placed in the thermostatic chamber until it could be removed in one piece was measured. (Excess cement dripping (small amount)) 0.3g of the kneaded glass ionomer cement composition for dental luting shown in the Examples and Comparative Examples was applied to the inner surface of a resin crown (mandibular first molar), and immediately pressed against an abutment tooth model, and the state of excess cement overflowing from the gap between the crown and the abutment tooth model was observed. At this time, the case where no excess cement dripped out was rated as A, the case where a small amount of excess cement dripped out but to an extent that did not adversely affect the removability after hardening was rated as B, the case where excess cement dripped out to an extent that made removal after hardening somewhat complicated was rated as C, and the case where excess cement dripped down to the bottom of the abutment tooth model was rated as D.

[0066] (Excess cement dripping (large amount)) 0.6g of the kneaded glass ionomer cement composition for dental luting shown in the Examples and Comparative Examples was applied to the inner surface of a resin crown (mandibular first molar), and immediately pressed against an abutment tooth model, and the state of excess cement overflowing from the gap between the crown and the abutment tooth model was observed. At this time, the case where no excess cement dripped out was rated as A, the case where a small amount of excess cement dripped out but to an extent that did not adversely affect the removability after hardening was rated as B, the case where excess cement dripped out to an extent that made removal after hardening somewhat complicated was rated as C, and the case where excess cement dripped down to the bottom of the abutment tooth model was rated as D. (mixability) When the powder and liquid materials of the dental glass ionomer cement compositions shown in the Examples and Comparative Examples were mixed, those that felt little resistance and could be mixed easily were rated as A, those that felt some resistance but could be mixed without any problems were rated as B, those that felt a lot of resistance and were difficult to mix were rated as C, and those that felt very much resistance and were practically difficult to mix were rated as D. (Viscosity of the kneaded product) 0.3g of the kneaded glass ionomer cement composition for dental luting shown in the Examples and Comparative Examples was applied to the inner surface of a resin crown (mandibular first molar), and immediately placed on an abutment tooth model, and 1 minute after the start of kneading, a load of 550g was applied to press the crown against the abutment tooth model. At this time, the kneaded product was rated as A when the viscosity was sufficiently low and no lifting of the crown was observed, as B when the viscosity was slightly low and no lifting of the crown was observed with the naked eye, but when pressed with a finger after an excessive load, there was a slight room for pressing it down, as C when the viscosity was slightly high and slight lifting was observed with the naked eye, and as D when the viscosity was extremely high and obvious lifting was observed with the naked eye.

[0067] (Coating thickness) The coating thickness was measured by the following procedure, referring to ISO 9917-1:2007 Coating thickness. The kneaded product of the dental glass ionomer cement composition shown in the Examples and Comparative Examples was sandwiched between two glass plates (circular) with a diameter of 15 mm, and a normal stress of 150±2N was applied one minute after the start of kneading. After the kneaded product was kept until it hardened, the thickness of the spread kneaded product was measured and this was taken as the coating thickness. In addition, the glass ionomer cement for dental luting must have a coating thickness of 25 μm or less according to the requirements of ISO 9917-1:2007. (Operation time) In the evaluation method of the coating thickness test, the timing of applying normal stress was changed every 30 seconds from 1 minute after the start of mixing to examine the change in coating thickness with time from the start of mixing. At this time, the time from the start of mixing that can maintain the coating thickness of 25 μm or less was defined as the operation time. In addition, for glass ionomer cement for dental luting, it is desirable to have an operation time of at least 1 minute from the start of mixing. (Compressive strength) The compressive strength was measured according to the following procedure in accordance with ISO 9917-1:2007. The kneaded product of the glass ionomer cement composition for dental luting shown in the examples and comparative examples was filled into a stainless steel mold (diameter 4 mm x height 6 mm: cylindrical) and left to stand for 1 hour in a thermo-hygrostat at 37°C and 100% humidity. After 1 hour, the test specimen was removed from the mold and immersed in ion-exchanged water at 37°C. 24 hours after the end of kneading, the test specimen was removed and the compressive strength was measured at a crosshead speed of 1 mm / min. using a universal testing machine (Instron 5567A: manufactured by Instron Japan Co., Ltd.). In addition, the glass ionomer cement for dental luting must have a compressive strength of 50 MPa or more according to the requirements of ISO 9917-1:2007.

[0068] (Example 1, Comparative Examples 1 to 6) The evaluation results of the glass ionomer cement compositions for dental luting shown in Example 1 and Comparative Examples 1 to 6 are shown in Table 4. In Example 1, no excess cement dripped off at all, and the product had desirable properties for a glass ionomer cement for dental luting in terms of kneadability, viscosity of the kneaded product, working time, coating thickness, and compressive strength. Comparative Example 1 is a composition prepared by kneading powder P1 (made of fluoroaluminosilicate glass 1 having an average particle size of 3.4 μm) in place of powder P4 (made of fluoroaluminosilicate glass 4 having an average particle size of 5.3 μm) in Example 1. In Comparative Example 1, no excess cement dripped off and good compressive strength was exhibited, but there was a strong sense of resistance during mixing, the viscosity of the mixture was extremely high, the operation time was short, and the coating thickness was thick. Comparative Example 2 is a composition prepared by mixing powder P7 (made of fluoroaluminosilicate glass 7 having an average particle size of 8.4 μm) instead of powder P4 (made of fluoroaluminosilicate glass 4 having an average particle size of 5.3 μm) in Example 1, and the time during which excess cement can be removed exceeds 2 minutes and 00 seconds. It was observed that excess cement dripped off in Comparative Example 2. In addition, although the mixing property, viscosity of the mixed product, and compressive strength were good, it was observed that the operation time was short and the coating thickness was thick. Comparative Example 3 is a composition prepared by mixing liquid L1 (containing acrylic acid-tricarboxylic acid copolymer 1 having a weight average molecular weight of 23,000) instead of liquid L4 (containing acrylic acid-tricarboxylic acid copolymer 4 having a weight average molecular weight of 70,000) in Example 1, and the time required for removing excess cement exceeds 2 minutes and 00 seconds. It was observed that excess cement dripped off in Comparative Example 3. As for other properties, the glass ionomer cement had desirable properties for dental luting. Comparative Example 4 is a composition prepared by mixing liquid L7 (containing acrylic acid-tricarboxylic acid copolymer 7 having a weight average molecular weight of 118,000) instead of liquid L4 (containing acrylic acid-tricarboxylic acid copolymer 4 having a weight average molecular weight of 70,000) in Example 1. In Comparative Example 4, no excess cement dripped off and good compressive strength was observed; however, there was a strong sense of resistance during mixing, the viscosity of the mixture was extremely high, the operation time was short, and the coating thickness was thick. Comparative Example 5 is a composition prepared by mixing the powder-liquid ratio of Example 1 at 1.0 / 1.0, and the time during which excess cement can be removed exceeds 2 minutes and 00 seconds. In Comparative Example 5, dripping was observed when a large amount of excess cement was used. As for other properties, the glass ionomer cement had desirable properties for dental luting. Comparative Example 6 is a composition obtained by mixing the powder-liquid ratio of Example 1 at 0.5 / 1.0, and the plastic flow distance exceeded 2 mm and the time during which excess cement could be removed exceeded 2 minutes and 00 seconds. In Comparative Example 6, the excess cement was significantly dripped off and the compressive strength was low. As for other properties, the glass ionomer cement had desirable properties for dental luting.

[0069] [Table 4]

[0070] (Examples 2 to 5) The evaluation results of the glass ionomer cement compositions for dental luting shown in Examples 2 to 5 are shown in Table 5. Example 2 is a composition prepared by kneading powder P2 (made of fluoroaluminosilicate glass 2 having an average particle size of 4.5 μm) instead of powder P4 (made of fluoroaluminosilicate glass 4 having an average particle size of 5.3 μm) in Example 1. Example 3 is a composition prepared by kneading powder P3 (made of fluoroaluminosilicate glass 3 having an average particle size of 5.0 μm) instead of powder P4 (made of fluoroaluminosilicate glass 4 having an average particle size of 5.3 μm) in Example 1. Example 4 is a composition prepared by kneading powder P5 (made of fluoroaluminosilicate glass 5 having an average particle size of 6.5 μm) instead of powder P4 (made of fluoroaluminosilicate glass 4 having an average particle size of 5.3 μm) in Example 1. Example 5 is a composition prepared by kneading powder P6 (made of fluoroaluminosilicate glass 6 having an average particle size of 7.0 μm) instead of powder P4 (made of fluoroaluminosilicate glass 4 having an average particle size of 5.3 μm) in Example 1. In Examples 2 to 5, the excess cement hardly dripped off, and other properties were also desirable for a glass ionomer cement for dental luting.

[0071] [Table 5]

[0072] (Examples 6 to 9) Table 6 shows the evaluation results of the glass ionomer cement compositions for dental luting shown in Examples 6 to 9. Example 6 is a composition prepared by mixing liquid L2 (containing acrylic acid-tricarboxylic acid copolymer 2 having a weight average molecular weight of 30,000) instead of liquid L4 (containing acrylic acid-tricarboxylic acid copolymer 4 having a weight average molecular weight of 70,000) in Example 1. Example 7 is a composition prepared by mixing liquid L3 (containing acrylic acid-tricarboxylic acid copolymer 3 having a weight average molecular weight of 51,000) instead of liquid L4 (containing acrylic acid-tricarboxylic acid copolymer 4 having a weight average molecular weight of 70,000) in Example 1. Example 8 is a composition prepared by mixing liquid L5 (containing acrylic acid-tricarboxylic acid copolymer 5 having a weight average molecular weight of 79,000) instead of liquid L4 (containing acrylic acid-tricarboxylic acid copolymer 4 having a weight average molecular weight of 70,000) in Example 1. Example 9 is a composition prepared by mixing liquid L6 (containing acrylic acid-tricarboxylic acid copolymer 6 having a weight average molecular weight of 100,000) instead of liquid L4 (containing acrylic acid-tricarboxylic acid copolymer 4 having a weight average molecular weight of 70,000) in Example 1. In Examples 6 to 9, the excess cement hardly dripped off, and other properties were also desirable for a glass ionomer cement for dental luting.

[0073] [Table 6]

[0074] Example 10 The evaluation results of the glass ionomer cement composition for dental luting shown in Example 10 are shown in Table 7. Example 10 is a composition prepared by kneading the liquid material L10 (containing maleic acid) in place of the liquid material L4 (containing tartaric acid) in Example 1. In Example 10, no excess cement dripped off, and other properties were also desirable for a glass ionomer cement for dental luting.

[0075] [Table 7]

[0076] (Examples 11 to 14) Table 8 shows the evaluation results of the glass ionomer cement compositions for dental luting shown in Examples 11 to 14. Example 11 is a composition prepared by mixing liquid L12 (45.0 wt% acrylic acid-tricarboxylic acid copolymer 6, 3.0 wt% tartaric acid, and the remainder water) instead of liquid L4 (40.0 wt% acrylic acid-tricarboxylic acid copolymer 4, 10.0 wt% tartaric acid, and the remainder water) in Example 2 at a powder-liquid ratio of 0.5 / 1.0. Example 12 is a composition obtained by kneading the same composition as in Example 11 with the powder-liquid ratio set to 1.0 / 1.0. Example 13 is a composition prepared by mixing liquid L17 (40.0 wt% acrylic acid-tricarboxylic acid copolymer 2, 20.0 wt% tartaric acid, and the remainder water) instead of liquid L4 (40.0 wt% acrylic acid-tricarboxylic acid copolymer 4, 10.0 wt% tartaric acid, and the remainder water) in Example 5 at a powder-liquid ratio of 3.0 / 1.0. Example 14 is a composition prepared by mixing liquid L16 (20.0 wt% acrylic acid-tricarboxylic acid copolymer 2, 20.0 wt% tartaric acid, and the remainder of water) instead of liquid L4 (40.0 wt% acrylic acid-tricarboxylic acid copolymer 4, 10.0 wt% tartaric acid, and the remainder of water) in Example 5 at a powder-liquid ratio of 3.0 / 1.0. In Examples 11 to 14, the excess cement hardly dripped off, and other properties were also desirable for a glass ionomer cement for dental luting.

[0077] [Table 8]

[0078] (Examples 15 and 16) The evaluation results of the dental glass ionomer cement compositions shown in Examples 15 and 16 are shown in Table 9. Example 15 is a composition prepared by mixing liquid L8 (containing polyacrylic acid 1 having a polydispersity of 1.77) instead of liquid L4 (containing acrylic acid-tricarboxylic acid copolymer 4 having a polydispersity of 3.16) in Example 1. Example 16 is a composition prepared by mixing liquid L9 (containing polyacrylic acid 2 having a polydispersity of 2.56) instead of liquid L4 (containing acrylic acid-tricarboxylic acid copolymer 4 having a polydispersity of 3.16) in Example 1. In Examples 15 and 16, the excess cement hardly dripped off, and other properties were also desirable for a glass ionomer cement for dental luting.

[0079] [Table 9]

[0080] (Examples 17 to 20) Table 10 shows the evaluation results of the glass ionomer cement compositions for dental luting shown in Examples 17 to 20. Example 17 is a composition prepared by mixing liquid L11 (containing 40.0 wt% acrylic acid-tricarboxylic acid copolymer 4, 3.0 wt% tartaric acid, and the remainder water) instead of liquid L4 (containing 40.0 wt% acrylic acid-tricarboxylic acid copolymer 4, 10.0 wt% tartaric acid, and the remainder water) in Example 1. Example 18 is a composition prepared by mixing liquid L13 (containing 40.0 wt% acrylic acid-tricarboxylic acid copolymer 4, 6.0 wt% tartaric acid, and the remainder water) instead of liquid L4 (containing 40.0 wt% acrylic acid-tricarboxylic acid copolymer 4, 10.0 wt% tartaric acid, and the remainder water) in Example 1. Example 19 is a composition prepared by mixing liquid L14 (containing 30.0 wt% acrylic acid-tricarboxylic acid copolymer 4, 24.0 wt% tartaric acid, and the remainder water) instead of liquid L4 (containing 40.0 wt% acrylic acid-tricarboxylic acid copolymer 4, 10.0 wt% tartaric acid, and the remainder water) in Example 1. Example 20 is a composition prepared by mixing liquid L15 (containing 30.0 wt% acrylic acid-tricarboxylic acid copolymer 4, 30.0 wt% tartaric acid, and the remainder water) instead of liquid L4 (containing 40.0 wt% acrylic acid-tricarboxylic acid copolymer 4, 10.0 wt% tartaric acid, and the remainder water) in Example 1. In Examples 17 to 20, the excess cement hardly dripped off, and other properties were also desirable for a glass ionomer cement for dental luting.

[0081] [Table 10]

[0082] (Examples 21 to 22) Table 11 shows the evaluation results of the glass ionomer cement compositions for dental luting shown in Examples 21 and 22. Example 21 is a composition obtained by kneading the same as in Example 14 with a powder-liquid ratio of 4.0 / 1.0. Example 22 is a composition prepared by mixing liquid L18 (containing 51.0 wt% acrylic acid-tricarboxylic acid copolymer 6, 1.0 wt% tartaric acid, and the remainder of water) instead of liquid L4 (containing 40.0 wt% acrylic acid-tricarboxylic acid copolymer 4, 10.0 wt% tartaric acid, and the remainder of water) in Example 2 at a powder-liquid ratio of 1.0 / 3.0. In Examples 21 and 22, the excess cement hardly dripped off, and other properties were also desirable for a glass ionomer cement for dental luting.

[0083] [Table 11] [Industrial Applicability]

[0084] According to the present invention, a glass ionomer cement composition for dental bonding can be provided that exhibits a thin coating thickness during bonding, yet has shape retention that prevents the kneaded product from dripping under its own weight, making it easy to remove excess cement after hardening, has little risk of water sensitivity, and allows excess cement to be removed quickly after application to the oral cavity, making it easy to use during bonding.

Claims

1. Component (a) 30.0 to 75.0 wt % of an acid-reactive glass powder having an average particle size of 4.5 to 7.0 μm; Component (b) 5.0 to 30.0 wt % of a polymer of an acidic group-containing polymerizable monomer having a weight average molecular weight of 30,000 to 100,000; Component (c) 1.0 to 10.0 wt % of a chelating agent, and Component (d) Water 10.0-35.0wt% A glass ionomer cement composition for dental bonding comprising at least one of the following: wherein the plastic flow distance of the kneaded material before hardening is 2 mm or less, and the time during which excess cement can be removed is within 2 minutes and 00 seconds.

2. 2. The glass ionomer cement composition for dental luting according to claim 1, characterized in that the plastic flow distance of the kneaded material before hardening is 1 mm or less, and the time required for removing excess cement is 1 minute 30 seconds or less.

3. 3. The glass ionomer cement composition for dental bonding according to claim 1, wherein the component (a) acid-reactive glass powder has an average particle size of 5.0 to 6.5 μm.

4. 4. The glass ionomer cement composition for dental luting according to claim 1, wherein the component (b) polymer of an acidic group-containing polymerizable monomer is a polymer of an α-β unsaturated carboxylic acid.

5. 5. The glass ionomer cement composition for dental luting according to claim 1, wherein the weight average molecular weight of the polymer of the acidic group-containing polymerizable monomer as component (b) is 50,000 to 80,000.

6. 6. The glass ionomer cement composition for dental bonding according to claim 1, wherein the chelating agent (c) is tartaric acid.

7. 7. The glass ionomer cement composition for dental luting according to any one of claims 1 to 6, wherein the component (b) polymer of an acidic group-containing polymerizable monomer is a polymer of acrylic acid and 1-butene-1,2,4-tricarboxylic acid, and / or a polymer of acrylic acid and 3-butene-1,2,3-tricarboxylic acid.

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