Dental resin-added glass ionomer composition and kit containing the composition

Abstract

The present invention relates to a dental resin-modified glass ionomer composition comprising: (a) water; (b) at least one polycarboxylic acid; (c) at least one compound having at least one phosphorus atom; and (d) at least one bisacrylamide having formula (I). The present invention further relates to a kit comprising such a dental resin-modified glass ionomer composition. TIFF2023505565000020.tif30161

Description

Technical Field

[0001] Field of the Invention The present invention relates to a resin-modified glass ionomer composition for dental use.

[0002] The present invention further targets a kit containing such a resin-modified glass ionomer composition for dental use.

[0003] Background of the Invention Dental cements are used to attach prosthetic appliances such as inlays, onlays, crowns or posts to the tooth structure so that the affected tooth can restore its function and aesthetics. Dental cements can also be used to attach orthodontic appliances such as orthodontic brackets or bands to the tooth structure to correct malocclusion of teeth or to adjust the interdental space. Dental cements can also be used as root canal filling materials.

[0004] When cementing prosthetic appliances and orthodontic appliances to the tooth structure, there are various types of dental cements available for dentists to choose from. For example, (1) zinc phosphate cement, (2) zinc carboxylate cement, (3) zinc oxide eugenol (ZOE) cement, (4) glass ionomer cement, (5) self-adhesive and adhesive resin cements, and (6) resin-modified glass ionomer (RMGI) cement. As will be described later, each type of cement has its own advantages and disadvantages.

[0005] For example, zinc phosphate cement (1) utilizes an acid-base condensation reaction between zinc oxide and phosphoric acid. Generally, zinc phosphate cement is provided as a powder / liquid system, which requires manual mixing of the powder component and the liquid component before application. Manual mixing can be a cumbersome process and often lacks consistency due to inappropriate weighing / formulation of the component powder and the liquid component. In addition, zinc phosphate cement has low adhesive strength to tooth structure, high optical opacity (low aesthetics), and high solubility in the oral environment. Zinc phosphate cement also has a substantially low initial pH, which can cause inflammation or hypersensitivity in the early stages of setting.

[0006] Zinc carboxylate cement (2) utilizes an acid-base condensation reaction between zinc oxide and polycarboxylic acid. Zinc carboxylate cement has relatively less irritation to pulp tissue and improved adhesion to tooth structure compared to its zinc phosphate counterpart. However, zinc carboxylate cement has a short working time, high optical opacity, low mechanical strength, and requires an additional conditioning step before cementation.

[0007] Zinc oxide eugenol (ZOE) cement (3) utilizes an acid-base condensation reaction between zinc oxide and eugenol in the presence of water to form a zinc eugenolate chelate. ZOE cement has low mechanical strength, low adhesion, low aesthetics, and high water solubility, whereby this cement is only suitable for use as a temporary or provisional cement.

[0008] The self - adhesive and adhesive resin cement (5) utilizes the free - radical polymerization condensation reaction of (meth)acrylate monomers. Self - adhesive and adhesive resin cements are generally reinforced with inorganic glass fillers and have very good mechanical strength, favorable aesthetics, and low water solubility. Self - adhesive resin cements have good adhesive strength to the tooth structure without using an adhesive, and adhesive resin cements show excellent adhesive strength to the tooth structure when used in combination with an adhesive. As a result, self - adhesive and adhesive resin cements are optimal for cementing aesthetic but brittle ceramic restorations. Nevertheless, self - adhesive and adhesive resin cements are rather hydrophobic and sensitive to water / saliva contamination. In particular, adhesive resin cements are also quite technique - sensitive and can cause hypersensitivity after treatment due to a complex adhesion protocol that requires another adhesive.

[0009] Glass ionomer cement (6) utilizes the acid - base condensation reaction between polycarboxylic acid and a fluoroaluminosilicate filler. Compared with zinc phosphate cement, glass ionomer cement generally shows improved adhesion, reduced water solubility, improved mechanical strength, and has the added benefit of cariogenicity due to the long - term sustained release of fluoride. However, glass ionomer cement has low aesthetics and low dryness at the early stage of condensation. Compared with resin cement, glass ionomer cement is rather brittle and has substantially lower adhesive strength to the tooth structure.

[0010] Various efforts have been made to combine resin cement chemistry with glass ionomer cement chemistry to form resin-modified glass ionomer (RMGI) cement (7). Akahane et al. (U.S. Patent No. 5,063,257) incorporated a polymerizable monomer, an initiator, and a surfactant into a glass ionomer composition so that the resulting RMGI composition can be cured through both acid-base reaction and free radical polymerization. Mitra et al. (U.S. Patents Nos. 5,130,347 and 5,925,715) incorporated a photoinitiator system into a glass ionomer composition and added polymerizable groups to polycarboxylic acids through amide linkages so that the resulting RMGI composition can be cured through both acid-base reaction and free radical photopolymerization. Jandourek (European Patent Application Publication No. 0,329,268 A2) incorporated a photoinitiator system, a polymerizable monomer, and a polymerizable polycarboxylic acid into a glass ionomer composition so that the resulting RMGI composition can be cured through both acid-base reaction and free radical photopolymerization. Mitra et al. (U.S. Patent No. 5,154,762) incorporated a redox initiator system into a glass ionomer composition, together with a polymerizable monomer and a polymerizable polycarboxylic acid, so that the resulting RMGI composition can be cured through acid-base reaction and free radical polymerization by either a photoinitiator or a redox initiator system. Nakaseko (U.S. Patent No. 6,214,101) prepared a paste / paste RMGI composition by incorporating a polymerizable monomer and an encapsulated polymerization initiator into a glass ionomer composition.

[0011] Thus, the RMGI cement composition combines the setting chemistry from glass ionomer cement and the setting chemistry from resin cement. The RMGI cement composition retains the beneficial property of sustained long-term fluoride release and provides improved mechanical strength, fracture toughness, and adhesion compared to conventional glass ionomer cement alone. Also, due to the hydrophilic and self-adhesive properties, the RMGI cement composition is generally less sensitive to moisture / saliva contamination and less technique-sensitive compared to self-adhesive and adhesive resin cements.

[0012] However, the adhesive strength of prior RMGI cement compositions to the tooth structure is still significantly lower than that of self - adhesive and adhesive resin cements.

[0013] Object of the Invention Therefore, in view of the prior art, an object of the present invention was to provide a resin - modified glass ionomer (RMGI) composition for dentistry that does not exhibit the drawbacks of the aforementioned known prior - art RMGI compositions.

[0014] Therefore, what is required is a means to further improve the adhesiveness of the RMGI composition.

[0015] Furthermore, it was also an object to provide an RMGI composition that exhibits a significantly increased adhesive strength compared to other conventional RMGI compositions.

[0016] Summary of the Invention These objects, and further objects that are immediately derivable or distinguishable from the relationships described hereinbefore as a preamble, are achieved by a resin - modified glass ionomer composition for dentistry having all the features of claim 1. Suitable modifications to the resin - modified glass ionomer composition of the present invention are protected in independent claims 2 - 12. Furthermore, claim 13 includes a kit containing such a resin - modified glass ionomer composition for dentistry, and simultaneously, independent claims 14 and 15 represent preferred embodiments of said kit.

[0017] Therefore, the present invention is a resin - modified glass ionomer composition for dentistry, comprising: (a) water; (b) at least one polycarboxylic acid; (c) At least one compound having at least one phosphorus atom selected from the group consisting of (meth)acrylates having at least one phosphate group, (meth)acrylates having at least one phosphonate group, (meth)acrylamides having at least one phosphate group, (meth)acrylamides having at least one phosphonate group, acrylic ethers having at least one phosphate group, and acrylic ethers having at least one phosphonate group; and (d) The following formula (I):

Chemical formula

[0018] Accordingly, it is possible to provide a resin-modified glass ionomer (RMGI) composition that unexpectedly does not exhibit the drawbacks of the known prior art RMGI compositions described above.

[0019] Furthermore, the RMGI composition of the present invention exhibits significantly increased adhesive strength compared to other conventional RMGI compositions.

[0020] In addition, the present invention further improves the adhesiveness of known RMGI compositions.

[0021] At least one compound having at least one phosphorus atom results in strong acidity, and thereby has a high effect on the dissolution of the smear layer on the tooth surface and tooth demineralization. In particular, (meth)acrylate having at least one phosphate group can be effective in improving the adhesion to enamel.

[0022] Detailed Description of the Invention The expression "substantially free" means, in the context of the present invention, a concentration of less than 5 weight percent, preferably less than 2.5 weight percent, more preferably less than 1 weight percent, based on the total weight of the dental (RMGI) composition.

[0023] As used herein, the term "resin-modified glass ionomer (RMGI)" and the alternative term "resin-modified glass ionomer (RMGI) Cement " are interchangeable in the context of the present invention.

[0024] The term "(meth)acrylate" in the context of the present disclosure means to refer to acrylate as well as the corresponding methacrylate.

[0025] The term "hydrocarbon moiety" refers to straight or branched saturated or unsaturated hydrocarbon chains of each length. Such hydrocarbon moieties may be further substituted with one or more substituents such as alkylene, alkoxy, acrylamide, acrylate, nitrile, aryl, cycloalkyl and hydroxyl.

[0026] The term "alkyl group" refers to straight or branched saturated hydrocarbon chains of each length. This term can be exemplified by groups such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-decyl, dodecyl, tetradecyl and the like. Such alkyl groups may be further substituted with one or more substituents such as alkylene, alkoxy, nitrile, aryl, cycloalkyl and hydroxyl.

[0027] The term "alkylene group" refers to straight or branched hydrocarbon chains of each length containing at least one carbon-carbon double bond. Such alkylene groups may be further substituted with one or more substituents such as alkyl, alkoxy, nitrile, aryl, cycloalkyl and hydroxyl.

[0028] The term "aryl group" refers to an aromatic, heterocyclic, fused aromatic, fused heterocyclic, bicyclic aromatic or bicyclic heterocyclic ring system having a given number of carbon atoms. "Aryl", as broadly defined, when used herein, can include 5- to 18-membered monocyclic aromatic groups that can contain zero to 4 heteroatoms, such as benzene, pyrrole, furan, thiophene, imidazole, oxazole, thiazole, triazole, pyrazole, pyridine, pyrazine, pyridazine, pyrimidine, and the like. An "aryl" group having a heteroatom in such a ring structure can also be referred to as a "heteroaryl" or "heterocyclic" or "heteroaromatic". The aromatic ring may be substituted at one or more ring positions with one or more substituents such as halogen, alkyl, alkylene, cycloalkyl, hydroxyl and alkoxy.

[0029] The term "cycloalkyl group" refers to a monocyclic or polycyclic cycloalkyl group. Examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl. Examples of polycyclic cycloalkyl groups include, for example, adamantyl, norbornyl, decalinyl, 7,7-dimethyl-bicyclo[2.2.1]heptanyl, tricyclo[5.2.1.02,6]decyl, and the like. Such cycloalkyl groups may be further substituted with one or more substituents such as alkyl, alkoxy, nitrile, aryl, cycloalkyl and hydroxyl.

[0030] With respect to component (a), water provides the medium necessary for the ionic acid-base reaction to occur between the polycarboxylic acid (b) and the fluoroaluminosilicate filler (f). According to an embodiment of the present invention, water (a) can be present in an amount of 0.5 to 40 weight percent, preferably 1.0 to 30 weight percent, more preferably 2.0 to 25 weight percent, based on the total weight of the dental RMGI composition.

[0031] Regarding component (c), at least one compound having at least one phosphorus atom selected from the group consisting of (meth)acrylates having at least one phosphate group, (meth)acrylates having at least one phosphonate group, (meth)acrylamides having at least one phosphate group, (meth)acrylamides having at least one phosphonate group, acrylic ethers having at least one phosphate group, and acrylic ethers having at least one phosphonate group is included in the dental RMGI composition of the present invention.

[0032] Such polymerizable monomers containing phosphorus are generally included only in water-free self-adhesive resin cements (also called SARC). These SARCs provide good aesthetics and good adhesion to dentin (superior compared to RMGI compositions), but have the weakness of poor applicatibility for users.

[0033] Such polymerizable monomers containing phosphorus have never been included in water-containing RMGI compositions that provide poor aesthetics and poor adhesion to dentin (inferior compared to resin cements) but good applicatibility for users.

[0034] Such a compound having at least one phosphorus atom can be a (meth)acrylate having at least one phosphate group. The term "phosphate group" in the present invention also includes the possibility of having a phosphate group in which each R residue of each oxygen atom of the phosphate group is hydrogen, as represented by the following MEP, GDMP, MDP, or PENTA-P.

[0035] Some specific examples are shown together below:

Chemical formula

[0036] Such a compound having at least one phosphorus atom can also be a (meth)acrylamide having at least one phosphate group, in which case (compared to (meth)acrylate), the oxygen atom of each (meth)acrylate ester group is replaced by a nitrogen atom, thereby forming a (meth)acrylamide instead of a (meth)acrylate.

[0037] Such a compound having at least one phosphorus atom can also be a (meth)acrylate having at least one phosphonate group. The term "phosphonate group" in the present invention also includes the possibility of having a phosphonic acid group in which each R residue of each oxygen atom of the phosphonate group is hydrogen, as shown by MAPA-1 or MAPA-2 below.

[0038]

Chemical formula

[0039] Such a compound having at least one phosphorus atom can also be a (meth)acrylamide having at least one phosphonate group, in which case (compared to (meth)acrylate), the oxygen atom of each (meth)acrylate ester group is replaced by a nitrogen atom, thereby forming a (meth)acrylamide instead of a (meth)acrylate.

[0040] Such a compound having at least one phosphorus atom can also be an acrylic ether having at least one phosphonate group. Some examples are shown below:

Chemical formula

[0041] Such a compound having at least one phosphorus atom can also be an acrylic ether having at least one phosphate group.

[0042] All compounds having at least one phosphorus atom among the components (c) contained in the dental RMGI composition (or, if a kit exists, all parts of the kit) are provided in an amount of 2 to 30% by weight, preferably 3 to 20% by weight, more preferably 4 to 10% by weight, based on the total weight of the dental RMGI composition.

[0043] In one embodiment, at least one compound having at least one phosphorus atom is selected from the group consisting of 2-(meth)acryloyloxyethyl dihydrogen phosphate, bis[2-(meth)acryloyloxyethyl] hydrogen phosphate, 2-(meth)acryloyloxyethyl phenyl hydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl phenyl hydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 1,3-di(meth)acryloylpropane-2-dihydrogen phosphate, 1,3-di(meth)acryloylpropane-2-phenyl hydrogen phosphate, dipentaerythritol pentaacryloyl dihydrogen phosphate, ethyl 2-[5-dihydroxyphosphoryl-5.2-dioxapentyl] acrylate, and bis[5-{2-(meth)acryloyloxyethoxycarbonyl}heptyl] hydrogen phosphate.

[0044] In a preferred embodiment thereof, at least one compound having at least one phosphorus atom is selected from the group consisting of 10-methacryloyloxydecyl dihydrogen phosphate (MDP), dipentaerythritol pentaacryloyl dihydrogen phosphate (PENTA-P), and ethyl 2-[5-dihydroxyphosphoryl-5.2-dioxapentyl] acrylate (DHPOBA).

[0045] In particular, these three individual compounds are preferred because they have excellent adhesiveness and self-stability of the acrylate compound.

[0046] Regarding component (d), at least one bisacrylamide having the formula (I) as described above is included.

[0047] Such bisacrylamides provide superior stability to hydrolysis compared to commonly used (meth)acrylates having no phosphorus atoms (usually, up to 80% is hydrolyzed at 50 °C over a given time in the presence of an acid such as water and methanesulfonic acid (MSA)), typically less than 20% being hydrolyzed at 50 °C over a given time in the presence of an acid such as water and methanesulfonic acid (MSA). It is known in the prior art that these commonly used esters of acrylic or methacrylic acid are sensitive to such environmental conditions of hydrolysis (presence of water and acid). However, the hydrolysis stability of (meth)acrylates is a problem in terms of the acidity of many dental compositions, which severely limits the storage stability of dental compositions. Moreover, hydrolysis occurring under biological conditions in a patient's oral cavity is a further concern regarding (meth)acrylates.

[0048] Such bisacrylamides can typically be the following:

Chemical formula

[0049] All bisacrylamides according to formula (I) contained in the dental RMGI composition (or, if a kit is present, all parts of the kit) are provided in an amount of 10 to 60 weight percent, preferably 15 to 50 weight percent, more preferably 20 to 40 weight percent, based on the total weight of the dental RMGI composition.

[0050] R2 is a difunctional C1-C substituted with at least one, preferably one or two acrylamide or acrylate groups 18In embodiments which are hydrocarbon moieties, even when containing one or two additional acrylamide groups to represent trisacrylamide or tetra-acrylamide, they are still referred to as "bisacrylamide" in the context of the present invention. When containing at least one acrylate group, a "mixed structure" containing at least two acrylamide groups and at least one ester group is formed.

[0051] In one embodiment, at least one bisacrylamide is selected from the group consisting of N,N'-dimethyl-1,3-bis(acrylamide)-propane, N,N'-dimethyl-1,3-bis(acrylamide)-hexane, N,N'-diethyl-1,3-bis(acrylamide)-propane (BADEP), and N,N'-bisacryloyl-N,N'-bisallyl-1,4-but-2-ene-diamine (BAABE).

[0052] In one embodiment, the dental resin-modified glass ionomer composition is substantially free, preferably completely free, of ascorbic acid and its salts; here, the expression "substantially free" means a concentration of less than 5% by weight, preferably less than 2.5% by weight, more preferably less than 1% by weight, based on the total weight of the dental (RMGI) composition in the context of the present invention.

[0053] The dental resin-modified glass ionomer composition of the present invention is substantially free, preferably completely free, of, inter alia, L(+) ascorbic acid, L(+)-calcium ascorbate, L(+)-sodium ascorbate, dehydroascorbic acid, isoascorbic acid, sodium isoascorbate, (+)-5,6-0-isopropylidene-L-ascorbic acid, 2,6-di-0-palmitoyl-L-ascorbic acid, 6-0-palmitoyl-L-ascorbic acid, D-araboascorbic acid, etc.

[0054] In one embodiment, the dental resin-modified glass ionomer composition further (e) the following formula (II): [Chemical formula] [wherein, R4 = hydrogen, C1-C 18 alkyl group, C3-C containing at least one carbon-carbon double bond 18 alkylene group, C3-C 18 cycloalkyl group, or C5-C 18 aryl group; and R5 = hydrogen, C1-C 18 alkyl group, C3-C containing at least one carbon-carbon double bond 18 alkylene group, C3-C 18 cycloalkyl group, or C5-C 18 aryl group; where The term "alkyl group" for R4 and R5 herein refers to a straight-chain or branched saturated hydrocarbon chain of each length, which may be further substituted with one or more substituents such as alkylene, alkoxy, nitrile, aryl, cycloalkyl, and hydroxyl] and contains at least one acrylamide.

[0055] Regarding component (e), at least one acrylamide having the formula (II) as described above is included.

[0056] All acrylamides having the formula (II) contained in the dental RMGI composition (or, if a kit exists, all parts of the kit) are provided in an amount of 2 to 15 weight percent, preferably 2 to 9 weight percent, more preferably 3 to 5 weight percent, based on the total weight of the dental RMGI composition.

[0057] Possible examples are as follows: [Chemical formula]

[0058] In its preferred embodiment, at least one acrylamide is selected from the group consisting of N-methylolacrylamide, N-methylolmethacrylamide, N-(2-hydroxyethyl)-methacrylamide, N-methyl-N-(2-hydroxyethyl)-acrylamide, N-methacryloyl-1-aminosalicylic acid, N-acryloylaspartic acid, and N-methacryloylglycine.

[0059] In one embodiment, the dental resin-modified glass ionomer composition is substantially free, preferably completely free, of (meth)acrylate having no at least one phosphorus atom; herein, the expression "substantially free" means a concentration of less than 5 wt%, preferably less than 2.5 wt%, more preferably less than 1 wt% based on the total weight of the dental (RMGI) composition in the context of the present invention.

[0060] Such (meth)acrylate having no at least one phosphorus atom can typically be one of the following known esters:

Chemical formula

[0061] In one embodiment, the dental resin-modified glass ionomer composition further comprises (f) at least one reactive filler, preferably a fluoroaluminosilicate filler.

[0062] The fluoroaluminosilicate filler is ion-reactive with acids such as polycarboxylic acid (b). As used herein, "ion-reactive" means that when the micronized fluoroaluminosilicate filler (f) and polycarboxylic acid (b) are mixed together in the presence of water (a), an increase in viscosity or solidification of the mixed composition can be observed. According to an embodiment of the present invention, the fluoroaluminosilicate filler is a micronized filler having an average particle size in the range of about 0.02 microns to about 20 microns. The average particle size of the micronized fluoroaluminosilicate filler can be measured by a conventional particle size measuring device using the laser light scattering method. In one embodiment, the average particle size of the micronized fluoroaluminosilicate filler is in the range of about 0.10 microns to about 10 microns. According to one aspect, the micronized fluoroaluminosilicate filler can further contain calcium, strontium, barium, rare earth metals, zirconium, zinc, and combinations thereof. Exemplary rare earth metals include, but are not limited to, ytterbium, yttrium, or combinations thereof. In one embodiment, to enhance the interfacial bond between the filler and the resin matrix and improve the mechanical properties, the surface of the fluoroaluminosilicate filler is treated or coated with a coupling agent. In one embodiment, the coupling agent is a silane compound having at least one polymerizable group selected from the group consisting of acrylate, methacrylate, acrylamide, methacrylamide, and vinyl groups. Useful examples of coupling agents include, but are not limited to, y-methacryloyloxypropyltrimethoxysilane (MPTMS), γ-methacryloyloxypropyltriethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane. Another useful example of a coupling agent is a compound having an acid functional group and a polymerizable group selected from the group consisting of acrylate, methacrylate, acrylamide, methacrylamide, and vinyl groups. Useful examples include, but are not limited to, acrylic acid, methacrylic acid, and maleic acid.

[0063] All fluor aluminosilicate fillers of component (f) included in the dental RMGI composition (or, if a kit exists, all parts of the kit) are provided in an amount of 10 to 55 weight percent, preferably 15 to 40 weight percent, more preferably 25 to 35 weight percent, based on the total weight of the dental RMGI composition.

[0064] In one embodiment, at least one polycarboxylic acid is at least one copolymer or homopolymer of monomers of acrylic acid, methacrylic acid, 2-chloroacrylic acid, 3-chloroacrylic acid, aconitic acid, mesaconic acid, maleic acid, itaconic acid, fumaric acid, glutaconic acid, and citraconic acid.

[0065] Such polycarboxylic acids do not contain polymerizable and ethylenically unsaturated double bonds. Further, such polycarboxylic acids have a weight average molecular weight of 10,000 to 130,000 g / mol. When the weight average molecular weight is less than 10,000 g / mol, the strength of the cured body easily decreases, and the adhesive strength to teeth tends to decrease. When the weight average molecular weight exceeds 130,000 g / mol, the processability tends to decrease.

[0066] All polycarboxylic acids of component (b) included in the dental RMGI composition (or, if a kit exists, all parts of the kit) are provided in an amount of 2 to 20 weight percent, preferably 2 to 12 weight percent, more preferably 3 to 7 weight percent, based on the total weight of the dental RMGI composition.

[0067] In one embodiment, the dental resin-modified glass ionomer composition further (g) includes at least one non-reactive filler, preferably glass flakes and / or inert silica particles.

[0068] Examples of fillers that are not ion-reactive with respect to the acidic moiety include, but are not limited to, inorganic salts, fluorides, glass flakes, aluminosilicate glass, aluminoborosilicate glass, quartz, silica, zirconia, zirconia-silica or polymer fillers.

[0069] Specific examples can be selected from the group consisting of strontium fluoride, ytterbium fluoride, yttrium fluoride, barium sulfate, barium tungstate, zirconium oxide, quartz, inert silica particles and polymer fillers. Suitable silica particle fillers include fumed silica, colloidal silica and / or precipitated silica. Examples of silica particle fillers include Aerosil® series such as OX-50, OX-130 and OX-200 silica sold by Degussa (Ridgefield Park, N.J.), and Cab-O-Sil® MS and Cab-O-Sil® TS-530 silica sold by Cabot Corp (Tuscola, Ill.).

[0070] All non-reactive fillers of the components (g) included in the dental RMGI composition (or, if a kit is present, all parts of the kit) are provided in an amount of 10 to 50 weight percent, preferably 12 to 35 weight percent, more preferably 15 to 25 weight percent, based on the total weight of the dental RMGI composition.

[0071] In one embodiment, the dental resin-modified glass ionomer composition further includes at least one polymerization initiator system selected from the group consisting of a photoinitiator system, a redox initiator system or a combination thereof.

[0072] In one embodiment, a photoinitiator is incorporated into the composition. The photoinitiator can be any compound or combination of compounds that can generate free radicals when exposed to a light source and cause polymerization or curing of the composition. The light source can be any dental curing light that emits in the visible or ultraviolet region. Examples of photoinitiators include, but are not limited to, diketone compounds; benzoin; benzoin ethers and esters; 2,2 - diethoxyacetophenone; monoacylphosphine oxides; bisacylphosphine oxides; diaryliodonium salts; triarylsulfonium salts, silylglyoxylates; and any mixtures thereof. Examples of diketone compounds include, but are not limited to, camphorquinone and 1 - phenyl - 1,2 - propanedione.

[0073] In addition, a co - initiator can be used together with the photoinitiator to enhance the curing efficiency. Examples of co - initiators include tertiary amines and sulfinate compounds. Exemplary co - initiators include ethyl 4-(N,N - dimethylamino)benzoate; 4-(N,N - dimethylamino)benzoic acid; 4-(N,N - dimethylamino)benzonitrile; 4-(N,N - dimethylamino)benzaldehyde; 2-(ethylhexyl)-4-(N,N - dimethylamino)benzoate; N,N - dimethylaminoethyl methacrylate; N,N - dimethylaminophenethyl alcohol; sodium benzenesulfinate; germane hydride (e.g., Ph3GeH); silicon hydride, phosphine (e.g., Ph3P); and sodium toluenesulfinate, but are not limited thereto.

[0074] According to one embodiment, the photoinitiator system includes a combination of camphorquinone and a tertiary amine.

[0075] All polymerization initiator systems of component (h) contained in the dental RMGI composition (or, if a kit exists, all parts of the kit) are provided in an amount of 0.01 to 10 weight percent, preferably 0.2 to 8 weight percent, more preferably 0.5 to 5 weight percent, based on the total weight of the dental RMGI composition.

[0076] According to another embodiment, a redox initiator system is incorporated into the dental RMGI composition. The redox initiator system typically includes at least one reducing agent and at least one oxidizing agent. When the reducing agent and the oxidizing agent are mixed together, a redox reaction proceeds, generating free radicals and initiating the polymerization of the monomer, resulting in the curing or solidification of the mixed composition.

[0077] Examples of reducing agents include, but are not limited to, aromatic sulfinates; aliphatic sulfinates; thiourea; substituted thioureas; Fe(II) salts; Cu(I) salts; Co(II) salts; ascorbic acid; ascorbic acid derivatives and salts; barbituric acid; and barbituric acid derivatives and salts.

[0078] According to an embodiment of the present invention, the reducing agent(s) may be present in an amount of 0.01 to 10 weight percent based on the total weight of the dental RMGI composition.

[0079] Examples of oxidizing agents include, but are not limited to, tertiary hydroperoxide compounds such as cumene hydroperoxide in which at least one hydroperoxy group is bonded to at least one tertiary carbon; Cu(II) salts such as Cu(II) acetylacetonate, Cu(II) benzoylacetonate or Cu(II) cyclohexylbutyrate; Fe(III) salts such as FeCl3, Fe(III) benzoylacetonate or Fe(III) cyclohexylbutyrate; Co(III) salts; persulfates; permanganates; and combinations thereof.

[0080] According to an embodiment of the present invention, the oxidizing agent(s) may be present in an amount of from 0.01 to 10 weight percent, based on the total weight of the dental RMGI composition.

[0081] The photoinitiator system and the redox initiator system can be incorporated alone or in combination.

[0082] Furthermore, the object of the present invention is also achieved by a kit comprising such a dental resin-modified glass ionomer composition, the kit comprising at least a first part and at least a second part; the first part comprising (c) at least one compound having at least one phosphorus atom selected from the group consisting of (meth)acrylates having at least one phosphate group, (meth)acrylates having at least one phosphonic acid group, and acrylic ethers having at least one phosphonic acid group; and (d) at least one bisacrylamide having formula (I); the second part comprising (a) at least water; (b) at least one polycarboxylic acid; and (d) at least one bisacrylamide having formula (I).

[0083] The provision of a kit containing such a dental resin-modified glass ionomer composition in the first and second parts initially maintains the isolation of the various reactive components. The mixture obtained by mixing the components of the dental RMGI composition of the present invention is suitable for use in a variety of direct and indirect dental applications, including but not limited to fillings, orthodontic retainers, bridges, space maintainers, dental prostheses, dentures, crowns, posts, jackets, inlays, onlays, facings, veneers, facets, implants, abutments, cements, adhesives and splints; it provides improved adhesion strength to dental substrates such as dentin, enamel, dental alloys, zirconia, ceramic materials or potteries, and further retains other desired properties.

[0084] In its preferred embodiment, the first part further (f) includes at least one reactive filler, preferably a fluoroaluminosilicate filler; The second part further (e) at least one acrylamide having formula (II); and (f) includes at least one non-reactive filler, preferably glass flakes and / or inert silica particles.

[0085] In its even more preferred embodiment, the first and second parts are each a paste; or, the first part is a powder and the second part is a liquid.

[0086] The two pastes can be mixed in any volume ratio. In one embodiment, the two pastes are mixed in a volume ratio of about 10:1 to about 1:10. In one embodiment, the two pastes are mixed in a volume ratio of 1:1.

[0087] The two parts need to be mixed immediately before application, applied to the restorative material, and cured inside the patient's oral cavity by self-curing or a combination of self-curing and photo-curing.

[0088] Generally, this is done manually with a spatula or by using a mixing tip that attaches a fixed static mixer to the outlet of a double cartridge to automatically knead the two parts of the kit before application.

[0089] Accordingly, the present invention addresses the issues of providing enhanced adhesion strength to dental structures and a simplified application procedure.

[0090] The following non-limiting examples are provided to illustrate certain embodiments of the present invention and to enhance understanding of the present invention, and are not intended to limit the scope of the present invention, which is defined by the appended claims.

[0091] All the experiments and comparative experiments of the present invention were carried out by using a resin-modified glass ionomer composition for dentistry, in which case the first and second parts are pastes.

[0092] All the values given in Tables 1, 2, 5 and 6 are given as weight percentages of the respective oxidized paste or reduced paste. All the components of each oxidized paste or reduced paste together provide 100 weight percent of the total of each individual paste.

[0093] Preparation: For the preparation of the reduced paste, first, PAA was dissolved in distilled water by premixing in a SpeedMixer DAC 600-2 VAC-P (Hauschild & Co. KG. E-QC-1936). All the other components according to the table were weighed directly into 50 mL plastic containers per paste (PP 30. Hauschild & Co. KG). For the preparation of the oxidized paste, all the components according to the table were also weighed directly into 50 mL plastic containers per paste (PP 30. Hauschild & Co. KG). The solid components were added first and the liquid was added last; the batch size per paste was 15 - 45 g. Then, each container was sealed with a perforated lid and placed in the SpeedMixer. Mixing was carried out twice at 2500 rpm for 2 minutes and once at 1000 rpm / 100 mbar for 1 minute. During the mixing process, the paste was simply stirred with a spatula. Finally, the holes in the lid were sealed with Scotch tape and the containers were stored at room temperature until further use.

[0094] For evaluation, both pastes were manually filled into a double-barrel syringe in a 1:1 volume ratio and placed in the SpeedMixer again. Mixing was carried out three times at 1000 rpm for 1 minute to remove residual air bubbles. A long mixing tip (MixPac) (for example, used for RelyX Luting Plus) was utilized to achieve homogeneous extrusion of the luting cement.

[0095] Shear bond strength (SBS): To determine the adhesive strength of each composite cement to dentin / enamel, extracted human molars were cylindrically embedded in a low-temperature-curing matrix resin and finally wet-polished using 320- and 600-grit sandpapers until a flat surface was exposed from the buccal / lingual side. A stainless steel bar (diameter 2.985 mm) was sandblasted, ultrasonically cleaned, and dried. Each cement was applied to the surface of the steel bar, placed on dentin / enamel, and self-cured at 37 °C / 50% R.H. for 5 minutes under a load of 220 g. Samples (n = 6 per group) were stored in water at 37 °C for 24 hours. Shear bond strength (SBS) was obtained using a Zwick at a crosshead speed of 1 mm / min.

[0096] Working time (WT): Bead-like objects were formed and periodically probed at 23 °C using metal instruments. The end of the working time was defined by the transition point from a viscous spreading material to an elastic gel-like material; the start of the working time was defined by the initiation of kneading.

[0097] Setting time (ST): The setting time of each material was measured according to ISO 9917-2.

[0098] Three-point bending: Mechanical data for flexural strength (FS) and flexural modulus (E-Mod.) were measured in three-point bending mode according to ISO 9917-2.

[0099] Opacity: The opacity of each material was examined using the following procedure (n = 2): Place a thin film piece on one of the metal plates and place a mold on it. Slightly overfill the mold with each material prepared according to the manufacturer's instructions. Place a second thin film piece on top of the material in the mold and cover this with a second metal plate. In that way, remove the excess material. Fix the mold with a clamp and immediately transfer the assembly to an oven maintained at 37 ± 2 °C and ≥ 95% R.H. After 60 minutes have elapsed since the start of mixing, remove the sample from the mold and surface-treat the outer edge of the sample to remove burrs and irregularities. Thereafter, place the sample in distilled water at 60 °C in the dark for 24 hours. Finally, measure the opacity of each sample using a Datacolor 800.

[0100] Examples of the present invention Table 1: Components of each first part (oxidation paste) of the resin-modified glass ionomer compositions for dental use of Examples 1 to 5 of the present invention

[0101] [Table 1]

[0102] Table 2: Components of each second part (reduction paste) of the resin-modified glass ionomer compositions for dental use of Examples 1 to 5 of the present invention

[0103] [Table 2]

[0104] Table 3: Experimental data of the resin-modified glass ionomer compositions for dental use of Examples 1 to 5 of the present invention

[0105] [Table 3]

[0106] Table 4: Experimental results of the resin-modified glass ionomer compositions for dental use of Examples 1 to 5 of the present invention

[0107]

Table 4

[0108] Comparative Example Table 5: Components of each first part (oxidation paste) of the resin-added glass ionomer compositions for dental use in Comparative Examples 6 to 10

[0109]

Table 5

[0110] Table 6: Components of each second part (reduction paste) of the resin-added glass ionomer compositions for dental use in Comparative Examples 6 to 10

[0111]

Table 6

[0112] Table 7: Experimental data of the resin-added glass ionomer compositions for dental use in Comparative Examples 6 to 10

[0113]

Table 7

[0114] Table 8: Experimental results of the resin-added glass ionomer compositions for dental use in Comparative Examples 6 to 10

[0115]

Table 8

[0116] The principle of the present invention has been described in relation to certain specific embodiments and is provided for illustrative purposes. It should be understood by those skilled in the art that various modifications will become apparent upon reading this specification. Therefore, the invention disclosed herein is intended to cover such modifications insofar as they are within the scope of the appended claims. The scope of the present invention is limited only by the appended claims.

Claims

**Claim 1** A resin-modified glass ionomer composition for dental use, comprising: (a) water; (b) at least one polycarboxylic acid; (c) at least one compound having at least one phosphorus atom selected from the group consisting of (meth)acrylates having at least one phosphate group, (meth)acrylates having at least one phosphonate group, (meth)acrylamides having at least one phosphate group, (meth)acrylamides having at least one phosphonate group, acrylic ethers having at least one phosphate group, and acrylic ethers having at least one phosphonate group; and (d) the following formula (I): 【Chemical Formula 9】 [In the formula, R １ = hydrogen, C １ ~ C １８ alkyl group, C containing at least one carbon-carbon double bond ３ ~ C １８ alkylene group, C ３ ~ C １８ cycloalkyl group, or C ５ ~ C １８ aryl group; R ２ = a difunctional C １ -C １８ alkyl group, a difunctional C ４ -C １８ alkylene group, a difunctional C ３ -C １８ cycloalkyl group, a difunctional C ５ -C １８ aryl group, or a difunctional C １ -C １８ hydrocarbon moiety; and R ３ = hydrogen, C １ ~ C １８ alkyl group, C containing at least one carbon-carbon double bond ３ ~ C １８ alkylene group, C ３ ~ C １８ cycloalkyl group, or C ５ ~ C １８ aryl group] at least one bisacrylamide having A resin-modified glass ionomer composition for dental use containing the same. **Claim 2** The resin-modified glass ionomer composition for dental use according to claim 1, wherein the bifunctional C1-C18 hydrocarbon moiety substituted with at least one acrylamide or acrylate group in R2 is a bifunctional C1-C18 hydrocarbon moiety substituted with one or two acrylamide or acrylate groups. **Claim 3** The resin-modified glass ionomer composition for dental use according to claim 1 or 2, wherein the at least one compound having at least one phosphorus atom is selected from the group consisting of 2-(meth)acryloyloxyethyl dihydrogen phosphate, bis[2-(meth)acryloyloxyethyl] hydrogen phosphate, 2-(meth)acryloyloxyethyl phenyl hydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl phenyl hydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 1,3-di(meth)acryloylpropane-2-dihydrogen phosphate, 1,3-di(meth)acryloylpropane-2-phenyl hydrogen phosphate, dipentaerythritol pentaacryloyl dihydrogen phosphate, ethyl 2-[5-dihydrophosphoryl-5.2-dioxapentyl] acrylate, and bis[5-{2-(meth)acryloyloxyethoxycarbonyl}heptyl] hydrogen phosphate. **Claim 4** The dental resin-modified glass ionomer composition according to claim 3, wherein at least one compound having at least one phosphorus atom is selected from the group consisting of 10-methacryloyloxydecyl dihydrogen phosphate, dipentaerythritol pentaacryloyl dihydrogen phosphate, and ethyl 2-[5-dihydroxyphosphoryl-5.2-dioxapentyl] acrylate. **Claim 5** The dental resin-modified glass ionomer composition according to any one of claims 1 to 4, wherein the concentration of ascorbic acid and its salts is less than 5% by weight based on the total weight of the dental resin-modified glass ionomer composition. **Claim 6** The dental resin-modified glass ionomer composition according to any one of claims 1 to 4, wherein the concentration of ascorbic acid and its salts is less than 2.5% by weight based on the total weight of the dental resin-modified glass ionomer composition. **Claim 7** The dental resin-modified glass ionomer composition according to any one of claims 1 to 4, wherein the concentration of ascorbic acid and its salts is less than 1% by weight based on the total weight of the dental resin-modified glass ionomer composition. **Claim 8** The dental resin-modified glass ionomer composition according to any one of claims 1 to 4, wherein the dental resin-modified glass ionomer composition is completely free of ascorbic acid and its salts. **Claim 9** The dental resin-modified glass ionomer composition according to any one of claims 1 to 8, wherein the concentration of (meth)acrylate having no phosphorus atom is less than 5% by weight based on the total weight of the dental resin-modified glass ionomer composition. **Claim 10** The dental resin-modified glass ionomer composition according to any one of claims 1 to 8, wherein the concentration of (meth)acrylate having no phosphorus atom is less than 2.5% by weight based on the total weight of the dental resin-modified glass ionomer composition. **Claim 11** The dental resin-modified glass ionomer composition according to any one of claims 1 to 8, wherein the concentration of (meth)acrylate having no phosphorus atom is less than 1% by weight based on the total weight of the dental resin-modified glass ionomer composition. **Claim 12**: The resin-modified glass ionomer composition for dental use according to any one of claims 1 to 8, wherein the resin-modified glass ionomer composition for dental use is completely free of (meth)acrylate having no phosphorus atom. **Claim 13** (e) The following formula (II): 【Chemical 10】 [wherein, R ４ = hydrogen, C １ ~ C １８ alkyl group, C containing at least one carbon-carbon double bond ３ ~ C １８ alkylene group, C ３ ~ C １８ cycloalkyl group, or C ５ ~ C １８ aryl group; R ５ = hydrogen, C １ ~C １８ alkyl group, C containing at least one carbon-carbon double bond ３ ~C １８ alkylene group, C ３ ~C １８ cycloalkyl group, or C ５ ~C １８ aryl group; where R ４ and R ５ The term "alkyl group" for R and R herein refers to a straight-chain or branched saturated hydrocarbon chain of each length in this formula, which may be further substituted with one or more substituents independently selected from the group consisting of alkylene, alkoxy, nitrile, aryl, cycloalkyl, and hydroxyl], and further comprises at least one acrylamide having the dental resin-modified glass ionomer composition according to any one of claims 1 to 12. **Claim 14** The resin-modified glass ionomer composition for dental use according to claim 13, wherein at least one acrylamide is selected from the group consisting of N-methylolacrylamide, N-methylolmethacrylamide, N-(2-hydroxyethyl)-methacrylamide, N-methyl-N-(2-hydroxyethyl)-acrylamide, N-methacryloyl-1-aminosalicylic acid, N-acryloylaspartic acid, and N-methacryloylglycine. **Claim 15**: The resin-modified glass ionomer composition for dental use according to claim 13, wherein the at least one acrylamide is N-(2-hydroxyethyl)-methacrylamide. **Claim 16** The resin-modified glass ionomer composition for dental use according to any one of claims 1 to 15, wherein at least one bisacrylamide is selected from the group consisting of N,N'-dimethyl-1,3-bis(acrylamide)-propane, N,N'-dimethyl-1,3-bis(acrylamide)-hexane, N,N'-diethyl-1,3-bis(acrylamide)-propane, and N,N'-bisacryloyl-N,N'-bisallyl-1,4-but-2-ene-diamine. **Claim 17**: The resin-modified glass ionomer composition for dental use according to any one of claims 1 to 15, wherein the at least one bisacrylamide is N,N'-dimethyl-1,3-bis(acrylamide)-propane. **Claim 18** **Claim 19**: The resin-modified glass ionomer composition for dental use according to claim 18, wherein the at least one reactive filler is a fluoroaluminosilicate filler. **Claim 20** **Claim 21** The dental resin-modified glass ionomer composition according to any one of claims 1 to 19, wherein at least one polycarboxylic acid is at least one copolymer or homopolymer of monomers of acrylic acid, methacrylic acid, 2-chloroacrylic acid, 3-chloroacrylic acid, aconitic acid, mesaconic acid, maleic acid, itaconic acid, fumaric acid, glutaconic acid and citraconic acid.

21.

22. The dental resin-modified glass ionomer composition according to any one of claims 1 to 20, further comprising (g) at least one non-reactive filler.

23. The dental resin-modified glass ionomer composition according to claim 21, wherein the at least one non-reactive filler is glass flakes and / or inert silica particles.

24.

25. The dental resin-modified glass ionomer composition according to any one of claims 1 to 22, further comprising (h) at least one polymerization initiator system selected from the group consisting of a photoinitiator system, a redox initiator system and combinations thereof.

26. A kit comprising the dental resin-modified glass ionomer composition according to any one of claims 1 to 23, comprising at least a first part and at least a second part; The first part comprises (c) at least one compound having at least one phosphorus atom selected from the group consisting of (meth)acrylates having at least one phosphate group, (meth)acrylates having at least one phosphonic acid group and acrylic ethers having at least one phosphonic acid group; and (d) at least one bisacrylamide having the formula (I) of claim 1; The second part comprises (a) at least water; (b) at least one polycarboxylic acid; and (c) at least one bisacrylamide having the formula (I) of claim 1.

27. The first part further comprises (f) at least one reactive filler; The second part further comprises (e) at least one acrylamide having the formula (II) of claim 13; and (f) at least one non-reactive filler.

28. The kit according to claim 27, wherein the at least one reactive filler is a fluoroaluminosilicate filler.

27. The kit according to claim 25 or 26, wherein the at least one non-reactive filler is glass flakes and / or inert silica particles.

28. The kit according to any one of claims 24 to 27, wherein the first and second parts are each a paste; or the first part is a powder and the second part is a liquid.

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