Direct dental filling composition

Abstract

To provide an aqueous dental glass ionomer composition for use as a permanent direct restoration in treatment of deep cavitated carious lesions.SOLUTION: A composition comprises (A) a reactive particulate glass, (B) a water-soluble, polymerizable polymer comprising an acidic group, which is reactive with the particulate glass in a cement reaction, whereby the polymerizable polymer has a polymer backbone and a pendant group having one or more polymerizable carbon-carbon double bonds, and (C) a polymerization initiator system.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a dental filling material for use as a permanent, stress-resistant dental restorative material. In particular, the present invention relates to an aqueous dental glass ionomer composition for use as a permanent, direct restoration in the treatment of deep cavitated caries lesions. [Background technology]

[0002] Caries lesions develop when oral bacteria release acids that demineralize and soften tooth surfaces. Initially, white spot lesions of demineralized enamel form. If the demineralization process is not interrupted or reversed, the caries lesion progresses further into the tooth structure, forming cavities. Ultimately, untreated caries leads to infection and tooth loss.

[0003] There are various options for repairing decayed tooth structure with direct restorations that are placed as malleable filling materials and then hardened. Depending on the choice of filling material, it may be necessary to use a liner to protect the pulp, or etching of the enamel, adhesives, and the use of light curing may be required.

[0004] In general, direct filling materials are required to have good mechanical properties, including adhesive properties to hard dental tissues, high biocompatibility, and sufficient mechanical and chemical resistance over long periods of time, given the harsh conditions experienced by restorative materials in the oral cavity. Furthermore, dental restorative materials should have good handling properties and should not be affected by changes in treatment conditions or application methods. Furthermore, inexpensive dental restorative materials are often preferred.

[0005] Direct filling materials can be classified as non-aesthetic or aesthetic. Non-aesthetic filling materials typically include amalgam. Esthetic restorations typically include dental compositions or glass ionomer cements.

[0006] Amalgam is said to offer dental professionals a strong, well-maintained, and cost-effective option, but it is considered undesirable due to toxicological concerns.

[0007] Dental composites rely on the radical polymerization of a polymerizable organic matrix containing dental fillers and typically have excellent mechanical properties, including flexural strengths exceeding 80 MPa. Furthermore, dental composites resemble the natural color of teeth. However, dental composites are more expensive to manufacture than amalgam and require more time and expertise to install, especially to ensure humidity control.

[0008] Glass ionomer cements containing reactive glass powder, polyalkenoic acid, and water exhibit adhesion to hard dental tissues and excellent biocompatibility. Furthermore, glass ionomer cements offer good chemical resistance in the oral cavity over long periods of time. Glass ionomer cements have excellent handling properties and do not require complicated application or curing processes. Furthermore, changes in application conditions and methods usually do not significantly affect the success of the treatment. Dental glass ionomer cements are inexpensive. Finally, fluoride-releasing dental glass ionomer cements offer caries resistance.

[0009] However, conventional glass ionomer cements have low flexural strength, typically less than 40 MPa, and are brittle due to the salt-like structure formed by the acid-base reaction between the reactive glass powder and the polyalkenoic acid when the glass hardens.

[0010] The mechanical properties of glass ionomer cements can be improved by the selection of functionalized polyacid polymers.

[0011] Chen et al. and Nesterova et al. (Chen et al., J. Appl. Polym. Sci., 109 (2008) 2802-2807; Nesterova et al., Russian Journal of Applied Chemistry, 82 (2009) 618-621) disclose copolymers of N-vinylformamide with acrylic acid and / or methacrylic acid, respectively.

[0012] Additionally, polymers having pendant polymerizable moieties can be crosslinked to increase the mechanical resistance of the resulting glass ionomer cement.

[0013] For example, WO 2003 / 011232 A1 discloses a polymerizable water-based dental glass ionomer cement containing two different polyacid polymers, one of which has pendant post-polymerizable moieties attached to the polymer via ester bonds, which are prone to hydrolytic cleavage in acidic media.

[0014] WO 2012 / 084206 A1 discloses polymers for dental glass ionomer cements, but WO 2012 / 084206 A1 does not disclose specific combinations of components for the composition of dental glass ionomer cements.

[0015] Conventional glass ionomer cements can be used to bond indirect restorations, such as inlays, onlays, crowns, bridges, and veneers, to hard dental tissue, provided that the indirect restoration protects the hardened dental glass ionomer cement from any excessive mechanical stress.

[0016] Conventional glass ionomer cements can also be used to prepare temporary direct restorations in non-stressed areas.

[0017] However, conventional dental glass ionomer cements cannot be used as permanent direct restorations in the treatment of cavitated caries lesions, for example, especially when the caries lesions are class I, II, IV, V, or VI, because the hardened cement will delaminate under high mechanical stress.

[0018] Therefore, amalgam or dental composites are traditionally used as direct restorations in the treatment of cavitated caries lesions, including Class I, II, and V caries lesions.

[0019] U.S. Patent Application Publication No. 2005 / 165136A discloses ionomer cements useful in dental and orthopedic medicine. According to Table 4 of this document, light-cured ionomer cements exhibit flexural strengths that are up to 5% higher than the flexural strength of Vitremer® light-cured glass ionomer (a 3M Dental product) under the test conditions used in accordance with U.S. Patent Application Publication No. 2005 / 165136A. WO 2012 / 084206A discloses polymers for dental glass ionomer cements. Summary of the Invention

[0020] It is an object of the present invention to provide a direct dental filling material for use as a permanent stress-resistant dental restorative material, which can be used as a permanent direct restoration in the treatment of deep cavitated carious lesions.

[0021] The present invention provides an aqueous dental glass ionomer composition for use in treating cavitated caries lesions, the glass ionomer composition comprising: (A) reactive particulate glass; (B) a water-soluble polymerizable polymer, the polymerizable polymer containing acidic groups and reactive with the particulate glass in a cement reaction, whereby the polymerizable polymer has a polymer backbone and pendant groups having one or more polymerizable carbon-carbon double bonds; (C) a polymerization initiator system; Dental glass ionomer compositions are used as permanent direct restorations. The present invention is based on the recognition that aqueous dental glass ionomer compositions can provide hardened direct dental restorations having a flexural strength of at least 80 MPa. The present invention is further based on the recognition that a combination of reactive particulate glass (A), a specific water-soluble polymerizable polymer (B), and a polymerization initiator system (C) in an aqueous dental glass ionomer composition is required to provide hardened direct dental restorations having a flexural strength of at least 80 MPa. Finally, the present invention is based on the recognition that aqueous dental glass ionomer compositions having a flexural strength of at least 80 MPa are suitable for use as permanent stress-resistant restorative materials, particularly as permanent direct restorations in the treatment of deep cavitated caries lesions. DETAILED DESCRIPTION OF THE INVENTION

[0022] The term "(co)polymerizable" refers to compounds that can be covalently linked to form polymers in an addition polymerization reaction. When the aqueous dental glass ionomer composition is cured, the "polymerizable polymer" can be linked to a crosslinker and to a hydrolytically stable, water-soluble monomer having a "polymerizable (carbon-carbon) double bond," respectively, to form a grafted polymer and / or a crosslinked polymer.

[0023] As used herein in connection with component (B), as defined below, and components (D) and (E) of the present aqueous dental glass ionomer compositions, the terms "first polymerizable organic moiety," "second polymerizable organic moiety," "polymerizable pendant group," and "polymerizable (carbon-carbon) double bond" refer to any double bond capable of addition polymerization, particularly free radical polymerization, preferably a carbon-carbon double bond.

[0024] The term "curing" includes the polymerization of functional monomers, oligomers, and even polymers into polymer networks, especially the polymerization of unsaturated monomers or oligomers in the presence of a crosslinking agent.

[0025] The term "hardenable" refers to an aqueous dental glass ionomer composition that polymerizes into a crosslinked polymer network, for example, when irradiated with actinic radiation, such as ultraviolet (UV), visible light, or infrared radiation, or when reacted with a polymerization initiator.

[0026] The present aqueous dental glass ionomer composition provides a hardened dental glass ionomer composition based on a cement reaction between a basic particulate glass and a polyacid, and a free radical polymerization of a polymerizable polymer according to (B) and an optional additional polymerizable compound, the free radical polymerization being initiated by a polymerization initiator system according to (C).

[0027] Treatment of cavitated carious lesions The aqueous dental glass ionomer compositions of the present invention are used in the treatment of cavitated carious lesions as permanent direct restorations.

[0028] Treatment of carious lesions can be achieved using conventional treatment methods, in which all soft, leathery dentin is removed from the carious lesion until the hard dentin is reached before a final direct restoration is placed. This conventional treatment method typically uses dental cutting devices. However, if the carious lesion is deep and cavitated, thereby posing a risk of pulp exposure, which would have a detrimental effect on the treated tooth, incomplete caries removal methods can be applied. For example, a non-invasive restorative treatment (ART) method can be considered, in which only the soft, infected dentin is manually removed using dental hand instruments. Therefore, the resulting cavity is smaller than that resulting from conventional treatment methods using dental cutting devices.

[0029] Caries lesions can be classified according to the severity of the lesion. Thus, caries lesions can be moderate, advanced, and severe. Moderate caries lesions extend to more than half of the enamel but do not involve the dentin-enamel junction (DEJ). Advanced caries lesions extend to or through the DEJ but do not extend more than half the distance to the pulp (deep caries). Severe caries lesions extend through the enamel, through the dentin, and more than half the distance to the pulp (complicated deep caries).

[0030] Preferably, the aqueous dental glass ionomer composition is used to treat cavitated lesions, where the caries lesion is a moderate, advanced or severe caries lesion, more preferably an advanced or severe caries lesion.

[0031] Caries lesions can be classified according to their location according to the classification established by GV Black, which distinguishes between the following classes I to VI: Class I: Cavities in the pits and fissures on the occlusal surfaces of the molars and premolars, the facial and lingual surfaces of the molars, and the lingual surfaces of the maxillary incisors. Class I corresponds to the surfaces of molars where the occlusal / lingual / buccal surfaces are clinically visible. Therefore, proximal surfaces are not classified as Class I. Class II: Cavities on the proximal surfaces of premolars and molars. Class III: Cavities on the proximal surfaces of the incisors and canines that do not involve the incisal angle. Class IV: Cavities on the proximal surfaces of incisors or canines involving the incisal angles. Class IV lesions are a larger subdivision of Class III that target the incisal angles. Class V: Cavity on the facial or lingual surface of any one-third of the tooth, e.g., cervical region. Class VI: Cavities on the incisal edges of anterior teeth and apical edges of molars. Class VI corresponds to the top surface of the tooth.

[0032] Preferably, the aqueous dental glass ionomer composition is used to treat cavitated lesions, where the caries lesions are Class I, II, IV, V, or VI caries lesions.

[0033] (A) Reactive glass particles The term "reactive particulate glass" refers to a solid mixture, primarily of metal oxides, that is converted into glass by a thermal fusion process and then pulverized by various processes, allowing the glass to react with a polymer containing acidic groups in a cementation reaction. The glass is in particulate form. Furthermore, the reactive particulate glass may be surface-modified, for example, by silanization or acid treatment. Any conventional reactive dental glass can be used for the present invention. Specific examples of particulate reactive glasses are selected from calcium aluminosilicate glass, calcium aluminofluorosilicate glass, calcium aluminum fluoroborosilicate glass, strontium aluminosilicate glass, strontium aluminofluorosilicate glass, and strontium aluminofluoroborosilicate glass. Suitable particulate reactive glasses can be in the form of metal oxides such as zinc oxide and / or magnesium oxide, and / or ion-eluting glasses, for example, as described in U.S. Pat. Nos. 3,655,605, 3,814,717, 4,143,018, 4,209,434, 4,360,605, and 4,376,835. Preferably, the reactive particulate glass according to (A) is 1) 20 to 45 wt. % silica; 2) 20 to 40 wt. % alumina; 3) 20 to 40 wt. % strontium oxide; 4) 1 to 10 wt% of P2O5; 5) A reactive particulate glass filler containing 3 to 25% by weight of fluoride.

[0034] The aqueous dental glass ionomer composition according to the present invention preferably comprises 20 to 90 wt %, more preferably 30 to 80 wt %, of reactive particulate glass, based on the total weight of the composition.

[0035] The reactive particulate glass generally has an average particle size of 0.005 to 100 μm, preferably 0.01 to 40 μm, as measured, for example, by electron microscopy or using conventional laser diffraction particle size distribution measurement techniques as embodied by a MALVERN Mastersizer S or MALVERN Mastersizer 2000 instrument.

[0036] The reactive particulate glass may have a unimodal or polymodal (eg, bimodal) particle size distribution, with polymodal reactive particulate glass representing a mixture of two or more particulate fractions having different average particle sizes.

[0037] The reactive particulate glass may be an agglomerated reactive particulate glass obtained by agglomerating reactive particulate glass in the presence of a modified polyacid and / or a polymerizable (meth)acrylate resin. The particle size of the agglomerated reactive particulate glass may be adjusted by a suitable size reduction process, such as milling.

[0038] The reactive particulate glass can be surface-modified with a component according to (B) or (C). In particular, the reactive particulate glass can be surface-modified with one or more components of the polymerization initiator system (C) to avoid contact of the one or more components of the polymerization initiator system (C) with acid under aqueous conditions.

[0039] Alternatively or additionally, the reactive particulate glass may be surface-modified with a surface modifier. Preferably, the surface modifier is a silane. The silane provides the reactive particulate glass with suitable hydrophobicity, which allows for advantageous intimate mixing with the organic components (B), (C), and (D) of the aqueous dental glass ionomer composition.

[0040] (B) Water-soluble polymer containing an acidic group The aqueous dental glass ionomer composition according to the present invention comprises (B) a water-soluble polymerizable polymer that is reactive with particulate glass in a cementation reaction and contains acidic groups, whereby the polymerizable polymer has a polymer backbone and pendant groups with one or more polymerizable carbon-carbon double bonds. The pendant groups are preferably hydrolytically stable. The aqueous dental glass ionomer composition may comprise one or more water-soluble polymerizable polymers containing acidic groups according to (B).

[0041] The water-soluble polymerizable polymer according to (B) contains acidic groups, e.g., carboxylic acid groups, in its backbone and, optionally, additional acidic groups in pendant groups, which carboxylic acid groups of the polymer are capable of reacting with reactive particulate glass in a cementation reaction to form a glass ionomer cement.

[0042] The term "polymerizable polymer" as used in connection with item (B) means a polymer that contains one or more polymerizable moieties that allow for polymerization and crosslinking of the polymer to improve the mechanical properties and long-term mechanical and chemical resistance of the hardened water-soluble dental glass ionomer composition.

[0043] The term "water soluble" when used in connection with the term "polymerizable polymer" means that at least 0.1 g, preferably 0.5 g, of the polymerizable polymer will dissolve in 100 g of water at 20°C.

[0044] The water-soluble polymerizable polymer according to (B) is preferably hydrolytically stable, meaning that the polymer is hydrolytically stable in an acidic medium, e.g., in a dental composition. Specifically, the polymer preferably does not contain groups, e.g., ester groups, that hydrolyze in an aqueous medium at pH 3 at room temperature within one month.

[0045] Preferably, the water-soluble polymerizable polymer containing acidic groups according to (B) is a) to obtain a copolymer containing amino groups, (i) a first copolymerizable monomer comprising at least one optionally protected carboxylic acid group and a first polymerizable organic moiety; (ii) copolymerizing a mixture comprising one or more optionally protected primary and / or secondary amino groups and a second copolymerizable monomer comprising a second polymerizable organic moiety; b) coupling a compound having a polymerizable moiety and a functional group reactive with the amino group of the repeating unit derived from the second copolymerizable monomer in the amino group-containing copolymer obtained in the first step to the amino group-containing copolymer, wherein the protected amino group is deprotected as necessary so that the polymerizable pendant group is connected to the backbone by a linking group that is stable to hydrolysis; and a step of deprotecting the protected carboxylic acid group after step a) or step b) as necessary to obtain a polymerizable polymer.

[0046] The first copolymerizable monomer used in step a) contains at least one, preferably one to three, more preferably one or two, and most preferably one optionally protected carboxylic acid group.

[0047] The protecting group for the optionally protected carboxylic acid group is not particularly limited, as long as it is a carboxyl protecting group known to those skilled in the art of organic chemistry (see P.G.W. Muts and T.W. Greene, Greene's Protective Groups in Organic Synthesis, 4th Edition, John Wiley and Sons Inc., 2007). Preferably, the carboxyl protecting group is selected from a trialkylsilyl group, an alkyl group, and an arylalkyl group. More preferably, the carboxyl protecting group is selected from an alkyl group or an arylalkyl group. Most preferably, the carboxyl protecting group is selected from a tert-butyl group and a benzyl group. In one preferred embodiment, the carboxyl protecting group is a tert-butyl group.

[0048] As used herein, the term "polymerizable organic moiety" means an organic portion of a molecule that can be used to covalently bond the molecule to other molecules reactive therewith in a chemical reaction (polymerization) to form macromolecules of repeating or alternating structural units. Preferably, the polymerizable organic moiety is a carbon-carbon double bond, similar to an ethylenically unsaturated moiety.

[0049] In a preferred embodiment of the water-soluble dental glass ionomer composition of the present invention, the first copolymerizable monomer is represented by general formula (1): [ka] In formula (1), R 1 is a hydrogen atom, a -COOZ group, or a linear or branched C 1-6 It is an alkyl group. Preferably, R 1 is a hydrogen atom, a -COOZ group, or a methyl group. More preferably, R 1 is a hydrogen atom or a methyl group.

[0050] In formula (1), R 2 is a hydrogen atom, a -COOZ group, or a linear or branched C 1-6 It is an alkyl group. Preferably, R 2 is a hydrogen atom or a -COOZ group. More preferably, R 2 is a hydrogen atom. In formula (1), the dotted line represents R 2 may be in either the cis or trans configuration.

[0051] In formula (1), A is a single bond or a linear or branched C 1-6It is an alkylene group, and the group may contain 1 to 3 heteroatoms between two carbon atoms of the alkylene carbon chain, and the heteroatoms are selected from oxygen atoms, nitrogen atoms, and sulfur atoms, and / or the alkylene group may contain 1 to 3 groups selected from amide bonds or urethane bonds between two carbon atoms of the alkylene carbon chain. Preferably, A is a single bond or a linear or branched C 1-6 It is an alkylene group, and the group may contain a heteroatom between two carbon atoms of the alkylene carbon chain, the heteroatom being selected from an oxygen atom or a nitrogen atom, and / or the alkylene group may contain a group selected from an amide bond or a urethane bond between two carbon atoms of the alkylene carbon chain. More preferably, A is a single bond or a linear C 1-6 It is an alkylene group. Most preferably, A is a single bond.

[0052] In formula (1), Z may be the same or different and independently represent a hydrogen atom, a metal ion, a protecting group for a carboxylic acid group, or Z forms an intramolecular anhydride group together with an additional -COOZ group present in the molecule. The metal ion may be a monovalent metal ion such as an alkali metal ion. In one embodiment, Z is a protecting group for a carboxylic acid group. In another embodiment, Z is a hydrogen atom. When Z forms an intramolecular anhydride group (-C(O)OC(O)-) together with an additional -COOZ group present in the molecule, the additional -COOZ group is preferably R, as in the case of itaconic anhydride. 1 It may be present on

[0053] In a preferred embodiment, Z is a hydrogen atom and the polymerization reaction is carried out in an alkaline environment. In an alternative preferred embodiment, Z is a hydrogen atom and the amino groups of the first copolymerizable monomer and the second copolymerizable monomer carry protecting groups.

[0054] Preferably, the first copolymerizable monomer is a blocked (meth)acrylic acid monomer. More preferably, the first polymerizable monomer is selected from tert-butyl acrylate and benzyl acrylate. Most preferably, the first polymerizable monomer is tert-butyl acrylate.

[0055] In a preferred embodiment of the water-soluble dental glass ionomer composition of the present invention, the second copolymerizable monomer is represented by general formula (2): [ka] In formula (2), R 3 is a straight-chain or branched C optionally substituted by a hydrogen atom or a -COOZ' group; 1-6 It is an alkyl group. Preferably, R 3 is a hydrogen atom. In formula (2), the dotted line represents R 3 may be in either the cis or trans configuration.

[0056] In formula (2), X is a hydrocarbon group having 1 to 20 carbon atoms substituted with a protected amino group or an amino group optionally bearing a protecting group, the hydrocarbon group optionally containing 1 to 6 heteroatoms selected from oxygen, nitrogen, and sulfur atoms, and / or the hydrocarbon group optionally containing a group selected from an amide bond or a urethane bond, the hydrocarbon group optionally being substituted with up to 6 groups selected from -COOZ', amino groups, hydroxyl groups, and thiol groups. Preferably, X is a hydrocarbon group having 1 to 20 carbon atoms substituted with an amino group optionally bearing a protecting group, the hydrocarbon group optionally containing a heteroatom selected from oxygen and nitrogen atoms, and / or the hydrocarbon group optionally containing a group selected from an amide bond or a urethane bond, the hydrocarbon group optionally being substituted with a -COOZ' group. More preferably, X is a hydrocarbon group having 1 to 20 carbon atoms, even more preferably 1 to 6 carbon atoms, substituted with an amino group optionally bearing a protecting group, the hydrocarbon group optionally containing an oxygen atom and / or the hydrocarbon group optionally containing an amide bond, the hydrocarbon group optionally being substituted with a -COOZ' group. In certain embodiments where X is a protected amino group, the compound of formula (2) is an allylamine, and the amino group bears a protecting group.

[0057] The protecting group of the protected amino group or the optionally protected amino group is not particularly limited and may be any conventional protecting group for an amino group, for example, as described in P.G.M.Wuts and T.W. Greene, Greene's Protective Groups in Organic Synthesis, 4th Edition, John Wiley and Sons Inc., 2007. Preferably, the amino protecting group is selected from an acyl group, an arylalkyl group, an alkoxycarbonyl group, and an aryloxycarbonyl group. More preferably, the amino protecting group is an acyl group. Most preferably, the amino protecting group is a formyl group.

[0058] In formula (2), Y is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, which may contain 1 to 6 heteroatoms selected from oxygen, nitrogen, and sulfur atoms, and / or which may contain a group selected from an amide bond or a urethane bond, and which may be further substituted with up to 6 groups selected from -COOZ', amino groups, hydroxyl groups, and thiol groups. Preferably, Y is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, which may contain a heteroatom selected from oxygen and nitrogen atoms, and / or which may contain a group selected from an amide bond or a urethane bond, and which may be further substituted with a -COOZ' group. More preferably, Y is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, even more preferably 1 to 6 carbon atoms, which may contain an oxygen atom and / or an amide bond, and which may be further substituted with a -COOZ' group. In one preferred embodiment, Y is a hydrogen atom.

[0059] In formula (2), Z' may be the same or different and independently represent a hydrogen atom, a metal ion, a protecting group for a carboxylic acid group, or Z' forms an intramolecular anhydride group together with an additional -COOZ' group present in the molecule. In one embodiment, Z' is a protecting group for a carboxylic acid group. In another embodiment, Z' is a hydrogen atom. The metal ion may be a monovalent metal ion such as an alkali metal ion. In another embodiment, Z' is a hydrogen atom. Z forms an intramolecular anhydride group (-C(O)OC(O)-) together with an additional -COOZ' group present in the molecule.

[0060] In a preferred embodiment, Z' is a hydrogen atom and the polymerization reaction is carried out in an alkaline environment. In an alternative preferred embodiment, Z' is a hydrogen atom and the amino group of the second copolymerizable monomer carries a protecting group.

[0061] In one embodiment, the second copolymerizable monomer comprises a second copolymerizable organic moiety selected from the group consisting of an optionally substituted (meth)acrylamide moiety and an optionally protected substituted (meth)acrylic acid. In another embodiment, the second copolymerizable monomer is selected from allylamine, aminopropyl vinyl ether, aminoethyl vinyl ether, N-vinylformamide, and 2-aminomethylacrylic acid. In a preferred embodiment, the second copolymerizable monomer is aminopropyl vinyl ether. The amino group may be in the form of an ammonium salt, such as ammonium chloride. A preferred structure is shown in Scheme 1 below, where the amino group may carry a protecting group.

[0062] [ka]

[0063] The molar ratio of the first copolymerizable monomer to the second copolymerizable monomer in the mixture copolymerized in step a) (moles of first copolymerizable monomer / moles of second copolymerizable monomer) is preferably within the range of 100:1 to 100:50, more preferably within the range of 100:2 to 100:20, and even more preferably within the range of 100:3 to 100:10.

[0064] The additional copolymerizable monomer optionally used in step a) contains at least one, preferably one to three, more preferably one or two, and most preferably one, optionally protected acidic group that is not a carboxylic acid group. Specific examples of acidic groups are sulfonic acid (-SO3M), phosphonic acid (-PO3M2), or phosphate ester (-OPO3M2), or salts thereof, where M can independently be a hydrogen atom or a monovalent ion such as an alkali metal ion or ammonium ion.

[0065] Specific examples of optional additional monomers are selected from 2-acrylamido-2-methylpropanesulfonic acid, vinyl phosphonate, and vinyl sulfonic acid.

[0066] In a preferred embodiment, the solutions containing the first copolymerizable monomer and the second copolymerizable monomer are separately saturated with nitrogen before combining them for copolymerization to minimize possible by-products of competing Aza-Michael additions.

[0067] Step a) to obtain the amino group-containing copolymer proceeds as a chain-growth polymerization. In one embodiment, step a) comprises a radical copolymerization.

[0068] The type of copolymer formed by step a) of the present invention may be a statistical copolymer, a random copolymer, an alternating copolymer, a block copolymer, or a combination thereof.

[0069] The copolymers obtained by step a) of the present invention are copolymers containing amino groups, such as, for example, copolymers obtainable by copolymerization of acrylates with aminopropyl vinyl ether.

[0070] The reaction conditions for the polymerization reaction according to step a) of the present invention are not particularly limited. Therefore, the reaction can be carried out in the presence or absence of a solvent. Suitable solvents can be selected from the group consisting of water, dimethylformamide (DMF), tetrahydrofuran (THF), and dioxane.

[0071] The reaction temperature is not particularly limited. Preferably, the reaction is carried out at a temperature between -10°C and the boiling point of the solvent. Preferably, the reaction temperature is within the range of 0°C to 80°C.

[0072] The reaction time is not particularly limited, but is preferably within the range of 10 minutes to 48 hours, more preferably 1 hour to 36 hours.

[0073] The reaction is preferably carried out in the presence of a polymerization initiator. In a preferred embodiment of the water-soluble dental glass ionomer composition, the polymerization initiator is selected from azobisisobutyronitrile (AIBN), 2,2-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(N,N'-dimethyleneisobutylamidine) dihydrochloride, and 4,4'-azobis(4-cyanopentanoic acid). The amount of the polymerization initiator is not particularly limited. Preferably, the amount is within the range of 0.001 mol % to 5 mol % based on the total amount of monomers.

[0074] The reaction product obtained in step a) may be isolated by precipitation and filtration or by lyophilization. The product may be purified by conventional methods.

[0075] Step b) of obtaining a water-soluble polymer having an acidic group by (B) is a step of coupling a compound having a polymerizable moiety with a functional group reactive with an amino group in a repeating unit derived from a second copolymerizable monomer in the amino group-containing copolymer obtained in step a) in which the amino group, which may be protected as needed, has been deprotected.

[0076] Preferably, the coupling reaction in step b) is an addition or condensation reaction forming a bond selected from an amide bond, a urea bond or a thiourea bond.

[0077] The term "functional group reactive with an amino group" as used herein means any group capable of forming a covalent bond with an amino group of an amino-containing copolymer. Preferably, the functional group reactive with an amino group is a carboxylic acid group, or a derivative thereof such as an ester group or an anhydride thereof, an isocyanate group, or an isothiocyanate group. More preferably, the functional group reactive with an amino group is a carboxylic acid group or a derivative thereof.

[0078] When the amino group of the repeating unit derived from the second copolymerizable monomer in the amino group-containing copolymer obtained in the first step is protected, the amino group can be deprotected before or simultaneously with step b).

[0079] The conditions for deprotection of the optionally protected amino group are selected according to the protecting group used. Preferably, the protected amino group is deprotected by hydrogenolysis or treatment with acid or base.

[0080] It will be understood by those skilled in the art that when deprotection of the protected amino group is carried out simultaneously with step b), the deprotection conditions and the conditions of step b) must be selected so that the deprotection and step b) proceed efficiently.

[0081] In a preferred embodiment of the water-soluble dental glass ionomer composition, the compound having a polymerizable moiety and a functional group reactive with the amino group of the repeating unit derived from the second copolymerizable monomer is a compound represented by formula (3): [ka] In formula (3), R 4 is a straight-chain or branched C optionally substituted by a hydrogen atom or a -COOZ'' group; 1-6 is an alkyl group, and R 5 is a straight-chain or branched C optionally substituted by a hydrogen atom or a -COOZ'' group; 1-6 It is an alkyl group. Preferably, R 4 is a hydrogen atom, and R 5 is a hydrogen atom or a methyl group. More preferably, R 4 is a hydrogen atom, and R 5 is a methyl group. In formula (3), the dotted line indicates R 4 may be in either the cis or trans configuration.

[0082] In formula (3), Z″ may be the same or different and independently represent a hydrogen atom, a metal ion, or a protecting group for a carboxylic acid group, or Z″ forms an intramolecular anhydride group together with an additional —COOZ″ group present in the molecule.

[0083] In one embodiment, Z" is a protecting group for the carboxylic acid group. In another embodiment, Z" is a hydrogen atom. In a preferred embodiment, Z" is a hydrogen atom and the polymerization reaction is carried out in an alkaline environment. In an alternative preferred embodiment, Z" is a hydrogen atom and the amino group of the second copolymerizable monomer carries a protecting group.

[0084] In one embodiment, in formula (3), LG is a leaving group. Preferably, LG is a chlorine atom or a bromine atom, or forms a carboxylic acid anhydride moiety with the adjacent carbonyl group. More preferably, LG is a group suitable for reacting the compound of formula (3) in a Schotten-Baumann type reaction.

[0085] In another embodiment, LG replaces Z″ and R 4 or R 5 Together with the carboxylic acid anhydride group, an intramolecular carboxylic acid anhydride group may be formed.

[0086] In yet another embodiment, two molecules of formula (3) form an intermolecular carboxylic acid anhydride group by sharing a common LG, where LG is an oxygen atom.

[0087] The compound of formula (3) is particularly preferably acrylic acid, (meth)acrylic acid, crotonic acid, isocrotonic acid, tiglic acid, angelic acid, or an anhydride of such an acid formed from two of the same or different acids, more preferably an anhydride of such an acid formed from two of the same acids, and most preferably (meth)acrylic anhydride.

[0088] The coupling according to step b) of the present invention serves to introduce one or more polymerizable moieties into the copolymer containing amino groups, which can be post-polymerized to provide additional covalent bonds and advantageously also ionic crosslinks, imparting additional strength to the dental material.

[0089] In one embodiment of the water-soluble dental glass ionomer composition, the carboxylic acid groups of the copolymer obtained in step b) are not protected and the copolymer can be used as a polymer according to the present invention without further processing. In an alternative embodiment, if the carboxylic acid groups of the copolymer obtained in step b) are protected, the carboxylic acid groups must be deprotected before the copolymer exhibits the characteristics of a polymer according to the present invention.

[0090] The reaction conditions for the reaction according to step b) of the present invention are not particularly limited.Therefore, the reaction can be carried out in the presence or absence of a solvent.Suitable solvents can be selected from the group consisting of dimethylformamide (DMF), tetrahydrofuran (THF), and dioxane.

[0091] The reaction temperature is not particularly limited. Preferably, the reaction is carried out at a temperature between -10°C and the boiling point of the solvent. Preferably, the reaction temperature is within the range of 0°C to 80°C.

[0092] The reaction time is not particularly limited, but is preferably within the range of 10 minutes to 48 hours, more preferably 1 hour to 36 hours.

[0093] The reaction product obtained in step b) may be isolated by precipitation and filtration. The product may be purified.

[0094] The water-soluble dental glass ionomer composition optionally includes a step of deprotecting the protected carboxylic acid groups after step a) or step b) to obtain a polymerizable polymer. In a preferred embodiment, the water-soluble dental glass ionomer composition includes a step of deprotecting the protected carboxylic acid groups to obtain a polymerizable polymer. In a further preferred embodiment, the water-soluble dental glass ionomer composition includes a step of deprotecting the protected carboxylic acid groups after step b).

[0095] The conditions for deprotection of the optionally protected carboxyl group are selected according to the protecting group used. Preferably, the protected carboxyl group is deprotected by hydrogenolysis or treatment with acid or base.

[0096] A first embodiment of the polymerizable polymer according to (B) is illustrated by the following scheme 2, in which an amino-protected vinylamine is reacted with acrylic acid to obtain a polymer backbone having protected amino groups. The copolymer is preferably a random copolymer. In a further step, the protected amino groups of the polymer backbone are released to couple to moieties containing polymerizable groups, thereby obtaining a polymer of the invention having acidic groups reactive in a cementation reaction in which ionic bonds are formed, and polymerizable groups reactive in a crosslinking reaction in which covalent bonds are formed.

[0097] [ka]

[0098] In Scheme 2 above, any acrylamide group may be replaced with a methacrylamide group.

[0099] A second embodiment of the polymerizable polymer according to (B) is illustrated by the following scheme 3, in which a protected acrylic acid is reacted with a polymerizable vinyl ether derivative containing an amino group to obtain a polymer backbone containing an amino group. In a further step, the amino group of the polymer backbone is coupled to a moiety containing a polymerizable group. Finally, a carboxylic acid group is liberated, thereby obtaining a polymer of the invention having an acidic group reactive in a cementation reaction in which ionic bonds are formed, and a polymerizable group reactive in a crosslinking reaction in which covalent bonds are formed.

[0100] [ka]

[0101] In Scheme 3 above, any acrylamide group may be replaced by a methacrylamide group.

[0102] The polymerizable polymer obtained in step b) can be illustrated by the following preferred structure shown in Scheme 4 below:

[0103] [ka]

[0104] In the structure illustrated in Scheme 4, the numbers refer to the number of additional carbon atoms introduced by each side chain compared to the corresponding polyacrylic acid. A polymer with (a+b) repeating units contains b times as many additional carbon atoms as the number of carbon atoms in a polyacrylic acid having (a+b) carboxylic acid groups, but the carboxylic acid groups are b times less, which may reduce water solubility. On the other hand, the introduction of additional ionic groups such as -COOH groups can compensate for the reduced water solubility, as shown above. Preferably, the number of side chains (b), the number of additional carbon atoms, and the number of additional carboxylic groups are adjusted to provide useful water solubility for the polymer of the present invention.

[0105] Thus, in a preferred embodiment, the side chains of the polymer, which are linked to the polymer backbone via amide, urea or thiourea linkages, contain one or more additional acidic groups, preferably carboxylic acid groups.

[0106] The polymerizable polymer according to (B) is preferably 10 3 , especially 10 4 ~106D a Average molecular weight M in the range w More preferably, the average molecular weight M w is 10 5 ~7×10 5 Da, or 3 x 10 4 ~2.5×10 5 It is within the range of Da.

[0107] The polymerizable polymer according to (B) should have a number or weight percent of carboxylic acid groups sufficient to cause a setting or curing reaction in the presence of the reactive particulate glass according to (A), or any additional unmodified or modified particulate active ingredient, and / or non-reactive filler. Preferably, the polymerizable polymer according to (B) is present in the water-soluble dental glass ionomer composition in an amount of 5 to 80 wt. %, more preferably 10 to 50 wt. %, and even more preferably 15 to 40 wt. %, based on the total weight of the composition.

[0108] (C) Polymerization initiator system As the polymerization initiator system according to (C), any compound or system capable of initiating the polymerization reaction according to the present invention can be suitably used. The polymerization initiator according to (C) can be a photoinitiator or a redox initiator, or a mixture thereof.

[0109] The term "photoinitiator" means any chemical that forms free radicals when activated, for example, by exposure to light or by interaction with a coinitiator, in a photochemical process.

[0110] The term "redox initiator" refers to an oxidizing agent and a reducing agent, optionally in combination with a catalyst, such as a metal salt. The redox initiator system results in a redox reaction that forms radicals. These radicals initiate the polymerization of the radically polymerizable compound. Typically, the redox initiator system is activated by contacting the redox initiator system with water and / or an organic solvent, which results in at least partial decomposition of the oxidizing agent and the reducing agent. An optional catalyst can be added to promote the redox reaction and, therefore, the polymerization of the radically polymerizable compound.

[0111] A mixture of a photoinitiator and a redox initiator is a "dual cure initiator system."

[0112] For example, suitable photoinitiator systems may be in the form of a two-component or three-component system. A two-component system may include a photoinitiator and an electron donor compound. For example, as described in U.S. Pat. No. 5,545,676, a three-component system may include an iodonium salt, a sulfonium salt, or a phosphonium salt, a photoinitiator, and an electron donor compound.

[0113] Suitable photoinitiators for the polymerization initiator system according to (C) are Norrish Type I and Norrish Type II photoinitiators.

[0114] Suitable Norrish Type I photoinitiators are, for example, phosphine oxides.

[0115] Phosphine oxide initiators have a functional wavelength range of about 380 nm to about 450 nm and include acylphosphine oxides and bisacylphosphine oxides such as those described in U.S. Pat. Nos. 4,298,738, 4,324,744, and 4,385,109, and European Patent Publication No. 0173567. Specific examples of the acylphosphine oxide include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, dibenzoylphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, tris(2,4-dimethylbenzoyl)phosphine oxide, tris(2-methoxybenzoyl)phosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide, benzoyl-bis(2,6-dimethylphenyl)phosphonate, and 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide. Commercially available phosphine oxide photoinitiators capable of free radical initiation when irradiated in the wavelength range from greater than about 380 nm to about 450 nm include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (IRGACURE 819), bis(2,6-dimethoxybenzoyl)-(2,4,4-trimethylpentyl)phosphine oxide (CGI 403), a 25:75 weight ratio mixture of bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide and 2-hydroxy-2-methyl-1-phenylpropan-1-one (IRGACURE 1700), a 1:1 weight ratio mixture of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2-hydroxy-2-methyl-1-phenylpropan-1-one (DAROCUR 4265), and ethyl 2,4,6-trimethylbenzoylphenylphosphinate (LUCIRIN 4265). LR8893X). Typically, the phosphine oxide initiator is present in the composition in a catalytically effective amount, for example, 0.1% to 5.0% by weight, based on the total weight of the composition.

[0116] Suitable Norrish Type II photoinitiators include, for example, monoketones and diketones that absorb light within the range of about 400 nm to about 520 nm (preferably about 450 nm to about 500 nm). Particularly suitable compounds include alpha diketones that absorb light within the range of about 400 nm to about 520 nm (even more preferably about 450 to about 500 nm). Examples include camphorquinone, benzil, furil, 3,3,6,6-tetramethylcyclohexanedione, phenolic anthraquinone, 1-phenyl-1,2-propanedione, and other 1-aryl-2-alkyl-1,2-ethanediones, as well as cyclic alpha diketones. Suitable electron donor compounds include substituted amines, such as ethyl dimethylaminobenzoate or dimethylaminobenzonitrile.

[0117] The tertiary amine reducing agent can be used in combination with the acylphosphine oxide. Examples of suitable aromatic tertiary amines include N,N-dimethylaniline, N,N-dimethyl-p-toluidine, N,N-dimethyl-m-toluidine, N,N-diethyl-p-toluidine, N,N-dimethyl-3,5-dimethylaniline, N,N-dimethyl-3,4-dimethylaniline, N,N-dimethyl-4-ethylaniline, N,N-dimethyl-4-isopropylaniline, N,N-dimethyl-4-t-butylaniline, N,N-dimethyl-3,5-di-t-butylaniline, N,N-bis(2-hydroxyethyl)-3,5-dimethylaniline, N,N-bis(2-hydroxyethyl)-p-toluidine, N,N-bis(2-hydroxyethyl)-3,4-dimethylaniline, and N,N-bis(2-hydroxyethyl)-4-ethylaniline. N,N-bis(2-hydroxyethyl)-4-isopropylaniline, N,N-bis(2-hydroxyethyl)-4-t-butylaniline, N,N-bis(2-hydroxyethyl)-3,5-di-isopropylaniline, N,N-bis(2-hydroxyethyl)-3,5-di-t-butylaniline, 4-N,N-dimethylaminobenzoic acid ethyl ester, 4-N,N-dimethylaminobenzoic acid methyl ester, 4-N,N-dimethylaminobenzoic acid n-butoxyethyl ester, 4-N,N-dimethylaminobenzoic acid 2-(methacryloyloxy)ethyl ester, 4-N,N-dimethylaminobenzophenone ethyl 4-(N,N-dimethylamino)benzoate, and N,N-dimethylaminoethyl methacrylate. Examples of aliphatic tertiary amines include trimethylamine, triethylamine, N-methyldiethanolamine, N-ethyldiethanolamine, Nn-butyldiethanolamine, N-lauryldiethanolamine, triethanolamine, 2-(dimethylamino)ethyl methacrylate, N-methyldiethanolamine dimethacrylate, N-ethyldiethanolamine dimethacrylate, triethanolamine monomethacrylate, triethanolamine dimethacrylate, and triethanolamine trimethacrylate.

[0118] The amine reducing agent may be present in the composition in an amount of 0.1% to 5.0% by weight, based on the total weight of the composition.

[0119] The photoinitiator system may further include diaryliodonium salts, triarylsulfonium salts, and tetraaryl or tetraalkylphosphonium salts, which may function as coinitiators to improve the polymerization performance of the photoinitiator, but may also function as initiators for cationic polymerization.

[0120] For example, diaryliodonium salts include (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium hexafluoroantimonate, (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium tetrafluoroborate, diphenyliodonium (DPI) tetrafluoroborate, di(4-methylphenyl)iodonium (Me2-DPI) tetrafluoroborate, phenyl-4-methylphenyliodonium tetrafluoroborate, di(4-heptylphenyl)iodonium tetrafluoroborate, di(3-nitrophenyl)iodonium hexafluorophosphate, di(4-chlorophenyl)iodonium hexafluorophosphate, di(naphthyl)iodonium tetrafluoroborate, di(4-trifluoromethylphenyl)iodonium tetrafluoroborate, DPI hexafluorophosphate, Me2-DPI hexafluorophosphate, DPI hexafluoroarsenate, di(4-phenoxyphenyl)iodonium tetrafluoroborate, di(4-phenoxyphenyl)iodonium tetrafluoroborate, di(4-phenoxyphenyl)iodonium hexafluorophosphate, di(4-phenoxyphenyl)iodonium hexafluorophosphate, di(4-phenoxyphenyl)iodonium hexafluorophosphate, di(4-phenoxyphenyl)iodonium hexafluorophosphate, di(4-phenoxyphenyl)iodonium hexafluorophosphate, di(4-phenoxyphenyl)iodonium hexafluoroborate ...borate, di(4-phenoxyphenyl)iodonium hexafluorophosphate, di(4-phen phenyl)iodonium tetrafluoroborate, phenyl-2-thienyliodonium hexafluorophosphate, 3,5-dimethylpyrazolyl-4-phenyliodonium hexafluorophosphate, DPI hexafluoroantimonate, 2,2'-DPI tetrafluoroborate di(2,4-dichlorophenyl)iodonium hexafluorophosphate, di(4-bromophenyl)iodonium hexafluorophosphate, di(4-methoxyphenyl)iodonium hexa fluorophosphate, di(3-carboxyphenyl)iodonium hexafluorophosphate, di(3-methoxycarbonylphenyl)iodonium hexafluorophosphate, di(3-methoxysulfonylphenyl)iodonium hexafluorophosphate, di(4-acetamidophenyl)iodonium hexafluorophosphate, di(2-benzothienyl)iodonium hexafluorophosphate, and DPI hexafluorophosphate.

[0121] Particularly preferred iodonium compounds include diphenyliodonium (DPI) hexafluorophosphate, di(4-methylphenyl)iodonium (Me2-DPI) hexafluorophosphate, diaryliodonium hexafluoroantimonate, (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium hexafluoroantimonate, (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium hexafluorophosphate (Irgacure® 250, a commercially available product from BASF SE), (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium tetrafluoroborate, 4-octyloxyphenylphenyliodonium hexafluoroantimonate, 4-(2-hydroxytetradecyloxyphenyl)phenyliodonium hexafluoroantimonate, and 4-isopropyl-4′-methyldiphenyliodonium borate.

[0122] According to a particularly preferred embodiment, the iodonium compound is DPI hexafluorophosphate and / or 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate.

[0123] Preferred triarylsulfonium salts are of the formula: [ka] S-(phenyl)thianthrenium hexafluorophosphate.

[0124] Particularly preferred phosphonium salts are tetraalkylphosphonium salts, tetrakis-(hydroxymethyl)-phosphonium (THP) salts or tetrakis-(hydroxymethyl)-phosphonium hydroxide (THPOH) salts, wherein the anion of the tetraalkylphosphonium salt is selected from the group consisting of formate, acetate, phosphate, sulfate, fluoride, chloride, bromide, and iodide.

[0125] A suitable redox initiator system comprises a reducing agent and an oxidizing agent, which generate free radicals capable of initiating polymerization of the polymerizable groups of (B) a water-soluble polymerizable polymer containing an acidic group, optionally (D) a hydrolytically stable water-soluble monomer having a polymerizable double bond and optionally a carboxylic acid group, and optionally (E) a polymerizable hydrolytically stable crosslinker having at least two polymerizable carbon-carbon double bonds, independent of the presence of light. The reducing agent and oxidizing agent are selected so that the (C) polymerization initiator system is sufficiently shelf-stable and free of undesirable coloration to permit storage and use under typical dental conditions. Furthermore, the reducing agent and oxidizing agent are selected so that the (C) polymerization initiator system is sufficiently miscible with the resin system to allow the redox initiator system to be dissolved in the composition.

[0126] Useful reducing agents include ascorbic acid, ascorbic acid derivatives, and metal-complexed ascorbic acid compounds as described in U.S. Pat. No. 5,501,727; amines, i.e., tertiary amines, preferably tertiary aromatic amines, such as 4-tert-butyldimethylaniline; aromatic sulfinates, such as p-toluenesulfinate, benzenesulfinate, most preferably sodium para-toluenesulfinate; thioureas, such as 1-ethyl-2-thiourea, tetraethylthiourea, tetramethylthiourea, 1,1-dibutylthiourea, and 1,3-dibutylthiourea; and mixtures thereof. Other auxiliary reducing agents may include cobalt(II) chloride, ferrous chloride, ferrous sulfate, hydrazine, hydroxylamine, salts of dithionite or sulfite anions, and mixtures thereof. Aliphatic sulfinates, such as linear or branched C 1-6 Sulfinates having an alkyl group are also preferred. Examples of aliphatic sulfonates include zinc isopropylsulfinate and zinc n-propylsulfinate, preferably zinc isopropylsulfinate.

[0127] Suitable oxidizing agents include persulfuric acid and its salts, such as ammonium, sodium, potassium, cesium, and alkylammonium salts, preferably inorganic peroxodisulfates, most preferably potassium peroxodisulfate. Additional oxidizing agents include peroxides such as benzoyl peroxide, hydroperoxides such as cumyl hydroperoxide, t-butyl hydroperoxide, and amyl hydroperoxide, as well as transition metal salts such as cobalt(III) chloride and ferric chloride, cerium(IV) sulfate, perborate and its salts, permanganate and its salts, superphosphoric acid and its salts, and mixtures thereof. One or more different oxidizing agents or one or more different reducing agents may be used in the initiator system. A small amount of a transition metal compound may be added to accelerate the rate of redox curing. The reducing agent and oxidizing agent are present in amounts sufficient to allow for adequate free radical reaction rates.

[0128] The reducing agent or oxidizing agent may be microencapsulated to enhance the storage stability of the composition and, if necessary, to allow the reducing agent and oxidizing agent to be packaged together (U.S. Pat. No. 5,154,762). By appropriately selecting an encapsulating agent, it may be possible to combine the oxidizing agent and reducing agent in a storage-stable state, and to combine them with an acid-functional component and, optionally, even a filler. Furthermore, by appropriately selecting a water-insoluble encapsulating agent, it is possible to combine the reducing agent and oxidizing agent together with particulate reactive glass and water in a storage-stable state.

[0129] A particularly preferred redox initiator contains (i) an inorganic peroxodisulfate, (ii) an aromatic amine, and (iii) an aromatic or aliphatic sulfinate. For particularly preferred redox initiators, the inorganic peroxodisulfate is potassium peroxodisulfate; and / or the aromatic amine is tert-butyl-N,N-dimethylaniline (4-tert-butyl-N,N-dimethylaniline); and / or the aromatic sulfinate is sodium para-toluenesulfinate; and / or the aliphatic sulfonate is zinc isopropylsulfinate. Most preferably, the redox initiator contains (i') potassium peroxodisulfate, (ii') 4-tert-butyl-N,N-dimethylaniline, and (iii') sodium para-toluenesulfinate and / or zinc isopropylsulfinate.

[0130] The (C) polymerization initiator system is preferably a dual-cure initiator system containing a photoinitiator and any one of the above-described redox initiator systems. More preferably, the dual-cure initiator system contains a photoinitiator (preferably an α-diketone photoinitiator, more preferably camphorquinone), and the redox initiator contains (i) an inorganic peroxodisulfate, (ii) an aromatic amine, and (iii) an aromatic sulfinate and / or zinc aliphatic sulfonate. Most preferably, the dual-cure initiator system contains a photoinitiator (preferably an α-diketone photoinitiator, more preferably camphorquinone), and the redox initiator contains (i') potassium peroxodisulfate, (ii') tert-butyl-N,N-dimethylaniline, and (iii') sodium para-toluenesulfinate and / or zinc isopropylsulfinate.

[0131] Surprisingly, it has been found that when the aqueous dental glass ionomer compositions are self-cured, i.e., cured without the use of an external power source, such as a light source, the mechanical properties, flexural strength and E-modulus, of the resulting self-cured compositions are significantly increased by a redox initiator containing (i) an inorganic peroxodisulfate, (ii) an aromatic amine, and (iii) an aromatic sulfinate.

[0132] For deep cavities, dark-cure polymerization initiator systems according to (C) containing a redox initiator are preferred. Dual-cure initiator systems containing a photoinitiator and a redox initiator are more preferred. Most preferably, the redox initiator is a redox initiator containing (i) an inorganic peroxodisulfate, (ii) an aromatic amine, and (iii) an aromatic sulfinate.

[0133] The amount of the active species in the initiator system is not particularly limited. Preferably, the amount of the photoinitiator in the polymerization initiator system (C) is in the range of 0.001 to 5 mol % based on the total amount of polymerizable compounds in the form of (B) a water-soluble polymerizable polymer containing an acidic group, (D) any hydrolytically stable water-soluble monomer having a polymerizable double bond and, optionally, a carboxylic acid group, and (E) any polymerizable hydrolytically stable crosslinker having at least two polymerizable carbon-carbon double bonds.

[0134] (D) Monomers with a single polymerizable double bond Optionally, the aqueous dental glass ionomer according to the present invention includes (D) a hydrolytically stable, water-soluble monomer having a single polymerizable double bond. The aqueous dental glass ionomer according to the present invention may include one or a mixture of two or more (D) hydrolytically stable, water-soluble monomers having a single polymerizable double bond.

[0135] The term "hydrolytically stable" as used in this context means that the monomer according to (D) is hydrolytically stable in an acidic medium, e.g., a dental composition. Specifically, the monomer according to (D) does not contain a group, e.g., an ester group, that hydrolyzes in an aqueous medium at pH 3 at room temperature within one month.

[0136] Furthermore, the term "water-soluble" as used in this context means that at least 0.1 g, preferably 0.5 g, of the monomer according to (D) dissolves in 100 g of water at 20°C.

[0137] The optional hydrolytically stable, water-soluble monomer (D) can provide further improvements in the mechanical properties of the aqueous dental glass ionomer composition in the cured form, since the monomer (D) polymerizes with the polymerizable polymer (B) in the presence of the polymerization initiator system (C). The monomer (D) can then polymerize with itself and / or with the polymerizable pendant group of the polymerizable compound (B). Thus, in addition to the formation of a polymer from the monomer (D), there is a graft polymerization in which the monomer (D) reacts with the polymerizable pendant group of the polymerizable polymer (B), thereby forming a graft polymer. Furthermore, the grafted side chain formed from the monomer (D) can undergo an addition reaction with the pendant polymerizable group of another polymerizable polymer (B), thereby obtaining a crosslinked polymer.

[0138] In the following Scheme 5, graft polymerization with a monomer according to (D) is exemplarily shown for the polymerizable polymer according to (B) illustrated in Scheme 3 above, where acrylic acid is selected merely as an example as the monomer according to (D). The letter "m" represents at least one integer. [ka]

[0139] A preferred monomer according to (D) is hydrolytically stable, i.e. it does not contain any groups which hydrolyze within one month at pH 3. In particular, a preferred monomer according to (D) does not contain any ester groups.

[0140] Furthermore, suitable monomers according to (D) contain one polymerizable double bond. Suitable polymerizable double bonds are carbon-carbon double bonds such as those in alkenyl and vinyl groups.

[0141] Preferably, the monomers according to (D) have a molecular weight of at most 200 Da, more preferably at most 150 Da, most preferably at most 100 Da.

[0142] Preferably, the hydrolytically stable, water-soluble monomer having a single polymerizable double bond has a carboxylic acid group and is a compound represented by the general formula (4): [ka]

[0143] In formula (4), R 6 is a hydrogen atom or a straight-chain or branched C 1-3 is an alkyl group, and R 7 is a straight-chain or branched C optionally substituted with a hydrogen atom or a -COOH group 1-6 In formula (4), the dotted line represents R 6 It indicates that R may be in either the cis or trans configuration. 6 is a hydrogen atom, and R 7 is a hydrogen atom or C optionally substituted with a -COOH group 1-3 More preferably, R 6 is a hydrogen atom, and R 7 is a methyl group substituted with a hydrogen atom or a -COOH group, i.e., the compound of formula (4) is acrylic acid or itaconic acid. Most preferably, the compound of formula (4) is acrylic acid.

[0144] Preferably, in formula (4), the residue R 6 and R 7 is selected with the proviso that the molecular weight of the monomer having a single polymerizable double bond according to (D) is at most 200 Da, preferably at most 150 Da, more preferably at most 100 Da.

[0145] Additionally, the hydrolytically stable water-soluble monomer having a single polymerizable double bond may be 2-hydroxyethylacrylamide (HEAA), N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-di-n-propyl(meth)acrylamide, and N-ethyl-N-methyl(meth)acrylamide.

[0146] The monomers according to (D) are preferably selected with a view to good processability and suitability of the final aqueous dental glass ionomer composition, in particular with regard to viscosity. The viscosity of the monomers according to (D) is therefore preferably in the range of 0.1 to 100 mPa s, more preferably 0.3 to 50 mPa s, even more preferably 0.5 to 25 mPa s, even more preferably 0.8 to 10 mPa s, and especially 0.9 to 3 mPa s.

[0147] Monomers according to (D) that contain carboxylic acid groups are particularly advantageous because such monomers introduce additional carboxylic acid groups into the acidic polymers in the aqueous dental glass ionomer composition, which can undergo a cementation reaction to further improve the hardening or hardening reaction in the presence of the reactive particulate glass according to (A).

[0148] The monomer (D) is preferably contained in the aqueous dental glass ionomer composition in an amount of 0.1 to 20 wt %, more preferably 1 to 15 wt %, and even more preferably 2 to 10 wt %, based on the total weight of the aqueous dental glass ionomer composition. Absence of the monomer (D) may result in reduced long-term mechanical resistance. On the other hand, if the amount of the monomer (D) exceeds 20 wt %, shrinkage of the dental glass ionomer cement obtained from the aqueous dental glass ionomer composition may occur.

[0149] (E) a polymerizable crosslinking agent having at least two polymerizable C—C double bonds Optionally, the aqueous dental glass ionomer composition according to the present invention contains (E) a polymerizable, hydrolytically stable crosslinker having at least two polymerizable carbon-carbon double bonds.

[0150] The crosslinking agent according to (E) can be alkylenediol dimethyl acrylates such as 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, alkylenediol divinyl ethers such as 1,4-butanediol divinyl ether, di(ethylene glycol) dimethacrylate, di(ethylene glycol) divinyl ether, pentaerythritol diacrylate monostearate, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate or triaryl ether, pentaerythritol tetraacrylate, and trimethylolpropane triacrylate. The crosslinking agent according to (E) can also be 1,3-bis(acrylamido)-N,N'-diethylpropane, N,N-di(cyclopropylacrylamido)propane.

[0151] Preferably, the crosslinking agent is a polymerizable compound of the following formula (5) disclosed in EP 2705827 and WO 2014040729:

[0152] A''-L(B) n’ (5) (In the formula, A″ is a group of formula (6): [ka] (X 10 is CO, CS, CH2, or a group [X 100 Z 10 ] k where X 100 is an oxygen atom, a sulfur atom, or NH, and Z 10 is a linear or branched C 1-4 an alkylene group, and k is an integer of 1 to 10; R 10 is a hydrogen atom, -COOM 10 , C 3-6 Cycloalkyl groups, C 6-14 Aryl group or C 3-14Heteroaryl group, -COOM 10 , -PO3M 10 , -O-PO3M 10 2, or -SO3M 10 Straight or branched C optionally substituted by 1-16 alkyl groups, C 1-16 Alkyl group, C 6-14 Aryl group or C 3-14 Heteroaryl group, -COOM 10 , -PO3M 10 , -O-PO3M 10 2, or -SO3M 10 C may be substituted by 3-6 cycloalkyl groups, -COOM 10 , -PO3M 10 , -O-PO3M 10 2, or -SO3M 10 C may be substituted by 6-14 Aryl group or C 3-14 a heteroaryl group, R 20 is a hydrogen atom, -COOM 10 , C 6-14 Aryl group or C 3-14 Heteroaryl group, -COOM 10 , -PO3M 10 , -O-PO3M 10 2 and -SO3M 10 Straight or branched C optionally substituted by 1-16 alkyl groups, C 1-16 Alkyl group, C 6-14 Aryl group or C 3-14 Heteroaryl group, -COOM 10 , -PO3M 10 , -O-PO3M 10 2 or -SO3M 10 C may be substituted by 3-6 a cycloalkyl group, or -COOM 10 , -PO3M 10 , -O-PO3M 102, and -SO3M 10 C may be substituted by 6-14 Aryl group or C 3-14 a heteroaryl group, L is a single bond or a linker group; B is independent, A group according to the definition of A″, A group of formula (7): [ka] (In the formula, X 20 are independently X in formula (6). 1 has the same meaning as defined for R 10 and R 20 have, independently of each other, the same meaning as defined for formula (6), R° is a hydrogen atom, C 3-6 Cycloalkyl groups, C 6-14 Aryl group or C 3-14 Heteroaryl group, -COOM 10 , -PO3M 10 , -O-PO3M 10 2, or -SO3M 10 Straight or branched C optionally substituted by 1-16 alkyl groups, C 1-16 Alkyl group, C 6-14 Aryl group or C 3-14 Heteroaryl group, -COOM 10 , -PO3M 10 , -O-PO3M 10 2, or -SO3M 10 C may be substituted by 3-6 Cycloalkyl group, -COOM 10 , -PO3M 10 , -O-PO3M 10 2, or -SO3M 10 C may be substituted by 6-14 an aryl group, A group of formula (8): [ka] (In the formula, X 30 is CO, -CHCO-, CS, or -CHCS-, R 10 and R 20 have the same meaning as defined for formula (6), or group [X 40 Z 200 ] p E. (In the formula, Z 200 is a linear or branched C 1-4 is an alkylene group, X 40 is an oxygen atom, a sulfur atom, or NH, E is a hydrogen atom, PO3M2, C 3-6 Cycloalkyl groups, C 6-14 Aryl group or C 3-14 Heteroaryl group, -COOM 10 , -PO3M 10 , -O-PO3M 10 2, or -SO3M 10 Straight or branched C optionally substituted by 1-16 alkyl groups, C 1-16 Alkyl group, C 6-14 Aryl group or C 3-14 Heteroaryl group, -COOM 10 , -PO3M 10 , -O-PO3M 10 2, or -SO3M 10 C may be substituted by 3-6 cycloalkyl groups, -COOM 10 , -PO3M 10 , -O-PO3M 10 2, or -SO3M 10 C may be substituted by 6-14 Aryl group or C 3-14is a heteroaryl group, and p is an integer from 1 to 10; and n' is an integer from 1 to 4, where M 10 and each represent a hydrogen atom or a metal atom. Preferably, when L is a single bond, B cannot be a group according to the definition of A″ or a group of formula (7).

[0153] The following groups are preferred groups of formula (6), where M is a hydrogen atom or a metal atom: [ka] Preferred divalent linker groups may be selected from methylene, ethylene, propylene, butylene and the following divalent groups: [ka] N,N'-(2E)-but-2-ene-1,4-diallylbis-[(N-prop-2-en-1)amide] and N,N-di(allylacrylamido)propane are preferred.

[0154] Other additional ingredients Aqueous dental glass ionomer compositions according to the present invention may contain additional optional ingredients in addition to optional ingredients (D) and (E).

[0155] For example, water soluble dental glass ionomer compositions according to the present invention may also contain additional ingredients to improve radiopacity, such as CaWO4, ZrO2, YF3, or to increase fluoride release, such as YF3.

[0156] For example, the water-soluble dental glass ionomer compositions of the present invention may also contain modifiers such as tartaric acid. Such modifiers adjust the working time and setting time, respectively, of the glass ionomer cement reaction when preparing the cement, as described in U.S. Patent Nos. 4,089,830, 4,209,434, 4,317,681, and 4,374,936. Moreover, an increase in working time generally increases the setting time.

[0157] "Working time" is the period of time measured from the start of mixing the powder and glass at the indicated P / L ratio, during which the material can be manipulated without adversely affecting its properties.

[0158] The "set time" is the point at which the mixture is no longer deformable even under pressure.

[0159] In the curing reaction, a polymerization reaction occurs due to the presence of polymerizable double bonds.

[0160] The water-soluble dental glass ionomer compositions according to the present invention may further contain ingredients such as solvents, pigments, non-vitreous fillers, free radical scavengers, polymerization inhibitors, reactive and non-reactive diluents, e.g., bisacrylamides such as N,N'-diethyl-1,3-bisacrylamido-propane (BADEP), 1,3-bisacrylamido-propane (BAP), and 1,3-bisacrylamido-2-ethyl-propane (BAPEN), surfactants (e.g., polyoxyethylene, for example, to increase the solubility of the reaction inhibitor), coupling agents to increase the reactivity of the fillers, e.g., 3-(trimethoxysilyl)propyl methacrylate, and rheology modifiers.

[0161] Suitable reactive diluents are α,β-unsaturated monomers that modify properties such as toughness, adhesion, and cure time. Such α,β-unsaturated monomers can be acrylates and methacrylates, such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate (HEMA), hydroxypropyl acrylate, hydroxypropyl methacrylate, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, glycidyl acrylate, glycidyl methacrylate, diglycidyl methacrylate of bis-phenol A ("bis-GMA"), glycerol monoacrylate and diacrylate, glycerol monomethacrylate and dimethacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, polyethylene glycol diacrylate (the number of ethylene oxide repeat units varies from 2 to 30), polyethylene glycol dimethacrylate, etc. (The number of ethylene oxide repeating units varies from 2 to 30, particularly triethylene glycol dimethacrylate ("TEGDMA"), neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol and dipentaerythritol mono- and monomethacrylates, diacrylates and dimethacrylates, triacrylates and trimethacrylates, and tetraacrylates. and tetramethacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, di-2-methacryloyloxyethyl hexamethylene dicarbamate, di-2-methacryloyloxyethyl trimethylhexaneethylene dicarbamate, di-2-methacryloyloxyethyl dimethylbenzene dicarbamate,Methylene-bis-2-methacryloxyethyl-4-cyclohexylcarbamate, di-2-methacryloxyethyl-dimethylcyclohexanedicarbamate, methylene-bis-2-methacryloxyethyl-4-cyclohexylcarbamate, di-1-methyl-2-methacryloxyethyl-trimethyl-hexamethylenedicarbamate, di-1-methyl-2-methacryloxyethyl-dimethylbenzenedicarbamate, di-1-methyl-2-methacryloxyethyl-dimethylcyclohexanedicarbamate, methylene-bis-1-methyl-2- Methacryloxyethyl-4-cyclohexylcarbamate, di-1-chloromethyl-2-methacryloxyethyl-hexamethylene dicarbamate, di-1-chloromethyl-2-methacryloxyethyl-trimethylhexamethylene dicarbamate, di-1-chloromethyl-2-methacryloxyethyl-dimethylbenzenedicarbamate, di-1-chloromethyl-2-methacryloxyethyl-dimethylcyclohexanedicarbamate, methylene-bis-2-methacryloxyethyl-4-cyclohexylcarbamate, di-1-methyl-2-methacryloxyethyl di-1-methyl-2-methacryloxyethyl-hexamethylene dicarbamate, di-1-methyl-2-methacryloxyethyl-trimethylhexamethylene dicarbamate, di-1-methyl-2-methacryloxyethyl-dimethylbenzenedicarbamate, di-1-methyl-2-methacryloxyethyl-dimethylcyclohexanedicarbamate, methylene-bis-1-methyl-2-methacryloxyethyl-4-cyclohexylcarbamate, di-1-chloromethyl-2-methacryloxyethyl-hexamethylene dicarbamate, di-1-chloromethyl-2-methacryloxyethyl methyl-trimethylhexamethylene dicarbamate, di-1-chloromethyl-2-methacryloxyethyl-dimethylbenzenedicarbamate, di-1-chloromethyl-2-methacryloxyethyl-dimethylcyclohexanedicarbamate, methylene-bis-1-chloromethyl-2-methacryloxyethyl-4-cyclohexylcarbamate, 2,2'-bis(4-methacryloxyphenyl)propane, 2,2'-bis(4-acryloxyphenyl)propane, 2,2'-bis[4(2-hydroxy-3-methacryloxy-phenyl)]propane,Examples thereof include 2,2'-bis[4(2-hydroxy-3-acryloxy-phenyl)]propane, 2,2'-bis(4-methacryloxyethoxyphenyl)propane, 2,2'-bis(4-acryloxyethoxyphenyl)propane, 2,2'-bis(4-methacryloxypropoxyphenyl)propane, 2,2'-bis(4-acryloxypropoxyphenyl)propane, 2,2'-bis(4-methacryloxydiethoxyphenyl)propane, 2,2'-bis(4-acryloxydiethoxyphenyl)propane, 2,2'-bis[3(4-phenoxy)-2-hydroxypropane-1-methacrylate]propane, and 2,2'-bis[3(4-phenoxy)-2-hydroxypropane-1-acrylate]propane. Other suitable examples of polymerizable components include isopropenyl oxazoline, vinyl azlactone, vinyl pyrrolidone, styrene, divinylbenzene, urethane acrylate or urethane methacrylate, epoxy acrylate or epoxy methacrylate, and polyol acrylate or polyol methacrylate. Optionally, a mixture of α,β-unsaturated monomers can be added. Preferably, the mixed but unhardened dental composition of the present invention contains about 0.5 to about 40%, more preferably about 1 to about 30%, and most preferably about 5 to 20% by combined weight of water, solvent, diluent, and α,β-unsaturated monomer, based on the total weight of the mixed but unhardened aqueous dental glass ionomer composition components (including water, solvent, diluent, and α,β-unsaturated monomer). An example of a suitable free radical scavenger is 4-methoxyphenol.

[0162] The aqueous dental glass ionomer composition according to the present invention preferably comprises an inhibitor of formula (9) and / or (10): [ka] (In the formula, The R may be the same or different, and the branched C 3-8 Alkyl or alkenyl group, or C 3-8each independently represents a cycloalkyl group or a cycloalkenyl group, R' is a hydrogen atom, C 1-6 Alkyl group or C 2-6 Alkenyl group, or C 1-6 Fluoroalkyl group or C 2-6 represents a fluoroalkenyl group, X is C 1-8 Alkyl group or C 3-8 represents a group selected from cycloalkyl groups, n is 0, 1, or 2).

[0163] The aqueous dental glass ionomer composition according to the present invention may contain one inhibitor of formula (9) and / or (10), or a mixture of two or more inhibitors. Preferably, the inhibitor is a compound of formula (9) and / or (10), wherein Rs may be the same or different and independently represent a branched C 3-8 Alkyl group or C 3-8 represents a cycloalkyl group, R' is a hydrogen atom, C 1-6 Alkyl group or C 1-6 represents a fluoroalkyl group, and n is 0 or 1; more preferably, the inhibitor is a compound of formula (9) and / or (10), wherein Rs may be the same or different and independently represent a branched C 3-8 represents an alkyl group, and R' is a hydrogen atom or C 1-6 represents an alkyl group and n is 0; even more preferably, the inhibitor is a compound of formula (9a), (9b) or (10a): [ka] In the formula, R 11 , R 12 , R 13 , R 14 , R 15 and R 16 may be the same or different and independently represent a methyl group or an ethyl group. It is particularly preferred that the inhibitor of formula (9a), (9b) or (10a) is a compound of the following formula: [ka] It is particularly preferred that the compound is DTBHQ.

[0164] 2,5-Di-tert-butylhydroquinone (DTBHQ), 2,5-di-tert-butyl-4-methoxyphenol, and 2,5-di-tert-butylbenzoquinone (DTBBQ) are standard commercially available chemicals. 1-6 Alkyl group, C 2-6 Alkenyl group, C 1-6 Fluoroalkyl group, or C 2-6 Monoethers of formula (9) which are fluoroalkenyl groups, such as 2,5-di-tert-butyl-hydroquinone monoalkyl ethers of formula (Ib), can be easily obtained from dihydroquinones of formula (9), such as DTBHQ, as starting materials by selective monoetherification catalyzed in the presence of NaNO in combination with inorganic acids, such as HSO or solid acid catalysts, such as styrene-based sulfonated polymers, such as the commercially available ion exchange resins Amberlyst® 15 and Aberlite® IR120, as described, for example, by C. Gambarotti et al. in Current Organic Chemistry 2013, 17, pp. 1108-1113. Alternatively, R' may be C 1-6 Alkyl, C 2-6 Alkenyl group, C 1-6 Fluoroalkyl or C 2-6 Monoethers of formula (9) which are fluoroalkenyl groups, such as 2,5-di-tert-butyl-hydroquinone monoalkyl ethers of formula (Ib), can be obtained by reacting dihydroquinones of formula (9), such as DTBHQ, with alkyl alcohols in the presence of transition metal salts selected from copper and iron salts, as described in U.S. Pat. No. 4,469,897.

[0165] This inhibitor, DTBHQ, is particularly preferred as this example shows that it provides the best results in terms of the problem of discoloration, i.e., the aqueous dental glass ionomer composition shows no or very little discoloration even after storage at 50°C for 30 days.

[0166] In another embodiment, R' is C 1-6 Alkyl group or C 2-6 Alkenyl group, or C 1-6 Fluoroalkyl group or C 2-6 Compounds of formula (9) are preferred in which R' represents a fluoroalkenyl group. 1-6 Alkyl group or C 1-6 More preferably, R' represents a fluoroalkyl group, and 1-6 Most preferably, it represents an alkyl group.

[0167] The aqueous dental glass ionomer composition according to the present invention contains the inhibitor in an amount of 0.001 to 3 weight percent, preferably 0.005 to 2 weight percent, more preferably 0.01 to 1.2 weight percent, and even more preferably 0.05 to 1.0 weight percent, even more preferably 0.075 to 0.9 weight percent, and most preferably 0.1 to 0.8 weight percent, based on the total weight of the aqueous dental glass ionomer composition.

[0168] If the amount of inhibitor is below the above lower limit of 0.001, the storage stability of the aqueous dental glass ionomer composition may be insufficient because the amount of inhibitor is too low to provide a stabilizing effect. However, if the amount of inhibitor exceeds the maximum threshold of 3 weight percent, application of the aqueous dental glass ionomer composition may be adversely affected because the greater amount of inhibitor may prevent or substantially prevent the intended polymerization hardening of the composition during application.

[0169] To provide advantageous stability of the aqueous dental glass ionomer composition during storage and / or light curing, to prevent or substantially prevent discoloration of the composition, as well as to provide a beneficial polymerization rate for light curing, it may be preferred to set the molar ratio of (ii)(a) 1,2-diketone photoinitiator:(ii)(b) co-initiator compound:inhibitor of formulas (9) and (10) within the range of 1:(0.3-3.0):(0.01-0.2), more preferably 1:(0.5-3.0):(0.01-0.1), and even more preferably 1:(1.0-3.0):(0.01-0.05).

[0170] The aqueous dental glass ionomer composition according to the present invention may further comprise a filler in addition to the reactive particulate glass according to (A). Preferably, the further filler is selected from inert glasses, fluoride-releasing glasses, particulate prepolymerized fillers, crushed prepolymerized fillers, and filler agglomerates.

[0171] The term "inert glass" refers to glass that cannot react with polymers containing acidic groups in cementation reactions.Inert glasses are described, for example, in Journal of Dental Research, June 1979, pages 1607-1619, or more recently in U.S. Patent Nos. 4,814,362, 5,318,929, 5,360,770, and U.S. Patent Application Publication No. 2004 / 0079258A1.Specifically, U.S. Patent Application Publication No. 2004 / 0079258A1 discloses inert glasses in which strong basic oxides, such as CaO, BaO, SrO, MgO, ZnO, NaO, KO, and LiO, are replaced with weak basic oxides, such as scandium or those in the lanthanide series.

[0172] The term "fluoride-releasing glass" refers to glass capable of releasing fluoride. Fluoride-releasing capability can be imparted by adding an oxide to a mixture to form fluoride-containing glass inorganic particles, provided that the glass has fluoride-releasing, preferably sustained, fluoride-releasing properties. Such inorganic particles can be selected from the group consisting of sodium fluoride, strontium fluoride, lanthanum fluoride, ytterbium fluoride, yttrium fluoride, and calcium-containing fluoroaluminosilicate glass.

[0173] As used herein, the term "silanated" means that the filler has a silane coupling agent on its surface, for example in the form of a coating that at least partially, preferably completely, covers the surface of the filler.

[0174] Typically, the silane coupling agent has the formula (11): (R 24 ,R 25 ,R 26 )Si(R H ) n (11) In the formula, n is 1 to 3, and the substituent R 24 , R 25 , R 26 The number of is 4-n, and R 24 , R 25 , R 26 At least one of the two or three groups R represents a polymerizable group. H When present, R may be the same or different from each other. H R represents a hydrolyzable group capable of reacting with the surface of the filler material to be coated. H may be selected from the group consisting of an alkoxy group, an ester group, a halogen atom and an amino group, and the alkoxy group is preferably a linear C 1-8 or branched or cyclic C 3-8 The alkoxy group and the ester group are preferably linear C 1-8 or branched or cyclic C 3-8 The carboxylates are those having an alkyl group. Most preferably, the hydrolyzable group RH represents an alkoxyl group.

[0175] base R 24 , R 25 and R 26 may be the same or different and represent a non-reactive group and / or a polymerizable group, provided that R 24 , R 25 and R 26 At least one of R represents a polymerizable group. 24 , R 25 and R 26 The non-reactive group is preferably an alkyl group, preferably a linear C 1-8 or branched or cyclic C 3-8 It can be represented by an alkyl group. 24 , R 25 and R 26 is preferably selected from the group consisting of a (meth)acrylic group, a vinyl group or an oxirane group, more preferably a (meth)acrylic group or a vinyl group, most preferably a (meth)acrylic group, and the (meth)acrylic group may be, for example, in the form of methacryloxy or methacryloxyalkyl, where alkyl is a linear C 1-8 or branched or cyclic C 3-8 It means an alkyl group.

[0176] Particularly preferred organosilanes are, for example, 3-methacryloxytrimethoxysilane, vinyltrichlorosilane, tris(2-methoxyethoxy)-vinylsilane or tris(acetoxy)-vinylsilane, or any one of the specific groups of organosilanes disclosed in EP 0 969 789 A1, namely, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyldimethoxy-monochlorosilane, 3-methacryloxypropyldichloromonomethoxysilane, methacryloxypropyltrichlorosilane, 3-methacryloxypropyldichloromonomethyl-silane, and 3-methacryloxypropylmonochlorodimethylsilane.

[0177] Instead of or in addition to the organosilanes of formula (11), so-called dipodal organosilanes can be used. Dipodal organosilanes are typically represented by formula (12): ((R 24 , R 25 , R 26 )Si-R 27 )2CH-R H (12) (In the formula, R 24 , R 25 , R 26 , and R H has the same meaning as defined above for the organosilane of formula (11), and R 27 is an alkylene group, preferably a linear C 1-8 or branched or cyclic C 3-8 It is a compound of the formula (representing an alkylene group).

[0178] Aqueous dental glass ionomer compositions according to the present invention preferably contain additional fillers in an amount of 1 to 85 weight percent based on the total weight of the composition.

[0179] To provide composite filler particles having a median particle size (D50) of 1 to 70 μm, the filler agglomerates are a) coating a particulate filler having a median particle size (D50) of 1 to 1200 nm, preferably the above-mentioned particulate glass filler, with a coating composition containing a polymerizable film-forming agent that forms a polymer coating layer on the surface of the particulate filler, wherein the polymer coating layer may exhibit reactive groups on the surface of the coating layer, the reactive groups being selected from addition polymerizable groups and step-growth polymerizable groups, thereby subsequently or simultaneously forming a coated particulate filler; b) agglomerating the coated particulate filler, optionally in the presence of a further crosslinking agent and optionally in the presence of a further particulate filler not exhibiting reactive groups, to granulate the coated particulate filler, the granulate containing coated particulate filler particles and any further particulate filler particles separated from one another by and bonded to one another by at least one coating layer, whereby the at least one coating layer may be crosslinked by crosslinking groups obtained by reacting the reactive groups with the optional further crosslinking agent; c) optionally grinding, classifying and / or sieving the granulated coated particulate filler; d) optionally further cross-linking the granules of the coated particulate filler; wherein the reactive groups are converted into crosslinkable groups obtained by reacting the reactive groups and, optionally, a further crosslinking agent, and wherein the particulate filler is the major component of the composite filler particles on a volume basis, as further described in EP 2 604 247 A1.

[0180] To obtain a granulated and ground prepolymerized filler, step b) of the above process is omitted and the grinding step c) is carried out using a suitable grinding device to obtain a suitable granulated or ground particle size.

[0181] Single-pack or multi-pack dental compositions The aqueous dental glass ionomer compositions can be single-pack or multi-pack dental compositions.

[0182] As used herein, the term "one-pack" means that all components of the aqueous dental glass ionomer composition are contained in one single pack, such as a capsule having at least two containers.

[0183] As used herein, the term "multi-pack" means that the components of the aqueous dental glass ionomer composition are contained in multiple separate packs, such as a first portion of the components contained in a first pack, a second portion of the components contained in a second pack, a third portion of the components contained in a third pack, a fourth portion of the components contained in a fourth pack, etc.

[0184] Preferably, the aqueous dental glass ionomer composition is a two-pack or more composition, more preferably a two-pack composition. For two-pack dental compositions, a two-pack powder / liquid composition is preferred.

[0185] Preferably, in a two-pack powder / liquid composition, the liquid pack contains water and (B) a water-soluble polymerizable polymer containing acid groups, and the powder pack contains (A) a reactive particulate glass.

[0186] More preferably, in the two-pack powder / liquid composition, the liquid pack comprises water, (B) a water-soluble polymerizable polymer containing an acid group, (D) a hydrolytically stable, water-soluble monomer having a single polymerizable double bond and optionally a carboxylic acid group, a photoinitiator, and optionally an inhibitor, and optionally an aromatic amine (ii), and the powder pack comprises (A) a reactive particulate glass, optionally an inorganic peroxodisulfate (i), and optionally an aromatic sulfinate (iii). Most preferably, in the two-pack powder / liquid composition, the liquid pack comprises water, (B) a water-soluble polymerizable polymer containing an acid group, (D) a hydrolytically stable, water-soluble monomer having a single polymerizable double bond and optionally a carboxylic acid group, a photoinitiator, and optionally an inhibitor, and an aromatic amine (ii), and the powder pack comprises (A) a reactive particulate glass, solid inorganic peroxodisulfate (i), and aromatic sulfinate (iii).

[0187] Hardened water-soluble dental glass ionomer composition The aqueous dental glass ionomer composition is a hardenable dental composition, i.e., a hardened dental glass ionomer composition / cement can be obtained therefrom by polymerizing a polymerizable polymer according to (B) and a monomer according to (C) in the presence of a polymerization initiator system according to reactive particulate glass (A) and (D).

[0188] It has been found that the present dental glass ionomer compositions can have particularly advantageous mechanical properties. the composition has a flexural strength of at least 80 MPa, measured according to ISO 4049; and / or the composition has an adhesion to enamel and / or dentin of at least 5 MPa, measured according to ISO 29022:2013;

[0189] For the cured dental glass ionomer compositions of the present invention, when the compositions were light-cured, high flexural strengths of at least 80 MPa were obtained in all experimental examples, as measured according to ISO 4049. Surprisingly, the self-cured dental glass ionomer compositions of the present invention can also achieve such high flexural strengths, especially when the dental glass ionomer compositions contain a polymerization initiator system in the form of a dual-cure initiator system comprising a photoinitiator and a redox initiator, the redox initiator containing (i) an inorganic peroxodisulfate, (ii) an aromatic amine, and (iii) an aromatic sulfinate.

[0190] Particularly Preferred Embodiments of Water-Soluble Dental Glass Ionomer Compositions According to a particularly preferred embodiment, the water-soluble dental glass ionomer composition according to the present invention comprises: (A) 1) 20 to 45% by weight of silica; 2) 20 to 40 wt. % alumina; 3) 20 to 40% by weight of strontium oxide; 4) 1 to 10 wt. % P2O5; 5) a reactive particulate glass containing 3 to 25 wt. % fluoride; (B) a water-soluble polymerizable polymer containing an acidic group, wherein the polymerizable polymer is reactive with the particulate glass in a cement reaction, whereby the polymerizable polymer has a polymer backbone and hydrolytically stable pendant groups having single or multiple polymerizable carbon-carbon double bonds, wherein the polymerizable polymer comprises: a) copolymerizing the mixture to obtain a copolymer containing amino groups, the mixture comprising: (i) a first copolymerizable monomer represented by general formula (1'): [ka] (In the formula, R 1’ is a hydrogen atom, -COOZ # group or a methyl group, R 2’ is a hydrogen atom, -COOZ # group or a methyl group, A' is a single bond or a linear or branched C 1-6 is an alkyl group, Z # may be the same or different and independently represent a hydrogen atom or a protecting group for a carboxylic acid group), (ii) a second copolymerizable monomer represented by general formula (2'): [ka] (In the formula, R 3 is a hydrogen atom, X' is a protected amino group or a hydrocarbon group having 1 to 6 carbon atoms, which is substituted with an amino group which may bear a protecting group, and wherein the hydrocarbon group may contain a nitrogen atom; Y' is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, and the hydrocarbon group may contain an oxygen atom or an amide bond, and the hydrocarbon group is -COOZ ## may be further substituted with a group, Z ##may be the same or different and independently represent a hydrogen atom or a protecting group for a carboxylic acid group; b) A copolymer containing an amino group is provided with a polymerizable moiety and a copolymer of the general formula (3'): [ka] (In the formula, R 4’ is a hydrogen atom or a methyl group, R 5’ is a hydrogen atom or a methyl group, LG' is a chlorine atom or a bromine atom, or forms a carboxylic acid anhydride moiety with the adjacent carbonyl group, or and coupling a compound having a functional group represented by formula (3) (two molecules of formula (3) form an intermolecular carboxylic acid anhydride group by condensation of LG′, where LG′ is an oxygen atom), deprotecting any protected amino groups as needed so that the polymerizable pendant groups are linked to the backbone by hydrolytically stable linking groups; and 3 x 10 4 ~2.5×10 5 Average molecular weight M in the range of Da w and optionally, after step a) or step b), a step of deprotecting the protected carboxylic acid groups to obtain a polymerizable polymer having the formula: (C) a polymerization initiator system comprising a radical initiator in the form of a photoinitiator, preferably a monoketone or diketone photoinitiator, more preferably an α-diketone photoinitiator, most preferably camphorquinone, optionally in combination with a redox initiator, (i) inorganic peroxodisulfates, preferably potassium peroxodisulfate; (ii) an aromatic amine, preferably tert-butyl-N,N-dimethylaniline, and (iii) in combination with a redox initiator containing an aromatic sulfinate, preferably sodium para-toluenesulfinate; Most preferably, (i') potassium peroxodisulfate, (ii') tert-butyl-N,N-dimethylaniline, preferably 4-tert-butyl-N,N-dimethylaniline, and (iii') a polymerization initiator system based on sodium para-toluenesulfinate, in combination with a redox initiator containing sodium para-toluenesulfinate; (D) optionally, a hydrolytically stable, water-soluble monomer having a single polymerizable double bond and a carboxylic acid group, said monomer having a molecular weight of up to 200 Da, preferably said monomer having the general formula (4'): [ka] (In the formula, R 6’ is a hydrogen atom or a straight-chain or branched C 1-3 is an alkyl group, R 7’ is a straight-chain or branched C optionally substituted with a hydrogen atom or a -COOH group; 1-3 is an alkyl group, where R 6’ and R 7’ is selected with the proviso that the molecular weight of the compound of formula (4) is at most 200 Da, Preferably, R 6’ is a hydrogen atom, R 7’ is a hydrogen atom or a C optionally substituted with a -COOH group 1-3 It is the basis, More preferably, R 6’ is a hydrogen atom, R 7’ is a hydrogen atom or a methyl group substituted with a -COOH group), and

[0191] In this particularly preferred embodiment, the (C) polymerization initiator system comprises an α-diketone photoinitiator, preferably (i') potassium peroxodisulfate, (ii') 4-tert-butyl-N,N-dimethylaniline, and (iii') Most preferred are those based on camphorquinone in combination with a redox initiator containing sodium para-toluenesulfinate.

[0192] Furthermore, in this particularly preferred embodiment, it is preferable to select, as follows, a first copolymerizable monomer represented by general formula (1 / 1'), a second copolymerizable monomer represented by general formula (2 / 2'), a compound having a polymerizable moiety and a functional group reactive with the amino group of the repeating unit derived from the second copolymerizable monomer represented by general formula (3 / 3'), and a water-soluble monomer that is stable to hydrolysis and has a single polymerizable double bond represented by general formula (4 / 4'). the first copolymerizable monomer is a protected (meth)acrylic acid monomer, more preferably tert-butyl acrylate or benzyl acrylate, most preferably tert-butyl acrylate; the second copolymerizable monomer is aminopropyl vinyl ether, the amino group may be in the form of an ammonium salt, such as ammonium chloride, more preferably a compound selected from the following, which may also carry a protecting group: [ka] a compound having a polymerizable portion and a functional group reactive with an amino group of a repeating unit derived from a second copolymerizable monomer, acrylic acid, (meth)acrylic acid, crotonic acid, isocrotonic acid, tiglic acid, angelic acid, or anhydrides of said acids formed from two of the same or different acids, more preferably anhydrides of said acids formed from two of the same acids; most preferably anhydride of acrylic acid, and - a hydrolytically stable, water-soluble monomer having a single polymerizable double bond and a carboxylic acid group; It is itaconic acid or acrylic acid, preferably acrylic acid.

[0193] In this last particularly preferred embodiment, the polymerizable polymer obtained in step b) most preferably has one of the following structures: [ka] The present invention is further illustrated by the following examples. [Example]

[0194] The following Examples 1-7 describe the preparation of preferred polymerizable polymers according to (B). Example 8 describes the preparation of aqueous dental glass ionomer compositions and testing of the mechanical properties of the hardened compositions. Example 9 describes the measurement of tensile bond strength, and Example 10 describes the treatment of cavitated caries lesions using aqueous dental glass ionomer compositions of the present invention as direct restorations.

[0195] Example 1 1. Copolymerization of tert-butyl acrylate (tButA) and 3-aminopropyl vinyl ether (APVE) to poly(tButA-co-APVE) [ka] 5.0 g (39 mmol) of tButA, 0.99 g (9.8 mmol, 20 mol%) of APVE, and 0.16 g (2 mol%) of AIBN were separately dissolved in DMF, and the solution was saturated with N2. The solutions were then combined and stirred at 70 °C for 24 h. After polymerization, the cooled solution was diluted with DMF to a 30 wt% polymer solution and precipitated in water / methanol (9:1). The isolated solid was dried under vacuum.

[0196] The resulting copolymer has a molecular weight M n =18kDa, M w = 51 kDa and a PD of 2.8.

[0197] IR spectroscopy of the product showed no vinyl ether vibrations, while 1 1 H-NMR showed broad peaks for aliphatic protons and no peaks for possible remaining double bond protons.

[0198] 1 H-NMR (500MHz, DMSO-d6): δ (ppm) = 3.5 (2H, 4), 2.7 (2H, 6), 2.2 (2H, 2), 1.8 (1H, 1), 1.6 (2H, 5), 1.44 (9H, 3).

[0199] 2. Methacrylation of poly(tButA-co-APVE) [ka] To a solution of 5 g (33.7 mmol) of the copolymer poly(tButA-co-APVE) dissolved in 31.5 g of dichloromethane was added 1.3 g (8.42 mmol) of methacrylic anhydride. After stirring the solution for 24 h at ambient temperature, the solvent was removed and the crude product was dissolved in 30 mL of methanol. From this solution, the polymer was precipitated in water, filtered, and dried under vacuum.

[0200] FT-IR:ν max [cm -1 ]=2976, 2932, 1785, 1722 (ester), 1670 (amide I), 1626 (C=C), 1526 (amide II), 1479, 1448, 1392, 1366, 1143, 844.

[0201] 3. Hydrolysis of the ester moiety [ka] To a solution of 1.0 g (8.15 mmol) of methacrylated poly(tButA-co-APVE) in 5 mL of chloroform, 20 wt % trifluoroacetic acid was added. The solution was stirred for 5 hours at 60 °C, and the precipitated crude polymer was separated from the solvent. The polymer was washed with chloroform, dissolved in methanol, and reprecipitated in chloroform. The yellow polymer was then vacuum dried.

[0202] 1 H-NMR (500MHz, DMSO-d6): δ(ppm)=12.2(1H,-COOH), 7.8(1H,-NH-), 5.6(1H,-C=CH), 5.3(1H,C=CH), 2.2 (2H,-CH2- skeleton), 1.8 (3H,-CH3), 1.8 (1H,-CH-, skeleton), 1.5 (2H,O-CH2CH2), 1.4 (9H,C-(CH3)3, remaining ester moiety).

[0203] Example 2 1. Copolymerization of tert-butyl acrylate (t-BA) and 3-aminopropyl vinyl ether (APVE) into poly(AA-co-APVE) In a three-necked round-bottom flask equipped with a condenser, 2.34 mL (0.0206 mol) of APVE and 8.97 mL (0.0618 mol) of t-BA were mixed with 20 mL of dioxane. 278 mg of AIBN (2 mol% based on total monomers) was also dissolved. The reaction mixture was immediately flushed with argon for approximately 20 minutes. Meanwhile, a metal bath preheated to 90 °C was placed under the flask. Polymerization was initiated immediately by placing the metal bath under the flask. After stirring for 1 hour, the reaction was complete. A 5 mL sample was removed and diluted to 20 mL with dioxane. The polymer was precipitated by adding this solution to 150 mL of excess water. The polymer was dried under a vacuum pump. The molecular weight was determined by SEC using DMF as the eluent. M n = 11500 g / mol, M w = 38100 g / mol, PD = 3.32

[0204] 2. Modification of poly(AA-co-APVE) with methacrylic anhydride To the remaining reaction mixture from Synthesis Step 1, cooled to room temperature, 26 mg of tert-butylhydroquinone (TBHQ) was added to deactivate the remaining initiator. Next, 0.0309 mol of methacrylic anhydride was added. After stirring the mixture for 2 hours at room temperature, the solvent was removed on a rotary evaporator (30 °C), and the sample was then dried under vacuum. The NMR spectrum showed broad peaks at 5.30 ppm and 5.64 ppm corresponding to the double bond, indicating successful modification.

[0205] 3. Hydrolysis of the tert-butyl ester moiety 20 g of polymer incorporating 5 mol% APVE was modified with methacrylic anhydride as described above. After removing the solvent on a rotary evaporator, the crude product was dissolved in 50 mL of trifluoroacetic acid. The mixture was cooled in a slowly dissolving ice bath and stirred for 24 hours. Overnight, the polymer precipitated. The suspension was decanted, and the polymer was dissolved in 100 mL of dioxane. It was then precipitated in a five-fold excess of acetone. The precipitate was redissolved in dioxane and precipitated again. The polymer was then first dried on a rotary evaporator and then dried under vacuum. NMR spectra showed that the tert-butyl group peak at 1.38 ppm had almost disappeared, corresponding to a degree of hydrolysis of 98 mol%.

[0206] Example 3 Copolymerization of tert-butyl acrylate and 3-aminopropyl vinyl ether - P(tBu-co-APVE) A solution of 15 g (117 mmol) of tert-butyl acrylate in 38 g of DMF was saturated with nitrogen under ice cooling. After 15 min, 3 g (29 mmol) of 3-aminopropyl vinyl ether was added to the solution. After an additional 5 min, 480 mg (2 mol%) of AIBN was added under a countercurrent of nitrogen. The solution was then stirred for 24 h at 70 °C. After polymerization, the cooled solution was diluted with DMF to a 33 wt % polymer solution and precipitated in 20 volumes of water. The solid was filtered off, washed with water, and dried under vacuum. FT-IR:ν max [cm -1 ]=2977(-CH2-), 1723(ester), 1481, 1449, 1392, 1366, 1255, 1144, 845. 1 H-NMR (500MHz, CDCl3): δ(ppm)=3.5(2H,-O-CH2-), 2.7(2H,-CH2-NH2), 2.2(2H, skeleton), 1.8(1H, skeleton), 1.6(2H,-O-CH2-CH2-), 1.44(9H,-tbutyl). GPC(DMF):M n = 26 kDa, M w = 70 kDa, M z = 124 kDa, PD = 2.7.

[0207] The following table shows typical molecular masses for various polymerization samples using a ratio of equivalents (tBA): equivalents (APVE) = 3:1: [Table 1] Itaconic acid amide modified P(tBA-co-APVE-IA) To a clear solution of 3.0 g of p(tBA-co-APVE) dissolved in 10 mL of dichloromethane, 0.4 g (3.6 mmol) of itaconic anhydride was added portionwise with stirring, causing the solution to turn red and then yellowish in color. The solution was then stirred for 24 hours at room temperature, after which the dichloromethane was evaporated. FT-IR:ν max [cm -1] = 2977 (-CH2-), 1718 (ester), 1668 (amide I), 1559 (amide II), 1476, 1437, 1392, 1367, 1252, 1146, 1100, 945, 843.

[0208] Hydrolysis of the ester moiety to P(AA-co-APVE-IA) [Table 2] FT-IR:ν max [cm -1 ]=3392, 2932 (-CH2-), 1699 (acid), 1625 (-C=C), 1546 (amide II), 1447, 1407, 1230, 1164, 1094, 934, 798, 610. 1 H-NMR (300MHz,D2O): δ(ppm)=8.0(1H,-NH-), 6.4(1H,-C=CH), 5.6(1H,-C=CH), 3.5(2H,-O-CH2-), 3.4(2H,-NH-CH2-), 3.3(2H,-NH-CO-CH2), 2.4(1H, skeleton), 2.0-1.5(2H, skeleton), 1.6(2H,-O-CH2-CH2-).

[0209] Example 4 Methacrylamide-modified P(tBA-co-APVE-MA) To a clear solution of 3.0 g of p(tBA-co-APVE) from Example 2 dissolved in 10 mL of dichloromethane, 0.6 g (4.1 mmol) of methacrylic anhydride was added in small portions. The solution was then stirred at room temperature for 24 hours, after which the dichloromethane was evaporated. The resulting crude product was used for further reactions without purification. FT-IR:ν max [cm -1 ]=3351, 2977 (-CH2-), 1721 (ester), 1668 (amide I), 1622 (-C=C), 1531 (amide II), 1452, 1392, 1366, 1255, 1146, 1089, 940, 845.

[0210] Hydrolysis of the ester moiety to P(AA-co-APVE-MA) [Table 3] FT-IR:ν max [cm -1 ] = 3180, 2934 (-CH2-), 2613, 1701 (acid), 1650 (amide I), 1597, 1537 (amide II), 1449, 1408, 1211, 1162, 1110, 919, 797, 611. 1 H-NMR (300MHz, D2O): δ(ppm)=8.0(1H,-NH-), 5.7(1H,-C=CH), 5.4(1H,-C=CH), 3.5(2H ,-O-CH2-), 3.5(2H,-NH-CH2-), 2.2(1H, skeleton), 1.8-1.6(2H, skeleton), 1.6(2H,-O-CH2-CH2-).

[0211] Example 5 Acrylamide-modified P(tBA-co-APVE-AA) To a solution of 5.0 g of p(tBA-co-APVE) from Example 4 dissolved in 30 mL of THF, 0.76 g (6.7 mmol) of acryloyl chloride was added dropwise under ice cooling, which immediately precipitated a white solid. The reaction mixture was stirred for an additional 24 hours at room temperature. The solid was filtered off, and the solvent was evaporated. The crude material was used for hydrolysis without further purification. FT-IR:ν max [cm -1 ]=3289, 2976 (-CH2-), 1722 (ester), 1659 (amide I), 1628 (-C=C), 1544 (amide II), 1480, 1448, 1366, 1254, 1143, 844.

[0212] Hydrolysis of the ester moiety to P(AA-co-APVE-AA) [Table 4] The solution was then dialyzed (MWCO=1000 g / mol) for 4 days, and a colorless solid was recovered after lyophilization. FT-IR:ν max [cm -1 ]=3361, 2930 (-CH2-), 1707 (acid), 1654 (amide I), 1620 (-C=C), 1544 (amide II), 1447, 1407, 1242, 1179, 1097, 980, 801. 1 H-NMR(300MHz,D2O): δ(ppm)=6.3(1H,-C=CH), 6.2(1H,-C=CH), 5.8(1H,-CH=C<), 3.6(2 H,-O-CH2-), 3.3(2H,-NH-CH2-), 2.2(1H, skeleton), 1.9-1.4(2H, skeleton), 1.6(2H,-O-CH2-CH2-).

[0213] Example 6 Copolymerization of acrylic acid and N-vinylformamide to P(AA-NVFA) 1 1 NANesterova et al.,Russian Journal of Applied Chemistry2008,Vol.82,No.4,pp.618-621 3 g (41.6 mmol) of acrylic acid and 590 mg (8.9 mmol) of N-vinylformamide were dissolved in 10.88 g of distilled isopropanol and sparged with nitrogen for 30 minutes. Next, 164 mg (2 mol%) of AIBN was added in a countercurrent of nitrogen, and the mixture was sparged with nitrogen for another 15 minutes. The solution was then stirred at 70°C for 24 hours, whereupon a colorless solid precipitated. The solid was filtered off, washed repeatedly with acetone, and dried under reduced pressure. A colorless, finely dispersed solid was obtained. FT-IR:ν max [cm -1 ] = 3272 (-NH2), 3054 (-CH2-), 2922, 1708 (acid), 1643 (amide I), 1532 (amide II), 1444, 1385 (-CH2-), 1244, 1178. 1H-NMR (300MHz, DMSO-d6): δ(ppm)=12.2(1H,-COOH), 7.9(1H,-NH-COH), 4.3(1H,-CH-NH), 2.2(1H,-CH-COOH), 1.7(2H,-CH2-CH-NH-), 1.5(2H,CH2-CHCOOH). GPC(HO):M n = 10 kDa, M w = 49 kDa, M z = 126 kDa, PD = 5.0. NANesterova et al.,Russian Journal of Applied Chemistry 2008,Vol.82,No.4,pp.618-621

[0214] Conversion of P(AA-co-NVFA) to P(AA-co-VAm) (Based on the hydrolysis of pure p(VFA) to give p(VAm) in K. Yamamoto et al., Journal of Applied Polymer Science 2002, Vol. 89, pp. 1277-1283.) 200 mg of copolymer p(AA-co-NVFA) was dissolved in 10 mL of 2N NaOH and stirred for 2 h at 100 °C. The solution was then neutralized with HCl and dialyzed for 3 days (MWCO = 1000 g / mol). After lyophilization, a fleece-like colorless solid was obtained. FT-IR:ν max [cm -1 ]=3274(-NH2), 2919(-CH2-), 1666(-COONa), 1559(-NH2), 1448, 1408(-CH2-), 1188(-CO-). 1 H-NMR (300MHz, D2O): δ(ppm)=2.5(1H,-CH-NH2), 2.0(1H,-CH-COOH), 1.4(2H,-CH2-CH-NH2), 1.3(2H,-CH2-CH-COOH).

[0215] Acrylamide-modified P(AA-co-VAm-MA) 0.5 g of hydrolyzed copolymer P(AA-co-VAm) was added to a round-bottom flask, and 1.0 g of excess methacrylic anhydride was added. The mixture was heated at 60°C for 4 hours. The product was then diluted with water and the polymer was precipitated twice in methanol. 1 The final polymer was analyzed for double bond functionalization by H-NMR (C=C bonds at 5.51 ppm and 5.31 ppm). After stirring for 24 hours, the polymer was soluble in water. The degree of functionalization reached 4.0 mol%.

[0216] Example 7 Copolymerization of acrylic acid with N-(2-aminoethyl) methacrylamide hydrochloride. 0.2 g (3 mmol) of acrylic acid and 0.5 g (3 mmol) of N-(2-aminoethyl)methacrylamide hydrochloride were dissolved in 1.4 g of DMF and aerated with nitrogen for 15 minutes. Next, 20 mg (2 mol%) of VA-044 was added in a countercurrent of nitrogen and aerated with nitrogen for another 5 minutes. The solution was then stirred at 70°C for 2 hours, whereupon a colorless solid precipitated. The solid was filtered off, washed repeatedly with acetone, and dried under reduced pressure. A colorless, finely dispersed solid was obtained. FT-IR:ν max [cm -1 ] = 3350 (-NH2), 2926, 1705 (acid), 1629 (amide I), 1527 (amide II), 1482, 1456, 1393, 1365, 1232, 1166, 837. 1 H-NMR(300MHz,DMSO-d6):δ(ppm)=12.3(1H,-OH), 8.3(1H,-NH-), 7.9(2H,-NH2), 4.2(1H,CH3 -CH<), 2.9(2H,-NH-CH2-), 2.6(2H,-NH-CH2-CH2-), 1.5(1H, skeleton), 1.2(3H,-CH3), 1.0(2H, skeleton).

[0217] Example 8 Preparation and Testing of Aqueous Dental Glass Ionomer Compositions The aqueous dental glass ionomer compositions of Examples 8A-8H and the Comparative Example were prepared by forming liquid and powder compositions of the components listed in Tables 1 and 2 below, each totaling 100% by weight.

[0218] To prepare resin-modified glass ionomer (RMGI) test specimens, each liquid of Examples 8A-8H and the Comparative Example was mixed with the respective powder at the powder / liquid (P / L) ratios shown in Tables 1 and 2.

[0219] To prepare test specimens, the resulting powder and liquid mixtures of Examples 8A-8H and the Comparative Example were filled into stainless steel molds measuring (25±2) mm x (2.0±0.1) mm x (2.0±0.1) mm. The dental glass ionomer compositions thus obtained were light-cured using a dental curing light and self-cured, i.e., cured without an external power source. In Tables 1 and 2, the abbreviation "LC" stands for light-cured, and the abbreviation "SC" stands for self-cured.

[0220] The flexural strength of the hardened dental glass ionomer compositions obtained in Examples 8A to 8H and the comparative examples was measured in accordance with ISO 4049 by irradiating the samples at 37°C and 100% humidity for 1 hour, and then storing them in water at 37°C for 23 hours, taking into account the properties of the materials.

[0221] For comparison with the disclosure of U.S. Patent Application Publication No. 2005 / 0165136A, under identical measurement conditions, the flexural strength (LC) of Vitremer® light-cured glass ionomer (a 3M Dental product) is 66±2 MPa, and the flexural strength (SC) of Vitremer® light-cured glass ionomer (a 3M Dental product) is 45±5 MPa.

[0222] "Set time" consists of the working time and setting time shown in Tables 1 and 2. The terms "working time" and "setting time" are defined above in the general description.

[0223] Table 1. Compositions of aqueous dental glass ionomer compositions of Examples 8A-8E, applied curing times and mechanical properties of the resulting cured compositions. [Table 5] [Table 6] In Tables 1 and 2, the abbreviations for the components have the following meanings: KPS: potassium peroxodisulfate; tBDA: tert-butyl-N,N-dimethylaniline, DMABN: (dimethylamino)benzonitrile, and NapTS: sodium para-toluenesulfinate Unmodified PAA poly(acrylic acid-co-itaconic acid) (p(AA-co-IA))

[0224] The mechanical properties listed in Tables 1 and 2 show that the aqueous dental glass ionomer compositions of Examples 8A-8G according to the present invention all provide advantageously high flexural strength and E-modulus when light-cured. For Example 8H, high flexural strength and E-modulus were not measured for the light-cured sample.

[0225] Specifically, according to Tables 1 and 2, light-cured aqueous dental glass ionomer compositions according to the present invention exhibit flexural strengths up to 80% higher than the flexural strength of Vitremer® light-cured glass ionomer (a 3MDental product) under the test conditions used in accordance with the present invention. Furthermore, the self-curing aqueous dental glass ionomer compositions of Examples 8A-8G impressively demonstrated significantly improved flexural strength and E-modulus compared to the self-curing compositions of Examples 8F, 8G, and 8H. From Examples 8A-8G, it appears that the specific redox initiators, including (i') potassium peroxodisulfate, (ii') tert-butyl-N,N-dimethylaniline, and (iii') sodium para-toluenesulfinate, are responsible for this significant improvement in flexural strength and E-modulus upon self-curing. Such superior self-curing properties are highly desirable for deep carious lesions, e.g., having a depth of about 1 mm or greater.

[0226] Furthermore, the cured composition of Example 8C, which also provides the highest flexural strength and excellent E-modulus upon self-curing, was further measured for tensile bond strength to enamel and dentin upon both self-curing and light-curing. Surprisingly, the tensile bond strength was found to be at least about 20 MPa, thus providing excellent reliable adhesion to enamel or dentin.

[0227] Example 9 Tensile adhesive strength measurement Extracted teeth, such as human or bovine molars, may be provided and immersed in water at a predetermined temperature for a predetermined time before use, for example, 24 hours at 4° C. In order to have good reproducibility, as a first model experiment, healthy teeth without (cavitated) carious lesions were used, and their enamel was appropriately conditioned, for example, by polishing under running water with, for example, wet 320-grit abrasive paper and then 600-grit abrasive paper.

[0228] The dental composition according to the invention is then applied to the extracted tooth using, for example, the Ultradent method (ISO / TS11405 Dental materials - Test for adhesion to tooth structure). A tensile bond strength test is then carried out using a suitable device, such as a Zwick Roell. A tensile load is applied at a crosshead speed of 1 mm / min until the post peels off. The load at break is recorded and the tensile bond strength is calculated in MPa.

[0229] Example 10 Use in the treatment of cavitated carious lesions as direct restorations A Class I advanced cavitated caries lesion located on the occlusal surface of a human molar, where the cavitated caries lesion is approximately 1 mm deep, is treated in vivo. In the carious molar, all soft, leathery dentin at the location of the carious lesion is removed with a dental cutting device until the hard dentin is reached. After cutting, the resulting cavity may be 2 mm or more deep. The cut carious lesion is cleaned by suitable means, for example, by having the patient gargle with water, optionally mixed with a suitable disinfectant. The cut carious lesion is dried, for example, using an airflow, and then filled with the aqueous dental glass ionomer composition of Example 8C. The composition is molded. Finally, the molded composition is cured under a suitable dental curing light, for example, at approximately 1000 mW / cm. 2 The self-curing composition was light-cured three times for 20 seconds using a SmartLite® Focus dental curing light (Dentsply DeTrey GmbH, Germany) with a wavelength of approximately 474 nm to further enhance adhesion of the self-curing composition to the surface of the treated molar.

Claims

1. 1. An aqueous dental glass ionomer composition for use in treating cavitated caries lesions, said glass ionomer composition comprising: (A) reactive particulate glass; (B) a water-soluble polymerizable polymer, the polymerizable polymer containing acidic groups and reactive with the particulate glass in a cement reaction, whereby the polymerizable polymer has a polymer backbone and pendant groups having one or more polymerizable carbon-carbon double bonds; (C) a polymerization initiator system, the polymerization initiator system is a dual-cure initiator system containing a photoinitiator and a redox initiator; The redox initiator is (i) inorganic peroxodisulfates, (ii) an aromatic amine, and (iii) an aromatic sulfinate, The dental glass ionomer composition is a two-pack type powder / liquid composition, wherein the liquid pack comprises water, the (B) water-soluble polymerizable polymer containing an acidic group, the photoinitiator, and the aromatic amine (ii), and the powder pack comprises the (A) reactive particulate glass, the inorganic peroxodisulfate (i), and the aromatic sulfinate (iii); An aqueous dental glass ionomer composition, wherein said dental glass ionomer composition is used as a permanent direct restoration.

2. 2. The aqueous dental glass ionomer composition for use according to claim 1, wherein said caries lesions are moderate, advanced or severe caries lesions, preferably advanced or severe caries lesions.

3. 3. The aqueous dental glass ionomer composition for use according to claim 1 or 2, wherein the caries lesion is a class I, IV, or VI caries lesion.

4. 4. The aqueous dental glass ionomer composition for use according to any one of claims 1 to 3, wherein the inorganic peroxodisulfate is potassium peroxodisulfate; and / or the aromatic amine is tert-butyl-N,N-dimethylaniline; and / or the aromatic sulfinate is sodium para-toluenesulfinate.

5. 5. The aqueous dental glass ionomer composition for use according to any one of claims 1 to 4, wherein the hardened dental glass ionomer composition provides a flexural strength of at least 80 MPa measured according to ISO 4049.

6. 6. The aqueous dental glass ionomer composition for use according to any one of claims 1 to 5, wherein the hardened dental glass ionomer composition provides an adhesion to enamel of at least 5 MPa measured according to ISO 29022:2013.

7. 7. The aqueous dental glass ionomer composition for use according to any one of claims 1 to 6, further comprising (D) a hydrolytically stable, water-soluble monomer having a single polymerizable double bond and optionally a carboxylic acid group, and having a molecular weight of up to 200 Da.

8. 8. The aqueous dental glass ionomer composition for use according to any one of claims 1 to 7, further comprising (E) a polymerizable, hydrolytically stable crosslinker having at least two polymerizable carbon-carbon double bonds.

9. A method for producing an aqueous dental glass ionomer composition for use according to any one of claims 1 to 8, comprising the steps of: The polymerizable polymer a) to obtain a copolymer containing amino groups, (i) a first copolymerizable monomer comprising at least one optionally protected carboxylic acid group and a first polymerizable organic moiety; (ii) a second copolymerizable monomer comprising one or more optionally protected primary and / or secondary amino groups and a second polymerizable organic moiety; copolymerizing a mixture comprising: b) coupling the amino group-containing copolymer with a compound having a polymerizable moiety and a functional group reactive with the amino group of the repeat unit derived from the second copolymerizable monomer in the amino group-containing copolymer obtained in step a), wherein the optionally protected amino group is deprotected so that the pendant group having one or more polymerizable carbon-carbon double bonds is linked to the polymer backbone by a hydrolytically stable linking group; and a step of deprotecting said optionally protected carboxylic acid groups after step a) or step b).

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