Parts kit for manufacturing glass ionomer cement having high compressive strength

Abstract

The present invention relates to a parts kit for obtaining a glass ionomer composition, the parts kit including a part P and a part L, the part P being a powder containing an acid-reactive glass, the part L being a liquid containing water, the parts kit further including a polycarboxylic acid, the polycarboxylic acid being present in the part P or the part L or in both the part P and the part L, the polycarboxylic acid including a copolymer of acrylic acid and maleic acid, the acid-reactive glass including P: 0 to 4 wt%, F: 10 to 18 wt%, O: 25 to 35 wt%, Si: 10 to 16 wt%, Al: 11 to 19 wt%, Sr: 20 to 40 wt%, La: 0 to 4 wt%, the total amount of Al, Sr and F being more than 48 wt% (wt% being based on the weight of the acid-reactive glass), and the ratio of Al to Si in the acid-reactive glass being more than 1 / 1 by weight. The present invention also relates to the use of a specific acid-reactive glass in combination with a specific polycarboxylic acid for improving the mechanical strength of a glass ionomer composition.

Description

Technical Field

[0001] The present invention relates to a parts kit for manufacturing a glass ionomer composition having particularly beneficial mechanical properties such as compressive strength.

[0002] Glass ionomer compositions can be used as filling materials and for fixing dental restorations such as crowns or bridges to the surface of teeth.

Background Art

[0003] Glass ionomer cements have been used for over 30 years for dental restorative treatment.

[0004] Typically, glass ionomer cements are reacted by mixing a powder part with a liquid part.

[0005] The powder component typically includes an acid-reactive filler (e.g., fluoroaluminosilicate glass) as an essential or important component.

[0006] The liquid component typically includes water, a polycarboxylic acid, and a complexing or chelating agent (e.g., tartaric acid) for adjusting the curing properties as essential components.

[0007] The main advantages of glass ionomer cements are said to be self-adhesion to tooth structure, fluoride release, and the ability to be placed in bulk at one time.

[0008] One drawback reported by some physicians is the brittle nature and relatively low physical-mechanical properties of glass ionomer cements compared to the physical-mechanical properties reported for resin-based composite filling materials.

[0009] There are various approaches for improving the mechanical properties of glass ionomer cements.

[0010] U.S. Patent No. 4,376,835 (Schmitt et al.) describes calcium aluminum fluorosilicate glass powder, where the calcium on the surface of the powder particles is depleted. The glass powder can be prepared by surface-treating calcium aluminum fluorosilicate powder particles with an acid that forms a calcium salt, washing and removing the calcium salt from the treated particles, and drying the washed particles.

[0011] International Publication No. 2015 / 088956 (A1) (3M IPC) relates to a parts kit for preparing glass ionomer cement. The kit includes Part P and Part L. Part P is a powder containing a certain amount of an acid-reactive inorganic filler having an average particle size in the range of 3.5 to 10 μm and a certain amount of a non-acid-reactive filler having an average particle size in the range of 1.0 to 3.5 μm. Part P does not contain more than 1 wt% of a polycarboxylic acid. Part L is a liquid containing a certain amount of a polycarboxylic acid, water, and a complexing agent.

[0012] U.S. Patent No. 10,080,708 (B2) (3M) describes a parts kit for preparing glass ionomer cement. This kit includes Part A and Part B. Part A is a powder containing more than about 60 wt% of an acid-reactive filler having an average particle size in the range of 3.5 to 10 μm and more than about 1 wt% of a non-acid-reactive filler having an average particle size in the range of 1 to 3.5 μm. Part B is a liquid containing a polyacid, water, and a complexing agent. Useful acid-reactive glasses are said to have an Si / Al ratio (wt%) of less than 1.5 or 1.4 or 1.3. Compressive strength values up to 271 MPa have been reported.

[0013] U.S. Patent No. 4,900,697 (GC) relates to a fluoroaluminosilicate glass powder for dental glass ionomer cement having an average particle size of 0.02 to 10 μm and consisting essentially of 20 to 50 wt% SiO2, 20 to 40 wt% Al2O3, 15 to 40 wt% SrO, 1 to 20 wt% F2, and 0 to 15 wt% P2O5, and containing no Li, Na, K, Rb, Cs, Be, Mg, and Ba ions. To produce a glass ionomer cement composition, the glass powder is reacted with a polymeric acid such as polyacrylic acid, an acrylic acid copolymer, or polymaleic acid. Compressive strength values up to 237 MPa have been reported.

[0014] International Publication No. 2021 / 049269 (A1) (GC) describes a glass powder for a chemical polymerization initiator, which contains at least one of aluminum, silicon, and copper or vanadium to improve the storage stability of a two-component dental polymerizable composition. The Al / Si ratio of the glass used in the examples is greater than 1.

Summary of the Invention

[0015] There is still a need for glass ionomer compositions having appropriate mechanical properties such as compressive strength and / or surface hardness, especially after a short time.

[0016] Furthermore, the glass ionomer composition should be easy to use, moisture-resistant, tooth-colored, and biocompatible.

[0017] Ideally, the glass ionomer composition should be useful as an amalgam alternative and should not contain monomers essentially.

[0018] In one embodiment, the present invention features a parts kit described herein and in the claims.

[0019] The parts kit includes a part P and a part L, where part P is a powder containing an acid-reactive glass and part L is a liquid containing water. The parts kit further contains a polycarboxylic acid, the polycarboxylic acid is present in part P or part L or in both part P and part L, and the polycarboxylic acid contains a copolymer of acrylic acid and maleic acid. The acid-reactive glass is P: 0 to 4% by weight, or 0 to 3% by weight, F: 10 to 18% by weight, or 11 to 16% by weight, O: 25 to 35% by weight, or 28 to 34% by weight, Si: 10 to 16% by weight, or 11 to 14% by weight, Al: 11 to 19% by weight, or 12 to 18% by weight, Sr: 20 to 40% by weight, or 20 to 38% by weight, characterized by containing 0 to 4% by weight, or 0 to 3% by weight of La, The total amount of Al, Sr and F is more than 48% by weight (the % by weight is based on the weight of the acid-reactive glass), and the ratio of Al to Si in the acid-reactive glass is more than 1 / 1 by weight.

[0020] In another embodiment, the present invention relates to a glass ionomer composition obtained from the parts kit described herein and in the claims.

[0021] The present invention also relates to a parts kit further comprising, alone or in combination, the following articles: an activation device, an application device, a mixing device, a dental milling block, a preformed dental restoration.

[0022] The present invention also relates to the use of a combination of the acid-reactive glass and polycarboxylic acid described herein for improving the mechanical strength of a glass ionomer composition.

[0023] A further embodiment of the present invention relates to a glass ionomer composition for use in a method of treating a dental defect in a patient's oral cavity as described herein and in the claims.

[0024] Unless otherwise defined, as used herein, the following terms shall have the meanings set forth below.

[0025] The term "compound" or "component" is a chemical substance having a specific molecular identity or a mixture of such substances, for example a polymeric substance.

[0026] A "curable or hardenable or polymerizable component" is any component that can be cured or hardened, for example by radiation-induced polymerization in the presence of a photoinitiator, or by a glass-ionomer reaction, i.e., a reaction between a polyacid and an acid-reactive filler. The polymerizable component may contain only one, two, or three or more polymerizable groups. Typical examples of polymerizable groups include, among others, unsaturated carbon groups such as vinyl groups present in (meth)acrylate groups.

[0027] As used herein, "(meth)acryl" is an abbreviation that refers to "acryl" and / or "methacryl". For example, a "(meth)acryloxy" group is an abbreviation that refers to either an acryloxy group (i.e., CH2=CH-C(O)-O-) and / or a methacryloxy group (i.e., CH2=C(CH3)-C(O)-O-).

[0028] As used herein, "curing" or "hardening" of a composition is used interchangeably and refers to polymerization and / or crosslinking reactions, including, for example, photopolymerization reactions and chemical polymerization techniques (e.g., ionic or chemical reactions that form radicals effective to polymerize ethylenically unsaturated compounds) in which one or more materials included in the composition are involved.

[0029] An "initiator" is a substance that can initiate or start the curing process of a radically polymerizable component or monomer, for example, a redox / self-curing chemical reaction, or a radiation-induced reaction, or a heat-induced reaction.

[0030] "Dental restoration" means a dental article used to restore a tooth to be treated. Examples of dental restorations include fillings, crowns, bridges, inlays, onlays, veneers, prefabricated restorations, copings, crown-bridge frameworks, and parts thereof.

[0031] "Particle" means a substance that is a solid having a geometrically definable shape. The shape may be regular or irregular. Particles can typically be analyzed, for example, with respect to particle size and particle size distribution.

[0032] The particle size (d50) of a powder can be obtained from the cumulative distribution curve of the particle size distribution. Each measurement can be carried out using a commercially available particle size analyzer (e.g., Malvern Mastersizer 3000). "D" represents the diameter of the powder particles, and "50" refers to the volume percentage of the particles. 50% may also be expressed as "0.5". For example, "(d50)=1 μm" means that 50% of the particles have a size of 1 μm or less.

[0033] "Powder" means a dry bulk solid composed of a large number of fine particles that can flow freely when shaken or tilted.

[0034] "Glass ionomer cement" or "GIC" shall mean a cement that hardens or solidifies by reaction between an acid-reactive glass and a polycarboxylic acid in the presence of water.

[0035] "Resin-modified glass ionomer cement" or "RM-GIC" shall mean a GIC that further contains a radically polymerizable component, an initiator system, and typically 2-hydroxyethyl methacrylate (HEMA).

[0036] The parts kit described herein relates to glass ionomer cement and does not relate to resin-modified glass ionomer cement.

[0037] "Acid-reactive filler or glass" shall mean a filler or glass that chemically reacts in the presence of an acidic component.

[0038] "Non-acid-reactive filler" shall mean a filler that shows no chemical reaction or only a reduced (i.e., time-delayed) reaction within 6 minutes when mixed with a (poly)acid.

[0039] To distinguish an acid-reactive filler from a non-acid-reactive filler, the following test can be or should be performed.

[0040] Prepare a composition by mixing part P and part L in a mass ratio of 3:1, where: Part P contains 100 wt% of the filler to be analyzed.

[0041] Part L contains 43.6 wt% of poly(acrylic acid co maleic acid) (Mw: about 18,000 + / - 3,000), 47.2 wt% of water, 9.1 wt% of tartaric acid, and 0.1 wt% of benzoic acid.

[0042] If the shear stress determined by performing vibration measurement using a rheometer by applying the following conditions: 8 mm plate, 0.75 mm gap, 28 °C, frequency: 1.25 Hz, deformation: 1.75% within 6 minutes after preparing the above composition is less than 50,000 Pa, the filler is characterized as non-acid-reactive.

[0043] "Cation-reduced aluminosilicate glass" shall mean a glass having a lower cation content in the surface region of the glass particles compared to the internal region of the glass particles.

[0044] These glasses react much more slowly when contacted with a solution of polyacrylic acid in water compared to typical acid-reactive fillers. Examples of non-acid-reactive fillers include fused silica glass. Further examples are shown in the following text.

[0045] The reduction of cations can be achieved by surface treatment of glass particles. Suitable surface treatments include, but are not limited to, acid cleaning (e.g., treatment with phosphoric acid or hydrochloric acid), treatment with phosphates, or treatment with a chelating agent such as tartaric acid.

[0046] "Polycarboxylic acid or polycarboxylic acid or polyalkenoic acid" shall mean a polymer having a plurality of acidic repeating units (e.g., more than 10, or more than 20, or more than 50). That is, the acidic repeating units are bonded to the main chain of the polymer or are pendant from the main chain.

[0047] "Complexing agent" or "chelating agent" shall mean a low-molecular agent containing a moiety that can form a complex with metal ions such as calcium or magnesium, e.g., tartaric acid. The terms "complexing agent" and "chelating agent" are interchangeable.

[0048] "Storage-stable composition" is a composition that can be stored for a suitable period (e.g., at least about 12 months under ambient conditions) without showing significant performance problems during use (e.g., a decrease in flexural strength or compressive strength, and / or not solidifying within the desired period (e.g., a curing time exceeding 6 minutes)). Suitable tests for determining storage stability are given in the Examples section below.

[0049] "Ambient conditions" means the conditions to which the compositions described herein are normally exposed during storage and handling. Ambient conditions may be, for example, a pressure of 900 - 1,100 mbar, a temperature of 10 - 40 °C, and a relative humidity of 10 - 100%. In the laboratory, ambient conditions are typically adjusted to 20 - 25 °C and 1,000 - 1,025 mbar (at sea level).

[0050] As used herein, the terms "a", "an", "the", "at least one", and "one or more" are used interchangeably. Also, in this specification, the recitation of a numerical range by endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0051] The addition of the term "(s)" to a term means that the term should include both the singular and plural forms. For example, the term "additive(s)" means one additive and more than one (e.g., two, three, four, etc.) additives.

[0052] Unless otherwise indicated, all numbers representing amounts of ingredients, measured values of physical properties, etc., as described below and used in this specification and the claims are to be understood as being modified in all instances by the term "about".

[0053] The terms "comprise" or "contain" and variations thereof do not have a limiting meaning when these terms are recited in this specification and the claims. "Consisting essentially of" means that certain additional ingredients, i.e., ingredients that do not substantially affect the essential characteristics of the article or composition, may be present. "Consisting of" means that no additional ingredients should be present. The term "comprise" shall also include the terms "consist essentially of" and "consists of".

[0054] If a composition does not contain a specific component as an essential feature, the composition is "essentially or substantially free of" the above component. Thus, the above component is not intentionally added to the composition as such, or in combination with other components or constituents of other components. A composition that is essentially free of a specific component usually contains none of that component. However, for example, due to impurities contained in the raw materials used (e.g., less than 1% by weight, or less than 0.5% by weight, or less than 0.1% by weight, or less than 0.01% by weight based on the entire composition or material), the presence of a small amount of the component may be unavoidable.

Embodiments for Carrying Out the Invention

[0055] The parts kits and glass ionomer compositions described herein have been found to have several advantageous properties.

[0056] The solidified glass ionomer composition exhibits advantageous mechanical strength properties such as high compressive strength and / or surface hardness.

[0057] In particular, the glass ionomer composition exhibits sufficient surface hardness after a short period of time. Thereby, the doctor can further adjust the surface and / or shape of the filling immediately after applying the material if necessary.

[0058] Furthermore, the components of the powder part and the liquid part of the parts kit can be easily mixed, and each component, particularly polycarboxylic acid and acid-reactive glass, exhibits a smooth solidification reaction.

[0059] The combination of a specific polycarboxylic acid and a specific acid-reactive glass has been found to contribute to the improvement of mechanical properties.

[0060] The acid-reactive glass having an Al / Si ratio described in the claims and a relatively high content of the combination of Al, Sr, and F exhibits reactivity that very well matches the reactivity of a polycarboxylic acid containing a copolymer of acrylic acid and maleic acid.

[0061] If desired, the particle size distribution of the non-acid-reactive glass can be adjusted to further improve the mechanical properties.

[0062] The present invention relates to a parts kit for obtaining a glass ionomer composition. The parts kit comprises, consists essentially of, or consists of parts P and parts L.

[0063] Part P is a powder component or composition. Part L is a liquid component or composition.

[0064] Part L is typically characterized by a viscosity in the range of 1 to 500 Pa * s, or 1 to 100 Pa * s, or 1 to 50 Pa * s, or 1 to 10 Pa * s (28 °C; diameter 10 mm; shear rate: 1 s -1 ), and a viscosity in the range of 1 to 50 Pa * s or 1 to 10 Pa * s is often preferred; the density is 1.1 to 2.0 g / cm 3 .

[0065] According to one embodiment, part L comprises water, a polycarboxylic acid, and optionally a complexing agent or chelating agent.

[0066] To obtain the glass ionomer composition, it is necessary to mix the parts of the parts kit described herein.

[0067] A suitable mixing ratio is typically in the range of 6:1 to 1:1 by weight. A mixing ratio of 4:1 to 1:1 by weight may be preferred.

[0068] The part P of the parts kit contains acid-reactive glass.

[0069] The following particle size distribution of the acid-reactive glass has been found to be useful: 15 μm (d90) and 2 μm (d50). That is, 90% of the particles have a size of 15 μm or less, and 50% of the particles have a size of 2 μm or less. This means that 10% of the particles still have a size greater than 15 μm.

[0070] Although not wishing to be bound by a particular theory, such a particle distribution is thought to help increase the packing density of the glass particles in the cured composition and contribute to an increase in compressive strength.

[0071] Alternatively, the following particle size distribution has been found to be useful: 10 μm (d90) and 1 μm (d50).

[0072] The composition of the acid-reactive glass is P: 0 to 4 wt%, F: 10 to 18 wt%, O: 25 to 35 wt%, Si: 10 to 16 wt%, Al: 11 to 19 wt%, Sr: 20 to 40 wt%, La: 0 to 4 wt%, and the total amount of Al, Sr and F is more than 48 wt% or more than 50 wt%.

[0073] Alternatively, the following acid-reactive glass composition can be used: P: 0 to 3 wt%, F: 11 to 16 wt%, O: 28 to 34 wt%, Si: 11 to 14 wt%, Al: 12 to 18 wt%, Sr: 20 to 38 wt%, La: 0 to 3 wt%, and the total amount of Al, Sr and F is more than 48 wt% or more than 50 wt%.

[0074] The acid-reactive glass can be produced by melting a glass frit containing each glass component and crushing and grinding the glass frit until the desired particle size distribution is obtained.

[0075] The glass components that can be used include Al2O3, SiO2, SrF2 and AlF3 hydrate or AlF3.

[0076] The milling or grinding of the glass frit can be carried out, for example, using a ball mill.

[0077] The Al / Si ratio of the acid-reactive glass of the present invention is greater than 1 / 1 by weight. This means that the acid-reactive glass contains more Al than Si. An Al / Si ratio in the range of greater than 1.0 / 1.0 to 1.6 / 1.0, or greater than 1.0 / 1.0 to 1.4 / 1.0 by weight is often preferred.

[0078] Such a ratio has been found to be useful as it affects the reactivity of the glass towards polycarboxylic acids.

[0079] The acid-reactive glass typically does not contain the following elements: Li, K, Rb, Cs, Be, Mg, either alone or in combination, in amounts exceeding 0.2 wt% each based on the weight of the acid-reactive glass.

[0080] To adjust its reactivity, the acid-reactive glass can be inactivated by treating the glass powder with an acid, particularly an acid having a pKs of less than 3, such as hydrochloric acid, followed by washing with water and drying.

[0081] The glass powder treated by such a method has low reactivity. By using a less reactive glass powder, the solidification reaction with the polycarboxylic acid proceeds more slowly and in a more controlled manner, which can further contribute to the mechanical properties of the solidified glass ionomer composition.

[0082] The glass obtained by such a process is often referred to as a cation-reduced aluminosilicate glass.

[0083] The acid-reactive glass is typically present in the following amounts: at least 25 wt% or at least 35 wt% or at least 45 wt%; up to 86 wt% or up to 83 wt% or up to 80 wt%; or in the range of 25 - 86 wt% or 35 - 83 wt% or 45 - 80 wt% (wt% is based on the weight of the composition obtained when parts P and parts L are combined).

[0084] If the amount of the acid-reactive inorganic filler is too low, a suitable paste cannot be obtained by mixing each part of the parts kit described herein. Also, the mechanical properties may be inferior.

[0085] The parts kit described herein also includes the liquid parts L.

[0086] One component of parts L is water.

[0087] Water is typically present in the following amounts: at least 2 wt% or at least 5 wt% or at least 7 wt%; up to 35 wt% or up to 25 wt% or up to 20 wt%; or in the range of 2 - 35 wt% or 5 - 25 wt% or 7 - 20 wt% (wt% is based on the weight of the composition obtained when parts P and parts L are combined).

[0088] These amounts have been found to be useful for obtaining a glass ionomer composition having suitable mechanical properties after curing.

[0089] The parts kit also includes a polycarboxylic acid. The polycarboxylic acid can be present in parts P or parts L or in both parts P and parts L.

[0090] When the polycarboxylic acid is present in parts P, the polycarboxylic acid is present in a dry form.

[0091] The dry polycarboxylic acid can be obtained, for example, by spray-drying an aqueous solution of a polycarboxylic acid (e.g., 10% by weight) under vacuum in a spray dryer.

[0092] According to the present invention, the polycarboxylic acid comprises, consists essentially of, or consists of a copolymer of acrylic acid and maleic acid.

[0093] The polycarboxylic acid should have a molecular weight sufficient to provide good storage, handling, and mixing properties, as well as good material properties in the glass ionomer material.

[0094] According to one embodiment, the polycarboxylic acid can be characterized by the following properties alone or in combination: Being solid (at 23°C); Molecular weight (Mw): 5,000 - 250,000 g / mol or 10,000 - 100,000 g / mol (evaluated against a sodium polyacrylate standard using gel permeation chromatography).

[0095] If the molecular weight of the polycarboxylic acid is too high, it may be difficult to obtain a workable viscosity of the resulting paste when mixing the compositions included in the parts kit described herein. Furthermore, the preparation of the composition may become difficult. In addition, the resulting mixture or composition may be too sticky (i.e., adhere to the dental instruments used for application).

[0096] If the molecular weight of the polycarboxylic acid is too low, the viscosity of the resulting paste may be too low, and the mechanical properties of the final product are considered to be inferior.

[0097] The polycarboxylic acid is a polymer having a plurality of acidic repeating units.

[0098] The polycarboxylic acid used in the glass ionomer composition described herein is substantially free of polymerizable groups.

[0099] The polycarboxylic acid need not be completely water-soluble but is typically at least sufficiently water-miscible so as not to undergo substantial precipitation when combined with other aqueous components.

[0100] The polycarboxylic acid is curable in the presence of an acid-reactive filler and water and does not contain ethylenically unsaturated groups.

[0101] That is, the polycarboxylic acid is a polymer obtained by polymerizing an unsaturated acid. However, due to the manufacturing process, the polycarboxylic acid may still contain inevitable trace amounts of free monomers (e.g., up to 1 wt% or up to 0.5 wt% or up to 0.3 wt% relative to the amount of monomers used).

[0102] The polycarboxylic acid typically contains acrylic acid and maleic acid in the following molar ratios: 35 - 65% maleic acid to 65 - 35% acrylic acid, or 40 - 60% maleic acid to 60 - 40% acrylic acid.

[0103] It has been found that polycarboxylic acids having such ratios are particularly suitable for obtaining glass ionomer compositions having high compressive strength when reacted with the acid-reactive glasses described herein.

[0104] The amount of polycarboxylic acid used should be sufficient to react with the acid-reactive filler and provide an ionomer composition having desirable curing properties.

[0105] The polycarboxylic acid is typically present in the following amounts: at least 3 wt% or at least 6 wt% or at least 8 wt%; up to 35 wt% or up to 25 wt% or up to 20 wt%; or in the range of 3 - 35 wt% or 6 - 25 wt% or 8 - 20 wt% (wt% is relative to the weight of the composition obtained when parts P and parts L are combined).

[0106] If the amount of polycarboxylic acid is too high, it may be difficult to obtain a workable viscosity of the resulting paste when mixing the compositions included in the parts kit described herein. Further, the preparation of the composition may become difficult. Additionally, the resulting mixture or composition may become too sticky (i.e., adhere to the dental instrument used for application).

[0107] If the amount of polycarboxylic acid is too low, it may also be difficult to obtain a workable viscosity of the resulting paste when mixing the compositions included in the parts kit described herein. Further, it may be difficult to achieve the desired mechanical properties.

[0108] The parts kit may further include a complexing agent. The complexing agent is often used to adjust the curing properties of the glass ionomer composition.

[0109] If present, the complexing agent can be present in part P or part L or in both part P and part L.

[0110] The nature and structure of the complexing agent are not particularly limited as long as the desired results are obtained.

[0111] The complexing agent can be characterized by the following properties alone or in combination: solubility properties: soluble in water (at least 50 g per liter of water at 23 °C); molecular weight: 50 - 500 g / mol, or 75 - 300 g / mol.

[0112] Specific examples of the complexing agent include tartaric acid, citric acid, ethylenediaminetetraacetic acid (EDTA), salicylic acid, mellitic acid, dihydroxy tartaric acid, nitrilotriacetic acid (NTA), 2,4 and 2,6 dihydroxybenzoic acid, phosphonocarboxylic acid, phosphonosuccinic acid, and mixtures thereof. The use of tartaric acid is often preferred.

[0113] Further examples can be found, for example, in U.S. Patent No. 4,569,954 (Wilson et al.).

[0114] The complexing agent is typically added to parts containing polycarboxylic acid. Typically, the complexing agent is present in part L.

[0115] The complexing agent is typically present in an amount in the range of at least 0 wt% or at least 1 wt% or at least 2 wt%; up to 15 wt% or up to 12 wt% or up to 10 wt%; or 0 to 15 wt% or 1 to 12 wt% or 2 to 10 wt% (wt% is based on the weight of the composition obtained when parts P and part L are combined).

[0116] Part P of the parts kit described herein may also contain other non-acid-reactive filler(s).

[0117] The non-acid-reactive filler may have a particle size of (d10): 0.2 μm to 2 μm; (d50): 0.5 μm to 5 μm; (d90) 1 μm to 15 μm.

[0118] Examples of suitable non-acid-reactive fillers include, but are not limited to, natural or synthetic materials such as quartz; nitrides (e.g., silicon nitride); glasses derived from, for example, Zr, Sr, Ce, Sb, Sn, Ba, Zn, and Al; borosilicate glass; kaolin; silica particles (e.g., quartz glass or pyrogenic silica of appropriate particle size), alumina, titania, and zirconia particles.

[0119] According to one embodiment, the non-acid-reactive filler is selected from quartz, quartz glass, silica, alumina, aluminosilicate, and mixtures thereof.

[0120] If desired, the surface of the particles of the acid-reactive filler can be surface-treated.

[0121] Performing the surface treatment can be beneficial in improving the compatibility of the filler with other components of the glass ionomer composition.

[0122] Suitable surface treatment agents include silanes, such as trimethoxysilane having an organic functional group for modifying the chemical properties of the particles. Suitable silanes are, for example, silanes for modifying acidic properties (having an amino group or a carboxylic acid group) or silanes for modifying hydrophobicity / hydrophilicity (having an alkane chain or a polyethylene glycol chain).

[0123] The non-acid-reactive filler is typically present in the following amounts: 0 wt% or at least 1 wt% or at least 2 wt%; up to 35 wt% or up to 30 wt% or up to 25 wt%; or in the range of 0 - 35 wt% or 1 - 30 wt% or 2 - 25 wt% (wt% is based on the weight of the composition obtained when parts P and parts L are combined).

[0124] Any one of parts P or parts L or both parts P and parts L of the parts kit described herein may also contain additives (s).

[0125] Possible additives include indicators, dyes, pigments, viscosity modifiers, surfactants, buffers, stabilizers, preservatives (e.g., benzoic acid).

[0126] When additives are present, parts P may contain additives (s) provided in powder form.

[0127] Also, any combination of the above additives may be used. The selection and amount of any one such additive can be selected by those skilled in the art to achieve the desired results without undue experimentation.

[0128] The additives may typically be present in the following amounts: at least 0 wt% or 0.1 wt% or 0.2 wt%; up to 10 wt% or 8 wt% or 6 wt%; or in the range of 0 - 10 wt% or 0.1 - 8 wt% or 0.2 - 6 wt% (wt% is based on the weight of the composition obtained when parts P and parts L are combined).

[0129] According to one embodiment, the parts kit includes the following amounts of the following components: Acid-reactive glass: 25 to 86% by weight, Non-acid-reactive filler: 0 to 35% by weight, Polycarboxylic acid: 3 to 35% by weight, Water: 2 to 35% by weight, Complexing agent: 0 to 15% by weight, Additives: 0 to 10% by weight, or consists essentially of or consists of them (% by weight is based on the weight of the composition obtained when parts P and parts L are combined).

[0130] According to another embodiment, the parts kit includes the following amounts of the following components: Acid-reactive glass: 35 to 83% by weight, Non-acid-reactive filler: 1 to 30% by weight, Polycarboxylic acid: 6 to 25% by weight, Water: 5 to 25% by weight, Complexing agent: 1 to 12% by weight, Additives: 0 to 8% by weight, or consists essentially of or consists of it (% by weight is relative to the weight of the composition obtained when parts P and parts L are combined).

[0131] Preferred embodiments of the parts kit can be characterized as follows: Consisting of parts P and parts L, Part P is a powder containing acid-reactive glass, Part L is a liquid containing water, polycarboxylic acid, and a complexing agent, The polycarboxylic acid includes a copolymer of acrylic acid and maleic acid, The acid-reactive glass is P: 0 to 4% by weight, or 0 to 3% by weight, F: 10 to 18% by weight, or 11 to 16% by weight, O: 25 to 35% by weight, or 28 to 34% by weight, Si: 10 to 16% by weight, or 11 to 14% by weight, Al: 11 to 19 wt%, or 12 to 18 wt%, Sr: 20 to 40 wt%, or 20 to 38 wt%, characterized by containing La: 0 to 4 wt%, or 0 to 3 wt%, wherein the total amount of Al, Sr and F exceeds 48 wt% (wt% is based on the weight of the acid-reactive glass), the ratio of Al to Si in the acid-reactive glass is more than 1 / 1 by weight, the acid-reactive glass has a particle size distribution of 10 μm (d90) and 2 μm (d50), the acid-reactive glass is inactivated by treatment with an acid followed by washing with water and drying, the polycarboxylic acid has a molecular weight Mw in the range of 10,000 to 100,000 g / mol, acrylic acid and maleic acid are present in the polycarboxylic acid in a molar ratio of 35 to 65% maleic acid and 65 to 35% acrylic acid, or 40 to 60% maleic acid to 60 to 40% acrylic acid, the complexing agent is tartaric acid, the part P further comprises a non-acid-reactive glass selected from aluminosilicates.

[0132] Typically, both part P and part L of the parts kit described herein contain the following components: a) HEMA in an amount greater than 1 wt% or greater than 0.5 wt%; b) a radical polymerizable component(s) in an amount greater than 1 wt% or greater than 0.5 wt%; c) an initiator component suitable for curing a radical polymerizable component(s) or monomer(s) in an amount greater than 1 wt% or greater than 0.5 wt%; d) does not contain, alone or in combination, an inhibitor(s) such as methoxyphenol or 3,5-di-tert-butyl-4-hydroxytoluene in an amount greater than 1 wt% or greater than 0.5 wt% (wt% is based on the weight of the composition obtained when parts P and parts L are combined).

[0133] Therefore, the composition obtained when mixing the powder parts and the liquid parts of the parts kit described herein is not a so-called resin-modified glass ionomer cement (RM-GIC) and thus does not contain a curing system suitable for curing radical polymerizable components.

[0134] In particular, the cement composition described herein does not contain a redox initiator system or a heat-induced initiator system or a radiation-induced initiator system.

[0135] In particular, the cement composition described herein does not contain the following components: (a) and (b), (a) and (c), (a), (b) and (c), (b), (c) and (d), (a), (b), (c) and (d) in an amount of 1% by weight or more, or 0.5% by weight or more, or 0.1% by weight or more based on the weight of the total composition.

[0136] That is, the cement composition described herein typically does not essentially contain these components alone or in combination.

[0137] The composition obtained or to be obtained by mixing two parts of the parts kit described herein can typically be characterized by the following parameters alone or in combination before or during solidification: Setting time: within about 5 minutes or 4 minutes or 3 minutes determined according to EN-ISO 9917-1:2007; Working time: within about 4 minutes or 3 minutes or 2 minutes or 1 minute determined according to EN-ISO 9917-1:2007; Viscosity: 2000 - 10,000 Pa * s measured 90 seconds after starting to mix the components of part P and part L at 28°C.

[0138] If desired, the setting time and setting behavior can be determined as described in more detail in the Examples section below.

[0139] The compositions described herein typically have sufficient working time for a physician not only to properly mix the composition but also to apply the composition to a cavity or the surface of a crown, bridge, root canal, or prepared tooth.

[0140] Furthermore, the compositions described herein have an appropriate setting time, which is time - saving for the physician and convenient for the patient.

[0141] According to another embodiment, a composition obtained or obtainable by mixing two parts of the parts kit described herein can be characterized, after solidification, by the following parameters alone or in combination: Flexural strength: 20 MPa to 80 MPa measured according to EN - ISO 9917 - 2:2010 (provided that a glass slab is used instead of foil for coating the composition); Compressive strength: 300 MPa to 400 measured according to EN - ISO 9917 - 1 / 2007 (provided that a glass slab is used instead of foil for coating the composition); Surface hardness: 150 - 250 MPa.

[0142] If desired, these parameters can be determined as described in the Examples section below.

[0143] Compared to state - of - the - art glass ionomer compositions available on the market, the glass ionomer compositions described herein can be easily mixed and have appropriate mechanical properties such as compressive strength and / or flexural strength without affecting other important parameters such as setting time.

[0144] Furthermore, the composition exhibits sufficient surface hardness already 10 minutes after mixing.

[0145] The parts of the parts kit of this specification can be manufactured by mixing the respective components.

[0146] If necessary, the filler particles can be milled to a desired particle size using an apparatus known to those skilled in the art, such as a ball mill.

[0147] Mixing can be achieved by hand or using a mechanical device such as a mixer or kneader. The mixing time can vary depending on the composition and the mixing device.

[0148] The parts kit is typically housed in a packaging device during storage and before use.

[0149] The powder of part P and / or the liquid of part L can be stored in any suitable device separated from each other before use, such as a container, vial or cartridge.

[0150] A preferred packaging device includes at least two compartments suitable for storing the liquid part and the powder part.

[0151] A suitable packaging device can be characterized as follows: An apparatus for storing and dispensing the parts kit described herein, comprising a compartment A and a compartment B separated from each other during storage, and a nozzle connected to either compartment A or compartment B, wherein compartment A contains part P, compartment B contains part L, compartment A has a volume in the range of 0.5 - 3 ml or 0.8 - 2 ml, and compartment B has a volume in the range of 0.05 - 1 ml or 0.08 - 0.5 ml.

[0152] Packaging devices that can be used similarly are described in the following documents: U.S. Patent No. 6,543,611 (B1) (3M), U.S. Patent No. 4,941,751 (Muehlbauer), U.S. Patent No. 5,088,830 (Muehlbauer), U.S. Patent No. 6,386,872 (Muasa et al.) or European Patent No. 0783872 (A2) (Voco).

[0153] The parts kit can be used to treat teeth, particularly teeth located in a patient's oral cavity, and will typically be used.

[0154] Treating a tooth includes, for example, restoring the tooth by filling a dental cavity and fixing a dental restoration to the surface of the tooth.

[0155] Therefore, the parts kit can be used to manufacture dental luting cement, dental filling material, dental core build-up material, dental liner, or as dental root canal filling material.

[0156] A method of treating a tooth typically includes the following steps: mixing the components or compositions of parts P and L to obtain a curable composition; applying the curable composition to the surface of the tooth tissue to be treated; and curing the curable composition.

[0157] The present invention also relates to a parts kit including the parts kit described herein and at least one or more of the following articles: an activation device; an application device; a mixing device; a dental milling block; a preformed dental restoration (including a crown or a bridge).

[0158] Suitable activation devices are commercially available, for example, 3M™ Maxicap™ and Aplicap™ Activator.

[0159] An application device is often used to extrude the mixed composition from a packaging device and apply the mixed composition to the surface to be treated.

[0160] A mixing device is used to mix the powder and liquid parts. Suitable mixing devices include a mixing pad and a spatula (particularly useful for manually mixing the parts), or an electric shaking or rotating mixing device. Such products are commercially available (for example, 3M™ RotoMix™ capsule mixing unit).

[0161] A dental milling block can be used to mill a dental restoration therefrom, and the dental restoration is fixed to the surface of the tooth to be treated later. Dental milling blocks are often made of zirconia and are also commercially available, such as the 3M (trademark) Lava (trademark) Plus zirconia disk.

[0162] Alternatively, pre-formed dental restorations can be used, including polycarbonate crowns and stainless steel crowns (3M Oral Care).

[0163] All components used in the compositions herein should be sufficiently biocompatible, i.e., the compositions should not cause toxic, adverse, or immune reactions in living tissue.

[0164] The complete disclosures of the patents, patent documents, and publications cited herein are incorporated by reference in their entirety as if each were individually incorporated. Various modifications and variations of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. The above specification, examples, and data provide a description of the manufacture and use of the compositions and methods of the invention. The invention is not limited to the embodiments disclosed herein. Those skilled in the art will understand that many alternative embodiments of the invention can be made without departing from the spirit and scope of the invention.

[0165] The following examples are presented to illustrate the invention.

Examples

[0166] Unless otherwise specified, all parts and percentages are by weight, all water is deionized water, and all molecular weights are weight average molecular weights. Further, unless otherwise specified, all experiments were carried out under ambient conditions (23 °C, 1013 mbar).

[0167] Method Viscosity If desired, the viscosity can be measured at 23 °C using a Physica MCR 301 Rheometer (Anton Paar, Graz, Austria) in plate / plate geometry under controlled shear rate. The diameter is 15 mm and the separation gap between the plates is 0.5 mm. The shear rate is increased from 1 s -1 to 500 s -1 until increased.

[0168] Particle size If desired, the particle size distribution, including the particle size per volume (d50), can be determined by laser diffraction using a Mastersizer 3000 (Malvern) particle size detector applying the Fraunhofer approximation. Ultrasonic waves are typically used to accurately disperse the sample during measurement. For water-insoluble particles, water is typically used as the dispersant.

[0169] pH value If desired, the pH value can be determined as follows: Disperse 1.0 g of the component (e.g., filler) in 10 ml of deionized water and stir for about 5 minutes. Immerse a calibrated pH electrode into the suspension and measure the pH value while stirring.

[0170] Elemental composition If desired, the elemental composition can be determined by X-ray fluorescence spectroscopy (XRF), for example, using a ZSX Primus II manufactured by Rigaku, Japan. This method is particularly suitable for the analysis of solids, such as zirconia ceramics or glass materials.

[0171] Compressive strength (CS) The measurement of the compressive strength was carried out in accordance with EN-ISO 9917-1:2007, but a glass slab was used instead of foil to coat the composition. Cylindrical specimens with a diameter of 4 mm and a height of 6 mm were used. Specimens of the material were prepared at room temperature and 50% relative humidity using a split mold. The mold was placed on a microscope slide and filled completely with the mixed material to avoid air bubble entrapment. The filled mold was immediately covered with another glass slab and fixed with a screw clamp at a slight pressure to extrude the excess material. The entire assembly was stored at 36 °C and at least 95% relative humidity. One hour after the start of mixing, the specimens were removed from the mold and immediately placed in water at 36 °C. Six specimens were prepared for each material. The materials were measured 24 hours after the start of mixing. The exact diameter of each specimen was measured before the measurement. The strength of the specimens was measured by applying a compressive load using a Zwick universal testing machine (Zwick GmbH & Co.KG, Ulm, Germany) operating at a crosshead speed of 1 mm / min. The results were reported as the average of six replicates.

[0172] Flexural strength (FS) The flexural strength was measured based on EN ISO 9917-2:2010, but specimens were prepared as described for the above compressive strength test, except that a rectangular split mold with dimensions of 25 mm × 2 mm × 2 mm was used to prepare the specimens. The specimens were subjected to three-point bending on supports 20 mm apart at a crosshead speed of 1 mm / min.

[0173] Working time (ta) and curing time (te) If desired, the curing behavior of the prepared glass ionomer cement composition can be determined using a Physica (trademark) MCR 301 rheometer (Anton Paar) by applying the following parameters: 8 mm disk in a disk setup; gap 0.75 mm; deformation 1.75%; frequency: 1.25 HZ; temperature: 28 °C, for oscillatory measurements. The loss angle (German: "Verlustwinkel") is recorded over time, and the maximum (ta) and minimum (te) values of the graph are determined. The average of the two measured values for the maximum and minimum values is given in minutes (min): seconds (sec).

[0174] Surface hardness (SFH) If desired, the surface hardness (given in MPa) is determined using a steel ball (d = 5 mm) in accordance with ISO 2039-1. The sample material is filled into an aluminum ring (inner diameter 6 mm ± 0.2 mm, height 3 mm ± 0.1 mm), closed on both sides with a plastic plate, and fixed with a clamp. Three minutes after the start of mixing, the sample is placed in a water bath at 36 °C ± 2 °C for 2 minutes, and then in a water bath at 23 °C ± 2 °C for 5 minutes. The plastic plate is removed 10 minutes after the start of mixing, and the penetration depth is measured for 30 seconds 10.5 minutes after the start of mixing. A hardness tester type 3106 (Zwick) can be used for the measurement.

[0175] Acid-reactive glass General preparation Weigh and homogenize the glass components. Preanneal the mixture in a crucible. Then, transfer the cooled mixture to a platinum crucible and heat to a temperature above 1500 °C. Remove the melt and pour it directly into deionized water. Next, dry the cooled melt and grind it in a planetary ball mill until the desired particle size distribution is achieved. Treat the glass powder with acid, wash it, and dry it.

[0176] The manufactured glass powder composition is shown in Table 1.

[0177] [Table 1]

[0178] ARG 1 to 8 are acid-reactive glasses according to the present invention. ARG9 is a comparative glass.

[0179] Polycarboxylic acid (PA) Different polycarboxylic acids were prepared (Table 2).

[0180] [Table 2]

[0181] The following liquid parts were manufactured:

[0182] [Table 3]

[0183] Glass ionomer composition (GIC) Each powder part and liquid part was weighed into a capsule and mixed at a given ratio (pbw - parts by weight) with respect to the weight by means of a CapMix (trademark) device (3M Oral Care). The properties of the solidified composition are shown in Table 5.

[0184] [Table 4]

[0185] For further comparison, the following commercially available materials were tested (Table 6):

[0186] [Table 5]

[0187] The glass ionomer cement composition according to the present invention showed improved mechanical properties compared to the glass ionomer cement composition according to the state of the art, particularly with respect to compressive strength and surface hardness.

Claims

1. A parts kit for obtaining a glass ionomer composition, wherein the parts kit includes part P and part L. Part P is a powder containing acid-reactive glass. Part L is a liquid containing water. The parts kit further comprises a polycarboxylic acid, the polycarboxylic acid being present in part P or part L, or in part P and part L, and the polycarboxylic acid comprising a copolymer of acrylic acid and maleic acid. The acid-reactive glass is characterized by containing P: 0-4% by weight, F: 10-18% by weight, O: 25-35% by weight, Si: 10-16% by weight, Al: 11-19% by weight, Sr: 20-40% by weight, and La: 0-4% by weight. A parts kit in which the total amount of Al, Sr, and F is greater than 48% by weight (weight percent is relative to the weight of the acid-reactive glass), and the ratio of Al to Si in the acid-reactive glass is greater than 1 / 1 by weight.

2. The aforementioned parts kit includes parts P and L, Part P is a powder containing acid-reactive glass, Part L is a liquid containing water and polycarboxylic acid. The polycarboxylic acid comprises a copolymer of acrylic acid and maleic acid. The acid-reactive glass, P: 0-4% by weight, or 0-3% by weight, F: 10-18% by weight, or 11-16% by weight. O: 25-35% by weight, or 28-34% by weight, Si: 10-16% by weight, or 11-14% by weight. Al: 11-19% by weight, or 12-18% by weight. Sr: 20-40% by weight, or 20-35% by weight, La: Characterized by containing 0 to 4% by weight, or 0 to 3% by weight. The parts kit according to claim 1, wherein the total amount of Al, Sr, and F is greater than 48% by weight (weight percent is relative to the weight of the acid-reactive glass), and the ratio of Al to Si in the acid-reactive glass is greater than 1 / 1 by weight.

3. The above components are in the following amounts: Acid-reactive glass: 25-86% by weight, Non-acid-reactive filler: 0-35% by weight, Polycarboxylic acid: 3-35% by weight, Water: 2-35% by weight, Complexing agent: 0-15% by weight, Additives: Present in amounts of 0-10% by weight. (The weight percentage is relative to the weight of the composition obtained when parts P and L are combined), the parts kit according to claim 1.

4. The aforementioned component is The acid-reactive glass has a particle size distribution of 10 μm (d90) and 2 μm (d50). The acid-reactive glass is deactivated by treatment with acid, followed by washing with water and drying. The polycarboxylic acid has a molecular weight Mw in the range of 10,000 to 100,000 g / mol. The acrylic acid and maleic acid are present in the polycarboxylic acid in a molar ratio of 35-65% maleic acid and 65-35% acrylic acid, or 40-60% maleic acid and 60-40% acrylic acid. Part P further comprises a non-acid-reactive glass selected from aluminosilicates. A parts kit according to claim 1, characterized by the following:

5. A glass ionomer composition obtained by mixing parts P and L of the parts kit described in claim 1, or obtained therefrom, having the following properties after solidification: Bending strength: 20 MPa to 80 MPa as measured according to EN-ISO 9917-2:2010; Compressive strength: 300-400 MPa, measured according to EN-ISO 9917-1 / 2007, when glass slabs are used instead of foil to coat the composition; A glass ionomer composition characterized by a surface hardness of 150 to 250 MPa, measured according to ISO 2039-1, either alone or in combination.

6. A parts kit comprising the parts kit described in claim 1, and at least one of the following articles: an activation device; a mixing device; an application device; a dental milling block; a pre-formed dental restoration.

7. Use of the acid-reactive glass according to claim 1, combined with the polycarboxylic acid according to claim 1, for improving the mechanical strength of a glass ionomer composition.