Surface-treated filler, dental composition containing such filler, method for the production thereof and

Abstract

The present invention relates to a dental composition comprising a curable component and a surface-treated filler comprising filler particles whose surfaces have been treated with a surface treatment agent, the surface treatment agent is characterized by comprising at least one (meth) acrylate moiety, comprising at least one hydrolysable silane moiety, comprising only one urethane moiety, comprising a linear alkanyl moiety AM1 linking the at least one (meth) acrylate moiety to the urethane moiety, and comprising at least one hydrolysable silane moiety. Comprising a linear alkyl subunit moiety AM2 linking the at least one hydrolysable silane moiety to the urethane moiety, the linear alkyl subunit moiety AM1 comprising more carbon atoms than the linear alkyl subunit moiety AM2. The invention also relates to a method for producing such a dental composition, to the use of the dental composition in a method for repairing dental teeth and to a kit comprising the dental composition.

Description

Technical Field

[0001] The present invention relates to a surface-treated filler and a dental composition containing the filler. Also described are a method for producing the filler and the use of the dental composition for restoring teeth. The surface-treated filler is particularly useful for producing flowable or injectable dental compositions having low viscosity at low shear rates. Background Art

[0002] Polymerizable dental compositions for restoring defective teeth are widely known.

[0003] Dental compositions generally comprise a resin matrix containing a polymerizable component, an initiator system suitable for curing the polymerizable component, and a filler system.

[0004] In order to obtain adequate mechanical properties after hardening, it is generally desirable to provide the composition with a high filler loading.

[0005] However, filler particles typically have a rather polar surface, while the polymerizable components are rather non-polar. Therefore, incorporating large amounts of polar fillers into a rather non-polar resin matrix can become challenging.

[0006] To address this issue, filler particles are typically surface treated with a silane component to make the filler particles more compatible with the resin matrix.

[0007] However, as filler loading increases, the viscosity or consistency of the polymerizable dental composition generally increases, which makes the dental composition more difficult to handle, particularly during the step of extruding the dental composition from the packaging device.

[0008] However, for certain applications, practitioners prefer dental compositions that have a rather low viscosity and flow easily, which should nevertheless exhibit adequate mechanical properties after curing.

[0009] In the patent literature, various attempts in this regard are described.

[0010] US Pat. No. 10,441,512 B2 (Tanaka et al.) describes a dental flowable composite composition comprising a polymerizable monomer, inorganic particles (A), and inorganic particles (B), wherein the inorganic particles (A) are surface-treated with a compound represented by the general formula (1), and the inorganic particles (B) contain at least one of a group represented by the general formula (A) and a group represented by the general formula (B) present on the surface of the inorganic particles (B). In the example, 3-methacryloyloxypropyltrimethoxysilane and 8-methacryloyloxyoctyltrimethoxysilane are primarily used as surface treatment agents. This composite composition is said to have excellent polishability, wear resistance, formability, handleability, and flexural strength.

[0011] US Patent No. 10,975,229 B2 (Fuchigami et al.) relates to a silane coupling agent and a medical and / or dental curable composition containing the same. The silane coupling agent is said to impart high affinity to free-radically polymerizable monomers, thereby imparting high mechanical strength, flexibility, and durability when used in medical and / or dental curable compositions and inorganic fillers surface-treated with the silane coupling agent. The silane coupling agent contains repeating units at specific positions, such as urethane bonds and polyethylene glycol (ether bonds).

[0012] US Pat. No. 10,561,584 B2 (Kojima et al.) describes a dental adhesive comprising a polymerizable monomer, first inorganic fine particles, second inorganic fine particles, and third inorganic fine particles, each of which has been surface-treated with a chemical compound. In this example, 3-methacryloxypropyltrimethoxysilane and 8-methacryloxyoctyltrimethoxysilane are primarily used as surface treatment agents.

[0013] US 10,918,578 B2 (Wang et al.) describes a dental curable composition comprising a polymerizable monomer; inorganic particles (A1) and / or inorganic particles (A2); and inorganic particles (B). Inorganic particles (A1) are particles surface-treated with a compound represented by general formula (1). Inorganic particles (A2) are particles surface-treated with a compound represented by general formula (2). Inorganic particles (B) are particles having a group represented by general formula (A) on their surface, particles having a group represented by general formula (B) on their surface, and / or particles surface-treated with a compound represented by general formula (3).

[0014] US 11,246,808 B2 (Craig et al.) describes a dental composition comprising a polymerizable resin containing one or more ethylenically unsaturated monomers or oligomers and nanoparticles. The nanoparticles have a refractive index of at least 1.600 and an average discrete or aggregate particle size of no greater than 100 nm. The dental composition also comprises an inorganic metal oxide filler having an average discrete or aggregate particle size of at least 200 nm.

[0015] US 9,050,252 B2 (Craig et al.) describes a method for surface-treating inorganic oxide particles, a hardenable (e.g., dental) composition comprising a polymerizable resin composition and the surface-treated particles, and surface-treated (e.g., nanoclustered) inorganic oxide particles and a silane surface treatment compound. In one embodiment, the method comprises forming the surface treatment compound by reacting a first functional group of a (meth)acrylate monomer having a molecular weight of at least 350 g / mol with a second functional group of a silane compound, wherein the first and second functional groups react to form a covalent bond; and combining the surface treatment compound with the inorganic oxide particles.

[0016] Various silane treating agents are also described in JP 6,904,646 B2, JP 6220723 B2, JP 6,173,254 and JP 2021 / 155395 A. Summary of the Invention

[0017] None of the options outlined in the prior art fully meet the needs of practitioners.

[0018] There remains a need for a curable dental composition that is easy to handle, particularly a dental composition that can be easily applied to a tooth surface to be restored.

[0019] In particular, there is a need for dental compositions having a small structure, which is generally accompanied by a low viscosity at low shear rates.

[0020] Furthermore, after curing, the dental composition should still have adequate mechanical properties.

[0021] The present invention described herein and in the claims addresses one or more of the above objectives.

[0022] According to one aspect, the present invention relates to a surface-treated filler comprising filler particles whose surfaces have been treated with a surface treatment agent characterized by the following features:

[0023] comprising at least one (meth)acrylate moiety,

[0024] comprising at least one hydrolyzable silane moiety,

[0025] Contains only one carbamate moiety,

[0026] comprising a linear alkylene moiety AM1 linking the at least one (meth)acrylate moiety to the urethane moiety,

[0027] comprising a linear alkylene moiety AM2 linking the at least one hydrolyzable silane moiety to the carbamate moiety,

[0028] The linear alkane subunit moiety AM1 contains more carbon atoms than the linear alkane subunit moiety AM2.

[0029] Another aspect of the present invention relates to a dental composition comprising a curable component and a surface-treated filler as described herein, particularly in an amount of 40% to 80% by weight relative to the weight of the dental composition.

[0030] Another aspect of the present invention relates to a method for producing a surface-treated filler as described herein, comprising the steps of

[0031] optionally combining the filler particles with a surface treatment agent using a dispersion,

[0032] reacting the surface treatment agent with the filler particles,

[0033] removing the optional dispersion,

[0034] The surface treated filler particles are optionally dried and sieved.

[0035] Yet another aspect of the present invention relates to a dental composition for use in a method of restoring a tooth in the oral cavity of a mammal, the dental composition being as described herein, the method comprising the steps of

[0036] contacting the dental composition with the surface of the tooth to be repaired,

[0037] The dental composition is cured by applying radiation.

[0038] Furthermore, the present invention relates to the use of a surface-treated filler for reducing the viscosity of a dental composition at low shear rates, the dental composition comprising a curable component and an amount of filler of 40% to 80% by weight relative to the weight of the dental composition.

[0039] Additional embodiments are directed to kits comprising the dental compositions described herein and the following, alone or in combination: a dental adhesive; a dental curing light; and an application instrument.

[0040] Unless defined differently, for the purposes of this specification, the following terms shall have the given meanings:

[0041] A "one-part composition" means that all components of the composition are present together during storage and use. That is, the composition to be administered or used is not prepared by mixing the different parts of the composition prior to use. In contrast to one-part compositions, those compositions are often referred to as two-part compositions (e.g., formulated as powder / liquid, liquid / liquid, or paste / paste compositions).

[0042] "Two-component composition" means that the components are provided as separate parts before use as a kit or system. For use, the corresponding components or parts need to be mixed.

[0043] The term "compound" or "component" is a chemical substance having specific molecular properties or a chemical substance made from a mixture of such substances, such as a polymeric substance.

[0044] A "hardenable or curable or polymerizable component" is any component that can be cured or solidified by radiation-induced polymerization in the presence of a photoinitiator. A hardenable component may contain only one, two, three, or more polymerizable groups. Typical examples of polymerizable groups include unsaturated carbon groups, such as vinyl groups present in, for example, (meth)acrylate groups.

[0045] As used herein, "(meth)acryloyl" is a shorthand term that refers to "acryloyl" and / or "methacryloyl." For example, a "(meth)acryloyloxy" group is a shorthand term that refers to an acryloyloxy group (i.e., CH2=CH-C(O)-O-) and / or a methacryloyloxy group (i.e., CH2=C(CH3)-C(O)-O-).

[0046] As used herein, "hardening" or "curing" a composition are used interchangeably and refer to polymerization and / or cross-linking reactions involving one or more materials contained in the composition, including, for example, photopolymerization reactions and chemical polymerization techniques (e.g., ionic reactions or chemical reactions that form free radicals effective to polymerize ethylenically unsaturated compounds).

[0047] "Radiation curable" shall mean that the component (or composition, as the case may be) can be cured by applying radiation (preferably electromagnetic radiation having a wavelength in the visible spectrum) under ambient conditions and within a reasonable time frame (e.g., within about 60 seconds, 30 seconds, or 10 seconds).

[0048] "Paste" refers to a soft, viscous substance of solids (ie, particles) dispersed in a liquid.

[0049] "Particle" means a solid substance with a geometrically definable shape. The shape can be regular or irregular. Particles can generally be analyzed with respect to, for example, particle size and particle size distribution.

[0050] The particle size (d50) of a powder can be obtained from the cumulative curve of the particle size distribution. This measurement can be performed using a commercially available particle size analyzer (e.g., the Malvern Mastersizer 2000). "D" represents the diameter of the powder particles, and "50" refers to the volume percentage of the particles. 50% is sometimes expressed as "0.5." For example, "(d50) = 1 μm" means that 50% of the particles have a size of 1 μm or smaller.

[0051] The term "primary particle size" refers to the size of non-associated individual particles. X-ray diffraction (XRD) is commonly used to measure primary particle size using the techniques described herein.

[0052] "Nanosized fillers" are fillers whose individual particles have a size in the nanometer range, for example an average particle size of less than 100 nm. Useful examples are given in US 6,899,948 (Zhang et al.) and US 6,572,693 (Wu et al.).

[0053] The measurement of the nanoparticle size is preferably based on the TEM (Transmission Electron Microscopy) method, whereby the population is analyzed to obtain the average particle size. The preferred method for measuring the particle size can be described as follows:

[0054] A sample approximately 80 nm thick was mounted on a 200-mesh copper grid with a carbon-stabilized polyvinyl acetate substrate (SPI Supplies-Structure Probe, Inc., West Chester, PA). Transmission electron micrographs (TEM) were taken at 200 kV using a JEOL 200CX (JEOL, Ltd., Akishima, Japan, and sold by JEOL USA, Inc.). The size of a population of approximately 50-100 particles was measured and the average diameter determined.

[0055] “Agglomeration” describes a weak association of particles that are usually held together by charge or polarity and can break down into smaller entities. The specific surface area of the agglomerated particles does not differ substantially from the specific surface area of the primary particles that make up the agglomerate (see DIN 53206; 1972).

[0056] Agglomerated fillers are available, for example, from Degussa, Cabot Corp. or Wacker under the product name Aerosil. ™ 、CAB-O-SIL ™ and HDK ™ Commercially available.

[0057] As used herein, "aggregated" describes a strong association of particles typically bound together by, for example, residual chemical treatment or partial sintering. The specific surface area of the aggregated particles is typically smaller than that of the primary particles constituting the aggregate (see DIN 53206; 1972).

[0058] Further breakdown of the aggregates into smaller entities may occur during the polishing step applied to the surface of the composition containing the aggregated filler, rather than during dispersion of the aggregated particles in the resin.

[0059] Agglomerated fillers and methods for their production and surface treatment are described, for example, in US 6,730,156 B1 (Windisch et al.) and US 6,730,156 (Windisch et al.).

[0060] The term "associated" refers to a grouping of two or more primary particles that are aggregated and / or agglomerated.

[0061] Similarly, the term "non-associated" refers to the absence or substantial absence of aggregation and / or agglomeration of two or more primary particles.

[0062] "Non-agglomerated filler" means that the filler particles are present in the resin in discrete, non-associated (ie, non-agglomerated and non-aggregated) phases. This can be demonstrated by TEM microscopy if desired.

[0063] "Acid-reactive filler or glass" shall mean a filler or glass that chemically reacts in the presence of an acidic component.

[0064] "Non-acid-reactive filler" shall mean a filler which, if mixed with a (poly)acid, shows no chemical reaction at all or only a reduced (ie time-delayed) reaction within 6 minutes.

[0065] To distinguish acid-reactive fillers from non-acid-reactive fillers, the following tests may or should be performed:

[0066] The composition was prepared by mixing Part P with Part L in a mass ratio of 3:1, wherein:

[0067] Part P contains: Filler to be analyzed: 100% by weight.

[0068] Part L contains: poly(acrylic acid-co-maleic acid) (Mw: about 18,000 + / - 3,000): 43.6 wt%, water: 47.2 wt%, tartaric acid: 9.1 wt%, benzoic acid: 0.1 wt%.

[0069] The filler is characterized as non-acid reactive if within 6 minutes after preparing the above composition, the shear stress is less than 50,000 Pa, the shear stress being determined by oscillatory measurement using a rheometer applying the following conditions: using 8 mm plates, 0.75 mm gap, at 28° C., frequency: 1.25 Hz, deformation: 1.75%.

[0070] "Cation-reduced aluminosilicate glass" shall mean a glass having a lower cation content in the surface region of the glass particles compared to the interior region of the glass particles.

[0071] Compared to typical acid-reactive fillers, these glasses react much more slowly when in contact with a solution of polyacrylic acid in water. Examples of non-acid-reactive fillers include quartz glass. Additional examples are given below.

[0072] Cationic reduction can be achieved by surface treatment of the glass particles. Suitable surface treatments include, but are not limited to, pickling (e.g., treatment with phosphoric acid or with hydrochloric acid), treatment with phosphates, or treatment with a chelating agent such as tartaric acid.

[0073] "Dispersed within the resin" means that the filler particles are present in the resin as agglomerated or aggregated or discrete (ie, non-associated, non-agglomerated, and non-aggregated) particles.

[0074] A "carbamate group" is a group having the structure "-NH-CO-O-".

[0075] A "urea group" is a group having the structure "-NH-CO-NH-".

[0076] An "amido" group is a group having the structure "-NH-CO-".

[0077] The term "visible light" is used to refer to light having a wavelength of about 400 nanometers (nm) to about 800 nm.

[0078] "Dental article" means an article intended for use in the dental field, in particular as or for the production of dental restorations. Dental articles generally have two distinct surface parts, an outer surface and an inner surface. The outer surface is the surface that generally does not come into permanent contact with the tooth surface. In contrast, the inner surface is the surface that serves to attach or secure the dental article to the tooth. If the dental article has the shape of a crown, the inner surface generally has a concave shape, while the outer surface generally has a convex shape. Dental articles should not contain components that are harmful to the patient's health and therefore do not contain hazardous and toxic components that could migrate out of the dental or orthodontic article.

[0079] "Dental restoration" means a dental product used to repair a tooth to be treated. Examples of dental restorations include crowns, bridges, inlays, onlays, veneers, facings, copings, crown-bridge frameworks, and parts thereof. "Adhesive" or "dental adhesive" refers to a composition used as a pretreatment on a dental structure (e.g., a tooth) to adhere a "dental material" (e.g., a "restoration," an orthodontic appliance (e.g., a bracket) or an "orthodontic adhesive") to a dental surface. "Orthodontic adhesive" refers to a composition for adhering an orthodontic appliance to a dental (e.g., tooth) surface. Typically, a dental surface is pretreated, for example by etching, priming, and / or applying an adhesive, to enhance adhesion of the "orthodontic adhesive" to the dental surface.

[0080] "Dental surface" or "tooth surface" refers to the surface of tooth structure (e.g., enamel, dentin, and cementum) and bone. A composition is "substantially or essentially free" of a component if it does not include that component as an essential feature. Thus, the component itself is not intentionally added to the composition, nor is it intentionally added to the composition with other components or ingredients of other components.

[0081] A composition that is substantially free of a component typically contains less than about 1% by weight, or less than about 0.5% by weight, or less than about 0.1% by weight, or less than about 0.01% by weight of the component relative to the entire composition or material. A composition may not contain the component at all. However, the presence of small amounts of the component is sometimes unavoidable, for example due to impurities in the raw materials used.

[0082] "Ambient conditions" refers to the conditions to which the compositions described herein are typically subjected during storage and handling. Ambient conditions can be, for example, a pressure of 900 to 1,100 mbar, a temperature of 10°C to 40°C, and a relative humidity of 10% to 100%. In the laboratory, ambient conditions are typically adjusted to 20°C to 25°C and 1,000 to 1,025 mbar (at sea level).

[0083] As used herein, "a," "an," "the," "at least one," and "one or more" are used interchangeably. Also herein, the recitations of numerical ranges by endpoints include all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0084] Adding "plural form" to a term means that the term should include both the singular and the plural forms. For example, the term "additive" refers to one additive and multiple additives (e.g., 2, 3, 4, etc.).

[0085] Unless otherwise indicated, all numbers expressing quantities of ingredients, measurements of physical properties (such as described below), and so forth, used in the specification and claims are to be understood as being modified in all instances by the term "about."

[0086] The terms "comprises" or "comprising" and variations thereof do not have a limiting meaning when these terms appear in the specification and claims. "Consisting essentially of means that certain additional components may be present, i.e., those components that do not materially affect the basic properties of the article or composition. "Consisting of means that no additional components should be present. The term "comprising" shall also encompass the terms "consisting essentially of" and "consisting of."

[0087] A composition is "substantially or essentially free" of a component if it does not include that component as an essential characteristic. Thus, the component itself is not intentionally added to the composition, nor is it intentionally added to the composition along with other components or ingredients of other components. A composition that is substantially free of a component typically does not contain that component at all. However, the presence of small amounts of a component is sometimes unavoidable, for example due to impurities in the raw materials used. DETAILED DESCRIPTION

[0088] The surface-treated fillers described herein have been found to have several advantageous properties.

[0089] Surface treatment of the filler particles not only makes the filler particles more compatible with the resin matrix of the dental composition, but also affects the rheological properties, particularly the viscosity profile, of the dental compositions containing these surface treated filler particles.

[0090] The dental composition becomes more flowable and can be dispensed more easily from the syringe-like packaging material.

[0091] In particular, dental compositions have low viscosities at low shear rates, which is indicative of a lack of internal structure, similar to Newtonian liquids.

[0092] Furthermore, it was found that the hardened dental composition still has sufficient mechanical properties, such as flexural strength and flexural modulus.

[0093] Without wishing to be bound by a particular theory, it is believed that the length of the two alkylene moieties plays a role, and it is important that the length of the alkylene moiety AM1 is longer than the length of the alkylene moiety AM2. Therefore, the carbamate moiety should be located closer to the hydrolyzable silane moiety than the (meth)acryloyl moiety.

[0094] It is hypothesized that by selecting the lengths suggested herein, the likelihood of unwanted hydrogen bridges forming is reduced and the surface treatment agent is more effective in shielding the surface of the treated filler.

[0095] According to one aspect, the present invention relates to a surface-treated filler.

[0096] The nature and structure of the filler are not particularly limited unless the intended purpose cannot be achieved. Various types of fillers can be used.

[0097] The dental compositions described herein may comprise one or more of filler (F1), filler (F2), filler (F3), filler (F4), filler (F5), or filler (F6).

[0098] The dental composition may contain only one filler (F1 ) or a plurality of fillers (F1 ), such as two, three or four different fillers.

[0099] The dental composition may contain only one filler (F2) or a plurality of fillers (F2), such as two, three or four different fillers.

[0100] The dental composition may contain only one filler (F3) or a plurality of fillers (F3), such as two, three or four different fillers.

[0101] The dental composition may contain only one filler (F4) or a plurality of fillers (F4), such as two, three or four different fillers.

[0102] The dental composition may contain only one filler (F5) or a plurality of fillers (F5), such as two, three or four different fillers.

[0103] The dental composition may contain only one filler (F6) or a plurality of fillers (F6), such as two, three or four different fillers.

[0104] In general, dental compositions typically contain filler in an amount of at least 40%, or 45%, or 50%, by weight; at most 80%, or 75%, or 70%, by weight; within the range of 40% to 80%, or 45% to 75%, or 50% to 70%, by weight; relative to the weight of the dental composition.

[0105] The filler (F1) comprises non-aggregated, non-agglomerated nano-sized particles of SiO2, ZrO2 and mixtures thereof.

[0106] The nanometer-sized particles are preferably substantially spherical and substantially non-porous.

[0107] Fillers (F1) can generally be characterized by at least one or all of the following characteristics:

[0108] a) Specific surface area (BET): 50m 2 / g to 400m 2 / g, or 60m 2 / g to 300m 2 / g, or 80m 2 / g to 250m 2 / g;

[0109] b) primary particle size: 5 nm to 30 nm, or 7 nm to 20 nm;

[0110] c) Particles comprising SiO2, ZrO2 and mixtures thereof.

[0111] Fillers (F1) characterized by features a) and c) are sometimes preferred.

[0112] If desired, the specific surface area can be determined according to Brunauer, Emmet and Teller (BET) by using an apparatus (Monosorb) from Quantachrome.

[0113] Silica is an example of a preferred nano-sized filler (F1).While the silica is preferably substantially pure, it may contain small amounts of stabilizing ions such as ammonium and alkali metal ions.

[0114] Zirconia is another preferred nanosized filler (F1). Useful methods for preparing zirconia are described, for example, in US 6,376,590 B1 (Kolb et al.).

[0115] This application discloses a zirconia sol comprising an aqueous phase having dispersed therein a plurality of single-crystalline zirconia particles having an average primary particle size of less than 20 nm, preferably 7 nm to 20 nm. The zirconia sol is substantially non-associated (i.e., non-aggregated and non-agglomerated).

[0116] Non-agglomerated nanosized silica is commercially available, for example, from Nalco Chemical Co. (Naperville, 111.) under the product name NALCO COLLOIDAL SILICAS, for example, NALCO Product Nos. 1040, 1042, 1050, 1060, 2327, and 2329. Non-agglomerated fillers are used and described, for example, in US 7,393,882 (3M).

[0117] The filler (F2) comprises aggregated nano-sized particles.

[0118] Fillers (F2) can generally be characterized by the following characteristics, either alone or in combination:

[0119] a) Specific surface area (BET): 30m 2 / g to 400m 2 / g, or 50m 2 / g to 400m 2 / g, or 60m 2 / g to 300m 2 / g, or 80m 2 / g to 250m 2 / g;

[0120] b) primary particle size: 5 nm to 100 nm or 10 nm to 80 nm or 10 nm to 50 nm;

[0121] c) Average particle size (aggregates): 0.5 μm to 2 μm;

[0122] d) Particles comprising SiO2, ZrO2 and mixtures thereof.

[0123] Fillers (F2) characterized by features a) and c), or a) and d), or a), c) and d) are sometimes preferred.

[0124] According to one embodiment, the filler (F2) is characterized by a primary particle size in the range of 50 nm to 100 nm and a primary particle size in the range of 30 nm. 2 / g to 50m 2 It is characterized by the BET surface area in the range of 1 / g.

[0125] If desired, the average particle size may be determined by light scattering using, for example, a Malvern Mastersizer 2000 apparatus available from Malvern Instruments.

[0126] Filler (F2) can be produced according to the method described, for example, in US 6,730,156 B1 (Windisch et al.).

[0127] In particular, filler (F2) can be prepared from a suitable sol and one or more oxygen-containing heavy metal compound solution precursors, which can be salts, sols, solutions, or nanosized particles; sols are preferred. For the purposes of this invention, a sol is defined as a stable dispersion of colloidal solid particles in a liquid. The solid particles are typically denser than the surrounding liquid and sufficiently small that the dispersion forces are greater than gravity. Furthermore, the particle size is sufficiently small that they generally do not refract visible light. Judicious selection of the precursor sol results in the desired degree of visual opacity, strength, etc. Factors guiding sol selection depend on a combination of the following properties: a) the average size of the individual particles, which are preferably less than about 100 nm in diameter; b) acidity: the pH of the sol should preferably be below 6, more preferably below 4; and c) the sol should be free of impurities that could cause excessive aggregation of the individual discrete particles during subsequent steps (such as spray drying or calcination) (during the filler preparation process), resulting in larger particles that cannot be easily dispersed or oriented, thereby reducing translucency and polishability.

[0128] If the starting sol is alkaline, it should be acidified to lower the pH, for example by adding nitric acid or other suitable acid. However, choosing an alkaline starting sol is less desirable because it requires additional steps and may result in the introduction of undesirable impurities. Typical impurities that are preferably avoided are metal salts, particularly alkali metal salts, such as sodium salts.

[0129] The non-heavy metal sol and heavy metal oxide precursor are preferably mixed together in a molar ratio that matches the refractive index of the hardenable resin. This imparts a low and desirable visual opacity. Preferably, the molar ratio of the non-heavy metal oxide ("non-HMO") to the heavy metal oxide ("HMO") (expressed as non-HMO:HMO) ranges from 0.5:1 to 10:1, more preferably from 3:1 to 9:1, and most preferably from 4:1 to 7:1.

[0130] In a preferred embodiment, wherein the aggregated nanosized particles contain silica and a zirconium-containing compound, the preparation method begins with a mixture of silica sol and zirconyl acetate in a molar ratio of about 5.5:1.

[0131] Prior to mixing the non-heavy metal oxide sol with the heavy metal oxide precursor, the pH of the non-heavy metal oxide sol is preferably lowered to provide an acidic solution having a pH of 1.5 to 4.0.

[0132] The non-heavy metal oxide sol is then slowly mixed with a solution containing a heavy metal oxide precursor and stirred vigorously. Preferably, vigorous stirring is performed throughout the blending process. The solution is then dried to remove water and other volatile components. Drying can be accomplished in a variety of ways, including, for example, tray drying, fluidized bed drying, and spray drying. In a preferred method using zirconyl acetate, drying is performed by spray drying.

[0133] The resulting dried material preferably consists of small, substantially spherical particles and broken hollow spheres. These fragments are then batch-calcined to further remove residual organic matter. Removal of residual organic matter renders the filler more brittle, which results in more effective particle size reduction. During calcination, the soaking temperature is preferably set at 200°C to 800°C, more preferably 300°C to 600°C. Soaking is carried out for 0.5 to 8 hours, depending on the amount of material being calcined. Preferably, the soaking time of the calcination step is such that a plateau surface area is obtained. Preferably, the time and temperature are selected such that the resulting filler is white, free of black, gray, or amber particles, as determined by visual inspection.

[0134] The calcined material is then preferably ground to a median particle size of less than 5 μm, preferably less than 2 μm (volume-based), as can be determined using a Sedigraph 5100 (Micrometrics, Norcross, Ga.). Particle size determination can be performed by first obtaining the specific density of the filler using an Accuracy 1330 Pycometer (Micrometrics, Norcross, Ga.). Milling can be accomplished by various methods, including, for example, stirred milling, vibratory milling, fluid energy milling, jet milling, and ball milling. Ball milling is a preferred method.

[0135] The resulting filler comprises, contains, consists essentially of, or consists of aggregated nanosized particles. If desired, this can be demonstrated by transmission electron microscopy (TEM).

[0136] Once dispersed in the resin, the filler (F2) is maintained in the aggregate stage. That is, the particles are not broken down into discrete (i.e., individual) and unassociated (i.e., non-agglomerated, non-aggregated) particles during the dispersion step.

[0137] Without wishing to be bound by a particular theory, it is believed that filler (F2) contributes to the polishability of the dental compositions described herein. It has been found that aggregates of filler (F2) particles can break up during the polishing step, thereby contributing to a smooth surface and lower light scattering compared to rough surfaces. From a clinical perspective, this generally results in high gloss retention and color stability.

[0138] If present, filler (F2) is typically present in an amount of at least 30 wt%, or 35 wt%, or 40 wt%; at most 70 wt%, or 60 wt%, or 50 wt%; in the range of 30 wt% to 70 wt%, or 35 wt% to 60 wt%, or 40 wt% to 50 wt%; relative to the weight of the dental composition.

[0139] The filler (F3) may comprise agglomerated nano-sized particles.

[0140] According to one embodiment, the filler (F3) may be characterized by the following features, alone or in combination:

[0141] a) Specific surface area (BET): 30m 2 / g to 400m 2 / g, or 50m 2 / g to 300m 2 / g, or 70m 2 / g to 250m 2 / g;

[0142] b) Particles comprising SiO2, ZrO2, Al2O3 and mixtures thereof.

[0143] If desired, the specific surface area can be determined as described above.

[0144] Suitable agglomerated nanoparticles include fumed silica, such as those sold under the trade name Aerosil ™Products sold include Aerosil OX-130, Aerosil OX-150, and Aerosil OX-200, Aerosil R8200 available from Degussa AG (Hanau, Germany), CAB-O-SIL available from Cabot Corporation (Tuscola, Ill.), and Aerosil OX-130, 150, and 200. ™ M5, and HDK ™ , such as HDK-H 2000, HDK H15; HDK H18, HDK H20 and HDK H30 available from WACKER.

[0145] Without wishing to be bound by a particular theory, it is believed that filler (F2) contributes to the rheological behavior of the dental compositions described herein.

[0146] The use of such fillers enables highly filled dental compositions to be provided which can nevertheless still be mixed using static mixing tips. From a clinical point of view, this generally results in improved handling characteristics such as easy mixing of the paste and low extrusion forces from cartridge systems.

[0147] If present, filler (F3) is typically present in an amount of at least 1 wt%, or 3 wt%, or 5 wt%; at most 20 wt%, or 15 wt%, or 10 wt%; in the range of 1 wt% to 20 wt%, or 3 wt% to 15 wt%, or 5 wt% to 10 wt%; relative to the weight of the dental composition.

[0148] Filler (F4) includes non-acid-reactive glasses such as lanthanum glass, borosilicate glass, soda glass, barium glass, strontium glass, glass ceramics, aluminosilicate glass, barium boroaluminosilicate glass, strontium boroaluminosilicate glass; silicates such as calcium silicate, zirconium silicate; and metal oxides such as quartz, cristobalite, alumina, titania, silica-titania, silica-titania-baria, silica-zirconia, silica-alumina.

[0149] In particular, the following glasses have been found to be useful: barium glass, strontium glass, aluminosilicate glass, barium boroaluminosilicate glass and strontium boroaluminosilicate glass.

[0150] Useful glasses are commercially available, for example, from Schott as GM32087, GM27884, G018-053, G018-308, G018-431 and G018-432.

[0151] If desired, the filler (F4) may also be characterized by the following characteristics, alone or in combination:

[0152] a) Specific surface area (BET): 10m2 / g to 50m 2 / g, or 15m 2 / g to 40m 2 / g;

[0153] b) Average particle size: 0.1 μm to 1 μm, or 0.2 μm to 0.6 μm.

[0154] If present, filler (F4) is typically present in an amount of at least 1 wt%, or 5 wt%, or 10 wt%; at most 80 wt%, or 70 wt%, or 60 wt%; in the range of 1 wt% to 80 wt%, or 5 wt% to 70 wt%, or 10 wt% to 60 wt%; relative to the weight of the dental composition.

[0155] Fillers (F5) include acid-reactive fillers, particularly acid-reactive glasses.

[0156] Acid-reactive fillers can help adjust the setting behavior and adhesion of the dental composition by adjusting the pH during the hardening process.

[0157] Acid-reactive fillers can generally be characterized by the following characteristics, alone or in combination:

[0158] a) average particle size: about 3 μm to about 10 μm;

[0159] b) (d10 / µm): 0.5µm to 3µm; (d50 / µm): 2µm to 7µm; (d90 / µm): 6µm to 15µm.

[0160] Examples of fillers (F5) include metal oxides and hydroxides, such as calcium, magnesium or zinc oxides and hydroxides, with the use of calcium hydroxide sometimes being preferred; and acid-reactive glasses, in particular fluoroaluminosilicate glasses (FAS glasses).

[0161] Acid-reactive glass can be produced by melting a glass frit containing the corresponding glass components, crushing, and grinding until the desired particle size distribution is achieved. Useful glass components include Al2O3, SiO2, SrF2, and AlF3 monohydrate or AlF3. Grinding or grinding the glass frit can be performed, for example, using a ball mill.

[0162] The Al / Si ratio of the acid-reactive glass is typically greater than 1 / 1 (relative to weight). This means that the acid-reactive glass contains more Al than Si. Al / Si ratios 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 are generally preferred.

[0163] If present, filler (F5) is typically present in an amount of at least 1 wt%, or 5 wt%, or 10 wt%; up to 80 wt%, or 70 wt%, or 60 wt%; in the range of 1 wt% to 80 wt%, or 5 wt% to 70 wt%, or 10 wt% to 60 wt%; relative to the weight of the dental composition.

[0164] The filler (F6) comprises a heavy metal oxide and a fluoride. The filler (F6) may help increase the radiopacity of the composition.

[0165] "Radiopacity" describes the ability to distinguish hardened dental material from tooth structure using standard dental X-ray equipment. Radiopacity of dental materials is advantageous in certain situations where X-rays are used to diagnose dental conditions. For example, radiopaque materials allow for the detection of secondary caries that may have formed in the tooth tissue surrounding a filling.

[0166] Oxides or fluorides of heavy metals with atomic numbers greater than 28 may be preferred. The heavy metal oxide or fluoride should be selected so that undesirable colors or shades are not imparted to the hardened resin in which the heavy metal oxide or fluoride is dispersed. For example, iron and cobalt are unfavorable because they impart a dark, contrasting color to the neutral tooth color of the dental material. More preferably, the heavy metal oxide or fluoride is an oxide or fluoride of a metal with an atomic number greater than 30. Suitable metal oxides include oxides of yttrium, strontium, barium, zirconium, hafnium, niobium, tantalum, tungsten, bismuth, molybdenum, tin, zinc, the lanthanides (i.e., elements with atomic numbers between 57 and 71, inclusive), cerium, and combinations thereof. Suitable metal fluorides include, for example, yttrium trifluoride and ytterbium trifluoride. Most preferably, oxides and fluorides of heavy metals with atomic numbers greater than 30 but less than 72 are optionally included in the materials of the present invention. Particularly preferred radiopaque metal oxides include lanthanum oxide, zirconium oxide, yttrium oxide, ytterbium oxide, barium oxide, strontium oxide, cerium oxide, and combinations thereof. The heavy metal oxide particles may be aggregated. If so, preferably, the average diameter of the aggregated particles is equal to or less than 200 nm. Other suitable fillers for enhancing radiopacity are barium and strontium salts, particularly strontium sulfate and barium sulfate.

[0167] If present, filler (F6) is typically present in an amount of at least 1 wt%, or 3 wt%, or 5 wt%; at most 50 wt%, or 40 wt%, or 30 wt%; in the range of 1 wt% to 50 wt%, or 3 wt% to 40 wt%, or 5 wt% to 30 wt%; relative to the weight of the dental composition.

[0168] In certain embodiments, the dental composition may comprise a combination of fillers (F1) and (F2), or (F1) and (F3), or (F2) and (F6), or (F1), (F2) and (F6), or (F2), (F3), and (F6), wherein the combination of fillers (F2) and (F6) is sometimes preferred.

[0169] The characteristics of surface treatment agents are as follows:

[0170] a. comprising at least one (meth)acrylate moiety,

[0171] b. comprising at least one hydrolyzable silane moiety,

[0172] c. contains only one carbamate moiety,

[0173] d. comprising a linear alkylene moiety AM1 connecting at least one (meth)acrylate moiety to a urethane moiety,

[0174] e. comprising a linear alkylene moiety AM2 linking at least one hydrolyzable silane moiety to a carbamate moiety,

[0175] f. The linear alkane subunit moiety AM1 contains more carbon atoms than the linear alkane subunit moiety AM2.

[0176] The surface treatment agent does not contain a polyol moiety (eg, a polyethylene or polypropylene moiety).

[0177] Without wishing to be bound by a particular theory, the presence of polyol moieties in combination with urethane moieties may result in interactions via hydrogen bonding and may create undesirable internal structures within the composition.

[0178] More precisely, the surface treatment agent may be characterized as follows:

[0179] a. contains only one (meth)acrylate moiety,

[0180] b. comprising at least one hydrolyzable silane moiety,

[0181] c. contains only one carbamate moiety,

[0182] d. comprising one linear alkylene moiety AM1 connecting the (meth)acrylate moiety to the urethane moiety, the alkylene moiety AM1 comprising 6 to 12 C atoms,

[0183] e. comprising one linear alkane substituent AM2 linking at least one hydrolyzable silane substituent to a carbamate substituent, the linear alkane substituent AM2 comprising 1 to 4 C atoms.

[0184] The hydrolyzable portion of the silane moiety is typically selected from

[0185] -Si(R 2 ) o (R 3 ) 3-o

[0186] where R 1 =H or CH3; R 2 = independently selected from Cl, Br, OC 1-4 Alkyl, OC 1-4 Acyl; R 3 = independently selected from C 1-4 Alkyl; X=O; Y=NH; n=6 to 12; m=1 to 4; o=1 to 3.

[0187] Preferred are generally trialkoxysilanes, especially trimethoxysilane, triethoxysilane, tripropoxysilane or tributoxysilane moieties.

[0188] Even more precisely, the surface treatment agent can be characterized by the following formula:

[0189] H2C=CHR 1 -CO-O-(CH2) n -X-CO-Y-(CH2) m -Si(R 2 ) o (R 3 ) 3-o

[0190] where R 1 =H or CH3; R 2 = independently selected from Cl, Br, OC 1-4 Alkyl, OC 1-4 Acyl; R 3 = independently selected from C 1-4 Alkyl; X=O; Y=NH; n=6 to 12; m=1 to 4; o=1 to 3.

[0191] A preferred embodiment of the hydrolyzable silane moiety is represented by the formula:

[0192] H2C=CHR 1 -CO-O-(CH2) n -X-CO-Y-(CH2) m -SiR 2 3

[0193] where R 1 =H or CH3; R 2 = independently selected from Cl, Br, OCH3, OCH2CH 3、OCH2CH2CH3, OCH2CH2CH2CH3; X=O; Y=NH; n=6 to 12 and m=1 to 4.

[0194] The surface treatment agent typically has a molecular weight (Mw) in the range of 300 g / mol to 800 g / mol or 350 g / mol to 600 g / mol.

[0195] Specific examples of surface treatment agents include the following molecules:

[0196]

[0197] The surface treatment agent can be prepared by a method comprising the following steps:

[0198] The (meth)acrylate component containing a hydroxyl moiety

[0199] Reacts with hydrolyzable isocyanate silane components.

[0200] The reaction is typically carried out at slightly elevated temperature (eg, 40°C to 80°C).

[0201] The surface treated filler can be prepared by a method comprising the following steps:

[0202] optionally combining the filler particles with a surface treatment agent using a dispersion,

[0203] reacting the surface treatment agent with the filler particles,

[0204] removing the optional dispersion,

[0205] The surface treated filler particles are optionally dried and sieved.

[0206] Suitable dispersing liquids include water and alcohols, such as methanol, ethanol or propanol. If necessary, the pH of the dispersion can be adjusted, for example by adding aqueous ammonia.

[0207] In some embodiments, the reaction of the surface treatment agent with the filler particles consists of hydrolysis (i.e., reaction of water with at least one of the hydrolyzable silane groups) and condensation of the resulting silanol groups with the filler surface and / or another surface treatment agent molecule. In some embodiments, the surface-treated filler comprises a partially or completely hydrolyzed surface treatment agent. In some embodiments, the partially or completely hydrolyzed surface treatment agent completely or partially condenses to form siloxane bonds between adjacent surface treatment agent molecules or between the surface treatment agent and the filler surface. In some embodiments, some of the hydrolyzed and / or condensed surface treatment agent can be removed from the surface-treated filler by a re-esterification reaction, i.e., immersing the surface-treated filler in an alcohol with an effective catalyst to reform the hydrolyzable silane moieties. Effective catalysts may include, but are not limited to, hydrofluoric acid, sodium fluoride, tetramethylammonium fluoride, tetrabutylammonium fluoride, hydrochloric acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid.

[0208] According to another aspect, the present invention is directed to a dental composition comprising a surface-treated filler as described herein.

[0209] The dental composition generally comprises a filler system, a resin matrix and an initiator system. The filler system comprises a surface-treated filler as described herein. The resin matrix comprises a curable component.

[0210] Dental compositions can generally be characterized prior to hardening by the following properties, alone or in combination:

[0211] capable of curing within 10 minutes after irradiation with light having a wavelength in the range of 400 nm to 700 nm;

[0212] pH: 7 or lower.

[0213] Dental compositions containing no rheology modifier at 25°C and 0.01s -1 The shear rate is usually 5Pa s to 1,500Pa Viscosity in the s range.

[0214] Dental compositions can generally be characterized after hardening by the following properties, alone or in combination:

[0215] Flexural strength: 100 MPa to 200 MPa, measured according to ISO 4049 (2019);

[0216] Flexural modulus: 4 GPa to 8 GPa, determined according to ISO 4049 (2019).

[0217] If desired, properties can be determined as described in the Examples section.

[0218] The dental composition comprises a curable component.

[0219] The curable component is part of the resin matrix. There may be one or more different curable components.

[0220] The curable component typically comprises one or more polymerizable moieties, particularly (meth)acrylate moieties. Additionally, the curable component may or may not comprise acidic moieties.

[0221] The curable component is typically present in an amount of at least 5 wt%, or 10 wt%, or 15 wt%; up to 50 wt%, or 45 wt%, or 40 wt%; within the range of 5 wt% to 50 wt%, or 10 wt% to 45 wt%, or 15 wt% to 40 wt%; wt% relative to the dental composition.

[0222] Suitable polymerizable components that do not contain an acidic moiety that may be used are characterized by the formula:

[0223] A n BA m

[0224] wherein A is an ethylenically unsaturated group, such as a (meth)acryloyl moiety,

[0225] B is selected from (i) a linear or branched C1 to C2 optionally substituted with other functional groups (eg, halogen (including Cl, Br, I), OH or a mixture thereof); 12 (ii) C6 to C6 alkyl, optionally substituted with other functional groups (e.g., halogen, OH or mixtures thereof) 12 aryl, or (iii) organic groups having 4 to 20 carbon atoms bonded to one another via one or more ether, thioether, ester, thioester, thiocarbonyl, amide, carbamate, carbonyl and / or sulfonyl bonds,

[0226] m and n are independently selected from 0, 1, 2, 3, 4, 5 or 6, with the proviso that n+m is greater than 0, ie, at least one A group is present.

[0227] Such polymerizable materials include

[0228] Monoacrylates, diacrylates or polyacrylates and methacrylates, such as methyl acrylate, methyl methacrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-hexyl (meth)acrylate, stearyl (meth)acrylate, allyl (meth)acrylate, glyceryl di(meth)acrylate,

[0229] Urethane dimethacrylate known as UDMA (a mixture of isomers, e.g., Plex 6661-0) is the reaction product of 2-hydroxyethyl methacrylate (HEMA) and 2,2,4-trimethyl-hexamethylidene diisocyanate (TMDI);

[0230] Glycerol tri(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate (TEGDMA), 1,3-propylene glycol diacrylate, 1,3-propylene glycol dimethacrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, 1,2,4-butanetriol tri(meth)acrylate, 1,4-cyclohexanediol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, sorbitol hexa(meth)acrylate, bis[1-(2-(meth)acryloyloxy)]-p-ethoxy-phenyldimethylmethane, and trishydroxyethyl-isocyanurate trimethacrylate;

[0231] diacrylates and dimethacrylates of polyethylene glycol having a molecular weight of 200 to 500, copolymerizable mixtures of acrylated monomers (see, for example, US 4,652,274 (Boettcher et al.)), and acrylated oligomers (see, for example, US 4,642,126 (Zador));

[0232] Vinyl compounds such as styrene, divinyl succinate, divinyl adipate, and divinyl phthalate; and

[0233] Multifunctional (meth)acrylates containing urethane, urea or amide groups.

[0234] If desired, mixtures of two or more of these free radically polymerizable materials can be used.

[0235] If present, the polymerizable component without an acidic moiety is typically present in an amount of at least 1 wt%, or at least 2 wt%, or at least 5 wt%; up to 20 wt%, or up to 15 wt%, or up to 10 wt%; within a range of 1 wt% to 20 wt%, or 2 wt% to 15 wt%, or 5 wt% to 10 wt%; the wt% being relative to the weight of the dental composition.

[0236] The dental composition may also comprise a polymerizable monomer having an acidic moiety.

[0237] The polymerizable component having an acid moiety can generally be characterized by the formula

[0238] A n BC m

[0239] wherein A is an ethylenically unsaturated group, such as a (meth)acryloyl moiety,

[0240] B is a spacer group, such as (i) a linear or branched C1 to C2 optionally substituted with other functional groups (e.g., halogen (including Cl, Br, I), OH or a mixture thereof); 12 (ii) C6 to C6 alkyl, optionally substituted with other functional groups (e.g., halogen, OH or mixtures thereof) 12 aryl, (iii) organic groups having 4 to 20 carbon atoms bonded to one another via one or more ether, thioether, ester, thioester, thiocarbonyl, amide, carbamate, carbonyl and / or sulfonyl bonds, and

[0241] C is an acidic group, or a precursor of an acidic group, such as an anhydride,

[0242] m and n are independently selected from 1, 2, 3, 4, 5 or 6,

[0243] Wherein the acidic group comprises one or more carboxylic acid residues, such as -COOH or -CO-O-CO-, phosphoric acid residues, such as -OP(O)(OH)OH, phosphonic acid residues, such as CP(O)(OH)(OH), sulfonic acid residues, such as -SO3H, or sulfinic acid residues, such as -SO2H.

[0244] Examples of polymerizable components having an acid moiety include glycerophosphate mono(meth)acrylate, glycerophosphate di(meth)acrylate, hydroxyethyl(meth)acrylate (e.g., HEMA) phosphate, bis((meth)acryloyloxyethyl)phosphate, (meth)acryloyloxypropyl phosphate, bis((meth)acryloyloxypropyl)phosphate, bis((meth)acryloyloxy)propoxy phosphate, (meth)acryloyloxyhexyl phosphate, bis((meth)acryloyloxyhexyl)phosphate, (meth)acryloyloxyoctyl phosphate, bis((meth)acryloyloxy

[0014] Examples of the present invention include poly((meth)acrylated octyl) phosphate, (meth)acryloyloxydecyl phosphate, bis((meth)acryloyloxydecyl) phosphate, caprolactone methacrylate phosphate, caprolactone methacrylate phosphate, citric acid dimethacrylate or trimethacrylate, poly(meth)acrylated oligomeric maleic acid, poly(meth)acrylated polymaleic acid, poly(meth)acrylated polyacrylic acid, poly(meth)acrylated polycarboxylic polyphosphonic acid, poly(meth)acrylated polychlorinated phosphoric acid, poly(meth)acrylated polysulfonate, poly(meth)acrylated polyboric acid, and the like. Derivatives of these hardenable components with acid moieties, such as acid halides or anhydrides, which readily react with, for example, water to form the above-mentioned specific examples are also contemplated.

[0245] Monomers, oligomers, and polymers of unsaturated carboxylic acids such as (meth)acrylic acid, aromatic (meth)acrylated acids (eg, methacrylated trimellitic acid), and their anhydrides may also be used.

[0246] Some of these compounds can be obtained, for example, as reaction products between isocyanatoalkyl (meth)acrylates and carboxylic acids. Additional compounds of this type having an acid function and an ethylenically unsaturated component are described in US Pat. No. 4,872,936 (Engelbrecht) and US Pat. No. 5,130,347 (Mitra). A variety of such compounds containing an ethylenically unsaturated moiety and an acid moiety can be used. If desired, mixtures of such compounds can be used.

[0247] The use of (meth)acrylate-functionalized polyalkenoic acids is generally preferred, since those components have been found to be useful for improving properties such as adhesion to hard dental tissue, uniform layer formation, viscosity or moisture resistance.

[0248] According to one embodiment, the composition contains a (meth)acrylate functionalized polyalkenoic acid, such as AA:ITA:IEM (copolymer of acrylic acid:itaconic acid with pendant methacrylates).

[0249] These components can be prepared by reacting, for example, an AA:ITA copolymer with 2-isocyanatoethyl methacrylate to convert a portion of the copolymer's acid groups into pendant methacrylate groups. Methods for producing these components are described in Example 11 of US Pat. No. 5,130,347 (Mitra); and those listed in US Pat. No. 4,259,075 (Yamauchi et al.), US Pat. No. 4,499,251 (Omura et al.), US Pat. No. 4,537,940 (Omura et al.), US Pat. No. 4,539,382 (Omura et al.), US Pat. No. 5,530,038 (Yamamoto et al.), US Pat. No. 6,458,868 (Okada et al.), EP 0 712 622 A1 (Tokuyama Corp.), and EP 1 051 961 A1 (Kuraray Co., Ltd.).

[0250] If present, the polymerizable component having an acidic moiety should be present in an amount such that the pH of the composition is below 6, or below 4, or below 2 if contacted with water.

[0251] If present, the polymerizable component having an acidic moiety is typically present in an amount of at least 1 wt%, or at least 2 wt%, or at least 5 wt%; up to 20 wt%, or up to 15 wt%, or up to 10 wt%; within a range of 1 wt% to 20 wt%, or 2 wt% to 15 wt%, or 5 wt% to 10 wt%; the wt% being relative to the weight of the dental composition.

[0252] If desired, addition fragmentation monomers (AFM) can also be added.

[0253] Addition-fragmentation monomers can be characterized by the following formula:

[0254]

[0255] in

[0256] R 1 、R 2 and R 3 Each independently is Z m -Q-, a (hetero)alkyl group or a (hetero)aryl group, provided that R 1 、R 2 and R 3 At least one of them is Z m -Q-; Q is a linking group with a valence of m+1; Z is an ethylenically unsaturated polymerizable group; m is 1 to 6; each X 1 are independently -O- or -NR 4 -, where R4 is H or C1-C4 alkyl; and n is 0 or 1.

[0257] These monomers are said to have lower stress. Suitable monomers are also described in US 9,056,043 (Joly et al).

[0258] Monomers containing hydroxyl moieties may also be present.

[0259] Suitable compounds include 2-hydroxyethyl (meth)acrylate (HEMA), 2- or 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, dialkylene glycol mono(meth)acrylates (e.g., diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, dipropylene glycol mono(meth)acrylate, mono- (meth)acrylate), and further, 1,2- or 1,3- and 2,3-dihydroxypropyl (meth)acrylate, 2-hydroxypropyl-1,3-di(meth)acrylate, 3-hydroxypropyl-1,2-di(meth)acrylate, N-(meth)acryloyl-1,2-dihydroxypropylamine, N-(meth)acryloyl-1,3-dihydroxypropylamine, an adduct of phenol and glycidyl (meth)acrylate (for example, 1-phenoxy-2-hydroxypropyl (meth)acrylate and 1-naphthyloxy-2-hydroxypropyl (meth)acrylate).

[0260] If desired, mixtures of one or more of these components may be used.

[0261] The dental composition also comprises an initiator system suitable for curing the curable component.

[0262] The initiator system can be a redox initiator system, a photoinitiator system or a thermal curing system.The initiator system is capable of starting the curing process of the hardenable components present in the resin matrix.

[0263] The initiator system is typically present in an amount of at least 0.1 wt%, or at least 0.2 wt%, or at least 0.5 wt%; up to 5 wt%, or up to 4 wt%, or up to 3 wt%; within a range of 0.1 wt% to 5 wt%, or 0.2 wt% to 4 wt%, or 0.5 wt% to 3 wt%; the wt% being relative to the weight of the dental composition.

[0264] To cure one-part compositions, a photoinitiator system is generally used.

[0265] Suitable photoinitiator systems for free-radical polymerization are generally known to those skilled in the art of processing dental materials.

[0266] Suitable photoinitiator systems typically contain a sensitizer comprising an α-α diketone moiety, an anthraquinone moiety, a thioxanthone moiety, or a benzoin moiety. Sensitizers containing an α-α diketone moiety are generally preferred.

[0267] A typical photoinitiator system comprises a combination of a sensitizer and a reducing agent or donor component, which is generally referred to as a photoinitiator system.

[0268] As the sensitizer, those which can polymerize a polymerizable monomer by the action of visible light having a wavelength of 390 nm to 830 nm are preferred.

[0269] Examples of usable sensitizers include camphorquinone, benzil, diacetyl, benzyl dimethyl ketal, benzyl diethyl ketal, benzyl di(2-methoxyethyl) ketal, 4,4,'-dimethylbenzyl dimethyl ketal, anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1,2-benzanthraquinone, 1-hydroxyanthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, 1-bromoanthraquinone, thioxanthone, 2-isopropylthioxanthone, 2-nitrothioxanthone, , 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chloro-7-trifluoromethylthioxanthone, thioxanthone-10,10-dioxide, thioxanthone-10-oxide, benzoin methyl ether, benzoin ethyl ether, isopropyl ether, benzoin isobutyl ether, benzophenone, bis(4-dimethyl-aminophenyl)ketone, 4,4,'-bisdiethylaminobenzophenone.

[0270] As the reducing agent or donor component, a tertiary amine or the like is generally used. Suitable examples of the tertiary amine include N,N-dimethyl-p-toluidine, N,N-dimethyl-aminoethyl methacrylate, triethanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, methyldiphenylamine, and isoamyl 4-dimethylaminobenzoate.

[0271] Additional suitable reducing agents include diarylalkylamines characterized by the formula: Ar 1 Ar 2 RN, of which Ar 1 and Ar 2 independently selected from phenyl or alkyl (e.g., C1 to C4) substituted phenyl, R is an alkyl (e.g., C1 to C4) group, wherein one or more H atoms may be substituted by halogen, and N is nitrogen. These reducing agents are described in more detail in US 8,314,162 (Hailand et al.).

[0272] In addition, a ternary photopolymerization initiation system consisting of a sensitizer, an electron donor, and an onium salt can be used.

[0273] Examples are described in US 6,187,833 (Oxman et al.), US 6,025,406 (Oxman et al.), US 6,043,295 (Oxman et al.), US 5,998,495 (Oxman et al.), US 6,084,004 (Weinmann et al.), US 5,545,676 (Palazzotto et al.), as well as US 8,314,162 B2 (Hailand et al.) and US 6,765,036 (Dede et al.).

[0274] In the ternary photoinitiator system, the first component is an onium, preferably an iodonium salt, ie, a diaryliodonium salt.

[0275] The iodonium salt is preferably soluble in the monomer and is storage stable (i.e., does not spontaneously promote polymerization) when dissolved therein in the presence of a sensitizer and a donor. Thus, the choice of a particular iodonium salt may depend to some extent on the particular monomer, polymer or oligomer, sensitizer, and donor selected. Suitable iodonium salts are described, for example, in US Pat. Nos. 3,729,313 (Smith et al.), 3,741,769, 3,808,006 (Smith et al.), 4,250,053 (Smith et al.), and 4,394,403 (Smith et al.).

[0276] The iodonium salt may be a simple salt (e.g., containing an anion such as Cl - Br - , I - or C4H5SO3 - ) or metal complex salts (e.g., containing SbF5OH - or AsF6 - If desired, a mixture of iodonium salts may be used. Preferred iodonium salts include diphenyliodonium salts such as diphenyliodonium chloride, diphenyliodonium hexafluorophosphate, and diphenyliodonium tetrafluoroborate.

[0277] The second component in the ternary photoinitiator system is the sensitizer.

[0278] The sensitizer is desirably soluble in the monomer and capable of light absorption in the wavelength range of greater than 400 nm to 1,200 nm, more preferably greater than 400 nm to 700 nm, and most preferably greater than 400 nm to 600 nm.

[0279] Suitable sensitizers may include compounds from the following classes: ketones, coumarin dyes (e.g., ketocoumarins), xanthene dyes, acridine dyes, thiazole dyes, thiazine dyes, oxazine dyes, azine dyes, aminoketone dyes, porphyrins, aromatic polycyclic hydrocarbons, para-substituted aminostyryl ketone compounds, aminotriarylmethanes, merocyanines, squarylium dyes, and pyridinium dyes. Ketones (e.g., monoketones or α-diketones), ketocoumarins, aminoaromatic ketones, and para-substituted aminostyryl ketone compounds are preferred sensitizers.

[0280] For example, one preferred class of ketone sensitizers has the formula: ACO(X) b B, where X is CO or CR 5 R 6 , where R 5 and R 6 A and B may be the same or different and may be hydrogen, alkyl, alkaryl or aralkyl, b is zero or one, and A and B are different and may be substituted (with one or more non-interfering substituents) and may be the same or unsubstituted aryl, alkyl, alkaryl or aralkyl groups, or A and B together may form a cyclic structure which may be a substituted or unsubstituted alicyclic, aromatic, heteroaromatic or fused aromatic ring.

[0281] Suitable ketones of the above formula include monoketones (b=0), such as 2,2-, 4,4- or 2,4-dihydroxybenzophenone, di-2-pyridyl ketone, di-2-furyl ketone, di-2-thienyl ketone, benzoin, fluorenone, chalcone, Michler's ketone, 2-fluoro-9-fluorenone, 2-chlorothioxanthone, acetophenone, benzophenone, 1- or 2-acetonaphthone, 9-acetylanthracene, 2-, 3- or 9-acetylphenanthrene, 4-acetylbiphenyl, propiophenone, butyrophenone, valerophenone, 2-, 3- or 4-acetylpyridine, 3-acetylcoumarin, and the like. Suitable diketones include aralkyl diketones such as anthraquinone, phenanthrenequinone, o-, m-, and p-diacetylbenzene, 1,3-, 1,4-, 1,5-, 1,6-, 1,7-, and 1,8-diacetylnaphthalene, 1,5-, 1,8-, and 9,10-diacetylanthracene, etc. Suitable α-diketones (b=1 and X=CO) include 2,3-butanedione, 2,3-pentanedione, 2,3-hexanedione, 3,4-hexanedione, 2,3-heptanedione, 3,4-heptanedione, 2,3-octanedione, 4,5-octanedione, benzil, 2,2'-3,3'- and 4,4'-dihydroxybenzil, furil, di-3,3'-indoleethyldione, 2,3-bornanedione (camphorquinone), biacetyl, 1,2-cyclohexanedione, 1,2-naphthoquinone, etc.

[0282] The third component of the ternary initiator system is the donor.

[0283] Preferred donors include, for example, amines (including aminoaldehydes and aminosilanes), amides (including phosphoramides), ethers (including thioethers), ureas (including thioureas), ferrocene, sulfinic acid and its salts, salts of ferrocyanide, ascorbic acid and its salts, dithiocarbamic acid and its salts, xanthates, ethylenediaminetetraacetate, and tetraphenylborate. The donor can be unsubstituted or substituted with one or more non-interfering substituents. Particularly preferred donors contain electron-donating atoms such as nitrogen, oxygen, phosphorus, or sulfur atoms, as well as abstractable hydrogen atoms bonded to carbon or silicon atoms alpha to the electron-donating atom. A variety of donors are disclosed in US Pat. No. 5,545,676 (Palazzotto et al.).

[0284] Alternatively, free radical initiators that may be used include acylphosphine oxides and bisacylphosphine oxides.

[0285] Suitable acylphosphine oxides can be described by the following general formula:

[0286] (R 9 )2 - P(=O) - C(=O)-R 10

[0287] Each R 9 R is independently a hydrocarbon group such as alkyl, cycloalkyl, aryl and aralkyl, any of which may be substituted by a halogen, alkyl or alkoxy group, or both R 9 The groups may be joined to form a ring together with the phosphorus atom, and wherein R 10 is a hydrocarbon group, a five- or six-membered heterocyclic group containing S-, O-, or N-, or –ZC(=O)-P(=O)-(R 9 )2 group, wherein Z represents a divalent hydrocarbon group, such as an alkylene group or a phenylene group having 2 to 6 carbon atoms.

[0288] Preferred acylphosphine oxides are those in which R 9 and R 10 The groups are those of phenyl or lower alkyl or lower alkoxy substituted phenyl. By "lower alkyl" and "lower alkoxy" are meant such groups having 1 to 4 carbon atoms. Examples can also be found in, for example, US 4,737,593.

[0289] Examples include bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-ethoxyphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-biphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2-naphthylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2-naphthylphosphine oxide, bis-( 2,6-dichloro-benzoyl)-4-chlorophenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,4-dimethoxyphenyl-phosphine oxide, bis-(2,6-dichlorobenzoyl)decylphosphine oxide, bis-(2,6-dichloro-benzoyl)-4-octylphenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethyl-phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-phenylphosphine oxide, bis-(2,4,6-trimethylbenzoyl)-2,5-dimethylphenyl Phosphine oxide, bis-(2,6-dichloro-3,4,5-trimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichloro-3,4,5-trimethoxybenzoyl)-4-ethoxyphenylphosphine oxide, bis-(2-methyl-1-naphthoyl)-2,5-dimethylphenylphosphine oxide, bis-(2-methyl-1-naphthoyl)phenylphosphine oxide, bis-(2-methyl-1-naphthoyl)-4-biphenylphosphine oxide, bis-(2-methyl-1-naphthoyl)-4-ethoxyphenylphosphine oxide phosphine, bis-(2-methyl-1-naphthoyl)-2-naphthylphosphine oxide, bis-(2-methyl-1-naphthoyl)-4-propylphenylphosphine oxide, bis-(2-methyl-1-naphthoyl)-2,5-dimethylphosphine oxide, bis-(2-methoxy-1-naphthoyl)-4-ethoxyphenylphosphine oxide, bis-(2-methoxy-1-naphthoyl)-4-biphenylphosphine oxide, bis-(2-methoxy-1-naphthoyl)-2-naphthylphosphine oxide and bis-(2-chloro-1-naphthoyl)-2,5-dimethylphenylphosphine oxide.

[0290] Tertiary amine reducing agents can be used in combination with acylphosphine oxides. Exemplary tertiary amines useful in the present invention include ethyl 4-(N,N-dimethylamino)benzoate and N,N-dimethylaminoethyl methacrylate.

[0291] Commercially available phosphine oxide photoinitiators capable of free radical initiation when irradiated at wavelengths greater than 400 nm to 1,200 nm include a 25:75 by weight mixture of bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide and 2-hydroxy-2-methyl-1-phenylpropan-1-one (formerly known as Irgacure ™1700, Ciba), 2-benzyl-2-(N,N-dimethylamino)-1-(4-morpholinophenyl)-1-butanone (formerly known as Irgacure ™ 369, Ciba), bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium (formerly known as Irgacure ™ 784 DC, Ciba), a 1:1 mixture by weight of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2-hydroxy-2-methyl-1-phenylpropan-1-one (formerly known as Darocur ™ 4265, Ciba), ethyl-2,4,6-trimethylbenzylphenylphosphine oxide (formerly known as Lucirin ™ LR8893X, BASF), and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (formerly known as Irgacure ™ 819, BASF).

[0292] Another free radical initiator system that may alternatively be used comprises the class of ionic dye counterion complex initiators containing a borate anion and a complementary cationic dye.

[0293] Borate photoinitiators are described, for example, in US 4,772,530 (Gottschalk et al.), US 4,954,414 (Adair et al.), US 4,874,450 (Gottschalk), US 5,055,372 (Shanklin et al.), and US 5,057,393 (Shanklin et al.).

[0294] The borate anions useful in these photoinitiators may generally have the formula R 1 R 2 R 3 R 4 B - , where R 1 、R 2 、R 3 and R 4 R can independently be an alkyl group, an aryl group, an alkaryl group, an allyl group, an aralkyl group, an alkenyl group, an alkynyl group, an alicyclic group, and a saturated or unsaturated heterocyclic group. 2 、R 3 and R 4 is an aryl group and more preferably a phenyl group, and R 1 is an alkyl group and more preferably a secondary alkyl group.

[0295] The cationic counter ion can be a cationic dye, a quaternary ammonium group, a transition metal coordination complex, etc. The cationic dye used as the counter ion can be a cationic methine, polymethylene, triarylmethylene, indoline, thiazine, xanthene, oxazine or acridine dye. More specifically, the dye can be a cationic cyanine, carbocyanine, hemicyanine, rhodamine and azomethine dye. The specific example of useful cationic dyes includes azurite, safranin O and malachite green. The quaternary ammonium group used as the counter ion can be trimethyl hexadecyl ammonium, cetylpyridinium and tetramethyl ammonium. Other organophilic cations can include pyridinium, phosphonium and sulfonium.

[0296] Photosensitive transition metal coordination complexes that can be used include complexes of cobalt, ruthenium, osmium, zinc, iron, and iridium with ligands such as pyridine, 2,2′-bipyridine, 4,4′-dimethyl-2,2′-bipyridine, 1,10-phenanthroline, 3,4,7,8-tetramethylphenanthroline, 2,4,6-tris(2-pyridyl-s-triazine), and related ligands.

[0297] In an alternative, heat may be used to initiate the hardening or polymerization of the free radical active groups.

[0298] Examples of heat sources suitable for use in the dental materials of the present invention include induction, convection, and radiation.The heat source should be capable of generating a temperature of at least 40°C to 15°C under normal conditions or under elevated pressure.

[0299] Heat curing procedures are sometimes preferred for initiating polymerization of materials that occurs outside the oral environment, for example, when the composition is used to produce mill blanks or in a post-curing step of an article obtained by processing the composition into a resin in a laminate manufacturing process.

[0300] The components of the photoinitiator system are typically present in the following amounts: at least 0.1 wt%, or 0.2 wt%, or 0.3 wt%; up to 4 wt%, or 3 wt%, or 2 wt%; in the range of 0.1 wt% to 4 wt%, or 0.2 wt% to 3 wt%, or 0.3 wt% to 2 wt%; wt% relative to the dental composition.

[0301] Alternatively or additionally, the dental composition may be cured by use of a redox initiator system.

[0302] Initiators that rely on redox reactions are often referred to as “self-cure catalysts” or “dark cure catalysts.” To avoid premature curing of the dental composition, the two main components of this system (oxidizing agent and reducing agent) should be kept separate during storage of the dental composition.

[0303] As the oxidizing component, a peroxy component such as peroxide is generally used. Organic peroxides that can be used include diperoxides and hydroperoxides.

[0304] According to one embodiment, the organic peroxide is a diperoxide, preferably a diperoxide comprising the moiety R1-OO-R2-OO-R3, wherein R1 and R3 are independently selected from H, alkyl (e.g., C1 to C6), branched alkyl (e.g., C1 to C6), cycloalkyl (e.g., C5 to C6), 10 ), alkylaryl (e.g., C7 to C 12 ) or aryl (e.g., C6 to C 10 ), and R2 is selected from an alkyl group (eg, C1 to C6) or a branched alkyl group (eg, C1 to C6).

[0305] Examples of suitable organic diperoxides include 2,2-di-(tert-butylperoxy)butane and 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, and mixtures thereof.

[0306] According to another embodiment, the organic peroxide is a hydroperoxide, in particular a hydroperoxide comprising the moiety

[0307] ROOH

[0308] Where R is (for example, C1 to C 20 ) alkyl, (e.g., C3 to C 20 ) branched alkyl, (e.g., C6 to C 12 ) cycloalkyl, (e.g., C7 to C 20 ), alkylaryl (e.g., C6 to C 12 ) or aryl (e.g., C6 to C 12 ).

[0309] Examples of suitable organic hydroperoxides include tert-butyl hydroperoxide, tert-amyl hydroperoxide, p-diisopropylbenzene hydroperoxide, cumene hydroperoxide, pinane hydroperoxide, p-methane hydroperoxide, and 1,1,3,3-tetramethylbutyl hydroperoxide, and mixtures thereof.

[0310] The use of hydroperoxides is sometimes preferred, particularly for formulating self-adhesive compositions.

[0311] Other peroxides that can be used are ketone peroxides, diacyl peroxides, dialkyl peroxides, peroxyketals, peroxyesters and peroxydicarbonates.

[0312] Examples of the ketone peroxide include methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, methyl cyclohexanone peroxide, and cyclohexanone peroxide.

[0313] Examples of peroxyesters include α-cumyl peroxyneodecanoate, t-butyl peroxypivalate, t-butyl peroxyneodecanoate, 2,2,4-trimethylpentyl peroxy-2-ethylhexanoate, t-pentyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, di-t-butyl peroxyisophthalate, di-t-butyl peroxyhexahydroterephthalate, t-butyl peroxy-3,3,5-trimethylhexanoate (TBPIN), t-butyl peroxyacetate, t-butyl peroxybenzoate, and t-butyl peroxymaleate.

[0314] Examples of peroxydicarbonates include di-3-methoxyperoxydicarbonate, di-2-ethylhexyl peroxydicarbonate, bis(4-tert-butylcyclohexyl)peroxydicarbonate, diisopropyl-1-peroxy-dicarbonate, di-n-propyl peroxydicarbonate, di-2-ethoxyethyl-peroxydicarbonate, and diallyl peroxydicarbonate.

[0315] Examples of the diacyl peroxide include acetyl peroxide, benzoyl peroxide, decanoyl peroxide, 3,3,5-trimethylhexanoyl peroxide, 2,4-dichlorobenzoyl peroxide, and lauroyl peroxide.

[0316] Examples of the dialkyl peroxide include di-tert-butyl peroxide, dicumyl peroxide, tert-butylcumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 1,3-bis(tert-butylperoxyisopropyl)benzene, and 2,5-dimethyl-2,5-di(tert-butylperoxy)-3-hexane.

[0317] Examples of peroxyketals include 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, 2,2-bis(tert-butylperoxy)octane, and n-butyl 4,4-bis(tert-butylperoxy)valerate.

[0318] If present, the peroxy component is typically present in an amount of 0.1% to 5% or 0.25 to 4% by weight of the dental composition.

[0319] In addition to the peroxide component, other oxidizing components may also be present, such as a persulfate component, in particular a water-soluble persulfate component.

[0320] The persulfate salts that can be used can be characterized by the formula D2S2O8, wherein D is selected from Li, Na, K, NH4, NR4, and wherein R is selected from H and CH3. Examples of persulfates that can be used include Na2S2O8, K2S2O8, (NH4)2S2O8, and mixtures thereof.

[0321] If present, the persulfate component is typically present in an amount of 0.1 wt% to 5 wt% or 0.25 wt% to 4 wt%.

[0322] As reducing agents, barbituric acid or thiobarbituric acid components, in particular their corresponding salts, can be used. Suitable barbituric acid components can be characterized by the following formula:

[0323]

[0324] wherein R1, R2 and R3 are independently selected from hydrogen, alkyl, substituted alkyl, alkenyl, cycloalkyl, substituted cycloalkyl, arylalkyl, aryl or substituted aryl; X is oxygen or sulfur; and Y is a metal cation or an organic cation.

[0325] The salt may comprise a metal cation or an inorganic cation. Suitable metal cations include those that provide a stable cation M + 、M 2+ or M 3+ Some possible inorganic cations include cations of Li, Na, K, Mg, Ca, Sr, Ba, Al, Fe, Cu, Zn, or La.

[0326] Examples of suitable barbituric acid components or thiobarbituric acid components include barbituric acid, thiobarbituric acid, 1,3,5-trimethylbarbituric acid, 1-phenyl-5-benzylbarbituric acid, 1-benzyl-5-phenylbarbituric acid, 1,3-dimethylbarbituric acid, 1,3-dimethyl-5-phenylbarbituric acid, 1-cyclohexyl-5-ethylbarbituric acid, 5-laurylbarbituric acid, 5-butylbarbituric acid, 5-allylbarbituric acid, 5-phenylthiobarbituric acid, 1,3-dimethylthiobarbituric acid, triclobarbituric acid, 5-nitrobarbituric acid, 5-aminobarbituric acid, and 5-hydroxybarbituric acid.

[0327] An exemplary salt is the calcium salt of 1-benzyl-5-phenyl-barbituric acid. Another example of a suitable barbiturate is the sodium salt of 1-benzyl-5-phenyl-barbituric acid. A possible salt is the calcium salt of 5-phenyl-thiobarbituric acid.

[0328] The salt may also contain an organic cation. Suitable possible organic cations include amine cations, such as ammonium cations or alkylammonium cations. An example is the triethanolammonium salt of 1-benzyl-5-phenyl-barbituric acid.

[0329] If present, the barbituric acid or thiobarbituric acid component is typically present in an amount of 0.1% to 3% or 0.5% to 2% by weight of the dental composition.

[0330] Other reducing agents that may be used include aromatic sulfinates or thiourea components.

[0331] Suitable sulfinic acid components may have the formula

[0332] R 1 SOO-R 2 ,

[0333] where R 1 is an alkyl, substituted alkyl, alkenyl, cycloalkyl, substituted cycloalkyl, arylalkyl, aryl or substituted aryl radical, and R 2 =H, a metal (such as lithium, sodium or potassium), or an alkyl, substituted alkyl, alkenyl, cycloalkyl, substituted cycloalkyl, arylalkyl, aryl or substituted aryl radical.

[0334] If the free radical R 1 or R 2 If one of the radicals is an unsubstituted alkyl radical, the radical may be straight-chain or branched and may contain, for example, 1 to 18 carbon atoms, preferably 1 to 10, in particular 1 to 6 carbon atoms. Examples of low molecular weight alkyl radicals are methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, isobutyl, n-pentyl and isopentyl.

[0335] If the free radical R 1 or R 2 is a substituted alkyl radical, the alkyl portion of the radical generally has the number of carbon atoms indicated above for unsubstituted alkyl. 1 or R 2 If one of the radicals R is an alkoxyalkyl radical or an alkoxycarbonylalkyl radical, the alkoxy radical contains, for example, 1 to 5 carbon atoms and is preferably a methyl radical, an ethyl radical, a propyl radical, an isopropyl radical, an n-butyl radical, a tert-butyl radical, an isobutyl radical, an n-pentyl radical or an isopentyl radical. 1 or R 2 If one of the groups is a haloalkyl, the halo portion is understood to be fluorine, chlorine, bromine or iodine.

[0336] If the free radical R 1 or R 2 If one of the radicals R is alkenyl, it is typically a C3 to C5 alkenyl radical, especially allyl. 1 or R 2 If one of the radicals R is unsubstituted cycloalkyl, it is typically a C4 to C7 cycloalkyl radical such as cyclopentyl or cyclohexyl. 1 or R 2 If one of the radicals R is a substituted cycloalkyl radical, it is typically one of the cycloalkyl radicals described above, where the substituents on the cycloalkyl radical may be, for example, C1 to C4 alkyl (such as methyl, ethyl, propyl, n-butyl or isobutyl), fluorine, chlorine, bromine, iodine or C1 to C4 alkoxy, especially methoxy. 1 or R 2If one of the radicals is aryl or aralkyl, it is typically phenyl or naphthyl as the aryl radical. Preferred arylalkyl radicals include benzyl and phenylethyl.

[0337] If necessary, R 1 or R 2 Substituted aryl radicals are also possible. In this case, phenyl and naphthyl are preferred, and as ring substituents, C1 to C4 alkyl, especially methyl, halogen or C1 to C4 alkoxy, especially methoxy.

[0338] In particular, the following components have been found to be useful: benzenesulfinic acid, sodium benzenesulfinic acid, sodium benzenesulfinic acid dihydrate, sodium toluenesulfinic acid, formamidinesulfinic acid, the sodium salt of hydroxymethanesulfinic acid, the sodium salt of 2,5-dichlorobenzenesulfinic acid, 3-acetamido-4-methoxybenzenesulfinic acid, with sodium toluenesulfinic acid or sodium benzenesulfinic acid and their hydrates sometimes being preferred.

[0339] If present, the sulfinic acid component is typically present in an amount of 0.1% to 3% or 0.5% to 2% by weight of the dental cement composition.

[0340] Suitable thiourea components include 1-ethyl-2-thiourea, tetraethylthiourea, tetramethylthiourea, 1,1-dibutylthiourea, and 1,3-dibutylthiourea, and mixtures thereof.

[0341] If desired, the dental cement composition may contain a combination or mixture of different reducing agents, including a combination of a barbituric acid component and a sulfinic acid component.

[0342] In addition to the above-mentioned components, the redox initiator system may also comprise an activator.

[0343] Suitable activators include aromatic tertiary amines such as N,N-bis(hydroxyalkyl)-3,5-dimethylaniline (e.g., described in U.S. Pat. No. 3,541,068) and N,N-bis(hydroxyalkyl)-3,5-di-tert-butylaniline, in particular N,N-bis([β]-oxybutyl)-3,5-di-tert-butylaniline and N,N-bis(hydroxyalkyl)-3,4,5-trimethylaniline.

[0344] If desired and for acceleration, the polymerization may also be carried out in the presence of a transition metal component. Suitable transition metal components include organic and / or inorganic salts of vanadium, chromium, manganese, iron, cobalt, nickel and / or copper, with copper, iron and vanadium sometimes being preferred.

[0345] According to one embodiment, the transition metal component is a copper-containing component. The oxidation stage of copper in the copper-containing component is preferably +1 or +2.

[0346] Typical examples of usable copper components include copper salts and complexes, including copper acetate, copper chloride, copper benzoate, copper acetylacetonate, copper naphthenate, copper carboxylate, bis(1-phenylpentane-1,3-dione)copper complex (copper iron proteinate), copper ethylhexanoate, copper salicylate, copper complex with thiourea, ethylenediaminetetraacetic acid, and / or mixtures thereof. The copper compound can be used in a hydrated form or anhydrous form.

[0347] Copper(II) acetate, bis(1-phenylpentane-1,3-dione)copper complex (copperferronite), and copper ethylhexanoate are sometimes particularly preferred.

[0348] According to one embodiment, the transition metal component is an iron-containing component. The oxidation stage of the iron in the iron-containing component is preferably +2 or +3.

[0349] Typical examples of usable iron-containing components include iron salts and complexes including iron (III) sulfate, iron (III) chloride, iron carboxylates, iron naphthenates, iron (III) acetylacetonate, including hydrates of these salts.

[0350] According to one embodiment, the transition metal component is a vanadium-containing component. The oxidation stage of the vanadium in the vanadium-containing component is preferably +4 or +5.

[0351] Typical examples of vanadium components that can be used include salts and complexes of vanadium, including vanadium acetylacetonate, vanadyl acetylacetonate, vanadyl stearate, vanadium naphthenate, vanadium benzoylacetonate, vanadyl oxalate, bis(maltosyl)oxyvanadium(IV), oxybis(1-phenyl-1,3-butanedione)vanadium(IV), triisopropoxyvanadium(V), ammonium(V)metavanadate, sodium(V)metavanadate, vanadium(V) pentoxide, vanadium(IV)tetroxide and vanadyl(IV) sulfate, and mixtures thereof, with vanadium acetylacetonate, vanadyl acetylacetonate and bis(maltosyl)oxyvanadium(IV) sometimes being preferred.

[0352] Suitable redox initiator systems are also described in US 2003 / 008967 A1 (Hecht et al.), US 2004 / 097613 A1 (Hecht et al.), US 2019 / 000721 A1 (Ludsteck et al.). The contents of these references are incorporated herein by reference.

[0353] The compositions may also contain suitable adjuvants or additives such as surfactants, rheology modifiers, retarders, stabilizers, pigments, dyes, photobleachable colorants, fluoride-releasing agents, solvents and other ingredients known to those skilled in the art.

[0354] Surfactants that may be added include polyethylene glycol-modified silicones (e.g., Silwet ™ type surfactants) and polyethylene glycol-modified carbosilanes (described, for example, in US 5,750,589 (Zech et al.)).

[0355] Rheology modifiers that may be added include surface-modified fumed silica as described above, organophilic phyllosilicates, modified ureas, and polyhydroxycarboxamides (e.g., Rheobyk® available from Byk-Chemie, Wesel, Germany). ™ type), dibenzylidene sorbitol, and diamide (e.g., Thixatrol available from Elementis, East Windsor, New Jersey, USA). ™ type).

[0356] Retarder that may be added includes 1,2-diphenylethylene and its derivatives.

[0357] Stabilizers that can be used include, in particular, free radical scavengers, such as substituted and / or unsubstituted hydroxyaromatic compounds (e.g., butylated hydroxytoluene (BHT), hydroquinone, hydroquinone monomethyl ether (MEHQ), 3,5-di-tert-butyl-4-hydroxy-anisole (2,6-di-tert-butyl-4-ethoxyphenol), 2,6-di-tert-butyl-4-(dimethylamino)methylphenol or 2,5-di-tert-butylhydroquinone, 2-(2'-hydroxy-5'-methylphenyl) )-2H-benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)-2H-benzotriazole, 2-hydroxy-4-methoxybenzophenone (UV-9), 2-(2'-hydroxy-4',6'-di-tert-amylphenyl)-2H-benzotriazole, 2-hydroxy-4-n-octyloxybenzophenone, 2-(2'-hydroxy-5'-methacryloyloxyethylphenyl)-2H-benzotriazole, phenothiazine and hindered amine light stabilizers (HALS).

[0358] Pigments and / or dyes that can be used include titanium dioxide or zinc sulfide (lithopone), red iron oxide 3395, Bayferrox ™ 920 Z yellow, Neazopon ™ Blue 807 (a copper phthalocyanine-based dye) or Helio ™ Fast Yellow ER. These additives can be used for individual coloring of the composition.

[0359] Examples of photobleachable colorants include Rose Bengal, Amethysine, Amethysine Blue, Fluorescein, Eosin Yellow, Eosin Y, Ethyleosin, Eosin Blue, Eosin B, Erythrosine B, Erythrosine Yellow blends, Toluidine Blue, 4',5'-dibromofluorescein, and blends thereof. Other examples of photobleachable colorants can be found in US 6,444,725 (Trom et al.).

[0360] Examples of fluoride-releasing agents include naturally occurring or synthetic fluoride minerals.These fluoride sources may optionally be treated with a surface treatment agent.

[0361] The solvents that may be present include linear, branched or cyclic saturated or unsaturated alcohols, ketones, esters, ethers or mixtures of two or more of these types of solvents having 2 to 10 carbon atoms. Preferred alcoholic solvents include methanol, ethanol, isopropanol and n-propanol. Other suitable organic solvents are THF, acetone, methyl ethyl ketone, cyclohexanol, toluene, alkanes and alkyl acetates, in particular ethyl acetate.

[0362] The presence of these additives is not required and therefore no additives may be present at all. However, if present, they are generally present in amounts that are not deleterious for their intended purpose.

[0363] The additive is typically present in an amount of at least 0 wt%, or 0.01 wt%, or 0.1 wt%; up to 20 wt%, or 15 wt%, or 10 wt%; in a range of 0 wt% to 20 wt%, or 0.01 wt% to 15 wt%, or 0.1 wt% to 10 wt%; wt% relative to the dental composition.

[0364] The dental composition comprises, consists essentially of, or consists of the following components:

[0365] a. in particular an amount of 40% to 80% by weight of a surface-treated filler,

[0366] b. in particular an amount of 5% to 50% by weight of a curable component,

[0367] c. an initiator system suitable for curing the curable component, in particular in an amount of 0.1% to 5% by weight,

[0368] d. in particular an amount of 0% to 10% by weight of additives,

[0369] Weight % is relative to the weight of the dental composition.

[0370] The dental compositions described herein are generally prepared by combining or mixing together the respective components (ie, the polymerizable component of the resin matrix, the filler, and the initiator component) with other optional components such as additives. Typically, the resin matrix is provided first and then the filler is added.

[0371] If necessary, a high-speed mixer can be used. Depending on the components to be mixed, mixing is carried out under dark conditions. Mixing also includes kneading. If necessary, during mixing or at the end of mixing, a vacuum can be applied to remove air introduced during mixing or kneading.

[0372] The dental compositions described herein are generally for use in a method of restoring a tooth in the oral cavity of a mammal, wherein the dental composition is as described herein, and wherein the method comprises the steps of:

[0373] a) contacting a dental composition with the surface of a tooth to be restored,

[0374] b) curing the dental composition by applying radiation.

[0375] More particularly, the method may comprise the following steps:

[0376] a) applying the dental composition to the surface of the hard dental tissue; if desired, the surface of the hard dental tissue can be an etched surface (e.g., with phosphoric acid) or a non-etched surface,

[0377] b) optionally spreading the dental composition onto the film, preferably using a stream of air,

[0378] c) Radiation curing of dental compositions.

[0379] For the curing step, a dental curing light is typically used. The radiation typically has a wavelength in the range of 400 nm to 800 nm and is applied for a time period in the range of 5 seconds to 1 minute.

[0380] The dental compositions are particularly suitable for use in the dental and orthodontic fields.The dental compositions can be used as or for producing dental restorations.

[0381] Examples of dental restorations include direct restorative materials (e.g., anterior and posterior restorations), prostheses, veneers, artificial crowns, artificial teeth, dentures, and the like.

[0382] As used herein, the term "prosthesis" refers to a composite that is shaped and polymerized for its ultimate use (eg, as a crown, bridge, veneer, inlay, onlay, etc.) prior to placement adjacent to a tooth.

[0383] When applying the dental material to the teeth, the teeth may optionally be pretreated with a primer such as a dentin or enamel adhesive by methods known to those skilled in the art.

[0384] In particular, the dental composition can be used as a composite filling material, a cavity liner, or a fixing material for orthodontic appliances.

[0385] The term "composite filling material" refers to a dental composition that is filled. Dental composites are commonly used to repair missing tooth structure in a patient's mouth.

[0386] "Cavity liner" refers to a composition used to protect the dental pulp prior to the application of a composite filling material or dental restoration.

[0387] In a preferred aspect, the dental material is a low viscosity dental filling material.

[0388] Another aspect of the present invention relates to the use of a surface-treated filler as described herein for reducing the viscosity of a dental composition comprising a curable component and an amount of filler of 40% to 80% by weight relative to the weight of the dental composition.

[0389] If no rheology modifier is present, the surface treated fillers are particularly useful for producing hardenable dental compositions having a filler content of 40% to 80% by weight and a flow rate of 100 % at 25°C and 0.01 s -1 At a shear rate of 5Pa s to 1,500Pa s viscosity.

[0390] In another aspect, the present invention relates to the following embodiments:

[0391] Implementation Plan 1

[0392] A dental composition comprising, consisting essentially of, or consisting of:

[0393] an amount of 40% to 80% by weight of a surface-treated filler,

[0394] an amount of 5% to 50% by weight of a curable component selected from the group consisting of a polymerizable component comprising an acidic moiety, a polymerizable component not comprising an acidic moiety, and mixtures thereof,

[0395] an initiator system suitable for curing the curable component in an amount of 0.1% to 5% by weight, comprising a photoinitiator system and / or a redox initiator system,

[0396] an additive in an amount of 0% to 10% by weight,

[0397] % by weight relative to the weight of the dental composition,

[0398] The surface treatment agent is characterized by the following features:

[0399] Contains only one (meth)acrylate moiety,

[0400] contains at least one trimethoxysilane or triethoxysilane moiety,

[0401] Contains only one carbamate moiety,

[0402] comprising one linear alkylene moiety AM1 connecting said (meth)acrylate moiety to said urethane moiety, said linear alkylene moiety AM1 comprising 6 to 12 C atoms,

[0403] Comprising one linear alkylene moiety AM2 linking said at least one trimethoxysilane or triethoxysilane moiety to said carbamate moiety, said linear alkylene moiety AM2 comprising 1 to 4 C atoms.

[0404] Implementation Plan 2

[0405] A dental composition comprising, consisting essentially of, or consisting of:

[0406] % to 80% by weight of a surface-treated filler, the filler particles being selected from the group consisting of non-aggregated, non-agglomerated nanosized particles of SiO2, ZrO2, or mixtures thereof, aggregated nanosized particles of SiO2, ZrO2, or mixtures thereof, agglomerated nanosized particles of SiO2, ZrO2, Al2O3, or mixtures thereof, non-acid-reactive particles of glass, silica, metal oxides, or mixtures thereof, acid-reactive particles of glass, metal oxides and hydroxides, or mixtures thereof,

[0407] an amount of 5% to 50% by weight of a curable component selected from the group consisting of a polymerizable component comprising an acidic moiety, a polymerizable component not comprising an acidic moiety, and mixtures thereof,

[0408] an initiator system suitable for curing the curable component in an amount of 0.1% to 5% by weight, comprising a photoinitiator system and / or a redox initiator system,

[0409] an additive in an amount of 0% to 10% by weight,

[0410] % by weight relative to the weight of the dental composition,

[0411] The surface treatment agent is characterized by the following features:

[0412] Contains only one (meth)acrylate moiety,

[0413] contains at least one trimethoxysilane or triethoxysilane moiety,

[0414] Contains only one carbamate moiety,

[0415] comprising one linear alkylene moiety AM1 connecting said (meth)acrylate moiety to said urethane moiety, said linear alkylene moiety AM1 comprising 6 to 12 C atoms,

[0416] Comprising one linear alkylene moiety AM2 linking said at least one trimethoxysilane or triethoxysilane moiety to said carbamate moiety, said linear alkylene moiety AM2 comprising 1 to 4 C atoms.

[0417] Implementation Plan 3

[0418] A dental composition comprising, consisting essentially of, or consisting of:

[0419] an amount of 40% to 80% by weight of a surface-treated filler,

[0420] an amount of 5% to 50% by weight of a curable component selected from the group consisting of a polymerizable component comprising an acidic moiety, a polymerizable component not comprising an acidic moiety, and mixtures thereof,

[0421] an initiator system suitable for curing the curable component in an amount of 0.1% to 5% by weight, comprising a photoinitiator system and / or a redox initiator system,

[0422] an additive in an amount of 0% to 10% by weight,

[0423] % by weight relative to the weight of the dental composition,

[0424] The surface treatment agent is characterized by the following formula:

[0425] H2C=CHR 1 -CO-O-(CH2) n -X-CO-Y-(CH2) m -Si(R 2 ) o (R 3 ) 3-o

[0426] where R 1 =H or CH3; R 2 = independently selected from Cl, Br, OC 1-4 Alkyl, OC 1-4 Acyl; R 3 = independently selected from C 1-4 Alkyl; X=O; Y=NH; n=6 to 12; m=1 to 4; o=1 to 3.

[0427] Implementation Plan 4

[0428] A dental composition comprising, consisting essentially of, or consisting of:

[0429] a surface-treated filler in an amount of 40 to 80 wt. %, wherein the filler particles are selected from aggregated nano-sized particles of SiO2, ZrO2 or a mixture thereof, agglomerated nano-sized particles of SiO2, ZrO2, Al2O3 or a mixture thereof,

[0430] an amount of 5% to 50% by weight of a curable component selected from the group consisting of a polymerizable component comprising an acidic moiety, a polymerizable component not comprising an acidic moiety, and mixtures thereof,

[0431] an initiator system suitable for curing the curable component in an amount of 0.1% to 5% by weight, comprising a photoinitiator system and / or a redox initiator system,

[0432] an additive in an amount of 0% to 10% by weight,

[0433] % by weight relative to the weight of the dental composition,

[0434] The surface treatment agent is characterized by the following features:

[0435] Contains only one (meth)acrylate moiety,

[0436] contains at least one trimethoxysilane or triethoxysilane moiety,

[0437] Contains only one carbamate moiety,

[0438] comprising one linear alkylene moiety AM1 connecting said (meth)acrylate moiety to said urethane moiety, said linear alkylene moiety AM1 comprising 6 to 12 C atoms,

[0439] Comprising one linear alkylene moiety AM2 linking said at least one trimethoxysilane or triethoxysilane moiety to said carbamate moiety, said linear alkylene moiety AM2 comprising 1 to 4 C atoms.

[0440] The dental compositions described herein typically do not contain bisphenol A glycidyl methacrylate (Bis-GMA), in particular in an amount of 1 wt. % or more relative to the weight of the dental composition.

[0441] Dental compositions are typically provided to practitioners under sanitary conditions. During storage, the compositions are typically packaged in suitable packaging and / or delivery devices.

[0442] A kind of possibility of realizing this point comprises packaging or storing the composition in a sealed container.Suitable container can have front and rear end, can move piston in the container and be used to deliver or distribute the nozzle or cannula of the composition in the container.This container only has a compartment or reservoir usually.The volume of container is usually in the scope of 0.1ml to 100ml or 0.5ml to 50ml or 1ml to 30ml.

[0443] Suitable disposable containers can have a volume in the range of 0.05 ml to 1 ml. This is the volume typically required for a single administration protocol. Such containers are typically used only once (e.g., disposable packaging).

[0444] The composition can be dispensed from the container by moving the piston in the direction of the nozzle. The piston can be moved manually or with the aid of an applicator or applicator designed to receive the container (for example, an applicator having a caulking gun design).

[0445] Examples of containers that can be used include pressurized capsules, syringes, and screw-on tubes.

[0446] A capsule typically has a cylindrical housing with front and rear ends and a nozzle. The rear end of the housing is typically sealed by a movable piston. Typically, dental composition is dispensed from the capsule or container using an applicator with a movable plunger (e.g., an applicator in the shape of a caulking gun).

[0447] Examples of suitable bladders or containers are described in US 5,624,260 (Wilcox et al.), EP 1 340 472 Al (Centrix), US 2007 / 0172789 Al (Mueller et al.), and US 5,865,803 (Major). Other suitable containers are exemplified in US 5,927,562 (Hammen et al.) and US 2011 / 151403 Al (Pauser et al.).

[0448] It is advantageous if the container used comprises a nozzle of a shape and size which allows an easy and safe application of the composition to the soft dental tissue surrounding the tooth to be restored, also in the vicinity of the interdental area.

[0449] The smaller the diameter of the nozzle, the easier it is to place the nozzle in the area between two teeth. However, a small diameter nozzle may result in an increase in the extrusion force required to dispense the composition out of the device. Therefore, not all cannula sizes and diameters are equally suitable. It has been found that devices with nozzles or cannulae having an outer diameter in the range of 0.6 mm to 1.3 mm and an inner diameter in the range of 0.2 mm to 0.9 mm are particularly useful.

[0450] Flowable dental composites are usually stored in packaging material having a syringe shape.

[0451] The packaging device may also comprise two compartments, wherein each compartment is equipped with a nozzle for delivering the composition or portion stored therein. Once delivered in sufficient portions, the portions may be mixed manually on a mixing plate.

[0452] Packaging devices having two compartments are particularly suitable for storing and delivering two-part compositions, i.e., compositions that need to be kept separate prior to use to avoid undesired polymerization. Two-part compositions are typically cured by redox initiator systems, wherein the part containing the oxidizing agent is kept separate from the part containing the reducing agent.

[0453] The packaging device may have an interface for receiving a static mixing tip. The mixing tip is used to mix the respective compositions.

[0454] The packaging device generally comprises two housings or compartments having a front end and a rear end with a nozzle and at least one piston movable in the housings or compartments.

[0455] Cartridges that can be used are also described, for example, in US 2007 / 0090079 A1 or US 5,918, 772. Some cartridges that can be used are commercially available, for example, from the Sulzer Mixpac company (Switzerland).

[0456] Static mixing tips that can be used are described, for example, in US 2006 / 0187752 A1 or US 5944419, the disclosures of which are incorporated by reference.Usable mixing tips are also commercially available from Sulzer Mixpac (Switzerland).

[0457] Other suitable storage devices are described, for example, in WO 2010 / 123800 A1 (3M), WO 2005 / 016783 A1 (3M), WO 2007 / 104037 A1 (3M), WO 2009 / 061884 A1 (3M), in particular the device shown in FIG 14 of WO 2009 / 061884 A1 (3M) or WO 2015 / 073246 A1 (3M), in particular the device shown in FIG 1 of WO 2015 / 07346 A1. These storage devices have the shape of a syringe.

[0458] The present invention also relates to a kit comprising the dental composition described herein and the following, alone or in combination: a dental adhesive; a dental curing light; an applicator.

[0459] Dental adhesives are generally of relatively low viscosity (eg, 0.01 Pa at 25°C). s to 3Pa Dental adhesives interact directly with the enamel or dentin surface of a tooth. Dental adhesives are typically one-part compositions that are radiation-curable and contain an ethylenically unsaturated component having an acidic moiety, an ethylenically unsaturated component not having an acidic moiety, water, a sensitizer, a reducing agent, and additives.

[0460] Examples of dental adhesives are described in US 2020 / 0069532 A1 (Thalacker et al.) and US 2017 / 0065495 A1 (Eckert et al.). Dental adhesives are also commercially available, for example from 3M ™ Scotchbond ™ Universal (3M Oral Care).

[0461] Suitable dental curing lights are described in US 10,758,126 B2 (Geldmacher et al.) or US 10,231,810 B2 (Gramann et al.). Dental curing lights are also commercially available, for example from 3M ™ Elipar ™ S10 or 3M ™ Elipar ™ DeepCure S LED curing light (3M Oral Care).

[0462] Suitable applicators include, for example, brushes, spatulas, syringes, and other suitable devices known to those skilled in the art.

[0463] The entire disclosures of the patents, patent documents, and publications cited herein are incorporated by reference in their entirety, as if each were incorporated individually. Various modifications and variations of the present invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. The above specifications, examples, and data provide a description of the manufacture and use of the compositions of the present invention and the methods of the present invention. The present invention is not limited to the embodiments disclosed herein. Those skilled in the art will appreciate that many alternative embodiments of the present invention may be prepared without departing from the spirit and scope of the present invention.

[0464] The following examples are given to illustrate the present invention.

[0465] Example

[0466] Unless otherwise noted, all parts and percentages are by weight, all water is deionized, and all molecular weights are weight average molecular weight. In addition, all experiments were performed under ambient conditions (23°C; 1013 mbar) unless otherwise noted.

[0467] method

[0468] Viscosity

[0469] Viscosity measurements were performed on a rheometer equipped with a plate-plate system (d = 15 mm or 20 mm) at 25°C using a 0.2 mm gap and a ramped shear from 100 / s to 0.008 / s in 1 minute.

[0470] Particle size (applicable to micron-sized particles)

[0471] If desired, the particle size distribution, including the particle size per volume (d50), can be determined by laser diffraction using a Mastersizer 2000 (Malvern) particle size analyzer, applying the Fraunhofer approximation. Ultrasound is typically used to accurately disperse the sample during measurement. For water-insoluble particles, water is typically used as the dispersant.

[0472] Particle size (applicable to nano-sized particles)

[0473] If desired, particle size measurements can be performed using a light scattering particle size analyzer equipped with a red laser having a wavelength of 633 nm (available from Malvern Instruments Inc., Westborough, MA under the trade designation "ZETA SIZER-Nano Series, Model ZEN3600"). Each sample is analyzed in a one square centimeter polystyrene sample cuvette. The sample is diluted 1:100, for example, 1 g of sample is added to 100 g of deionized water and mixed. The sample cuvette is filled with approximately 1 gram of the diluted sample. The sample cuvette is then placed in the instrument and equilibrated at 25°C. The instrument parameters are set as follows: dispersant refractive index 1.330, dispersant viscosity 0.8872 mPa s, a material refractive index of 1.43, and a material absorption value of 0.00 units. The automatic size measurement program is then run. The instrument automatically adjusts the laser beam position and attenuator settings to obtain the optimal particle size measurement.

[0474] A light scattering particle size analyzer illuminates a sample with laser light and analyzes the intensity fluctuations of light scattered from particles at an angle of 173 degrees. This instrument can calculate particle size using photon correlation spectroscopy (PCS). PCS uses the fluctuating light intensity to measure the Brownian motion of particles in a liquid. The particle size is then calculated as the diameter of a sphere moving at the measured velocity.

[0475] The intensity of light scattered by a particle is proportional to the sixth power of the particle diameter. The Z-average size, or cumulative mean, is the average value calculated from the intensity distribution and is based on the assumption that the particles are unimodal, monodisperse, and spherical. The correlation function calculated from the fluctuating light intensity is the intensity distribution and its mean. The mean of the intensity distribution is calculated based on the assumption that the particles are spherical. The Z-average size and the intensity distribution mean are more sensitive to larger particles than to smaller particles.

[0476] The volume distribution gives the percentage of the total particle volume that corresponds to particles within a given size range. The volume-average size is the size of the particle corresponding to the mean of the volume distribution. Since the volume of a particle is proportional to the cube of its diameter, this distribution is less sensitive to larger particles than the Z-average size. Therefore, the volume-average size is usually a smaller value than the Z-average size. Within the scope of this document, the Z-average size is referred to as the "average particle size."

[0477] pH

[0478] If necessary, the pH value can be determined as follows: Disperse 1.0 g of the material to be tested in 10 ml of deionized water and stir for about 5 minutes. Immerse a calibrated pH electrode in the suspension and measure the pH value during stirring.

[0479] Elemental composition

[0480] If desired, elemental composition can be determined by X-ray fluorescence spectroscopy (XRF), for example using a ZSX Primus II from Rigaku, Japan.

[0481] Flexural strength (FS)

[0482] If required, flexural strength can be increased by using a size 2 2 The flexural strength is determined using a three-point flexural strength test on 25 mm test specimens according to ISO 4049:2019. The flexural strength is given in MPa.

[0483] Flexural modulus (FM)

[0484] If desired, the flexural modulus can be determined in conjunction with flexural strength testing using a universal testing machine (eg, Zwick) as the slope of the linear elastic portion of the stress-strain curve. The flexural modulus is given in GPa.

[0485] Material

[0486]

[0487] Table 1

[0488] Synthesis of 11-(3-trimethoxysilylpropylcarbamoyloxy)undecyl 2-methylprop-2-enoate

[0489] (C11 methoxy)

[0490]

[0491] 11-Hydroxyundecyl 2-methylprop-2-enoate (35.0 g, 137 mmol) was charged into a 3-neck RBF 250 mL equipped with an internal thermometer and a magnetic stirrer, and 3-isocyanatopropyl-trimethoxysilane (29.0 g, 141 mmol) was added, and the mixture was stirred at 60° C. for 48 hours. Infrared absorption analysis indicated that the isocyanate was completely consumed.

[0492] Synthesis of 9-(3-trimethoxysilylpropylcarbamoyloxy)nonyl 2-methylprop-2-enoate

[0493] (C9 methoxy)

[0494]

[0495] 9-Hydroxynonyl-2-methylprop-2-enoate (35.0 g, 153 mmol) was charged into a 3-neck 250 mL RBF equipped with an internal thermometer and a magnetic stirrer, and 3-isocyanatopropyl-trimethoxysilane (32.5 g, 158 mmol) was added and the mixture was stirred for 48 hours at 60° C. Infrared absorption analysis indicated complete consumption of the isocyanate.

[0496] Synthesis of 6-(3-trimethoxysilylpropylcarbamoyloxy)hexyl 2-methylprop-2-enoate

[0497] (C6 methoxy)

[0498]

[0499] 6-Hydroxyhexyl 2-methylprop-2-enoate (35.0 g, 188 mmol) was charged into a 3-neck 250 mL RBF equipped with an internal thermometer and a magnetic stirrer, and 3-isocyanatopropyl-trimethoxysilane (40.0 g, 195 mmol) was added and the mixture was stirred for 48 hours at 60° C. Infrared absorption analysis indicated complete consumption of the isocyanate.

[0500] Synthesis of 11-(3-triethoxysilylpropylcarbamoyloxy)undecyl 2-methylprop-2-enoate become

[0501] (C11 ethoxy)

[0502]

[0503] 11-Hydroxyundecyl 2-methylprop-2-enoate (24.0 g, 93.6 mmol) was charged into a flask, 3-isocyanatopropyltriethoxysilane (23.1 g, 93.4 mmol) was added, and the mixture was stirred at 60° C. for 48 hours. Infrared absorption analysis indicated that the isocyanate was completely consumed.

[0504] Synthesis of 2-(3-trimethoxysilylpropylcarbamoyloxy)ethyl 2-methylprop-2-enoate

[0505] (C2 methoxy)

[0506]

[0507] 3-Isocyanatopropyltrimethoxysilane (34.46 g, 0.1678 mol) and K-Kat XK-672 (0.055 g, 1000 ppm based on total solids) were placed in a flask and cooled. Next, HEMA (20.54 g, 0.1578 mol) was added dropwise. The reaction was monitored by FTIR at 2265 cm -1 The presence of -NCO peak.

[0508] M-C2-U-C11-TMS

[0509] M-C2-U-C11-TMS was prepared according to US 10,975,229 Bl (column 50; comparative synthesis example 1).

[0510]

[0511] Surface treatment of fillers

[0512] Glass filler (G)

[0513] Filler GM32087 (UF 0.4), ethanol (ratio 1:2) and 1 wt% (relative to the weight of the filler) of 25% aqueous ammonia were added to the slurry and mixed in an ultrasonic bath for 3 hours before the addition of silane.

[0514] The mixture was stirred at RT for 3 h, then freed from the solvent at 45° C. in a rotary evaporator (approximately 20 mbar), sieved through a 200 μm sieve, and further evaporated at 100° C. in a rotary evaporator (approximately 20 mbar) for 1 h.

[0515] Silica-zirconia cluster fillers (SiO2 / ZrO2)

[0516] Dissolve the corresponding silane (10.5% relative to the weight of the filler) in ethyl acetate (EtOAc) or 1-methoxy-2-propanol (PGME). Use a solvent in a ratio of 100% to 200% relative to the weight of the filler. Use a magnetic stir bar to mix the silane into the solvent.

[0517] Slowly add the SiO2 / ZrO2 cluster filler to the solution, ensuring the magnetic stir bar continues to stir the solution as its viscosity increases with the addition of the filler. Once the filler is added, add 2 wt% (relative to the filler weight) of 30% aqueous ammonia to the slurry. If using EtOAc, allow the slurry to react overnight at room temperature. Pour the slurry into a glass casserole dish and dry it by evaporating the ethyl acetate in a solvent oven set at 85°C for 90 minutes. The filler is then sieved through a 70-micron sieve. If using PGME, after adding the ammonia, place the slurry on a rotary evaporator and heat to 85°C for 1 hour. Then, dry it in a glass dish like the other one.

[0518] Resin for glass filler (Re-G)

[0519] The following resins were used: BisEMA2 (68.8 wt %), UDMA (19.7 wt %), TEGDMA (9.8 wt %), CPQ (0.16 wt %), DPIFP6 (0.3 wt %), EDMAB (0.6 wt %), BHT (0.09 wt %), TR796 (0.6 wt %).

[0520] The resin composition was prepared by mixing and slightly heating the components in the dark until a clear solution was formed.

[0521] Resins for silica-zirconia cluster fillers (Re-SiO2 / ZrO2)

[0522] The following resins were used: BisEMA2 (78.6%), TEGDMA (19.65%), CPQ (0.16%), DPIFP6 (0.3%), EDMAB (0.6%), BHT (0.09%), TR796 (0.6%).

[0523] The resin composition was prepared by mixing and slightly heating the components in the dark until a clear solution was formed.

[0524] Curable composition

[0525] The surface treated filler was mixed / kneaded with the resin composition until a homogeneous composition was obtained. Mixing was performed using a Flak-Tek high speed mixer. The composition was degassed by appropriately applying a vacuum.

[0526] The content of the glass filler G in the composition Re-G was 65 wt %. The content of the cluster filler SiO 2 / ZrO 2 in the composition Re-SiO 2 / ZrO 2 was 66 wt %.

[0527] The resulting compositions were filled into syringes and centrifuged. The compositions were further analyzed for viscosity (at various shear rates), flexural strength, and flexural modulus (Tables 2 and 3).

[0528]

[0529] Table 2 - Re-SiO2 / ZrO2; CE: Comparative Examples

[0530]

[0531] Table 3 - Re-G; CE: Comparative Examples

[0532] Tables 2 and 3 show the viscosity distribution of different compositions of fillers surface treated with various silanes.

[0533] It can be seen that the use of a surface treated filler according to the invention results in a desirable low viscosity of the curable composition containing such a filler at low shear rates. A nearly Newtonian fluid behavior is observed.

[0534] On the other hand, as shown in the comparative examples, the use of surface treated fillers having short alkylene bridging moieties results in undesirably high viscosities at low shear rates.

Claims

1. A dental composition comprising a curable component and a surface-treated filler, wherein the surface-treated filler comprises filler particles whose surfaces have been treated with a surface treatment agent, wherein the surface treatment agent is characterized by: comprising at least one (meth)acrylate moiety, comprising at least one hydrolyzable silane moiety, Contains only one carbamate moiety, comprising a linear alkylene moiety AM1 connecting said at least one (meth)acrylate moiety to said urethane moiety, comprising a linear alkylene moiety AM2 linking said at least one hydrolyzable silane moiety to said carbamate moiety, and The linear alkane subunit moiety AM1 comprises more carbon atoms than the linear alkane subunit moiety AM2.

2. The dental composition according to the preceding claim, wherein the surface treatment agent is characterized by the following features: Contains only one (meth)acrylate moiety, Contains at least one hydrolyzable silane moiety, preferably selected from -Si(R 2 ) o (R 3 ) 3-o where R 2 = independently selected from Cl, Br, OC 1-4 Alkyl, OC 1-4 Acyl; R 3 = independently selected from C 1-4 Alkyl; o = 1 to 3, Contains only one carbamate moiety, comprising a linear alkylene moiety AM1 connecting said (meth)acrylate moiety to said one urethane moiety, said linear alkylene moiety AM1 comprising 6 to 12 C atoms, and Comprising one linear alkane substituent AM2 linking said at least one hydrolyzable silane substituent to said carbamate substituent, said linear alkane substituent AM2 comprising 1 to 4 C atoms.

3. The dental composition according to any one of the preceding claims, wherein the surface treatment agent is characterized by the formula: H2C=CHR 1 -CO-O-(CH2) n -X-CO-Y-(CH2) m -Si(R 2 ) o (R 3 ) 3-o where R 1 = H or CH3; R 2 = independently selected from Cl, Br, OC 1-4 Alkyl, OC 1-4 Acyl; R 3 = independently selected from C 1-4 Alkyl; X = O; Y = NH; n = 6 to 12; m = 1 to 4; o = 1 to 3.

4. The dental composition according to any one of the preceding claims, the surface treatment agent having a molecular weight Mw in the range of 300 g / mol to 800 g / mol.

5. The dental composition according to any one of the preceding claims, wherein the surface treatment agent is selected from the following molecules and mixtures thereof: 。 6. The dental composition of any one of the preceding claims, wherein the filler comprises particles selected from the group consisting of: non-aggregated and non-agglomerated nanosized particles of SiO2, ZrO2, and mixtures thereof; aggregated nanosized particles of SiO2, ZrO2, and mixtures thereof; agglomerated nanosized particles of SiO2, ZrO2, Al2O3, and mixtures thereof; non-acid-reactive particles of glass, silica, metal oxides, or mixtures thereof; acid-reactive particles of glass, metal oxides and hydroxides, and mixtures thereof; and mixtures thereof, The individual particles of the nano-sized particles have an average particle size of less than 100 nm.

7. The dental composition according to any one of the preceding claims, comprising the surface-treated filler in an amount of 40% to 80% by weight relative to the weight of the dental composition.

8. The dental composition according to any one of the preceding claims, comprising the following components: a. an amount of 40% to 80% by weight of a surface-treated filler, b. in particular an amount of 5% to 50% by weight of a curable component, c. an initiator system suitable for curing the curable component, in particular in an amount of 0.1% to 5% by weight, d. in particular an amount of 0% to 10% by weight of additives, The wt% are relative to the weight of the dental composition.

9. The dental composition according to any one of the preceding claims, comprising: % to 80% by weight of a surface-treated filler, wherein the filler particles are selected from the group consisting of: non-aggregated, non-agglomerated nanosized particles of SiO2, ZrO2, or mixtures thereof; aggregated nanosized particles of SiO2, ZrO2, or mixtures thereof; agglomerated nanosized particles of SiO2, ZrO2, Al2O3, or mixtures thereof; non-acid-reactive particles of glass, silica, metal oxides, or mixtures thereof; acid-reactive particles of glass, metal oxides and hydroxides, or mixtures thereof, wherein individual particles of the nanosized particles have an average particle size of less than 100 nm, an amount of 5% to 50% by weight of a curable component selected from the group consisting of a polymerizable component comprising an acidic moiety, a polymerizable component not comprising an acidic moiety, and mixtures thereof, an initiator system in an amount of 0.1% to 5% by weight, said initiator system being suitable for curing the curable component and comprising a photoinitiator system and / or a redox initiator system, an additive in an amount of 0% to 10% by weight, The weight % is relative to the weight of the dental composition, The surface treatment agent is characterized by the following features: Contains only one (meth)acrylate moiety, contains at least one trimethoxysilane or triethoxysilane moiety, Contains only one carbamate moiety, comprising one linear alkylene moiety AM1 connecting said (meth)acrylate moiety to said urethane moiety, said linear alkylene moiety AM1 comprising 6 to 12 C atoms, Comprising one linear alkylene moiety AM2 linking said at least one trimethoxysilane or triethoxysilane moiety to said carbamate moiety, said linear alkylene moiety AM2 comprising 1 to 4 C atoms.

10. The dental composition according to any one of the preceding claims, which does not comprise a rheology modifier, and which is characterized before hardening by the following features, alone or in combination: a. Viscosity: at 25°C and 0.01s -1 At a shear rate of 5Pa s to 1,500Pa s, b. capable of hardening within 10 minutes after irradiation with light having a wavelength in the range of 400 nm to 700 nm; c. pH value: 7 or lower.

11. The dental composition according to any one of the preceding claims, characterized after hardening by the following features, alone or in combination: a. Flexural strength: 100 MPa to 200 MPa, measured according to ISO 4049 (2019); b. Flexural modulus: 4 GPa to 8 GPa, measured according to ISO 4049 (2019).

12. A kit comprising the dental composition according to any one of the preceding claims and the following, alone or in combination: a dental adhesive; a dental curing light; an application instrument.

13. A dental composition for use in a method of restoring teeth in the oral cavity of a mammal, the dental composition being a dental composition as described in any one of claims 1 to 11, the method comprising the steps of: contacting the dental composition with the surface of the tooth to be repaired, The dental composition is cured by applying radiation.

14. A method for producing a dental composition according to any one of claims 1 to 11, comprising the steps of: optionally combining filler particles with the surface treatment agent using a dispersion, reacting the surface treatment agent with the filler particles, removing the optional dispersion, The surface treated filler particles are optionally dried and sieved.

15. Use of a surface-treated filler as described in any one of claims 1 to 11 for reducing the viscosity of a dental composition as described in any one of claims 1 to 11 at low shear rates.

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