Curable composition for use in method of treating dental condition in oral cavity of patient

Abstract

The present invention relates to a curable composition for use in a method of treating a dental condition in the oral cavity of a patient, the curable composition comprising a radiation curable component; a photoinitiator that exhibits absorption in the ultraviolet light region and exhibits absorption in the visible light region, the absorption in the ultraviolet light region being stronger than the absorption in the visible light region; optionally, a filler; optionally, an additive; the method comprises the steps of: layer-by-layer manufacturing of a dental or orthodontic article using radiation having a wavelength in the region of the ultraviolet light; attaching the dental or orthodontic article to a surface of hard dental tissue or dental material; radiation having a wavelength in the visible light region is applied to the dental or orthodontic article.

Description

Technical Field

[0001] The present invention relates to a curable composition and a related kit box used in a method for treating the dental condition in a patient's oral cavity. The curable composition comprises a radiation-curable component, a photoinitiator having a specific absorption spectrum, optional fillers and additives, and can be cured by ultraviolet light and visible light. Background Art

[0002] The use of additive manufacturing techniques, especially 3D printing for the production of dental articles, is known in the art. However, articles produced especially by 3D printing cannot be used directly, but typically require post-processing steps.

[0003] Post-processing generally includes steps such as cleaning or removing uncured resin on the article removed from the printing bath, and removing pins used to support the article in the printing method.

[0004] In addition, 3D printed articles generally need to be post-cured to obtain articles with sufficient mechanical properties. Depending on the use, the conditions for the 3D printing method and the post-curing step are different, especially regarding the wavelength of the radiation used for curing.

[0005] In the dental field, the curing of a radiation-curable composition in a patient's oral cavity can be carried out without using ultraviolet light, even though ultraviolet light is more effective, while 3D printing is typically carried out using ultraviolet light.

[0006] Therefore, depending on the intended use, it is necessary to select a suitable photoinitiator that is sensitive at the corresponding wavelengths of the light used for 3D printing and post-curing.

[0007] To meet this need, radiation-curable compositions containing two different types of photoinitiators have been proposed.

[0008] For example, WO 2013 / 153183 A2 (Ivoclar) describes the use of a composite resin composition comprising: (a) at least one multi-reactive binder; (b) a first photo-polymerization initiator having a maximum absorption at a wavelength less than 400 nm; (c) a second photo-polymerization initiator having a maximum absorption at a wavelength of at least 400 nm; and (d) an absorber having a maximum absorption at a wavelength less than 400 nm for the stereolithographic production of dental molding parts based on the composite resin. Summary of the Invention

[0009] However, there is still a need for a radiation-curable composition which, on the one hand, can be economically processed by an additive manufacturing method to obtain an article having sufficient mechanical properties and, on the other hand, allows an article to be provided which still contains a sufficient amount of uncured parts which can be used to fix the article to hard dental tissue in a light-induced adhesion manner.

[0010] If desired, the mechanical properties of an article obtained by an additive manufacturing method should also be able to mechanically manipulate the 3D printed article before further processing such as trimming or cutting.

[0011] Ideally, the degree of light scattering which is not desired during the additive manufacturing method should also be reduced.

[0012] Furthermore, it may be desirable if the 3D printed article has high flexibility after the 3D printing step, which would allow the 3D printed article to be more easily placed on another object (an object having an undercut).

[0013] The invention described in this text and the claims solves at least one of the above objects.

[0014] Specifically, the invention relates to a curable composition for use in a method of treating a dental condition in a patient's oral cavity,

[0015] The curable composition comprises

[0016] a radiation-curable component,

[0017] a photoinitiator which exhibits absorption in the ultraviolet region and absorption in the visible region, the absorption in the ultraviolet region being stronger than the absorption in the visible region,

[0018] optionally a filler,

[0019] optionally additives,

[0020] The method comprises the steps of:

[0021] performing layer-by-layer additive manufacturing of a dental or orthodontic article using radiation having a wavelength in the ultraviolet region,

[0022] attaching the dental or orthodontic article to the surface of hard dental tissue or a dental material,

[0023] applying radiation having a wavelength in the visible region to the dental or orthodontic article.

[0024] The invention also relates to a kit comprising a curable composition as used herein, a dental adhesive or cement, optionally a tooth positioning tray and optionally instructions for use.

[0025] In addition, the present invention relates to a pre-cured composition which can be obtained by processing the curable composition described in this text in a laminate manufacturing method, and the pre-cured composition has the shape of a dental or orthodontic article. Description of the Drawings

[0026] Figure 1 The UV / Vis spectrum of camphorquinone is shown.

[0027] Figure 2 The UV / Vis spectrum of phenyl-1,2-propanedione is shown.

[0028] Figure 3 The flexural strength test of a 3D printed article obtained from the curable composition described in this text is shown. Detailed Description

[0029] 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.

[0030] 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. The 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 particularly present in (meth)acrylate groups.

[0031] As used herein, "(meth)acryloyl" is an abbreviated term which refers to "acryloyl" and / or "methacryloyl". For example, the "(meth)acryloyloxy" group is an abbreviated term which refers to the acryloyloxy group (i.e., CH2=CH-C(O)-O-) and / or the methacryloyloxy group (i.e., CH2=C(CH3)-C(O)-O-).

[0032] The "carbamate group" has the structure "-NH-CO-O-".

[0033] As used herein, "harden" or "cure" a composition are used interchangeably and refer to a polymerization and / or crosslinking reaction involving one or more materials contained in the composition, including for example, a photopolymerization reaction and chemical polymerization techniques (e.g., a chemical reaction that forms free radicals that effectively polymerize ethylenically unsaturated compounds).

[0034] "Radiation curable" shall mean that the component (or composition, as the case may be) can be cured by applying radiation, preferably electromagnetic radiation in the spectral range of 350 nm to 500 nm wavelength, under ambient conditions and within a reasonable time frame (e.g., within about 15 min, 10 min or 5 min).

[0035] "Dental article" refers to an article used in the dental or orthodontic field. Dental articles typically have two different surface portions, an outer surface and an inner surface. The outer surface is the surface that is not normally in permanent contact with the tooth surface. In contrast, the inner surface is the surface used to attach or fix the dental article to the tooth. If the dental article has the shape of a crown, the inner surface typically has a concave shape, while the outer surface typically has a convex shape. Dental articles should not contain components harmful to the health of the patient and thus do not contain hazardous and toxic components that can migrate out of the dental or orthodontic article.

[0036] "Orthodontic article" includes orthodontic brackets, buccal tubes, tongue retainers, orthodontic bands, bite openers, buttons, attachments and splints.

[0037] "Hard dental tissue" includes enamel and dentin.

[0038] "Particle" means a solid substance whose shape can be geometrically determined. The shape can be regular or irregular. Particles can usually be analyzed with respect to, for example, particle size and particle size distribution.

[0039] "Agglomeration" describes the weak association of particles that are usually held together by charge or polarity and can be broken down into smaller entities. The specific surface area of agglomerated particles is essentially not different from the specific surface area of the primary particles that make up the agglomerate (see DIN 53206; 1972).

[0040] Agglomerated fillers can be obtained commercially, for example, from Degussa, Cabot Corp or Wacker under the product names Aerosil ™ , CAB-O-SIL ™ and HDK.

[0041] "Non-agglomerated or discrete filler particles" means that the filler particles are present in the resin in a discrete, non-associated (i.e., non-agglomerated and non-aggregated) phase. If desired, this can be demonstrated by TEM microscopy.

[0042] Non-agglomerated nano-sized silica can be commercially obtained, for example, from Nalco Chemical Co. (Naperville, Ill.) under the product name NALCO COLLOIDAL SILICAS, such as NALCO product numbers 1040, 1042, 1050, 1060, 2327, and 2329.

[0043] Non-agglomerated fillers are used and described, for example, in US 8,329,776 B2 (Hecht et al.). The content of this reference is incorporated herein by reference.

[0044] As used herein, "aggregation" describes the strong association of particles that are typically bound together by, for example, residual chemical treatment or partial sintering. The specific surface area of aggregated particles is generally smaller than the specific surface area of the primary particles that make up the aggregates (see DIN 53206; 1972).

[0045] A "nano filler" is a filler whose individual particles have dimensions in the nanometer range, e.g., an average particle size of less than 200 nm or less than 100 nm or less than 50 nm. Available examples are given in US 6,899,948 (Zhang et al.) and US 6,572,693 (Wu et al.). The content regarding nano-sized silica particles is incorporated herein by reference.

[0046] "Additive manufacturing" or "3D printing" means a process that includes creating an object layer by layer from digital data. The article can be of almost any shape or geometry and is produced from a three-dimensional model or other electronic data source.

[0047] There are many 3D printing technologies, one of which is vat polymerization that uses a radiation curing step to fabricate three-dimensional articles. Examples of vat polymerization techniques include stereolithography (SLA) and digital light processing (DLP).

[0048] "Stereolithography" is an example of an additive manufacturing technique in which a laser beam is typically aimed at the entire printing area using two motors, thereby curing the printing resin. This process breaks down the design layer by layer into a series of points.

[0049] "Digital light processing" is another example of an additive manufacturing technique and generally includes using a digital projector screen to flash an image of each layer on the build platform of an additive manufacturing unit. This image typically consists of square pixels, thereby producing a layer formed by small rectangular bricks called voxels.

[0050] "Ultraviolet light region" means light having a wavelength in the range of 350 nm to 410 nm.

[0051] "Visible light region" means light having a wavelength in the range of 440 nm to 500 nm.

[0052] "Environmental conditions" means the conditions to which the compositions described in this text are normally subjected during storage and handling. The environmental conditions can be, for example, a pressure of 900 mbar to 1,100 mbar, a temperature of 10 °C to 40 °C, and a relative humidity of 10% to 100%. In the laboratory, the environmental conditions are usually adjusted to 20 °C to 25 °C and 1,000 mbar to 1,025 mbar (at sea level).

[0053] As used herein, "a", "an", "the", "at least one", and "one or more" are used interchangeably. Also herein, numerical ranges expressed by endpoints include all the numbers included within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0054] Adding the "plural form" to a term means that the term shall include the singular and plural forms. For example, the term "additive" means one additive and multiple additives (e.g., 2, 3, 4, etc.).

[0055] Unless otherwise specified, all numbers used in the specification and claims to indicate amounts of ingredients, physical property measurements (such as those described below), etc. should be understood to be modified in all cases by the term "about".

[0056] When these terms appear in the specification and claims, the terms "comprising" or "including" and their variants do not have a limiting meaning. "Consisting essentially of" means that certain additional components may be present, i.e., those components that do not substantially affect the basic properties of the article or composition. "Consisting of" means that no additional components should be present. The term "including" should also include the terms "consisting essentially of" and "consisting of".

[0057] If a composition does not contain a certain component as an essential feature, the composition is "substantially or essentially free of" the component. Thus, the component itself is not intentionally added to the composition, or the component is not intentionally added to the composition together with other components or the components of other components. A composition substantially free of a certain component generally does not contain the component at all. However, sometimes a small amount of the component is inevitable, for example, due to impurities contained in the raw materials used. "Substantially free of" generally means a content of less than 1 wt%, 0.5 wt%, or 0.1 wt%.

[0058] The present invention is advantageous for several reasons:

[0059] The photoinitiators described in this text absorb not only light in the visible light region but also light in the ultraviolet light region. This is an advantage over, for example, the photoinitiator camphorquinone (CQ) Figure 1 which shows absorption mainly in the visible light region as shown.

[0060] In Figure 1 the absorption spectrum of CQ is labeled A, the emission spectrum of a typical 3D printing device is labeled B, and the emission spectrum of a typical dental curing light device is labeled C.

[0061] The photoinitiators described in this text are sensitive not only to the light commonly used in additive manufacturing devices but also to the light commonly used in dental curing lights. For the photoinitiator phenyl-1,2-propanedione (PPD), this is shown in Figure 2 .

[0062] In Figure 2 the absorption spectrum of PPD is labeled A, the emission spectrum of a typical 3D printing device is labeled B, and the emission spectrum of a typical dental curing light device is labeled C.

[0063] Furthermore, the absorption of the photoinitiator in the ultraviolet light region is high enough to obtain a pre-cured article having suitable mechanical properties, especially high flexibility.

[0064] The flexibility of the pre-cured article can even be so high that a typical flexural strength determination is not possible because the test bar used for measurement does not break. Thus, the pre-cured article can be considered to be fully elastic or rubber-elastic. This is shown in Figure 3 .

[0065] However, the obtained pre-cured article still contains a sufficient amount of uncured portions and photoinitiator, allowing the pre-cured article not only to be cured at a later stage but also to provide the option of adhesively fixing the pre-cured article to hard dental tissue or to provide the option of adhesively fixing the pre-cured article to other dental materials, where the adhesive fixing is triggered by a curing step induced by light in the visible light region.

[0066] From an aesthetic point of view, the photoinitiators described in this text are also advantageous because they are substantially colorless or only have a pale yellow color in the visible light region. Thus, the color of dental or orthodontic articles obtained by radiation curing of curable compositions containing the photoinitiator is not negatively affected or influenced and does not show an undesired color change after curing.

[0067] Since the photoinitiator is substantially colorless, the photoinitiator can also be used in relatively large amounts without negatively affecting the aesthetic properties. This allows for high process flexibility during the additive manufacturing process and, if desired, also enables a high conversion rate of the curable part.

[0068] Furthermore, since the photoinitiator exhibits high absorption and sensitivity in the ultraviolet region, the curing reaction during the additive manufacturing process proceeds rapidly, which allows for the economical production of pre-cured articles.

[0069] These properties are particularly useful in dental or orthodontic procedures that require an extraoral pre-curing and a final intraoral post-curing step, for example, for the production of preformed dental composite crowns, orthodontic attachments for clear tray aligners, and / or orthodontic brackets.

[0070] The curable compositions described in this text are used in methods for treating dental conditions in a patient's oral cavity.

[0071] The curable composition comprises one or more radiation-curable components, a photoinitiator for curing the radiation-curable components, an optional filler, and an optional additive.

[0072] The curable compositions described in this text can be characterized as single-component photocurable compositions.

[0073] The curable compositions can be further characterized by the following features, alone or in combination:

[0074] a. Viscosity: at 23 °C and a shear rate of 1 s -1 −1, <50 Pa s; or at 23 °C, a shear rate of 1 s -1 −1, in the range from 1 Pa s to less than 40 Pa s;

[0075] b. Capable of being cured by radiation having a wavelength in the range from 350 nm to 500 nm.

[0076] It has been found that the viscosity of the curable compositions within the above ranges is particularly suitable for processing the curable compositions in an additive manufacturing process.

[0077] The radiation-curable components are generally components comprising one or more ethylenically unsaturated moieties.

[0078] The radiation-curable components can be selected from (meth)acrylate components, urethane (meth)acrylate components, and mixtures thereof. Mixtures of (meth)acrylate components are sometimes preferred, and urethane (meth)acrylate components are sometimes preferred.

[0079] The radiation-curable component is usually present in the following amounts: at least 20% by weight, or at least 25% by weight or at least 30% by weight; at most 95% by weight, or at most 90% by weight or at most 80% by weight; 20% by weight to 95% by weight, or 25% by weight to 90% by weight or 30% by weight to 80% by weight; % by weight relative to the curable composition.

[0080] The curable composition may comprise one or more (meth)acrylate components that do not contain a urethane moiety.

[0081] The (meth)acrylate that does not contain a urethane moiety is different from urethane (meth)acrylate, for example in terms of functionality, chemical moiety, molecular weight or a combination thereof.

[0082] The (meth)acrylate component that does not contain a urethane moiety can generally be characterized by the following properties alone or in combination: a) containing at least 2 (meth)acrylate moieties; b) molecular weight: 170 g / mol to 1,000 g / mol.

[0083] Examples include diacrylates or polyacrylates and methacrylates, such as glycerol diacrylate, glycerol triacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, 1,3-propanediol diacrylate, 1,3-propanediol dimethacrylate, trimethylolpropane triacrylate, 1,2,4-butanetriol trimethacrylate, 1,4-cyclohexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, sorbitol hexaacrylate, bis[1-(2-acryloyloxy)]-p-ethoxyphenyldimethylmethane, bis[1-(3-acryloyloxy-2-hydroxy)]-p-propoxyphenyl-dimethylmethane; bisacrylates and bismethacrylates of polyethylene glycol with a molecular weight of 200 to 500, copolymerizable mixtures of acrylated monomers. Suitable monomers are also described in US 4,652,274 (Boettcher et al.) and US 4,642,126 (Zador et al.), the contents of which are incorporated herein by reference.

[0084] Preferred ethylenically unsaturated monomers are methacrylate and acrylate monomers, such as di(meth)acrylates of propylene glycol, butylene glycol, hexylene glycol, octylene glycol, nonylene glycol, decylene glycol and eicosanediol, di(meth)acrylates of ethylene glycol, polyethylene glycol and polypropylene glycol, di(meth)acrylates of ethoxylated bisphenol A, such as 2,2'-bis(4-(meth)acryloxytetraethoxyphenyl)propane and (meth)acrylamide. The monomers used can also be esters of [α]-cyanoacrylic acid, crotonic acid, cinnamic acid and sorbic acid.

[0085] Methacrylates may also be used, including those mentioned in US 4,795,823 (Schmitt et al.), including bis[3[4]-methacryloxymethyl-8(9)-tricyclo[5.2.1.0 2,6 decylmethyl glycolate. 2,2-bis-4(3-methacryloxy-2-hydroxypropoxy)phenyl-propane (Bis-GMA), 2,2-bis-4(3-methacryloxypropoxy)phenylpropane, triethylene glycol dimethacrylate (TEGDMA), and di(meth)acrylate of bis(hydroxymethyl)tricyclo-(5.2.1.0 2,6 )decane are also suitable.

[0086] If desired, the curable composition may further comprise a (meth)acrylate component containing only one (meth)acrylate moiety, such as methyl acrylate, methyl methacrylate, (meth)ethyl acrylate, (meth)isopropyl acrylate, (meth)n-hexyl acrylate, (meth)stearyl acrylate, (meth)allyl acrylate, di(meth)acrylate of glycerol, and mixtures thereof.

[0087] 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, mono(meth)acrylate of dialkylene glycol (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, polypropylene glycol 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, adducts of phenol and glycidyl (meth)acrylate (e.g., 1-phenoxy-2-hydroxypropyl (meth)acrylate and 1-naphthyloxy-2-hydroxypropyl (meth)acrylate). If desired, a mixture of one or more of these components may be used.

[0088] If present, and if present in combination with other polymerizable components such as urethane (meth)acrylate components, the (meth)acrylate component is typically present in the following amounts: at least 20% by weight, or at least 25% by weight or at least 30% by weight; at most 75% by weight, or at most 70% by weight or at most 65% by weight; 20% by weight to 75% by weight, or 25% by weight to 70% by weight or 30% by weight to 65% by weight; % by weight relative to the curable composition.

[0089] The curable composition may further comprise one or more urethane (meth)acrylates.

[0090] Urethane (meth)acrylates typically comprise at least two (meth)acrylate moieties and at least two urethane moieties.

[0091] The molecular weight of the urethane (meth)acrylate is typically at least 400 g / mol or at least 800 g / mol or at least 1,000 g / mol.

[0092] Useful ranges include from 400 g / mol to 3,000 g / mol, or from 800 g / mol to 2,700 g / mol or from 1,000 g / mol to 2,500 g / mol.

[0093] The urethane (meth)acrylate employed in the composition is typically obtained by reacting an NCO-terminated compound with a suitable monofunctional (meth)acrylate monomer such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, preferably hydroxyethyl methacrylate and hydroxypropyl methacrylate.

[0094] Urethane (meth)acrylates can be obtained by a variety of methods known to those skilled in the art.

[0095] For example, polyisocyanates and polyols can react to form an isocyanate-terminated urethane prepolymer, which is then reacted with a (meth)acrylate such as 2-hydroxyethyl (meth)acrylate. These types of reactions can be carried out at room temperature or higher temperatures, optionally in the presence of catalysts such as tin catalysts, tertiary amines, etc.

[0096] The polyisocyanates useful for forming the isocyanate-functional urethane prepolymer can be any organic isocyanate having at least two free isocyanate groups. This includes aliphatic, cycloaliphatic, aromatic and araliphatic isocyanates.

[0097] Any known polyisocyanates can be employed, such as alkyl and alkylene polyisocyanates, cycloalkyl and cycloalkylene polyisocyanates, and combinations such as alkylene and cycloalkylene polyisocyanates.

[0098] Preferably, a diisocyanate of the formula X(NCO)₂ is used, where X represents an aliphatic hydrocarbon group having 2 to 12 C atoms, an alicyclic hydrocarbon group having 5 to 18 C atoms, an aromatic hydrocarbon group having 6 to 16 C atoms, and / or an araliphatic hydrocarbon group having 7 to 15 C atoms.

[0099] Examples of suitable polyisocyanates include 2,2,4-trimethylhexamethylene-1,6-diisocyanate, hexamethylene-1,6-diisocyanate (HDI), cyclohexyl-1,4-diisocyanate, 4,4'-methylene-bis(cyclohexyl isocyanate), 1,1'-methylenebis(4-isocyanato)cyclohexane, isophorone diisocyanate, 4,4'-methylenediphenyl diisocyanate, 1,4-tetramethylene diisocyanate, m-tetramethylxylene diisocyanate and p-tetramethylxylene diisocyanate, 1,4-phenylene diisocyanate, 2,6-toluene diisocyanate and 2,4-toluene diisocyanate, 1,5-naphthalene diisocyanate, 2,4'-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate, and mixtures thereof.

[0100] Higher-functional polyisocyanates or modified polyisocyanates known in polyurethane chemistry may also be used, such as modified polyisocyanates containing carbodiimide groups, urethane groups, isocyanurate groups, and / or biuret groups. Particularly preferred isocyanates are isophorone diisocyanate, 2,4,4-trimethyl-hexamethylene diisocyanate, and higher-functional polyisocyanates having an isocyanurate structure.

[0101] The isocyanate-capped urethane compound is capped with a (meth)acrylate to produce a urethane (meth)acrylate compound. Generally, any (meth)acrylate-type capping agent having a terminal hydroxyl group and also having an acrylic or methacrylic acid moiety may be used, with a methacrylic acid moiety being preferred.

[0102] Examples of suitable capping agents include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, glycerol di(meth)acrylate, and / or trimethylolpropane di(meth)acrylate. Particularly preferred are 2-hydroxyethyl methacrylate (HEMA) and / or 2-hydroxyethyl acrylate (HEA).

[0103] The equivalent ratio of the isocyanate group to the compound reactive with respect to the isocyanate group is from 1.1:1 to 8:1, preferably from 1.5:1 to 4:1.

[0104] The polyaddition reaction of isocyanates can be carried out in the presence of catalysts known in polyurethane chemistry, such as organotin compounds, such as dibutyltin dilaurate, or amine catalysts, such as diazabicyclo[2.2.2]octane. In addition, the synthesis can be carried out in the melt or in a suitable solvent, which can be added before or during the preparation of the prepolymer. Suitable solvents are, for example, acetone, 2-butanone, tetrahydrofuran, dioxane, dimethylformamide, N-methyl-2-pyrrolidone (NMP), ethyl acetate, alkyl ethers of ethylene glycol and propylene glycol, and aromatic hydrocarbons. Ethyl acetate is particularly preferably used as the solvent.

[0105] Suitable examples of urethane (meth)acrylates include 7,7,9-trimethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16-dioxy-dimethacrylate (e.g., Plex ™ 666-1, Röhm), urethane (meth)acrylates derived from 1,4-bis(1-isocyanato-1-methylethyl)benzene and 1,3-bis(1-isocyanato-1-methylethyl)benzene (e.g., as described in EP 0 934 926 A1), and mixtures thereof.

[0106] According to one embodiment, the urethane (meth)acrylate is characterized as follows:

[0107] Having the structure A-(-S1-U-S2-MA) n , wherein

[0108] A is a connector element comprising at least one unit,

[0109] S1 is a spacer group comprising at least 4 units connected to each other,

[0110] S2 is a spacer group comprising at least 4 units connected to each other,

[0111] The units A, S1, and S2 are independently selected from CH3-, -CH2-, -O-, -S-, -NR 1 -, -CO-, -CR 1 =, , , , , , -N=, -CR 1 R 2 -,

[0112] wherein R 1 and R 2Independently selected from hydrogen, alkyl, substituted alkyl, alkenyl, cycloalkyl, substituted cycloalkyl, arylalkyl, aryl or substituted aryl, wherein these units can form linear, branched or cyclic structures, such as alkyl, cycloalkyl, aryl, ester, carbamate or amide groups,

[0113] U is a carbamate group connecting spacer groups S1 and S2,

[0114] MA is an acrylate or methacrylate group, and

[0115] n is from 3 to 6.

[0116] According to one embodiment, the carbamate (meth)acrylate is represented by the following structure:

[0117] A(-S1-U-S2-MA) n

[0118] wherein

[0119] A is a connector element comprising at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 units,

[0120] S1 is a spacer group comprising units connected to each other and comprising at least 4, 5, 6, 7, 8, 9 or 10 units,

[0121] S2 is a spacer group comprising units connected to each other and comprising at least 4, 5, 6, 7, 8, 9, 10, 12, 15, 20 or 25 units,

[0122] U is a carbamate group connecting spacer groups S1 and S2,

[0123] MA is an acrylate or methacrylate group, and

[0124] n is from 3 to 6, or from 4 to 6 or from 5 to 6.

[0125] It may be preferred if A has a cyclic structure and comprises at least about 6 units.

[0126] It may be further preferred if S1 has a linear or branched structure and comprises at least 4 or 6 units.

[0127] It may be further preferred if S2 has a linear or branched structure and comprises at least 6 or 8 units.

[0128] It is also possible to preferably use a urethane (meth)acrylate, wherein A has a cyclic structure and contains at least 6 units, and S1 has a linear structure and contains at least 4 units, and S2 has a linear structure and contains at least 8 units, and U is a urethane group.

[0129] The atoms of the urethane group connecting S1 and S2 and the atoms of the (meth)acryloyl group do not belong to the spacer group S1 or S2. Therefore, the atoms of the urethane group are not counted as units of the spacer group S1 or S2.

[0130] The nature and structure of the connector element are not particularly limited. The connector element may contain saturated (no double bonds) or unsaturated (at least one or two double bonds) units, aromatic or heteroaromatic units (aromatic structures containing atoms including N, O, and S).

[0131] Specific examples of the connector element A having a cyclic structure include:

[0132] (6 units) (6 units)

[0133] Specific examples of the connector element A having a non-cyclic but branched structure include:

[0134] (5 units) (1 unit) (16 units) (15 units) (12 units) (15 units) (17 units) (10 units) (13 units) (16 units)

[0135] The dashed line indicates the bonding to the spacer group S1.

[0136] The nature and structure of the spacer group S1 or S2 are also not particularly limited.

[0137] The spacer group contains units connected to each other. Typical units include: CH3-, -CH2-, -O-, -S-, -NR 1 -, -CO-, -CR 1 =, ,, ,, ,, ,, , -N=, -CR 1 R 2 -, wherein R 1 and R 2 are independently selected from hydrogen, alkyl, substituted alkyl, alkenyl, cycloalkyl, substituted cycloalkyl, arylalkyl, aryl or substituted aryl.

[0138] These units can form linear, branched or cyclic structures, such as alkyl, cycloalkyl, aryl, ester, carbamate or amide groups.

[0139] The structure of S1 can be the same as the structure of S2. However, in some embodiments, the structure of S1 is different from S2. In a specific embodiment, the number of units present in S1 is less than or equal to the number of units present in S2.

[0140] In a specific embodiment, S1 may have a saturated hydrocarbon structure.

[0141] In another specific embodiment, S2 may have a saturated hydrocarbon structure.

[0142] Typical examples of the spacer group that can be used for S1 include:

[0143] (4 units) (6 units) (8 units) (13 units) (13 units) (8 units) (8 units)

[0144] The dashed line represents the chemical bonding to group A or group U.

[0145] Typical examples of the spacer group that can be used for S2 include:

[0146] (9 units) (16 units) (6 units)

[0147] The dashed line represents the chemical bonding to the (meth)acrylate group or group U. The number of units counted according to the present invention is given in the parentheses.

[0148] Specific examples of the carbamate (meth)acrylate include

[0149]

[0150] Alternatively, suitable urethane (meth)acrylates are based on α,ω-capped poly(meth)acrylate diols (e.g., as described in EP 1 242 493 B1), or can be polyester, polyether, polybutadiene or polycarbonate urethane (meth)acrylates (e.g., as described in US 6,936,642 B2).

[0151] If present, the urethane (meth)acrylate is generally present in an amount of at least 5% by weight, or at least 8% by weight or at least 10% by weight; at most 30% by weight, or at most 25% by weight or at most 20% by weight; 5% by weight to 30% by weight, or 8% by weight to 25% by weight or 10% by weight to 20% by weight; based on the weight of the curable composition.

[0152] The (meth)acrylate that does not contain a urethane moiety is generally used in an amount that exceeds that of the (meth)acrylate containing a urethane moiety, by weight.

[0153] The ratio of (meth)acrylate without urethane moiety / (meth)acrylate with urethane moiety relative to weight is generally in the range of 10 / 1 to 2 / 1.

[0154] The curable composition further comprises one or more photoinitiators.

[0155] Suitable photoinitiators are those that are capable of initiating or triggering the curing reaction of the radiation-curable components upon irradiation. In this regard, the photoinitiators described in this text are capable of generating free radicals upon exposure to radiation in the wavelength regions described in this text (i.e., in the visible light region and the ultraviolet light region).

[0156] These photoinitiators are also referred to as multi-wavelength photoinitiators.

[0157] The curable composition generally contains only photoinitiators having absorption bands in the ultraviolet light region and the visible light region.

[0158] According to one embodiment, the curable composition contains only one photoinitiator.

[0159] The photoinitiators described in this text have a special absorption behavior.

[0160] The absorption spectrum covers not only the region of ultraviolet light but also the region of visible light. Thus, the absorption spectrum includes two regions, one for absorbing ultraviolet light and one for absorbing visible light, where the absorption in the ultraviolet light region is stronger than that in the visible light region.

[0161] Greater absorption means that the absorption curve or absorption value obtained from the UV / Vis spectrometer at a given wavelength lies above the absorption curve or absorption value at different wavelengths.

[0162] For the photoinitiators described in this text, the ratio of the absorption in the range of 350 nm to 410 nm (especially at 390 nm) to the absorption in the range of 440 nm to 500 nm (especially at 450 nm) is generally in the range of 1.05 to 13 or 1.10 to 10 or 1.15 to 5.

[0163] In addition, certain embodiments of the photoinitiator are generally non-fluorescent.

[0164] The photoinitiator may comprise a diketone moiety, a titanocene moiety or an acylgermane moiety.

[0165] Examples of suitable photoinitiators include components containing a phenyl-1,2-propanedione (PPD) moiety, components containing a benzil moiety, bis(cyclopentadienyl)bis[2,6-difluoro-3-(1-pyrrolyl)phenyltitanium (Omnirad ™ 784), a monoacylgermane or diacylgermane moiety, and mixtures thereof.

[0166] The structural formulas of the corresponding moieties are shown below:

[0167]

[0168] Specifically, it has been found that components containing a phenyl-1,2-propanedione moiety are useful because the 3D articles obtained by radiation curing the corresponding curable compositions show substantially no discoloration after the second curing step. In addition, components containing a phenyl-1,2-propanedione moiety are generally liquids, which is beneficial for mixing with other components of the radiation curable composition.

[0169] The photoinitiator is generally used in combination with an activator. Tertiary amines are commonly used as activators.

[0170] Suitable examples of tertiary amines include N,N-dimethyl-p-toluidine, N,N-dimethyl-aminoethyl methacrylate (DMAEMA), triethanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethyl-aminobenzoate (EDMAB), methyldiphenylamine, 4-(N,N-dimethylamino)phenylethanol (DMPOH), and isoamyl 4-dimethylaminobenzoate.

[0171] A photoinitiator, optionally in combination with an activator, is usually present in the following amounts: lower limit: at least 0.01 wt%, at least 0.02 wt% or at least 0.03 wt%; upper limit: at most 5 wt%, at most 4 wt%, or at most 3 wt%; range: 0.01 wt% to 5 wt%, or 0.02 wt% to 4 wt% or 0.03 wt% to 3 wt%, by weight relative to the curable composition.

[0172] The curable composition may further comprise one or more fillers. The nature of the filler is not particularly limited, unless the intended use cannot be achieved.

[0173] Suitable fillers include non-acid-reactive glasses such as lanthanum glass, borosilicate glass, soda glass, barium glass, strontium glass, glass ceramics, aluminosilicate glass, barium borosilicate glass, strontium borosilicate glass; silicates such as calcium silicate, zirconium silicate; and metal oxides such as quartz, cristobalite, alumina, titanium dioxide, silica-titanium dioxide, silica-titanium dioxide-barium oxide, silica-zirconia, silica-alumina and mixtures thereof.

[0174] Fillers that can be additionally used include those containing discrete nano-sized filler particles, aggregated filler particles, and mixtures thereof can be used.

[0175] Compositions containing nano-sized filler particles are generally more transparent than those containing larger filler particles.

[0176] The average particle size of the nano-sized filler particles is usually 40 nm or less, or 35 nm or less or 30 nm or less. The average particle size is usually in the range of 10 nm to 40 nm, or 10 nm to 35 nm or 10 nm to 30 nm.

[0177] The specific surface area (BET) of the nano-sized filler is preferably 80 m 2 / g or greater, or 100 m 2 / g or greater or 120 m 2 / g or greater. The specific surface area (BET) is usually in the range of 80 m 2 / g to 500 m 2 / g, or 100 m 2 / g to 400 m 2 / g or 120 m 2 / g to 300 m 2 / g.

[0178] If desired, according to Brunauer, Emmet and Teller (BET), by using a device purchased from Quantachrome Corporation (Monosorb ™) to measure the specific surface area.

[0179] The nano-sized filler comprises aggregated nano-sized particles, contains aggregated nano-sized particles, consists essentially of aggregated nano-sized particles or consists of aggregated nano-sized particles. If desired, this can be demonstrated by transmission electron microscopy (TEM).

[0180] The filler particles generally comprise oxides of Si, Zr, Al and mixtures thereof, with oxides of Si and Zr sometimes being preferred.

[0181] Suitable pyrogenic silicas include, for example, those sold under the trade name Aerosil ™ products of the series OX-50, OX-130, OX-150 and OX-200, Aerosil ™ R8200, R805, CAB-O-SIL from Cabot Corp (Tuscola) of Tuscola ™ M5, and the HDK type from Wacker, for example, HDK ™ -H2000, HDK ™ H15, HDK ™ H18, HDK ™ H20 and HDK ™ H30.

[0182] Nano-sized silica can also be commercially obtained from Naperville, Ill of Nalco Chemical Company in the United States under the product name NALCO ™ COLLOIDAL SILICAS. For example, the preferred silica particles can be obtained by using NALCO ™ products 1040, 1042, 1050, 1060, 2327 and 2329. Other suitable nano-sized silicas can be obtained from Covestro (Leverkusen, Germany) of Leverkusen, Germany under the product name Dispercoll ™ (e.g., Dispercoll ™ S 3030 or Dispercoll ™ S 4020), Grace GmbH & Co. KG (Worms, Germany) of Worms, Germany under the product name Ludox ™ (e.g., Ludox ™ P-X30 or Ludox ™P-W30) and Nouryon (Amsterdam, Netherlands) under the product name Levasil ™ (such as Levasil ™ CS50-34P) were commercially obtained.

[0183] The aggregated filler particles generally include nanoclusters.

[0184] Compared with other fillers, the use of nanoclusters can be beneficial because it allows the formulation of compositions with high filler loadings, which can result in better mechanical properties such as polishability or abrasion resistance and higher aesthetics.

[0185] Suitable nanofillers comprising aggregated nanoparticles of nanosize can be prepared according to the methods described in Preparation Example A and Preparation Example B of, for example, US 6,730,156 (Windisch et al.).

[0186] Once dispersed in the resin, the filler particles can remain in the aggregated stage. That is, during the dispersion step, the particles do not break into discrete (i.e., individual) and unassociated (i.e., non-aggregated) particles.

[0187] The nanoparticles of nanosize are surface-treated.

[0188] The surface treatment makes the nanoparticles of nanosize more easily dispersed in the monomer matrix and can prevent the filler from precipitating from the formulation during storage.

[0189] Available surface treatment agents include silanes.

[0190] The silane surface treatment agent may or may not contain a polymerizable moiety, especially a (meth)acrylate moiety. Only one silane surface treatment agent or a mixture of different silane treatment agents can be used.

[0191] In a specific embodiment, a mixture of a silane surface treatment agent containing a polymerizable moiety, especially a (meth)acrylate moiety, and a silane surface treatment agent not containing a polymerizable moiety is used.

[0192] If the surface treatment is carried out with two different silane surface treatment agents, the usually used amount of the polymerizable silane surface treatment agent is higher than that of the non-polymerizable silane surface treatment agent by weight.

[0193] It has been found that the ratio of the polymerizable silane surface treatment agent to the non-polymerizable silane surface treatment agent by weight in the range of 90 / 10 to 60 / 40 or 80 / 20 to 70 / 30 is available.

[0194] If desired, FT-IR or NMR techniques can be used to analyze the surface of the treated particles.

[0195] The polymerizable silane surface treatment agent is generally an alkoxysilane, preferably a trialkoxysilane containing (meth)acrylate groups.

[0196] Typical embodiments can be characterized by the following formula:

[0197] A m BSi(R 1 ) n (OR 2 ) 3-n

[0198] wherein A contains a (meth)acryloyl moiety,

[0199] B contains a spacer group such as (i) a straight-chain or branched C1 to C 12 alkyl group, (ii) a C6 to C 12 aryl group, (iii) an organic group having 2 to 20 carbon atoms bonded to each other by one or more ether, thioether, ester, thioester, thiocarbonyl, amide, carbamate, carbonyl, and / or sulfonyl bonds,

[0200] R 1 includes an alkyl group (e.g., C1 to C6) or an aryl group (e.g., C6 to C 12 ), and

[0201] R 2 includes an alkyl group (e.g., C1 to C6),

[0202] where m = 1, 2 or 3, and n = 0, 1 or 2.

[0203] Examples of (meth)acrylate-functionalized trialkoxysilanes include, but are not limited to, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropyltris(methoxyethoxy)silane, 3-(meth)acryloxyallyltrimethoxysilane, (meth)acryloxyethyldimethyl(3-trimethoxysilylpropyl)ammonium chloride, N-(3-(meth)acryloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane, O-((meth)acryloxyethyl)-N-(triethoxysilylpropyl)carbamate, (meth)acryloxymethyltrimethoxysilane, (meth)acryloxymethyltriethoxysilane, (meth)acryloxymethylmethyldimethoxysilane, (meth)acryloxymethylmethyldiethoxysilane, (meth)acryloxyoctyltrimethoxysilane, [(meth)acryloxymethyl]phenethyltrimethoxysilane, O-[(meth)acryloxyethyl]-N-(triethoxysilylpropyl)carbamate, (meth)acryloxypropyltriisopropoxysilane, (meth)acryloxypropylmethyldimethoxysilane, (meth)acryloxypropylmethyldiethoxysilane, 3-(meth)acryloxypropyldimethylmethoxysilane, 3-(meth)acryloxypropyldimethylethoxysilane, (meth)acryloxymethyldimethylmethoxysilane, (meth)acryloxymethyldimethylethoxysilane, oligomeric hydrolysis products of 3-(meth)acryloxypropyltrimethoxysilane, and oligomeric hydrolysis products of 3-(meth)acryloxypropyltriethoxysilane.

[0204] Non-polymerizable silane surface treatment agents are typically alkoxysilanes, preferably trialkoxysilanes.

[0205] Typical embodiments can be characterized by the following formula:

[0206] DSi(R 1 ) n (OR 2 ) 3-n

[0207] wherein D includes (i) a straight-chain or branched unsubstituted or substituted (e.g., substituted with one or more amino or mercapto groups) C1 to C 16 alkyl group, (ii) an unsubstituted or substituted (e.g., substituted with one or more amino or mercapto groups) C6 to C 12 aryl group, or (iii) an organic group having 2 to 20 carbon atoms bonded to each other through one or more ether, thioether, ester, thioester, thiocarbonyl, amide, carbamate, carbonyl, and / or sulfonyl bonds,

[0208] R1 comprises an alkyl group (e.g., C1 to C6) or an aryl group (e.g., C6 to C 12 ), and

[0209] R 2 comprises an alkyl group (e.g., C1 to C6),

[0210] where n = 0, 1 or 2.

[0211] Suitable non-polymerizable silane surface treating agents include phenyltrimethoxysilane, phenyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, cetyltrimethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, propyltrimethoxysilane, 3-aminopropyl-methyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-cyclohexyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, (cyclohexyl)methyldimethoxysilane, and mixtures thereof.

[0212] Polymerizable and non-polymerizable silane surface treating agents are commercially available, for example, from Wacker (München, Germany) under the product name Geniosil ™ or from Evonik (Hanau, Germany) under the product name Dynasylan ™ commercially.

[0213] A method for surface treating discrete nanosized filler particles generally comprises the following steps:

[0214] mixing a sol containing nanosized particles with a silane surface treating agent; and

[0215] stirring the mixture in a solvent such as ethanol under reflux for several hours (e.g., 2 hours to 10 hours);

[0216] after stirring for several hours (e.g., 2 hours to 10 hours), undermixing a monomer into the resulting mixture and stirring again for several hours (e.g., 2 hours to 10 hours);

[0217] removing the solvent under vacuum.

[0218] A suitable method is also described in US 6,899,948 (Zhang et al.).

[0219] If present, specifically filler particles of nanometer size are generally present in the following amounts: at least 10% by weight, or at least 15% by weight or at least 20% by weight; or at most 70% by weight, or at most 60% by weight, or at most 50% by weight; or 10% by weight to 70% by weight, or 15% by weight to 60% by weight, or 20% by weight to 50% by weight; % by weight relative to the curable composition.

[0220] Using such amounts of filler generally contributes to the physical and mechanical properties of the composition, especially in its cured state.

[0221] The curable composition generally further comprises one or more additives.

[0222] Additives that may be present include stabilizers, fluorescent dyes, ultraviolet light absorbers, fluoride releasing agents, and mixtures thereof.

[0223] Suitable stabilizers include radical scavengers such as substituted and / or unsubstituted hydroxyaromatic compounds (e.g., butylated hydroxytoluene (BHT), hydroquinone, methyl ether of hydroquinone (MEHQ), 3,5 - di - tert - butyl - 4 - hydroxyanisole (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 - octoxybenzophenone, 2 - (2'-hydroxy - 5'-methacryloyloxyethylphenyl)-2H - benzotriazole, phenothiazine, and hindered amine light stabilizers (HALS).

[0224] Suitable fluorescent dyes generally include anthracene or perylene moieties. Fluorescent dyes generally have an absorption peak in the range of 350 nm to 450 nm. Commercially available fluorescent dyes include, for example, Lumilux ™ Blau LZ, Lumilux ™ Gelb LZ and dyes containing an anthracene moiety (e.g., 2 - ethyl - 9,10 - dimethoxyanthracene; EDMO).

[0225] If present, the fluorescent dye is generally present in an amount of 0.001% by weight to 0.5% by weight relative to the weight of the composition.

[0226] Suitable ultraviolet light absorbers include components containing a benzotriazole moiety. The ultraviolet absorber generally has an absorption peak in the range of 350 nm to 420 nm. Commercially available ultraviolet light absorbers include Tinuvin™ 326, Tinuvin ™ 328, Tinuvin ™ P, Uvinul ™ M40

[0227] If present, the ultraviolet light absorber is typically present in an amount of from 0.001% to 1.0% by weight, based on the weight of the composition.

[0228] Examples of fluoride releasing agents include naturally occurring or synthetic fluoride minerals. These fluoride sources may optionally be treated with a surface treating agent.

[0229] The additives are typically present in the following amounts: 0% by weight, or at least 0.01% or at least 0.1% by weight; or at most 10% by weight, or 7.5% or 5% by weight; or from 0% to 10% by weight, or from 0.01% to 7.5% or from 0.1% to 5% by weight; % by weight relative to the curable composition.

[0230] The curable compositions described herein typically comprise, consist essentially of, or consist of the following amounts of the respective components:

[0231] Radiation curable component: 20% to 95% by weight,

[0232] Photoinitiator, optionally in combination with an activator: 0.01% to 5% by weight,

[0233] Filler: 0% to 70% by weight,

[0234] Additive: 0% to 10% by weight,

[0235] % by weight relative to the curable composition, wherein the above components are those described herein.

[0236] The curable composition may also comprise, consist essentially of, or consist of the following amounts of the respective components:

[0237] Methacrylate not containing a urethane moiety: 20% to 75% by weight,

[0238] Urethane (meth)acrylate: 5% to 30% by weight,

[0239] Photoinitiator, optionally in combination with an activator: 0.01% to 5% by weight,

[0240] Filler: 10% to 60% by weight,

[0241] Additive: 0.01% to 7.5% by weight,

[0242] % by weight relative to the curable composition, where the above components are those described in this text.

[0243] The curable composition may further comprise the corresponding components in the following amounts, consist essentially of the corresponding components in the following amounts, or consist of the corresponding components in the following amounts:

[0244] Methacrylate not containing a urethane moiety: 30% to 65% by weight,

[0245] Urethane (meth)acrylate: 10% to 20% by weight,

[0246] Photoinitiator, optionally in combination with an activator: 0.02% to 4% by weight,

[0247] Filler: 15% to 50% by weight,

[0248] Additive: 0.1% to 5% by weight,

[0249] % by weight relative to the curable composition, where the above components are those described in this text.

[0250] More specific embodiments are as follows:

[0251] Embodiment 1

[0252] A curable composition for use in a method of treating a dental condition in a patient's oral cavity,

[0253] The curable composition comprises the following, consists essentially of the following, or consists of the following:

[0254] A radiation-curable component selected from the group consisting of (meth)acrylate components, urethane (meth)acrylate components, and mixtures thereof,

[0255] A photoinitiator selected from the group consisting of components containing a phenyl-1,2-propanedione moiety, components containing a benzil moiety, bis(cyclopentadienyl)bis[2,6-difluoro-3-(1-pyrrolyl)phenyltitanium], and mixtures thereof,

[0256] Optional filler,

[0257] Optional additive,

[0258] The method comprises the following steps:

[0259] Using radiation in the ultraviolet light region of the wavelength to perform layer-by-layer fabrication on a dental or orthodontic article,

[0260] Attach the dental or orthodontic article to the surface of hard tooth tissue or dental material.

[0261] Apply radiation having a wavelength in the visible light region to the dental or orthodontic article.

[0262] Embodiment 2

[0263] A curable composition for use in a method of treating a dental condition in a patient's oral cavity,

[0264] The curable composition comprises, consists essentially of, or consists of:

[0265] A radiation-curable component in an amount of 20 wt% to 95 wt%, the radiation-curable component being selected from (meth)acrylate components, urethane (meth)acrylate components, and mixtures thereof,

[0266] A photoinitiator selected from components containing a phenyl-1,2-propanedione moiety, components containing a benzil moiety, bis(cyclopentadienyl)bis[2,6-difluoro-3-(1-pyrrolyl)phenyltitanium], and mixtures thereof,

[0267] Optionally in combination with an activator,

[0268] A filler in an amount of 1 wt% to 70 wt%,

[0269] Additives,

[0270] The method comprises the steps of:

[0271] Using radiation having a wavelength in the ultraviolet light region to perform layer-by-layer fabrication of a dental or orthodontic article,

[0272] Attach the dental or orthodontic article to the surface of hard tooth tissue,

[0273] Apply radiation having a wavelength in the visible light region to the dental or orthodontic article.

[0274] wt% is relative to the curable composition.

[0275] Embodiment 3

[0276] A curable composition for use in a method of treating a dental condition in a patient's oral cavity, the curable composition comprising, consisting essentially of, or consisting of:

[0277] A radiation-curable component in an amount of 20 wt% to 75 wt%, the radiation-curable component being selected from (meth)acrylate components, urethane (meth)acrylate components, and mixtures thereof,

[0278] A photoinitiator selected from components containing a phenyl-1,2-propanedione moiety, components containing a benzil moiety, bis(cyclopentadienyl)bis[2,6-difluoro-3-(1-pyrrolyl)phenyltitanium], and mixtures thereof,

[0279] Optionally in combination with an activator,

[0280] A filler in an amount of 10% to 50% by weight,

[0281] Additives,

[0282] The method comprises the steps of:

[0283] Performing layer-by-layer additive manufacturing of a dental or orthodontic article using radiation having a wavelength in the ultraviolet light region,

[0284] Applying a dental adhesive or dental cement to a surface section of the dental or orthodontic article intended to be attached to hard tooth tissue,

[0285] Attaching the dental or orthodontic article to the surface of hard tooth tissue,

[0286] Applying radiation having a wavelength in the visible light region to the dental or orthodontic article,

[0287] % by weight relative to the curable composition.

[0288] Embodiment 4

[0289] A curable composition for use in a method of treating a dental condition in a patient's oral cavity, the curable composition comprising, consisting essentially of, or consisting of:

[0290] A radiation-curable component in an amount of 20% to 75% by weight, the radiation-curable component being selected from (meth)acrylate components, urethane (meth)acrylate components, and mixtures thereof,

[0291] A photoinitiator selected from components containing a phenyl-1,2-propanedione moiety,

[0292] Optionally in combination with an activator,

[0293] A filler in an amount of 10% to 50% by weight,

[0294] Additives,

[0295] The method comprises the steps of:

[0296] Performing layer-by-layer additive manufacturing of a dental or orthodontic article using radiation having a wavelength in the ultraviolet light region,

[0297] Apply a dental adhesive or dental cement to a surface section of the dental or orthodontic article intended to be attached to hard tooth tissue.

[0298] Attach the dental or orthodontic article to the surface of the hard tooth tissue.

[0299] Apply radiation having a wavelength in the visible light region to the dental or orthodontic article.

[0300] Weight % is relative to the curable composition.

[0301] The curable compositions described in this text can be produced by mixing the corresponding components under light - shielding conditions. If desired, a high - speed mixer can be used.

[0302] During storage, the curable compositions described in this text are generally stored under light - shielding conditions, in particular in sealed containers, vessels or foil bags. The volume of the container can range from 1 ml to 10 l, or 5 ml to 5 l or 100 ml to 2 l.

[0303] The curable compositions can be processed in a layer manufacturing method to produce 3D printed articles. Thus, 3D printing methods are generally known to those skilled in the art.

[0304] An example of such a technique is described in US 8,003,040 B2 (El - Siblani), which relates to a method for producing a three - dimensional object by curing each layer in a pattern with co - stimulating electromagnetic radiation.

[0305] Specifically, it has been found that so - called SLA or DLP 3D printing methods are applicable. The technical equipment that can be used can be commercially obtained from companies such as 3Shape, Rapid Shape 3D Printing, Formlabs, Lithoz, Prodways 3D Printing, Stratasys, EnvisionTec 3D Printing, etc.

[0306] The layer manufacturing device operates at a specific radiation wavelength, which is typically in the range of 350 nm to 500 nm.

[0307] The layer manufacturing device can also be characterized by the achievable resolution. A suitable resolution is typically in the range of 5 µm to 100 µm, or 10 µm to 80 µm or 20 µm to 60 µm.

[0308] After performing the layer manufacturing method, if necessary, the printed article can be post - processed.

[0309] Available post - processing steps include cleaning and optionally post - curing of the cleaned article.

[0310] Cleaning of the 3D - printed article can be accomplished by using a cleaning solution and / or by performing a so - called spin - cleaning method.

[0311] By performing the cleaning step, residues of the undesirable curable resin remaining on the surface of the 3D - printed article can be removed.

[0312] Suitable cleaning solutions include alcohols such as ethanol or isopropanol; esters of carboxylic acids such as diesters and / or triesters of carboxylic acids; or mixtures thereof. Suitable cleaning solutions are also described in WO 2018 / 222395 A1 (3M).

[0313] The spin - cleaning method includes the step of moving or rotating the three - dimensional article. By doing so, a mass inertial force is generated.

[0314] The term "mass inertial force" mentioned herein can be specified as the force per unit mass and can thus be specified in m / s 2 units. Additionally, the mass inertial force can be represented by G - force which is a factor of the acceleration due to gravity. For the purposes of this text, the acceleration due to gravity is 9.81 m / s 2 . Thus, for example, a mass inertial force of 9.81 m / s 2 can be represented as 1G.

[0315] The accelerating force or mass inertial force is caused by moving, e.g., rotating an object.

[0316] The centrifugal force on the particles on the surface of the three - dimensional article generally depends on the rotational speed and the radius of the particle from the axis of rotation.

[0317] By varying parameters such as the speed of moving or rotating, the duration of moving or rotating, and / or the axis of rotation, the technique allows adjustment of the amount and layer thickness of the radiation - curable composition remaining on the surface of the three - dimensional article.

[0318] In one embodiment, the mass inertial force corresponds to a G - force of at least 100G. A mass inertial force of 100G has been shown to be suitable for removing moderately to highly viscous radiation - curable materials. Those skilled in the art will recognize that the mass inertial force required for cleaning can be lower for less viscous materials and higher for more viscous materials. This method is described, for example, in WO 2019 / 023120 A1 (3M).

[0319] For additive manufacturing of the dental or orthodontic articles described in this text, commercially available 3D - printing devices can be used.

[0320] The use of the photoinitiators described in this text allows for the curing of radiation-curable compositions, especially when applying the following processing parameters: layer thickness: 10 µm to 50 µm; wavelength of the curing light: 350 nm to 420 nm; curing light intensity: 5 to 100 W / m 2 ; radiation exposure time: 1 s to 20 s.

[0321] After performing the additive manufacturing step, a pre-cured dental or orthodontic article is obtained. Since a post-curing step is not applied, the pre-cured article typically still contains unpolymerized unsaturated moieties, such as (meth)acrylate moieties, on its surface.

[0322] If desired, the presence and optional amount of unpolymerized (meth)acrylate functional groups can be characterized by determining the degree of conversion or alternatively by IR spectroscopy (e.g., Raman spectroscopy).

[0323] Pre-cured dental or orthodontic articles can generally be characterized by the following features, either alone or in combination: a) being rubber-elastic; b) having an elongation at break in the range of 10% to 200% as determined according to DIN EN ISO 527-1:2012-06.

[0324] Cured dental or orthodontic articles can generally be characterized by the following features, either alone or in combination: a) having a flexural strength in the range of 60 MPa to 200 MPa as determined according to ISO / DIN 4049 (2019); b) having an elongation at break in the range of 1% to 40% as determined according to DIN EN ISO 527-1:2012-06.

[0325] Dental or orthodontic articles in the pre-cured or cured stage can have different shapes. The volume of the dental or orthodontic article is generally in the range of 0.1 ml to 10 ml or 0.2 ml to 5 ml.

[0326] For example, a dental article can have the shape of a dental crown, dental bridge, dental onlay, inlay, veneer.

[0327] The curable compositions described in this text can be particularly used for producing dental articles having the shape of a dental crown, especially dental articles having the shape of a dental crown for pediatric use.

[0328] These types of dental composite crowns are described, for example, in 10,610,330 B2 (Herrmann et al.) or US 2020 / 0206092 A1 (Herrmann et al.). The content of this reference is incorporated herein by reference.

[0329] Dental composite crowns obtained by processing the curable compositions of the present text in an additive manufacturing method are generally malleable and can be shaped or adapted by a doctor before or during the step of attaching the dental composite crown to the surface of a dental post in a patient's mouth, if desired.

[0330] In addition, due to their elastic properties, preformed dental composite crowns can be easily placed on a dental post, even in the presence of undercuts.

[0331] Then the final curing or hardening step of the dental composite crown can be carried out subsequently, for example, after placing the dental composite crown on a dental post in a patient's mouth, using a dental curing light within the wavelength in the visible light region.

[0332] This provides more flexibility for the doctor.

[0333] Orthodontic articles can have the shape of orthodontic attachments, orthodontic brackets.

[0334] Orthodontic articles that can be produced by using the curable compositions described in the present text are described, for example, in WO 2021 / 130624 A1 (3M), WO 2022 / 149083 (3M), or WO 2022 / 149084 A1 (3M). The content of this reference is incorporated herein by reference.

[0335] The present invention also relates to a kit box.

[0336] The kit box includes the curable compositions described in the present text, and a dental adhesive, dental cement, or dental primer and optionally a curing light, optionally a tooth positioning tray, and optionally instructions for use, consisting essentially of them, or consisting of them.

[0337] Dental adhesives are generally acidic dental compositions having a relatively low viscosity (e.g., 0.01 Pa s to 3 Pa s) at 23 °C. Dental adhesives interact directly with the enamel or dentin surface of the tooth. Dental adhesives are generally single-part compositions, 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.

[0338] 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, such as 3M ™ Scotchbond ™ Universal or 3M ™Scotchbond ™ Universal Plus (3M Oral Care).

[0339] Suitable dental primers are described in US 6,126,922 (Rozzi et al.) and WO 00 / 69393 A1 (3M). Dental primers are also commercially available, e.g., 3M ™ Transbond ™ XT Primer (3M OralCare).

[0340] Dental cements that can be added to the kit particularly include self-adhesive resin cements that contain an acidic polymerizable component (e.g., a (meth)acrylate component having a phosphoric acid or carboxylic acid moiety), a polymerizable component without an acidic moiety, an initiator system, and a filler.

[0341] Suitable dental cements are also commercially available, such as RelyX ™ Unicem 2, RelyX ™ Universal or RelyX ™ Luting Plus (3M Oral Care).

[0342] Tooth positioning trays are typically used to place orthodontic attachments onto a patient's teeth. Examples of tooth positioning trays and related methods are described in US 2015 / 0313687 A1 (Blees et al.), US 2020 / 131356 A1 (Zech et al.).

[0343] 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, e.g., 3M ™ Elipar ™ S10 or 3M ™ Elipar ™ Deep-Cure S LED curing light (3M Oral Care).

[0344] Instructions for use describe how a dental product or curable composition should be used in daily practice, e.g., outlining the application steps and optional curing conditions.

[0345] The curable composition can be used in a method of treating a dental condition in a patient's oral cavity.

[0346] As described above, a pre-cured dental or orthodontic article or a dental or orthodontic article comprising a pre-cured composition is first produced.

[0347] If desired, such pre-cured articles can be post-treated, in particular cleaned.

[0348] The pre-cured article is then attached to the surface of hard tooth tissue or another dental material. If desired, the method can be supported by using a dental adhesive or dental cement.

[0349] Thus, the method can include the following additional steps:

[0350] Optionally post-treating the pre-cured dental or orthodontic article; and

[0351] Applying a dental adhesive or dental cement to the surface of the dental or orthodontic article intended to be attached to the hard tooth tissue or dental material.

[0352] In another step, the pre-cured article is typically radiation-cured using wavelengths in the visible light region.

[0353] If the dental adhesive or dental cement is also radiation-curable, the radiation curing of the pre-cured dental or orthodontic article and the dental adhesive or dental cement can be carried out simultaneously.

[0354] More specifically, a suitable method can include the following steps:

[0355] a. Processing a curable composition in a layer manufacturing method, optionally followed by post-treatment steps such as cleaning, to obtain a 3D printed pre-cured orthodontic article,

[0356] b. Inserting the 3D printed pre-cured orthodontic article into a cavity of a tooth positioning tray,

[0357] c. Applying a dental adhesive or dental cement to the surface of the 3D printed pre-cured orthodontic article intended to be attached to the tooth surface,

[0358] d. Inserting the transparent tooth positioning tray into the patient's mouth,

[0359] e. Radiation-curing the 3D printed pre-cured orthodontic article,

[0360] f. Removing the tooth positioning tray from the patient's mouth,

[0361] g. Optionally inserting a tooth aligner tray that engages with the orthodontic article.

[0362] For effective radiation curing of the 3D printed pre-cured orthodontic article, the tooth positioning tray should be transparent to the light used for radiation curing.

[0363] Dental aligner trays are used to correct teeth like braces. They move teeth to the desired position using gentle and constant force. They are typically transparent and customized.

[0364] The method generally does not include the following additional steps:

[0365] roughening the surface of a 3D printed dental or orthodontic article intended to be attached to hard tooth tissue or dental material; and / or

[0366] performing a further radiation curing step on a pre-cured dental or orthodontic article before attaching the article to hard tooth tissue or dental material.

[0367] Since the pre-cured article contains a sufficient amount of polymerizable moieties which can be used for copolymerization reactions with other (meth)acrylate components present in, for example, dental adhesives or dental cements, it is not necessary to roughen the surface of the pre-cured article in order to increase the surface size.

[0368] For the same reason, it would be disadvantageous to apply an additional radiation curing or post-curing step before attaching the article to hard tooth tissue or another dental material as the amount of polymerizable moieties would be reduced.

[0369] Furthermore, the radiation curable composition of the present text generally does not contain the following components:

[0370] a) a peroxide component in an amount of 0.1 wt% to 0.3 wt% or more, wt% relative to the weight of the radiation curable composition,

[0371] b) a (meth)acrylate having an acidic moiety in an amount of 2 wt% or more,

[0372] wt% relative to the weight of the radiation curable composition.

[0373] Thus, the radiation curable composition is substantially free of a peroxide component or a (meth)acrylate having an acidic moiety and does not contain a peroxide component or a (meth)acrylate having an acidic moiety which has been intentionally added.

[0374] The entire disclosures of all patents, patent documents, and publications cited herein are incorporated herein by reference in their entirety as if each were incorporated individually. Various modifications and variations of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. The above specifications, examples, and data provide a description of the manufacture and use of the compositions of the invention and the methods of the invention. The invention is not limited to the embodiments disclosed herein. Those skilled in the art will understand that many alternative embodiments of the invention can be prepared without departing from the spirit and scope of the invention.

[0375] The following examples are given to illustrate the present invention.

[0376] Example

[0377] Method

[0378] Viscosity

[0379] If desired, the viscosity can be measured using a Physica MCR 301 (Anton Paar Germany GmbH, Ostfildern-Scharnhausen, Germany) at 23.0 °C with a shear rate between 0.1 s -1 and 1,000 s -1 using a 25 mm plate / cone system.

[0380] Method for determining the optical absorption band

[0381] If desired, the light absorption spectrum can be determined by using a Spectramax 190 spectrophotometer (purchased from Molecular Devices LLC., Sunnyvale, CA, USA). A porous sample cell such as a Microtest 96-well 370 µl clear plate (purchased from BD Biosciences Franklin Lakes, NJ, USA) is used as the sample cell. 200 µl of solution (photoinitiator dissolved in TEGDMA) is placed in one well of the 96-well sample cell and placed in the Spectromax 190. The spectrum is recorded at 1 nm steps between 200 nm and 800 nm.

[0382] Particle size distribution (particles not of nanoscale size)

[0383] If desired, the particle size can be measured using a Malvern Mastersizer 2000 (Malvern Instruments, Malvern, Worcestershire, UK) light scattering instrument. The Mastersizer 2000 uses an integrated optical system to cover a range of 0.02 µm to 2000 µm. The mixture to be analyzed is added to a test cell filled with isopropanol until a obscuration of approximately 8% to 15% is reached. No ultrasonic waves are applied so as not to change the particle size distribution. The raw data is processed using the instrument software, which uses the refractive index of non-nano-sized fillers and applies Mie correction and the Fraunhofer approximation (a commonly known technique among experts).

[0384] Particle size distribution (nanoscale particles)

[0385] The measurement of the nanoparticle size is preferably based on the transmission electron microscopy (TEM) method, whereby a population is analyzed to obtain the average particle size. The preferred method for measuring the particle size can be described as follows:

[0386] A sample approximately 80 nm thick is placed on a 200-mesh copper grid with a carbon-stabilized polyvinyl acetate methyl ester substrate (SPI Supplies-Structure Probe, Inc., West Chester, PA). Transmission electron micrographs (TEM) are taken at 200 kV using a JEOL 200CX (JEOL, Ltd., Akishima, Japan, and sold by JEOL USA, Inc.). The population size of approximately 50 - 100 particles can be measured and the average diameter determined.

[0387] Flexural strength (FS)

[0388] If desired, the flexural strength can be measured according to ISO 4049 (2019) using a universal testing machine (Zwick Z010, chuck speed 2 mm / min) and specimens with dimensions of 2 mm × 2 mm × 25 mm. The flexural strength is usually given in MPa.

[0389] Elongation at break (EaB)

[0390] If required, the elongation at break of the material can be determined according to DIN EN ISO 527-1:2012-06. The elongation is given as % of the initial length. The elongation data can be evaluated on a Zwick Z010 universal testing machine by tearing at least three I-shaped specimens with the following dimensions: central unit: 10 mm × 2 mm × 2 mm; total length: 25 mm; width of the wider part: 5 mm; radius of the rounded edges: R = 10 mm on the central unit; 25 mm on the wider part.

[0391] Material

[0392]

[0393] Table 1

[0394] The light absorption properties of the photoinitiators are given in Table 2.

[0395]

[0396] Table 2

[0397] Prepare the resin compositions (RCx) given in Table 3:

[0398]

[0399] Table 3; values are given in parts by weight; CE: Comparative Example; IE: Example of the present invention

[0400] General method for producing a curable composition

[0401] Mix the corresponding components using a high-speed mixer under light protection conditions and then carry out a roll milling step. In addition, evacuate the mixture in a laboratory kneader.

[0402] General method for producing a 3D printed article

[0403] Laminated manufacturing method :

[0404] Pour the composition into the working tray of a commercially available DLP printer (Rapidshape, Heimsheim, Germany). Load the preprocessing data (STL file; shape of a three-dimensional cuboid object; 25 mm × 2 mm × 2 mm) into the printer. The following printing conditions can be applied: curing light wavelength: 360 nm to 420 nm light; curing light intensity: 5 W / m 2 to 100 W / m 2 ; exposure time: 1 s to 11 s; layer thickness: 25 µm.

[0405] Three-dimensional article

[0406] A three-dimensional article can be produced as follows: Place the composition in the cartridge of a stereolithography apparatus. The three-dimensional article is produced layer by layer using the above parameters in a stereolithography process. Optionally, the three-dimensional article can have the shape of a test sample or an orthodontic article. Remove the three-dimensional article from the cartridge of the stereolithography apparatus.

[0407] Cleaning process:

[0408] The three-dimensional article can be cleaned in excess material using the parameters described in the above text as described in WO 2019 / 023120 A1 (3M).

[0409] Post-curing

[0410] Use an Elipar ™ Deep-Cure S dental curing light (3M Oral Care) for the post-curing step. The dental curing light provides light having a wavelength in the range of 430 nm to 480 nm. Apply the following conditions: 1470 mW / cm 2 , for 60 s.

[0411] Testing (general method)

[0412] Prepare samples (2 mm × 2 mm × 25 mm) for flexural strength (FS) testing using the formulation given in Table 3 by the stereolithography process described above, followed by the post-curing step. The results are given in Table 4.

[0413]

[0414] Table 4

[0415] The results in Table 4 show that TPO (CE1) can be used to obtain 3D printed specimens having a flexural strength of about 40 MPa.

[0416] Additional post-curing using visible light does not result in an increase in flexural strength.

[0417] Using a combination of TPO and camphorquinone (CE2) results in a flexural strength of about 30 MPa after 3D printing and an increase in flexural strength to above 70 MPa after additional treatment with visible light.

[0418] In contrast, using PPD (IE1) results in specimens having very high flexibility after 3D printing that cannot be broken by the testing machine ( Figure 3 ), and thus the flexural strength cannot be determined.

[0419] Performing an additional photocuring step increases the flexural strength to a value close to 80 MPa.

[0420] This clearly shows that PPD can be used to 3D print polymerizable compositions into a highly flexible pre-cured state, which allows for the manipulation and handling of the obtained articles, such as the manipulation and handling of stainless steel dental crowns is possible.

[0421] Furthermore, if needed, in terms of 3D printed attachments, the 3D printed articles in the pre-cured state have a (meth)acrylate adhesion sufficient for achieving good adhesion to the binder.

[0422] Final curing (post-curing) can be achieved with visible light in the patient's mouth to ensure strength and durability.

Claims

1. A curable composition for use in a method of treating the dental condition in a patient's oral cavity, the curable composition comprising: A radiation-curable component, A photoinitiator that exhibits absorption in the ultraviolet region and absorption in the visible region, with stronger absorption at 390 nm than at 450 nm, Optional filler, Optional additives, The method comprises the following steps: Layer-by-layer manufacturing of dental or orthodontic articles using radiation in the ultraviolet light region, Attach the dental or orthodontic article to the surface of hard tooth tissue or dental material, Apply radiation in the visible light region to the dental or orthodontic article, The ultraviolet light region is defined as light having a wavelength in the range of 350 nm to 410 nm, The visible light region is defined as light having a wavelength in the range of 440 nm to 500 nm.

2. The curable composition for use according to any one of the preceding claims, the photoinitiator Comprises a diketone moiety, and / or Is non-fluorescent.

3. The curable composition for particular use according to any one of the preceding claims, the photoinitiator is selected from components comprising a phenyl-1,2-propanedione moiety, components comprising a benzil moiety, bis(cyclopentadienyl)bis[2,6-difluoro-3-(1-pyrrolyl)phenyltitanium], monoacylgermanium or diacylgermanium moieties, and mixtures thereof.

4. The curable composition for use according to any one of the preceding claims, the curable composition comprises only one photoinitiator, which is optionally combined with an activator.

5. The curable composition for use according to any one of the preceding claims, the curable composition is characterized in that the viscosity at 23 °C and a shear rate of 1 s -1 Is < 50 Pa s.

6. The curable composition for use according to any one of the preceding claims, the radiation-curable component is selected from (meth)acrylate components, urethane (meth)acrylate components, and mixtures thereof.

7. The curable composition for use according to any one of the preceding claims, the filler comprises filler particles of nanoscale size.

8. The curable composition for use according to any one of the preceding claims, the curable composition comprises the following amounts of components: Radiation-curable component: 20% to 95% by weight, Photoinitiator optionally combined with an activator: 0.01% to 5% by weight, Filler: 0 wt% to 70 wt%, Additive: 0 wt% to 10 wt%.

9. The curable composition used according to any one of the preceding claims, wherein the curable composition comprises the following amounts of components: Methacrylate not containing a urethane moiety: 30 wt% to 65 wt%, Urethane (meth)acrylate: 10 wt% to 20 wt%, Photoinitiator, optionally combined with an activator: 0.02 wt% to 4 wt%, Filler: 15 wt% to 50 wt%, Additive: 0.1 wt% to 5 wt%, wt% is relative to the curable composition.

10. The curable composition used according to any one of the preceding claims, wherein the curable composition comprises the following amounts of components: Methacrylate not containing a urethane moiety: 30 wt% to 65 wt%, Urethane (meth)acrylate: 10 wt% to 20 wt%, Photoinitiator, optionally combined with an activator: 0.02 wt% to 4 wt%, Filler comprising nano-sized filler particles having an average particle size of 40 nm or less: 15 wt% to 50 wt%, Additive: 0.1 wt% to 5 wt%, wt% is relative to the curable composition.

11. The curable composition used according to any one of the preceding claims, wherein the dental or orthodontic article has a surface section for attaching the dental or orthodontic article to the surface of hard dental tissue or dental material, The method comprises the following additional steps: Optionally post-treating the pre-cured dental or orthodontic article; and Applying a dental adhesive or dental cement to the surface section of the dental or orthodontic article intended to be attached to the hard dental tissue or dental material.

12. The curable composition used according to any one of the preceding claims, wherein the method does not include the following additional steps: Roughening the surface section of the dental or orthodontic article intended to be attached to the hard dental tissue or the dental material; and / or Performing a further radiation curing step on the dental or orthodontic article before attaching the dental or orthodontic article to the hard dental tissue or the dental material.

13. A kit box, said kit box comprising a curable composition, a dental adhesive or a dental cement for use according to any one of the preceding claims, an optional tooth positioning tray and optional instructions for use.

14. A pre-cured composition obtainable by processing a curable composition for use according to any one of claims 1 to 12 in an additive manufacturing method, said pre-cured composition having the shape of a dental or orthodontic article.

15. The pre-cured composition according to the preceding claim, characterized by the following features, alone or in combination: being Rubber-elastic; The elongation at break, determined according to DIN EN ISO 527-1:2012-06, is in the range of 10% to 200%.

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