Milling blanks based on polymerized prosthetic material, in particular a polymerized, fracture-tough prosthetic material, in the form of milling blanks

Abstract

Milling blank comprising polymeric prosthesis material based on the reaction of at least one (A) liquid monomer component and one (B) powdered component, wherein the (A) liquid monomer component comprises a mixture of monomers comprising at least one urethane(meth)acrylate, preferably one urethane dimethacrylate, and a multi-crosslinker comprising tris(2-hydroxyethyl) isocyanurate triacrylate, and Core-shell particles, wherein the core-shell particles are primary particles with a mean particle size of less than or equal to d 50 ≤ 500 nm to 10 nm characterized in that the milling blank comprises core-shell particles modified by an elastic phase to 0.001 to 20 wt.% with respect to the overall composition, and the prosthesis material is in the form of a three-dimensional molded body suitable for subtractive machining, and wherein the molded body has a fracture toughness of ≥ 1.9 MPa · m 1 / 2and a total fracture energy of ≥ 900 J / m 2 exhibits.

Description

[0001] The invention relates to a three-dimensional shaped body, in particular a milling blank, made of a polymeric prosthesis material, which is suitable for subtractive machining using CNC and / or CAD / CAM, with a fracture toughness of greater than or equal to 1.9 MPa·m 1 / 2 and a total fracture energy of greater than or equal to 900 J / m 2 The milling blank comprises core-shell particles modified by an elastic phase and is based on a content of polymerized urethane (meth)acrylate and tris(2-hydroxyethyl) isocyanurate triacrylate. Furthermore, the invention relates to the use of the milling blanks for the production of at least parts of dental prosthetic components, such as dentures, bite splints, drilling templates, artificial teeth, crowns and bridges, or also orthodontic appliances and instruments in the medical field. The milling blank is particularly preferably suitable for machining by milling.

[0002] Due to the limited motor skills of denture wearers, who are generally older, dentures sometimes fall onto hard surfaces (tiles, sinks) during cleaning, which can lead to chipping or breakage. These chips result in additional work and costs for the dental laboratory and are therefore undesirable. Furthermore, especially with implant-supported dentures, the significantly higher chewing forces can cause damage to the prosthesis.

[0003] DE 10 2005 012 825 A1 and EP1 702 633 A2 disclose the use of modified pearl polymers in two-component denture materials, which are used together with the powder component and a liquid monomer component. US 2014 / 0162216 A1 discloses the production of a milling blank from a heat-curing or light-curing material. US 2009 / 0192240 A1 discloses the production of a composite material comprising core-shell particles (Genioperl® P22; Wacker) with a silicone elastomer core. US 2011 / 0269894 A1 discloses a composite material comprising an elastic phase and modified polymeric particles in a vinyl monomer. DE 10 2012 013 514 A1 discloses PMMA plastics comprising poly(orgno)siloxanes. DE 10 2012 022 693 A1 discloses a 2-component system comprising a liquid component containing components for impact modification.

[0004] For these reasons, there is a need for a prosthetic material that can tolerate short-term stresses, such as the aforementioned short-term, high mechanical loads, without material damage. These prosthetic materials are referred to as high-impact materials. The requirements for these materials are described in DIN ISO 20795-1. Products that meet these requirements have been on the market for several years; however, these are predominantly classified as heat-curing prosthetic materials. Furthermore, there is a need for milling blocks for CAD / CAM processing. For certain prosthetic applications, such as implant-supported dentures, occlusal splints, or orthodontic appliances, there is a need for materials that can also withstand short-term, high mechanical loads without material damage. To date, however, only PMMA milling blocks for CAD / CAM processing are known.However, these materials are not always able to withstand the chewing forces of the aforementioned prosthetic parts or orthodontic appliances.

[0005] The object of the invention was to provide a millable material, preferably in the form of a milling blank, such as a material suitable for medical applications, which exceeds the requirements of the DIN ISO 20795-1 standard with regard to fracture toughness. Furthermore, it was an object that the millable material, particularly in the form of a milling blank, be available. It was also an object that the milling blank meet the aesthetic requirements for the transparency of prosthetic materials and contain no or only a very small number of bubbles. A further object was to provide a highly fracture-resistant material in the form of a milling blank, in particular a milling blank made of a prosthetic material whose transparency is not impaired compared to the base material. A further object was to optionally provide the milling blank in multiple colors, i.e., flesh-colored and tooth-colored.

[0006] It was surprisingly discovered that a milling blank can be provided from a material, in particular a prosthetic material, with the required properties regarding fracture toughness and preferably regarding the specified transparency. The milling blank is based on a fully polymerized prosthetic material comprising core-shell particles and polymerized urethane (meth)acrylate and tris(2-hydroxyethyl) isocyanurate triacrylate.

[0007] Furthermore, millable materials are subject to increased demands regarding the properties of their surface and the surfaces obtained after the milling process. For example, microcracks must not form as a result of the machining.

[0008] Liquid additives potentially suitable for increasing fracture toughness, such as acrylonitrile butadiene copolymers, tend to yellow the denture material. This typically occurs in the presence of oxidizing substances such as peroxides or atmospheric oxygen. Furthermore, liquid additives such as silicone acrylates have a significantly different refractive index than PMMA, typically resulting in an opaque material. While urethane acrylate-based liquid additives, such as urethane acrylates, often improve the fracture toughness of materials, they do not meet the minimum fracture toughness requirements of ISO 20795-1. Another disadvantage of some additives is water absorption during the polymerization process, leading to an undesirable whitening of the denture material during wear.

[0009] The problems were solved by a milling blank according to claim 1 and a method for producing the milling blanks according to claim 9, wherein specific embodiments are explained in the dependent claims and in the description.

[0010] The invention thus relates to a milling blank comprising polymeric prosthesis material based on the reaction of at least one (A) liquid monomer component and one (B) powdered component, wherein the (A) liquid monomer component comprises a mixture of monomers comprising at least one urethane(meth)acrylate, preferably one urethane dimethacrylate, as well as a multi-crosslinker comprising tris(2-hydroxyethyl) isocyanurate triacrylate, and core-shell particles, wherein the core-shell particles are primary particles with a mean particle size of less than or equal to d 50≤ 500 nm to 10 nm, wherein the milling blank comprises core-shell particles modified by an elastic phase to 0.001 to 20 wt.% with respect to the overall composition, and the prosthesis material is in the form of a three-dimensional mold suitable for subtractive machining, and wherein the mold has a fracture toughness of ≥ 1.9 MPa · m 1 / 2 and a total fracture energy of ≥ 900 J / m 2 exhibits.

[0011] In particular, the milling blank exhibits a fracture toughness of greater than or equal to 2.3 MPa · m 1 / 2 and optionally a total fracture energy of greater than or equal to 1000 J / m 2 on.

[0012] The milling blank according to the invention can preferably be multicolored, in particular defined areas of the milling blank are tooth colors and / or defined areas are color-matched to the gingiva, in particular these areas are flesh-colored.

[0013] According to another alternative, the milling blank can be purely tooth-colored or purely color-matched to the gingiva. Both the tooth and flesh colors can be adapted to natural color gradients. Furthermore, the milling blanks according to the invention preferably comprise (i) core-shell particles modified by an elastic phase and / or (ii) at least one polymer comprising at least one polymerized urethane (meth)acrylate.

[0014] The core-shell particles preferably comprise primary particles with a mean particle size of less than or equal to d 50 ≤ 500 nm to 10 nm, preferably from 100 to 450 nm, particularly preferably from 200 to 400 nm. The primary particles of the core-shell particles can exist as aggregates of primary particles. These aggregates preferably have an average particle size of less than or equal to d 50 400 µm (micrometers).

[0015] To adjust the properties of the milling blank, it may also be preferred if the milling blank comprises (i) 0.001 to 20 wt.% core-shell particles modified by at least one elastic phase with respect to the overall composition, preferably comprising up to 10 wt.% core-shell particles, and particularly preferably up to 5 wt.%.

[0016] Furthermore, it is preferred if the milling blank contains up to iii) 0.001 to 20 wt.% at least one polymerized urethane (meth)acrylate, in particular a urethane dimethacrylate, in relation to the overall composition, preferably up to 10 wt.%, particularly preferably up to 5 wt.%. Preferably, the urethane dimethacrylate is polymerized into the prosthesis material.

[0017] According to the invention, the problem is solved by the synergistic use of core-shell particles and at least one urethane methacrylate in the denture base material. Particularly good results in the fully polymerized denture material can be achieved by combining core-shell particles in the liquid monomer component with at least one urethane acrylate or urethane methacrylate in the liquid. High transparency of the denture material was ensured by selecting specific core-shell particles with a refractive index similar to that of the fully polymerized denture material. Therefore, the core-shell particles preferably have a refractive index of approximately 1.49 (Rl ∼ 1.4900).

[0018] According to the invention, particularly preferred core-shell particles are present in aggregated form. The objectives can be achieved by using aggregated core-shell particles (irregularly shaped aggregates, d 50The additive is dissolved in liquids with a particle size of approximately 50–400 µm (particularly 50–300 µm), and the primary particle size is approximately 200–400 nm. The core-shell particles are presumably aggregated in the solid due to surface interactions. The additive is mixed with the liquid and forms a stable suspension, which only settles slightly within a few weeks. Upon suspension in MMA, the aggregates decompose relatively quickly into the primary particles, which can then be homogeneously distributed and are preferably homogeneously distributed within the milling blanks.

[0019] By using the core-shell particles as a high-impact additive in combination with at least one urethane acrylate, preferably a urethane methacrylate, prosthetic materials can be produced that meet the requirements of ISO 20795-1 with regard to high-impact properties. Furthermore, a prosthetic material can be provided whose flexural strength and modulus of elasticity are on the same order of magnitude as non-high-impact materials and which is simultaneously highly transparent and color-stable. The prostheses according to the invention do not exhibit any white discoloration due to contact with water-containing materials such as duplicating gels or plasters during and after the polymerization process.

[0020] To distinguish prosthetic materials, such as the material used here for the milling blank, from conventional dental materials, it is emphasized that prosthetic materials contain significant amounts of polymeric powder components, such as PMMA (poly(meth)methylacrylate) and / or poly(ethyl)methacrylate, particularly at a concentration of 50% by weight or greater in the overall composition. Dental materials for the fabrication of fillings are essentially based on polymerizable monomers, which are preferably present in polymerizable compositions at a concentration of less than 35% by weight.

[0021] Conventional denture materials are typically offered in a kit containing a powder component and a liquid component. According to the invention, a milled blank in the form of a polymerized denture material, optionally color-matched to the tooth situation and / or gingiva, is provided.

[0022] According to the invention, core-shell particles, which may be present as aggregates, are particularly suitable for use, whereby these aggregates can be separated into individual particles within the short swelling time, in particular they break down into individual particles after the addition of the liquid monomer component.

[0023] According to a further embodiment, the milling blanks according to the invention may additionally contain one or more substances from the groups of fillers, pigments, stabilizers, regulators, antimicrobial additives, UV absorbers, thixotropic agents, catalysts and crosslinkers.

[0024] According to the invention, milling blanks preferably comprise 55 wt% or more of PMMA as a percentage of the total composition, in particular 60, 70, 75, 80, 85, 90, 95, or 97 wt% of PMMA as a percentage of the total composition, and optionally 0.001 to 5 wt% of core-shell particles, preferably 0.5 to 2 wt%, and particularly preferably 0.5 to 1.5 wt%. Furthermore, it may be preferred if the milling blanks also contain 0.001 to 10 wt% urethane (meth)acrylate, preferably 0.5 to 5 wt%, and particularly preferably 0.5 to 2 wt%.

[0025] According to a further particularly preferred embodiment, the milling blanks are based on a fully polymerized, fracture-resistant prosthesis material, which is preferably obtainable according to the inventive method. According to an alternative, the invention relates to a method for producing a fully polymerized prosthesis base material and a prosthesis material, in particular a prosthesis material in the form of a milling blank, in which the components A) at least one liquid monomer component, and B) at least one powdered component, of the prosthesis material are mixed and subsequently fully polymerized.

[0026] The invention also relates to a method for producing a fully polymerized prosthetic material in the form of a three-dimensional molded body, preferably in the form of a milling blank, in which a polymerizable prosthetic material comprising component (A) and / or (B), wherein component A) is at least a liquid monomer component, and B) is at least a powdered component, and the polymerizable prosthetic material in component (A) and / or (B) contains (i) core-shell particles modified by an elastic phase and (ii) at least one urethane (meth)acrylate, the component (A) and / or (B) (a) are mixed, (b) are transferred into a three-dimensional shape, in particular into the shape of a semi-finished product shape of milling blanks or into the shape of milling blanks, (c) and subsequently the polymerizable prosthesis material is polymerized.

[0027] The process can preferably be carried out in such a way that the mixture comprising the A) monomer component and the B) powdered component, in particular as a polymerizable prosthesis base material, is introduced into a negative mold, such as a casting mold, in particular a semi-finished product mold of milling blanks or a negative mold of a milling blank or at least one dental, prosthetic component, and is polymerized, in particular under increased pressure, in particular greater than or equal to 2 bar, such as 2.5 to 10 bar, preferably 2 to 4 bar.

[0028] According to the invention, a three-dimensional shape preferably refers to semi-finished product shapes of milling blanks, such as rod-shaped, disc-shaped, cylindrical, or other semi-finished product shapes and finished product shapes of milling blanks known to those skilled in the art; disc-shaped, preferably cylindrical milling blanks are particularly preferred. Cylindrical can encompass mathematical or circular cylindrical shapes, such as circular discs. Likewise, the milling blanks can be cuboid-shaped or otherwise have a polyhedral shape, or any other suitable three-dimensional shape.

[0029] According to the invention, it is preferred if in the process the A) monomer component and the B) powdered component are mixed in a weight ratio of 1 : 50 to 50 : 1, in particular in a weight ratio of 8 to 11 powdered component to 5 to 8 monomer component.

[0030] Component A), the liquid monomer component, preferably comprises at least one monomer or a mixture of monomers comprising a) methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, n-hexyl methacrylate, 2-phenoxyethyl methacrylate, isobornyl methacrylate, isodecyl methacrylate, polypropylene glycol monomethacrylate, tetrahydrofuryl methacrylate, polypropylene glycol monomethacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, n-hexyl acrylate, 2-phenoxyethyl acrylate, isobornyl acrylate, isodecyl acrylate, polypropylene glycol monoacrylate, tetrahydrofuryl acrylate, polypropylene glycol monoacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, benzyl, furfuryl, or Phenyl(meth)acrylate, a mixture containing at least one of these (meth)acrylates and / or copolymers comprising one or at least two of the aforementioned monomers, and / or b) a double and / or multiple crosslinker comprising 1,4-butanediol dimethacrylate (1,4-BDMA) or pentaerythritol tetraacrylate, bis-GMA monomer (bisphenyl-A glycidyl methacrylate), triethylene glycol dimethacrylate (TEGDMA) and diethylene glycol dimethacrylate (DEGMA), tetraethylene glycol di(meth)acrylate, decanediol di(meth)acrylate, dodecanediol di(meth)acrylate, hexyldecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, as well as butanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylates, ethoxylated / propoxylated bisphenol-A di(meth)acrylates, a mixture containing at least one of these (meth)acrylates and / or copolymers comprising one or at least two of the the aforementioned monomers.

[0031] Component B), the powdered component, preferably comprises polymeric particles comprising polymers in the form of polymer powder comprising polyalkyl(meth)acrylates, which are optionally cross-linked and exist as homo- or co-polymers, wherein the polymers are based on at least one of the monomers comprising a (meth)acrylate group, selected from methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, n-hexyl methacrylate, 2-phenoxyethyl methacrylate, isobornyl methacrylate, isodecyl methacrylate, polypropylene glycol mono-methacrylate, tetrahydrofuryl methacrylate, polypropylene glycol mono-methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, n-hexyl acrylate, 2-phenoxyethyl acrylate, isobornyl acrylate, isodecyl acrylate, polypropylene glycol mono-acrylate, tetrahydrofuryl methacrylate, Polypropylene glycol mono-acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate,A mixture containing at least one of these (meth)acrylates and / or copolymers comprising one or at least two of the aforementioned monomers, polyamide particles, polyamide fibers, particularly preferably polymethyl methacrylate (PMMA). Furthermore, the polymeric particles may also comprise mixtures of dental monomers such as MMA and additionally at least one crosslinking agent.

[0032] Particularly preferred are powdered components B) comprising polymethyl methacrylate (PMMA) beads as polymeric particles and / or splinter polymers, as well as copolymers comprising, as incorporated comonomers, styrene, alpha-methylstyrene, vinyltoluene, substituted vinyltoluenes such as vinylbenzyl chlorides, vinyl halides such as vinyl chloride, vinyl esters such as vinyl acetate, heterocyclic vinyl compounds such as 2-vinylpyridine, vinyl acetate and vinyl propionate, butadiene, isobutylene, 2-chlorobutadiene, 2-methylbutadiene, vinylpyridine, cyclopentene, (meth)acrylic acid esters such as methyl methacrylate, butyl methacrylate, butyl acrylate and hydroxyethyl methacrylate, furthermore acrylonitrile, maleic acid and maleic acid derivatives such as maleic anhydride, fumaric acid and fumaric acid derivatives such as fumaric acid esters, acrylic acid, methacrylic acid, aryl(meth)acrylates such as benzyl methacrylate or phenyl methacrylate and optional mixtures of these comonomers.

[0033] Furthermore, the prosthesis material preferably comprises in component (A) and / or (B) (iii) at least one initiator or an initiator system for autopolymerization, radiation curing, in particular UV curing, hot polymerization or dual curing.

[0034] According to a further particularly preferred alternative, the subject of the invention is a polymerized prosthesis material obtainable by a method according to an inventive method, which is in the form of a three-dimensional molded body, in particular in the form of a milling blank or a semi-finished product mold.

[0035] It is further preferred if the polymerized prosthesis material has a fracture toughness of ≥ 1.9 MPa · m 1 / 2 and a total fracture energy of ≥ 900 J / m 2 exhibits.

[0036] The milling blank according to the invention, made from the prosthesis material, preferably exhibits a fracture toughness (k) as fully polymerized prosthesis material.max ; maximum stress intensity factor) of greater than or equal to 1.9 MPa · m 1 / 2 on, especially greater than or equal to 2 MPa · m 1 / 2 , and preferably also a total fracture work (W f ) of greater than or equal to 900 J / m 2 A fracture toughness of ≥ 2.1 MPa · m is particularly preferred. 1 / 2 , preferably at ≥ 2.3 MPa · m 1 / 2 , ≥ 2.4 MPa · m 1 / 2 Furthermore, it is preferred if the total fracture energy is also greater than ≥ 900 J / m². 2 is, in particular, greater than or equal to ≥ 950 J / m² 2 , ≥ 1000 J / m 2 , especially preferred greater than or equal to 1030 J / m² 2 A flexural strength greater than 65 MPa is particularly preferred, greater than 70 MPa is particularly preferred, and more preferably greater than or equal to 75 MPa. A particularly preferred prosthesis material exhibits a fracture toughness of > 2.3 MPa*m 1 / 2 and a total fracture energy of > 1000 J / m 2 on.

[0037] Furthermore, it is preferred if the transparency of the unpigmented, polymerized milling blanks and the prosthetic parts or orthodontic appliances produced therefrom is greater than or equal to 85%, in particular greater than or equal to 90% (measured on a 3 mm thick plate).

[0038] According to one embodiment of the invention, the subject matter of the invention is an autopolymerizable or cold-polymerizable or heat-polymerizable two-component denture base material, in particular a polymerizable denture material, comprising A) at least one liquid monomer component, B) at least one powdered component, in particular for use in the production of milling blanks, . wherein the prosthetic material is in component (A) and / or (B) (i) at least one initiator or initiator system for autopolymerization or cold polymerization or hot polymerization, (ii) core-shell particles modified by an elastic phase and (iii) contains at least one urethane(meth)acrylate, in particular a urethane dimethacrylate, preferably a bis(methacryloxy-2-ethoxycarbonylamino) alkylene, diurethane acrylate oligomer, alkyl-functional urethane dimethacrylate oligomers, aromatic-functionalized urethane dimethacrylate oligomers, aliphatic unsaturated urethane acrylates, bis(methacryloxy-2-ethoxycarbonylamino) substituted polyether, aromatic urethane diacrylate oligomers, aliphatic urethane diacrylate oligomers, monofunctional urethane acrylates, aliphatic urethane diacrylates, hexafunctional aliphatic urethane resins, aliphatic urethane triacrylate, UDMA, aliphatic urethane acrylate oligomer, unsaturated aliphatic urethane acrylate.

[0039] The components of the initiator system can be divided into components A) and B), as explained below. The invention also relates to a method for producing the milling blank from the aforementioned polymerizable prosthesis material, as well as a three-dimensional blank obtainable by mixing, shaping, and polymerizing the polymerizable prosthesis material.

[0040] Particularly preferably, the component (A) comprises at least one liquid monomer component, (i) at least one initiator or initiator system for autopolymerization or hot polymerization or part of the components of the initiator system, (ii) core-shell particles modified by at least one elastic phase and (iii) at least one urethane(meth)acrylate, in particular urethane dimethacrylate.

[0041] It is particularly preferred if component (ii) is present in a proportion of 0.001 to 20 wt.%, in particular up to 10 wt.%, preferably up to 5 wt.%, of at least one elastic phase-modified core-shell particles, in relation to the total composition of component (A), and (iii) is present in a proportion of at least one urethane (meth)acrylate, preferably a urethane dimethacrylate, in a proportion of 0.001 to 20 wt.%, preferably up to 10 wt.%, further preferably up to 5 wt.%, of the total composition of component (A) (i.e., in relation to 100 wt.% of component (A)).

[0042] The milling blank according to the invention, made of denture base material, in particular of autopolymerized denture base material, shows no negative influence on the sun test according to ISO 20795-1 despite the added high-impact modifier (core-shell particles and urethane (meth)acrylate). The core-shell particles are also referred to as high-impact modifiers.

[0043] Particularly preferred milled blanks made of prosthetic materials preferably have core-shell particles in which the distribution of the elastic phase of the modified core-shell particles is selected from the possibilities a to d: a) elastic phase as core (e.g. made of butyl acrylate) in hard outer shell (e.g. made of PMMA) (core-shell particles); b) several elastic phases as cores in a hard matrix, c) core-shell particles from a), distributed in a hard matrix and d) hard core with elastic phase as outer shell.

[0044] Core-shell particles according to the invention can also have the following multi-layer structure, e) an inner core with several layers as shells and an outer shell, wherein in particular (i) at least one of the shells, preferably the outer shell, is hard and the remaining shells and the core each consist independently of elastic phases. Alternatively, the elastic phases and the hard phases can be distributed differently between the shells and the core.

[0045] Furthermore, preferred core-shell particles have a refractive index similar to that of the polymerized prosthesis material. Preferably, the refractive index of the core-shell particles is around 1.4900 with a range of plus / minus 0.02, particularly + / - 0.01. According to the invention, particularly preferred core-shell particles are present in aggregated form. The aggregates of the core-shell particles, which may be irregularly shaped, have a mean diameter d as an irregularly shaped aggregate. 50 ~ 50 - 300 µm. The preferred primary particle size is less than 500 nm, particularly up to 100 nm, preferably from 200 - 400 nm. Likewise, core-shell particles with a primary particle size of less than or equal to 200 nm down to 2 nm, as well as those between 150 and 10 nm, can be used as core-shell particles.

[0046] Preferably, the core-shell particles have a refractive index of 1.48 to 1.60, particularly of 1.49 to 1.55. The refractive index of the core-shell particles is particularly preferably in the range of the refractive index of PMMA or PEMA; therefore, the refractive index is preferably around 1.48 to 1.50.

[0047] Core-shell particles with a density of 0.9 to 1.5 g / ml, particularly 0.95 to 1.4 g / ml, are also preferred. Preferably, the bulk density is also between 0.1 and 0.6 g / ml.

[0048] A hard outer shell, hard matrix, and / or hard core is understood to be a material that preferably has a lower elasticity than the material of the elastic phase. Preferably, the elasticity of the hard materials is at least 40% lower than that of the elastic phase. Preferred inorganic hard cores exhibit essentially no deformation under the influence of a force, while the organic hard materials undergo significantly less deformation under the influence of a force than the elastic phase. The hard materials, as a hard outer shell, hard matrix, and / or hard core, stabilize the elastic phase in its shape. An elastic phase is formed from at least one elastic material that undergoes reversible deformation under the influence of a force. The deformation of the elastic phase is advantageously completely reversible without the application of a force.

[0049] Particularly preferably, the powdered component B) polymethyl methacrylate (PMMA) comprises beads as polymeric particles and / or splinter polymers, especially with particle sizes of 10–100 µm, and / or is based on copolymers comprising polymerized comonomers styrene, alpha-methylstyrene, vinyltoluene, substituted vinyltoluenes such as vinylbenzyl chlorides, vinyl halides such as vinyl chloride, vinyl esters such as vinyl acetate, heterocyclic vinyl compounds such as 2-vinylpyridine, vinyl acetate and vinyl propionate, butadiene, isobutylene, 2-chlorobutadiene, 2-methylbutadiene, vinylpyridine, cyclopentene, (meth)acrylic acid esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, butyl acrylate and hydroxyethyl methacrylate, furthermore acrylonitrile, maleic acid and maleic acid derivatives such as maleic anhydride, fumaric acid and Fumaric acid derivatives such as fumaric acid esters, acrylic acid,Methacrylic acid and aryl(meth)acrylates such as benzyl methacrylate or phenyl methacrylate, and optionally mixtures of these comonomers.

[0050] Optionally, the powdered component may additionally comprise: b) inorganic fillers comprising pyrogenic or precipitated silicas, dental glasses such as aluminosilicate glasses or fluoroaluminosilicate glasses, barium aluminum silicate, strontium silicate, strontium borosilicate, lithium silicate, lithium aluminum silicate, layered silicates, zeolites, amorphous spherical fillers based on oxides or mixed oxides, in particular mixed oxides of SiO2 and ZrO2, glass fibers and / or carbon fibers, and mixtures comprising the powdered components a) and b).

[0051] The b) inorganic fillers are generally used at a concentration of 0 to 10 wt.%, preferably 0.0001 to 3 wt.%, based on the total prosthetic resin composition or the sum of components (A) and (B). In component (B), with respect to the total composition of component (B) of 100 wt.%, they are generally present in the range of 0 to 20 wt.%, preferably 0.001 to 10 wt.%.

[0052] Also within the scope of the invention are polymeric particles based on at least one (meth)acrylate monomer with only one (meth)acrylate group or based on a mixture of at least two of these (meth)acrylate monomers.

[0053] The core-shell particles according to the invention preferably comprise, as an elastic phase, at least one poly(n-butyl acrylate) PBA, butadiene-styrene copolymer, nitrile-butadiene copolymer, silicone rubber (graft copolymer), polyurethane polymer, or polyolefin-based polyurethane (polybutadiene-based polyurethane), which may preferably be in MMA. The particle size of the core-shell particles can be less than or equal to 500 nm, such as between 50 nm and 500 nm, in particular less than or equal to 400 nm to 100 nm, or alternatively less than 100 nm to 2 nm. Likewise, the elastic phase can be based on polydimethylsiloxane-modified polyurethanes and / or epoxy-functionalized elastic phases.

[0054] The core-shell particles according to the invention comprise, as a hard shell, hard core and / or hard matrix, at least a (meth)acrylate polymer, preferably an alkyl(meth)acrylate polymer, such as PMMA; polystyrene, an epoxy-functionalized core, as well as homo- or co-condensates of the aforementioned polymers.

[0055] Particularly favored core-shell particles, in combination with the urethane (meth)acrylate, give the polymerized prosthesis material in the milling blank high-impact properties, with a fracture toughness of ≥ 1.9 MPa · m 1 / 2 , preferably ≥ 2 MPa · m 1 / 2 and a total fracture energy of ≥ 900 J / m 2 Preferred core-shell particles include aggregates with d 50 < 400 µm and primary particle sizes of d 50 smaller than 500 nm. Preferably, the primary particles of the core-shell particles can be greater than or equal to 100 nm, especially as d 50 -Value.

[0056] Equally suitable core-shell particles comprise an elastic core comprising acrylate polymers with a hard outer shell, particularly with a particle size of less than 1 micrometer. More preferably, the core-shell particles have reactive groups towards polymerizable monomers; preferably, the outer shell is functionalized with (meth)acrylate groups. Alternative core-shell particles comprise a silicon dioxide as the solid core and an elastic shell comprising at least one nitrile-butadiene copolymer. Further core-shell particles can be present in a monomer liquid.

[0057] According to the invention, difunctional and multifunctional urethane(meth)acrylates are preferably suitable as urethane(meth)acrylates, in particular urethane di(meth)acrylates, especially preferred is the at least one (iii) urethane dimethacrylate (UDMA) selected from linear or branched alkyl-functionalized urethane dimethacrylates, urethane dimethacrylate functionalized polyethers, in particular bis(methacryloxy-2-ethoxycarbonylamino)-alkylenes, bis(methacryloxy-2-ethoxycarbonylamino) substituted polyethers, preferably 1,6-bis(methacryloxy-2-ethoxycarbonylamino)-2,4,4-trimethylhexanes. Suitable urethane (meth)acrylates are available under the following brand names: Ebecryl 230 (aliphatic urethane diacrylate), Actilane 9290, Craynor 9200 (di-urethane acrylate ooligomer), Ebecryl 210 (aromatic urethane diacrylate oligomers), Ebecryl 270 (aliphatic urethane diacrylate oligomer), Actilane 165, Actilane 250, Genomer 1122 (monofunctional urethane acrylate), Photomer 6210 (cas no.52404-33-8 (aliphatic urethane diacrylate), Photomer 6623 (hexafunctional aliphatic urethane resin), Photomer 6891 (aliphatic urethane triacrylate), UDMA, Roskydal LS 2258 (aliphatic urethane acrylate oligomer), Roskydal XP 2513 (unsaturated aliphatic urethane acrylate).

[0058] Furthermore, the invention relates to a milling blank comprising prosthesis material based on the reaction of at least one (A) liquid monomer component and one (B) powdered component, wherein the (A) liquid monomer component comprises at least one monomer, in particular a mixture of monomers of a) methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, n-hexyl methacrylate, 2-phenoxyethyl methacrylate, isobornyl methacrylate, isodecyl methacrylate, polypropylene glycol monomethacrylate, tetrahydrofuryl methacrylate, polypropylene glycol monomethacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, n-hexyl acrylate, 2-phenoxyethyl acrylate, isobornyl acrylate, isodecyl acrylate, polypropylene glycol monoacrylate, tetrahydrofuryl acrylate, polypropylene glycol monoacrylate, hydroxyethyl acrylate, Hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, benzyl,Furfuryl or phenyl (meth)acrylate, a mixture containing at least one of these (meth)acrylates and / or copolymers comprising one or at least two of the aforementioned monomers, and / or , b) Double and / or multiple crosslinking agents (>2) comprising 1,4-butanediol dimethacrylate (1,4-BDMA) or pentaerythritol tetraacrylate, bis-GMA monomer (bisphenyl A glycidyl methacrylate), triethylene glycol dimethacrylate (TEGDMA) and diethylene glycol dimethacrylate (DEGMA), tetraethylene glycol di(meth)acrylate, decanediol di(meth)acrylate, dodecanediol di(meth)acrylate, hexyldecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, as well as butanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylates, ethoxylated / propoxylated bisphenol A di(meth)acrylates, a mixture containing at least one of these (meth)acrylates and / or Copolymers comprising one or at least two of the aforementioned monomers.

[0059] Suitable alkyl methacrylates for the liquid component (A) include methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, i-butyl, benzyl, and furfuryl methacrylates, or mixtures thereof. Methyl methacrylate is particularly preferred.

[0060] Preferably, the (A) liquid monomer component comprises: a.1) at least one monofunctional (meth)acrylate-functional monomer component of > 85 wt.%, in particular 85 to 90 wt.%; a.2) at least one difunctional di(meth)acrylate-functional monomer component of 0 to 15 wt.%, in particular 0.01 to 15 wt.%, 1 to 10 wt.%; and a.3) at least one (meth)acrylate-functional trifunctional (meth)acrylate or one multifunctional (meth)acrylate of 0 to 10 wt.%, in particular 0.01 to 10 wt.%, preferably 1.0 to 8 wt.%; b) stabilizers and activators, initiators of 0 to 5 wt.%, in particular 0.01 to 5 wt.%, preferably 0.1 to 3 wt.%; c) urethane(meth)acrylate of 0.001 to 20 wt.%. in particular 0.01 to 10 wt.%, preferably 0.5 to 5 wt.%, particularly preferably 0.01 to 3 wt.%, d) core-shell particles from 0.001 to 20 wt.%, in particular 0.001 to 10 wt.%, preferably 1 to 10 wt.%, particularly preferably 0.001 to 5 wt.%.-%, preferably between 0.5 and 5 wt.%, wherein the total composition of the liquid monomer component A) is 100 wt.%. Likewise, the total composition of all components of the powdered component (B) is 100 wt.%. The core-shell particles are generally suspended in the monomers.

[0061] According to the invention, the overall composition of the powdered component (B) is as follows: b.1) 100 wt.% polymeric particles and optionally inorganic fillers or a mixture thereof, the content of which may preferably be composed as follows: 100 to 80 wt.% polymeric particles, such as PMMA, PEMA; 0 to 20 wt.% inorganic fillers, such as dental glasses, metal oxide or mixed oxide base (SiO2, ZrO2 and / or TiO2), in particular 0.01 to 10 wt.%; b.2) 0 to 5 wt.% at least a part of an initiator system, in particular 0.01 to 4 wt.%; and b.3) 0 to 5 wt.% pigments, additives, stabilizers or mixtures comprising at least one of the aforementioned components, in particular 0.01 to 4 wt.%. The aforementioned overall composition of the powdered component (B) is 100 wt.%.

[0062] Preferably, powdered polymeric components, such as PMMA, of different particle sizes can be used, optionally as homo- and / or co-polymers: a) Homo-polymer bead 1 (d 50 ~40 - 50 µm) and b) bead 2 (d 50 ~ 55 - 70 µm), and optional co-polymer c) bead 3 (d 50 ~ 40 - 50 µm) can be used.

[0063] The total composition (A) with 100 wt.% and the total composition (B) with 100 wt.% are then mixed in a weight ratio of (A) to (B) of 1 to 20 to 20 to 1, preferably in a weight ratio of (A) to (B) of 5 to 15 to 9 to 8, more preferably of 5 to 8 to 8 to 12, more preferably in a weight ratio of (A) to (B) of 7 to 10, in particular with a range of plus / minus 1, preferably of 0.5.

[0064] Other liquid monomers that can be considered are those commonly used in dentistry: examples include radically polymerizable monofunctional monomers such as mono(meth)acrylates, methyl, ethyl, butyl, benzyl, furfuryl or phenyl(meth)acrylate.

[0065] Typical difunctional monomers, also known as crosslinkers or multi-crosslinkers, are BDMA, 1,4-butanediol dimethacrylate (1,4-BDMA), bis-GMA monomer (bisphenyl-A glycidyl methacrylate, an addition product of methacrylic acid and bisphenol-A diglycidyl ether), diethylene glycol di(meth)acrylate, bisphenol-A di(meth)acrylate, decanediol di(meth)acrylate, dodecanediol di(meth)acrylate, hexyldecanediol di(meth)acrylate, as well as butanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylates, and ethoxylated / propoxylated bisphenol-A di(meth)acrylates. The following difunctional monomers can also be used as diluents (low-viscosity acrylates such as triethylene glycol dimethacrylate (TEGDMA) and Diethylene glycol dimethacrylate (DEGMA) is added. Tri- and tetrafunctional monomers or multi-crosslinkers include tri- or tetraethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tris(2-hydroxyethyl) isocyanurate triacrylate, and pentaerythritol tetraacrylate.Further crosslinking agents are disclosed below, including polymeric particles comprising copolymers, which include at least one (meth)acrylate monomer with two, three, four, five or six (meth)acrylate groups.

[0066] The proportion of liquid aliphatic (meth)acrylate at room temperature in the inventive, mixed, unpolymerized denture base material, in particular comprising components (A) and (B), is, for example, 0.5% to 40% by weight, preferably 20% to 40% by weight. The aliphatic (meth)acrylate can be present in the liquid monomer component (A) or optionally at least partially in the solid component or powder component (B), or in both. Preferably, it is located in component (A).

[0067] Furthermore, the invention relates to a milling blank made of a prosthetic material, which preferably contains in component (A), (B) or in (A) and (B) additionally at least one or more substances from the groups of fillers, pigments, stabilizers, regulators, antimicrobial additives, UV absorbers, thixotropic agents, catalysts, and crosslinking agents. Such additives—like pigments, stabilizers, and regulators—are present in the milling blank in relatively small quantities, e.g., a total of 0.01 to 3.0, particularly 0.01 to 1.0 wt% based on the total mass of the material. Suitable stabilizers are, for example, hydroquinone monomethyl ether or 2,6-di-tert-butyl-4-methylphenol (BHT).

[0068] The invention also relates to a polymerizable prosthesis material for the production of the polymerized milling blanks, which optionally additionally comprises at least one initiator or at least one initiator system for autopolymerization or hot polymerization, which, depending on the reaction conditions or polymerization system, is present in the liquid component (A), the powdered component (B) or in (A) and (B).

[0069] The following initiators and / or initiator systems for auto- or cold polymerization comprise: a) at least one initiator, in particular at least one peroxide and / or azo compound, in particular LPO: dilauroyl peroxide, BPO: dibenzoyl peroxide, t-BPEH: tert-butyl per-2-ethylhexanoate, AIBN: 2,2'-azobis(isobutyronitrile), DTBP: di-tert-butyl peroxide, and optionally b) at least one activator, in particular at least one aromatic amine, such as N,N-dimethyl p-toluidine, N,N-dihydroxyethyl p-toluidine and / or p-dibenzylaminobenzoic acid diethyl ester; or c) at least one initiator system selected from redox systems, in particular a combination selected from dibenzoyl peroxide, dilauroyl peroxide and camphorquinone with amines selected from N,N-dimethyl p-toluidine. NN-Dihydroxyethyl-p-toluidine and p-Dimethylaminobenzoic acid diethyl ester or a redox system comprising a peroxide, and a reducing agent selected from ascorbic acid, ascorbic acid derivative,Barbituric acid or a barbituric acid derivative, sulfinic acid, a sulfinic acid derivative, a redox system comprising (i) barbituric acid or thiobarbituric acid or a barbituric acid or thiobarbituric acid derivative and (ii) at least one copper salt or copper complex and (iii) at least one compound with an ionic halogen atom, a redox system comprising 1-benzyl-5-phenylbarbituric acid, copper acetylacetonate and benzyldibutylammonium chloride is particularly preferred. Polymerization in the two-component denture base material is particularly preferably initiated via a barbituric acid derivative.

[0070] Known peroxides such as dibenzoyl peroxide, dilauroyl peroxide, tert-butyl peroctoate or tert-butyl perbenzoate can be used as initiators for hot polymerization, but alpha, alpha'-azo-bis(isobutyroethyl ester), benzpinacol and 2,2'-dimethylbenzpinacol are also suitable.

[0071] Suitable photoinitiators include, for example, benzoin alkyl ethers or esters, benzil monoketals, acylphosphine oxides, or aliphatic and aromatic 1,2-diketo compounds such as 2,2-diethoxyacetophenone, 9,10-phenanthrenequinone, diacetyl, furil, anisil, 4,4'-dichlorobenzil, 4,4'-dialkoxybenzil, or camphorquinone. Photoinitiators are preferably used together with a reducing agent. Examples of reducing agents include amines such as aliphatic or aromatic tertiary amines, for example, N,N-dimethyl-p-toluidine or triethanolamine, cyanoethylmethylaniline, triethylamine, N,N-dimethylaniline, N-methyldiphenylamine, N,N-dimethyl-syn.-xylidine, N,N-3,5-tetramethylaniline, and ethyl 4-dimethylaminobenzoate, or organic phosphites. Common photoinitiator systems include, for example, camphorquinone plus ethyl 4-(N,N-dimethylamino)benzoate, 2-(ethylhexyl)-4-(N,N-dimethylamino)benzoate, or N,N-dimethylaminoethyl methacrylate.

[0072] 2,4,6-Trimethylbenzoyldiphenylphosphine oxide is particularly suitable as an initiator for UV-initiated polymerization. UV photoinitiators can be used alone, in combination with a visible light initiator, a cold curing initiator, and / or a hot curing initiator.

[0073] Dual-curing systems can also be used, e.g., photoinitiators with amines and peroxides. The initiators are preferably used in amounts of 0.01 to 1% by weight based on the total composition.

[0074] The invention also relates to a method for producing a milling blank comprising polymerized prosthesis material, as well as a milling blank or three-dimensional molded body obtainable by the method in which a polymerizable prosthesis material comprising component (A) and / or (B), wherein the component A) at least one liquid monomer component, and B) at least one powdered component, and the polymerizable prosthetic material in component (A) and / or (B) (i) core-shell particles modified by an elastic phase, wherein the core-shell particles are primary particles with a mean particle size of less than or equal to d 50 ≤ 500 nm to 10 nm, and (ii) contains at least one urethane(meth)acrylate and a multi-crosslinker comprising tris(2-hydroxyethyl)-isocyanurate triacrylate, and the components (A) and (B) (a) are mixed, (b) are transformed into a three-dimensional shape, (c) and subsequently the polymerizable prosthesis material is polymerized or cured.

[0075] Particularly preferably, A) comprises the liquid monomer component methyl methacrylate, butanediol methacrylate, and optionally at least one methacrylate-based di-, tri-, and / or tetrafunctional monomer as a multi-crosslinker, such as tris(2-hydroxyethyl) isocyanurate triacrylate and / or pentaerythritol tetraacrylate, as well as a urethane diacrylate, at least part of an initiator system, and B) comprises PMMA beads, barbituric acid or a barbituric acid derivative, and optionally pigments. Components A) and B) are mixed to produce the denture base material.

[0076] According to a preferred method variant, the A) monomer component and the B) powdered component are mixed in a weight ratio of 1:50 to 50:1, particularly in a weight ratio of 7:10 (150 g powder to 105 ml liquid or 10 g powder to 7 ml liquid, with similar density), particularly with a tolerance of plus / minus 1, preferably plus / minus 0.5. The powder-to-liquid ratio is approximately 1.35 to 1.5:1, preferably the weight ratio of powder to liquid is approximately 1.4 to 1.5:1.

[0077] According to the invention, the mixing of components A) and B) can be carried out using simple methods known to dental technicians, such as using a spatula.

[0078] The invention also relates to a pigmented milling blank made of fully polymerized prosthetic material. Furthermore, the invention relates to a milling blank made of unpigmented, fully polymerized prosthetic material with a transparency of greater than 85%, in particular greater than 90% (measured on 3 mm thick plates with a height of 3 mm).

[0079] According to a further embodiment, the invention relates to the use of core-shell particles modified with at least one elastic phase and at least one urethane di(meth)acrylate or a derivative of a urethane di(meth)acrylate in autopolymerizable or cold polymerizable prosthesis materials for the production of milling blanks.

[0080] The invention also relates to the use of core-shell particles modified with at least one elastic phase in prosthetic materials and optionally prosthetic materials containing at least one urethane dimethacrylate for the production of milling blanks or semi-finished products or semi-finished product forms of milling blanks, in particular for the production of dental milling blanks or orthopedic milling blanks. The production of CNC and / or CAD / CAM milling blanks is particularly preferred.

[0081] Furthermore, the invention relates to the use of a milling blank, in particular with at least one elastic phase-modified core-shell particles and optionally comprising a urethane dimethacrylate, for the manufacture of components, in particular dental or orthopedic components, including denture base plates, occlusal splints, crowns, bridges, artificial teeth, veneers, inlays, onlays, orthodontic appliances, active or passive orthodontic appliances, Crozat appliances, modified activators, implants, superstructures, dental bars, abutments, dental ceiling devices, dental screws, drilling templates for implantology, telescopic crowns, veneers, mouthguards, artificial joint prostheses, braces, twin-plate implants, implant components, invisible braces, brackets, multibracket appliances, orthodontic instruments and / or multiband appliances, or at least parts of the aforementioned. components,or in the veterinary field, especially for hoof repair components.

[0082] According to another alternative, the invention relates to a kit comprising an autopolymerizable prosthesis material, wherein the kit comprises separated components (A) and (B) for the production of milling blanks.

[0083] A prosthetic material according to the invention is considered autopolymerizable or cold polymerizable if the criteria of ISO 20795-1 (section 3.1) are met. Cold polymerizing plastics are defined as compositions that polymerize below 65 °C. Cold polymerizing prosthetic materials according to the invention can preferably self-cure or polymerize within a temperature range of 50 °C to 65 °C, more preferably 50 °C to 60 °C, and more preferably 50 °C to 55 °C, after mixing the two components (A) and (B). According to the aforementioned standard, polymerizable compositions that self-cure or polymerize above 65 °C are referred to as hot-curing compositions.

[0084] The powder component of the two-component denture base material typically contains a polymer powder, particularly methacrylate-based, and / or a methacrylate-based pearl polymer. Pearl polymers are often referred to as powders in this field.

[0085] Pearl polymers, especially those made from (meth)acrylates, are known to those skilled in the art. Pearl polymers based on polyalkyl(meth)acrylates are obtained in a known manner by precipitation polymerization or suspension polymerization. Suspension polymerization generally yields larger particles. The average particle sizes cover a wide range and can, for example, range from 0.1 µm to 250 µm. These can also be cross-linked pearl polymers. Suitable multifunctional cross-linking molecules can be found in the above list of monomers commonly used in dentistry. Further comonomers, as explained above, can also be incorporated into the pearl polymer.

[0086] In a preferred embodiment, crosslinkers are at least partially polymerized into the beads of the first (co)polymer and / or into the beads of the second (co)polymer. The first and second bead polymers thus also include crosslinked and partially crosslinked bead polymers.

[0087] Multifunctional comonomers or multifunctional oligomers are regularly used for crosslinking. Besides di-, tri-, and polyfunctional (meth)acrylates, graft crosslinkers with at least two different reactive C-C double bonds are also suitable, for example, alkyl methacrylates and alkyl acrylates, as well as aromatic crosslinkers such as 1,2-divinylbenzene, 1,3-divinylbenzene, and 1,4-divinylbenzene.Among the difunctional (meth)acrylates are, in particular, the (meth)acrylates of propanediol, butanediol, hexanediol, octanediol, nonanediol, decanediol, and eicosandiol, as well as the di(meth)acrylates of ethylene glycol, triethylene glycol, tetraethylene glycol, dodecaethylene glycol, tetradecaethylene glycol, propylene glycol, dipropylene glycol, and tetradecapropylene glycol, and also glycerin di(meth)acrylate, 2,2-bis[(gamma-methacryloxy-beta-oxypropoxy)phenylpropane], bis-GMA, bisphenol A dimethacrylate, neopentyl glycol di(meth)acrylate, 2,2-di-methacryloxypolyethoxyphenyl)propane with 2 to 10 ethoxy groups per molecule, and 1,2-bis(3-methacryloxy-2-hydroxypropoxy)butane. Examples include multifunctional (meth)acrylates, e.g. di-, tri- and / or tetra(meth)acrylates, such as 1,4-butanediol dimethacrylate, ethylene glycol dimethacrylate, and di- or trivinylic compounds such as divinylbenzene.

[0088] The content of such crosslinking molecules is preferably in the range of 0.1 wt.% to 10 wt.%, in particular in the range of 0.5 wt.% to 5 wt.%, in the starting mixture for the pearl polymer.

[0089] In a suitable embodiment, the liquid component (A) contains at least one of the aforementioned monofunctional alkyl methacrylate monomers and at least one crosslinking agent. These crosslinking agents can be, for example, multifunctional monomers, comonomers, or multifunctional oligomers. Besides di-, tri-, and polyfunctional (meth)acrylates, graft crosslinking agents with at least two different reactive C-C double bonds, such as alkyl methacrylates and alkyl acrylates, as well as aromatic crosslinking agents like 1,2-divinylbenzene, 1,3-divinylbenzene, and 1,4-divinylbenzene, are also suitable.Among the difunctional (meth)acrylates are, in particular, the (meth)acrylates of propanediol, butanediol, hexanediol, octanediol, nonanediol, decanediol, and eicosandiol, as well as the di(meth)acrylates of ethylene glycol, triethylene glycol, tetraethylene glycol, dodecaethylene glycol, tetradecaethylene glycol, propylene glycol, dipropylene glycol, and tetradecapropylene glycol, and also glycerin di(meth)acrylate, 2,2-bis[(gamma-methacryloxy-beta-oxypropoxy)phenylpropane], bis-GMA, bisphenol A dimethacrylate, neopentyl glycol di(meth)acrylate, 2,2-di-methacryloxypolyethoxyphenyl)propane with 2 to 10 ethoxy groups per molecule, and 1,2-bis(3-methacryloxy-2-hydroxypropoxy)butane. Examples include multifunctional (meth)acrylates, e.g. di-, tri- and / or tetra(meth)acrylates, such as 1,4-butanediol dimethacrylate, ethylene glycol dimethacrylate, and di- or trivinylic compounds such as divinylbenzene.Of course, mixtures of the aforementioned crosslinking molecules can also be used. Multifunctional compounds, especially di- and / or tri-functional compounds, are particularly suitable, as they possess elastic units and are therefore capable of imparting flexible properties to the prosthetic materials obtained from the prosthetic base materials.

[0090] Dimethacrylates, such as 1,4-butanediol dimethacrylate, serve as an example. Such crosslinking molecules can be present in the liquid monomer component (A) in amounts ranging from 0.1 to 20 wt.%, preferably from 1 to 10 wt.%, for example 5 wt.%.

[0091] In another embodiment, the liquid component (A) may contain, in addition to e.g. methyl methacrylate as the preferred main monomer (> 50 wt%), other comonomers.

[0092] The radical initiator system required for polymerization is contained in the liquid component (A) and / or the powdered component (B), depending on the reaction conditions and / or polymerization system. Details of this are known to those skilled in the art. For example, in base mixtures for cold polymers, the initiator system is usually present in both components, the liquid component and the powdered component, and is therefore combined when these components are mixed. Consequently, an initiator component (c) is generally present in the powdered component (B), particularly in the form of peroxides, perketals, peresters, and / or azo compounds. Another part of the initiator system (c) may be located in the liquid component (A), usually a co-initiator. Residual amounts of an initiator component that did not react during the production of the powdered components can also be used as initiators, e.g.,Peroxides such as dibenzoyl peroxide.

[0093] Suitable initiators for the polymerization reaction of cold- or autopolymerizing starting mixtures are, in principle, those that can initiate radical polymerization reactions. Preferred initiators are peroxides and azo compounds, such as the following: LPO: dilauroyl peroxide, BPO: dibenzoyl peroxide, t-BPEH: tert-butyl per-2-ethylhexanoate, AIBN: 2,2'-azobis-(isobutyronitrile), DTBP: di-tert-butyl peroxide.

[0094] To accelerate the initiation of radical polymerization by peroxides, suitable activators, such as aromatic amines, can be added. Examples of suitable amines include N,N-dimethyl-p-toluidine, N,N-dihydroxyethyl-p-toluidine, and diethyl p-dibenzylaminobenzoate. These amines regularly act as co-initiators and are typically present in amounts up to 0.5 wt%.

[0095] The aforementioned redox systems are suitable as radical initiator systems. In a convenient embodiment, such a redox system contains barbituric acid or thiobarbituric acid or a barbituric acid or thiobarbituric acid derivative (for example, 25 to 80 wt%), at least one copper salt or a copper complex (for example, 0.1 to 8 wt%), and at least one compound with an ionically present halogen atom (for example, 0.05 to 7 wt%). By way of example, 1-benzyl-5-phenylbarbituric acid, copper acetylacetonate, and benzyldibutylammonium chloride are suitable components of the aforementioned redox system.

[0096] The curing of polymerizable prosthetic materials is preferably carried out by redox-induced radical polymerization at room temperature or at a slightly elevated temperature under slight pressure to prevent bubble formation. Redox initiator combinations, such as combinations of benzoyl or lauryl peroxide with N,N-dimethyl symmetric-xylidine or N,N-dimethyl p-toluidine, are used as initiators for polymerization carried out at room temperature. A particularly preferred initiator system is a combination of barbituric acids with copper and chloride ions, as well as the peroxides mentioned above. This system is characterized by high color stability.

[0097] Furthermore, the powdered component (B) and / or the liquid component (A) can be supplemented in a known manner with further additives from the groups of stabilizers, UV absorbers, thixotropic agents and fillers.

[0098] The Fig.Sections 1a to d describe the subject matter of the invention in more detail without limiting it to these embodiments.

[0099] As described above, the milling blank according to the invention can preferably be tooth-colored, color-matched to the gingiva, or partially multicolored. To adjust the tooth color and / or the color or color gradients of the gingiva, color pigments can be added to the polymerizable denture material or contained within the denture material of the milling blank. Fig. 1a and Fig. 1b: SEM images of the nucleus-shell particles (left: 100x, right: 10,000x); Fig. 1c and d. SEM image of the additive suspended in MMA and dried before image capture (left: 500x, right: 10,000x); Fig. 2a and Fig. 2b - Examples of milling blanks (0) Example implementation:

[0100] Production of the powder mixture according to the invention (B): A mixture is produced from PMMA beads of different grain sizes (bead 1 homo-polymer (d50 ∼ 40 - 50 µm) 60 - 70 %, bead 2 (d50 ∼ 55 - 70 µm) 15 %, bead 3 co-polymer (d50 ∼ 40 - 50 µm) 15 %) with the addition of barbituric acid and color pigments. Preparation of the liquid / monomer mixture according to the invention (A):

[0101] A mixture is prepared from methyl methacrylate and another methacrylate-based multi-crosslinker with the addition of stabilizers and initiators (barbituric acid / copper system). Furthermore, the urethane dimethacrylate according to the invention and the core-shell particle according to the invention are added.

[0102] Example according to the invention: powder and liquid mixture: liquid Example 1 Methyl methacrylate 93,3 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-((hexyl)oxy)-phenol 0,3 N-Methyl-N, N-dioctyloctan-1-ammonium chloride 0,2 Copper(II) chloride solution 0,1 N,N-Bis(2-hydroxyethyl)-p-toluidine 0,1 total 94,00 Difunctional aliphatic urethane acrylate oligomer 3,00 tris(2-hydroxy ethyl) isocyanurate triacrylate 1,00 core-shell particles 2,00 total 100,00 powder PMMA / PMA d 50 ∼ 40-45 µm 67,5 PMMA d 50 ∼ 40-55 µm 15,000 Cross-linked PMMA d 50 ~ 55-70 µm 15,000 Phenylbenzylbarbituric acid 2,5 total 100,000 Table 1: Comparison of the example according to the invention and the comparative examples Physical properties (standard ISO 20795-1) Example 1 PMMA Flexural strength [MPa] >60 71,1 85,9 E-modulus [MPa] >1500 2389 2518 Fracture toughness [MPa m1 / 2] >1,9 2,36 1,42 Total fracture energy [J / m 2 ] >900 1030,85 197,64 Transparency [delta %] (after 6 d / 37 °C in Ringer's solution) -3,16 Production of test specimens, determination of color values, determination of mechanical properties: Color test specimens: The following powder and monomer mixtures are used in the ratio

[0103] 10 g powder : 7 ml liquid intensively mixed and after the swelling phase (approx. 5 min at 23 °C) test specimens with dimensions of 30 x 30 x 3 mm were cast and polymerized for 30 min at 55°C and 2 bar pressure in the Palamat elite.

[0104] Test specimens for mechanical strength: The following powder and monomer mixtures are mixed intensively for approximately 30 seconds at a ratio of 150 g powder to 105 ml liquid and, after the swelling phase (approx. 3 min. at 23 °C), poured into a metal mold. The metal mold is a brass tube closed at one end with an inner diameter of 102 mm and a height of 50 mm. Polymerization takes place in a Palamat elite pressure pot for 30 min. at 55 °C and 3.8 bar pressure.

[0105] The test pieces are milled from the received milling blank using CAD / CAM according to the specifications of ISO 20795-1 and tested.

[0106] Test specimens for colorimetric testing are produced in duplicating gel.

[0107] To determine transparency, the test specimens are immersed in Ringer's solution for 5 days at 37°C, and the color values ​​and transparency of 3 mm plates are determined before and after immersion. The measurements in Table 1 were performed according to DIN EN ISO 20795-1.

[0108] The monomer mixture according to the invention shows a significantly improved fracture toughness compared to all comparative examples, increased transparency and the lowest loss of transparency after storage in a Ringer's solution (reduced tendency to white discoloration).

Claims

[1] Milling blank comprising polymeric prosthesis material based on the reaction of at least one (A) liquid monomer component and one (B) powdered component, wherein the (A) liquid monomer component comprises a mixture of monomers comprising at least one urethane(meth)acrylate, preferably one urethane dimethacrylate, and a multi-crosslinker comprising tris(2-hydroxyethyl) isocyanurate triacrylate, and Core-shell particles, wherein the core-shell particles are primary particles with a mean particle size of less than or equal to d 50 ≤ 500 nm to 10 nm characterized by that the milling blank comprises core-shell particles modified by an elastic phase to 0.001 to 20 wt.% with respect to the overall composition, and that the prosthesis material is in the form of a three-dimensional molded body suitable for subtractive machining, and wherein the molded body has a fracture toughness of ≥ 1.9 MPa · m 1 / 2and a total fracture energy of ≥ 900 J / m 2 exhibits. [2] Milling blank according to claim 1, characterized by , that the core-shell particles comprise aggregates of primary particles, the aggregates having a mean particle size of less than or equal to (d 50 ) have a thickness of 400 µm (micrometers). [3] Milling blank according to claim 1 or 2, comprising iii) 0.001 to 20 wt.% of at least one polymerized urethane(meth)acrylate, in particular a urethane dimethacrylate, in relation to the overall composition. [4] Milling blank according to one of claims 1 to 3, characterized by , that the distribution of the elastic phase in the modified core-shell particles is selected from the possibilities a to d a) elastic phase as core in hard outer shell (core-shell particle); b) several elastic phases as nuclei in a hard matrix, c) Nucleus-shell particles from a), distributed in a hard matrix and d) hard core with elastic phase as outer shell. [5] Milling blank according to one of claims 1 to 4, characterized by that the unpigmented denture material has a transparency of greater than or equal to 90% (measured on plates with a height of 3 mm). [6] Milling blank according to one of claims 1 to 5, characterized by that it additionally contains one or more substances from the groups of fillers, pigments, stabilizers, regulators, antimicrobial additives, UV absorbers, thixotropic agents, catalysts and crosslinkers. [7] Milling blank according to one of claims 1 to 6, characterized by that it is monochromatic in tooth colors or color-matched to the gingiva, or that the milling blank is multicolored, in particular defined areas are tooth-colored and / or defined areas are color-matched to the gingiva. [8] Milling blank according to one of claims 1 to 7, characterized bythat it contains at least 55 wt% PMMA. [9] Method for producing a polymerized prosthetic material in the form of a three-dimensional molded body, in particular in the form of a milling body, by polymerizing a prosthetic material comprising the component (A) and / or (B), - where the component A) at least one liquid monomer component, and B) at least one powdered component, and the polymerizable prosthetic material in component (A) and / or (B) (i) core-shell particles modified by an elastic phase, wherein the core-shell particles are primary particles with a mean particle size of less than or equal to d 50 ≤ 500 nm to 10 nm, and (ii) comprising at least one urethane (meth)acrylate and multiple crosslinking agents - contains tris(2-hydroxyethyl)-isocyanurate triacrylate, and components (A) and (B) - (a) be mixed, (b) be transformed into a three-dimensional form, (c) and subsequently polymerize the polymerizable prosthetic material. [10] Method according to claim 9, characterized by that the A) The monomer component and B) the powdered component are mixed in a weight ratio of 1 : 50 to 50 : 1, in particular in a weight ratio of 8 to 11 powdered component to 5 to 8 monomer component. [11] Method according to claim 9 or 10, characterized by , that A) the liquid monomer component comprises at least one monomer or a mixture of monomers of a) methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, n-hexyl methacrylate, 2-phenoxyethyl methacrylate, isobornyl methacrylate, isodecyl methacrylate, polypropylene glycol monomethacrylate, tetrahydrofuryl methacrylate, polypropylene glycol monomethacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, n-hexyl acrylate, 2-phenoxyethyl acrylate, isobornyl acrylate, isodecyl acrylate, polypropylene glycol monoacrylate, tetrahydrofuryl acrylate, polypropylene glycol monoacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, benzyl, furfuryl or phenyl (meth)acrylate, a mixture containing at least one of these (Meth-)acrylates and / or copolymers comprising one or at least two of the aforementioned monomers, and / or b) bi- and / or multi-crosslinkers comprising 1,4-butanediol dimethacrylate (1,4-BDMA) or pentaerythritol tetraacrylate, Bis-GMA monomer (bisphenyl-A glycidyl methacrylate), triethylene glycol dimethacrylate (TEGDMA) and diethylene glycol dimethacrylate (DEGMA), tetraethylene glycol di(meth)acrylate, decanediol di(meth)acrylate, dodecanediol di(meth)acrylate, hexyldecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, as well as butanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylates, ethoxylated / propoxylated bisphenol-A di(meth)acrylates, a mixture containing at least one of these (meth)acrylates and / or copolymers comprising one or at least two of the aforementioned monomers, and / or, B) The powdered component comprises polymeric particles comprising polymers in the form of polymer powder comprising polyalkyl(meth)acrylates, which are optionally cross-linked and exist as homo- or co-polymers, wherein the polymers are based on at least one of the monomers comprising a (meth)acrylate group, selected from methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, n-hexyl methacrylate, 2-phenoxyethyl methacrylate, isobornyl methacrylate, isodecyl methacrylate, polypropylene glycol monomethacrylate, tetrahydrofuryl methacrylate, polypropylene glycol monomethacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, n-hexyl acrylate, 2-phenoxyethyl acrylate, isobornyl acrylate, isodecyl acrylate, polypropylene glycol monoacrylate, tetrahydrofuryl acrylate, polypropylene glycol monomethacrylate, Hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate,a mixture containing at least one of these (meth)acrylates and / or copolymers comprising one or at least two of the aforementioned monomers, polyamide particles, polyamide fibers, polymethyl methacrylate (PMMA) being particularly preferred. [12] Polymerized denture material obtainable by a method according to any one of claims 9 to 11, characterized by that the prosthetic material is in the form of a three-dimensional molded body, in particular in the form of a milling blank. [13] Polymerized prosthetic material according to claim 12, characterized by that it has a fracture toughness of ≥ 1.9 MPa · m 1 / 2 and a total fracture energy of ≥ 900 J / m 2 exhibits. [14] Use of core-shell particles modified with at least one elastic phase, wherein the core-shell particles are primary particles with a mean particle size of less than or equal to d 50≤ 500 nm to 10 nm, and the core-shell particles comprise aggregates of primary particles, with the aggregates having a mean particle size of less than or equal to (d 50 ) 400 µm (micrometers), wherein the primary particles are homogeneously dispersible and preferably homogeneously distributed in the milling blanks, for the production of milling blanks, in particular for the production of dental milling blanks or orthopedic milling blanks, preferably for the production of CNC and / or CAD / CAM milling blanks. [15] Use of a milling blank according to any one of claims 1 to 8, for the manufacture of components, in particular dental or orthopedic components, comprising denture base plates, bite splints, crowns, bridges, artificial teeth, veneers, inlays, onlays, orthodontic appliances, active or passive orthodontic appliances, Crozat appliances, modified activators, implants, superstructures, dental bars, abutments, dental clasps, dental screws, drilling templates for implantology, telescopes, veneers, mouthguards, artificial joint prostheses, braces, twin plates, implant parts, invisible braces, brackets, multibracket appliances, orthodontic instruments and / or multiband appliances or at least parts of the aforementioned components, or in the veterinary field, in particular for hoof repair components.

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