WO2024227533A1

WO2024227533A1 - Radically polymerisable compound and composition

Info

Publication number: WO2024227533A1
Application number: PCT/EP2024/056523
Authority: WO
Inventors: Stephan Neffgen; Henrik Böttcher; Swen Neander
Original assignee: Mühlbauer Technology Gmbh
Priority date: 2023-05-02
Filing date: 2024-03-12
Publication date: 2024-11-07

Abstract

The invention relates to a radically polymerisable compound represented by a structure of formula 1: PG-Sp-PCA-Sp- [OG (O) NH-K-NHC (O) O-Sp-PCA-Sp]_n-PG (formula 1), wherein PG = in each case independently selected from a radically polymerisable group, R¹ = selected from hydrogen, a C1-C8 alkyl group, an aryl group and an araliphatic group having C6-C8 carbon atoms, R² = selected from hydrogen, a C1-C4 alkyl group; Sp = in each case independently of one another a spacer group selected from unbranched and branched alkylene with C1-C19 carbon atoms, which may additionally contain oxygen, sulfur and/or -OOC- in the carbon chain, or Sp is absent; PCA = in each case independently of one another a polycyclic group; K = an aliphatic acyclic, saturated or unsaturated unit having C1-C15 carbon atoms, an aliphatic cyclic, saturated or unsaturated unit having C3-C15 carbon atoms, or an aromatic or araliphatic unit having C6-C14 carbon atoms; n = 1 to 9. The invention also relates to a process for preparing such a compound, a radically polymerisable composition containing such a compound, the use thereof and a cured dental material.

Description

03/12/2024/MR Radically polymerizable compound and composition The invention relates to a radically polymerizable compound, a method for producing such a compound, a radically polymerizable composition containing such a compound, the use of such and a cured dental material. Radically polymerizable dental materials primarily contain (meth)acrylate monomers. Dimethacrylate systems are usually used for restorative and prosthetic dental materials, such as dental fillings or dental prostheses, due to their properties such as rapid radical polymerization, good mechanical properties and aesthetic appearance. Common monomers include linear structures containing aliphatic or aromatic groups with terminal methacrylate functionalities that have a high molecular weight, such as 2,2-bis-[4-(2-hydroxy-3-methacryloxypropoxy)-phenyl]propane (BisGMA) and 7,7,9-trimethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16-diyl-bis(2-methyl-acrylate)(UDMA). For some time now, there has been an effort to largely avoid the use of BisGMA or other monomers with structural elements derived from bisphenol A and to replace them, at least in part, with other compounds. The focus here is primarily on urethane monomers and oligomers. UDMA is the most widely used commercially as at least a partial replacement for BisGMA in the field of dental materials. Monomers such as BisGMA and UDMA, although they are widely used in commercial radically polymerizable Compositions for the production of dental materials have some disadvantages. They are generally highly viscous to solid substances. Mixtures with monomers with a significantly low viscosity, such as triethylene glycol dimethacrylate (TEDMA), are therefore used. TEDMA is a very flexible, low-molecular monomer with a low viscosity (of 0.01 Pa s at 23°C) and has a high mobility during polymerization, which promotes the polymerization conversion. However, the polymerizable compositions containing these monomer mixtures and the dental materials obtained from them have some problematic properties that can impair their clinical treatment success. For example, compositions with dimethacrylate monomers have a relatively low polymerization conversion, a strong polymerization shrinkage, poor toughness and undesirable water absorption. The known systems can often only achieve a comparatively low conversion of the double bonds, which not only contributes to poor mechanical properties and wear resistance, but is also disadvantageous in terms of the toxicology and biocompatibility of the polymerized dental materials. In addition, the volume shrinkage of the dimethacrylate monomers currently used and the shrinkage stresses of a dental filling can lead to failure of the bond between the tooth and the filling, which leads to micro-leakage and subsequently to secondary caries, which in turn can significantly reduce the longevity of the restoration. Attempts to increase the double bond conversion in order to reduce unreacted monomers unfortunately lead to an increase in polymerization shrinkage and shrinkage stress. Low molecular weight monomers with oligo[ethyleneoxy] groups, such as TEDMA, which have a certain water solubility and thus bioavailability, are now being critically assessed due to their toxicological properties and their sensitivity to biodegradative processes. Monomers with the structural element bis-2,2-[p-oxyphenyl]propane, i.e. monomers based on bisphenol-A, are also being critically assessed, since dental materials containing monomers or oligomers with these structural elements have been found to release detectable amounts of bisphenol-A, which is said to have toxicologically critical properties. There are various approaches to increasing the conversion or reducing volume shrinkage. In the case of dental composites for tooth fillings that contain filler in a matrix made of organic resin, attempts are being made to reduce volume shrinkage by increasing the filler content. However, if the filler content is too high, it is difficult to mix the fillers with the organic resin. In addition, the filler content is limited for dental composites, which must have a certain flowability. To increase the conversion and reduce polymerization shrinkage, new monomers are still being developed, for example urethane methacrylate monomers with high molecular weights. The synthesis of these monomers is complex and usually requires purification steps, which leads to a limited availability of such monomers. The increase in molecular weight is usually associated with a deterioration in the mechanical properties of the cured dental materials for a given functionality of the monomers. In addition, the increased viscosity of such monomers requires the use of higher amounts of monomers with lower molecular weights. Viscosity in order to be able to use them for dental composites, which has an adverse effect on shrinkage. EP 2436365 B1 describes low-shrinkage dental composites containing monomer mixtures which contain the monomers (b1) and (b2) in a ratio of 1:20-5:1. The example compositions each contain 4.8-76.6 wt.% bis((meth)acryloyloxymethyl)tricyclo [5.2.1.0^2.6]decane (b1), 90.9-19.1 wt.% UDMA (b2) and 4.3 wt.% TEDMA (b2). These composites exhibit a polymerization shrinkage of about 1.50% regardless of the ratio (b1) to (b2). If, as in comparative example 11, the filler content is reduced and the proportion of TEDMA is increased, the polymerization shrinkage increases. Vaidyanathan et al., Visible light cure characteristics of a cycloaliphatic polyester dimethacrylate alternative oligomer to bisGMA; Acta Biomater Odontol Scand. 2015; 1:59–65, disclose the use of PEM-665 as a BPA-free alternative to BisGMA in combination with 30 or 50 wt.% TEDMA. The polymerization conversions of these mixtures were investigated, with the combinations of PEM with TEDMA showing a higher percentage polymerization conversion than the combinations of BisGMA with TEDMA. There is still a need for radically polymerizable compounds or radically polymerizable compositions containing such compounds that can enable a reduced toxicity potential and a reduced volume shrinkage while at the same time providing good mechanical properties of the dental material produced from them and that are easily available. The present invention is therefore based on the object of providing a radically polymerizable compound or a radically polymerizable composition containing such a compound that overcomes the disadvantages of the prior art listed above. In particular, it should be possible to provide a radically polymerizable compound and a radically polymerizable composition with which it is possible to obtain dental materials with reduced polymerization shrinkage and at the same time good mechanical properties of the dental material, such as very good flexural strength and tensile strength as well as good fracture toughness, which are also toxicologically safe. Furthermore, it should be possible to obtain a radically polymerizable compound or a radically polymerized composition containing such a compound that has a refractive index that is particularly suitable for producing materials that contain fillers that are common in the dental field and that have advantageous optical properties, in particular with regard to translucency and opacity. Furthermore, it is also the object of the present invention to provide a process which makes it possible to produce such a radically polymerizable compound in a simple manner, in high purity and without undesirable discoloration. The invention solves this problem by means of a radically polymerizable compound represented by a structure of the formula 1: PG-Sp-PCA-Sp-[OC(O)NH-K-NHC(O)O-Sp-PCA-Sp]_n-PG (Formula 1), where PG = each independently selected from a radically polymerizable group, preferably selected from (NR¹)OC-CR²=CH₂and OOC-CR²=CH₂, preferably selected from OOC-CR²=CH₂, R¹= selected from hydrogen, a C1-C8 alkyl group, an aryl group and an araliphatic group with C6-C8 carbon atoms, preferably selected from a C1-C8 alkyl group and a benzyl group, R²= selected from hydrogen, a C1-C4 alkyl group, preferably selected from hydrogen and methyl; Sp = each independently a spacer group selected from unbranched and branched alkylene with C1-C19 carbon atoms, which may additionally contain oxygen, sulfur and/or -OOC- in the carbon chain, or Sp is omitted; PCA = each independently a polycyclic group, preferably an aliphatic polycyclic group, more preferably an aliphatic bi- or tricyclic group; K = an aliphatic acyclic, saturated or unsaturated unit with C1-C15 carbon atoms, preferably C3-C13 carbon atoms, more preferably C6-C9 carbon atoms, where the unit may be substituted with one or more aliphatic C1-C3 carbon substituents,an aliphatic cyclic, saturated or unsaturated unit with C3-C15 carbon atoms, preferably C5-C13 carbon atoms, more preferably C6-C13 carbon atoms, where the unit can be substituted with one or more aliphatic C1-C3 carbon substituents, or an aromatic or araliphatic unit with C6-C14 carbon atoms, preferably C6-C13 carbon atoms, where the unit can be substituted with one or more aliphatic C1-C3 carbon substituents; n = 1 to 9, preferably 1 to 6. Preferred embodiments are in the subclaims. First, some terms used in the context of the invention will be explained. In the context of the present invention, (polymerizable) dental materials are understood to mean materials for (bio)medical use, in particular on hard tooth substance, such as tooth enamel and dentin, or on bone tissue, such as jawbone. In the context of the present invention, the radically polymerizable compounds are monomers in the case where n = 1, and oligomers in the cases where n = 2 to 9. K is preferably selected from a linear aliphatic, saturated unit with C6-C9 carbon atoms, where the Unit can be substituted with one or more aliphatic C1-C3 carbon substituents, aliphatic cyclic, saturated unit with C6-C13 carbon atoms, where the unit can be substituted with one or more aliphatic C1-C3 carbon substituents, and an aromatic or araliphatic unit with C6-C13 carbon atoms, which has at least two aliphatic substituents, preferably C1-C3 substituents, on the aromatic ring. Furthermore, K can be 1,3- and 1,4-cyclohexanylene, preferably 1,3-cyclohexanylene. Preferably, the spacer group Sp is selected from methylene, *CH₂-(OC₂H₄)_p, *CH₂-(OC₃H₆)_p, *(OC₂H₄)_p, *(OC₃H₆)_p, *CH₂-(O-C(O)-R⁵- )_p, *(O-C(O)-R⁵-)_pand *S-R⁵, where p = 1-5, preferably 1-3 and R⁵a C1-C12 alkylene group, preferably a C2-C6 alkylene group. The symbol * indicates the binding site to the PCA unit. The spacer group Sp is more preferably methylene. The polycyclic PCA group is preferably selected from structures of the following formulas 2 to 13: (Formula 2)

(Formula 3) (Formula 4) (Formula 5) (Formula 6) (Formula 7) (Formula 8) (Formula 9) (Formula 10) (Formula 11) (Formula 12)

(Formula 13), which can optionally be substituted with one or more C1-C4 alkyl groups. This also includes all stereoisomers of these formulas, in particular enantiomers and diastereomers. Furthermore, the polycyclic group PCA is preferably selected from 2-methyl-3,3-norbornanediyl, 2-ethyl-3,3-norbornanediyl, 2-propyl-3,3-norbornanediyl, 2-butyl-3,3-norbornanediyl, bicyclo[2.2.2]octane-1,4-diyl, bicyclo[2.2.2]octane-2,3-diyl, bicyclo[2.2.2]oct-5-en-5,6-diyl, 1,3-adamantanediyl, tetracyclo[6.6.2.0^2.7.0^9.14]hexadeca-2,4,6,9,11,13-hexaen-15,16-diyl, 1,4-cubane-diyl, 2,6,6-trimethylbicyclo(3.1.1)heptane-2,3-diyl and 1,7,7-trimethylbicyclo(3.1.1)heptane-2,3-diyl. In a preferred embodiment, the polycyclic group PCA is an aliphatic tricyclic group, more preferably tricyclo[5.2.1.0/2,6]decanylene (TCD) (Formula 2). Preferably, K is selected from the structures of the following formulas 14 to 26:

. Furthermore, K is preferably selected from the following groups: 1,5-naphthylene (from naphthylene-1,5-disocyanate), 2,4,6-triisopropyl-m-phenylene (from 2,4,6-triisopropyl-m-phenylene diisocyanate), 2,5-bis(methanediyl-bicyclo-[2.2.1]-heptane and 2,6-bis(methanediyl-bicyclo-[2.2.1]-heptane (from norbornane-2,5-diylbis(methylene)diisocyanate or norbornane-2,6-diylbis(methylene)diisocyanate). More preferably, K is selected from a structure of the formulas 14, 15, 16, 17, 18, 19 and 20. In one embodiment, the radically polymerizable compound is preferably represented by a structure of formula 27:

(Formula 27), where R²= hydrogen or a methyl group; Sp = in each case independently a spacer group selected from unbranched and branched alkylene with C1-C19 carbon atoms, which may additionally contain oxygen, sulfur and/or -OOC- in the carbon chain, or Sp is omitted; PCA = in each case independently a polycyclic group, preferably an aliphatic polycyclic group, more preferably an aliphatic bi- or tricyclic group, even more preferably a tricyclic group, most preferably tricyclo[5.2.1.0/2,6]decanylene; K = an aliphatic acyclic, saturated or unsaturated unit with C1-C15 carbon atoms, preferably C3-C13 carbon atoms, more preferably C6-C9 carbon atoms, where the unit is linked to one or more aliphatic C1-C3 carbon substituents, an aliphatic cyclic, saturated or unsaturated moiety having C3-C15 carbon atoms, preferably C5-C13 carbon atoms, more preferably C6-C13 carbon atoms, wherein the moiety may be substituted with one or more aliphatic C1-C3 carbon substituents, or an aromatic or araliphatic moiety having C6-C14 carbon atoms, preferably C6-C13 carbon atoms, wherein the moiety may be substituted with one or more aliphatic C1-C3 carbon substituents; r = 1 to 9, preferably 1 to 6. Preferably, the radically polymerizable compound is represented by a structure selected from the following formulas 28-31:

(Formula 29),

(Formula 31), where t, u, v and w = each independently 1-9, preferably 1-6; and R²= selected from hydrogen, a C1-C4 alkyl group, preferably selected from hydrogen and a methyl group. In the radically polymerizable compound, which is represented by a structure selected from the following formulas 28-31, it should be noted that an opposite direction of the tricyclo[5.2.1.0/2,6]decanylene groups is included. The invention further relates to a process for producing a radically polymerizable compound, characterized in that the process comprises the following steps: a) reacting a diol of a polycyclic PCA group with a (meth)acrylic acid ester to form a PCA mono(meth)acrylate which has a hydroxy group by means of enzymatic catalysis, b) reacting the PCA mono(meth)acrylate containing the hydroxy group from step a) with a diisocyanate compound, preferably using a catalyst. The reaction product PCA mono(meth)acrylate with hydroxy group from step a) can be produced by transesterification from PCA di(meth)acrylate and PCA diol, preferably TCD di(meth)acrylate (TCD-D(M)A) and TCD dimethanol. Preferably, the corresponding mono(meth)acrylate is formed, each with one (meth)acrylate group and one OH group, in a mixture with PCA-D(M)A and residues of PCA-dimethanol. Surprisingly, this reaction step makes it possible to produce reaction products that are low in color to colorless, which differ significantly from, for example, compounds produced using acid catalysis, which are usually intensely colored. The latter compounds generally have to be cleaned more extensively before they can be used, at least in areas where appearance is also important. The conversion (transesterification) in step a) is carried out by enzymatic catalysis. Preferred enzymes are lipases or mixtures of lipases. In a preferred embodiment, CALB is used. In a particularly preferred embodiment, CALB is used immobilized on a carrier. The diol from step a) is preferably selected from primary and secondary alcohols containing a polycyclic group PCA. Suitable primary diols can be Bis(hydroxymethyl)tricyclo[5.2.1.0^2.6]decane (mixture of isomers), 5-norbornene-2,2-dimethanol, 5-norbornene-2,3-dimethanol, bicyclo[2.2.1]heptane-2,3-dimethanol, 2-methyl-3,3-nor- bornanedimethanol, 2-ethyl-3,3-norbornanedimethanol, 2-propyl-3,3-norbornanedimethanol, 2-butyl-3,3-norbornanedimethanol, bicyclo[2.2.2]octane-1,4-dimethanol, bicyclo[2.2. 2]oct-5-ene-5,6-diyldimethanol, bicyclo[2.2.2]octane-2,3-dimethanol, tricyclo[3.3.1.1^3.7]decane-1,3-diethanol, 1,3-adamantanediethanol, pentacyclopentadecanedimethanol, tetracyclo[6.6.2.0^2.7.0^9:14]hexadeca-2,4,6,9,11,13-hexaen-15,16-diyl dimethanol, 1,4-bis(hydroxymethyl)cubane and [5-(hydroxymethyl)-5,6-dimethyl-6-bicyclo[2.2.1]hept-2-enyl]methanol. Suitable secondary diols can be bicyclo[2.2.1]hept-2-en-1,2-diol, bicyclo[2.2.1]heptane-1,2-diol, bicyclo[2.2.1]heptane-2,5-diol, bicyclo[2.2.1]heptane-1,4-diol, 2,6,6-trimethyl-bicyclo(3.1.1)heptane-2,3-diol, 1,7,7-trimethyl-bicyclo[2.2.1]heptane-2,3-diol, 2,3-dihydroxynorbornane, 2-(propyl-1,2-diol)norbornane, tricyclo[5.2.1.0^2.6]decane-3,4-diol and 2,6-dihydroxyadamantane. The diols are generally commercially available. The (meth)acrylic acid ester from step a) is preferably selected from alkyl esters, vinyl esters, aryl esters and other active esters. Both mono(meth)acrylates and di(meth)acrylates can be used. In the case of mono(meth)acrylates, it is preferred that the monoalcohol formed is removed from the mixture during the reaction. In the case of di(meth)acrylates, the use of the di(meth)acryloyl ester of the PCA diol is preferred. In this case, the mono(meth)acryloyl ester of the PCA diol is formed in a mixture with the diol and the di(meth)acryloyl ester of the PCA diol. It is particularly advantageous that this mixture is particularly colorless and contains a high proportion of mono(meth)acrylate, which is favorable for the subsequent reaction in step b). A catalyst can be used for step b). Suitable catalysts in step b) are preferably urethanization catalysts. Such catalysts accelerate the reaction rate of the reaction between a hydroxy group and an isocyanate group. Examples of the urethanization catalyst include organotin compounds such as dimethyltin dineodecanoate, dibutyltin dilaurate, dibutyltin dioctate and tin octoate; organobismuth compounds such as bismuth neodecanoate; organic compounds of metals other than tin, such as copper naphthenate, cobalt naphthenate, zinc naphthenate, acetylacetonatozirconium, acetylacetonatoiron and acetylacetonatogermanium; Amine compounds and their salts, such as triethylamine, 1,4-dizabicyclo-[2.2.2]octane, 1,8-diazabicyclo[5.4.0]undecene, N,N-dimethylcyclohexylamine, pyridine, N-methylmorpholine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethyl-1,3-butanediamine, N,N,N',N'-pentamethyldiethylenetriamine, N,N,N',N'-tetra(340 dimethylaminopropyl)methanediamine, N,N'-dimethylpiperazine and 1,2-dimethylimidazole; and trialkylphosphine compounds such as tri-n-butylphosphine, tri-n-hexylphosphine, tricyclohexylphosphine and tri-n-octylphosphine. Dibutyltin dilaurate, dimethyltin dineodecanoate and bismuth neodecanoate are preferred. The diisocyanate compound used in step b) is preferably selected from diisocyanates containing aliphatic, cycloaliphatic, polycyclic, araliphatic or aromatic structural elements. Suitable diisocyanate compounds can be 4,4'-methylenediphenyl diisocyanate (MDI), 4-methyl-m-phenylene diisocyanate and other isomers (TDI), 1,5-naphthylene diisocyanate (NDI), 1,3-bis(isocyanatomethyl)benzene (XDI), 1,3-bis(1-isocyanato-1-methylethyl)benzene (TMXDI), 2,4,6-triisopropyl-m-phenylene diisocyanate (TRIDI), 3,3'-dimethyl-biphenyl-4,4'-diyl diisocyanate (TODI), 1,4-phenylene diisocyanate, hexamethylene diisocyanate (HDI), 2,2,4- and 2,4,4-trimethylhexamethylene-1,6-diisocyanate (TMDI), 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate and other isomers (IPDI), 4,4'-methylenedicyclohexyl diisocyanate (H12MDI), 2,5- and 2,6-bis(isocyanatomethyl)bicyclo[2.2.1]heptane (NBDI), 1,4-cyclohexane diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane (BIMC) and octahydro-2,5-bis(isocyanatomethyl)-4,7-methano-1H-indene (TCDDI). The diisocyanate compounds are generally commercially available. A ratio of one mole of the hydroxy group from the PCA mono(meth)acrylate to one mole of the isocyanate group from the diisocyanate compound is preferably 0.5 to 1.5, more preferably 0.8 to 1.2. Even more preferably, this ratio is 1.0. A ratio of an amount of all hydroxy groups to an amount of all isocyanate groups in the reaction in step b) is preferably 1.1 to 1.0, more preferably 1.02 to 1.0. The reactions in steps a) and b) can be carried out in an inert solvent or solvent mixture or, if appropriate, also without a solvent. A wide variety of solvents can be used as the solvent for step a), as long as they are a solvent that is inert to the reaction. Examples include non-polar hydrocarbon-based solvents such as n-hexane, benzene, toluene and xylene; non-polar halogen-based solvents such as dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane and perchloroethylene; solvents of medium polarity ketone-based solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; medium polarity ether-based solvents such as diethyl ether, diisopropyl ether, dibutyl ether, methyl tert-butyl ether, tetrahydrofuran and dioxane; and polar solvents such as acetonitrile, tert-butyl alcohol, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylimidazolidinone, dimethyl sulfoxide and sulfolane. These solvents can be used individually or as a mixture. Nonpolar solvents and medium polarity solvents are preferred. A variety of solvents can be used as the solvent for step b) as long as they are a solvent inert to the reaction. Examples include hydrocarbon-based solvents such as n-hexane, benzene, toluene and xylene; ketone-based solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; Ester-based solvents such as ethyl acetate and butyl acetate; ether-based solvents such as diethyl ether, diisopropyl ether, dibutyl ether, methyl tert-butyl ether, tetrahydrofuran and dioxane; halogen-based solvents such as dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane and perchloroethylene; and polar solvents such as acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylimidazolidinone, dimethyl sulfoxide and sulfolane. These solvents can be used individually or as a mixture. The reactions in steps a) and b) can be carried out in a temperature range from 0°C to 100°C. The temperature range between 20°C and 80°C is preferred, more preferably between 40°C and 60°C. The reactions in steps a) and b) can be carried out in the presence of polymerization inhibitors Polymerization inhibitors prevent the radical polymerization of the (meth)acrylate groups. Examples of polymerization inhibitors are 2,6-di-tert-butyl-4-methylphenol (BHT), hydroquinone (HQ), hydroquinone monomethyl ether (MEHQ), 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO) and phenothiazine (PTZ). Following step b), it may be necessary in a further step c) to remove any solvents still present from the resulting reaction mixture. The present invention further relates to a radically polymerizable composition comprising: a) one or more radically polymerizable compounds according to the invention, preferably according to one of claims 1 to 7; b) optionally one or more other radically polymerizable monomers and/or oligomers that do not fall under the at least one radically polymerizable compound of formula 1; c) optionally at least one initiator or one initiator system for the polymerization; d) optionally one or more stabilizers; e) optionally one or more fillers; f) optionally additives commonly used in dentistry. It is preferred that the radically polymerizable composition contains one or more radically polymerizable compounds of formula 1 in a mass fraction of 1-100 wt. %, preferably 2-80 wt. %, preferably 2-65 wt. %, even more preferably 10-65 wt. %, based on the total mass of all radically polymerizable monomers and oligomers of the polymerizable composition. Preferably, the radically polymerizable composition contains several compounds of formula 1, selected from monomers (n = 1) and/or oligomers (n = 2-9, preferably n = 2-5). One or more of the following components can be contained in the radically polymerizable composition in the following mass proportions, based on the total mass of the polymerizable composition: a) one or more radically polymerizable compounds of formula 1 from 1 to 99% by weight, preferably from 2 to 95% by weight, more preferably from 2 to 80% by weight, even more preferably from 2 to 65% by weight, even more preferably 10-65% by weight; b) one or more further radically polymerizable monomers or oligomers that do not fall under the at least one compound of formula 1, from 0 to 99% by weight, more preferably from 10 to 99% by weight, even more preferably from 20 to 98% by weight, even more preferably from 35 to 90% by weight;c) the at least one initiator or initiator system for the polymerization from 0 to 5% by weight, preferably from 0.01 to 5% by weight; d) the stabilizers from 0 to 5% by weight, preferably from 0.001 to 5% by weight, more preferably 0.005-2% by weight; e) the fillers or filler particles from 0 to 95% by weight, preferably from 1 to 95% by weight, more preferably from 5 to 92% by weight; f) the usual dental additives from 0 to 5% by weight, preferably from 0.001 to 5% by weight. In a preferred embodiment, the radically polymerizable composition is a radically polymerizable dental material. b) further polymerizable monomers or oligomers The radically polymerizable composition can, in addition to the at least one radically polymerizable compound of formula 1, also contain one or more further radically polymerizable monomers or oligomers that do not fall under the at least one radically polymerizable compound of formula 1. The selection of these further radically polymerizable monomers and oligomers is preferably made depending on which material is to be produced. This also applies to the proportion of the further radically polymerizable Monomers and/or oligomers in the radically polymerizable composition. Suitable other radically polymerizable monomers are selected, for example, from bis(methacryloyloxymethyl)tricyclo[5.2.1.0/2,6]decane, bis(acryloyloxymethyl)tricyclo[5.2.1.0/2,6]decane. They can also be monomers which can be obtained by esterification reaction, e.g. according to the preparation examples in EP 0235836 B1 or US 4131729 / DE 2816823. Suitable other radically polymerizable monomers can be selected from urethane (meth)acrylates with two or more (meth)acrylate groups. These are preferably urethane di(meth)acrylates and/or urethane tri(meth)acrylates. Preference is given to urethane (meth)acrylates selected from linear or branched alkylene-functionalized urethane (meth)acrylates and urethane (meth)acrylate-functionalized polyethers. Preference is given to difunctional urethane (meth)acrylates selected from difunctional urethane (meth)acrylates with a divalent alkylene group and those with a divalent cyclic aliphatic hydrocarbon group. Such difunctional urethane (meth)acrylates with a bivalent alkylene group are preferably selected from linear or branched urethane di(meth)acrylates functionalized with a bivalent alkylene group, urethane di(meth)acrylate-functionalized polyethers with alkylene group(s), such as bis(methacryloxy-2-ethoxycarbonylamino)alkylene, bis(methacryloxy-2-ethoxycarbonylamino)-substituted polyalkylene ethers. Bis(methacryloxy-2-ethoxycarbonylamino)alkylenes which contain linear or branched C3-C20 alkylene groups, preferably C3-C9, are preferred. Alkylene group. An alkylene substituted with methyl groups is also particularly preferred. Furthermore, the further radically polymerizable monomer can be a reaction product of 3-hydroxypropyl methacrylate and trimethylhexamethylene diisocyanate, or a reaction product of 3-hydroxypropyl acrylate and trimethylhexamethylene diisocyanate. Suitable other radically polymerizable monomers are available, for example, under the following trade or brand names: Ebecryl 230 (aliphatic urethane diacrylate), Actilane 9290, Craynor 9200 (di-urethane acrylate oligomer), Ebecryl 210 (aromatic urethane diacrylate oligomers), Ebecryl 270 (aliphatic urethane diacrylate oligomer), Actilane 165, Actilane 250, Photomer 6210 (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), Genomer 4256, Genomer 4267 (urethane acrylates), Genomer 4259 (aliphatic urethane dimethacrylate), RCX 18-059 (aliphatic urethane dimethacrylate), UN 1963CG (aliphatic urethane methacrylate), CN 1993CG (aliphatic urethane methacrylate), PRO 21252 (aliphatic urethane acrylate), H1391 (hydroxypropyl urethane dimethacrylate), H1391 (urethane dimethacrylate), X851-1066 (urethane dimethacrylate IP-DI), X726-000 (PEG 400 extended urethane dimethacrylate), urethane methacrylate 11-70 and urethane methacrylate 14-774. Particularly preferred are other radically polymerizable monomers which have a structure of the following formula 32: PG´-Sp´-PCA´-Sp´-PG (Formula 32), where PG´ = each independently selected from a radically polymerizable group, preferably selected from (NR³)OC-CR⁴=CH₂and OOC-CR⁴=CH₂, preferably selected from OOC-CR⁴=CH₂, R³= is selected from hydrogen, a C1-C8 alkyl group, an aryl group and an araliphatic group with C6-C8 carbon atoms, preferably selected from a C1-C8 alkyl group and a benzyl group; R⁴= selected from hydrogen, C1-C4 alkyl group, preferably selected from hydrogen and a methyl group; Sp´ = each independently a spacer group is selected from unbranched and branched alkylene with C1-C19 carbon atoms, which may additionally contain oxygen, sulfur and/or -OOC- in the carbon chain, preferably selected from methylene, *CH₂- (OC₂H₄)_q, *CH₂-(OC₃H₆)_q, where q = 1-5 and the symbol * indicates the binding site to PCA', or Sp' is omitted; PCA' = each independently a polycyclic group, preferably an aliphatic polycyclic group, more preferably an aliphatic bi- or tricyclic group, even more preferably a tricyclic group, most preferably tricyclo[5.2.1.0/2,6]decanylene. The monomers of formula 32 can in particular be bis(methacryloyloxymethyl)tricyclo[5.2.1.0/2,6]decane and bis(acryloyloxymethyl)tricyclo[5.2.1.0/2,6]decane. Suitable other radically polymerizable monomers can also be selected from methyl, ethyl, 2-hydroxyethyl, butyl, benzyl, tetrahydrofurfuryl or isobornyl (meth)acrylate, p-cumylphenoxyethylene glycol methacrylate, bisphenol A di(meth)acrylate, bis-GMA, ethoxylated or propoxylated bisphenol A dimethacrylate (e.g. SR-348c (Sartomer)) with three ethoxy groups, 2,2-bis[4-(2-methacryloxypropoxy)phenyl]propane, di-, tri- and tetraethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, glycerol di- and glycerol trimethacrylate, 1,4-butanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate and 1,12-dodecanediol di(meth)acrylate. Preferred monomers are 1,6-hexanediol dimethacrylate, benzyl, tetrahydrofurfuryl or isobornyl methacrylate, p-cumylphenoxyethylene glycol methacrylate, 2,2-bis[4-(2-methacryloxyp-propoxy)phenyl]propane, bis-GMA and SR-348C (Sartomer). Suitable further radically polymerizable monomers can be selected, for example, from N-monosubstituted and N-disubstituted acrylamides, such as N-ethylacrylamide and N,N-dimethacrylamide, bisacrylamides, such as N,N'-diethyl-1,3-bis(acrylamido)propane, 1,3-bis(methacrylamido)propane, 1,4-bis(acrylamido)butane, and 1,4-bis(acryloyl)piperazine. The radically polymerizable compositions preferably comprise further radically polymerizable monomers or oligomers whose viscosity is below the viscosity of the radically polymerizable compound represented by the structure of formula 1. In such a case, it is The other radically polymerizable monomers or oligomers are so-called thinners. The thinners preferably have viscosities of less than 10 Pa s, more preferably less than 5 Pa s, even more preferably less than 1 Pa s. This is particularly preferred and advantageous for the production of materials by means of tank-based photopolymerization. The radically polymerizable composition preferably comprises one or more other radically polymerizable monomers or oligomers that do not fall under the at least one compound of formula 1, in a mass fraction of 0 to 99% by weight, more preferably 10 to 99% by weight, even more preferably 20 to 98% by weight, even more preferably 35 to 90% by weight, based on the total mass of the polymerizable composition. In a particular embodiment, it is preferred that the composition does not contain any monomer or oligomer that has a bisphenol A structure. In particular, it does not contain 2,2-bis[4-(2-hydroxy-3-(meth)acryloxypropoxy)phenyl]propane (BisGMA) and/or ethoxylated bisphenol A di(meth)acrylate (BisEMA). Acidic monomers and/or water-soluble monomers can be used in particular for dental adhesives or self-adhesive composite cements. A typical proportion of acidic monomers is known from the state of the art. Acidic monomers are compounds that have an acidic group and a radically polymerizable group in one molecule. Examples of radically polymerizable, unsaturated groups are: (meth)acryloyl, (meth)acrylamide, styryl, vinyl and allyl groups. Examples of acidic groups that can be present in acidic monomers are: carboxylic acid, Carboxylic anhydride, phosphate, thiophosphate, pyrophosphate, thiopyrophosphate, phosphonate, thiophosphonate and sulfonate groups. The acidic groups can also occur in the form of an acid chloride, an alkali metal salt, an alkaline earth metal salt or an ammonium salt. Suitable acidic monomers are, for example, 2-(methacryloyloxyethyl)phenyl hydrogen phosphate (phenyl-P); 2-Hydroxyethylmethacryldihyd- rogenphosphat (HEMA-Phosphate), Dipentaerythritolpentamethac- rylatphosphat (PENTA), Di-2-Hydroxyethylmethacrylhydrogen- phophat (di-HEMA Phosphate), 10-Methacryloyloxydecyldihydro- genphosphat (MDP), 1,3-Glyceroldimethacrylatphosphat (GDMAP), 2,5-Dimethacryloyloxyethyloxycarbonyl-l,4-benzendicarbonsäure (PMDM), Butan-l,2,3,4-tetracarbonsäure-di-(2-hydroxyethylme- thacryl)ester (TCB), 4-Methacryloyloxyethyl trimellithsäure (4-MET), 4-Methacryloxyethyltrimellithanhydrid (4-META), Py- romellithsäure-bis-glycerindimethacrylat (PMGDM) und 11-Me- thacryloyloxy-1,1-undecanedicarboxylic acid (MAC-10). Furthermore, radically polymerizable antibacterial monomers can also be used as additional monomers. c) Initiator or initiator system Suitable initiators or initiator systems are able to start radical polymerization reactions. Such initiators or initiator systems are known to the person skilled in the art. Initiator systems consist of at least one initiator and at least one other compound, such as a coinitiator. These can be distributed over various components of the polymerizable dental material. The dental material according to the invention can be thermally, chemically, photochemically, i.e. cured by irradiation with UV and/or visible light. Suitable initiators can be, for example, photoinitiators. These are characterized by the fact that they can cause the material to cure by absorbing light in the wavelength range from 300 nm to 700 nm, preferably from 350 nm to 600 nm and particularly preferably from 380 nm to 500 nm and optionally by additional reaction with one or more coinitiators. Preference is given here to phosphine oxides, acylphosphine oxides, bisacylphosphine oxides and derivatives thereof, acylgermanes, acylsilanes and tin compounds, as described for example in EP 2649981 A1, WO 2017/055209 A1, WO 2017/060527 A1, EP 3068363 A1, US 2020/0087329 A1, EP 3868767 A1, EP 3293215 A1 and EP 3153150 A1, benzoin ethers, benzil ketals, acetophenones, benzophenones, thioxanthones, bisimidazoles, metallocenes, fluorones, α-dicarbonyl compounds, aryldiazonium salts, arylsulfonium salts, aryliodonium salts, ferrocenium salts, trans salts, phenylphosphonium salts or a mixture of these compounds are used. Particularly preferred are diphenyl-2,4,6-trimethylbenzoylphosphine oxide, phenyl-bis-2,4,6-trimethylbenzoylphosphine oxide, benzoin, benzoin alkyl ethers, benzil dialkyl ketals, α-hydroxyacetophenone, dialkoxyacetophenones, α-aminoacetophenones, isopropylthioxanthone, camphorquinone, phenylpropanedione, 5,7-diiodo-3-butoxy-6-fluorone, (eta-6-cumene)(eta-5-cyclopentadienyl)iron hexafluorophosphate, (eta-6-cumene)(eta-5-cyclopentadienyl)iron tetrafluoroborate, (eta-6-cumene)(eta-5-cyclopentadienyl)iron hexafluoroantimonate, substituted Diaryliodonium salts, triarylsulfonium salts or a mixture of these compounds are used. Preferred co-initiators for photochemical curing are tertiary amines, borates, organic phosphites, diaryliodonium compounds, thioxanthones, xanthene, fluorenes, fluorones, α-dicarbonyl compounds, dicarbonyl systems as described in WO 2021/048313 A1, condensed polyaromatics or a mixture of these compounds. Particular preference is given to using N,N-dimethyl-p-toluolidine, N,N-dialkyl-alkylanilines, N,N-dihydroxyethyl-p-toluidine, 2-ethylhexyl-p-(dimethylamino)-benzoate, ethyl-p-(dimethylamino)-benzoate, butyrylcholinetriphenylbutylborate or a mixture of these compounds. So-called thermal initiators can also be used as initiators, which can cause the material to harden by absorbing thermal energy at elevated temperatures. Inorganic and/or organic peroxides, inorganic and/or organic hydroperoxides, α,α'-azo-bis(isobutyroethyl ester), α,α'-azo-bis(isobutyronitrile), benzpinacols or a mixture of these compounds are preferably used. Diacyl peroxides such as benzoyl peroxide or lauroyl peroxide, cumene hydroperoxide, benzpinacol, 2,2'-dimethylbenzpinacol or a mixture of these compounds are particularly preferably used. For chemical curing at room temperature, a redox initiator system is generally used, which consists of one or more initiators and a coinitiator or coinitiators serving as an activator. For reasons of storage stability, individual components of an initiator system are incorporated into spatially separate parts of the dental material according to the invention, i.e. a multi-component, preferably a two-component material is present. The initiator or initiators used are preferably inorganic and/or organic Peroxides, inorganic and/or organic hydroperoxides, barbituric acid derivatives, malonyl sulfamides, protonic acids, Lewis or Broensted acids or compounds that release such acids, carbenium ion donors such as methyl triflate or triethyl perchlorate or a mixture of these compounds and as coinitiator or coinitiators preferably tertiary amines, heavy metal compounds, in particular compounds of the 8th and 9th groups of the periodic table (“iron and copper group”), compounds with ionically bound halogens or pseudohalogens such as quaternary ammonium halides, weak Broensted acids such as alcohols and water or a mixture of these compounds. The dental material according to the invention can also contain any conceivable combination of the initiators and coinitiators described above. An example of this are so-called dual-curing dental materials, which contain both photoinitiators and optionally the corresponding coinitiators for photochemical curing as well as initiators and corresponding coinitiators for chemical curing at room temperature. The polymerizable composition or the polymerizable dental material is preferably light-curing. In a preferred embodiment, the polymerizable composition comprises an initiator system that initiates the rapid polymerization in the wavelength range of 395-700 nm, more preferably in a wavelength range of 400-500 nm. A preferred initiator system contains camphorquinone (CQ) as initiator and tertiary aromatic and aliphatic amines as coinitiators. A preferred aliphatic amine is N,N-(dimethylamino)ethyl(meth)acrylate. Preferred aromatic coinitiators are aromatic amines, such as 2-ethylhexyl-p- (dimethylamino)benzoate (EHA) or ethyl p-(dimethylamino)benzoate (EDAB). Furthermore, the photoinitiator system can comprise another synergist in addition to camphorquinone and a tertiary amine. Preferred synergists can be diaryliodonium salts as described in EP 3427716 A1, EP 3888616 A1, EP 3881818 A1 and M. Topa, J. Ortyl, Materials 13, 4093 (2020). In another preferred embodiment, which is particularly suitable for 3D printing applications, the dental material according to the invention contains an initiator system that initiates the radical polymerization in the wavelength range of 300-500 nm, more preferably in a wavelength range of 350-420 nm, particularly preferably 365-410 nm. Preferred initiator types are those that function according to the Norrish type 1 mechanism. The at least one initiator or the initiator system for the polymerization can be contained in the polymerizable composition in a mass fraction of 0 to 5 wt.%, preferably 0.01 to 5 wt.%, based on the total mass of the polymerizable composition. d) Stabilizer The radically polymerizable composition can contain one or more stabilizers. Such stabilizers are known to the person skilled in the art. Suitable stabilizers are preferably benzotriazoles, triazines, benzophenones, cyanoacrylates, salicylic acid derivatives, hindered amine light stabilizers (HALS) and mixtures thereof. Particularly suitable are o-Hydroxyphenylbenzotriazoles, such as 2-2H-benzotriazol-2-yl)-4-methylphenol, 2-(5-chloro-2H-benzotriazol-2-yl)-4-methyl-6-tert-butyl-phenol, 2- (5-Chloro-2H-benzotriazol-2-yl)-4,6-di-tert-butyl-phenol, 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentyl- phenol, 2-(2H-benzotriazol-2-yl)-4-methyl-6-dodecyl-phenol, 2-(2H-benzotriazol-2-yl)-4, 6-bis-(l-methyl-l -phenylethyl)-phenol, 2-(2H-benzotriazol-2-yl)-6-(l-methyl-l-phe- nylethyl)-4-(l,l,3,3-tetramethylbutyl)phenol, 2-(2H-benzotriazol-2-yl)-4-(l,l,3,3-tetramethylbutyl)phenol and 3 -(2H-Benzotriazol-2-yl)-5-ter-butyl-4-hydroxy-benzenepropanoic acid esters, o-hydroxyphenyltriazines, such as 2-(2-hydroxy-4-hexyloxy-phenyl)-4,6-diphenyl- 1,3,5-triazine or 2-(2-hydroxy-4-[2-hydroxy-3-dodecyloxy-propyloxy]-phenyl)-4,6-bis-(2, 4-dimethylphenyl)-1,3, 5-triazine, o-hydroxy-benzophenones, such as 2-hydroxy-4-octyloxybenzophenone, cyanoacrylates, such as Ethyl 2-cyano-3,3-diphenylacrylate, 2-ethylhexyl 2-cyano-3,3-diphenylacrylate and tetrakis-[(2-cyano-3,3-diphenylacryloyl)oxymethyl]-methane, - Hindered Amine Light Stabilizers (HALS) such as N,N'-bisformyl-N,N'-bis-(2,2,6,6-tetramethyl-4-piperidin-yl )-hexamethylenediamine, bis-(2,2,6,6-tetra- methyl-4-piperidyl)-sebacate, bis-(l,2,2,6,6-pentamethyl-4-piperidyl)-sebacate and methyl- (l,2,2,6,6-pentamethyl-4-piperidyl)-sebacate, salicylic acid esters and Mixtures thereof. Other suitable stabilizers are phenols such as hydroquinone monomethyl ether (HQME), 2,6-di-tert-butyl-4-methylphenol (BHT) or tert-butylhydroxyanisole (BHA). 2,6-di -tert-butyl-4-methylphenol (BHT) can be used. The stabilizers can be used in the radically polymerizable composition in a mass fraction of 0 to 5 wt.%, preferably 0.001 to 5 wt.%, more preferably 0.005 to 2 wt.%, based on the total mass of the polymerizable composition. In one embodiment, the radically polymerizable composition can comprise stabilized radicals. Suitable stabilized radicals are preferably those such as 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO) and bis(2,2,6,6-tetramethyl-4-piperidyl-l-oxyl) sebacate. Bis(2,2,6,6-tetramethyl-4-piperidyl-l-oxyl) sebacate is particularly preferred. The stabilized radicals are preferably contained in a mass fraction of 0.005 to 0.01 wt.% in the radically (photo)polymerized compositions, based on the total mass of the polymerizable composition. e) Fillers The radically polymerizable composition can comprise fillers or filler particles. The filler particles are not limited to a specific particle shape. Rather, fillers with a spherical, flaky, platelet-like, needle-like, leaf-like or irregular shape can be used very well. The filler particles preferably have an average particle diameter of 5 nm to 100 µm, preferably 5 nm to 50 µm. Suitable fillers can be selected from a wide variety of materials that are usually used in dental materials or products. The choice of filler can, for example, influence the fluidity, viscosity, consistency, color, radiopacity and mechanical stability of a composition or product. Dental material. The fillers can be roughly divided into three different classes based on their chemical nature: inorganic fillers, organic fillers and organic-inorganic composite fillers. The fillers can be used not only individually, but also in combination with one another. Ground powders of natural or synthetic glasses or crystalline inorganic substances in different sizes and states (monodisperse, polydisperse) can be used as inorganic fillers. Suitable materials include quartz, cristobalite, glass ceramics, feldspar, barium silicate glasses (such as those available under the trade names Kimble RAY-SORB T3000, Schott 8235, Schott GM27884, Schott G018-053, and Schott GM39923), barium fluorosilicate glasses, strontium silicate glasses, strontium borosilicate glasses (such as those available under the trade names RAY-SORB T4000, Schott G018-093, Schott G018- 163, and Schott GM32087), lithium aluminum silicate glasses, barium glasses, calcium silicates, sodium aluminum silicates, fluoroaluminum silicate glasses (such as those available under the trade names Schott G018-091 and Schott G018-117), Zirconium or cesium boroaluminosilicate glasses (such as those available under the trade names Schott G018-307, G018-308 and G018-310), zeolites and apatites. The fillers preferably have an average particle size d50 of 0.01-15 µm, preferably an average particle size d50 of 0.2-5 µm and particularly preferably an average particle size of 0.2-1.5 µm. It may be preferred that the average particle size d50 is between 0.1-0.5 µm. In such cases it is particularly preferred that the average particle size d90 is less than 1.0 µm. Furthermore, discrete, non-agglomerated, non-aggregated, organically surface-modified nanoparticles are used to ensure a more uniform filling of the dental material and to increase the hardness and abrasion resistance. Nanoparticles in this context are understood to mean spherical particles with an average particle size of less than 200 nm. The average particle size is preferably less than 100 nm and particularly preferably less than 60 nm. The smaller the nanoparticles are, the better they can fulfill their function of filling the cavities between the coarser particles. The materials for the nanoparticles are preferably oxides or mixed oxides and are preferably selected from the group consisting of oxides and mixed oxides of the elements silicon, titanium, yttrium, strontium, barium, zirconium, hafnium, niobium, tantalum, tungsten, bismuth, molybdenum, tin, zinc, ytterbium, lanthanum, cerium, aluminum and mixtures thereof. The preferred oxide nanoparticles are not agglomerated. In order to enable the nanoparticles to be integrated well into the polymer matrix of a composite material, the surfaces of the nanoparticles are organically modified. The surface treatment of the fillers is preferably carried out with a silanizing agent. Methacryloxypropyltrimethoxysilane is particularly suitable as an adhesion promoter. Commercially available nanoscale, non-agglomerated and non-aggregated silica sols that can be used are, for example, available under the name "NALCO COLLOIDALSILICAS" (Nalco Chemical Co.), "Ludox colloidal silica" (Grace) or "Highlink OG" (Clariant). Submicron fillers or microfillers consisting of agglomerated, nanoscale particles can also be used, especially if their specific surface area (determined according to Brunauer, Emmet, Teller) is in the range between 100 to 400 m²/g. Fumed silica or wet precipitated silica are preferred. Suitable, applicable products of non-surface treated silica fillers are commercially available under the names AEROSIL™ ("OX50", "90", "130", "150", "200", "300" and "380", "R8200" from Evonik Industries AG, Essen, Germany), Cab-O-Sil ("LM-150", "M-5", "H-5", "EH-5" from Cabot Corp., Tuscola, IL), HDK™ ("S13", "V15", "N20", "T30", "T40" Wacker-Chemie AG, Munich, Germany) and Orisil™ ("200", "300", "380" Orisil, Lviv, Ukraine). Particularly advantageous abrasion and gloss resistance properties of the composition or a dental material can be achieved by using aggregated, nanoscale particles based on mixed oxides of silicon dioxide and zirconium dioxide. A suitable filler can be produced using a process described, for example, in US 6,730,156 (Example A). The filler produced in this way can then be surface-treated using a process as described in US 6,730,156 (e.g. Production Example B). The use of spherical submicroparticles based on silicon-zirconium mixed oxides, as described in DE 19524362 A1 or US2020/0121564 A1, can be particularly advantageous in order to achieve high filling levels with high aesthetics and abrasion stability. The aggregated fillers preferably have an average particle size of 1-15 µm, more preferably an average particle size of 1-10 µm, even more preferably an average particle size of 2-5 µm. In addition, significant amounts of selected, X-ray-opaque fillers can be present. The addition of X-ray visible particles for the polymerizable composition or dental material is advantageous because it makes it possible to distinguish between healthy tooth substance and the restoration. Suitable, X-ray visible fillers contain particles of metal oxides, metal fluorides or barium sulfate. Oxides and fluorides of heavy metals with an atomic number greater than 28 are preferred. The metal oxides and fluorides should be selected so that they have as little influence as possible on the color of the restoration. Metal oxides and fluorides with an atomic number greater than 30 are more suitable. Suitable metal oxides are oxides of yttrium, strontium, barium, zirconium, hafnium, niobium, tantalum, tungsten, bismuth, molybdenum, tin, zinc, lanthanides (elements with an atomic number of 57 to 71), cerium and combinations thereof. Suitable metal fluorides are, for example, yttrium trifluoride and ytterbium trifluoride. Particularly preferred here are irregularly shaped or spherical YbF3 or YF3 particles with an average particle size of the primary particles of 40 nm to 1.5 µm, and particularly preferred are core-shell combination products made of YF3 or YbF3 core and SiO2 shell, with the SiO2 shell surface being very particularly preferably silanized. In particular, such a core-shell combination product has a refractive index of 1.48 to 1.54 and a measured average particle size of the agglomerated particles between 0.5 and 5 µm. Examples of suitable organic fillers are filled and unfilled, powdered polymers or copolymers based on polymethyl methacrylate (PMMA), polyethyl methacrylate, polypropyl methacrylate, polybutyl methacrylate (PBMA), polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), polyurethanes (PU), polyurea, methyl methacrylate-ethyl methyl acrylate copolymer, Ethylene-vinyl acetate copolymer, and styrene-butadiene copolymer. The organic filler can also contain a biologically active component, a specific pigment, a polymerization initiator, a stabilizer or something similar that has been added during the manufacturing process. The organic fillers can be used alone or as mixtures. Advantageous polishing properties with a higher degree of filling can be achieved in the composition or in the dental materials if so-called organic-inorganic composite fillers are used. These fillers can be produced by processing a polymerizable monomer with an inorganic filler to form a paste, then curing it by polymerization and then finely grinding it before it is used as a filler. Microfillers are preferably used as inorganic fillers here. After grinding, the fillers preferably have an average particle size of 0.05-100 µm, more preferably an average particle size of 0.5-50 µm, even more preferably an average particle size of 1-30 µm. The average particle size is preferably determined by means of static and/or dynamic light scattering of the particles in a dispersion with a suitable dispersant (e.g. Coulter LS, Beckman Coulter GmbH, Krefeld, Germany and/or e.g. Zetasizer, Malvern Panalytical GmbH, Kassel, Germany). Field flow fractionation (e.g. AF2000 AT, Postnova Analytics GmbH, Landsberg, Germany) or calibration with particle size standards is particularly preferably used for this purpose. The average particle size can also be determined by microscopy, in particular Electron microscopy. The absolute particle size and preferably the d50 value are preferably specified. It is preferred that the fillers in the radically polymerizable composition or in the dental material are surface-modified. For this purpose, for example, the inorganic or organic-inorganic composite fillers described are subjected to a surface treatment before use in order to improve the compatibility, affinity and incorporability of the fillers into the resin mixture. This treatment organically modifies the surfaces of the inorganic particles, i.e. the surfaces have organic structural elements. All methods known to the person skilled in the art can be used here. Silanizing agents are preferred for the inorganic fillers that have OH groups on the surface. Examples of these are γ-methacryloxyalkyltri-methoxysilane (number of C atoms between the methacryloxy group and the silicon atom: 3 to 12), γ-methacryloxyalkyltriethoxysilane (number of C atoms between the methacryloxy group and the silicon atom: 3 to 12) or silicone compounds such as vinyltrimethoxysilane, vinylethoxysilane and vinyltriacetoxysilane. Methacryloxypropyltrimethoxysilane is particularly preferred as a silanizing agent. Inorganic fillers that have hardly any or no OH groups on the surface are preferably surface-treated with other surface modifiers such as titanates, aluminates, zircoaluminates, surfactants, fatty acids, organic acids, inorganic acids or metal alkoxides. Organic compounds containing N-, P-, S- and/or O-containing functional groups (e.g. polyols, sulfoxides, phosphinic acid esters, etc.) are suitable as surface modification agents for salts of barium, strontium and rare earth metals. Phosphonic acid esters, trialkylphosphines, carboxylic acids and carboxylic acid esters) are particularly preferred. 10-methacryloyloxydecyl dihydrogen phosphate is particularly suitable here. Particularly in the case of agglomerated nanofillers based on silicon dioxide, the surface modifications can consist of radically reactive groups, such as the above-mentioned methacryloyloxyalkyl groups, or also radically unreactive groups. Suitable unreactive groups are, for example, trimethylsilyl, dimethylsilylene or methylsilylidene groups, which can be applied to the surface by silanization, e.g. with hexamethyldisilazane, dimethyldimethoxysilane or methyltrimethoxysilane. Suitable non-reactively surface-modified agglomerated nanofillers are commercially available, for example, under the names Aerosil R8200, Aerosil R812S, Aerosil R805, Aerosil R202, Aerosil R974 (Evonik Industries AG, Essen, Germany) or HDKH2000, HDKH200/4 (Wacker Chemie, Burghausen, Germany). The agglomerated nanofillers can also preferably be modified with groups that are reactive in radical processes, e.g. methacryloyl groups. A commercially available product of a radically reactive modified agglomerated nanofiller is available under the name Aerosil R7200 (Evonik Industries AG, Essen, Germany). The agglomerated nanofillers can preferably be largely deagglomerated, as described, for example, in EP 1720206. The radically polymerizable composition according to the invention can have a mass fraction of filler or filler particles of 0 to 95 wt.%, preferably 1 to 95 wt.%, more preferably 5 to 92 wt.%, even more preferably from 15 to 85% by weight, based on the total mass of the polymerizable composition. The amount of filler fraction can be selected depending on the indication of the dental product. For example, the highest possible filler amounts can be used for stable, moldable filling composites, for dental compositions for the production of inlays, onlays or overlays, and for compositions for the production of dental CAD-CAM materials. As a rule, these compositions have filler contents of 75% by weight to 92% by weight, based on the total composition. Flowable dental composites, bonding composites, core build-up materials, crown and bridge materials generally have an average filler range of 40 to 80% by weight, based on the total composition, while dental varnishes, dental sealing materials, dental infiltrants or dental adhesives use fillers in the range of 1 to 40% by weight, based on the total composition. The filler ranges given above are only to be understood as guide values; there may also be deviations from this depending on the choice of fillers. In a preferred embodiment, the radically polymerizable composition contains a selection of microfillers such that the difference in refractive index between the microfillers and the other components of the polymerized composition (polymer matrix) is as small as possible. Δn ≤ 0.03 is preferred, more preferably ≤ 0.02, more preferably ≤ 0.01. f) additives commonly used in dentistry The radically polymerizable composition can contain other additives commonly used in dentistry. Suitable additives commonly used in dentistry are preferably those that can be contained in radically polymerizable dental and dental technology materials. Common dental additives are known to the person skilled in the art. Common dental additives can be, for example, solvents or solvent mixtures. For example, the use of a mixture of water and water-miscible solvents, such as ethanol or acetone, is preferred for the production of dental adhesives. In addition, other components of the radically polymerizable composition can include, for example, pharmacologically active compounds, such as antibacterial compounds, chlorhexidine or other enzyme-inhibiting active ingredients. The composition can also contain one or more fluoride-releasing substances in finely distributed, particulate form as a dental additive. Fluoride-releasing substances can be water-soluble fluorides such as sodium fluoride or amine fluoride. Other suitable fluoride-releasing substances are poorly soluble fluorides from the 2nd main group. Fluoride-containing glasses are also suitable fluoride sources. Other suitable additives are fine-particle substances that release calcium and/or phosphate and thus have a remineralizing effect. Suitable remineralizing substances are calcium-phosphate compounds such as hydroxyapatite, brushite, monocalcium phosphate, fluorapatite, bioactive glasses such as those in DE10111449A1, DE102005053954A1 or US9517186B2 mentioned glasses. The dental material according to the invention can contain a colorant or colorant mixture selected from fluorescent dyes, fluorescent pigments, organic color pigments, inorganic color pigments and mixtures thereof. A fluorescent colorant or pigment is preferably an organic fluorescent dye or an organic fluorescent pigment, in particular a non-polymerizable, organic fluorescent colorant, optionally comprising arylcarboxylic acid esters, such as diethyl-2,5-dihydroxyterephthalate, arylcarboxylic acids, coumarin, rhodamine, naphthalene linimide or derivatives thereof. Inorganic fluorescent pigments can be, for example, CaAl₄O₇:Mn2+ (Ba0.98Eu0.02)MgAl₁₀O₁₇, BaMgF₄:Eu²⁺, Y(1.995)Ce(0.005)SiO₅As color pigments, the dental material according to the invention can contain organic pigments and inorganic pigments, such as N,N'-bis(3,5-xylyl)perylene-3,4:9,10-bis(dicarbimide), copper phthalocyanine, titanate pigment, in particular chromium antimony titanate (rutile structure), spinel black, in particular pigments based on iron oxide (Fe₂O₃) or iron oxide black (Fe₃O₄), where iron is partially substituted by chromium and copper or nickel and chromium or manganese, zinc iron chromium spinel brown spinel, ((Zn,Fe)(Fe,Cr)₂O₄) Cobalt zinc aluminate blue spinel and/or titanium oxide. The additives commonly used in dentistry can be contained in the polymerizable composition in a mass fraction of 0 to 5 wt.%, preferably 0.001 to 5 wt.%, based on the total mass of the radically polymerizable composition. The invention has the advantage that the radically polymerizable compound according to the invention and also the radically polymerizable composition according to the invention overcome the disadvantages of the prior art listed above. The radically polymerizable compounds and the radically polymerizable composition have excellent properties that are particularly necessary or desirable for the production of dental materials. In addition, the invention has the surprising advantage that the radically polymerizable compounds according to the invention can be synthesized by the production process according to the invention not only inexpensively, but also in high purity and without undesirable discoloration. Furthermore, the radically polymerizable compositions have a high conversion of the monomers during radical polymerization. As a result, dental materials and devices that are produced from the radically polymerizable compositions contain only a low residual monomer content. The radically polymerizable composition can also be produced from monomers that are easily available and that have a reduced toxicity potential. Since the radically polymerizable compositions preferably do not contain any compounds that contain a bisphenol A group and/or another bisphenol group, it can also be largely ruled out that the dental materials obtained and devices made from them have a harmful effect on health. The use of the radically polymerizable compounds or the radically polymerizable composition for Production of a dental material leads to reduced polymerization shrinkage and at the same time good mechanical properties of the resulting dental material. This means that the radically polymerizable compositions have low polymerization shrinkage and reduced shrinkage stress. The radically polymerized compositions or the dental materials produced from them have good mechanical properties, such as in particular very good flexural strength and tensile strength as well as good fracture toughness. These advantageous properties of the radically polymerizable compound according to the invention and the corresponding compositions are surprising in view of the molecular sizes and structures of the radically polymerizable compounds, since the person skilled in the art would expect a reduced crosslinking density and flexural strength associated with them. The radically polymerizable compounds or compositions surprisingly have a refractive index that is particularly suitable for producing dental materials containing fillers that are common in the dental field and that have desired optical properties, in particular with regard to translucency or opacity. In addition, the radically polymerized compositions (i.e. the dental material produced) have only a low water solubility and a low water absorption, which is also advantageous. The invention also relates to the use of the radically polymerizable compound, preferably according to one of claims 1 to 7, or the radically polymerizable composition, preferably according to one of claims 9 to 12, for producing a polymerizable Dental material, preferably a dental composite, dental cement, self-adhesive dental cement, dental varnish, stump build-up, root canal filling, filling, underfilling, fixing, crown, bridge, restoration, orthodontic and/or prosthetic material. The filling material can be a moldable and/or flowable filling material, preferably a moldable filling material. In a preferred embodiment, the polymerizable dental material is used as a 3D printing material. In this way, orthodontic materials, aligners, splint materials, prosthetic base materials, model materials, crowns + bridge materials, drilling templates, gingival masks, spoon materials, mouth guards and/or veneers can be produced from the polymerizable dental material using a 3D printer. Furthermore, the present invention also relates to a dental material produced from a radically polymerizable composition according to the invention, preferably according to one of claims 9 to 12. The invention also relates to a radically polymerizable dental material according to the invention for use in a therapeutic process as a dental composite, dental cement, dental varnish, filling, underfilling, fixing, stump build-up, root canal filling, crown, bridge, restoration, orthodontic and/or prosthesis material. The invention also relates to a hardened dental material produced from a radically polymerizable composition according to the invention. polymerizable composition, preferably according to one of claims 9 to 12. The cured dental material can be produced in a process in which a radically polymerizable composition is provided which hardens or is cured in whole or in part. In a particular embodiment, the radically polymerizable composition can be 3D printed before hardening. The invention will now be described by way of example using some advantageous embodiments with reference to the attached figure. It shows: Fig. 1: GPC diagram in which the peak of a radically polymerizable compound of formula 31 according to the invention can be seen. Fig. 2: GPC diagram in which the peak of a radically polymerizable compound of formula 33 according to the invention can be seen. Examples 1. Chemicals and their pretreatment/use The following chemicals were used in the preparation of the examples (Table 1) and processed as described in this paragraph before further use. Table 1: Compounds and substances used in the examples. TCD-DM 4,8-Bis(hydroxymethyl)tricyclo[5.2.1.0^2.6]decane, isomer mixture 96%, CAS 26896-48-0, Sigma Aldrich TCDDA Genomer 1231 (tricyclodecanedimethanol diacrylate), CAS 42594-17-2, Rahn AG, Zurich, Switzerland TCD-MA (Hydroxymethyl)(acryloyloxymethyl)-tricy- clo[5.2.1.0^2.6]decan IPDI isophorone diisocyanate, > 99%, CAS 4098-71-9; TCI Deutschland GmbH, Eschborn, Germany H12MDI 4,4'-diisocyanatodicyclohexylmethane, > 90%, CAS: 5124-30-1; TCI Deutschland GmbH TMXDI 1,3-Bis(1-isocyanato-1-methylethylbenzene, > 97%, CAS: 2778-42-9; TCI Deutschland GmbH H6XDI 1,3-Bis(isocyanatomethyl)cyclohexane, > 99%, CAS: 38661-72-2; Sigma Aldrich TMDI Trimethylhexamethylene diisocyanate, 97%, CAS: 28679- 16-5, abcr GmbH, Karlsruhe, Germany CALB Candida Antarctica Lipase B, immobilized on Im- mobead 150; Sigma Aldrich MTBE Methyl tert-butyl ether, 99%, CAS:1634-04-4 THF Tetrahydrofuran anhydrous, min. 99.9% Toluene Toluene for analysis, 96%, CAS 108-88-3 Toluene-t Toluene dry, 99.8%, CAS 108-88-3 Cyclohexane, > 99%, CAS 110-82-7 Ethyl acetate, > 99.8%, CAS 141-78-6 BHT 2,6-Di-tert-butyl-4-methylphenol e.g. Synthesis, >99%, CAS 128-37-0 DMTND Dimethyltin dineodecanoate, CAS: 68928-76-7 TCDDMA Bis(methacryloyloxymethyl)tricy- clo[5.2.1.0^2.6]decane; CAS 43048-08-4 UDMA 7,7,9-(or 7,9,9-)trimethyl-4,13-dioxo-3,14-di-oxa-5,1 2-diaza-hexadecane-1, 16-diol dimethacrylate, CAS 72869-86-4 BisGMA Propane-2,2-diylbis[4,1-phenyleneoxy(2-hydroxypropane-3,1-diyl)] bis(2-methylprop-2-enoate), CAS 1565-94-2 TEDMA Triethylene glycol dimethacrylate, CAS 109-16-0 CQ Camphorquinone EHA 2-ethylhexyl p-(dimethylamino)benzoate BaF Dental glass G018-053 (average particle size 0.7 µm, 6 wt.% silane); Schott AG, Mainz, Germany Drying TCD-DM The TCD-DM was dried by azeotropic distillation with about 2.5 times the volume of toluene until a solution of 83.6 wt.% TCD-DM in toluene was obtained. The TCD-DM was used in the form of this solution unless otherwise stated, whereby weight information refers to the TCD-DM. 2. Methods Thin layer chromatography (TLC) The TLC was performed using silica gel as stationary phase (TLC cards: Polygram Sil G/UV_254,Macherey-Nagel GmbH & Co. KG, Germany). A sample of the substance to be analyzed was diluted 1:10 with tetrahydrofuran. A mixture of cyclohexane and ethyl acetate 2:1 was used as the mobile phase. The developed DC card was viewed under UV light (254 nm wavelength) and then stained in an iodine chamber. Loss on drying The loss on drying was determined gravimetrically. A sample was diluted for 2 hours at 110°C or 2 hours at 50°C in dried in a convection oven and the residue was weighed. Viscosity The viscosity measurements were carried out with a rotational viscometer (type Kinexus, Malvern Instruments GmbH, Germany) with a plate-plate geometry (d = 25 mm, gap distance h = 0.1 mm, shear stress ramp 1–50 Pa) at 23°C and the viscosity was determined at a shear stress of 50 Pa. FT-IR spectroscopy FT-IR spectra (types iS10 and iS20, Thermo Scientific Nicolet) were each produced with an ATR unit. 32 scans were taken with a resolution of 4 cm^-1recorded. Liquid chromatography/mass spectrometry coupling (HPLC-MS) This analysis was carried out on a Waters Alliance 2695 HPLC system. The following column was used for separation: 250/2 Nucleodur C8 ec. The column temperature was 20°C. Elution was carried out at a flow of 0.2 ml/min with a gradient of the following mobile phases: 0.1% formic acid in acetonitrile (A) and 0.1% formic acid in water (B). Time [min] 0 0.5 40 45 50 60 Proportion B [%] 70 70 10 10 70 70 Detection was carried out using a Waters Micromass ZQ mass detector. Ionization was carried out in ESI+ mode. HPLC method for quantifying TCDDA The TCDDA content_HPLCin wt.-% in the samples was determined on a Thermo Ultimate 3000 HPLC system. The following column was used for separation: 250/4 LiChrospher RP select B (5 µm). The column temperature was 20°C. Elution was carried out at a flow rate of 1 ml/min with a gradient of the following mobile phases: water (A) and methanol (B). Time [min] 0 0.5 14.5 15.0 20.0 Proportion B [%] 70 70 95 70 70 Detection was carried out with a UV detector at 205 nm. The TCDDA reference sample concentration was approx. 25 mg/50 ml methanol. The sample concentration of the examples was approx. 15 mg/10 ml methanol. 3 µl of sample were injected for the measurement. The content of monomers and oligomers according to the invention in the samples was calculated as follows: Content required monomer + oligomer (wt.%) = 100% - dry loss (wt.%) – TCDDA content_HPLC(Wt.%) Gel permeation chromatography (GPC) The GPC was carried out with a GPC Agilent 1200 with RI detector (PSS, Germany). The following column combination (PSS, Germany) was used: pre-column/100Å/100Å/1000Å. THF was used as the eluent with a flow rate of 1 ml/min. The sample concentration was approximately 5 mg/ml. The GPC was carried out at 20°C. Determination of the refractive indices The refractive indices of uncured compositions were determined using an Abbe refractometer AR (A. Krüss Optronik, Germany) at 23°C ±1°C against air based on the D line of sodium light. A triplicate determination was carried out in each case and the mean value was calculated. The refractive index of cured compositions was determined using an Abbe refractometer AR (A. Krüss Optronik) of test specimens in accordance with ISO 489:1999. A drop of cinnamon oil was placed on the test specimen and brought into contact with the measuring prism of the refractometer. A triplicate determination was carried out for each test specimen and the mean value was calculated. To produce the test specimens, the composition was placed in a steel mold (8 mm × 20 mm × 0.5 mm) which was placed on a steel mold covered with a clear, colorless polyester film (Hostaphan^®) covered slide. Another foil, followed by another slide, was placed on the resin without bubbles, secured with clamps and cured using a light polymerization device (Hi-Lite Power^®; Heraeus Kulzer) for 90 s. The hardened test specimen was then removed from the mold. Determination of flexural strength (BF) and modulus of elasticity (EM) For the determination of flexural strength and modulus of elasticity, test specimens were produced analogously to ISO 4049:2009. In deviation from this, the test specimens were exposed to light with a light polymerization device (Hi-Lite Power^®; Heraeus Kulzer). For this purpose, the dental composites in the test specimen shapes (40 mm x 2 mm x 2 mm) were exposed to light from both sides for 90 s. The test specimens were stored in distilled water at 37°C for 24 hours. The flexural strength and the E-modulus were determined using a Zwick universal testing machine (type Z010 or type Z2.5, Zwick-Roell, Germany). The mean value and standard deviation are given. Measurement of the volume shrinkage of resin mixtures (liquid pycnometer) The volume shrinkage of resin mixtures was determined using liquid pycnometers (Blaubrand, Brand GmbH + Co KG, Germany) via the change in density before and after curing at 20°C. First, the density of the uncured compositions was determined using a 10 ml liquid pycnometer. Higher viscosity compositions (viscosity >10 Pas) were first tempered to 60°C in a heating cabinet so that they could then be filled into the pycnometer with as few air bubbles as possible. Air bubbles were also removed by applying a vacuum in the desiccator. The filled pycnometer was then tempered to 20°C. When the measuring temperature was reached, the mass of the filled pycnometer was measured and the density of the uncured composition was determined from this. To determine the density of the cured compositions, cuboid-shaped test specimens (35 mm x 20 mm x 3 mm) were produced. For this purpose, the uncured compositions were filled into the appropriate test specimen molds without any air bubbles and cured for 90 s from above and below using the light polymerization device (Hi-Lite Power^®; Heraeus Kulzer). The cured test specimens were stored for 24 ± 2 hours at 23°C. To determine the density of the cured compositions, the mass of the cured test specimen m1 and the empty weight of the pycnometer m0 were determined. The pycnometer was then filled 4/5 with distilled, degassed water and heated to 20°C. tempered before the hardened test specimen was immersed in the pycnometer. The pycnometer was then completely filled with water. When the measuring temperature of 20°C was reached, the pycnometer was closed and dried on the outside, the mass m3 of the pycnometer filled with water and test specimen was measured and the density of the hardened test specimen ρ was calculated from this._N/Adetermined according to equation 1: ^^ ^ ^,^^^^ ρ_N/A= ^^^^,^^^^ ^ ^^^^^^^^ (Equation 1) ^^ = specified volume of the pycnometer used at 20°C In this way, 3 cured test specimens were measured. The volume shrinkage (VS) as a mean value (MW_VS) was calculated from the difference between the density before (ρVA) and the mean of the densities after curing (MWρNA) (Equation 2). ^^^^^ ^^^^ MW_VS= × ^^^^^ (Equation 2) The determination of the standard deviation of the volume shrinkage SD_VSwas carried out according to equation 3. SD_VS= 100 × ρ_VA× SDρ_N/A/MW²ρ_N/A(Equation 3) Measurement of the volume shrinkage of composites (gas pycnometer) The volume shrinkage of the composites was determined using a helium gas pycnometer (Accupyc III 1340, Micromeritics, USA) via the change in density before and after curing. Three density determinations of the uncured composite were carried out. For each measurement, approximately 0.3 to 0.4 g of the composite was placed in the measuring chamber of the gas pycnometer without any voids. The weight of the uncured composite was determined using a scale and the density of the uncured composite was determined from the volume measurement of the gas pycnometer using the AccuPYKII 1340 software. Three density determinations of the cured composite were then carried out. To determine the density, two cylindrical test specimens (h = 2 mm, D = 8 mm) of the composite were produced by curing (90 s from each side) using the HiLite Power light polymerization device. The test specimen molds were filled without air bubbles and covered with a slide from above and below during curing. After curing, the test specimens were removed from the mold, deburred, cleaned with ethanol and dried with compressed air. Then both test specimens were placed on top of each other in the measuring chamber of the gas pycnometer. The weight of the cured composite was determined using a scale and the density of the cured composite was determined from the volume measurement of the gas pycnometer using the AccuPYKII 1340 software. The density was determined within 15-60 minutes after curing. The volume shrinkage (VS) as a mean value (MW_VS) was calculated from the difference between the mean density of the composite before (MWρVA) and the mean density after curing (MWρNA) (Equation 4). ^^^^^ ^^^^^^ Mean volume shrinkage MW_VS= 100 % × ^^^^^ (Equation 4) Determining the standard deviation of the volume shrinkage SD_VSwas calculated according to equation 5 from the standard deviation SDρ_N/Athe density of the cured composite and the standard deviation SDρ_VAthe density of the uncured composite and the corresponding mean values MWρNA and MWρVA. SDVS= 100/MWρNA²×√((MWρNA²× SDρVA²)+(MWρVA²× SDρNA²)) (Equation 5) Conversion measurement The conversion was determined by FT-NIR spectroscopy (Nicolet iS20, Thermo Scientific) before and after polymerization of a composition in transmission geometry. The conversion or the progress of the polymerization reaction was determined by measuring the degree of reduction of the C=C overtone band at 6160-6170 cm^-1was determined. For this purpose, the uncured, i.e. non-polymerized composition or composite was placed in a cylindrical test specimen (D = 15 mm, h = 1.0 mm), covered with slides from above and below and then attached to an IR holder. A spectrum was recorded with 12 scans. The uncured, i.e. non-polymerized composition or composite was then exposed to the light polymerization device (Hi-Lite Power^®; Heraeus Kulzer). The FT-NIR spectrum of the polymerized composition was recorded within 60 minutes at the latest. The integrals of the C=C overtone band at 6160-6170 cm were then calculated from both spectra using the IR software Omnic (Series 9.11.727; Thermo Scientific).^-1determined. The conversion U in % is calculated from both integrals according to equation 6: ^^^^^^ä^^^ ^^^^^^^^^^^^^^^ ^^^^^^^^ Conversion in % = 100% - ^^^^^^ä^^^ ^^^^^^^^^^^^^^^^^ ^^^^^^^^ x100% (equation 6) 3. Synthesis examples Example 1 Enzymatic transesterification of TCDDA and TCD-DM to TCD-MA A solution of 24.00 g TCD-DM and 92.16 g TCDDA in 80 ml MTBE was placed in a 250 ml round-bottom flask with a magnetic stir bar. 2 g CALB were added and the flask was filled with a CaCl₂-drying tube closed. The mixture was slowly stirred for 42 hours in a water bath at 40°C and left to stand for 128 hours at room temperature (RT). The mixture was filtered, washed twice with a little MTBE, the filtrate was concentrated on a rotary evaporator and then dried under fine vacuum. A thin, colorless oil remained. Yield: 104.5 g TCD-DM (9.55), TCD-MA (21.5) and TCDDA (33.6) were detected using HPLC-MS. The respective running time in minutes is given in brackets. The loss on drying (2 hours, 50°C) was 0.34% by weight. Example 2 Synthesis of radically polymerizable compounds with a structure of formula 33 In a 250 ml two-necked flask with magnetic stir bar, internal thermometer and dropping funnel with CaCl₂-Drying tube, 50 g of oil according to Example 1 were placed in 50 g of THF and 9.55 ml of IPDI were slowly added dropwise at RT. Then 10 µl of catalyst solution (DMTND in toluene-t, weight ratio 1:1) were added and the mixture was stirred for 8 hours at 40°C and 85 hours at RT. To convert remaining isocyanate groups, 5.77 g of oil from Example 1 in 5.77 g of THF were added and the mixture was stirred for 2 hours at 40°C. stirred. Isocyanate groups were then no longer detectable by FT-IR spectroscopy. The reaction mixture was transferred to a 250 ml one-neck flask and THF was largely removed on a rotary evaporator at 25 mbar and 50°C water bath temperature. Further removal of volatile components was carried out in a fine vacuum at 50°C. A colorless, clear oil remained. Yield: 57.68 g Loss on drying (2 hours, 110°C): 1.69% Using HPLC-MS, TCDDA (M+H⁺= 305) and with a running time of 45.4 min a compound of formula 33 (M+H⁺= 724). The elution profile of the GPC performed is shown in Fig. 1. TCDDA had an elution volume of 29.8 ml, the compounds of structure 33 with x = 1 of 26.3 ml and with x = 2 – 3 of 25.0 and 24.0 ml respectively. TCDDA content_HPLC: 48.09 wt.% Content of compounds Formula 31: 50.22 wt.%

Example 3 Synthesis of radically polymerizable compounds with a structure of formula 34 In a 250 ml two-necked flask with magnetic stir bar, internal thermometer and dropping funnel with CaCl₂-Drying tube, 30 g of oil from Example 1 was placed in 30 g of THF and 7.17 g of H12MDI were added at RT. slowly added dropwise. Then 10 µl of a catalyst solution (DMTND in toluene-t, weight ratio 1:1) were added and stirred for 4 hours at 40°C and 19 hours at RT. To convert remaining isocyanate groups, a further 11.61 g of oil from example 1 in 11.61 g of THF (4 steps) were added step by step. After each addition, the mixture was stirred for 3 hours at 45°C and 18 hours at RT. Isocyanate groups were then no longer detectable by FT-IR spectroscopy. The reaction mixture was transferred to a 250 ml one-neck flask and THF was largely removed on a rotary evaporator at 25 mbar and 50°C water bath temperature. Further removal of volatile components was carried out in a fine vacuum at 50°C. A colorless, clear oil remained. Yield: 42.79 g Dry loss (2 hours, 110°C): 2.07% Using HPLC-MS, TCDDA (M+H⁺= 305) and with a running time of 48.6 min a compound of formula 34 (M+H⁺= 764). GPC: TCDDA had an elution volume of 29.6 ml, the compounds of structure 34 with y = 1 of 26.0 ml and those with y = 2 and 3 of 24.3 and 23.2 ml respectively. TCDDA content_HPLC: 47.35 wt.% Content of compounds of formula 32: 50.58 wt.%

(Formula 34) Example 4 Synthesis of radically polymerizable compounds of formula 35 In a 250 ml three-necked flask with magnetic stir bar, internal thermometer, reflux condenser, dropping funnel and CaCl₂11.35 g of TMDI in 25 ml of THF and 50 µl of catalyst solution (DMTND in toluene-t, 50:50 wt.%) were placed in a drying tube. A solution of 50.0 g of oil from example 1 in 25 ml of THF was slowly added dropwise at RT while stirring. The mixture was then stirred for 5 hours at 45°C and for a further 18 hours at RT. To convert remaining isocyanate groups, a further 6.44 g of oil were added step by step (4 steps) until isocyanate groups were no longer detectable by FT-IR spectroscopy. After each addition, the mixture was stirred for 5 hours at 45°C and 18 hours at RT. The reaction mixture was transferred to a 250 ml one-neck flask and mixed with 0.01 g of BHT. The majority of the THF was removed on a rotary evaporator. Further removal of solvent and other volatile components was carried out in a fine vacuum at 50°C. A colorless, clear oil remained. Yield: 55.94 g Loss on drying (2 hours, 110°C): 0.99% Using HPLC-MS, TCDDA (M+H⁺= 305) and with a running time of 45.2 min a compound of formula 35 (M+H⁺= 712) were detected. The elution profile of the GPC performed is shown in Fig. 2. TCDDA had an elution volume of 29.8 ml, the compound of the structure of formula 35 with z = 1 of 26.5 ml and higher oligomers (z = 2 – 4) of 24.9, 23.9 and 23.2 ml. TCDDA content_HPLC: 44.97 wt.% Content of compounds Formula 35: 54.04 wt.%

(Formula 35) Example 5 Synthesis of radically polymerizable compounds with the structure of formula 36 In a 250 ml two-necked flask with magnetic stir bar, internal thermometer and dropping funnel with CaCl₂30 g of oil from example 1 in 30 g of THF and 0.005 g of BHT were placed in a drying tube and 6.67 g of TMXDI were slowly added dropwise at RT. 10 µl of a catalyst solution (DMTND in toluene-t, weight ratio 1:1) were added and the mixture was stirred for 4 hours at 40°C and 18 hours at RT. To convert remaining isocyanate groups, a further 5.22 g of oil from example 1 and 10 µl of the catalyst solution were added and the mixture was stirred for 5.5 hours at 40°C and 18 hours at RT. Isocyanate groups were then no longer detectable using FT-IR spectroscopy. The reaction mixture was transferred to a 250 ml one-neck flask and THF was largely removed on a rotary evaporator at 25 mbar and 50°C water bath temperature. Further removal of volatile components was carried out in a fine vacuum at 45°C. A colorless, clear oil remained. Yield: 33.75 g Loss on drying (2h, 110°C): 1.49% Using HPLC-MS, TCDDA (M+H⁺= 305) and at a running time of 45.4 min a compound of the structure of formula 36 (M+H⁺= 746). GPC: TCDDA had an elution volume of 29.7 ml, the compound of the structure of formula 36 with l = 1 of 26.5 ml and l = 2 - 4 of 24.9, 24.0 and 23.2 ml respectively. TCDDA content_HPLC: 46.06 wt.% Content of compounds of formula 36: 52.45 wt.%

Example 6 Synthesis of radically polymerizable compounds with H6XDI In a 100 ml two-necked flask with magnetic stir bar, internal thermometer and dropping funnel with CaCl₂22 g of oil from example 1 in 15 ml of THF were placed in a drying tube and 3.89 g of H6XDI in 15 ml of THF were slowly added dropwise at RT. 10 µl of catalyst solution (DMTND in toluene-t, weight ratio 1:1) were added and the mixture was stirred for 5 hours at 40°C and 18 hours at RT. Isocyanate groups were then no longer detectable by FT-IR spectroscopy. The reaction mixture was transferred to a 100 ml one-neck flask, a spatula tip of BHT was added and THF was largely removed on a rotary evaporator. Further removal of volatile components took place under a fine vacuum. A colorless, clear oil remained. Yield: 21.48 g Loss on drying (2 hours, 110°C): 1.43% Using HPLC-MS, TCDDA was isolated after a run time of 34.0 min and the product (M+H⁺= 696). GPC: TCDDA had an elution volume of 29.7 ml, the product of 26.6 ml, 25.1 ml, 24.1 ml and 23.4 ml, respectively. It is understood that, starting from the isomers or isomer mixtures of the isocyanates and/or alcohols used, various isomeric structures are formed during the synthesis of the radically polymerizable compounds, in particular with regard to the dimethylenetricyclodecane groups and their direction in the polymerizable compounds, for example in an oligomer chain. The simple compounds of the structures of formulas 33 to 34 shown here are intended, however, to include all the isomeric compounds that are formed. 5. Properties of the radically polymerizable compositions To produce the compositions, the individual components were mixed using a magnetic stirrer until a homogeneous composition was obtained. Table 2: Composition, viscosity (η), flexural strength (BF), modulus of elasticity (EM), conversion (U), volume shrinkage (VS), refractive index uncured (n_DVA), refractive index cured (n_DNA) of compositions according to the invention (Ex. A, B, C, D) containing the radically polymerizable compounds synthesized in Examples 2-5 (oil from Ex. 2-5) and of comparison compositions (VB A, B) Component Ex. A Ex. B Ex. C Ex. D VB A VB B [% by weight] Ex. 2 97.4 Ex. 3 97.4 Ex. 4 97.4 Ex. 5 97.4 BisGMA 68.2 48.7 TEDMA 29.2 48.7 CQ 1.0 1.0 1.0 1.0 1.0 1.0 EHA 1.598 1.598 1.598 1.598 1.598 1.598 BHT 0.002 0.002 0.002 0.002 η [Pa s] 18.8 13.8 16.6 20.6 BF [MPa] 100±7 129±8 105±8 96±7 EM [GPa] 2.6±0.1 3.3±0.1 2.6±0.1 2.4±0.2 U [% ] 72.0 74.4 68.3 - VS [%] 4.4±0.3 4.6±0.2 6.4±0.3 8.2±0.3 n_DVA 1.5144 1.5157 1.5121 1.5198 1.5214 1.5046 n_DNA 1.5425 1.5463 1.5529 1.5388 Table 3: Composition, flexural strength (BF), Young's modulus (EM), volume shrinkage (VS), refractive index uncured (n_DVA), refractive index cured (n_DNA) of comparison compositions (VB C-F) Component VB C VB D VB E VB F [% by weight] UDMA 77.9 77.9 53.6 53.6 TCDDA 43.8 TCDDMA 19.5 TEDMA 19.5 43.8 CQ 1.0 1.0 1.0 1.0 EHA 1.598 1.598 1.598 1.598 BHT 0.002 0.002 0.002 0.002 BF [MPa] 102±4 94±6 - - EM [GPa] 2.4±0.1 2 .5±0.1 - - VS [%] 7.0±0.6 6.9±0.3 - - n_DVA 1.479 1.488 1.4940 1.4749 n_DNA 1.5100 1.5215 1.5170 1.5108 The inventive examples B and D show a significantly lower volume shrinkage than the comparative examples A-F. The conversions, flexural strengths and the modulus of elasticity of the inventive examples are in the range of the comparative examples A-F and in some cases even higher. The difference in the refractive indices of the cured inventive examples B and D to the dental glass used (n_D= 1.53) is comparable to the difference between the comparative examples A-F and the same dental glass. This results in similarly low levels of cloudiness in the dental composites for the inventive examples B and D, which lead to very good aesthetic product properties. Production of the dental composites To produce the dental composites, the components oil example 3, example 5 or BisGMA and TEDMA were first mixed with CQ, EHA and BHT using a magnetic stirrer until a homogeneous composition was obtained. A total of 75% by weight of BaF, based on the total mass of the dental composite, was then gradually added, homogenized using a Speedmixer DAC 400-1 VAC-P (Hauschild, Germany) and degassed for 3 minutes at 20 mbar. The compositions and measurement results are shown in Table 4. Table 4: Composition, flexural strength (BF), Young's modulus (EM), conversion (U) and volume shrinkage (VS) of dental composites (Ex. E, F) containing the radically polymerizable compounds synthesized in Examples 3 and 5 (Ex. 3, Ex. 5) and the comparative composition G (VB G) Component Ex. E Ex. F VB G [% by weight] Ex. 3 24.8325 Ex. 5 24.8325 BisGMA 12.41625 TEDMA 12.41625 CQ 0.0625 0.0625 0.0625 EHA 0.1045 0 .1045 0.1045 BHT 0.0005 0.0005 0.0005 BaF 75 75 75 Total 100 100 100 BM [MPa] 133±6 134±6 128±16 EM [GPa] 9.4±0.4 10.3 ±0.2 9.9±0.2 U [%] 65.0 65.9 73.2 VS [%] 1.9±0.3 2.1±0.1 3.6±0.3 Examples E and F, in which the compounds according to the invention were used, show significantly lower volume shrinkage than the comparative example G, in which a monomer mixture from the prior art was used. Conversions, flexural strengths and the moduli of elasticity of the examples according to the invention are comparable with comparative example G. For comparison, the properties of known prior art , commercially available dental composites with a higher filler level are shown in Table 5. Despite the higher filler level, the shrinkage data for these composites are higher than those for the invention examples. Table 5: Properties of commercially available dental composites known in the state of the art containing BPA-containing polymerizable compositions and 78.5 to 83 wt.% filler. Dental composite BF [MPa] VS [%] (batch) EM [GPa] Ecosite Elements A2 135±9 2.5±0.1 (#798872) 10.7±0.8 Filtek Supreme XTE 149±15 2.2±0.0 Dentin A2 (#N902487) 11.7±0.4 Tetric EvoCeram A2 118±5 2.3±0.2 (#W97572) 9.2±0.9

Claims

Claims 1. A radically polymerizable compound represented by a structure of the formula 1: PG-Sp-PCA-Sp-[OC(O)NH-K-NHC(O)O-Sp-PCA-Sp]n-PG (formula 1), where PG = each independently selected from a radically polymerizable group, preferably selected from (NR ¹ )OC-CR ² =CH ₂ and OOC-CR ² =CH ₂ , more preferably selected from OOC-CR ² =CH ₂ , R ¹ = selected from hydrogen, a C1-C8 alkyl group, an aryl group and an araliphatic group having C6-C8 carbon atoms, preferably selected from a C1-C8 alkyl group and a benzyl group, R ² = selected from hydrogen, a C1-C4 alkyl group, preferably selected from hydrogen and methyl; Sp = each independently a spacer group selected from unbranched and branched alkylene with C1-C19 carbon atoms, which may additionally contain oxygen, sulfur and/or -OOC- in the carbon chain, or Sp is omitted; PCA = each independently a polycyclic group, preferably an aliphatic polycyclic group, more preferably an aliphatic bi- or tricyclic group; K = an aliphatic acyclic, saturated or unsaturated unit with C1-C15 carbon atoms, preferably C3-C13 carbon atoms, more preferably C6-C9 carbon atoms, where the unit can be substituted with one or more aliphatic C1-C3 carbon substituents, an aliphatic cyclic, saturated or unsaturated unit with C3-C15 carbon atoms, preferably C5-C13 carbon atoms, more preferably C6-C13 carbon atoms, where the unit can be substituted with one or more aliphatic C1-C3 carbon substituents, or an aromatic or araliphatic unit with C6-C14 carbon atoms, preferably C6-C13 carbon atoms, where the unit can be substituted with one or more aliphatic C1-C3 carbon substituents; n = 1 to 9, preferably 1 to 6. 2. Radically polymerizable compound according to claim 1, characterized in that the spacer group Sp is selected from methylene, *CH ₂ -(OC ₂ H ₄ ) _p , * CH ₂ -(OC ₃ H ₆ ) _p , *(OC ₂ H ₄ ) _p , *(OC ₃ H ₆ ) _p , *CH ₂ -(OC(O)-R ⁵ -)p, *(OC(O)-R ⁵ -)p and *SR ⁵ , where p = 1-5, preferably 1-3 and R ⁵ is a C1-C12 alkylene group, preferably a C2-C6 alkylene group. 3. Radically polymerizable compound according to claim 1 or claim 2, characterized in that the polycyclic group PCA is selected from structures of the formulas 2 to 13: (Formula 2) (Formula 3) (Formula 4) (Formula 5) (Formula 6)

(Formula 7) (Formula 8) (Formula 9) (Formula 10) (Formula 11) (Formula 12)

(Formula 13), which may optionally be substituted with one or more C1-C4 alkyl groups. 4. Radically polymerizable compound according to one of claims 1 to 3, characterized in that the polycyclic group PCA is an aliphatic tricyclic group, preferably tricyclo[5.2.1.0/2,6]decanylene (TCD) (formula 2). 5. Radically polymerizable compound according to one of claims 1 to 4, characterized in that K is selected from the following structures of the formulas 14 to 26:

, preferably selected from a structure of formulas 14, 15, 16, 17, 18, 19 and 20. 6. Radically polymerizable compound according to one of claims 1 to 5, characterized in that the radically polymerizable compound is represented by a structure of formula 27:

(Formula 27), where R ² = hydrogen or a methyl group; Sp = in each case independently a spacer group selected from unbranched and branched alkylene with C1-C19 carbon atoms, which may additionally contain oxygen, sulfur and/or -OOC- in the carbon chain, or Sp is omitted; PCA = in each case independently a polycyclic group, preferably an aliphatic polycyclic group, more preferably an aliphatic bi- or tricyclic group, even more preferably a tricyclic group, most preferably tricyclo[5.2.1.0/2,6]decanylene; K = an aliphatic acyclic, saturated or unsaturated unit with C1-C15 carbon atoms, preferably C3-C13 carbon atoms, more preferably C6-C9 carbon atoms, where the unit may be substituted with one or more aliphatic C1-C3 carbon substituents, an aliphatic cyclic, saturated or unsaturated unit with C3-C15 carbon atoms, preferably C5-C13 carbon atoms, more preferably C6-C13 carbon atoms, where the unit may be substituted with one or more aliphatic C1-C3 carbon substituents, or an aromatic or araliphatic unit with C6-C14 carbon atoms, preferably C6-C13 carbon atoms, where the unit may be substituted with one or more aliphatic C1-C3 carbon substituents; r = 1 to 9, preferably 1 to 6. 7. Radically polymerizable compound according to one of claims 1 to 6, characterized in that the radically polymerizable compound is represented by a structure selected from the formulas 28-31:

(Formula 28),

(Formula 31), where t, u, v and w = each independently of one another are 1-9, preferably 1-6; and R ² = selected from hydrogen, a C1-C4 alkyl group, preferably selected from hydrogen and a methyl group. 8. Process for preparing a radically polymerizable compound, characterized in that the process comprises the following steps: a) reacting a diol of a polycyclic group PCA with a (meth)acrylic acid ester to form a PCA- Mono(meth)acrylate which has a hydroxy group, by means of enzymatic catalysis, b) reacting the PCA mono(meth)acrylate containing the hydroxy group from step a) with a diisocyanate compound, preferably using a catalyst. 9. Radically polymerizable composition, comprising: a) one or more radically polymerizable compounds according to one of claims 1 to 7; b) optionally one or more further radically polymerizable monomers or oligomers which do not fall under the at least one compound of formula 1; c) optionally at least one initiator or one initiator system for the polymerization; d) optionally one or more stabilizers; e) optionally one or more fillers; f) optionally additives commonly used in dentistry. 10. Radically polymerizable composition according to claim 9, characterized in that the radically polymerizable composition contains one or more radically polymerizable compounds of formula 1 in a mass fraction of 1-100 wt. %, preferably 2-80 wt. %, preferably 2-65 wt. %, even more preferably 10-65 wt. %, based on the total mass of all radically polymerizable Monomers and oligomers of the polymerizable composition are included. 11. Radically polymerizable composition according to claim 9 or 10, characterized in that several compounds of formula 1, selected from monomers (n = 1) and/or oligomers (n = 2-9), are present. 12. Radically polymerizable composition according to one of claims 9 to 11, characterized in that the radically polymerizable composition is a radically polymerizable dental material. 13. Use of the radically polymerizable compound according to one of claims 1 to 7 or the radically polymerizable composition according to one of claims 9 to 12 for producing a polymerizable dental material, preferably a dental composite, dental cement, self-adhesive dental cement, dental varnish, stump build-up, root canal filling, filling, underfilling, fixing, crown, bridge, restoration, orthodontic and/or prosthesis material. 14. Use according to claim 13, characterized in that the polymerizable dental material is used as a 3D printing material, wherein preferably orthodontic materials, aligners, splint materials, denture base materials, model materials, crown and bridge materials, drilling templates, gingiva masks, spoon materials, mouth guards or veneers are produced from the polymerizable dental material by means of 3D printing. 15. Cured dental material made from a polymerizable composition according to one of claims 9