EP4346743A1 - Monomer mixture for producing a dental material - Google Patents

Abstract

The invention relates to a monomer mixture for producing a dental material comprising: a. at at least one base monomer M1 of the following formula 1: PG–S–A–S–[OOC–K–COO–S–A–S]_n–PG (formula 1), where PG = a polymerizable group selected from OOC- CH=CH₂ and -OOC-C(CH₃)=CH₂; S = a spacer group selected from an unbranched and a branched alkylene, which has C1-C10 carbon atoms and which can also contain oxygen or -OOC- in the carbon chain, or S is omitted; A = an aliphatic polycyclic group; K = an aliphatic acyclic or cyclic saturated or unsaturated unit with C1-C10 carbon atoms; and n = 1-9; b. at least one base monomer M2 of the following formula 2: PG'–S'–A'–S'–PG' (formula 2), where PG' = a polymerizable group selected from OOC- CH=CH₂ and -OOC-C(CH₃)=CH₂; S' = a spacer group selected from an unbranched and a branched alkylene, which has C1-C10 carbon atoms and which can also contain oxygen or -OOC- in the carbon chain, or S' is omitted; and A' = an aliphatic polycyclic group, wherein the mass ratio Y = m(M2)/m(M1) of the base monomers M2 to M1 is 0.9 ≤ Y ≤ 20. The invention also relates to the use of the monomer mixture, to a polymerizable dental material containing such a monomer mixture, to a polymerizable dental material for use in a therapeutic method, and to a cured dental material.

Description

Monomer mixture for the production of a dental material

The invention relates to a monomer mixture for producing a dental material, a use of the monomer mixture, a polymerizable dental material containing such a monomer mixture, a polymerizable dental material containing such a monomer mixture for use in a therapeutic method, and a cured dental material.

Radically polymerizable dental materials mainly contain (meth)acrylate monomers. Dimethacrylate systems are mostly used for restorative and prosthetic dental materials, such as tooth fillings or dentures, due to their properties, such as rapid radical polymerization, good mechanical properties and aesthetic appearance. Common base monomers are linear aliphatic or aromatic group-containing structures with terminal methacrylate functionalities that have 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 there has been an attempt to avoid using BisGMA as far as possible and to replace it, at least in part, with other compounds. The main focus is on urethane monomers and oligomers. The most commercially widespread use as at least a partial replacement of BisGMA is in the field of dental materials UDMA.

Basic monomers, such as BisGMA and UDMA, although they have commercial free-radically polymerizable den- valley materials are included, some disadvantages. They are generally highly viscous to solid substances. Mixtures with monomers with a significantly low viscosity, such as triethylene glycol dimethacrylate (TEGDMA), are therefore used. TEGDMA is a very flexible, low molecular weight monomer with a low viscosity (of 0.01 Pas) and exhibits high mobility during polymerisation, which promotes polymerisation conversion.

However, these monomer mixtures and the dental materials obtained from them have some problematic properties that can impair their clinical treatment success. For example, monomer mixtures of these dimethacrylate monomers have a relatively low polymerization conversion, high 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 a lack of mechanical properties and wear resistance, but is also disadvantageous with regard to the toxicology and biocompatibility of the polymerized dental materials. In addition, the volume shrinkage of currently used dimethacrylate monomers and the shrinkage stresses of a dental filling can lead to failure of the bond between the tooth and the filling, which leads to microleakage and subsequent secondary caries, which in turn can significantly reduce the longevity of the restoration. Unfortunately, attempts to increase double bond conversion to reduce unreacted monomers lead to an increase in polymerization shrinkage and shrinkage stress.

Low-molecular monomers with oligo[ethyleneoxy] groups, such as TEGDMA, which have a certain water solubility and thus bioavailability, are now being logical properties and their sensitivity to biodegradative processes. Equally critical are monomers with the structural element bis-2,2-[p-oxyphenyl]propane, ie monomers based on bisphenol-A, since dental materials containing monomer mixtures with these structural elements have been found to release detectable amounts of bisphenol-A, the toxicologically critical properties are assigned.

There are different approaches to increasing sales or reducing volume shrinkage. In the case of dental composites for tooth fillings, which contain filler in a matrix of organic resin, an attempt is made to reduce the volumetric shrinkage by increasing the filler content. However, when 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. New monomers, such as high molecular weight urethane methacrylate monomers, continue to be developed to increase sales and reduce polymerization shrinkage. The synthesis of these monomers is complicated and usually also requires purification steps, which leads to the limited availability of such monomers. With a given functionality of the monomers, the increase in the molecular weight is generally associated with a deterioration in the mechanical properties of the cured dental materials. Moreover, the increased viscosity of such monomers requires use with higher amounts of low viscosity monomers in order to use them for dental composites, which has an unfavorable effect on shrinkage.

EP 2436365 Bl describes low-shrinkage dental composites containing tend monomer mixtures which contain the monomers (bl) and (b2) in in a ratio of 1:20-5:1. The example compositions each contain 4.8-76.6% by weight of bis((meth)acryloyloxymethyl)tricyclo[ ^5.2.1.02,6 ]decane (bl), 90.9-19.1% by weight UDMA (b2) and 4.3% by weight TEDMA (b2). Irrespective of the ratio (b1) to (b2), these composites exhibit a polymerization shrinkage of around 1.50%. If, as in Comparative Example 11, the proportion of fillers is reduced and the proportion of TEDMA is increased, the polymerization shrinkage increases.

Vaidyanathan et al., Visible light your 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% by weight TEGDMA. The polymerization conversions of these mixtures were investigated, with the combinations of PEM and TEGDMA exhibiting a higher percentage polymerization conversion than the combinations of Bis-GMA with TEGDMA.

There is therefore a need for monomers or monomer mixtures which can enable a reduced toxicity potential and reduced volume shrinkage while at the same time having good mechanical properties in the dental material to be produced from them, and which are easily available.

The present invention is therefore based on the object of providing a monomer mixture which overcomes the above-mentioned disadvantages of the prior art and which in particular makes it possible to produce dental materials, in particular dental composites, with improved volume shrinkage and improved flexural strength.

The invention solves this problem with a monomer mixture for the production of a dental material, comprising: a. at least one base monomer Ml of the following formula 1:

PG-SAS-[OOC-K-COO-SAS ] _n -PG (Formula 1) with

PG = a polymerizable group selected from OOC-CH=CH ₂ and -OOC-C(CH ₃ )=CH ₂ ;

S=a spacer group selected from unbranched and branched alkylene with Cl—ClO carbon atoms, which can additionally contain oxygen and/or -OOC- in the carbon chain, preferably methylene, or S is omitted;

A=an aliphatic polycyclic group, preferably an aliphatic tricyclic hydrocarbon group, in which one or more hydrogen atoms can be independently replaced by Cl-C4-alkyl radicals, Cl-C4-alkoxy radicals, fluorine atoms, chlorine atoms or trifluoromethyl groups, more preferably tricyclodecanylene, more preferably tricyclo[5.2.1.0/2,6]decanylene;

K=an aliphatic acyclic or cyclic, saturated or unsaturated moiety with C1-ClO-hydrocarbon, preferably with C3-C1O-hydrocarbon, more preferably a saturated cycloaliphatic moiety, even more preferably 1,4-cyclohexanylene; n = 1-9, preferably 1-5, more preferably 1-4; b. at least one base monomer M2 of the following formula 2:

PG' — S — A'-S'-PG' (Formula 2) With

PG' = a polymerizable group selected from OOC-CH=CH ₂ and -OOC-C(CH ₃₎ =CH ₂ ;

S'=a spacer group selected from unbranched and branched alkylene with Cl-ClO carbon atoms, which can additionally contain oxygen and/or -OOC- in the carbon chain, preferably methylene, or S' is omitted;

A' = an aliphatic polycyclic group, an aliphatic tricyclic hydrocarbon group in which one or more hydrogen atoms can each independently be replaced by Cl-C4-alkyl radicals, Cl-C4-alkoxy radicals, fluorine atoms, chlorine atoms or trifluoromethyl groups, more preferably tricyclodecanylene , more preferably tricyclo[5.2.1.0/2,6]decanylene; where a mass ratio Y=m(M2)/m(M1) of the basic mono mers M2 to M1 is 0.9<Y<20, preferably 0.9<Y<10, preferably 0.95<Y<3.

Preferred embodiments are in the sub-claims.

First, some of the handles used in the context of the invention are explained.

According to the invention, polymerizable dental materials are materials for (bio)medical use, in particular on hard tooth substance, such as tooth enamel and dentine, or on bone tissue, such as on the jawbone. The polymerizable dental material is usually a resin-based material that is a mixture of different components that can be hardened. In the context of this invention, a resin essentially consists of the monomer mixture and other components that are soluble in the monomers, such as initiators, stabilizers, etc.

In the context of the present invention, a monomer mixture is a mixture which comprises basic monomers M1 and M2 and optionally basic monomers M3 and/or other monomers of the polymerizable dental material. Other constituents of the polymerizable dental material, such as initiator, filler, customary dental additive, etc., are not part of the monomer mixture.

In the context of the present invention, base monomer M1 is monomers when n=1 and oligomers when n=2 to 9. In the present case, monomers and oligomers with n=1 to 9 are referred to as basic monomers M1.

The monomer mixture preferably contains a plurality of base monomers M1, more preferably at least two base monomers M1, even more preferably more than two base monomers M1, more preferably more than three base monomers M1, even more preferably more than four base monomers M1.

In one embodiment, all of the base monomers M1 of a monomer/oligomer series with n=1-9, preferably with n=1-5, more preferably with n=1-4, can be present next to one another. Ie for n = 1-9 there would then be at least 9 compounds (ie one monomer and eight oligomers), for n = 1-5 at least 5 compounds (ie one monomer and four oligomers) and for n = 1-4 min- at least 4 compounds (ie one monomer and three oligomers) present.

The mass distribution of the base monomers M1 can vary widely. It may be that the base monomers M1 in which n=2-5 or n=2-4 have the highest mass fraction, based on the total mass fraction of the base monomers M1. However, it can also be the case that the base monomer or monomers M1 with n=1 have the highest mass fraction compared to each individual base monomer M1 with n=2-9 contained in the monomer mixture.

The base monomer M2 can be selected from bis(methacryloyloxymethyl)tricyclo[5.2.1.0/2.6]decane, bis(acryloyloxymethyl)tricyclo[5.2.1.0/2.6]decane and mixtures thereof. More preferably, the base monomer M2 is bis(methacryloyloxymethyl)tricyclo[5.2.1.0/2,6]decane. The base monomer M2 can be a commercially available monomer, such as tricyclo[5.2.1.0/2.6]decanedimethanol diacrylate from Polyscience. However, they can also be monomers which can be obtained by an esterification reaction, for example according to the preparation examples of EP0235836B1 or US4131729/DE2816823. Technically available basic monomers M2 based on tricyclo[5.2.1.0/2.6]decanedimethanol di(meth)acrylate generally contain isomer mixtures in which the exocyclic methylene groups are on different skeletal carbon atoms, depending on the isomer are bound.

The monomer mixture can include a base monomer M3, which differs from the base monomers M1 of formula 1 and M2 of formula 2.

The base monomer M3 is preferably selected from urethane-based monomers. Suitable base monomers M3 can be selected from difunctional urethane (meth)acrylates, polyfunctional urethane (meth)acrylates and mixtures thereof.

The base monomer M3 is preferably a urethane di(meth)acrylate. Preference is given to urethane di(meth)acrylates selected from linear or branched alkylene-functionalized urethane di(meth)acrylates and urethane di(meth)acrylate-functionalized polyethers.

Preference is given to difunctional urethane (meth)acrylates which are 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 divalent alkylene group are preferably selected from linear or branched urethane di(meth)acrylates functionalized with a divalent 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 comprise linear or branched alkylene groups with C3 to C20, preferably C3 to C9, are preferred. An alkylene substituted with methyl groups is particularly preferred. The divalent alkylene preferably includes 2,2,4-trimethylhexamethylene and/or 2,4,4-trimethylhexamethylene.

Furthermore, the base monomer M3 can also be a reaction product of 3-hydroxypropyl methacrylate and trimethylhexamethylene diisocyanate, or a reaction product of 3-hydroxypropyl acrylate and trimethylhexamethylene diisocyanate. Urethane (meth)acrylates with a bivalent cyclic aliphatic hydrocarbon group can be obtained by reacting 2 moles of 2-hydroxyethyl methacrylate (HEMA) or 2 moles of 2-hydroxyethyl acrylate (HEA) with 1 mole of cyclic aliphatic diisocyanate. Suitable diisocyanates are isophorone diisocyanate (1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane) or H12-MDI (1-isocyanato-4-[(4-isocyanatocyclohexyl)methyl]cyclohexane and other cyclic diisocyanates. Examples of this are the reaction product of 2 molecules of 2-hydroxyethyl acrylate (HEA) and one molecule of isophorone diisocyanate (IPDI), as well as the adduct of 2 molecules of 2-hydroxyethyl methacrylate (HEMA) and one molecule of isophorone diisocyanate.

Suitable base monomers M3 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 oligomer), 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. In a preferred embodiment, the base monomer M3 is selected from 7,7,9-(or 7,9,9-)trimethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1, 16-diyl bis(2-methyl acrylate) (UDMA), 7,7,9-(or 7,9,9-)trimethyl-4,13-dioxo-3,14-dioxa-5,12-diaza - hexadecane-1,16-diol diacrylate (UDA) and mixtures thereof.

The base monomers can each be present in the following proportions by mass, based on the total mass of the monomer mixture:

Base monomer Ml from 2 to 52.5% by weight, preferably from 5 to 52.5% by weight, more preferably from 12.5 to 52.5% by weight;

base monomer M2 from 23 to 96% by weight, preferably from 47.5 to 95.5% by weight, more preferably from 47.5 to 87.5% by weight;

Base monomer M3 from 0 to 50% by weight, preferably from 0.1 to 30% by weight, more preferably from 1 to 15% by weight.

It is preferred that the monomer mixture contains the basic monomers M1 and M2 in a mass fraction of 25% by weight or more, more preferably 50% by weight or more, even more preferably 70% by weight or more, more preferably 85% by weight % by weight or more, more preferably 100% by weight, based on the total weights of the monomer mixture.

The monomer mixture can comprise or contain the basic monomers M1, M2 and M3 in a mass fraction of 95 to 100% by weight, preferably 99 to 100% by weight, more preferably 100% by weight, based on the total mass of the monomer mixture. consist of these. According to the invention, it is preferred that the monomer mixture does not contain any monomer that has a bisphenol A structure. In particular, no 2,2-bis[4-(2-hydroxy-3-(meth)acryloxypropoxy)phenyl]propane (BisGMA) and/or ethoxylated bisphenol A di(meth)acrylate (BisEMA) is contained. The same applies to the polymerizable dental material.

According to the invention, it is preferred that no monomer selected from low molecular weight and low-viscosity mono- and di(meth)acrylates is present in the monomer mixture. In addition, it is preferred that no monomer with a viscosity at a temperature of 23° C. of less than 0.05 Pas and/or with a partial water solubility is present. In particular, no monomers consisting of an oligo[ethyleneoxy] group or a linear or branched C1-C1O-alkylene group and one or two (meth)acrylate group(s) are present in the monomer mixture. The monomer mixture is preferably free from hexanediol diacrylate (HDDA), hexanediol dimethacrylate (HDDMA), triethylene glycol diacrylate (TEGDA) and/or triethylene glycol dimethacrylate (TEGDMA). The same applies to the polymerizable dental material.

The viscosity of monomers or organic resins is regularly specified by the manufacturer and can be determined using a viscometer (e.g. Kinexus DSR from Malvern Instruments Ltd.).

At a temperature of 23° C., the monomer mixture according to the invention preferably has a viscosity of from 0.2 to 10 Pa s, more preferably from 1 to 6 Pa s.

The invention has the advantage that the mono mer mixture according to the invention and consequently also the polymerizable dental material according to the invention have the disadvantages of the previously listed overcome the state of the art. The monomer mixture and the polymerizable dental material can be made from basic monomers which are readily available and which also have a reduced potential for toxicity. The use of the monomer mixture according to the invention for the production of a dental material leads to reduced polymerization shrinkage while at the same time having good mechanical properties in the dental material obtained. In particular, dental materials, in particular dental composites, with improved volume shrinkage and improved flexural strength can be obtained with the mono mer mixture. In view of the molecular sizes and structures of the base monomer M1, this is surprising since one would expect a reduced crosslinking density and flexural strength associated with this.

The monomer mixture and the polymerizable dental material therefore preferably contain no monomers or other compounds with structural elements derived from bisphenol A and also no low-molecular mono- and di(meth)acrylates with partial water solubility, in particular no TEGDMA.

The invention also relates to the use of the monomer mixture according to the invention, preferably according to one of claims 1 to 10, for the production of a radically polymerizable dental material, preferably a dental composite, core build-up, root canal filling, filling, underfilling, fastening, crowns -, bridge, restoration and / or prosthesis material.

The subject matter of the invention is also a polymerizable dental material, comprising: a) the monomer mixture according to the invention, preferably according to any one of claims 1 to 9; b) optionally at least one initiator or an initiator system for the free-radical polymerization; c) optional fillers; d) optional customary dental additives.

The polymerizable dental material can be built up in the form of a kit. The kit can contain one or more components. In the case of the multi-component kit or system, the dental material is produced immediately before the dental material is used by mixing the components in the specified mixing ratio and then curing. b) initiator(s)

Suitable initiators or initiator systems are capable of starting free-radical polymerization reactions. Such initiators or initiator systems are known to those skilled in the art.

Initiator systems consist of at least one initiator and at least one other compound, such as a coinitator. These can be distributed among various components of the polymerizable dental material. The dental material according to the invention can be cured thermally, chemically, photochemically, i.e. by irradiation with UV and/or visible light.

Suitable initiators can be, for example, photoinitiators. These are characterized in that they absorb 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 through the additional reaction with one or more co-initiators can cause the material to harden. Preference is given here to phosphine oxides, acylphosphine oxides, bisacylphosphine oxides and derivatives thereof, acylgermanans, as described for example in EP2649981A1, WO2017/055209A1 and EP3153150A1, benzoin ethers, benzil ketals, acetophenones, benzophenones, thioxanthones, bisimidazoles, metallocenes, fluorones , a-Dicarbonyl compounds, aryldiazonium salts, arylsulfonium salts, aryliodonium salts, ferrocenium salts, phenylphosphonium salts or a mixture of these compounds are used.

Particular preference is given to diphenyl-2,4,6-trimethylbenzoylphosphine oxide, phenylbis-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.

Tertiary amines, borates, organic phosphites, diaryliodonium compounds, thioxanthones, xanthenes, fluorenes, fluorines, -dicarbonyl compounds, dicarbonyl systems as described in WO2021/048313A1, fused polyaromatics or a mixture of these compounds are preferably used as coinitiators for photochemical curing. N,N-dimethyl-p-toluidine, N,N-dialkyl-alkylanilines, N,N-dihydroxyethyl-p-toluidine, 2-ethylhexyl-p-(dimethylamino)benzoate, ethyl-p -(dimethylamino)benzoate, butyryl choline-triphenylbutyl borate or a mixture of these compounds is used.

So-called thermal initiators can also be used as initiators, which can bring about the hardening of the material by absorbing thermal energy at elevated temperature. Preference is given here to using inorganic and/or organic peroxides, inorganic and/or organic hydroperoxides, ,'-azobis(isobutyroethyl ester), a,a'-azobis(isobutyronitrile), benzpinacols or a mixture of these compounds. 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, ie a multi-component, preferably a two-component, material is present. The initiator or initiators are preferably inorganic and / or organic peroxides, inorganic and / or organic hydroperoxides, barbituric acid derivatives, malonylsulfamide, 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 connec tions and as coinitiator or as coinitiators preferably tertiary amines, heavy metal compounds, in particular connec tions of the 8th and 9th group of the periodic table ("iron and copper group") _/ compounds with ionogenically bound halogens or pseudohalogens such as B. quaternary ammonium halogen nide, weak Broensted acids such. B. alcohols and water or a mixture of these compounds are used.

Any conceivable combination of the initiators and co-initiators described above can also be contained in the dental material according to the invention. An example of this are so-called dual-curing dental materials, which contain both photoinitiators and optionally the corresponding coinitiators for photochemical curing and initiators and corresponding coinitiators for chemical curing at room temperature.

The polymerizable dental material according to the invention is preferably light-curing. In a preferred embodiment, camphorquinone (CQ) is present as an initiator and 2-ethylhexyl p-(dimethylamino)benzoate (EHA) as a co-initiator. c) fillers

The polymerizable dental material according to the invention can contain other customary dental additives. The filler particles are not limited to a specific particle shape. Rather, fillers having a spherical, scaly, platelet-like, needle-like, sheet-like or irregular shape can be used very well. The filler particles preferably have an average particle diameter of from 5 nm to 100 μm, preferably from 5 nm to 50 μm.

Suitable fillers can be selected from a wide variety of materials commonly used in dental products. By selecting the filler, for example, the fluidity, viscosity, consistency, color tone, X-ray visibility and mechanical stability of the Dental material are set. Based on their chemical nature, the fillers can be roughly divided into three different classes: inorganic fillers, organic fillers and organic-inorganic composite fillers. The fillers can be used not only individually, but also in combination with each other.

Ground powders of natural or synthetic glasses or crystalline inorganic substances in various sizes and states (monodisperse, polydisperse) can be used as inorganic fillers. Suitable examples are 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 (e.g available under the trade names RAYSORB T4000, Schott G018-093, Schott G018-163, and Schott GM32087), lithium aluminum silicate glasses, barium glasses, calcium silicate glasses, sodium aluminum silicates, fluoro aluminum silicate glasses (such as under the trade names Schott G018-091 and Schott G018- 117 available), zirconium or cesium boroaluminosilica glasses (such as 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 can be preferred that the mean 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 can be used in order to bring about a more uniform filling of the dental material and to increase the hardness and abrasion resistance. In this context, nanoparticles are understood as meaning 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 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 their mixtures. The preferred oxidic nanoparticles are not agglomerated. The surfaces of the nanoparticles are organically modified to enable the nanoparticles to be well integrated into the polymer matrix of a composite material. The surfaces of the fillers are preferably treated 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, under the name "NALCO COLLOIDAL SILICAS" (Nalco Chemical Co.), "Ludox colloidal silica" (Grace) or "Highlink OG " (Clariant) on sale.

Submicron fillers or microfillers consisting of agglomerated, nanoscale particles can also be used, especially when their specific surface area (determined according to Brunauer, Emmet, Teller) is in the range between 100 and 400 m ² /g. Fumed silica or wet-precipitated silica are preferred. Suitable non-surface treated silica filler products that can be used are commercially available under the designations AEROSIL™ ("0X50", "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 Ca- Bot Corp., Tuscola, IL), HDK™ ("S13", "V15", "N20", "T30", "T40 "

Wacker-Chemie AG, Munich, Germany) and Orisil™ ("200", "300", "380" Orisil, Lviv, Urkraine).

Particularly advantageous abrasion and gloss retention properties can be achieved by using aggregated, nanoscale particles based on mixed oxides of silicon dioxide and zirconium dioxide in the dental material. A suitable filler can be made by 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 method as described in US Pat. No. 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 combined with high aesthetics and abrasion resistance.

The aggregated fillers preferably have an average secondary particle size of 1-15 μm, preferably an average secondary particle size of 1-10 μm and particularly preferably an average secondary particle size of 2-5 μm.

In addition, appreciable amounts of selected radiopaque fillers may be present. The addition of X-ray-visible particles to the dental material is advantageous because it makes it possible to distinguish between intact tooth structure and the restoration. Suitable X-ray visible fillers contain particles of metal oxides, metal fluorides or barium sulfate. Oxides and fluorides of heavy metals having an atomic number greater than 28 are preferred. The metal oxides and fluorides should be selected so that they match the shade of the restoration. have little influence. 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 57-71), cerium, and combinations thereof. Examples of suitable metal fluorides are yttrium trifluoride and ytterbium trifluoride. Irregularly shaped or spherical YbF ₃ or YF ₃ particles with an average grain size of the primary particles of 40 nm to 1.5 μm are particularly preferred here, and core-shell combination products made of YF ₃ or YbF ₃ core are particularly preferred and Si0 ₂ shell, where the Si0 ₂ shell surface is 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 mean particle size of the agglomerated particles of 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), polyethylene glycol (PEG), polypropylene glycol (PPG), Polyvinyl alcohol (PVA), polyurethane (PU), polyurea, methyl methacrylate-ethyl methyl acrylate copolymer, ethylene vinyl acetate copolymer, and styrene-butadiene copolymer. Furthermore, the organic filler may 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 dental materials if so-called organic-inorganic composite fillers are used. the. These fillers can be produced by processing a polymerizable monomer with an inorganic filler into a paste, then curing it by polymerization and then finely grinding it before using it as a filler. Microfillers are preferably used here as inorganic fillers. After grinding, the fillers preferably have an average particle size of 0.05-100 μm, preferably an average particle size of 0.5-50 μm and particularly preferably an average particle size of 1-30 μm.

It is preferred that the fillers in the dental materials 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 ease of incorporation of the filler into the resin mixture. As a result of this treatment, the surfaces of the inorganic particles are organically modified, i.e. the surfaces have organic structural elements. In this case, all the procedural known to the person skilled in the art can be used. Silanizing agents are preferred for the inorganic fillers that carry OH groups on the surface. Examples here are the γ-methacryloxyalkyltrimethoxysilane (number of carbon atoms between the methacryloxy group and the silicon atom: 3 to 12), γ-methacryloxyalkyltriethoxysilane (number of carbon 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 the silanizing agent.

Inorganic fillers that have hardly any or no OH groups on the surface are preferred with other surface modifiers, such as titanates, aluminates, zircoaluminates, surfactants, fatty acids, organic acids, inorganic Acids or metal alkoxides surface treated. As surface modification agents for salts of barium, strontium and rare earth metals are organic compounds that carry N-, P-, S- and/or O-containing functional groups (e.g. polyols, sulfoxides, phosphinic esters, phosphonic esters, trialkylphosphines, carboxylic acids and Carboxylic acid ester) particularly be preferred. 1O-Methacryloyloxydecyl dihydrogen phosphate is particularly suitable here.

Especially 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 in radically unreactive groups. Suitable non-reactive groups are, for example, trimethylsilyl, dimethylsilylene or methylsilylidene groups, which can be applied to the surface by silanization, for example with hexamethyldisilazane, dimethyldimethoxysilane or methyltrimethoxysilane. Suitable unreactive 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 ) available. The agglomerated nanofillers can also preferably be modified with groups that are reactive in free-radical processes, for example methacryloyl groups. A commercial 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 present in largely deagglomerated form, as is described, for example, in EP1720206.

A dental material according to the invention can have a proportion of filler particles between 0 and 95% by weight, preferably from 1 to 95% by weight, based on the total mass of the polymerizable material Dental materials included. The quantity of the filler fraction is selected depending on the indication of the dental product. Thus, the highest possible amounts of filler are used for stable, modelable 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 up to 92% by weight, based on the composition as a whole. Flowable dental composites, luting 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 have fillers in the range from 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 depending on the selection of the filler. d) customary dental additives

The polymerizable dental material according to the invention can contain other customary dental additives. Customary dental additives are known to the person skilled in the art, preferred additives are inhibitors, stabilizers, accelerators, dyes, fluoride agents, remineralizing agents, X-ray opaques and film formers.

Inhibitors and stabilizers serve in particular to prevent premature polymerization. They are substances that react with reactive radicals to form more stable trapping products. The addition of inhibitors or stabilizers improves the storage stability of the compositions that are still to be cured. Moreover, inhibitors can do this serve to set the processing time of hardening systems within a suitable range. Examples of suitable inhibitors are phenol derivatives such as hydroquinone monomethyl ether (HQME) or 2,6-di-tert-butyl-4-methylphenol (BHT). Other inhibitors such as tert-butylhydroxyanisole (BHA), 2,2-diphenyl-l-picrylhydra- zyl, galvinoxyl, triphenylmethyl radicals, 2,3,6,6-tetramethylpiperidinyl-l-oxyl radicals (TEMPO) and Derivatives of TEM PO or phenothiazine and derivatives of this compound are described in EP 0783880 B1. Alternative inhibitors can be found in DE 10119831 A1 or EP 1563821 A1.

The polymerizable dental material can contain, in particular, 2,6-di-tert-butyl-4-methylphenol (BHT) as a stabilizer.

The dental material according to the invention can contain UV stabilizers as an additive customary in dentistry. UV stabilizers serve in particular to stabilize the dental material against degradation or discoloration due to UV radiation. Examples of UV absorbers are 2-hydroxy-4-methoxybenzophenone, phenyl salicylate 3-(2'-hydroxy-5'-methylphenyl)benzotriazole or diethyl 2,5-dihydroxyterephthalate.

The dental material according to the invention can contain one or more fluoride-releasing substances in finely divided, particulate form as a customary 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 of the 2nd main group. Glasses containing fluoride are also suitable sources of fluoride.

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.

The dental material according to the invention can contain a colorant or mixture of colorants 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 colorant or an organic fluorescent pigment, in particular a non-polymerizable, organic fluorescent colorant optionally comprising aryl carboxylic acid esters such as diethyl 2,5-dihydroxyterephthalate, aryl carboxylic acids, coumarin, rhodamine, naphthanimide or derivatives thereof. Inorganic fluorescent pigments can, for example, CaAl ₄ O ₇ :Mn ²⁺

(BaO.98EuO.02)MgAli ₀ Oi ₇ , BaMgF ₄ :Eu ²⁺ , Y (1.995)Ce (0.005)Si0 ₅ . The dental material according to the invention can contain organic pigments and inorganic pigments as color 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 black (Fe ₃ 0 ₄ ), iron being partially substituted by chromium and copper or nickel and chromium or manganese, zinc iron chromium spinel brown spinel,

((Zn,Fe)(Fe,Cr) ₂ 0 ₄ ) cobalt zinc aluminate blue spinel and/or titanium oxide.

The components in the dental material can be contained in the following proportions by mass, based on the total mass of the dental material according to the invention: the monomer mixture from 1 to 99% by weight, preferably from

20 to 95% by weight; the at least one initiator or initiator system for free radical polymerization from 0 to 5% by weight, preferably from 0.01 to 5% by weight; the fillers from 0 to 95% by weight, preferably from 1 to 95% by weight, more preferably from 5 to 85% by weight, even more preferably from 20 to 80% by weight; the usual dental additives from 0 to 5% by weight, preferably from 0.001 to 5% by weight.

The dental material preferably contains no compound with a bisphenol A-based structural element.

The invention also relates to the dental material according to the invention, preferably according to one of claims 11 to 13, for use in a therapeutic method as a dental composite, filling, underfilling, fastening, stump build-up, root canal filling, crown, bridge -, restoration and/or prosthetic material.

The subject matter of the invention is also a hardened dental material, produced from the polymerizable dental material according to the invention, in particular according to one of claims 11 to 13.

The invention will now be described by way of example with reference to some advantageous embodiments.

examples

In the examples, a mixture containing oligoester dimethacrylate and bis(methacryloyloxymethyl) tricyclo- [5.2.1.0/2.6]decane (TCDDMA) is used. The structural formula of the mixture of OEDMA with n=1-4 and TCDDMA with n=0 used in the examples is shown below.

The mixture used can be produced by esterification reactions, known in the prior art, of tricyclodecanedimethanol with 1,4-cyclohexanedicarboxylic acid and with methacrylic acid.

The mass ratio of the components of the mixture of OEDMA and TCDDMA used was examined by means of GPC measurement. There was a mass fraction TCDDMA: oligoester n =

1: oligoester n=2: oligoester n=3: oligoester n=4 from 31:29:18:16:7. The TCDDMA mass fraction in the OEDMA mixture was thus 31% by weight, based on the total mass of the mixture of OEDMA and TCDDMA.

Furthermore, bis(methacryloyloxymethyl)tricyclo[5.2.1.0/2.6]decane, bis(acryloyloxymethyl)tricyclo[5.2.1.0/2.6]decane (TCDDA), 7,7,9-(or 7, 9,9-)Trimethyl-4,13-dioxo-3,14-dioxa-5,1,2-diazahexadecane-1,16-diol dimethacrylate (UDMA) and 7,7,9-(or 7, 9,9-)Trimethyl-4,13-dioxo-3,14-dioxa-5,1-2-diazahexadecane-1,16-diol diacrylate (UDA), the reaction product of 1 mol isophorone diisocyanate and 2 mol 2 -Hydroxyethyl methacrylate (UDMA-IPDI), triethylene glycol dimethacrylate (TEGDMA), 1,6-hexanediol dimethacrylate (HDDMA) and bisphenol A glycidyl methacrylate (BisGMA) are used.

Production of the resins Monomer mixtures were prepared according to Tables 1 and 2 listed below and an initiator system was added (all data in % by weight, in each case based on the total masses of the polymerizable dental material). In all examples, this consisted of the same amounts of camphorquinone (CQ) and 2-ethylhexyl p-(dimethylamino)benzoate (EHA) used as co-initiator. 2,6-Di-tert-butyl-4-methylphenol (BHT) was used as a stabilizer in the same concentration in all mixtures. The resulting resins were homogenized overnight using a magnetic stirrer.

Table 1: Composition, volumetric shrinkage, flexural strength and Young's modulus of dental material compositions not according to the invention

Examples 1 to 4 show the properties of prior art monomer mixtures as a comparison. comparative example Game 3 corresponds to a polymerizable dental material containing a monomer mixture from EP 2436365 Bl.

Table 2: Composition, volumetric shrinkage and flexural strength and modulus of elasticity of dental material compositions according to the invention

Examples 5 to 9 correspond to dental materials that can be polymerized according to the invention. In example 7 are volumetric shrinkage and flexural strength significantly improved. Examples 5 and 6 show that the volume shrinkage is further reduced and good flexural strengths were also obtained.

Production of dental composites

Dental composites were produced in accordance with Tables 3 and 4 listed below. To produce dental composites, a total of 75 wt. added and homogenized using a Speedmixer (Hauschild). Then it was degassed.

Table 3: Composition, volume shrinkage, flexural strength and modulus of elasticity of the dental composites K1 and K-2 not according to the invention

Table 4: Composition, volume shrinkage, flexural strength and modulus of elasticity of the dental composites K-3 and K-4 according to the invention

Determination of the flexural strength and the modulus of elasticity

Flexural strength and Young's modulus were determined. For this purpose, test specimens were produced in accordance with ISO 4049:2009.

The test specimens were produced by exposure to light using a HiLite®power light polymerisation device (from Heraeus). For this purpose, the dental composites in the test specimen molds (40 mm x 2 mm x 2 mm) were each exposed for 90 s from both sides. The test specimens were stored in distilled water at 37°C for 24 hours. The flexural strength and the modulus of elasticity were determined using a Zwick universal testing machine. The mean value from 6 individual measurements and the standard deviation are given.

volume shrinkage

The volume shrinkage was calculated from the difference in density p of the dental composites before (VA) and 24 hours after (NA) curing. 3 samples were measured for each composite, the mean value was used as the density. To determine the density of the composites after curing, cylindrical test specimens (8 mm in diameter and 2 mm in height) were exposed to light using a HiLite power light polymerisation device (from Hera- eu) produced. The exposure took place for 90 s from both sides of the specimen. These were stored dry at 23°C for 24 hours. A helium gas pycnometer (Accupyc III 1340) was used to measure the density of the cured and uncured composites.

The volume shrinkage VS resulted from the following formula:

VS = 100% ^x (P _NA - P _VA ) / P _NA

Dynamic viscosity (shear rates)

Dynamic viscosity was measured using a Kinexus DSR from Malvern Instruments Ltd. measured. A plate-plate geometry with a diameter of the upper plate of 25 mm and a gap width of 0.1 mm was used. A shear stress range of 1 Pa to 50 Pa was covered during the measurement. The value at 50 Pa shear stress was used for the evaluation. The measurement is carried out at a constant sample temperature of 23 °C, which is monitored and kept constant by the internal temperature control of the device.

GPC measurement

The GPC measurement was carried out on a GPC system (PSS SECcurity GPC System, from PSS Polymer Standards Service GmbH) with a column oven and RI detector. The following column combination was used to separate the components: precolumn VA 50/7.7 Nucleogel GP 5 P, separation columns VA 300/7.7 Nucleogel GPC 104-5 and VA 300/7.7 Nucleogel GPC 500-5 (all from Macherey & Nagel). The columns were thermostated at 20°C. The sample concentration was 1%. 20 mΐ samples were injected and THF ((Merck 109731) was used as the mobile phase. The flow of the mobile phase was 0.5 ml/min. The subject matter of the disclosure also includes the other aspects which, even without a specific mass ratio Y=m(M2)/m(M1) of the basic monomers M2 to M1 of 0.9<Y<20, preferably 0.9<Y< 10, more preferably 0.95<Y<3, have an intrinsic inventive content. The further aspects of the disclosure are set out in the form of clauses (within the meaning of decision J15/81 of the EPO's Legal Board of Appeal) below:

Clause 1. A monomer mixture for preparing a dental material, comprising: a. at least one base monomer Ml of the following formula 1:

PG-S-A-S- [OOC— K— COO— S— A— S ] n— PG (Formula 1), with

PG = a polymerizable group selected from OOC-CH=CH ₂ and -OOC-C(CH ₃ )=CH ₂ ;

S=a spacer group selected from unbranched and branched alkylene having Cl-ClO carbon atoms, which may additionally contain oxygen or -OOC- in the carbon chain, preferably methylene, or S is absent;

A = an aliphatic polycyclic group, preferably an aliphatic tricyclic hydrocarbon group, in which one or more hydrogen atoms can be independently replaced by Cl-C4-alkyl radicals, Cl-C4-alkoxy radicals, fluorine atoms, chlorine atoms or trifluoromethyl groups, more preferably tricyclodecanylene , more preferably tricyclo[5.2.1.0/2,6]decanylene; K = an aliphatic, acyclic or cyclic, saturated or unsaturated moiety having C1-ClO hydrocarbyl atoms, preferably having C3-C1O hydrocarbyl atoms, more preferably a saturated cycloaliphatic moiety, even more preferably 1,4-cyclohexanylene; n = 1-9, preferably 1-5, more preferably 1-4; b. at least one base monomer M2 of the following formula 2:

PG' -S' -A' -S' -PG' (Formula 2), with

PG' = a polymerizable group selected from OOC-CH=CH ₂ and -OOC-C(CH ₃ )=CH ₂ ;

S'=a spacer group selected from unbranched and branched alkylene having Cl-ClO carbon atoms, which may additionally contain oxygen or -OOC- in the carbon chain, preferably methylene, or S' is absent;

A' = an aliphatic polycyclic group, an aliphatic tricyclic hydrocarbon group in which one or more hydrogen atoms can each independently be replaced by C1-C4 alkyl, C1-C4 alkoxy, fluorine, chlorine or trifluoromethyl, more preferably tricyclodecanylene, even more preferably tricyclo[5.2.1.0/2.6]decanylene.

Clause 2. Monomer mixture according to Clause 1, characterized in that in the monomer mixture there are several basic monomers M1, preferably at least two basic monomers M2, more preferably more than two base monomers M1, more preferably more than three base monomers M1, more preferably more than four base monomers M1 are present.

Clause 3. Monomer mixture according to Clause 1 or 2, characterized in that the base monomer M2 is selected from bis(methacryloyloxymethyl)tricyclo[5.2.1.0/2,6]decane,

Bis(acryloyloxymethyl)tricyclo[5.2.1.0/2.6]decane and mixtures thereof, preferably the base monomer M2 is bis(methacryloyloxymethyl)tricyclo[5.2.1.0/2.6]decane.

Clause 4. Monomer mixture according to one of Clauses 1 to 3, characterized in that the monomer mixture comprises a base monomer M3, which differs from the base monomers M1 of formula 1 and M2 of formula 2.

Clause 5. Monomer mixture according to Clause 4, characterized in that the base monomer M3 is selected from urethane-based monomers, preferably selected from difunctional urethane (meth)acrylates, polyfunctional urethane (meth)acrylates and mixtures thereof, more preferably urethanedi (Meth)acrylates, more preferably urethane di (meth)acrylates selected from linear or branched alkylene-functionalized urethane di(meth)acrylates and urethane (meth)acrylate-functionalized polyethers.

Clause 6. Monomer mixture according to Clause 4 or 5, characterized in that the base monomer M3 is selected from

7.7.9-Trimethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane

1,16-diyl-bis(2-methyl acrylate), 7,9,9-trimethyl-4,13-dioxo-

3,14-dioxa-5,12-diazahexadecane-1,16-diylbis(2-methyl acrylate),

7.7.9-Trimethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane

1,16-diol diacrylate, 7,9,9-trimethyl-4,13-dioxo-3,14-dioxa-5,1,2-diaza-hexadecane-1,1,6-diol diacrylate and mixtures thereof. Clause 7. Monomer mixture according to one of clauses 1 to 6, characterized in that the base monomers can be present in the following proportions by mass, based on the total mass of the monomer mixture:

Base monomer M1 from 2 to 52.5% by weight, preferably from 5 to 52.5% by weight, more preferably from 12.5 to 52.5% by weight

Base monomer M2 from 23 to 96% by weight, preferably from

47.5 to 95.5% by weight, more preferably from 47.5 to

87.5% by weight;

Base monomer M3 from 0 to 50% by weight, preferably from 0.1 to 30% by weight, more preferably from 1 to 15% by weight.

Clause 8. Monomer mixture according to one of clauses 1 to 7, characterized in that the monomer mixture contains the base monomers M1 and M2 in a mass fraction of 25% by weight or more, more preferably 50% by weight or more, even more preferably 70% % by weight or more, more preferably 85% by weight or more, even more preferably 100% by weight, based on the total weights of the monomer mixture.

Clause 9. Monomer mixture according to one of Clauses 1 to 8, characterized in that the monomer mixture contains the base monomers M1, M2 and optionally M3 in a mass fraction of 95 to 100% by weight, preferably 99 to 100% by weight preferably 100% by weight, based on the total mass of the monomer mixture, comprises or consists of these.

Clause 10. Monomer mixture according to one of clauses 1 to 9, characterized in that the monomer mixture contains no monomer which has a bisphenol A structure, preferably no 2,2-bis[4-(2-hydroxy-3-(meth)acryloxypropoxy)phenyl]propane (BisGMA) and no ethoxylated bisphenol A di(meth)acrylate (BisEMA) is contained.

Clause 11. Monomer mixture according to one of Clauses 1 to 10, characterized in that no monomer selected from low molecular weight and low viscosity mono- and di(meth)acrylates, preferably no monomer with a viscosity at a temperature of 23°C lower, is present in the monomer mixture than 0.05 Pa s and/or with a partial water solubility.

Clause 12. The monomer mixture according to any one of clauses 1 to 11, characterized in that the monomer mixture is free from hexanediol diacrylate (HDDA), hexanediol dimethacrylate (HDDMA), triethylene glycol diacrylate (TEGDA) and/or triethylene glycol dimethacrylate (TEGDMA).

Clause 13. Monomer mixture according to one of Clauses 1 to 12, characterized in that the monomer mixture has a viscosity of 0.2 to 10, preferably 1 to 6 Pa s at a temperature of 23°C.

Clause 14. Use of the monomer mixture according to one of clauses 1 to 13 for the production of a radically polymerizable dental material, preferably a dental composite, core build-up, root canal filling, filling, base filling, attachment, crown, bridge, restoration and/or prosthetic material.

Clause 15. A polymerizable dental material comprising: a) the monomer mixture of any one of clauses 1 to 13; b) optionally at least one initiator or an initiator system for the free-radical polymerization; c) optional fillers; d) optional customary dental additives.

Clause 16. Dental material according to Clause 15, characterized in that the components in the dental material can be contained in the following proportions by mass, based on the total mass of the dental material: a) the monomer mixture from 1 to 99% by weight, preferably from 20 to 95% by weight; b) the at least one initiator or initiator system for free-radical polymerization from 0 to 5% by weight, preferably from 0.01 to 5% by weight; c) the fillers from 0 to 95% by weight, preferably from 1 to 95% by weight, more preferably from 1 to 85% by weight, even more preferably from 20 to 80% by weight; d) the usual dental additives from 0 to 5% by weight, preferably from 0.001 to 5% by weight.

Clause 17. Dental material according to any one of clauses 15 to 16 for use in a therapeutic method as a dental composite, filling, base filling, fixing, core build-up, root canal filling, crown, bridge, restorative and/or prosthetic material.

Clause 18. Dental material according to one of clauses 15 to 17, characterized in that the dental material is thermally, chemically and/or photochemically, preferably cured by UV and/or visible light.

Clause 19. Dental material according to any one of clauses 15 to 18, characterized in that the dental material is light-curable.

Clause 20. Dental material according to one of Clauses 15 to 19, characterized in that the dental material contains camphorquinone (CQ) as an initiator and 2-ethylhexyl p-(dimethylamino)benzoate (EHA) as a co-initiator.

Clause 21. Dental material according to one of Clauses 15 to 20, characterized in that the dental material contains no bisphenol-containing compound, preferably no compound with a bisphenol A-based structural element.

Clause 22. A cured dental material made from a polymerisable dental material according to any one of Clauses 15 to 21.

Claims

patent claims

Claims 1. A monomer mixture for preparing a dental material, comprising: a. at least one base monomer Ml of the following formula 1:

PG-SAS-[OOC-K-COO-SAS ] _n -PG (Formula 1) with

PG = a polymerizable group selected from OOC-CH=CH ₂ and -OOC-C(CH ₃ )=CH ₂ ; S = a spacer group selected from unbranched and branched alkylene with Cl-ClO carbon atoms, which can additionally contain oxygen or -OOC- in the carbon chain, preferably methylene, or S is absent; A = an aliphatic polycyclic group, preferably an aliphatic tricyclic hydrocarbon group, in which one or more hydrogen atoms can each independently be replaced by Cl-C4-alkyl radicals, Cl-C4-alkoxy radicals, fluorine atoms, chlorine atoms or trifluoromethyl groups, more preferably tricyclodecanylene, even further preferably tricyclo[5.2.1.0/2.6]decanylene;

K = an aliphatic acyclic or cyclic, saturated or unsaturated unit with Cl-ClO-carbon atoms, preferably with C3-C1O-carbon atoms, more preferably a saturated cycloaliphatic unit, even more preferably 1,4-cyclohexanylene; n = 1-9, preferably 1-5, more preferably 1-4; b. at least one base monomer M2 of the following formula

2:

PG' -S' -A' -S' -PG' (Formula 2) with

PG' = a polymerizable group selected from OOC-CH=CH ₂ and -OOC-C(CH ₃ )=CH ₂ ; S'=a spacer group selected from unbranched and branched alkylene having Cl-ClO carbon atoms, which may additionally contain oxygen or -OOC- in the carbon chain, preferably methylene, or S' is absent; A' is an aliphatic polycyclic group, an aliphatic tricyclic hydrocarbon group in which one or more hydrogen atoms can be replaced independently of one another by Cl-C4-alkyl radicals, Cl-C4-alkoxy radicals, fluorine atoms, chlorine atoms or trifluoromethyl groups, more preferably tricyclodecanylene more preferably tricyclo[5.2.1.0/2,6]decanylene; where a mass ratio Y=m(M2)/m(M1) of the basic monomers M2 to M1 is 0.9<Y<20, preferably 0.9<Y<10, preferably 0.95<Y<3.

2. The monomer mixture as claimed in claim 1, characterized in that the monomer mixture contains a plurality of basic monomers M1, preferably at least two basic monomers M2, more preferably more than two basic monomers M1, even more preferably more than three basic monomers M1, even more preferably more than four basic monomers M1 .

3. The monomer mixture as claimed in claim 1 or 2, characterized in that the base monomer M2 is selected from bis(methacryloyloxymethyl)tricyclo[5.2.1.0/2.6]decane,

Bis(acryloyloxymethyl)tricyclo[5.2.1.0/2.6]decane and mixtures thereof, preferably the base monomer M2 is bis(methacryloyloxymethyl)tricyclo[5.2.1.0/2.6]decane.

4. The monomer mixture as claimed in any of claims 1 to 3, characterized in that the monomer mixture comprises a base monomer M3 which differs from the base monomers M1 of formula 1 and M2 of formula 2.

5. Monomer mixture according to claim 4, characterized in that the base monomer M3 is selected from urethane-based monomers, preferably the base monomer M3 is selected from 7,7,9-trimethyl-4,13-dioxo-3,14-dioxa -5,12-diazahexadecane-1,16-diylbis(2-methyl acrylate), 7,9,9-trimethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1, 16-diyl-bis(2-methyl acrylate), 7,7,9-trimethyl-4,13-dioxo-

3,14-dioxa-5,1-2-diazahexadecane-1,16-diol diacrylate,

7,9,9-trimethyl-4,13-dioxo-3,14-dioxa-5,1,2-diaza-hexadecane-1,16-diol diacrylate and mixtures thereof.

6. The monomer mixture as claimed in any of claims 1 to 5, characterized in that the basic monomers can each be present in the following proportions by mass, based on the total mass of the monomer mixture: - Base monomer Ml from 2 to 52.5% by weight, preferably from 5 to 52.5% by weight, more preferably from 12.5 to 52.5% by weight.

- base monomer M2 from 23 to 96% by weight, preferably from

47.5 to 95.5% by weight, more preferably from 47.5 to

87.5% by weight;

- Base monomer M3 from 0 to 50% by weight, preferably from 0.1 to 30% by weight, more preferably from 1 to 15% by weight.

7. The monomer mixture as claimed in any of claims 1 to 6, characterized in that the monomer mixture contains the basic monomers M1, M2 and optionally M3 in a mass fraction of from 95 to 100% by weight, preferably from 99 to 100% by weight, further preferably 100% by weight, based on the total mass of the monomer mixture, comprises or consists of these.

8. The monomer mixture as claimed in any of claims 1 to 7, characterized in that the monomer mixture contains no monomer which has a bisphenol A structure, preferably no 2,2-bis[4-(2-hydroxy-3-(meth )acryloxypropoxy)phenyl]propane (BisGMA) and no ethoxylated bisphenol A di(meth)acrylate (BisEMA).

9. The monomer mixture as claimed in any of claims 1 to 8, characterized in that no monomer selected from low-molecular and low-viscosity mono- and di(meth)acrylates, no monomer with a viscosity at a temperature of 23°C of less than 0, 05 Pas and/or with a partial water solubility and/or no monomer selected from hexanediol diacrylate (HDDA), hexanediol dimethacrylate (HDDMA), triethylene glycol diacrylate (TEGDA) and triethylene glycol dimethacrylate (TEGDMA).

10. The monomer mixture as claimed in any of claims 1 to 9, characterized in that the monomer mixture has a viscosity of 0.2 to 10, preferably 1 to 6 Pa s at a temperature of 23°C.

11. Use of the monomer mixture according to any one of claims 1 to 10 for the production of a radically polymerizable dental material, preferably a dental composite,

Stump build-up, root canal filling, filling, lining, fixing, crown, bridge, restoration and/or prosthesis material.

12. A polymerizable dental material comprising: a) the monomer mixture according to any one of claims 1 to 10; b) optionally at least one initiator or initiator system for free-radical polymerization; c) optional fillers; d) optional customary dental additives.

13. Dental material according to claim 12, characterized in that the components in the dental material can be contained in the following proportions by mass, based on the total mass of the dental material: a) the monomer mixture from 1 to 99% by weight, preferably from 20 to 95% by weight; b) the at least one initiator or initiator system for the free-radical polymerization from 0 to 5% by weight, preferably from 0.01 to 5% by weight; c) the fillers from 0 to 95% by weight, preferably from 1 to 95% by weight, more preferably from 1 to 85% by weight, even more preferably from 20 to 80% by weight d) the usual dental additives from 0 to 5% by weight, preferably from 0.001 to 5% by weight. 14. Dental material according to one of claims 12 to 13 for use in a therapeutic method as a dental composite, filling, underfilling, fastening,

Core build-up, root canal filling, crown, bridge, restoration and/or prosthesis material. 15. Hardened dental material produced from a polymerizable dental material according to any one of claims 12 to 13.