Dental materials for producing temporary crowns and bridges

Abstract

To provide dental materials for production of temporary crowns and bridges.SOLUTION: A radically polymerizable dental material contains, as initiator system for the radical polymerization, a combination of at least three thiourea derivatives, a hydroperoxide and preferably a transition metal compound. The object of the invention is to provide dental materials which have a processing time suitable for dental purposes and high storage stability, pass through a long elastic phase during hardening, and have good mechanical properties after complete hardening. The materials are to be suitable in particular for production of temporary dental restorations such as crowns and bridges.SELECTED DRAWING: None

Description

[Technical Field]

[0001] [Field] The present invention relates to a radically polymerizable composition with improved curing behavior that is particularly suitable as a dental material, in particular as a prosthetic material, for producing temporary crowns and bridges. The composition contains a redox system as an initiator for radical polymerization, the composition containing a hydroperoxide and at least two different thiourea derivatives. [Background technology]

[0002] [Background information] Polymerizable compositions based on radically polymerizable monomers are commonly used to produce dental restorations, and especially temporary restorations such as temporary crowns and bridges. Mixtures of monofunctional and polyfunctional (meth)acrylates are commonly used as monomers. The dimethacrylates most often used are 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropyl)phenyl]propane (bis-GMA) and 1,6-bis-[2-methacryloyloxyethoxycarbonylamino]-2,2,4-trimethylhexane (UDMA), which have high viscosities and produce polymers with excellent mechanical properties. These are diluted with low-viscosity monomers such as triethylene glycol dimethacrylate (TEGDMA), 1,10-decanediol dimethacrylate (D3MA), and bis(3-methacryloyloxymethyl)tricyclo[5.2.1.02.6]decane (DCP). For curing, a suitable initiator is added, in which case a photoinitiator, a thermal initiator, a redox initiator system or a combination thereof is used depending on the field of use. Materials for producing temporary crowns and bridges usually contain a redox system.

[0003] To ensure sufficient storage stability of the material, materials based on redox initiators are usually used as so-called two-component systems (2C systems), in which the oxidizing agent (peroxide or hydroperoxide) and the reducing agent (amine, sulfinic acid, barbiturate, thiourea, etc.) are each formulated into individual components. These components are mixed together immediately before use. These components must be compatible so that they can be easily mixed homogeneously with each other and be easy to handle. Furthermore, there must be a processing time sufficient for dental purposes. Processing time refers to the time between blending the components and the onset of hardening of the mixed material.

[0004] For the production of a temporary crown or bridge, an impression is made of the tooth(s) to be treated. The tooth(s) are then ground, and the impression is then filled with a self-hardening restorative material and pressed onto the prepared tooth surface. After hardening, the material is removed from the impression and reworked by trimming with a scalpel or scissors, or by milling. This is best achieved if the material is still elastic. If hardening proceeds too slowly, the material will be hard and brittle, making post-processing difficult and risking cracking and sharp edges in the temporary prosthesis. Therefore, materials for producing temporary restorations must have as long an elastic phase as possible during hardening.

[0005] Self-curing repair materials often contain redox initiator systems based on mixtures of dibenzoyl peroxide (DBPO) with tertiary aromatic amines, such as N,N-diethanol-p-toluidine (DEPT), N,N-dimethyl-sym.-xylidine (DMSX), or N,N-diethyl-3,5-di-tert.-butylaniline (DABA). When using such redox initiator systems, processing and curing times can be relatively well-defined in combination with phenolic inhibitors. A drawback of DBPO / amine systems is discoloration caused by the slow oxidation of the amine.

[0006] Hydroperoxide redox initiator systems do not have this drawback because an amine is not required as a reducing agent. Furthermore, hydroperoxides are more thermally stable than peroxides. DE 2635595C2 discloses a polymerizable dental filling compound containing a substituted thiourea reducing agent in combination with a hydroperoxide as an oxidizing agent in the initiator system. This material is said to have improved color stability, excellent curing speed, and improved storage stability.

[0007] EP1693046B1 discloses dental cements and core building materials comprising (2-pyridyl)-2-thiourea derivatives in combination with hydroperoxides in which the hydroperoxide group is attached to a tertiary carbon atom.

[0008] WO 2007 / 016508 A1 discloses a polymerizable dental composition containing a hydroperoxide in combination with a thiourea derivative and 2-mercapto-1-methylimidazole as an initiator system. The material is characterized by the absence of acid group-containing components.

[0009] According to EP 1 754 465 B1, the cumene hydroperoxide / acetylthiourea system is stated to have a curing speed that is unsuitable for use. To overcome this problem, the addition of a soluble copper compound is proposed.

[0010] US 7,275,932 B2 proposes the use of hydroperoxides and thiourea derivatives in combination with acid compounds as accelerators. Preferred acid compounds are acrylates and methacrylates having an acid group, such as methacrylic acid.

[0011] EP 2233544 A1 and EP 2258336 A1 disclose dental materials containing hydroperoxides and thiourea derivatives in combination with vanadium compounds as accelerators.

[0012] To avoid the drawbacks associated with organic peroxides and tertiary amines, US Pat. No. 6,815,470 B2 proposes using arylborate in combination with an acid compound and peroxide as an initiator system. It is stated that the reaction with the acid compound causes the arylborate to form an arylborane, which, upon reaction with oxygen, releases a polymerizable radical. Polymerizable monomers having an acid group can be used as the acid compound.

[0013] EP 3692975 A1 discloses a radically polymerizable dental material containing a combination of a thiourea derivative, a hydroperoxide, and a peroxide as an initiator system for radical polymerization. The reactivity of an initiator system based on a hydroperoxide and a thiourea derivative can be significantly accelerated by adding a small amount of peroxide.

[0014] EP3692974A1 discloses a radically polymerizable dental material containing an initiator system for radical polymerization, which further contains at least one transition metal compound in addition to a thiourea derivative, a hydroperoxide, and a peroxide. The mechanical properties of the cured material can be substantially improved by adding the transition metal compound.

[0015] Low-odor hydroperoxides suitable in combination with thiourea derivatives as initiators for radically polymerizable dental materials are known from EP 3 692 976 A1. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] European Patent Application Publication No. 1693046 [Patent Document 2] International Publication No. 2007 / 016508 [Patent Document 3] European Patent No. 1754465 [Patent Document 4] U.S. Patent No. 7,275,932 [Patent Document 5] European Patent Application Publication No. 2233544 [Patent Document 6] European Patent Application Publication No. 2258336 [Patent Document 7] U.S. Patent No. 6,815,470 [Patent Document 8] European Patent Application Publication No. 3692975 [Patent Document 9] European Patent Application Publication No. 3692974 [Patent Document 10] European Patent Application Publication No. 3692976 Summary of the Invention [Means for solving the problem]

[0017] The object of the present invention is to provide a dental material with a suitable processing time and high storage stability for dental purposes, which undergoes a long elastic phase during hardening and has good mechanical properties after complete hardening. This material will be particularly suitable for producing temporary dental restorations such as crowns and bridges.

[0018] According to the invention, this object is achieved by a radically polymerizable dental material which comprises a hydroperoxide in combination with at least three different thiourea derivatives as initiator system.

[0019] The dental material according to the present invention preferably contains at least one cyclic thiourea derivative and at least one acyclic thiourea derivative.It has been found that the cyclic thiourea derivative used according to the present invention has a relatively high reactivity, which leads to the rapid initiation of polymerization.However, this polymerization is rapidly terminated.In contrast, it has been found that the acyclic thiourea derivative reacts more slowly but remains reactive for a longer period of time.By combining a fast-reacting thiourea derivative with a slow-reacting thiourea derivative, on the one hand, the rapid initiation of this reaction can be caused, and on the other hand, the material can be completely cured as a whole and have good mechanical properties after curing.

[0020] This rapid onset of reaction allows for rapid removal of the material from the patient's mouth, thus keeping stress on the patient low. Because the impression tray must be held by hand during curing, this also significantly reduces the hassle for the treating staff. Once the polymerization initiated by the cyclic thiourea derivatives subsides, the material is not fully cured throughout and remains in an elastic state, which allows for easy post-processing, for example, by trimming or polishing. Because the final cure initiated by the acyclic thiourea derivatives proceeds much more slowly, the elastic phase is significantly longer than with conventional materials, making post-processing of the restoration much easier.

[0021] It has been found that a long elastic phase can be obtained by combining thiourea derivatives of different reactivity. It is particularly surprising that storage stability can be substantially improved by adding a third thiourea derivative. Intended uses provide, for example: (Reclaim) [Item 1] A radically polymerizable dental material containing a combination of a thiourea derivative and a hydroperoxide as an initiator system for radical polymerization, characterized in that it contains at least three different thiourea derivatives. [Item 2] Item 10. A dental material according to any one of the preceding items, comprising at least one cyclic thiourea derivative and at least one acyclic thiourea derivative. [Item 3] At least one cyclic thiourea derivative of formula (I): [ka] (In the formula, R 1 , R 2 is, in each occurrence, H or a C1-C4 alkyl radical, at least one of which is H; R 3 , R 4 are, independently of one another, in each case H, a C1-C4 alkyl radical or a C1-C4 alkoxy radical or, together with the carbon atoms to which they are attached and the intervening carbon atoms, form a 6-membered carbocyclic, aliphatic or aromatic ring which can be substituted by one or more, preferably one or two, C1-C4 alkyl radicals and / or C1-C4 alkoxy radicals, n is 0, 1, 2 or 3, preferably 0 or 1. 2. A dental material according to any one of the preceding items, comprising: [Item 4] At least one acyclic thiourea derivative of formula (II): [ka] (In the formula, X is H or Y; Y is an alkyl radical having 1 to 8 carbon atoms, a cycloalkyl radical having 5 or 6 carbon atoms, a chlorine-, hydroxy-, or mercapto-substituted alkyl radical having 1 to 8 carbon atoms, an alkenyl radical having 3 to 4 carbon atoms, an aryl radical having 6 to 8 carbon atoms, a chlorine-, hydroxy-, methoxy-, or sulfonyl-substituted phenyl radical, an acyl radical having 2 to 8 carbon atoms, a chlorine- or methoxy-substituted acyl radical, an aralkyl radical having 7 or 8 carbon atoms, or a chlorine- or methoxy-substituted aralkyl radical; Z is NH2, NHX or NX2), and / or At least one acyclic thiourea derivative of formula (III): [ka] (In the formula, R 5 is C1~C 12 Alkyl radical, preferably C2-C 10 alkyl radicals, particularly preferably C3-C8 alkyl radicals, very particularly preferably C4-C6 alkyl radicals, C1~C 12 Alkene radicals, preferably C2-C 10 alkene radicals, particularly preferably C3-C8 alkene radicals, very particularly preferably C4-C6 alkene radicals, C1~C 12 Acyl radicals, preferably C2-C 10 acyl radicals, particularly preferably C3-C8 acyl radicals, very particularly preferably C4-C6 acyl radicals; pyridyl or phenyl radical) 2. A dental material according to any one of the preceding items, comprising: [Item 5] A dental material according to one of the preceding items, containing 3,4,5,6-tetrahydro-2-pyrimidinethiol, 2-imidazolidinethione, 2-mercaptobenzimidazole, 1-methyl-1H-benzimidazole-2-thiol and / or 2-mercapto-5-methoxybenzimidazole as cyclic thiourea derivatives, and hexanoylthiourea as acyclic thiourea derivatives. [Item 6] Item 10. A dental material according to any one of the preceding items, comprising several cyclic thiourea derivatives and one or more acyclic thiourea derivatives. [Item 7] As hydroperoxides, compounds of formula R 6 -(OOH) m (In the formula, R 6 is an aliphatic or aromatic hydrocarbon radical and m is 1 or 2, and / or A compound of formula (IV), [ka] wherein the variables have the following meanings: Q 1 is p-valent, aromatic, aliphatic, linear or branched C1-C 14 Hydrocarbon radicals, which may be interrupted by one or more S and / or O atoms and may be unsubstituted or may be -OH, -OR 7 , -Cl and -Br, R 7 is aliphatic, linear or branched C1-C 10 is a hydrocarbon radical, X and Y, independently of one another, in each occurrence, are absent, -O-, -COO-; -CONR 8 -or -O-CO-NR 9 - and R 8 and R 9are, independently of one another, H or a C1-C5 alkyl radical, preferably H, methyl and / or ethyl, particularly preferably H, and X and Y are preferably not simultaneously absent, Q 2 is absent, aliphatic, linear or branched C1-C 14 Alkylene radicals, which may be interrupted by S and / or O atoms and may further be unsubstituted or may be substituted with -OH, -OR 10 , -Cl and / or -Br, R 10 is aliphatic, linear or branched C1-C 10 is a hydrocarbon radical, Q 3 is a C1-C3 alkylene group or is absent, preferably -CH2- or is absent, and Q 2 is not present, then X and / or Y are not present, p is 1, 2, 3 or 4; The substitution on the aromatic compound occurs at the 2, 3, or 4 position relative to the cumene hydroperoxide group. 2. A dental material according to any one of the preceding items, comprising: [Item 8] Item 10. The dental material according to any one of the preceding items, containing as hydroperoxide t-amyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, t-butyl hydroperoxide, t-hexyl peroxide, 2,5-dimethyl-2,5-di(hydroperoxy)hexane, diisopropylbenzene monohydroperoxide, paramenthane hydroperoxide, p-isopropylcumene hydroperoxide, 4-(2-hydroperoxypropan-2-yl)phenylpropionate or a mixture thereof, preferably cumene hydroperoxide (CHP) and / or 4-(2-hydroperoxypropan-2-yl)phenylpropionate. [Item 9] 10. The dental material according to claim 1, further comprising a transition metal compound, preferably a compound of iron, cobalt, nickel, manganese or a mixture thereof, particularly preferably a compound of copper, very particularly preferably Cu(I). [Item 10] A dental material according to any one of the preceding items, comprising two components, wherein the first component contains 0.01 to 5 wt %, preferably 0.05 to 4.0 wt %, and particularly preferably 0.1 to 3.75 wt %, of a hydroperoxide relative to the mass of the first component, and the second component contains 50 to 400 mol %, preferably 75 to 300 mol %, and particularly preferably 100 to 200 mol %, of a thiourea derivative relative to the molar mass of the hydroperoxide in the first component. [Item 11] The dental material according to any one of the preceding items further contains at least one radically polymerizable monomer, preferably at least one monofunctional or polyfunctional (meth)acrylate, particularly preferably at least one dimethacrylate, or a mixture of monomethacrylate and dimethacrylate. [Item 12] The radically polymerizable monomers include methyl (meth)acrylate, ethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, butyl (meth)acrylate, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate or isobornyl (meth)acrylate, p-cumylphenoxyethylene glycol methacrylate (CMP-1E), 2-(2-biphenyloxy)ethyl methacrylate, bisphenol A dimethacrylate, bis-GMA (methacrylic acid and bisphenol A diglycidyl ether). ter), ethoxylated or propoxylated bisphenol A dimethacrylate, 2-[4-(2-methacryloyloxyethoxyethoxy)phenyl]-2-[4-(2-methacryloyloxyethoxy)phenyl]propane (SR-348c), 2,2-bis[4-(2-methacryloxypropoxy)phenyl]propane, UDMA (addition product of 2-hydroxyethyl methacrylate and 2,2,4-trimethylhexamethylene-1,6-diisocyanate), V-380 (addition product of 0.7 mol of methacrylic acid 2- hydroxyethyl and a mixture of 0.3 mol of 2-hydroxypropyl methacrylate with 1 mol of α,α,α',α'-tetramethyl-m-xylylene diisocyanate), diethylene glycol dimethacrylate, triethylene glycol dimethacrylate or tetraethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, glycerol dimethacrylate and glycerol trimethacrylate, 1,4-butanediol dimethacrylate, di Item 1. The dental material of any one of the preceding items, containing 1,10-decanediol methacrylate (D3MA), bis(methacryloyloxymethyl)tricyclo-[5.2.1.02,6]decane (DCP), polyethylene glycol dimethacrylate or polypropylene glycol dimethacrylate, polyethylene glycol 200 dimethacrylate, polyethylene glycol 400 dimethacrylate (PEG200DMA or PEG400DMA), 1,12-dodecanediol dimethacrylate, or a mixture thereof. [Item 13] 10. The dental material according to any one of the preceding items, further comprising at least one organic or inorganic filler, preferably an oxide such as SiO2, ZrO2 and TiO2 or a mixture of oxides of SiO2, ZrO2, ZnO and / or TiO2, a nanoparticle or ultrafine filler such as pyrogenic silica or precipitated silica, a radiopaque filler such as quartz, glass ceramic or a radiopaque glass powder, preferably a glass powder such as barium or strontium aluminum silicate glass powder, a radiopaque filler such as ytterbium trifluoride, tantalum(V) oxide, barium sulfate, a mixture of oxides of SiO2 and ytterbium(III) oxide or tantalum(V) oxide, a finely divided prepolymer or a pearl polymer. [Item 14] in each case relative to the total weight of the composition (a) 0.005 to 3% by weight, preferably 0.025 to 2.5% by weight, particularly preferably 0.05 to 2.0% by weight of at least one hydroperoxide, preferably cumene hydroperoxide and / or 4-(2-hydroperoxypropan-2-yl)phenylpropionate, (b) 0.005 to 3.0% by weight, preferably 0.015 to 2.125% by weight, particularly preferably 0.025 to 1.5% by weight of a thiourea derivative; (c) 0.00005 to 0.5% by weight, preferably 0.00025 to 0.25% by weight, particularly preferably 0.00035 to 0.01% by weight of at least one transition metal compound; (d) 5 to 95% by weight, preferably 10 to 95% by weight, particularly preferably 10 to 90% by weight, of at least one radically polymerizable monomer; (e) 0 to 85 wt. % of at least one filler, and (f) optionally 0.01 to 5% by weight, preferably 0.1 to 3% by weight, particularly preferably 0.1 to 2% by weight, of one or more additives; 2. A dental material according to any one of the preceding items, comprising: [Item 15] Preferably, a dental material according to any one of the preceding items for therapeutic use as a dental cement, a filling composite, a coating material, or as a material for producing a temporary crown or bridge. [Item 16] Use of the dental material according to any one of the preceding items for the production or correction of dental restorations, such as prostheses, dentures, inlays, onlays, crowns, bridges and full dentures. [Brief explanation of the drawings]

[0022] [Figure 1] Figure 1 shows the storage stability of pastes with two different thiourea derivatives. The working time of the paste increases with storage time, which is an indicator of instability. The paste is stable for approximately 3 months at 37°C. [Figure 2] Figure 2 shows the storage stability of a paste with three different thiourea derivatives. The paste is stable for 5 months, even at 50°C. Only after that can a decrease in processing time be observed. DETAILED DESCRIPTION OF THE INVENTION

[0023] [Description of the embodiment] A radically polymerizable dental material comprising, as an initiator system for radical polymerization, a combination of at least three thiourea derivatives, a hydroperoxide and preferably a transition metal compound.

[0024] By cyclic thiourea derivatives is meant herein compounds in which the nitrogen atom of the thiourea group, together with the intervening carbon atoms and further carbon atoms, forms a heterocyclic ring system. Cyclic thiourea derivatives of formula (I): [ka] (In the formula, R 1 , R 2 is, in each occurrence, H or a C1-C4 alkyl radical, at least one of which is H; R 3 , R 4 are, independently of one another, in each case H, a C1-C4 alkyl radical or a C1-C4 alkoxy radical or, together with the carbon atoms to which they are attached and the intervening carbon atoms, form a 6-membered carbocyclic, aliphatic or aromatic ring which can be substituted by one or more, preferably one or two, C1-C4 alkyl radicals and / or C1-C4 alkoxy radicals, n is 0, 1, 2 or 3, preferably 0 or 1. But it is preferable.

[0025] The variables of formula I preferably have the following meanings: R 1 , R 2 is in each case H or a C1-C2 alkyl radical, preferably H or methyl, at least one of these radicals being H, R 3 , R 4 are in each case H, a C1-C2 alkyl radical, preferably methyl, a C1-C2 alkoxy radical, preferably methoxy, or together with the carbon atoms to which they are attached and the intervening carbon atoms form a benzene ring which can be substituted by a C1-C2 alkyl radical, preferably methyl, or a C1-C2 alkoxy radical, preferably methoxy, n is 0 or 1.

[0026] The variables of formula I particularly preferably have the following meanings: R 1 , R 2 is in each case H or methyl, and at least one of these radicals is H, R 3 , R 4 is in each case H, a C1-C2 alkyl radical, preferably methyl, or a C1-C2 alkoxy radical, preferably methoxy, n is 1, or R1 , R 2 is in each case H or methyl, and at least one of these radicals is H, R 3 , R 4 together with the carbon atoms to which they are attached and the intervening carbon atoms form a benzene ring which may be substituted by a C1-C2 alkyl radical, preferably methyl, or a C1-C2 alkoxy radical, preferably methoxy, n is 0.

[0027] In all cases, formula I also includes the corresponding isothiourea derivatives. 3,4,5,6-tetrahydro-2-pyrimidinethiol (1), 2-imidazolidinethione (2), 2-mercaptobenzimidazole (4), 1-methyl-1H-benzimidazole-2-thiol, and 2-mercapto-5-methoxybenzimidazole are particularly preferred. [ka]

[0028] By acyclic thiourea derivatives is meant herein compounds in which the nitrogen atom of the thiourea group is not incorporated into a ring system, however, acyclic thiourea derivatives can still contain cyclic groups.

[0029] Acyclic thiourea derivatives of formula (II) [ka] (In the formula, X is H or Y; Y is an alkyl radical having 1 to 8 carbon atoms, a cycloalkyl radical having 5 or 6 carbon atoms, a chlorine-, hydroxy-, or mercapto-substituted alkyl radical having 1 to 8 carbon atoms, an alkenyl radical having 3 to 4 carbon atoms, an aryl radical having 6 to 8 carbon atoms, a chlorine-, hydroxy-, methoxy-, or sulfonyl-substituted phenyl radical, an acyl radical having 2 to 8 carbon atoms, a chlorine- or methoxy-substituted acyl radical, an aralkyl radical having 7 or 8 carbon atoms, or a chlorine- or methoxy-substituted aralkyl radical; Z is NH2, NHX or NX2 But it is preferable.

[0030] Further preferred thiourea derivatives are the compounds listed in paragraph

[0009] of EP1754465A1.

[0031] Acyclic thiourea derivatives of formula (III): [ka] (In the formula, R 5 is C1~C 12 Alkyl radical, preferably C2-C 10 alkyl radicals, particularly preferably C3-C8 alkyl radicals, very particularly preferably C4-C6 alkyl radicals, C1~C 12 Alkene radicals, preferably C2-C 10 alkene radicals, particularly preferably C3-C8 alkene radicals, very particularly preferably C4-C6 alkene radicals, C1~C 12 Acyl radicals, preferably C2-C 10 acyl radicals, particularly preferably C3-C8 acyl radicals, very particularly preferably C4-C6 acyl radicals; pyridyl or phenyl radical) is particularly preferred.

[0032] Very particularly preferred acyclic thiourea derivatives are acetyl, allyl, pyridyl and phenylthiourea, hexanoylthiourea (3) and mixtures thereof. Hexanoylthiourea (3) is most preferred. [ka]

[0033] The composition according to the invention contains at least three, preferably three to six, particularly preferably three or four, and very particularly preferably three different thiourea derivatives. The composition may contain several acyclic and one or more cyclic thiourea derivatives, or preferably several cyclic and one or more acyclic thiourea derivatives. Compositions containing two to four, preferably two cyclic thiourea derivatives and one acyclic thiourea derivative are preferred.

[0034] Preferred is a combination containing hexanoylthiourea as the acyclic thiourea derivative and at least two, preferably exactly two, cyclic thiourea derivatives. Particularly preferred is a composition containing hexanoylthiourea, 2-mercaptobenzimidazole or 2-imidazolinethione, and at least one, preferably exactly one, additional cyclic thiourea derivative (1). Very particularly preferred is a composition containing hexanoylthiourea, 2-mercaptobenzimidazole or 2-imidazolinethione, and 3,4,5,6-tetrahydro-2-pyrimidinethiol. A particularly preferred combination of three thiourea derivatives is a mixture of 3,4,5,6-tetrahydro-2-pyrimidinethiol (1), 2-imidazolidinethione (2), and hexanoylthiourea (3).

[0035] The hydroperoxides preferred according to the invention are of the formula R 6 -(OOH) m (In the formula, R 6is an aliphatic or aromatic hydrocarbon radical, and m is 1 or 2. Preferred radicals R are alkyl and aryl groups. The alkyl group can be linear, branched, or cyclic. The cyclic alkyl radical can be substituted by an aliphatic alkyl group. Alkyl groups having 4 to 10 carbon atoms are preferred. The aryl group can be unsubstituted or substituted by an alkyl group. A preferred aromatic hydrocarbon radical is a benzene radical substituted by one or two alkyl groups. The aromatic hydrocarbon radical preferably contains 6 to 12 carbon atoms. Particularly preferred hydroperoxides are t-amyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, t-butyl hydroperoxide, t-hexyl peroxide, 2,5-dimethyl-2,5-di(hydroperoxy)hexane, diisopropylbenzene monohydroperoxide (DIHP), paramenthane hydroperoxide, p-isopropylcumene hydroperoxide, and mixtures thereof. DIHP and cumene hydroperoxide (CHP) are very particularly preferred.

[0036] Furthermore, hydroperoxides according to formula (IV) [ka] wherein the variables have the following meanings: Q 1 is p-valent, aromatic, aliphatic, linear or branched C1-C 14 Hydrocarbon radicals, which may be interrupted by one or more S and / or O atoms and may be unsubstituted or may be -OH, -OR 7 , -Cl and -Br, R 7 is aliphatic, linear or branched C1-C 10 is a hydrocarbon radical, X and Y, independently of one another, in each occurrence, are absent, -O-, -COO-; -CONR 8 -or -O-CO-NR9 - and R 8 and R 9 are, independently of one another, H or a C1-C5-alkyl radical, preferably H, methyl and / or ethyl, particularly preferably H, and X and Y are preferably not simultaneously absent, Q 2 is absent, aliphatic, linear or branched C1-C 14 Alkylene radicals, which may be interrupted by S and / or O atoms and may further be unsubstituted or may be substituted with -OH, -OR 10 , -Cl and / or -Br, R 10 is aliphatic, linear or branched C1-C 10 is a hydrocarbon radical, Q 3 is a C1-C3 alkylene group or is absent, preferably —CH2— or is absent, Q 2 is not present, then X and / or Y are not present, p is 1, 2, 3 or 4; The substitution on the aromatic compound occurs at the 2, 3, or 4 position relative to the cumene hydroperoxide group. is preferred according to the invention.

[0037] The variables preferably have the following meanings: Q 1 is a monovalent or divalent, aliphatic, linear or branched C1-C 10 Hydrocarbon radicals, which may be interrupted by one or more O atoms, preferably one O atom, and further include -OH and -OR 7 or is preferably unsubstituted by one or more, preferably one, substituents selected from R 7 is an aliphatic, linear or branched C1-C6 hydrocarbon radical, X and Y, independently of one another, in each occurrence, are absent, -O-, -COO- or -O-CO-NR 9 - and R9 represents H or a C1-C5 alkyl radical, preferably H, methyl and / or ethyl, very particularly preferably H, and X and Y are preferably not simultaneously absent, Q 2 is not present, linear or branched C1-C 10 Alkylene radicals, which may be interrupted by one or more O atoms, preferably one O atom, and further include -OH and -OR 10 or is preferably unsubstituted by one or more, preferably one, substituents selected from R 10 is an aliphatic, linear or branched C1-C6 hydrocarbon radical, p is 1 or 2; Substitution on the aromatic compound occurs at the 3-position, preferably the 4-position.

[0038] The variables particularly preferably have the following meanings: Q 1 is a monovalent or divalent aliphatic, linear or branched C1-C5 hydrocarbon radical, which may be interrupted by one O atom and further substituted by one OH group, X is -COO-, Y does not exist, Q 2 is absent or a linear C1-C3 alkylene radical, p is 1 or 2 and the substitution on the aromatic compound occurs at the 4-position.

[0039] The variables very particularly preferably have the following meanings: Q 1 is a monovalent or divalent aliphatic, branched, preferably linear, C1-C4 hydrocarbon radical, X is -COO-, Y does not exist, Q 2 is absent or a methylene radical, p is 1 or 2 and the substitution on the aromatic compound occurs at the 4-position.

[0040] The hydroperoxides of formula (IV) and their preparation are described in more detail in EP 3692976 A1. They are characterized in particular by the absence of an unpleasant odor. A very particularly preferred hydroperoxide of formula (IV) is 4-(2-hydroperoxypropan-2-yl)phenylpropionate (K220): [ka] is.

[0041] Further preferred are the hydroperoxides specifically named in paragraph

[0025] of EP3692976A1.

[0042] According to a preferred embodiment, the material according to the invention further contains a transition metal compound.

[0043] The preferred transition metal compounds according to the present invention are compounds derived from transition metals having at least two stable oxidation states. Compounds of copper, iron, cobalt, nickel, and manganese are particularly preferred. These metals have the following stable oxidation states: Cu(I) / Cu(II), Fe(II) / Fe(III), Co(II) / Co(III), Ni(II) / Ni(III), Mn(II) / Mn(III). Materials containing at least one copper compound are particularly preferred.

[0044] The transition metals are preferably used in the form of their salts, preferred salts being the nitrates, acetates, 2-ethylhexanoates and halides, with the chlorides being particularly preferred.

[0045] The transition metals can be used more advantageously in complex form, with complexes with chelating ligands being particularly preferred. Preferred single ligands for complexing with the transition metal are 2-ethylhexanoate and THF. Preferred chelating ligands are 2-(2-aminoethylamino)ethanol, aliphatic amines, particularly preferably 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA), N,N,N',N",N"-pentamethyldiethylenetriamine (PMDETA), tris[2-(dimethylamino)ethyl]amine (Me6TREN), N,N,N',N'-tetramethylethylenediamine (TMEDA), 1,4,8,11-tetraaza-1,4,8,11-tetramethylcyclotetramethyl ... Decane (Me4CYCLAM), diethylenetriamine (DETA), triethylenetetramine (TETA) and 1,4,8,11-tetraazacyclotetradecane (CYCLAM); pyridine-containing ligands, particularly preferred are N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), N,N-bis(2-pyridylmethyl)amine (BPMA), N,N-bis(2-pyridylmethyl)octylamine (BPMOA), 2,2'-bipyridine and 8-hydroxyquinoline. Very particularly preferred ligands are acetylacetone, dimethylglyoxime and 1,10-phenanthroline.

[0046] In the case of electrically neutral ligands, the charge of the transition metal ion must be balanced by a suitable counterion. For this reason, the ions specified above are preferred for forming salts, with acetate or chloride being particularly preferred. The chlorides and complexes are characterized by relatively good solubility in the monomers used to prepare dental materials.

[0047] Instead of transition metal complexes, dental materials can be prepared using non-complex salts of transition metals combined with complex-forming organic compounds, with the chelating compounds specified above being preferred. When the organic ligands are mixed with the transition metal salts, they form catalytically active complexes. It is preferred to use such combinations of transition metal salts and organic ligands.

[0048] Transition metal compounds of the metals copper, iron, cobalt and nickel are preferred.

[0049] Preferred copper salts are Cu(II) carboxylic acids (e.g., acetic acid or 2-ethylhexanoic acid), CuCl, CuBr, CuI, particularly preferably CuBr, and very particularly preferably CuCl. Preferred copper complexes are those with the ligands acetylacetone, phenanthrolines (e.g., 1,10-phenanthroline (phen)), and aliphatic amines (e.g., 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA), N,N,N',N",N"-pentamethyldiethylenetriamine (PMDETA), tris[2-(dimethylamino)ethyl]amine (Me6TREN), etc.).

[0050] Preferred iron salts are FeCl3, FeBr2 and FeCl2. Preferred iron complexes are those with the ligands acetylacetone, triphenylphosphine, 4,4'-di(5-nonyl)-2,2'-bipyridine (dNbpy) or 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (PriIm). The complexes Fe(acac)2 and FeCl2(PPh3)2 are very particularly preferred.

[0051] Preferred nickel salts are NiBr2 and NiCl2, and preferred nickel complexes are nickel acetylacetonate and NiBr2(PPh3)2.

[0052] According to the present invention, copper compounds, copper complexes, and in particular mixtures of copper salts with complexing organic ligands, are particularly preferred. +) salts and complexes are very particularly preferred, with copper(I) chloride (CuCl) being most preferred. Compositions containing salts of monovalent copper, in particular CuCl, are characterized by particularly good storage stability.

[0053] The initiator system according to the invention is particularly suitable for curing radically polymerizable compositions.

[0054] In addition to the initiator system, the composition according to the invention preferably contains at least one radically polymerizable monomer. Particularly preferred are compositions containing at least one mono- or polyfunctional (meth)acrylate as the radically polymerizable monomer. By monofunctional (meth)acrylate is meant a compound having one radically polymerizable group, and by polyfunctional (meth)acrylate is meant a compound having two or more, preferably two to four, radically polymerizable groups. According to a very particularly preferred embodiment, the composition according to the invention contains at least one dimethacrylate or a mixture of monomethacrylate and dimethacrylate. Materials that are to harden in the oral cavity preferably contain mono- and / or polyfunctional methacrylates as the radically polymerizable monomer.

[0055] Preferred mono- or polyfunctional (meth)acrylates are methyl (meth)acrylate, ethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, butyl (meth)acrylate, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate or isobornyl (meth)acrylate, p-cumylphenoxyethylene glycol methacrylate (CMP-1E), 2-(2-biphenyloxy)ethyl methacrylate, bisphenol A dimethacrylate, bis-GMA (methacrylic acid and bisphenol A diglycidyl ester). ethoxylated or propoxylated bisphenol A dimethacrylates (e.g., 2-[4-(2-methacryloyloxyethoxyethoxy)phenyl]-2-[4-(2-methacryloyloxyethoxy)phenyl]propane) (SR-348c from Sartomer; contains three ethoxy groups), and 2,2-bis[4-(2-methacryloxypropoxy)phenyl]propane), UDMA (an adduct of 2-hydroxyethyl methacrylate with 2,2,4-trimethylhexamethylene-1,6-diisocyanate), V-380 (an addition product of a mixture of 0.7 mol of 2-hydroxyethyl methacrylate and 0.3 mol of 2-hydroxypropyl methacrylate with 1 mol of α,α,α',α'-tetramethyl-m-xylylene diisocyanate), diethylene glycol dimethacrylate, triethylene glycol dimethacrylate or tetraethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, and glycerol dimethacrylate and glycerol trimethacrylate, The copolymer may be 1,4-butanediol dimethacrylate, 1,10-decanediol dimethacrylate (D3MA), bis(methacryloyloxymethyl)tricyclo-[5.2.1.02,6]decane (DCP), polyethylene glycol dimethacrylate or polypropylene glycol dimethacrylate (e.g., polyethylene glycol 200 dimethacrylate or polyethylene glycol 400 dimethacrylate (PEG200DMA or PEG400DMA)), or 1,12-dodecanediol dimethacrylate, or a mixture thereof.

[0056] In addition to the initiator system according to the present invention, the composition according to the present invention can advantageously further contain an initiator for radical photopolymerization. Such compositions are dual-curable, i.e., they can be cured both chemically and by light. Preferred photoinitiators are benzophenone, benzoin and their derivatives, α-diketones and their derivatives (such as 9,10-phenanthrenequinone, 1-phenyl-propane-1,2-dione, diacetyl, and 4,4'-dichlorobenzyl). Camphorquinone (CQ) and 2,2-dimethoxy-2-phenyl-acetophenone are preferably used as reducing agents in combination with amines, such as 4-(dimethylamino)-benzoic acid ethyl ester (EDMAB) or N,N-dimethylaminoethyl methacrylate.

[0057] According to the present invention, amine-free compositions are preferred. Thus, Norrish Type I photoinitiators are particularly preferred. Norrish Type I photoinitiators do not require an amine component.

[0058] Preferred Norrish type I photoinitiators are acylphosphine oxides or bisacylphosphine oxides. Particularly preferred are monoacyltrialkylgermanes, diacyldialkylgermanes, and tetraacylgermanes, such as benzoyltrimethylgermane, dibenzoyldiethylgermane, bis(4-methoxybenzoyl)diethylgermane (Ivocerin®), tetrabenzoylgermane, and tetrakis(o-methylbenzoyl)germane. Furthermore, a mixture of different photoinitiators, such as bis(4-methoxybenzoyl)diethylgermane or tetrakis(o-methylbenzoyl)germane, can be used in combination with camphorquinone and 4-dimethylaminobenzoic acid ethyl ester.

[0059] The compositions according to the invention can further advantageously contain one or more organic or inorganic fillers. Particulate fillers are preferred. Filler-containing compositions are particularly suitable as dental fixing cements or filling composites, as well as for the production of temporary crowns and bridges.

[0060] Preferred inorganic fillers are oxides such as SiO, ZrO, and TiO, or oxide mixtures of SiO, ZrO, ZnO, and / or TiO, nanoparticle or ultrafine fillers such as pyrogenic or precipitated silica, quartz, glass ceramics, borosilicate or radiopaque glass powders, preferably glass powders such as barium or strontium aluminum silicate glass, and radiopaque fillers such as ytterbium trifluoride, tantalum(V) oxide, barium sulfate, or oxide mixtures of SiO with ytterbium(III) oxide or tantalum(V) oxide. The dental material according to the invention can further contain fibrous fillers, nanofibers, whiskers, or mixtures thereof.

[0061] Preferably, the oxide has a particle size of 0.010 to 15 μm, the nanoparticles or fine fillers have a particle size of 10 to 300 nm, the glass powder has a particle size of 0.01 to 15 μm, preferably 0.2 to 1.5 μm, and the radiopaque filler has a particle size of 0.2 to 5 μm.

[0062] Particularly preferred fillers are oxide mixtures of SiO2 and ZrO2 with a particle size of 10 to 300 nm, glass powders with a particle size of 0.2 to 1.5 μm, in particular radiopaque glass powders, for example barium or strontium aluminum silicate glasses, and radiopaque fillers with a particle size of 0.2 to 5 μm, in particular ytterbium trifluoride and / or oxide mixtures of SiO2 and ytterbium(III) oxide.

[0063] Furthermore, ground prepolymers or pearl polymers (isofillers) are suitable as fillers. These can consist exclusively of organic polymers or organic polymers which are themselves filled with inorganic fillers such as radiopaque glass powder and ytterbium trifluoride. The monomers and fillers defined above are suitable for preparing ground prepolymers and pearl polymers. Compositions for producing complete dentures preferably contain as fillers exclusively organic fillers, particularly preferably ground polymers or pearl polymers based on polymethyl methacrylate (PMMA), very particularly preferably pearl polymers based on PMMA.

[0064] Unless otherwise specified, all particle sizes are weight-average particle sizes. Particle size determinations in the 0.1 μm to 1000 μm range are preferably performed by static light scattering using an LA-960 Static Laser Scattering Particle Size Analyzer (Horiba, Japan). Here, a laser diode with a wavelength of 655 nm and an LED with a wavelength of 405 nm are used as light sources. The use of two light sources with different wavelengths allows the entire particle size distribution of a sample to be measured in just one measurement, which is performed as a wet measurement. In this case, a 0.1-0.5% aqueous dispersion of the filler is prepared, and its scattered light is measured in a flow cell. Scattered light analysis to calculate particle size and particle size distribution is performed according to Mie theory in accordance with DIN / ISO 13320.

[0065] Particle sizes less than 0.1 μm are preferably determined by dynamic light scattering (DLS). Measurements of particle sizes in the range of 5 nm to 0.1 μm are performed by dynamic light scattering (DLS) of aqueous particle dispersions at 25°C and a scattering angle of 90°, preferably using a Malvern Zetasizer Nano ZS (Malvern Instruments, Malvern, UK) with a He-Ne laser having a wavelength of 633 nm.

[0066] Particle sizes below 0.1 μm can also be determined by SEM or TEM spectroscopy. Transmission electron microscopy (TEM) is preferably performed using a Philips CM30 TEM at an accelerating voltage of 300 kV. For sample preparation, a few drops of the particle dispersion are applied to a carbon-coated 50 Å thick copper grid (mesh size 300), and the solvent is then evaporated.

[0067] As particle size decreases, light scattering decreases, but fillers with smaller particle sizes have a greater thickening effect. Fillers are classified into macrofillers and microfillers according to their particle size. Fillers with an average particle size of 0.2 to 10 μm are called macrofillers, and fillers with an average particle size of about 5 to 100 nm are called microfillers. Macrofillers are obtained, for example, by grinding quartz, radiopaque glass, borosilicate, or ceramic, and usually consist of friable parts. Microfillers, such as oxide mixtures, can be prepared, for example, by co-condensation with metal alkoxides via hydrolysis.

[0068] To improve the bond between the filler particles and the crosslinked polymeric matrix, the fillers are preferably surface-modified, particularly preferably by silanization, very particularly preferably by radically polymerizable silanes, in particular 3-methacryloyloxypropyltrimethoxysilane. In the case of surface modification of non-silicate fillers, such as ZrO or TiO, functionalized acid phosphates can also be used, such as 10-methacryloyloxydecyl dihydrogen phosphate.

[0069] Furthermore, the compositions according to the invention may contain one or more further additives, any of the above-mentioned stabilizers, colorants, biocidal active ingredients, fluoride ion-releasing additives, foaming agents, optical whitening agents, plasticizers and / or UV absorbers.

[0070] The material according to the present invention preferably comprises two physically separate components that are mixed together for use. The first component (catalyst paste) comprises a hydroperoxide(s), and the second component (base paste) comprises a thiourea derivative and, optionally, a transition metal compound. The base paste and catalyst paste are preferably mixed together in a 1:1 volume ratio. The curing reaction is initiated by mixing the base paste and catalyst paste.

[0071] The base paste preferably contains 0.07 to 3.50% by weight, particularly preferably 0.07 to 3.3% by weight, very particularly preferably 0.20 to 2.50% by weight, most preferably 0.35 to 2.10% by weight of at least one cyclic thiourea derivative and 0.04 to 2.3% by weight, particularly preferably 0.04 to 2.00% by weight, particularly preferably 0.10 to 1.5% by weight, most preferably 0.20 to 1.2% by weight of at least one acyclic thiourea derivative.

[0072] According to a preferred embodiment, the base paste contains 0.03 to 2.50% by weight, particularly preferably 0.10 to 2.00% by weight, and most preferably 0.15 to 1.50% by weight, of 3,4,5,6-tetrahydro-2-pyrimidinethiol and / or 0.04 to 1.30% by weight, particularly preferably 0.10 to 1.00% by weight, and most preferably 0.15 to 0.60% by weight of 2-mercaptobenzimidazole and / or 0.04 to 2.00% by weight, particularly preferably 0.10 to 1.50% by weight, and most preferably 0.25 to 1.20% by weight of hexanoylthiourea, wherein materials containing in each case all three named cyclic thiourea derivatives in the recited amounts are particularly advantageous.

[0073] The amounts of the individual thiourea derivatives are preferably selected so that the weight ratio of 3,4,5,6-tetrahydro-2-pyrimidinethiol to 2-mercaptobenzimidazole is in the range of 0.15 to 4.00, particularly preferably 0.20 to 3.50, and most preferably 0.25 to 3.00. The weight ratio of 3,4,5,6-tetrahydro-2-pyrimidinethiol to hexanoylthiourea is preferably in the range of 0.04 to 3.50, particularly preferably 0.40 to 3.00, and most preferably 0.60 to 2.70. The weight ratio of 2-mercaptobenzimidazole to hexanoylthiourea is preferably in the range of 0.05 to 2.50, particularly preferably 0.10 to 1.2, and most preferably 0.20 to 0.90.

[0074] The base paste preferably contains a total of 0.10 to 4.00% by weight, particularly preferably 0.50 to 2.50% by weight, and most preferably 1.00 to 2.00% by weight of thiourea derivatives.

[0075] The thiourea derivatives are preferably used in a total molar amount of 50 to 400 mol %, preferably 75 to 300 mol %, very particularly preferably 100 to 200 mol %, relative to the molar amount of hydroperoxides in the catalyst paste.

[0076] Preferably, the base paste further contains 0.0001 to 1% by weight, preferably 0.0005 to 0.500% by weight, particularly preferably 0.0007 to 0.020% by weight, of one or more transition metal compounds. The total mass of the transition metal compounds relative to the mass of the base paste is specified.

[0077] The base paste has the following composition: - 0.10 to 5.00% by weight, preferably 0.50 to 4.00% by weight, particularly preferably 1.00 to 2.00% by weight of a thiourea derivative, - 0.0001 to 1% by weight, preferably 0.0005 to 0.5% by weight, particularly preferably 0.0007 to 0.02% by weight, of at least one transition metal compound, - 5 to 95% by weight, preferably 10 to 95% by weight, particularly preferably 10 to 90% by weight, of at least one radically polymerizable monomer, - 0 to 85% by weight of at least one filler, and - if necessary 0.01 to 5% by weight, preferably 0.1 to 3% by weight, particularly preferably 0.1 to 2% by weight, of one or more additives Preferably,

[0078] The above data in all cases relate to the mass of the base paste.

[0079] The catalyst paste preferably contains one or more hydroperoxides, preferably in a total amount of 0.01 to 5.0% by weight, particularly preferably 0.05 to 4.0% by weight, very particularly preferably 0.1 to 3.75% by weight, based on the mass of the catalyst paste.

[0080] The catalyst paste has in each case, relative to the mass of the catalyst paste, the following composition: - 0.01 to 6% by weight, preferably 0.05 to 5.0% by weight, particularly preferably 0.1 to 4.0% by weight of at least one hydroperoxide, preferably CHP and / or K220, - 5 to 95% by weight, preferably 10 to 95% by weight, particularly preferably 10 to 90% by weight, of at least one radically polymerizable monomer, - 0 to 85% by weight of at least one filler, and - if necessary 0.01 to 5% by weight, preferably 0.1 to 3% by weight, particularly preferably 0.1 to 2% by weight, of one or more additives Preferably,

[0081] After mixing the catalyst paste and the base paste, the material according to the invention has the following total composition, in each case relative to the total mass of the composition: (a) 0.005 to 3% by weight, preferably 0.025 to 2.5% by weight, particularly preferably 0.05 to 2.0% by weight of at least one hydroperoxide, preferably CHP and / or K220, (b) 0.005 to 3.0% by weight, preferably 0.015 to 2.125% by weight, particularly preferably 0.025 to 1.5% by weight of a thiourea derivative; (c) 0.00005 to 0.5% by weight, preferably 0.00025 to 0.25% by weight, particularly preferably 0.00035 to 0.01% by weight of at least one transition metal compound; (d) 5 to 95% by weight, preferably 10 to 95% by weight, particularly preferably 10 to 90% by weight, of at least one radically polymerizable monomer; (e) 0 to 85 wt. % of at least one filler, and (f) optionally 0.01 to 5% by weight, preferably 0.1 to 3% by weight, particularly preferably 0.1 to 2% by weight, of one or more additives; Preferably,

[0082] The filler content is adapted to the desired intended use of the material. Filled composites preferably have a filler content of 50-85% by weight, particularly preferably 70-80% by weight. Materials for producing temporary crowns and bridges preferably have a filler content of 40-70% by weight, particularly preferably 45-60% by weight, and dental cements preferably have a filler content of 10-70% by weight, particularly preferably 60-70% by weight. The data relate to the total mass of the material.

[0083] Particularly preferred are compositions consisting of the specified substances.Furthermore, preferred are compositions in which the individual components are in each case selected from the preferred substances, particularly preferred materials, specified above.In all cases, individual components or mixtures of several components, for example mixtures of monomers, can in each case be used.

[0084] The composition according to the present invention is particularly suitable as a dental material, in particular as a dental cement, a filling composite and a coating material, and for producing prostheses, dentures, inlays, onlays, crowns and bridges, very particularly as a material for producing temporary crowns and bridges.The composition is suitable for intraoral application by dentists for the repair of damaged teeth, i.e., for example, as a dental cement, a filling composite and a coating material for therapeutic use.However, the composition can also be used non-therapeutically (extraorally), for example, when producing or correcting dental restorations such as prostheses, dentures, inlays, onlays, crowns and bridges.

[0085] The compositions according to the invention are further suitable for producing shaped bodies for dental but also for non-dental purposes, which can be produced, for example, by cast forming, compression molding, and in particular by additional processes such as 3D printing.

[0086] For the production of temporary crowns and bridges, an impression of the tooth(s) to be treated is first made. Next, the tooth(s) is / are ground, and then the impression is filled with a self-hardening restorative material. The blended material is applied from the mixing tip using light pressure or a deep-drawing film directly onto the impression. To achieve bubble-free filling of the impression, the tip should be immersed in the material during filling. If necessary, the prepared tooth can be surrounded by restorative material for bubble-free formation of the preparation margin.

[0087] The material-filled impression is then pressed into the prepared tooth. After about 1-2 minutes, the material is in a hard, elastic, partially cured state and can be removed from the mouth along with the impression.

[0088] The temporary plastic prosthesis is removed from the anatomical impression, possibly from the core, and excess material is removed after further hardening (approximately 4-5 minutes) using a rotary instrument, e.g., a cross-cut tungsten carbide burr, or a scalpel. The blocking layer is preferably removed with alcohol or by polishing. The restoration is then allowed to fully harden.

[0089] The invention will now be explained in more detail with reference to the following embodiment examples and figures.

[0090] Figure 1 shows the storage stability of pastes with two different thiourea derivatives. The working time of the paste increases with storage time, which is an indicator of instability. The paste is stable for approximately 3 months at 37°C.

[0091] Figure 2 shows the storage stability of a paste with three different thiourea derivatives. The paste is stable for 5 months, even at 50°C. Only after that can a decrease in processing time be observed. [Example]

[0092] Example of an embodiment The following materials are used in the example embodiment: DCP Bis(methacryloyloxymethyl)tricyclo-[5.2.1.02,6]-decane (CAS number 43048-08-4) RM3 UDMA (CAS number 72869-86-4) SR348C 2-[4-(2-methacryloyloxyethoxyethoxy)-phenyl]-2-[4-(2-methacryloyloxyethoxy)-phenyl]-propane (SR-348c from Sartomer; contains three ethoxy groups; CAS number 41637-38-1) CHP Cumene hydroperoxide (CAS number 80-15-9) K220 4-(2-hydroperoxypropan-2-yl)phenylpropionate (CAS number 2515246-70-3) 2-MBI 2-Mercaptobenzimidazole (CAS number 583-39-1) 1-Methyl-MBI 1-Methyl-1H-benzimidazole-2-thiol (CAS number 2360-22-7) THPT 3,4,5,6-Tetrahydro-2-pyrimidinethiol (CAS number 2055-46-1) K107 Hexanoylthiourea (CAS number 41510-13-8) CuCl Copper(I) chloride (CAS number 7758-89-6) HDK2000 trimethylsilane-treated pyrogenic silica, BET surface area approximately 200m 2 / g(Wacker Chemie AG) SG-SO100NCMP8 SiO2 coated with methacryloxypropyltrimethoxysilane (CAS No. 7631-86-9) BHT Butylhydroxytoluene (CAS number 128-37-0) Optamint® Flavors (Symrise AG) Example 1 Determining the effect of the number of thiourea derivatives on storage stability

[0093] The materials listed in Table 1 were prepared by homogeneously mixing the components specified in the table. In each case, a base paste (Base) and a catalyst paste (Catalyst) were prepared. To prepare the pastes, the individual initiator components and additives were added to the monomer, and the mixture was then stirred for several hours until the solids were completely dissolved. The filler was then added and homogeneously blended in a centrifugal mixer (SpeedMixer®, manufactured by Hauschild). After vacuum treatment, the pastes were individually poured into double-push syringes. The base paste and catalyst paste were then blended together in a 1:1 volume ratio in each case, and the processing time (PT) was measured according to the EN ISO-4049 standard. To determine the mechanical properties of the materials, test specimens were produced, and their flexural strength and flexural modulus were determined according to the EN ISO-4049 standard (Dentistry - Polymer-based filling, restorative, and luting materials). To determine the length of the elastic phase, the catalyst paste and base paste were blended in a 1:1 volume ratio. After the onset of hardening (established by pressing into the test specimen), a stopwatch was started and stopped when the test specimen could no longer be cut using a scalpel. The results are listed in Table 3.

[0094] To determine storage stability, the pastes were stored at 37°C or 50°C for 5 months. Processing times were measured periodically. The results are reproduced in Figures 1 and 2. Figure 1 shows the storage stability of pastes containing two different thiourea derivatives, and Figure 2 shows the storage stability of pastes containing three different thiourea derivatives. Figure 1 shows that the processing time of the pastes increases with storage time, an indicator of instability. The pastes containing two different thiourea derivatives are stable for approximately 3 months at 37°C. Figure 2 shows that the pastes containing three different thiourea derivatives were stable even at 50°C for 5 months. [Table 1] Example 2 Determination of mechanical properties of restorative materials

[0095] The materials listed in Table 2 were prepared similarly to Example 1. The processing time, length of the elastic phase, and mechanical properties were then determined as described in Example 1. The results are listed in Table 3. Materials 1 and 2 contain only two thiourea derivatives in each case. These materials have good flexural strength, good flexural modulus, and a sufficiently long elastic phase. However, the processing time is relatively short and the storage stability is unsatisfactory (Figure 1). The remaining materials contain three different thiourea derivatives in each case. These materials are characterized by extended processing times, along with comparable mechanical properties and comparable elastic phase lengths. [Table 2] [Table 3]

Claims

1. A radically polymerizable dental material comprising a combination of a thiourea derivative and a hydroperoxide as an initiator system for radical polymerization, characterized in that it contains at least two cyclic thiourea derivatives and one or more acyclic thiourea derivatives, Each of the at least two cyclic thiourea derivatives has the formula (I): 【Chemistry 12】 (In the formula, R 1 , R 2 in each case are H or C 1 -C 4 alkyl radicals, at least one of which is H; R 3 , R 4 independently of one another are in each case H, a C 1 -C 4 alkyl radical or a C 1 -C 4 alkoxy radical or, together with the carbon atoms to which they are attached and the intervening carbon atoms, form a 6-membered carbocyclic, aliphatic or aromatic ring which can be substituted by one or more C 1 -C 4 alkyl radicals and / or C 1 -C 4 alkoxy radicals; n is 0, 1, 2 or 3. It is of At least one of the one or more acyclic thiourea derivatives has the formula (II): 【Chemistry 13】 (In the formula, X is H or Y; Y is an alkyl radical having 1 to 8 carbon atoms, a cycloalkyl radical having 5 or 6 carbon atoms, a chlorine-, hydroxy- or mercapto-substituted alkyl radical having 1 to 8 carbon atoms, an alkenyl radical having 3 to 4 carbon atoms, an aryl radical having 6 to 8 carbon atoms, a chlorine-, hydroxy-, methoxy- or sulfonyl-substituted phenyl radical, an acyl radical having 2 to 8 carbon atoms, a chlorine- or methoxy-substituted acyl radical, an aralkyl radical having 7 or 8 carbon atoms, or a chlorine- or methoxy-substituted aralkyl radical; Z is NH 2 , NHX or NX 2 ), and / or Formula (III): 【Chemistry 14】 (In the formula, R 5 is a C 1 -C 12 alkyl radical, a C 1 -C 12 alkene radical, a C 1 -C 12 acyl radical, pyridyl or a phenyl radical; A dental material comprising:

2. At least one cyclic thiourea derivative of formula (I): 【Chemistry 12】 (In the formula, R １ , R ２ is in each case H or C １ ~C ４ alkyl radicals, at least one of which is H; R ３ , R ４ are, independently of one another, in each case H, C １ ~C ４ Alkyl radical or C １ ~C ４ Alkoxy radicals or, together with the carbon atoms to which they are attached and the intervening carbon atoms, one or two C １ ~C ４ Alkyl radicals and / or C １ ~C ４ forming a 6-membered carbocyclic, aliphatic or aromatic ring which may be substituted by an alkoxy radical, n is 0 or 1. The dental material according to claim 1, comprising:

3. At least one acyclic thiourea derivative of formula (II): 【Chemistry 13】 (In the formula, X is H or Y; Y is an alkyl radical having 1 to 8 carbon atoms, a cycloalkyl radical having 5 or 6 carbon atoms, a chlorine-, hydroxy- or mercapto-substituted alkyl radical having 1 to 8 carbon atoms, an alkenyl radical having 3 to 4 carbon atoms, an aryl radical having 6 to 8 carbon atoms, a chlorine-, hydroxy-, methoxy- or sulfonyl-substituted phenyl radical, an acyl radical having 2 to 8 carbon atoms, a chlorine- or methoxy-substituted acyl radical, an aralkyl radical having 7 or 8 carbon atoms, or a chlorine- or methoxy-substituted aralkyl radical; Z is NH ２ , NHX or NX ２ and / or At least one acyclic thiourea derivative of formula (III): 【Chemistry 14】 (In the formula, R ５ is C ２ ~C １０ Alkyl radicals, particularly preferably C ３ ~C ８ Alkyl radicals, very particularly preferably C ４ ~C ６ Alkyl radical, C ２ ~C １０ Alkene radicals, particularly preferably C ３ ~C ８ Alkene radicals, very particularly preferably C ４ ~C ６ Alkene radical, C ２ ~C １０ Acyl radicals, particularly preferably C ３ ~C ８ Acyl radicals, very particularly preferably C ４ ~C ６ acyl radicals, pyridyl or phenyl radical) The dental material according to claim 1 or 2, comprising:

4. 4. The dental material according to claim 1, which contains 3,4,5,6-tetrahydro-2-pyrimidinethiol, 2-imidazolidinethione, 2-mercaptobenzimidazole, 1-methyl-1H-benzimidazole-2-thiol and / or 2-mercapto-5-methoxybenzimidazole as a cyclic thiourea derivative, and hexanoylthiourea as an acyclic thiourea derivative.

5. As hydroperoxides, compounds of the formula R ６ -(OOH) ｍ (In the formula, R ６ is an aliphatic or aromatic hydrocarbon radical and m is 1 or 2, and / or Compound of formula (IV) 【Chemistry 15】 wherein the variables have the following meanings: Q １ is a p-valent aromatic, aliphatic, linear or branched C １ ~C １４ Hydrocarbon radicals, which may be interrupted by one or more S and / or O atoms and may be unsubstituted or may be -OH, -OR ７ , —Cl and —Br, and R ７ is an aliphatic, linear or branched C １ ~C １０ is a hydrocarbon radical, X and Y are independently in each occurrence absent, —O—, —COO—; or —CONR ８ -or -O-CO-NR ９ - and R ８ and R ９ are, independently of one another, H or C １ ~C ５ represents an alkyl radical, preferably H, methyl and / or ethyl, particularly preferably H, and X and Y are preferably not simultaneously absent, Q ２ is absent, aliphatic, linear or branched C １ ~C １４ Alkylene radicals, which may be interrupted by S and / or O atoms and may further be unsubstituted or may be substituted with -OH, -OR １０ , -Cl and / or -Br, R １０ is an aliphatic, linear or branched C １ ~C １０ is a hydrocarbon radical, Q ３ is C １ ~C ３ an alkylene group or absent, preferably —CH ２ - or absent, Q ２ is not present, then X and / or Y are not present; p is 1, 2, 3 or 4; The substitution on the aromatic compound occurs at the 2, 3, or 4 position relative to the cumene hydroperoxide group.

5. The dental material according to claim 1, which contains

6. 6. The dental material according to claim 5, comprising as hydroperoxide t-amyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, t-butyl hydroperoxide, t-hexyl hydroperoxide, 2,5-dimethyl-2,5-di(hydroperoxy)hexane, diisopropylbenzene monohydroperoxide, paramenthane hydroperoxide, p-isopropylcumene hydroperoxide, 4-(2-hydroperoxypropan-2-yl)phenylpropionate or mixtures thereof, preferably cumene hydroperoxide (CHP) and / or 4-(2-hydroperoxypropan-2-yl)phenylpropionate.

7. 7. The dental material according to claim 1, further comprising a transition metal compound, preferably a compound of iron, cobalt, nickel, manganese, copper or a mixture thereof, particularly preferably a compound of copper, and very particularly preferably a compound of Cu(I).

8. 8. The dental material according to claim 1, comprising two components, wherein the first component contains 0.01 to 5 wt. %, preferably 0.05 to 4.0 wt. %, particularly preferably 0.1 to 3.75 wt. %, of hydroperoxide, based on the weight of the first component, and the second component contains 50 to 400 mol. %, preferably 75 to 300 mol. %, particularly preferably 100 to 200 mol. %, of thiourea derivative, based on the molar mass of hydroperoxide in the first component.

9. 9. The dental material according to claim 1, further comprising at least one radically polymerizable monomer, preferably at least one mono- or polyfunctional (meth)acrylate, particularly preferably at least one dimethacrylate, or a mixture of monomethacrylate and dimethacrylate.

10. Radically polymerizable monomers include methyl (meth)acrylate, ethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, butyl (meth)acrylate, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and isobornyl (meth)acrylate, p-cumylphenoxyethylene glycol methacrylate (CMP-1E), 2-(2-biphenyloxy)ethyl methacrylate, bisphenol A dimethacrylate, bis-GMA (an addition product of methacrylic acid and bisphenol A diglycidyl ether), ethoxylated or propoxylated bisphenol A dimethacrylate, 2-[4-(2-methacryloyloxyethoxyethoxy)phenyl]-2-[4-(2-methacryloyloxyethoxy)phenyl]propane (SR-348c), 2,2-bis[4-(2 -methacryloxypropoxy)phenyl]propane, UDMA (addition product of 2-hydroxyethyl methacrylate and 2,2,4-trimethylhexamethylene-1,6-diisocyanate), V-380 (addition product of a mixture of 0.7 mol of 2-hydroxyethyl methacrylate and 0.3 mol of 2-hydroxypropyl methacrylate and 1 mol of α,α,α',α'-tetramethyl-m-xylylene diisocyanate), diethylene glycol dimethacrylate, triethylene glycol dimethacrylate or tetraethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, glycerol dimethacrylate and glycerol trimethacrylate, 1,4-butanediol dimethacrylate, 1,10-decanediol dimethacrylate (D ３ 10. The dental material of claim 9, comprising a copolymer of 1,12-dodecanediol dimethacrylate and 1,12-dodecanediol dimethacrylate, selected from the group consisting of bis(methacryloyloxymethyl)tricyclo-[5.2.1.02,6]decane (DCP), polyethylene glycol dimethacrylate or polypropylene glycol dimethacrylate, polyethylene glycol 200 dimethacrylate, polyethylene glycol 400 dimethacrylate (PEG200DMA or PEG400DMA), 1,12-dodecanediol dimethacrylate, or a mixture thereof.

11. at least one organic or inorganic filler, preferably SiO ２ , ZrO ２ and TiO ２ oxides such as SiO ２ , ZrO ２ , ZnO and / or TiO ２ oxide mixtures of, nanoparticle or ultrafine fillers such as pyrogenic or precipitated silica, quartz, glass ceramic or radiopaque glass powder, preferably glass powder such as barium or strontium aluminum silicate glass powder, ytterbium trifluoride, tantalum(V) oxide, barium sulfate, SiO ２ 11. The dental material according to claim 1, further comprising a radiopaque filler, such as an oxide mixture of ytterbium(III) oxide and tantalum(V) oxide, a finely divided prepolymer or a pearl polymer.

12. in each case relative to the total weight of the composition (a) 0.005 to 3% by weight, preferably 0.025 to 2.5% by weight, and particularly preferably 0.05 to 2.0% by weight of at least one hydroperoxide, preferably cumene hydroperoxide and / or 4-(2-hydroperoxypropan-2-yl)phenylpropionate; (b) 0.005 to 3.0% by weight, preferably 0.015 to 2.125% by weight, particularly preferably 0.025 to 1.5% by weight of a thiourea derivative, (c) 0.00005 to 0.5% by weight, preferably 0.00025 to 0.25% by weight, particularly preferably 0.00035 to 0.01% by weight, of at least one transition metal compound; (d) 5 to 95% by weight, preferably 10 to 95% by weight, particularly preferably 10 to 90% by weight, of at least one radically polymerizable monomer; (e) 0 to 85 wt. % of at least one filler, and (f) optionally 0.01 to 5% by weight, preferably 0.1 to 3% by weight, and particularly preferably 0.1 to 2% by weight, of one or more additives; The dental material according to claim 1 , comprising:

13. Dental material according to any one of claims 1 to 12 for therapeutic use.

14. 13. Use of a dental material according to one of claims 1 to 12 for the extraoral production or correction of dental restorations, such as prostheses, dentures, inlays, onlays, crowns, bridges and complete dentures.

Images