Powder-liquid system and method for the production of hypoallergenic methyl methacrylate-free dental prostheses

Abstract

Powder-liquid system for the production of hypoallergenic methyl methacrylate monomer-free dental prostheses, characterized in that the presorbable powder of the powder-liquid system contains a part of one or more compounds of a monomer mixture A of mono- and / or multifunctional methacrylates excluding methyl methacrylate in presorbed form.

Description

[0001] The present invention relates to a powder-liquid system and a method for the production of hypoallergenic methyl methacrylate-free dental prostheses.

[0002] Denture base plastics are used for the manufacture of dental prostheses, in particular the denture base as the part of the removable denture that rests against the denture base and to which the teeth are attached (DIN EN ISO 20795-1).

[0003] It is known to produce denture base resins based on a powder component containing polymethyl methacrylate pearl polymers as the main component, and a liquid component containing methyl methacrylate as the main component (M. Braden, R.L. Clarke, J. Nicholson, S. Parker. Polymeric Dental Materials. Springer-Verlag Berlin Heidelberg New York 1997, p. 56). However, in recent years, it has become apparent that allergic reactions associated with dentures made from these denture base resins have increased significantly. Methyl methacrylate has proven to be a detrimental allergen not only for the patients wearing these dentures, but also, and especially, for the dental technicians fabricating them.

[0004] Plastic casting compounds for the production of hypoallergenic dental prostheses are now known that do not contain methyl methacrylate and are based on a completely different polymer, consisting of a polyurethane made from an aliphatic isocyanate and a polyether polyol (DE 10 2008 058 039). A disadvantage of this system is that it is composed of liquid components and can only be processed as a casting compound, making it difficult to adapt to the processing requirements of the dental technician. This also precludes the possibility of a step-by-step construction of a cast partial denture by the dental technician.

[0005] A self-polymerizing denture and relining material with minimized allergy potential, containing pearl polymers and polymerizable acrylate monomers, is also known, in which no monomethacrylates are used (EP 1 214 042). Although this material possesses sufficient stiffness, its lack of the fracture toughness required for long-term use as a denture base material, due to the absence of impact-resistant components, proves to be a disadvantage.

[0006] Finally, hypoallergenic dental resins are known that do not contain monomeric methyl methacrylate in their formulation, but as pearl polymers, they do not preclude the possibility of using polymethyl methacrylate (DE 10 2012 022 693). To maintain good mechanical properties, such dental resins are preferably formulated as a two-component paste system and, as liquid components, therefore also exhibit the disadvantages already mentioned for the resin casting compounds mentioned above. For example, they cannot be adapted to the processing requirements of the dental technician regarding variable viscosity of the mixture before polymerization by using a variable powder-to-liquid ratio.

[0007] The invention is therefore based on the objective of developing a powder-liquid system and a process for the production of hypoallergenic methyl methacrylate-free dental prostheses, in which the disadvantages described above are completely or partially avoided and which, in addition to the exclusion of methyl methacrylate as a monomer, is characterized in particular by very good fracture toughness of the prosthesis materials both up to the point of crack initiation and especially during crack growth, while simultaneously exhibiting good processing properties and good stiffness properties.

[0008] According to the invention, the problem is solved by the powder of the powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses containing a portion of one or more compounds of a monomer mixture A consisting of mono- and / or multifunctional methacrylates, excluding methyl methacrylate, in pre-absorbed form.

[0009] According to the invention, the problem is solved by using the powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses. a) 30 to 65 percent by mass of a monomer mixture A consisting of mono- and / or multifunctional methacrylates, excluding methyl methacrylate, b) 65 to 25 percent by mass of an impact-modified pearl polymer B based on one or more monomers contained in the monomer mixture A, including methyl methacrylate, c) 0.1 to 8 mass percent of a reactive impact modifier C, d) 0.2 to 3 mass percent of an initiator system D, e) 0.1 to 4 mass percent of a vent E, f) Contains 0.005 to 20% by mass of additives F, wherein – the powder contains component B, parts of the initiator system D and parts of additives F and 0.1 to 5.0 mass percent, based on 100 mass percent of component B, of one or more compounds of component A are pre-absorbed in the powder and – the liquid contains components A, C, E, parts of the initiator system D and parts of additives F.

[0010] The liquid in the powder-liquid system can be either a liquid in the true sense or a gel.

[0011] According to the invention, the powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses can be composed of mono- and / or multifunctional methacrylates selected from the group consisting of the following monomers: ethyl methacrylate, butyl methacrylate, benzyl methacrylate, tetrahydrofurfuryl methacrylate, isobornyl methacrylate, phenyl methacrylate, ethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, triethylene glycol dimethacrylate, 1,10-decanediol dimethacrylate, 1,12-dodecanediol dimethacrylate, ethoxylated bisphenol A dimethacrylates, polyethylene glycol dimethacrylates, urethane dimethacrylates, higher molecular weight urethane dimethacrylates such as Exothane, butanediol dimethacrylate, tetraethylene glycol dimethacrylate, neopentyl glycol dimethacrylate. 2-Hydroxypropyl-1,3-dimethacrylate, 3-Hydroxypropyl-1,2-dimethacrylate, Pentaerythritol dimethacrylate, Glycerine dimethacrylate, Bisphenol-A Glycidyl methacrylate and / or dimethacrylates of dihydroxymethyltricyclo[5.2.1.Contains 02,6]decane, trimethylolpropane trimethacrylate and / or pentaerythritol tetramethacrylate.

[0012] According to the invention, the powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses can contain a polymer with a mean particle diameter of 5 μm to 160 μm as an impact-modified pearl polymer B. This polymer, based on one or more monomers including methyl methacrylate contained in the monomer mixture A, can be a homopolymer, a copolymer, a multipolymer, or a graft polymer, and can also be partially cross-linked or represent another type of polymer.

[0013] According to the invention, the powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses can contain one or more compounds from the groups of reactive polydimethylsiloxanes, reactive liquid rubbers such as vinyl-terminated liquid polymers and oligomers of butadiene and other dienes and comonomers, higher urethane (meth)acrylates, oligo- and polybutadienes and other dienes reactively modified with urethane (meth)acrylates, and / or other reactive elast-based impact modifiers as a reactive impact modifier C.

[0014] According to the invention, the powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses can preferably contain a redox system as initiator system D, in particular based on peroxides, azo compounds, barbituric acids, ascorbic acids, or sulfinic acids.

[0015] According to the invention, the powder-liquid system for the production of hypoallergenic, methyl methacrylate-free dental prostheses can contain one or more compounds from the groups of dimethylpolysiloxanes, aryl-alkyl-modified polysiloxanes, fluorosilicones, silicone-free organic polymers such as polyethers, polyesters, or polyacrylates, as well as mixtures of various substances, as a deaerator E. Compounds known as defoamers can also function as deaerators.

[0016] According to the invention, the powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses can be used with additives F selected from the groups – Polymerization inhibitors, molecular weight regulators, – Dyes, pigments, opaques, UV stabilizers, plasticizers, rheology additives, dispersing additives, antimicrobial additives, – inorganic fillers such as dental glasses, glass ceramics, nanoparticles, silicates and / or silicon dioxide, – as well as other additives.

[0017] According to the invention, the powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses can contain, as a further additive, reactive fibrous reinforcing materials made of silanized glass and / or polymer fibers, preferably silanized ultra-high molecular weight polyethylene, with a fiber length of up to 3 mm.

[0018] According to the invention, the process for producing hypoallergenic methyl methacrylate-free dental prostheses can be carried out by homogeneously mixing the powder and liquid of the powder-liquid system and then producing hypoallergenic methyl methacrylate-free dental prostheses by pressureless curing at temperatures of 10 to 100°C, preferably at temperatures of 15 to 65°C.

[0019] The powder-liquid system according to the invention is particularly suitable for use in dentistry as a denture base resin in the production of hypoallergenic, methyl methacrylate-free dental prostheses. It can be produced in a wide variety of application forms, such as a heat-polymerizable, cold-polymerizable, light-polymerizable, or microwave-polymerizable dental resin.

[0020] It was surprising to find that the powder-liquid system according to the invention for the production of hypoallergenic methyl methacrylate-free dental prostheses leads to denture resins with significantly improved fracture toughness properties through the presorption of compounds of the monomer mixture of component A in the powder of the powder-liquid system. These properties had previously always been critical in dental prostheses made from hypoallergenic methyl methacrylate-free dental materials in the form of powder-liquid systems and frequently led to the fracture of these prostheses. It was particularly surprising that the inventive method yields dental materials which, in addition to improved processing properties and acceptable stiffness properties, exhibit significantly increased fracture toughness not only up to crack initiation but also, and especially, during crack growth.It was also surprising to find that the powder-liquid system can be cured without pressure to produce high-quality, hypoallergenic, methyl methacrylate-free dental prostheses, especially since processing under a pressure of approximately 2 bar is required for commercially available denture base materials.

[0021] The invention will be explained in more detail below using some selected exemplary embodiments. Example 1 (comparative example)

[0022] In this example, a powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses containing a) 54.27 mass percent of a monomer mixture A from – 35.0% by mass hexanediol dimethacrylate – 25.0% by mass diurethane dimethacrylate – 40.0 mass percent bisphenol A glycidyl methacrylate, b) 39.7 mass percent of an impact-modified pearl polymer B (available under the trade name Evident High Impact Polymer from Esschem Europe Ltd.) with a mean particle diameter of 63.5 μm, c) 4.47% by mass of reactive liquid rubber (available under the trade name TE 2000 from Nippon Soda Co.) as reactive impact modifier C, d) 0.773 mass percent of an initiator system D from – 62.53% by mass of 1-benzyl-5-phenylbarbituric acid – 20.84% ​​by mass of 5-n-butylbarbituric acid – 16.48 percent by mass trioctylmethylammonium chloride – 0.15% by mass copper(II) chloride dihydrate, e) 0.744 mass percent of a deaerator E (available under the trade name TEGO Airex 922 from Evonik Industries AG), f) Containing 0.043% by mass of additives F – Butylhydroxytoluene as a polymerization inhibitor, whereby – the powder contains components B and the barbituric acids of the initiator system D, without one or more compounds of component A being pre-absorbed in the powder and – the liquid containing components A, C, E, trioctylmethylammonium chloride and copper(II) chloride dihydrate of the initiator system D and butylhydroxytoluene as additives F, is converted into the hypoallergenic methyl methacrylate-free denture base plastic by homogeneous mixing of powder and liquid using a SpeedMixer (DAC 150.1 from Hauschild Engineering) through polymerization first at room temperature and then at 55°C for 30 minutes.

[0023] At room temperature, the processing time was defined as the time from the start of mixing the components until the first inhomogeneities appear in the liquid mixture, and the hardening time as the time until the entire mixture has hardened.

[0024] To test the mechanical properties of the prosthesis materials, specimens measuring 8 mm × 4 mm × 39 mm were produced according to DIN EN ISO 20795-1. After conditioning for at least one week at room temperature and storage for 24 hours under standard climate conditions, the notched specimens were tested for the total fracture energy W, a property characterizing the fracture toughness of the denture base materials. f until crack initiation at maximum force or total fracture energy W f EThe existing load was reduced to 5% of the maximum load according to DIN EN ISO 20795-1 without water immersion. The stiffness of the denture base materials was characterized on unnotched specimens of the same dimensions by determining the flexural modulus E using Dynamic Mechanical Analysis (DMA) in the temperature range of -20°C to 190°C, with the value given for 25°C. The test results, together with the results of the processing properties, are summarized in Table 1. Table 1 Example Processing time [min] hardening time [min] Biegemodul E (DMA) MPa Total fracture work W f [J / m 2 ] Total fracture work W f E [J / m 2 ] 1 (Comparative example) 3:40 4:10 2445 101,93 119,94 2 4:30 5:00 2160 136,07 186,41 3 13:50 15:50 1995 115,41 149,09 4 (Comparative example) > 20 > 20 1453 85,43 119,44 Example 2

[0025] According to the invention, in this example, a hypoallergenic, methyl methacrylate-free denture base material was produced by pressureless curing using the same impact-modified pearl polymer B with a mean particle diameter of 63.5 μm from Example 1, in accordance with the composition and procedure also specified in Example 1. However, 1.44 wt%, based on 100 wt% of pearl polymer B, of the hexanediol dimethacrylate compound of component A was pre-absorbed in the powder. The processing time, curing time, flexural modulus, and total fracture work of this denture base material were determined analogously to the test conditions of Example 1 and are given in Table 1.

[0026] In contrast to comparison example 1, this example demonstrates the significantly improved fracture toughness of the prosthesis base material both up to the point of crack initiation and especially during crack growth, while simultaneously improving processing and hardening times and achieving acceptable stiffness properties (flexural modulus) of the dental material through the presorption of a compound of component A in the powder. Example 3

[0027] According to the invention, in this example, a hypoallergenic, methyl methacrylate-free denture base material was produced by pressureless curing using the same impact-modified pearl polymer B with a mean particle diameter of 63.5 μm from Example 1, according to the composition and procedure also specified in Example 1. However, 2.87 wt%, based on 100 wt% of pearl polymer B, of the hexanediol dimethacrylate compound of component A was pre-absorbed in the powder. The processing time, curing time, flexural modulus, and total fracture work of this dental material were determined analogously to the test conditions of Example 1 and are given in Table 1.

[0028] In contrast to example 1, this example also demonstrates the significantly improved fracture toughness of the denture base material both up to the point of crack initiation and especially during crack growth, while simultaneously providing sufficient processing and hardening times and acceptable stiffness properties (flexural modulus) of the dental material through the presorption of hexanediol dimethacrylate in the powder. Example 4 (comparative example)

[0029] In this example, using the same impact-modified pearl polymer B from Example 1, an amount of 5.74% by mass (based on 100% by mass of pearl polymer B) of hexanediol dimethacrylate was pre-absorbed as a compound of component A in the powder. Following the composition and procedure also specified in Example 1, a hypoallergenic, methyl methacrylate-free denture base material was produced by pressureless curing. The processing time, curing time, flexural modulus, and total fracture work of this dental material were determined analogously to the test conditions of Example 1 and are listed in Table 1.

[0030] This non-inventive procedure did not result in improved fracture toughness properties of the prosthesis base material, especially since, in addition to undesirably long processing and hardening times, a significant decrease in the stiffness properties (flexural modulus) of the dental material also occurred. Example 5

[0031] In this example, a powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses containing a) 54.27 mass percent of a monomer mixture A from – 35.0% by mass hexanediol dimethacrylate – 22.08% by mass diurethane dimethacrylate – 35.34 percent by mass of bisphenol A glycidyl methacrylate – 7.58% by mass Exothane 8 (a urethane-based dimethacrylate from Esschem Europe Ltd.), b) 39.0 mass percent of an impact-modified pearl polymer B (available under the trade name Evident High Impact Polymer from Esschem Europe Ltd.) with a mean particle diameter of 63.5 μm, c) 4.47% by mass of reactive liquid rubber (available under the trade name TE 2000 from Nippon Soda Co.) as reactive impact modifier C, d) 0.773 mass percent of an initiator system D from – 62.53% by mass of 1-benzyl-5-phenylbarbituric acid – 20.84% ​​by mass of 5-n-butylbarbituric acid – 16.48 percent by mass trioctylmethylammonium chloride – 0.15% by mass copper(II) chloride dihydrate, e) 0.744 mass percent of a deaerator E (available under the trade name TEGO Airex 922 from Evonik Industries AG), f) 0.743% by mass of additives F from – 94.2% by mass of silanized ultra-high molecular weight polyethylene (UHMWPE short cut fiber from Hercules High Performance Materials Co., Ltd.) with a fiber length of 0.5 mm as a reactive fibrous reinforcement material – 5.8% by mass of butylhydroxytoluene as a polymerization inhibitor, wherein – the powder contains components B and the barbituric acids of the initiator system D, and 1.46% by mass, based on 100% by mass of the pearl polymer B, of the hexanediol dimethacrylate as a compound of component A were pre-absorbed in the powder and – the liquid containing components A, C, E, trioctylmethylammonium chloride and copper(II) chloride dihydrate of the initiator system D and the silanized ultra-high molecular weight polyethylene fibers as well as butylhydroxytoluene as additives F, is converted into the hypoallergenic methyl methacrylate-free denture base plastic by homogeneous mixing of powder and liquid using a SpeedMixer (DAC 150.1 from Hauschild Engineering) through polymerization first at room temperature and then at 55°C for 30 minutes without pressure.

[0032] The processing properties (processing time and hardening time) and the mechanical properties (flexural modulus E and fracture toughness as total fracture work W) were determined for this fiber-reinforced prosthesis base material analogously to the procedure and test conditions of Example 1. f and W f E determined and shown in Table 2. Table 2 Example Processing time [min] hardening time [min] Biegemodul (DMA) MPa Total fracture work W f [J / m 2 ] Total fracture work W f E [J / m 2 ] 5 6:00 7:00 3046 128,12 370,51 6 8:10 9:10 2891 124,83 296,47 Example 6

[0033] A powder-liquid system for the production of hypoallergenic, methyl methacrylate-free dental prostheses containing a) 52.7 mass percent of a monomer mixture A from – 35.0% by mass hexanediol dimethacrylate – 25.0% by mass diurethane dimethacrylate – 40.0 mass percent bisphenol A glycidyl methacrylate, b) 37.98 mass percent of an impact-modified pearl polymer B (available under the trade name Evident High Impact Polymer from Esschem Europe Ltd.) with a mean particle diameter of 63.5 μm, c) 4.34% by mass of reactive liquid rubber (available under the trade name TE 2000 from Nippon Soda Co.) as reactive impact modifier C, d) 0.75 mass percent of an initiator system D from – 62.53% by mass of 1-benzyl-5-phenylbarbituric acid – 20.84% ​​by mass of 5-n-butylbarbituric acid – 16.48 percent by mass trioctylmethylammonium chloride – 0.15% by mass copper(II) chloride dihydrate, e) 0.722 mass percent of a deaerator E (available under the trade name TEGO Airex 922 from Evonik Industries AG), f) 3.508% by mass of additives F from – 16.48 mass percent silanized ultra-high molecular weight polyethylene (UHMWPE short cut fiber from Hercules High Performance Materials Co., Ltd.) with a fiber length of 0.5 mm as a reactive fibrous reinforcement material – 1.18% by mass of butylhydroxytoluene as a polymerization inhibitor – 82.34% by mass of highly dispersed silicon dioxide (available under the trade name HDK H 2000 from Wacker Silicones), wherein – the powder contains components B and the barbituric acids of the initiator system D, as well as the silanized ultra-high molecular weight polyethylene fibers and the highly dispersed silicon dioxide of the additives F, and 1.46% by mass, based on 100% by mass of the pearl polymer B, of the hexanediol dimethacrylate as a compound of component A were pre-absorbed in the powder and – the liquid containing components A, C, E, trioctylmethylammonium chloride and copper(II) chloride dihydrate of the initiator system D and butylhydroxytoluene as additives F, was converted into the hypoallergenic methyl methacrylate-free denture resin by homogeneous mixing of the free-flowing powder and the liquid using a SpeedMixer (DAC 150.1 from Hauschild Engineering) by polymerization first at room temperature and then at 55°C for 30 minutes without pressure.

[0034] Analogous to the procedure and test conditions of Example 1, the processing properties processing time and hardening time, as well as the mechanical properties of the flexural modulus E and the fracture toughness as total fracture work W, were determined for this fiber-reinforced prosthesis base material. f and W f E determined and shown in Table 2.

[0035] Examples 5 and 6 demonstrate the very good fracture toughness of the hypoallergenic methyl methacrylate-free denture materials produced by pressureless curing, both up to the point of crack initiation and especially during crack growth, while simultaneously exhibiting good processing properties, processing and curing time, and good stiffness properties according to the inventive method. Example 7 (comparative example)

[0036] Alldent Sinomer Kalt N from Novodent Ets., Eschen, LI, was used as a commercially available, cold-curing, methyl methacrylate-free denture material containing polymethyl methacrylate as a bead polymer and formulated as a powder / liquid for the fabrication of hypoallergenic, methyl methacrylate-free dental prostheses. It was processed according to the manufacturer's enclosed instructions, the processing and curing times were determined, and corresponding test specimens measuring 8 mm × 4 mm × 39 mm were prepared according to DIN EN ISO 20795-1. After at least one week of conditioning at room temperature and 24 hours of storage under standard climate conditions, the notched test specimens were tested for the total fracture energy W, a property characterizing the fracture toughness of the denture base resins. f until crack initiation at maximum force or total fracture energy W f EThe existing load was reduced to 5% of the maximum load according to DIN EN ISO 20795-1 without water immersion. The stiffness of the denture base materials was characterized on unnotched specimens of the same dimensions by determining the flexural modulus E using Dynamic Mechanical Analysis (DMA) in the temperature range of -20°C to 190°C, with the value given for 25°C. The test results for the resulting denture base resin are summarized in Table 3. Table 3 Example Processing time [min] hardening time [min] Biegemodul E (DMA) MPa Total fracture work W f [J / m 2 ] Total fracture work W f E [J / m 2 ] 7 24 26 2850 94,98 113,03 (Comparative example) 8 7:20 8:20 2423 139,81 318,93 Example 8

[0037] In this example, a powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses containing a) 53.69 mass percent of a monomer mixture A from – 36.52% by mass hexanediol dimethacrylate – 22.98% by mass diurethane dimethacrylate – 36.74 percent by mass of bisphenol A glycidyl methacrylate – 3.76% by mass Exothane 8 (a urethane-based dimethacrylate from Esschem Europe Ltd.), b) 38.41 mass percent of an impact-modified pearl polymer B (available under the trade name Evident High Impact Polymer from Esschem Europe Ltd.) with a mean particle diameter of 63.5 μm, c) 3.41% by mass of reactive liquid rubber (available under the trade name TE 2000 from Nippon Soda Co.) as reactive impact modifier C, d) 0.796 mass percent of an initiator system D from – 62.53% by mass of 1-benzyl-5-phenylbarbituric acid – 20.84% ​​by mass of 5-n-butylbarbituric acid – 16.48 percent by mass trioctylmethylammonium chloride – 0.15% by mass copper(II) chloride dihydrate, e) 0.974 mass percent of a deaerator E (available under the trade name TEGO Airex 922 from Evonik Industries AG), f) 2.720% by mass of additives F from – 21.41 mass percent silanized ultra-high molecular weight polyethylene (UHMWPE short cut fiber from Hercules High Performance Materials Co., Ltd.) with a fiber length of 0.5 mm as a reactive fibrous reinforcement material – 1.54% by mass of butylhydroxytoluene as a polymerization inhibitor – 60.67% by mass of highly dispersed silicon dioxide (available under the trade name HDK H 2000 from Wacker Silicones) – 8.92% by mass Chisorb 327 (Double Bond Chemicals Ind. Co., Ltd.) – 7.14 mass percent Doubletex OB (Double Bond Chemicals Ind. Co., Ltd.) – 0.32 mass percent Colortherm Red 140 M (Harold Scholz & Co. GmbH), wherein – the powder contains components B and the barbituric acids of the initiator system D, as well as Colortherm Red 140 M and the highly dispersed silicon dioxide of the additives F, and 1.44% by mass, based on 100% by mass of the pearl polymer B, of the hexanediol dimethacrylate as a compound of component A were pre-absorbed in the powder and – the liquid containing components A, C, E, trioctylmethylammonium chloride and copper(II) chloride dihydrate of the initiator system D, as well as Chisorb 327, Doubletex OB, the silanized ultra-high molecular weight polyethylene fibers and butylhydroxytoluene as additives F, is converted into the hypoallergenic methyl methacrylate-free denture base plastic by homogeneous mixing of the free-flowing powder and the liquid using a SpeedMixer (DAC 150.1 from Hauschild Engineering) through polymerization first at room temperature and then at 55°C for 30 minutes without pressure.

[0038] The processing properties (processing time and hardening time) and the mechanical properties (flexural modulus E and fracture toughness as total fracture work W) were determined for this prosthesis base material analogously to the procedure and test conditions of example 7. f and W f E determined and shown in Table 3.

[0039] Example 8 shows, in comparison to the commercially available hypoallergenic methyl methacrylate-free dental material of comparison example 7, the very good fracture toughness of the produced hypoallergenic methyl methacrylate-free denture materials both up to the point of crack initiation and especially during crack growth, as well as the significantly improved processing properties, processing and hardening time with good stiffnesses due to the method according to the invention. QUOTES INCLUDED IN THE DESCRIPTION

[0040] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0041] DE 102008058039

[0004] EP 1214042

[0005] DE 102012022693

[0006] Cited non-patent literature

[0042] DIN EN ISO 20795-1

[0002] M Braden, RL Clarke, J Nicholson, S Parker. Polymeric Dental Materials. Springer-Verlag Berlin Heidelberg New York 1997, p. 56

[0003] DIN EN ISO 20795-1

[0024] DIN EN ISO 20795-1

[0024] DIN EN ISO 20795-1

[0036] DIN EN ISO 20795-1

[0036]

Claims

[1] Powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses, characterized by that the powder of the powder-liquid system contains part of one or more compounds of a monomer mixture A consisting of mono- and / or multifunctional methacrylates, excluding methyl methacrylate, in pre-absorbed form. [2] Powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses according to claim 1, characterized by that it contains a) 30 to 65 percent by mass of a monomer mixture A consisting of mono- and / or multifunctional methacrylates, excluding methyl methacrylate, b) 65 to 25 percent by mass of an impact-modified pearl polymer B based on one or more monomers contained in the monomer mixture A, including methyl methacrylate, c) 0.1 to 8 mass percent of a reactive impact modifier C, d) 0.2 to 3 mass percent of an initiator system D, e) 0.1 to 4 mass percent of a vent E, f) 0.005 to 15 percent by mass of additives F, where – the powder contains component B, parts of the initiator system D and parts of additives F and 0.1 to 5.0 mass percent, based on 100 mass percent of component B, of one or more compounds of component A are pre-absorbed in the powder and – the liquid contains components A, C, E, parts of the initiator system D and parts of additives F. [3] Powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses according to at least one of the preceding claims, characterized bythat the monomer mixture A contains mono- and / or multifunctional methacrylates selected from the group of monomers ethyl methacrylate, butyl methacrylate, benzyl methacrylate, tetrahydrofurfuryl methacrylate, isobornyl methacrylate, phenyl methacrylate, ethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, triethylene glycol dimethacrylate, 1,10-decanediol dimethacrylate, 1,12-dodecanediol dimethacrylate, ethoxylated bisphenol A dimethacrylates, polyethylene glycol dimethacrylates, urethane dimethacrylates, higher molecular weight urethane dimethacrylates such as Exothane, butanediol dimethacrylate, tetraethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 2-hydroxypropyl-1,3-dimethacrylate, 3-hydroxypropyl-1,2-dimethacrylate, pentaerythritol dimethacrylate, Glycerine dimethacrylate, bisphenol-A glycidyl methacrylate and / or dimethacrylates of dihydroxymethyltricyclo[5.2.1.02,6]decane, trimethylolpropane trimethacrylate and / or pentaerythritol tetramethacrylate. [4] Powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses according to at least one of the preceding claims, characterized by that the impact-modified pearl polymer B has a mean particle diameter of 5 μm to 160 μm. [5] Powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses according to at least one of the preceding claims, characterized by that the reactive impact modifier C contains one or more compounds from the groups of reactive polydimethylsiloxanes, reactive liquid rubbers such as vinyl-terminated liquid polymers and oligomers of butadiene and other dienes and comonomers, higher urethane (meth)acrylates, oligo- and polybutadienes and other dienes reactively modified with urethane (meth)acrylates, and / or other reactive elast-based impact modifiers. [6] Powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses according to at least one of the preceding claims, characterized by that the initiator system D preferably contains a redox system, in particular based on peroxides, azo compounds, barbituric acids, ascorbic acids, or sulfinic acids. [7] Powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses according to at least one of the preceding claims, characterized by that the vent E contains one or more compounds from the groups of dimethylpolysiloxanes, aryl-alkyl-modified polysiloxanes, fluorosilicones, silicone-free organic polymers such as polyethers, polyesters or polyacrylates, as well as mixtures of various substances. [8] Powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses according to at least one of the preceding claims, characterized bythat the additives G are selected from the groups – Polymerization inhibitors, molecular weight regulators, – Dyes, pigments, opaques, UV stabilizers, plasticizers, rheology additives, dispersing additives, antimicrobial additives, – inorganic fillers such as dental glasses, glass ceramics, nanoparticles, silicates and / or silicon dioxide, – as well as other additives. [9] Powder-liquid system for the production of hypoallergenic methyl methacrylate-free dental prostheses according to at least one of the preceding claims, characterized by that, as another additive, reactive fibrous reinforcing materials made of silanized glass and / or polymer fibers, preferably silanized ultra-high molecular weight polyethylene, with a length of up to 3 mm, are included. [10] Method for the production of hypoallergenic methyl methacrylate-free dental prostheses, characterized bythat the powder and liquid of the powder-liquid system according to at least one of the preceding claims are homogeneously mixed and hypoallergenic methyl methacrylate-free dental prostheses are subsequently produced from this mixture by pressureless curing at temperatures of 10 to 100°C, preferably at temperatures of 15 to 65°C.