Dental materials based on polymerizable waxes

The present invention relates to dental materials based on polymerizable waxes which are particularly suitable as materials for temporary and permanent dental prostheses, inlays and crowns.

The term wax is a collective term for a series of natural and artificial materials. In general, hereunder means materials that are already below their melting or softening easily plastically deformable, a translucent have to opaque appearance, above 40 ° C. without decomposition melt and already little result above the melting point relatively low viscosity liquids and which have a highly temperature-dependent consistency and solubility. In addition, waxes can usually be polished under light pressure (Ullmann's Encyclopedia of Industrial Chemistry, 4th Edition, Volume 24, Verlag Chemie, Weinheim 1989).

In dentistry waxes are used as modeling, casting, or bite or adhesive wax application. Here almost exclusively mixtures of natural and synthetic waxes are used, wherein the physical characteristics of the wax on the desired use set (K. Körber, K. Ludwig, Dental Materials and Technology, G. Thieme Verlag, Stuttgart 1982, p 90) , For example, should a suitable modeling of moldings modeling have a perfect formability at mouth temperature the best possible form of resistance. For this purpose, suitable are mixtures of paraffinic, stearic, Japan and beeswax.

Conventional waxes are heated to processing in general. The curing takes place by the solidification of the wax during the subsequent cooling. This usually occur in relatively large, uncontrollable volume changes. Furthermore, conventional waxes have the disadvantage that they break easily when removed from the model and deform even under relatively low mechanical and especially thermal stress.

To avoid these disadvantages blends of natural and partially or fully synthetic waxes with polymerizable monomers or oligomers, such as polyfunctional acrylates and methacrylates are used recently. These mixtures can be selectively harden after processing and then have a higher mechanical stability than the pure waxes.

For example, 4748 (CA 120 (1993) 136156) are and JP-A-91/330047 (CA 119 (1993) 282306) mixtures of polyethylene waxes with styrene or acrylate monomers disclosed in JP-A-92 /. Further described in the dental field on the basis of mixtures of natural or synthetic waxes with conventional acrylic compounds and photoinitiators in JP-A-90/312256 (CA 128 (1992) 27523) photopolymerizable waxes. A disadvantage of these mixtures is that conventional dental waxes and dental Vernetzermonomere mix poorly with each other and that, in particular, the wax is not incorporated into the polymer during the polymer network. It may therefore come to the formation of wax domains, ie it forms a multiphase system, its mechanical strength is correspondingly low.

EP-B-0110193 discloses wax-free wax substitutes for producing casting models. These compositions are based on mixtures of di- or poly-functional methacrylic or acrylic acid esters, a photoinitiator and optionally a photoactivator as well as organic fillers. Due to the composition of the invention claimed in EP-B-0110193, these materials exhibit no wax-like properties, that is, the materials such as waxes can not be modeled and accordingly, the dental technician must replace the usual wax technique by a complicated layer technique. In this case, changes or corrections of the model can not be made because after application of the respective layer is carried out by its curing polymerization. Moreover, in this process has the disadvantage that thin layers can be produced only acrylic acid esters having at or unfilled blends of di- or polyfunctional (meth) in the polymerization thereof, there is a considerable volume contraction.

EP-B-0380116 discloses mixtures which contain, in addition to influence the expansion behavior of the molding compositions in the range above 150 ° C, an organic compound having a boiling point and / or a sublimation point, which do not react with the organic polymerizable mass. Said compositions are characterized in particular by the fact that they are burns without residue.

The US Patent 5,403,188 discloses thermoplastic molding compositions which are suitable for producing dental castings. The compositions comprise a polymeric thermoplastic material, preferably a polycaprolactone, a polymerizable resin, an initiator, and optionally a filler. They are at 38 ° C fixed and practically non-deformable and are heated for processing. Curing takes place then by cooling. After forming of the impression the masses are additionally cured by a radical polymerization. The materials have the disadvantage that they melt only to highly viscous products. A dental molding is extremely difficult, because the materials are not the tough-viscous but also very sticky when molten.

The object of the invention is the provision of waxy dental materials which do not have the disadvantages mentioned above and also particularly suitable for producing temporary and permanent prostheses.

The object is achieved by dental materials based on polymerizable waxes which<ul><li>a) 0 to 70 wt .-%, preferably 5 to 70 wt .-%, particularly preferably 5 to 60 wt .-% and very particularly preferably 20 to 50 wt .-% of at least one polymerizable monomer and / or oligomer;</li><li>b) 0.1 to 5 wt .-%, preferably 0.2 to 2.0 wt .-% of at least one polymerization initiator;</li><li>c) 0 to 60 wt .-%, preferably 0 to 50 wt .-% and particularly preferably 0 to 30 wt .-% fillers; and</li><li>d) at least 20 wt .-%, preferably at least 40 wt .-% of a waxy substance polymerizable</li></ul> contain.

Suitable polymerizable monomers and oligomers are known for example from DE-C-3941629 or DE-A-4029230. Preferably, crosslinking compounds, such as di-, tri- or tetraethylene glycol di (meth) acrylate, decanediol di (meth) acrylate, bisphenol A di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, 2,2- bis (4-methacryloyloxy-2-hydroxypropoxy) phenylpropane (bis-GMA) and the reaction product of 1 mole of 2,2,4-trimethylhexamethylene diisocyanate with 2 moles of 2-hydroxyethyl (meth) acrylate and mixtures of these monomers.

Suitable polymerization initiators are known eg from DE-A 4,029,230. Preferred initiators are camphorquinone, 9,10-phenanthrenequinone or diacetyl. The polymerization initiators may be combined with a suitable reducing agent beyond. For this purpose, especially 4-Dimethylaminobenzoesäureester, N, N 'are - (2-cyanoethyl) methylaniline, triethanolamine, or 2- (dimethylamino) ethyl methacrylate.

The dental materials of the invention can be up to 60 wt .-% fillers, although dental materials are preferred with little or no filler. The fillers are used to increase the mechanical strength, to reduce the polymerization shrinkage and to control viscosity. Preferred fillers are for example known from DE-C-3941629. Particularly preferred fillers are in the form of amorphous spherical materials based on mixed oxides of SiO₂, ZrO₂ and / or TiO₂Microfine fillers such as pyrogenic silica or precipitated silica as well as macro- or mini fillers such as quartz, glass ceramic or glass powder.

As a waxy polymerizable substances such substances are preferred which represent a long-chain carboxylic acid, a carboxylic acid derivative, an OH-functionalized compound and / or a derivative of an OH-functional compound and having one or more polymerizable groups. Preferred carboxylic acid derivatives are the esters with polymerizable alcohols, preferred alcohols are OH-functionalized compounds. As derivatives of the OH-functionalized compounds, the esters with polymerizable carboxylic acid derivatives are preferred. The waxy polymerizable substances are preferably used in monomeric form.

Suitable wax-like polymerizable substances are commercially available in some cases, such as stearyl (melting point 23 ° C, from Christ Chem.), PEG 1000 dimethacrylate (melting point 20 ° C) and PEG-4000 diacrylate (melting point 52 ° C, both Polysciences, Inc.), or can be prepared by chemical modification of suitable carboxylic acids and alcohols.

For this purpose, carboxylic acids having a melting point of about 60 ° C, in particular those are preferred having a chain length of 16 to 32 carbon atoms. Most particularly preferred are palmitic acid (melting point: 64 ° C), stearic acid (melting point: 69 ° C), eicosanoic (C₂₀H₄₀O₂; Melting point: 74-76 ° C), docosanoic (C₂₂H₄₄O₂; Melting point: 80-82 ° C), tricosanoic (C₂₃H₄₆O₂; Melting point: 75-83 ° C), hexacosanoic (C₂₆H₅₂O₂; Melting point: 87-89 ° C), heptacosanoic (C₂₇H₅₄O₂; Melting point: 88-89 ° C) or octacosanoic (C₂₈H₅₆O₂; Melting point: 61-63 ° C). Mixtures of these carboxylic acids are also suitable. Mixtures of palmitic or stearic acid with Hexacosan- or heptacosanoic are. A particularly suitable starting material for the production of waxy polymerizable substances of the invention is the Hoechst-Wachs S (Hoechst, melting point 80 ° C), comprising a mixture of long-chain aliphatic carboxylic acids (C₁₆ -C₃₆) Represents.

As alcohols, long-chain alcohols having a melting point of above 55 ° C as Augangsmaterialien for the preparation of the polymerizable wax-like substances are preferred, especially those having a chain length of 18 to 32 carbon atoms. Very particularly preferred are 1,2-octadecanediol (C₁₈H₃₈O₂; Melting point: 74-76 ° C), 1-eicosanol ((C₂₀H₄₁OH; Melting point: 64-66 ° C), 1-docosanol (C₂₂H₄₅OH; Melting point: 65-72 ° C) or 1-hexacosanol (C₂₆H₅₃OH; Melting point: 79-81 ° C), and Hoechst-Wachs KST (Hoechst, melting point 57-59 ° C; based on OH-terminated polyethylene oxide).

Based on the foregoing waxy carboxylic acids is carried out, the introduction of polymerizable groups, preferably by reaction with suitable unsaturated compounds, especially vinyl halides, (meth) acrylic or allyl compounds, according to the known methods of organic chemistry. Polymerizable methacrylate groups can be introduced, for example, by activation of the COOH groups eg with chloroformate by the mixed anhydride method in a one-pot reaction by reacting with 2-hydroxyethyl methacrylate (HEMA), hydroxypropyl methacrylate or glycerol (GDMA). Moreover, the introduction of methacryloyl groups also by direct reaction of carboxylic acids with waxy methacrylic acid-2,3-epoxypropyl ester (GMA) can take place.

Based on the foregoing waxy OH-functionalized compounds introducing polymerizable groups such as methacrylic example by their simple azeotropic esterification with methacrylic acid or by acylation with methacrylic acid or methacrylic anhydride is possible. Furthermore, the reaction of the OH-functionalised compounds with 2-isocyanatoethyl methacrylate (IEMA) is particularly suitable.

Similarly, the COOH or OH-functionalized waxy starting compounds can also be reacted with other suitable unsaturated compounds, so that introduced other groups capable of polymerization, such as acrylic, allyl, vinyl, vinyl ether or styryl groups instead of methacryl radicals will. Suitable reagents are for example 2-hydroxyethyl acrylate, acrylic acid, acrylic acid chloride, allyl alcohol, 3-buten-1-ol, 2-hydroxyethyl vinyl ether, 4-hydroxymethylstyrene, or 4-vinyl benzoic acid. As of polymerization ähige groups are preferably methacrylate, acrylate and styryl.

To prepare the dental materials according to the invention, the starting materials are mixed in the amounts indicated. Besides the components mentioned, the dental materials can contain further substances such as pigments or dyes. In addition, mixtures of different wax-like polymerizable substances can be used.

The dental materials of the invention have a waxy consistency, ie they are at room or body temperature kneadable ductile to hard and can be modeled in the non-polymerised state without additional heating as conventional waxes, plastically deform or edit differently nondestructively. They show an opaque to partially translucent appearance and can be polished under light pressure. Above about 40 ° C to give low viscosity, droppable melts which are not prone to fiber formation.

After modeling the materials can be cured by polymerization. Curing takes place preferably by photopolymerization. The necessary for initiating the photopolymerization wavelength of light depends on the photoinitiator used, in which photoinitiators are preferred with an excitation wavelength in the wavelength range of 390 to 500 nm. The photopolymerization can be carried out stepwise with increasing temperatures, ie first the dental material is at room temperature cured by irradiation and then continued in the temperature range of about 40 to 80 ° C, whereby the strength of the materials is increasing.

A particular advantage of the waxy polymerizable substances of the invention is that they are characterized by a low polymerization, which is very advantageous for the dimensional stability of the overall material. The pure polymerizable waxes preferably have a polymerization shrinkage of not more than 2.2 vol .-%, whereas, for example methyl methacrylate, which is the monomer component of most prosthetic materials, has a volume shrinkage of 20.7 vol .-%.

The wax component is covalently incorporated during polymerization in the polymer formed, so that a single-phase system is formed. Therefore, the cured dental materials exhibit after polymerization, at a much greater strength than known wax-containing materials. By combining the waxy polymerizable substances of the invention with other, preferably crosslinking monomers dental materials can be prepared by the polymerization of the modulus of elasticity of conventional polymethylmethacrylate (PMMA -) - get close materials. Thus, a preferred dental material from 66.3 wt .-% Wachsmonomer, 32.9 wt .-% of pentaerythritol tetraacetate and 0.8 wt .-% photoinitiator combination according to the polymerization of a modulus of elasticity of about 1.9 GPa.

The dental materials of the invention show a much higher resistance to oral than conventional materials and are therefore suitable, in contrast to known materials also for the production of temporary and permanent prostheses.

The dental materials according to the invention allow a considerable simplification of the manufacturing process such as full dentures. So far, it is common in the production of full dentures, first to prepare a wax prosthesis which is adapted to the patient's mouth. Once the result is satisfactory, the wax prosthesis is transferred via the "Lost Wax technique" in a permanent prosthesis PMMA. This additional step can be avoided when using the dental materials according to the invention, since the prosthesis can be polymerized and worked directly after the adjustment. This means a substantial reduction in the workload and thus the costs incurred in the production of prostheses costs.

Another field of dental materials according to the invention lies in the production of temporary crowns, bridges and inlays. The dental materials of the invention can be adapted to the tooth stump machined because of their good formability in the patient's mouth, wherein the material can be formed simply by scraping, and then hardened by polymerization. For reinforcement of bridges in particular reinforcements can be used in the material prior to polymerization.

<b>Examples</b>

Example 1: Synthesis of polymerizable waxes by esterification of Hoechst wax S with HEMA

A mixture of 70 g Hoechst-Wachs S (186.7 mmol), 22.6 g of collidine (186.7 mmol), 20.3 g of ethyl chloroformate (186.7 mmol) and 1000 ml of toluene is the absence of moisture at 60 h 72 C. stirred. Man giving 24.4 g HEMA (186.7 mmol) and some p-toluene sulfonic acid as catalyst, and then stirred for 3 days at 60 ° C. Thereafter, the reaction mixture is filtered at 60 ° C, leaving the filtrate for 12 hours in the refrigerator at 4 ° C, whereby a voluminous white precipitate is formed, the above after separating and washing with slightly acidified water and with ethanol in a desiccator anhydrous CaCl₂ is dried. There are about 60 g (70% yield) of a waxy solid (Melting range: 47 - 61 ° C, determined by differential scanning calorimetry (DSC)).

The viscosity of the wax is above the melting range from about 0.5 Pa · s (measured at 85 ° C; from about 61 ° C, the viscosity not more significantly with temperature).

The evaluation of the ¹H-NMR spectrum shows that 48% of the COOH groups are esterified with HEMA.<ul><li>¹H-NMR (CDCl₃): Δ = 5.6 and 6.2 (2s, C =<u>H</u>₂), 4.3 (t, C<u>H</u>₂O), 2.2 (t, C<u>H</u>₂COO), 1.9 (s, C<u>H</u>₃) And 1.2 to 1.4 ppm (broad, C<u>H</u>₂).</li></ul>

Example 2: Synthesis of a polymerizable wax by esterification of Hoechst wax S with GDMA

is prepared analogously to Example 1, a mixture of 140 g of Hoechst wax S (373.4 mmol), 45.2 g of collidine (373.4 mmol), ethyl chloroformate 40.5 g (373.4 mmol) and 1000 ml of toluene with 85 , 2 g (373.4 mmol) GDMA implemented. After working 80 g (yield 50%) of a waxy solid (melting point 55 - 70 ° C).<ul><li>¹H-NMR (CDCl₃): Δ = 5.6 and 6.2 (2s, C =<u>H</u>₂), 4.0 to 4.5 (m, C<u>H</u>₂O and C<u>H</u>O), 2.2 (t, C<u>H</u>₂COO), 1.9 (s, C<u>H</u>₃) And 1.2 to 1.6 ppm (broad, C<u>H</u>₂).</li><li>IR (film): 3450 (OH), 2918 (CH), 1737 (C = O), 1638 (C = C) and 1171 cm^-1(CO).</li></ul>

Example 3: Synthesis of a polymerizable wax by reaction of Hoechst wax S with GMA

A mixture of 40 g (0.11 mol) of Hoechst wax S, 44.6 g (0.31 mol) of GMA, 0.7 g of 1,4-diazabicyclo [2.2.2] octane and 600 ml of toluene is 5 days stirred at 65 ° C. After concentration of the mixture to about 200 ml, the mixture is allowed to stand overnight in a refrigerator. The precipitate formed is filtered, washed with some acidified water and with ethanol and then in a desiccator over anhydrous CaCl₂ dried. This results in approximately 51 g (yield: nearly 100%) of a waxy solid (mp: 40-67 ° C by DSC). The evaluation of the¹H-NMR spectrum shows that 90% of the COOH groups have reacted with GMA.<ul><li>¹H-NMR (CDCl₃): Δ = 5.8 and 6.3 (2s, C =<u>H</u>₂), 4.3 to 4.7 (m, HOC<u>H</u>-C<u>H</u>₂), 2.4 to 2.6 (m, C<u>H</u>₂-C = O), 2.2 (s, C<u>H</u>₃) And 1.9 to 2.1 ppm (broad, C<u>H</u>₃).</li><li>IR (film): 3368 (OH), 2927 (CH), 1719 (C = O) and 1638 cm^-1 (C = C).</li></ul>

Example 4 Synthesis of a polymerizable wax by reacting octadecane-1,2 with IEMA

7.8 g (50.3 mmol) of IEMA to a solution of 7.4 g (25.6 mmol) 1,2-octadecanediol and 20 mg Metatin 812 added dropwise in 80 ml THF such that the temperature is not 26 ° C exceeds. After five days of stirring, the solvent is removed by vacuum distillation, whereby 14.6 g (yield: 97%) of a waxy solid (mp 42 ° C).<tables id="tabl0001" num="0001"><table frame="all"><tgroup cols="5" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="31.50mm" /><colspec colnum="2" colname="col2" colwidth="31.50mm" /><colspec colnum="3" colname="col3" colwidth="31.50mm" /><colspec colnum="4" colname="col4" colwidth="31.50mm" /><colspec colnum="5" colname="col5" colwidth="31.50mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" morerows="1" rowsep="1" align="left">C₃₂H₅₆N₂O_8th (596.8)</entry><entry namest="col2" nameend="col2" align="left">Ber .:</entry><entry namest="col3" nameend="col3" align="char" char=",">C 64.42</entry><entry namest="col4" nameend="col4" align="char" char=",">H 9.53</entry><entry namest="col5" nameend="col5" align="char" char=",">N 4.65</entry></row><row><entry namest="col2" nameend="col2" align="left">Gef .:</entry><entry namest="col3" nameend="col3" align="char" char=",">C 64.38</entry><entry namest="col4" nameend="col4" align="char" char=",">H 9.41</entry><entry namest="col5" nameend="col5" align="char" char=",">N 4.61</entry></row></tbody></tgroup></table></tables><ul><li>¹H-NMR (CDCl₃): Δ = 5.6 and 6.1 (2s, C =<u>H</u>₂), 5.0 (m,&gt; C<u>H</u>O), 4.2 (t, C<u>H</u>₂O), 3.5 (t, C<u>H</u>₂N), 1.9 (s, C<u>H</u>₃) And 1.1 to 1.3 ppm (broad, C<u>H</u>₂).</li><li>IR (film): 3365 (NH), 2835 (CH), 1720 (C = O) and 1637 cm^-1 (C = C).</li></ul>

Example 5: Synthesis of a polymerizable wax by reaction of Hoechst wax KST with IEMA

A solution of 15 g (10 mmol) of Hoechst wax KST, 2.1 g (20 mmol) of IEMA and 2 drops of di-n-octyltindilaurate as a catalyst (Metatin 812, Acima company AG) in 225 ml of toluene for 3 days at 60 C. stirred. After concentrating the solution to 80 ml in a vacuum is allowed to stand, the mixture in the refrigerator overnight. The precipitate formed is filtered, washed with some acidified water and with ethanol and then in a desiccator over anhydrous CaCl₂ dried. This results in 6.7 g (yield: 45%) of a waxy solid (mp 45 ° C). The evaluation of the¹H-NMR spectrum shows that the OH groups were almost quantitatively reacted with IEMA.<ul><li>¹H-NMR (CDCl₃): Δ = 5.7 and 5.0 (2s, C =<u>H</u>₂), 5.0 (broad, N<u>H</u>), 4.3 (t, C<u>H</u>₂O), 3.6 (broad, C<u>H</u>₂), 3.5 (m, C<u>H</u>₂N), 2.0 ppm (s, C<u>H</u>₃).</li><li>IR (KBr): 2918, 2849 (CH), 1737 (C = O) and 1637 cm^-1 (C = C).</li></ul>

Example 6: bulk of waxy monomers

The 2 g waxy monomer from the above examples are mixed with 10 mg dibenzoyl. which during the heating from room temperature to 200 ° C (10 ° C / min) resulting polymerization enthalpy is then determined by DSC. Based on the polymerization enthalpy of lauryl methacrylate as a standard is obtained for the waxes of Examples 1 and 4, a complete C = C-sales, while for the waxes of Examples 2, 3 and 5, a C = C-turnover of 78 69 or 42 mol% results. The C = C revenues show that let the methacrylate monomers polymerize the waxy radically. Moreover, it was determined from the difference of the densities of certain pycnometrically Wachsmonomer and polymer takes place during the polymerization volume shrinkage (Δ-V). The Δ V values ​​range from minimal - 0.7 vol .-% (monomer of Example 2) and a maximum of - 2.2 vol .-% (monomer of Example 4).

Example 7: Formulations and properties of waxy dental materials based on waxy monomers

Means a 3-roll mill the dental materials listed in Table 1 are prepared (all amounts indicated in wt .-%).

From the dental materials specimens are then formed and by irradiating the Spectramat (Vivadent, min 10) hardened. The property values ​​obtained with the bending test according to DIN 53452 and 53457 are shown in Table 2.<tables id="tabl0002" num="0002"><table frame="all"><title>Table 1</title><tgroup cols="4" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="39.37mm" /><colspec colnum="2" colname="col2" colwidth="39.37mm" /><colspec colnum="3" colname="col3" colwidth="39.37mm" /><colspec colnum="4" colname="col4" colwidth="39.37mm" /><thead valign="top"><row><entry namest="col1" nameend="col4" align="center"><b>Composition of dental materials</b></entry></row><row><entry namest="col1" nameend="col1" align="left">component</entry><entry namest="col2" nameend="col2" align="center">example 7a</entry><entry namest="col3" nameend="col3" align="center">example 7b</entry><entry namest="col4" nameend="col4" align="center">example 7c</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Wachsmonomer</entry><entry namest="col2" nameend="col2" align="center">Example 1: 72.5%</entry><entry namest="col3" nameend="col3" align="center">Example 3: 72.0%</entry><entry namest="col4" nameend="col4" align="center">Example 2: 66.3%</entry></row><row><entry namest="col1" nameend="col1" align="left">SR-295^a)</entry><entry namest="col2" nameend="col2" align="center">26.7%</entry><entry namest="col3" nameend="col3" align="center">27.2%</entry><entry namest="col4" nameend="col4" align="center">32.9%</entry></row><row><entry namest="col1" nameend="col1" align="left">camphorquinone</entry><entry namest="col2" nameend="col2" align="center">0.3%</entry><entry namest="col3" nameend="col3" align="center">0.3%</entry><entry namest="col4" nameend="col4" align="center">0.3%</entry></row><row><entry namest="col1" nameend="col1" align="left">CEMA^b)</entry><entry namest="col2" nameend="col2" align="center">0.5%</entry><entry namest="col3" nameend="col3" align="center">0.5%</entry><entry namest="col4" nameend="col4" align="center">0.5%</entry></row></tbody></tgroup><tgroup cols="4" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="39.37mm" /><colspec colnum="2" colname="col2" colwidth="39.37mm" /><colspec colnum="3" colname="col3" colwidth="39.37mm" /><colspec colnum="4" colname="col4" colwidth="39.37mm" /><tbody valign="top"><row><entry namest="col1" nameend="col4" align="justify">^a) pentaerythritol</entry></row><row><entry namest="col1" nameend="col4" align="justify">^b) 2-cyanoethylmethylaniline</entry></row></tbody></tgroup></table></tables>

<tables id="tabl0003" num="0003"><table frame="all"><title>Table 2</title><tgroup cols="4" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="39.37mm" /><colspec colnum="2" colname="col2" colwidth="39.37mm" /><colspec colnum="3" colname="col3" colwidth="39.37mm" /><colspec colnum="4" colname="col4" colwidth="39.37mm" /><thead valign="top"><row><entry namest="col1" nameend="col4" align="center"><b>Properties of dental materials</b></entry></row><row><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" align="center">example 7a</entry><entry namest="col3" nameend="col3" align="center">example 7b</entry><entry namest="col4" nameend="col4" align="center">example 7c</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Flexural strength (MPa)</entry><entry namest="col2" nameend="col2" align="center">5</entry><entry namest="col3" nameend="col3" align="center">20</entry><entry namest="col4" nameend="col4" align="center">12</entry></row><row><entry namest="col1" nameend="col1" align="left">Flexural modulus (MPa)</entry><entry namest="col2" nameend="col2" align="center">1010</entry><entry namest="col3" nameend="col3" align="center">1320</entry><entry namest="col4" nameend="col4" align="center">1940</entry></row></tbody></tgroup></table></tables>

With the material according to Example 7c after the usual wax method were modeled crowns and inlays, which were then cured in Spectramat. There were obtained solid models with a very good dimensional stability and excellent in comparison with conventional wax models heat resistance.

Example 8: Comparative Example

Analogously to Example 7 were fabricated using conventional, non-polymerizable waxes dental materials (Table 3, all amounts in wt .-%).

Due to the low strength of the materials, the manufacture of test specimens was not possible after the irradiation showed the materials a strong cracking. Mechanical studies could therefore not be performed.<tables id="tabl0004" num="0004"><table frame="all"><title>Table 3</title><tgroup cols="3" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="52.50mm" /><colspec colnum="2" colname="col2" colwidth="52.50mm" /><colspec colnum="3" colname="col3" colwidth="52.50mm" /><thead valign="top"><row><entry namest="col1" nameend="col3" align="center"><b>Composition of Comparative materials with non-polymerizable waxes</b></entry></row><row><entry namest="col1" nameend="col1" align="left">component</entry><entry namest="col2" nameend="col2" align="center">example 8a</entry><entry namest="col3" nameend="col3" align="center">example 8b</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Wachsmonomer</entry><entry namest="col2" nameend="col2" align="center">Hoechst wax S 66.1%</entry><entry namest="col3" nameend="col3" align="center">SU-aesthetic wax-O^c) 66.1%</entry></row><row><entry namest="col1" nameend="col1" align="left">SR-295^a)</entry><entry namest="col2" nameend="col2" align="center">33.1%</entry><entry namest="col3" nameend="col3" align="center">33.1%</entry></row><row><entry namest="col1" nameend="col1" align="left">camphorquinone</entry><entry namest="col2" nameend="col2" align="center">0.3%</entry><entry namest="col3" nameend="col3" align="center">0.3%</entry></row><row><entry namest="col1" nameend="col1" align="left">CEMA^b)</entry><entry namest="col2" nameend="col2" align="center">0.5%</entry><entry namest="col3" nameend="col3" align="center">0.5%</entry></row></tbody></tgroup><tgroup cols="3" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="52.50mm" /><colspec colnum="2" colname="col2" colwidth="52.50mm" /><colspec colnum="3" colname="col3" colwidth="52.50mm" /><tbody valign="top"><row><entry namest="col1" nameend="col3" align="justify">^a) pentaerythritol</entry></row><row><entry namest="col1" nameend="col3" align="justify">^b) 2-cyanoethylmethylaniline</entry></row><row><entry namest="col1" nameend="col3" align="justify">^c) Schuler-Dental</entry></row></tbody></tgroup></table></tables>

Example 9: Comparative Example

According to US-A-5,403,188 (Example 1, Run-No. 1, 12, 13, 16 and 17) were Dental materials having the composition shown in Table 4 manufactured. Here, no waxy materials were obtained, but thermoplastic materials, which are rubbery tough during melting. Moreover, the melting of highly viscous (polycaprolactone TONE 767: 8500 Pa.s above the melting point (65 ° C)) and non-dripping, while wax melts the invention have a low viscosity show (Example 1: about 0.5 Pa · s above the are melting range) and form droplets.<tables id="tabl0005" num="0005"><table frame="all"><title>Table 4</title><tgroup cols="3" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="52.50mm" /><colspec colnum="2" colname="col2" colwidth="52.50mm" /><colspec colnum="3" colname="col3" colwidth="52.50mm" /><thead valign="top"><row><entry namest="col1" nameend="col3" align="center"><b>Thermoplastic dental materials</b></entry></row><row><entry namest="col1" nameend="col1" align="center">TONE P-767^a) Wt .-%</entry><entry namest="col2" nameend="col2" align="center">Acrylate wt .-%</entry><entry namest="col3" nameend="col3" align="center">Viscosity at 65 ° C (Pa · s)</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="center">100</entry><entry namest="col2" nameend="col2" align="center">0</entry><entry namest="col3" nameend="col3" align="center">8500</entry></row><row><entry namest="col1" nameend="col1" align="center">70</entry><entry namest="col2" nameend="col2" align="center">30^b)</entry><entry namest="col3" nameend="col3" align="center">1140</entry></row><row><entry namest="col1" nameend="col1" align="center">55</entry><entry namest="col2" nameend="col2" align="center">45^b)</entry><entry namest="col3" nameend="col3" align="center">1540</entry></row><row><entry namest="col1" nameend="col1" align="center">70</entry><entry namest="col2" nameend="col2" align="center">30^c)</entry><entry namest="col3" nameend="col3" align="center">100</entry></row><row><entry namest="col1" nameend="col1" align="center">55</entry><entry namest="col2" nameend="col2" align="center">45^c)</entry><entry namest="col3" nameend="col3" align="center">30</entry></row></tbody></tgroup><tgroup cols="3" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="52.50mm" /><colspec colnum="2" colname="col2" colwidth="52.50mm" /><colspec colnum="3" colname="col3" colwidth="52.50mm" /><tbody valign="top"><row><entry namest="col1" nameend="col3" align="justify">^a) polycaprolactone; Molar mass: 40,000 g / mol (Union Carbide)</entry></row><row><entry namest="col1" nameend="col3" align="justify">^b) Ebercryl 230, aliphatic urethane resin (UCB Chemicals)</entry></row><row><entry namest="col1" nameend="col3" align="justify">^c) Ebercryl 830, hexafunctional polyester acrylate oligomer (UCB Chemicals)</entry></row></tbody></tgroup></table></tables>