Basic prosthesis material, in particular for dental prosthetics

p0001The present invention relates to a prosthetic starting material, in particular a prosthesis starting material for dental prostheses, the use of this prosthesis starting material for the production of prostheses and in particular of dental prostheses.

p0002Prosthetic materials have to meet high requirements in many respects. You have to be not only extremely biocompatible and excel by a very high degree of accuracy over a very long period, but also to provide adequate protection against microorganisms.

p0003From the dental field, the antimicrobial effect of the dental material silver amalgam is known.

p0004Antimicrobial plastic body should be in accordance with the <patcit id="pcit0001" dnum="DE19936059A1"><text>DE 199 36 059 A1</text></patcit> characterized can be produced in a particularly simple manner, that is treated prior to the actual molding of the plastic body at least one constituent of the precursor with a metal colloid. In the<patcit id="pcit0002" dnum="WO0143788A2"><text>WO 01/43788 A2</text></patcit> is described, which has a polymer coating, which has to contain a metal colloid an antimicrobially equipped molding. Dentures that should be characterized by a satisfactory antimicrobial activity, according to the<patcit id="pcit0003" dnum="DE10331324A1"><text>DE 103 31 324 A1</text></patcit> obtained in that first treating a preliminary product with an antimicrobial metal colloid, and then adding a soluble or poorly soluble salt of an antimicrobial metal.

p0005A resilient moldings can be referred <patcit id="pcit0004" dnum="GB696912A"><text>GB 696 912 A</text></patcit> characterized antimicrobially austatten that one these, treated with a complex compound of silver, which has two monohydroxy monoaminoalkan Substituents.

p0006According to the <patcit id="pcit0005" dnum="EP1375700A1"><text>EP 1375700 A1</text></patcit> is thereby obtained that is chemically depositing a silver layer on the surface of the molded body an antimicrobially equipped molding.

p0007The <patcit id="pcit0006" dnum="DE102006056284A1"><text>DE 10 2006 056 284 A1</text></patcit> deals with a process for the preparation of a antimicrobial aqueous dispersion containing nanoscale particles which comprise at least one antibacterial metal or an antimicrobial metal compound, and a polymerization, polycondensation or polyaddition product. Agent processing obtained a solid intermediate which is can be further processed into a plastic article or a plastic coating.

p0008The <patcit id="pcit0007" dnum="DE102005041005A1"><text>DE 10 2005 041 005 A1</text></patcit> describes silver-containing compositions as biocides, which have to have next nanoparticulate silver at least a silver salt, nanoparkituläres zinc oxide, chitosan or chitosan derivative. From the<patcit id="pcit0008" dnum="WO0124839A1"><text>WO 01/24839 A1</text></patcit> it is apparent a biocompatible polymer matrix of a Polyacrylamidgerüst and a non-gelling polysaccharide, which may be provided with silver.

p0009In the <patcit id="pcit0009" dnum="DE60309383T2"><text>DE 603 ​​09 383 T2</text></patcit> is directed to dental compositions containing silver-zinc glass, at least one monomer having at least one ethylenically unsaturated group and a polymerization initiator. The silver ceramics obtained therefrom should be antimicrobial equipped without the mechanical strength of the dental compositions must be sacrificed. However, no low silver amounts of additive to be used in order to achieve a reasonably acceptable anti-microbial effect. Also sufficient transparency, color neutrality and storage stability as a rule can not be complied with. However, these properties are in dental prosthetics and earmoulds crucial.

p0010The above-described, known from the prior art antimicrobial compositions can be particularly suitable for use as a prosthetic materials have always desired, not least in the degree and duration of antimicrobial activity.

p0011Today's prosthetic materials, especially in the dental field have reached a quality that makes it possible to may also carry so-called provisional prosthesis over a longer period. This development reflects the fact that, in particular in the dental field can often correctly identify only after a long waiting period, the shape of the final prosthesis. In order to bridge this period appropriately, these so-called temporary dentures are becoming more and more important. Provisional prostheses are sometimes worn in the dental field already for a period of about 12 months. The based plastic materials provisional prosthesis should, especially when worn over a longer period, not give rise to the formation of bacteria and not be a source of danger for potential infections. That this problem is of primary concern, documented, not least the many known from the prior art, attempts to tackle the issue.

p0012The present invention was therefore based on the object to provide prostheses starting materials for the production of prostheses are available, which also show a significant period of a particularly pronounced antimicrobial action.

p0013Accordingly, a prosthesis starting material containing silver sulfate and optionally precipitated silver was found.

p0014It can be provided that the prosthesis starting material is a polymerizable, especially cold-polymerizable prosthetic feedstock. Such polymerizable prosthetic feedstocks include, for example so-called heat-curing polymers based on powder and liquid. According to DIN EN ISO 1567: 2000, the boundary between cold-curing and hot curing systems is 65 ° C.

p0015Have proved particularly suitable as inventive prosthesis starting materials so-called multi-component prosthesis starting materials, in particular two-component prosthesis starting materials comprising at least one solid, particularly powder component, and at least one liquid component. Particularly preferred in these systems are two-component prostheses starting materials on the basis of polymethyl acrylates (PMMA), both as hot as well as cold curing.

p0016As excess or 2-component Prothesenausgangsmaterialal is understood in the context of the present invention, such a composition thereof from the prosthetic materials or prostheses or components, such as dental prostheses, temporary crowns and bridges, orthodontic parts (called Ortho sculptures) or ear molds for hearing aids. Suitable dental prosthetic materials, which are accessible from the prosthesis starting materials according to the invention include in particular the denture base, which can be equipped with improved properties. The denture base comprises at dental prostheses such areas or components, in which the dentures are incorporated and which are intended ultimately for access to areas of the palate.

p0017The silver sulfate and / or the precipitated silver is in the inventive prostheses starting materials preferably in an average particle size in the range of> 0.1 .mu.m to 20 .mu.m, preferably in the range from 1 .mu.m to 10 .mu.m, before. Be particularly preferable such prostheses starting materials have been found, in which silver sulfate and / or precipitated silver having an average particle size in the range of 1.5 to 45 microns, more preferably having an average particle size in the range of 1.5 to 10 microns and especially in the area 2-9 microns, for example in the range of 5 to 8 microns, is present. With such embodiments, prostheses are available, which are still always equipped over a very long period of use at a very high antimicrobial activity. This means that the antimicrobial activity decreases not significant by washing or other migration processes.

p0018Based on the total weight prostheses have starting materials according to the invention advantageously has an amount of silver precipitated in the range of 0.01 to 5 wt .-%, preferably from 0.1 to 1 wt .-%, based on the total weight of the prosthesis starting material, by weight % and / or an amount of 0.01 to 5 wt.%, preferably from 0.1 to 1 wt .-% of silver sulfate. Expedient embodiments set precipitated silver and / or silver sulfate in amounts of at least 0.15 or at least 0.2 wt .-%, based on the total weight of the denture base material, a.

p0019Particularly preferred prostheses starting materials according to the invention on the basis of multi-component prostheses starting materials comprise at least one liquid component (component A) containing at least one alkyl methacrylate, especially methyl methacrylate, and at least one solid component (component B) containing at least one homo- and / or copolymer of an alkyl ( methacrylate), particularly methyl methacrylate.

p0020The solid component (component B) is in this case a regular bulk material is that is preferably in powdered or free-flowing consistency.

p0021In one advantageous embodiment, it is provided that the homo- and / or copolymer of alkyl (meth) acrylate is in powder form and / or in the form of beads in the solid component (B). It is advantageous if the beads are present at least partially crosslinked.

p0022The weight ratio of solid component (B) to said liquid component (A) is advantageously in the range from 10: 8 to 10: 2, preferably in the range from 10: 6 to 10: 2 and particularly in the range of from 10: 7 to 10: 2, . 5 It can for example be readily weight ratios of 10: 4 or 10: Setting. 3 By may have recourse to mixtures with a low content of liquid component, ie, the monomer to be polymerized, resulting with the prosthesis starting materials according to the invention is always a very low residual monomer content in the manufactured prosthetic materials, both with hot and with cold-curing polymers.

p0023Bead polymers, in particular those of (meth) acrylates, are known in the art in general. acrylates bead polymers based on polyalkyl (meth), in particular polymethyl methacrylates, especially those with small average particle sizes, for example in the range from 1 .mu.m to 30 .mu.m, for. example by precipitation can be obtained. By way of suspension are usually polymer beads with average particle sizes greater than 35 microns readily accessible. is an example in this regard to the disclosure of<patcit id="pcit0010" dnum="EP0443609A2"><text>EP 0443609 A2</text></patcit> referenced, which are incorporated herein by reference. According to the<patcit id="pcit0011" dnum="DE10065501A1"><text>DE 100 65 501 A1</text></patcit> can be reached by means of suspension polymerization to polymer beads with average particle sizes in the range of 1 micron to 40 microns, when the polymerizable composition comprises at least 50 wt .-% of (meth) acrylates having and when dispersed and polymerized in an aqueous phase. The suspension shall be stabilized by means of aluminum compounds. Crosslinked bead polymers having an average particle diameter of 10 to 100 microns based on methacrylate removes one<patcit id="pcit0012" dnum="DE2850916"><text>DE 28 50 916</text></patcit>, there ethylene and divinylbenzene are explicitly mentioned as suitable multifunctional cross-linker.

p0024In a further expedient embodiment is the B component at least one crosslinking agent, in particular in the range of 0.1 wt .-% to 10 wt .-% or in the range of 0.5 wt .-% to 5 wt .-% as crosslinked comonomer polymerized before. Furthermore, the component can represent a B having at least one elastic phase modified polymer beads personalized.

p0025For networking to it also regularly calls on multifunctional comonomers or multifunctional oligomers. In addition to di-, tri- and poly-functional (meth) acrylates are suitable for this purpose also graft-linking agents having at least two different reactive CC double bonds, for example, alkyl acrylates and methacrylates, and aromatic crosslinkers such as 1,2-divinylbenzene, 1,3-divinylbenzene and 1,4 divinylbenzene. acrylates are the di-functional (meth) in particular are the (meth) acrylates of propanediol, butanediol, hexanediol, octanediol, nonanediol, decanediol and eicosanediol and also the di (meth) acrylates of ethylene glycol, triethylene glycol, tetraethylene glycol, Dodecaethylenglycols, Tetradecaethylenglycols, propylene glycol , dipropylene glycol and Tetradecapropylenglycols, also acrylate, glyceryl di (meth) acrylate, 2,2-bis [(gamma-methacryloxy-beta-oxopropoxy) -phenylpropane], bis-GMA, bisphenol A dimethacrylate, neopentyl glycol di (meth) acrylate, 2,2 -dimethacryloxypolyethoxyphenyl) propane having 2 to 10 ethoxy groups per molecule and 1,2-bis (3-methacryloxy-2-hydroxypropoxy) butane called. Exemplary are as multifunctional (meth) acrylates, eg. B. di-, tri- and / or tetra (meth) acrylates such as 1,4-butanediol dimethacrylate, ethylene glycol dimethacrylate and urethane dimethacrylate and di- or trivinylische compounds such as divinylbenzene highlighted. Of course, possible to use mixtures of said crosslinker. Particularly suitable are also those polyfunctional compounds, in particular di- and / or trifunctional compounds having elastic units and are thus suitable to provide the prosthetic materials obtained from the starting materials prostheses with flexible properties.

p0026Suitable alkyl methacrylates for the liquid component A may be made to methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, i-butyl, benzyl, and mixtures thereof Furfurylmethacrylate or referenced. Methyl methacrylate is particularly preferred as the monomer for the liquid component (component A).

p0027The required for the polymerization is free radical initiator system, depending on the reaction conditions, or polymerization in the liquid component A and / or the solid component (component B). Details in this regard are known to the skilled artisan. For example, in base mixtures for cold-cured polymers the initiator system mostly in two components, the liquid component and the solid component before and accordingly stirred together during mixing of these components. In the base materials for heat-curing polymers the initiator is usually in the polymeric component, that is the solid component before. Only when mixing the initiator then passes into the liquid monomer component. Accordingly prostheses starting materials may be provided in which the solid component (B) a content of reactive initiator component, especially in the form of peroxides, perketals, peresters, azo compounds and / or barbituric acid, thiobarbituric acid, barbituric or thiobarbituric acid derivatives present. This may be as well to residual contents of in the manufacture of solid components act unreacted initiator component, for example, peroxides such as dibenzoyl.

p0028As initiators for the polymerization of cold as well as hot cured output mixtures generally are those which, let start with which radical polymerization reactions. Preferred initiators are peroxides such as dibenzoyl peroxide, dilauroyl peroxide, t-Butanperbenzoat and di-t-butyl peroxide as well as azo compounds such as azobis (isobutyronitrile) (AIBN) or azobis- (4-cyanovaleric acid). For hot curing may further be made to make use Perketals and benzpinacols.

p0029In order to accelerate the initiation of the radical polymerization is initiated by peroxides, suitable activators, for example aromatic amines, can be added. By way of example may be mentioned as suitable amines N, N-dimethyl-p-toluidine, N, N-dihydroxyethyl-p-toluidine and p-Dibenzylaminobenzoesäurediethylester. Here, the amines act regularly as co-initiators and are usually present in an amount of up to 3% by weight.

p0030Suitable free-radical initiator systems, redox systems are also suitable, in particular combinations of dibenzoyl peroxide, dilauroyl camphorquinone or with amines such as N, N-dimethyl-p-toluidine, NN-dihydroxyethyl-p-toluidine and p-dimethylamino benzoic acid, diethyl ester. Furthermore, can be used which in addition to a peroxide also ascorbic acid or derivatives thereof, barbituric acid or barbituric acid derivative or a sulfinic acid as a reducing agent, such as redox systems also. Particularly suitable barbituric acid derivatives include 5-substituted barbituric acid, for example, 1-benzyl-5-phenyl-barbituric acid, 5-n-butylbarbituric acid, and Sn-cyclohexyl-barbituric acid. In an expedient embodiment, such a redox system barbituric or thiobarbituric or barbituric or thiobarbituric acid derivative (for example, 0.5<i>-</i> 5%% by weight), at least one peroxidic compound, such as a Peroxodisulphat- and / or peroxodiphosphate compound (for example, 25 to 65% by weight), at least one copper salt or a copper complex (for example, 0.01 to 8% by weight, preferably 0.01 to 1 wt .-%) and at least one compound with a ionogenic present halogen atom (for example, 0.05 to 7% by weight, preferably 0.05 to 1 wt .-%). are exemplified as suitable components of the above-mentioned redox system in the 5-position substituted barbituric acid such as 1-benzyl-5-phenyl-barbituric acid, 5-n-butylbarbituric acid, 5-n-cyclohexyl-barbituric acid, copper naphthenate, copper (II) chloride dihydrate, dilauryl, trioctylmethylammonium, Natriumperoxodisulphat, copper acetylacetonate and / or Benzyldibutylammoniumchlorid called. Alternatively, photoinitiators which are started by means of UV or visible light means, are used. Suitable photoinitiators are, for example Dialkylbenzilketone, bisacylphosphine oxides, alpha-diketones, Phoril, anisil or 4,4-dichlorobenzil, or mixtures thereof.

p0031In particular for cold-curing polymerizable prosthetic starting materials, it has proven to be advantageous to make use of redox systems which are based on barbituric acid, thiobarbituric acid, barbituric and / or thiobarbituric acid derivatives or containing. In this way, regularly achieve increased storage stability. is particular when using such prostheses starting materials, unlike some cold-curing amine / peroxide systems, the problem of discoloration observed with the use of silver and / or silver sulfate in the starting materials and prostheses in the prosthesis can be obtained therefrom.

p0032Furthermore, you can see the solid component (B) and / or the liquid component (A) in a known manner, depending on the polymerization conditions (cold / hot polymerization), provided with further additives, for example, with at least one stabilizer, at least one UV absorber, at least one thixotropic agents, at least one filler or mixtures of the foregoing components.

p0033Fillers used are for example pyrogenic or precipitated silicas, dental glasses as aluminosilicate or fluoroaluminosilicate, strontium silicate, Strontiumborsilikat, layer silicates, zeolites, metal oxides or fibers or mixtures thereof. Suitable fibers include, for example glass fibers, polyamide or carbon fibers.

p0034Inventive prostheses starting materials are characterized in one embodiment by the fact that the liquid component (A) contains at least one group capable of cross-linking cross-linking agent comonomer and / or at least one polymerization and / or that the solid component (B) contains at least one initiator.

p0035In the inventive prosthesis starting materials and / or the inventive prosthetic materials available from these prostheses starting materials the precipitated silver and / or silver sulfate are preferably substantially homogeneously distributed before.

p0036The object underlying the invention is further achieved by a prosthetic material, in particular by dental prostheses, available from the prosthesis starting material according to the invention.

p0037The present invention is the surprising finding that with silver sulphate prosthetic materials, in particular dental prostheses, very effective can provide antimicrobial, particularly when use is made of silver sulfate particles having an average particle size above 0.1 microns. It was also found that when the prosthesis starting materials according to the invention, as well as prosthetic materials obtainable therefrom therein present silver sulfate and the precipitated silver optionally contained therein tend not out transferring from the plastic matrix by means of migration, especially when the average particle size of silver sulfate and / or the precipitated silver greater than 0.1 microns. The prosthesis starting materials according to the invention and obtainable therefrom prosthetic materials of the invention show in continuous use still always a high antimicrobial effect. Furthermore, it was found at the prosthesis starting materials according to the invention and the resulting available prosthetic materials according to the invention even in long-term studies, no or only a very vemachlässigbare discoloration. The products of the invention are also characterized by a good and reliable transparency and color neutrality.

p0038To better illustrate the present invention is illustrated by the following examples in detail. Naturally, the present invention is not limited to these examples.

p0039Examples:<ul><li>Test specimens were obtained over a two-component prosthesis starting material based on PMMA (retec press LT). The test specimens obtained were investigated according to the test standard JIS Z 2801 for their antimicrobial effect. It was used a test suspension of the following test organisms:<i>Escherichia coli</i> ATTC 8739 (1.0 x 10⁶ CFU / test area) (cfu = colony forming units).</li></ul>

p0040The reduction of antimicrobial activity was determined as follows: reduction = log (unheated sample 0h / unheated sample 24..) - Log (treated sample 24 / unheated sample 0h.). The reduction is indicated in the following tables in log steps.

p0041The assessment performed was based on the following evaluation scheme:<ul><li>Reduction after 24 h &lt;1 log = no significant bactericidal / fungicidal action</li><li>Reduction after 24 h ≥ 1 log &lt;2 log = low bactericidal / fungicidal action</li><li>Reduction after 24 h ≥ 2 log &lt;3 orders of magnitude significant bactericidal / fungicidal action</li><li>Reduction after 24 h ≥ 3 orders of magnitude = strong bactericidal / fungicidal action</li></ul>

p0042For location times 24h 8 weeks to 12 months, the following results were obtained:<ul><li>Table 1: storage of test specimens: 24 hours at 37 ° C in demineralised water</li></ul><tables id="tabl0001" num="0001"><table frame="all"><tgroup cols="3"><colspec colnum="1" colname="col1" colwidth="74mm" /><colspec colnum="2" colname="col2" colwidth="43mm" /><colspec colnum="3" colname="col3" colwidth="30mm" /><thead><row><entry align="center" valign="top" /><entry align="center" valign="top">CFU * / test area after 24</entry><entry align="center" valign="top" /></row></thead><tbody><row><entry>Specimens - 0% silver sulfate</entry><entry>9.3 x 10⁶</entry><entry>(After 0h 4,8x10⁵)</entry></row><row><entry>Prüfkörper- 1.0% silver sulfate</entry><entry><10</entry><entry>Reduction> 6.0</entry></row><row><entry>Specimens - 0.5% silver sulfate</entry><entry><10</entry><entry>Reduction> 6.0</entry></row><row><entry>Specimen-0.1% silver sulfate</entry><entry><10</entry><entry>Reduction> 6.0</entry></row><row><entry>Specimens - 0.1% silver sulfate + 0, 1% silver like</entry><entry><10</entry><entry>Reduction> 6.0</entry></row></tbody></tgroup><tgroup cols="3" rowsep="0"><colspec colnum="1" colname="col1" colwidth="74mm" /><colspec colnum="2" colname="col2" colwidth="43mm" /><colspec colnum="3" colname="col3" colwidth="30mm" /><tbody><row><entry namest="col1" nameend="col3" align="justify">* CFU = Colony Forming Units</entry></row></tbody></tgroup></table></tables><tables id="tabl0002" num="0002"><table frame="all"><title>Table 2: storage of test specimens: 8 weeks at 37 ° C in demineralised water</title><tgroup cols="3"><colspec colnum="1" colname="col1" colwidth="47mm" /><colspec colnum="2" colname="col2" colwidth="42mm" /><colspec colnum="3" colname="col3" colwidth="40mm" /><thead><row><entry align="center" valign="top" /><entry align="center" valign="top">CFU * / test area after 24</entry><entry align="center" valign="top" /></row></thead><tbody><row><entry>Specimens - 0% silver sulfate</entry><entry>9.8 x 10⁶</entry><entry>(After 0h 3,4x10⁵)</entry></row><row><entry>Prüfkörper- 1.0% silver sulfate</entry><entry><10</entry><entry>Reduction> 5.9</entry></row><row><entry>Specimens - 0.5% silver sulfate</entry><entry><10</entry><entry>Reduction> 5.9</entry></row><row><entry>Specimens - 0.1% silver sulfate</entry><entry><10</entry><entry>Reduction> 5.9</entry></row></tbody></tgroup><tgroup cols="3" rowsep="0"><colspec colnum="1" colname="col1" colwidth="47mm" /><colspec colnum="2" colname="col2" colwidth="42mm" /><colspec colnum="3" colname="col3" colwidth="40mm" /><tbody><row><entry namest="col1" nameend="col3" align="justify">* CFU = Colony Forming Units</entry></row></tbody></tgroup></table></tables><tables id="tabl0003" num="0003"><table frame="all"><title>Table 3: storage of test specimens: 12 months at 37 ° C in demineralised water</title><tgroup cols="3"><colspec colnum="1" colname="col1" colwidth="51mm" /><colspec colnum="2" colname="col2" colwidth="44mm" /><colspec colnum="3" colname="col3" colwidth="39mm" /><thead><row><entry align="center" valign="top" /><entry align="center" valign="top">KBE * 1 / test area after 24</entry><entry align="center" valign="top" /></row></thead><tbody><row><entry>Specimens - 0% silver sulfate</entry><entry>8.0 x 10⁶</entry><entry>(After 0h 5,4x10⁵)</entry></row><row><entry>Prüfkörper- 1.0% silver sulfate</entry><entry><10</entry><entry>Reduction> 6.0</entry></row><row><entry>Specimens - 0.5% silver sulfate</entry><entry><10</entry><entry>Reduction> 6.0</entry></row><row><entry>Specimens - 0.1% silver sulfate</entry><entry>5.7 x 10⁶</entry><entry>reduction 0.1</entry></row><row><entry>Specimens - 0.1% silver (like)¹⁾</entry><entry>1.1 x 10⁷</entry><entry>reduction 0.0</entry></row></tbody></tgroup><tgroup cols="3" rowsep="0"><colspec colnum="1" colname="col1" colwidth="51mm" /><colspec colnum="2" colname="col2" colwidth="44mm" /><colspec colnum="3" colname="col3" colwidth="39mm" /><tbody><row><entry namest="col1" nameend="col3" align="justify">*¹ CFU = Colony Forming Units ¹⁾ The test piece was stored only 9 months.</entry></row></tbody></tgroup></table></tables>

p0043The features disclosed in the foregoing description and in the claims the invention may be both separately and in any combination essential for the realization of the invention in its various embodiments.