Stable, cationically polymerizable/crosslinkable dental compositions having high filler contents

Abstract

Stable, highly filled cationic dental compositions useful for the production of dental prostheses and dental restoration materials contain: (1) at least one compound which is reactive cationically when activated, advantageously at least one UV-and cationically reactive oxirane-functionalized silicone; (2) at least one dental filler, advantageously SiO 2 ; (3) at least one organic polymer or copolymer dispersant having an amine index less than or equal to 100 mg of potassium hydroxide per gram of dispersant, advantageously a polyurethane/acrylate copolymer or alkylammonium salt thereof; (4) at least one cationic photoinitiator, advantageously iodonium borate; and (5) optionally, at least one photosensitizer.

1 . A dental composition useful for the production of dental prostheses and dental restoration materials, comprising: 
 (1) at least one compound which is reactive cationically and under activation;    (2) at least one dental filler present in a proportion of at least 10% by weight relative to the total weight of the composition;    (3) at least one organic polymer or copolymer dispersant having an amine index less than or equal to 100 mg of potassium hydroxide per gram of dispersant;    (4) at least one cationic photoinitiator; and    (5) optionally, at least one photosensitizer.    
     
     
         2 . The dental composition as defined by  claim 1 , said at least one dispersant ( 3 ) having an acid index of less than 200 mg of potassium hydroxide per gram of dispersant.  
     
     
         3 . The dental composition as defined by  claim 1 , said dental filler ( 2 ) comprising from 10 to 85% by weight thereof.  
     
     
         4 . The dental composition as defined by  claim 1 , said at least one dispersant ( 3 ) comprising a polyurethane/acrylate copolymer, optionally in alkylammonium salt form.  
     
     
         5 . The dental composition as defined by  claim 1 , said at least one dispersant ( 3 ) comprising from 50 ppm to 1% by weight thereof.  
     
     
         6 . The dental composition as defined by  claim 1 , said at least one cationically reactive compound ( 1 ) being selected from the group consisting of monomers and/or (co)polymers of epoxies, vinyl ethers, oxetanes, spiroorthocarbonates, spiroorthoesters and combinations thereof.  
     
     
         7 . The dental composition as defined by  claim 1 , said at least one cationically reactive compound ( 1 ) comprising at least one crosslinkable and/or polymerizable silicone oligomer or polymer which is liquid at ambient temperature or thermofusible at a temperature of less than 100° C. and which comprises: 
 at least one unit of formula (FS):                          in which a=0, 1 or 2; the radicals R 0 , which may be identical or different, are each an alkyl, cycloalkyl, aryl, vinyl, or alkoxy radical, or hydrogen; and the radicals Z, which may be identical or different, are each an organic substituent containing at least one reactive epoxy and/or alkenyl ether and/or oxetane and/or dioxolane and/or carbonate function; and    at least two silicon atoms.    
     
     
         8 . The dental composition as defined by  claim 7 , wherein formula (FS) Z is an organic substituent Z 1  containing at least one reactive epoxy and/or dioxolane function.  
     
     
         9 . The dental composition as defined by  claim 6 , said at least one oligomer or polymer ( 1 ) further comprising reactive alkenyl ether, oxetane and/or carbonate functions Z 2 .  
     
     
         10 . The dental composition as defined by  claim 6 , wherein formula (FS) the reactive function or functions Z 1  are selected from among the following radicals:  
       
         
           
           
               
               
           
         
       
     
     
         11 . The dental composition as defined by  claim 1 , said at least one photoinitiator ( 4 ) comprising a borate photoinitiator selected from the group consisting of those of the formulae: 
 the cationic borate moiety of which comprising:    (1) onium salts of formula (I):      [(R 1 ) n -A-(R 2 ) m ] +   (I)    in which formula:    A represents an element from Groups 15 to 17 of the Periodic Table;    R 1  represents a C 6 -C 20  heterocyclic or carbocyclic aryl radical, with the proviso that said heterocyclic radical may contain nitrogen or sulfur as heteroelements,    R 2  represents R 1  or a C 1 -C 30  linear or branched alkyl or alkenyl radical, the said radicals R 1  and R 2  being optionally substituted by a C 1 -C 25  alkoxy, C 1 -C 25  alkyl, nitro, chloro, bromo, cyano, carboxyl, ester or mercapto group, 
 n is an integer ranging from 1 to v+1, v being the valency of the element A, and  
 m is an integer ranging from 0 to v−1 with n+m=v+1; 
 (2) an oxoisothiochromanium salt;  
 (3) organometallic salts of formula (III):  
   (L 1 L 2 L 3 M) +q   (III)  
 in which formula:  
 
   M represents a metal from Group 4 to 10 of the Periodic Table;    L 1  represents 1 ligand attached to the metal M by π electrons, the ligand being selected from η 3 -alkyl, η 5 -cyclopentadienyl and η 7 -cycloheptatrienyl ligands and η 6 -aromatic compounds selected from optionally substituted η 6 -benzene ligands and compounds having 2 to 4 fused rings, each ring being capable of contributing to the valence shell of the metal M by 3 to 8 π electrons,    L 2  represents one ligand attached to the metal M by π electrons, the ligand being selected from η 7 -cycloheptatrienyl ligands and η 6 -aromatic compounds selected from optionally substituted η 6 -benzene ligands and compounds having 2 to 4 fused rings, each ring being capable of contributing to the valence shell of the metal M by 6 or 7 π electrons,    L 3  represents from 0 to 3 identical or different ligands attached to the metal M by σ electrons and selected from CO and NO 2   + , the total electronic charge q of the complex to which L 1 , L 2  and L 3  contribute and the ionic charge of the metal M being positive and equal to 1 or 2; and    the anionic borate moiety of which having the formula [BX a R b ] − , in which: 
 a and b are integers ranging from 0 to 3 for a and from 1 to 4 for b, with a+b=4,  
 the symbols X represent:  
 a halogen atom with a=0 to 3, or  
 an OH function with a=0 to 2,  
 the symbols R, which may be identical or different, are each:  
 a phenyl radical substituted by at least one electron-withdrawing group and/or by at least 2 halogen atoms when the cationic moiety is an onium of an element from Groups 15 to 17 of the Periodic Table;  
 a phenyl radical substituted by at least one electron-withdrawing element or group;  
 an aryl radical containing at least two aromatic nuclei, optionally substituted by at least one electron-withdrawing element or group.  
   
     
     
         12 . The dental composition as defined by  claim 1 , said at least one photoinitiator ( 4 ) being selected from the group consisting of: 
 [(C 8 H 17 )—O-φ-I-φ] + ,[B(C 6 F 5 ) 4 ] − ;    [C 12 H 25 -φ-I-φ] + ,[B(C 6 F 5 ) 4 ] − ;    [(C 8 H 17 —O-φ) 2 I] + ,[B(C 6 F 5 ) 4 ] − ;    [(C 8 H 17 )—O-φ-I-φ)]+,[B(C 6 F 5 ) 4 ] − ;    [(φ) 2 S-φ-O—C 8 H 17 ] + ,[B(C 6 H 4 CF 3 ) 4 ] − ;    [(C 12 H 25 -φ) 2 I] + ,[B(C 6 F 5 ) 4 ] − ;    [CH 3 -φ-I-φ-CH(CH 3 ) 2 ] + ,[B(C 6 F 5 ) 4 ] − ;    (η 5 -cyclopentadienyl)(η 6 -toluene)Fe + ,[B(C 6 F 5 ) 4 ] − ;    (η 5 -cyclopentadienyl)(η 6 -methyl-1-naphthalene)Fe + , [B(C 6 F 5 ) 4 ] − ;    (η 5 -cyclopentadienyl)(η 6 -cumene)Fe + ,[B(C 6 F 5 ) 4 ] − ;    [(C 12 H 25 -φ) 2 I] + ,[B(C 6 H 3 (CF 3 ) 2 )] − ;    [CH 3 -φ-I-φCH 2 CH(CH 3 ) 2 ]+,[B(C 6 F 5 ) 4 ] − ; and    [CH 3 -φ-I-φ-CH 2 CH(CH 3 ) 2 ] + ,[B(C 6 H 3 (CF 3 ) 2 ) 4 ] − .    
     
     
         13 . The dental composition as defined by  claim 1 , comprising at least one aromatic hydrocarbon photosensitizer ( 5 ) containing one or more substituted or unsubstituted aromatic nuclei and having a residual absorption of light between 200 and 500 nm.  
     
     
         14 . The dental composition as defined by  claim 13 , said at least one photosensitizer ( 5 ) being selected from the group consisting of: 
 4,4′-dimethoxybenzoin;    2,4-diethylthioxanthone;    2-ethylanthraquinone;    2-methylanthraquinone;    1,8-dihydroxyanthraquinone;    dibenzoyl peroxide;    2,2-dimethoxy-2-phenylacetophenone; benzoin;    2-hydroxy-2-methylpropiophenone; benzaldehyde;    4-(2-hydroxyethoxy)phenyl 2-hydroxy-2-methylpropyl ketone;    benzoylacetone;                          2-isopropylthioxanthone;    1-chloro-4-propoxythioxanthone;    4-isopropylthioxanthone;                          and mixtures thereof.    
     
     
         15 . The dental composition as defined by  claim 1 , comprising at least one silicone oligomer and/or polymer ( 1 ) which comprises at least one silicone having one of the following average formulae:  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         16 . A dental prosthesis shaped from the dental composition as defined by  claim 1 .  
     
     
         17 . A dental restoration material prepared from the dental composition as defined by  claim 1 .  
     
     
         18 . The dental composition as defined by  claim 1 , comprising at least one compound ( 1 ) which is reactive cationically under actinic activation.  
     
     
         19 . The dental composition as defined by  claim 5 , said at least one dispersant ( 3 ) comprising from 100 ppm to 5,000 ppm therein.  
     
     
         20 . The dental composition as defined by  claim 1 , comprising (1) at least one UV- and cationically reactive oxirane-functionalized silicone.