Dental composition based on silicone crosslinkable by cation process

Abstract

The invention concerns dental compositions. Said composition comprises (1) a silicone crosslinkable and/or polymerizable by cation process; (2) an efficient amount of at least an initiator such as onium borate; (3) at least a photosensitizer ; and (4) a dental filler present in the composition in a proportion of at least 10 wt. % relative to the composition total weight. Said dental compositions are useful for making dental prostheses or for dental restoration.

1 - 11 . (canceled)  
   
   
       12 . A low shrinking polymerizable or crosslinkable dental composition comprising a mixture of: 
 (1) at least one crosslinkable and/or polymerizable silicone oligomer or polymer which is liquid at room temperature or which is heat-meltable at a temperature of less than 100° C., and which comprises: 
 at least one unit of formula (FS):  
   Z—SiR a   0 —O (3−a)/2    
 wherein:  
 a=0, 1 or 2,  
 R 0 , identical or different, represents an alkyl, cycloalkyl, aryl, vinyl, hydrogeno or alkoxy radical,  
 Z, identical or different, is an organic substituent comprising at least one reactive epoxy, or alkenyl ether or oxetane or dioxolane or carbonate functional group,  
 and at least two silicon atoms,  
   (2) at least one aromatic hydrocarbon photosensitizer, having a residual light absorption of between 200 and 500 nm, and selected from the group consisting of the following formulae (VIII), (X), (XII) and (XXII):    thioxanthones of formula (VIII):                          wherein: 
 m=0 to 8,  
 R 17 , identical or different substituent(s) on the aromatic nucleus (nuclei), represent a linear C 1 -C 12  alkyl radical, a branched C 1 -C 12  alkyl radical, a C 6 -C 12  cycloalkyl radical, a radical Ar 1 , a halogen atom, an —OH, —CN, —NO 2 , —COOR 6 , —CHO, Ophenyl, —CF 3 , —SR 6 , —Sphenyl, —SO 2 phenyl, Oalkenyl, or —SiR 6   3  group; xanthones of formula (X):  
                     
 wherein p=0 to 8  
   anthracene of formula (XII):                        wherein=0 to 10, and      biscoumarins of formula (XXII):                        wherein:      R 18 , identical or different, has the same meaning as R 17  above or represents a group: —NR 6   2 , wherein R 6  represents a linear C 1 -C 12  alkyl radical,    (3) at least one dental filler present in a proportion of at least 10% by weight relative to the total weight of the composition, and    (4) an effective quantity of at least one borate-type photoinitiator, whose cationic entity of the borate is:    1′: [B(C 6 F 5 ) 4 ] −  5′: [B(C 6 H 3 (CF 3 ) 2 ) 4 ] −     2′: [(C 6 F 5 ) 2 BF 2 ] −  6′: [B (C 6 H 3 F 2 ) 4 ] −     3′: [B(C 6 H 4 CF 3 ) 4 ] −  7′: [C 6 F 5 BF 3 ] −     4′: [B(C 6 F 4 OCF 3 ) 4 ] − ;    wherein the cationic entity of the borate is:    [(Φ) 2 I] +  [C 8 H 17 —O—Φ—I—Φ] +  [(Φ—CH 3 ) 2 I] +     [C 12 H 25 —Φ—I—Φ] +  [(C 8 H 17 —O—Φ) 2 I] +  [(C 8 H 17 —O—Φ—I—Φ)] +     [(Φ) 3 S] +  [(Φ) 2 —S—Φ—O—C 8 H 17 ] +  [(CH 3 —Φ—I —Φ—CH 3 ) 2 ] +     [Φ—S—Φ—S—(Φ) 2 ] +  [(C 12 H 25 —Φ) 2 I] +  [(CH 3 —φ—I—Φ—OC 2 H 5 ] + ; and    wherein the composition has a volumetric polymerization and/or crosslinking shrinkage of less than 1.5% v/v.    
   
   
       13 . The dental composition as claimed in  claim 12 , wherein Z is an organic substituent Z1 comprising at least one reactive epoxy, or dioxolane functional group.  
   
   
       14 . The dental composition as claimed  claim 13 , wherein the reactive functional group Z1 is:  
     
       
         
         
             
             
         
       
     
   
   
       15 . The dental composition as claimed in  claim 12 , wherein the photoinitiator is: 
 [(Φ) 2 I] + , [(C 6 F 5 ) 4 ] −  [(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 17l )—O—Φ—I—Φ)]   + , [B(C 6 F 5 ) 4 ] −  [(Φ) 3 S] + , [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 ] −     [(Φ) 3 S] + , [B(C 5 F 4 OCF 3 ) 4 ] −  [(Φ—CH 3 ) 2 I] + , [B(C 6 F 5 ) 4 ] −     [(Φ—CH 3 ) 2 I] + , [B(C 6 F 4 OCF 3 ) 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 ] −   
 or (η 5 -cyclopentadienyl) (η 6 -cumene) Fe + , [B(C 6 F 5 ) 4 ] − .  
   
   
   
       16 . The dental composition as claimed in  claim 12 , wherein the photosensitizer of formula (XXII) is 3,3′-carbonylbis(7-diethylaminocoumarin) or 3,3′-carbonylbis(7-methoxycoumarin).  
   
   
       17 . A process for the preparation of a dental prosthesis or dental restoration, comprising the step of using a dental composition as defined in  claim 12.