Dental composition comprising a particulate carrier supporting a coinitiator

Abstract

The present invention relates to a dental composition comprising a photoinitiator system comprising a particulate carrier supporting a coinitiator covalently bonded to the surface of the carrier. Furthermore, the present invention relates to a use of the particulate carrier in a dental composition. The particulate carrier displays multiple covalently bonded tertiary amino groups and/or tertiary phosphine groups on the surface, for crosslinking monomers, oligomers and/or polymers having one or more polymerizable double bonds.

1 . A dental composition comprising
 (a) a compound having a polymerizable double bond,   (b) a photoinitiator system comprising
 (b1) a photosensitizer absorbing light in the range of from 400 to 800 nm, and 
 (b2) a particulate carrier supporting a coinitiator covalently bonded to the surface of the carrier, wherein the coinitiator is selected from a compound having a tertiary amino group and/or a compound having a tertiary phosphino group; wherein the particulate carrier displays multiple covalently bonded tertiary amino groups and/or tertiary phosphine groups on the surface, for crosslinking monomers, oligomers and/or polymers having one or more polymerizable double bonds; 
 wherein the covalently bonded tertiary amino groups and/or tertiary phosphine groups are selected from moieties of the following formulae (I) and (II): 
   
       
         
           
           
               
               
           
         
         
           wherein 
           R 1  and R 2  which may be a same or different, and independently represent a C 1-6  straight-chain alkyl group, C 3-6  branched alkyl group or cyclic alkyl group; and 
         
       
       
         
           
           
               
               
           
         
         
           wherein L is a single bond or a divalent linker group. 
         
       
     
     
         2 . The dental composition according to  claim 1 , wherein the particulate carrier is selected from a microparticle or a nanoparticle. 
     
     
         3 . The dental composition according to  claim 1 , wherein the photosensitizer is a 1,2-diketone compound. 
     
     
         4 . The dental composition according to  claim 1 , wherein the particulate carrier is a microparticle or nanoparticle comprising silica, alumina, zirconia, titania, or a mixture thereof. 
     
     
         5 . The dental composition according to  claim 4 , wherein the nanoparticle has an average particle size of from 1 to 50 nm. 
     
     
         6 . The dental composition according to  claim 4 , wherein the nanoparticle has a density of covalently bonded tertiary amino groups and/or tertiary phosphine group of from 0.1 to 100 groups per nm 2 . 
     
     
         7 . The dental composition according to  16 , wherein the polycondensate is obtained by
 (i) hydrolysing a mixture containing
 (A) a silica precursor component, and optionally 
 (B) one or more compounds selected from the group consisting compounds of aluminum, zinc, titanium, zirconium, tungsten, ytterbium, hafnium, bismuth, barium, strontium, silver, tantalum, lanthanum, tin, boron, and cerium; 
   (ii) converting the silica precursor component (A) and the optionally compounds (B) into a particulate oxide having an average particle size of from 1 to 50 nm;   (iii) treating the particulate oxide with a silane treatment agent having one or more covalently bonded tertiary amino groups or tertiary phosphine groups for obtaining the polycondensate displaying multiple covalently bonded tertiary amino groups or tertiary phosphine groups on the surface.   
     
     
         8 . (canceled) 
     
     
         9 . The dental composition according to  claim 1 , wherein in formula (I) or (II), L is a divalent linker group of formula (III) 
       
         
           
           
               
               
           
         
         wherein a is 0 or an integer of from 1 to 10, and Het is selected from the group consisting of sulfur, oxygen, and a nitrogen atom substituted with a hydrogen atom or a straight-chain C 1-6  alkyl group or a branched or cyclic C 3-6  alkyl group. 
       
     
     
         10 . The dental composition according to  claim 1 , wherein the dental composition is selected from the group consisting of dental glass ionomer cement, a dental cement, a dental adhesive composition, a dental bonding agent, a dental primer, a dental infiltrant, a pit and fissure sealant, a dental desensitizing composition, a pulp capping composition, a dental composite, and a sealing and protecting composition for naked tooth necks. 
     
     
         11 . The dental composition according to  claim 10 , wherein the dental composition further comprises
 (c) a reactive particulate filler, and   (d) a polyacidic polymer which is reactive with the reactive particulate filler in a cement reaction.   
     
     
         12 . The dental composition according to  claim 1 , wherein (a) the compound having a polymerizable double bond is selected from
 (a1) a water-soluble, hydrolysis-stable monomer having a single polymerizable double bond and optionally a carboxylic acid group or hydroxyl group; and   (a2) a water-soluble, hydrolysis-stable polymerizable crosslinker having at least two polymerizable carbon-carbon double bonds.   
     
     
         13 . A method of forming a dental composition, the method comprising:
 polymerizing a compound having a polymerizable double bond with a photosensitizer absorbing light in the range of from 400 to 800 nm and a particulate carrier displaying multiple covalently bonded tertiary amino groups and/or tertiary phosphine groups on the surface,   wherein the covalently bonded tertiary amino groups and/or tertiary phosphine groups are selected from moieties of the following formulae (I) and (II):   
       
         
           
           
               
               
           
         
         wherein 
         R 1  and R 2  which may be a same or different, and independently represent a C 1-6  straight-chain alkyl group, C 3-6  branched alkyl group or cyclic alkyl group; and 
       
       
         
           
           
               
               
           
         
         wherein L is a single bond or a divalent linker group. 
       
     
     
         14 . The method according to  claim 13 , wherein the particulate carrier is a nanoparticle or a microparticle. 
     
     
         15 . The method according to  claim 14 , wherein the particulate carrier is a polycondensate. 
     
     
         16 . The dental composition according to  claim 2 , wherein the nanoparticle is a polycondensate. 
     
     
         17 . The dental composition according to  claim 4 , wherein the microparticle has an average particle size of from 0.05 to 50 μm