Radical polymerization inhibitors for light-curable dental materials

Abstract

The invention relates to light-curable dental materials comprising at least one polymerizable compound, a photopolymerization initiator and a polymerization inhibitor.

1 . A light-curable dental material comprising
 (i) a polymerizable compound having at least one ethylenically unsaturated bond;   (ii) a photopolymerization initiator for polymerizing said polymerizable compound, and   (iii) a 1,3-dipolar compound.   
     
     
         2 . The light-curable dental material according to  claim 1 , wherein said 1,3-dipolar compound is a polymerization inhibitor. 
     
     
         3 . The light-curable dental material according to any one of  claim 1  or  2 , wherein the 1,3-dipolar compound is a sydnone of the following formula (VII): 
       
         
           
           
               
               
           
         
       
       wherein R 4  and R 5  are independently hydrogen or a substituted or unsubstituted aryl group, arylalkyl group, alkyl group, alkenyl group, alkynyl group, cycloalkyl group or cycloalkylalkyl group. 
     
     
         4 . The light-curable dental material according to any of  claim 1  or  2 , wherein the 1,3-dipolar compound is a nitrone of the following formula (VIII): 
       
         
           
           
               
               
           
         
       
       wherein
 R 6 , R 7  and R 8  are independently hydrogen; or a substituted or unsubstituted aryl group, arylalkyl group, alkyl group, alkenyl group, alkynyl group, cycloalkyl group or cycloalkylalkyl group; or R 7  and R 8  form a 5-membered, 6-membered or 7-membered nitrogen-containing ring together with atoms to which they are attached to. 
 
     
     
         5 . The light-curable dental material according to any one of  claim 1  or  2 , wherein the 1,3-dipolar compound is a munchnone of the following formula (II): 
       
         
           
           
               
               
           
         
       
       wherein R 1 , R 2 , and R 3  are independently hydrogen; or a substituted or unsubstituted aryl group, arylalkyl group, alkyl group, alkenyl group, alkynyl group, cycloalkyl group or cycloalkylalkyl group. 
     
     
         6 . The light-curable dental material according to any one of  claim 1  or  2 , wherein the 1,3-dipolar compound is an azide of the following formula (IV): 
       
         
           
           
               
               
           
         
       
       wherein R 1  is a substituted or unsubstituted aryl group, arylalkyl group, alkyl group, alkenyl group, alkynyl group, cycloalkyl group or cycloalkylalkyl group. 
     
     
         7 . The light-curable dental material according to any one of  claim 1  or  2 , wherein the 1,3-dipolar compound is a diazo compound of the following formula (V): 
       
         
           
           
               
               
           
         
       
       wherein R 1  and R 2  are independently hydrogen; or a substituted or unsubstituted aryl group, arylalkyl group, alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkylalkyl group or benzoyl group. 
     
     
         8 . The light-curable dental material according to any one of  claim 1  or  2 , wherein the 1,3-dipolar compound is a nitrilylide of the following formula (VI): 
       
         
           
           
               
               
           
         
       
       wherein R 1 , R 2 , and R 3  are independently hydrogen; or a substituted or unsubstituted aryl group, arylalkyl group, alkyl group, alkenyl group, alkynyl group, cycloalkyl group or cycloalkylalkyl group, preferably one of R 1 , R 2 , and R 3  is not hydrogen. 
     
     
         9 . The light-curable dental material according to any one of  claims 3  to  8 , wherein each of the substituted aryl groups, arylalkyl groups, alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups or cycloalkylalkyl groups has 1 to 5 substituents that are independently selected from C 1-6 -alkyl, C 1-6 -alkoxy, hydroxy, halo, cyano, nitro, nitroso, mercapto, carboxyl, sulfonate, thiol, amino, trifluoromethyl and polyoxyalkylene groups. 
     
     
         10 . The light-curable dental material according to any one of  claims 1  to  9 , wherein said photopolymerization initiator is an α,β-diketone. 
     
     
         11 . The light-curable dental material according to any one of  claims 1  to  10 , further comprising a solid particulate filler. 
     
     
         12 . The light-curable dental material according to any one of  claims 1  to  11 , wherein the content of said 1,3-dipolar compound based on the total weight of all polymerizable compounds in the dental material is from 0.01 to 2.0, preferably from 0.05 to 1.0, and more preferably from 0.1 to 0.5 weight-%. 
     
     
         13 . The light-curable dental material according to any one of  claims 1  to  12 , wherein the light-curable dental material is selected from the group consisting of a dental composite, dental ionomer cement, dental sealant, dental adhesive, dental adhesion promoter, dental adhesion preventer, dental cement, dental crown-forming material, and dental impression material. 
     
     
         14 . Light-cured dental material obtained or obtainable by light curing the light-curable dental material of any one of  claims 1  to  13 . 
     
     
         15 . Use of a 1,3-dipolar compound as a polymerization inhibitor in a light-curable dental material. 
     
     
         16 . A light-curable surface coating, light-curable ink, or light-curable adhesive material comprising a polymerizable compound having at least one ethylenically unsaturated bond and a 1,3-dipolar compound as a polymerization inhibitor. 
     
     
         17 . The light-curable surface coating, light-curable ink, or light-curable adhesive material of  claim 16 , wherein the 1,3-dipole is a sydnone or a nitrone.