Dental adhesive

Abstract

Non-aqueous dental adhesive comprising a mixture containing (i) one or more polymerizable monomers optionally containing an acidic group, (ii) a polymerization initiator, and (iii) a thermal polymerization inhibitor of the following formula (I): wherein R′ 1 represents a hydrogen atom, or a saturated hydrocarbon group having 1 to 18 carbon atoms. R′ 2 , which may be the same or different if more than one R′ 2 is present, independently represent a saturated hydrocarbon group having 1 to 18 carbon atoms, and c represents an integer of from 1 to 4, and (iv) optionally an organic solvent.

1 . Non-aqueous dental adhesive comprising a mixture containing
 (i) one or more polymerizable monomers optionally containing an acidic group,   (ii) a polymerization initiator, and   (iii) a thermal polymerization inhibitor of the following formula (I):   
     
       
         
         
             
             
         
       
       
         wherein 
         R′ 1  represents
 a hydrogen atom, or a saturated hydrocarbon group having 1 to 18 carbon atoms. 
 
         R′ 2 , which may be the same or different if more than one R′ 2  is present, independently represent
 a saturated hydrocarbon group having 1 to 18 carbon atoms, and 
 
         c represents an integer of from 1 to 4, 
       
       (iv) optionally an organic solvent. 
     
   
   
       2 . The dental adhesive according to  claim 1 , which is stable at storage for at least 10 days at 60° C. 
   
   
       3 . The dental adhesive according to  claim 1  or  2 , wherein the saturated hydrocarbon group is a straight chain or branched C 1-18  alkyl group or a C 3-8  cycloalkyl group optionally substituted by one or more C 1-5  alkyl groups or a C 4-8  cycloalkylalkyl group optionally substituted by one or more C 1-5  alkyl groups. 
   
   
       4 . The dental adhesive according to any one of the preceding claims, wherein R′ 2  is a tert.-butyl group. 
   
   
       5 . The dental adhesive according to any one of the preceding claims, wherein the inhibitor is TBHQ or BHA. 
   
   
       6 . The dental adhesive according to any one of the preceding claims, wherein the inhibitor is contained in an amount of from 0.01 to 0.5 mol %. 
   
   
       7 . The dental adhesive according to any one of the preceding claims, wherein the aqueous mixture further contains an organic water soluble solvent selected from the group of alcohols and ketones such as ethanol, propanol, butanol, acetone, methyl ethyl ketone. 
   
   
       8 . The dental adhesive according to any one of the preceding claims, wherein said polymerization initiator is a photo initiator such as camphor quinone. 
   
   
       9 . The dental adhesive according to any one of the preceding claims, which further contains an inorganic filler and/or an organic filler; preferably the filler is a nanofiller. 
   
   
       10 . Use of a compound of the following formula (I): 
     
       
         
         
             
             
         
       
       wherein 
       R′ 1  represents
 a hydrogen atom, or a saturated hydrocarbon group having 1 to 18 carbon atoms. 
 
       R′ 2 , which may be the same or different if more than one R′ 2  is present, independently represent
 a saturated hydrocarbon group having 1 to 18 carbon atoms, and 
 
       c represents an integer of from 1 to 4, 
       as a thermal polymerization inhibitor in a dental composition.