Method for bleaching teeth and bleaching agent for teeth

Abstract

A method for bleaching teeth comprises steps of applying a solution containing nitrogen-deeped titanium oxide powder on a surface of teeth, and irradiating the applied part with light to bleach the teeth based on a photocatalytic action thus produced, and a bleaching agent for teeth suitable for carrying out the method comprises a solution containing nitrogen-deeped titanium oxide powder, in which the nitrogen-deeped titanium oxide is preferably a photocatalytic substance having a Ti—O—N structure having a titanium oxide crystalline lattice containing nitrogen and exhibiting a photocatalytic action in a visible light region, the bleaching agent contains preferably 0.01 to 5% by weight of the nitrogen-deeped titanium oxide powder, the nitrogen-deeped titanium oxide powder has a specific surface area of from 10 to 500 m 2 /g, the solution contains water and/or an alcohol as a solvent, and the bleaching agent further contains preferably 0.5 to 20% by weight of a thickener, 1 to 20% by weight of hydrogen peroxide, and 2 to 45% by weight of urea peroxide.

What is claimed is:  
     
         1 . A method for bleaching teeth comprising steps of applying a solution containing nitrogen-deeped titanium oxide powder on a surface of teeth, and irradiating the applied part with light to bleach the teeth based on a photocatalytic action thus produced.  
     
     
         2 . A method for bleaching teeth as claimed in  claim 1 , wherein visible light is irradiated as the light.  
     
     
         3 . A bleaching agent for teeth comprising a solution containing nitrogen-deeped titanium oxide powder, which is attached to a surface of teeth and irradiated with light to bleach the teeth based on a photocatalytic action thus produced.  
     
     
         4 . A bleaching agent for teeth as claimed in  claim 3 , wherein the nitrogen-deeped titanium oxide is a photocatalytic substance having a Ti—O—N structure having a titanium oxide crystalline lattice containing nitrogen and exhibiting a photocatalytic action in a visible light region.  
     
     
         5 . A bleaching agent for teeth as claimed in  claim 4 , wherein the nitrogen-deeped titanium oxide contains titanium oxide containing no nitrogen on the outer surface thereof.  
     
     
         6 . A bleaching agent for teeth as claimed in  claim 4 , wherein a surface of the nitrogen-deeped titanium oxide comprises a ceramic carried in an island form, needle form or a mesh form.  
     
     
         7 . A bleaching agent for teeth as claimed in  claim 4 , wherein a surface of the nitrogen-deeped titanium oxide carries a charge separation substance.  
     
     
         8 . A bleaching agent for teeth as claimed in any one of  claims 3  to  7 , wherein the bleaching agent for teeth contains 0.01 to 5% by weight of the nitrogen-deeped titanium oxide powder.  
     
     
         9 . A bleaching agent for teeth as claimed in any one of  claims 3  to  8 , wherein the nitrogen-deeped titanium oxide powder has a specific surface area of 10 to 500 m 2 /g.  
     
     
         10 . A bleaching agent for teeth as claimed in any one of  claims 3  to  9 , wherein the solution contains water and/or an alcohol as a solvent.  
     
     
         11 . A bleaching agent for teeth as claimed in  claim 10 , wherein the alcohol is a polyhydric alcohol.  
     
     
         12 . A bleaching agent for teeth as claimed in any one of  claims 3  to  11 , wherein the bleaching agent for teeth further comprises 0.5 to 20% by weight of a thickener.  
     
     
         13 . A bleaching agent for teeth as claimed in any one of  claims 3  to  12 , wherein the bleaching agent for teeth further comprises 1 to 20% by weight of hydrogen peroxide.  
     
     
         14 . A bleaching agent for teeth as claimed in any one of  claims 3  to  13 , wherein the bleaching agent for teeth further comprises 2 to 45% by weight of urea peroxide.