Dental impression material

Abstract

The present invention relates to a dental impression material adapted to be cured by visible light, comprising a compound having one or more aliphatic unsaturated groups, a compound containing at least one silicon-bonded hydrogen atom and not having more than three hydrogen atoms attached to any one silicon atom, a photoactivatable catalyst component, and a specific initiator component.

1 . A dental impression material adapted to be cured by light having a wavelength in the range of from 200 to 800 nm, comprising:
 (i) a compound having one or more aliphatic unsaturated groups;   (ii) a compound containing at least one silicon-bonded hydrogen atom and not having more than three hydrogen atoms attached to any one silicon atom;   (iii) a particulate filler;   (iv) a photoactivatable metal catalyst component;   (v) a retarder, and   (vi) optionally a photosensitizes   wherein the retarder is different from the compound having one or more aliphatic unsaturated group according to component (i).   
     
     
         2 . The dental impression material according to  claim 1 , wherein the photoactivatable metal catalyst component contains a transition metal selected from the group consisting of Pt, Pd, Rh, Co, Ni, Ir and Ru. 
     
     
         3 . The dental impression material according to  claim 1 , wherein the dental impression material further comprises a stabilizer. 
     
     
         4 . The dental impression material according to  claim 1 , wherein the photosensitizer when present 2-isopropylthioxanthone or 1-Chloro-4-propoxy-9H-thioxanthen-9-one. 
     
     
         5 . The dental impression material according to  claim 1 , wherein the dental impression material is a two-pack composition. 
     
     
         6 . The dental impression material according to  claim 1 , wherein the compound having one or more -aliphatic, unsaturated groups of component (i) is a linear vinyl group-containing polymethylsiloxane having a molecular weight of more than 5000 Da, and the retarder of component (v) is a cyclic vinyl-group-containing polymethylsiloxane having a molecular weight of at most 5000 Da. 
     
     
         7 . A method for preparing a dental impression, said method comprising: providing a dental impression material comprising;
 (i) a compound having one or more aliphatic unsaturated groups;   (ii) a compound containing at least one silicon-bonded hydrogen atom and not having more than three hydrogen atoms attached to any one silicon atom;   (iii) a particulate filler;   (iv) a photoactivatable metal catalyst component;   (v) a retarder, and   (vi) optionally a photosensitizer;   wherein the retarder is different from the compound having one or more aliphatic unsaturated group according to component (i);   (b) taking an impression of a dental structure; and   (c) curing the dental impression material with light having a wavelength in the range of 200 to 800 nm.   
     
     
         8 . (canceled) 
     
     
         9 . The dental impression material according to  claim 2 , wherein the metal catalyst component contains a transition metal compound selected from platinum (II)acetylacetonate and (Cp)Pt(C 1-6  alkyl) 3 , wherein Cp represents a cyclopentadienyl group which may be substituted by one or more alkyl groups. 
     
     
         10 . The dental impression material according to  claim 1 , wherein the photoactivatable metal catalyst component is a Karstedt catalyst.