The invention relates to a curable composition to be prepared by mixing a base paste and a catalyst paste, the base paste comprising (A) a hardenable compound comprising at least two aziridine moieties, and (B) a metal containing component containing anions and/or ligands, the metal containing component being present in an amount of about 0.1 to about 5 wt.-%, the metal being selected from Zn, Cu, Co, Ni, Ag and combinations thereof, the anions or ligands being selected from oxide, hydroxyl, (hydro)carbonate, sulphate, nitrate, halide, lactate, benzoate, wolframate, linear or branched aliphatic carboxylic acid anions, ligands having not more than two coordinating moieties and combinations thereof, the catalyst paste comprising (C) a Lewis acid,the composition optionally further comprising (D) a retarder, (E) filler and (F) additive(s).The invention also relates to a kit of parts, the use of a metal containing component as a means for reducing the curing time of a cationically curable composition and a method of taking a dental impression.
