To provide a paste-like polymerizable composition in which two or three pastes are intimately mixed with each other to polymerize, the pastes not gelling and their polymerization curing times being stable, even when the pastes have been preserved for a long time before the polymerization, the paste-like polymerizable composition comprising a first paste containing (a) a (meth)acrylate having at least one unsaturated double bond, (b) a filler and (c) a pyrimidinetrione derivative; and a second paste containing (a) a (meth)acrylate having at least one unsaturated double bond, (b) a filler, (d) an organic halide and (e) an organometallic compound, or a third paste containing (a) a (meth)acrylate having at least one unsaturated double bond, (b) a filler and (d) an organic halide and a fourth paste containing (a) a (meth)acrylate having at least one unsaturated double bond, (b) a filler and (e) an organometallic compound.
To separate a catalyst for polymerizing a monomer contained in a liquid or paste dental composition containing at least a monomer, such as a dental resin cement, an autopolymerizing dental resin or a resin-reinforeced dental glass ionomer cement, from the liquid or paste dental composition to thereby improve storage stability of the dental composition and reduce number of division of the dental composition, an extrusion nozzle for a dental composition mounted on one end of an extruder for extruding a liquid or paste dental composition containing at least a monomer, the extrusion nozzle contains a catalyst for polymerizing the monomer contained in the dental composition during extrusion, and the catalyst is attached to an inner wall of an extruding channel of the extrusion nozzle.