The present invention relates to a polymerizable composition, which comprises (a) at least one radically polymerizable oligomer, (b) at least one radically polymerizable monomer and (c) at least one initiator for the radical polymerization, characterized in that the radically polymerizable oligomer (a) is selected from the group consisting of aliphatic urethane (meth)acrylate oligomers, epoxy (meth)acrylate oligomers and polyether urethane (meth)acrylate oligomers, and the radically polymerizable monomer (b) is polyfunctional.