Polymer blocks for use in the pressing technique, which include a polymer foam and use of the polymer blocks for the production of dental restorations or restoration parts by pressing. The polymer block may be selected from the group consisting of polystyrene, polymethyl methacrylate, polyurethane, phenol- or urea-formaldehyde resins, polyethylene, polypropylene and styrene-acrylonitrile copolymers.