The plastic block useful for the production of dental restorations or restoration part using pressing technology, consists of an open-pore and closed-pore foamed plastic. The foamed plastic has a density of smaller than 130 kg/m 3>, a high rigidity at 20-40[deg] C and an average pore diameter of 0.05-0.15 mm, and is dimensionally stable, watertight and burned out in residue free manner. A plastic holder is mounted on the plastic block.