A method is provided for producing a dental prosthesis from a blank using a CAD/CAM device, wherein the blank consists partially of base material and partially of tooth material, and a boundary surface between these materials is formed as a wave, the wave crests and wave valleys of which alternate with each other along the outer periphery of the blank. The apex of each wave crest extends substantially radially with respect to the blank. The CAD/CAM device fixes the position of a retention part, which serves to fasten the prosthesis to the alveolar crest of a patient, in particular of an external telescope, of a cover of a bar, or of an abutment in the prosthesis in such a way that it passes through the boundary surface. The retention part is fastened by means of gluing or incorporation by polymerisation.