The invention relates to a parts assembly for a prosthesis, particularly a cervical spine intervertebral disc prosthesis, comprising two base parts (1, 2), which are coupled to one another in an articulated manner by means of coupling parts (11, 12) formed on said base parts. These base parts, together with an associated coupling part, are provided as a single piece. The base parts and the coupling parts are made of one material, which is selected from the following group of materials: polyetherketone (PEK) polyetheretherketone (PEEK), polyacryletherketone (PAEK), polyetherketoneketone (PEKK), polyetherketoneetherketoneketone (PEKEKK) and polyetherketoneetherketone (PEKEK).