An impression device includes an impression taking-cap (6) designed for adapting on an implant (1) or the like along one prosthetic bearing surface formed by a mount (2) and an annular peripheral shoulder (4). The impression taking-cap (6) includes an annular bearing surface (1) bearing on the annular peripheral shoulder (4) when placed in the mouth. The impression taking-cap (6) is maintained in this position by a retaining peg (13) extending axially from the bottom surface (8) in an inner chamber (9) and capable of axial engagement by friction in a retaining female geometry (2b) provided at the end of the mount (2). It is thus possible to insure an axial fixation of the impression taking-cap (6) on the implant (1) or the like and thus a very reliable impression taking of the annular peripheral shoulder (4), which results in the peripheral tightness of the prosthesis on the implant (1).