Abstract: The device (1) for forming a dental prosthesis has at least one support (3) with a base (4) which in the use of the device (1) is inserted into a jawbone (13) of a patient or into a jaw model. The support (3) has a conical bearing surface (4n) and also a shoulder (7e) which faces the base (4) and for example is formed by a flank of an annular groove (7d). The device (1) has for the or each support (3) a cap (8) which bears with a conical countersurface (8f) on the conical bearing surface (4n) of the support (44) when the device (1) has been assembled. The cap (8) has a hole (8k) with an internal thread (8m) and with an axis (11) which forms an angle with the axis (10) of the two conical surfaces (4n, 8f). A screw (9) screwed into the hole (8k) engages with a tapering end section (9b) on the outer border (7f) of the shoulder (7e) and thus presses the countersurface (8f) against the bearing surface (4n).