Abstract: In order to activate, through a fine adjustment, the retention element (16) of an attachment for a partial, removable, dental prosthesis made up of two coulisses (1, 51), one of which being incorporated in the prosthesis (P) and the other (51) secured to a pillar tooth (D) there are utilized: a horizontal pivot (14) mounted in a sheath (2) and carrying, at one end, a retaining small head (16) and, at the other end, a bevel gear (5); and a cylindrical body (4') with vertical axis, mounted in a box (3) and carrying a bevel gear (4) which is in meshing engagement with the other hand gear (5). The base of the body (4') is provided with an operative groove (12) surfacing in the alveolar saddle (5) of the prosthesis (P). The rotation of the element (4') causes the displacement, along the pivot (14), of a plate (19) which compresses a counteracting spring (18) whose tensioning determines the retaining force of the attachment.