Abstract: A device for making, duplicating and fixing dental models in articulator, using dental replicas (19) of plaster or other material with bases (20) for the manufacture of dental models (18). The device incorporates at least three pins (3) that have elements to be embedded in the bases (20) in charge of said pins (3) for positioning and fixing the dental models (18) to platens (7) that have a minimum of three protruding protrusions (8) on its surface and arranged to fit with the pins (3) and, where appropriate, provide a releasable connection with the pins (3). The platens (7) are attached to the articulator (1) with a height or ratio (h) between protrusions (8) of the platens (7), upper and lower, preset and reproducible.

Abstract: A coupling structure between a screw head and a tightening tool includes a recess (3) with a curved concave surface on the free base of the head (1) of the screw (2) and a protuberance (6) with a curved convex surface finishing the end of the tool (5). The recess has axial projections (4) internally and the protuberance (6) has meridional grooves (7).