The present invention relates to a dental flask -a cavity (2) defined by the side walls of said flask (1) apt to receive a three-dimensional reproduction of a dental cast (3) and to be filled up with a polymerizable material, - means (4) for locking said reproduction (3) inside said cavity (2), said locking means (4) comprising: - at least one screw apt to engage a corresponding thread made through side walls of said flask (1) so as to protrude inside said cavity (2) by an adjustable length (L)； and - at least one contact surface (5) for said reproduction (3)； said contact surface consisting of a peripheral surface of said cavity (2)； - support elements (6) of said screw with said reproduction (3)； wherein said at least one screw and said at least one contact surface are apt to cooperate so as to achieve a locking seat for said reproduction (3) inside said cavity (2).
