METHOD FOR MAKING ONE-PIECE METAL FRAMES FOR REMOVABLE DENTURES BY THERMAL VACUUM STAMPING OF THERMOPLASTIC CAST PIECES (VERSIONS) Russian patent published in 2011 - IPC A61C13/00 A61C13/10 

FIELD: medicine.

SUBSTANCE: method involves a reverse procedure of setting of artificial teeth and wax reproduction of a denture basis in an articulator or an occluder, separation of a plaster model with a wax reproduction of the removable denture from the articulator or the occluder, and plastering of the wax reproduction of the removable denture in a flask. The wax composition is removed from the opened flask with marking a border of a one-piece metal frame in an orthopedic bed of a base of the flask with its bottom detached from the base. Further a thermoplastic cast piece is made in a vacuum-moulding machine with using plates of a thickness ranging 0.3 mm to 1 mm. Further the base of the bottomless flask is placed in the vacuum-moulding machine with its denture bed upwards under a thermoplastic plate, while a production process is started with fixing the thermoplastic plate in a movable clamping frame of the vacuum-moulding machine. An electric heater is used to heat the thermoplastic material, and after achieving an optimum flow point the frame with the thermoplastic plate is moved downwards to provide a contact of the thermoplastic plate and the base of the flask. It is combined with hermetic seal of a space between the thermoplastic plate and the base of the flask with evacuating air by means of a vacuum pump; a difference of atmospheric pressure and pressure over the base of the flask enables deformation of a thermoplastic plate which fits the base of the flask and is curved after contours of a denture bed in the base of the flask. The prepared impression is cooled, removed from the orthopedic bed of the base of the flask, then excess material is cut off by the frame borders to match with a specific denture, the edges are cleaned out. If necessary, desired retention holes and saw cuts of any configuration are formed in a cast frame piece with using dental instruments, and additional fragments for wax or thermoplastic cast moulding are glued to the thermoplastic cast piece with heated wax. The prepared cast thermoplastic piece is shaped both after vestibular, oral, palatal surfaces of the denture along the whole perimetre from outside, and after each of the surfaces separately. Then an internal surface of the thermoplastic cast piece is coated with a retention coating, namely a brush is used to lacquer the cast piece which is then powdered with small plastic balls and triangles of size 0.1 mm. The prepared thermoplastic cast piece is delivered to foundry laboratory. The one-piece metal frame prepared in foundry laboratory is finished, polished, either gilded, or coated with titanium nitrite or ceramics and placed in the orthopedic bed in the base of the flask; the bottom of the base of the flask is landed; thereafter a basis of the removable denture is moulded of acrylic resins and (or) silicone.

EFFECT: possibility to make the cast pieces practically of any configuration and complexity.

3 cl, 26 dwg