METHOD FOR MANUFACTURING HOLLOW OBTURATOR OF MAXILLARY RESECTION PROSTHESIS Russian patent published in 2003 - IPC

FIELD: medical engineering. SUBSTANCE: method involves carrying out packing and polymerizing under pressure in vertical and horizontal direction in a cell at the same time. The cell has lateral opening, slide valve and screw with external handle on one side and disk on the other side. Mold model is produced in the cell in horizontally placing the mold by filling lower and upper part of the cell in turn until gypsum hardens in each of them. The cell is disassembled so that a half of the model is in each cell part. Trapezoid stem is formed by connecting both halves of the cell and cutting out the stem in gypsum connecting model base with the lateral cell opening. The cell is opened into two halves and obturator is modeled from wax of predefined wall thickness. The cells halves are joined and gypsum is poured into the lateral opening. The gypsum is hold until its full hardening. The cell is opened and wax is removed by evaporating and gypsum stamp is produced. Then supporting stamp is manufactured. To do it, gypsum stamp with congruent surface is placed in the lower half of obturator model positioned in cell base with closed bottom. An auxiliary cell is used. This cell is a copy of upper cell part with cover. The auxiliary cell is put on over cell base and sand is supplied into it so that the protruding portion of the gypsum stamp is retained above the sand surface. The auxiliary cell is filled with gypsum and protruding portion imprint is produced after its being hardened. Two-staged packing is carried out. Paste-like plastic is poured into lower model part placed in the model base at the first packing stage. Gypsum stamp with congruent surface is placed over it and covered with the auxiliary cell with supporting stamp. The protruding gypsum stamp is superimposed over the supporting stamp. Packing is carried out in vertical and horizontal direction at the same time. Paste-like plastic is poured into the rest of the model placed in the upper part of the cell at the second stage. The second stage is completed in joining both cell parts. Packing takes place both in vertical and horizontal direction simultaneously. Then plastic polymerization takes place. EFFECT: uniform pressure distribution. 8 dwg