[The production of denture by preform compression molding method. Part 2. Model material and fittability]

A preform compression molding method to make polysulfone denture was reported previously by paper. Properties of the mold, adaptability of the molded denture to master model and the movement of artificial teeth were examined. It was necessary to raise the temperature of the crystbalite-stone model above 270 degrees C to obtain stable expansion. Mold made using 22 wt%-colloidal silica showed strong compressive strength under the compression molding condition. Displacement of artificial teeth between wax denture and polysulfone denture was independent of the mold expansion, and the displacement was equal to that of heat-curing acrylic denture. Adaptability of the molded denture to the master model was associated with expansion of the model. Good adaptability was obtained under the expansion of the model, such as setting expansion about 0.30% and total expansion 1.05-1.10%, with about 0.2 mm average discrepancy.