Evaluation of a compactation of gypsum for prosthetic purposes as an alternative to achieve a proper water/powder relationship

Abstract

The water-powder relationship is essential to achieve a proper performance of gypsum for prosthetic purposes. The ideal measure can be obtained with a balance, but this is clinically unavailable, once it is timeconsuming. A powder-compacting technique using a volume measurement is suggested in order to substitute the balance. The technique consists of using a gypsum meter within the gypsum bag. While the operator holds the gypsum meter with one hand, the palm of the other hand is pressed over the surface of the meter, supported by the ventral aspect of the fingers of the hand that is pressing. This procedure is based upon three compactation movements for each operator, then counting the average of compacting sample. Each of the ten operators repeated six times the procedure, and the final average was defined. The resulting samples for each procedure, of each operator, were weighted, and the statistical analysis showed significant differences (p = 0,006) among the operators.