Dimensional Accuracy of Stone Casts Obtained with Multiple Pours into the Same Mold. (24th December 2012) - Valente, Valdimar da Silva
Abstract : Aim . The aim of the present study was to compare the dimensional accuracy of stone casts obtained with vinyl polysiloxane molds through the double-impression technique with three pours into the same mold. Methods . A stainless steel master model was constructed simulating a three-unit fixed prosthesis. Twelve impressions were taken of this master model with addition silicone, using the double-impression technique. Three pours of type IV gypsum were then made into each mold, thus producing 36 casts. The pours were made 1 hour, 6 hours and 24 hours after the impression procedure. Next, intra- and interabutment measurements were made in a coordinate measuring machine. Results . Comparative analysis of the dimensional accuracy of stone casts resulting from multiple pours was not statistically significant in pours first and second (P > 0.05 ). These values, however, were statistically significant at third pour in the height in abutment 1 and upper distance interabutment. Conclusion . The wait time (1 hour, and 6 hours) observed before pouring the stone into the same molds did not cause significant dimensional accuracy of the casts.