title: Dimensional accuracy of stone casts obtained with multiple pours into the same mold.
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.
authors: Department of Restorative Dentistry, Federal University of Piaui (UFPI), Terezina, PI, Brazil.
authors: Valdimar da Silva
authors: Vda S
authors: Valente
authors: Artêmio Luiz
authors: AL
authors: Zanetti
authors: Pedro Paulo
authors: PP
authors: Feltrin
authors: Ricardo Tatsuo
authors: RT
authors: Inoue
authors: Carmem Dolores Vilarinho Soares
authors: CD
authors: de Moura
authors: Luiz Evaldo de Moura
authors: LE
authors: Pádua