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.

Impact of Aging on the Accuracy of 3D-Printed Dental Models: An In Vitro Investigation

“…Therefore, the question of clinical relevance remains, provided that the prosthetic reconstruction can be completed on the model within 3 or 4 weeks and that the models have been properly stored during this time (constant conditions at 20 • C and 50% humidity without direct light exposure). It must be critically emphasized that the dimensional changes of the 3D-printed models were small and comparable to investigations analyzing the accuracy of dental stone casts obtained from classical impression taking [24,25].…”

Influence of water/powder ratio in the mineral and synthetic casts

“…Moreover, high accuracy is required to reproduce details and for dimensional stability [1][2][3] . Type IV and V casts are the materials of choice in these cases, as they have favorable mechanical properties such as high resistance, minimal setting expansion, and high surface hardness [4][5][6][7] . Depending on the fabrication process, casts may be classified as mineral or synthetic.…”

Analysis of linear dimensional change of different materials used for casting dental models: plaster type 4, nanocomposites carbon nanostructures, polyurethane resin and epoxy resin

“…17 According one author, a common deficiency is failure to follow basic principles inherent to the manipulation of impression materials. 18 In all studied impression techniques, the addition silicones produced more accurate stone casts than the condensation silicones. 15 There is a need for compatibility 19 between impression and casting materials for faithful models.…”