Edition V17N01 | Year 2020 | Editorial Artigo de Pesquisa | Pages 102 to 111
ABSTRACT: Objective: The aim of this study was to evaluate and compare the dimensional accuracy of models made with type IV dental stone and epoxy resin with different base/catalyst pastes ratios. Methods: A metallic maxillary model with 14 and 16 teeth prepared for full crown without 15 tooth was used for the impression. The impressions were performed with addition silicone (Express XT). The models (n = 10) were made with type IV dental stone (Durone, Dentsply), epoxy resin (Sikadur 32, Sika) with 2:1 ratio (base/ catalyst pastes) and modified epoxy resin with a 2:0.8 ratio (base/catalyst pastes). The dimensional change were measured with a digital caliper on the occlusal (M-D), cervical (V-P) and occlusal-cervical (O-C) surfaces. Three measurements were made on each surface. The data were analyzed by analysis of variance (one-way ANOVA) and Tukey’s test (α = 0.05). Results: On V-P surface (16), the modified epoxy resin showed differences with dental stone. On M-D (14 and 16), the dental stone showed no difference with metallic model, however the epoxy resin and the modified epoxy resin showed differences with metallic model well as dental stone. On O-C surface (14) there was a difference in dimensional accuracy between epoxy resins and dental stone. On O-C surface (16), the dental stone showed no difference compared to the metallic model. Dental stone showed 0.27% of horizontal expansion and 2.85% of vertical expansion. The epoxy resin showed -1.15% (horizontal) and from -1.00% to -2.94% (vertical) shrinkage mean. Conclusions: Type IV dental stone special showed no dimensional change with metallic model. Epoxy resin, regardless of the proportion used, showed the highest values of dimensional change (shrinkage).