title: Accuracy of the second pour casts using dual-arch trays.
abstract: OBJECTIVE
  To compare, in vitro, the accuracy between dental stone casts obtained from the first and the second pour using metallic (Smart) and plastic (Triple Tray) dual-arch trays.
  
  
  METHODS
  The impressions were taken using Flexitime® vinyl polysiloxane from a typodont model with a mandibular right first molar prepared for a full crown. Ten impressions were made with each tray and poured using type IV die stone. After 1 hour, the casts were removed from the impressions and, 1-hour later, second pours were completed. The mesio-distal and the buccal-lingual widths at the gingival margin of the prepared tooth on the cast were measured in a perfil projector. The results were submitted to Student's t-test (α=0.05) using SPSS version 10.0.
  
  
  RESULTS
  There was a statistically significant difference between the first and second pours using the plastic tray in the mesio-distal width.
  
  
  CONCLUSIONS
  It could be suggested that a repeated pour is more accurate using a metallic tray.
authors.affiliation: Pontificial Catholic University of Rio Grande do Sul, Av. Ipiranga 6681, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Josué Ricardo
authors.initials: JR
authors.lastname: Broilo
authors.forename: Paula Cristine
authors.initials: PC
authors.lastname: Ghiggi
authors.forename: Gilberto Antonio
authors.initials: GA
authors.lastname: Borges
authors.forename: Luiz Henrique
authors.initials: LH
authors.lastname: Burnett
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Spohr
mesh_terms: D003442:Crowns; D003760:Dental Impression Materials; D003761:Dental Impression Technique / Q000295:instrumentation; D006801:Humans; D008670:Metals; D003765:Models, Dental; D010969:Plastics; D011145:Polyvinyls; D015203:Reproducibility of Results; D012833:Siloxanes; D018709:Statistics, Nonparametric
chemical_list: D003760:Dental Impression Materials; D008670:Metals; D010969:Plastics; D011145:Polyvinyls; D012833:Siloxanes; C034183:vinyl polysiloxane