title: Influence of delayed pouring on irreversible hydrocolloid properties.
abstract: The aim of this study was to evaluate the physical properties of irreversible hydrocolloid materials poured immediately and after different storage periods. Four alginates were tested: Color Change (Cavex); Hydrogum (Zhermack); Hydrogum 5 (Zhermack); and Hydro Print Premium (Coltene). Their physical properties, including the recovery from deformation (n = 3), compressive strength (n = 3), and detail reproduction and gypsum compatibility (n = 3), were analyzed according to ANSI/ADA specification no. 18. Specimens were stored at 23ºC and humidity and were then poured with gypsum immediately and after 1, 2, 3, 4, and 5 days. The data were analyzed by two-way analysis of variance (ANOVA) and Tukey's test at p < 0.05. All of the alginate impression materials tested exhibited detail reproduction and gypsum compatibility at all times. Hydro Print Premium and Hydrogum 5 showed recovery from deformation, as established by ANSI/ADA specification no. 18, after 5 days of storage. As the storage time increased, the compressive strength values also increased. Considering the properties of compounds' recovery from deformation, compressive strength, and detail reproduction and gypsum compatibility, irreversible hydrocolloids should be poured immediately.
authors.affiliation: Dental Materials Laboratory, School of Dentistry, Univ Federal do Rio Grande do Sul - UFRGS, Porto Alegre, RS, Brazil.
authors.forename: Stéfani Becker
authors.initials: SB
authors.lastname: Rodrigues
authors.forename: Carolina Rocha
authors.initials: CR
authors.lastname: Augusto
authors.forename: Vicente Castelo Branco
authors.initials: VC
authors.lastname: Leitune
authors.forename: Susana Maria Werner
authors.initials: SM
authors.lastname: Samuel
authors.forename: Fabrício Mezzomo
authors.initials: FM
authors.lastname: Collares
mesh_terms: D000704:Analysis of Variance; D002133:Calcium Sulfate / Q000737:chemistry; D003102:Colloids / Q000737:chemistry*; D019245:Compressive Strength; D003760:Dental Impression Materials / Q000737:chemistry*; D003761:Dental Impression Technique; D006801:Humans; D008422:Materials Testing; D013499:Surface Properties; D013997:Time Factors
chemical_list: D003102:Colloids; D003760:Dental Impression Materials; D002133:Calcium Sulfate