title: Sulcus depth reproduction with polyvinyl siloxane impression material: effects of hydrophilicity and impression temperature.
abstract: OBJECTIVE
  To determine the sulcus penetration ability of hydrophilic and hydrophobic polyvinyl siloxane (PVS) impression materials by impression technique, temperature, and sulcus width.
  
  
  METHODS
  Hydrophilic Flexitime (FLE; Heraeus Kulzer) and its hydrophobic counterpart (EXP) without surfactant were investigated, using light (L), monophase (M), and heavy (H) consistencies. A truncated steel cone surrounded by a 2-mm-deep and 50-, 100-, or 200-microm-wide sulcus, simulating the gingival tissue with agar, served as the test model. Impressions were made with single-mix (L or M) and double-mix (LM or LH) techniques at 23 degrees C and 37 degrees C, respectively. The reproduced sulcus heights were measured with a 3D laser scanner. Data were analyzed by ANOVA and Tukey HSD (P < .05).
  
  
  RESULTS
  Irrespective of sulcus widths and temperature FLE-L penetrated deepest (> 1.9 mm); FLE-M, -LM, and-LH reproductions were shorter with narrow sulci. Reproductions of 50- and 100-microm sulci with EXP-L were shallower than with FLE-L. The shortest reproduction was, however, greater than 1.6 mm.
  
  
  CONCLUSIONS
  In spite of some significant differences found in sulcus-reproducing ability with hydrophilic and hydrophobic impression materials applied at different impression-making temperatures and with different techniques, the practical relevance is limited.
authors.affiliation: Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. takahashi.abm@tmd.ac.jp
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Takahashi
authors.forename: Werner J
authors.initials: WJ
authors.lastname: Finger
authors.forename: Rie
authors.initials: R
authors.lastname: Kurokawa
authors.forename: Masae
authors.initials: M
authors.lastname: Furukawa
authors.forename: Masashi
authors.initials: M
authors.lastname: Komatsu
mesh_terms: D000704:Analysis of Variance; D003760:Dental Impression Materials / Q000737:chemistry*; D003761:Dental Impression Technique; D005881:Gingiva / Q000033:anatomy & histology*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D003765:Models, Dental; D011145:Polyvinyls / Q000737:chemistry; D012212:Rheology; D012826:Silicone Elastomers / Q000737:chemistry; D012833:Siloxanes / Q000737:chemistry; D018709:Statistics, Nonparametric; D013696:Temperature; D014783:Viscosity; D017155:Wettability
chemical_list: D003760:Dental Impression Materials; D011145:Polyvinyls; D012826:Silicone Elastomers; D012833:Siloxanes; C034183:vinyl polysiloxane