title: Sulcus reproduction with elastomeric impression materials: a new in vitro testing method.
abstract: OBJECTIVE
  Aim of this study was to investigate the depth reproduction of differently wide sulci with elastomeric impression materials by single- and double-mix techniques using a tooth and sulcus model, simulating clinical conditions.
  
  
  METHODS
  Impressions with one vinyl polysiloxane (VPS; FLE), two polyethers (PE; IMP and P2), and one hybrid VPS/PE elastomer (FUS) were taken from a truncated steel cone with a circumferential 2 mm deep sulcus, 50, 100 or 200 microm wide. The "root surface" was in steel and the "periodontal tissue" in reversible hydrocolloid. Single-mix impressions were taken with light-body (L) or monophase (M) pastes, double-mix impressions with L as syringe and M or heavy-body (H) as tray materials (n=8). Sulcus reproduction was determined by 3D laser topography of impressions at eight locations, 45 degrees apart. Statistical data analysis by ANOVA and multiple comparison tests (p<0.05).
  
  
  RESULTS
  For 200 microm wide sulci, significant differences were found between impression materials only: FLE=IMP>FUS=P2. At 50 and 100 microm width, significant differences were found between materials (IMP>FUS=FLE>P2) and techniques (L+H=L+M>M>L).
  
  
  CONCLUSIONS
  The sulcus model is considered useful for screening evaluation of elastomeric impression materials ability to reproduce narrow sulci. All tested materials and techniques reproduced 200 microm wide sulci to almost nominal depth. Irrespective of the impression technique used, IMP showed the best penetration ability in 50 and 100 microm sulci. Double-mix techniques are more suitable to reproduce narrow sulci than single-mix techniques.
authors.affiliation: Department of Preclinical Dentistry, School of Dental Medicine, University of Cologne, Kerpenerstr. 32, 50931 Cologne, Germany. wjfinger@aol.com
authors.forename: Werner J
authors.initials: WJ
authors.lastname: Finger
authors.forename: Rie
authors.initials: R
authors.lastname: Kurokawa
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Takahashi
authors.forename: Masashi
authors.initials: M
authors.lastname: Komatsu
mesh_terms: D003760:Dental Impression Materials; D003761:Dental Impression Technique; D020724:Elastomers; D005881:Gingiva / Q000033:anatomy & histology*; D008422:Materials Testing / Q000295:instrumentation; D003765:Models, Dental; D015203:Reproducibility of Results
chemical_list: D003760:Dental Impression Materials; D020724:Elastomers