title: Changing the bonding force of impression tray to edentulous maxillary jaw simulator with impression valve system: in vitro study.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effect of an impression valve system (IVS) on the bonding force between an impression tray and an edentulous maxillary jaw.
  
  
  METHODS
  In this in vitro study, a polyether-coated maxillary jaw simulator (PM) was used to model an edentulous maxillary jaw. The IVS was placed into individual impression trays. An irreversible hydrocolloid impression was taken of the PM when the IVS was open and closed. The impression tray bonding force was measured using a digital dynamometer. Student's t-test was used to determine the significance of the difference between these two groups.
  
  
  RESULTS
  The impression tray was more easily separated from the PM when the IVS was open (108 ± 3.9 N). The separation was more difficult when the IVS was closed (153.7 ± 14.2 N). The difference between these two findings (P = 0.000) was significant.
  
  
  CONCLUSIONS
  The use of an IVS facilitates the removal of the impression tray from the mouth when taking impressions from an edentulous maxillary jaw.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, University of Abant Izzet Baysal, Bolu, Turkey.
authors.forename: Y Z
authors.initials: YZ
authors.lastname: Akpinar
authors.forename: B
authors.initials: B
authors.lastname: Yilmaz
authors.forename: N
authors.initials: N
authors.lastname: Tatar
authors.forename: Z
authors.initials: Z
authors.lastname: Demirtag
mesh_terms: D003760:Dental Impression Materials; D003761:Dental Impression Technique; D006801:Humans; D066298:In Vitro Techniques; D007575:Jaw, Edentulous; D008437:Maxilla
chemical_list: D003760:Dental Impression Materials