title: Polymerization shrinkage strain of interocclusal recording materials.
abstract: OBJECTIVE
  The aim of this in vitro study was to investigate the polymerization shrinkage behavior and to measure the polymerization shrinkage-strain of interocclusal recording materials.
  
  
  METHODS
  The materials investigated in this study were five polyvinylsiloxane (Imprint Bite, Silagum Automix Bite, O-Bite, Blu-Mousse Classic and Exabite II), one polyether (Ramitec) and one dimethacrylatebased (Luxabite) materials. The polymerization shrinkage values of ten specimens for each material were measured by the Bonded-disk method at 1, 3, 5, 7 and 10 min after mixing at 37 degrees C. The amount of shrinkage-strain (%) was derived and all data were statistically analyzed by one-way ANOVA and the multiple comparison Scheffé test (alpha=0.05).
  
  
  RESULTS
  The representative shrinkage-strain kinetic graphs showed that all specimens shrank immediately, except Luxabite which expanded for the initial few seconds. After that, the shrinkage-strain values increased in the magnitude up to 10 min, but its rate decreased gradually with time. The shrinkage-strain values (0.18+/-0.03-0.16+/-0.03%) of O-Bite at 5, 7 and 10 min were significantly lower than the other materials, but Luxabite exhibited the highest values (3.10+/-0.17-3.30+/-0.16%).
  
  
  CONCLUSIONS
  The interocclusal recording materials investigated presented significantly different polymerization shrinkage-strain kinetics and showed dimensional changes even after the setting time indicated by respective manufacturers.
authors.affiliation: Graduate School of Dentistry, Ewha Womans University, Yangcheon-gu, Seoul, Republic of Korea.
authors.forename: Jung-hyun
authors.initials: JH
authors.lastname: Chun
authors.forename: Ahran
authors.initials: A
authors.lastname: Pae
authors.forename: Sung-hun
authors.initials: SH
authors.lastname: Kim
mesh_terms: D003760:Dental Impression Materials / Q000737:chemistry*; D006801:Humans; D007574:Jaw Relation Record / Q000295:instrumentation*; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D011145:Polyvinyls / Q000737:chemistry; D012833:Siloxanes / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors
chemical_list: D003760:Dental Impression Materials; C521416:Imprint II; D008689:Methacrylates; D011108:Polymers; D011145:Polyvinyls; D012833:Siloxanes; C034183:vinyl polysiloxane; C056844:Ramitec