title: Detail reproduction, contact angles, and die hardness of elastomeric impression and gypsum die material combinations.
abstract: OBJECTIVE
  This study compared surface detail parameters, interfacial contact angles, and die hardness for some combinations of elastomeric impression and die materials.
  
  
  METHODS
  Representative polyvinyl siloxanes, polyether, polysulfide, and reversible hydrocolloid impression materials and Type IV, Type V, and resin reinforced-Type IV die materials were evaluated using a factorial design. For the evaluation of surface detail reproduction, the width of the thinnest continuous line observed and the visually observed shape of the thick line were determined from samples formed using a master die conforming to American Dental Association specification 19. The contact angle of freshly mixed die material on the set impression was measured using a contact angle goniometer. Finally, hardness of the die material was determined. After conversion of the data to ranks if necessary, 2-way analysis of variance with Ryan-Einot-Gabriel-Welsch (REGWQ) multiple comparison tests where appropriate were used to determine statistical significance.
  
  
  RESULTS
  The thinnest continuous line demonstrated statistically significant impression material effects, and the observed shape of the thick line showed both statistically significant impression material and die material effects. For both contact angle and die hardness, a statistically significant interaction between the impression and die materials was found.
  
  
  CONCLUSIONS
  Although statistically significant differences in each property were found, no specific combination of impression and die materials was identified as superior to another for all surface properties studied.
authors.affiliation: Naval Dental Research Institute, 310A, B Street, Building 1-H, Great Lakes, Illinois 60088-5259, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Ragain
authors.forename: M L
authors.initials: ML
authors.lastname: Grosko
authors.forename: M
authors.initials: M
authors.lastname: Raj
authors.forename: T N
authors.initials: TN
authors.lastname: Ryan
authors.forename: W M
authors.initials: WM
authors.lastname: Johnston
mesh_terms: D000704:Analysis of Variance; D002133:Calcium Sulfate / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry; D003734:Dental Casting Investment / Q000737:chemistry*; D003760:Dental Impression Materials / Q000737:chemistry*; D020724:Elastomers / Q000737:chemistry*; D004987:Ethers / Q000737:chemistry; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D003765:Models, Dental; D011145:Polyvinyls / Q000737:chemistry; D012117:Resins, Synthetic / Q000737:chemistry; D012833:Siloxanes / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry; D013499:Surface Properties
chemical_list: D003102:Colloids; D003734:Dental Casting Investment; D003760:Dental Impression Materials; D020724:Elastomers; D004987:Ethers; D011145:Polyvinyls; D012117:Resins, Synthetic; D012833:Siloxanes; D013440:Sulfides; C034183:vinyl polysiloxane; C032915:polysulfide; D002133:Calcium Sulfate