title: Comparative evaluation of few physical properties of epoxy resin, resin-modified gypsum and conventional type IV gypsum die materials: an in vitro study.
abstract: OBJECTIVE
  To compare and evaluate few physical properties of epoxy resin, resin-modified gypsum and conventional type-IV gypsum die material.
  
  
  METHODS
  In the present study, dimensional accuracy, surface detail reproduction and transverse strength of three die materials like epoxy resin (Diemet-E), resin-modified gypsum (Synarock) and conventional type-IV gypsum (Ultrarock) are analyzed. For dimensional accuracy, master die (Bailey's die) is used and calibrations were made with digital microscope. For surface detail reproduction and transverse strength, rectangular stainless steel master die (Duke's die) was used and calibrations were made with Toolmaker's microscope and Instron universal testing machine respectively. One-way analysis of variance (ANOVA) was performed on the means and standard deviation for groups of each test.
  
  
  RESULTS
  The results of the study showed statistically significant difference among these materials in dimensional accuracy, surface detail reproduction and transverse strength.
  
  
  CONCLUSIONS
  Epoxy resin exhibited superiority in dimensional accuracy, surface detail reproduction and transverse strength and is nearest to the standards of accurate die material.
authors.affiliation: Department of Prosthodontics, MNR Dental College Hyderabad, Andhra Pradesh, India. drmanumds@yahoo.com
authors.forename: Manmohan Choudary
authors.initials: MC
authors.lastname: Gujjarlapudi
authors.forename: S Varalakshmi
authors.initials: SV
authors.lastname: Reddy
authors.forename: Praveen Kumar
authors.initials: PK
authors.lastname: Madineni
authors.forename: Kranti Kiran Reddy
authors.initials: KK
authors.lastname: Ealla
authors.forename: Venkata Narayana
authors.initials: VN
authors.lastname: Nunna
authors.forename: Sanjay Dutt
authors.initials: SD
authors.lastname: Manne
mesh_terms: D000497:Alloys; D002133:Calcium Sulfate / Q000138:chemical synthesis / Q000737:chemistry*; D055598:Chemical Phenomena; D003300:Copper; D003734:Dental Casting Investment / Q000138:chemical synthesis / Q000737:chemistry*; D003764:Dental Materials / Q000138:chemical synthesis / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D004853:Epoxy Resins / Q000138:chemical synthesis / Q000737:chemistry*; D006801:Humans; D006813:Humidity; D008422:Materials Testing; D003765:Models, Dental; D011208:Powders; D012117:Resins, Synthetic / Q000138:chemical synthesis / Q000737:chemistry*; D013193:Stainless Steel; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014618:Vacuum; D014867:Water / Q000737:chemistry; D015032:Zinc
chemical_list: D000497:Alloys; D003734:Dental Casting Investment; D003764:Dental Materials; D004853:Epoxy Resins; D011208:Powders; D012117:Resins, Synthetic; D014867:Water; D013193:Stainless Steel; C048399:brass; D003300:Copper; D015032:Zinc; D002133:Calcium Sulfate