Comparative evaluation of few physical properties of epoxy resin, resin-modified gypsum and conventional type IV gypsum die materials: an in vitro study.

AIM To compare and evaluate few physical properties of epoxy resin, resin-modified gypsum and conventional type-IV gypsum die material. MATERIALS AND 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. CONCLUSION Epoxy resin exhibited superiority in dimensional accuracy, surface detail reproduction and transverse strength and is nearest to the standards of accurate die material.