title: A micro-mechanical evaluation of the effects of die hardener on die stone.
abstract: The purpose of this study was to investigate the properties of a die hardener penetrated layer and evaluate its protective effects on the surface of die stone. A commercial die hardener (PDQ die hardener, Whipmix corp., USA) was tested on a die stone (GC Fujirock EP die stone, GC Europe, Belgium) and a dental plaster (Dental Stone, United States Gypsum Company, USA). Nanoindentation and micro-scratch tests were performed on both coated and uncoated specimens. The scratch damage was observed by SEM and the penetration depth of die hardener was detected by the affiliated EDX. Upon drying, the die hardener penetrated into the die stone to a depth of 3-5 microm, and deposited a thin film on the surface of die stone. Although the die hardener penetrated layer did not show improved mechanical properties, the die hardener film on the surface did protect the specimens from abrasion damage.
authors.affiliation: Sir John Walsh Institute, School of Dentistry, University of Otago, Dunedin, New Zealand. lihong.he@otago.ac.nz
authors.forename: Li-Hong
authors.initials: LH
authors.lastname: He
authors.forename: Ludwig Jansen
authors.initials: LJ
authors.lastname: van Vuuren
authors.forename: Nina
authors.initials: N
authors.lastname: Planitz
authors.forename: Michael V
authors.initials: MV
authors.lastname: Swain
mesh_terms: D002133:Calcium Sulfate / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing / Q000295:instrumentation; D003890:Desiccation; D018130:Diamond / Q000737:chemistry; D055119:Elastic Modulus; D004577:Electron Probe Microanalysis; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D018583:Pliability; D013314:Stress, Mechanical; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D003764:Dental Materials; D013501:Surface-Active Agents; D018130:Diamond; D002133:Calcium Sulfate