title: Investigation of dental materials as skin simulants for forensic skin/skull/brain model impact testing.
abstract: OBJECTIVE
  The purpose of this study was to measure the tear strength and hardness of four different dental silicones in comparison to that of porcine skin.
  
  
  METHODS
  Specimens were prepared (n = 20/group) according to ASTM D624-00, using three hydrophilic vinyl polysiloxane impression materials, one duplication silicone, and fresh porcine skin. A universal testing machine was used to strain each test specimen until complete rupture and calculate its tear strength (kNm(-1)). Failure analysis was then conducted using a stereoscopic zoom light microscope, as well as a scanning electron microscope (SEM). A shore A-type durometer was used to measure the hardness of all specimens.
  
  
  RESULTS
  The tear strength for the silicones ranged from 1.75 to 9.58 kNm(-1) and the pigskin from 3.65 to 56.40 kNm(-1). The mean shore hardness for the silicones ranged from 16.275 to 62.65DU and the pigskin had a mean shore hardness of 22.65DU, with p values <0.0125 (0.05/4). Failure analysis of the silicone materials showed the origin of failure being in the tension side of the specimens and typical failure patterns were observed. Examining the materials under a SEM revealed that materials with higher viscosity presented with a larger amount of filler particle content than silicones with low viscosity, with the duplication silicone having no filler content.
  
  
  CONCLUSIONS
  Dental silicones are a good alternative for skin in studies that require a skin simulant.
authors.affiliation: Sir John Walsh Research Institute, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand. falland.ohio@gmail.com.
authors.forename: Lisa
authors.initials: L
authors.lastname: Falland-Cheung
authors.affiliation: Sir John Walsh Research Institute, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Pittar
authors.affiliation: Sir John Walsh Research Institute, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand.
authors.forename: Darryl
authors.initials: D
authors.lastname: Tong
authors.affiliation: Sir John Walsh Research Institute, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand.
authors.forename: J Neil
authors.initials: JN
authors.lastname: Waddell
mesh_terms: D000818:Animals; D001930:Brain Injuries; D003760:Dental Impression Materials; D044707:Forensic Sciences; D006245:Hardness Tests; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008954:Models, Biological; D011145:Polyvinyls; D012828:Silicones; D012833:Siloxanes; D012867:Skin / Q000293:injuries; D012879:Skin Physiological Phenomena; D012886:Skull / Q000293:injuries; D013552:Swine; D014949:Wounds, Nonpenetrating
chemical_list: D003760:Dental Impression Materials; D011145:Polyvinyls; D012828:Silicones; D012833:Siloxanes; C034183:vinyl polysiloxane
keywords: Forensic head model; Pigskin; Silicone; Skin simulant