title: Characterization of mouthguard materials: physical and mechanical properties of commercialized products.
abstract: OBJECTIVE
  Contemporary mouthguard materials need to perform consistently over a wide range of possible temperatures (-20 to 40 degrees C). Therefore the specific aim of this study was to characterize commercialized mouthguard materials' properties and investigate the effect of temperature on these properties.
  
  
  METHODS
  Five commercially representative thermoplastic mouthguard materials (Essix Resin, Erkoflex, Proform-regular, Proform-laminate, and Polyshok) were tested. The durometer hardness, water absorption, tear strength, and impact attenuation of the mouthguard materials were measured according to ASTM D2240-05, D570-98 (2005), D624-00, and ASTM D6110-06f (modified) guidelines. Tests were conducted on five separate specimens at both room 23+/-2 degrees C and intra-oral 37+/-2 degrees C temperatures. Independent t-tests (alpha=0.05) were used to test for differences between room and intra-oral temperatures.
  
  
  RESULTS
  Material hardness decreased (p<0.05) from room to intra-oral temperatures for all mouthguard materials. Water absorption increased (p<0.05) from room to intra-oral temperatures for all mouthguard materials. Tear strength decreased (p<0.05) from room to intra-oral temperatures for all mouthguard materials. Impact attenuation between room and intra-oral temperatures was different (p<0.05) for the Erkoflex, Proform-laminate, and Polyshok material respectfully. However, there was no difference between temperatures for the Essix Resin (p=.058) or Proform-regular (p=.275) materials.
  
  
  CONCLUSIONS
  Temperature measureably affects the physical and mechanical properties of mouthguard materials. It is particularly noteworthy that none of the commercialized products met current ANSI and SAI standards for impact attenuation.
authors.affiliation: School of Human Performance, University of Southern Mississippi, Hattiesburg, MS 39406, USA. Trent.Gould@usm.edu
authors.forename: Trenton E
authors.initials: TE
authors.lastname: Gould
authors.forename: Scott G
authors.initials: SG
authors.lastname: Piland
authors.forename: Junghwan
authors.initials: J
authors.lastname: Shin
authors.forename: Charles E
authors.initials: CE
authors.lastname: Hoyle
authors.forename: Sergei
authors.initials: S
authors.lastname: Nazarenko
mesh_terms: D000042:Absorption; D019245:Compressive Strength; D003799:Dental Stress Analysis; D006244:Hardness; D008422:Materials Testing; D009064:Mouth Protectors / Q000145:classification / Q000592:standards; D011145:Polyvinyls; D012015:Reference Standards; D012117:Resins, Synthetic; D013314:Stress, Mechanical; D013696:Temperature; D013718:Tensile Strength; D014867:Water
chemical_list: D011145:Polyvinyls; D012117:Resins, Synthetic; D014867:Water; C016438:ethylenevinylacetate copolymer