title: Stress relaxation properties of human dentin.
abstract: OBJECTIVE
  This study compared the stress relaxation properties of moist and air-dried human dentin to determine if air drying modifies this mechanical property.
  
  
  METHODS
  Cylindrical dentin specimens, prepared from human canine and maxillary incisor teeth, were subjected to a controlled compressive stress applied at a constant strain rate to a predetermined maximum value, and the stress relaxation response recorded. Groups of moist and air-dried specimens were tested at both low and high stress. After a period of 1 wk, the incisor specimens were retested.
  
  
  RESULTS
  The dentin exhibited a linear stress relaxation with the logarithm of time. Air-dried dentin consistently demonstrated a decreased stress relaxation. When subjected to a second high load, the air-dried dentin displayed significantly slower stress relaxation. Air-dried incisor dentin was found to be significantly stiffer than air-dried canine dentin.
  
  
  CONCLUSIONS
  These data suggest that the stress relaxation properties of human dentin are modified by air drying and by previous exposure to a constant compressive strain.
authors.affiliation: Department of Restorative Dentistry, University of Otago, Dunedin, New Zealand.
authors.forename: H G
authors.initials: HG
authors.lastname: Trengrove
authors.forename: G M
authors.initials: GM
authors.lastname: Carter
authors.forename: J A
authors.initials: JA
authors.lastname: Hood
mesh_terms: D001696:Biomechanical Phenomena; D003481:Cuspid / Q000502:physiology; D003799:Dental Stress Analysis; D003804:Dentin / Q000502:physiology*; D006801:Humans; D007180:Incisor / Q000502:physiology; D008962:Models, Theoretical; D013314:Stress, Mechanical; D014867:Water
chemical_list: D014867:Water