Stress relaxation properties of human dentin.
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.
Trengrove
H G
HG
Department of Restorative Dentistry, University of Otago, Dunedin, New Zealand.
Carter
G M
GM
Hood
J A
JA
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
D014867:Water