[Relationship between the microstructure and nanohardness of dentin and enamel of human teeth].
OBJECTIVE
To investigate the relationship between the nanohardness and microstructure of the dentin and enamel of human teeth.


METHODS
Nano indentation was used to determine the nanohardness of enamel and dentin; TEM and IR were utilized to observe the microstructure and crystalline characteristic.


RESULTS
The mean nanohardness of the enamel [(4.92 +/- 0.40) GPa] was significantly higher than that of dentin [(1.17 +/- 0.14) GPa]. A large quantity of hydroxyapatite (HA) crystals and uniform lattice stripe were found in enamel but not in dentin.


CONCLUSIONS
The difference of nanohardness between enamel and dentin is related to their density, the inorganic morphology and phase structure.
Chen
Long
L
State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China.
Song
Xi-ping
XP
Zhang
Bei
B
Yang
Kai
K
Bai
Yu-xing
YX
D000328:Adult; D003743:Dental Enamel / Q000502:physiology* / Q000648:ultrastructure*; D003804:Dentin / Q000502:physiology* / Q000648:ultrastructure*; D006244:Hardness; D006801:Humans; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures