Article

Nanoscopic dynamic mechanical properties of intertubular and peritubular dentin.

Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, USA.
Journal of the mechanical behavior of biomedical materials 03/2012; 7:3-16. DOI:10.1016/j.jmbbm.2011.08.010
Source: PubMed

ABSTRACT An experimental evaluation of intertubular and peritubular dentin was performed using nanoindentation and Dynamic Mechanical Analysis (DMA). The objective of the investigation was to evaluate the differences in dynamic mechanical behavior of these two constituents and to assess whether their response is frequency dependent. Specimens of hydrated coronal dentin were evaluated by DMA using single indents over a range of parametric conditions and using scanning probe microscopy. The complex (E∗), storage (E') and loss moduli (E″) of the intertubular and peritubular dentin were evaluated as a function of the dynamic loading frequency and static load in the fully hydrated condition. The mean complex E∗ (19.6 GPa) and storage E' (19.2 GPa) moduli of the intertubular dentin were significantly lower than those for peritubular dentin (E∗ = 31.1 GPa, p < 0.05; E' = 30.3 GPa, p < 0.05). There was no significant influence of dynamic loading frequency on these measures. Although there was no significant difference in the loss modulus (E″) between the two materials (p > 0.05), both constituents exhibited a significant increase in E″ with dynamic load frequency and reduction in the quasi-static component of indentation load. The largest difference in dynamic behavior of the two tissues was noted at small quasi-static indentation loads and the highest frequency.

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Keywords

dynamic behavior
 
dynamic load frequency
 
dynamic loading frequency
 
Dynamic Mechanical Analysis
 
dynamic mechanical behavior
 
highest frequency
 
hydrated condition
 
hydrated coronal dentin
 
indentation load
 
largest difference
 
loss modulus
 
mean complex Eāˆ—
 
peritubular dentin
 
quasi-static component
 
scanning probe microscopy
 
significant influence
 
small quasi-static indentation loads
 
two constituents
 
two materials
 
two tissues
 

Heonjune Ryou