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Precision of nanoindentation protocols for measurements of viscoelasticity in cortical and trabecular bone

Isaksson, Hanna LU ; Nagao, Shijo; Malkiewicz, Marta; Julkunen, Petro; Nowak, Roman and Jurvelin, Jukka (2010) In Journal of Biomechanics 43(12). p.2410-2417
Abstract (Swedish)
Abstract in Undetermined

Nanoindentation has recently gained attention as a characterization technique for mechanical properties of biological tissues, such as bone, on the sub-micron level. However, optimal methods to characterize viscoelastic properties of bones are yet to be established. This study aimed to compare the time-dependent viscoelastic properties of bone tissue obtained with different nanoindentation methods. Bovine cortical and trabecular bone samples (n=8) from the distal femur and proximal tibia were dehydrated, embedded and polished. The material properties determined using nanoindentation were hardness and reduced modulus, as well as time-dependent parameters based on creep, loading-rate, dissipated... (More)
Abstract in Undetermined

Nanoindentation has recently gained attention as a characterization technique for mechanical properties of biological tissues, such as bone, on the sub-micron level. However, optimal methods to characterize viscoelastic properties of bones are yet to be established. This study aimed to compare the time-dependent viscoelastic properties of bone tissue obtained with different nanoindentation methods. Bovine cortical and trabecular bone samples (n=8) from the distal femur and proximal tibia were dehydrated, embedded and polished. The material properties determined using nanoindentation were hardness and reduced modulus, as well as time-dependent parameters based on creep, loading-rate, dissipated energy and semi-dynamic testing under load control. Each loading protocol was repeated 160 times and the reproducibility was assessed based on the coefficient of variation (CV). Additionally, three well-characterized polymers were tested and CV values were calculated for reference.



The employed methods were able to characterize time-dependent viscoelastic properties of bone. However, their reproducibility varied highly (CV 9–40%). The creep constant increased with increasing dwell time. The reproducibility was best with a 30s creep period (CV 18%). The dissipated energy was stable after three repeated load cycles, and the reproducibility improved with each cycle (CV 23%). The viscoelastic properties determined with semi-dynamic test increased with increase in frequency. These measurements were most reproducible at high frequencies (CV 9–10%). Our results indicate that several methods are feasible for the determination of viscoelastic properties of bone material. The high frequency semi-dynamic test showed the highest precision within the tested nanoindentation protocols. (Less)
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author
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Biomechanics
volume
43
issue
12
pages
2410 - 2417
publisher
Elsevier
external identifiers
  • scopus:77955555513
ISSN
1873-2380
DOI
10.1016/j.jbiomech.2010.04.017
language
English
LU publication?
no
id
ca1dd34f-9da4-4541-8bd6-8128146bbdba (old id 2277178)
date added to LUP
2012-01-27 10:16:51
date last changed
2017-01-22 04:27:12
@article{ca1dd34f-9da4-4541-8bd6-8128146bbdba,
  abstract     = {<b>Abstract in Undetermined</b><br/><br>
Nanoindentation has recently gained attention as a characterization technique for mechanical properties of biological tissues, such as bone, on the sub-micron level. However, optimal methods to characterize viscoelastic properties of bones are yet to be established. This study aimed to compare the time-dependent viscoelastic properties of bone tissue obtained with different nanoindentation methods. Bovine cortical and trabecular bone samples (n=8) from the distal femur and proximal tibia were dehydrated, embedded and polished. The material properties determined using nanoindentation were hardness and reduced modulus, as well as time-dependent parameters based on creep, loading-rate, dissipated energy and semi-dynamic testing under load control. Each loading protocol was repeated 160 times and the reproducibility was assessed based on the coefficient of variation (CV). Additionally, three well-characterized polymers were tested and CV values were calculated for reference.<br/><br>
<br/><br>
The employed methods were able to characterize time-dependent viscoelastic properties of bone. However, their reproducibility varied highly (CV 9–40%). The creep constant increased with increasing dwell time. The reproducibility was best with a 30s creep period (CV 18%). The dissipated energy was stable after three repeated load cycles, and the reproducibility improved with each cycle (CV 23%). The viscoelastic properties determined with semi-dynamic test increased with increase in frequency. These measurements were most reproducible at high frequencies (CV 9–10%). Our results indicate that several methods are feasible for the determination of viscoelastic properties of bone material. The high frequency semi-dynamic test showed the highest precision within the tested nanoindentation protocols.},
  author       = {Isaksson, Hanna and Nagao, Shijo and Malkiewicz, Marta and Julkunen, Petro and Nowak, Roman and Jurvelin, Jukka},
  issn         = {1873-2380},
  language     = {eng},
  number       = {12},
  pages        = {2410--2417},
  publisher    = {Elsevier},
  series       = {Journal of Biomechanics},
  title        = {Precision of nanoindentation protocols for measurements of viscoelasticity in cortical and trabecular bone},
  url          = {http://dx.doi.org/10.1016/j.jbiomech.2010.04.017},
  volume       = {43},
  year         = {2010},
}