The use of nanoindentation for characterizing the properties of mineralized hard tissues: State‐of‐the art review

Abstract

The use of nanoindentation to determine nanomechanical properties of mineralized tissues has been investigated extensively. A detailed, critical, and comprehensive review of this literature is the subject of the present work. After stating the motivation for the review, a succinct presentation of the challenges, advantages, and disadvantages of the various quasi-static nanoindentation test methods (to obtain elastic modulus, E, and hardness, H) and dynamic test methods (to obtain storage and loss moduli and/or loss/damping factor) is given in the form of a primer. Explicative summaries of literature reports on various intrinsic and extrinsic factors that significantly influence E and H, followed by 15 suggested topics for future research, are included additionally. This review is designed to present a compact guide to the principles of the nanoindentation technique and to emphasize considerations when determining material properties of mineralized tissues.

Biocompatible Phosphorus Containing Photopolymers

“…Astonishingly, the highly crosslinked Type II polymer with n=3 exhibited even better mechanical properties than the semicrystalline reference PLA which finds also wide-spread use as biodegradable material. Moreover, the IM of this polymer already approached that of human bone (Lewis & Nyman, 2008) and also an extraordinary high hardness was found for this compound. …”

Mechanical Behavior of Osteoporotic Bone at Sub-Lamellar Length Scales

“…Indeed, glassy polymers such as polystyrene are analogous to this potential situation where mechanical testing of smaller volumes of material removes the effect of defects, causing increases in strain to failure (van der Sanden et al, 1993). Other mechanical testing techniques such as nanoindentation typically probe significantly smaller volumes than the micro-beams of this work and are potentially sensitive to more variability from the location of the indenting probe at the sample surface, with considerable issues related to the uncertainty in the composition of the material and resultant contact area with the indenting probe previously reviewed (Lewis and Nyman, 2008). The enhanced sensitivity of the micro-beam compression in our work indicates a clear decrease of bone elastic modulus properties with osteoporosis as shown in Figure 3, which potentially contradicts some works in Table 1 that indicate little variability in the elastic modulus of osteoporotic bone compared to healthy bone.…”

Nanostructured Hydroxyapatite Coating on Bioalloy Substrates: Current Status and Future Directions

“…Among these are fracture toughness of the coating (K IC ), resistance to localized indentation (hardness) of the coating (HN), elastic modulus of the coating (E), residual stress in the coating (σ r ) scratch hardness of the coating (HS), corrosion fatigue life of the coated specimen (CF), steady-state corrosion fatigue crack propagation rate of the coated specimen (CFCP), wear rate of the coated specimen (WR), and corrosion adhesion (CAD) properties of the coating-substrate system. The third suggestion is that all of these properties should be determined using well-established methods; for example, compact tension specimen and ASTM E399 (K IC ); nanoindentation (HN and E) [61]; and nanoindentation [62], neutron diffraction [63], and Raman piezo-spectroscopy [64](σ r ). Note that HN, E, and σ r should each be determined not only on the coating but through the thickness of the coating (that is, spatial variation of the property).…”