Microscopic Approach for Testing Mechanical Properties of Hard Tissues

The term bone refers to a family of tissues all of which are built up of mineralized collagen fibrilswith a somewhat different structural pattern (Weiner and Traub 1992).They have highly complex structures, described as a function of hierarchical levels of structural organization. Each level has to fulfil a variety of mechanical functions, for which the structures are fine-tuned.Detailed descriptions of the structural features of bone abound in the literature; however, the mechanical properties of bone, in particular at the micro- and nano-structural level, remain poorly understood (Rho et al. 1998).Here we introduce the current microscopic approaches based on nanoindentation teststo investigate mechanicalproperties, highlighting the relationship between the complex hierarchical structure of bone and its functions.Taking into account the relevance of viscoelastic properties of bone in understanding many clinical and research problems, we emphasizethe role of bone viscoelasticity on affecting multiple factors related to hierarchicalorganization of bone tissue.