Nanoindentation of wet and dry compact bone: influence of environment and indenter tip geometry on the indentation modulus

Griselda María Guidoni (1, 2) , Michael Swain (3, 4) , Ingomar Jäger (5)

1 ESI - Erich Schmid Institute of Materials Science
2 Materials Physics Department
3 Biomaterials Science Research Unit
4 Faculty of Dentistry
5 Materials Physics Department

The indentation derived elastic modulus, E, of bovine compact bone was obtained by means of nanoindentation. The indentation modulus of the dry condition (i.e. under atmospheric conditions) is 40 % higher than when measured wet (i.e. immersed in buffer solution). Although this difference is independent of orientation, there is 20 % difference in indentation modulus within the same tested environment between longitudinal and transversal directions. In addition, the estimated indentation modulus of the same samples when tested wet in buffer solution after deep freezing (-15°C) was not affected. The discrepancy between wet and dry results was attributed to the non mineralized phase contribution and rationalized by a simple mechanical model [1]. Anisotropy effects could be explained in terms of deformation mechanisms with orientation. The effect of frozen storage temperatures could be clarified by the biomechanics of the helicoidal arrangement of lamellar bone. Viscoelastic effects were also considered and incorporated into the analysis of the force-displacement data.

Mots clés: Physical Sciences

Griselda María Guidoni, Michael Swain, Ingomar Jäger. Nanoindentation of wet and dry compact bone: influence of environment and indenter tip geometry on the indentation modulus. Philosophical Magazine, 2010, 90 (05), pp.553-565. ⟨10.1080/14786430903201853⟩. ⟨hal-00560312⟩