Table of Contents
ISRN Biomaterials
Volume 2013 (2013), Article ID 545791, 6 pages
http://dx.doi.org/10.5402/2013/545791
Research Article

Micro-Pop-In Issues in Nanoscale Contact Deformation Resistance of Tooth Enamel

1Mechanical Property Evaluation Section, CSIR-Central Glass and Ceramic Research Institute, Kolkata 700 032, India
2Thermal Systems Group, ISRO Satellite Centre, Vimanapura, Bangalore 560 017, India

Received 14 August 2012; Accepted 6 September 2012

Academic Editors: J.-Y. Cognard and N. Dunne

Copyright © 2013 Nilormi Biswas et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Human tooth enamel is a natural nanocomposite with a hierarchical structural architecture that spans from macroscale to nanoscale. Thus it offers the unique opportunity to study the physics of deformation at the nanoscale in a controlled manner using the novel nanoindentation technique. In spite of the wealth of literature, however, the information about the effect of loading rate on the nanoindentation behavior of human tooth enamel is far from being significant. Therefore, the major objective of the present work was to study the loading rate effect on nanoindentation behavior of enamel with a view to improve our understanding that could be used for development of better bioinspired synthetic structures for functional as well as biomedical utilities. The nanoindentation experiments were conducted at loading rates in the range of to at peak load of at room temperature with a Berkovich tip on the longitudinal section from a freshly extracted premolar tooth enamel surface from a 65-year-old Indian male. To the best of our knowledge here we report for the first time the experimental observation of the increase in intrinsic resistance against contact-induced deformation at the nanoscale with the loading rate applied to the enamel surface. The results were explained by considering the microstructural details and the shear stress underneath the nanoindenter.