Biomedical Engineering Reference
In-Depth Information
CHAPTER
16
Nanomechanical
Characterization of Mineralized
Tissues in the Oral Cavity
Y.L. Chan,
1
, A.H.W. Ngan,
1
and N.M. King
2
1
Department of Mechanical Engineering, The University of Hong Kong, Pokfulam, Hong Kong
2
Paediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Pokfulam, Hong Kong
CONTENTS
16.1 Introduction .................................................................................................................................273
16.2 Basic Data Analysis Protocol for Nanoindentation ..........................................................................274
16.3 Nanoindentation of Oral Mineralized Tissues .................................................................................276
16.3.1 Sample Preparation.............................................................................................. 276
16.3.2 Hydration............................................................................................................ 276
16.3.3 Indenter Tips ....................................................................................................... 277
16.3.4 Load Function and Data Analysis........................................................................... 278
16.3.5 Microstructural Influence 280
16.4 Conclusions.................................................................................................................................284
References ............................................................................................................................................286
16.1
INTRODUCTION
Enamel, dentin, cementum, and bone are the four main types of mineralized tissues in the oral cavity.
They are produced and maintained by different mechanisms; hence, they differ from each other in
the arrangement and quantity of their constituent materials and also in their mechanical properties.
However, despite the long history of dental research, the mechanical properties of these mineralized
tissues have not been well characterized. This is because the tissues are small in size and complex
in shape, e.g., conventional characterization techniques such as compressive or tensile tests cannot
be easily conducted. Nanoindentation, with its relative ease in sample preparation, high spatial res-
olution, and ability to make nano/microscale measurements, is able to overcome these difficulties.
The advent of nanoindentation in the 1990s has led to a surge in the number of investigations on the
mechanical properties of the oral mineralized tissues, which have contributed greatly to our under-
standing of their structure-property relationship
[1]
. The nanomechanical properties have provided
credible explanations to both the superior performance in healthy tissues
[2-4]
and the degraded per-
formance associated with pathological conditions
[5-7]
. Concurrent with our increasing knowledge
