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Elastic modulus of dental enamel: effect of enamel prism orientation and mineral content

Published online by Cambridge University Press:  01 February 2011

V. L. Ferguson ,
Alan Boyde  and
Andrew J. Bushby
V. L. Ferguson
Affiliation:
Department of Materials, Queen Mary, University of London, London, UK. BioServe Space Technologies, Department of Aerospace Engineering Sciences, , Boulder, CO, USA.
Alan Boyde
Affiliation:
Dental Biophysics, Queen Mary, University of London, London, UK.
Andrew J. Bushby
Affiliation:
Department of Materials, Queen Mary, University of London, London, UK.
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Abstract

Nanomechanical properties of mineralized tissues are determined by microstructural tissue organization and relative composition of organic, mineral, and water phases. We combine nanoindentation and quantitative backscattered electron (qBSE) imaging to understand how these factors influence material properties at the ultrastructural and tissue level. Developmental stages of equine tooth enamel provide a good situation for studying the effects of enamel prism orientation and mineralization. Equine cheek teeth continue to form new enamel whilst mature tissue is being worn away. Hence we can study graded mineral content that increases with enamel maturity. Hunter-Schreger bands (HSBs) containing enamel prisms of contrasting orientations allow investigation of the effect of orientation on modulus. An equine second mandibular molar (2-year-old) was embedded in poly-methylmethacrylate, sectioned longitudinally, polished, carbon coated, imaged in qBSE, and subjected to nanoindentation testing. Elastic modulus increases significantly during maturation as enamel protein matrix degradation makes space for increased mineral content with closer proximity of enamel crystals, finally reaching values exceeding 80 GPa for little further increase in mineral content. Indentations spanning HSBs in immature, poorly mineralized enamel yielded modulus values that varied with prism orientation in a sinusoidal pattern where modulus varies by as much as a factor of three. Nanoindentation helps to elucidate how the composition and ultrastructural organization of enamel contribute to mechanical properties.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 841: Symposium R – Fundamentals of Nanoindentation and Nanotribology III , 2004 , R2.7/Y2.7
Copyright
Copyright © Materials Research Society 2005

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References

REFERENCES

1. Reith, E.J. and Boyde, A., Archs Oral Biol 26, 983 (1981).Google Scholar
2. Boyde, A. and Reith, E.J., Calcif Tissue Intl 35, 762 (1983).Google Scholar
3. Boyde, A. and Reith, E.J., Histochem 75, 341 (1982).Google Scholar
4. Reith, E.J., Boyde, A. and Schmid, M.I., J Dent Res 61 (special issue), 1563 (1982).Google Scholar
5. Reid, S.A., Boyde, A. and Reith, E.J., Histochem 81, 521 (1984).Google Scholar
6. Boyde, A., “Enamel”. In: Handbook of Microscopic Anatomy 6, 309: Eds Oksche, A. and Vollrath, L. (Springer Verlag, 1989), Berlin.Google Scholar
7. Boyde, A., “Amelogenesis and the structure of enamel”. In: Scientific Foundations of Dentistry, Eds Cohen, B. and Kramer, I.R.H.; (William Heinemann Medical Books, 1976) pp335–352.Google Scholar
8. Boyde, A., “Enamel”. In: The Dentition and Dental Care: Ed Elderton, R.J. (Heinemann, 1990) pp30–48.Google Scholar
9. Banerjee, A. and Boyde, A., Scanning 19, 151 (1997).Google Scholar
10. Kierdorf, H., Kierdorf, U. and Boyde, A., Annals of Anatomy 179, 405 (1997).Google Scholar
11. Bushby, A.J, Ferguson, V.L and Boyde, A., J Mater Res 19, 249 (2004).Google Scholar
12. Ferguson, V.L., Bushby, A.J. and Boyde, A., J Anat 203, 191 (2003).Google Scholar
13. Boyde, A. and Fortelius, M., Zool J Linn Soc 87, 181 (1986).Google Scholar
14. Boyde, A., “Dental Enamel”. In: CIBA Foundation Symposium Proceedings, Vol 205, (John Wiley & Sons, 1997), pp27–45.Google Scholar
15. Boyde, A., Connective Tissue Research 38, 43 (1998).Google Scholar