Amorphous intergranular phases control the properties of rodent tooth enamel

Lyle M. Gordon, Michael J. Cohen, Keith W. MacRenaris, Jill D. Pasteris, Takele Seda, Derk Joester*

*Corresponding author for this work

Research output: Contribution to journalArticle

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Abstract

Dental enamel, a hierarchical material composed primarily of hydroxylapatite nanowires, is susceptible to degradation by plaque biofilm-derived acids. The solubility of enamel strongly depends on the presence of Mg2+, F-, and CO32-. However, determining the distribution of these minor ions is challenging. We show - using atom probe tomography, x-ray absorption spectroscopy, and correlative techniques - that in unpigmented rodent enamel, Mg2+ is predominantly present at grain boundaries as an intergranular phase of Mg-substituted amorphous calcium phosphate (Mg-ACP). In the pigmented enamel, a mixture of ferrihydrite and amorphous iron-calcium phosphate replaces the more soluble Mg-ACP, rendering it both harder and more resistant to acid attack. These results demonstrate the presence of enduring amorphous phases with a dramatic influence on the physical and chemical properties of the mature mineralized tissue.

Original languageEnglish (US)
Pages (from-to)746-750
Number of pages5
JournalScience
Volume347
Issue number6223
DOIs
StatePublished - Feb 13 2015

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ASJC Scopus subject areas

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Cite this

Gordon, L. M., Cohen, M. J., MacRenaris, K. W., Pasteris, J. D., Seda, T., & Joester, D. (2015). Amorphous intergranular phases control the properties of rodent tooth enamel. Science, 347(6223), 746-750. https://doi.org/10.1126/science.1258950