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Atomic-scale compositional mapping reveals Mg-rich amorphous calcium phosphate in human dental enamel.
Sci Adv. 2016 09; 2(9):e1601145.SA

Abstract

Human dental enamel, the hardest tissue in the body, plays a vital role in protecting teeth from wear as a result of daily grinding and chewing as well as from chemical attack. It is well established that the mechanical strength and fatigue resistance of dental enamel are derived from its hierarchical structure, which consists of periodically arranged bundles of hydroxyapatite (HAP) nanowires. However, we do not yet have a full understanding of the in vivo HAP crystallization process that leads to this structure. Mg(2+) ions, which are present in many biological systems, regulate HAP crystallization by stabilizing its precursor, amorphous calcium phosphate (ACP), but their atomic-scale distribution within HAP is unknown. We use atom probe tomography to provide the first direct observations of an intergranular Mg-rich ACP phase between the HAP nanowires in mature human dental enamel. We also observe Mg-rich elongated precipitates and pockets of organic material among the HAP nanowires. These observations support the postclassical theory of amelogenesis (that is, enamel formation) and suggest that decay occurs via dissolution of the intergranular phase. This information is also useful for the development of more accurate models to describe the mechanical behavior of teeth.

Authors+Show Affiliations

School of Aerospace, Mechanical, and Mechatronic Engineering, University of Sydney, Sydney, New South Wales 2006, Australia.; Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006, Australia.Faculty of Dentistry, University of Sydney, Sydney, New South Wales 2006, Australia.; Institute of Dental Research, Westmead Centre for Oral Health, Sydney, New South Wales 2145, Australia.Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006, Australia.School of Physics, University of Sydney, Sydney, New South Wales 2006, Australia.Faculty of Dentistry, University of Sydney, Sydney, New South Wales 2006, Australia.; Faculty of Dentistry, Kuwait University, P. O. Box 24923, Safat 13110, Kuwait.School of Aerospace, Mechanical, and Mechatronic Engineering, University of Sydney, Sydney, New South Wales 2006, Australia.; Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006, Australia.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

27617291

Citation

La Fontaine, Alexandre, et al. "Atomic-scale Compositional Mapping Reveals Mg-rich Amorphous Calcium Phosphate in Human Dental Enamel." Science Advances, vol. 2, no. 9, 2016, pp. e1601145.
La Fontaine A, Zavgorodniy A, Liu H, et al. Atomic-scale compositional mapping reveals Mg-rich amorphous calcium phosphate in human dental enamel. Sci Adv. 2016;2(9):e1601145.
La Fontaine, A., Zavgorodniy, A., Liu, H., Zheng, R., Swain, M., & Cairney, J. (2016). Atomic-scale compositional mapping reveals Mg-rich amorphous calcium phosphate in human dental enamel. Science Advances, 2(9), e1601145. https://doi.org/10.1126/sciadv.1601145
La Fontaine A, et al. Atomic-scale Compositional Mapping Reveals Mg-rich Amorphous Calcium Phosphate in Human Dental Enamel. Sci Adv. 2016;2(9):e1601145. PubMed PMID: 27617291.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Atomic-scale compositional mapping reveals Mg-rich amorphous calcium phosphate in human dental enamel. AU - La Fontaine,Alexandre, AU - Zavgorodniy,Alexander, AU - Liu,Howgwei, AU - Zheng,Rongkun, AU - Swain,Michael, AU - Cairney,Julie, Y1 - 2016/09/07/ PY - 2016/05/19/received PY - 2016/08/09/accepted PY - 2016/9/13/entrez PY - 2016/9/13/pubmed PY - 2018/1/26/medline KW - Human dental enamel KW - Mg-rich amorphous phase KW - atom probe tomography KW - tooth decay SP - e1601145 EP - e1601145 JF - Science advances JO - Sci Adv VL - 2 IS - 9 N2 - Human dental enamel, the hardest tissue in the body, plays a vital role in protecting teeth from wear as a result of daily grinding and chewing as well as from chemical attack. It is well established that the mechanical strength and fatigue resistance of dental enamel are derived from its hierarchical structure, which consists of periodically arranged bundles of hydroxyapatite (HAP) nanowires. However, we do not yet have a full understanding of the in vivo HAP crystallization process that leads to this structure. Mg(2+) ions, which are present in many biological systems, regulate HAP crystallization by stabilizing its precursor, amorphous calcium phosphate (ACP), but their atomic-scale distribution within HAP is unknown. We use atom probe tomography to provide the first direct observations of an intergranular Mg-rich ACP phase between the HAP nanowires in mature human dental enamel. We also observe Mg-rich elongated precipitates and pockets of organic material among the HAP nanowires. These observations support the postclassical theory of amelogenesis (that is, enamel formation) and suggest that decay occurs via dissolution of the intergranular phase. This information is also useful for the development of more accurate models to describe the mechanical behavior of teeth. SN - 2375-2548 UR - https://www.unboundmedicine.com/medline/citation/27617291/Atomic_scale_compositional_mapping_reveals_Mg_rich_amorphous_calcium_phosphate_in_human_dental_enamel_ L2 - https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/27617291/ DB - PRIME DP - Unbound Medicine ER -