Abstract
Enamel is the hardest and most resilient tissue in the human body. Enamel includes morphologically aligned, parallel, ∼50 nm wide, microns-long nanocrystals, bundled either into 5-μm-wide rods or their space-filling interrod. The orientation of enamel crystals, however, is poorly understood. Here we show that the crystalline c-axes are homogenously oriented in interrod crystals across most of the enamel layer thickness. Within each rod crystals are not co-oriented with one another or with the long axis of the rod, as previously assumed: the c-axes of adjacent nanocrystals are most frequently mis-oriented by 1°–30°, and this orientation within each rod gradually changes, with an overall angle spread that is never zero, but varies between 30°–90° within one rod. Molecular dynamics simulations demonstrate that the observed mis-orientations of adjacent crystals induce crack deflection. This toughening mechanism contributes to the unique resilience of enamel, which lasts a lifetime under extreme physical and chemical challenges.
| Original language | English (US) |
|---|---|
| Article number | 4383 |
| Journal | Nature Communications |
| Volume | 10 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 1 2019 |
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ASJC Scopus subject areas
- Chemistry(all)
- Biochemistry, Genetics and Molecular Biology(all)
- Physics and Astronomy(all)
Cite this
The hidden structure of human enamel. / Beniash, Elia; Stifler, Cayla A.; Sun, Chang Yu; Jung, Gang Seob; Qin, Zhao; Buehler, Markus J.; Gilbert, Pupa U.P.A.
In: Nature Communications, Vol. 10, No. 1, 4383, 01.12.2019.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The hidden structure of human enamel
AU - Beniash, Elia
AU - Stifler, Cayla A.
AU - Sun, Chang Yu
AU - Jung, Gang Seob
AU - Qin, Zhao
AU - Buehler, Markus J.
AU - Gilbert, Pupa U.P.A.
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Enamel is the hardest and most resilient tissue in the human body. Enamel includes morphologically aligned, parallel, ∼50 nm wide, microns-long nanocrystals, bundled either into 5-μm-wide rods or their space-filling interrod. The orientation of enamel crystals, however, is poorly understood. Here we show that the crystalline c-axes are homogenously oriented in interrod crystals across most of the enamel layer thickness. Within each rod crystals are not co-oriented with one another or with the long axis of the rod, as previously assumed: the c-axes of adjacent nanocrystals are most frequently mis-oriented by 1°–30°, and this orientation within each rod gradually changes, with an overall angle spread that is never zero, but varies between 30°–90° within one rod. Molecular dynamics simulations demonstrate that the observed mis-orientations of adjacent crystals induce crack deflection. This toughening mechanism contributes to the unique resilience of enamel, which lasts a lifetime under extreme physical and chemical challenges.
AB - Enamel is the hardest and most resilient tissue in the human body. Enamel includes morphologically aligned, parallel, ∼50 nm wide, microns-long nanocrystals, bundled either into 5-μm-wide rods or their space-filling interrod. The orientation of enamel crystals, however, is poorly understood. Here we show that the crystalline c-axes are homogenously oriented in interrod crystals across most of the enamel layer thickness. Within each rod crystals are not co-oriented with one another or with the long axis of the rod, as previously assumed: the c-axes of adjacent nanocrystals are most frequently mis-oriented by 1°–30°, and this orientation within each rod gradually changes, with an overall angle spread that is never zero, but varies between 30°–90° within one rod. Molecular dynamics simulations demonstrate that the observed mis-orientations of adjacent crystals induce crack deflection. This toughening mechanism contributes to the unique resilience of enamel, which lasts a lifetime under extreme physical and chemical challenges.
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U2 - 10.1038/s41467-019-12185-7
DO - 10.1038/s41467-019-12185-7
M3 - Article
C2 - 31558712
AN - SCOPUS:85072706040
VL - 10
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
IS - 1
M1 - 4383
ER -