Cracking of human teeth: An avalanche and acoustic emission study

Lei Wang; Shutian Cao; Xiang Jiang; Ekhard K H Salje

doi:10.1016/j.jmbbm.2021.104666

Cracking of human teeth: An avalanche and acoustic emission study

J Mech Behav Biomed Mater. 2021 Oct:122:104666. doi: 10.1016/j.jmbbm.2021.104666. Epub 2021 Jun 29.

Authors

Lei Wang¹, Shutian Cao², Xiang Jiang³, Ekhard K H Salje⁴

Affiliations

¹ School of Civil Engineering, Chongqing University, 400045, Chongqing, People's Republic of China.
² Department of Geotechnical Engineering College of Civil Engineering, Tongji University, 200092, Shanghai, People's Republic of China.
³ School of Civil Engineering, Chongqing University, 400045, Chongqing, People's Republic of China; Department of Earth Sciences, Cambridge University, Cambridge CB2 3EQ, UK. Electronic address: jiangxiang@cqu.edu.cn.
⁴ School of Civil Engineering, Chongqing University, 400045, Chongqing, People's Republic of China; Department of Earth Sciences, Cambridge University, Cambridge CB2 3EQ, UK.

PMID: 34229170
DOI: 10.1016/j.jmbbm.2021.104666

Abstract

Teeth are the hardest part of the human body. Cracking of human teeth under compression progresses by avalanches emitting acoustic noise. Acoustic emission (AE) spectroscopy reveals that tooth avalanches are statistically fully compatible with predictions of mean field (MF) theory. Avalanche energies collapse into a power law distributed which is stable over more than five decades with an energy exponent ε = 1.4. Acoustic amplitudes (exponent ~τ), durations (~α), correlations between amplitudes and energies (~x), and correlations between amplitude and duration (~χ) follow equally power laws with MF values of all exponents. The exponents correlation: τ-1 = x(ε-1) = (α-1)/χ is confirmed. Crack propagation bifurcates and shows the hallmarks of avalanches where main cracks nucleate secondary cracks.

Keywords: Acoustic emission; Cracking; Human teeth; Mean field theory; Power law.

Publication types

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

MeSH terms

Acoustics
Avalanches*
Humans
Physical Phenomena