Human teeth function as nature’s cutting and grinding tools and represent a remarkable biocomposite. This study investigates the rate-dependent mechanical behavior of the enamel-dentin (ED) complex at low strain rates. High-precision ED specimens were prepared from healthy human premolars and tested under uniaxial compression using a universal testing machine at strain rates ranging from 0.0005 to 2.5 s−1. The results demonstrated that, with increasing strain rate, the maximum stress and elastic modulus increased by 17.0% and 24.7%, respectively, while the maximum strain decreased by 12.5%. One-way ANOVA with Tukey’s HSD post-hoc testing indicated that strain rate had a statistically significant effect on all three mechanical properties (p < 0.01 for each). This rate sensitivity is attributed to the hierarchical structure and complex organic-inorganic composition of the ED biocomposite. Based on the experimental findings, quantitative relationships were proposed to describe the maximum stress, elastic modulus, and maximum strain as functions of strain rate. These results highlight that the mechanical properties of the ED complex are sensitive to strain rate even within the low rate regime. The present findings can contribute to computational simulations of dental structures, the development of restorative materials, and the design of tissue-engineered artificial teeth.
ZhengLLiYZhengJ, et al. A comparative study on the sliding wear behaviors of human tooth enamel, Cu–Zn alloy and Al2O3 ceramic. Wear2013; 301: 308–315. https://doi.org/10.1016/j.wear.2012.12.024
4.
ChunKChoiHLeeJ. Comparison of mechanical property and role between enamel and dentin in the human teeth. J Dent Biomech2014; 5(1): 1–7. https://doi.org/10.1177/1758736014520809
5.
DesoutterAFelbacqDGergelyC, et al. Properties of dentin, enamel and their junction, studied with Brillouin scattering and compared to Raman microscopy. Arch Oral Biol2023; 152: 105733. https://doi.org/10.1016/j.archoralbio.2023.105733
ZhangYFZhengJYuJX, et al. Impact of strain rate on the hardness and elastic modulus of human tooth enamel. J Mech Behav Biomed Mater2018; 78: 491–495. https://doi.org/10.1016/j.jmbbm.2017.12.011
10.
CuyJLMannABLiviKJ, et al. Nanoindentation mapping of the mechanical properties of human molar tooth enamel. Arch Oral Biol2002; 47(4): 281–291. https://doi.org/10.1016/S0003-9969(02)00006-7
11.
NanciA. Ten Cate’s oral histology-e-book: development, structure, and function. Elsevier Health Sciences, 2017.
TangZShanSChenZ, et al. Progress in the application of biomimetic mineralization for tooth repair. Minerals2023; 13(11): 1433. https://doi.org/10.3390/min13111433
15.
HasegawaMTanakaRZhongJ, et al. Deciphering load attenuation mechanisms of the dentin-enamel junction: Insights from a viscoelastic constitutive model. Acta Biomater2023; 171: 193–201. https://doi.org/10.1016/j.actbio.2023.08.050
ZhangYRDuWZhouXD, et al. Review of research on the mechanical properties of the human tooth. Int J Oral Sci2014; 6(2): 61–69. https://doi.org/10.1038/ijos.2014.21
ChunKJLeeJY. Comparative study of mechanical properties of dental restorative materials and dental hard tissues in compressive loads. J Dent Biomech2014; 5: 1–6. https://doi.org/10.1177/1758736014555246
20.
ReedRXuCLiuY, et al. Radiotherapy effect on nano-mechanical properties and chemical composition of enamel and dentine. Arch Oral Biol2015; 60(5): 690–697. https://doi.org/10.1016/j.archoralbio.2015.02.020
21.
KhosravaniMR. Mechanical behavior of restorative dental composites under various loading conditions. J Mech Behav Biomed Mater2019; 93: 151–157. https://doi.org/10.1016/j.jmbbm.2019.02.009
22.
RadwanskiMZmyslowska-PolakowskaEOsicaK, et al. Mechanical properties of modern restorative “bioactive” dental materials - an in vitro study. Sci Rep2025; 15(1): 3552. https://doi.org/10.1038/s41598-025-86595-7
23.
NakamuraKTajimaKChenKK, et al. Dental application of novel finite element analysis software for three-dimensional finite element modeling of a dentulous mandible from its computed tomography images. Proc Inst Mech Eng Part H: J Eng Med2013; 227(12): 1312–1318. https://doi.org/10.1177/0954411913508054
24.
ShettyPPMeshramkarRPatilKN, et al. A finite element analysis for a comparative evaluation of stress with two commonly used esthetic posts. Eur J Dent2013; 7(4): 419–422. https://doi.org/10.4103/1305-7456.120668
25.
GrzebieluchWBędzińskiRCzaplińskiT, et al. The mechanical properties of human dentin for 3-D finite element modeling: Numerical and analytical evaluation. Adv Clin Exp Med2017; 26(4): 645–653. https://doi.org/10.17219/acem/67441
MogaRAOlteanuCDDanielBM, et al. Finite elements analysis of tooth-a comparative analysis of multiple failure criteria. Int J Environ Res Public Health2023; 20(5): 1–25. https://doi.org/10.3390/ijerph20054133
28.
OuldyerouAMehboobHMehboobA, et al. Biomechanical performance of resin composite on dental tissue restoration: a finite element analysis. PLoS One2023; 18(12): e0295582. https://doi.org/10.1371/journal.pone.0295582
29.
XuHHSmithDTJahanmirS, et al. Indentation damage and mechanical properties of human enamel and dentin. J Dent Res1998; 77(3): 472–480. https://doi.org/10.1177/00220345980770030601
30.
FongHSarikayaMWhiteSN, et al. Nano-mechanical properties profiles across dentin–enamel junction of human incisor teeth. Mater Sci Eng C1999; 7(2): 119–128. https://doi.org/10.1016/s0928-4931(99)00133-2
31.
MarshallGWJrBaloochMGallagherRR, et al. Mechanical properties of the dentinoenamel junction: AFM studies of nanohardness, elastic modulus, and fracture. J Biomed Mater Res2001; 54(1): 87–95. https://doi.org/10.1002/1097-4636(200101)54:1<>3.0.co;2-z
32.
HabelitzSMarshallSJMarshallGWJr, et al. Mechanical properties of human dental enamel on the nanometre scale. Arch Oral Biol2001; 46(2): 173–183. https://doi.org/10.1016/S0003-9969(00)00089-3
33.
ArcísRWLópez-MacipeAToledanoM, et al. Mechanical properties of visible light-cured resins reinforced with hydroxyapatite for dental restoration. Dent Mater2002; 18(1): 49–57. https://doi.org/10.1016/S0109-5641(01)00019-7
GeJCuiFZWangXM, et al. Property variations in the prism and the organic sheath within enamel by nanoindentation. Biomaterials2005; 26(16): 3333–3339. https://doi.org/10.1016/j.biomaterials.2004.07.059
Fereshteh-SanieeFMajzoobiGHBahramiM. An experimental study on the behavior of glass–epoxy composite at low strain rates. J Mater Process Technol2005; 162-163: 39–45. https://doi.org/10.1016/j.jmatprotec.2005.02.011
42.
ShokriehMMJamalOmidi M. Tension behavior of unidirectional glass/epoxy composites under different strain rates. Compos Struct2009; 88(4): 595–601. https://doi.org/10.1016/j.compstruct.2008.06.012
43.
ShokriehMMJamalOmidi M. Compressive response of glass–fiber reinforced polymeric composites to increasing compressive strain rates. Compos Struct2009; 89(4): 517–523. https://doi.org/10.1016/j.compstruct.2008.11.006
MajzoobiGHNejadSHASabetSAR. Mechanical characterization of graphene oxide reinforced epoxy at different strain rates. Polym Eng Sci2019; 59(8): 1636–1647. https://doi.org/10.1002/pen.25162
46.
ShokriehMMJamal-OmidiM. The impact resistance of fiber-reinforced polymer composites: a review. Iran J Polym Sci Technol2011; 24(4): 255–277. https://doi.org/10.22063/jipst.2012.574
47.
HeLHSwainMV. Understanding the mechanical behaviour of human enamel from its structural and compositional characteristics. J Mech Behav Biomed Mater2008; 1(1): 18–29. https://doi.org/10.1016/j.jmbbm.2007.05.001
48.
AngSFScholzTKlockeA, et al. Determination of the elastic/plastic transition of human enamel by nanoindentation. Dent Mater2009; 25(11): 1403–1410. https://doi.org/10.1016/j.dental.2009.06.014
49.
ChengZJWangXMGeJ, et al. The mechanical anisotropy on a longitudinal section of human enamel studied by nanoindentation. J Mater Sci Mater Med2010; 21(6): 1811–1816. https://doi.org/10.1007/s10856-010-4052-2
AngkerLNockoldsCSwainMV, et al. Correlating the mechanical properties to the mineral content of carious dentine—a comparative study using an ultra-micro indentation system (UMIS) and SEM-BSE signals. Arch Oral Biol2004; 49(5): 369–378. https://doi.org/10.1016/j.archoralbio.2003.12.005
52.
KinneyJHNallaRKPopleJA, et al. Age-related transparent root dentin: mineral concentration, crystallite size, and mechanical properties. Biomaterials2005; 26(16): 3363–3376. https://doi.org/10.1016/j.biomaterials.2004.09.004
53.
ZiskindDHasdayMCohenSR, et al. Young’s modulus of peritubular and intertubular human dentin by nano-indentation tests. J Struct Biol2011; 174(1): 23–30. https://doi.org/10.1016/j.jsb.2010.09.010
54.
KinneyJHGladdenJRMarshallGW, et al. Resonant ultrasound spectroscopy measurements of the elastic constants of human dentin. J Biomech2004; 37(4): 437–441. https://doi.org/10.1016/j.jbiomech.2003.09.028
