Acta Mechanica Sinica

, Volume 33, Issue 2, pp 260–266 | Cite as

The race to the nociceptor: mechanical versus temperature effects in thermal pain of dental neurons

  • Min Lin
  • Fusheng Liu
  • Shaobao Liu
  • Changchun Ji
  • Ang Li
  • Tian Jian Lu
  • Feng Xu
Research Paper


The sensing of hot and cold stimuli by dental neurons differs in several fundamental ways. These sensations have been characterized quantitatively through the measured time course of neural discharge signals that result from hot or cold stimuli applied to the teeth of animal models. Although various hypotheses have been proposed to explain the underlying mechanism, the ability to test competing hypotheses against experimental recorded data using biophysical models has been hindered by limitations in our understanding of the specific ion channels involved in nociception of dental neurons. Here we apply recent advances in established biophysical models to test the competing hypotheses. We show that a sharp shooting pain sensation experienced shortly following cold stimulation cannot be attributed to the activation of thermosensitive ion channels, thereby falsifying the so-called neuronal hypothesis, which states that rapidly transduced sensations of coldness are related to thermosensitive ion channels. Our results support a central role of mechanosensitive ion channels and the associated hydrodynamic hypothesis. In addition to the hydrodynamic hypothesis, we also demonstrate that the long time delay of dental neuron responses after hot stimulation could be attributed to the neuronal hypothesis—that a relatively long time is required for the temperature around nociceptors to reach some threshold. The results are useful as a model of how multiphysical phenomena can be combined to provide mechanistic insight into different mechanisms underlying pain sensations.


Thermomechanics Dentinal fluid flow Dental neuron Neural discharge pattern Time delay 



This work was supported by the National Natural Science Foundation of China (Grants 11372243, 11522219, 11532009, and 11402192), the Fundamental Research Funds for the Central Universities (Grants 2016qngz03, 2015qngz09), and the Openning Project of Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi’an Jiaotong University (Grant 2016LHM-KFKT007).

Supplementary material

10409_2017_634_MOESM1_ESM.docx (85 kb)
Supplementary material 1 (docx 85 KB)


  1. 1.
    Oskui, I.Z., Ashtiani, M.N., Hashemi, A., et al.: Effect of thermal stresses on the mechanism of tooth pain. J. Endod. 40, 1835–1839 (2014)CrossRefGoogle Scholar
  2. 2.
    Lin, M., Genin, G.M., Xu, F., et al.: Thermal pain in teeth: electrophysiology governed by thermomechanics. Appl. Mech. Rev. 66, 031001 (2014)CrossRefGoogle Scholar
  3. 3.
    Kim, Y.S., Kim, T.H., Mckemy, D.D., et al.: Expression of vesicular glutamate transporters in transient receptor potential melastatin 8 (TRPM8)-positive dental afferents in the mouse. Neuroscience 303, 378–388 (2015)CrossRefGoogle Scholar
  4. 4.
    El Karim, I.A., Linden, G.J., Curtis, T.M., et al.: Human odontoblasts express functional thermo-sensitive trp channels: implications for dentin sensitivity. Pain 152, 2211–2223 (2011)CrossRefGoogle Scholar
  5. 5.
    Carda, C., Peydro, A.: Ultrastructural patterns of human dentinal tubules, odontoblasts processes and nerve fibres. Tissue Cell 38, 141–150 (2006)CrossRefGoogle Scholar
  6. 6.
    Sessle, B.J.: The neurobiology of facial and dental pain: present knowledge, future directions. J. Dent. Res. 66, 962–981 (1987)CrossRefGoogle Scholar
  7. 7.
    Su, K.-C., Chuang, S.-F., Ng, E.Y.-K., et al.: An investigation of dentinal fluid flow in dental pulp during food mastication: simulation of fluid-structure interaction. Biomech. Model Mechanobiol. 13, 527–535 (2013)CrossRefGoogle Scholar
  8. 8.
    Brännström, M., Linden, L.A., Astrom, A.: The hydrodynamics of the dental tubule and of pulp fluid. A discussion of its significance in relation to dentinal sensitivity. Caries Res. 1, 310–317 (1967)CrossRefGoogle Scholar
  9. 9.
    Andrew, D., Matthews, B.: Displacement of the contents of dentinal tubules and sensory transduction in intradental nerves of the cat. J. Physiol. (Lond) 529, 791–802 (2000)CrossRefGoogle Scholar
  10. 10.
    Lin, M., Liu, S.B., Niu, L., et al.: Analysis of thermal-induced dentinal fluid flow and its implications in dental thermal pain. Arch. Oral Biol. 56, 846–854 (2011)CrossRefGoogle Scholar
  11. 11.
    Lin, M., Luo, Z.Y., Bai, B.F., et al.: Fluid dynamics analysis of shear stress on nerve endings in dentinal microtubule: a quantitative interpretation of hydrodynamic theory for tooth pain. J. Mech. Med. Biol. 11, 205–219 (2011)CrossRefGoogle Scholar
  12. 12.
    Lin, M., Luo, Z.Y., Bai, B.F., et al.: Fluid mechanics in dentinal microtubules provides mechanistic insights into the difference between hot and cold dental pain. PLoS ONE 6, e18068 (2011)CrossRefGoogle Scholar
  13. 13.
    Jyvasjarvi, E., Kniffki, K.D.: Cold stimulation of teeth: a comparison between the responses of cat intradental a delta and C fibres and human sensation. J. Physiol. (Lond) 391, 193–207 (1987)CrossRefGoogle Scholar
  14. 14.
    Matthews, B.: Responses of intradental nerves to electrical and thermal stimulation of teeth in dogs. J. Physiol. (Lond) 264, 641–664 (1977)CrossRefGoogle Scholar
  15. 15.
    Trowbridge, H.O., Franks, M., Korostoff, E., et al.: Sensory response to thermal stimulation in human teeth. J. Endod. 6, 405–412 (1980)CrossRefGoogle Scholar
  16. 16.
    Chul-Kyu, P., Mi, S.K., Zhi, F., et al.: Functional expression of thermo-transient receptor potential channels in dental primary afferent neurons: Implication for tooth pain. J. Biol. Chem. 281, 17304–17311 (2006)CrossRefGoogle Scholar
  17. 17.
    Mengel, M.K., Stiefenhofer, A.E., Jyväsjärvi, E., et al.: Pain sensation during cold stimulation of the teeth: differential reflection of a \(\delta \) and C fibre activity? Pain 55, 159–169 (1993)CrossRefGoogle Scholar
  18. 18.
    Linsuwanont, P., Versluis, A., Palamara, J.E., et al.: Thermal stimulation causes tooth deformation: A possible alternative to the hydrodynamic theory? Arch. Oral Biol. 53, 261–272 (2008)CrossRefGoogle Scholar
  19. 19.
    Byers, M.R., Narhi, M.V.O.: Dental injury models: experimental tools for understanding neuroinflammatory interactions and polymodal nociceptor functions. Crit. Rev. Oral Biol. Med. 10, 4–39 (1999)CrossRefGoogle Scholar
  20. 20.
    Holland, G.R., Matthews, B., Robinson, P.P.: An electrophysiological and morphological study of the innervation and reinnervation of cat dentine. J. Physiol. 386, 31–43 (1987)CrossRefGoogle Scholar
  21. 21.
    Berggren, G., Brännström, M.: The rate of flow in dentinal tubules due to capillary attraction. J. Dent. Res. 44, 408–415 (1965)CrossRefGoogle Scholar
  22. 22.
    Lin, M., Liu, Q.D., Kim, T., et al.: A new method for characterization of thermal properties of human enamel and dentine: Influence of microstructure. Infrared Phys. Technol. 53, 457–463 (2010)CrossRefGoogle Scholar
  23. 23.
    De Vree, J.H., Spierings, T.A., Plasschaert, A.J.: A simulation model for transient thermal analysis of restored teeth. J. Therm. Biol. 62, 756–759 (1983)Google Scholar
  24. 24.
    Brown, W.S., Dewey, W.A., Jacobs, H.R.: Thermal properties of teeth. J. Dent. Res. 49, 752–755 (1970)CrossRefGoogle Scholar
  25. 25.
    Xu, H.H., Smith, D.T., Jahanmir, S., et al.: Indentation damage and mechanical properties of human enamel and dentin. J. Dent. Res. 77, 472–480 (1998)CrossRefGoogle Scholar
  26. 26.
    Fenner, D.N., Robinson, P.B., Cheung, P.M.Y.: Three-dimensional finite element analysis of thermal shock in a premolar with a composite resin mod restoration. Med. Eng. Phys. 20, 269–275 (1998)CrossRefGoogle Scholar
  27. 27.
    Xu, H.C., Liu, W.Y., Wang, T.: Measurement of thermal expansion coefficient of human teeth. Aust. Dent. J. 34, 530–535 (1989)CrossRefGoogle Scholar
  28. 28.
    Hodgkin, A.L., Huxley, A.F.: A quantitative description of membrane current and its application to conduction and excitation in nerve. J. Physiol. 117, 500–544 (1952)CrossRefGoogle Scholar
  29. 29.
    Xu, F., Wen, T., Lu, T.J., et al.: Modeling of nociceptor transduction in skin thermal pain sensation. J. Biomech. Eng. 130, 041013-13 (2008)CrossRefGoogle Scholar
  30. 30.
    Xu, F., Lu, T.J., Seffen, K.A.: Skin thermal pain modeling–a holistic method. J. Therm. Biol. 33, 223–237 (2008)CrossRefGoogle Scholar
  31. 31.
    Xu, F., Lin, M., Lu, T.J.: Modeling skin thermal pain sensation: role of non-fourier thermal behavior in transduction process of nociceptor. Comput. Biol. Med. 40, 478–486 (2010)CrossRefGoogle Scholar
  32. 32.
    Linsuwanont, P., Palamara, J.E.A., Messer, H.H.: An investigation of thermal stimulation in intact teeth. Arch. Oral Biol. 52, 218–227 (2007)CrossRefGoogle Scholar
  33. 33.
    Charoenlarp, P., Wanachantararak, S., Vongsavan, N., et al.: Pain and the rate of dentinal fluid flow produced by hydrostatic pressure stimulation of exposed dentine in man. Arch. Oral Biol. 52, 625–631 (2007)CrossRefGoogle Scholar
  34. 34.
    Pashley, D.H.: Dynamics of the pulpo-dentin complex. Crit. Rev. Oral Biol. Med. 7, 104–133 (1996)CrossRefGoogle Scholar
  35. 35.
    Brännström, M., Astroem, A.: A study on the mechanism of pain elicited from the dentin. J. Dent. Res. 43, 619–625 (1964)CrossRefGoogle Scholar

Copyright information

© The Chinese Society of Theoretical and Applied Mechanics; Institute of Mechanics, Chinese Academy of Sciences and Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  • Min Lin
    • 1
    • 2
  • Fusheng Liu
    • 3
    • 4
  • Shaobao Liu
    • 3
    • 4
  • Changchun Ji
    • 1
    • 2
    • 5
  • Ang Li
    • 6
  • Tian Jian Lu
    • 2
    • 3
    • 4
  • Feng Xu
    • 1
    • 2
  1. 1.The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and TechnologyXi’an Jiaotong UniversityXi’anChina
  2. 2.Bioinspired Engineering and Biomechanics Center (BEBC)Xi’an Jiaotong UniversityXi’anChina
  3. 3.State Key Laboratory for Strength and Vibration of Mechanical StructuresXi’an Jiaotong UniversityXi’anChina
  4. 4.MOE Key Laboratory for Multifunctional Materials and StructuresXi’an Jiaotong UniversityXi’anChina
  5. 5.Department of AcupunctureShaanxi Hospital of Traditional Chinese MedicineXi’anChina
  6. 6.Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of StomatologyXi’an Jiaotong UniversityXi’anChina

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