title: Analysis of thermal-induced dentinal fluid flow and its implications in dental thermal pain.
abstract: OBJECTIVE
  The initiation of the pain sensation experienced following the thermal stimulation of dentine has been correlated with fluid flow in the dentinal tubules. There may be other mechanisms.
  
  
  METHODS
  This study examines this possibility using a mathematical model to simulate the temperature and thermal stress distribution in a tooth undergoing thermal stimulation. The results obtained were then used to predict the fluid flow in a single dentinal tubule by considering the deformation of the dentinal tubules and dentinal fluid.
  
  
  RESULTS
  Deformation of the pulp chamber was observed before a noticeable temperature change was recorded at the dentine-enamel junction. Tubule deformation leads to changes in fluid flow more rapidly than fluid expansion or contraction. This finding agreed with previously reported experimental observations. An initially high rate of outward fluid flow under cooling was found to correspond to short latency neural responses whilst heating was associated with long latency neural responses.
  
  
  CONCLUSIONS
  Rapid fluid flow caused by thermal deformation of dentinal tubules may account for the short latency (<1s) activation of mechano-sensitive receptors after of cooling. Long latency (>10s) neural responses could be associated with the activation of thermo-sensitive receptors.
authors.affiliation: Biomedical Engineering and Biomechanics Center, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Lin
authors.forename: ShaoBao
authors.initials: S
authors.lastname: Liu
authors.forename: Lin
authors.initials: L
authors.lastname: Niu
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
authors.forename: Tian Jian
authors.initials: TJ
authors.lastname: Lu
mesh_terms: D003799:Dental Stress Analysis; D003804:Dentin / Q000648:ultrastructure; D003807:Dentin Sensitivity / Q000209:etiology*; D019234:Dentinal Fluid / Q000502:physiology*; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D008465:Mechanoreceptors / Q000502:physiology; D008954:Models, Biological; D009619:Nociceptors / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013823:Thermoreceptors / Q000502:physiology