title: Analysis on the nature of thermally induced deformation in human dentine by electronic speckle pattern interferometry (ESPI).
abstract: OBJECTIVE
  To examine the in-plane and out-of-plane response of human dentine to thermal loads in real time.
  
  
  METHODS
  An Electronic Speckle Pattern Interferometry (ESPI) system sensitive to both the in-plane and out-of-plane displacements was configured and used in conjunction with an advanced fringe processing technique. Specimens were prepared from freshly extracted lower central incisor teeth and were separately mounted on a thermal block to apply thermal loads from room temperature (25 degrees C) to 60 degrees C. The real time speckle patterns were acquired using a digital camera. These digital fringe patterns were subjected to further image processing to enhance the quality of fringes. The resultant images were later analyzed to study the out-of-plane and in-plane displacement gradients in the facio-lingual plane of the dentine.
  
  
  RESULTS
  The out-of-plane deformations were observed in the plane perpendicular to the long axis of the tooth, while the in-plane deformations occurred in the plane parallel to the long axis of the tooth.
  
  
  CONCLUSIONS
  The ESPI analysis revealed whole-field and distinct thermal response in human dentine in-plane and out-of-plane. The cervical dentine experienced distinct and conspicuous displacement to the temperature changes.
authors.affiliation: Biomedical Engineering Research Center, School of Mechanical & Production Engineering, Nanyang Technological University, 639798, Singapore. ekishen@ntu.edu.sg
authors.forename: A
authors.initials: A
authors.lastname: Kishen
authors.forename: V M
authors.initials: VM
authors.lastname: Murukeshan
authors.forename: V
authors.initials: V
authors.lastname: Krishnakumar
authors.forename: A
authors.initials: A
authors.lastname: Asundi
mesh_terms: D000328:Adult; D003804:Dentin / Q000033:anatomy & histology / Q000502:physiology*; D006358:Hot Temperature; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007180:Incisor / Q000033:anatomy & histology / Q000502:physiology; D007368:Interferometry / Q000379:methods; D007834:Lasers; D008027:Light; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted; D013696:Temperature; D013816:Thermodynamics; D019237:Tooth Cervix / Q000033:anatomy & histology / Q000502:physiology