Characterization of blood flow rate in dental pulp by speckle patterns of backscattered light from an in vivo tooth

Abstract. Experimental data on the hemodynamics of dental pulp at different stages of caries treatment are given. Observations of speckle patterns in backscattered laser light are used as a measurement method to qualitatively characterize changes in blood flow rate through the dental pulp. The measurements were made by the author-designed experimental setup. Theoretical estimations showed that stationary reflected light from an in vivo tooth contains a negligibly small information body on changes in the pulpal blood flow due to the shadowing of the pulp by optically thick enamel and dentin. Therefore, the temporal variations in the speckle patterns are the only possible way that can provide monitoring of blood conditions in the pulp by using backscattered light. Various statistical characteristics of the random reflected light fields are studied as indicators of blood flow rate changes. There were selected five statistical parameters of backscattered speckle images that give self-consistent data on these changes. The parameters include four combinations of integrals of the Fourier transforms of the observed temporal variations as well as the speckle image contrast. The selected parameters are shown to qualitatively agree with general considerations on the effects of reduced or increased blood flow rates on the selected integral quantities.

[1]  V. Tuchin.  Handbook of Optical Biomedical Diagnostics , 2002 .

[2]  Cynthia L. Darling,et al.  Near-Infrared Imaging of Dental Decay at 1310 nm , 2010 .

[3]  M. Arnold,et al.  Optical detection of pulpal blood. , 1994, Journal of endodontics.

[4]  B. Matthews,et al.  The Vascularity of Dental Pulp in Cats , 1992, Journal of dental research.

[5]  Eleonora P. Zege,et al.  Image Transfer Through a Scattering Medium , 1991 .

[6]  P. Hariharan,et al.  Holographic and Speckle Interferometry , 2007 .

[7]  J. David Briers,et al.  Laser Doppler and time-varying speckle: a reconciliation , 1996 .

[8]  R A Groenhuis,et al.  HeNe-Laser Light Scattering by Human Dental Enamel , 1995, Journal of dental research.

[9]  Simone Schweitzer,et al.  Speckle Photography For Fluid Mechanics Measurements , 2016 .

[10]  Jacob Rudolf Zijp.  Optical properties of dental hard tissues , 2001 .

[11]  Alwin Kienle,et al.  Light guiding in biological tissue due to scattering. , 2006, Physical review letters.

[12]  A. Kienle,et al.  Magnification—a New Look at a Long-known Optical Property of Dentin , 2006, Journal of dental research.

[13]  Sergey S. Ulyanov.  New type of manifestation of the Doppler effect: an application to blood and lymph flow measurements , 1995 .

[14]  S. Chien,et al.  Arteriovenous distribution of hemodynamic parameters in the rat dental pulp. , 1984, Microvascular research.

[15]  Z. Kırzıoglu,et al.  Comparison of the reliability of laser Doppler flowmetry, pulse oximetry and electric pulp tester in assessing the pulp vitality of human teeth. , 2011, Journal of oral rehabilitation.

[16]  M. Stern,et al.  Laser Doppler velocimetry in blood and multiply scattering fluids: theory. , 1985, Applied optics.

[17]  A. P. Ivanov,et al.  Light and thermal fields in multilayer skin tissue exposed to laser irradiation , 2006 .

[18]  S. Jacques.  Optical properties of biological tissues: a review , 2013, Physics in medicine and biology.

[19]  C. Riva,et al.  Laser Doppler measurements of blood flow in capillary tubes and retinal arteries. , 1972, Investigative ophthalmology.

[20]  V. Gopikrishna,et al.  Assessment of pulp vitality: a review. , 2009, International journal of paediatric dentistry.

[21]  E H Verdonschot,et al.  Light propagation through teeth containing simulated caries lesions. , 1995, Physics in medicine and biology.

[22]  P. Abbott,et al.  An overview of the dental pulp: its functions and responses to injury. , 2007, Australian dental journal.

[23]  J J ten Bosch,et al.  Angular dependence of HeNe-laser light scattering by bovine and human dentine. , 1991, Archives of oral biology.

[24]  A. P. Ivanov,et al.  Absorption spectra and light penetration depth of normal and pathologically altered human skin , 2007 .

[25]  Ashish Amit Sinha,et al.  Pulse oximetry and laser doppler flowmetry for diagnosis of pulpal vitality , 2011 .

[26]  J. J. Bosch,et al.  Theoretical model for the scattering of light by dentin and comparison with measurements. , 1993, Applied optics.

[27]  H Jafarzadeh,et al.  Laser Doppler flowmetry in endodontics: a review. , 2009, International endodontic journal.

[28]  A. P. Shepherd,et al.  Laser-Doppler Blood Flowmetry , 2010, Developments in Cardiovascular Medicine.

[29]  L. Orekhova,et al.  Doppler flowmetry as a tool of predictive, preventive and personalised dentistry , 2013, EPMA Journal.

[30]  V. V. Tuchin.  Light scattering study of tissues , 1997 .

[31]  M. Stern,et al.  In vivo evaluation of microcirculation by coherent light scattering , 1975, Nature.

[32]  Vladimir N. Grisimov,et al.  New optical effects in the human hard tooth tissues , 1990, Other Conferences.

[33]  J. Briers,et al.  Laser Doppler, speckle and related techniques for blood perfusion mapping and imaging. , 2001, Physiological measurement.

[34]  J. T. ten Bosch,et al.  The absorption and scattering of light in bovine and human dental enamel , 2006, Calcified Tissue Research.

[35]  N. Fomin,et al.  New possibilities of investigating blood flow in soft tissues of the mouth , 2008 .

[36]  T Tanaka,et al.  Measurement of the Velocity of Blood Flow (in vivo) Using a Fiber Optic Catheter and Optical Mixing Spectroscopy. , 1975, Applied optics.

[37]  P. Abbott,et al.  Dental Pulp Testing: A Review , 2009, International journal of dentistry.