title: Assessment of tissue oxygenation of periodontal inflammation in smokers using optical spectroscopy.
abstract: BACKGROUND
  We have recently developed a periodontal diagnostic tool that was validated in non-smokers with periodontitis. Tobacco smoking is a recognized risk factor for periodontal diseases that can mask gingival bleeding and lead to a false negative diagnosis. Therefore, the purpose of current study is to further validate this instrument in smokers with periodontal diseases.
  
  
  METHODS
  Using a portable optical near-infrared spectrometer, optical spectra were obtained, processed and evaluated from healthy (n = 108), gingivitis (n = 100), and periodontitis (n = 79) sites of 54 systemically healthy smokers. A modified Beer-Lambert unmixing model that incorporates a non-parametric scattering loss function was used to determine the relative contribution of deoxygenated haemoglobin (Hb) and oxygenated haemoglobin (HbO2 ) to the overall spectrum. The balance between tissue oxygen delivery and utilization in periodontal tissues was then assessed.
  
  
  RESULTS
  Tissue oxygen saturation was significantly decreased in the gingivitis (p = 0.016) and periodontitis (p = 0.007) sites, compared to the healthy sites. There was a trend towards increased concentration of Hb and decreased concentration of HbO2 from healthy to diseased sites, without statistical significance (p > 0.05).
  
  
  CONCLUSIONS
  Optical spectroscopy can determine tissue oxygenation profiles of healthy and diseased sites in smokers. The spectral profile of periodontal sites in smokers generally resembles those from non-smoking patients.
authors.affiliation: Medical Devices Portfolio, National Research Council of Canada, Winnipeg, Canada; Department of Dental Diagnostics and Surgical Sciences, University of Manitoba, Winnipeg, Canada.
authors.forename: Kan-Zhi
authors.initials: KZ
authors.lastname: Liu
authors.forename: Poliana Mendes
authors.initials: PM
authors.lastname: Duarte
authors.forename: Vanessa Renata
authors.initials: VR
authors.lastname: Santos
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Xiang
authors.forename: Minqi
authors.initials: M
authors.lastname: Xu
authors.forename: Tamires Szeremeske
authors.initials: TS
authors.lastname: Miranda
authors.forename: Daiane
authors.initials: D
authors.lastname: Fermiano
authors.forename: Tiago Eduardo Dias
authors.initials: TE
authors.lastname: Gonçalves
authors.forename: Micheal G
authors.initials: MG
authors.lastname: Sowa
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005881:Gingiva / Q000378:metabolism; D005884:Gingival Hemorrhage / Q000378:metabolism; D005891:Gingivitis / Q000378:metabolism; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D055100:Optical Fibers; D061848:Optical Imaging / Q000295:instrumentation / Q000379:methods; D010101:Oxygen Consumption / Q000502:physiology*; D010108:Oxyhemoglobins / Q000032:analysis; D017622:Periodontal Attachment Loss / Q000378:metabolism; D010514:Periodontal Pocket / Q000378:metabolism; D010518:Periodontitis / Q000378:metabolism*; D010519:Periodontium / Q000378:metabolism; D012907:Smoking / Q000378:metabolism*; D019265:Spectroscopy, Near-Infrared / Q000379:methods
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin
keywords: gingivitis; near-infrared spectroscopy; periodontitis; smoking