Assessment of tissue oxygenation of periodontal inflammation in smokers using optical spectroscopy

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 (HbO(2)) 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 HbO(2) 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.