Clinical application of tissue reflectance spectrophotometry to periodontal disease.

Rapid, accurate, and non-invasive measurements of hemodynamics and oxygen utilization in gingiva are clinically important in evaluation of the severity of the inflammatory response in periodontal disease. In the present study, tissue reflectance spectrophotometry was used to examine gingiva in vivo to estimate hemoglobin concentration (Hb index) and the oxygen saturation level of hemoglobin in gingiva (HbSO2 index). Reflectance spectrophotometry was also used to examine these parameters in experimental periodontitis in dogs, and in patients with periodontal disease.Both in vitro and in vivo experiments confirmed that the Hb index was positively correlated with hemoglobin concentration in gingival tissue. The relationship between the HbSO2 index and PO2 in gingiva was a sigmoid curve resembling the hemoglobin-oxygen dissociation curve. In rapidly advancing periodontitis resulting from ligature placement in dogs, the Hb index was significantly enhanced, but the HbSO2 index was reduced. This reduction corres...