Assessment of local hemodynamics in periodontal inflammation using optical spectroscopy

Among the newly emerging diagnostic approaches for periodontitis, optical spectroscopy is a promising complementary diagnostic tool. The objective of this study is to verify the reproducibility of this method at a geographically distinct location (Suzhou, China) to a broader patient population using similar instrumentation to that in a previous report.

Using a portable optical near-infrared spectrometer, optical spectra were obtained, processed, and evaluated from healthy (n = 62), gingivitis (n = 98), and periodontitis (n = 47) sites from a total of 51 patients. A modified Beer-Lambert unmixing model that incorporates a non-parametric scattering loss function was used to determine the relative contribution of oxyhemoglobin and deoxyhemoglobin to the overall spectrum. The balance between tissue oxygen delivery and oxygen use in periodontal tissues was then assessed.

Tissue oxygenation decreased significantly from healthy sites to sites with gingivitis (P <0.01) and between gingivitis and periodontitis (P = 0.015). This is largely caused by a significant increase in deoxyhemoglobin between normal and gingivitis (P <0.01) and a concomitant decrease in oxyhemoglobin between gingivitis and periodontitis (P = 0.02).

This study supports previous findings that tissue oxygenation as measured by optical spectroscopy is significantly decreased in periodontitis and that optical spectroscopy can simultaneously determine multiple inflammatory indices related to periodontal disease directly in gingival tissues in vivo.