Hemoglobin concentration and oxygen saturation of clinically healthy and inflamed gingiva in human subjects

The hemoglobin concentration (Hb index) and oxygen saturation (apparent SO2) in human gingiva were estimated by tissue reflectance spectrophotometry (TRS). The gingiva had significantly lower Hb index and higher apparent SO2 than those in alveolar mucosa, but there was no difference in either parameter among different gingival areas. The reproducibility in repeated measurements was high for both Hb index and apparent SO2 in gingiva. In inflamed gingiva, Hb index was significantly higher than that in clinically healthy gingiva. A lower apparent SO2 was observed in inflamed gingiva. This suggests that the increase in blood supply is insufficient to meet the oxygen demand in inflamed gingiva. There were significant correlations between either the Hb index or the apparent SO2 and the clinical parameters of gingival inflammation such as gingival index, plaque index, Periotron score and probing depth. Thus, TRS may be clinically available to estimate the blood volume and oxygen saturation in inflamed gingiva.