反射スペクトル解析法による歯肉微小循環機能の測定 特に，プローブと歯肉との接触条件および測定部位の影響

Abstract

The purpose of this study was to examine the effect of contact between the probe and gingiva, and to compare the parameters between arches, regions, and surfaces in measurement of gingival microvascular function by tissue reflectance spectrophotometry (TRS). The index of hemoglobin concentration (Hb index) and the index of oxygen saturation (SO2 index) in papillary gingiva were assessed with TRS in a standardized manner. Gingival spectra were measured immediately before and during contact between the optical probe and gingival tissue. The Hb index showed a maximum value during the procedure when the probe was in the first contact with gingiva. The SO2 index showed lower values before the contact and higher values after the first contact. When the probe/gingiva surface angle increased, the Hb index decreased but the SO2 index showed little change. These results indicate that good reliability of the measurement could be obtained by selection of a representative spectrum showing the maximum Hb index among several spectra measured at the same site. Reflectance spectra were also measured at various locations of the upper and lower arches in subjects with clinically healthy gingiva. Coefficients of variation of both indices in lingual/palatal surfaces and in molar teeth were higher than those in facial surfaces and incisor teeth, respectively. Analysis of variances indicated significant differences in both indices between facial and lingual/palatal surfaces and among the teeth but no difference between the sides and between the arches. Significant interactions were observed in both indices between arch and surface, and in Hb index between arch and tooth. Thus, the application of TRS measurements in periodontal practice should consider differences in TRS parameters at a given location in the mouth.