色素を用いた唾液量の簡便スクリーニングシートの開発

dry mouth

北海道歯学会

北海道歯学雑誌

The early diagnosis and appropriate treatment of dry mouth in the elderly is important for health promotion and the extension of healthy life expectancy. The diagnosis of dry mouth requires an evaluation of the amount of saliva at rest. 　Previously, we reported the invention of a simple screening paper, which uses the principles of paper chromatography for use in the screening of dry mouth. However, there were a number of issues with the paper that required improvement. In the present study, we focused on the transfer of pigment absorbed into the sheet due to the permeation of saliva and, to find a pigment suited to this purpose, we evaluated various pigments, particularly food additives. Additionally, the pigment that was evaluated as optimal was absorbed into the paper and used with outpatients as test subjects to evaluate the volume of resting saliva. 　In the present study, we evaluated 11 pigments, which were mainly food pigments, including 3 red pigments, 2 yellow pigments, 1 blue pigments, 1 green pigments, 2 purple pigments, and 2 brown pigments. A total of 50 μL of pigment solutions were absorbed into the tips of the chromatography paper by permeation and used for evaluation after drying. The evaluation papers for each of the absorbed pigments were allowed to absorb from dishes of 0-600 μL of saliva for 2 minutes, after which the migration length (mm) for the pigment was measured and the optimum pigment determined. As a result, it was found that the optimum pigment was melanoidin. 　Next, 111 participants, which were patients of the Department of Preventive Dentistry of Dental Clinical Division of Hokkaido University Hospital, and from whom we received cooperation were selected. We inserted melanoidin-absorbed evaluation papers into the sublingual region for 2 minutes and measured the migration length (mm) of the melanoidin due to the saliva. Additionally, the volume of resting saliva (over 10 minutes) was measured, those with a volume of 1 ml/10 minutes or less were judged as having dry mouth. A high, positive correlation was found between the volume of resting saliva and migration length of the pigment (Spearman’s rank correlation coefficient : r=0.738, p<0.05). Next, to determine the optimal cutoff value, an ROC curve was constructed from the sensitivity and specificity for the migration lengths of the pigment between 0 mm-10 mm. Additionally, the positive likelihood ratio, the Youden Index, and the distance of each spot and from point (0, 1) were calculated. As a result, the optimal cutoff for screening for dry mouth was found to be 4 mm. Additionally, using simple stimulated saliva screening paper, onto which solutions of capsicin and citric acid were absorbed at the same time as the melanoidin, it was suggested that it was also possible to evaluate stimulated saliva.