A pH curve of human resting saliva sampled with a small paper slip and its medical application

This paper described physiochemical characteristics of the pH curve of saliva that accompanied escape of CO(2) and that was recorded by a previously reported method. Monthly sample of the resting saliva was collected by a small paper slip from five adults (59.9+/-16.5 years old) over 36 months. The pH curves were examined to represent differences in secretion characteristics among individuals. The following results were obtained: (1) Three variables, pH(1), Delta pH(I), and Delta pH(L), that represent a saliva pH curve indicated secretory characteristics of each individual since the intra-individual variance of them was significantly smaller than the inter-individual variance. (2) These values (mean+/-S.D.) obtained from five adults were 7.03+/-0.54, 0.24+/-0.21, and -0.10+/-0.12, and those obtained from 663 young adults (21.7+/-2.4 years old) were 7.14+/-0.44, 0.26+/-0.23, and -0.08+/-0.13. (3) A characteristic about amplitude of the Delta pH(I) of each individual was maintained over 36 months under the healthy condition. Seasonal variation of the three pH variables and their statistical distribution were also investigated.