Viscosity of whole saliva

Abstract

This study investigates within-subject variations and associations of salivary viscosities and flow rates in a test panel of healthy adults. After several practice sessions, unstimulated and stimulated whole saliva samples were collected 5 times daily (at 0800, 1100, 1400, 1700, and 2000 h) from 30 university students. There was a significant within-subject variation in viscosity and flow rate of unstimulated saliva (P < 0.001). Intra-item correlations were significantly different for salivary flow rates (r = 0.82 for unstimulated, r = 0.88 for stimulated, P < 0.001) and viscosity of unstimulated saliva (r = 0.54, P < 0.05), but viscosity of stimulated saliva was different in this respect. Our results indicate that there is a significant within-subject variation in viscosity of unstimulated saliva.