Abstract
Objectives: Oral dryness may be caused not only by a decrease in the amount of saliva, but also by abnormality of the saliva. However, the relationship between oral dryness and the properties of saliva has not been not clarified. The purpose of this study, therefore, was to examine the relationship between objective assessment of oral dryness and the properties of saliva.
Methods: The subjects were 20 healthy adults (mean age 28.3±2.7 years). Eating, drinking and smoking were prohibited 30 minutes before measurements so that the effects of a meal and moisture intake could be excluded. To evaluate the oral dryness, the following were measured: 1) mucosal moisture (a moisture checking devise for oral mucosa, Mucus®), 2) saliva wetness (test paper, L-salivo®) and 3) saliva flow (unstimulated whole saliva flow rate). To evaluate the properties of saliva, we measured both 1) viscosity (capillary tube method), and 2) spinnability (a thread-forming property meter, NEVA METER®). Correlation coefficients among the three factors of oral dryness and both factors of saliva properties were calculated.
Results: A decrease in saliva flow led to high viscosity (r=-0.73, p<0.05). A rise of viscosity led to high spinnability (r=0.64, p<0.05). High spinnability led to a decrease in saliva wetness (r=-0.45, p<0.05). There was no other significant correlation in other combinations.
Conclusion: This study clearly showed that oral dryness and the properties of saliva were mutually related, which suggests that saliva abnormality is one of the causes of oral dryness.
