The pH change after HCl titration into resting and stimulated saliva for a buffering capacity test

Background: Saliva collection can provide clinical information about individual patients. However, a correlation between ranking buffering capacity using resting and stimulated saliva is still unknown. The aim of this study was to evaluate the pH change after HCl titration into resting and stimulated saliva for a salivary buffering capacity test. Methods: Resting and stimulated saliva (by chewing paraffin wax) were collected from 80 patients. After the pH of both saliva samples was measured using a hand-held pH meter, the saliva samples were titrated with 0.1N HCl to evaluate the buffering capacity. Correlations of ranking buffering capacity (high, medium, low) between stimulated saliva and resting saliva with 30μL HCl titration and between stimulated saliva and resting saliva with 40μL HCl titration were statistically analysed by Spearman Rank Correlation Test (p<0.05). Results: At 50μL HCl titration, stimulated saliva buffering capacities were ranked into high (above pH 5.5), medium (pH from 5.5 to 4.5) and low (below pH 4.5). At 30-40μL HCl titration, the resting saliva buffering capacities were ranked into the same categories. Spearman Rank Correlation indicated significant positive coefficients for the stimulated saliva and resting saliva buffering capacity at 30μL titration and the stimulated saliva and resting saliva at 40μL titration. Conclusion: Stimulated saliva is more resistant to variation in pH change during HCl titration than resting saliva. Stimulated saliva sampling is a good method to determine buffering capacity during a comprehensive oral health assessment.link_to_subscribed_fulltex

Quantitative assessment for stimulated saliva flow rate and buffering capacity in relation to different ages

Objectives: To evaluate salivary flow rate and buffering capacity using a quantitative pH measurement among three broad age groups. Methods: The population consisting of 117 patients was classified into three age groups: young, middle-aged, and elderly group. The volume of stimulated saliva after chewing gum was measured. Saliva samples were titrated with 0.1N HCl to evaluate the buffering capacity. Saliva pH change was measured directly using a hand-held pH meter. At the point of 50 μL of titrated HCl, individual salivary buffering capacities were ranked into one of the following three categories; high buffering capacity (above pH 5.5), medium buffering capacity (from pH 5.5 to 4.5), and low buffering capacity (below pH 4.5). Results: χ2-test showed that the proportional distribution of individuals in the three buffering capacity groups was not statistically different among the age groups (p > 0.05). One-way ANOVA and Tukey's HSD test showed the flow rate of stimulated whole saliva in the young group was significantly greater than that of the middle-aged and elderly groups (p < 0.05). Two-way ANOVA showed there was no significant interaction between the independent variables buffering capacity and age group (F = 0.419, p = 0.7950). One-way ANOVA and Tukey's HSD test indicated the flow rate showed significant differences among the three age and buffering capacity groups. Conclusions: Although a limited number of subjects were investigated in this study, the quantitative saliva assessment is useful as a screening method for different ages to identify patients with a low saliva flow rate and/or buffering capacity. © 2006 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex