Abstract
To study the reproducibility of salivary buffer capacity determined with Checkbuff^[○!R], we measured the flow rate, pH, and buffer capacity of saliva as well as its PO_4^<3-> and protein concentrations contributing to the buffer capacity. In addition, to clarify the relations among these factors in saliva, we not only studied the correlations among them but also examined whether there were differences in these factors related to the degree of caries risk estimated by Checkbuff^[○!R]. On the basis of the results of this study,the following conclusions were obtained. (1) Because the variance in the stimulated salivary flow rate was smaller than that of resting saliva,stimulated saliva showed a more adequate reproducibility. The values for pH and the buffer capacity measured with Checkbuff^[○!R] showed a high reproducibility with both resting and stimulated saliva. (2) Significant positive correlations were noted in the flow rate between resting and stimulated saliva,as well as between the flow rate and pH of both resting and stimulated saliva. Accordingly, those who had a large resting salivary flow rate showed a large stimulated salivary flow rate, and those who had a large salivary flow rate also showed a high salivary pH. (3) In relation to the risk of caries, significant differences were observed in the pH of saliva, the buffer capacity of resting saliva, and the protein concentration in stimulated saliva, between the high and mild buffer capacity groups. Thus, it became clear that the risk classification based on the buffer capacity obtained from stimulated saliva measured with Checkbuff^[○!R] reflected the differences not only in the pH but also in the protein concentration of saliva.
