Measurement of unstimulated salivary flow rate in healthy children aged 6 to 15 years

The aim of the present study was to measure unstimulated saliva flow rate (uSFR), pH value and buffer capacity in healthy children aged 6 to 15 years to serve as reference values for subsequent investigations, in particular to define threshold values for abnormality. Our basic data will power the limited amount of currently available data on salivary flow rate in healthy children. The uSFR was evaluated for correlations with pH value and buffer capacity. The unstimulated saliva of 274 children aged 6 to 15 years was collected (n: 154) by the spitting method within three minutes. The samples were examined immediately after saliva collection in terms of uSFR, pH value and buffer capacity. From the 274 participating children 18 were excluded due to the intake of medication. The medians (IQR) of uSFR of the tested children were 0.87 (0.54, 1.11) ml/min for boys, 0.65 (0.37, 0.98) ml/min for girls and 0.76 (0.49, 1.05) ml/min in total. The uSFR correlated with the pH value and the buffer capacity (p < 0.001). For different genders there was a statistically significant difference regarding uSFR (p = 0.008) and pH value (p = 0.016). Based on the available data, the pH value and the buffer capacity were closely related to the uSFR. Boys seemed to have a higher uSFR than girls.