Studies on fluoride excretion in human whole saliva and its relation to flow rate and plasma fluoride levels

Five volunteers participated in two separate experiments where whole saliva was collected without stimulation or with stimulation by chewing on paraffin wax. The saliva was collected continuously for 120 min after ingestion of 1 mg fluoride as NaF. Blood was collected at intervals throughout the experiments. The results showed that the concentration of fluoride in whole saliva mirrored the fluoride concentration in plasma, but at a lower level. Variations in salivary flow rate (0.34 +/- 0.15 ml/min for unstimulated and 1.06 +/- 0.28 ml/min for stimulated) did not affect the salivary fluoride concentration. The amount of fluoride excreted into stimulated whole saliva was significantly correlated with the salivary flow rate, with a correlation coefficient of 0.98. The fraction of the ingested fluoride dose recovered in whole saliva within 2 h was 0.05 +/- 0.02 and 0.18 +/- 0.09% for the unstimulated and the stimulated whole saliva, respectively.