DIRECT DETERMINATION OF FLUORIDE IN HUMAN SALIVA BY A FLUORIDE ELECTRODE - FLUORIDE LEVELS IN PAROTID SALIVA AFTER INGESTION OF SINGLE DOSES OF SODIUM FLUORIDE

The concentration of F in human parotid saliva has been determined by means of a specific F ion electrode. Best results were obtained when the pH of the saliva was adjusted to pH 4.7-4.8 prior to measurements. Known amounts of F added to saliva were accurately assessed by this approach and there was good agreement between electrode determinations of F taken directly on saliva and chemical analyses of ashed salivary samples. The findings indicate that F levels in stimulated duct saliva range from less than 0.01-0.05 ppm. Ingestion of single doses of F resulted in an increase in salivary F starting after 5-15 min, and reaching a maximum in 30-60 min. Thereafter concentrations decreased slowly, approaching the original concentration in 2-6 hr depending on the amount of fluoride ingested. Representative maximal values for parotid salivary F after ingestion of 10, 5 and 1 mg were 0.3 ppm, 0.2 ppm and 0.06 ppm respectively. It was noted that the maxima tended to increase after repeated ingestions. © 1968.