Fluoride concentrations were measured in whole saliva samples collected from 16 subjects at different intervals up to 60 min after chewing of various supplementary F preparations: chewable F tablets (0.21 mg F), plain F tablets (0.25 mg F) or F-containing chewing gum (0.25 mg F). Each of the F preparations was administered in a low dose (0.21--0.25 mg F) or in a high dose (0.42--0.50 mg F). Mean resting levels of fluoride in saliva ranged from 0.03 to 0.05 parts/10(6). Peak values averaging 15--25 parts F/10(6) in the low-dose group and 25--40 parts F/10(6) in the high-dose group were recorded within 5 min after intake. After 30 min, the salivary fluoride concentrations in both groups had decreased to levels below 1 part/10(6) and approached resting levels 60 min after intake. The availability of fluoride in saliva, as estimated from AUC values (areas under curves, relating fluoride concentrations to the time from 0 to 60 min), was similar with each of the preparations applied in the low dose. When used in the high dose, the chewing gum and also the plain tablets provided significantly more fluoride in saliva than the chewable tablets. The data may suggest that unflavored plain F tablets are equally suitable as a vehicle for fluoride aiming at a topical cariostatic effect as specially designed chewable tablets or chewing gum.