Fluoride Concentration in Different Sites on Tooth Surfaces of Permanent Premolars After Use of Dentifrices with Different Fluoride Levels.

The present study was undertaken to examine fluoride concentrations at different sites on tooth surfaces of permanent premolars after use of dentifrices with different fluoride concentrations.A pair of extracted premolars from each subject was examined; one was used for a control, and the other was extracted for this experiment two weeks after the control. During the two weeks the subject used one of three kinds of dentifrices: 1, 000ppmF, 100ppmF, and 0ppmF.The fluoride and phosphorus concentrations of surface enamel were determined by Weatherell's micro-sampling with an electrode and by colorimetry, respectively. Three sites on the buccal, one site on the occlusal, and one site on the mesial surface were investigated. The results were as follows;Fluoride concentrations at the center and occlusal buccal sites were higher in the 1, 000ppm group than in the control groups. Significant differences were observed at 10 and 20μm depths in the enamel.Fluoride concentrations tended to be higher in the 100ppm group than in the control groups at the outermost surfaces of the bucco cervical and mesial surfaces. There were no significant differences in 0ppm dentifrice between the two groups.It was concluded that the use of 1, 000ppm dentifrices was the most effective for the uptake of fluoride on enamel surfaces in vivo.