Objective: As the concentration of F in the oral fluids plays a significant role in enamel de- and remineralization, this study evaluated the effects of F concentration and pH of dentifrices on the resulting F levels in saliva.
Method: Volunteers (n=23, 21-40 years old) were residents in an optimally fluoridated area and randomly assigned to brush with CD (1,100 µg F/g), LFD (550 µg F/g) and a placebo dentifrice (PD – F free), both at pH 4.5 and 7.0, comprising 6 treatments. They were instructed to brush 3 times/day with approximately 0.5 g of dentifrice (transversal technique) and to rinse after brushing with 10 mL of tap water, following a double-blind, crossover protocol. Stimulated saliva samples were collected on the 7thday of dentifrice use, at 1 and approximately 12 h after brushing. Samples were centrifuged and the supernatant was buffered with TISAB III prior to analysis using microelectrode techniques. Data were analyzed by 3-way repeated measures ANOVA and Student-Newman-Keuls’ test (p<0.05).
Result: Salivary fluoride levels were influenced by fluoride concentration in the dentifrices and time after brushing, but not by dentifrice pH. No significant interactions were observed among the variables. The use of LFD and CD significantly increased salivary fluoride concentrations when compared to PD, with no statistic difference between LFD and CD. Moreover, results obtained 1 h after brushing were significantly higher than those found 12 h after.
Conclusion: Salivary fluoride levels are significantly increased after the use of CD and LFD in an optimally fluoridated community, but this effect is not influenced by dentifrice pH.