This study aimed to evaluate the gastrointestinal absorption and renal excretion of fluoride after the ingestion of high-fluoride dentifrice. Twelve volunteers participated in this in vivo, crossover, and blinded study. In three experimental phases, the volunteers were randomly assigned to one of three treatment groups, who ingested either the following: distilled and deionized water (control), conventional dentifrice (1100 μg/g), or high-fluoride dentifrice (5000 μg/g). Both dentifrices contained fluoride in the form of NaF/SiO. To determine the rate of fluoride absorption, non-stimulated saliva was collected for up to 120 min after ingestion and the area under the curve of the salivary fluoride concentration was plotted as a function of time and the maximum concentration determined. All urine produced during the 24 h before and after ingestion was collected, and urinary excretion was calculated from the difference between the urinary fluoride concentrations in the two periods. A specific ion electrode coupled to an ion analyzer was used to measure fluoride concentrations. Statistical analysis was performed by ANOVA followed by Tukey's test with p set at 5%. All measured parameters were highest after the ingestion of the dentifrice with 5000 μg/g (p < 0.001), confirming that this has an increased level of bioavailable fluoride compared with the conventional dentifrice. The high-fluoride dentifrice increases the concentration of salivary fluoride, which may explain its greater anticaries effect. However, it poses a potential risk of causing dental fluorosis and so should not be used by children.

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ObjectiveThe objective of the study was to evaluate the kinetics of salivary F bioavailability after the use of high‐fluoride dentifrices with different compositions and their amount of total soluble fluoride (TSF).MethodsA short‐term clinical randomized trial was performed in which 15 adult participants were randomly allocated into three groups: 5000 ppm F‐dentifrice, 5000 ppm F‐dentifrice + TCP (tri‐calcium phosphate) and 1450 ppm F‐dentifrice. Unstimulated saliva was collected at different times: baseline (before toothbrushing), immediately after brushing/water rinsing and at 5, 15 and 30 min and 1, 2, 4, 8 and 12 h after brushing. The TSF in dentifrices and saliva samples was analysed using an ion‐specific electrode. For statistical analysis, the paired t‐test and Kruskal–Wallis were used with Dunn's post‐test with a 95% confidence interval.ResultsThere was no significant difference between the declared TSF and that found in 5000 ppm F‐dentifrice and 1450 ppm F‐dentifrice (p ≥ 0.13); however, in the 5000 ppm F‐dentifrice + TCP, approximately 500 ppm less TSF was observed (p = 0.0024). The area under the curve (AUC, μg F/ml min−1) of both high‐fluoride dentifrices (321.7 ± 84.0 and 223.6 ± 55.1 for the one without and with TCP, respectively) was higher than the conventional one (89.97 ± 15.6) attesting a higher F‐bioavailability (p = 0.04). Furthermore, they were able to provide F‐salivary levels higher than the baseline for up to 2 h, while this time was 1 h for the 1450 ppm F‐dentifrice (p ≤ 0.003).ConclusionBoth high‐fluoride dentifrices similarly increased the salivary‐F bioavailability in comparison with 1450 ppm F‐dentifrice, despite the lower TSF presented by the dentifrice containing TCP.

<p><strong>Objective.</strong> This <em>in vitro</em> study investigated the effect of Fluoride (F), Chlorhexidine (CHX), and their association on the viability of <em>Streptococcus mutans</em> using a biofilm model. <strong>Materials and Methods.</strong> Biofilms were anaerobically grown on glass slides that were vertically suspended in 24-well plates for 5 days.  After 48 h of initial growth, biofilms were treated for the next 72 h, 2x/day with CHX at 0.12% and 2%, F as NaF at 0.08% and 0.4% and their association. <strong>Results.</strong> CHX treatment decreased the bacteria counts either alone or in association with both F concentrations, when compared with control group and the F treatments alone (p&lt;0.05). <strong>Conclusion.</strong> No addition effect was observed when CHX and F were used in combination, when compared with CHX used alone.     </p>

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