One way to reduce dental fluorosis is by reducing the fluoride (F) concentration in dentifrice, but low-F dentifrice should be as effective as a standard dentifrice. This study evaluated in vitro whether the supplementation with sodium trimetaphosphate (TMP) of a dentifrice with low F content (500 μg/g) would provide a similar effect to that of a standard dentifrice. Bovine enamel blocks were submitted to a pH cycling regime incorporating daily exposures to a slurry of dentifrice: a low-F dentifrice with or without 0.1–3.0% TMP; an F-free, phosphate-free dentifrice (negative control), or a dentifrice with 1,100 μg/g F (positive control). The addition of TMP to dentifrice with or without F was associated with higher surface hardness and decreased loss of integrated subsurface hardness after pH cycling. The combination of 1% TMP and 500 μg F/g had a greater effect than the positive control dentifrice. It is concluded that the addition of TMP to the 500-μg F/g dentifrice allowed a similar or larger effect as compared with a standard dentifrice in this in vitro model.

It has been suggested that fluoride products are able to reduce erosive tooth wear. Thus, the purpose of this in vitro study was to evaluate the effect of dentifrices with different fluoride concentrations as well as of a low-fluoridated dentifrice supplemented with trimetaphosphate (TMP) on enamel erosion and abrasion. One hundred twenty bovine enamel blocks were assigned to the following experimental dentifrices: placebo, 1,100 µg F/g, 500 µg F/g plus 3% TMP and 5,000 µg F/g. The groups of enamel blocks were additionally subdivided into conditions of erosion (ERO) and of erosion plus abrasion (ERO + ABR). For 7 days, the blocks were subjected to erosive challenges (immersion in Sprite® 4 times a day for 5 min each time) followed by a remineralizing period (immersion in artificial saliva between erosive challenges for 2 h). After each erosive challenge, the blocks were exposed to slurries of the dentifrices (10 ml/sample for 15 s). Sixty of the blocks were additionally abraded by brushing using an electric toothbrush (15 s). The alterations of the enamel were quantified using the Knoop hardness test and profilometry (measurements in micrometers). The data were analyzed using a 2-way ANOVA test followed by a Bonferroni correction (p < 0.05). In in vitro conditions, the 5,000 µg F/g and 500 µg F/g plus 3% TMP dentifrices had a greater protective effect when compared with the 1,100 µg F/g dentifrice, under both ERO and ERO + ABR conditions. The results suggest that dentifrices alone are not capable of completely inhibiting tooth wear.

Objective:In the present investigation, the anticariogenic effect of fluoride released by two products commonly applied in infants was evaluated.Methods:Bovine sound enamel blocks were randomly allocated to each one of the treatment groups: control (C), varnish (V) and diamine silver fluoride solution (D). The blocks were submitted to pH cycles in an oven at 37°C. Next, surface and cross-sectional microhardness were assessed to calculate the percentage loss of surface microhardness (%SML) and the mineral loss (∆Z). The fluoride present in enamel was also determined.Results:F/Px10-3(ANOVA, p<0.05) in the 1stlayer of enamel before pH-cycling were (C, V and D): 1.61a; 21.59band 3.98c. The %SMH (Kruskal-Wallis, p<0.05) were: - 64.0a, -45.2band -53.1c. %∆Z values (ANOVA, p<0.05) were: -18.7a, -7.7band -17.3a.Conclusion:The data suggested that the fluoride released by varnish showed greater interaction with sound enamel and provided less mineral loss when compared with silver diamine solution.

This study evaluated the effectiveness of acidic low-fluoride dentifrices compared to conventional neutral dentifrices. Enamel blocks were submitted to pH cycling and treatment with slurries of dentifrices containing 0, 275, 412, 550 and 1,100 µg F/g (pH 4.5 or 7.0), and also a commercial dentifrice (1,100 µg F/g) and a commercial children’s dentifrice (500 µg F/g). Variations in surface microhardness and in the mineral content in enamel after pH cycling were calculated. Enamel blocks treated with acidic dentifrices exhibited less mineral loss compared to neutral dentifrices (ANOVA; p < 0.05). The acidic dentifrices with 412 and 550 µg F/g had the same effectiveness as the neutral 1,100-µg F/g dentifrice and commercial 1,100-µg F/g dentifrice.

Objective: The aim of the present study was to evaluate in situ whether a toothpaste with low fluoride associated with sodium trimetaphosphate (TMP) would provide similar effect to that of a 1,100 ppm F toothpaste. Design: This crossover double-blind study consisted of 4 phases (14 days each), during which 10 volunteers wore oral appliances containing 4 enamel bovine blocks. The cariogenic challenge was performed by the application of a 20% sucrose solution (6×/day). The toothpaste treatments (2×/day) were: placebo, 500 ppm F, 500 ppm F plus 1% TMP, and 1,100 ppm F. At the end, enamel mineral loss and biofilm composition were analyzed. Results: The toothpaste with 500 ppm F plus 1% TMP showed the lowest mineral loss (p < 0.05). Regarding the fluoride and calcium concentrations in the enamel and in the biofilm, there were no significant differences between 500 ppm F plus 1% TMP, and 1,100 ppm F toothpastes (p > 0.569), but they were significantly different when compared to toothpaste with 500 ppm F (p < 0.050). Conclusion: The addition of 1% TMP to a low-fluoride toothpaste reduces enamel demineralization in situ similar to a 1,100 ppm F toothpaste.