Anticaries effect of low-fluoride dentifrices with phosphates in children: A randomized, controlled trial.

UNLABELLED: Low-fluoride dentifrices (LFD) have been recommended for young children aiming to minimize excessive fluoride intake during tooth brushing. Given the uncertainties surrounding the clinical efficacy of such formulations, alternatives to increase their anticaries effect have been investigated. OBJECTIVES: This double-blind, randomized controlled trial assessed the clinical efficacy of LFDs supplemented with Calcium Glycerophosphate (CaGP) or Sodium Trimetaphosphate (TMP) on the progression of dental caries in the deciduous dentition. METHODS: Children (average age 48 months old) from two Brazilian cities (Araçatuba and Fernandópolis) were randomly assigned into 3 groups, according to the dentifrice to be used: 500ppm F plus 1% TMP ("500TMP", n=206), 500ppm F plus 0.25% CaGP ("500CaGP, n=201) and 1100ppm F ('1100F', n=193). Clinical exams (dmfs) were performed at baseline and 18 months after dentifrices started to be used, and the increment in the number of carious lesions (final dmfs - initial dmfs) was calculated. Data were analyzed by multivariate linear regression analysis to verify the influence of city, gender, previous caries experience and type of dentifrice on dmfs increment (p<0.05). RESULTS: Mean caries increment observed for 500TMP (0.26) was significantly lower when compared with 1100F (0.74), while values found for 500CaGP (0.54) were not significantly different from 1100F. Caries increment was significantly higher in children from Araçatuba and in those with previous caries experience. CONCLUSION: The results indicate that clinical efficacy of LFDs supplemented with TMP is superior to that observed for a conventional formulation (1100F), while the addition of CaGP leads to similar efficacy when compared to 1100F. CLINICAL SIGNIFICANCE: Children brushing with 500ppm F toothpastes containing phosphate salts developed fewer caries lesions when compared with those using a 1100ppm F dentifrice. The tested toothpastes can be regarded as a safe alternative to conventional formulations for children under 6 years of age, based on risk-benefit considerations.

Effect of fluoride varnish supplemented with sodium trimetaphosphate on enamel erosion and abrasion: an in situ/ex vivo study.

OBJECTIVE: To evaluate the effect of fluoride (F) varnishes supplemented or not with sodium trimetaphosphate (TMP) on enamel erosive wear followed or not by abrasion in situ. METHODS: Ten volunteers were selected and randomly divided into four groups, according to the varnishes tested: placebo (no F or TMP), 5% NaF (positive control), 2.5% NaF and 2.5% NaF/5% TMP. Enamel blocks (n=4) were mounted in palatal devices and received an application of each test varnish, following a double-blind, crossover protocol. After 6h, varnishes were completely removed and the blocks were subjected to erosive challenges by ex vivo immersion in citric acid (5 min, 4×/dia, 5 days). Following, half of the blocks were subjected to abrasion by brushing with a placebo dentifrice slurry for 15s. Enamel wear (µm), surface hardness (SHf) and cross-sectional hardness (ΔKHN) were assessed after each experimental period. Results were analyzed by ANOVA, Student-Newman-Keuls's test and Pearson correlation coefficient (p<0.05). RESULTS: The fluoride varnish supplemented with TMP promoted significantly lower wear and ΔKHN when compared to the other groups after erosive challenges, followed or not by abrasion (p<0.05). As for (SHf) the fluoride varnish supplemented with TMP promoted similar results to the 5% NaF product, being significantly higher than the remaining groups after erosive and erosive+abrasive challenges (p<0.05). CONCLUSION: TMP significantly enhanced the effects of F on enamel wear after erosive challenges, followed or not by abrasion.

Effect of different fluoride concentrations of experimental dentifrices on enamel erosion and abrasion.

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 microg F/g, 500 microg F/g plus 3% TMP and 5,000 microg 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 microg F/g and 500 microg F/g plus 3% TMP dentifrices had a greater protective effect when compared with the 1,100 microg F/g dentifrice, under both ERO and ERO + ABR conditions. The results suggest that dentifrices alone are not capable of completely inhibiting tooth wear.

Analysis of fingernails and urine as biomarkers of fluoride exposure from dentifrice and varnish in 4- to 7-year-old children.

The use of fingernails and urine as biomarkers of exposure to fluoride (F) from fluoridated dentifrice and varnish was evaluated in twenty 4- to 7-year-old children, who were divided into two groups: group A (9 caries-free children) and group B (11 children with past caries experience). They used a placebo dentifrice for 28 days, fluoridated dentifrice (1,570 ppm F) for the following 28 days, and placebo dentifrice for an additional 28 days, then returned to their usual dentifrices. Group B children also received 4-week applications of a varnish (2.26% F) while using the fluoridated dentifrice. Urinary collections were performed 24 h before the use of fluoridated dentifrice and 24 h (group A) or 48 h (group B) after. Fingernails were clipped every 2 weeks, for 26 weeks. Total F intake from diet and dentifrice was estimated. Fingernail F concentrations did not vary significantly throughout the study. Twenty-four-hour urinary F outputs (mean +/- SD, microg) were: 414 +/- 200 and 468 +/- 253 for placebo and F dentifrices, respectively (group A) and 402 +/-206, 691 +/- 345, 492 +/- 243 for placebo dentifrice, F dentifrice plus F varnish and F dentifrice, respectively (group B). The use of F dentifrice did not cause a significant increase in the urinary F output. However, when F varnish was used, a transitory increase in the urinary F output was detected (p = 0.001), returning to baseline levels in the last 24 h. Thus, F varnish is a safe method for topical F application even in children that use F dentifrice regularly. According to our protocol, urine was a suitable biomarker of exposure to F from dentifrice plus varnish, but not from dentifrice alone, while nails were not.