Fluoride ingestion from toothpaste and diet in 1- to 3-year-old Brazilian children

Toothpaste ingestion-evaluating the problem and ensuring safety: systematic review and meta-analysis

This systematic review and meta-analysis aimed to evaluate the ingestion of toothpaste and its sequelae. The study adhered to the PRISMA guidelines and was registered in the PROSPERO database. A comprehensive search strategy was conducted across multiple databases, resulting in the inclusion of 18 relevant publications. Eligible studies encompassed various designs and included both children and adults as the study population. Data extraction was carried out systematically, and relevant information on study characteristics, interventions, and outcomes were collected. The assessment of bias was performed using the Joanna Briggs Institute's Critical Appraisal Tools showing variations of bias among the included studies. The overall risk of systemic toxicity was found to be low, and no severe or life-threatening events were reported in the included studies. Furthermore, some toothpaste formulations containing higher concentrations of fluoride were associated with an increased risk of dental fluorosis. These findings have several implications for practice and policy. Healthcare providers and dental professionals should emphasize the importance of promoting safe toothpaste use, especially in vulnerable populations such as young children who are more prone to accidental ingestion. Public health campaigns and educational initiatives should aim to raise awareness about appropriate toothpaste usage and the potential risks. In addition, toothpaste manufacturers and regulatory bodies should consider revising guidelines and regulations to ensure the safety of oral care products, including the appropriate concentration of active ingredients. Future research should focus on investigating the long-term effects of toothpaste ingestion, exploring potential interactions between different active ingredients, and evaluating the efficacy of current preventive measures.

Distribution of Dental Fluorosis in the Southern Zone of Ecuador: An Epidemiological Study

In recent decades, the increase in fluoride exposure has raised the numbers of dental fluorosis in fluoridated and non-fluoridated communities In Ecuador, but the last national epidemiological study on DF was conducted more than a decade ago. The objective of this cross-sectional descriptive study was to determine the prevalence, distribution and severity of dental fluorosis (DF) using the Dean index in 1606 schoolchildren aged 6 to 12 years from urban and rural environments in provinces that make up the Southern Region of Ecuador. Participants met the inclusion criteria which were age, locality, informed consent document and no legal impediment. The results are presented using percentage frequency measures and chi-square associations. The prevalence of dental fluorosis was 50.1% in the areas of Azuay, Cañar and Morona Santiago, with no significant differences (x2 = 5.83, p = 0.054). The types of DF found most frequently were very mild and mild in all provinces; a moderate degree was more prevalent in Cañar (17%). There was no significant association (p > 0.05) between sex and the presence of dental fluorosis and, with respect to severity, the most frequent degree was moderate at the age of 12 years. The prevalence of dental fluorosis in the area evaluated is high, especially in the light and very light degrees, with a tendency toward moderate levels. It is necessary to carry out studies on the factors that are predisposing to the development of this pathology in the population studied. This research is an update regarding this pathology in Ecuador, so it is concluded that it is necessary to continue developing studies based on the findings obtained, thus contributing to the public health of the country.

Fluoride Intake and Salivary Fluoride Retention after Using High-Fluoride Toothpaste Followed by Post-Brushing Water Rinsing and Conventional (1400-1450 ppm) Fluoride Toothpastes Used without Rinsing

This study aimed to compare the fluoride intake and salivary fluoride levels after brushing with conventional (1400-1450 ppm) fluoride toothpaste containing different fluoride agents: amine fluoride (AmF), sodium fluoride (NaF), sodium monofluorophosphate (SMFP), potassium fluoride (KF), and a high-fluoride (5000 ppm) toothpaste containing NaF. Fourteen volunteers took part in the study. They were instructed to brush and spit without rinsing after using conventional toothpaste or brush and rinse with water after using a high-fluoride toothpaste. Fluoride concentrations were determined using ion-selective fluoride (09-37 type) in the saliva samples before and after procedures. Fluoride intake was estimated based on fluoride recovered after brushing. Additionally, the amount of fluoride present in the oral fluids and lost during the rapid clearance phase after toothbrushing was calculated based on salivary fluoride levels and saliva flow immediately after brushing. Salivary fluoride after using high-fluoride toothpaste was significantly higher than those observed after conventional products. Two hours after brushing, salivary fluoride concentrations did not differ significantly from baseline values (p > 0.05) unless a high-fluoride product was used. Results indicate that by refraining from rinsing after brushing with conventional toothpaste, we cannot obtain fluoride retention in saliva as with high-fluoride toothpaste. Fluoride ingestion was higher after using a high-fluoride product.

Fluoride Intake Through Dental Care Products: A Systematic Review

Fluoride (F) is added to many dental care products as well as in drinking water to prevent dental decay. However, recent data associating exposure to F with some developmental defects with consequences in many organs raise concerns about its daily use for dental care. This systematic review aimed to evaluate the contribution of dental care products with regard to overall F intake through drinking water and diet with measurements of F excretion in urine used as a suitable biomarker. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using keywords related to chronic exposure to F in the human population with measurements of F levels in body fluids, 1,273 papers published between 1995 and 2021 were screened, and 28 papers were finally included for data extraction concerning daily F intake. The contribution of dental care products, essentially by toothbrushing with kinds of toothpaste containing F, was 38% in the mean regardless of the F concentrations in drinking water. There was no correlation between F intake through toothpaste and age, nor with F levels in water ranging from 0.3 to 1.5 mg/L. There was no correlation between F intake and urinary F excretion levels despite an increase in its content in urine within hours following exposure to dental care products (toothpastes, varnishes, or other dental care products). The consequences of exposure to F on health are discussed in the recent context of its suspected toxicity reported in the literature. The conclusions of the review aim to provide objective messages to patients and dental professionals worried about the use of F-containing materials or products to prevent initial caries or hypomineralized enamel lesions, especially for young children.

Effect of dentifrices with different pH and fluoride concentrations on fluoride levels in biofilm and nails: an RCT

PURPOSE

to evaluate the effect of dentifrice pH and fluoride concentration ([F]) on fluoride uptake on the biofilm and nails of children from a non-fluoridated area.

METHODS

two hundred and twenty-eight two- to four-year-old children were randomly allocated into 3 groups according to the type of dentifrice: G1: 1100 μg F/g, pH 4.5 (n = 76); G2: 750 μg F/g, pH 4.5 (n = 74); and G3: 1100 μg F/g, pH 7.0 (n = 78). Nails were collected at 4, 8, and 12 months after starting dentifrice use and biofilm was collected 5 and 60 minutes after toothbrushing. The concentrations of F in nails and biofilm were analyzed by HMDS facilitated diffusion. Data were analyzed by Kruskal-Wallis/Mann-Whitney's test and the comparison between biofilm collection times was done using Wilcoxon test (p £ 0.05).

RESULTS

a significant reduction of [F] in biofilm was observed 60 minutes after toothbrushing, regardless of the dentifrice used. However, 5 minutes after toothbrushing, G1 had a significantly higher [F] compared to G2 and G3, and 60 minutes after toothbrushing, [F] was significantly higher for G1 and G2 compared to G3. G1 and G3 had significantly higher [F] in the nails compared to G2.

CONCLUSION

a lower dentifrice concentration is a relevant factor for the reduction of excessive fluoride intake. The use of a low-F acidified dentifrice combines the reduction of fluoride uptake with caries prevention by leading to greater incorporation of F into the biofilm over time.

Use of fluoridated dentifrices by children in Araçatuba, Brazil: factors affecting brushing habits and amount applied on the brush

PURPOSE

To evaluate the type and the amount of fluoridated dentifrice applied on children's toothbrushes by parents/guardians according to descriptions typically recommended by scientific societies, as well as to assess the influence of demographic and socioeconomic variables on dentifrice use.

METHODS

Parents/guardians of children (0-7 years old; n = 306; convenience sample) attending vaccination centres from Araçatuba (Brazil), answered to a structured questionnaire comprising items related to interviewees' education, child's age, gender, brushing habits and use of fluoridated dentifrice. The amount of toothpaste used by children during toothbrushing was estimated using a portable scale. Similarly, the interviewees were requested to apply dentifrices on toothbrushes according to eight descriptions, ranging from "smear" to "all bristles", following a random sequence. Data were submitted to Mann-Whitney's, Kruskal-Wallis' and Friedman's tests, and Spearman's correlation coefficient (p < 0.05).

RESULTS

The type of toothpaste and the amount of product used at home were not affected by the respondents' educational level or family income. However, child's age was significantly correlated with the amount of toothpaste placed on the toothbrush (r = 0.324, p < 0.001). Also, the amount of toothpaste placed on the toothbrush increased according to what would be expected from the descriptions, although wide variations were observed within each description, with large interquartile and overall ranges.

CONCLUSION

The amount and the type of dentifrice used by children were influenced by their age, while parents/caregivers' interpretation on verbal instructions regarding appropriate dentifrice quantities varied widely. This reinforces the need for educative measures on the appropriate use by dentifrices by children.

In situ evaluation of 200 ppm fluoride toothpaste content trimetaphosphate, xylitol and erythritol on enamel demineralization and dental biofilm

OBJECTIVE

To evaluate the effect of low-fluoride (F^-) toothpaste and sodium trimetaphosphate (TMP) associated with xylitol and erythritol (XE) on enamel demineralization and biofilm composition.

METHODS

This crossover double-blind in situ study consisted of five phases (seven days each), in which 14 volunteers wore oral appliances containing four enamel bovine blocks. The cariogenic challenge was performed by exposure to a 30% sucrose solution (6x/day). The toothpaste treatments (3x/day) were as follows: placebo (no F^-/TMP/XE); 200 ppm F^- (NaF) (200F); 1,100 ppm F^- (1100F); 16% Xylitol and 4% Erythritol (XE); and 200 ppm F^-, 0.2% TMP, 16% xylitol, and 4% erythritol (200F-TMP-XE). Percentage of surface hardness loss (%SH) and integrated loss of subsurface hardness (ΔKHN), and calcium (Ca²⁺), phosphate (PO₄^3-), and F^- on enamel and biofilm were determined; as well as insoluble extracellular polysaccharide (EPS).

RESULTS

XE and 1100F groups showed no significant difference for %SH and ΔKHN values (p = 0.220 and p = 0.886), and the 200F-TMP-XE group had the lowest mineral loss (p < 0.001). Ca²⁺ and PO₄^3- in the enamel showed the highest values (p < 0.001) for the 200F-TMP-XE group. Higher values of F^- in the enamel and biofilm were observed for the 1100F group (p < 0.001). There was no difference for Ca²⁺ (p = 1.00) and EPS (p =0.918) values between XE and 200-TMP-XE groups in the biofilm, but their values were higher and lower than the 1100F (p = 0.002 and p = 0.029), respectively.

CONCLUSIONS

200F-TMP-XE promoted a greater protective effect against enamel demineralization and significantly affected the composition of biofilm formed in situ compared to 1100F toothpaste.

CLINICAL SIGNIFICANCE

Low-F^- toothpaste containing TMP and polyols can be considered an effective and safe measure to improve the oral health of individuals, especially patients with high caries activity.

Amount of Dentifrice and Fluoride Concentration Influence Salivary Fluoride Concentrations and Fluoride Intake by Toddlers

The present study evaluated fluoride (F) concentrations in saliva of toddlers after brushing with dentifrices containing different F concentrations, applied in different quantities, and estimated F intake from toothbrushing. The study comprised a double-blind, crossover protocol, in which toddlers (n = 18, 2-3 years old) were randomly assigned into six groups, according to possible combinations of dentifrices (0/550/1,100 ppm F, as NaF) and amounts (rice grain, pea size, and transverse technique). Volunteers used a F-free dentifrice during 1 week. On the 7th day, saliva samples were collected before (baseline), and at 5/15/30/60 min after toothbrushing. All dentifrice expectorated after brushing was collected. F concentrations (saliva and expectorate) were determined with an ion-specific electrode. Data were submitted to ANOVA or Kruskal-Wallis test, followed by Fisher's LSD or Student-Newman-Keuls' tests (p <0.05). Brushing with 550 ppm F dentifrice (pea size or transversal technique) increased the area under the curve (AUC) at similar levels compared to 1,100 ppm F (rice grain). The highest AUC and salivary F at 5 min after brushing were achieved by 1,100 ppm F (pea size), followed by 550 ppm F (transversal technique). Regarding F intake, the highest values were observed for 550 ppm F (transversal technique), followed by 1,100 ppm F (pea size). It is possible to conclude that the amount of dentifrice and F concentration in the product significantly affected both salivary F concentrations and F intake during toothbrushing.

Review of Fluoride Intake and Appropriateness of Current Guidelines

Since the classical epidemiological studies by Dean, it has been known that there should be an optimum level of exposure to fluoride that would be able to provide the maximum protection against caries, with minimum dental fluorosis. The "optimal" daily intake of fluoride for children (0.05-0.07 mg per kilogram bodyweight) that is still accepted worldwide was empirically determined. In the present review, we discuss the appropriateness of the current guidance for fluoride intake, in light of the windows of susceptibility to caries and fluorosis, the modern trends of fluoride intake from multiple sources, individual variations in fluoride metabolism, and recent epidemiological data. The main conclusion is that it is very difficult to think about a strict recommendation for an "optimal" range of fluoride intake at the individual level in light of existing knowledge of 1) the mechanisms of action of fluoride to control caries, 2) the mechanisms involved in dental fluorosis development, 3) the distinct factors that interfere in the metabolism of fluoride, and 4) the windows of susceptibility to both dental caries and fluorosis development. An "optimal" range of fluoride intake is, however, desirable at the population level to guide programs of community fluoridation, but further research is necessary to provide additional support for future decisions on guidance in this area. This list includes the effect of factors affecting fluoride metabolism, clinical trials on the effectiveness of low-fluoride dentifrices to prevent caries in the primary dentition, and validation of biomarkers of exposure to fluoride.

Current Guidance for Fluoride Intake: Is It Appropriate?

The purpose of this report is to examine critically the appropriateness of the current guidance for fluoride intake in the population (0.05-0.07 mg F/kg bodyweight/d), consider whether changes to the current guidance are desirable, and suggest further research that will strengthen the evidence base for future decisions on guidance/advice in this area. The benefits and the risks of using fluoride particularly concern preschool children because it is at this age that excessive fluoride intake may result in dental fluorosis. Data from mostly cross-sectional studies show a wide variation in exposure and a considerable variation in the amount of fluoride ingested. Fluorosis, mostly mild, is commonly observed. For considering changes in current guidance, there is a need for more knowledge on the relationship between exposure to fluoride at an early age and the development of fluorosis. For that, prospective epidemiological studies with sufficiently large and representative samples of children are required. It is also important to study children in communities both with and without water fluoridation and to include populations where salt or milk fluoridation is used. There is also a need for professional agreement on acceptable levels of mild and moderate/severe fluorosis and a more comprehensive knowledge on the appreciation of mild fluorosis among the public.

Bone Strength in Growing Rats Treated with Fluoride: a Multi-dose Histomorphometric, Biomechanical and Densitometric Study

Bone deformation and fragility are common signs of skeletal fluorosis. Disorganisation of bone tissue and presence of inflammatory foci were observed after fluoride (F^-) administration. Most information about F^- effects on bone has been obtained in adult individuals. However, in fluorosis areas, children are a population very exposed to F^- and prone to develop not only dental but also skeletal fluoroses. The aim of this work was to evaluate the bone parameters responsible for the effect of different doses of F^- on fracture load of the trabecular and cortical bones using multivariate analysis in growing rats. Twenty-four 21-day-old Sprague-Dawley rats were divided into four groups: F0, F20, F40 and F80, which received orally 0, 20, 40 or 80 μmol F^-/100 g bw/day, respectively, for 30 days. After treatment, tibiae were used for measuring bone histomorphometric and connectivity parameters, bone mineral density (BMD) and bone cortical parameters. The femurs were used for biomechanical tests and bone F^- content. Trabecular bone volume was significantly decreased by F^-. Consistently, we observed a significant decrease in fracture load and Young's modulus (YM) of the trabecular bone in F^--treated groups. However, cortical bone parameters were not significantly affected by F^-. Moreover, there were no significant differences in cortical nor trabecular BMD. Multivariate analysis revealed a significant correlation between the trabecular fracture load and YM but not with bone volume or BMD. It is concluded that when F^- is administered as a single daily dose, it produces significant decrease in trabecular bone strength by changing the elasticity of the trabecular bone.

Understanding Optimum Fluoride Intake from Population-Level Evidence

Policy on fluoride intake involves balancing caries against dental fluorosis in populations. The origin of this balance lies with Dean’s research on fluoride concentration in water supplies, caries, and fluorosis. Dean identified cut points in the Index of Dental Fluorosis of 0.4 and 0.6 as critical. These equate to 1.3 and 1.6 mg fluoride (F)/L. However, 1.0 mg F/L, initially called a permissible level, was adopted for fluoridation programs. McClure, in 1943, derived an “optimum” fluoride intake based on this permissible concentration. It was not until 1944 that Dean referred to this concentration as the “optimal” concentration. These were critical steps that have informed health authorities through to today. Several countries have derived toxicological estimates of an adequate and an upper level of intake of fluoride as an important nutrient. The US Institute of Medicine (IOM) in 1997 estimated an Adequate Intake (AI) of 0.05 mg F/kg bodyweight (bw)/d and a Tolerable Upper Intake Level (UL) of 0.10 mg F/kg bw/d. These have been widely promulgated. However, a conundrum has existed with estimates of actual fluoride intake that exceed the UL without the expected adverse fluorosis effects being observed. Both the AI and UL need review. Fluoride intake at an individual level should be interpreted to inform more nuanced guidelines for individual behavior. An “optimum” intake should be based on community perceptions of caries and fluorosis, while the ultimate test for fluoride intake is monitoring caries and fluorosis in populations.

Influence of Toothpaste pH on Its Capacity to Prevent Enamel Demineralization

Aim:

This study evaluated in vitro the remineralization capacity of commercial toothpastes with different fluoride (F) concentrations and their effectiveness when they are acidified.

Materials and Methods:

One hundred and twelve caries-free teeth were used to prepare enamel specimens, and the specimens were divided into 16 groups (n = 7). Baseline surface Vickers microhardness was measured for all the specimens and all the tested groups were subjected to the pH-cycling regime involved five demineralization challenges each day for 10 days, and surface Vickers microhardness was then measured. Once daily, specimens were exposed for 30 min after last demineralization challenge of the day to the slurry of each toothpaste containing 1450 ppm F, 1000 ppm F, 450 ppm F, and 0 ppm F. The slurry was in original pH or acidulated on 6.5, 6.0, or 5.5 pH. The difference among tested group was assessed by analysis of variance and Newman–Keuls test (P < 0.05).

Results:

The highest increase in microhardness was detected after treatment with toothpaste containing 1450 ppm fluoride (percentage of increase in microhardness was 6.20%), and the biggest loss was detected after treatment with toothpaste containing no fluoride (percentage of decrease was 6.82%), but there was no significant difference between tested groups.

Conclusions:

The highest increase in microhardness was detected after treatment with toothpaste containing more fluorides (1450 ppm F) regardless of the acidity.

Biomarkers of chronic fluoride exposure in groundwater in a highly exposed population

This study examined the relation between fluoride (F-) concentrations in fingernail clippings and urine and the prevalence and severity of enamel fluorosis (EF) among Ethiopian Rift Valley populations exposed to high levels of F- in drinking water. The utility of fingernail clippings as a biomarker for F- exposure and EF was also assessed for the first time in a high-F- region. The study recorded the EF status of 386 individuals (10 to 50years old), who consume naturally contaminated groundwater with widely varying F- concentration (0.6-15mg/L). The mean F- concentrations among residents of communities with primary reliance on groundwater were 5.1mg/kg (range: 0.5-34mg/kg) in fingernails and 8.9mg/L (range: 0.44-34mg/L) in urine. We show strong positive correlations between F- in drinking water and 12-hour urinary excretion (r=0.74, p<0.001, n=287), fingernail F- content (r=0.6, p<0.001, n=258), and mean individual measures of EF severity as measured using the Thylstrup and Fejerskov (TF) Index (r=0.42, p<0.001, n=316). The data indicate that both fingernail and urine measures are good biomarkers for F- exposure and EF outcomes, the latter being slightly more sensitive. Cases of moderate/severe EF were significantly more common among younger subjects (10 to 15years old) than older subjects (mostly >25years old) (p<0.001), consistent with their greater exposure to F- during early childhood, which is the only period of life the enamel is at risk of fluorosis. In this younger population, EF may be useful as a biomarker for identifying individuals with other potential health effects that depend on a specific age window of susceptibility. The finding of exceptionally high F- concentrations in water, fingernail clippings and urine in this region should motivate further investigations of other potential health consequences such as bone disease and abnormalities in the function of the neurological and endocrine systems.

iTRAQ-Based Proteomics Analysis of Serum Proteins in Wistar Rats Treated with Sodium Fluoride: Insight into the Potential Mechanism and Candidate Biomarkers of Fluorosis

Fluorosis induced by exposure to high level fluoride is quite widespread in the world. The manifestations of fluorosis include dental mottling, bone damage, and impaired malfunction of soft tissues. However, the molecular mechanism of fluorosis has not been clarified until now. To explore the underlying mechanisms of fluorosis and screen out serum biomarkers, we carried out a quantitative proteomics study to identify differentially expressed serum proteins in Wistar rats treated with sodium fluoride (NaF) by using a proteomics approach of isobaric tagging for relative and absolute quantitation (iTRAQ). We fed Wistar rats drinking water that had 50, 150, and 250 mg/L of dissolved NaF for 24 weeks. For the experimental duration, each rat was given an examination of the lower incisors to check for the condition of dental fluorosis (DF). By the end of the treatment, fluoride ion concentration in serum and lower incisors were detected. The results showed that NaF treatment can induce rat fluorosis. By iTRAQ analysis, a total of 37 differentially expressed serum proteins were identified between NaF-treated and control rats. These proteins were further analyzed by bioinformatics, out of which two proteins were validated by enzyme-linked immunoadsorbent assays (ELISA). The major proteins were involved in complement and coagulation cascade, inflammatory response, complement activation, defense response, and wound response, suggesting that inflammation and immune reactions may play a key role in fluorosis pathogenesis. These proteins may contribute to the understanding of the mechanism of fluoride toxicity, and may serve as potential biomarkers for fluorosis.

Fluoride concentrations of milk, infant formulae, and soy-based products commercially available in Brazil

OBJECTIVES

To assess the fluoride (F) content in commercially available milk formulae in Brazil and to estimate the F intake in children from this source in the first year of life.

METHODS

Samples of cow's milk (n = 51), infant formulae (n = 15), powdered milk (n = 13), and soy-based products (n = 4) purchased in Araçatuba (Brazil) had their F content measured using an ion-specific electrode, after hexamethyldisiloxane-facilitated diffusion. Powdered milk and infant formulae were reconstituted with deionized water, while ready-to-drink products were analyzed without any dilution. Using average infant body masses and suggested volumes of formula consumption for infants 1-12 months of age, possible F ingestion per body mass was estimated. Data were analyzed by descriptive analysis.

RESULTS

Mean F content ranged from 0.02 to 2.52 mg/L in all samples. None of the cow's milk provided F intake higher than 0.07 mg/kg. However, two infant formulae, one powdered milk, and one soy-milk led to a daily F intake above the suggested threshold for fluorosis when reconstituted with deionized water. Assuming reconstitution of products with tap water at 0.7 ppm F, two infant formulae, five powdered milk, and four soymilks led to daily F intake ranging from 0.108 to 0.851 mg/kg.

CONCLUSIONS

The results suggest that the consumption of some brands of infant formulae, powdered milk, and soy-based milk in the first year of age could increase the risk of dental fluorosis, reinforcing the need for periodic surveillance of the F content of foods and beverages typically consumed by young children.

Estimation of daily dietary fluoride intake: 3-d food diary v. 2-d duplicate plate

The 3-d food diary method (3-d FD) or the 2-d duplicate plate (2-d DP) method have been used to measure dietary fluoride (F) intake by many studies. This study aimed to compare daily dietary F intake (DDFI) estimated by the 3-d FD and 2-d DP methods at group and individual levels. Dietary data for sixty-one healthy children aged 4-6 years were collected using 3-d FD and 2-d DP methods with a 1-week gap between each collection. Food diary data were analysed for F using the Weighed Intake Analysis Software Package, whereas duplicate diets were analysed by an acid diffusion method using an F ion-selective electrode. Paired t test and linear regression were used to compare dietary data at the group and individual levels, respectively. At the group level, mean DDFI was 0·025 (sd 0·016) and 0·028 (sd 0·013) mg/kg body weight (bw) per d estimated by 3-d FD and 2-d DP, respectively. No statistically significant difference (P=0·10) was observed in estimated DDFI by each method at the group level. At an individual level, the agreement in estimating F intake (mg/kg bw per d) using the 3-d FD method compared with the 2-d DP method was within ±0·011 (95 % CI 0·009, 0·013) mg/kg bw per d. At the group level, DDFI data obtained by either the 2-d DP method or the 3-d FD method can be replaced. At an individual level, the typical error and the narrow margin between optimal and excessive F intake suggested that the DDFI data obtained by one method cannot replace the dietary data estimated from the other method.

Development of caries adjacent to composite restorations after exposure to dentifrices with different fluoride concentrations

Objective To evaluate the development of recurrent caries after exposure to fluoride dentifrices with different concentrations. Material and method: 48 samples of bovine incisors (4x4mm2) were exposed to pH cycling for 7 days before the preparation of the cavities (2mm deep). The samples were restored with a microhybrid resin composite. Then, the samples were exposed to thermal cycling (350 cycles) and they were randomly allocated into 4 treatment groups (n = 12): Group A - non-fluoridated dentifrice (negative control); Group B - 500 ppm dentifrice; Group C - 750 ppm dentifrice; group D - 1100 ppm dentifrice (positive control). The samples were treated with solutions of each dentifrice (9.6 ml water/1.6 g dentifrice) for 60 seconds and then were immersed in demineralizing (3 h) and remineralizing (2 h) solutions 3 times a day. Next, the samples were immersed in a remineralizing solution for 18 hours. Then, the blocks were sectioned for examination of the length of the outer caries lesion, using polarized light microscopy. The ANOVA parametric test complemented by the Tukey test with a confidence level of 95%, were used in the statistical analysis. Result: A smaller lesion length was observed in the group treated with the fluoride concentration of 1100 ppm F, but there were no differences between toothpastes with fluoride concentrations of 500 and 750 ppm F. Conclusion: The use of fluoride dentifrices (1100 ppm) reduces the development of caries adjacent to dental restorations.

Dental fluorosis associated with chronic ingestion of dentifrices – what health professionals should know

This paper reports on two cases of dental fluorosis caused by inadvertent ingestion of fluoridated dentifrice. An eight-year-old child showed whitish spots and loss of dental enamel in first permanent molars and whitish spots without structure loss in permanent incisors and primary second molars, whereas a fourteen-year-old teenager showed whitish spots in all permanent teeth. In both cases, homologue teeth were affected similarly and mothers did not report on the use of fluoride supplements during pregnancy or children’s infancy. The water fluoridation of the city where they live is considered optimal. Both patients reported eating dentifrice frequently during tooth brushing and in other occasions. Mothers also stated that they did not receive instructions about oral hygiene or about the fact that chronic ingestion of dentifrice could contribute to the development of dental fluorosis. It is believed that the cooperative work between dentists and other health professionals is a way to prevent the occurrence of this condition.

Dentifrice pH but not consistency may affect fluoride uptake in plaque

OBJECTIVE

Test the ability of acidic fluoridated solutions to enhance fluoride (F) bound on bacteria (1) and the effect of dentifrice consistency on plaque fluid F uptake (2).

METHODS

(1) Streptococcus mutans isolates were grown in BHI medium (37°C/18h). Bacteria were washed either with EDTA or CaCl2 both at 1mM to remove or add calcium, respectively. Pellets were incubated with 12 mM NaF at pH 4.5 or 7 for 1 min and F was quantified in the lysates and supernatants with the electrode, after HMDS-facilitated diffusion. (2) A randomized, double-blind, crossover clinical trial was performed in three phases with nineteen adults (20-35 years) that used one of the dentifrices: commercial toothpaste (1100 ppm F, pH7.0 and conventional viscosity (Sorriso Fresh(®))); experimental liquid dentifrice (ELD) (1100 ppm F, pH7.0 and low viscosity [1.1% carboxymethylcellulose (CMC)]) and ELD (1100 ppm F and high viscosity pH7.0 (2.2% CMC)). F concentration in plaque fluid was analyzed using an inverted F electrode.

RESULTS

(1) Significantly higher F amounts were detected in the lysates of bacteria incubated with NaF solution at pH4.5 compared to the supernatant, which was not seen at pH7.0, being this effect calcium-dependent. (2) Significantly higher F concentrations in plaque fluid were found 1h after toothbrushing compared to 12h, but no significant differences were seen among the toothpastes.

CONCLUSIONS

F at low pH binds more efficiently to S. mutans than at neutral pH and dentifrice viscosity does not interfere in plaque fluid fluoride incorporation.

CLINICAL SIGNIFICANCE

pH of the dentifrice but not consistency may be important to F uptake in plaque.

Mechanisms of action of fluoridated acidic liquid dentifrices against dental caries

OBJECTIVE

This study attempted to clarify the mechanisms of action of fluoridated acidic liquid dentifrices against dental caries.

DESIGN

In the in vitro leg, enamel specimens were submitted to a pH-cycling model, treated with distinct dentifrices (0, 550 μgF/g pH 4.5 and pH 7.0, 1100 or 5000 μgF/g pH 7.0) and analyzed using hardness. Alkali-soluble fluoride (F) deposition was quantified on pre-demineralized specimens treated with the dentifrices. In the clinical leg, 2-to-4-year-old children who had been using liquid dentifrices for 6 months (550 μgF/g pH 4.5 or pH 7.0 or 1100 μgF/g pH 7.0) had their plaque samples collected 5 and 60 min after the last brushing. Fluoride uptake in whole plaque was evaluated.

RESULTS

The reduction of the pH had a partial preventive effect on subsurface hardness loss only. [F] had a significant influence on the deposition of fluoride, surface and subsurface hardness loss. In vivo, the reduction of the pH was able to significantly increase plaque F uptake, leading to similar levels as those found for the neutral dentifrice containing twice [F].

CONCLUSION

The results obtained from in vitro studies whose design does not include the presence of dental plaque should be interpreted with caution.

Quantification of fluoride in food by microwave acid digestion and fluoride ion-selective electrode

To quantify fluoride in food it is necessary to extract the fluoride from the matrix. Dry ashing (alkali fusion) and facilitated diffusion are the methods most commonly used, but their application requires lengthy treatments. The present study proposes the use of a microwave oven and 7 mol/L nitric acid for simple, rapid digestion of foods for fluoride analysis. The analyte is subsequently quantified by fluoride ion-selective electrode. The various steps of the method were optimized and an in-house validation was performed. The limit of quantification (0.130 mg/kg), trueness (92%), recovery (84-101%), and precision (1-8%) were determined. These analytical characteristics are satisfactory and show the suitability of the method for analysis of fluoride in foods of various kinds. The method's ease of application and the use of equipment normally found in food analysis laboratories may help to further increase research on fluoride concentrations in foods consumed by the population.

Fluoride intake from food items in 2- to 6-year-old Brazilian children living in a non-fluoridated area using a semiquantitative food frequency questionnaire

BACKGROUND

Estimating fluoride intake (FI) using the 'duplicate plate' method is difficult and can raise ethical dilemmas.

AIM

To apply a semiquantitative food frequency questionnaire (FFQ) to 2- to 6-year-old Brazilian children in a non-fluoridated area (i) to estimate their FI and (ii) to provide additional validity to the questionnaire by comparing the results obtained with those found previously in a fluoridated municipality.

DESIGN

The FFQ was administered to parents of 398 children residing in a non-fluoridated community. Constituents of the diet were divided into solids, water and other beverages and their fluoride content was analysed with the electrode. Data were analysed using unpaired t-test.

RESULTS

The mean (±SD) FIs from solids, water and other beverages were 0.009 ± 0.004, 0.001 ± 0.001 and 0.007 ± 0.007 mg F/kg body weight/day, respectively, totalling 0.017 ± 0.009 mg F/kg body weight/day. Total FI from food/beverage items ingested in the non-fluoridated area was significantly lower than that observed in a study previously conducted in a fluoridated area (P < 0.0001).

CONCLUSIONS

This result reinforces the use of the FFQ as a promising alternative to duplicate diet in order to estimate FI in children in this age range, with potential application in broad epidemiological surveys.

Estimated fluoride doses from toothpastes should be based on total soluble fluoride

The fluoride dose ingested by young children may be overestimated if based on levels of total fluoride (TF) rather than levels of bioavailable fluoride (total soluble fluoride—TSF) in toothpaste. The aim of the present study was to compare doses of fluoride intake based on TF and TSF. Fluoride intake in 158 Brazilian children aged three and four years was determined after tooth brushing with their usual toothpaste (either family toothpaste (n = 80) or children’s toothpaste (n = 78)). The estimated dose (mg F/day/Kg of body weight) of TF or TSF ingested was calculated from the chemical analysis of the toothpastes. Although the ingested dose of TF from the family toothpastes was higher than that from the children’s toothpastes (0.074 ± 0.007 and 0.039 ± 0.003 mg F/day/Kg, respectively; p < 0.05), no difference between types of toothpaste was found regarding the ingested dose based on TSF (0.039 ± 0.005 and 0.039 ± 0.005 mg F/day/Kg, respectively; p > 0.05). The fluoride dose ingested by children from toothpastes may be overestimated if based on the TF of the product. This finding suggests that the ingested dose should be calculated based on TSF. Dose of TSF ingested by children is similar whether family or children’s toothpaste is used.

Estimation of toothpaste fluoride intake in preschool children

The objective of this study was to estimate the intake of toothpaste fluoride used by children aged 2 to 6 years (n=87) treated at a hospital of a medium-sized city (Campina Grande, PB) in the Northeastern region of Brazil. Data regarding sociodemographic characteristics of families and children's toothbrushing were collected from questionnaire-based interviews with parents/guardians, and the amount of fluoride used during toothbrushing was estimated using a precision scale for assessment of the risk of dental fluorosis, considering a cutoff value of 0.07 mgF/kg body weight/day. Fluoride content in the toothpastes was analyzed using a specific fluoride electrode. Data were analyzed using descriptive and inferential statistics using the chi-square and Fisher's exact tests (α=0.05). Considering the use of the derice, the risk of fluorosis in the children was 19.5%. There was significant association (p<0.05) between the risk of fluorosis, brushing frequency, type of derice and who performed the child's oral hygiene. It was concluded that a high percentage of children in the studied sample used toothpaste inappropriately and were at risk of developing dental fluorosis.

Dental fluorosis in the primary dentition and intake of manufactured soy-based foods with fluoride

BACKGROUND & AIMS

To identify manufactured soy-based products more recommended by pediatricians and nutritionists; to determine fluoride concentrations in these products; to evaluate children concerning fluorosis in primary teeth and its association with the consumption of soy-based products.

METHODS

Pediatricians and Nutritionists answered a questionnaire about soy-based products they most recommended to children. Fluoride concentrations of the 10 products more cited were analyzed with the ion-specific electrode. Dental fluorosis exams were performed in 315 4-6-year-old children. Dean's Index was used to assess fluorosis. Among the children examined, 26 had lactose intolerance. Their parents answered a questionnaire about children's and family's profile, besides permitting the identification of soy-based products use. Chi-squared and Multivariable Logistic Regression tests were used (p < 0.05).

RESULTS

Fluoride content in the analyzed products ranged from 0.03 to 0.50 μg F(-)/mL. Dental fluorosis was detected in 11% of the children, with very mild and mild degrees. Dental fluorosis in primary teeth was associated with lactose intolerance (p < 0.05), but there was no significant association with the use of manufactured soy-based products.

CONCLUSIONS

Isolated consumption of soy-based products recommended by health professionals to children do not offer risk of dental fluorosis in primary teeth, which had a low prevalence and severity.

Spatial distribution and temporal variation of high fluoride contents in groundwater and prevalence of fluorosis in humans in Yuanmou County, Southwest China

Successive surveys conducted in 1984, 2006 and 2007, of all villages in Yuanmou County, China, highlighted 40 villages with groundwater fluoride levels higher than 1.0mg/L and related cases of human fluorosis. Using the data from these surveys and by employing geographic information system (GIS) techniques, high fluoride levels and fluorosis cases were mapped. The results show high fluoride concentrations and fluorosis hotspots were found to be predominately located in the lowlands of central Yuanmou County. Spatial distribution of high fluoride levels was found to be primarily determined by geology, arid climate, and topography. Both dental and skeletal fluorosis had dramatically decreased due to a program of low-fluoride drinking water supply supported by local governments. The prevalence of dental fluorosis in children had dropped from 43.26% in 1984 to 21.97% in 2006, and the number of skeletal fluorosis cases had decreased from 327 in 1984 to 148 in 2006, respectively. Despite a decline in fluorosis cases, the emergence of fluorosis in new areas indicates the need for both continuous monitoring of drinking water in affected areas and increased public awareness.

Fluoridated toothpaste: usage and ingestion of fluoride by 4- to 6-yr-old children in England

Fluoridated toothpaste is effective for dental caries control, yet may be a risk factor for dental fluorosis. This study aimed to quantify fluoride ingestion from toothpaste by children and to investigate the effects of age, gender, and social class on the amount of fluoride ingested per toothbrushing session. Sixty-one children, 4-6 yr of age, were recruited: 38 were from low socio-economic (LSE) areas of Newcastle, UK, and 23 were from high socio-economic (HSE) areas of Newcastle, UK. All expectorated saliva, rinse water (if used), and residual toothpaste were collected after brushing at home and were analysed for fluoride. Of the children, 74% and 69% from HSE and LSE areas, respectively, claimed that they brushed twice per day. The mean (SD) weight of toothpaste dispensed was 0.67 (0.36) g. The mean (SD) amount of fluoride ingested per toothbrushing session and per day was 17.0 (14.7) and 29.3 (32.8) μg kg(-1) of body weight, respectively. Daily fluoride intake per kilogram of body weight did not differ significantly between children from LSE and HSE areas. Fluoride intake per toothbrushing session was significantly influenced by weight of toothpaste, its fluoride concentration, and the child's age. Whilst the average amount of toothpaste used per toothbrushing session was more than twice the recommended amount (of 0.25 g), only one child had a daily fluoride intake that exceeded the tolerable upper intake level of 0.1 mg kg(-1) of body weight for this age group.

Association between socioeconomic factors and the choice of dentifrice and fluoride intake by children

It is questionable whether socioeconomic factors influence the choice of marketed children’s dentifrices and whether these products are associated with greater fluoride (F) intake in children. The present cross-sectional study involving 197 children (mean age: 40.98 ± 6.62 months) was carried out in Montes Claros, Brazil. Parents completed a questionnaire on socioeconomic status and the tooth brushing habits of their children. The children brushed their teeth and saliva residues were collected for F analysis. F intake from dentifrice was determined with an ion-specific electrode. Univariate analysis and logistic regression were used to test whether the type of dentifrice (children’s or family) and F dose (<0.05 and ≥0.05 mg F/Kg of body weight/day) were associated with the independent variables (p < 0.05). No differences were found between children’s and family dentifrices regarding daily F intake (0.046 and 0.040 mg F/Kg/day, respectively; p = 0.513). The following were strong predictors for the use of a children’s dentifrice: studying at a private kindergarten (OR: 6.89; p < 0.001); age that the child begun to tooth brush <2 years (OR: 2.93; p = 0.041), and the interaction between the variables “use of the same dentifrice as parents” and “type of tooth brush used” (OR: 27.20; p < 0.001). “The amount of dentifrice used” and “frequency of tooth brushing” (p ≤ 0.004) had a statistically and synergistic effect over the daily F dose. The present study found a social influence over the choice of dentifrice: children with a high socioeconomic status tend to use a children’s dentifrice. The amount of dentifrice used can strongly increase the risk of exposure to higher doses of F, regardless of the type of dentifrice.

Fluoride content of solid foods impacts daily intake

OBJECTIVE

To determine the amount of fluoride received from solid foods for a cohort of children.

METHODS

Parents were asked to complete questionnaires for the preceding week and dietary diaries for 3 days for their children. Data collected at 6, 9, 12, 16, 20, 24, 36, 48, and 60 months were analyzed cross-sectionally.

RESULTS

At 6 months of age, children ingested an estimated mean of 8 percent of dietary fluoride from solid foods. At 12 months of age, children ingested an estimated 39 percent of dietary fluoride from solid foods. Although the percentage of fluoride intake from solid foods stabilized from 24 to 60 months (means of 36-39 percent), some children received as much as 85-88 percent of their dietary fluoride from solid foods.

CONCLUSIONS

Some children receive a substantial portion of dietary fluoride from solid foods.

Alimentary fluoride intake in preschool children

Background

The knowledge of background alimentary fluoride intake in preschool children is of utmost importance for introducing optimal and safe caries preventive measures for both individuals and communities. The aim of this study was to assess the daily fluoride intake analyzing duplicate samples of food and beverages. An attempt was made to calculate the daily intake of fluoride from food and swallowed toothpaste.

Methods

Daily alimentary fluoride intake was measured in a group of 36 children with an average age of 4.75 years and an average weight of 20.69 kg at baseline, by means of a double plate method. This was repeated after six months. Parents recorded their child's diet over 24 hours and collected duplicated portions of food and beverages received by children during this period. Pooled samples of food and beverages were weighed and solid food samples were homogenized. Fluoride was quantitatively extracted from solid food samples by a microdiffusion method using hexadecyldisiloxane and perchloric acid. The content of fluoride extracted from solid food samples, as well as fluoride in beverages, was measured potentiometrically by means of a fluoride ion selective electrode.

Results

Average daily fluoride intake at baseline was 0.389 (SD 0.054) mg per day. Six months later it was 0.378 (SD 0.084) mg per day which represents 0.020 (SD 0.010) and 0.018 (SD 0.008) mg of fluoride respectively calculated per kg bw/day.

When adding the values of unwanted fluoride intake from the toothpaste shown in the literature (0.17-1.21 mg per day) the estimate of the total daily intake of fluoride amounted to 0.554-1.594 mg/day and recalculated to the child's body weight to 0.027-0.077 mg/kg bw/day.

Conclusions

In the children studied, observed daily fluoride intake reached the threshold for safe fluoride intake. When adding the potential fluoride intake from swallowed toothpaste, alimentary intake reached the optimum range for daily fluoride intake. These results showed that in preschool children, when trying to maximize the benefit of fluoride in caries prevention and to minimize its risk, caution should be exercised when giving advice on the fluoride containing components of child's diet or prescribing fluoride supplements.

In vitro evaluation of fluoride products in the development of carious lesions in deciduous teeth

The purpose of this study was to evaluate the effect of the application of fluoride products on the development of enamel caries in deciduous teeth. A total of 108 deciduous teeth were chosen for the study. Acid-resistant varnish was applied on the teeth, leaving only one area of 5 mm x 1 mm of dental enamel exposed. The teeth were allocated randomly to one of the following groups: 1) control - toothpaste without fluoride; 2) 1.23% fluoride gel; 3) Duraflur fluoride varnish; 4) Duraphat fluoride varnish; 5) Fluorniz fluoride varnish; 6) Fluorphat fluoride varnish; 7) varnish with Duofluorid; 8) 12% silver fluoride diamine (Cariestop); 9) children's fluoride toothpaste (500 ppm). The tested products were applied on the teeth according to the manufacturer's recommendations and the teeth were stored in a moist environment for 24 hours. Each group of teeth was then subjected to a pH cycling model for 14 days, after which the teeth were cut through the center for an analysis of the depth of the carious lesion by polarized light microscopy. Comparisons were made between the treatments and the control group. The mean lesion depth values were 318 microm +/- 39 (control), 213 microm +/- 27 (fluoride gel), 203 microm +/- 34 (Duraflur), 133 microm +/- 25 (Duraphat), 207 microm +/- 27 (Fluor-niz), 212 microm +/- 27 (Fluorphat), 210 +/- 28 (Duofluorid), 146 +/- 31 (Cariestop) and 228 +/- 24 (fluoride toothpaste). None of the products used here was able to completely prevent the formation of lesions. The highest cariostatic effect was achieved by fluoride varnish Duraphat and the lowest by the fluoride toothpaste.

Fingernail may not be a reliable biomarker of fluoride body burden from dentifrice

Fingernail has been suggested as a biomarker of fluoride (F) body burden, but there is no consensus if it would be a reliable indicator of F exposure from dentifrice. Therefore, the present study was conducted to investigate if fingernails would have sensitivity to detect F exposure from dentifrice in young children. Twenty-three 1-3-year-old children living in the city of Piracicaba (0.72 ppm F in water), Brazil, were enrolled in two phases of different F exposure: in phase A (1st to 11th week), they were exposed to the combination of F from diet (solids and liquids) and dentifrice (1,500 microg F/g as MFP), and in phase B (12th to 29th week), only to F from diet (the use of F dentifrice was interrupted). Fingernails were weekly clipped during 35 weeks for F determination. F intake from diet and dentifrice in each phase was also determined. Both analyses were made with ion-specific electrode. F intake (Mean +/- SD) was significantly higher (p<0.01) when the children were exposed to F from diet+dentifrice than only to F from diet (0.086 +/- 0.032 and 0.040 +/- 0.009 mg F/day/kg body weight, respectively). However, F concentrations in nails collected during the whole experimental period of 35 weeks presented great variation with no trend of decreasing after F dentifrice intake interruption. The findings suggest that fingernail may not be a reliable F biomarker of body burden from dentifrice.

Guidelines on the use of fluoride in children: an EAPD policy document

The EAPD strongly endorses that the daily use of fluoride should be a major part of any comprehensive preventive program for the control of dental caries in children. Regardless of the type of program, community or individually based, the suggested use of fluoride must be balanced between the estimation of caries risks and the possible risks for toxic effects of the fluorides. Such a preventive program should be re-evaluated at regular intervals and adapted to a patient's needs and risks. For the majority of European communities, the EAPD recommends the use of appropriate fluoride toothpaste in conjunction with good oral hygiene to be the basic fluoride regimen.

Fluoride intake from drinking water and dentifrice by children living in a tropical area of Brazil

Objective:

To assess fluoride (F^-) intake from water and toothpaste by children aged 18 to 36 months and to monitor the F^- concentrations in the drinking water system in a tropical city of Brazil.

Methods:

Children (n=58) aged 18-36 months, all lifetime residents of Penedo, state of Alagoas, Brazil, participated in this study. Water F^- analyses were carried out in 7 different occasions at least a week apart. For 2 days all the water drunk by each child was accounted for. Fluoride intake from water for each child was estimated using the mean F^- concentration of water in 7 different occasions. Fluoride intake from toothpaste was estimated by subtracting the recovered post-brushing F^- from the original amount placed in the toothbrush. The F^- intake from water and toothpaste was estimated by dividing the total amount of F^- ingested by the weight of each child.

Results:

The mean F^- concentration in the drinking water was 0.94 ppm (mean range 0.78-1.1 ppm), which is above the 0.7 ppm recommended for this area of Brazil. Mean total F^- intake from water and toothpaste was 0.128 mg F^-/Kg Body Weight/day. The daily means of F^- intake from water and toothpaste were 0.021 and 0.107 mg F^-/Kg Body Weight, respectively. Ninety six percent of children showed F^- intake above 0.07 mg F^-/Kg Body Weight/day.

Conclusions:

Children in Penedo are at risk for developing dental fluorosis due to high F^- intake from fluoridated toothpastes. Water fluoridation showed low contribution to the total F^- intake. However, high water F^- concentrations in the water indicate the need of surveillance of the artificial water fluoridation system.

Fluoride ingestion from food items and dentifrice in 2-6-year-old Brazilian children living in a fluoridated area using a semiquantitative food frequency questionnaire

OBJECTIVES

The aim of this study was to evaluate the fluoride intake of 2-6-year-old Brazilian children using a semiquantitative food frequency questionnaire (FFQ) which also estimated fluoride intake from dentifrice.

METHODS

The FFQ was previously validated through application to 78 2-6-year-old Brazilian children and then administered to 379 children residing in an optimally fluoridated community in Brazil (Bauru, State of São Paulo). The FFQ was applied to the parents and used to estimate the food intake of the children. The constituents of the diet were divided into solids, water and other beverages. The fluoride content of the diet items was analyzed with the fluoride electrode. The questionnaire also estimated fluoride intake from dentifrice.

RESULTS

The average (+/-SD) fluoride intake from solids, water, other beverages and dentifrice was 0.008 +/- 0.005; 0.011 +/- 0.004; 0.009 +/- 0.014 and 0.036 +/- 0.028 mg F/kg body weight/day, respectively, totalizing 0.064 +/- 0.035 mg F/kg body weight/day. The dentifrice and the diet contributed with 56.3% and 43.7% of the daily fluoride intake, respectively. Among the children evaluated, 31.2% are estimated to have risk to develop dental fluorosis (intake>0.07 mg F/kg body weight/day).

CONCLUSIONS

The dentifrice was the main source of fluoride intake by the children evaluated. However, the fluoride concentration in food items also significantly contributed to the daily ingestion by 2-6-year-old children. The questionnaire used seems to be a promising alternative to duplicate diet to estimate the fluoride intake at this age range and may have potential to be used in broad epidemiological surveys.

Remineralization of initial carious lesions in deciduous enamel after application of dentifrices of different fluoride concentrations

The aim of the present study was to evaluate the remineralization potential of five dentifrices with different fluoride concentrations. Initial caries lesions were created in 72 cylindrical enamel blocks from deciduous teeth. The specimens were randomly distributed among six experimental groups corresponding to six experimental periods. Each of the six volunteers carried two deciduous enamel specimens fixed in an intraoral appliance for a period of 4 weeks. They brushed their teeth and the enamel blocks at least two times a day with dentifrices containing 0 ppm (period 1), 250 ppm (period 2), and 500 ppm fluoride (period 3), respectively. A second group of volunteers (n = 6) used dentifrices with a fluoride content of 0 ppm (period 4), 1,000 ppm (period 5), or 1,500 ppm (period 6). At the end of the respective period, the mineral content was determined by transversal microradiography (TMR). The use of dentifrices containing 500 ppm fluoride (38% MR), 1,000 ppm fluoride (42% MR), and 1,500 ppm fluoride (42% MR) resulted in a statistically significant higher mineral recovery compared to the control group (0 ppm fluoride). Mineral recovery was similar after use of dentifrices containing 0 and 250 ppm fluoride (24%; 25%). It is concluded that it is possible to remineralize initial carious lesions in deciduous enamel in a similar way as it has been described for enamel of permanent teeth.

Dietary Fluoride Intake by Children Receiving Different Sources of Systemic Fluoride

There has been no comparison of fluoride (F) intake by pre-school children receiving more traditional sources of systemic F. The aim of this study was to estimate the dietary F intake by children receiving F from artificially fluoridated water (AFW-Brazil, 0.6–0.8 mg F/L), naturally fluoridated water (NFW-Brazil, 0.6–0.9 mg F/L), fluoridated salt (FS-Peru, 180–200 mg F/Kg), and fluoridated milk (FM-Peru, 0.25 mg F). Children (n = 21–26) aged 4–6 yrs old participated in each community. A non-fluoridated community (NoF) was evaluated as the control population. Dietary F intake was monitored by the “duplicate plate” method, with different constituents (water, other beverages, and solids). F was analyzed with an ion-selective electrode. Data were tested by Kruskall-Wallis and Dunn’s tests (p < 0.05). Mean (± SD) F intake (mg/Kg b.w./day) was 0.04 ± 0.01b, 0.06 ± 0.02a,b, 0.05 ± 0.02a,b, 0.06 ± 0.01a, and 0.01 ± 0.00c for AFW/NFW/FS/FM/NoF, respectively. The main dietary contributors for AFW/NFW and FS/FM/NoF were water and solids, respectively. The results indicate that the dietary F intake must be considered before a systemic method of fluoridation is implemented.

What is next for the Dietary Reference Intakes for bone metabolism related nutrients beyond calcium: phosphorus, magnesium, vitamin D, and fluoride?

The science supporting the Dietary Reference Intakes (DRI) for phosphorus, magnesium, vitamin D, and fluoride was examined in this review. Along with the previous article on calcium in this series both of these reviews represent all the DRI for nutrients considered essential for bone metabolism and health, as reported in the Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride (Institute of Medicine, Food and Nutrition Board (FNB), 1997). The Recomended Dietary Allowances (RDA) or adequate intake (AI), and the tolerable upper intake level (UL) were recommended for each of these essential nutrients. For adults and in the case of fluoride, for infants as well, UL were calculated since all of these nutrients have the potential for mild to detrimental side effects. Dietary intake data and controversies regarding the role these nutrients may play in other chronic diseases have also been discussed. Advances and controversies reported since the publication of the DRI for these nutrients were also addressed in this review. A recent Dietary Reference Intake Research Synthesis Workshop report identified an extensive range of suggested future research directions needed to improve our understanding of these bone-related nutrients and their contributions to human health.