Dietary Fluoride Research Articles

Associations between Dietary Patterns, Fluoride Intake and Excretion in Women Exposed to Fluoridated Salt: A Preliminary Study

Abundant information exists on fluoride intake and excretion in populations exposed to fluoridated water, but not fluoridated salt, where fluoride is eaten through a combination of foods and beverages. This study assessed associations between dietary patterns, fluoride intake and excretion in Mexican women exposed to fluoridated salt. We estimated dietary fluoride intake and excretion (mg/day) from 31 women using 24-h recalls (ASA24) and 24-h urine collections (HDMS diffusion method) and assessed agreement among both estimates of exposure with a Bland-Altman plot. Dietary patterns among the sample were explored by Principal Component Analysis and associations between these patterns and both fluoride intake and excretion were estimated. using Quantile Regressions. Median dietary fluoride intake and excretion were 0.95 and 0.90 mg/day, respectively, with better agreement at values below 1.5 mg/day. We identified three dietary patterns: “Urban Convenience”, “Plant-based” and “Egg-based”. The “Urban Convenience” pattern, characterized by dairy and convenience foods was associated with an increase of 0.25 mg and 0.34 mg of F in the 25th and 50th percentiles of intake respectively, (p < 0.01), and a marginal 0.22 mg decrease in urinary fluoride (p = 0.06). In conclusion, in this sample of Mexican women, a dietary pattern rich in dairy and convenience foods, was associated with both fluoride intake and excretion.

Longitudinal associations between early-life fluoride exposures and cardiometabolic outcomes in school-aged children

Background/AimFluoride is a natural mineral present in food, water, and dental products, constituting ubiquitous long-term exposure in early childhood and across the lifespan. Experimental evidence shows fluoride-induced lipid disturbances with potential implications for cardiometabolic health. However, epidemiological studies are scarce. For the first time, we evaluated associations between repeated fluoride measures and cardiometabolic outcomes in children. MethodsWe studied ∼ 500 Mexican children from the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) cohort with measurements on urinary fluoride at age 4, and dietary fluoride at ages 4, 6, and 8 years approximately. We used covariate-adjusted linear mixed-effects and linear regression models to assess fluoride associations with multiple cardiometabolic outcomes (ages 4–8): lipids (total cholesterol, HDL, LDL, and triglycerides), glucose, HbA1c, adipokines (leptin and adiponectin), body fat, and age- and sex-specific z-scores of body mass index (zBMI), waist circumference, and blood pressure. ResultsDietary fluoride intake at age 4 was associated with annual increases in triglycerides [β per-fluoride-doubling = 2.02 (95 % CI: 0.37, 3.69)], cholesterol [β = 1.46 (95 % CI: 0.52, 2.39)], HDL [β = 0.39 (95 % CI: 0.02, 0.76)], LDL [β = 0.87 (95 % CI: 0.02, 1.71)], and HbA1c [β = 0.76 (95 % CI: 0.28, 1.24)], and decreased leptin [β = -3.58 (95 % CI: −6.34, −0.75)] between the ages 4 and 8. In cross-sectional analyses at age 8, higher tertiles of fluoride exposure were associated with increases in zBMI, triglycerides, glucose, and leptin (p-tertile trend < 0.05). Stronger associations were observed in boys at year 8 and in girls prior to year 8 (p-sex interaction < 0.05). Fewer but consistent associations were observed for urinary fluoride at age 4, indicating increased annual changes in HDL and HbA1c with higher fluoride levels. ConclusionDietary fluoride exposures in early- and mid-childhood were associated with adverse cardiometabolic outcomes in school-aged children. Further research is needed to elucidate whether these associations persist at later ages.

Fluoride as a potential contributory factor in pathogenesis of oral submucous fibrosis: A novel hypothesis

Oral submucous fibrosis (OSMF) is a chronic premalignant condition of the oral cavity characterized by progressive submucosal fibrosis and high malignant transformation risk. Areca nut chewing is an established aetiological factor, but OSMF's sporadic incidence in nut users indicates other contributing cofactors. This paper propose a novel hypothesis on the potential role of fluoride exposure in OSMF pathogenesis. Evidence in the literature demonstrates fluoride readily accumulates in oral tissues upon topical exposure and can elicit oxidative stress, chronic inflammation, collagen changes, and muscle degeneration through various mechanisms. We hypothesize chronic topical fluoride exposure from gutkha, areca nut or other smokeless tobacco products, along with other aetiologic factors, may induce an aberrant microenvironment in the oral mucosa, initiating and propagating submucosal fibrosis. Resultant repetitive injury coupled with fluoride's interference in collagen metabolism and wound healing may culminate in OSMF pathogenesis. We further speculate that chronic ingestion of dietary fluoride especially from drinking water and food may predispose individuals to OSMF when it interacts synergistically with direct contact of gutkha or other smokeless products. In addition, it is also speculated that the cellular effects of fluoride in a dose-dependent manner, could contribute to dysplastic changes and malignant transformation in severe OSMF cases. Further research should systematically investigate fluoride levels in OSMF cohorts and correlate with disease severity and malignant transformation rates. Confirming the aetiopathologic role of fluoride as a promoting factor would highlight public health efforts to limit its topical exposure from oral habits and diet to combat this oral potentially malignant disorder.

Longitudinal Dietary Fluoride Exposures in Association with Cardiometabolic Outcomes in School-Aged Children living in Mexico

Longitudinal Dietary Fluoride Exposures in Association with Cardiometabolic Outcomes in School-Aged Children living in Mexico

A National Study Exploring the Association Between Fluoride Levels and Dental Fluorosis

While the effects of fluoride on health have been widely researched, fewer high-quality studies examine the association of fluoride levels in water and dental fluorosis. To investigate the association between fluoride exposure from drinking water and dental fluorosis. This cross-sectional study used the 2013-2014 and 2015-2016 National Health and Nutrition Examination Survey (NHANES) data (January 1, 2013, through December 31, 2016). NHANES uses a complex sampling technique to develop nationally representative sample estimates of the US population that consists of interviews and physical assessments. Children and adolescents aged 6 to 15 years were included because NHANES contains their data for all 3 forms of fluoride measures: plasma fluoride levels, water levels of fluoride, and dietary fluoride supplementation. Data were analyzed from January 1 to April 30, 2023. Water and plasma fluoride levels were measured by laboratory personnel. Dietary fluoride supplement data were self-reported. The Dean's Fluorosis Index was used to evaluate fluorosis status for each tooth. The dental fluorosis severity value was based on the second most affected tooth. Independent variables included plasma and water fluoride concentrations and dietary fluoride supplementation. An independent samples t test was used to compare fluoride exposures between groups, and Pearson correlation assessed the association between plasma and water fluoride levels. To assess whether fluoride exposures were associated with dental fluorosis, logistic regression analyses were conducted. There were 1543 participants in the 2013-2014 NHANES cycle (weighted proportion male, 51.9%; mean [SD] age, 11.0 [2.7] years) and 1452 in the 2015-2016 cycle (weighted proportion male, 52.6%; mean [SD] age, 11.1 [2.8] years). A weighted 87.3% exhibited some degree of fluorosis in the 2013-2014 cycle and 68.2% in the 2015-2016 cycle. Higher fluoride levels in water and plasma were significantly associated with higher odds of dental fluorosis (adjusted odds ratios, 2.378 [95% CI, 2.372-2.383] in the 2013-2014 cycle and 1.568 [95% CI, 1.564-1.571] in the 2015-2016 cycle). The findings of this cross-sectional study suggest that exposure to higher concentrations of fluoride in water and having higher plasma levels of fluoride were associated with a greater risk of dental fluorosis. Further research can help policy makers develop policies that balance substantial caries prevention with the risk of dental fluorosis.

Estimated Dietary Fluoride Intake by 24-Month-Olds from Chocolate Bars, Cookies, Infant Cereals, and Chocolate Drinks in Brazil.

The use of fluoride (F) in the prevention of dental caries is established. However, a high amount of F intake during tooth development can cause dental fluorosis The aim of this study was to analyze variations in F concentrations in chocolate bars (CB), chocolate cookies (CC), infant cereals (IC), and chocolate milk drinks (CD) to determine the daily intake of F from different sources by children at the age of risk for developing dental fluorosis. Distinct brands of CB, CC, IC, and CD were analyzed. Fluoride was separated by hexamethyldisiloxane-facilitated diffusion. Analysis was made in triplicate with an F ion-specific electrode. F ingestion (mg/kg body weight) was evaluated with the suggested consumption (0.05-0.07 mg/kg/day) for children aged 24 months (12 kg). The concentrations for all the analyzed products ranged from 0.025 to 1.827 µg/g F. The mean (range) F concentrations were CB= 0.210 ± 0.205 µg/g (0.073-0.698, n = 8), CC = 0.366 ± 0.416 µg/g (0.320-1.827, n = 9), IC = 0.422 ± 0.395 µg/g (0.073-1.061, n = 5), and CD = 0.169 ± 0.170 µg/mL (0.025-0.443, n = 12). The products that had the highest concentration in the categories CB, CC, IC, and CD, respectively, were Nescau-Ball (0.698 µg/g), Passatempo (1.827 µg/g), Milnutri (1.061 µg/g), and Toddynho (0.443 µg/mL). The consumption of only one unit of Toddynho (CD) is equivalent to more than 11% of the maximum suggested daily intake for a 24-month-old child (0.07 mg/kg body weight). When one product from each category is consumed together only once a day, this consumption is equivalent to approximately 24% of the suggested daily intake of fluoride for a 24-month-old child. The presence of high levels of fluoride in certain products suggests that they play a significant role in overall fluoride intake. It is crucial to closely monitor the fluoride content of food and drinks that are consumed by children who are at risk for dental fluorosis, and for product labels to clearly display the fluoride concentrations.

Patterns of fluoride intake from 6 to 17 years of age: The Iowa Fluoride Study.

This article reports on estimated daily fluoride intake from water, other beverages and selected foods, dentifrice, and dietary fluoride supplements by both individual sources, and all sources combined, among 787 children participating in the Iowa Fluoride Study (IFS) from 6 to 17 years of age. Total daily fluoride intake (mg F) and fluoride intake per kilogram bodyweight (mg F/kg bw) were estimated using responses to questionnaires sent every 3-6months. Dietary assessments included frequencies and amounts of beverage intake for the previous week from water, milk, ready-to-drink beverages, beverages made by adding water to concentrate or powder, and selected foods with substantial water content. Descriptive statistics and bivariate and multivariable analyses with linear mixed models were used to assess associations with each of mg F and mg F/kg bw. Mean combined dietary fluoride (mg F) from all sources examined in the study increased slightly with age, whereas the fluoride intake per kg bw decreased with age. Age, sex, and socioeconomic status were significantly associated with fluoride intake (mg F and mg F/kg bw). Each year increase in age was associated with a 0.02-mg increase in fluoride consumption, on average, after adjusting for the effects of covariates. Daily mean fluoride intakes from single and combined sources were relatively stable, while the intake of fluoride per kg bw decreased from 6 to 17 years of age. Fluoridated water was the major source of ingested fluoride, contributing over 50% of total daily intake at all ages.

Association Between Dietary Fluoride and Calcium Intake of School-Age Children With Symptoms of Dental and Skeletal Fluorosis in Halaba, Southern Ethiopia.

BackgroundIn the Ethiopian Rift Valley, ways to reduce the fluoride (F) burden from drinking water have been unsuccessful. Calcium (Ca) intake may mitigate fluorosis by binding with F ions and preventing absorption. The purpose of this study was to examine the association between Ca intake and proportion of fluorosis symptoms in school-age children in an area where F levels are known to be higher than WHO limit of 1.5 mg F/L water.MethodsA cross-sectional survey in the Halaba zone involved 135 eligible children aged 6–13 year who were recruited to have dental fluorosis assessed by a dentist and skeletal fluorosis assessed by a physiotherapist. Dietary Ca intake was determined by 24-h recall. Food items and samples from ground wells, taps and spring water were collected for F concentration. Associations were measured using bivariate logistic regression, adjusted for known confounders.ResultsWater F averaged 5.09 mg/L. Total F intake was high, 10.57 mg/day, and Ca intake was low, 520 mg/day. Prevalence of dental fluorosis (from very mild to severe symptoms) was 73.1% for younger children (6–8 years) and 68.3 % for older children (9–13 years). The prevalence of children having symptoms of skeletal fluorosis ranged between 55.1 and 72.4%, with no apparent age difference. Dietary F intake of children was significantly positively associated with presence of dental fluorosis. Dietary Ca intake of children was significantly negatively associated with dental fluorosis. Higher than average dietary F intake significantly increased the odds of developing skeletal fluorosis symptoms when measured as inability to stretch and fold arms to touch back of head. Higher than average Ca intake was significantly associated with decreased odds of developing skeletal fluorosis measured as inability to bend body to touch the toes or floor.ConclusionsHigh dietary F, as expected, was associated with fluorosis in children. In the presence of higher Ca intake (>520 mg/day) some fluorosis symptoms were mitigated. There is a need to improve Ca intakes as all were below recommended levels, and this nutritional strategy may also reduce burden of excess F.

Prevalence of White Spot Caries Lesions in Primary Teeth in Preschool Children: Systematic Review and Meta-analysis.

The first clinically detectable stage of caries lesion is a non-cavitated white spot lesion (WSL). The detection of early stages of caries lesions allows non-invasive management by fluoride usage, oral hygiene and diet control. There is a lack of information in the literature regarding the prevalence of these caries lesions in preschool children, which is important especially for public health strategies. The aim of this study was to conduct a systematic review with meta-analysis to verify the WSLs prevalence in primary teeth of preschool children. A literature search with MEDLINE/PubMed, Scopus, Web of Science, and Open Gray databases was conducted. Included studies fulfilled the eligibility criteria. Meta-analyses were performed using random effects model, for prevalence of pooled WSLs and subgroups analyses. The search strategy identified 4922 potentially relevant articles, with final inclusion of 16 studies. The pooled prevalence of WSLs in primary teeth was 14.0% (95% CI: 8.0-24.0), without publication bias (p=0.2668). For subgroup analyses, an increase in WSLs prevalence for children of low-income economy (24.0%; 95% CI: 20.0-28.0), for age >31 months (22.0%; 95% CI: 12.0-37.0), for validated visual criteria assessment (20.0%; 95% CI: 11.0-33.0), and for tactile assessment with ball-ended probe (26.0%; 95% CI: 11-50.0) were detected. It is suggested that the prevalence of WSLs in primary teeth of preschool children increases in countries with low income economy, with age greater than 31 months or texture assessment with visual validated criteria or ball-ended probe. PROSPERO Registration: Protocol number #CDR42017078434.

Fluoride Pharmacokinetics in Urine and Plasma Following Multiple Doses of MK-8507, an Investigational, Oral, Once-Weekly Nonnucleoside Reverse Transcriptase Inhibitor.

MK‐8507 is an investigational HIV‐1 nonnucleoside reverse transcriptase inhibitor being developed for the treatment of HIV‐1 infection. MK‐8507 contains 2 trifluoromethyl groups that may result in fluoride release through metabolism, but the extent of MK‐8507–related fluoride release in humans has yet to be determined. This double‐blind, placebo‐controlled, 2‐period, parallel‐group, multiple‐dose trial in healthy participants without HIV‐1 who were administered a fluoride‐restricted diet and once‐weekly doses of MK‐8507 aimed to estimate the relationship between MK‐8507 dose and fluoride exposure. A total of 15 adult male and 3 adult female (of non‐childbearing potential) participants were randomized to receive MK‐8507 200 mg (n = 6), MK‐8507 800 mg (n = 6), or placebo (n = 6). Change from baseline in mean daily fluoride excretion averaged over 7 days following the administration of MK‐8507 200 mg resulted in a net mean increase of 19.8 μmol (90% confidence interval, 12.2‐27.4) relative to placebo and did not exceed 57 μmol, a threshold related to the mean difference between the daily reference dose set by the US Environmental Protection Agency and the average dietary fluoride intake in the United States. However, daily urinary fluoride excretion exceeded the threshold following administration of 800 mg MK‐8507 (75.1 μmol [90% confidence interval, 67.5‐82.7]). Assuming a linear relationship between MK‐8507 dose and estimated mean daily fluoride released at steady‐state, data interpolation suggests that the US Environmental Protection Agency reference dose for fluoride would not be exceeded in most patients when administering MK‐8507 at doses currently under clinical investigation (≤400 mg once weekly).

Dietary fluoride intake during pregnancy and neurodevelopment in toddlers: A prospective study in the progress cohort

Foods and beverages provide a source of fluoride exposure in Mexico. While high fluoride concentrations are neurotoxic, recent research suggests that exposures within the optimal range may also pose a risk to the developing brain. This prospective study examined whether dietary fluoride intake during pregnancy is associated with toddlers' neurodevelopment in 103 mother-child pairs from the PROGRESS cohort in Mexico City. Food and beverage fluoride intake was assessed in trimesters 2 and 3 using a food frequency questionnaire and Mexican tables of fluoride content. We used the Bayley-III to evaluate cognitive, motor, and language outcomes at 12 and 24 months of age. Adjusted linear regression models were generated for each neurodevelopment assessment time point (12 and 24 months). Mixed-effects models were used to consider a repeated measurement approach. Interactions between maternal fluoride intake and child sex on neurodevelopmental outcomes were tested. Median (IQR) dietary fluoride intake during pregnancy was 1.01 mg/d (0.73, 1.32). Maternal fluoride intake was not associated with cognitive, language, or motor outcomes collapsing across boys and girls. However, child sex modified the association between maternal fluoride intake and cognitive outcome (p interaction term = 0.06). A 0.5 mg/day increase in overall dietary fluoride intake was associated with a 3.50-point lower cognitive outcome in 24-month old boys (95 % CI: -6.58, -0.42); there was no statistical association with girls (β = 0.07, 95 % CI: -2.37, 2.51), nor on the cognitive outcome at 12-months of age. Averaging across the 12- and 24-month cognitive outcomes using mixed-effects models revealed a similar association: a 0.5 mg/day increase in overall dietary fluoride intake was associated with a 3.46-point lower cognitive outcome in boys (95 % CI: -6.23, -0.70). These findings suggest that the development of nonverbal abilities in males may be more vulnerable to prenatal fluoride exposure than language or motor abilities, even at levels within the recommended intake range.

Dietary Influences on Urinary Fluoride over the Course of Pregnancy and at One-Year Postpartum.

Dietary factors are known to influence urinary fluoride (UF) levels in nonpregnant people. Maternal UF is used as a biomarker of fluoride exposure; however, dietary influences on UF during pregnancy are unknown. We compared UF levels and assessed the associations between UF and five select dietary influences in pregnancy vs. one-year postpartum: dietary fluoride (F), calcium intake from diet (Ca-diet), calcium intake from supplements (Ca-sup), dietary acid load (AL), and table salt use (TS) in 421 women exposed to fluoridated salt in the Mexican diet. Spot UF (mg/L) was measured by microdiffusion/fluoride-specific electrode and dilution-corrected with specific gravity (SG). Dietary variables were estimated from a validated Food Frequency Questionnaire. Comparisons among UF in pregnancy vs. one-year postpartum were performed with non-parametric tests. Associations between dietary variables and UF were assessed using random effect models (for pregnancy) and linear regression (for one-year postpartum). SG-corrected UF (median, range) during pregnancy (0.77, 0.01-4.73mg/L) did not significantly differ from one-year postpartum (0.75, 0.15-2.62mg/L) but did increase every 10 gestational weeks, β = 0.05 (CI: 0.00-0.10). Different dietary influences on UF were identified at each state. Although Ca-diet and AL were not associated with UF in either state, Ca-sup decreased UF only during pregnancy, β = - 0.012mg/L (CI: - 0.023-0.00). Reporting TS use was associated with 12% increase in UF only at one-year postpartum (p = 0.026). These results suggest different dietary influences on UF in the pregnant state, which need consideration when using UF as a biomarker of fluoride exposure.

Urinary Fluoride Levels among Canadians with and without Community Water Fluoridation.

Drinking water is a major source of dietary fluoride intake in communities with water fluoridation. We examined the association between urinary fluoride adjusted for specific gravity (UFSG) and tap water fluoride levels, by age and sex, among individuals living in Canada. Participants included 1629 individuals aged 3 to 79 years from Cycle 3 (2012–2013) of the Canadian Health Measures Survey. We used multiple linear regression to estimate unique associations of tap water fluoride levels, age, sex, ethnicity, body mass index (BMI), use of fluoride-containing dental products, smoking in the home, and tea consumption with UFSG. UFSG concentration was significantly higher among participants who received fluoridated drinking water (mean = 1.06 mg/L, standard deviation = 0.83) than among those who did not (M = 0.58 mg/L, SD = 0.47), p < 0.01. UFSG increased over adulthood (ages 19 to 79). Higher UFSG concentration was associated with being female, tea drinking, and smoking in the home. In conclusion, community water fluoridation is a major source of contemporary fluoride exposure for Canadians. Lifestyle factors including tea consumption, as well as demographic variables such as age and sex, also predict urinary fluoride level, and are therefore important factors when interpreting population-based fluoride biomonitoring data.

Dietary Fluoride Intake by Children: When to Use a Fluoride Toothpaste?

Fluoride is recommended for its cariostatic effect, but excessive fluoride intake may have health risks. Increased prevalence of dental fluorosis in areas with low fluoride content in drinking water has been attributed to the inappropriate excessive intake of fluoride supplements (tablets and drops) and toothpaste ingestion. The aim of the present study was to estimate the fluoride intake and the risk of fluorosis in children (6 months–6 years) in the Castelli Romani area (province of Rome, Italy), which is volcanic, therefore with a higher concentration of fluorine. Measurements of the fluoride content in drinking water, mineral waters, vegetables and commercial toothpaste for children were performed. The fluoride concentrations of all samples were determined using a Fluoride Ion Selective Electrode (GLP 22, Crison, Esp). Data were analyzed by descriptive statistics. Differences between samples were determined by Student’s t-test. The fluoride content in tap water samples collected from public sources averaged from 0.35 to 1.11 ppm. The Pavona area showed the highest content of fluoride with respect to the others (p ≤ 0.05). The fluoride content in mineral water samples averaged from 0.07 to 1.50 ppm. The fluoride content of some vegetables showed increased mean values when compared to control vegetables (p ≤ 0.05). Within the limitations of the present study, considerations should be made when prescribing fluoride toothpaste for infants (6 months–4 years) in the areas with high fluoride content, because involuntary ingestion is consistent.

Fluoride in Drinking Water, Diet, and Urine in Relation to Bone Mineral Density and Fracture Incidence in Postmenopausal Women.

Background:Although randomized controlled trials (RCTs) have demonstrated that high fluoride increases bone mineral density (BMD) and skeletal fragility, observational studies of low-dose chronic exposure through drinking water (, the maximum recommended by the World Health Organization) have been inconclusive.Objective:We assessed associations of fluoride in urine, and intake via diet and drinking water, with BMD and fracture incidence in postmenopausal women exposed to drinking water fluoride .Methods:Data were from participants in the Swedish Mammography Cohort–Clinical, a population-based prospective cohort study. At baseline (2004–2009), fluoride exposure was assessed based on urine concentrations () and estimated dietary intake (including drinking water) (), and BMD was measured using dual energy X-ray absorptiometry. Incident fractures were ascertained via register-linkage through 2017. Residential history was collected to identify women with long-term consistent drinking water exposures prior to baseline.Results:At baseline, mean urine fluoride was creatinine () and mean dietary intake was (), respectively. During follow-up, 850, 529, and 187 cases of any fractures, osteoporotic fractures, and hip fractures, respectively, were ascertained. Baseline BMD was slightly higher among women in the highest vs. lowest tertiles of exposure. Fluoride exposures were positively associated with incident hip fractures, with multivariable-adjusted hazard ratios of 1.50 (95% CI: 1.04, 2.17) and 1.59 (95% CI: 1.10, 2.30), for the highest vs. lowest tertiles of urine fluoride and dietary fluoride, respectively. Associations with other fractures were less pronounced for urine fluoride, and null for dietary fluoride. Restricting the analyses to women with consistent long-term drinking water exposures prior to baseline strengthened associations between fractures and urinary fluoride.Discussion:In this cohort of postmenopausal women, the risk of fractures was increased in association with two separate indicators of fluoride exposure. Our findings are consistent with RCTs and suggest that high consumption of drinking water with a fluoride concentration of may increase both BMD and skeletal fragility in older women. https://doi.org/10.1289/EHP7404

A case-control study of topical and supplemental fluoride use and osteosarcoma risk

BackgroundA relationship between fluoride and osteosarcoma has been hypothesized but not validated. To the authors’ knowledge, there are no published studies examining topical fluoride or dietary fluoride supplements and osteosarcoma risk. The purpose of this study was to examine the association between ever or never use of topical and dietary fluoride supplements and osteosarcoma. MethodsThe authors performed a secondary data analysis on data from 2 separate but linked studies. Patients for Phase 1 and Phase 2 were selected from US hospitals using a hospital-based matched case-control study design. Case patients were those who had received diagnoses of osteosarcoma, and control patients were those who had received diagnoses of other bone tumors or nonneoplastic conditions. In Phase 1, case patients (N = 209) and control patients (N = 440) were those seeking treatment at orthopedic departments from 1989 through 1993. In Phase 2, incident case patients (N = 108) and control patients (N = 296) were identified and treated by physicians from 1994 through 2000. This analysis included all patients who met eligibility criteria and on whom the authors had complete data on exposure, outcome, and covariates. The authors used conditional logistic regression to estimate odds ratios and 95% confidence intervals (CIs) for the association of topical fluoride use and supplemental fluoride use with osteosarcoma. ResultsThe adjusted odds ratios were 0.94 (95% CI, 0.60 to 1.46) and 0.78 (95% CI, 0.46 to 1.33) for topical fluoride and supplemental fluoride, respectively. ConclusionsNeither topical nor dietary fluoride supplements are associated with an increased risk of developing osteosarcoma. Practical ImplicationsSupplemental and topical fluorides used in the dental office and in over-the-counter products are not related to an increased risk of developing osteosarcoma.

Dietary fluoride intake over the course of pregnancy in Mexican women.

To estimate dietary fluoride intake (F) over the course of pregnancy and the overall adjusted difference in dietary F intake by pregnancy stages and levels of compliance with dietary recommendations. Secondary data analysis from a longitudinal pregnancy cohort study in a population exposed to fluoridated salt. Women were followed during the early, middle and late stages of their pregnancy (n 568). The dietary intake of recommended prenatal nutrients according to Mexican dietary guidelines and F intake (mg/d) was estimated with a validated FFQ. Data were summarised with descriptive statistics. Levels of F intake were compared with the USA's Institute of Medicine adequate intake (AI) of 3 mg/d for pregnancy. Adjusted differences in F intake by pregnancy stages and levels of compliance with recommendations were estimated using random effects models. Mexico City. Women participating in the Early Life Exposures in Mexico to ENvironmental Toxicants (ELEMENT) project, from 2001 to 2003. Median dietary F intake throughout pregnancy ranged from 0·64 (interquartile range (IQR) 0·38) in the early to 0·70 (IQR 0·42) in the middle, and 0·72 (IQR 0·44) mg/d in the late stage (0·01 mg F/kg per d). Corresponding adjusted intakes of F were 0·72 (95 % CI 0·70, 0·74), 0·76 (95 % CI 0·74, 0·77) and 0·80 (95 % CI 0·78, 0·82) mg/d. Women who were moderately and highly compliant with Mexican dietary recommendations ingested, on average, 0·04 and 0·14 mg F/d more than non-compliant women (P < 0·005). Dietary F intake was below current AI, was greater with the progression of pregnancy and in women who were moderately and highly compliant with dietary recommendations.

In vitro determination of potentially bioavailable fluoride in diet and toothpaste after ingestion

Aim: To propose a new method to determine in vitro potentially bioavailable fluoride (F) in diet and toothpaste after ingestion. Methods: Diet samples (D) were obtained from 15 portions of a meal served to children in a day care centre. To simulate the ingestion of toothpaste during brushing after meals, a specific amount of toothpaste was added to the diet samples (D + T). F was determined in D and D + T after incubation in a solution that simulated “gastric juice” (0.01 M hydrochloric acid) at 37oC for 30, 60 and 120 min. Microdiffusion facilitated by HMDS was used to determine the total F concentrations in samples D and D + T. The analyses were performed using an ion specific electrode. Results: For D samples, incubation in “gastric juice” for 30, 60 and 120 min resulted in F concentrations (μg F/mL) of 0.75 ± 0.06c, 0.77 ± 0.07c and 0.91 ± 0.09b, corresponding to 75.3, 77.3 and 90.7% of the total F (1.02 ± 0.12a), respectively (p = 0.0001; ANOVA + Tukey). For D + T samples, these values of F concentrations (μg F/mL) were 2.55 ± 0.46b, 2.83 ± 0.44ab and 3.15 ± 0.37a, corresponding to 86.9, 94.8 and 106.7% of the total F (2.99 ± 0.34a), respectively (p = 0.0023; ANOVA + Tukey). Conclusion: Then, it can be concluded that the proposed method of “gastric juice” is a promising protocol for determining potentially bioavailable fluoride in the diet and toothpaste after ingestion. However, additional studies are desirable.

Association of Dietary Fluoride Intake and Diet Variables with Dental Caries in Adolescents from the ELEMENT Cohort Study

To examine the association of dietary fluoride intake, total carbohydrate consumption and other key dietary variables with dental caries experience among adolescents, a cross-sectional analysis was conducted in a sample of 402 participants from the Early Life Exposures in Mexico to Environmental Toxicants cohort. The presence and severity of dental caries were assessed using the International Caries Detection and Assessment System (ICDAS) to calculate the number of decayed, missing, and filled teeth or surfaces (D1MFT/D4MFT). The dietary intake of fluoride, energy, carbohydrates, and food groups was estimated using a validated food frequency questionnaire (FFQ). Multivariate zero-inflated negative binomial regression models and negative binomial regression models were run to estimate the association of fluoride intake (mg/day) and total carbohydrate intake (g/day) with the D1MFT/D4MFT index. We found that 80% of the adolescents experienced dental caries (D1MFT >0), with 30% presenting cavitated lesions (D4MFT >0). The mean scores for D1MFT and D4MFT were 6.2 (SD 5.3) and 0.67 (SD 1.3), respectively. The median intake of fluoride estimated by the FFQ was 0.015 mg/kg/day. This intake was statistically higher in participants with a D4MFT = 0 compared to those with a D4MFT >0 (0.90 vs. 0.82 mg/day; 0.016 vs. 0.014 mg/kg/day; p < 0.05). For D1MFT, D1MFS, D4MFT, and D4MFS scores, a higher fluoride consumption (mg/day) from foods and beverages was associated with a statistically significant reduction in the number of lesions. The reported frequency of consumption of sugary foods in a whole day was statistically higher in those with D1MFT >0 than in those with D1MFT = 0 (p < 0.05). The total carbohydrate intake (g/day) was positively associated with dental caries experience. We conclude that a higher fluoride intake through foods and beverages is associated with a lower dental caries experience among adolescents; this effect was seen even when the dietary intake of fluoride was 0.015 mg/kg/day, which is lower than the average intake recommendation. In contrast, a higher total carbohydrate intake and the frequency of intake of sugary foods were associated with a higher dental caries experience, with no apparent threshold for the effects.

Exogenous Intake of Fluorides in Caries Prevention: Benefits and Risks.

Caries incidence and prevalence have decreased significantly over the last few decades due to widespread use of fluoride. However, an increase in the prevalence of dental fluorosis has been reported in both fluoridated and non-fluoridated communities. Care must be taken to ensure that a balance between the optimal fluoride preventive effect at the individual and community level and minimal risk of dental fluorosis is maintained. This review describes the main sources of fluoride intake that have been identified: fluoridated drinking water, dietary fluoride supplement, and topical forms comprising toothpastes, rinses, gels and varnishes. The cited data were taken from meta-analytic studies and reports from Cochrane database systematic reviews up to December 2019. Efficiency, but safety, of topically applied fluorides in individual home care is dependent on the degree of compliance of individuals/parents and on the level of competence of providers of preventive counselling. The broad spectrum of these resources allows individualization of fluoride prevention based on risk analysis of caries attack and taking into consideration other preventive measures.