The fluorosis conundrum: bridging the gap between science and public health.

Fluorosis, a chronic condition brought on by excessive fluoride ingestion which, has drawn much scientific attention and public health concern. It is a complex and multifaceted issue that affects millions of people worldwide. Despite decades of scientific research elucidating the causes, mechanisms, and prevention strategies for fluorosis, there remains a significant gap between scientific understanding and public health implementation. While the scientific community has made significant strides in understanding the etiology and prevention of fluorosis, effectively translating this knowledge into public health policies and practices remains challenging. This review explores the gap between scientific research on fluorosis and its practical implementation in public health initiatives. It suggests developing evidence-based guidelines for fluoride exposure and recommends comprehensive educational campaigns targeting the public and healthcare providers. Furthermore, it emphasizes the need for further research to fill the existing knowledge gaps and promote evidence-based decision-making. By fostering collaboration, communication, and evidence-based practices, policymakers, healthcare professionals, and the public can work together to implement preventive measures and mitigate the burden of fluorosis on affected communities. This review highlighted several vital strategies to bridge the gap between science and public health in the context of fluorosis. It emphasizes the importance of translating scientific evidence into actionable guidelines, raising public awareness about fluoride consumption, and promoting preventive measures at individual and community levels.

Community Water Fluoridation Levels To Promote Effectiveness and Safety in Oral Health - United States, 2016-2021.

Drinking water fluoridated at the level recommended by the U.S. Public Health Service (USPHS) reduces dental caries (cavities) by approximately 25% in children and adults (1). USPHS recommends fluoride levels to achieve oral health benefits and minimize risks associated with excess fluoride exposure. To provide the benefits of community water fluoridation, water systems should target a level of 0.7 mg/L and maintain levels ≥0.6 mg/L (2). The Environmental Protection Agency (EPA) sets a safety standard at 2.0 mg/L to prevent mild or moderate dental fluorosis, a condition that causes changes in the appearance of tooth enamel caused by hypermineralization resulting from excess fluoride intake during tooth-forming years (i.e., before age 8 years). During 2016-2021, fluoride measurements for 16.3% of population-weighted monthly fluoride measurements (person-months) reported by community water systems to CDC's Water Fluoridation Reporting System (WFRS) were <0.6 mg/L; only 0.01% of person-months exceeded 2.0 mg/L. More than 80% of population-weighted fluoride measurements from community water systems reporting to WFRS were above 0.6 mg/L. Although 0.7 mg/L is the recommended optimal level, ≥0.6 mg/L is still effective for the prevention of caries. A total of 4,080 community water systems safely fluoridated water 99.99% of the time with levels below the secondary safety standard of 2.0 mg/L. Water systems are encouraged to work with their state programs to report their fluoride data into WFRS and meet USPHS recommendations to provide the full benefit of fluoridation for caries prevention.

Effects of calcium supplements on oral bioavailability of fluoride in soil based on In Vivo and In Vitro methods.

Dietary calcium (Ca) intake can alleviate fluoride (F) induced fluorosis to maintain bone health. However, it is unclear whether calcium supplements can reduce the oral bioavailability of F present in contaminated soils. Here we evaluated the effects of Ca supplements on F bioavailability in three soils using an in vitro method (Physiologically Based Extraction Test) and an in vivo mouse model. Seven Ca salts, commonly used in calcium supplements, significantly reduced the F bioaccessibility in the gastric and small intestinal phases. Particularly for Ca phosphate at 150 mg Ca supplementation, F bioaccessibility in the small intestinal phase was reduced from 35.1-38.8% to 0.7-1.9% where soluble F concentrations were less than 1 mg/L. Overall, the eight Ca tablets tested in this study showed greater efficiency at decreasing F solubility. The in vitro bioaccessibility after Ca supplementation was consistent with the relative bioavailability of F. As supported by X-ray photoelectron spectroscopy, a possible mechanism is that freed F can be bound by Ca to form insoluble CaF2 and exchanged with OH groups from Al/Fe hydroxide to strongly adsorb F. These findings provide evidence of Ca supplementation in reducing health risks associated soil F exposure.

The Protective Effect of Breastfeeding on Dental Fluorosis Among Children in Rural Fluoride-Endemic Areas.

Background: Living in fluoride-endemic areas and the inevitable use of groundwater for consumption have imposed children at high risk of dental fluorosis. To mitigate exposure to excessive fluoride at age of developing dentition, breastfeeding might serve as a natural public health intervention against dental fluorosis in that socially disadvantaged context. Objective: This study aimed to evaluate the preventive effect of breastfeeding against dental fluorosis in children living in fluoride-endemic areas in Nakhon Pathom Province, Thailand. Evaluation of the association through several epidemiological models depicted by a directed acyclic graph (DAG) was undertaken. Methods: A case-control study of 127 cases of dental fluorosis and 85 controls was conducted. Independent factor of breastfeeding, along with other past exposure variables, were traced backwardly since infancy by caregiver history taking. Fluoride concentrations in groundwater utilized for household supply matching to residence and number of years by age of each child were collected from 2008 to 2015. Multivariable Poisson regression with robust standard errors was sequentially executed to estimate prevalence ratio (PR) according to models in DAG. Results: Breastfeeding was significantly higher (95.3%) among controls compared to cases (84.2%), p = 0.014. Contrastingly, prevalence of using toothpaste larger than pea-sized and having fluoride ≥1.5 ppm in household water supply was higher among cases. Univariable and subsequent five multivariable regression models according to DAG consistently unveiled significant protective effect of breastfeeding on dental fluorosis with PR ranging from 0.66 to 0.75. Conclusions: Breastfeeding for at least 6 months had preventive effect against dental fluorosis among children living in fluoride-endemic areas.

Toothbrushing practices as risk factors for dental fluorosis in an area with varying fluoride levels in drinking water.

BACKGROUND: Despite contributing to a reduction in dental caries, improper use of fluoridated toothpaste could add to the burden of dental fluorosis in children. AIM: To assess the association between tooth-brushing practices such as the type and amount of toothpaste used, frequency of tooth brushing, parental assistance in tooth brushing, timing of tooth brushing and dental fluorosis in school children in Kurunegala district, an endemic area for dental fluorosis in Sri Lanka. METHODS: For this case-control study, a sex-matched sample of 15-year-old school children attending government schools in Kurunegala district and who were lifetime residents of the district was selected. Dental fluorosis was measured using the Thylstrup and Ferjeskov (TF) Index. Those children with a TF⟩1 were considered as cases and those with a TF score of 0 or 1 served as controls. An interview of parents/caregivers of the participants was used to assess risk factors for dental fluorosis. The fluoride concentration in drinking water was measured using spectrophotometry. Data analysis used chi-square tests and conditional logistic regression. RESULTS: Tooth brushing ≥ twice/day, brushing after breakfast and parent/care giver brushing the child's teeth reduced the likelihood of developing fluorosis. CONCLUSION: Use of fluoridated toothpaste adhering to the recommended guidelines could prevent dental fluorosis in children in this endemic area.

Extended caries prevention programme with biannual application of fluoride varnish for toddlers: prevalence of dental fluorosis at ages 7-9 years and associated factors.

OBJECTIVE: To investigate the prevalence of and factors associated with dental fluorosis in children living in areas of high caries risk in Stockholm and who had participated in a prospective, parallel, cluster-randomized, controlled caries prevention trial between ages 1 and 3 years. MATERIALS AND METHODS: The study group comprised a random sample of the children who had completed the 2-year prevention trial (n = 2536) in 2011-2014. All children were instructed to use fluoride toothpaste; the test group received fluoride varnish applications twice a year. Dental fluorosis prevalences in the reference (n = 220) and the test (n = 234) groups were compared. Presence of fluorosis was determined using the Thylsturp & Fejerskov (TF) index on photos of the permanent maxillary incisors. RESULTS: No significant difference in dental fluorosis was observed between the two groups. Nearly one-third (29.7%) of the children in the study cohort exhibited dental fluorosis (TF index ≥ 1). Associations with use of fluoride toothpaste at age 1 year and with socioeconomic status factors were found. CONCLUSIONS: Biannual applications of fluoride varnish in toddlers was not associated with dental fluorosis, which when found was rarely of aesthetic concern. Parental education in tooth-brushing routines is recommended.

Oral Condition of Adolescents who Participated in an Oral Health Program During the First Decade of Life

ABSTRACT Objective: To evaluate the oral health of adolescents who participated in an oral health preventive program during the first decade of life. Material and Methods: For the evaluation of dental caries and gingival condition, DMFT and Community Periodontal Index were used, both recommended by the World Health Organization. To verify the occurrence of dental fluorosis, the Dean index was used. Results: Data collection was obtained from 252 patients aged 12 to 16 years. The average DMFT index was 1.14; in relation to the gingival condition, the index of healthy gingival tissue prevailed and the average of this value was 84%, with code 0 being more registered in tooth 11, code 1, more frequently in teeth 16/17 and 36/37 and for last, code 2, in tooth 31 most frequently. Dean's index showed a percentage of 89% of patients without clinical signs of dental fluorosis. Conclusion: Adolescents participating in an oral health preventive program in the first decade of life exhibited very satisfactory results regarding the prevention of caries disease, healthy periodontal condition and reduced prevalence of dental fluorosis.

A comparative evaluation of the fluoride content in commercially available infant formulae in India: An in vitro study.

CONTEXT: The most critical period for enamel fluorosis to develop is during the early years of life when enamel formation occurs. To minimize the risk of dental fluorosis development, monitoring fluoride intake during teeth development has been suggested. As infant formulae are major source of nutrition in infants, it is important to determine the fluoride content in them in order to monitor the fluoride intake in infants. AIMS: To estimate and comparatively evaluate the fluoride content in different commercially available infant formulae in India. METHODOLOGY: A total of 16 commercially available infant formulae were collected from local pharma/grocery stores, in which 14 were milk based (Group M) and 2 were soy based (Group S). Fluoride content of the formulae was evaluated using ORION F selective electrode. STATISTICAL ANALYSIS USED: ANOVA test, t-test. RESULTS: The mean F values for groups M and S were found to be 0.031 and 0.07 ppm, respectively. Fluoride content of milk-based formulae was significantly lesser (P < 0.001) than soy-based formulae. Daily fluoride intake through the tested formulae was in the range of 0.013 mg and 0.105 mg when calculated following the manufacturer's preparation guidelines. CONCLUSIONS: Infant formulae alone were unlikely to be a risk factor for dental fluorosis, but when reconstituted with optimally fluoridated water, they can be a risk factor for the development of dental fluorosis.

Mapping the evidence for monitoring fluoride exposure in community prevention programmes for oral health using nail clippings and spot urine samples: a scoping review.

BACKGROUND: There is an increased interest in identifying practical and accurate biomarkers for fluoride exposure. Due to the narrow 'dose-gap' between the benefit of caries reduction and the risk of dental fluorosis, monitoring of fluoride exposure is vital when introducing any fluoridation programme for the prevention of dental caries. This scoping review aimed to ascertain the nature and extent of the available evidence on how spot urine and nail clippings are used to measure fluoride intake/exposure, by using a unique approach of mapping the studies according to population, setting, type of study design, methodology and analytical approach in community prevention programmes. METHODS: Multiple relevant databases were searched up to July 2021 for any study designs, including randomised controlled studies, quasi-experimental studies, surveys, retrospective and prospective cohort studies, case studies, phenomenological studies, and expert opinions. RESULTS: The search retrieved 9,222 studies of which 155 met the inclusion criteria. A high proportion of the studies (25.2%) originated from Latin America and the Caribbean continent subregion. However, per country, China recorded the highest number, followed by India and Mexico. The majority (62.6%) employed a cross-sectional study design, and 65.8% combined participants from different age groups. Of the included studies, 82.6% used spot urine samples as a biomarker for assessing fluoride intake/exposure. Water fluoride concentration was reported in 66.5% of the studies with 46.6% of all included studies reporting a water fluoride concentration of > 1.2 mg/L. The methods used in assessing oral hygiene and dietary intake were not reported in 72.3% and 71.0% of the included studies, respectively. Only 35.5% of the included studies assessed the relationship between fluoride exposure and excretion. CONCLUSIONS: This review revealed a large variability in the way in which spot urine samples and/or nail clippings are used to measure fluoride exposure in different settings and situations. Particularly, there are inconsistencies in the methodologies and the analytical approaches used in assessing fluoride exposure. Therefore, there is a need for more rigorous primary research studies using standardised approaches to determine the suitability of spot urine samples and nail clipping as biomarkers for monitoring fluoride exposure.

A comprehensive review on endemic and experimental fluorosis in sheep: Its diverse effects and prevention.

Fluoride is a natural element widely distributed in the environment and plays an important role in the growth of humans and animals. However, in many species, high concentrations of fluoride induce several problems, such as dental, skeletal, and non-skeletal fluorosis. Sheep living in endemic areas are sensitive to the chronic toxicity of fluoride, and they have been found to suffer not only from teeth and bone problems but also from other organs. Studies indicating the chronic harmful effects of fluoride on teeth, bones, blood biochemical parameters, kidney, liver, heart, reproductive system and growth in sheep have been clearly summarized in this review. Besides, this work also includes updated progress in terms of prevention or reduction of fluoride toxicity in this species.

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.

Efficacy of Calcium-Containing Eggshell Powder Supplementation on Urinary Fluoride and Fluorosis Symptoms in Women in the Ethiopian Rift Valley.

Dietary calcium binds Fluoride (F), thus preventing excess F absorption. We aimed to assess the efficacy of supplementing calcium-containing Eggshell Powder (ESP) on F absorption using urine F excretion and on fluorosis symptoms. In total, 82 women (41 Intervention Group, IG; 41 Control Group, CG) were recruited; overall, 39 in each group completed the trial. Morning spot urine was collected before (baseline, BL) and after (endline, EL) the intervention that was 6-months daily supplementation with 2.4 g ESP (providing ~1000 mg of calcium). Dental, skeletal, and non-skeletal fluorosis assessments was carried out at BL and, except for dental, at EL. Relative risk (RR) and linear generalized estimating equation were used to compare outcomes between groups. At BL, urinary F excretion in the IG and CG groups was similar, ~10 mg/L. At EL, urinary F excretion in IG women was six-fold lower (ß = -6.1 (95% CI: -7.1, -5.1)) compared to CG. The risk of developing skeletal and non-skeletal fluorosis were significantly (p < 0.001) reduced in the intervention group. A significant reduction in urinary F excretion and reduction in many fluorosis symptoms were observed among women supplemented with calcium-containing ESP, thus providing evidence for using this dietary calcium source for mitigation of fluorosis. Clinical trials registration: NCT03355222.

Impact of Reducing Water Fluoride on Dental Caries and Fluorosis.

Guidance intended to reduce fluoride toothpaste ingestion in early childhood was introduced in Ireland in 2002. In 2007, water fluoride concentration was adjusted from 0.8-1.0 to 0.6-0.8 ppm. The objective of this study was to determine the difference in caries and fluorosis levels following introduction of these 2 policy measures. A before-and-after study compared caries and fluorosis in random samples of 8-y-olds in Dublin (n = 707) and Cork-Kerry (n = 1148) in 2017 with 8-y-olds in Dublin (n = 679) and Cork-Kerry (n = 565) in 2002. Dentinal caries experience (primary teeth, d3vcmft(cde)) and fluorosis (permanent teeth, Dean's index of very mild or higher) were clinically measured. Lifetime exposure to community water fluoridation (CWF) was classified as "full CWF"/"no CWF." Effect of examination year on caries prevalence and severity and fluorosis prevalence was assessed using multivariate regression adjusting for other explanatory variables. There was little change in commencement of fluoride toothpaste use at ≤24 mo following introduction of toothbrushing guidance. Among children with full CWF, there was no statistically significant difference in caries prevalence or severity between 2017 and 2002. In 2017, caries prevalence was 55% in Dublin (full CWF) and 56% in Cork-Kerry (full CWF), and mean d3vcmft(cde) among children with caries was 3.4 and 3.7, respectively. Caries severity was less in 2017 (mean 4.2) than 2002 (mean 4.9) among children with no CWF (P = 0.039). The difference in caries severity between children with full CWF and no CWF was less in 2017 than in 2002 (interaction P = 0.013), suggesting a reduced benefit for CWF in 2017. In 2017, fluorosis prevalence was 18% in Dublin (full CWF) and 12% in Cork-Kerry (full CWF). Fluorosis was predominantly "very mild" with no statistically significant difference between 2017 and 2002. CWF at 0.6 to 0.8 ppm is an effective caries-preventive measure. Results suggested low uptake of toothbrushing guidance, a reduced caries-preventive effect for CWF in primary teeth, and no reduction in fluorosis following introduction of the policy measures.

Supplementation of Calcium and Fluoride-Free Water Mitigates Skeletal Fluorosis in Fluoride-Intoxicated Rats.

Fluorosis is a public health concern in 25 countries around the globe. The present study is about the mitigation of fluoride (F) toxicity by giving F-free water (FFW) and calcium (Ca). A study was conducted by taking 76 Wistar rats in two phases, phase I (6 months), where rats were randomly divided into four groups: normal-Ca diet (NCD) 0.5%; low-Ca diet (LCD) 0.25%; NCD + 100 ppm F and LCD + 100 ppm F in groups 1, 2, 3 and 4, respectively. F and Ca were given through water and diet respectively. Phase II is the reversal of fluorosis for 3 months, where LCD group 2 was treated with NCD. Groups 3 and 4 were divided into two subgroups each: 3X and 3Y, and 4X and 4Y, respectively. Groups 3X and 4X received FFW with NCD. Group 3Y continued as phase I and 4Y NCD and F. The biochemical expression, gene expression, biomechanical properties and DXA were studied by standard methods. The results revealed that in phase I, bone turnover was significantly increased whereas bone mineral content and biomechanical properties of group 4 were significantly decreased (p ≤ 0.05) as compared with that of all other groups. Trabecular separation and total porosity increased in groups 2 and 4. Expression of osteocalcin, osteonectin and osteopontin genes was significantly downregulated in group 4. Bone turnover in group 4X was normalised. Expressions of osteocalcin, osteonectin and osteopontin were upregulated after providing NCD and FFW. In conclusion, low calcium aggravates skeletal fluorosis which could be mitigated on supplementation of Ca and FFW.

[Etiology, diagnosis, prevention and treatment of dental fluorosis].

Dental fluorosis is the most common and prominent symptom in the early stage of chronic fluorosis, which is caused by excessive fluorine intake during tooth development. In severe cases, it may be accompanied by skeletal fluorosis. There are also systemic damages to the nervous system, cardiovascular system, endocrine system and so on. The pathogenesis of dental fluorosis is not totally clear, which may be a complex pathological process involving both genetic and environmental factors. The prevalence of dental fluorosis has an upward trend arround the world, thus certain public prevention and treatment strategies need to be taken. This article focuses on the prevalence, etiology, diagnosis and scoring system, as well as the public prevention and treatment strategies, of dental fluorosis, so that to provide reference for the research and prevention of the disease.

Prevalence of Dental Fluorosis in Saudi Arabia: A Meta-Analysis

Abstract Objective: To identify the prevalence of dental fluorosis in Kingdom of Saudi Arabia. Material and Methods: Literature search for the present study aimed to include all the relevant studies conducted in Saudi Arabia that reported prevalence of dental fluorosis. A literature search was done using keywords (dental, fluorosis, prevalence) using three databases (Scopus, PubMed, and Web of Science). Grey literature was also searched using Google Scholar and research gate. Literature was searched from 1939 till April 2020. The risk of bias was reported using JBI Critical Appraisal Checklist for Studies Reporting Prevalence Data. Twelve studies were included based on inclusive criteria. The only inclusive criteria were studies that were conducted among people living in Saudi Arabia, and studies that reported the prevalence of dental fluorosis. Samples from all age groups that reported prevalence of dental fluorosis were included. MedCalc statistical software was used to perform the analysis. Results: The overall prevalence of dental fluorosis was found to be 46.52%, 95 CI (26.52% to 67.12%). I2 value was reported 99.8%, 95 CI (99.78% to 99.83%), indicating high heterogeneity amongst the finding of studies. Funnel plots indicate the presence of a strong publication bias. Overall, we found some contrasting findings. One study reported prevalence of dental fluorosis as 0% and other with a comparatively large sample size found dental fluorosis to be 90.6%. Conclusion: The present study adds to the literature regarding dental fluorosis in Saudi Arabia by providing an overview of its prevalence. It is concluded that prevalence of dental fluorosis was a bit high. However, findings indicate publication bias. We did not account for severity of dental fluorosis. All the available data was analyzed to measure dental fluorosis prevalence without considering the sample size and sampling technique.

[Fluoride and heavy metals concentration in bottled waters: barrier measures against dental caries and fluorosis]. / Concentración de flúor y metales pesados en aguas embotelladas: medidas barrera frente a caries dental y fluorosis.

OBJECTIVE: The daily consumption of fluoridated water is one of the most beneficial measures in dental caries prevention. The objective of this paper was to analyze the content of fluorine and heavy metals in the bottled natural mineral water available in stores in Spain. METHODS: A descriptive and transversal study was done throughout 2019. Analysing a total of 20 bottled waters marketed in Spain during this year. Mainly, fluoride concentration (ppm/ml) was analyzed with an ion-specific electrode (Orion model 96-09, Orion Research, Cambridge, MA) coupled to an ion analyzer (Orion EA-940). The heavy metals were analyzed by ICP-MS (Agilent model 7900). A descriptive statistical study of the data was carried out. RESULTS: The minimum value of fluorine found was 0.05 ppm and the maximum 0.95ppm. 80% of the brands analyzed contain less than 0.6 ppm F. Only 1 brand exceeds 0.8 ppm F. Chromium and arsenic were the heavy metals present in all brands, without exceeding the maximum dose. No brand of bottled water indicated heavy metals on the label, and only 1 mark indicated the fluoride concentration on the label. CONCLUSIONS: There is a great variability in the chemical composition of bottled waters marketed in Spain. Most have a fluoride concentration lower than that recommended to prevent tooth decay, which would require an extra supply of fluoride. In the bottled waters analyzed there are heavy metals but they did not exceed the maximum doses established by legislation.

OBJETIVO: El consumo diario de agua fluorada es una de las medidas mas beneficiosas en la prevención de la caries dental. El objetivo de este estudio fue analizar el contenido de flúor y metales pesados en el agua mineral natural embotellada disponible en los comercios de España. METODOS: Se realizó un estudio descriptivo y transversal a lo largo de 2019, analizando 20 marcas de aguas embotelladas comercializadas en España en ese año. Se midió principalmente la concentración de flúor (partes por millón/mililitro) (ppm/ml), que fue analizada con un electrodo ion-específico (modelo Orión 96-09, Orion Research, Cambridge) acoplado a un analizador de iones (Orion EA-940). Los metales pesados se analizaron mediante ICP-MS (Agilent modelo 7900). Se realizó un estudio estadístico descriptivo de los datos. RESULTADOS: El valor mínimo de flúor encontrado fue de 0,05 ppm y el máximo de 0,95 ppm. El 80% de las marcas analizadas contenían menos de 0,6 ppm F. Solamente una marca superó las 0,8 ppm F. Cromo y arsénico fueron los metales pesados presentes en todas las marcas, sin superar la dosis máxima. Ninguna marca de agua embotellada indicaba los metales pesados en la etiqueta, y solo una marca indicó la concentración de flúor en la etiqueta. CONCLUSIONES: Existe una gran variabilidad en la composición química de las aguas embotelladas comercializadas en España. La mayoría tienen una concentración de fluoruro inferior a la recomendada para prevenir la caries dental, por lo que se necesitaría un aporte extra de flúor. En las aguas embotelladas analizadas existen metales pesados, pero no superan las dosis máximas establecidas por la legislación.

The use of urinary fluoride excretion to facilitate monitoring fluoride intake: A systematic scoping review.

BACKGROUND: As a recognised effective and economical agent for dental caries prevention, fluoride has been used in many different fluoridation schemes implemented across the world. Considering the narrow 'dose-gap' between the benefit of caries reduction and the risk of dental fluorosis, it is recommended that fluoride intake is monitored by measuring urinary fluoride excretion. The aim of this scoping review is to map the current literature/evidence on fluoride intake and excretion studies in relation to the study population, settings, type of study design, methodology, and analytical approach. METHODS: Embase/Ovid, MEDLINE/Ovid, CINAHL/EBSCO, Scopus/Elsevier were searched for relevant articles until April 2018. Studies were included if they reported intake and excretion of fluoride in healthy humans of all age groups. Findings were explored using a narrative synthesis to summarise studies characteristics and outcome measures. RESULTS: Removal of duplicates from the originally 2295 identified records yielded 1093 studies of which 206 articles were included. Only 21.6% of the studies were conducted in children (<8-year-olds). Most studies (38.8%) used drinking water concentration as a proxy for fluoride intake, whereas only 11.7% measured fluoride intake from all sources. Of the 72 studies that measured dietary fluoride intake, only 10 reported the validity of the employed dietary assessment method. Only 14 studies validated the urine sample collection methods. No information on the validity of the employed analytical method was reported by the majority (64.6%) of studies. Only a small proportion (8.7%) of the included studies investigated the association between fluoride intake and excretion. CONCLUSION: The findings reveal much variability in terms of conducting the studies and reporting the findings, illustrating a high heterogeneity in data collection across settings and populations. Future studies should provide more detail on sampling technique, measurement protocols (including validation), and on clearly defining the relationship between intake and urinary excretion of fluoride.

Fluoride Revolution and Dental Caries: Evolution of Policies for Global Use.

Epidemiological studies over 70 y ago provided the basis for the use of fluoride in caries prevention. They revealed the clear relation between water fluoride concentration, and therefore fluoride exposure, and prevalence and severity of dental fluorosis and dental caries. After successful trials, programs for water fluoridation were introduced, and industry developed effective fluoride-containing toothpastes and other fluoride vehicles. Reductions in caries experience were recorded in many countries, attributable to the widespread use of fluoride. This is a considerable success story; oral health for many was radically improved. While previously, water had been the only significant source of fluoride, now there are many, and this led to an increase in the occurrence of dental fluorosis. Risks identified for dental fluorosis were ingestion of fluoride-containing toothpaste, water fluoridation, fluoride tablets (which were sometimes ingested in areas with water fluoridation), and infant formula feeds. Policies were introduced to reduce excessive fluoride exposure during the period of tooth development, and these were successful in reducing dental fluorosis without compromising caries prevention. There is now a much better understanding of the public perception of dental fluorosis, with mild fluorosis being of no aesthetic concern. The advantages of water fluoridation are that it provides substantial lifelong caries prevention, is economic, and reduces health inequalities: it reaches a substantial number of people worldwide. Fluoride-containing toothpastes are by far the most important way of delivering the beneficial effect of fluoride worldwide. The preventive effects of conjoint exposure (e.g., use of fluoride toothpaste in a fluoridated area) are additive. The World Health Organization has informed member states of the benefits of the appropriate use of fluoride. Many countries have policies to maximize the benefits of fluoride, but many have yet to do so.