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Excessive fluoride intake has been reported in many studies, which can lead to diseases such as autism, mental retardation, low birth weight, reproductive disorder, as well as dental and bone fluorosis. The potential risk assessment of fluoride intake for the health of people living in Fars Province, Iran, is investigated. Hence, 1700 drinking water samples were taken from April 2018 to March 2020 in four seasons in 29 cities of Fars Province and were analyzed. Non-carcinogenic health risks of exposure to fluoride through drinking water were evaluated. Moreover, the spatial distribution maps of fluoride and hazard quotient (HQ) risk index were prepared using GIS software. The results showed that the concentration of fluoride in the drinking water of the studied area was in the range of 0.086 to 2.61 mg/L. Accordingly, in 48.27% of the cities, fluoride was in the range below the national and international standards, 34.48% of the cities were in the permissible range of 0.5 to 1.5 mg/L, and 17.24% of the urban areas of the province had fluoride contents above the permissible range. Hazard quotient index had the health risk of HQ > 1 in 27.58% of children, 17.24% of teenagers, and 10.34% of adults in the urban areas of Fars Province. In the cities with HQ > 1, there was risk of diseases associated with excessive fluoride intake. Therefore, it is necessary to replace water supply sources in these cities.

Fluoride is highly present in the environment, especially in water and its derivatives. Excessive fluoride contribution to diet poses a health risk. Tea leaves accumulate fluoride and the consumption of tea (Camellia sinensis) could pose a risk to human by the excessive fluoride intake. Ninety tea samples were analyzed by potentiometry using a selective fluoride ion electrode. Mixed tea samples (2.82 ± 1.11 mg/L) and black tea samples (2.28 ± 0.79 mg/L) recorded the highest fluoride levels. The contribution of drinking water is important for increasing fluoride levels in teas. The daily consumption of two cups (250 mL per cup) of mixed and black teas prepared with La Laguna tap water does pose a health risk for children (4–8 years old) because of the high contribution percentages (74.4% and 63.6%, respectively) of the Tolerable Upper Intake Level set in 2.5 mg/day by the EFSA (European Food Safety Authority). A minor consumption in children (4–8 years old) and adults during pregnancy is advisable.

Introduction Excessive fluoride intake during tooth development causes dental fluorosis. Aim This study aimed to (1) determine the prevalence of dental fluorosis in association with fluoride concentrations in drinking water, (2) explore the effects of altitude on the severity of fluorosis in two towns with high fluoride levels in the drinking water, and (3) assess decayed, missing, and filled teeth (DMFT) and oral hygiene practices among participants. Material and methods The sample consisted of 100 and 141 schoolchildren, aged 15.3 ± 1.4 and 16.1 ± 1.3 years, living in Ruwaished and Kuraymah, respectively. Oral examinations were carried out, and dental fluorosis was assessed using the Dean’s index. The DMFT index was also used for assessment. Samples of drinking water were analyzed using a fluoride-ion selective electrode. SPSS was used to analyze the data. Results Two-thirds (68.8%) of adults from Kuraymah had moderate to severe fluorosis, with only 7% being unaffected. In Ruwaished, 50% of the sample had severe fluorosis, 22% showed moderate fluorosis, and none were unaffected. The average DMFT scores were 3.18 ± 1.81 and 3.81 ± 1.41 for Kuraymah and Ruwaished, respectively. In both towns, males had significantly higher caries scores than females. Oral hygiene was poor, as 64% and 57% of the participants from Kuraymah and Ruwaished, respectively, did not brush their teeth. A significant correlation was found between poor oral hygiene and increased DMFT scores. Conclusions This study concluded that higher fluorosis incidence and severity were present in the higher-altitude location (Ruwaished). Moreover, this study also indicated that fluorosed teeth are not immune to caries, and the preventive management of dental fluorosis should be directed to de-fluoridation of drinking water in endemic areas.

Fluoride is a widely distributed ion in the environment and, consequently, in water as well. High levels of fluoride in waters can be found in the Canary Islands because of their volcanic origin. Due to the risk and detrimental effects associated with a high fluoride intake, the content of this ion has been potentiometrically determined in 256 supply water samples from the islands of Tenerife, El Hierro, and La Palma, using a fluoride selective ion electrode. Fluoride mean concentration found on Tenerife is 4.22 mg/L, exceeding the parametric value of 1.5 mg/L set out in Spanish legislation. The consumption of 2 L of water from the studied municipalities of Tenerife would mean there is an excessive fluoride intake. The consumption of this water poses a serious risk to health. It is necessary to take action aimed at reducing the level of fluoride in the north of the island of Tenerife.

Fluoride is a natural element essential in minute quantities in human's to maintain dental and skeletal health. However, the disease fluorosis manifests itself due to excessive fluoride intake mostly through drinking water and sometimes through food. At the cellular energetics level, fluoride is a known inhibitor of glycolysis. At the tissue level, the effect of fluoride has been more pronounced in the musculoskeletal systems due to its ability to retain fluoride. Fluoride alters dentinogenesis, thereby affecting the tooth enamel formation. In bones, fluoride alters the osteogenesis by replacing calcium, thus resulting in bone deformities. In skeletal muscles, high concentration and long term exposure to fluoride causes loss of muscle proteins leading to atrophy. Although fluorosis is quite a familiar problem, the exact molecular pathway is not yet clear. Extensive research on the effects of fluoride on various organs and its toxicity was reported. Indeed, it is clear that high and chronic exposure to fluoride causes cellular apoptosis. Accordingly, in this review, we have highlighted fluoride-mediated apoptosis via two vital pathways, mitochondrial-mediated and endoplasmic reticulum stress pathways. This review also elaborates on new cellular energetic, apoptotic pathways and therapeutic strategies targeted to treat fluorosis.

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.

Chronic fluorosis is an endemic disease that severely impairs human health. Studies have proved that the change of various receptors in the body is attributed to excessive fluoride intake. For instance, it will reduce the expression of acetylcholine receptor that affects the release of neurotransmitters and will cause changes of N-methyl-D-aspartic acid receptor that impacts cellular Ca2+ influx and of advanced glycation end product receptor, augmenting the inflammatory response of the body, etc. These changes are the key mechanism of multi-system injuries caused by fluorosis. With the increased attention on more and more receptors in recent years, the role they played in the pathogenesis of chronic fluorosis is becoming ever more essential. Therefore, an in-depth study of its mechanism of action is possibly vital to uncover the injury of chronic fluorosis and can also provide a theoretical basis for prevention and clinical treatments.

Background The amount of fluoride accumulation in tea leaves was gradually increase as the matures of tea plants, and the excessive fluoride intake can threaten people's health. Based on years of field investigations, a low level of fluoride variety Xiangbo Lǜ (XBL) and a high level of fluoride variety Zhenong 139 (ZN139) were selected. Results In this study, the root, 1st and the 5th leaf of the two-year-old tea trees were used for morphological, physiological and comparative transcriptomics analysis to understand the different features of “XBL” and “ZN139” under fluoride stress conditions. The color of the 1st and 5th leaves of XBL were yellower, the activity of peroxidase, catalase and antioxidant enzyme were lower than ZN139 under the high-fluoride stress. Transcriptomics analysis indicated that core genes involved in photosynthesis rates regulation showed no significantly exchanged expression, the co-downregulation of magnesium ions transportation, while the ROS scavenging, vegetative growth and self-compatibility between the two varieties were different. Crucial genes' expression were also identified by the real-time RT-PCR. Conclusion The tea tree is one of the few plants that has a high-fluoride content, but the different varieties respond differently to fluoride stress. High-fluoride tea tree varieties, such as ZN139, have stronger ROS scavenging abilities through the use of both their non-enzymatic and enzymatic antioxidant systems which act by increasing the expression levels of inositol-1-monophosphatases and peroxidases, among others. ZN139 can also compensate for the decrease in photosynthetic rate that is associated with the ionic imbalance caused by the reduced consumption of light energy during long-periods of high fluoride stress. Reproductive development was protected in ZN139 by the up-regulated expression of S-locus glycoprotein, Mildew resistance locus o and Phospholipase D under fluoride stress, while the vegetative development of low-fluoride varieties such as XBL was retarded. More starch and cellulose were redistributed to glucose by increasing the expression levels of glycosyl transferases and hydrolases to provide more energy for processes involved in the response and tolerance towards fluoride stress.

Fluoride ions are highly reactive, and their incorporation in forming dental enamel at low concentrations promotes mineralization. In contrast, excessive fluoride intake causes dental fluorosis, visually recognizable enamel defects that can increase the risk of caries. To investigate the molecular bases of dental fluorosis, we analyzed the effects of fluoride exposure in enamel cells to assess its impact on Ca2+ signaling. Primary enamel cells and an enamel cell line (LS8) exposed to fluoride showed decreased internal Ca2+ stores and store-operated Ca2+ entry (SOCE). RNA-sequencing analysis revealed changes in gene expression suggestive of endoplasmic reticulum (ER) stress in fluoride-treated LS8 cells. Fluoride exposure did not alter Ca2+ homeostasis or increase the expression of ER stress-associated genes in HEK-293 cells. In enamel cells, fluoride exposure affected the functioning of the ER-localized Ca2+ channel IP3R and the activity of the sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) pump during Ca2+ refilling of the ER. Fluoride negatively affected mitochondrial respiration, elicited mitochondrial membrane depolarization, and disrupted mitochondrial morphology. Together, these data provide a potential mechanism underlying dental fluorosis.

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.

Fluoride is recognized as beneficial to dental health because of its ability to prevent tooth decay. However, excessive fluoride intake may cause dental fluorosis, and at much higher levels skeleta...

Fluoride is one of the most abundant elements found in nature. Water is the major dietary source of fluoride. The only known association with low fluoride intake is the risk of dental caries. Initially, fluoride was considered beneficial when given systemically during tooth development, but later research has shown the importance and the advantages of its topical effects in the prevention or treatment of dental caries and tooth decay. Water fluoridation was once heralded as one of the best public health achievements in the twentieth century. Since this practice is not feasible or cost effective in many regions, especially rural areas, researchers and policy makers have explored other methods of introducing fluoride to the general population such as adding fluoride to milk and table salt. Lately, major concerns about excessive fluoride intake and related toxicity were raised worldwide, leading several countries to ban fluoridation. Health-care professionals and the public need guidance regarding the debate around fluoridation. This paper reviews the different aspects of fluoridation, their effectiveness in dental caries prevention and their risks. It was performed in the PubMed and the Google Scholar databases in January 2018 without limitation as to the publication period.

Excessive fluoride intake over a long period of time can lead to fluorosis, which may cause dental and skeletal manifestations. Metabolic, functional and structural damage caused by chronic fluorosis have been reported in many tissues, but the exact mechanisms modulated by fluoride remain unclear. The aim of this study was to evaluate the effect of fluoride administered in drinking water on the antioxidant defense system of rats. Four groups of Wistar rats were used for the study (n = 10/group). The animals received drinking water containing 0 (control), 5, 15 or 50 mg/L of fluoride over 60 days. They were then euthanized, and their livers and kidneys were collected and homogenized. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), antioxidants, thiobarbituric acid reactive substances (TBARS), lipid hydroperoxide (LH), and fluoride levels were analyzed. Data were analyzed by ANOVA and Tukey's test or by the Kruskal–Wallis and Dunn's tests (p

Fluoride is a naturally occurring mineral that can be obtained from foods and fluids originating from soils containing fluoride, as well as by drinking water that has been fluoridated. While consuming adequate fluoride intake can deliver benefits for dental and bone health, there have been concerns that excessive fluoride intake could lead to dental fluorosis, or even cause harm to bones. This article considers the balance of evidence in this area, and discusses the benefits and potential risks of fluoride in the UK diet. The role of tea as a major contributor to normal fluoride intake is highlighted, alongside some positive implications of this. Information is also provided to help nurses and midwives communicate the latest advice and guidance on fluoride to their patients.

Exposure to excessive fluoride intake during the early childhood years can disrupt the normal development of enamel, resulting in dental fluorosis. This varies in severity, ranging from white opacities in mild cases to more severe black and brown discoloration or enamel pitting. This article aims to give the reader a better understanding of the aetiology, diagnosis and subsequent treatment of dental fluorosis in the paediatric patient. Clinical Relevance: Fluorosis can have a marked effect on dental aesthetics. The prevalence of fluorosis in the United Kingdom may increase following the publication of Delivering Better Oral Health, published by the Department of Health in 2007, 1 which suggested changes to fluoride levels in children's toothpastes. This article highlights the importance of accurate diagnosis of fluorosis and also explains the treatment options available to paediatric patients.

Made available in DSpace on 2018-12-11T17:03:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-07-01 Low-fluoride dentifrices (LFD) have been recommended for young children aiming to minimize excessive fluoride intake during tooth brushing. Given the uncertainties surrounding the clinical efficacy of such formulations, alternatives to increase their anticaries effect have been investigated. Objectives This double-blind, randomized controlled trial assessed the clinical efficacy of LFDs supplemented with Calcium Glycerophosphate (CaGP) or Sodium Trimetaphosphate (TMP) on the progression of dental caries in the deciduous dentition. Methods Children (average age 48 months old) from two Brazilian cities (Araçatuba and Fernandópolis) were randomly assigned into 3 groups, according to the dentifrice to be used: 500 ppm F plus 1% TMP (500TMP, n = 206), 500 ppm F plus 0.25% CaGP (500CaGP, n = 201) and 1100 ppm F ('1100F', n = 193). Clinical exams (dmfs) were performed at baseline and 18 months after dentifrices started to be used, and the increment in the number of carious lesions (final dmfs - initial dmfs) was calculated. Data were analyzed by multivariate linear regression analysis to verify the influence of city, gender, previous caries experience and type of dentifrice on dmfs increment (p < 0.05). Results Mean caries increment observed for 500TMP (0.26) was significantly lower when compared with 1100F (0.74), while values found for 500CaGP (0.54) were not significantly different from 1100F. Caries increment was significantly higher in children from Araçatuba and in those with previous caries experience. Conclusion The results indicate that clinical efficacy of LFDs supplemented with TMP is superior to that observed for a conventional formulation (1100F), while the addition of CaGP leads to similar efficacy when compared to 1100F. Clinical Significance Children brushing with 500 ppm F toothpastes containing phosphate salts developed fewer caries lesions when compared with those using a 1100 ppm F dentifrice. The tested toothpastes can be regarded as a safe alternative to conventional formulations for children under 6 years of age, based on risk-benefit considerations. Department of Pediatric Dentistry and Public Health Araçatuba Dental School Univ. Estadual Paulista (UNESP) Department of Pediatric Dentistry and Public Health Araçatuba Dental School Univ. Estadual Paulista (UNESP)

Fluorine is unique chemical element which occurs naturally, but is not an essential nutrient for plants. Fluoride toxicity can arise due to excessive fluoride intake from a variety of natural or manmade sources. Fluoride is phytotoxic to most plants. Plants which are sensitive for fluorine exposure even low concentrations of fluorine can cause leave damage and a decline in growth. All vegetation contains some fluoride absorbed from soil and water. The highest levels of F in field-grown vegetables are found up to 40 mg kg -1 fresh weight although fluoride is relatively immobile and is not easily leached in soil because most of the fluoride was not readily soluble or exchangeable. Also, high concentrations of fluoride primarily associated with the soil colloid or clay fraction can increase fluoride levels in soil solution, increasing uptake via the plant root. In soils more than 90 percent of the natural fluoride ranging from 20 to 1,000 μg g -1 is insoluble, or tightly bound to soil particles. The excess accumulation of fluorides in vegetation leads to visible leaf injury, damage to fruits, changes in the yield. The amount of fluoride taken up by plants depending on the type of plant, the nature of the soil, and the amount and form of fluoride in the soil should be controlled. Conclusively, fluoride is possible and long-term pollution effects on plant growth through accumulation of the fluoride retained in the soil.

Fluoride is a naturally occurring element with multiple implications for human health. This review discusses its metabolism and toxicity, along with the current understanding of the mechanism of action of fluoride and its role as a safe and effective agent in the prevention of dental caries. The relationship between excessive fluoride intake during periods of dental enamel formation and the development of dental fluorosis is also reviewed.

The presented review summarizes literature data on pathways of the inorganic fluoride intake into the plant, animal, and human organisms, on its metabolism, distribution, and accumulation in the organism, forms of fluoride in biological tissues, toxic effects of fluoride on physiological and reproductive functions of living organisms of various phylogenetic groups, as well as clinical symptoms of deficient and excessive fluoride intake into the human organism.

Risk of enamel fluorosis associated with excessive fluoride intake during infancy and early childhood has been widely reported in literature. Results of several studies indicate that infant formula consumption, especially in the form of powdered concentrate, may appreciably increase children's fluoride exposure in optimally fluoridated communities. The aim of the study was to measure fluoride content of infant and toddler formulas available in Poland and to discuss implications of the results. Twenty nine brands of powdered formulas were evaluated. Analyzes were performed with the use of ionselective fluoride electrode (09-37 type) and a RAE 111 chloride-silver reference electrode (MARAT). Results revealed that concentration of fluoride in all products was low (mean 29.0 μg/100 g), and that the formula itself is not a significant source of fluoride exposure. However, when reconstituted with water containing more than 0.5 ppm of fluoride, starting formulas and follow-on formulas may provide a daily fluoride intake of above the suggested threshold for fluorosis. Thus, fully formula-fed infants consuming mother milk substitutes prepared with optimally fluoridated water may be at increased risk of dental fluorosis.

Context Dental and skeletal fluorosis is endemic in the Ethiopian Rift Valley. Children are especially vulnerable to excessive fluoride intake because their permanent teeth are still being formed. Strategies to reduce the total fluoride intake by children are thus warranted. Case presentation By combining the results of field studies in Ethiopia, the relevant pathways for fluoride intake have been identified in 28 children 2–5 years of age living in two villages on the Wonji Shoa Sugar Estate in the Ethiopian Rift Valley. The focus of the present study was to simulate the fluoride intake of the children using the methods of material flow analysis (MFA) and substance flow analysis. Discussion With a model based on MFA, we quantified the potential reduction in total fluoride intake given different scenarios—for example, by reducing the fluoride intake from drinking water and cooking water. The results show clearly that only by removing fluoride completely from both drinking and cooking water does the probability of remaining below the daily tolerable upper intake level exceed 50%. Both prepared food and food ingredients must be taken into consideration when assessing the total fluoride intake by children living in high-fluoride areas. Relevance This knowledge will help health personnel, the government, and the food authorities to give scientifically based advice on strategies for reducing the total fluoride intake by children living in high-fluoride areas in the Ethiopian Rift Valley.

Thirty-one ground samples were collected in the Hidehran and Alburayhi basin, northwest of Taiz city, from Tertiary age aquifers. A hydrogeochemical investigation was conducted in the study area. The fluoride ions along with other chemical parameters were analyzed to determine the hydrochemical characteristics, water types and evaluate the main source of fluoride in groundwater of the aquifer. Fluoride ion concentrations in the groundwater in excess of WHO recommended limit of 1.5 mg/l for drinking water occurs throughout the area. Of the 31 well samples to be contained with fluoride concentration in excess of the recommended limit, the hydrogeochemical concentration of ions in the groundwater. The saturation indices (SI) of fluorite (CaF2) and calcite (CaCo3) in the groundwater samples showed that the majority of the samples are oversaturated with respect to calcite; and undersaturated with respect to fluorite. The population of the study area is at a high risk due to excessive fluoride intake, especially when they are unaware of the amount of fluoride being ingested.

Objective To explore the relationships between the daily total intake of fluoride, dental fluorosis and dental caries. Methods An epidemiological method was used to investigate the daily total intake of fluoride, dental fluorosis, and dental caries among 236 and 290 children aged 8-13 years in a severe endemic area and in a non-fluorosis control area, respectively. The children were divided into eight subgroups according to each child's estimated daily total intake of fluoride. The prevalence of dental fluorosis and dental caries in each group was calculated. Results As expected, elevated levels of fluoride intake were significantly associated with a higher prevalence of dental fluorosis and an increasing amount of more severe defect dental fluorosis. When the daily total F intake was 2.78 mg/child/day, the prevalence of dental fluorosis was nearly 100%, with the prevalence of defect dental fluorosis increasing with increasing fluoride intake. There was also a significant negative(inverse) dose-response relationship between the daily total intake of fluoride and the overall prevalence of dental caries, the prevalence of which decreased when the daily total intake of fluoride increased up to 3.32 mg/child/day. However, at higher levels of daily total intake of fluoride the prevalence of dental caries increased, giving rise to a U-shaped dose-response relationship curve. Conclusion It is important to monitor total fluoride exposure and protect children from excessive fluoride intake, especially during the years of tooth development.

High fluoride groundwater occurs in Maku area, in the north of West Azarbaijan province, northwest of Iran. Groundwater is the main source of drinking water for the area residents. Groundwater samples were collected from 72 selected points including 40 basaltic and 32 nonbasaltic springs and wells, in two stages, during June and August 2006. The areas with high fluoride concentrations have been identified, and the possible causes for its variation have been investigated. Regional hydrogeochemical investigation indicates that water-rock interaction is probably the main reason for the high concentration of ions in groundwater. The concentration of F− in groundwater is positively correlated with that of HCO3 − and Na+, indicating that groundwater with high HCO3 − and Na+ concentrations help to dissolve some fluoride-rich minerals. All of the water samples, collected from the basaltic areas do not meet the water quality standards for fluoride concentration and some other parameters. Hence, it is not suitable for consumption without any prior treatment. Inhabitants of the area that obtain their drinking water supplies from basaltic springs and wells are suffering from dental fluorosis. The population of the study area is at a high risk due to excessive fluoride intake especially when they are unaware of the amount of fluoride being ingested due to lack of awareness.

The Republic of Ireland (RoI) is the only European Country with a mandatory national legislation requiring artificial fluoridation of drinking water and has the highest per capita consumption of black tea in the world. Tea is a hyperaccumulator of fluoride and chronic fluoride intake is associated with multiple negative health outcomes. In this study, fifty four brands of the commercially available black tea bag products were purchased and the fluoride level in tea infusions tested by an ion-selective electrode method. The fluoride content in all brands tested ranged from 1.6 to 6.1 mg/L, with a mean value of 3.3 mg/L. According to our risk assessment it is evident that the general population in the RoI is at a high risk of chronic fluoride exposure and associated adverse health effects based on established reference values. We conclude that the culture of habitual tea drinking in the RoI indicates that the total cumulative dietary fluoride intake in the general population could readily exceed the levels known to cause chronic fluoride intoxication. Evidence suggests that excessive fluoride intake may be contributing to a wide range of adverse health effects. Therefore from a public health perspective, it would seem prudent and sensible that risk reduction measures be implemented to reduce the total body burden of fluoride in the population.

BACKGROUND: Fluoridation of drinking water, despite being regarded as one of the top ten public health achievements of the twentieth century, has remained a much debated concept. Various studies on animals and aborted human fetuses have confirmed that excessive fluoride intake during infancy and early childhood, causes a number of irreversible structural and functional changes in the CNS leading to memory, learning and intellectual deficits. AIM: To compare the IQ levels of school children of two different locations, having different fluoride levels in water, and to establish a relationship between fluoride levels, prevalence of fluorosis and its effect on IQ levels. MATERIALS AND METHODS: A cross-sectional study was conducted among 429 children aged 6 - 12 years, selected by stratified random sampling from two different areas with different levels of fluoride in drinking water in and around Lucknow district. Dental fluorosis was measured using Dean's Fluorosis Index. Intelligence Quotient was measured using Raven's Coloured Progressive Matrices (1998 edition). RESULTS: Majority of the fluorosis free children (76.3%) had an IQ grade 2 (definitely above the average). Majority of the children suffering from very mild and mild dental fluorosis were found to have IQ grade 3 (Intellectually average). Children with moderate cases of dental fluorosis were found to have IQ grade 4 (Definitely below average). Only 5 children with severe fluorosis were included in the study and they all were found to have an IQ grade 5. Hence, a trend of increase in the IQ grade (decrease in intellectual capacity) was observed indicating a strong correlation between fluorosis grade and IQ grade. CONCLUSION: Findings of this study suggest that the overall IQ of the children exposed to high fluoride levels in drinking water and hence suffering from dental fluorosis were significantly lower than those of the low fluoride area. Language: en

Introduction: Besides dental and skeletal fluorosis, excessive fluoride intake can also affect the central nervous system without first causing the physical deformities associated with skeletal fluorosis. With the existence of widespread endemic fluorosis in India, the possible adverse effect of elevated fluoride in drinking water on the Intelligence Quotient (IQ) level of children is a potentially serious public health problem. Aims and Objectives: This study assessed the Intelligence Quotient (IQ) of school going children aged 10-12 years in villages of Mysore district with different fluoride levels. Materials and Methods: In this cross-sectional study, 405 school children aged 10-12 years were selected from three villages in Mysore district with normal fluoride (1.20 mg F/l), low fluoride (0.40 mg F/l) and high fluoride (2.20 mg F/l) in their water supplies. A pre designed questionnaire was used to collect the required data for the survey which included socio demographic details, oral hygiene practices, diet history, body mass index and dental fluorosis. Intelligence Quotient was assessed using Raven′s colored Progressive Matrices Test. Results: In bivariate analysis, significant relationships were found between water fluoride levels and Intelligence Quotient of school children (P < 0.05). In the high fluoride village, the proportion of children with IQ below 90, i.e. below average IQ was larger compared to normal and low fluoride village. Age, gender, parent education level and family income had no significant association with IQ. Conclusion: School children residing in area with higher than normal water fluoride level demonstrated more impaired development of intelligence when compared to school children residing in areas with normal and low water fluoride levels. Thus, children′s intelligence can be affected by high water fluoride levels.

Fluoride has been used in the treatment of osteoporosis and in the prevention of dental caries. However, excessive fluoride intake causes significant systemic alterations in animals and human beings. In this chapter disturbances induced in glucose homeostasis are discussed: hyperglycemia, impaired glucose tolerance and modification of metabolic pathways of glucose and glycogen. These changes are the consequence of an inhibition of insulin secretion and/or a reduction in insulin sensitivity.

Fluoride is an essential trace element. It is incorporated in calcified tissues. At doses lower than 1.5 mg/day, fluoride has a prophylactic action against dental caries by absorption on the enamel surface. At doses ranging from 15 to 25 mg/day, it is used as a therapeutic agent in adults, in the treatment of post-menopausal osteoporosis with vertebral crush fractures. At high doses, fluoride may induce skeletal fluorosis leading in children to pseudorachitism. In children, fluoride supplement has been recommended for several years, as a prophylactic agent against dental caries. It may be given either as dentifrices and toothwash solutions, easy to use and economic but contraindicated in very young children; or as tablets, sure and effective but requiring a daily intake; or as domestic salts supplemented with 250 mg/kg. Fluoride supplement may also be given through drinking water. Fluoride content is limited to 1.5 mg/l but some mineral waters contain high amounts of fluoride and may have a beneficial effect on bone mass. In order to prevent an excessive fluoride intake in children and in adults, different forms of fluoride supplements must not be associated.

Caries incidence and prevalence have decreased significantly over the last few decades due to the widespread use of fluoride. However, an increase in the prevalence of dental fluorosis has been reported simultaneously in both fluoridated and non-fluoridated communities. Dental fluorosis occurs due to excessive fluoride intake during the critical period of tooth development. For the permanent maxillary central incisors, the window of maximum susceptibility to the occurrence of fluorosis is the first 3 years of life. Thus, during this time, a close monitoring of fluoride intake must be accomplished in order to avoid dental fluorosis. This review describes the main sources of fluoride intake that have been identified: fluoridated drinking water, fluoride toothpaste, dietary fluoride supplements and infant formulas. Recommendations on how to avoid excessive fluoride intake from these sources are also given.

BAS, BURCU/0000-0003-0593-3400; Aksoy, Abdurrahman/0000-0001-9486-312X; GULBAHAR, MUSTAFA YAVUZ/0000-0001-8268-7659; LUTFIOGLU, MUGE/0000-0003-1499-5902; Sakallioglu, Umur/0000-0002-8823-755X WOS: 000311362300008 PubMed: 22143481 Objectives This study evaluated the influence of fluoride on periodontal soft tissues by investigating any alterations in their MMP-2, TIMP-1 and TGF-beta profiles secondary to excessive fluoride intake. Material and methods Fluorosis was induced in 18 rabbits (test group) through consumption of fluoride added to drinking water, whereas 10 rabbits consumed regular tap water as daily supply (control group). Following fluorosis verification, animals were sacrificed and their 1st mandibular molar teeth were utilized in the assessments. MMP-2, TIMP-1 and TGF-beta were separately investigated for gingival epithelium (GE), gingival connective tissue (GC) and periodontal ligament (PL) to evaluate periodontal soft tissues. Histological sections were prepared from the groups, the parameters were determined by immunohistochemistry, and their levels were calculated by quantification of the immunostainings. Results Staining intensity of MMP-2 in GC and PL (p < 0.01); TIMP-1 and TGF-beta of GE, GC and PL (p < 0.01) were higher in the test group compared to those of the control group. Intra-group staining of TIMP-1 was higher than MMP-2 in all test group compartments (p < 0.01) and in the control group GE (p < 0.01). TIMP-1 was also higher than TGF-beta in the GE and PL of the test group (p < 0.05) and in the GE of the control group (p < 0.01). Conclusion These results suggest that excessive fluoride intake may affect periodontal soft tissues by increasing MMP-2, TIMP-1 and TGF-beta, and thereby altering the MMP-2/TIMP-1 and TIMP-1/TGF-beta ratios. Clinical relevance Excessive fluoride consumption may alter the periodontal tissue homeostasis which may be detrimental in the maintenance of periodontal health. Ondokuz Mayis UniversityOndokuz Mayis University The study was supported by the Scientific Research Fund of Ondokuz Mayis University. The authors report no conflict of interest related to this study.

Tea is the second most commonly consumed beverage world wide. Tea (Camellia sinensis) is a naturally rich source of fluoride. The quantity of fluoride intake is important in optimizing its dental caries-preventive role. Intense concentration of fluoride in tea, can lead to excessive fluoride intake which may cause health problems in turn. The measurement of fluoride intake usually requires information on the fluoride concentration in food and beverages. The main objective of this study was to investigate the fluoride content of various commercial brands of tea bag available on the market in Iran. Furthermore, daily fluoride intake from these brands is assessed. The results of this study showed that among 15 brands of tea bag assessed in this study, Nemooneh TM had the highest fluoride concentration (0.41 ± 0.01 mg/100 ml/3 min), whereas Ahmad TM had the lowest level (0.10 ± 0.01 mg/100 ml/3 min). The average fluoride concentration was 0.23 ± 0.01 mg/100 ml/3 min. Thus, it seems that daily consumption of four cups of tea could provide up to 73% of recommended daily dose of fluoride in children 2-5 years old and up to 50% recommended daily dose for adults. It seems that existing tea bag in Iranian market contain proper amounts of fluoride and there is no toxicity with their regular consumption.

It has been revealed that excessive fluoride intake on long-term is associated with toxic effects and can damage a variety of organs and tissues in the human body, for example, the liver tissue. The molecular mechanisms of fluoride-induced hepato-toxicity are not well understood. The study wants to offer up-to-date insights concerning the effects of natrium fluoride on hepatic tissues when this substance is administrated to a population of mice. The study was conducted on NMRI mice descending from the pregnant females treated with 0.25 mg and 0.5 mg natrium fluoride by daily gavage, from the beginning of pregnancy until the lactation was ceased. Then, the mice, males and females, were divided in six groups, three groups descending from the pregnant females treated with 0.5 mg natrium fluoride (Groups 1A, 1B and 1C ) and three groups from the pregnant females with 0.25 mg natrium fluoride (Groups 2D, 2E and 2F). From the moment the lactation is finished until adulthood, the animals received the following treatments: homeopathic (a CH7 solution of natrium fluoride – Groups A and D), allopathic-homeopathic (0.25 mg‰ natrium fluoride administered like drinking water ad libitum and CH7 solution of natrium fluoride – Group E; 0.5 mg‰ natrium fluoride administered like drinking water ad libitum and CH7 solution of natrium fluoride – Group B), and allopathic administration of natrium fluoride (0.25 mg‰ natrium fluoride like drinking water ad libitum – Group F; 0.5 mg‰ natrium fluoride like drinking water ad libitum – Group C). When the males reached adulthood, the administration of natrium fluoride was stopped and, by randomization, they were selected for euthanasia. The euthanasia was realized by cervical dislocation. The testes for the histopathological examination were preserved in a 10% formalin solution. The preparation of samples for optical microscopy was realized with Hematoxylin-Eosin staining. The results indicate that natrium fluoride administered in different doses, even in homeopathic dose or in allopathic-homeopathic dose, determined centrolobular vacuolar dystrophy of hepatic tissue, cariomegalia, granulovacuolar dystrophy, centrolobular hyperemia centrolobular degenerescences of hepatocytes and discreet centrolobular apoptosis.

Spontaneous motor activity and motor coordination were tested in adult female rats after treating with sodium fluoride at 20 or 40 mg/kg dose level daily for 60 days, using an activity chamber and a rota-rod apparatus, respectively. Total protein concentrations were determined in skeletal muscle, liver and serum of similarly treated animals. The activities of total cholinesterase and acetylcholinesterase were determined in blood and brain regions, respectively. Sodium fluoride treatment suppressed spontaneous motor activity. But no change was observed in the motor coordination of these animals. Tissue and serum protein concentrations were decreased. Cholinesterase activity was decreased in the blood and not in brain regions. A failure of sodium fluoride to impair motor coordination indicated that neuromuscular function required for a forced task was not deteriorated in these animals, although skeletal muscles were deprived of protein and blood cholinesterase activity was suppressed. A suppression of spontaneous motor activity suggests that fluoride has, by a central action, inhibited motivation of these animals to exhibit locomotor behavior. A cholinergic mechanism through a change in the activity of acetylcholinesterase may not account for this effect, since sodium fluoride treatment did not alter the activity this enzyme in brain regions. However, an involvement of monoamines may be proposed in view of previously reported finding that excessive fluoride intake has decreased the concentrations of 5-hydroxyindoleacetic acid and increased that of norepinephrine in rat brain.

Wide variations in fluoride intake among children make estimating fluoride intake difficult. This paper discusses the various sources of fluoride intake among children, beginning with a review of the fluoride concentrations of water and other beverages, foods, and therapeutic fluoride products. A review of previous studies' estimates of fluoride intake from diet, dentifrice, fluoride supplements, fluoride mouthrinses, and gels, as well as total fluoride intake also is presented. Then, estimates of fluoride intake among young children of different age groups are summarized, and examples demonstrating the high level of variability of fluoride intake, both from individual sources and in total, are presented. Lastly, this paper discusses the implications of our current level of knowledge of children's fluoride intake, and presents recommendations for the use of fluoride for children in light of this current knowledge. The major recommendations are that: (1) the fluoride content of foods and beverages, particularly infant formulas and water used in their reconstitution, should continue to be monitored closely in an effort to limit excessive fluoride intake; (2) ingestion of fluoride from dentifrice by young children should be controlled, and the use of only small quantities of dentifrice by young children should be emphasized; and (3) dietary fluoride supplements should be considered a targeted preventive regimen only for those children at higher risk for dental caries and with low levels of ingested fluoride from other sources.

Background Exposure to Fluoride (F) has increased significantly, so that individuals may be consuming more than recommended. Reported effects of excessive intake include reduced serum free thryroxine (FT4), triiodothyronine (FT3), calcium and increased parathyroid hormone (PTH) concentration. Objective To investigate the prevalence of excessive Fluoride intake in apparently healthy children and adolescents, and explore its association changes in thyroid and parathyroid function in Jeddah-Saudi Arabia. Methods 145 apparently healthy children and adolescents were recruited. 60 individuals satisfied selection criteria, and agreed to be enrolled. Subjects were examined dentally and clinically. Weights and heights were measured to calculate body mass index. Dental hygiene practices and fluoride intakes were recorded using recall method and food frequency questionnaires. Blood samples were obtained for the estimation of free thyroxine, triiodothyronine, thyroid stimulating hormone, Parathyroid hormone, calcium and phosphate. Fluoride was estimated in a samples of drinking water, beverages, and fasting urine of subjects. Total Fluoride intakes were calculated and used to subdivide groups into high and low or optimal intake subgroups. Results Excessive Fluoride intake was identified among 36.7% of the individuals. Calculated intake correlated with urinary excretion (r = 0.54, p=0.0003). Significantly higher mean thyroid stimulating hormone and Parathyroid hormone and lower mean of free thyroxine, triiodothyronine, calcium and phosphate were found in various high intake subgroups, with some subjects having abnormal values. Conclusion Excessive F intake is common, and is associated with hyperparathyroidism and hypothyroidism in studied population.

Recently, questions have been raised about the possible reduced effectiveness and cost-effectiveness of water fluoridation in the prevention of dental caries in developed countries. The increase in environmental fluorides since water fluoridation was first introduced in 1945 (particularly from fluoride toothpastes, mouthrinses, and from foods and drinks) generally provided the basis for these questions. A related phenomenon which might decrease the efficiency of water fluoridation is the reduced caries levels in many developed countries. It has also been suggested that excessive fluoride intake, especially in fluoridated communities where there is widespread use of fluoride toothpastes, is likely to manifest itself in an increased dental fluorosis prevalence. In this paper, recent data from Ireland which are similar to those recorded in many developed countries are used to answer these questions in part. It is concluded that water fluoridation continues to be an effective and cost-effective strategy for caries prevention in areas where the overall caries level has declined and where the cost of water fluoridation implementation has increased. Also, there is no evidence of excessive fluoride intake in fluoridated communities where fluoride toothpastes are widely used.

Media reports have raised concerns about the health effects of excessive fluoride intake in young children, particularly if they swallow adult toothpaste containing fluoride.