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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 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.

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.

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

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.

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.

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.

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.

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.

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