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Sample records for fluoride samples ii

  1. Monitoring of fluoride in water samples using a smartphone

    International Nuclear Information System (INIS)

    Levin, Saurabh; Krishnan, Sunderrajan; Rajkumar, Samuel; Halery, Nischal; Balkunde, Pradeep

    2016-01-01

    In several parts of India, groundwater is the only reliable, year round source for drinking water. Prevention of fluorosis, a chronic disease resulting from excess intake of fluoride, requires the screening of all groundwater sources for fluoride in endemic areas. In this paper, the authors present a field deployable colorimetric analyzer based on an inexpensive smartphone embedded with digital camera for taking photograph of the colored solution as well as an easy-fit, and compact sample chamber (Akvo Caddisfly). Phones marketed by different smartphone makers were used. Commercially available zirconium xylenol orange reagent was used for determining fluoride concentration. A software program was developed to use with the phone for recording and analyzing the RGB color of the picture. Linear range for fluoride estimation was 0–2 mg l"−"1. Around 200 samples, which consisted of laboratory prepared as well as field samples collected from different locations in Karnataka, India, were tested with Akvo Caddisfly. The results showed a significant positive correlation between Ion Selective Electrode (ISE) method and Akvo Caddisfly (Phones A, B and C), with correlation coefficient ranging between 0.9952 and 1.000. In addition, there was no significant difference in the mean fluoride content values between ISE and Phone B and C except for Phone A. Thus the smartphone method is economical and suited for groundwater fluoride analysis in the field. - Highlights: • Fluoride is an inorganic pollutant in ground water, affecting human health. • A colorimetric method for measurement of fluoride in drinking water with smartphone • Measurement is by mixing water with zirconyl xylenol orange complex reagent. • Results are comparable with laboratory-based ion selective fluoride electrode method.

  2. Monitoring of fluoride in water samples using a smartphone

    Energy Technology Data Exchange (ETDEWEB)

    Levin, Saurabh [Akvo Foundation (Netherlands); Krishnan, Sunderrajan [INREM Foundation (India); Rajkumar, Samuel; Halery, Nischal; Balkunde, Pradeep [Akvo Foundation (Netherlands)

    2016-05-01

    In several parts of India, groundwater is the only reliable, year round source for drinking water. Prevention of fluorosis, a chronic disease resulting from excess intake of fluoride, requires the screening of all groundwater sources for fluoride in endemic areas. In this paper, the authors present a field deployable colorimetric analyzer based on an inexpensive smartphone embedded with digital camera for taking photograph of the colored solution as well as an easy-fit, and compact sample chamber (Akvo Caddisfly). Phones marketed by different smartphone makers were used. Commercially available zirconium xylenol orange reagent was used for determining fluoride concentration. A software program was developed to use with the phone for recording and analyzing the RGB color of the picture. Linear range for fluoride estimation was 0–2 mg l{sup −1}. Around 200 samples, which consisted of laboratory prepared as well as field samples collected from different locations in Karnataka, India, were tested with Akvo Caddisfly. The results showed a significant positive correlation between Ion Selective Electrode (ISE) method and Akvo Caddisfly (Phones A, B and C), with correlation coefficient ranging between 0.9952 and 1.000. In addition, there was no significant difference in the mean fluoride content values between ISE and Phone B and C except for Phone A. Thus the smartphone method is economical and suited for groundwater fluoride analysis in the field. - Highlights: • Fluoride is an inorganic pollutant in ground water, affecting human health. • A colorimetric method for measurement of fluoride in drinking water with smartphone • Measurement is by mixing water with zirconyl xylenol orange complex reagent. • Results are comparable with laboratory-based ion selective fluoride electrode method.

  3. Environmental monitoring of fluoride emissions using precipitation, dust, plant and soil samples

    International Nuclear Information System (INIS)

    Franzaring, J.; Hrenn, H.; Schumm, C.; Klumpp, A.; Fangmeier, A.

    2006-01-01

    A pollution gradient was observed in precipitation, plants and soils sampled at different locations around a fluoride producing chemical plant in Germany. In all samples the influence of emissions was discernible up to a distance of 500 m from the plant. However, fluoride concentrations in plant bioindicators (leaves of birch and black berry) and in bulk precipitation showed a more pronounced relationship with the distance from the source than fluoride concentrations in soil. Vegetables sampled in the vicinity of the plant also had elevated concentrations of fluoride, but only the consumption of larger quantities of this material would lead to exceedances of recommended daily F-intake. The present study did not indicate the existence of low phytotoxicity thresholds for fluoride in the plant species used in the study. Even at very high fluoride concentrations in leaf tissue (963 ppm) plants did not show injury due to HF. Dust sampling downwind of the chemical plant confirmed that particulate fluoride was of minor importance in the study area. - A pronounced pollution gradient was observed in precipitation, plants and soils sampled at different locations around a fluoride emitting chemical plant in Germany

  4. Urinary fluoride output in children following the use of a dual-fluoride varnish formulation

    Directory of Open Access Journals (Sweden)

    Kelly Polido Kaneshiro Olympio

    2009-06-01

    Full Text Available OBJECTIVE: This study evaluated the bioavailability of fluoride after topical application of a dual-fluoride varnish commercially available in Brazil, when compared to DuraphatTM. MATERIAL AND METHODS: The urinary fluoride output was evaluated in seven 5-year-old children after application of the fluoride varnishes, in two different phases. In the first phase (I, children received topical application of the fluoride varnish Duofluorid XII (2.92% fluorine, calcium fluoride + 2.71% fluorine, sodium fluoride, FGM TM. After 1-month interval (phase II, the same amount (0.2 mL of the fluoride varnish Duraphat (2.26% fluorine, sodium fluoride, ColgateTM was applied. Before each application all the volunteers brushed their teeth with placebo dentifrice for 7 days. Urinary collections were carried out 24 h prior up to 48 h after the applications. Fluoride intake from the diet was also estimated. Fluoride concentration in diet samples and urine was analyzed with the fluoride ion-specific electrode and a miniature calomel reference electrode coupled to a potentiometer. Data were tested by ANOVA and Tukey's post hoc test (p<0.05. RESULTS: There were significant differences in the urinary fluoride output between phases I and II. The use of Duofluorid XII did not significantly increase the urinary fluoride output, when compared to baseline levels. The application of Duraphat caused a transitory increase in the urinary fluoride output, returning to baseline levels 48 h after its use. CONCLUSIONS: The tested varnish formulation, which has been shown to be effective in in vitro studies, also can be considered safe.

  5. Fluorides in groundwater and its impact on health.

    Science.gov (United States)

    Shailaja, K; Johnson, Mary Esther Cynthia

    2007-04-01

    Fluoride is a naturally occurring toxic mineral present in drinking water and causes yellowing of teeth, tooth problems etc. Fluorspar, Cryolite and Fluorapatite are the naturally occurring minerals, from which fluoride finds its path to groundwater through infiltration. In the present study two groundwater samples, Station I and Station II at Hyderabad megacity, the capital of Andhra Pradesh were investigated for one year from January 2001 to December 2001. The average fluoride values were 1.37 mg/l at Station I and 0.91 mg/l at Station II. The permissible limit given by BIS (1983) 0.6-1.2 mg/l and WHO (1984) 1.5 mg/l for fluoride in drinking water. The groundwaters at Station I exceeded the limit while at Station II it was within the limits. The study indicated that fluoride content of 0.5 mg/l is sufficient to cause yellowing of teeth and dental problems.

  6. A rapid method for the determination on fluoride in geological samples

    International Nuclear Information System (INIS)

    Josephson, M.; Cook, E.B.T.; Dixon, K.

    1977-01-01

    An account is given of a rapid procedure for the determination by use of the specific-ion electrode of fluoride in geological samples. The sample is fused with sodium hydroxide in a nickel crucible in a muffle furnace. The melt is leached with water, a buffer solution of ammonium citrate is added, and the fluoride activity is measured with a specific-ion electrode. All operations are carried out in the crucible, making possible approximately 100 determinations a day. The precision of the method is approximately 10 per cent at a fluoride concentration of 500 p.p.m., which is acceptable for geological-survey work [af

  7. Fluoride release and recharge abilities of contemporary fluoride-containing restorative materials and dental adhesives.

    Science.gov (United States)

    Dionysopoulos, Dimitrios; Koliniotou-Koumpia, Eugenia; Helvatzoglou-Antoniades, Maria; Kotsanos, Nikolaos

    2013-01-01

    The aim of this study was to evaluate the fluoride release of five fluoride-releasing restorative materials and three dental adhesives, before and after NaF solution treatment. Five restorative materials (Fuji IX GP, GC Corp.; Ketac N100, 3M ESPE; Dyract Extra, Dentsply; Beautifil II, Shofu Inc.; Wave, SDI) and three dental adhesives (Stae, SDI; Fluorobond II - Shofu Inc.; Prime & Bond NT, Dentsply) were investigated before and after NaF solution treatment. A fluoride ion-selective electrode was to measure fluoride concentrations. During the 86-day period before NaF solution treatment, Fuji IX GP released the highest amount of fluoride among the restorative materials while Prime & Bond NT was the highest among the dental adhesives. After NaF solution treatment, Fuji IX GP again ranked the highest in fluoride release among the restorative materials while Fluorobond II ranked the highest among dental adhesives. It was concluded that the compositions and setting mechanisms of fluoride-containing dental materials influenced their fluoride release and recharge abilities.

  8. Fluoride absorption: independence from plasma fluoride levels

    International Nuclear Information System (INIS)

    Whitford, G.M.; Williams, J.L.

    1986-01-01

    The concept that there are physiologic mechanisms to homeostatically regulate plasma fluoride concentrations has been supported by results in the literature suggesting an inverse relationship between plasma fluoride levels and the absorption of the ion from the gastrointestinal tract of the rat. The validity of the relationship was questioned because of possible problems in the experimental design. The present work used four different methods to evaluate the effect of plasma fluoride levels on the absorption of the ion in rats: (i) the percentage of the daily fluoride intake that was excreted in the urine; (ii) the concentration of fluoride in femur epiphyses; (iii) the net areas under the time-plasma fluoride concentration curves after intragastric fluoride doses; and (iv) the residual amounts or fluoride in the gastrointestinal tracts after the intragastric fluoride doses. None of these methods indicated that plasma fluoride levels influence the rate or the degree or fluoride absorption. It was concluded that, unless extremely high plasma fluoride levels are involved (pharmacologic or toxic doses), the absorption of the ion is independent of plasma levels. The results provide further evidence that plasma fluoride concentrations are not homeostatically regulated

  9. The electrochemical performance and mechanism of cobalt (II) fluoride as anode material for lithium and sodium ion batteries

    International Nuclear Information System (INIS)

    Tan, Jinli; Liu, Li; Guo, Shengping; Hu, Hai; Yan, Zichao; Zhou, Qian; Huang, Zhifeng; Shu, Hongbo; Yang, Xiukang; Wang, Xianyou

    2015-01-01

    Highlights: •The as-prepared CoF 2 shows excellent electrochemical performance as anode material for lithium ion batteries. •The Li insertion/extraction mechanism of CoF 2 below 1.2 V was firstly proposed. •The electrochemical performance of CoF 2 as anode material in sodium ion batteries was firstly studied. -- Abstract: Cobalt (II) fluoride begins to enter into the horizons of people along with the research upsurge of metal fluorides. It is very significative and theoretically influential to make certain its electrochemical reaction mechanism. In this work, we discover a new and unrevealed reversible interfacial intercalation mechanism reacting below 1.2 V for cobalt (II) fluoride electrode material, which contributes a combined discharge capacity of about 400 mA h g −1 with the formation of SEI film at the initial discharge process. A highly reversible storage capacity of 120 mA h g −1 is observed when the cell is cycled over the voltage of 0.01-1.2 V at 0.2 C, and the low-potential voltage reaction process has a significant impact for the whole electrochemical process. Electrochemical analyses suggest that pure cobalt (II) fluoride shows better electrochemical performance when it is cycled at 3.2-0.01 V compared to the high range (1.0-4.5 V). So, we hold that cobalt (II) fluoride is more suitable to serve as anode material for lithium ion batteries. In addition, we also try to reveal the relevant performance and reaction mechanism, and realize the possibility of cobalt (II) fluoride as anode material for sodium ion batteries

  10. Urinary fluoride excretion after application of fluoride varnish and use of fluoride toothpaste in young children

    DEFF Research Database (Denmark)

    Lockner, Frida; Twetman, Svante; Stecksén-Blicks, Christina

    2017-01-01

    BACKGROUND: The efficacy and safety of combined use of topical fluoride products are essential issues that must be monitored. AIM: To assess urinary excretion of fluoride after application of two different dental varnishes containing 2.26% fluoride in 3- to 4-year-old children and to compare...... the levels with and without parallel use of fluoride toothpaste. DESIGN: Fifteen healthy children were enrolled to a randomized crossover trial that was performed in two parts: Part I with twice-daily tooth brushing with fluoride toothpaste and Part II with twice-daily brushing with a non-fluoride toothpaste....... After a 1-week run-in period, 0.1 mL of the two fluoride varnishes (Duraphat and Profluorid Varnish) was topically applied in a randomized order. Baseline and experimental urine was collected during 6-h periods. The fluoride content was determined with an ion-sensitive electrode. RESULTS...

  11. Statistical analysis of fluoride levels in human urine and drinking water samples of fluorinated area of punjab (pakistan)

    International Nuclear Information System (INIS)

    Qayyum, M.; Zaman, W.U.; Rehman, R.; Ahmad, B.; Ahmad, M.; Ali, S.; Murtaza, S

    2013-01-01

    Increasing fluoride levels in drinking water of fluorinated areas of world leading to fluorosis. For bio-monitoring of fluorosis patients, fluoride levels were determined in drinking water and human urine samples of different individuals having dental fluorosis and bony deformities from fluorotic area of Punjab (Sham Ki Bhatiyan, Pakistan) and then compared with reference samples of non fluorotic area (Queens Road, Lahore, Pakistan) using ion selective electrode methodology. Fluoride levels in fluorinated area differ significantly from control group (p < 0.05). In drinking water and human urine samples, fluoride levels in fluorinated areas were: 136.192 +- 67.836 and 94.484 +- 36.572 micro molL/sup -1/ respectively, whereas in control samples, fluoride concentrations were: 19.306 +- 2.109 and 47.154 +- 22.685 micro molL/sup -1/ in water and urine samples correspondingly. Pearson's correlation data pointed out the fact that that human urine and water fluoride concentrations have a significant positive dose response relationship with the prevalence of dental and skeletal fluorosis in fluorotic areas having higher fluoride levels in drinking water. (author)

  12. Extractive separation of Al(III) and Ni(II) by Di-2-Ethylhexyl phosphoric acid-kerosene system from aqueous fluoride medium

    International Nuclear Information System (INIS)

    Islam, M.F.; Begum, D.A.; Rahman, M.; Rahman, M.S.

    2009-01-01

    In the study of the extractive separation of Al(III) and Ni(II) by di-2-ethylhexyl phosphoric acid D2EHPA-kerosene from aqueous fluoride medium, about 94% Al(III) and 2% Ni(II) were extracted with 0.3 M D2EHPA (pH 2.1 and temperature 30+-1 degree C). Extraction of Ni(II) decreased with increasing extractant concentration. D2EHPA-kerosene-fluoride system showed better extraction of Al(III) with higher extractant concentration and aqueous pH and vice versa for the extraction of Ni(II). The maximum separation factor (beta 1380) was obtained for Al(III) at 20 degree C and decreased to (beta 732) at 60 degree C. The separation of Al(III) from Ni(II) was favoured at normal temperature. Extraction followed the order Al(III), Ni(II). About 99% stripping of Al(III) was attained from the loaded 0.20 M D2EHPA. Much faster extraction of Al(III) compared to Ni(II) and preferential loading were shown by D2EHPA-kerosene in the presence of fluoride ion in the aqueous phase. Separation of Al(III) was the most outstanding from Ni-Al-F-complex solution. (author)

  13. No Calcium-Fluoride-Like Deposits Detected in Plaque Shortly after a Sodium Fluoride Mouthrinse

    OpenAIRE

    Vogel, G.L.; Tenuta, L.M.A.; Schumacher, G.E.; Chow, L.C.

    2010-01-01

    Plaque ‘calcium-fluoride-like’ (CaF2-like) and fluoride deposits held by biological/bacterial calcium fluoride (Ca-F) bonds appear to be the source of cariostatic concentrations of fluoride in plaque fluid. The aim of this study was to quantify the amounts of plaque fluoride held in these reservoirs after a sodium fluoride rinse. 30 and 60 min after a 228 μg/g fluoride rinse, plaque samples were collected from 11 volunteers. Each sample was homogenized, split into 2 aliquots (aliquots 1 and 2...

  14. A Comparison of Fluoride Uptake by Sound Enamel Following Application of Sodium Fluoride Mouthrinses and APF Gels Produced in Iran with Standardized Foreign Samples

    Directory of Open Access Journals (Sweden)

    A Kowsari

    2002-02-01

    Full Text Available The goal of this investigation is to compare the extent of fluoride uptake by sound enamel following application of two commercial mouthrinses containing sodium fluoride (0.2% and a topical gel containing APF (1.23% produced in Iran with those of foreign standardized ones. Sixty extracted premolars were used. Each tooth was divided into two lingual and buccal halves, one half as control, the other one as experimental. Enamel biopsy technique (two- step acid etching was used to determine the concentration of fluoride and calcium in each sample. For data comparison and fluoride uptake estimation, the depths of layers with the use of linear regression analysis were standardized to 25 and 50um. The analysis showed that in Iranian mouthrinse no. 1, there is linear correlation between fluoride concentration and enamel depth, in both control and experimental group at the first and second layers, while, in other groups, this correlation was observed just at the first layer (superficial enamel layer. The greatest fluoride uptake was seen at Iranian mouthrinse no.2 and the least was seen at foreign mouthrinse no. 3. From among two APF gels, the greatest uptake was observed at gel no. 1 (Iranian. The results showed that all three Iranian products increase fluoride content of enamel, moreover the level of fluoride uptake, while applying Iranian products, in comparison with foreign ones, shows considerable increase.

  15. Comparison of concentrations of drugs between blood samples with and without fluoride additive-important findings for Δ9-tetrahydrocannabinol and amphetamine.

    Science.gov (United States)

    Wiedfeld, Christopher; Krueger, Julia; Skopp, Gisela; Musshoff, Frank

    2018-02-17

    Fluoride is a common stabilizing agent in forensic toxicology to avoid the frequent problem of degradation of drugs in blood samples especially described for cocaine. In cases only samples with addition of fluoride are available, it is a crucial question if also concentrations of common drugs other than cocaine (amphetamines, opiates and cannabinoids) are affected by fluoride. So far, there are only rare literature data available on discrepant results especially for Δ 9 -tetrahydrocannabinol (THC). In this study, comparative analysis of positive tested paired routine plasma/serum samples (n = 375), collected at the same time point (one device with and one without fluoride), was carried out with special focus on cannabinoids. Samples were measured with validated routine liquid chromatography-tandem mass spectrometry methods for THC, 11-hydroxy-THC (THC-OH), 11-nor-9-carboxy-THC (THC-COOH), cocaine, benzoylecgonine, ecgonine methyl ester, morphine, codeine, amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine, and 3,4-methylenedioxyethylamphetamine, and results were statistically evaluated. Beside the expected stabilization effect on cocaine and the consequently reduced concentration of ecgonine methyl ester in fluoride samples, benzoylecgonine was elevated compared to respective samples without fluoride. Most importantly, new findings were significantly reduced mean concentrations of THC (- 17%), THC-OH (- 17%), and THC-COOH (- 22%) in fluoride samples. Mean amphetamine concentration was significantly higher in samples with the additive (+ 6%). For the other amphetamine type of drugs as well as for morphine and codeine, no significant differences could be seen. Whenever specified thresholds have been set, such as in most European countries, the use of different blood sample systems may result in a motorist being differently charged or prosecuted. The findings will support forensic toxicologists at the

  16. Fluoride analysis

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, C S

    1963-01-01

    The methods and procedures for the detection and estimation of fluoride are varied and numerous. The problems of sampling, contamination, and loss in sampling waters, plant and animal tissues and atmospheres are discussed, along with brief descriptors of methods most commonly used. Techniques for separating fluorides from matrixes are discussed, as well as gravimetric, calorimetric, and spectrophotometric analytical techniques.

  17. Topographic assessment of human enamel surface treated with different topical sodium fluoride agents: Scanning electron microscope consideration

    Directory of Open Access Journals (Sweden)

    Gurlal Singh Brar

    2017-01-01

    Full Text Available Introduction: Continuous balanced demineralization and remineralization are natural dynamic processes in enamel. If the balance is interrupted and demineralization process dominates, it may eventually lead to the development of carious lesions in enamel and dentine. Fluoride helps control decay by enhancing remineralization and altering the structure of the tooth, making the surface less soluble. Methodology: One hundred and twenty sound human permanent incisors randomly and equally distributed into six groups as follows: Group I - Control, II - Sodium fluoride solution, III - Sodium fluoride gel, IV - Sodium fluoride varnish, V - Clinpro Tooth Crème (3M ESPE, and VI-GC Tooth Mousse Plus or MI Paste Plus. The samples were kept in artificial saliva for 12 months, and the topical fluoride agents were applied to the respective sample groups as per the manufacturer instructions. Scanning electron microscope (SEM evaluation of all the samples after 6 and 12 months was made. Results: Morphological changes on the enamel surface after application of fluoride in SEM revealed the presence of globular precipitate in all treated samples. Amorphous, globular, and crystalline structures were seen on the enamel surface of the treated samples. Clear differences were observed between the treated and untreated samples. Conclusion: Globular structures consisting of amorphous CaF2precipitates, which acted as a fluoride reservoir, were observed on the enamel surface after action of different sodium fluoride agents. CPP-ACPF (Tooth Mousse and Tricalcium phosphate with fluoride (Clinpro tooth crème are excellent delivery vehicles available in a slow release amorphous form to localize fluoride at the tooth surface.

  18. Crystal structure of a dinuclear CoII complex with bridging fluoride ligands: di-μ-fluorido-bis{tris[(6-methylpyridin-2-ylmethyl]amine}dicobalt(II bis(tetrafluoridoborate

    Directory of Open Access Journals (Sweden)

    Masataka Inomata

    2014-11-01

    Full Text Available Reaction of Co(BF42·6H2O with tris[(6-methylpyridin-2-ylmethyl]amiine in methanol results in a fluoride abstraction from BF4−, yielding the unexpected title compound, [Co2F2(C21H24N42](BF42. The complex cation consists of two inversion-related [Co(C21H24N4]2+ moieties bridged by a pair of fluoride ligands. The CoII cation is six-coordinated in a distorted octahedral geometry and forms a +II high-spin state. In the crystal, the complex cation and the BF4− anion are connected by C—H...F hydrogen bonds, forming a three-dimensional network. An intramolecular C—H...F hydrogen bond is also observed.

  19. Spatial distribution mapping of drinking water fluoride levels in Karnataka, India: fluoride-related health effects.

    Science.gov (United States)

    Chowdhury, Chitta R; Shahnawaz, Khijmatgar; Kumari, Divya; Chowdhury, Avidyuti; Bedi, Raman; Lynch, Edward; Harding, Stewart; Grootveld, Martin

    2016-11-01

    (1) To estimate the concentrations of fluoride in drinking water throughout different zones and districts of the state of Karnataka. (2) To investigate the variation of fluoride concentration in drinking water from different sources, and its relationships to daily temperature and rainfall status in the regional districts. (3) To develop an updated fluoride concentration intensity map of the state of Karnataka, and to evaluate these data in the context of fluoride-related health effects such as fluorosis and their prevalence. Aqueous standard solutions of 10, 100 and 1,000 ppm fluoride (F - ) were prepared with analytical grade Na + /F - and a buffer; TISAB II was incorporated in both calibration standard and analysis solutions in order to remove the potentially interfering effects of trace metal ions. This analysis was performed using an ion-selective electrode (ISE), and mean determination readings for n = 5 samples collected at each Karnataka water source were recorded. The F - concentration in drinking water in Karnataka state was found to vary substantially, with the highest mean values recorded being in the north-eastern zone (1.61 ppm), and the lowest in the south-western one (only 0.41 ppm). Analysis of variance (ANOVA) demonstrated that there were very highly significant 'between-zone' and 'between-districts-within-zones' sources of variation (p water source F - levels within this state. The southern part of Karnataka has low levels of F - in its drinking water, and may require fluoridation treatment in order to mitigate for dental caries and further ailments related to fluoride deficiency. However, districts within the north-eastern region have contrastingly high levels of fluoride, an observation which has been linked to dental and skeletal fluorosis. This highlights a major requirement for interventional actions in order to ensure maintenance of the recommended range of fluoride concentrations (0.8-1.5 ppm) in Karnataka's drinking water

  20. Alimentary fluoride intake in preschool children

    Directory of Open Access Journals (Sweden)

    Lencova Erika

    2011-10-01

    Full Text Available Abstract Background The knowledge of background alimentary fluoride intake in preschool children is of utmost importance for introducing optimal and safe caries preventive measures for both individuals and communities. The aim of this study was to assess the daily fluoride intake analyzing duplicate samples of food and beverages. An attempt was made to calculate the daily intake of fluoride from food and swallowed toothpaste. Methods Daily alimentary fluoride intake was measured in a group of 36 children with an average age of 4.75 years and an average weight of 20.69 kg at baseline, by means of a double plate method. This was repeated after six months. Parents recorded their child's diet over 24 hours and collected duplicated portions of food and beverages received by children during this period. Pooled samples of food and beverages were weighed and solid food samples were homogenized. Fluoride was quantitatively extracted from solid food samples by a microdiffusion method using hexadecyldisiloxane and perchloric acid. The content of fluoride extracted from solid food samples, as well as fluoride in beverages, was measured potentiometrically by means of a fluoride ion selective electrode. Results Average daily fluoride intake at baseline was 0.389 (SD 0.054 mg per day. Six months later it was 0.378 (SD 0.084 mg per day which represents 0.020 (SD 0.010 and 0.018 (SD 0.008 mg of fluoride respectively calculated per kg bw/day. When adding the values of unwanted fluoride intake from the toothpaste shown in the literature (0.17-1.21 mg per day the estimate of the total daily intake of fluoride amounted to 0.554-1.594 mg/day and recalculated to the child's body weight to 0.027-0.077 mg/kg bw/day. Conclusions In the children studied, observed daily fluoride intake reached the threshold for safe fluoride intake. When adding the potential fluoride intake from swallowed toothpaste, alimentary intake reached the optimum range for daily fluoride intake

  1. Fluoride release and recharge behavior of a nano-filled resin-modified glass ionomer compared with that of other fluoride releasing materials.

    Science.gov (United States)

    Mitra, Sumita B; Oxman, Joe D; Falsafi, Afshin; Ton, Tiffany T

    2011-12-01

    To compare the long-term fluoride release kinetics of a novel nano-filled two-paste resin-modified glass-ionomer (RMGI), Ketac Nano (KN) with that of two powder-liquid resin-modified glass-ionomers, Fuji II LC (FLC) and Vitremer (VT) and one conventional glass-ionomer, Fuji IX (FIX). Fluoride release was measured in vitro using ion-selective electrodes. Kinetic analysis was done using regression analysis and compared with existing models for GIs and compomers. In a separate experiment the samples of KN and two conventional glass-ionomers, FIX and Ketac Molar (KM) were subjected to a treatment with external fluoride source (Oral-B Neutra-Foam) after 3 months of fluoride release and the recharge behavior studied for an additional 7-day period. The cumulative amount of fluoride released from KN, VT and FLC and the release profiles were statistically similar but greater than that for FIX at P coating of KN with its primer and of DY with its adhesive did not significantly alter the fluoride release behavior of the respective materials. The overall rate for KN was significantly higher than for the compomer DY. DY showed a linear rate of release vs. t and no burst effect as expected for compomers. The nanoionomer KN showed fluoride recharge behavior similar to the conventional glass ionomers FIX and KM. Thus, it was concluded that the new RMGI KN exhibits fluoride ion release behavior similar to typical conventional and RMGIs and that the primer does not impede the release of fluoride.

  2. Effect of exercise on fluoride metabolism in adult humans: a pilot study.

    Science.gov (United States)

    V Zohoori, Fatemeh; Innerd, Alison; Azevedo, Liane B; Whitford, Gary M; Maguire, Anne

    2015-11-19

    An understanding of all aspects of fluoride metabolism is critical to identify its biological effects and avoid fluoride toxicity in humans. Fluoride metabolism and subsequently its body retention may be affected by physiological responses to acute exercise. This pilot study investigated the effect of exercise on plasma fluoride concentration, urinary fluoride excretion and fluoride renal clearance following no exercise and three exercise intensity conditions in nine healthy adults after taking a 1-mg Fluoride tablet. After no, light, moderate and vigorous exercise, respectively, the mean (SD) baseline-adjusted i) plasma fluoride concentration was 9.6(6.3), 11.4(6.3), 15.6(7.7) and 14.9(10.0) ng/ml; ii) rate of urinary fluoride excretion over 0-8 h was 46(15), 44(22), 34(17) and 36(17) μg/h; and iii) rate of fluoride renal clearance was 26.5(9.0), 27.2(30.4), 13.1(20.4) and 18.3(34.9) ml/min. The observed trend of a rise in plasma fluoride concentration and decline in rate of fluoride renal clearance with increasing exercise intensity needs to be investigated in a larger trial. This study, which provides the first data on the effect of exercise with different intensities on fluoride metabolism in humans, informs sample size planning for any subsequent definitive trial, by providing a robust estimate of the variability of the effect.

  3. Time and temperature affect glycolysis in blood samples regardless of fluoride-based preservatives: a potential underestimation of diabetes.

    Science.gov (United States)

    Stapleton, Mary; Daly, Niamh; O'Kelly, Ruth; Turner, Michael J

    2017-11-01

    Background The inhibition of glycolysis prior to glucose measurement is an important consideration when interpreting glucose tolerance tests. This is particularly important in gestational diabetes mellitus where prompt diagnosis and treatment is essential. A study was planned to investigate the effect of preservatives and temperature on glycolysis. Methods Blood samples for glucose were obtained from consented females. Lithium heparin and fluoride-EDTA samples transported rapidly in ice slurry to the laboratory were analysed for glucose concentration and then held either in ice slurry or at room temperature for varying time intervals. Paired fluoride-citrate samples were received at room temperature and held at room temperature, with analysis at similar time intervals. Results No significant difference was noted between mean glucose concentrations when comparing different sample types received in ice slurry. The mean glucose concentrations decreased significantly for both sets of samples when held at room temperature (0.4 mmol/L) and in ice slurry (0.2 mmol/L). A review of patient glucose tolerance tests reported in our hospital indicated that 17.8% exceeded the recommended diagnostic criteria for gestational diabetes mellitus. It was predicted that if the results of fasting samples were revised to reflect the effect of glycolysis at room temperature, the adjusted diagnostic rate could increase to 35.3%. Conclusion Preanalytical handling of blood samples for glucose analysis is vital. Fluoride-EDTA is an imperfect antiglycolytic, even when the samples are transported and analysed rapidly provides such optimal conditions. The use of fluoride-citrate tubes may offer a viable alternative in the diagnosis of diabetes mellitus.

  4. Fluoride concentrations in soils, vegetation samples and soil fauna in the direct vicinity of a pollution source

    International Nuclear Information System (INIS)

    Vogel, J.; Ottow, J.C.G.; Breimer, R.F.

    1989-01-01

    Fluoride analyses CF t = total F; F w = water soluble F and F HCI HCI-extractable F) of different soils, vegetation samples and soil fauna (Helix pomatia, Lumbricus spp., arthropodes) in a locally polluted area (for nearly 65 years) clearly revealed an F-accumulation in top soil, vegetation and animals. Based on 1N HCI-extractable fluoride, two contamination zones around the emitting industry could be identified. In the calcareous soils, leaching of fluoride seems to be insignificant because of a strong immobilization as CaF 2 . A highly significant correlation between the F HCI content of soils and Lumbricus spp. (with and without gut content) or Helix pomatia shells was found. Fluoride concentrations in washed leaves of Hedera helix and in decaying grass reached levels of 306 and 997 μgF/g respectively. Saprophagous soil arthropods contained high fluoride levels, up to 732 μgF/g in Armadillidium vulgare. (orig.)

  5. Water fluoridation in 40 Brazilian cities: 7 year analysis

    Directory of Open Access Journals (Sweden)

    Suzely Adas Saliba MOIMAZ

    2013-01-01

    Full Text Available Objectives Fluoride levels in the public water supplies of 40 Brazilian cities were analyzed and classified on the basis of risk/benefit balance. Material and Methods Samples were collected monthly over a seven-year period from three sites for each water supply source. The samples were analyzed in duplicate in the laboratory of the Center for Research in Public Health - UNESP using an ion analyzer coupled to a fluoride-specific electrode. Results A total of 19,533 samples were analyzed, of which 18,847 were artificially fluoridated and 686 were not artificially fluoridated. In samples from cities performing water fluoridation, 51.57% (n=9,720 had fluoride levels in the range of 0.55 to 0.84 mg F/L; 30.53% (n=5,754 were below 0.55 mg F/L and 17.90% (n=3,373 were above 0.84 mg F/L (maximum concentration=6.96 mg F/L. Most of the cities performing fluoridation that had a majority of samples with fluoride levels above the recommended parameter had deep wells and more than one source of water supply. There was some variability in the fluoride levels of samples from the same site and between collection sites in the same city. Conclusions The majority of samples from cities performing fluoridation had fluoride levels within the range that provides the best combination of risks and benefits, minimizing the risk of dental fluorosis while preventing dental caries. The conduction of studies about water distribution systems is suggested in cities with high natural fluoride concentrations in order to optimize the use of natural fluoride for fluoridation costs and avoid the risk of dental fluorosis.

  6. Accumulation of fluoride by plants and vegetables

    International Nuclear Information System (INIS)

    Njenga, L.W.; Kariuki, D.N.

    1994-01-01

    Fluoride in plant and vegetable samples has been determined using ion selective electrode. The analysis was carried out after ashing the sample on an open flame, adding perchloric acid and allowing the hydrogen fluoride to diffuse into sodium hydroxide layer.The results obtained show that kale and pumpkins can accumulate more than ten times their normal values of fluoride while plants were found to accumulate upto 100μg/g fluoride when exposed to highlevels of fluoride in water or soil. (author)

  7. No calcium-fluoride-like deposits detected in plaque shortly after a sodium fluoride mouthrinse.

    Science.gov (United States)

    Vogel, G L; Tenuta, L M A; Schumacher, G E; Chow, L C

    2010-01-01

    Plaque 'calcium-fluoride-like' (CaF(2)-like) and fluoride deposits held by biological/bacterial calcium fluoride (Ca-F) bonds appear to be the source of cariostatic concentrations of fluoride in plaque fluid. The aim of this study was to quantify the amounts of plaque fluoride held in these reservoirs after a sodium fluoride rinse. 30 and 60 min after a 228 microg/g fluoride rinse, plaque samples were collected from 11 volunteers. Each sample was homogenized, split into 2 aliquots (aliquots 1 and 2), centrifuged, and the recovered plaque fluid combined and analyzed using microelectrodes. The plaque mass from aliquot 1 was retained. The plaque mass from aliquot 2 was extracted several times with a solution having the same fluoride, calcium and pH as the plaque fluid in order to extract the plaque CaF(2)-like deposits. The total fluoride in both aliquots was then determined. In a second experiment, the extraction completeness was examined by applying the above procedure to in vitro precipitates containing known amounts of CaF(2)-like deposits. Nearly identical fluoride concentrations were found in both plaque aliquots. The extraction of the CaF(2)-like precipitates formed in vitro removed more than 80% of these deposits. The results suggest that either CaF(2)-like deposits were not formed in plaque or, if these deposits had been formed, they were rapidly lost. The inability to form persistent amounts of CaF(2)-like deposits in plaque may account for the relatively rapid loss of plaque fluid fluoride after the use of conventional fluoride dentifrices or rinses. (c) 2010 S. Karger AG, Basel.

  8. Fluoride exposure and indicators of thyroid functioning in the Canadian population: implications for community water fluoridation.

    Science.gov (United States)

    Barberio, Amanda M; Hosein, F Shaun; Quiñonez, Carlos; McLaren, Lindsay

    2017-10-01

    There are concerns that altered thyroid functioning could be the result of ingesting too much fluoride. Community water fluoridation (CWF) is an important source of fluoride exposure. Our objectives were to examine the association between fluoride exposure and (1) diagnosis of a thyroid condition and (2) indicators of thyroid functioning among a national population-based sample of Canadians. We analysed data from Cycles 2 and 3 of the Canadian Health Measures Survey (CHMS). Logistic regression was used to assess associations between fluoride from urine and tap water samples and the diagnosis of a thyroid condition. Multinomial logistic regression was used to examine the relationship between fluoride exposure and thyroid-stimulating hormone (TSH) level (low/normal/high). Other available variables permitted additional exploratory analyses among the subset of participants for whom we could discern some fluoride exposure from drinking water and/or dental products. There was no evidence of a relationship between fluoride exposure (from urine and tap water) and the diagnosis of a thyroid condition. There was no statistically significant association between fluoride exposure and abnormal (low or high) TSH levels relative to normal TSH levels. Rerunning the models with the sample constrained to the subset of participants for whom we could discern some source(s) of fluoride exposure from drinking water and/or dental products revealed no significant associations. These analyses suggest that, at the population level, fluoride exposure is not associated with impaired thyroid functioning in a time and place where multiple sources of fluoride exposure, including CWF, exist. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  9. Spectrographic determination of impurities in ammonium hydrogen fluoride samples

    International Nuclear Information System (INIS)

    Roca, M.; Capdevila, C.; Alduan, F.A.

    1976-01-01

    The quantitative spectrographic trace determination of Al, B, Cr, Cu, Fe, Mn, Mo, Ni, Pb and Si in ammonium hydrogen fluoride samples is considered. 10 A dc arc excitation and graphite electrodes with crate either 4.5 mm or 8 mm deep are employed. A comparison of various matrices such as graphite, gallium oxide, germanium oxide, magnesium oxide and zinc oxide, in the ratios 1:1 and 1:3, as well as a mixture 50% graphite - 50% zinc oxide in the ratio 1:1 is included. Zinc oxide in the ratio 1:1 and 4x8 mm craters show the best over-all results. (author)

  10. Estimation of atmospheric fluoride by limed filter papers

    International Nuclear Information System (INIS)

    Smith, D.R.

    1988-09-01

    The limed filter paper method of static sampling of atmospheric fluoride is reviewed in this report. Use of the technique, in conjunction with precise measurement of the absorbed fluoride and calibration with dynamic air sampling techniques, to estimate atmospheric fluoride levels, is considered to give only qualitative data (± 50%). The limed filter paper method is site specific due to variations in meteorological conditions. Its main value is to indicate seasonal and annual trends in fluoride exposure of vegetation. Subject to these considerations, the lower and upper limits of atmospheric fluoride exposure and the applicability to atmospheric fluoride estimation under routine or emergency fluoride release conditions are discussed, with special emphasis on the limiting factors

  11. Well Waters Fluoride in Enugu, Nigeria

    Directory of Open Access Journals (Sweden)

    ISI Ogbu

    2012-03-01

    Full Text Available Abnormal fluoride levels in drinking water have been associated with adverse health effects. To determine the fluoride content of well waters in Enugu, southeastern Nigeria, water samples from 50 artisan wells chosen by multistage sampling procedure from the 5 zones of Enugu municipality were analyzed in duplicates for their fluoride content. The zonal mean values were 0.60, 0.70, 0.62, 0.62, and 0.63 mg/L for Abakpa Nike, Achara Layout, Obiagu/ Ogui, Trans Ekulu and Uwani, respectively (p<0.05. The mean value for the whole city was 0.63 mg/L. Although, the mean level of fluoride recorded in this study is currently within safe limits (1.5 mg/L, WHO 2011, it is important to monitor continuously the fluoride content of well waters in the municipality in view of the increasing industrial activities going on in the city and heavy reliance on well water for domestic purposes and the widespread use of consumer products containing fluoride.

  12. Fluoride release, recharge and flexural properties of polymethylmethacrylate containing fluoridated glass fillers.

    Science.gov (United States)

    Al-Bakri, I A; Swain, M V; Naoum, S J; Al-Omari, W M; Martin, E; Ellakwa, A

    2014-06-01

    The purpose of this study was to investigate the effect of fluoridated glass fillers on fluoride release, recharge and the flexural properties of modified polymethylmethacrylate (PMMA). Specimens of PMMA denture base material with various loading of fluoridated glass fillers (0%, 1%, 2.5%, 5% and 10% by weight) were prepared. Flexural properties were evaluated on rectangular specimens (n = 10) aged in deionized water after 24 hours, 1 and 3 months. Disc specimens (n = 10) were aged for 43 days in deionized water and lactic acid (pH 4.0) and fluoride release was measured at numerous intervals. After ageing, specimens were recharged and fluoride re-release was recorded at 1, 3 and 7 days after recharge. Samples containing 2.5%, 5% and 10% glass fillers showed significantly (p glass fillers specimens. All experimental specimens exhibited fluoride release in both media. The flexural strength of specimens decreased in proportion to the percentage filler inclusion with the modulus of elasticity values remaining within ISO Standard 1567. The modified PMMA with fluoridated glass fillers has the ability to release and re-release fluoride ion. Flexural strength decreased as glass filler uploading increased. © 2014 Australian Dental Association.

  13. Atmospheric fluoride levels in some Ontario peach orchards

    Energy Technology Data Exchange (ETDEWEB)

    Drowley, W B; Rayner, A C; Jephcott, C M

    1963-10-01

    As a result of suture injury to peaches, a survey was taken to determine monthly atmospheric fluoride levels in the soft fruit-growing area of the Niagara Peninsula of Ontario. Although the injury was confined to a few orchards, it was found necessary to locate stations for fluoride sampling over a wide area. The limed-paper candle method was used for fluoride collection. Unwashed and washed peach leaves were analyzed for fluoride content. Fluoride was separated from all samples by the Willard-Winter distillation procedure and estimated colorimetrically. It was found that a general background level of atmospheric fluoride existed in the whole surveyed area and that the levels were highest in and near the area of peach injury. The fluoride content of peach leaves was also highest in this area. The coincidence of high fluoride levels and suture injury to peaches suggests that atmospheric fluoride was the causal agent. When lime sprays were applied to peach trees in the damaged area, a reduction in the incidence of suture injury was observed.

  14. Metal Fluorides, Metal Chlorides and Halogenated Metal Oxides as Lewis Acidic Heterogeneous Catalysts. Providing Some Context for Nanostructured Metal Fluorides.

    Science.gov (United States)

    Lennon, David; Winfield, John M

    2017-01-28

    Aspects of the chemistry of selected metal fluorides, which are pertinent to their real or potential use as Lewis acidic, heterogeneous catalysts, are reviewed. Particular attention is paid to β-aluminum trifluoride, aluminum chlorofluoride and aluminas γ and η, whose surfaces become partially fluorinated or chlorinated, through pre-treatment with halogenating reagents or during a catalytic reaction. In these cases, direct comparisons with nanostructured metal fluorides are possible. In the second part of the review, attention is directed to iron(III) and copper(II) metal chlorides, whose Lewis acidity and potential redox function have had important catalytic implications in large-scale chlorohydrocarbons chemistry. Recent work, which highlights the complexity of reactions that can occur in the presence of supported copper(II) chloride as an oxychlorination catalyst, is featured. Although direct comparisons with nanostructured fluorides are not currently possible, the work could be relevant to possible future catalytic developments in nanostructured materials.

  15. Biochemical studies on the effect of fluoride on higher plants. II. The effect of fluoride on sucrose-synthesizing enzymes from higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Yang, S F; Miller, G W

    1963-01-01

    A study was initiated to characterize the properties of partially purified phosphoglucomutase, uridine diphosphate glucose pyrophosphorylase and uridine diphosphate glucose-fructose transglucosyalse, from various plant sources, with respect to activation by metal ions and inhibition by fluoride. Of the three enzymes studied, only phosphoglucomutase was very sensitive to fluoride. It is likely that the inhibition of sucrose synthesis in fluoride-fumigated plants might be due to the inhibition of phosphoglucomutase, which plays an important role in carbohydrate metabolism. However, at present, there is insufficient evidence to show the inhibition of phosphoglucomutase in vivo by fumigation with hydrogen fluoride.

  16. Removal of fluoride from drinking water using a modified fly ash adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Debasis Goswami; Arabinda K. Das

    2006-01-15

    Fly ash from a coal-fired power station was chemically modified and utilized for the removal of fluoride from drinking water. Two types of beds were used. Bed I was prepared by treatment with 12M HCl followed by neutralization with 5M NaOH solution. The reaction mass was filtered, washed, dried, and crushed to fine powder. Bed I material was mixed with alum and MgCl{sub 2} solutions and treated with 0.9M Na{sub 2}CO{sub 3} until pH reached to 4.5. Mass was again filtered, washed, dried at 120{sup o}C for 4 h and crushed to fine powder. This bed material is Bed II, which was used for defluoridation. Bed I was used to maintain pH (7.5-8.5) of the final effluent. Fluoride (100 ppm) present in both synthetic mixtures and drinking water samples was allowed to pass through Bed II (15 g) absorbent and effluents were found to contain no fluoride but pH of the effluent was 5.4-5.5. To maintain WHO guidelines for drinking water on pH, this effluent was again passed through Bed I. The effectiveness of the modified fly ash bed was satisfactory.

  17. PREPARATION AND CHARACTERIZATION OF STRONTIUM FLUORIDE POWDERS ACTIVATED BY NEODYMIUM FLUORIDE

    Directory of Open Access Journals (Sweden)

    S. V. Kuznetsov

    2015-07-01

    Full Text Available Subject of Study. The paper deals with preparation processes of ultradisperse, homogeneous powder Sr1-хNdхF2+х (х= 0.003-0.2, with use of ammonium fluoride as the fluorinating agent taken over 114-120 % from stoichiometry. Method. Nitrate of strontium, neodymium nitrate hexahydrate, with the content equal to 99. 99 % of the basic substance and ammonium fluoride were used as the source of substances. Activated powders of strontium fluoride were obtained by the method of deposition from aqueous solutions by washing the precipitate with a solution of ammonium fluoride, taken over 114 - 120% from stoichiometry. The washed precipitate was centrifuged for 5-7 min, dried in the air at 30-350 C. Heat treatment of the dried precipitate was carried out in two stages: the first stage at the temperature of 200- 2500 C for 0.5-1 hour, the second one at 550- 6000 C for 2-3 hours. X-ray analysis of the synthesized samples was carried out on a Bruker D8 Advance diffractometer, radiation Cu K. The size and shape measuring of the particles of activated strontium fluoride was carried out by means of electron microscope Carl Zeiss NVision 40. The content of neodymium in activated powders of strontium fluoride was determined by the method of spectral emission analysis on the device LEA - S500. Chemical analysis for determination of ammonium ion (NH4+ content in the obtained samples was performed by the method of Kjeldahl. Calculations of lattice parameters, size of coherent scattering regions and the values of micro-deformations were carried out by TOPAS program. Main Results. Preparation processes of ultradisperse, homogeneous powder Sr1-хNdхF2+х (х= 0.003-0.2, with use of ammonium fluoride as the fluorinating agent taken over 114-120 % from stoichiometry, provides obtaining the firm solution Sr1-x-yNdx(NH4yF2+x-y of the cubic fluorite structure. It has been found out that the morphology and size of the resulting product depend on the quantity of

  18. Emissions of fluorides from welding processes.

    Science.gov (United States)

    Szewczyńska, Małgorzata; Pągowska, Emilia; Pyrzyńska, Krystyna

    2015-11-01

    The levels of fluoride airborne particulates emitted from welding processes were investigated. They were sampled with the patented IOM Sampler, developed by J. H. Vincent and D. Mark at the Institute of Occupational Medicine (IOM), personal inhalable sampler for simultaneous collection of the inhalable and respirable size fractions. Ion chromatography with conductometric detection was used for quantitative analysis. The efficiency of fluoride extraction from the cellulose filter of the IOM sampler was examined using the standard sample of urban air particle matter SRM-1648a. The best results for extraction were obtained when water and the anionic surfactant N-Cetyl-N-N-N-trimethylammonium bromide (CTAB) were used in an ultrasonic bath. The limits of detection and quantification for the whole procedure were 8μg/L and 24μg/L, respectively. The linear range of calibration was 0.01-10mg/L, which corresponds to 0.0001-0.1mg of fluorides per m(3) in collection of a 20L air sample. The concentration of fluorides in the respirable fraction of collected air samples was in the range of 0.20-1.82mg/m(3), while the inhalable fraction contained 0.23-1.96mg/m(3) of fluorides during an eight-hour working day in the welding room. Copyright © 2015. Published by Elsevier B.V.

  19. Fluoride levels in commercially available rice in Ethiopia | Tegegne ...

    African Journals Online (AJOL)

    Alkaline fusion was used for sample preparation of six varieties for both the raw rice and rice cooked with tap water and fluoridated water. Fluoride levels ranged from 0.1-5.5 mg/kg in raw rice sample. Rice which was cooked with different fluoride levels of water showed increment depending on the method of cooking.

  20. In Vitro Inhibition of Enamel Demineralisation by Fluoride-releasing Restorative Materials and Dental Adhesives.

    Science.gov (United States)

    Dionysopoulos, Dimitrios; Koliniotou-Koumpia, Eugenia; Helvatzoglou-Antoniades, Maria; Kotsanos, Nikolaos

    2016-01-01

    To determine the ability of 5 contemporary fluoride-releasing restoratives and 3 fluoride-releasing adhesives to inhibit enamel demineralisation surrounding restorations, and the associations between inhibition and the levels of fluoride released from these materials. Five fluoride-releasing restoratives (Fuji IX GP, Ketac N100, Dyract Extra, Beautifil II and Wave) and 3 fluoride-releasing adhesives (Stae, Prime & Bond NT and Fluoro Bond II) were investigated. Eight disks of each material were prepared. Fluoride release was measured daily using a fluoride-ion-selective electrode for 15 days. Twenty-four cavities for each group were restored with a restorative and an adhesive. Specimens were subjected to thermal stress and stored for 30 days in saline solution. After a 15-day pH-cycling regimen, two 150-μm-thick sections were derived from each specimen. Enamel lesion depth was measured at 0, 100, and 200 μm from each restoration's margin via polarised light microscopy. Of the restoratives investigated, Fuji IX GP released the most fluoride. The fluoride-releasing restoratives tested exhibited shallower enamel lesions than did the control group at all distances tested (p < 0.05). Fuji IX GP yielded significantly lower enamel lesion depth than did the other experimental materials. The depths of enamel lesions did not differ significantly when comparing restoratives applied with a fluoride-releasing adhesive with those applied with a non-fluoride-releasing adhesive. The fluoride-releasing materials tested reduced enamel demineralisation but to different extents, depending on their levels of fluoride release. Fluoride-releasing adhesives did not influence enamel lesion formation.

  1. Fluoride releasing and enamel demineralization around orthodontic brackets by fluoride-releasing composite containing nanoparticles.

    Science.gov (United States)

    Melo, Mary A S; Morais, Weslanny A; Passos, Vanara F; Lima, Juliana P M; Rodrigues, Lidiany K A

    2014-05-01

    Fluoride-containing materials have been suggested to control enamel demineralization around orthodontic brackets during the treatment with fixed appliances. The improvement of their properties has been made through innovations, such as the application of nanotechnology by incorporation of nanofillers. This in vitro study evaluated the capacity of fluoride releasing and enamel demineralization inhibition of fluoride-releasing nanofilled cement around orthodontic brackets using an artificial caries biofilm model. Forty bovine enamel discs were selected by evaluating surface microhardness and randomized into four groups (n = 10): non-fluoride-releasing microfilled composite, fluoride-releasing microfilled composite, resin-modified glass ionomer cement (RMGI), and fluoride-releasing nanofilled composite (FN). After brackets bonding in each disc, the specimens were subjected to a cariogenic challenge through a Streptococcus mutans biofilm model. After the experimental period, the biofilm formed around the brackets was collected for fluoride analysis and the mineral loss around the brackets was determined by integrated demineralization via cross-sectional microhardness measurement at 20 and 70 μm from the bracket margin. Additionally, samples of each group were subjected to energy-dispersive X-ray spectroscopy (EDX) analysis examined under a scanning electron microscopy (SEM). ANOVA followed by Tukey test were applied for fluoride concentration and mineral loss data, respectively. At both distances, only RMGI statistically differed from the other groups presenting the lowest demineralization, although there was a trend to a lower demineralization of enamel around brackets in FN group. Similar condition was found to fluoride concentration and EDX/SEM analysis. Under the cariogenic exposure condition of this study, the fluoride-releasing nanofilled material had similar performance to fluoride-releasing microfilled materials. The presence of nanofillers in the fluoride

  2. Fluoride varnish or fluoride mouth rinse?

    DEFF Research Database (Denmark)

    Keller, M K; Klausen, BJ; Twetman, S

    2016-01-01

    OBJECTIVE: In many Danish communities, school-based fluoride programs are offered to children with high caries risk in adjunct to tooth brushing. The purpose of this field trial was to compare the caries-preventive effectiveness of two different fluoride programs in 6-12 year olds. BASIC RESEARCH...... different schools were enrolled after informed consent and their class unit was randomly allocated to one of two fluoride programs. INTERVENTIONS: One group received a semi-annual fluoride varnish applications (FV) and the other group continued with an existing program with fluoride mouth rinses once per...... in caries development over two years among children participating in a school-based fluoride varnish or mouth rinse program....

  3. Histopathological changes of renal tissue following sodium fluoride administration in two consecutive generations of mice. Correlation with the urinary elimination of fluoride.

    Science.gov (United States)

    Dimcevici Poesina, Nicoleta; Bălălău, Cristian; Nimigean, Vanda Roxana; Nimigean, Victor; Ion, Ion; Baconi, Daniela; Bârcă, Maria; Băran Poesina, Violeta

    2014-01-01

    The present study was designed to investigate the toxic effects (evaluated as histopathological changes) of sodium fluoride on the kidney in two consecutive generations of NMRI mice. An attempt to correlate the toxicity with the urinary elimination of fluoride has been made, as urinary fluoride excretion has been widely used as an indicator of fluoride intake and exposure. Six mixed (males and females) animal groups have been constituted by dividing the populations of mice derived from pregnant females (named "mothers" 0.5 mg sodium fluoride) treated with 0.5 mg sodium fluoride by daily gavage and pregnant females (named "mothers" 0.25 mg sodium fluoride) treated with 0.25 mg sodium fluoride by daily gavage; three types of sodium fluoride treatments were administrated: homeopathic, allopathic-homeopathic and allopathic. When the animals reached the adulthood, by randomization, they were selected in pairs for giving birth to the second generation of mice. No treatments were administrated to the second generation of mice; thus, the urinary elimination of fluoride in the second generation is attributed to exposure at sodium fluoride before birth. The administration of sodium fluoride to the first generation (F1) is realized until the mice reached the adulthood. For the first generation, the urine was collected at three times, every three weeks: at the age of four weeks, seven weeks and 11 weeks; single sampling urine, at the age of four weeks, has been conducted for the second generation. The urine samples have been analyzed using the ion selective electrode method for fluoride. For the histopathological examination, the animals were killed by cervical dislocation; the kidneys were collected in a 10% formalin solution. The preparation of samples for optical microscopy was realized with Hematoxylin-Eosin staining. The results indicate that the elimination of fluoride was similar (at the second evaluation, at 7-week-old of the first generation) for the both generations

  4. Biomonitoring Equivalents for interpretation of urinary fluoride.

    Science.gov (United States)

    Aylward, L L; Hays, S M; Vezina, A; Deveau, M; St-Amand, A; Nong, A

    2015-06-01

    Exposure to fluoride is widespread due to its natural occurrence in the environment and addition to drinking water and dental products for the prevention of dental caries. The potential health risks of excess fluoride exposure include aesthetically unacceptable dental fluorosis (tooth mottling) and increased skeletal fragility. Numerous organizations have conducted risk assessments and set guidance values to represent maximum recommended exposure levels as well as recommended adequate intake levels based on potential public health benefits of fluoride exposure. Biomonitoring Equivalents (BEs) are estimates of the average biomarker concentrations corresponding to such exposure guidance values. The literature on daily urinary fluoride excretion rates as a function of daily fluoride exposure was reviewed and BE values corresponding to the available US and Canadian exposure guidance values were derived for fluoride in urine. The derived BE values range from 1.1 to 2.1mg/L (1.2-2.5μg/g creatinine). Concentrations of fluoride in single urinary spot samples from individuals, even under exposure conditions consistent with the exposure guidance values, may vary from the predicted average concentrations by several-fold due to within- and across-individual variation in urinary flow and creatinine excretion rates and due to the rapid elimination kinetics of fluoride. Thus, the BE values are most appropriately applied to screen population central tendency estimates for biomarker concentrations rather than interpretation of individual spot sample concentrations. Copyright © 2015. Published by Elsevier Inc.

  5. Potentiometric chip-based multipumping flow system for the simultaneous determination of fluoride, chloride, pH, and redox potential in water samples.

    Science.gov (United States)

    Chango, Gabriela; Palacio, Edwin; Cerdà, Víctor

    2018-08-15

    A simple potentiometric chip-based multipumping flow system (MPFS) has been developed for the simultaneous determination of fluoride, chloride, pH, and redox potential in water samples. The proposed system was developed by using a poly(methyl methacrylate) chip microfluidic-conductor using the advantages of flow techniques with potentiometric detection. For this purpose, an automatic system has been designed and built by optimizing the variables involved in the process, such as: pH, ionic strength, stirring and sample volume. This system was applied successfully to water samples getting a versatile system with an analysis frequency of 12 samples per hour. Good correlation between chloride and fluoride concentration measured with ISE and ionic chromatography technique suggests satisfactory reliability of the system. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Fluoride release from fluoride varnishes under acidic conditions.

    Science.gov (United States)

    Lippert, F

    2014-01-01

    The aim was to investigate the in vitro fluoride release from fluoride varnishes under acidic conditions. Poly(methyl methacrylate) blocks (Perspex, n=3 per group) were painted with 80 ± 5 mg fluoride varnish (n=10) and placed into artificial saliva for 30 min. Then, blocks were placed into either 1% citric acid (pH 2.27) or 0.3% citric acid (pH 3.75) solutions (n=3 per solution and varnish) for 30 min with the solutions being replaced every 5 min. Saliva and acid solutions were analyzed for fluoride content. Data were analyzed using three-way ANOVA (varnish, solution, time). The three-way interaction was significant (p>0.0001). Fluoride release and release patterns varied considerably between varnishes. Fluoride release in saliva varied by a factor of more than 10 between varnishes. Some varnishes (CavityShield, Nupro, ProFluorid, Vanish) showed higher fluoride release in saliva than during the first 5 min of acid exposure, whereas other varnishes (Acclean, Enamel-Pro, MI Varnish, Vella) showed the opposite behavior. There was little difference between acidic solutions. Fluoride release from fluoride varnishes varies considerably and also depends on the dissolution medium. Bearing in mind the limitations of laboratory research, the consumption of acidic drinks after fluoride varnish application should be avoided to optimize the benefit/risk ratio.

  7. Monitoring of fluoride and iodide levels in drinking water using ion selective electrodes

    International Nuclear Information System (INIS)

    Ahmed, R.; Viqar-Un-Nisa; Hussain, M.; Tanwir, R.; Qureshi, S.A.

    2004-01-01

    Fluoride and iodide, the most important constituents of drinking water are essential as well as toxic depending on their levels. For their analysis in water mostly ion-selective electrodes, spectrophotometry, titrimetry and coulometry etc; have been used and literature has been briefly reviewed. Ion-selective electrodes offer an efficient method for the measurement of the two halides and were mostly used during this work. Fabrication of these electrodes is briefly described. Comparison of results obtained by ion selective electrode and coulometry is given. Recoveries of the added fluoride ions from the samples were good. A large number of water samples from Rawalpindi-Islamabad area were analyzed for fluoride and iodide. Levels of fluoride and iodide from two main water reservoirs of Rawalpindi and Islamabad are reported before and after treatment. Both surface and ground water samples were analyzed and results are compared and discussed. Some samples from northern areas were also analyzed for iodide and fluoride and compared. Intake of fluoride and iodide from water of different areas is also compared. Water samples, which caused bone deformation in certain areas in Punjab due to excess fluoride, were also analyzed for fluoride and results are presented. (author)

  8. Method for identifying particulate fluoride compounds

    Energy Technology Data Exchange (ETDEWEB)

    Tufts, B J

    1960-01-01

    A method is described for identifying particulates containing fluorides and other complex fluorine compounds such as fluorosilicate in samples collected on membrane filters. The filter is treated with lead chloride to precipitate lead chlorofluoride at each fluoride-containing spot. This microspot is identified by examination in a light microscope. Sulfate and phosphate, which also precipitate if present, can be distinguished and do not interfere. Calibrations are given for the fluorides and the more insoluble salts, relating the original particle size to the reaction site size. Thus, the mass of the particles can be calculated. Results of some field tests in an area of fluoride pollution are given, and compared with standard testing procedures.

  9. Fluoridated Water

    Science.gov (United States)

    ... Genetics Services Directory Cancer Prevention Overview Research Fluoridated Water On This Page What is fluoride, and where is it found? What is water fluoridation? When did water fluoridation begin in the ...

  10. The Effect of Calcium Pre-Rinse on Salivary Fluoride After 900 ppm Fluoride Mouthwash: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Nahid Ramazani

    2013-01-01

    Full Text Available Objective: Calcium fluoride deposit during fluoride application. Uptake and retention of fluoride by saliva depends generally on the concentration of calcium. In this study, the ef-fect of calcium pre-rinse on salivary fluoride concentration after a 900 ppm fluoride mouthwash was investigated.Materials and Methods: This cross-over double-blind randomized clinical trial was con-ducted in a girls' dormitory in Zahedan University of Medical Sciences, southeast Iran. In this study, 42 female dental students were chosen using simple randomization. During the first phase, 21 subjects (group A used fluoride rinse (F regimen and the remaining (group B used calcium pre-rinse followed immediately by fluoride rinse (Ca + F regi-men. In the second phase, participants rinsed using the mouthwashes not previously used. Prior to each phase prophylaxis was performed and no fluoridated product was used dur-ing a two-week interval between the phases. Salivary samples were taken immediately be-fore (baseline, 1 and 12 hours after rinsing. The salivary fluoride concentration was de-termined using fluoride sensitive electrode. Repeated measures ANOVA was used for sta-tistical analysis and the significance level was set at P<0.05.Results: There was significant difference between fluoride concentrations at different time points (P< 0.001. Significant differences were observed when the different time points of two regimens were examined. In contrast to this, the baseline before using F regimen and the baseline before using Ca + F regimen did not show any significance (P= 0.070.Conclusion: Pre-rinsing with calcium before fluoride is recommended because of signifi-cant increases in salivary fluoride concentration.

  11. Haematological evaluation of sodium fluoride toxicity in oryctolagus cunniculus

    Directory of Open Access Journals (Sweden)

    Maryam Abbas

    Full Text Available Blood is promptly affected by environmental pollutants and toxicants that can cause many metabolic disorders. The high level of fluoride acts as a potential pollutant, insecticide and rodenticide with very high toxicity, associated with the hematological damage. This study aimed to determine the toxicity of Sodium Fluoride on hematological parameters in Oryctolagus cunniculus. Twenty rabbits were acclimatized and divided in to control group and three experimental groups.Experimental group-I, II and III were treated with 10, 30 and 50 mg/kg body weight doses of Sodium Fluoride orally. Various blood parameters such as TEC, Hb, HCT, MCV, MCH, MCHC, TLC and PLT count were investigated. Result findings showed that values of blood indices in experimental groups were significantly lower than the control group. Oneway ANOVA was applied for statistical analysis. The outcomes of the current studies indicated the reduction in RBC counts (anemia, leukocyte count (leukocytopenia, monocytosis, eosinopenia, neutrophilia and thrombocytosis on fluoride intoxication. Hematological disruptions like microcytic hypochromic anemia and decreased leukocyte count may be linked to the inflammatory effects of Sodium Fluoride on lymphatic organs. Keywords: Fluoride intoxication, Hypochromic anemia, Hematological, Parameters, Leukocyte alterations, Fluorosis

  12. Correlation among fluoride and metals in irrigation water and soils of ...

    African Journals Online (AJOL)

    Correlation among fluoride and metals in irrigation water and soils of Ethiopian Rift Valley. ... The fluoride concentrations in water samples were found in the range of 0.14-8.0 mg/L which is below the WHO limit of fluoride concentration for irrigation (less than 10 mg/L). ... KEY WORDS: Fluoride, Metals, Water, Soil, Ethiopia.

  13. Effect of fluoride pretreatment on the solubility of synthetic carbonated apatite.

    Science.gov (United States)

    Barry, A B; Zhuang, H; Baig, A A; Higuchi, W I

    2003-03-01

    The purpose of this research was to address the following question: How is the solubility of fluoride-pretreated carbonated apatite (CAP) in aqueous acidic media related to the equilibrium solution fluoride and/or the CAP adsorbed fluoride levels? A CAP sample prepared by a precipitation method at 70 degrees C containing approximately 6% carbonate was fluoride-treated (F adsorption from neutral aqueous solutions) to yield a approximately 1000 ppm F CAP and a approximately 3300 ppm F CAP. Metastable equilibrium solubility distributions were determined in acetate buffers at pH 5.0. Solution fluoride, calcium, phosphate, and pH were determined from the equilibrated solutions. The equilibrium solution fluoride levels were extremely low, e.g., as low as approximately 0.10 ppb to approximately 0.30 ppb at 50% dissolved for the two CAP preparations. The approximately 3300 ppm F CAP yielded a lower solubility than the approximately 1000 ppm F CAP (shift in the mean pKHAP value of 1.5-2 units). This can be attributed to the lower solution F(-) for the sample containing approximately 1000 ppm fluoride compared with the approximately 3300 ppm fluoride-containing CAP. These important findings suggest that a fluoride treatment simply may provide an adsorption fluoride depot for subsequent release, providing a solution fluoride effect upon the CAP solubility and not necessarily any intrinsic alteration of the mineral solubility.

  14. [The effect of fluoride-containing tooth paste on dental plaque and on fluoride level in the mouth].

    Science.gov (United States)

    Oomori, H

    1989-01-01

    Various kinds of fluoride have been used for a long time and there are many reports concerning fluorides and their effects. Recently, the caries-inhibiting action of fluoride-containing tooth paste has been given much attention. In this study, I tried to clarify the residual time and amount of fluoride derived from the fluoride-containing tooth paste in the mouth, as well as to assess possible variation in bacterial composition in the dental plaque bacteriologically and biochemically. In the study on the fluoride clearance from the mouth, both 1.0 g and 0.5 g of paste showed the same reduction rates; and about an 80% reduction was recognized between the value at 3 minutes and that at 30 minutes, and about a 40% reduction from the 30-minute to the 60-minute interval. Next, a study on the variation in plaque bacteria was carried out. The total number of the CFU on each plate was not different between samples obtained before and after the use of the tooth paste; moreover, no difference was noted between aerobic and anaerobic culture. However, when plaque before and after brushing with fluoride-containing tooth paste were cultured in 10% sucrose solution, the differences of acid production such as lactic acid, acetic acid, and formic acid were demonstrated. Namely, these acid productions were inhibited after the use of fluoride, especially lactic acid was strongly inhibited. On the other hand, when Str. mutans from the plaque obtained after the use of fluoride-containing tooth paste was cultured in fluoride-free BHI broth, the inhibition of acid from carbohydrates was not shown clearly.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Comparative evaluation of fluoride release and recharge of pre-reacted glass ionomer composite and nano-ionomeric glass ionomer with daily fluoride exposure: An in vitro study

    Directory of Open Access Journals (Sweden)

    Jayanthi Mungara

    2013-01-01

    Full Text Available Aim: This in vitro study was designed to investigate the effects of daily fluoride exposures on fluoride release and recharge by prereacted glass ionomer (PRG composite and nano-ionomeric glass ionomer. Materials and Methods: Seventy-two specimens (36 of each material were prepared and by placing the restorative materials into Teflon mold. Each specimen was subjected to one of three daily treatments (n = 12: (1 No fluoride treatment (control; (2 application of a fluoride dentifrice (1,000 ppm once daily; and (3 the same regimen as (2, plus immersion in a 0.05% sodium fluoride (NaF mouth rinse (225 ppm immediately following the dentifrice application. Specimens were suspended in a storage vial containing 10 ml demineralizing solution for 6 h and transferred to a new test tube containing 10 ml remineralizing solution for 18 h. Fluoride treatments of the specimens were completed every day prior to their immersion in the demineralizing solution. Media solutions were buffered with equal volumes of total ionic strength adjustment buffer (TISAB II; fluoride levels were measured using a digital ion analyzer and fluoride electrode throughout the 21 day duration of the experiment. Results: Nano-ionomeric glass ionomer showed a better amount of fluoride release than PRG composite irrespective of the fluoride treatment supplementation (P < 0.01. Additional fluoride supplementation improved fluoride release and recharge ability for both the materials when compared to their respective control groups. The fluoride recharge for both materials did not show any sustained pattern of release. Conclusion: Nano-ionomeric glass ionomer demonstrated a greater ability to release and recharge compared with that of PRG composite.

  16. [The effect of alternating administration of aluminum chloride and sodium fluoride in drinking water on the concentration of fluoride in serum and its content in bones of rats].

    Science.gov (United States)

    Lubkowska, Anna; Chlubek, Dariusz; Machoy-Mokrzyniska, Anna

    2006-01-01

    Fluorine and aluminum remain a very interesting research topic due to equivocal and relatively unknown toxic action, role in the etiology of various diseases, and interactions of both elements. Fluorine and aluminum compounds are absorbed by organisms through the gastric and respiratory systems, although the latter route operates only at very high concentrations in air. Chronic exposure to fluorine and aluminum leads to accumulation of both elements, especially in bones and teeth, but also in lung, brain, kidney, and liver. Organisms excrete these elements with urine, faeces, and to a minor extent with sweat and bile. In the light of reports suggesting that aluminum has protective properties against fluorine toxicity during exposure to both elements, we decided to examine the effect of alternating doses of aluminum fluoride and sodium fluoride in drinking water on rats. Four female groups received: I--100 ppm fluorine ions during one month; II--100 ppm fluorine ions alternating every two days with 300 ppm aluminum ions during one month; III--100 ppm fluoride ions during four months; IV--100 ppm fluorine ions alternating every two days with 300 ppm aluminum ions during four months. The respective male groups called IA, IIA, IIIA, and IVA were treated identically. Subsequently, the animals were anesthetized and sacrificed. Blood was sampled from the heart and the right femur was removed for fluorine determination. Fluorine content in the femur and serum was determined with an ion-selective electrode (Orion). The results were analyzed statistically (Statistica 6). We observed higher fluoride concentrations in serum as compared with control values in all groups of female and male rats exposed to sodium fluoride only. Longer exposure time (4 months) did not result in further increase in serum fluoride concentration. However, longer exposure increased fluoride accumulation in the femur (p Fluorine content in the femur of rats exposed to NaF and AlCI3 for four months was

  17. Protective effect of fluoride varnish and fluoride gel on enamel erosion: roughness, SEM-EDS, and µ-EDXRF studies.

    Science.gov (United States)

    Soares, Luís Eduardo Silva; De Carvalho Filho, Antonio Carlos Belfort

    2015-03-01

    The effects of fluoride treatment on bovine enamel subjected to acid erosion were studied by roughness (Ra) measurements, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and microenergy-dispersive X-ray fluorescence spectrometry (μ-EDXRF). Enamel samples (63) were divided into nine groups (n = 7): artificial saliva (AS), Pepsi Twist(®) (PT), orange juice (OJ), Duraphat(®)  + Pepsi Twist(®) (DPH/PT), Duraphat(®)  + orange juice (DPH/OJ), Duofluorid(®)  + Pepsi Twist(®) (DUO/PT), Duofluorid(®)  + orange juice (DUO/OJ), fluoride gel + Pepsi Twist(®) (FG/PT), and fluoride gel + orange juice (FG/OJ). Fluoride was applied and the samples were submitted to six cycles (demineralization: Pepsi Twist(®) or orange juice, 10 min; remineralization: saliva, 1 h). The enamel surface in depth was exposed and 63 line-scan maps were performed. The elemental analysis by EDS revealed that only fluoride treated groups had any detectable fluorine after erosion cycles (DPH/PT: 3.50 wt%; DPH/OJ: 3.37 wt%; DUO/PT: 2.69 wt%; DUO/OJ: 3.54 wt%; FG/PT: 2.17 wt%; FG/OJ: 2.77 wt%). PT treatment resulted in significantly higher Ra values than the artificial saliva (P < 0.001). Scanning electron microscopy (SEM) analysis of fluoride protected enamel showed areas with some globular structures or a residual layer of varnish. The enamel thickness was significantly lower in PT (0.63 ± 0.087 mm) than in DPH/PT (0.87 ± 0.16 mm) and DUO/PT (0.92 ± 0.14 mm) groups (P < 0.01). Fluoride treatments protected enamel without Ra increase and loss of enamel tissue. © 2015 Wiley Periodicals, Inc.

  18. Simultaneous removal of Ni(II and fluoride from a real flue gas desulfurization wastewater by electrocoagulation using Fe/C/Al electrode

    Directory of Open Access Journals (Sweden)

    Shinian Liu

    2017-09-01

    Full Text Available Large amounts of anions and heavy metals coexist in flue gas desulfurization (FGD wastewater originating from coal-fired power plants, which cause serious environmental pollution. Electrocoagulation (EC with Fe/C/Al hybrid electrodes was investigated for the separation of fluoride and nickel ions from a FGD wastewater. The study mainly focused on the technology parameters including anode electrode type, time, inter-electrode distance (5–40 mm, current density (1.88–6.25 mA/cm2 and initial pH (4–10. The results showed that favorable nickel and fluoride removal were obtained by increasing the time and current density, but this led to an increase in energy consumption. Eighty-six percent of fluoride and 98% of Ni(II were removed by conducting the Fe/C/Al EC with a current density of 5.00 mA/cm2 and inter-electrode distance of 5 mm at pH 4 for 25 min and energy consumption was 1.33 kWh/m3. Concomitant pollutants also achieved excellent treatment efficiency. The Hg, Mn, Pb, Cd, Cu, SS and chemical oxygen demand were reduced by 90%, 89%, 92%, 88%, 98%, 99.9% and 89%, respectively, which met stringent environmental regulations.

  19. Bone fluoride determination for clinical investigation of osteoporosis

    International Nuclear Information System (INIS)

    Krishnan, S.S.; McNeill, K.G.; Hitchman, A.J.W.; Mernagh, J.R.; Lin, S.C.; Harrison, J.E.

    1984-01-01

    Sodium fluoride is the therapeutic agent known to stimulate bone growth with net increase in bone mineral mass in patients afflicted with osteoporosis, a common crippling bone disease. In order to study the effect of sodium fluoride treatment, a method of analysis for fluoride in bone has been developed using Neutron Activation Analysis (NAA). The technique proved to be simple, fast, reliable and non-destructive. Thus the sample, often bone biopsy specimen, is available, after fluoride analysis, for further histological studies. NAA was used to analyze both fluoride and calcium in the bone and the results expressed as F/Ca ratio was meaningful since it normalizes the fluoride to bone mineral mass which is the important factor in this study. Four years of fluoride treatment of osteoporotics showed significant increase of bone mass (up to 30%) in several patients. These increases were associated with histological bone picture of fluorosis. In the case of patients with renal osteodystrophy, there was evidence that fluorosis contributes to the bone disease. 3 references, 2 figures, 2 tables

  20. Determination of zirconium by fluoride ion selective electrode

    International Nuclear Information System (INIS)

    Mahanty, B.N.; Sonar, V.R.; Gaikwad, R.; Raul, S.; Das, D.K.; Prakash, A.; Afzal, Md.; Panakkal, J.P.

    2010-01-01

    Full text: Zirconium is used in a wide range of applications including nuclear clad, catalytic converters, surgical appliances, metallurgical furnaces, superconductors, ceramics, lamp filaments, anti corrosive alloys and photographical purposes. Irradiation testing of U-Zr and U-Pu-Zr fuel pins has also demonstrated their feasibility as fuel in liquid metal reactors. Different methods that are employed for the determination of zirconium are spectrophotometry, potentiometry, neutron activation analysis and mass spectrometry. Ion-selective electrode (ISE), selective to zirconium ion has been studied for the direct potentiometric measurements of zirconium ions in various samples. In the present work, an indirect method has been employed for the determination of zirconium in zirconium nitrate sample using fluoride ion selective electrode. This method is based on the addition of known excess amount of fluoride ion to react with the zirconium ion to produce zirconium tetra fluoride at about pH 2-3, followed by determination of residual fluoride ion selective electrode. The residual fluoride ion concentrations were determined from the electrode potential data using calibration plot. Subsequently, zirconium ion concentrations were determined from the concentration of consumed fluoride ions. A precision of about 2% (RSD) with the mean recovery of more than 94% has been achieved for the determination of zirconium at the concentration of 4.40 X 10 -3 moles lit -1

  1. Cytotoxic effects of glass ionomer cements on human dental pulp stem cells correlate with fluoride release.

    Science.gov (United States)

    Kanjevac, Tatjana; Milovanovic, Marija; Volarevic, Vladislav; Lukic, Miodrag L; Arsenijevic, Nebojsa; Markovic, Dejan; Zdravkovic, Nebojsa; Tesic, Zivoslav; Lukic, Aleksandra

    2012-01-01

    Glass ionomer cements (GICs) are commonly used as restorative materials. Responses to GICs differ among cell types and it is therefore of importance to thoroughly investigate the influence of these restorative materials on pulp stem cells that are potential source for dental tissue regeneration. Eight biomaterials were tested: Fuji I, Fuji II, Fuji VIII, Fuji IX, Fuji Plus, Fuji Triage, Vitrebond and Composit. We compared their cytotoxic activity on human dental pulp stem cells (DPSC) and correlated this activity with the content of Fluoride, Aluminium and Strontium ions in their eluates. Elution samples of biomaterials were prepared in sterile tissue culture medium and the medium was tested for toxicity by an assay of cell survival/proliferation (MTT test) and apoptosis (Annexin V FITC Detection Kit). Concentrations of Fluoride, Aluminium and Strontium ions were tested by appropriate methods in the same eluates. Cell survival ranged between 79.62% (Fuji Triage) to 1.5% (Fuji Plus) and most dead DPSCs were in the stage of late apoptosis. Fluoride release correlated with cytotoxicity of GICs, while Aluminium and Strontium ions, present in significant amount in eluates of tested GICs did not. Fuji Plus, Vitrebond and Fuji VIII, which released fluoride in higher quantities than other GICs, were highly toxic to human DPSCs. Opposite, low levels of released fluoride correlated to low cytotoxic effect of Composit, Fuji I and Fuji Triage.

  2. Assessment of fluoride contaminations in groundwater of hard rock aquifers in Madurai district, Tamil Nadu (India)

    Science.gov (United States)

    Thivya, C.; Chidambaram, S.; Rao, M. S.; Thilagavathi, R.; Prasanna, M. V.; Manikandan, S.

    2017-05-01

    The fluoride contamination in drinking water is already gone to the alarming level and it needs the immediate involvement and attention of all people to solve this problem. Fluoride problem is higher in hard rock terrains in worldwide and Madurai is such type of hard rock region. Totally 54 samples were collected from the Madurai district of Tamilnadu with respect to lithology. The samples collected were analysed for major cations and anions using standard procedures. The higher concentration of fluoride is noted in the Charnockite rock types of northern part of the study area. 20 % of samples are below 0.5 ppm and 6 % of samples are above 1.5 ppm exceeding the permissible limit. The affinity between the pH and fluoride ions in groundwater suggests that dissolution of fluoride bearing minerals in groundwater. The higher concentration of fluoride ions are observed in the lower EC concentration. The isotopic study suggests that fluoride is geogenic in nature. In factor scores, fluoride is noted in association with pH which indicates the dissolution process.

  3. The effects of water filtration systems on fluoride: Washington, D.C. metropolitan area.

    Science.gov (United States)

    Jobson, M D; Grimm, S E; Banks, K; Henley, G

    2000-01-01

    According to the U.S. Environmental Protection Agency (EPA), approximately one in eight Americans is exposed to potentially harmful microbes, pesticides, lead, or radioactive radon whenever they drink a glass of tap water or take a shower. One reason for this exposure is that the water plants are aging or ill equipped to process the huge amounts of raw sewage and agricultural pollutants that are still being discharged into our drinking-water sources. Other compounds such as fluoride and chloride have been added to the community water supplies for health benefits. Water filtration systems are becoming more popular as people become concerned with pollutants in the public water supply and questions are being raised as to whether fluoride is affected by these filters. The aim of this pilot study was to assess the efficacy of three types of water filtration systems and to determine their impact on fluoride content of the water in the Washington, D.C. metropolitan area. One sample of water was collected daily for fourteen days, from one location. The sample was divided to use as a control and the test samples which were processed through various filter systems. With the use of a fluoride ion specific electrode, the fluoride concentration level was tested in all samples in order to determine the percentage of fluoride removed. This study was intended to prove that the water filtration systems did not affect the advantage offered by optimum water fluoride levels. The experimental samples were ascertained and compared to the control group, resulting in three of the four carbon filters showing statistically significant amounts of fluoride removed from the water. Both Reverse Osmosis and Distillation, as expected, removed the fluoride at a high rate.

  4. Sustainable approach for recycling waste lamb and chicken bones for fluoride removal from water followed by reusing fluoride-bearing waste in concrete.

    Science.gov (United States)

    Ismail, Zainab Z; AbdelKareem, Hala N

    2015-11-01

    Sustainable management of waste materials is an attractive approach for modern societies. In this study, recycling of raw waste lamb and chicken bones for defluoridation of water has been estimated. The effects of several experimental parameters including contact time, pH, bone dose, fluoride initial concentration, bone grains size, agitation rate, and the effect of co-existing anions in actual samples of wastewater were studied for fluoride removal from aqueous solutions. Results indicated excellent fluoride removal efficiency up to 99.4% and 99.8% using lamb and chicken bones, respectively at fluoride initial concentration of 10 mg F/L and 120 min contact time. Maximum fluoride uptake was obtained at neutral pH range 6-7. Fluoride removal kinetic was well described by the pseudo-second order kinetic model. Both, Langmuir and Freundlich isotherm models could fit the experimental data well with correlation coefficient values >0.99 suggesting favorable conditions of the process. Furthermore, for complete sustainable management of waste bones, the resulted fluoride-bearing sludge was reused in concrete mixes to partially replace sand. Tests of the mechanical properties of fluoride sludge-modified concrete mixes indicated a potential environmentally friendly approach to dispose fluoride sludge in concrete and simultaneously enhance concrete properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Sample Exchange Evaluation (SEE) Report - Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Winters, W.I.

    1994-09-28

    This report describes the results from Phase II of the Sample Exchange Evaluation (SEE) Program, a joint effort to compare analytical laboratory performance on samples from the Hanford Site`s high-level waste tanks. In Phase II, the program has been expanded to include inorganic constituents in addition to radionuclides. Results from Phase II that exceeded 20% relative percent difference criteria are identified.

  6. Sample Exchange Evaluation (SEE) Report - Phase II

    International Nuclear Information System (INIS)

    Winters, W.I.

    1994-01-01

    This report describes the results from Phase II of the Sample Exchange Evaluation (SEE) Program, a joint effort to compare analytical laboratory performance on samples from the Hanford Site's high-level waste tanks. In Phase II, the program has been expanded to include inorganic constituents in addition to radionuclides. Results from Phase II that exceeded 20% relative percent difference criteria are identified

  7. Study on the removal of fluoride from drinking water and effluents

    International Nuclear Information System (INIS)

    Charbel, M.Y.

    1990-01-01

    A study for removal of excess fluoride from drinking water and aqueous effluents from nuclear power plants is presented. Inorganic and organic ion exchangers were used for this purpose: 1. Alumina microspheres form, granular alumina and zirconium oxide (powder or granular form with the aid of agglutinants) were experimented. 2. Strong cation exchange resins as Al-III, Fe-III, Zr-IV, RE-III, Ca-II and Mg-II salt form were examined. 3. Retention on hydrous oxide of Al-III, Fe-III, Zr-IV and RE-III supported on strong cation ion exchanger was performed. 4. Strong anion exchange resins in the form of OH sup(-), Cl sup(-), NO3 sup(-), CO3 sup(2-), SO4 sup(2-), ClO4 sup(-) and Zr(SO4)3 sup(2-) were examined. For the experiments pure fluoride solutions or dilute solutions containing the cations of Fe-III, Ca-II, Mn-II, Cu-II, Al-III, Cd-II and U-VI were used. Cation exchange resin loaded with zirconium, anion exchange resin as hydroxyl and zirconium sulfate complex form exhibited very good results, but the last performed best and we suggest it for industrial application. (author)

  8. Fluoride

    Science.gov (United States)

    Opalescence® ... Fluoride is used to prevent tooth decay. It is taken up by teeth and helps to strengthen ... and block the cavity-forming action of bacteria. Fluoride usually is prescribed for children and adults whose ...

  9. Fluoride, boron and nitrate toxicity in ground water of northwest Rajasthan, India.

    Science.gov (United States)

    Chaudhary, Veena; Kumar, Mukesh; Sharma, Mukesh; Yadav, B S

    2010-02-01

    The study was carried out to access the fluoride, boron, and nitrate concentrations in ground water samples of different villages in Indira Gandhi, Bhakra, and Gang canal catchment area of northwest Rajasthan, India. Rural population, in the study site, is using groundwater for drinking and irrigation purposes, without any quality test of water. All water samples (including canal water) were contaminated with fluoride. Fluoride, boron, and nitrate were observed in the ranges of 0.50-8.50, 0.0-7.73, and 0.0-278.68 mg/l, respectively. Most of the water samples were in the categories of fluoride 1.50 mg/l, of boron 2.0-4.0 mg/l, and of nitrate availability of these compounds in groundwater was due to natural reasons and by the use of chemical fertilizers.

  10. Fluoride in the drinking water of Pakistan and the possible risk of crippling fluorosis

    Directory of Open Access Journals (Sweden)

    M. A. Tahir

    2013-02-01

    Full Text Available To explore the possibility of fluoride toxicity, 747 water samples were collected from surface water and groundwater sources of 16 major cities of Pakistan, adopting a uniform sampling design with distribution of samples: Lahore (79, Kasur (46, Faisalabad (30, Khushab (50, Chakwal (51, Mianwali (30, Jhelum (53, Bahawalpur (60, Karachi (60, Mirpur Khas (55, Peshawar (38, Risalpur (35, Quetta (81, Ziarat (21, Loralai (21, and Mastung (37. Comparison of analytical findings with WHO Guidelines of Drinking Water for Fluoride (i.e., 1.5 ppm has concluded that 16% of the monitored water sources have fluoride concentration beyond the permissible safe limit of 1.5 mg L−1 falling in the concentration range of 1.6–25 mg L−1. The highest fluoride contamination (22% is detected in the Balochistan province followed by 19% in Punjab province. Comparatively higher fluoride levels of > 20% in the groundwater sources like hand pumps supported the possibility of increased groundwater contamination as excessive fluoride concentrations are expected to come from calcium-poor aquifers and in areas where fluoride-bearing minerals are common or where cation exchange of sodium for calcium occurs. Field observations have also indicated the prevalence of fluoride-associated health implications in the study areas with excessive fluoride in water sources. Findings of this study have provided bidirectional vision for the epidemiological investigations as well as to mitigate the issues in the affected vicinities of fluoride-rich areas.

  11. The effect of water purification systems on fluoride content of drinking water

    Directory of Open Access Journals (Sweden)

    Prabhakar A

    2008-03-01

    Full Text Available Objective: The purpose of the present study was to determine the effect of different water purification systems on the fluoride content of drinking water and to compare the efficacy of these water purification systems in reducing the fluoride content. Materials and Methods: Five different water purification systems were tested in this study. They were reverse osmosis, distillation, activated carbon, Reviva ® , and candle filter. The water samples in the study were of two types, viz, borewell water and tap water, these being commonly used by the people of Davangere City, Karnataka. The samples were collected before and after purification, and fluoride analysis was done using fluoride ion-specific electrode. Results: The results showed that the systems based on reverse osmosis, viz, reverse osmosis system and Reviva ® showed maximum reduction in fluoride levels, the former proving to be more effective than the latter; followed by distillation and the activated carbon system, with the least reduction being brought about by candle filter. The amount of fluoride removed by the purification system varied between the system and from one source of water to the other. Interpretation and Conclusion: Considering the beneficial effects of fluoride on caries prevention; when drinking water is subjected to water purification systems that reduce fluoride significantly below the optimal level, fluoride supplementation may be necessary. The efficacy of systems based on reverse osmosis in reducing the fluoride content of water indicates their potential for use as defluoridation devices.

  12. Other Fluoride Products

    Science.gov (United States)

    ... Private Wells Infant Formula Fluorosis Public Health Service Recommendation Water Operators & Engineers Water Fluoridation Additives Shortages of Fluoridation Additives Drinking Water Pipe Systems CDC-Sponsored Water Fluoridation Training Links to Other ...

  13. Industrial fluoride pollution: chronic fluoride poisoning in Cornwall Island cattle

    Energy Technology Data Exchange (ETDEWEB)

    Krook, L.; Maylin, G.A.

    1979-04-01

    An aluminum plant on the south bank of the St. Lawrence River, southwest of Cornwall Island, Ontario, Canada, has emitted 0.816 metric tons of fluoride daily since 1973. Considerably higher amounts were emitted from 1959 to 1973. The plant was designated as the major source of fluoride emissions impacting on Cornwall Island. Cattle located on this island showed signs of chronic fluoride poisoning. This poisoning was manifested clinically by stunted growth and dental fluorosis to a degree of severe interference with drinking and mastication. This Cornwall Island herds study indicates that the established tolerance level of fluoride for performance of dairy and beef cattle is not valid since the tolerance level was set based on experiments with healthy calves which were exposed to dietary fluoride from 3 to 4 months of age and not on cattle which were chronically exposed to fluoride from conception to death. 56 references.

  14. Risk perception, psychological heuristics and the water fluoridation controversy.

    Science.gov (United States)

    Perrella, Andrea M L; Kiss, Simon J

    2015-04-29

    Increasingly, support for water fluoridation has come under attack. We seek an explanation, focusing on the case of Waterloo, Ontario, where a 2010 referendum overturned its water fluoridation program. In particular, we test whether individuals perceive the risks of water fluoridation based not on 'hard' scientific evidence but on heuristics and cultural norms. A sample of 376 residents in Waterloo were surveyed in June 2012 using random digit dialing. We use factor analysis, OLS regression, as well as t-tests to evaluate a survey experiment to test the credibility hypothesis. Perceptions of fluoride as a risk are lower among those who perceive fluoride's benefits (B = .473, p < 0.001) and those whose cultural view is 'egalitarian' (B = .156, p < 0.05). The experiment shows a lower level of perception of fluoride's benefits among respondents who are told that water fluoridation is opposed by a national advocacy group (Group A) compared to those who are told that the government and the World Health Organization support fluoridation (Group B) (t = 1.6547, p < 0.05), as well as compared to the control group (t = 1.8913, p < 0.05). There is no difference between Group B and the control, possibly because people's already general support for fluoridation is less prone to change when told that other public organizations also support fluoridation. Public health officials should take into account cultural norms and perceptions when individuals in a community appear to rise up against water fluoridation, with implications for other public health controversies.

  15. The sampling of hydrogen fluoride in air with impregnated filter paper

    NARCIS (Netherlands)

    Huygen, C.

    1963-01-01

    A method isproposed for the quantitative collection of hydrogen fluoride in air by drawing a known quantity of the air through filter paper impregnated with solutions of potassium hydroxide and glycerol or triethanolamine. Somu possibilities and limitations of the method are discussed.

  16. Urinary fluoride excretion in preschool children after intake of fluoridated milk and use of fluoride-containing toothpaste

    DEFF Research Database (Denmark)

    Norman, M; Twetman, S; Hultgren Talvilahti, A

    2017-01-01

    Objective: To assess the urinary fluoride excretion in preschool children after drinking fluoridated milk with 0.185 mg F and 0.375 mg F and to study the impact of use of fluoride toothpaste. Basic research design: Double-blind cross-over study. Participants: Nine healthy children, 2.5-4.5 years...

  17. Fluor determination by alkaline hydrolysis of the uranium and thorium fluorides

    International Nuclear Information System (INIS)

    Barrachina Gomez, L.; Gasco Sanchez, L.

    1961-01-01

    The alkaline hydrolysis of the uranium and thorium fluorides is studded and a new method for the determination of the fluoride, on the basis of a indirect volumetric titration with standard soda, is proposed. The compounds that may influence the hydrolysis of the uranium fluoride and that may be occasionally found in it as impurities are also studied. the method can be applied to the uranium fluoride except when there is a great quantity of F 2 UO 2 or UO 3 present in the sample. (Author) 20 refs

  18. Oral fluoride retention after professional topical application in children with caries activity: comparison between 1.23% fluoride foam and fluoride gel

    Directory of Open Access Journals (Sweden)

    Cecília Claudia Costa Ribeiro

    2008-01-01

    Full Text Available Objective: This study evaluated fluoride retention in the saliva of children with caries activity after topical fluoride application in the form of gel and foam. Methods: A cross-sectional, blind and randomized study, conducted with ten caries-active children aged between 8 and 10 years, in two stage, with a washout interval of two weeks between them. The treatments consisted of: a application of 2mL acidulated phosphate fluoride of the gel type in a mold and b application of 2mL acidulated phosphate fluoride of the foam type in a mold. After the washout, the treatments were inverted. Non-stimulated saliva was collected from the children at the times of 5, 15, 30 and 60 minutes after topical fluoride application. For statistical analysis the Student’s-t test was used, with a level of significance of 5%. Results: Saliva analysis was performed using a fluoride-specific electrode (ISE25F/ Radiometer, Copenhagen, Denmark at the Aquatic Science Center of the Federal University of Marana, which revealed differences after 5 minutes (p=0.0055 and 15 minutes (p=0.0208. The topical application of fluoride in the gel form revealed a higher concentration of fluoride in the saliva. Conclusion: There were differences in the retention of fluoride in the saliva of children with caries activity after the topical application of fluoride gel and the topical application of fluoride foam after 5 and 15 minutes of their application. The topical application of fluoride foam is recommended, on the basis of the lower probability of toxicity during its use.

  19. Eukaryotic resistance to fluoride toxicity mediated by a widespread family of fluoride export proteins.

    Science.gov (United States)

    Li, Sanshu; Smith, Kathryn D; Davis, Jared H; Gordon, Patricia B; Breaker, Ronald R; Strobel, Scott A

    2013-11-19

    Fluorine is an abundant element and is toxic to organisms from bacteria to humans, but the mechanisms by which eukaryotes resist fluoride toxicity are unknown. The Escherichia coli gene crcB was recently shown to be regulated by a fluoride-responsive riboswitch, implicating it in fluoride response. There are >8,000 crcB homologs across all domains of life, indicating that it has an important role in biology. Here we demonstrate that eukaryotic homologs [renamed FEX (fluoride exporter)] function in fluoride export. FEX KOs in three eukaryotic model organisms, Neurospora crassa, Saccharomyces cerevisiae, and Candida albicans, are highly sensitized to fluoride (>200-fold) but not to other halides. Some of these KO strains are unable to grow in fluoride concentrations found in tap water. Using the radioactive isotope of fluoride, (18)F, we developed an assay to measure the intracellular fluoride concentration and show that the FEX deletion strains accumulate fluoride in excess of the external concentration, providing direct evidence of FEX function in fluoride efflux. In addition, they are more sensitive to lower pH in the presence of fluoride. These results demonstrate that eukaryotic FEX genes encode a previously unrecognized class of fluoride exporter necessary for survival in standard environmental conditions.

  20. The effect of different fluoride application methods on the remineralization of initial carious lesions.

    Science.gov (United States)

    Byeon, Seon Mi; Lee, Min Ho; Bae, Tae Sung

    2016-05-01

    The purpose of this study was to assess the effect of single and combined applications of fluoride on the amount of fluoride release, and the remineralization and physical properties of enamel. Each of four fluoride varnish and gel products (Fluor Protector, FP, Ivoclar Vivadent; Tooth Mousse Plus, TM, GC; 60 Second Gel, A, Germiphene; CavityShield, CS, 3M ESPE) and two fluoride solutions (2% sodium fluoride, N; 8% tin(ii) fluoride, S) were applied on bovine teeth using single and combined methods (10 per group), and then the amount of fluoride release was measured for 4 wk. The electron probe microanalysis and the Vickers microhardness measurements were conducted to assess the effect of fluoride application on the surface properties of bovine teeth. The amount of fluoride release was higher in combined applications than in single application (p < 0.05). Microhardness values were higher after combined applications of N with FP, TM, and CS than single application of them, and these values were also higher after combined applications of S than single application of A (p < 0.05). Ca and P values were higher in combined applications of N with TM and CS than single application of them (p < 0.05). They were also increased after combined applications of the S with A than after single application (p < 0.05). Combined applications of fluoride could be used as a basis to design more effective methods of fluoride application to provide enhanced remineralization.

  1. Spectrophotometric determination of fluorides in water with Hach equipment

    International Nuclear Information System (INIS)

    Acosta L, E.

    1994-11-01

    The spectrophotometric method for the determination of the fluoride ion in water, demineralized water, raw waters, laundry waters and waters treated with ion exchange resins , using the technique and the SPADNS coloring indicated in the operation manual of the Hach equipment is described. This method covers the determination of the fluoride ion in the range from 0 to 2 mg/l on 25 ml. of radioactive base sample. These limits can be variable if the size of the used aliquot one is changed for the final determination of the fluoride ion. (Author)

  2. Laboratory investigations into the potential anticaries efficacy of fluoride varnishes.

    Science.gov (United States)

    Lippert, Frank; Hara, Anderson Takeo; Martinez-Mier, Esperanza Angeles; Zero, Domenick T

    2014-01-01

    The purpose of this study was to investigate the potential anticaries efficacy of fluoride varnishes (FVs) by studying their ability to reharden and deliver fluoride to carious lesions and to release fluoride into saliva. Enamel carious lesions were created and allocated to 24 groups (11 FVs with two FV incubation times and two control groups) based on Knoop microhardness test values. FVs were applied to lesions, which were incubated in artificial saliva for two or six hours, with saliva being renewed hourly. FV was removed and lesions were remineralized in artificial saliva for 22 hours. Microhardness was measured and enamel fluoride uptake (EFU) was determined. Saliva samples (six-hour groups) were analyzed to determine fluoride release characteristics. Data were analyzed using analysis of variance. FVs differed considerably in their ability to reharden and deliver fluoride to carious lesions and in their fluoride release characteristics. Little consistency was found between investigated study variables for virtually all tested FVs. For example, a particular FV showed the highest EFU and fluoride release values but the lowest rehardening value. A longer FV contact time led to increased EFU for five of the 11 FVs. Some FVs delivered more fluoride to lesions in two hours than others did in six hours. Fluoride varnishes differ greatly in their in vitro anticaries efficacy.

  3. Fluoride Rinses, Gels and Foams

    DEFF Research Database (Denmark)

    Twetman, Svante; Keller, Mette K

    2016-01-01

    AIM: The aim of this conference paper was to systematically review the quality of evidence and summarize the findings of clinical trials published after 2002 using fluoride mouth rinses, fluoride gels or foams for the prevention of dental caries. METHODS: Relevant papers were selected after...... (6 on fluoride mouth rinse, 10 on fluoride gel and 3 on fluoride foam); 6 had a low risk of bias while 2 had a moderate risk. All fluoride measures appeared to be beneficial in preventing crown caries and reversing root caries, but the quality of evidence was graded as low for fluoride mouth rinse......, moderate for fluoride gel and very low for acidulated fluoride foam. No conclusions could be drawn on the cost-effectiveness. CONCLUSIONS: This review, covering the recent decade, has further substantiated the evidence for a caries-preventive effect of fluoride mouth rinse, fluoride gel and foam...

  4. Stabilization of fluoroindate glasses by magnesium fluoride and other heavy metal fluorides

    Directory of Open Access Journals (Sweden)

    B. J. Costa

    1998-06-01

    Full Text Available Their extended transparency in the IR makes them attractive for use as optical fibers for CO laser power delivery and optical amplification. This paper firstly describes the spectacular stabilizing effect of MgF2 on the binary system InF3-BaF2. The investigation of the InF3-BaF2-MgF2 system led to samples up to 5mm in thickness. Further optimization of this system was achieved by incorporation of limited amounts of other fluorides and resulted in increased resistence to devitrification. The second approach of this work was concerned to the investigation of the pseudo-ternary system InF3-GdF3-GaF3 at constant concentrations of ZnF2-SrF2-BaF2-NaF. Several compositions were studied in this system. The samples presented a better thermal stability when compared to other families of fluoride glasses. Therefore, these glasses seem to be very promising for the fabrication of special optical fibers. Thermal data are reported.

  5. Sources of fluoride pollution in Kasur district, Pakistan

    International Nuclear Information System (INIS)

    Khan, I.H.; Haq, M.M.I.

    2005-01-01

    Serious bone problems were reported in certain localities in Pakistan due to contamination of drinking water by fluoride pollution. Against WHO recommended threshold limit of 0.7 mg/L, about 40 mg/L of fluoride is determined by ion chromatographic technique of HPLC. The compositions of pollutants were investigated in the present study by examination the chemical and mineralogical studies of water and soil samples. It is found that main problem in Manga Mandi area of District Kasur, was caused due to the decomposition of phosphorus containing minerals in soil under acidic conditions. The other sources of fluoride contamination in different areas of Pakistan is being investigated. (author)

  6. The cariostatic mechanisms of fluoride

    Directory of Open Access Journals (Sweden)

    Kata Rošin-Grget

    2013-11-01

    Full Text Available This article discusses the possible cariostatic mechanisms of the action of fluoride. In the past, fluoride inhibition of caries was ascribed to reduced solubility of enamel due to incorporation of fluoride (F– into the enamel minerals. The present evidence from clinical and laboratory studies suggests that the caries-preventive mode of action of fluoride is mainly topical. There is convincing evidence that fluoride has a major effect on demineralisation and remineralisation of dental hard tissue. The source of this fluoride could either be fluorapatite (formed due to the incorporation of fluoride into enamel or calcium fluoride (CaF2-like precipitates, which are formed on the enamel and in the plaque after application of topical fluoride. Calcium fluoride deposits are protected from rapid dissolution by a phosphate –protein coating of salivary origin. At lower pH, the coating is lost and an increased dissolution rate of calcium fluoride occurs. The CaF2, therefore, act as an efficient source of free fluoride ions during the cariogenic challenge. The current evidence indicates that fluoride has a direct and indirect effect on bacterial cells, although the in vivo implications of this are still not clear. Conclusion. A better understanding of the mechanisms of the action of fluoride is very important for caries prevention and control. The effectiveness of fluoride as a cariostatic agent depends on the availability of free fluoride in plaque during cariogenic challenge, i.e. during acid production. Thus, a constant supply of low levels of fluoride in biofilm/saliva/dental interference is considered the most beneficial in preventing dental caries.

  7. The cariostatic mechanisms of fluoride.

    Science.gov (United States)

    Rošin-Grget, Kata; Peroš, Kristina; Sutej, Ivana; Bašić, Krešimir

    2013-11-01

    This article discusses the possible cariostatic mechanisms of the action of fluoride. In the past, fluoride inhibition of caries was ascribed to reduced solubility of enamel due to incorporation of fluoride (F-) into the enamel minerals. The present evidence from clinical and laboratory studies suggests that the caries-preventive mode of action of fluoride is mainly topical. There is convincing evidence that fluoride has a major effect on demineralisation and remineralisation of dental hard tissue. The source of this fluoride could either be fluorapatite (formed due to the incorporation of fluoride into enamel) or calcium fluoride (CaF2)-like precipitates, which are formed on the enamel and in the plaque after application of topical fluoride. Calcium fluoride deposits are protected from rapid dissolution by a phosphate -protein coating of salivary origin. At lower pH, the coating is lost and an increased dissolution rate of calcium fluoride occurs. The CaF2, therefore, act as an efficient source of free fluoride ions during the cariogenic challenge. The current evidence indicates that fluoride has a direct and indirect effect on bacterial cells, although the in vivo implications of this are still not clear. A better understanding of the mechanisms of the action of fluoride is very important for caries prevention and control. The effectiveness of fluoride as a cariostatic agent depends on the availability of free fluoride in plaque during cariogenic challenge, i.e. during acid production. Thus, a constant supply of low levels of fluoride in biofilm/saliva/dental interference is considered the most beneficial in preventing dental caries. Copyright © 2013 by Academy of Sciences and Arts of Bosnia and Herzegovina.

  8. Root caries prevention via sodium fluoride, chlorhexidine and silver diamine fluoride in vitro.

    Science.gov (United States)

    Göstemeyer, Gerd; Kohls, Anna; Paris, Sebastian; Schwendicke, Falk

    2018-01-31

    Uncertainty exists as to how to best prevent root caries development. The aim of the present study was to compare sodium fluoride (NaF), chlorhexidine (CHX) and silver diamine fluoride (SDF) varnishes (V) and rinses (R) regarding their caries preventive effect in an artificial caries biofilm model. 140 bovine root dentin samples were cut, polished and embedded. Samples were allocated to seven treatment groups (n = 20/group): Four varnishes (applied once prior biofilm challenge): 38% SDF (SDFV), 35% CHX-varnish (CHXV), 22,600 ppm NaF-varnish (NaFV), placebo-varnish (PV); two rinses (applied once daily during biofilm challenge): 500 ppm NaF solution (NaFR), 0.1% CHX solution (CHXR); one untreated group. Caries was induced in a multi-station, continuous-culture Lactobacillus rhamnosus GG (LGG) biofilm model. Bacteria were inoculated 1 × daily, while 2% sucrose was supplied 8 ×/day followed by artificial saliva for 10 min. After 12 days, mineral loss (ΔZ) was measured in the effect area and adjacent to the varnished areas. Bacterial counts were assessed on de-Man-Rogosa-Sharpe agar. ΔZ was significantly lower in the NaFR group compared with all other groups. Varnishes did not significantly prevent mineral loss in adjacent areas. None of the agents had a significant antimicrobial effect on LGG. Regular fluoride rinses showed highest root caries-preventive effect.

  9. Terrestrial bryophytes as indicators of fluoride emission from a phosphorus plant, Long Harbour, Newfoundland, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, B.A.; Thompson, L.K.; Sidhu, S.S.

    1979-01-01

    A study of the effects of fluoride emissions (HF, SiF/sub 4/) on certain species of bryophytes was carried out in the vicinity of an industrial palnt producing elemental phosphorus at Long Harbour, Nfld. Damage symptoms varied from mild phyllid chlorosis (yellowing) to severe browning of up to 95% of the phyllids. Polytrichum commune Hedw. was the main bryophyte species used in the survey. Random collections from 45 sample sites were analysed for total fluoride. The fluoride concentrations in phyllid tissue ranged from a high of 6066 ppm (dry weight) at a distance of 1 km northeast of the emission source to 44 ppm (dry weight) 11.7 km northeast of the emission source in the direction of the prevailing wind. Control samples were obtained from similar sites in areas far removed from the industrial plant and contained, on average, 11.3 ppm (dry weight). The concentration of fluoride in the bryophyte phyllid tissue was inversely correlated with distance from the emission source, in the direction of the prevailing wind. The severity of acropetal scorching was found to be correlated with the concentration of fluoride in the bryophyte phyllid tissue, and in addition, samples high in fluoride had fewer sporophytes. Fluoride concentrations in bryophyte tissue are compared with concentrations of fluoride in the needles of balsam fir, Abies Balsamea I., in four damage zones, and also with available and total fluoride in soil humus and concentrations of fluoride in air. The total area affected by fluoride emissions was increased using bryophytes as the pollution indicator species, especially in areas far from the industrial plant.

  10. The effects of fluoride concentration and the level of cariogenic challenge on caries development in desalivated rats.

    Science.gov (United States)

    Tabchoury, C M; Holt, T; Pearson, S K; Bowen, W H

    1998-12-01

    Dental caries is an infectious and transmissible disease that continues to affect the majority of people. The presence of carbohydrate, mainly sucrose in the diet, is an important factor in its occurrence. The amount of fluoride required for optimal protective effect where there is a high caries challenge is unclear. Differences in the intensity of cariogenic challenge, for whatever reason, may play a part in determining fluctuations in the effectiveness of fluoride. The purpose of this study was to evaluate the effect of different concentrations of fluoride on the development of caries and explore the cariostatic effect of fluoride under various levels of cariogenic challenge. The study comprises two experiments. In experiment I, 60 desalivated Sprague Dawley rats infected with Streptococcus sobrinus were offered the following to drink for 21 days: group (1), sterile distilled water (SDW); (2) 10 parts/10(6) F SDW; (3) 20 parts/10(6) F SDW; (4) 30 parts/10(6) F SDW; (5) 40 parts/10(6) F SDW. In experiment II, eight groups of 9 rats were placed in a König Höfer programmed feeder and were exposed to different levels of cariogenic challenge through varying frequency of eating and offered water containing 10 parts/10(6) F. In experiment I, exposure to 20, 30 and 40 parts/10(6) F reduced caries development significantly: fluoride, at 10 parts/10(6), reduced the severity of the carious lesions. In this model of severe cariogenic challenge, the results suggest that elevated concentrations of fluoride might be effective in patients at high caries risk. In experiment II, fluoride reduced the incidence and severity of smooth-surface caries in all groups. The protective effect of fluoride decreased as the number of exposures to sugar increased. It is concluded that the effectiveness of fluoride is influenced by the level of cariogenic challenge and that consideration should be given to adjusting the level of fluoride exposure based on perceived caries risk, and that there

  11. Fluoride and Oral Health.

    Science.gov (United States)

    O'Mullane, D M; Baez, R J; Jones, S; Lennon, M A; Petersen, P E; Rugg-Gunn, A J; Whelton, H; Whitford, G M

    2016-06-01

    The discovery during the first half of the 20th century of the link between natural fluoride, adjusted fluoride levels in drinking water and reduced dental caries prevalence proved to be a stimulus for worldwide on-going research into the role of fluoride in improving oral health. Epidemiological studies of fluoridation programmes have confirmed their safety and their effectiveness in controlling dental caries. Major advances in our knowledge of how fluoride impacts the caries process have led to the development, assessment of effectiveness and promotion of other fluoride vehicles including salt, milk, tablets, toothpaste, gels and varnishes. In 1993, the World Health Organization convened an Expert Committee to provide authoritative information on the role of fluorides in the promotion of oral health throughout the world (WHO TRS 846, 1994). This present publication is a revision of the original 1994 document, again using the expertise of researchers from the extensive fields of knowledge required to successfully implement complex interventions such as the use of fluorides to improve dental and oral health. Financial support for research into the development of these new fluoride strategies has come from many sources including government health departments as well as international and national grant agencies. In addition, the unique role which industry has played in the development, formulation, assessment of effectiveness and promotion of the various fluoride vehicles and strategies is noteworthy. This updated version of 'Fluoride and Oral Health' has adopted an evidence-based approach to its commentary on the different fluoride vehicles and strategies and also to its recommendations. In this regard, full account is taken of the many recent systematic reviews published in peer reviewed literature.

  12. Fluoride level in saliva after bonding orthodontic brackets with a fluoride containing adhesive

    NARCIS (Netherlands)

    Ogaard, B; Arends, J; Helseth, H; Dijkman, G; vanderKuijl, M

    The fluoride level in saliva is considered an important parameter in caries prevention. Elevation of the salivary fluoride level by a fluoride-releasing orthodontic bonding adhesive would most likely be beneficial in the prevention of enamel caries. In this study, the fluoride level in saliva was

  13. An Investigation of Fluoride Concentration in Drinking Water of Sanganer Tehsil, Jaipur District, Rajasthan, India and Defluoridation from Plant Material

    Directory of Open Access Journals (Sweden)

    Mohammed Arif

    2014-01-01

    Full Text Available Forty water samples of 20 villages of Sanganer tehsil, Jaipur district were analyzed for determining fluoride ion concentrations. High fluoride containing regions were identified on the basis of fluoride levels of the water samples and also on the prevalence rate of dental and skeletal fluorosis of the study area. Fluoride maps, which distinguish the regions containing the water sources of different ranges of fluoride ion concentrations, were also prepared by isopleth’s technique, a statistical method. Water samples containing high fluoride levels were defluoridated with low-cost materials prepared from plant byproducts. These materials successfully decrease the fluoride ions concentration to an acceptable limit (from 0.5 to 1.5 mg/L without disturbing drinking water quality standards.

  14. Determination of fluoride ions in water by condutometric titration with lanthanum nitrates

    International Nuclear Information System (INIS)

    Alves, J.C.

    1986-01-01

    An alternative method for determining fluoride ions in drinking water by condutometric titration using La(NO 3 ) 3 as titrant is presented. The method is based on previous separation of fluoride from sample by distillation at 135 0 C. The pH of the distillated is adjusted between 5,5 - 6,0; ethanol is adicioned in 50% titrating the resultant solution with La(NO 3 ) 3 . In these conditions, fluoride ions are determined with accuracy respectively, 5% and 4%. Natural samples of drinking water were analysed by this method and by the ion selective method, with agreement among the results. (author) [pt

  15. Estimation of Fluoride Concentration of Various Citrus and Non-Citrus Fruits Commonly Consumed and Commercially Available in Mathura City

    Directory of Open Access Journals (Sweden)

    Navin Anand Ingle

    2013-01-01

    Full Text Available Background: Since fluoride is available from various sources, the total ingestion of fluoride by a person should be estimated taking into consideration the fluoride consumed from all the sources including fruits. There are very few epidemiological studies carried out associated with fluoride estimation in fruit samplesand especially in the Indian scenario Objective: To estimate and compare the fluoride concentration of different commercially available citrus and non-citrus fruits in Mathura city. Materials & Method: Fifteen different types of fruits commercially available and consumed by people ofMathura City were collected. Out of the 15 fruit samples 5 were citrus fruits and 10 were non-citrus fruits. The fluoride estimation of fruit samples was done at Central Laboratory,Lucknow. Juices of all 15 fruit samples were prepared, from each sample 10 ml of juice was measured and fluoride testing of each sample was carried out by using Orion 4 star -ion electrode analyzer. The collected data was analyzed using the statistical software program SPSS, version 17. Results: The fluoride concentration in citrus fruits ranged from 0.04ppm (Orange to 0.08 ppm (Tomato while in non-citrus fruits it ranged from 0.04ppm (chikoo to 0.18 ppm (Guava. No significant difference was observed between the mean fluoride concentration of citrus and non citrus fruits. Conclusions: Both citrus and non citrus fruits have fluorides. Guava was found to have the maximumamount of fluoridecontent (0.18 ppm among both the citrus and non citrus fruits.

  16. Implementing a geographical information system to assess endemic fluoride areas in Lamphun, Thailand.

    Science.gov (United States)

    Theerawasttanasiri, Nonthaphat; Taneepanichskul, Surasak; Pingchai, Wichain; Nimchareon, Yuwaree; Sriwichai, Sangworn

    2018-01-01

    Many studies have shown that fluoride can cross the placenta and that exposure to high fluoride during pregnancy may result in premature birth and/or a low birth weight. Lamphun is one of six provinces in Thailand where natural water fluoride (WF) concentrations >10.0 mg/L were found, and it was also found that >50% of households used water with high fluoride levels. Nevertheless, geographical information system (GIS) and maps of endemic fluoride areas are lacking. We aimed to measure the fluoride level of village water supplies to assess endemic fluoride areas and present GIS with maps in Google Maps. A cross-sectional survey was conducted from July 2016 to January 2017. Purpose sampling was used to identify villages of districts with WF >10.0 mg/L in the Mueang Lamphun, Pasang, and Ban Thi districts. Water samples were collected with the geolocation measured by Smart System Info. Fluoride was analyzed with an ion-selective electrode instrument using a total ionic strength adjustment buffer. WF >0.70 mg/L was used to identify unsafe drinking water and areas with high endemic fluoride levels. Descriptive statistics were used to describe the findings, and MS Excel was used to create the GIS database. Maps were created in Google Earth and presented in Google Maps. We found that WF concentrations ranged between 0.10-13.60 mg/L. Forty-four percent (n=439) of samples were at unsafe levels (>0.70 mg/L), and. 54% (n=303) of villages and 46% (n=79,807) of households used the unsafe drinking water. Fifty percent (n=26) of subdistricts were classified as being endemic fluoride areas. Five subdistricts were endemic fluoride areas, and in those, there were two subdistricts in which every household used unsafe drinking water. These findings show the distribution of endemic fluoride areas and unsafe drinking water in Lamphun. This is useful for health policy authorities, local governments, and villagers and enables collaboration to resolve these issues. The GIS data are

  17. Effect of Fluoride, Casein Phosphopeptide–Amorphous Calcium Phosphate and Casein Phosphopeptide–Amorphous Calcium Phosphate Fluoride on Enamel Surface Microhardness After Microabrasion: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Ghazaleh Ahmadi Zenouz

    2016-03-01

    Full Text Available Objectives: This study aimed to assess the effect of applying casein phosphopeptide–amorphous calcium phosphate (CPP-ACP paste, casein phosphopeptide–amorphous calcium phosphate fluoride (CPP-ACPF paste and sodium fluoride gel on surface microhardness of enamel after microabrasion.Materials and Methods: Thirty freshly extracted human premolars were selected. All samples were subjected to hardness indentations made with the Vickers hardness machine and the average value was recorded as the initial surface microhardness. The specimens were then randomly divided into three groups (n=10 of CPP-ACPF, fluoride and CPP-ACP. The teeth were micro-abraded with Opalustre. Microhardness test was performed to assess the post-abrasion hardness. Three remineralization modalities were performed on samples of each group. The enamel surface microhardness measurements were performed. To compare the difference between groups, the rehardening and softening values were defined. One-way ANOVA and Tukey’s post hoc test at a significance level of 5% were used for statistical analysis.Results: The mean microhardness value (MMV had a significant decrease after microabrasion from baseline. The MMV had a significant increase after remineralization in all groups. The MMV of CPP-ACPF group was significantly more than that of fluoride group (P=0.027. The rehardening value of fluoride group was significantly more than that of other groups (P<0.001.Conclusion: All the remineralizing agents were effective for rehardening the enamel after microabrasion. The CPP-ACP and CPP-ACPF pastes are effective, but to a lesser extent than neutral sodium fluoride gel in remineralizing enamel surface. Incorporation of fluoride to CPP-ACP formulation does not provide any additional remineralizing potential.Keywords: Casein phosphopeptide-amorphous calcium phosphate nanocomplex; Enamel Microabrasion; Hardness; Sodium Fluoride

  18. Comparative Analysis of Fluoride Concentrations in Groundwaters in Northern and Southern Ghana: Implications for the Contaminant Sources

    Science.gov (United States)

    Sunkari, Emmanuel Daanoba; Zango, Musah Saeed; Korboe, Harriet Mateko

    2018-04-01

    Bongo and Sekyere South districts, both in the northern and southern parts of Ghana, respectively, have high populations living in rural areas and most of them use groundwater for drinking purposes. The groundwater in these areas is prone to contamination from natural and/or artificial sources. Therefore this study aims; (1) to present a comparative analysis of the fluoride concentration in groundwater samples from Bongo and Sekyere South districts and the associated groundwater-rock interaction that may be the cause for the varied fluoride concentrations, (2) to determine the leaching potential of fluoride from the host rocks as the possible mechanism for groundwater contamination. Sixty (60) groundwater samples from active pumping wells and twelve (12) rock samples from outcrops were collected from various communities in the two districts for fluoride concentration and mineralogical analysis. Based on the variations in fluoride concentration, fluoride spatial distribution maps were prepared using empirical Bayesian kriging interpolation method and analysed by means of hierarchical cluster analysis. The fluoride concentration in Bongo district varies between 1.71 and 4.0 mg/L, whereas that in Sekyere South district changes from 0.3 to 0.8 mg/L. From the mineralogical studies, biotite has the highest percentage in the Bongo district and has positive correlation with fluoride concentration in the analysed water samples than in the Sekyere South district. The elevated fluoride concentration in the Bongo district relative to the Sekyere South district is due to the dissolution of biotite in the groundwater and the sufficient groundwater-rock interaction since the water samples are mainly sourced from deeper boreholes. This high fluoride concentration has resulted in a plethora of reported cases of dental fluorosis and other health-related issues in Bongo.

  19. Energy dispersive X-ray spectrometry study of the protective effects of fluoride varnish and gel on enamel erosion.

    Science.gov (United States)

    De Carvalho Filho, Antonio Carlos Belfort; Sanches, Roberto Pizarro; Martin, Airton Abrahão; Do Espírito Santo, Ana Maria; Soares, Luís Eduardo Silva

    2011-09-01

    Dental erosion is a risk factor for dental health, introduced by today's lifestyle. Topical fluoride applications in the form of varnishes and gel may lead to deposition of fluoride on enamel. This in vitro study aimed to evaluate the effect of two fluoride varnishes and one fluoride gel on the dissolution of bovine enamel by acids. Enamel samples (72) were divided (n = 8): artificial saliva (control-G1), Pepsi Twist® (G2), orange juice (G3), Duraphat® + Pepsi Twist® (G4), Duraphat® + orange juice (G5), Duofluorid® + Pepsi Twist® (G6), Duofluorid® + orange juice (G7), fluoride gel + Pepsi Twist® (G8), and fluoride gel + orange juice (G9). Fluoride gel was applied for 4 min and the varnishes were applied and removed after 6 h. The samples were submitted to six cycles (demineralization: Pepsi Twist® or orange juice, 10 min; remineralization: saliva, 1 h). Samples were analyzed by energy-dispersive X-ray fluorescence (144 line-scanning). The amount of Ca and P decreased significantly in the samples of G2 and G3, and the Ca/P ratio decreased in G3. Mineral gain (Ca) was greater in G9 samples than in G4 > G3 > G5 > G1, and (P) greater in G7 samples than in G9 > G4-6 > G2-3. The protective effect of Duofluorid® was significantly lower than fluoride gel against orange juice. The fluoride varnishes can interfere positively with the dissolution of dental enamel in the presence of acidic beverages. Fluoride gel showed the best protection level to extrinsic erosion with low costs. Copyright © 2010 Wiley-Liss, Inc.

  20. Geochemical characterization of fluoride in water, table salt, active sediment, rock and soil samples, and its possible relationship with the prevalence of enamel fluorosis in children in four municipalities of the department of Huila (Colombia).

    Science.gov (United States)

    Martignon, Stefania; Opazo-Gutiérrez, Mario Omar; Velásquez-Riaño, Möritz; Orjuela-Osorio, Iván Rodrigo; Avila, Viviana; Martinez-Mier, Esperanza Angeles; González-Carrera, María Clara; Ruiz-Carrizosa, Jaime Alberto; Silva-Hermida, Blanca Cecilia

    2017-06-01

    Fluoride is an element that affects teeth and bone formation in animals and humans. Though the use of systemic fluoride is an evidence-based caries preventive measure, excessive ingestion can impair tooth development, mainly the mineralization of tooth enamel, leading to a condition known as enamel fluorosis. In this study, we investigated the geochemical characterization of fluoride in water, table salt, active sediment, rock and soil samples in four endemic enamel fluorosis sentinel municipalities of the department of Huila, Colombia (Pitalito, Altamira, El Agrado and Rivera), and its possible relationship with the prevalence of enamel fluorosis in children. The concentration of fluoride in drinking water, table salt, active sediment, rock, and soil was evaluated by means of an ion selective electrode and the geochemical analyses were performed using X-ray fluorescence. Geochemical analysis revealed fluoride concentrations under 15 mg/kg in active sediment, rock and soil samples, not indicative of a significant delivery to the watersheds studied. The concentration of fluoride in table salt was found to be under the inferior limit (less than 180 μg/g) established by the Colombian regulations. Likewise, exposure doses for fluoride water intake did not exceed the recommended total dose for all ages from 6 months. Although the evidence does not point out at rocks, soils, fluoride-bearing minerals, fluoridated salt and water, the hypothesis of these elements as responsible of the current prevalence of enamel fluorosis cannot be discarded since, aqueducts might have undergone significant changes overtime.

  1. Fluoride glass fiber optics

    CERN Document Server

    Aggarwal, Ishwar D

    1991-01-01

    Fluoride Glass Fiber Optics reviews the fundamental aspects of fluoride glasses. This book is divided into nine chapters. Chapter 1 discusses the wide range of fluoride glasses with an emphasis on fluorozirconate-based compositions. The structure of simple fluoride systems, such as BaF2 binary glass is elaborated in Chapter 2. The third chapter covers the intrinsic transparency of fluoride glasses from the UV to the IR, with particular emphasis on the multiphonon edge and electronic edge. The next three chapters are devoted to ultra-low loss optical fibers, reviewing methods for purifying and

  2. A simple and colorimetric fluoride receptor and its fluoride-responsive organogel

    Energy Technology Data Exchange (ETDEWEB)

    Yu Xudong, E-mail: 081022009@fudan.edu.cn [College of Science, Hebei University of Science and Technology, Yuhua Road 70, Shijiazhuang 050080 (China); Li Yajuan [College of Science, Hebei University of Science and Technology, Yuhua Road 70, Shijiazhuang 050080 (China); Yin Yaobing; Yu Decai [College of Science, Hebei University of Engineering, 199 South street of Guangming, Handan 056038 (China)

    2012-08-01

    In this paper, a new p-nitrophenylhydrozine-based anion receptor 1 containing cholesterol group had been designed and synthesized. It could selectively recognize fluoride among different anions tested with color changes from pale yellow to red for visual detection. Simultaneously, it could gel in cyclohexane, and the gel was also fluoride-responsive. When treated with TBAF (tetra-n-butylammonium fluoride), the gel could undergo gel-sol transition accompanied by color, morphology and surface changes. The binding mechanism had been investigated by UV-vis and {sup 1}HNMR (proton nuclear magnetic resonance spectra) titrations. From SEM (scanning electron microscope), SAXS (small-angle X-ray scattering), IR (Infrared Spectroscopy) and CA (contact angle) experiments, it was indicated that the addition of F{sup -} could destroy the molecule assembly of host 1 in the gel state, thus resulting in the gel-to-sol transition due to the binding site competition effect. To the best of our knowledge, this was the simplest fluoride-responsive organogel with high selectivity. Highlights: Black-Right-Pointing-Pointer A novel kind receptor for selective recognition of fluoride had been designed. Black-Right-Pointing-Pointer Its organogel was also fluoride-responsive. Black-Right-Pointing-Pointer This is the simplest fluoride-responsive organogel with high selectivity.

  3. Fabrication of dense panels in lithium fluoride

    International Nuclear Information System (INIS)

    Farcy, P.; Roger, J.; Pointud, R.

    1958-04-01

    The authors report a study aimed at the fabrication of large and dense lithium fluoride panels. This sintered lithium fluoride is then supposed to be used for the construction of barriers of protection against a flow of thermal neutrons. They briefly present the raw material which is used under the form of chamotte obtained through a pre-sintering process which is also described. Grain size measurements and sample preparation are indicated. Shaping, drying, and thermal treatment are briefly described, and characteristics of the sintered product are indicated

  4. Influence of the Relative Enamel Abrasivity (REA) of Toothpastes on the Uptake of KOH-soluble and Structurally Bound Fluoride.

    Science.gov (United States)

    Elmazi, Valbona; Sener, Beatrice; Attin, Thomas; Imfeld, Thomas; Wegehaupt, Florian J

    2015-01-01

    To determine the influence of the relative enamel abrasivity (REA) of fluoridated toothpaste on the uptake of KOH-soluble and structurally bound fluoride into enamel. Bovine enamel samples were randomly allocated to 6 groups (n=36 per group). Groups A to C were treated with sodium fluoride (NaF) toothpastes and groups D to F with amine fluoride (AmF) toothpastes (1500 ppm F each). The REA in groups A and D was 2, in groups B and E it was 6 and in groups C and F it was 9. Twice a day, 18 samples of each group were immersed for 2 min in a slurry (toothpaste:artificial saliva=1:3), while the remaining samples were brushed with the respective slurry (2.5 N force; 60 strokes/min; 2 min). All samples were stored at 37°C and 100% humidity. After five days, the amount of KOH-soluble and structurally bound fluoride was determined and statistically compared by Scheffe's post-hoc tests. REA value and mode of application (immersion or brushing) had no significant influence on the amount of either kind of fluoride from NaF toothpastes. Only for the NaF toothpaste with REA 6 was the amount of KOH-soluble fluoride significantly higher after brushing. With AmF toothpastes, KOH-soluble and structurally bound fluoride concentrations were significantly higher when the samples were brushed. Furthermore, in the REA-2 group, the amounts of KOH-soluble fluoride (brushed or immersed) and structurally bound fluoride (brushed) were significantly higher than in the other groups. The REA dependency of KOH-soluble and structurally bound fluoride was found only for the AmF toothpastes. Using AmF toothpaste, the mode of application influenced the uptake of KOH-soluble and structurally bound fluoride into enamel.

  5. Fluoride metabolism in plants

    Energy Technology Data Exchange (ETDEWEB)

    Peters, R; Shorthouse, M

    1964-04-04

    Grass seedlings exposed to inorganic fluoride solutions do not take up appreciable amounts of fluoride until concentrations of more than 1.0 mM (19 p.p.m.) are used. No formation of organic fluoride has been found, even with exposure to 15.75 mM fluoride, indicating that there is no formation of fluoroacetate or similar compounds. 8 references, 2 tables.

  6. Bottled Water and Fluoride

    Science.gov (United States)

    ... Private Wells Infant Formula Fluorosis Public Health Service Recommendation Water Operators & Engineers Water Fluoridation Additives Shortages of Fluoridation Additives Drinking Water Pipe Systems CDC-Sponsored Water Fluoridation Training Links to Other ...

  7. Removal of Fluoride from Drinking Water Using Modified Immobilized Activated Alumina

    Directory of Open Access Journals (Sweden)

    Aneeza Rafique

    2013-01-01

    Full Text Available The study describes the removal of fluoride from drinking water using modified immobilized activated alumina (MIAA prepared by sol-gel method. The modification was done by adding a specific amount of alum during the sol formation step. The fluoride removal efficiency of MIAA was 1.35 times higher as compared to normal immobilized activated alumina. A batch adsorption study was performed as a function of adsorbent dose, contact time, stirring rate, and initial fluoride concentration. More than 90% removal of fluoride was achieved within 60 minutes of contact time. The adsorption potential of MIAA was compared with activated charcoal which showed that the removal efficiency was about 10% more than the activated charcoal. Both the Langmuir and Freundlich adsorption isotherms fitted well for the fluoride adsorption on MIAA with the regression coefficient R2 of 0.99 and 0.98, respectively. MIAA can both be regenerated thermally and chemically. Adsorption experiments using MIAA were employed on real drinking water samples from a fluoride affected area. The study showed that modified immobilized activated alumina is an effective adsorbent for fluoride removal.

  8. Direct photometric determination of fluorides in potassium chloride and iodide

    International Nuclear Information System (INIS)

    Dedkova, V.P.; Savvin, S.B.

    1985-01-01

    An attempt is made to apply the technique of determining fluorides with xylenol orange and sulfochlorophenol S as being the most sensitive in the analysis of of fiber optics. It is known that an increase of the sensitivity of the determination can be achieved on increasing the sample size of the substance to be analyzed, and the length of the absorbing layer. However, a high salt background may have a strong influence on the course of the reaction, and a supplementary of this effect is mad. Potassium chloride and iodide were selected as model compounds. A direct photometric procedure is proposed for determining fluorides in the samples, with a determination limit of 5 x 10 -6 %. Such a low determination limit is achieved by increasing the sample weight to 3 g, by increasing the length of the absorbing layer in the cell to 50 mm, and by using a highly sensitive reaction for determining fluorides with zirconium and xylenol orange

  9. γ-Aminobutyric acid ameliorates fluoride-induced hypothyroidism in male Kunming mice.

    Science.gov (United States)

    Yang, Haoyue; Xing, Ronge; Liu, Song; Yu, Huahua; Li, Pengcheng

    2016-02-01

    This study evaluated the protective effects of γ-aminobutyric acid (GABA), a non-protein amino acid and anti-oxidant, against fluoride-induced hypothyroidism in mice. Light microscope sample preparation technique and TEM sample preparation technique were used to assay thyroid microstructure and ultrastructure; enzyme immunoassay method was used to assay hormone and protein levels; immunohistochemical staining method was used to assay apoptosis of thyroid follicular epithelium cells. Subacute injection of sodium fluoride (NaF) decreased blood T4, T3 and thyroid hormone-binding globulin (TBG) levels to 33.98 μg/l, 3 2.8 ng/ml and 11.67 ng/ml, respectively. In addition, fluoride intoxication induced structural abnormalities in thyroid follicles. Our results showed that treatment of fluoride-exposed mice with GABA appreciably decreased metabolic toxicity induced by fluoride and restored the microstructural and ultrastructural organisation of the thyroid gland towards normalcy. Compared with the negative control group, GABA treatment groups showed significantly upregulated T4, T3 and TBG levels (42.34 μg/l, 6.54 ng/ml and 18.78 ng/ml, respectively; Plevel and apoptosis inhibition in thyroid follicular epithelial cells. To the best of our knowledge, this is the first study to establish the therapeutic efficacy of GABA as a natural antioxidant in inducing thyroprotection against fluoride-induced toxicity. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Effect of various rinsing protocols after use of amine fluoride/stannous fluoride toothpaste on the bacterial composition of dental plaque.

    Science.gov (United States)

    van Loveren, C; Gerardu, V A M; Sissons, C H; van Bekkum, M; ten Cate, J M

    2009-01-01

    This clinical study evaluated the effect of different oral hygiene protocols on the bacterial composition of dental plaque. After a 2-week period of using fluoride-free toothpaste, 30 participants followed three 1-week experimental protocols, each followed by 2-week fluoride-free washout periods in a randomized crossover examiner-blind controlled trial. The 1-week experimental protocols comprised the use of AmF/SnF(2) toothpaste twice daily, after which participants either (1) rinsed with tap water, (2) did not rinse but only spat out the toothpaste, or (3) rinsed with an AmF/SnF(2) mouthwash. In the fluoride-free washout periods, the participants brushed their teeth with fluoride-free toothpaste without further instructions. Six hours after the last brushing (+/- rinsing) of each period, buccal plaque samples in the upper molar region were taken. The microbiota composition of the plaque samples was analyzed by checkerboard DNA:DNA hybridization. A statistically significant reduction was found in the total amount of DNA of the 39 major plaque species measured, and in the proportions of some acid-producing bacterial strains after the period having used the AmF/SnF(2) toothpaste + AmF/SnF(2) mouthrinsing. The results indicate that using the AmF/SnF(2) toothpaste and rinse combination could result in plaque of lower cariogenicity. Copyright 2009 S. Karger AG, Basel.

  11. Fluoride sample matrices and reaction cells — new capabilities for isotope measurements in accelerator mass spectrometry

    Directory of Open Access Journals (Sweden)

    Eliades J.

    2012-04-01

    Full Text Available Two new techniques, which extend the range of elements that can be analyzed by Accelerator Mass Spectrometry (AMS, and which increase its isobar selection capabilities, have been recently introduced. The first consists of embedding the sample material in a fluoride matrix (e.g. PbF2, which facilitates the production, in the ion source, of fluoride molecular anions that include the isotope of interest. In addition to forming anions with large electron binding energies and thereby increasing the range of analysable elements, in many cases by selection of a molecular form with a particular number of fluorine atoms, some isobar discrimination can be obtained. The second technique, for the significant reduction of atomic isobar interferences, is used following mass selection of the rare isotope. It consists of the deceleration, cooling and reaction of the rare mass beam with a gas, selected so that unwanted isobars are greatly attenuated in comparison with the isotope of interest. Proof of principle measurements for the analysis of 36C1 and 41Ca have provided encouraging results and work is proceeding on the integration of these techniques in a new AMS system planned for installation in late 2012 at the University of Ottawa.

  12. [Influence of dental caries prophylaxis using fluor-vigantoletten 1000 on plasma fluoride levels in infants (author's transl)].

    Science.gov (United States)

    Fuchs, C; Pohlandt, F; Abigt, J; Töllner, U; Heimann, G

    1979-04-01

    A group of 57 newborns was divided into two: group I (27 subjects) received solely 1,000 I.U. vitamin D3 per day for 6 months, whereas group II (30 subjects) were given a combination of 1,000 I.U. vitamin D3 and 0.25 mg fluoride. At the end of the time of observation there was a significant difference between the plasma concentrations in the two groups. The median value was 13.06 microgram/l (range: 8:18-39.4 microgram/l) in group I and 16.54 microgram/l (range: 9.9--41.2 microgram/l) in group II. Fluoride is obviously available to infants when administered in combination with Vitamin D3. In addition, it could be proven, that after 6 month administration of fluoride there are no signs of cumulation, overdosage or even intoxication.

  13. Estimation of fluoride concentration in drinking water and common beverages in United Arab Emirates (UAE).

    Science.gov (United States)

    Walia, Tarun; Abu Fanas, Salem; Akbar, Madiha; Eddin, Jamal; Adnan, Mohamad

    2017-07-01

    To assess fluoride concentration in drinking water which include tap water of 4 emirates - Abu Dhabi, Dubai, Sharjah and Ajman plus bottled water, commonly available soft drinks & juices in United Arab Emirates. Five different samples of tap water collected from each of the four emirates of UAE: Ajman, Sharjah, Abu Dhabi and Dubai; twenty-two brands of bottled water and fifteen brands of popular cold beverages, purchased from different supermarkets in U.A.E were tested using ion selective electrode method and the fluoride concentration was determined. The mean fluoride content of tap water samples was 0.14 mg F/L with a range of 0.04-0.3 mg F/L; with Ajman tap water samples showing the highest mean fluoride content of 0.3 mg F/L. The mean fluoride content for both bottled drinking water and beverages was 0.07 mg F/L with a range of 0.02-0.50 mg F/L and 0.04-0.1 mg F/L respectively. Majority (68.2%) of the bottled water are produced locally within U.A.E while a few (31.8%) are imported. The tap water, bottled water and beverages available in U.A.E show varying concentrations of fluoride, however none showed the optimal level necessary to prevent dental caries. Dental professionals in U.A.E should be aware of the fluoride concentrations before prescribing fluoride supplements to children.

  14. Fluoride concentration in urine after silver diamine fluoride application on tooth enamel

    Science.gov (United States)

    Sari, D. L.; Bahar, A.; Gunawan, H. A.; Adiatman, M.; Rahardjo, A.; Maharani, D. A.; Toptanci, I. R.; Yavuz, I.

    2017-08-01

    Silver Diammine Fluoride (SDF), which contains fluoride, is known to inhibit tooth enamel demineralization and increase fluoride concentrations in saliva and urine. The aim of this study is to analyze the fluoride concentration in urine after application of SDF on tooth enamel. Urine from four subjects was collected prior to, 30 minutes after, and two and three hours after the application of SDF, and an ion-selective electrode was used to measure the fluoride concentrations. There was no significant difference between time 1 and time 2, time 1 and time 3, time 1 and time 4, time 2 and 3 (p > 0.05), and there was a significant difference between time 2 and time 4 as well as time 3 and time 4 (p < 0.05). There was a decrease in the concentration of fluoride ions in urine from the baseline to 30 minutes after application, and an increase from baseline to two and three hours after the application of SDF.

  15. Association of Hypertension, Body Mass Index, and Waist Circumference with Fluoride Intake; Water Drinking in Residents of Fluoride Endemic Areas, Iran.

    Science.gov (United States)

    Yousefi, Mahmood; Yaseri, Mehdi; Nabizadeh, Ramin; Hooshmand, Elham; Jalilzadeh, Mohsen; Mahvi, Amir Hossein; Mohammadi, Ali Akbar

    2018-03-14

    Hypertension is becoming a global epidemic for both rural and urban populations; it is a major public health challenge in Iran. Fluoride can be a risk factor for hypertension. Cross-sectional analysis was conducted in two study areas to assess the relation of fluoride with blood pressure prevalence, BMI, waist circumference, and waist-to-hip ratio (WHR) among different age groups in both sexes. The mean value of fluoride concentration in the drinking water from the four study villages varied from 0.68 to 10.30 mg/L. The overall prevalence of HTN and prehypertension in all subjects was 40.7%. The prevalence of isolated systolic hypertension, isolated diastolic hypertension, systolic-diastolic hypertension, and prehypertension in the total sample population was 1.15, 0.28, 9.53, and 29.76%, respectively. The odd ratio of hypertension in residents who drank water with high fluoride levels was higher than that in residents who drank water with lower level of fluoride (OR 2.3, 1.03-5.14). Logistic regression results showed that age (P water (P = 0.041) had a significant relationship with increased blood pressure. There were no statistically significant correlations between fluoride and BMI, hip circumference, and waist to hip ratio (WHR). The findings of this study are important for health care personnel and policymakers.

  16. Lithological Influences on Occurrence of High-Fluoride Waters in The Central Kenya Rift

    Science.gov (United States)

    Olaka, L. A.; Musolff, A.; Mulch, A.; Olago, D.; Odada, E. O.

    2013-12-01

    Within the East African rift, groundwater recharge results from the complex interplay of geology, land cover, geomorphology, climate and on going volcano-tectonic processes across a broad range of spatial and temporal scales. The interrelationships between these factors create complex patterns of water availability, reliability and quality. The hydrochemical evolution of the waters is further complex due to the different climatic regimes and geothermal processes going on in this area. High fluoridic waters within the rift have been reported by few studies, while dental fluorosis is high among the inhabitants of the rift. The natural sources of fluoride in waters can be from weathering of fluorine bearing minerals in rocks, volcanic or fumarolic activities. Fluoride concentration in water depends on a number of factors including pH, temperature, time of water-rock formation contact and geochemical processes. Knowledge of the sources and dispersion of fluoride in both surface and groundwaters within the central Kenya rift and seasonal variations between wet and dry seasons is still poor. The Central Kenya rift is marked by active tectonics, volcanic activity and fumarolic activity, the rocks are majorly volcanics: rhyolites, tuffs, basalts, phonolites, ashes and agglomerates some are highly fractured. Major NW-SE faults bound the rift escarpment while the rift floor is marked by N-S striking faults We combine petrographic, hydrochemistry and structural information to determine the sources and enrichment pathways of high fluoridic waters within the Naivasha catchment. A total of 120 water samples for both the dry season (January-February2012) and after wet season (June-July 2013) from springs, rivers, lakes, hand dug wells, fumaroles and boreholes within the Naivasha catchment are collected and analysed for fluoride, physicochemical parameters and stable isotopes (δ2 H, δ18 O) in order to determine the origin and evolution of the waters. Additionally, 30 soil and

  17. Geochemical evaluation of fluoride contamination of groundwater in the Thoothukudi District of Tamilnadu, India

    Science.gov (United States)

    Singaraja, C.; Chidambaram, S.; Anandhan, P.; Prasanna, M. V.; Thivya, C.; Thilagavathi, R.; Sarathidasan, J.

    2014-09-01

    Fluoride is a chemical element that has been shown to cause significant effects on human health through drinking water. Different forms of fluoride exposure are of importance and have shown to affect the body's fluoride content and thus increasing the risks of fluoride-prone diseases. Fluoride has beneficial effects on teeth; however, low concentrations of fluoride intensify the risk of tooth decay. Fluoride can also be quite detrimental at higher concentrations at skeletal fluorosis. The Thoothukudi District is a hard rock and alluvial plain marked as one of the Fluoride-increase area in Tamilnadu due to occurrence of various rock types including fluoride-bearing minerals. The F- content of groundwater can thus originate from the dissolution of Fluoride-bearing minerals in the bed rock. Hundred representative groundwater samples from Thoothukudi District were collected during two different seasons. Samples were analysed for F-, other major cations and anions. The study area is chiefly composed of hornblende biotite gneiss, charnockite, alluvio marine, fluvial marine and granite with small patches of quartzite and sandstone. Higher concentration of fluoride is observed during pre-monsoon (3.3 mg l-1) compared to the post-monsoon (2.4 mg l-1) due to the dilution effect. Spatial distribution and factor score show that higher concentrations of F- are noted in the north and central part of the study area owing to lithology. Bicarbonate is well correlated with F- which explains that both ions were derived from the weathering. While F- has a very weak correlation with pH which may be due to the increase of alkalinity resulting from the increase of carbonate and bicarbonate ions.

  18. Determination of fluoride source in ground water using petrographic studies in Dashtestan area, south of Iran

    Science.gov (United States)

    Battaleb-Looie, Sedigheh; Moore, Farid, ,, Dr.

    2010-05-01

    The groundwater occurs in Dashtestan area, contains a high level of fluoride. Since groundwater is vastly used for drinking and irrigation purposes, the local residents are at high risk of fluoride toxicity, as already evidenced by the occurrence of dental Fluorosis in many residents. 35 surface and groundwater samples were collected in September, 2009. The results show that in 23 samples the fluoride concentration is above the permissible level (1.5ppm). Petrographic study of lithological units in the catchment area indicates that mica minerals are the most probable source of fluoride content in the study area.

  19. Water Fluoridation Statistics - Percent of PWS population receiving fluoridated water

    Data.gov (United States)

    U.S. Department of Health & Human Services — 2000-2014. Water Fluoridation Statistics is a biennial report of the percentage and number of people receiving fluoridated water from 2000 through 2014, originally...

  20. Water Fluoridation Statistics - Percent of PWS population receiving fluoridated water

    Data.gov (United States)

    U.S. Department of Health & Human Services — 2000-2014 Water Fluoridation Statistics is a biennial report of the percentage and number of people receiving fluoridated water from 2000 through 2014, originally...

  1. Detection of trace fluoride in serum and urine by online membrane-based distillation coupled with ion chromatography.

    Science.gov (United States)

    Lou, Chaoyan; Guo, Dandan; Wang, Nani; Wu, Shuchao; Zhang, Peimin; Zhu, Yan

    2017-06-02

    An online membrane-based distillation (MBD) coupled with ion chromatography (IC) method was proposed for automatic detection of trace fluoride (F - ) in serum and urine samples. The system consisted of a sample vessel, a lab-made membrane module and an ion chromatograph. Hydrophobic polytetrafluoroethylene (PTFE) hollow fiber membrane was used in MBD which was directly performed in serum and urine samples to eliminate the matrix interferences and enrich fluoride, while enabling automation. The determination of fluoride in biological samples was carried out by IC with suppressed conductometric detection. The proposed method feasibly determined trace fluoride in serum and urine matrices with the optimized parameters, such as acid concentration, distillation temperature, and distillation time, etc. Fluoride exhibited satisfactory linearity in the range of 0.01-5.0mg/L with a correlation coefficient of 0.9992. The limit of detection (LOD, S/N=3) and limit of quantification (LOQ, S/N=10) were 0.78μg/L and 2.61μg/L, respectively. The relative standard deviations of peak area and peak height were all less than 5.15%. The developed method was validated for the determination of fluoride in serum and urine with good spiked recoveries ranging between 97.1-101.9%. This method also can be proposed as a suitable alternative for the analysis of fluoride in other complex biological samples. Copyright © 2017. Published by Elsevier B.V.

  2. Determination of fluoride in spices using microwave induced oxygen combustion

    Directory of Open Access Journals (Sweden)

    Emanuel Šucman

    2012-01-01

    Full Text Available Fluorine is essential in human and/or animal nutrition; therefore, so it is important to know its concentration in a diet. One of the possible sources of fluorine for humans is spice, containing various amounts of this trace element. This work describes the method for fluoride determination in various kinds ofspices using microwave-supported sample preparation in high pressure oxygen atmosphere followed by potentiometry with a fluoride ion-selective electrode. Parameters of the microwave device for combustion procedure were checked and optimized in order to find settings ensuring complete sample combustion and/or absorption of the analyte in the absorption solution. For the ion-selective electrode measurement, the technique of standard straight line was chosen. Concentrations of fluorides in spices and spice blends under investigation ranged from 3.15 mg·kg-1 to 26.08 mg·kg-1. In order to check the accuracy of the method Certified Reference Material Fluoride in Vegetation NIST 2695 was used and a good agreement between certified and found values was found. The precision expressed as the relative standard deviation ranged from 0.6% to 5.0%. The method is fast, accurate and reliable for this kind of analysis. In recent literature data on fluoride concentrations in spices and/or spice blends have not been found.

  3. Oral fluoride levels 1 h after use of a sodium fluoride rinse: effect of sodium lauryl sulfate.

    Science.gov (United States)

    Vogel, Gerald L; Schumacher, Gary E; Chow, Laurence C; Tenuta, Livia M A

    2015-01-01

    Increasing the concentration of free fluoride in oral fluids is an important goal in the use of topical fluoride agents. Although sodium lauryl sulfate (SLS) is a common dentifrice ingredient, the influence of this ion on plaque fluid and salivary fluid fluoride has not been examined. The purpose of this study was to investigate the effect of SLS on these parameters and to examine the effect of this ion on total (or whole) plaque fluoride, an important source of plaque fluid fluoride after a sufficient interval following fluoride administration, and on total salivary fluoride, a parameter often used as a surrogate measure of salivary fluid fluoride. Ten subjects accumulated plaque for 48 h before rinsing with a 12 mmol/l NaF (228 µg/g F) rinse containing or not containing 0.5% (w/w) SLS. SLS had no statistically significant effect on total plaque and total saliva fluoride but significantly increased salivary fluid and plaque fluid fluoride (by 147 and 205%, respectively). These results suggest that the nonfluoride components of topical agents can be manipulated to improve the fluoride release characteristics from oral fluoride reservoirs and that statistically significant change may be observed in plaque fluid and salivary fluid fluoride concentrations that may not be observed in total plaque and total saliva fluoride concentrations.

  4. Implementing a geographical information system to assess endemic fluoride areas in Lamphun, Thailand

    Directory of Open Access Journals (Sweden)

    Theerawasttanasiri N

    2018-01-01

    Full Text Available Nonthaphat Theerawasttanasiri,1,2 Surasak Taneepanichskul,1 Wichain Pingchai,3 Yuwaree Nimchareon,4 Sangworn Sriwichai5 1College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand; 2Department of Health, Health Promotion Center Region 1, Chiang Mai, Thailand; 3Mueang Lamphun District Public Health Office, 4Pasang District Public Health Office, 5Ban Thi District Public Health Office, Lamphun, Thailand Introduction: Many studies have shown that fluoride can cross the placenta and that exposure to high fluoride during pregnancy may result in premature birth and/or a low birth weight. Lamphun is one of six provinces in Thailand where natural water fluoride (WF concentrations >10.0 mg/L were found, and it was also found that >50% of households used water with high fluoride levels. Nevertheless, geographical information system (GIS and maps of endemic fluoride areas are lacking. We aimed to measure the fluoride level of village water supplies to assess endemic fluoride areas and present GIS with maps in Google Maps.Methods: A cross-sectional survey was conducted from July 2016 to January 2017. Purpose sampling was used to identify villages of districts with WF >10.0 mg/L in the Mueang Lamphun, Pasang, and Ban Thi districts. Water samples were collected with the geolocation measured by Smart System Info. Fluoride was analyzed with an ion-selective electrode instrument using a total ionic strength adjustment buffer. WF >0.70 mg/L was used to identify unsafe drinking water and areas with high endemic fluoride levels. Descriptive statistics were used to describe the findings, and MS Excel was used to create the GIS database. Maps were created in Google Earth and presented in Google Maps.Results: We found that WF concentrations ranged between 0.10–13.60 mg/L. Forty-four percent (n=439 of samples were at unsafe levels (>0.70 mg/L, and. 54% (n=303 of villages and 46% (n=79,807 of households used the unsafe drinking water. Fifty percent

  5. Fluoride contamination in the lakes region of the Ethiopian rift: origin, mechanism and evolution

    International Nuclear Information System (INIS)

    Travi, Y.; Chernet, T.

    1998-01-01

    The closed lake basins occupying the Main Ethiopian Rift are characterised by unique hydrogeological conditions which have resulted in very high contents of fluoride associated with highly concentrated sodium bicarbonate waters. The origin, mechanism and evolution of fluoride contents have been examined successively by studying (i) the reservoirs which provide this element in solution, (ii) the hydrochemical context, and (iii) the hydrological evolution which modifies the concentrations. Groundwaters of the ignimbrites present low values compared to those of the lacustrine sediments which can provide contents 5 to 10 times greater. The non equilibrium initial stage between the alkalinity and the calcium, derived from weathering of volcanic rocks, is responsible for the specific chemical evolution and the very high fluoride values. Furthermore, in the thermal waters, the high temperatures (especially those up to 100 deg. C) and the presence of large amounts of CO 2 coming from depth increase significantly the fluoride contents. Finally, the fluoride concentrations can change depending on the interrelation of ancient or present surface waters and groundwaters (mixing) and on the hydrological balance (concentration and dilution processes). (author)

  6. The cariostatic mechanisms of fluoride

    OpenAIRE

    Kata Rošin-Grget; Kristina Peroš; Ivana Šutej; Krešimir Bašić

    2013-01-01

    This article discusses the possible cariostatic mechanisms of the action of fluoride. In the past, fluoride inhibition of caries was ascribed to reduced solubility of enamel due to incorporation of fluoride (F–) into the enamel minerals. The present evidence from clinical and laboratory studies suggests that the caries-preventive mode of action of fluoride is mainly topical. There is convincing evidence that fluoride has a major effect on demineralisation and remineralisation of dental hard t...

  7. Taurine Ameliorates Renal Oxidative Damage and Thyroid Dysfunction in Rats Chronically Exposed to Fluoride.

    Science.gov (United States)

    Adedara, Isaac A; Ojuade, Temini Jesu D; Olabiyi, Bolanle F; Idris, Umar F; Onibiyo, Esther M; Ajeigbe, Olufunke F; Farombi, Ebenezer O

    2017-02-01

    Excessive exposure to fluoride poses several detrimental effects to human health particularly the kidney which is a major organ involved in its elimination from the body. The influence of taurine on fluoride-induced renal toxicity was investigated in a co-exposure paradigm for 45 days using five groups of eight rats each. Group I rats received normal drinking water alone, group II rats were exposed to sodium fluoride (NaF) in drinking water at 15 mg/L alone, group III received taurine alone at a dose of 200 mg/kg group IV rats were co-administered with NaF and taurine (100 mg/kg), while group V rats were co-administered with NaF and taurine (200 mg/kg). Administration of taurine significantly reversed the fluoride-mediated decrease in absolute weight and organo-somatic index of the kidney in the exposed rats. Taurine significantly prevented fluoride-induced elevation in plasma urea and creatinine levels in the exposed rats. Moreover, taurine restored fluoride-mediated decrease in the circulatory concentrations of triiodothyronine, thyroxine, and the ratio of triiodothyronine to thyroxine. Taurine ameliorated fluoride-mediated decrease in renal antioxidant status by significantly enhancing the antioxidant enzyme activities as well as glutathione level in the exposed rats. Additionally, taurine inhibited fluoride-induced renal oxidative damage by markedly decreasing the hydrogen peroxide and malondialdehyde levels as well as improved the kidney architecture in the treated rats. Collectively, taurine protected against fluoride-induced renal toxicity via enhancement of thyroid gland function, renal antioxidant status, and histology in rats.

  8. Synthesis of pillar and microsphere-like magnesium oxide particles and their fluoride adsorption performance in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Gool; Ha, Jong-Wook; Sohn, Eun-Ho; Park, In Jun; Lee, Soo-Bok [Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of)

    2017-10-15

    We synthesized pillar and microsphere-like MgO particles and their fluoride removal performance. Samples of MgO were synthesized by calcination of precursors derived from MgCO{sub 3}·3H{sub 2}O and characterized using field emission scanning electron microscopy, X-ray diffraction, and N{sub 2} adsorption-desorption isotherms. The fluoride removal performance of the MgO samples was investigated in terms of adsorption kinetics and adsorption equilibrium. The effects of pH and the presence of other anions on the fluoride adsorption were also considered. The adsorption capacities of pillar and microsphere-like MgO particles were 151.51 and 166.66mg/g, respectively. The pH of the aqueous solutions did not significantly affect the fluoride adsorption at pH 9 or lower. Except for phosphate, the effect of co-existing anions on fluoride adsorption was not considerable. Fluoride removal occurred through the substitution of hydroxyl groups on the surface of MgO with fluorides.

  9. Small molecule fluoride toxicity agonists.

    Science.gov (United States)

    Nelson, James W; Plummer, Mark S; Blount, Kenneth F; Ames, Tyler D; Breaker, Ronald R

    2015-04-23

    Fluoride is a ubiquitous anion that inhibits a wide variety of metabolic processes. Here, we report the identification of a series of compounds that enhance fluoride toxicity in Escherichia coli and Streptococcus mutans. These molecules were isolated by using a high-throughput screen (HTS) for compounds that increase intracellular fluoride levels as determined via a fluoride riboswitch reporter fusion construct. A series of derivatives were synthesized to examine structure-activity relationships, leading to the identification of compounds with improved activity. Thus, we demonstrate that small molecule fluoride toxicity agonists can be identified by HTS from existing chemical libraries by exploiting a natural fluoride riboswitch. In addition, our findings suggest that some molecules might be further optimized to function as binary antibacterial agents when combined with fluoride. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Fluoride varnishes and enamel caries

    NARCIS (Netherlands)

    Bruyn, Hugo de

    1987-01-01

    Topical fluoride applications have the aim of increasing the fluoride uptake in enamel and consequently reducing caries. In the early ‘60s fluoride varnishes were introduced because they had a long contact period with the enamel which resulted in a higher fluoride uptake than from other topical

  11. Daily Fluoride Intake from Iranian Green Tea: Evaluation of Various Flavorings on Fluoride Release

    Directory of Open Access Journals (Sweden)

    Afshin Maleki

    2016-01-01

    Full Text Available With increased awareness of the health benefits of the compounds in green tea, especially polyphenols, its consumption is rising. The main purpose of this study is to determine the effect of different additives on the released fluoride into tea liquor and also daily fluoride intake. The concentrations of fluoride, nitrate, sulfate, and chloride were measured in 15 different flavored green teas (Refah-Lahijan. The fluoride and other anion concentrations were measured by ion chromatography method. The data were analyzed with Statistical Package for the Social Sciences version 16.0. The results showed that the minimum and maximum concentrations of fluoride in the green tea infusions were 0.162 mg/L (cinnamon-flavored green tea and 3.29 mg/L (bagged peach-flavored green tea, respectively. The mean concentration of fluoride in the green tea leaves was 52 mg/kg, and approximately 89% of the fluoride was released from the green tea leaves into the infusions after brewing. The fluoride concentrations varied significantly among the examined green teas ( P 0.05. Finally, drinking of the studied green teas cannot make a significant contribution to the daily dietary intake of F for consumers.

  12. Preparation of uranium ingots from double fluorides

    International Nuclear Information System (INIS)

    Le Boulbin, E.

    1967-05-01

    A simple method has been developed for the preparation of uranium double fluorides and has given a new impetus to the study of the reduction of these compounds with a view to obtaining very pure uranium ingots. This reduction can be carried out using calcium or magnesium as the reducing agent, this latter metal being very interesting from the practical point of view. A comparative study of the heat balances of the reduction processes for the double fluorides and for uranium tetrafluoride has shown that reduction of the double fluorides is possible. The exact experimental conditions for these reductions have been determined. Our study has shown in particular that the reduction of the double salt UF 4 , CaF 2 by magnesium leads to the production of small (20 to 500 g) samples of high-purity uranium with a yield of 99 per cent. (author) [fr

  13. Uranyl fluoride luminescence in acidic aqueous solutions

    International Nuclear Information System (INIS)

    Beitz, J.V.; Williams, C.W.

    1996-01-01

    Luminescence emission spectra and decay rates are reported for uranyl species in acidic aqueous solutions containing HF or added NaF. The longest luminescence lifetime, 0.269 ± 0.006 ms, was observed from uranyl in 1 M HF + 1 M HClO 4 at 296 K and decreased with increasing temperature. Based on a luminescence dynamics model that assumes equilibrium among electronically excited uranyl fluoride species and free fluoride ion, this long lived uranyl luminescence in aqueous solution is attributed primarily to UO 2 F 2 . Studies on the effect of added LiNO 3 or Na 2 WO 4 ·2H 2 O showed relatively weak quenching of uranyl fluoride luminescence which suggests that high sensitivity determination of the UF 6 content of WF 6 gas should be feasible via uranyl luminescence analysis of hydrolyzed gas samples of impure WF 6

  14. Comparative evaluation of fluoride release from PRG-composites and compomer on application of topical fluoride: An in-vitro study

    Directory of Open Access Journals (Sweden)

    Dhull K

    2009-03-01

    Full Text Available Aims and Objective: To determine the fluoride release from Giomer and Compomer, using different topical fluoride regimes, and to compare the amount of fluoride release from giomer with that of compomer. Materials and Method: Forty-eight specimens of each giomer and compomer were divided into four treatment groups, namely, control group, fluoridated dentifrice (500 ppm once daily group, fluoridated dentifrice (500 ppm twice daily group, fluoridated dentifrice (500 ppm once daily + fluoridated mouthwash (225 ppm group. Each specimen was suspended in demineralizing solution for six hours and remineralizing solution for 18 hours. Fluoride release was measured in both the demineralizing solution and remineralizing solution daily for seven days. Total daily fluoride release for each specimen was calculated by adding the amount released in the demineralizing solution to that released in remineralizing solution. Results and Conclusion: The fluoride release (ppm was found to be more in Giomer when compared to Compomer. The fluoride released from Giomer and Compomer was significantly greater in the acidic demineralizing solution than in the neutral remineralizing solution. It was found that increasing fluoride exposure significantly increased fluoride release from the giomer and compomer. It was found that the fluoride release from the subgroups of giomer and compomer was in the following order: fluoridated dentifrice twice daily > fluoridated dentifrice once daily + fluoridated mouthwash > fluoridated dentifrice once daily > control group. It was found that the giomer showed a greater fluoride uptake than the compomer.

  15. "Effect of nano-filled surface coating agent on fluoride release from conventional glass ionomer cement: an in vitro trial".

    Science.gov (United States)

    Tiwari, S; Nandlal, B

    2013-01-01

    To overcome the drawbacks of glass ionomer cement of sensitivity to initial desiccation and moisture contamination the use of surface coating agent is recommended. The search in this area led to invent of use of nanofillers in surface coating agent, but its effect on fluoride release is not clear. The aim of this study is to evaluate and compare the fluoride release from conventional glass ionomer cement with and without surface coating agent. This in vitro study comprised of total 80 samples (40 samples of each with and without surface coating). Specimens were prepared, G coat plus was applied and light cured. Fluoride release of the sample was measured every 24 h for 7 days and weekly from 7th to 21 st day using Sension4 pH/ISE/MV Meter. Descriptive Statistics, Repeated Measure ANOVA, Paired Sample t-test, Independent Sample t-test, Scheffe post hoc test. Mean values clearly reveal a significant decrease in the fluoride release from day 1 to day 21 for both groups. Non-coated group released significantly more fluoride than surface coated group (Pagent will reduce the amount of fluoride released into oral environment as compared to non-coated group and at the same time releasing fluoride into surrounding cavity walls to create zones of inhibition into the cavity floor to help internal remineralization.

  16. Hydrothermal preparation of nickel(II)/uranium(IV) fluorides with one-, two-, and three-dimensional topologies.

    Science.gov (United States)

    Bean, Amanda C; Sullens, Tyler A; Runde, Wolfgang; Albrecht-Schmitt, Thomas E

    2003-04-21

    A modified compositional diagram for the reactions of Ni(C(2)H(3)O(2))(2).4H(2)O with UO(2)(C(2)H(3)O(2))(2).2H(2)O and HF in aqueous media under mild hydrothermal conditions (200 degrees C) has been completed to yield three Ni(II)/U(IV) fluorides, Ni(H(2)O)(4)UF(6).1.5H(2)O (1), Ni(2)(H(2)O)(6)U(3)F(16).3H(2)O (2), and Ni(H(2)O)(2)UF(6)(H(2)O) (3). The structure of 1 consists of one-dimensional columns constructed from two parallel chains of edge-sharing dodecahedral [UF(8)] units. The sides of the columns are terminated by octahedral Ni(II) units that occur as cis-[Ni(H(2)O)(4)F(2)] polyhedra. In contrast, the crystal structure of 2 reveals a two-dimensional Ni(II)/U(IV) architecture built from edge-sharing tricapped trigonal prismatic [UF(9)] units. The top and bottom of the sheets are capped by fac-[Ni(H(2)O)(3)F(3)] octahedra. The structure of 3 is formed from [UF(8)(H(2)O)] tricapped trigonal prisms that edge share with one another to form one-dimensional chains. These chains are then joined together into a three-dimensional network by corner sharing with trans-[Ni(H(2)O)(2)F(4)] octahedra. Crystallographic data: 1, orthorhombic, space group Cmcm, a = 14.3383(8) A, b = 15.6867(8) A, c = 8.0282(4) A, Z = 8; 2, hexagonal, space group P6(3)/mmc, a = 7.9863(5) A, c = 16.566(1) A, Z = 2; 3, monoclinic, space group C2/c, a = 12.059(1) A, b = 6.8895(6) A, c = 7.9351(7) A, beta = 92.833(2) degrees, Z = 4.

  17. Fluoride retention by kaolin clay

    DEFF Research Database (Denmark)

    Kau, P. M. H.; Smith, D. W.; Binning, Philip John

    1997-01-01

    To evaluate the potential effectiveness of kaolin clay liners in storage of fluoride contaminated waste, an experimental study of the sorption and desorption behaviour of fluoride in kaolin clay was conducted. The degree of fluoride sorption by kaolin was found to depend on solution p......H and available fluoride concentration with equilibrium being achieved within 24 h. A site activation process involving the uptake of fluoride was also observed at the initial stages of sorption. This behaviour was attributed to a layer expansion process of the clay during sorption. The maximum fluoride sorption...... capacity was found to be 18.3 meq/100 g at pH 6 and 8.6 meq/100 g at pH 7. A competitive Langmuir sorption isotherm where sorption is dependant on both pH and fluoride concentration is employed to characterise the experimental sorption and desorption data. The sorption and desorption isotherms revealed...

  18. Story of Fluoridation

    Science.gov (United States)

    ... Home Health Info Health Topics Fluoride Share The Story of Fluoridation It started as an observation, that ... this time using photospectrographic analysis, a more sophisticated technology than that used by McKay. Churchill asked an ...

  19. Private Well Water and Fluoride

    Science.gov (United States)

    ... Private Wells Infant Formula Fluorosis Public Health Service Recommendation Water Operators & Engineers Water Fluoridation Additives Shortages of Fluoridation Additives Drinking Water Pipe Systems CDC-Sponsored Water Fluoridation Training Links to Other ...

  20. Fluoride in diet

    Science.gov (United States)

    Diet - fluoride ... bones and teeth. Too much fluoride in the diet is very rare. Rarely, infants who get too ... of essential vitamins is to eat a balanced diet that contains a variety of foods from the ...

  1. Level of Fluoride in Soil, Grain and Water in Jalgaon District, Maharashtra, India.

    Science.gov (United States)

    Naik, Rahul Gaybarao; Dodamani, Arun Suresh; Vishwakarma, Prashanth; Jadhav, Harish Chaitram; Khairnar, Mahesh Ravindra; Deshmukh, Manjiri Abhay; Wadgave, Umesh

    2017-02-01

    Fluoride has an influence on both oral as well as systemic health. The major source of fluoride to body is through drinking water as well as through diet. Staple diet mainly depends on local environmental factors, food grains grown locally, its availability etc. Determination of fluoride level in these food grains is important. So, estimation of the amount of fluoride in grains and its relation to the sources of fluoride used for their cultivation viz., soil and water is important. To estimate the relation of fluoride concentration in grains (Jowar) with respect to that of soil and water used for their cultivation. Fifteen samples each of soil, water and grains were collected using standardized method from the same farm fields of randomly selected villages of Jalgaon district. Fluoride ion concentration was determined in laboratory using SPADNS technique. Mean difference in fluoride levels in between the groups were analyzed using ANOVA and Post-Hoc Tukey test. Linear regression method was applied to analyse the association of the fluoride content of grain with water and soil. There was a significant difference in between mean fluoride levels of soil and water (pwater and grain was found to be non significant (p=0.591). Also fluoride levels in all the three groups showed significant association with each other. Fluoride level of soil, grains and water should be adjusted to an optimum level. Soil has positive correlation with respect to uptake of fluoride by Jowar grains. So, Jowar grains with optimum fluoride content should be made available in the commercial markets so that oral and general health can be benefitted.

  2. Measurement of the deuterium concentration in water samples using a CW chemical deuterium fluoride laser

    International Nuclear Information System (INIS)

    Trautmann, M.

    1979-10-01

    In this study a new method for the determination of the deuterium content in water samples is described. The absorption of the radiation of a CW deuterium fluoride laser by the isotope HDO in the water vapor of the sample is measured by means of an optoacoustic detector (spectrophone). Thereby advantage is taken of the fact that H 2 O hardly absorbs the laser radiation and that D 2 O only exists in negligible concentrations. The isotope ratio of hydrogen can be calculated from the measured relative concentration of HDO. In the course of this investigation the relative absorption cross sections of HDO for the different laser lines were determined. It was thereby established that there exists a very good coincidence of an HDO absorption line with the 2P2 laser line. Using a very sensitive nonresonant spectrophone the relative concentration of HDO in natural water samples could be determined with an accuracy of about 10%. The experiments also demonstrated that with appropriate improvements made to the apparatus and using a second spectrophone as a reference it should be possible to increase this accuracy to 0,1%. (orig.)

  3. Effect of CO2 Laser and Fluoride Varnish Application on Microhardness of Enamel Surface Around Orthodontic Brackets.

    Science.gov (United States)

    Mahmoudzadeh, Majid; Rezaei-Soufi, Loghman; Farhadian, Nasrin; Jamalian, Seyed Farzad; Akbarzadeh, Mahdi; Momeni, Mohammadali; Basamtabar, Masome

    2018-01-01

    Introduction: Orthodontic treatment has many advantages such as esthetic improvement and self-esteem enhancement; yet it has some disadvantages such as increasing the risk of formation of white spot lesions, because it makes oral hygiene more difficult. It is rational to implement procedures to prevent these lesions. The present study was aimed to assess the effect of CO 2 laser and fluoride varnish on the surface of the enamel surface microhardness around the orthodontic braces. Methods: Eighty extracted premolar teeth were selected, scaled, polished with nonfluoridated pumic and metal brackets were bonded to them. Then, they were randomly allocated to 5 groups: control (neither fluoride nor laser is used on enamel surfaces), fluoride (4 minutes fluoride varnish treatment of the enamel surfaces), CO 2 laser (10.6 µm CO 2 laser irradiation of the teeth), laserfluoride (fluoride application after laser irradiation) and fluoride-laser (fluoride was applied and then teeth were irradiated with laser). After surface treatment around brackets on enamel, the samples were stored in 0.1% thymol for less than 5 days and then they were exposed to a 10-day microbiological caries model. Microhardness values of enamel were evaluated with Vickers test. One sample of each group (5 teeth from 80 samples) was prepared for SEM (scanning electron microscopy) and the data from 75 remaining teeth were analyzed with analysis of variance (ANOVA) and chi-square tests (α =0.05). Results: Microhardness mean values from high to low were as follow: fluoride-laser, laser-fluoride, laser, fluoride and control. Microhardness in fluoride-laser group was significantly higher compared with that of the control group. Distribution adhesive remnant index (ARI) scores were significantly different between groups and most of bond failures occurred at the enamel-adhesive interface in groups 2 to 5 and at the adhesive-bracket interface in the control group. Conclusion: Combination of fluoride varnish and

  4. Urinary fluoride excretion by children 4-6 years old in a south Texas community

    Directory of Open Access Journals (Sweden)

    Ramon J. Baez

    2000-04-01

    Full Text Available This study evaluated urinary fluoride excretion by school children 4-6 years old who were living in a south Texas rural community that had concentrations of fluoride in drinking water supplies generally around the optimal level. We took supervised collections of urine samples in the morning and afternoon at school, and parents of the participating students collected nocturnal samples. We recorded the beginning and end times of the three collection periods and then determined the urinary volume and urinary flow for each of the periods. We measured urinary fluoride concentrations and calculated the urinary excretion rate per hour. The children had breakfast and lunch provided at the school, where the drinking water contained 1.0-1.3 milligrams/liter (mg/L fluoride. Fluoride concentrations in the tested household water supplies, from wells, ranged from 0.1 to 3.2 mg/L fluoride. The children's average urinary fluoride concentrations found for the day were similar to those for the night, with means ranging from 1.26 mg/L to 1.42 mg/L. Average excretion was 36.4 µg/h in the morning, 45.6 µg/h in the afternoon, and 17.5 µg/h at night. The lower nocturnal excretion rates are easily explained by low urinary flow at night. Based on the 15 hours of urine collected, the extrapolated 24-hour fluoride excretion was 749 µg. In conjunction with similar studies, the data from this study will help in developing upper limits for urinary fluoride excretion that are appropriate for avoiding unsightly fluorosis while providing optimal protection against dental decay.

  5. Correlation among fluoride and metals in irrigation water and soils of Ethiopian Rift Valley

    Directory of Open Access Journals (Sweden)

    Elias Gizaw

    2014-05-01

    Full Text Available The levels of fluoride and selected metals in Ethiopian Rift Valley soils and irrigation water in the nearby sources were determined by fluoride ion selective electrode and flame atomic absorption spectrophotometer, respectively. The pH, conductivity, salinity and total dissolved solids in water and soil samples were also determined. Accuracy of the optimized procedure was evaluated using standard addition (spiking method and an acceptable percentage recovery was obtained. The fluoride concentrations in water samples were found in the range of 0.14-8.0 mg/L which is below the WHO limit of fluoride concentration for irrigation (less than 10 mg/L. The water soluble and total fluorides in soil were 2.3-16 µg/g and 209-1210 µg/g, respectively and are within the ranges recommended by FAO and WHO. The range of metal concentration in soil samples (µg/g dry weight basis and in water samples (mg/L respectively were: Na (684-6703, 8.6-67, Mg (1608-11229, 23-67, K (1776-4394, 1.1-20, Ca (7547-22998, 17-267, Cr (9.8-79, 0.07-0.17, Mn (143-700, 0.05-37, Co (50-112, 0.35-1.5, Ni (446-1288, 0.27-41, Fe (12180-32681, 6.0-48, Cu (8.9-45, 0.09-0.25 and Zn (31-89, 0.14-0.56. Fluoride was found to have significant correlation with major trace metals (Fe, Cu and Cr, but the correlation with other trace metals was not significant. DOI: http://dx.doi.org/10.4314/bcse.v28i2.7

  6. Organoboron compounds as Lewis acid receptors of fluoride ions in polymeric membranes.

    Science.gov (United States)

    Jańczyk, Martyna; Adamczyk-Woźniak, Agnieszka; Sporzyński, Andrzej; Wróblewski, Wojciech

    2012-07-06

    Newly synthesized organoboron compounds - 4-octyloxyphenylboronic acid (OPBA) and pinacol ester of 2,4,6-trifluorophenylboronic acid (PE-PBA) - were applied as Lewis acid receptors of fluoride anions. Despite enhanced selectivity, the polymer membrane electrodes containing the lipophilic receptor OPBA exhibited non-Nernstian slopes of the responses toward fluoride ions in acidic conditions. Such behavior was explained by the lability of the B-O bond in the boronic acids, and the OH(-)/F(-) exchange at higher fluoride content in the sample solution. In consequence, the stoichiometry of the OPBA-fluoride complexes in the membrane could vary during the calibration, changing the equilibrium concentration of the primary anion in membrane and providing super-Nernstian responses. The proposed mechanism was supported by (19)F NMR studies, which indicated that the fluoride complexation proceeds more effectively in acidic solution leading mainly to PhBF(3)(-) species. Finally, the performances of the membranes based on the phenylboronic acid pinacol ester, with a more stable B-O bond, were tested. As it was expected, Nernstian fluoride responses were recorded for such membranes with worsened fluoride selectivity. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. 40 CFR Appendix II to Part 600 - Sample Fuel Economy Calculations

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Sample Fuel Economy Calculations II... FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Pt. 600, App. II Appendix II to Part 600—Sample Fuel Economy Calculations (a) This sample fuel economy calculation is applicable to...

  8. Effect of Resveratrol on Hematological and Biochemical Alterations in Rats Exposed to Fluoride

    Directory of Open Access Journals (Sweden)

    Nurgül Atmaca

    2014-01-01

    Full Text Available We investigated the protective effects of resveratrol on hematological and biochemical changes induced by fluoride in rats. A total of 28 rats were divided into 4 groups: control, resveratrol, fluoride, and fluoride/resveratrol (n=7 each, for a total of 21 days of treatment. Blood samples were taken and hematological and biochemical parameters were measured. Compared to the control group, the fluoride-treated group showed significant differences in several hematological parameters, including decreases in WBC, RBC, and PLT counts and neutrophil ratio. The group that received resveratrol alone showed a decrease in WBC count compared to the control group. Furthermore, in comparison to the control group, the fluoride group showed significantly increased ALT enzyme activity and decreased inorganic phosphorus level. The hematological and biochemical parameters in the fluoride + resveratrol treated group were similar to control group. In the fluoride + resveratrol group, resveratrol restored the changes observed following fluoride treatment, including decreased counts of WBC, RBC, and PLT, decreased neutrophil ratio and inorganic phosphorus levels, and elevated ALT enzyme activity. The present study showed that fluoride caused adverse effects in rats and that resveratrol reduced hematological and biochemical alterations produced by fluoride exposure.

  9. Fluoride concentration level in rural area in Poldasht city and daily fluoride intake based on drinking water consumption with temperature.

    Science.gov (United States)

    Mohammadi, Ali Akbar; Yousefi, Mahmood; Mahvi, Amir Hossein

    2017-08-01

    Long-term exposure to high level of fluoride can caused several adverse effects on human health including dental and skeletal fluorosis. We investigated all the drinking water source located in rural areas of Poldasht city, west Azerbaijan Province, North West Iran between 2014 and 2015. Fluoride concentration of water samples was measured by SPADNS method. We found that in the villages of Poldasht the average of fluoride concentration in drinking water sources (well, and the river) was in the range mg/l 0.28-10.23. The average daily received per 2 l of drinking water is in the range mg/l 0.7-16.6 per day per person. Drinking water demands cause fluorosis in the villages around the area residents and based on the findings of this study writers are announced suggestions below in order to take care of the health of area residents.

  10. Evaluation of the precision in fluoride determination in uranium concentrate

    International Nuclear Information System (INIS)

    Palmieri, Helena E. Leonhardt; Rocha, Zildete; Mata, Maria Olivia Cintra

    1995-01-01

    The fluoride in uranium concentrate is previously separated by steam distillation and then determined by direct potentiometric with an ion-select electrode. The potential of all ion-specific electrodes is a logarithmic function of the concentration of the ion to which the electrode in question responds. This relationship is expressed by the Nernst equation. A calibration curve, potential (mV) versus standard fluoride concentration is established and then the sample concentration is determined by interpolation. A least squares curve-fitting procedure has been used to determine the parameters of this calibration curve equation. Using these parameters are determined the standard deviation, the confidence limits and the precision of the fluoride concentrations. (author). 3 refs., 2 figs., 1 tab

  11. Physiology and toxicity of fluoride

    Directory of Open Access Journals (Sweden)

    Dhar Vineet

    2009-01-01

    Full Text Available Fluoride has been described as an essential element needed for normal development and growth of animals and extremely useful for human beings. Fluoride is abundant in the environment and the main source of fluoride to humans is drinking water. It has been proved to be beneficial in recommended doses, and at the same time its toxicity at higher levels has also been well established. Fluoride gets accumulated in hard tissues of the body and has been know to play an important role in mineralization of bone and teeth. At high levels it has been known to cause dental and skeletal fluorosis. There are suggested effects of very high levels of fluoride on various body organs and genetic material. The purpose of this paper is to review the various aspects of fluoride and its importance in human life.

  12. Physiology and toxicity of fluoride.

    Science.gov (United States)

    Dhar, Vineet; Bhatnagar, Maheep

    2009-01-01

    Fluoride has been described as an essential element needed for normal development and growth of animals and extremely useful for human beings. Fluoride is abundant in the environment and the main source of fluoride to humans is drinking water. It has been proved to be beneficial in recommended doses, and at the same time its toxicity at higher levels has also been well established. Fluoride gets accumulated in hard tissues of the body and has been know to play an important role in mineralization of bone and teeth. At high levels it has been known to cause dental and skeletal fluorosis. There are suggested effects of very high levels of fluoride on various body organs and genetic material. The purpose of this paper is to review the various aspects of fluoride and its importance in human life.

  13. Relationship between water, urine and serum fluoride and fluorosis in school children of Jhajjar District, Haryana, India

    Science.gov (United States)

    Kumar, Sunil; Lata, Suman; Yadav, Jyoti; Yadav, J. P.

    2017-10-01

    The present study was undertaken to determine the relationship between fluoride in water, urine and serum and dental fluorosis. The fluoride level in water and urine were measured spectrophotometrically by using acid zirconyl and SPADNS reagents, while the fluoride level in serum was determined by ion selective electrode meter. Dental fluorosis survey was conducted with the help of Performa prescribed by Rajiv Gandhi Drinking Water Mission and the use of Tooth Surface Index for Fluorosis. Mean fluoride values in water samples of Jhajjar City and Dadanpur and Dariyapur villages of Jhajjar District were measured to be 2.17 (range from 1.92 to 2.60 mg/L), 2.81 (range from 2.53 to 3.14 mg/L) and 2.22 mg/L (range from 1.63 to 3.33 mg/L), respectively. The mean fluoride values in the urine samples of children were found to be 1.51 (range from 0.05 to 2.64 mg/L), 1.71 (range from 0.69 to 2.80 mg/L) and 1.45 mg/L (range from 0.31 to 2.50 mg/L) at Jhajjar City and Dadanpur and Dariyapur sites, respectively. Serum fluoride was detected in the blood samples of children, who have high urinary fluoride at these three sites. The mean serum fluoride level was reported to be 0.15, 0.34 and 0.17 mg/L, respectively. A total of 842 children were also analyzed for dental fluorosis. The mean values of fluorosis-affected children in Jhajjar, Dadanpur and Dariyapur were 51.90, 94.63 and 36.84 %, respectively. A significantly positive correlation between water, urine, serum fluoride concentration and fluorosis was seen.

  14. Fluoride barriers in Nb/Pb Josephson junctions

    Science.gov (United States)

    Asano, H.; Tanabe, K.; Michikami, O.; Igarashi, M.; Beasley, M. R.

    1985-03-01

    Josephson tunnel junctions are fabricated using a new class of artificial barriers, metal fluorides (Al fluoride and Zr fluoride). These fluoride barriers are deposited on the surface of a Nb base electrode, which are previously cleaned using a CF4 cleaning process, and covered by a Pb counterelectrode. The junctions with both Al fluoride and Zr fluoride barriers exhibit good tunneling characteristics and have low specific capacitance. In the case of Zr fluoride, it is observed that reasonable resistances are obtained even at thickness greater than 100 A. This phenomenon might be explained by tunneling via localized states in Zr fluoride.

  15. Fluoride release and surface roughness of a new glass ionomer cement: glass carbomer

    Directory of Open Access Journals (Sweden)

    Célia Maria Condeixa de França LOPES

    2018-02-01

    Full Text Available Abstract Objective This study analyzed the fluoride release/recharge and surface roughness of glass carbomer compared to other encapsulated glass ionomer cements (GICs. Material and method The GICs tested were Glass Fill® (GC-GCP Dental, Riva Self Cure® (RS-SDI, Riva Light Cure® (RL-SDI, Equia Fil® (EF-GC Europe. The composite resin Luna® (LU-SDI was used as control. Five samples of each material were prepared and kept in a humidifier for 24 hours (37 °C, 100% relative humidity. Fluoride release was measured in two times: before (T1: days 1, 2, 7, 14 and after topical application of fluoride (T2: days 15, 16, 21 and 28. The surface roughness was also measured in both times (T1: days 1 and 14; T2: days 15 and 28. All samples were submitted to a single topical application of acidulated fluoride phosphate (Fluor Care - FGM. Two-way ANOVA with repeated measures and Tukey's post-test (p <0.05 were used in the statistical analysis. Result Equia Fil presented the highest fluoride release in both evaluation periods, with a higher release in T1 (p <0.05. The other materials tested, including glass carbomer presented similar release in both periods (T1 and T2. Regarding surface roughness, no significant differences were observed in the interaction between the material × time factors (T1 and T2 (p=0.966. Conclusion The GICs tested presented fluoride release and recharge ability and showed no surface roughness increase by topical application of fluoride.

  16. Water Fluoridation: A Critical Review of the Physiological Effects of Ingested Fluoride as a Public Health Intervention

    Science.gov (United States)

    2014-01-01

    Fluorine is the world's 13th most abundant element and constitutes 0.08% of the Earth crust. It has the highest electronegativity of all elements. Fluoride is widely distributed in the environment, occurring in the air, soils, rocks, and water. Although fluoride is used industrially in a fluorine compound, the manufacture of ceramics, pesticides, aerosol propellants, refrigerants, glassware, and Teflon cookware, it is a generally unwanted byproduct of aluminium, fertilizer, and iron ore manufacture. The medicinal use of fluorides for the prevention of dental caries began in January 1945 when community water supplies in Grand Rapids, United States, were fluoridated to a level of 1 ppm as a dental caries prevention measure. However, water fluoridation remains a controversial public health measure. This paper reviews the human health effects of fluoride. The authors conclude that available evidence suggests that fluoride has a potential to cause major adverse human health problems, while having only a modest dental caries prevention effect. As part of efforts to reduce hazardous fluoride ingestion, the practice of artificial water fluoridation should be reconsidered globally, while industrial safety measures need to be tightened in order to reduce unethical discharge of fluoride compounds into the environment. Public health approaches for global dental caries reduction that do not involve systemic ingestion of fluoride are urgently needed. PMID:24719570

  17. Solid-phase extraction of Mn(II), Co(II), Ni(II), Cu(II), Cd(II) and Pb(II) ions from environmental samples by flame atomic absorption spectrometry (FAAS)

    Energy Technology Data Exchange (ETDEWEB)

    Duran, Celal [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey); Gundogdu, Ali [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey); Bulut, Volkan Numan [Department of Chemistry, Giresun Faculty of Art and Science, Karadeniz Technical University, 28049 Giresun (Turkey); Soylak, Mustafa [Department of Chemistry, Faculty of Art and Science, Erciyes University, 38039 Kayseri (Turkey)]. E-mail: soylak@erciyes.edu.tr; Elci, Latif [Department of Chemistry, Faculty of Art and Science, Pamukkale University, 20020 Denizli (Turkey); Sentuerk, Hasan Basri [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey); Tuefekci, Mehmet [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey)

    2007-07-19

    A new method using a column packed with Amberlite XAD-2010 resin as a solid-phase extractant has been developed for the multi-element preconcentration of Mn(II), Co(II), Ni(II), Cu(II), Cd(II), and Pb(II) ions based on their complex formation with the sodium diethyldithiocarbamate (Na-DDTC) prior to flame atomic absorption spectrometric (FAAS) determinations. Metal complexes sorbed on the resin were eluted by 1 mol L{sup -1} HNO{sub 3} in acetone. Effects of the analytical conditions over the preconcentration yields of the metal ions, such as pH, quantity of Na-DDTC, eluent type, sample volume and flow rate, foreign ions etc. have been investigated. The limits of detection (LOD) of the analytes were found in the range 0.08-0.26 {mu}g L{sup -1}. The method was validated by analyzing three certified reference materials. The method has been applied for the determination of trace elements in some environmental samples.

  18. Estimating concentration of fluoride in edible leaves locally grown around Raipur, Chhattisgarh

    Directory of Open Access Journals (Sweden)

    Anubhuti Jain

    2017-01-01

    Full Text Available Introduction: Fluorine is the 13th most abundant element in the earth crust and is available in various environmental, clinical, and food samples in varied concentrations. Aim: To estimate concentration of fluoride in five medicinal and five nonmedicinal edible leaves locally grown around Raipur, Chhattisgarh, India. Materials and Methods: Samples of ten medicinal and nonmedicinal edible leaves, namely, spinach (Spinacia oleracea, coriander leaves (Coriandrum sativum, chawli bhaji (Amaranthus spinach, lal bhaji (Alternanthera bettzickiana, mooli bhaji (Raphanus sativus, neem (Azadirachta indica, tulsi (Ocimum tenuiflorum, mint leaves (Mentha longifolia, betel leaves (Piper betle, and bael leaves (Aegle marmelos were collected in the clean polyethene bags. After thorough washing with water, leaves were left to dry in ambient temperature and crushed into powder using a mixer grinder. One gram of each of the powdered samples was taken and analyzed for fluoride concentration using a 2-(4-sulfophenylazo 1,8-dihydroxy-3,6-naphthalenedisulfonic acid trisodium salt spectrophotometric method. Results: The presence of fluoride in varied concentrations in locally grown edible leaves were analyzed. The highest concentration of fluoride was reported in tulsi (6.0 μg/g and lowest in mint leaves (1.1 μg/g. Two edible leaves, neem and bael, showed fluoride concentration below detection limit. Conclusion: Knowledge regarding the importance of edible leaves may be lost in the near future unless efforts are made to educate younger generations about their importance. Hence, the time has come to make good use of centuries-old knowledge through modern approaches for their better economic and therapeutic utilization.

  19. Fluoride Concentration in Water, Cow Milk and Cow Urine from Smallholder Dairy Farms in Kiambu- Kenya

    International Nuclear Information System (INIS)

    Gikunju, J.K.; Maitho, T.E.; Kyule, M.N.; Mitema, E.S.; Mugera, G.M.

    1999-01-01

    Kiambu district is situated in central part of Kenya. most of the available land is suitable for agricultural use. majority of the farmers are small scale or subsistence farmers and they are involve in a variety of livestock activities e.g. dairy production, pig production and others in combination or as separate operations. excessive fluoride ingestion can cause specific dental and skeletal lesions and in severe cases adversely influence the health and productivity performance of domestic animals.therefore a study was designed to investigate the levels of flouride in urine, milk and water samples from small scale dairy farms in Kiambu. Water, cow urine and milk samples were collected in clean plastic containers from 84 small scale farms belonging to 6 dairy farmers co-operative societies (DFCs). The DFCs in this study were Kiambaa, Lari, Nderi, Kikuyu, Chania and Limuru. The fluoride concentration in water milk and urine were analysed using the potentiometric method of fluoride ion specific electrode. overall urine contained the highest fluoride concentration while milk contained the lowest fluoride levels. Fluoride levels in water, milk and urine were significantly different, (P>0.05). The mean fluoride concentration in water from all societies was 0.29 ppm while the mean fluoride concentration in milk 0.05 ppm. urine samples had the highest fluoride concentration, (1.5 ppm). The cooperative specific mean fluoride concentrations arranged in descending order were as follow: Nderi (2.8 ppm), Kikuyu (2.4 ppm), Kiambaa(1.9 ppm), Chania (1.6 ppm), Limuru (1.3 ppm) and Lari (1.0 ppm). The maximum fluoride concentration encountered in water in this study was 3.4 ppm, however adverse productivity has been reported in dairy animals consuming as low as 2.15 ppm in drinking water. The mean milk production in in kilograms per day per cow ranged from 2.5 to 6.9 when all six dairy co-operative societies were taken into consideration. this is far below the expected production

  20. Review on fluoride-releasing restorative materials--fluoride release and uptake characteristics, antibacterial activity and influence on caries formation.

    Science.gov (United States)

    Wiegand, Annette; Buchalla, Wolfgang; Attin, Thomas

    2007-03-01

    The purpose of this article was to review the fluoride release and recharge capabilities, and antibacterial properties, of fluoride-releasing dental restoratives, and discuss the current status concerning the prevention or inhibition of caries development and progression. Information from original scientific full papers or reviews listed in PubMed (search term: fluoride release AND (restorative OR glass-ionomer OR compomer OR polyacid-modified composite resin OR composite OR amalgam)), published from 1980 to 2004, was included in the review. Papers dealing with endodontic or orthodontic topics were not taken into consideration. Clinical studies concerning secondary caries development were only included when performed in split-mouth design with an observation period of at least three years. Fluoride-containing dental materials show clear differences in the fluoride release and uptake characteristics. Short- and long-term fluoride releases from restoratives are related to their matrices, setting mechanisms and fluoride content and depend on several environmental conditions. Fluoride-releasing materials may act as a fluoride reservoir and may increase the fluoride level in saliva, plaque and dental hard tissues. However, clinical studies exhibited conflicting data as to whether or not these materials significantly prevent or inhibit secondary caries and affect the growth of caries-associated bacteria compared to non-fluoridated restoratives. Fluoride release and uptake characteristics depend on the matrices, fillers and fluoride content as well as on the setting mechanisms and environmental conditions of the restoratives. Fluoride-releasing materials, predominantly glass-ionomers and compomers, did show cariostatic properties and may affect bacterial metabolism under simulated cariogenic conditions in vitro. However, it is not proven by prospective clinical studies whether the incidence of secondary caries can be significantly reduced by the fluoride release of

  1. Silver diamine fluoride: a caries "silver-fluoride bullet".

    Science.gov (United States)

    Rosenblatt, A; Stamford, T C M; Niederman, R

    2009-02-01

    The antimicrobial use of silver compounds pivots on the 100-year-old application of silver nitrate, silver foil, and silver sutures for the prevention and treatment of ocular, surgical, and dental infections. Ag(+) kills pathogenic organisms at concentrations of linings, water purification systems, hospital gowns, and caries prevention. To distill the current best evidence relative to caries, this systematic review asked: Will silver diamine fluoride (SDF) more effectively prevent caries than fluoride varnish? A five-database search, reference review, and hand search identified 99 human clinical trials in three languages published between 1966 and 2006. Dual review for controlled clinical trials with the patient as the unit of observation, and excluding cross-sectional, animal, in vitro studies, and opinions, identified 2 studies meeting the inclusion criteria. The trials indicated that SDF's lowest prevented fractions for caries arrest and caries prevention were 96.1% and 70.3%, respectively. In contrast, fluoride varnish's highest prevented fractions for caries arrest and caries prevention were 21.3% and 55.7%, respectively. Similarly, SDF's highest numbers needed to treat for caries arrest and caries prevention were 0.8 (95% CI=0.5-1.0) and 0.9 (95% CI=0.4-1.1), respectively. For fluoride varnish, the lowest numbers needed to treat for caries arrest and prevention were 3.7 (95% CI=3.4-3.9) and 1.1 (95% CI=0.7-1.4), respectively. Adverse events were monitored, with no significant differences between control and experimental groups. These promising results suggest that SDF is more effective than fluoride varnish, and may be a valuable caries-preventive intervention. As well, the availability of a safe, effective, efficient, and equitable caries-preventive agent appears to meet the criteria of both the WHO Millennium Goals and the US Institute of Medicine's criteria for 21st century medical care.

  2. Development of multifunctional chitosan beads for fluoride removal

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, Natrayasamy [Department of Chemistry, Gandhigram Rural University, Gandhigram 624 302, Tamilnadu (India); Sairam Sundaram, C. [Department of Science and Humanities, Karaikal Polytechnic College, Karaikal 609 609, Puducherry (India); Meenakshi, S., E-mail: drs_meena@rediffmail.com [Department of Chemistry, Gandhigram Rural University, Gandhigram 624 302, Tamilnadu (India)

    2009-08-15

    Chitosan beads (CB) which have negligible defluoridation capacity (DC) have been chemically modified by introducing multifunctional groups, viz., NH{sub 3}{sup +} and COOH groups by means of protonation and carboxylation in order to utilize both amine and hydroxyl groups for fluoride removal. The protonated cum carboxylated chitosan beads (PCCB) showed a maximum DC of 1800 mg F{sup -}/kg whereas raw chitosan beads displayed only 52 mg F{sup -}/kg. Sorption process was found to be independent of pH and slightly influenced in the presence of other common anions. The fluoride sorption on modified forms was reasonably explained by Freundlich and Langmuir isotherms. The sorbents were characterised by FTIR and SEM with EDAX analysis. The sorption process follows pseudo-second-order and intraparticle diffusion kinetic models. The suitability of PCCB has been tested with field sample collected from a nearby fluoride endemic area.

  3. 49 CFR 173.163 - Hydrogen fluoride.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Hydrogen fluoride. 173.163 Section 173.163... Hydrogen fluoride. (a) Hydrogen fluoride (hydrofluoric acid, anhydrous) must be packaged as follows: (1) In... filling ratio of 0.84. (b) A cylinder removed from hydrogen fluoride service must be condemned in...

  4. FLUORIDE TOXICITY – A HARSH REALITY

    OpenAIRE

    Bandlapalli Pavani; Mandava Ragini; David Banji; Otilia J F Banji; N Gouri Pratusha

    2011-01-01

    There are many incidents of fluoride toxicity whether it is acute or chronic. Fluoride toxicity is an environmental hazard which arises from the upper layers of geological crust and is dissolved in water. Prolonged drinking of such water causes chronic fluoride toxicity. Use of fluoride containing compounds for various purposes such as dental products, metal, glass, refrigerator and chemical industries act as a source of fluoride poisoning and increase the risk of toxicity. This review reflec...

  5. Fluoride in groundwater: toxicological exposure and remedies.

    Science.gov (United States)

    Jha, S K; Singh, R K; Damodaran, T; Mishra, V K; Sharma, D K; Rai, Deepak

    2013-01-01

    Fluoride is a chemical element that is found most frequently in groundwater and has become one of the most important toxicological environmental hazards globally. The occurrence of fluoride in groundwater is due to weathering and leaching of fluoride-bearing minerals from rocks and sediments. Fluoride when ingested in small quantities (dental health by reducing dental caries, whereas higher concentrations (>1.5 mg/L) may cause fluorosis. It is estimated that about 200 million people, from among 25 nations the world over, may suffer from fluorosis and the causes have been ascribed to fluoride contamination in groundwater including India. High fluoride occurrence in groundwaters is expected from sodium bicarbonate-type water, which is calcium deficient. The alkalinity of water also helps in mobilizing fluoride from fluorite (CaF2). Fluoride exposure in humans is related to (1) fluoride concentration in drinking water, (2) duration of consumption, and (3) climate of the area. In hotter climates where water consumption is greater, exposure doses of fluoride need to be modified based on mean fluoride intake. Various cost-effective and simple procedures for water defluoridation techniques are already known, but the benefits of such techniques have not reached the rural affected population due to limitations. Therefore, there is a need to develop workable strategies to provide fluoride-safe drinking water to rural communities. The study investigated the geochemistry and occurrence of fluoride and its contamination in groundwater, human exposure, various adverse health effects, and possible remedial measures from fluoride toxicity effects.

  6. Antibacterial Properties of Calcium Fluoride-Based Composite Materials: In Vitro Study

    Science.gov (United States)

    Zarzycka, Beata; Grzegorczyk, Janina; Sokołowski, Krzysztof; Półtorak, Konrad; Sokołowski, Jerzy

    2016-01-01

    The aim of the study was to evaluate antibacterial activity of composite materials modified with calcium fluoride against cariogenic bacteria S. mutans and L. acidophilus. One commercially available conventional light-curing composite material containing fluoride ions (F2) and two commercially available flowable light-curing composite materials (Flow Art and X-Flow) modified with 1.5, 2.5, and 5.0 wt% anhydrous calcium fluoride addition were used in the study. Composite material samples were incubated in 0.95% NaCl at 35°C for 3 days; then dilution series of S. mutans and L. acidophilus strains were made from the eluates. Bacteria dilutions were cultivated on media afterwards. Colony-forming unit per 1 mL of solution (CFU/mL) was calculated. Composite materials modified with calcium fluoride highly reduced (p composite materials containing fluoride compounds. The greatest reduction in bacteria growth was observed for composite materials modified with 1.5% wt. CaF2. All three tested composite materials showed statistically greater antibacterial activity against L. acidophilus than against S. mutans. PMID:28053976

  7. Formation and transformation of the radiation-induced nearsurface color centers in sodium and lithium fluorides nanocrystals

    Science.gov (United States)

    Novikov, A. N.; Kalinov, V. S.; Radkevich, A. V.; Runets, L. P.; Stupak, A. P.; Voitovich, A. P.

    2017-11-01

    Near-surface color centers in sodium fluoride nanocrystals have been formed. At pre-irradiation annealing of sodium and lithium fluorides samples at temperatures of 623 K and above, the near-surface color centers in them have not been found after γ-irradiation. Annealing lithium fluoride nanocrystals with the near-surface defects leads to their transformation into bulk ones of the same composition.

  8. Effect of Fluoride Mouthrinse and Toothpaste on Number of Streptococcal Colony Forming Units of Dental Plaque

    Directory of Open Access Journals (Sweden)

    SE Jabbarifar

    2005-11-01

    Full Text Available Background: Frequent topical fluoride therapy through toothpaste, mouthrinse, professional gels and solutions causes decrease in incidence, pause and repair of dental caries in the enamel. These mechanisms are done through penetration of fluoride ions (F- and their replacement with hydroxyl ions (OH- of hydroxyappatite of enamel, interfere with microbial metabolism of dental plaque and bacteriostatic effect on some cariogenic bacterial strains such as streptococci. The aim of this study was to examine the effect of fluoride mouthrinse and toothpaste on the number of streptococcal colony forming units of dental plaque. Methods: 62 children with 6-7 years old were put in two groups. Samples of dental plaque from each group were collected both before and after use of the fluoride mouthrinse and or toothpaste. The samples were cultured on blood agar to find the number of streptococcal colony forming units (CFU. The mean colony forming unit was compared inter and intra groups before and after application of Fluoride products. Results: The streptococcal CFU of dental plaque before and after use of the mouthrinse and toothpaste respectively was (1240±1367, 1253±1341.5 and (551±716, 898±1151. Statistically, the streptococcal CFU in each group before and after use of the toothpaste and mouthrinse was significantly different. Conclusion: The findings of this study indicated that the fluoride toothpaste and mouthrinse reduce number of streptococcal colony forming units of dental plaque. Also this reduction was not depended on level of (F- Ions, sort of vehicle of fluoride and frequent application of the fluoride mouthrinse and toothpaste. Keywords: fluoride mouthrinse, fluoride toothpaste, colony forming unit (CFU, streptococcus

  9. Effect of fluoride in drinking water on children′s intelligence in high and low fluoride areas of Delhi

    Directory of Open Access Journals (Sweden)

    Hansa Kundu

    2015-01-01

    Full Text Available Introduction: Fluoride is one of the indispensable elements for the living being. However, the intake of F above the threshold level can affect the central nervous system even before causing dental or skeletal fluorosis. Aim: The aim was to assess the effect of fluoride in drinking water on the intelligence quotient (IQ of 8-12 years old school going children residing in high and low Fluoride (F areas of Delhi. Materials and Methods: A total of 200 school children were selected, 100 from low F area and 100 from high F area. The IQ of the children was assessed using Ravens Standardized Progressive Matrices Test. Information for each child′s sociodemographic data, mother′s diet during pregnancy, duration of residency in the village, source of drinking water, and duration of drinking water from the source was entered on a specially designed proforma from mothers of children. Height and weight were also recorded for each child to assess the nutritional status. Independent t-test and Chi-square test was used to compare mean IQ scores in high and low fluoridated areas. Pearson′s correlation and multivariate linear regression were used to appraise the issue of all the study variables on IQ. Results: Comparison of mean IQ of children in both high (76.20 ± 19.10 and low F (85.80 ± 18.85 areas showed a significant difference (P = 0.013. Multiple regression analysis between child IQ and all other independent variables revealed that mother′s diet during pregnancy (P = 0.001 along with F in drinking water (P = 0.017 were the independent variables with the greatest explanatory power for child IQ variance (r2 = 0.417 without interaction with other variables. Conclusion: Fluoride in the drinking water was significantly related with the IQ of children. Along with fluoride, mother′s diet during pregnancy was also found to be significantly related with IQ of children. Researches in the same field are further advocated with large sample size and over a

  10. Seasonal Variation in Fluoride Content in Groundwaters of Langtang Area, Northcentral Nigeria

    Science.gov (United States)

    Dibal, H. U.; Dajilak, W. N.; Lekmang, I. C.; Nimze, L. W.; Yenne, E. Y.

    2017-06-01

    Thirty groundwater samples were collected at the peak of the rainy season and analysed for fluoride and other cations and anions in drinking water sources of Langtang area. For comparative purposes, thirty seven groundwater samples were collected in the dry season. The aim of the study was to determine variation in fluoride content with respect to the seasons. Fluoride in water was determined by the Ion Selective Electrode (ISE) and the cations by the Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The anion (sulphate) was determined by Multi - Ion Colorimeter, bicarbonate and chloride by titration method. In addition fluorine content in aquifer materials from a borehole section were determined by Fusion method. The two seasons show variation in content of fluoride in groundwater. Fluoride content in groundwater is higher in the dry season ranging from 0.13 - 10.3 mg/l compared to the 0.06 - 4.60 mg/l values in the rainy season. Content of fluorine (0.01 wt %) in the aquifer materials (sands) is low from depth of 0 to 7.95 m. However, fluorine content increases with depth, from 7.95 to 10.60 m with concentration of 0.04 wt %, 0.05 wt % from 10.60 to 13.25m, and 0.07 wt % from 13.25 to 15.70 m, the content of fluorine however, decreased at depth 15.70 to18.55m with concentration of 0.02 wt % even with fluorite mineral in the aquifer material at this depth. Dilution of fluoride ion as a result of rain input which recharges the aquifer may be the main reason for lower values recorded in the rainy season. Over fifty and sixty percent of waters in both dry and rainy season have fluoride concentration above the WHO upper limit of 1.5 mg/l. Consumption of these elevated values of fluoride in groundwater of the study area, clearly manifests as symptoms of dental fluorosis.

  11. Seasonal Variation in Fluoride Content in Groundwaters of Langtang Area, Northcentral Nigeria

    Directory of Open Access Journals (Sweden)

    Dibal H.U.

    2017-06-01

    Full Text Available Thirty groundwater samples were collected at the peak of the rainy season and analysed for fluoride and other cations and anions in drinking water sources of Langtang area. For comparative purposes, thirty seven groundwater samples were collected in the dry season. The aim of the study was to determine variation in fluoride content with respect to the seasons. Fluoride in water was determined by the Ion Selective Electrode (ISE and the cations by the Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES. The anion (sulphate was determined by Multi – Ion Colorimeter, bicarbonate and chloride by titration method. In addition fluorine content in aquifer materials from a borehole section were determined by Fusion method. The two seasons show variation in content of fluoride in groundwater. Fluoride content in groundwater is higher in the dry season ranging from 0.13 – 10.3 mg/l compared to the 0.06 – 4.60 mg/l values in the rainy season. Content of fluorine (0.01 wt % in the aquifer materials (sands is low from depth of 0 to 7.95 m. However, fluorine content increases with depth, from 7.95 to 10.60 m with concentration of 0.04 wt %, 0.05 wt % from 10.60 to 13.25m, and 0.07 wt % from 13.25 to 15.70 m, the content of fluorine however, decreased at depth 15.70 to18.55m with concentration of 0.02 wt % even with fluorite mineral in the aquifer material at this depth. Dilution of fluoride ion as a result of rain input which recharges the aquifer may be the main reason for lower values recorded in the rainy season. Over fifty and sixty percent of waters in both dry and rainy season have fluoride concentration above the WHO upper limit of 1.5 mg/l. Consumption of these elevated values of fluoride in groundwater of the study area, clearly manifests as symptoms of dental fluorosis.

  12. Purification process of uranium hexafluoride containing traces of plutonium fluoride and/or neptunium fluoride

    International Nuclear Information System (INIS)

    Aubert, J.; Bethuel, L.; Carles, M.

    1983-01-01

    In this process impure uranium hexafluoride is contacted with a metallic fluoride chosen in the group containing lead fluoride PbF 2 , uranium fluorides UFsub(4+x) (0 3 at a temperature such as plutonium and/or neptunium are reduced and pure uranium hexafluoride is recovered. Application is made to uranium hexafluoride purification in spent fuel reprocessing [fr

  13. The influence of salivary variables on fluoride retention in dental plaque exposed to a mineral-enriching solution.

    Science.gov (United States)

    Kato, K; Nakagaki, H; Arai, K; Pearce, E I F

    2002-01-01

    This study was carried out to examine interindividual differences in salivary variables related to plaque accumulation and to estimate their influence on the fluoride retention in plaque in vivo by a mineral-enriching solution. Two saliva samples were taken from 10 subjects, once after brushing and once after 24 h without brushing. Calcium, phosphate and monofluorophosphatase (MFPase) activity in the saliva samples were determined. The salivary flow rate and the debris index were also recorded. After plaque had formed over 3 days within in situ plaque-generating devices, subjects were instructed to rinse with a mineral-enriching mouthrinse three times a day on 4 consecutive days. Plaque exposed to distilled water plus flavoring agents served as a control. Fluoride-free dentifrice was used during the experimental period. Twenty-four hours after the last rinsing, the samples were removed from the mouth, and fluoride and mineral distributions in plaque analyzed using a method previously reported by the authors. Salivary flow, MFPase activity and calcium concentration in saliva were significantly higher after 24 h of plaque accumulation. Rinsing with the mineral-enriching solution produced retention of fluoride and phosphate in the outer and middle layers of plaque. Salivary calcium concentration had a direct effect on fluoride uptake in plaque, but no obvious relationship was found between other salivary variables and the plaque fluoride retention. The salivary calcium effect may be due to enhanced bacterial cell wall binding of fluoride via calcium bridging. Copyright 2002 S. Karger AG, Basel

  14. Physiology and toxicity of fluoride

    OpenAIRE

    Dhar Vineet; Bhatnagar Maheep

    2009-01-01

    Fluoride has been described as an essential element needed for normal development and growth of animals and extremely useful for human beings. Fluoride is abundant in the environment and the main source of fluoride to humans is drinking water. It has been proved to be beneficial in recommended doses, and at the same time its toxicity at higher levels has also been well established. Fluoride gets accumulated in hard tissues of the body and has been know to play an important role in mineralizat...

  15. Quantification of trace level of fluoride content in uranium oxide produced by deconversion of HEX gas by ion chromatography

    International Nuclear Information System (INIS)

    Unnikrishnan, E.K.; Padmakumar, P.R.; Shanmugavelu, P.; Sudhakar, T.M.; Bhowmik, A.

    2015-01-01

    Fluoride content in nuclear fuel is detrimental due to its corrosion behavior with cladding material. It is essential to monitor and control the fluoride concentration in nuclear material at various processing stages. Deconversion of upgraded HEX gas is carried out to produce uranium oxide. The performance of the deconversion process of HEX gas is evaluated for which trace level of fluoride concentration accompanying uranium oxide is considered as a marker. An analytical method has been developed for testing the uranium oxide produced from deconversion process of HEX gas. The method involves sample pretreatment followed by analysis using ion chromatography. The test method was validated for its performance using in house synthetic uranyl fluoride (UO 2 F 2 ) standard solutions prepared with different level of fluoride content. The results are in agreement with the expected values with the recovery in the range of 80-95%. This method has been successfully implemented for routine analysis of samples at our lab. Since UO 2 F 2 reference material is not available to validate this method, in house UO 2 F 2 standards were prepared from U 3 O 8 prepared from nuclear grade uranyl nitrate solution. UO 2 F 2 standards were prepared by converting U 3 O 8 to UO 2 F 2 by the addition of HF followed by H 2 O 2 at 200°C on a hot plate. The entire yellow colored UO 2 F 2 was dissolved in nano pure water and recrystallised several times to ensure that all free HF is removed. The crystals dried in air oven at 120° for three hours. Samples containing 1000 mg kg -1 fluoride prepared from this UO 2 F 2 , and subsequently from this sample containing 5 mg kg -1 to 35 mg kg -1 fluoride samples were prepared and analysed against fluoride CRM and the fluoride concentration obtained was analysed

  16. Fluoride resistance in Streptococcus mutans

    NARCIS (Netherlands)

    Liao, Ying

    2017-01-01

    Fluoride has been used as the most effective anti-caries agent for over five decades. It functions not only on the dental hard tissues, but also as an antimicrobial agent. It is known that oral bacteria are able to develop resistance to fluoride, which may affect the effectiveness of fluoride in

  17. Molecular mechanisms of fluoride toxicity.

    Science.gov (United States)

    Barbier, Olivier; Arreola-Mendoza, Laura; Del Razo, Luz María

    2010-11-05

    Halfway through the twentieth century, fluoride piqued the interest of toxicologists due to its deleterious effects at high concentrations in human populations suffering from fluorosis and in in vivo experimental models. Until the 1990s, the toxicity of fluoride was largely ignored due to its "good reputation" for preventing caries via topical application and in dental toothpastes. However, in the last decade, interest in its undesirable effects has resurfaced due to the awareness that this element interacts with cellular systems even at low doses. In recent years, several investigations demonstrated that fluoride can induce oxidative stress and modulate intracellular redox homeostasis, lipid peroxidation and protein carbonyl content, as well as alter gene expression and cause apoptosis. Genes modulated by fluoride include those related to the stress response, metabolic enzymes, the cell cycle, cell-cell communications and signal transduction. The primary purpose of this review is to examine recent findings from our group and others that focus on the molecular mechanisms of the action of inorganic fluoride in several cellular processes with respect to potential physiological and toxicological implications. This review presents an overview of the current research on the molecular aspects of fluoride exposure with emphasis on biological targets and their possible mechanisms of involvement in fluoride cytotoxicity. The goal of this review is to enhance understanding of the mechanisms by which fluoride affects cells, with an emphasis on tissue-specific events in humans. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  18. The synthesis and structural characterization of novel transition metal fluorides

    Energy Technology Data Exchange (ETDEWEB)

    Casteel, Jr., William Jack [Univ. of California, Berkeley, CA (United States)

    1992-09-01

    High purity KMF6 and K2MF6 salts (M = Mo,Re, Ru, Os, Ir, Pt) are obtained from reduction hexafluorides. A rhombohedral unit cell is observed for KReF6. Fluoride ion capture by Lewis acids from the hexafluorometallate (IV) salts affords high purity tetrafluorides for M = Mo, Re, Ru, Os, and Pd. The structure of RuF4 is determined from X-ray synchrotron and neutron powder data. Unit cells based on theorthorhombic PdF4 type cell are derived from X-ray powder data for ReF4 and OsF4. Fluoride ion capture from KAgF4 provides the thermally unstable trifluoride as a bright, red, diamagnetic solid. The structure solution of AgF3 and redetermination of the AuF3 structure from X-ray synchrotron and neutron powder data demonstrate that the two are isostnictural. Thermal decomposition product of AgF3 is the mixed valence compound AgIIAg2IIIF8. Several new salts containing the (Ag - F)$n+\\atop{n}$ chain cation are prepared. The first linear (Ag - F)$n+\\atop{n}$ chain is observed in AgF+BF4- which crystallizes in a tetragonal unit. AgFAuF4 has a triclinic unit cell and is isostructural with CuFAuF4. AgFAuF6 has an orthorhombic unit cell and appears to be isostructural with AgFAsF6. A second mixed valence silver fluoride, AgIIAgIIIF5, is prepared, which magnetic measurements indicate is probably an AgF+ salt. Magnetic data for all of the AgF+ salts exhibit low magnitude, temperature independent paramagnetism characteristic of metallic systems. Cationic AG(II) in acidic AHF solutions is a powerful oxidizer, capable of oxidizing Xe to Xe(II) and O2 to O2+. Reactions with C6F6 and C3F6 suggest an electron capture

  19. The determination of small amounts of fluoride in uranium compounds by use of an ion-selective electrode

    International Nuclear Information System (INIS)

    Shelton, B.M.

    1975-01-01

    A method is presented for the determination of fluoride in uranium metal and oxide at levels from 16 p.p.m. upwards. Uranium is separated from fluoride by extraction into a solution of di(2-ethylhexyl)-phosphoric acid (HDEHP) in carbon tetrachloride. The fluoride remaining in the aqueous phase is determined by potentiometric measurement with an ion-selective electrode. A correction is made for the fluoride lost during the dissolution or extraction step, or both, which is based on a determination of the apparent loss of fluoride on spiked samples that are taken through the whole procedure [af

  20. Fluoride-releasing restorative materials and secondary caries.

    Science.gov (United States)

    Hicks, John; Garcia-Godoy, Franklin; Donly, Kevin; Flaitz, Catherine

    2003-03-01

    Secondary caries is responsible for 60 percent of all replacement restorations in the typical dental practice. Risk factors for secondary caries are similar to those for primary caries development. Unfortunately, it is not possible to accurately predict which patients are at risk for restoration failure. During the past several decades, fluoride-releasing dental materials have become a part of the dentist's armamentarium. Considerable fluoride is released during the setting reaction and for periods up to eight years following restoration placement. This released fluoride is readily taken up by the cavosurface tooth structure, as well as the enamel and root surfaces adjacent to the restoration. Resistance against caries along the cavosurface and the adjacent smooth surface has been shown in both in vitro and in vivo studies. Fluoride-releasing dental materials provide for improved resistance against primary and secondary caries in coronal and root surfaces. Plaque and salivary fluoride levels are elevated to a level that facilitates remineralization. In addition, the fluoride released to dental plaque adversely affects the growth of lactobacilli and mutans streptococci by interference with bacterial enzyme systems. Fluoride recharging of these dental materials is readily achieved with fluoridated toothpastes, fluoride mouthrinses, and other sources of topical fluoride. This allows fluoride-releasing dental materials to act as intraoral fluoride reservoirs. The improvement in the properties of dental materials with the ability to release fluoride has improved dramatically in the past decade, and it is anticipated that in the near future the vast majority of restorative procedures will employ fluoride-releasing dental materials as bonding agents, cavity liners, luting agents, adhesives for orthodontic brackets, and definitive restoratives.

  1. Hexamethyldisilazane Removal with Mesoporous Materials Prepared from Calcium Fluoride Sludge.

    Science.gov (United States)

    Kao, Ching-Yang; Lin, Min-Fa; Nguyen, Nhat-Thien; Tsai, Hsiao-Hsin; Chang, Luh-Maan; Chen, Po-Han; Chang, Chang-Tang

    2018-05-01

    A large amount of calcium fluoride sludge is generated by the semiconductor industry every year. It also requires a high amount of fuel consumption using rotor concentrators and thermal oxidizers to treat VOCs. The mesoporous adsorbent prepared by calcium fluoride sludge was used for VOCs treatment. The semiconductor industry employs HMDS to promote the adhesion of photo-resistant material to oxide(s) due to the formation of silicon dioxide, which blocks porous adsorbents. The adsorption of HMDS (Hexamethyldisiloxane) was tested with mesoporous silica materials synthesized from calcium fluoride (CF-MCM). The resulting samples were characterized by XRD, XRF, FTIR, N2-adsorption-desorption techniques. The prepared samples possessed high specific surface area, large pore volume and large pore diameter. The crystal patterns of CF-MCM were similar with Mobil composite matter (MCM-41) from TEM image. The adsorption capacity of HMDS with CF-MCM was 40 and 80 mg g-1, respectively, under 100 and 500 ppm HMDS. The effects of operation parameters, such as contact time and mixture concentration, on the performance of CF-MCM were also discussed in this study.

  2. The occurrence and geochemistry of fluoride in some natural waters of Kenya

    Science.gov (United States)

    Gaciri, S. J.; Davies, T. C.

    1993-03-01

    In recent years the acquisition of considerable additional data on the hydrogeochemical behaviour of fluoride in natural waters of Kenya has been made possible by extensive surface-water and groundwater sampling campaigns as well as by improvements in analytical techniques. Ultimately, the principal source of fluoride relates to emissions from volcanic activity associated with the East African Rift System. Through various intermediate steps, but also directly, fluoride passes into the natural water system and components of the food chain. Ingestion by man is mainly through drinking water and other beverages. River waters in Kenya generally have a fluoride concentration lower than the recommended level (1.3 ppm) for potable water, thus promoting susceptibility to dental caries. Groundwaters and lake waters show considerably higher fluoride contents, resulting in the widespread incidence of fluorosis in areas where groundwater is the major source of drinking water, and lake fish is a regular component of the diet. This paper presents a synthesis of the data so far obtained on the sources and distribution of fluoride in the hydrological system of Kenya, examines the extent of fluorine toxicity and puts forward recommendations to combat or minimise the problem.

  3. Health risk assessment to fluoride in drinking water of rural residents living in the Poldasht city, Northwest of Iran.

    Science.gov (United States)

    Yousefi, Mahmood; Ghoochani, Mahboobeh; Hossein Mahvi, Amir

    2018-02-01

    This study analyzes the concentrations and health risks of fluoride in 112 drinking water samples collected from 28 villages of the Poldasht city, West Azerbaijan province in Iran. Results indicated that fluoride content in drinking water ranged from0.27 to 10.3mgL -1 (average 1.70mgL -1 ). The 57% of samples analyzed exceeded the limit set for fluoride in drinking water. Based on findings from health risk assessment this study, the highest fluoride exposure for different regions of Poldasht city was observed in young consumers, children and teenager's groups. Also, most of the rural residents suffered from fluoride contaminated drinking water. The calculated HQ value was > 1 for all groups of residents in Agh otlogh and Sari soo areas. Therefore, it is imperative to take measures to reduce fluoride concentration in drinking water and control of fluorosis. Action should be implemented to enhance monitoring of fluoride levels to avoid the potential risk to the population. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Evaluation of exposure to fluoride in child population of North Argentina.

    Science.gov (United States)

    Rocha, René Antonio; Calatayud, Marta; Devesa, Vicenta; Vélez, Dinoraz

    2017-09-01

    Fluoride is an important element for humans. It inhibits initiation and progression of dental caries and stimulates bone formation. However, excessive intake may lead to the appearance of dental and/or skeletal fluorosis and a decrease in intellectual coefficient in child populations. This study evaluates exposure to fluoride in the child population of Chaco province (Argentina) by analysis of drinking water, food and its bioaccessible fraction (quantity of fluoride solubilised by gastrointestinal digestion and available for intestinal absorption) and urine as a biomarker of internal dose. The concentration of fluoride in drinking water varied between 0.050 and 4.6 mg L -1 , and 80% of the samples exceeded the WHO drinking-water guideline value (1.5 mg L -1 ). Fluoride concentrations in food ranged between 0.80 and 3.0 mg kg -1 fresh weight (fw), being lower in bioaccessible fraction (0.43-1.9 mg kg -1 , fw). On the basis of the consumption data declared for the young child population, fluoride intake varies between 4.1 and 6.5 mg day -1 , greater than the level recommended for this age group. Moreover, in some cases, concentrations of fluoride found in urine (0.62-8.9 mg L -1 ) exceeded those reported in areas with declared fluorosis. All data obtained show the worrying situation of child population in this area of Argentina.

  5. Groundwater fluoride enrichment in an active rift setting: Central Kenya Rift case study

    Energy Technology Data Exchange (ETDEWEB)

    Olaka, Lydia A., E-mail: lydiaolaka@gmail.com [Department of Geology, University of Nairobi, P.O Box 30197, Nairobi (Kenya); Wilke, Franziska D.H. [Geoforschungs Zentrum, Telegrafenberg, 14473 Potsdam (Germany); Olago, Daniel O.; Odada, Eric O. [Department of Geology, University of Nairobi, P.O Box 30197, Nairobi (Kenya); Mulch, Andreas [Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325 Frankfurt (Germany); Institut für Geowissenschaften, Goethe Universität Frankfurt, Altenhöferallee 1, 60438 Frankfurt (Germany); Musolff, Andreas [UFZ-Helmholtz-Centre for Environmental Research, Department of Hydrogeology, Permoserstr. 15, 04318 Leipzig (Germany)

    2016-03-01

    Groundwater is used extensively in the Central Kenya Rift for domestic and agricultural demands. In these active rift settings groundwater can exhibit high fluoride levels. In order to address water security and reduce human exposure to high fluoride in drinking water, knowledge of the source and geochemical processes of enrichment are required. A study was therefore carried out within the Naivasha catchment (Kenya) to understand the genesis, enrichment and seasonal variations of fluoride in the groundwater. Rocks, rain, surface and groundwater sources were sampled for hydrogeochemical and isotopic investigations, the data was statistically and geospatially analyzed. Water sources have variable fluoride concentrations between 0.02–75 mg/L. 73% exceed the health limit (1.5 mg/L) in both dry and wet seasons. F{sup −} concentrations in rivers are lower (0.2–9.2 mg/L) than groundwater (0.09 to 43.6 mg/L) while saline lake waters have the highest concentrations (0.27–75 mg/L). The higher values are confined to elevations below 2000 masl. Oxygen (δ{sup 18}O) and hydrogen (δD) isotopic values range from − 6.2 to + 5.8‰ and − 31.3 to + 33.3‰, respectively, they are also highly variable in the rift floor where they attain maximum values. Fluoride base levels in the precursor vitreous volcanic rocks are higher (between 3750–6000 ppm) in minerals such as cordierite and muscovite while secondary minerals like illite and kaolinite have lower remnant fluoride (< 1000 ppm). Thus, geochemical F{sup −} enrichment in regional groundwater is mainly due to a) rock alteration, i.e. through long residence times and natural discharge and/or enhanced leakages of deep seated geothermal water reservoirs, b) secondary concentration fortification of natural reservoirs through evaporation, through reduced recharge and/or enhanced abstraction and c) through additional enrichment of fluoride after volcanic emissions. The findings are useful to help improve water management

  6. Fluoridated elastomers: effect on the microbiology of plaque.

    Science.gov (United States)

    Benson, Philip E; Douglas, C W Ian; Martin, Michael V

    2004-09-01

    The objective of this study was to investigate the effect of fluoridated elastomeric ligatures on the microbiology of local dental plaque in vivo. This randomized, prospective, longitudinal, clinical trial had a split-mouth crossover design. The subjects were 30 patients at the beginning of their treatment with fixed orthodontic appliances in the orthodontic departments of the Liverpool and the Sheffield dental hospitals in the United Kingdom. The study consisted of 2 experimental periods of 6 weeks with a washout period between. Fluoridated elastomers were randomly allocated at the first visit to be placed around brackets on tooth numbers 12, 11, 33 or 22, 21, 43. Nonfluoridated elastomers were placed on the contralateral teeth. Standard nonantibacterial fluoridated toothpaste and mouthwash were supplied. After 6 weeks (visit 2), the elastomers were removed, placed in transport media, and plated on agar within 2 hours. Nonfluoridated elastomers were placed on all brackets for 1 visit to allow for a washout period. At visit 3, fluoridated elastomers were placed on the teeth contralateral to those that received them at visit 1. At visit 4, the procedures at visit 2 were repeated. Samples were collected on visits 2 and 4. A logistic regression was performed, with the presence or absence of streptococcal or anaerobic growth as the dependent variable. A mixed-effects analysis of variance was carried out with the percentage of streptococcal or anaerobic bacterial count as the dependent variable. The only significant independent variables were the subject variable (P =bacterial count and the visit variable for the percentage of streptococcal count (P =fluoridated or nonfluoridated elastomers was not significant for percentage of either streptococcal (P =.288) or anaerobic count (P =.230). Fluoridated elastomers are not effective at reducing local streptococcal or anaerobic bacterial growth after a clinically relevant time in the mouth.

  7. Fluoride uptake into the developing enamel and dentine of sheep incisors following daily ingestion of fluoridated milk or water

    International Nuclear Information System (INIS)

    Cuttress, T.W.; Suckling, G.W.; Gao, J.; Coote, G.E.

    1996-01-01

    The caries preventive action of fluoride is common knowledge, although some of the mechanisms involved remain equivocal. At present, raised local levels of fluoride at, or in, the surface of tooth enamel is the most commonly accepted explanation of the anti-cariogenic action of fluoride. However, fluoride incorporated as fluorapatite into the tooth during its formation remains a possible alternative or complementary anti-cariogenic mechanism. If so, regular ingestion of fluoride during tooth formation is beneficial. Although use of fluoridated water is the preferred method in public health programmes, access to suitable potable water is required, and often this in not feasible. Fresh, preserved, or dried cow's milk products are widely used as nutritional and dietary items in most populations, particularly for young children. Milk is a practical, controllable means for regular delivery of fluoride. Processing of milk is commonly centralised and uses standardised conditions, allowing easy supplementation of fluoride for distribution to communities. The purpose of this study was to resolve the question of availability of fluoride ingested in milk compared with fluoride ingested in water by measuring fluoride deposition in the developing permanent incisors of young sheep. Incisors were analysed using a proton microprobe. (author). 18 refs., 1 tabs., 3 figs

  8. Influence of the method of fluoride administration on toxicity and fluoride concentrations in Japanese quail

    Science.gov (United States)

    Fleming, W.J.; Schuler, C.A.

    1988-01-01

    Young Japanese quail (Coturnix japonica) were administered NaF for 16 d either in their diet or by esophageal intubation. Based on the total fluoride ion (Emg F-) intake over the l6-d experimental period, fluoride administered by intubation was at least six times more toxic than that fed in the diet. Dietary concentrations of 1,000 ppm F- (Emg F- for 16 d = approx. 144) produced no mortality, whereas intubated doses produced 73% or greater mortality in all groups administered 54 mg F- /kg/d or more (Emg F- for 16 d _ approx. 23 mg). GraphIc companson of the regression of log F- ppm in femurs/mg F- intake showed that fluoride levels in the femurs of quail administered fluoride by intubation were higher than in those administered fluoride in the diet.

  9. Oral microflora in preschool children attending a fluoride varnish program

    DEFF Research Database (Denmark)

    Anderson, Maria; Grindefjord, Margaret; Dahllöf, Göran

    2016-01-01

    hundred seven 3-year-old children were enrolled from a cohort of 3403 preschool children taking part in a community based oral health project. Two hundred sixty-three of them had attended caries-preventive program with semi-annual applications of a fluoride varnish since the age of 1 year (test group......BACKGROUND: To compare the oral microflora in preschool children attending a fluoride varnish program with a reference group receiving a standard oral health program without fluoride varnish applications. A second aim was to relate the microbial composition to the caries prevalence. METHODS: Five......) while 237 had received standard preventive care (reference group). Oral samples were collected with a sterile swab and analysed with checkerboard DNA-DNA hybridization using 12 pre-determined bacterial probes. Caries and background data were collected from clinical examinations and questionnaires...

  10. Liberação de flúor de materiais restauradores Fluoride releasing of restorative materials

    Directory of Open Access Journals (Sweden)

    Adriana Silva de CARVALHO

    1998-10-01

    Full Text Available Atualmente no mercado odontológico existem diversos tipos de materiais restauradores que liberam flúor com o objetivo de diminuir ou eliminar as cáries recorrentes. Considerando-se a diferença de composição desses materiais, foi avaliada sua capacidade de liberação de flúor. Foram avaliados os materiais restauradores: Chelon-fil (ESPE, Vitremer (3M, Variglass (Dentsply, Dyract (Dentsply e Tetric (Vivadent. Confeccionaram-se seis amostras cilíndricas (área = 1,65 cm2 de cada material, as quais foram imersas individualmente em 2,0 ml de água deionizada, que foi trocada diariamente durante 15 dias. A liberação de flúor foi determinada após adição de volume igual de tampão TISAB II às soluções. Para a análise da concentração de flúor foi utilizado um eletrodo específico para flúor Orion 96-09, acoplado a um analisador de íons Orion EA-940. Todos os materiais seguiram o mesmo padrão de liberação de flúor. As maiores médias de flúor liberado dentro de cada material foram encontradas no 1º dia, decrescendo bruscamente no 2º e 3º dias, e a quantidade de flúor liberado apresentou um decréscimo com o passar dos dias até atingir um nível quase constante. A liberação média de flúor durante o período de avaliação (média e desvio padrão em µg F/cm2 foi: CHE = 7,62 ± 0,76A, VIT = 5,91 ± 0,79B, VAR = 2,72 ± 0,25C, DYR = 1,50 ± 0,17 D, TET = 0,136 ± 0,016 E. Médias seguidas por letras distintas diferem entre si ao nível de significância de 5% (Tukey. Os resultados mostraram que a composição dos materiais restauradores influencia de maneira significativa sua liberação de flúor.Nowadays there are several types of restorative materials with fluoride release properties. Thus, the purpose of this study was to analyze the fluoride release from the following restorative materials, considering their different compositions. The materials used were: Chelon Fil-ESPE (CHE, Vitremer-3M (VIT, Variglass

  11. Groundwater fluoride contamination and its possible health implications in Indi taluk of Vijayapura District (Karnataka State), India.

    Science.gov (United States)

    Ugran, Vidyavati; Desai, Naveen N; Chakraborti, Dipankar; Masali, Kallappa A; Mantur, Prakash; Kulkarni, Shreepad; Deshmukh, Niranjan; Chadchan, Kailash S; Das, Swastika N; Tanksali, Anuradha S; Arwikar, Asha S; Guggarigoudar, Suresh P; Vallabha, Tejaswini; Patil, Shailaja S; Das, Kusal K

    2017-10-01

    Groundwater fluoride concentration and fluoride-related health problems were studied in twenty-two villages of Indi taluk of Vijayapura district, Karnataka, India. Present study (2015) was also used to compare groundwater fluoride concentration in same 22 villages with previous government report (2000). Groundwater fluoride concentrations of 62 bore wells of 22 villages were analyzed by using an ion-sensitive electrode. A total of 660 adults and 600 children were screened for fluorosis symptoms and signs. Sixty clinically suspected fluorosis patients' urine samples were further analyzed for fluoride. The mean value (1.22 ± 0.75 mg/L) of fluoride concentration of 62 bore wells and 54.83 % bore wells with ≥1.0 mg/L of fluoride concentrations in Indi taluk indicates higher than the permissible limit of drinking water fluoride concentration recommended for India. Clinical symptoms like arthritis, joint pains, gastrointestinal discomfort and lower limb deformities with high urinary fluoride concentrations in some subjects suggest fluorosis. Results also showed an increase in groundwater fluoride concentration of the same 22 villages between previous and present study. Preliminary arthritis symptom of the villagers could be due to drinking fluoride-contaminated water. Increase in fluoride concentration with time to the bore wells definitely indicates future danger.

  12. THE USE OF FLUORIDE CONTAINING MINERAL WATER IN WORT PRODUCTION

    Directory of Open Access Journals (Sweden)

    Gunka Yonkova

    2011-12-01

    Full Text Available The present work aims to study the quality of wort produced using fluoride containing mineral water. The results show that the mineral water has a negative impact on the enzymatic destruction of starch, proteins, color intensity and pH of the wort. The changes of pH during mashing process using tap and mineral water was studied. The lower acidity of wort obtained using mineral water didn’t change during the brewing process. The fluoride content of beer is lower than 5 mg.L-1 when wort is produced using mineral and tap water in 1:1 ratio and citric acid for pH correction. At the same time, the final degree of fermentation, α-amine nitrogen content and the intensity of color of produced wort are close to the control sample. The changes in fluoride ion concentration are monitored using ion-selective potentiometry. The fluoride content is decreased from 5.7 to 4.75 mg.L-1, the most intense change is observed during the mashing process.

  13. Application of Titanium Compounds to Reduce Fluoride Ion in Water Resources with High Fluoride Ion Contents

    Directory of Open Access Journals (Sweden)

    Fariborz Riahi

    2005-06-01

    Full Text Available The present work describes studies on the sorption of fluoride ions from water by titanium compounds used in water treatment to reduce fluoride content in water resources. There are different methods of reducing fluoride ion in water, each associated with specific problems such as secondary contamination, environmental contamination, high costs, or the need for primary and secondary treatment. In this study, application of titanium sulfate and Metatitanic acid produced from titanium ore concentrate (ileminite is investigated in the removal of fluoride ion and the possibility of complete purification of fluorine containing wastewater is examined to determine the optimal conditions. Metatitanic acid has a great sorption property for fluoride ion. Also titanium sulfate is a suitable and more effective material for this purpose. Efficiency of this material in reducing fluoride ion content is 99.9% and it is possible to refresh sorbet material for reuse without problems arising from Ti+4 ion contamination.

  14. Environmental evaluation of fluoride in drinking water at "Los Altos de Jalisco," in the central Mexico region.

    Science.gov (United States)

    Hurtado, Roberto; Gardea-Torresdey, Jorge

    Naturally occurring fluoride has been detected and quantified in drinking water in several cities of the "Los Altos de Jalisco" (LAJ) region. LAJ is located in the northeastern part of the state of Jalisco-Mexico, covering an area of 16,410 km2 with a population of 696,318 in 20 municipalities. Drinking water comes mainly from groundwater aquifers, located in the Trans-Mexican Volcanic Belt, which is a volcanic region characterized by hydrothermal activity. Results indicated that water supply from 42% of the municipalities had a fluoride concentration over the Mexican standards of 1.5 mg/L. It is important to notice that there are three cities, Lagos de Moreno (1.66-5.88 mg/L F(-)), Teocaltiche (3.82-18.58 mg/L F(-)), and Encarnación de Díaz (2.58-4.40 mg/L F(-)) where all water samples resulted in fluoride concentration over the maximum contaminant level. The total population from these three cities is over 122,000 inhabitants. Another important city with high levels of fluoride in the water supply was Tepatitlán de Morelos (2 wells with 6.54 and 13.47 mg/L F(-)). In addition to water supply, 30 samples of brand-name bottled water were tested. Surprisingly, 8 samples (27%) demonstrated fluoride level over the standards, mainly Agua de Lagos with 5.27 mg/L. Fluoridated table salt (200-300 mg/kg F(-)) is another important source of fluoride. A large number of people living in the region, mainly school children, might be under adverse health risk because they are consuming contaminated drinking water. It is well known that long-term exposure to water with high levels of fluoride produces severe health problems.

  15. Toxic effects of fluoride on organisms.

    Science.gov (United States)

    Zuo, Huan; Chen, Liang; Kong, Ming; Qiu, Lipeng; Lü, Peng; Wu, Peng; Yang, Yanhua; Chen, Keping

    2018-04-01

    Accumulation of excess fluoride in the environment poses serious health risks to plants, animals, and humans. This endangers human health, affects organism growth and development, and negatively impacts the food chain, thereby affecting ecological balance. In recent years, numerous studies focused on the molecular mechanisms associated with fluoride toxicity. These studies have demonstrated that fluoride can induce oxidative stress, regulate intracellular redox homeostasis, and lead to mitochondrial damage, endoplasmic reticulum stress and alter gene expression. This paper reviews the present research on the potential adverse effects of overdose fluoride on various organisms and aims to improve our understanding of fluoride toxicity. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Excessive apoptosis and defective autophagy contribute to developmental testicular toxicity induced by fluoride

    International Nuclear Information System (INIS)

    Zhang, Shun; Niu, Qiang; Gao, Hui; Ma, Rulin; Lei, Rongrong; Zhang, Cheng; Xia, Tao; Li, Pei; Xu, Chunyan; Wang, Chao; Chen, Jingwen; Dong, Lixing; Zhao, Qian; Wang, Aiguo

    2016-01-01

    Fluoride, a ubiquitous environmental contaminant, is known to impair testicular functions and fertility; however the underlying mechanisms remain obscure. In this study, we used a rat model to mimic human exposure and sought to investigate the roles of apoptosis and autophagy in testicular toxicity of fluoride. Sprague–Dawley rats were developmentally exposed to 25, 50, or 100 mg/L sodium fluoride (NaF) via drinking water from pre-pregnancy to post-puberty, and then the testes of offspring were excised on postnatal day 56. Our results demonstrated that developmental NaF exposure induced an enhanced testicular apoptosis, as manifested by a series of hallmarks such as caspase-3 activation, chromatin condensation and DNA fragmentation. Further study revealed that fluoride exposure elicited significant elevations in the levels of cell surface death receptor Fas with a parallel increase in cytoplasmic cytochrome c, indicating the involvement of both extrinsic and intrinsic apoptotic pathways. Intriguingly, fluoride treatment also simultaneously increased the number of autophagosomes and the levels of autophagy marker LC3-II but not Beclin1. Unexpectedly, the expression of p62, a substrate that is degraded by autophagy, was also significantly elevated, suggesting that the accumulated autophagosomes resulted from impaired autophagy degradation rather than increased formation. Importantly, these were associated with marked histopathological lesions including spermatogenic failure and germ cell loss, along with severe ultrastructural abnormalities in testes. Taken together, our findings provide deeper insights into roles of excessive apoptosis and defective autophagy in the aggravation of testicular damage, which could contribute to a better understanding of fluoride-induced male reproductive toxicity. - Highlights: • Rats were developmentally exposed to fluoride from pre-pregnancy to post-puberty. • Both excessive apoptosis and defective autophagy are involved in

  17. Magnetic interactions through fluoride

    DEFF Research Database (Denmark)

    Pedersen, Kasper Steen; Sigrist, Marc; Weihe, Høgni

    2014-01-01

    support the parameter values and resolve |E| ≈ 0.04 cm(-1). The exchange coupling constant (J) is 1 order of magnitude smaller than that found in comparable systems with linear oxide bridging but comparable to typical magnitudes through cyanide, thus underlining the potential of fluoride complexes......The nature of the magnetic interaction through fluoride in a simple, dinuclear manganese(III) complex (1), bridged by a single fluoride ion in a perfectly linear fashion, is established by experiment and density functional theory. The magnitude of the antiferromagnetic exchange interaction...

  18. Teor de fluoretos em infusões de chá verde (Camellia sinensis Fluoride content in green tea infusions (Camellia sinensis

    Directory of Open Access Journals (Sweden)

    Márcia Reto

    2008-01-01

    Full Text Available The aim of this work was to study the influence of green tea consumption on fluoride ingestion. The extraction conditions of fluorides from green tea infusions were defined and nine brands of green tea available in Portugal were analyzed. The quantification of fluorides in the green tea was preceded by the implementation and validation of the potentiometric method (commercial fluoride selective electrode. The concentration of fluorides in the samples ranged from 0. 8 to 2. 0 mg L-1.

  19. Tissue distributions of fluoride and its toxicity in the gills of a freshwater teleost, Cyprinus carpio.

    Science.gov (United States)

    Cao, Jinling; Chen, Jianjie; Wang, Jundong; Wu, Xiangtian; Li, Yundong; Xie, Lingtian

    2013-04-15

    Fish take up fluoride directly from water and are susceptible to fluoride contamination of their environment. In this study, we examined the tissue distributions of fluoride and its toxicity in the gills of the common carp (Cyprinus carpio) chronically exposed to fluoride. Carp were exposed to a range of aqueous fluoride (35-124 mg/L) and sampled at 30, 60 and 90 days. The accumulation of fluoride in the tissues increased with the level and duration of exposure. Steady state was not achieved under the experimental conditions. The gills accumulated the highest levels of fluoride followed by the liver>brain>kidney>muscle>intestine. A dose-dependent inhibition was observed for the enzyme activities of Na(+)-K(+)-ATPase and Ca(2+)-ATPase in the gills after the fish were exposed for 90 days. Also, accumulation of fluoride was associated with the inhibition of superoxide dismutase (SOD) activities and a dose-dependent stimulation of malondialdehyde (MDA) levels in the gill tissues, suggesting that fluoride promoted oxidative stress in the fish. Microscopic examinations revealed injuries to gill tissues and chloride cells, with the severity of injury increasing with exposure concentration. These results suggest that chronic exposure to elevated concentrations of fluoride may induce toxicity in the common carp. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Acid demineralization susceptibility of dental enamel submitted to different bleaching techniques and fluoridation regimens.

    Science.gov (United States)

    Salomão, Dlf; Santos, Dm; Nogueira, Rd; Palma-Dibb, Rg; Geraldo-Martins, Vr

    2014-01-01

    The aim of the current study was to assess the acid demineralization susceptibility of bleached dental enamel submitted to different fluoride regimens. One hundred bovine enamel blocks (6×6×3 mm) were randomly divided into 10 groups (n=10). Groups 1 and 2 received no bleaching. Groups 3 to 6 were submitted to an at-home bleaching technique using 6% hydrogen peroxide (HP; G3 and G4) or 10% carbamide peroxide (CP; G5 and G6). Groups 7 to 10 were submitted to an in-office bleaching technique using 35% HP (G7 and G8) or 35% CP (G9 and G10). During bleaching, a daily fluoridation regimen of 0.05% sodium fluoride (NaF) solution was performed on groups 3, 5, 7, and 9, while weekly fluoridation with a 2% NaF gel was performed on groups 4, 6, 8, and 10. The samples in groups 2 to 10 were pH cycled for 14 consecutive days. The samples from all groups were then assessed by cross-sectional Knoop microhardness at different depths from the outer enamel surface. The average Knoop hardness numbers (KHNs) were compared using one-way analysis of variance and Tukey tests (α=0.05). The comparison between groups 1 and 2 showed that the demineralization method was effective. The comparison among groups 2 to 6 showed the same susceptibility to acid demineralization, regardless of the fluoridation method used. However, the samples from groups 8 and 10 showed more susceptibility to acid demineralization when compared with group 2 (penamel to acid demineralization. However, the use of 35% HP and 35% CP must be associated with a daily fluoridation regimen, otherwise the in-office bleaching makes the bleached enamel more susceptible to acid demineralization.

  1. Physiologic Conditions Affect Toxicity of Ingested Industrial Fluoride

    Directory of Open Access Journals (Sweden)

    Richard Sauerheber

    2013-01-01

    Full Text Available The effects of calcium ion and broad pH ranges on free fluoride ion aqueous concentrations were measured directly and computed theoretically. Solubility calculations indicate that blood fluoride concentrations that occur in lethal poisonings would decrease calcium below prevailing levels. Acute lethal poisoning and also many of the chronic effects of fluoride involve alterations in the chemical activity of calcium by the fluoride ion. Natural calcium fluoride with low solubility and toxicity from ingestion is distinct from fully soluble toxic industrial fluorides. The toxicity of fluoride is determined by environmental conditions and the positive cations present. At a pH typical of gastric juice, fluoride is largely protonated as hydrofluoric acid HF. Industrial fluoride ingested from treated water enters saliva at levels too low to affect dental caries. Blood levels during lifelong consumption can harm heart, bone, brain, and even developing teeth enamel. The widespread policy known as water fluoridation is discussed in light of these findings.

  2. Physiologic conditions affect toxicity of ingested industrial fluoride.

    Science.gov (United States)

    Sauerheber, Richard

    2013-01-01

    The effects of calcium ion and broad pH ranges on free fluoride ion aqueous concentrations were measured directly and computed theoretically. Solubility calculations indicate that blood fluoride concentrations that occur in lethal poisonings would decrease calcium below prevailing levels. Acute lethal poisoning and also many of the chronic effects of fluoride involve alterations in the chemical activity of calcium by the fluoride ion. Natural calcium fluoride with low solubility and toxicity from ingestion is distinct from fully soluble toxic industrial fluorides. The toxicity of fluoride is determined by environmental conditions and the positive cations present. At a pH typical of gastric juice, fluoride is largely protonated as hydrofluoric acid HF. Industrial fluoride ingested from treated water enters saliva at levels too low to affect dental caries. Blood levels during lifelong consumption can harm heart, bone, brain, and even developing teeth enamel. The widespread policy known as water fluoridation is discussed in light of these findings.

  3. Potential fluoride toxicity from oral medicaments: A review.

    Science.gov (United States)

    Ullah, Rizwan; Zafar, Muhammad Sohail; Shahani, Nazish

    2017-08-01

    The beneficial effects of fluoride on human oral health are well studied. There are numerous studies demonstrating that a small amount of fluoride delivered to the oral cavity decreases the prevalence of dental decay and results in stronger teeth and bones. However, ingestion of fluoride more than the recommended limit leads to toxicity and adverse effects. In order to update our understanding of fluoride and its potential toxicity, we have described the mechanisms of fluoride metabolism, toxic effects, and management of fluoride toxicity. The main aim of this review is to highlight the potential adverse effects of fluoride overdose and poorly understood toxicity. In addition, the related clinical significance of fluoride overdose and toxicity has been discussed.

  4. Effects of hydrogen fluoride on plants

    Energy Technology Data Exchange (ETDEWEB)

    Yamazoe, F

    1970-07-15

    Symptoms of fluorosis in plants are chlorotic markings around the tip or edges of young leaves. Examples of damage to plants and livestock by fluorides are listed, including the retarded growth of silkworms fed on mulberry leaves polluted by more than 30 ppm fluorides. Plants can be classified into six groups according to their resistance to hydrogen fluoride. Threshold values of the fluoride concentration range from 5-10 ppb for the plants. Gladiolus is normally employed as a plant indicator for hydrogen fluoride and silkworms as indicator insects. The relationship between plant damage by fluorides and exposure time, density, soil, fertilizer, meteorology and location are examined. Several preventive measures are listed, including the spraying of water or lime on plant leaves. It is concluded that the establishment of an environmental standard is difficult because of the extremely high sensitivity of the plants to the gas. 8 references.

  5. Determination of fluoride in drainage by ion electrode method

    International Nuclear Information System (INIS)

    Terakado, Shigeru; Ochiai, Ken-ichi; Motoyama, Shigeji; Tsutsumi, Ken-ichi

    1975-01-01

    The fluoride ion selective electrode method for rapidly and precisely determining fluoride in drainage was studied. This method enables the analysis of the samples with fluoride concentration above 0.1 mg/l in about five minutes. Six buffer solutions were selected to compare the masking effect against aluminum. Solution A is TISAB made by dissolving 57 ml of gracial acetic acid and 10 g of sodium chloride in 500 ml of water, thereafter adjusting pH to 5.5 and diluting to 1 liter with water. Solution B is phosphoric acid solution (17 M/L). Solution C is 3 M ammonium phosphate dibasic aqueous solution. Solution D is 1 M sodium citrate aqueous solution adjusted to pH 6 with hydrochloric acid. Solution E is 0.5 M sodium phosphate dibasic aqueous solution. Solution F is 2 M ammonium phosphate monobasic aqueous solution. As a result of studying the effect of coexisting elements, the buffer solutions A,B,E and F were greatly influenced by the coexistence of aluminum, while C and D show remarkable masking effect against aluminum. The amount of interfering ions in normal drainage is so small that no problem is anticipated for D. When fluoride recovery treatment is performed, it is important in dilution measurement to confirm whether the measured values are accurate or not, because there are high and low concentrations of fluoride at the same potential. (Iwakiri, K.)

  6. Sirt1 overexpression suppresses fluoride-induced p53 acetylation to alleviate fluoride toxicity in ameloblasts responsible for enamel formation.

    Science.gov (United States)

    Suzuki, Maiko; Ikeda, Atsushi; Bartlett, John D

    2018-03-01

    Low-dose fluoride is an effective caries prophylactic, but high-dose fluoride is an environmental health hazard that causes skeletal and dental fluorosis. Treatments to prevent fluorosis and the molecular pathways responsive to fluoride exposure remain to be elucidated. Previously we showed that fluoride activates SIRT1 as an adaptive response to protect cells. Here, we demonstrate that fluoride induced p53 acetylation (Ac-p53) [Lys379], which is a SIRT1 deacetylation target, in ameloblast-derived LS8 cells in vitro and in enamel organ in vivo. Here we assessed SIRT1 function on fluoride-induced Ac-p53 formation using CRISPR/Cas9-mediated Sirt1 knockout (LS8 Sirt/KO ) cells or CRISPR/dCas9/SAM-mediated Sirt1 overexpressing (LS8 Sirt1/over ) cells. NaF (5 mM) induced Ac-p53 formation and increased cell cycle arrest via Cdkn1a/p21 expression in Wild-type (WT) cells. However, fluoride-induced Ac-p53 was suppressed by the SIRT1 activator resveratrol (50 µM). Without fluoride, Ac-p53 persisted in LS8 Sirt/KO cells, whereas it decreased in LS8 Sirt1/over . Fluoride-induced Ac-p53 formation was also suppressed in LS8 Sirt1/over cells. Compared to WT cells, fluoride-induced Cdkn1a/p21 expression was elevated in LS8 Sirt/KO and these cells were more susceptible to fluoride-induced growth inhibition. In contrast, LS8 Sirt1/over cells were significantly more resistant. In addition, fluoride-induced cytochrome-c release and caspase-3 activation were suppressed in LS8 Sirt1/over cells. Fluoride induced expression of the DNA double strand break marker γH2AX in WT cells and this was augmented in LS8 Sirt1/KO cells, but was attenuated in LS8 Sirt1/over cells. Our results suggest that SIRT1 deacetylates Ac-p53 to mitigate fluoride-induced cell growth inhibition, mitochondrial damage, DNA damage and apoptosis. This is the first report implicating Ac-p53 in fluoride toxicity.

  7. Eukaryotic resistance to fluoride toxicity mediated by a widespread family of fluoride export proteins

    OpenAIRE

    Li, Sanshu; Smith, Kathryn D.; Davis, Jared H.; Gordon, Patricia B.; Breaker, Ronald R.; Strobel, Scott A.

    2013-01-01

    Although fluoride is plentiful in the environment and is commonly used at high concentrations in oral hygiene products, little has been known about how biological systems overcome the toxic effects of this anion. We demonstrate that a protein called FEX in many fungi is essential for cell survival in the presence of high fluoride concentrations. The protein is required for the rapid expulsion of cytoplasmic fluoride, indicating that many eukaryotic species that carry FEX genes likely avoid fl...

  8. Gramicidin D enhances the antibacterial activity of fluoride

    OpenAIRE

    Nelson, James W.; Zhou, Zhiyuan; Breaker, Ronald R.

    2014-01-01

    Fluoride is a toxic anion found in many natural environments. One of the major bacterial defenses against fluoride is the cell envelope, which limits passage of the membrane-impermeant fluoride anion. Accordingly, compounds that enhance the permeability of bacterial membranes to fluoride should also enhance fluoride toxicity. In this study, we demonstrate that the pore-forming antibiotic gramicidin D increases fluoride uptake in B. subtilis and that the antibacterial activity of this compound...

  9. Enriched fluoride sorption using alumina/chitosan composite

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, Natrayasamy, E-mail: natrayasamy_viswanathan@rediffmail.com [Department of Chemistry, Anna University Tiruchirappalli - Dindigul Campus, Dindigul 624 622, Tamil Nadu (India); Meenakshi, S., E-mail: drs_meena@rediffmail.com [Department of Chemistry, Gandhigram Rural University, Gandhigram 624 302, Tamil Nadu (India)

    2010-06-15

    Alumina possesses an appreciable defluoridation capacity (DC) of 1566 mg F{sup -}/kg. In order to improve its DC, it is aimed to prepare alumina polymeric composites using the chitosan. Alumina/chitosan (AlCs) composite was prepared by incorporating alumina particles in the chitosan polymeric matrix, which can be made into any desired form viz., beads, candles and membranes. AlCs composite displayed a maximum DC of 3809 mg F{sup -}/kg than the alumina and chitosan (52 mg F{sup -}/kg). The fluoride removal studies were carried out in batch mode to optimize the equilibrium parameters viz., contact time, pH, co-anions and temperature. The equilibrium data was fitted with Freundlich and Langmuir isotherms to find the best fit for the sorption process. The calculated values of thermodynamic parameters indicate the nature of sorption. The surface characterisation of the sorbent was performed by FTIR, AFM and SEM with EDAX analysis. A possible mechanism of fluoride sorption by AlCs composite has been proposed. Suitability of AlCs composite at field conditions was tested with a field sample taken from a nearby fluoride-endemic village. This work provides a potential platform for the development of defluoridation technology.

  10. Excessive apoptosis and defective autophagy contribute to developmental testicular toxicity induced by fluoride.

    Science.gov (United States)

    Zhang, Shun; Niu, Qiang; Gao, Hui; Ma, Rulin; Lei, Rongrong; Zhang, Cheng; Xia, Tao; Li, Pei; Xu, Chunyan; Wang, Chao; Chen, Jingwen; Dong, Lixing; Zhao, Qian; Wang, Aiguo

    2016-05-01

    Fluoride, a ubiquitous environmental contaminant, is known to impair testicular functions and fertility; however the underlying mechanisms remain obscure. In this study, we used a rat model to mimic human exposure and sought to investigate the roles of apoptosis and autophagy in testicular toxicity of fluoride. Sprague-Dawley rats were developmentally exposed to 25, 50, or 100 mg/L sodium fluoride (NaF) via drinking water from pre-pregnancy to post-puberty, and then the testes of offspring were excised on postnatal day 56. Our results demonstrated that developmental NaF exposure induced an enhanced testicular apoptosis, as manifested by a series of hallmarks such as caspase-3 activation, chromatin condensation and DNA fragmentation. Further study revealed that fluoride exposure elicited significant elevations in the levels of cell surface death receptor Fas with a parallel increase in cytoplasmic cytochrome c, indicating the involvement of both extrinsic and intrinsic apoptotic pathways. Intriguingly, fluoride treatment also simultaneously increased the number of autophagosomes and the levels of autophagy marker LC3-II but not Beclin1. Unexpectedly, the expression of p62, a substrate that is degraded by autophagy, was also significantly elevated, suggesting that the accumulated autophagosomes resulted from impaired autophagy degradation rather than increased formation. Importantly, these were associated with marked histopathological lesions including spermatogenic failure and germ cell loss, along with severe ultrastructural abnormalities in testes. Taken together, our findings provide deeper insights into roles of excessive apoptosis and defective autophagy in the aggravation of testicular damage, which could contribute to a better understanding of fluoride-induced male reproductive toxicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. The influence of lifelong exposure to environmental fluoride on bone quality in humans

    Science.gov (United States)

    Chachra, Debbie

    The objective of this study was to determine if lifelong exposure to environmental sources of fluoride (including fluoridated water) had an effect on bone quality in humans. Ninety-two femoral heads were obtained from individuals undergoing total hip arthroplasty in regions with and without fluoridated water (Toronto and Montreal, respectively), so that the donors would have had a wide range of fluoride exposure. As the samples were obtained at surgery, the femoral heads were affected by osteoarthritis (75), osteoporosis (9) and other diseases. The fluoride content of cancellous bone was assessed by instrumental neutron activation analysis. A number of contributors to bone quality were assessed. The compressive and torsional mechanical properties were measured for cancellous cores excised from the centre of the femoral head. The architecture was assessed by image analysis of an x-ray of a 5 mm thick coronal section of the femoral head, as well as of histological sections taken from the superior (weightbearing) and the inferior (nonweightbearing) surface of the femoral head. The degree of mineralization was measured using backscattered electron imaging and microhardness, again at the superior and the inferior surface. Femoral heads from Toronto donors had a greater mean fluoride content than those from Montreal donors (1033 +/- 438 ppm vs. 643 +/- 220 ppm). However, the fluoride content of the Toronto donors ranged approximately twelve-fold (192--2264 ppm) and entirely contained the range of Montreal donors. Therefore, fluoridated water exposure is not the only determinant of fluoride content. The logarithm of the bone fluoride content increased with age. No substantive effect of fluoride, independent of age, was observed for the mechanical properties. Similarly, at the inferior surface, the architecture was affected by age but not by fluoride incorporation but the degree of mineralization was not affected by either. However, the degree of mineralization (measured

  12. Assessment of Fluoride Concentration of Soil and Vegetables in Vicinity of Zinc Smelter, Debari, Udaipur, Rajasthan.

    Science.gov (United States)

    Bhat, Nagesh; Jain, Sandeep; Asawa, Kailash; Tak, Mridula; Shinde, Kushal; Singh, Anukriti; Gandhi, Neha; Gupta, Vivek Vardhan

    2015-10-01

    As of late, natural contamination has stimulated as a reaction of mechanical and other human exercises. In India, with the expanding industrialization, numerous unsafe substances are utilized or are discharged amid generation as cleans, exhaust, vapours and gasses. These substances at last are blended in the earth and causes health hazards. To determine concentration of fluoride in soils and vegetables grown in the vicinity of Zinc Smelter, Debari, Udaipur, Rajasthan. Samples of vegetables and soil were collected from areas situated at 0, 1, 2, 5, and 10 km distance from the zinc smelter, Debari. Three samples of vegetables (i.e. Cabbage, Onion and Tomato) and 3 samples of soil {one sample from the upper layer of soil (i.e. 0 to 20 cm) and one from the deep layer (i.e. 20 - 40 cm)} at each distance were collected. The soil and vegetable samples were sealed in clean polythene bags and transported to the laboratory for analysis. One sample each of water and fertilizer from each distance were also collected. The mean fluoride concentration in the vegetables grown varied between 0.36 ± 0.69 to 0.71 ± 0.90 ppm. The fluoride concentration in fertilizer and water sample from various distances was found to be in the range of 1.4 - 1.5 ppm and 1.8 - 1.9 ppm respectively. The fluoride content of soil and vegetables was found to be higher in places near to the zinc smelter.

  13. Gramicidin D enhances the antibacterial activity of fluoride.

    Science.gov (United States)

    Nelson, James W; Zhou, Zhiyuan; Breaker, Ronald R

    2014-07-01

    Fluoride is a toxic anion found in many natural environments. One of the major bacterial defenses against fluoride is the cell envelope, which limits passage of the membrane-impermeant fluoride anion. Accordingly, compounds that enhance the permeability of bacterial membranes to fluoride should also enhance fluoride toxicity. In this study, we demonstrate that the pore-forming antibiotic gramicidin D increases fluoride uptake in Bacillus subtilis and that the antibacterial activity of this compound is potentiated by fluoride. Polymyxin B, another membrane-targeting antibiotic with a different mechanism of action, shows no such improvement. These results, along with previous findings, indicate that certain compounds that destabilize bacterial cell envelopes can enhance the toxicity of fluoride. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Potential fluoride toxicity from oral medicaments: A review

    Directory of Open Access Journals (Sweden)

    Rizwan Ullah

    2017-08-01

    Full Text Available The beneficial effects of fluoride on human oral health are well studied. There are numerous studies demonstrating that a small amount of fluoride delivered to the oral cavity decreases the prevalence of dental decay and results in stronger teeth and bones. However, ingestion of fluoride more than the recommended limit leads to toxicity and adverse effects. In order to update our understanding of fluoride and its potential toxicity, we have described the mechanisms of fluoride metabolism, toxic effects, and management of fluoride toxicity. The main aim of this review is to highlight the potential adverse effects of fluoride overdose and poorly understood toxicity. In addition, the related clinical significance of fluoride overdose and toxicity has been discussed.

  15. Drinking Water Fluoride Levels for a City in Northern Mexico (Durango Determined Using a Direct Electrochemical Method and Their Potential Effects on Oral Health

    Directory of Open Access Journals (Sweden)

    Nelly Molina Frechero

    2013-01-01

    Full Text Available Fluoride is ingested primarily through consuming drinking water. When drinking water contains fluoride concentrations >0.7 parts per million (ppm, consuming such water can be toxic to the human body; this toxicity is called “fluorosis.” Therefore, it is critical to determine the fluoride concentrations in drinking water. The objective of this study was to determine the fluoride concentration in the drinking water of the city of Durango. The wells that supply the drinking water distribution system for the city of Durango were studied. One hundred eighty-nine (189 water samples were analyzed, and the fluoride concentration in each sample was quantified as established by the law NMX-AA-077-SCFI-2001. The fluoride concentrations in such samples varied between 2.22 and 7.23 ppm with a 4.313 ± 1.318 ppm mean concentration. The highest values were observed in the northern area of the city, with a 5.001 ± 2.669 ppm mean value. The samples produced values that exceeded the national standard for fluoride in drinking water. Chronic exposure to fluoride at such concentrations produces harmful health effects, the first sign of which is dental fluorosis. Therefore, it is essential that the government authorities implement water defluoridation programs and take preventative measures to reduce the ingestion of this toxic halogen.

  16. Drinking Water Fluoride Levels for a City in Northern Mexico (Durango) Determined Using a Direct Electrochemical Method and Their Potential Effects on Oral Health

    Science.gov (United States)

    Molina Frechero, Nelly; Sánchez Pérez, Leonor; Castañeda Castaneira, Enrique; Oropeza Oropeza, Anastasio; Gaona, Enrique; Salas Pacheco, José; Bologna Molina, Ronell

    2013-01-01

    Fluoride is ingested primarily through consuming drinking water. When drinking water contains fluoride concentrations >0.7 parts per million (ppm), consuming such water can be toxic to the human body; this toxicity is called “fluorosis.” Therefore, it is critical to determine the fluoride concentrations in drinking water. The objective of this study was to determine the fluoride concentration in the drinking water of the city of Durango. The wells that supply the drinking water distribution system for the city of Durango were studied. One hundred eighty-nine (189) water samples were analyzed, and the fluoride concentration in each sample was quantified as established by the law NMX-AA-077-SCFI-2001. The fluoride concentrations in such samples varied between 2.22 and 7.23 ppm with a 4.313 ± 1.318 ppm mean concentration. The highest values were observed in the northern area of the city, with a 5.001 ± 2.669 ppm mean value. The samples produced values that exceeded the national standard for fluoride in drinking water. Chronic exposure to fluoride at such concentrations produces harmful health effects, the first sign of which is dental fluorosis. Therefore, it is essential that the government authorities implement water defluoridation programs and take preventative measures to reduce the ingestion of this toxic halogen. PMID:24348140

  17. Drinking water fluoride levels for a city in northern Mexico (durango) determined using a direct electrochemical method and their potential effects on oral health.

    Science.gov (United States)

    Molina Frechero, Nelly; Sánchez Pérez, Leonor; Castañeda Castaneira, Enrique; Oropeza Oropeza, Anastasio; Gaona, Enrique; Salas Pacheco, José; Bologna Molina, Ronell

    2013-01-01

    Fluoride is ingested primarily through consuming drinking water. When drinking water contains fluoride concentrations>0.7 parts per million (ppm), consuming such water can be toxic to the human body; this toxicity is called "fluorosis." Therefore, it is critical to determine the fluoride concentrations in drinking water. The objective of this study was to determine the fluoride concentration in the drinking water of the city of Durango. The wells that supply the drinking water distribution system for the city of Durango were studied. One hundred eighty-nine (189) water samples were analyzed, and the fluoride concentration in each sample was quantified as established by the law NMX-AA-077-SCFI-2001. The fluoride concentrations in such samples varied between 2.22 and 7.23 ppm with a 4.313±1.318 ppm mean concentration. The highest values were observed in the northern area of the city, with a 5.001±2.669 ppm mean value. The samples produced values that exceeded the national standard for fluoride in drinking water. Chronic exposure to fluoride at such concentrations produces harmful health effects, the first sign of which is dental fluorosis. Therefore, it is essential that the government authorities implement water defluoridation programs and take preventative measures to reduce the ingestion of this toxic halogen.

  18. Growth of fluoride treated Kalanchoe pinnata plants

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, H N; Applegate, H G

    1962-01-01

    Kalanchoe pinnata plants can absorb fluoride through roots. The absorption is related to the amount of fluoride applied to the soil. There appeared to be a relationship between the amount of fluoride adsorbed and the subsequent growth of the plants. Plants which adsorbed the largest amounts of fluoride had the greatest increase in growth.

  19. Toxicity assessment of sodium fluoride in Drosophila melanogaster after chronic sub-lethal exposure.

    Science.gov (United States)

    Dutta, Moumita; Rajak, Prem; Khatun, Salma; Roy, Sumedha

    2017-01-01

    Sodium fluoride (NaF), one of the most frequently used fluoride compound is composed of Na + and F - . Apart from its use in water fluoridation, NaF also acts as a major component for different dental products like toothpastes, gels and mouth rinses etc. The present study was carried out to explore the toxic impact of chronic NaF exposure on a non-target organism, Drosophila melanogaster. The larvae exposed to different concentrations of NaF through food showed a significant increase in HSP70 expression both qualitatively and quantitatively. The altered tail length and tail intensity in Comet assay validate the increased DNA damage in treated larvae. The activity of AChE, oxidative stress marker enzymes, phase I and phase II detoxifying enzymes were found to be significantly inhibited in the treated larvae when compared to control though there was no evidence of dose dependent change in each case. The alterations in the mentioned parameters can be due to increased body Fluoride ion (F - ) concentration since the analysis with ion electrode analyzer revealed that F - concentration increased significantly with NaF treatment. Hence, the results suggest that D. melanogaster manifest prominent toxic response when subjected to chronic exposure to sub-lethal NaF concentrations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Fluoride Levels in Urine, Blood Plasma and Serum of People Living in an Endemic Fluorosis Area in the Thar Desert, Pakistan

    International Nuclear Information System (INIS)

    Rafique, T.; Shirin, K.; Ahmed, I.; Khan, M. H.; Soomro, F.

    2015-01-01

    Fluoride (F/sup -/) levels in the urine, blood plasma and serum samples of people living in a village in the Thar Desert have been analysed where fluorosis is endemic and groundwater contains fluoride as high as 9.76 mg/L. Average values of fluoride levels in these human specimens i.e. urine, blood plasma and serum have been found to be 12.98 mg/L, 0.61 mg/L and 0.75 mg/L, respectively. These values are much higher than the normal values reported from other parts of the world. It was observed that urinary fluoride levels increase with age of an individual but with an insignificant correlation (r = 0.116), however, fluoride levels in plasma and serum samples did not vary considerably with age in male and female subjects. It has been found that after the age of 50 years the urinary fluoride decreases with its concomitant increase in serum fluoride level. Since groundwater is the only available source of water for human consumption and it contains higher fluoride (av. 7.09 mg/L) than WHO limit (1.5 mg/L), therefore, it is the main cause of fluorosis in the area. (author)

  1. Lichens as indicators of fluoride emission from a phosphorus plant, Long Harbour, Newfoundland, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, B.A.; Thompson, L.K.

    1980-01-01

    Fluoride concentrations in the terrestrial lichens Cladina rangiferina (L.) Harm. and Cladina stellaris (Opiz.) Brodo. were correlated inversely with distance from an industrial plant producing elemental phosphorus at Long Harbour, Nfld., in the direction (NE) of the prevailing wind. The fluoride concentrations ranged from 2830 ppm dry weight in a severely damaged area close to the emission source to 15.5 ppm (dry weight) 12 km NE of the industrial plant. Control samples from unpolluted areas had an average fluoride content of 6.4 ppm dry weight. The minimum observed damage symptoms occurred when these lichens had a fluoride content of 25 ppm dry weight. Damage symptoms included discolouration and structure loss. Discolouration effects were not as pronounced as observed on Abies balsamea (L.) Mill. or on Polytrichum commune (Hedw.) but combined with structure loss allowed the degree of damage to be readily identified in the field. Fluoride concentrations in these terrestrial lichens are compared with levels in soil humus, A. balsamea and some terrestrial bryophytes in four damage zones. The lichen tissue had, on average, twice as much fluoride as occurred in soil humus from the same site and about one half the amount of fluoride found in the terrestrial bryophyte P. commune. The effects of fluoride emissions on the epiphytic lichens Hypogymnia physodes (L.) W. Wats. and Alectoria sarmentosa (Ach.) Ach. in this area are also discussed.

  2. Risk Assessment Study of Fluoride Salts: Probability-Impact Matrix of Renal and Hepatic Toxicity Markers.

    Science.gov (United States)

    Usuda, Kan; Ueno, Takaaki; Ito, Yuichi; Dote, Tomotaro; Yokoyama, Hirotaka; Kono, Koichi; Tamaki, Junko

    2016-09-01

    The present risk assessment study of fluoride salts was conducted by oral administration of three different doses of sodium and potassium fluorides (NaF, KF) and zinc fluoride tetrahydrate (ZnF2 •4H2O) to male Wistar rats. The rats were divided into control and nine experimental groups, to which oral injections of 0.5 mL distilled water and 0.5 mL of fluoride solutions, respectively, were given. The dosage of fluoride compounds was adjusted to contain 2.1 mg (low-dose group, LG), 4.3 mg (mid-dose group, MG), and 5.4 mg fluoride per 200 g rat body weight (high-dose group, HG) corresponding to 5, 10, and 12.5 % of LD50 values for NaF. The 24-h urine volume, N-acetyl-β-D-glucosaminidase (NAG) and creatinine clearance (Ccr) were measured as markers of possible acute renal impact. The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined in serum samples as markers of acute hepatic impact. The levels of serum and urinary fluoride were determined to evaluate fluoride bioavailability. The results reveal that higher doses of NaF, KF, and ZnF2 induced renal damage as indicated by higher urinary NAG (p fluoride is a potential, dose-dependent risk factor of renal tubular damage.

  3. The effects of fluoride, strontium, theobromine and their combinations on caries lesion rehardening and fluoridation.

    Science.gov (United States)

    Lippert, Frank

    2017-08-01

    The aim was to investigate the effects of fluoride, strontium, theobromine and their combinations on caries lesion rehardening and fluoridation (EFU) under pH cycling conditions. Human enamel specimens were demineralized at 37°C for 24h using a pH 5.0 solution containing 50mM lactic acid and 0.2% Carbopol 907 which was 50% saturated with respect to hydroxyapatite. Lesions were assigned to nine treatment groups (n=16) based on Knoop surface microhardness indentation length. aqueous solutions were: placebo, 11.9mM sodium fluoride (F), 23.8mM sodium fluoride (2×F), 1.1mM strontium chloride hexahydrate (Sr), 1.1mM F theobromine, Sr+theobromine, F+Sr, F+theobromine, F+Sr+theobromine. Lesions were pH cycled for 5d (daily protocol: 3×1min-treatment; 2×60min-demineralization; 4×60min & overnight-artificial saliva). Knoop indentation length was measured again and%surface microhardness recovery (%SMHr) calculated. EFU was determined using the acid-etch technique. Data were analysed using ANOVA. Model showed fluoride dose-response for both variables (2×F>F>placebo). For%SMHr, F+Sr+/-theobromine resulted in more rehardening than F, however less than 2×F. F+theobromine was similar to F. For EFU, F+Sr was inferior to F, F+theobromine and F+Sr+theobromine which were similar and inferior to 2×F. In absence of fluoride, Sr, theobromine or Sr+theobromine were virtually indistinguishable from placebo and inferior to F. It can be concluded that a) strontium aids rehardening but not EFU and only in presence of fluoride; b) theobromine does not appear to offer any anti-caries benefits in this model; c) there are no synergistic effects between strontium and theobromine in the presence or absence of fluoride. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Fluoride exposure of East African consumers using alkaline salt deposits known as magadi (trona) as a food preparation aid

    DEFF Research Database (Denmark)

    Nielsen, Joan Maj; Dahi, E.

    2002-01-01

    that the fluoride content varied significantly even for magadi originating from the individual lake, e. g. the fluoride content in magadi from Lake Magadi was between 0.1 and 8.7 mg g(-1). In a lump of magadi originating from Lake Magadi, it was found that the fluoride content in 20 smaller part samples was subject...

  5. Comparison of molten chloride and fluoride salts potentialities for An/Ln separation by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Laplace, A.; Peron, F.; Marrot, F.; Lacquement, J. [DRCP/SCPS/LPP - CEA/CEN Valrho - BP 17171 - 30207 Bagnols/Ceze (France)

    2008-07-01

    The objective of this paper is the comparison of molten fluoride and chloride salts potentialities for Am/Nd separation by electrodeposition on inert cathode, on a purely thermodynamic point of view. The molten LiF-CaF{sub 2} eutectic (77-23 mol.%, at 780 deg. C) was considered for this study. Cyclic voltammetry showed a one step Am(III)/Am reduction at a potential of {approx_equal}+0.5 V vs. Li{sup +}/Li. A potential difference of 290 mV between Am and Nd metallic deposition was estimated by square-wave voltammetry. This Am/Nd potential difference is more important than in molten chlorides (220 mV in the LiCl-KCl eutectic at 500 deg. C). Moreover in molten fluoride salt, the americium and neodymium (+II) oxidation state is not stable contrary to the molten chloride one where corrosion of deposited Am would be potential. However this larger potential difference in molten fluorides is quite balanced by the higher working temperature. (authors)

  6. SITUATION OF FLUORIDES RATE IN WATERS AND MAJOR CONSUMED FOOD IN WILAYA EL-OUED

    Directory of Open Access Journals (Sweden)

    A. Zobeidi

    2013-12-01

    Full Text Available The effects of mineral salts in the drinking water, beneficial or harmful depending on their concentration, are known for many years and thus the problem posed by fluoride ions in the waters of the region (Fluorosis Dental and skeletal. This study proposes, the estimated daily intake of fluoride from its water distribution and the main food consumed per capita in the region of El-Oued (dates, tea, couscous, lentils, carrots, potatoes, pumpkin ..., which has a significant content of fluoride in their composition. In addition to the arid climatic conditions, the air temperature is very high in summer, leads to a strong human perspiration. This preliminary result leads us to propose a standard fluoride-specific region of El-Oued. The results showed that the majority of water samples and analyzed the main foods of the region of El-Oued is charged fluoride ions and exceed the maximum dose recommended for adults from 0.05 to 0.07 mg / kg / day.

  7. Comparison of the Amount of Fluoride Release from Nanofilled Resin Modified Glass Ionomer Conventional and Resin Modified Glass Ionomer Cements

    Directory of Open Access Journals (Sweden)

    Sumitha Upadhyay

    2013-01-01

    Full Text Available Objective: To investigate and compare the amount of fluoride release of conventional, resin modified and nanofilled resin modified glass ionomer cements.Materials and Methods: Tablets of glass-ionomer cements were immersed in deionized water and incubated at 37◦C. After 1, 2, 7, 15 and 30 days, fluoride ion was measured under normal atmospheric conditions by fluoride ion selective electrode. Buffer (TISAB II was used to decomplex the fluoride ion and to provide a constant background ionic strength and to maintain the pH of water between 5.0 and 5.5 as the fluoride electrode is sensitive to changes in pH. Statistical evaluation was carried out by one way ANOVA (Analysis of Variance using SPSS 11.0. The significance level was set at p< 0.05.Results: The release of fluoride was highest on day 1 and there was a sudden fall on day 2 in all three groups. Initially fluoride release from conven-tional glass-ionomer cement was highest compared to the other two glass-ionomer cements, but the amount drastically reduced over the period. Although the amount of fluoride release was less than both the resin modified and nanofilled resin modified glass-ionomer cement, the release was sustained consistently for 30 daysConclusion: The cumulative fluoride release of nanofilled resin modified glass ionomer cement was very less compared to the conventional and resin modified glass ionomer cements and Nanofilled resin modified glass ionomer cement released less but steady fluoride as compared to other resin modified glass ionomer cements.

  8. A review of slow-release fluoride devices.

    Science.gov (United States)

    Toumba, K J; Al-Ibrahim, N S; Curzon, M E J

    2009-09-01

    Fluoride has been used to combat dental caries using a number of different clinical approaches. An exciting relatively new development is fluoride slow-releasing devices that consistently elevate intra-oral fluoride levels of plaque and saliva for prolonged periods of up to two years. The literature on the use of slow-releasing fluoride devices in dentistry were reviewed. A Medline search on key words was carried out. All papers in English were individually reviewed. Slow-releasing fluoride devices have been shown to be effective in elevating salivary fluoride levels in both animals and human studies and to enhance the remineralisation of dental enamel. They have been demonstrated to be safe to use and without the risk of fluoride toxicity. A double blind randomised clinical trial demonstrated 76% fewer new carious surface increment in high caries-risk children after two years. These devices have a number of potential uses in dentistry and in particular have great potential for caries prevention of non-compliant high caries-risk groups.

  9. Effects of fluoridated milk on root dentin remineralization.

    Directory of Open Access Journals (Sweden)

    Wolfgang H Arnold

    Full Text Available The prevalence of root caries is increasing with greater life expectancy and number of retained teeth. Therefore, new preventive strategies should be developed to reduce the prevalence of root caries. The aim of this study was to investigate the effects of fluoridated milk on the remineralization of root dentin and to compare these effects to those of sodium fluoride (NaF application without milk.Thirty extracted human molars were divided into 6 groups, and the root cementum was removed from each tooth. The dentin surface was demineralized and then incubated with one of the following six solutions: Sodium chloride NaCl, artificial saliva, milk, milk+2.5 ppm fluoride, milk+10 ppm fluoride and artificial saliva+10 ppm fluoride. Serial sections were cut through the lesions and investigated with polarized light microscopy and quantitative morphometry, scanning electron microscopy (SEM and energy-dispersive X-ray spectroscopy (EDS. The data were statistically evaluated using a one-way ANOVA for multiple comparisons.The depth of the lesion decreased with increasing fluoride concentration and was the smallest after incubation with artificial saliva+10 ppm fluoride. SEM analysis revealed a clearly demarcated superficial remineralized zone after incubation with milk+2.5 ppm fluoride, milk+10 ppm fluoride and artificial saliva+10 ppm fluoride. Ca content in this zone increased with increasing fluoride content and was highest after artificial saliva+10 ppm fluoride incubation. In the artificial saliva+10 ppm fluoride group, an additional crystalline layer was present on top of the lesion that contained elevated levels of F and Ca.Incubation of root dentin with fluoridated milk showed a clear effect on root dentin remineralization, and incubation with NaF dissolved in artificial saliva demonstrated a stronger effect.

  10. Highly selective single-use fluoride ion optical sensor based on aluminum(III)-salen complex in thin polymeric film

    International Nuclear Information System (INIS)

    Badr, Ibrahim H.A.; Meyerhoff, Mark E.

    2005-01-01

    A highly selective optical sensor for fluoride ion based on the use of an aluminum(III)-salen complex as an ionophore within a thin polymeric film is described. The sensor is prepared by embedding the aluminum(III)-salen ionophore and a suitable lipophilic pH-sensitive indicator (ETH-7075) in a plasticized poly(vinyl chloride) (PVC) film. Optical response to fluoride occurs due to fluoride extraction into the polymer via formation of a strong complex with the aluminum(III)-salen species. Co-extraction of protons occurs simultaneously, with protonation of the indicator dye yielding the optical response at 529 nm. Films prepared using dioctylsebacate (DOS) are shown to exhibit better response (e.g., linear range, detection limit, and optical signal stability) compared to those prepared using ortho-nitrophenyloctyl ether (o-NPOE). Films formulated with aluminum(III)-salen and ETH-7075 indicator in 2 DOS:1 PVC, exhibit a significantly enhanced selectivity for fluoride over a wide range of lipophilic anions including salicylate, perchlorate, nitrate, and thiocyanate. The optimized films exhibit a sub-micromolar detection limit, using glycine-phosphate buffer, pH 3.00, as the test sample. The response times of the fluoride optical sensing films are in the range of 1-10 min depending on the fluoride ion concentration in the sample. The sensor exhibits very poor reversibility owing to a high co-extraction constant (log K = 8.5 ± 0.4), indicating that it can best be employed as a single-use transduction device. The utility of the aluminum(III)-salen based fluoride sensitive films as single-use sensors is demonstrated by casting polymeric films on the bottom of standard polypropylene microtiter plate wells (96 wells/plate). The modified microtiter plate optode format sensors exhibit response characteristics comparable to the classical optode films cast on quartz slides. The modified microtiter is utilized for the analysis of fluoride in diluted anti-cavity fluoride rinse

  11. Fluoride Increase in Saliva and Dental Biofilm due to a Meal Prepared with Fluoridated Water or Salt: A Crossover Clinical Study.

    Science.gov (United States)

    Lima, Carolina V; Tenuta, Livia M A; Cury, Jaime A

    2018-06-07

    Knowledge about fluoride delivery to oral fluids from foods cooked with fluoridated water and salt is scarce, and no study has evaluated fluoride concentrations in saliva or biofilm during meal consumption. In this randomized double-blind crossover study, 12 volunteers ingested meals (rice, beans, meat, and legumes) prepared with nonfluoridated water and salt (control group), fluoridated water (0.70 mg F/L; water group), and fluoridated salt (183.7 mg F/kg; salt group). Whole saliva was collected before meal ingestion, during mastication, and up to 2 h after meal ingestion. Dental biofilm was collected before and immediately after meal ingestion. Fluoride concentrations in saliva and dental biofilm were determined by an ion-specific electrode. The mean (±standard deviation; n = 4) fluoride concentrations in meals prepared for the control, water, and salt groups were 0.039 ± 0.01, 0.43 ± 0.04, and 1.71 ± 0.32 μg F/g, respectively. The three groups had significantly different fluoride concentrations in saliva collected during mastication (p water > control). The fluoride concentration in saliva returned to baseline 30 min after meal ingestion in the water group but remained high for up to 2 h in the salt group (p = 0.002). The fluoride concentration in biofilm fluid differed only between the salt and control groups (p = 0.008). The mastication of foods cooked with fluoridated water and salt increases fluoride concentrations in oral fluids and may contribute to the local effect of these community-based fluoride interventions on caries control. © 2018 S. Karger AG, Basel.

  12. Scandium fluorides

    International Nuclear Information System (INIS)

    Melnikov, P.; Nalin, M.; Messaddeq, Y.

    1997-01-01

    A new modification of scandium fluoride has been synthesised. The compound is deficient in fluorine, with the composition ScF 2.76 . It belongs to the tetragonal system, lattice parameters being a=3.792 and c=6.740 A and may be obtained at low temperatures by the decomposition of the precursor NH 4 ScF 4 . The reaction is topotactic, tetragonal parameters of the precursor are a=4.021 and c=6.744 A. Structural relationships with various fluorides and ammonium aminofluorides are discussed. This synthesis route with IR-assisted decomposition should be considered as a soft-chemistry approach. (orig.)

  13. Measurement of fluoride in bone

    International Nuclear Information System (INIS)

    Mernagh, J.R.; Harrision, J.E.; Hancock, R.; McNeill, K.G.

    1977-01-01

    The fluorine concentration in bone biopsy samples was measured by neutron activation analysis. The fluorine content was expressed in terms of the calcium content. Samples were irradiated in a reactor to induce the 19 F(n,γ) 20 F and 48 Ca(n,γ) 49 Ca reactions and after rapid transport from the reactor the resulting activities were measured with a Ge(Li) detector. Reproducibility was better than 10% for the F/Ca ratio. The detection limit for F is 50 μg. This nondestructive technique will be used to assess the effect of fluoride therapy on bone metabolism of patients with idiopathic osteoporosis. (author)

  14. Matrix supported tailored polymer for solid phase extraction of fluoride from variety of aqueous streams

    International Nuclear Information System (INIS)

    Thakur, Neha; Kumar, Sanjukta A.; Wagh, D.N.; Das, Sadananda; Pandey, Ashok K.; Kumar, Sangita D.; Reddy, A.V.R.

    2012-01-01

    Highlights: ► Th complexed with poly (bis[2-(methacryloyloxy)-ethyl]phosphate) as tailored polymer membranes. ► Membranes offered high capacity and selectivity for fluoride in aqueous media. ► Quantitative uptake (80 ± 5%) of fluoride. ► Fast sorption kinetics. ► Reusability of polymer membranes. - Abstract: Fluoride related health hazards (fluorosis) are a major environmental problem in many regions of the world. It affects teeth; skeleton and its accumulation over a long period can lead to changes in the DNA structure. It is thus absolutely essential to bring down the fluoride levels to acceptable limits. Here, we present a new inorganic–organic hybrid polymer sorbent having tailored fixed-sites for fluoride sorption. The matrix supported poly (bis[2-(methacryloyloxy)-ethyl]phosphate) was prepared by photo-initiator induced graft-polymerization in fibrous and microporous (sheet) host poly(propylene) substrates. These substrates were conditioned for selective fluoride sorption by forming thorium complex with phosphate groups on bis[2-methacryloyloxy)-ethyl] phosphate (MEP). These tailored sorbents were studied for their selectivity towards fluoride in aqueous media having different chemical conditions. The fibrous sorbent was found to take up fluoride with a faster rate (15 min for ≈76% sorption) than the sheet sorbent. But, the fluoride loading capacity of sheet sorbent (4320 mg kg −1 ), was higher than fibrous and any other sorbent reported in the literature so far. The sorbent developed in the present work was found to be reusable after desorption of fluoride using NaOH solution. It was tested for solid phase extraction of fluoride from natural water samples.

  15. Adverse effects of fluoride towards thyroid hormone metabolism

    Directory of Open Access Journals (Sweden)

    Enggar Abdullah Idris MZ

    2008-03-01

    Full Text Available An easily ionized fluoride compound like Sodium Fluoride (NaF has been used thus far as a dental caries prevention substance. However, fluoride ions also have a negative effect because it is very toxic. Several types of research on the effect of fluoride on guinea pigs and human beings indicate the presence synthesis obstruction of T3 and T4 that causes declined production, known as hypothyroidism. Hypothyroidism condition may obstruct tissue growth process and metabolism so as to impact various body organ systems. Preventive efforts against hypothyroidism caused by fluoride include avoiding diffusible fluoride compound intake, like NaF, in a long run systemic use, whereas efforts to overcome fluoride intoxication include consuming food that is rich in calcium, vitamin D, and antioxidant.

  16. Factors affecting fluoride and natural organic matter (NOM) removal from natural waters in Tanzania by nanofiltration/reverse osmosis.

    Science.gov (United States)

    Shen, Junjie; Schäfer, Andrea I

    2015-09-15

    This study examined the feasibility of nanofiltration (NF) and reverse osmosis (RO) in treating challenging natural tropical waters containing high fluoride and natural organic matter (NOM). A total of 166 water samples were collected from 120 sources within northern Tanzania over a period of 16 months. Chemical analysis showed that 81% of the samples have fluoride levels exceeding the WHO drinking guideline of 1.5mg/L. The highest fluoride levels were detected in waters characterized by high ionic strength, high inorganic carbon and on some occasions high total organic carbon (TOC) concentrations. Bench-scale experiments with 22 representative waters (selected based on fluoride concentration, salinity, origin and in some instances organic matter) and 6 NF/RO membranes revealed that ionic strength and recovery affected fluoride retention and permeate flux. This is predominantly due to osmotic pressure and hence the variation of diffusion/convection contributes to fluoride transport. Different membranes had distinct fluoride removal capacities, showing different raw water concentration treatability limits regarding the WHO guideline compliance. BW30, BW30-LE and NF90 membranes had a feed concentration limit of 30-40 mg/L at 50% recovery. NOM retention was independent of water matrices but is governed predominantly by size exclusion. NOM was observed to have a positive impact on fluoride removal. Several mechanisms could contribute but further studies are required before a conclusion could be drawn. In summary, NF/RO membranes were proved to remove both fluoride and NOM reliably even from the most challenging Tanzanian waters, increasing the available drinking water sources. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Salivary Fluoride level in preschool children after toothbrushing with standard and low fluoride content dentifrice, using the transversal dentifrice application technique: pilot study

    Directory of Open Access Journals (Sweden)

    Fabiana Jandre Melo

    2008-01-01

    Full Text Available Objective: To investigate the salivary fluoride concentration in pre-school children after toothbrushing with dentifrice containing standard (1100ppmF/NaF and low (500ppmF/NaF fluoride concentration, using the transversal technique of placing the product on the toothbrush. Methods: Eight children of both sexes, ranging from 4 to 9 years, and 5 years and 6 months of age, participated in the study. The experiment was divided into two phases with a weekly interval. In the first stage, the children used the standard concentration dentifrice for one week, and in the second, the low concentration product. Samples were collected at the end of each experimental stage, at the following times: Before brushing, immediately afterwards, and after 15, 30 and 45 minutes. The fluoride contents were analyzed by the microdiffusion technique. Statistical analysis was done by the analysis of variance ANOVA and Student’s-t test (p<0.05. Results: The salivary fluoride concentration was significantly higher at all times, when the standard concentration product was used. The comparison between the Halogen concentration found before bushing and immediately afterwards, showed that there was a 6.8 times increase in the standard dentifrice (0.19 x 1.29μgF/ml and in the low concentration product, an increase of 20.5 times (0.02 x 0.41μgF/ml. Conclusion: Toothbrushing with both products promoted relevant increases in the salivary fluoride concentration; however, longitudinal studies are necessary to verify the clinical result of this measurement.

  18. Fluoride and Water (For Parents)

    Science.gov (United States)

    ... risk of tooth decay" on the label. The Controversy Over Fluoride Opponents of water fluoridation have questioned ... Us Contact Us Partners Editorial Policy Permissions Guidelines Privacy Policy & Terms of Use Notice of Nondiscrimination Visit ...

  19. Measurement of europium (III)/europium (II) couple in fluoride molten salt for redox control in a molten salt reactor concept

    Science.gov (United States)

    Guo, Shaoqiang; Shay, Nikolas; Wang, Yafei; Zhou, Wentao; Zhang, Jinsuo

    2017-12-01

    The fluoride molten salt such as FLiNaK and FLiBe is one of the coolant candidates for the next generation nuclear reactor concepts, for example, the fluoride salt cooled high temperature reactor (FHR). For mitigating corrosion of structural materials in molten fluoride salt, the redox condition of the salts needs to be monitored and controlled. This study investigates the feasibility of applying the Eu3+/Eu2+ couple for redox control. Cyclic voltammetry measurements of the Eu3+/Eu2+ couple were able to obtain the concentrations ratio of Eu3+/Eu2+ in the melt. Additionally, the formal standard potential of Eu3+/Eu2+ was characterized over the FHR's operating temperatures allowing for the application of the Nernst equation to establish a Eu3+/Eu2+ concentration ratio below 0.05 to prevent corrosion of candidate structural materials. A platinum quasi-reference electrode with potential calibrated by potassium reduction potential is shown as reliable for the redox potential measurement. These results show that the Eu3+/Eu2+ couple is a feasible redox buffering agent to control the redox condition in molten fluoride salts.

  20. Physiologic Conditions Affect Toxicity of Ingested Industrial Fluoride

    OpenAIRE

    Richard Sauerheber

    2013-01-01

    The effects of calcium ion and broad pH ranges on free fluoride ion aqueous concentrations were measured directly and computed theoretically. Solubility calculations indicate that blood fluoride concentrations that occur in lethal poisonings would decrease calcium below prevailing levels. Acute lethal poisoning and also many of the chronic effects of fluoride involve alterations in the chemical activity of calcium by the fluoride ion. Natural calcium fluoride with low solubility and toxicity ...

  1. Fluoride Removal from Water by Reverse Osmosis Membrane

    Directory of Open Access Journals (Sweden)

    Sara Namavar

    2013-09-01

    Full Text Available As fluoride concentration in drinking water is one of the effective parameters in human health, finding the way to remove excess amount of fluoride from drinking water is very important in water supply projects. Today, with developing in technology and finding new methods, the use of membrane technology for producing fresh water get improved. In this study the efficiency of reverse osmosis method to remove fluoride from water was investigated. Initial concentration of fluoride, sulfate and electrical conductivity in feed water and the effect of associated cation with fluoride ion were studied. All tests adapted from “Standard Methods for Examination of Water and Wastewater”. Determination of fluoride concentration was done according the standard SPANDS method by using a spectrophotometer DR/5000. Obtain results show that with increasing in concentration of fluoride and sulfate and electrical conductivity in feed water the efficiency of RO membrane to remove fluoride reduced. In addition, this efficiency for CaF2 was higher than NaF.

  2. Parental preference for fluoride varnish: a new concept in a rapidly developing nation.

    Science.gov (United States)

    Hendaus, Mohamed A; Jama, Hibaq A; Siddiqui, Faisal J; Elsiddig, Sohair A; Alhammadi, Ahmed H

    2016-01-01

    The objective of this study was to investigate parental preference for fluoride varnish in a country where the average percentage of dental caries in young children is up to ~73%. Consequently, the aim of this study, despite being a pilot, was to create a nationwide project in the State of Qatar to promote oral health in children. A cross-sectional perspective study was conducted at Hamad Medical Corporation in Qatar. Parents of children aged ≤5 years were offered an interview survey. A total of 200 questionnaires were completed (response rate =100%). The study was conducted between December 1, 2014 and March 30, 2015, and included all children aged >1 year and parents' knowledge and awareness of dental health, we found that >90% of families were aware that dental health affects the health of the whole body. The study showed that ~70% of parents were not aware of the existence of fluoride varnish, but would allow a health provider to apply fluoride varnish. Furthermore, ~80% of parents would not stop brushing their child's teeth and would not skip dentist appointments if varnish was to be applied. Approximately 40% of parents conveyed some concerns regarding the safety of fluoride varnish, despite being considered as a new concept. The main concern was that the child might swallow some of the fluoride. Another important concern expressed by parents was the availability of the fluoride varnish in all clinics. The robust positive attitude of parents in this sample suggests that introducing fluoride varnish is feasible and acceptable in our community. Actions to augment fluoride varnish acceptability in the developing world, such as focusing on safety, could be important in the disseminated implementation of fluoride varnish.

  3. FLUORIDE: A REVIEW OF USE AND EFFECTS ON HEALTH.

    Science.gov (United States)

    Kanduti, Domen; Sterbenk, Petra; Artnik, Barbara

    2016-04-01

    Appropriate oral health care is fundamental for any individual's health. Dental caries is still one of the major public health problems. The most effective way of caries prevention is the use of fluoride. The aim of our research was to review the literature about fluoride toxicity and to inform physicians, dentists and public health specialists whether fluoride use is expedient and safe. Data we used in our review were systematically searched and collected from web pages and documents published from different international institutions. Fluoride occurs naturally in our environment but we consume it in small amounts. Exposure can occur through dietary intake, respiration and fluoride supplements. The most important factor for fluoride presence in alimentation is fluoridated water. Methods, which led to greater fluoride exposure and lowered caries prevalence, are considered to be one of the greatest accomplishments in the 20th century`s public dental health. During pregnancy, the placenta acts as a barrier. The fluoride, therefore, crosses the placenta in low concentrations. Fluoride can be transmitted through the plasma into the mother's milk; however, the concentration is low. The most important action of fluoride is topical, when it is present in the saliva in the appropriate concentration. The most important effect of fluoride on caries incidence is through its role in the process of remineralization and demineralization of tooth enamel. Acute toxicity can occur after ingesting one or more doses of fluoride over a short time period which then leads to poisoning. Today, poisoning is mainly due to unsupervised ingestion of products for dental and oral hygiene and over-fluoridated water. Even though fluoride can be toxic in extremely high concentrations, it`s topical use is safe. The European Academy of Paediatric Dentistry (EAPD) recommends a preventive topical use of fluoride supplements because of their cariostatic effect.

  4. Assessment of fluoride-induced changes on physicochemical and structural properties of bone and the impact of calcium on its control in rabbits.

    Science.gov (United States)

    Gopalakrishnan, Subarayan Bothi; Viswanathan, Gopalan

    2012-03-01

    Bone deformities caused by the chronic intake of large quantities of fluoride and the beneficial effect of calcium on its control have been studied for many years, but only limited data are available on the quantitative effect of fluoride intake and the beneficial impact of calcium on fluoride-induced changes in bone at the molecular level. It is necessary to determine the degree of fluoride-induced changes in bone at different levels of fluoride intake to evaluate the optimum safe intake level of fluoride for maintaining bone health and quality. The ameliorative effect of calcium at different dose levels on minimizing fluoride-induced changes in bone is important to quantify the amount of calcium intake necessary for reducing fluoride toxicity. Thirty rabbits, 2 months old, were divided into five groups. Group I animals received 1 mg/l fluoride and 0.11% calcium diet; groups II and III received 10 mg/l fluoride and diet with 0.11% or 2.11% calcium, respectively; and groups IV and V received 150 mg/l fluoride and diet with 2.11% or 0.11% calcium, respectively. Analysis of bone density, ash content, fluoride, calcium, phosphorus, and Ca:P molar ratio levels after 6 months of treatment indicated that animals that received high fluoride with low-calcium diet showed significant detrimental changes in physicochemical properties of bone. Animals that received fluoride with high calcium intake showed notable amelioration of the impact of calcium on fluoride-induced changes in bone. The degree of fluoride-induced characteristic changes in structural properties such as crystalline size, crystallinity, and crystallographic "c"-axis length of bone apatite cells was also assessed by X-ray diffraction and Fourier transform infrared studies. X-ray images showed bone deformity changes such as transverse stress growth lines, soft tissue ossification, and calcification in different parts of bones as a result of high fluoride accumulation and the beneficial role of calcium

  5. Strontium-90 fluoride data sheet

    Energy Technology Data Exchange (ETDEWEB)

    Fullam, H.T.

    1981-06-01

    This report is a compilation of available data and appropriate literature references on the properties of strontium-90 fluoride and nonradioactive strontium fluoride. The objective of the document is to compile in a single source pertinent data to assist potential users in the development, licensing, and use of /sup 90/SrF/sub 2/-fueled radioisotope heat sources for terrestrial power conversion and thermal applications. The report is an update of the Strontium-90 Fluoride Data Sheet (BNWL-2284) originally issued in April 1977.

  6. Potential fluoride toxicity from oral medicaments: A review

    OpenAIRE

    Rizwan Ullah; Muhammad Sohail Zafar; Nazish Shahani

    2017-01-01

    The beneficial effects of fluoride on human oral health are well studied. There are numerous studies demonstrating that a small amount of fluoride delivered to the oral cavity decreases the prevalence of dental decay and results in stronger teeth and bones. However, ingestion of fluoride more than the recommended limit leads to toxicity and adverse effects. In order to update our understanding of fluoride and its potential toxicity, we have described the mechanisms of fluoride metabolism, tox...

  7. Low-levels of fluoride in plaque and saliva and their effects on the demineralisation and remineralisation of enamel; role of fluoride toothpastes.

    Science.gov (United States)

    Lynch, R J M; Navada, R; Walia, R

    2004-01-01

    To summarise support for current consensus on the likely means by which fluoride toothpastes reduce caries and review some relevant studies of the effect of low levels of fluoride on the demineralisation and remineralisation of enamel. The major anti-caries effect of fluoride toothpastes is thought to result from small but protracted elevations in levels of fluoride in plaque and saliva. Fluoride incorporated into enamel systemically does not reduce enamel solubility sufficiently to exert an anti-caries effect. Fluoride has the potential to exert an anti-caries benefit largely through three mechanisms; inhibition of demineralisation, promotion of remineralisation and interference with bacterial growth and metabolism. However, the low levels of fluoride thought to influence caries are insufficient to have a significant effect via the latter mechanism. Thus reductions in caries resulting from the use of fluoride toothpastes can be linked to modification of the demineralisation/remineralisation balance by direct effects on dental mineral exerted topically by low levels of fluoride. Numerous in vitro studies have shown that low levels of fluoride, typical of those found after many hours in resting plaque and saliva, and resulting from the regular use of fluoride toothpastes, can have a profound effect on enamel demineralisation and remineralisation.

  8. Fluoride release and cariostatic potential of orthodontic adhesives with and without daily fluoride rinsing.

    NARCIS (Netherlands)

    Chin, M.Y.; Sandham, A.; Rumachik, E.N.; Ruben, J.L.; Huysmans, M.C.D.N.J.M.

    2009-01-01

    INTRODUCTION: In this study, we aimed to evaluate the fluoride-release profiles and caries lesion development in an enamel model with brackets cemented with 4 orthodontic adhesives with and without daily fluoride exposure. METHODS: Four orthodontic adhesives (Ketac Cem mu, 3M ESPE, Seefeld, Germany;

  9. Fluoride release and cariostatic potential of orthodontic adhesives with and without daily fluoride rinsing

    NARCIS (Netherlands)

    Chin, Yeen; Sandham, John; Rumachik, Elena N.; Ruben, Jan L.; Huysmans, Marie-Charlotte D. N. J. M.

    2009-01-01

    Introduction: In this study, we aimed to evaluate the fluoride-release profiles and caries lesion development in an enamel model with brackets cemented with 4 orthodontic adhesives with and without daily fluoride exposure. Methods: Four orthodontic adhesives (Ketac Cem mu, 3M ESPE, Seefeld, Germany;

  10. Selective solid-phase extraction of Ni(II) by an ion-imprinted polymer from water samples

    International Nuclear Information System (INIS)

    Saraji, Mohammad; Yousefi, Hamideh

    2009-01-01

    A new ion-imprinted polymer (IIP) material was synthesized by copolymerization of 4-vinylpyridine as monomer, ethyleneglycoldimethacrylate as crosslinking agent and 2,2'-azobis-sobutyronitrile as initiator in the presence of Ni-dithizone complex. The IIP was used as sorbent in a solid-phase extraction column. The effects of sampling volume, elution conditions, sample pH and sample flow rate on the extraction of Ni ions form water samples were studied. The maximum adsorption capacity and the relative selectivity coefficients of imprinted polymer for Ni(II)/Co(II), Ni(II)/Cu(II) and Ni(II)/Cd(II) were calculated. Compared with non-imprinted polymer particles, the IIP had higher selectivity for Ni(II). The relative selectivity factor (α r ) values of Ni(II)/Co(II), Ni(II)/Cu(II) and Ni(II)/Cd(II) were 21.6, 54.3, and 22.7, respectively, which are greater than 1. The relative standard deviation of the five replicate determinations of Ni(II) was 3.4%. The detection limit for 150 mL of sample was 1.6 μg L -1 using flame atomic absorption spectrometry. The developed method was successfully applied to the determination of trace nickel in water samples with satisfactory results.

  11. Acute toxicity of ingested fluoride.

    Science.gov (United States)

    Whitford, Gary Milton

    2011-01-01

    This chapter discusses the characteristics and treatment of acute fluoride toxicity as well as the most common sources of overexposure, the doses that cause acute toxicity, and factors that can influence the clinical outcome. Cases of serious systemic toxicity and fatalities due to acute exposures are now rare, but overexposures causing toxic signs and symptoms are not. The clinical course of systemic toxicity from ingested fluoride begins with gastric signs and symptoms, and can develop with alarming rapidity. Treatment involves minimizing absorption by administering a solution containing calcium, monitoring and managing plasma calcium and potassium concentrations, acid-base status, and supporting vital functions. Approximately 30,000 calls to US poison control centers concerning acute exposures in children are made each year, most of which involve temporary gastrointestinal effects, but others require medical treatment. The most common sources of acute overexposures today are dental products - particularly dentifrices because of their relatively high fluoride concentrations, pleasant flavors, and their presence in non-secure locations in most homes. For example, ingestion of only 1.8 ounces of a standard fluoridated dentifrice (900-1,100 mg/kg) by a 10-kg child delivers enough fluoride to reach the 'probably toxic dose' (5 mg/kg body weight). Factors that may influence the clinical course of an overexposure include the chemical compound (e.g. NaF, MFP, etc.), the age and acid-base status of the individual, and the elapsed time between exposure and the initiation of treatment. While fluoride has well-established beneficial dental effects and cases of serious toxicity are now rare, the potential for toxicity requires that fluoride-containing materials be handled and stored with the respect they deserve. Copyright © 2011 S. Karger AG, Basel.

  12. Inhibition of cellular oxidation by fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Borei, H

    1945-01-01

    An attempt has been made to investigate the inhibition by fluoride of the oxidative processes which occur in the cell by way of the cytochrome oxidase-cytochrome system. Some chemical and physical properties of the fluoride ion are discussed, together with certain quantitative methods for the determination of fluoride. An exhaustive review of the literature concerning the effect of fluoride on enzymic processes has been compiled. The experiments have shown that the point of the attack by fluoride is to be found among the cytochromes. The inhibitory mechanism appears to be such that the haemoprotein is prevented from taking part in the preceding and succeeding links in the reaction chain. The blocking action leaves the prosthetic group of the haemoprotein completely unchanged. The experimental results indicate the formation of a fluorophosphoprotein complex, analogous to that found in the case of enolase. Magnesium may possibly play a part in this process.

  13. Acute toxicity of uranium hexafluoride, uranyl fluoride and hydrogen fluoride

    International Nuclear Information System (INIS)

    Just, R.A.

    1988-01-01

    Uranium hexafluoride (UF 6 ) released into the atmosphere will react rapidly with moisture in the air to form the hydrolysis products uranyl fluoride (UO 2 F 2 ) and hydrogen fluoride (HF). Uranium compounds such as UF 6 and UO 2 F 2 exhibit both chemical toxicity and radiological effects, while HF exhibits only chemical toxicity. This paper describes the development of a methodology for assessing the human health consequences of a known acute exposure to a mixture of UF 6 , UO 2 F 2 , and HF. 4 refs., 2 figs., 5 tabs

  14. Evaluation of toxic action of fluorides on agricultural plants

    Directory of Open Access Journals (Sweden)

    V. N. Grishko

    2007-03-01

    Full Text Available The toxicity of potassium fluoride, sodium fluoride and ammonium fluoride for pea, maize, oat and onion was studied. It was found that the level of the toxic influence had grown with increase of fluoride concentration in the media of growth (from 5 to 100 mg of F–/l. By increase of the toxic influence the agricultural crops are disposed in the following row: oat < onion < maize < pea. Ammonium fluoride demonstrates lesser toxicity, than potassium and sodium fluorides. Under low concentrations of fluoride compounds (5 and 10 mg of F–/l stimulation of roots growth is noted only for the oat.

  15. Comparative study of fluoride concentration in human serum and drinking water in fluorinated endemic and non endemic areas of pakistan

    International Nuclear Information System (INIS)

    Qayyum, M.; Ahmad, B.; Ahmad, M.

    2013-01-01

    For comparing the human blood serum and drinking water fluoride levels of subjects with dental fluorosis and bony deformities, this study is carried out with individuals ranging 8-17 age group fluorinated Sham Ki Bhatiyan, Punjab (endemic) and Queens Road, Lahore, Punjab (non-endemic) areas. Fluoride concentrations were determined using ion selective electrode methodology and statistically compared. Both the groups showed a significant difference (p < 0.05). Subjects from fluorotic area showed high concentration of fluoride in water and blood serum samples (mean value: 135.587+-77.435 and 2.765+-0.469 micro molL/sup -1/ in water and blood serum samples respectively) as compared to controls (mean value: 19.509+-2.432 and 2.364+- 0.667 micro molL -1). These findings indicate that serum and water fluoride concentrations have a significant positive dose response relationship with the prevalence of dental fluorosis in an area associated with high fluoride level in drinking water. (author)

  16. Determination of Fluoride in Different Toothpaste Formulations

    International Nuclear Information System (INIS)

    Kamau, N.G.; Njoroge, M.; Njau, M.

    1998-01-01

    Fluoride ion selective electrode was used to determine fluoride ion concentrations in seven brands of toothpaste. These were the only available formulations found in Kenya. The brands were classified into three groups-fluoridated, non fluoridated or not indicated. However, there was no independent indication of their quantitative composition. The analysed brands had fluoride content between 0.0033% and 0.096%. These values compared favourably with those obtained elsewhere. The calculated lowest limit of detection (LLD) was 0.01 ppmF- . The mean calibration curve gave a slope of of -50.0mV. which was not significantly different from the theoretical value of 5.88mV at 23 degrees celsius at 95% confidence level

  17. Decreased in vitro fertility in male rats exposed to fluoride-induced oxidative stress damage and mitochondrial transmembrane potential loss

    International Nuclear Information System (INIS)

    Izquierdo-Vega, Jeannett A.; Sanchez-Gutierrez, Manuel; Razo, Luz Maria del

    2008-01-01

    Fluorosis, caused by drinking water contamination with inorganic fluoride, is a public health problem in many areas around the world. The aim of the study was to evaluate the effect of environmentally relevant doses of fluoride on in vitro fertilization (IVF) capacity of spermatozoa, and its relationship to spermatozoa mitochondrial transmembrane potential (ΔΨ m ). Male Wistar rats were administered at 5 mg fluoride/kg body mass/24 h, or deionized water orally for 8 weeks. We evaluated several spermatozoa parameters in treated and untreated rats: i) standard quality analysis, ii) superoxide dismutase (SOD) activity, iii) the generation of superoxide anion (O 2 ·- ), iv) lipid peroxidation concentration, v) ultrastructural analyses of spermatozoa using transmission electron microscopy, vi) ΔΨ m , vii) acrosome reaction, and viii) IVF capability. Spermatozoa from fluoride-treated rats exhibited a significant decrease in SOD activity (∼ 33%), accompanied with a significant increase in the generation of O 2 · (∼ 40%), a significant decrease in ΔΨ m (∼ 33%), and a significant increase in lipid peroxidation concentration (∼ 50%), relative to spermatozoa from the control group. Consistent with this finding, spermatozoa from fluoride-treated rats exhibited altered plasmatic membrane. In addition, the percentage of fluoride-treated spermatozoa capable of undergoing the acrosome reaction was decreased relative to control spermatozoa (34 vs. 55%), while the percentage fluoride-treated spermatozoa capable of oocyte fertilization was also significantly lower than the control group (13 vs. 71%). These observations suggest that subchronic exposure to fluoride causes oxidative stress damage and loss of mitochondrial transmembrane potential, resulting in reduced fertility

  18. Anhydrous hydrogen fluoride electrolyte battery. [Patent application

    Science.gov (United States)

    Not Available

    1972-06-26

    It is an object of the invention to provide a primary cell or battery using ammonium fluoride--anhydrous hydrogen fluoride electrolyte having improved current and power production capabilities at low temperatures. It is operable at temperatures substantially above the boiling point of hydrogen fluoride. (GRA)

  19. Fluoride ions vs removal technologies: A study

    Directory of Open Access Journals (Sweden)

    Jagvir Singh

    2016-11-01

    Full Text Available Literature reported that drinking water is a precious and scarce resource and it has to be protected and kept free from any kind of contamination. Further, it has to be used carefully without wasting. Literature also reported that fluoride bearing rocks are abundant in India, as a result, fluoride leaches out and contaminates the adjacent water and soil resources. A high concentration of fluoride ions in ground water increases up to more than 30 mg/L. This high concentration of fluoride ions causes many harmful and dangerous effects on our datum. Fluoride ions in larger quantities i.e. 20–80 mg/day taken over a period of 10–20 years result in crippling and skeletal fluorosis, severely damaging the bone. In the present scenario, there is a continuously increasing worldwide concern for the development of fluoride treatment technologies. Possibilities of reducing the high fluorine content in groundwater are by defluorination process/dilution with the surface water which is a very simple technique but the addition of Ca2+ ions to a solution in contact with fluorite when experimented in distilled water caused an appreciable decrease in fluoride concentration. In this review article, we emphasized the relationship between high concentrations of fluoride ions and their compounds and their health impact.

  20. Risk Assessment of Fluoride Intake from Tea in the Republic of Ireland and its Implications for Public Health and Water Fluoridation

    Science.gov (United States)

    Waugh, Declan T.; Potter, William; Limeback, Hardy; Godfrey, Michael

    2016-01-01

    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. PMID:26927146

  1. Recovery of agricultural odors and odorous compounds from polyvinyl fluoride film bags

    Science.gov (United States)

    Accurate sampling methods are necessary when quantifying odor and volatile organic compound emissions at agricultural facilities. The commonly accepted methodology in the U.S. has been to collect odor samples in polyvinyl fluoride bags (PVF, brand name Tedlar®) and, subsequently, analyze with human ...

  2. Sampling for Air Chemical Emissions from the Life Sciences Laboratory II

    Energy Technology Data Exchange (ETDEWEB)

    Ballinger, Marcel Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lindberg, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-03-30

    Sampling for air chemical emissions from the Life Science Laboratory II (LSL-II) ventilation stack was performed in an effort to determine potential exposure of maintenance staff to laboratory exhaust on the building roof. The concern about worker exposure was raised in December 2015 and several activities were performed to assist in estimating exposure concentrations. Data quality objectives were developed to determine the need for and scope and parameters of a sampling campaign to measure chemical emissions from research and development activities to the outside air. The activities provided data on temporal variation of air chemical concentrations and a basis for evaluating calculated emissions. Sampling for air chemical emissions was performed in the LSL-II ventilation stack over the 6-week period from July 26 to September 1, 2016. A total of 12 sampling events were carried out using 16 sample media. Resulting analysis provided concentration data on 49 analytes. All results were below occupational exposure limits and most results were below detection limits. When compared to calculated emissions, only 5 of the 49 chemicals had measured concentrations greater than predicted. This sampling effort will inform other study components to develop a more complete picture of a worker’s potential exposure from LSL-II rooftop activities. Mixing studies were conducted to inform spatial variation in concentrations at other rooftop locations and can be used in conjunction with these results to provide temporal variations in concentrations for estimating the potential exposure to workers working in and around the LSL-II stack.

  3. Prenatal Fluoride Exposure and Cognitive Outcomes in Children at 4 and 6-12 Years of Age in Mexico.

    Science.gov (United States)

    Bashash, Morteza; Thomas, Deena; Hu, Howard; Martinez-Mier, E Angeles; Sanchez, Brisa N; Basu, Niladri; Peterson, Karen E; Ettinger, Adrienne S; Wright, Robert; Zhang, Zhenzhen; Liu, Yun; Schnaas, Lourdes; Mercado-García, Adriana; Téllez-Rojo, Martha María; Hernández-Avila, Mauricio

    2017-09-19

    Some evidence suggests that fluoride may be neurotoxic to children. Few of the epidemiologic studies have been longitudinal, had individual measures of fluoride exposure, addressed the impact of prenatal exposures or involved more than 100 participants. Our aim was to estimate the association of prenatal exposure to fluoride with offspring neurocognitive development. We studied participants from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) project. An ion-selective electrode technique was used to measure fluoride in archived urine samples taken from mothers during pregnancy and from their children when 6-12 y old, adjusted for urinary creatinine and specific gravity, respectively. Child intelligence was measured by the General Cognitive Index (GCI) of the McCarthy Scales of Children's Abilities at age 4 and full scale intelligence quotient (IQ) from the Wechsler Abbreviated Scale of Intelligence (WASI) at age 6-12. We had complete data on 299 mother-child pairs, of whom 287 and 211 had data for the GCI and IQ analyses, respectively. Mean (SD) values for urinary fluoride in all of the mothers (n=299) and children with available urine samples (n=211) were 0.90 (0.35) mg/L and 0.82 (0.38) mg/L, respectively. In multivariate models we found that an increase in maternal urine fluoride of 0.5mg/L (approximately the IQR) predicted 3.15 (95% CI: -5.42, -0.87) and 2.50 (95% CI -4.12, -0.59) lower offspring GCI and IQ scores, respectively. In this study, higher prenatal fluoride exposure, in the general range of exposures reported for other general population samples of pregnant women and nonpregnant adults, was associated with lower scores on tests of cognitive function in the offspring at age 4 and 6-12 y. https://doi.org/10.1289/EHP655.

  4. Structural study of chlorine tri-fluoride and bromine penta-fluoride in liquid and solid phase

    International Nuclear Information System (INIS)

    Rousson, R.

    1973-01-01

    This research thesis reports the structural study of chlorine tri-fluoride and bromine penta-fluoride between 20 C and about -265 C. After some generalities on these compounds and a presentation of the experimental technique, the author reports and discusses results obtained with these both compounds: Raman spectrum for the liquid and for the solid phase, infrared spectrum for the solid phase, calorimetric measurements. In the case of chlorine tri-fluoride, the author studies the evolution of the liquid spectrum with temperature, shows the existence of an intermediate solid phase, and compares results obtained by Raman spectroscopy and nuclear magnetic resonance. He also applies to bromine penta-fluoride an analysis of normal coordinates of a XF 5 molecule: relationship between force constants and vibration frequencies, application of Wilson method, resolution of the molecular equation, determination of normal vibration modes [fr

  5. Current status of fluoride volatility method development

    Energy Technology Data Exchange (ETDEWEB)

    Uhlir, J.; Marecek, M.; Skarohlid, J. [UJV - Nuclear Research Institute, Research Centre Rez, CZ-250 68 Husinec - Rez 130 (Czech Republic)

    2013-07-01

    The Fluoride Volatility Method is based on a separation process, which comes out from the specific property of uranium, neptunium and plutonium to form volatile hexafluorides whereas most of fission products (mainly lanthanides) and higher transplutonium elements (americium, curium) present in irradiated fuel form nonvolatile tri-fluorides. Fluoride Volatility Method itself is based on direct fluorination of the spent fuel, but before the fluorination step, the removal of cladding material and subsequent transformation of the fuel into a powdered form with a suitable grain size have to be done. The fluorination is made with fluorine gas in a flame fluorination reactor, where the volatile fluorides (mostly UF{sub 6}) are separated from the non-volatile ones (trivalent minor actinides and majority of fission products). The subsequent operations necessary for partitioning of volatile fluorides are the condensation and evaporation of volatile fluorides, the thermal decomposition of PuF{sub 6} and the finally distillation and sorption used for the purification of uranium product. The Fluoride Volatility Method is considered to be a promising advanced pyrochemical reprocessing technology, which can mainly be used for the reprocessing of oxide spent fuels coming from future GEN IV fast reactors.

  6. Fluoride ions vs removal technologies: A study

    OpenAIRE

    Singh, Jagvir; Singh, Prashant; Singh, Anuradha

    2016-01-01

    Literature reported that drinking water is a precious and scarce resource and it has to be protected and kept free from any kind of contamination. Further, it has to be used carefully without wasting. Literature also reported that fluoride bearing rocks are abundant in India, as a result, fluoride leaches out and contaminates the adjacent water and soil resources. A high concentration of fluoride ions in ground water increases up to more than 30 mg/L. This high concentration of fluoride ions ...

  7. In Vitro Comparison of the Effects of Diode Laser and CO2 Laser on Topical Fluoride Uptake in Primary Teeth.

    Science.gov (United States)

    Bahrololoomi, Zahra; Fotuhi Ardakani, Faezeh; Sorouri, Milad

    2015-08-01

    Fluoride therapy is important for control and prevention of dental caries. Laser irradiation can increase fluoride uptake especially when combined with topical fluoride application. The objective of this study was to compare the effects of CO2 and diode lasers on enamel fluoride uptake in primary teeth. Forty human primary molars were randomly assigned to four groups (n=10). The roots were removed and the crowns were sectioned mesiodistally into buccal and lingual halves as the experimental and control groups. All samples were treated with 5% sodium fluoride (NaF) varnish. The experimental samples in the four groups were irradiated with 5 or 7W diode or 1 or 2W CO2 laser for 15 seconds and were compared with the controls in terms of fluoride uptake, which was determined using an ion selective electrode after acid dissolution of the specimens. Data were analyzed by SPSS version 16 using ANOVA treating the control measurements as covariates. The estimated amount of fluoride uptake was 59.5± 16.31 ppm, 66.5± 14.9 ppm, 78.6± 12.43 ppm and 90.4± 11.51 ppm for 5W and 7 W diode and 1W and 2 W CO2 lasers, respectively, which were significantly greater than the values in the conventional topical fluoridation group (Pdiode laser and 1W CO2 laser, 5W and 7W diode laser, or 1W and 2W CO2 laser in this regard. The results showed that enamel surface irradiation by CO2 and diode lasers increases the fluoride uptake.

  8. Arrest of Root Carious Lesions via Sodium Fluoride, Chlorhexidine and Silver Diamine Fluoride In Vitro

    Directory of Open Access Journals (Sweden)

    Gerd Göstemeyer

    2017-12-01

    Full Text Available Objective: To compare the root carious lesion arrest of chlorhexidine (CHX and silver diamine fluoride (SDF varnishes and/or sodium fluoride rinses (NaF in vitro. Background: Effective and easily applicable interventions for treating root carious lesions are needed, as these lesions are highly prevalent amongst elderly individuals. Methods: In 100 bovine dentin samples, artificial root carious lesions were induced using acetic acid and a continuous-culture Lactobacillus rhamnosus biofilm model. One quarter of each induced lesion was excavated and baseline dentinal bacterial counts assessed as Colony-Forming-Units (CFU per mg. Samples were allocated to one of four treatments (n = 25/group: (1 untreated control; (2 38% SDF or (3 35% CHX varnish, each applied once, plus 500 ppm daily NaF rinse in the subsequent lesion progression phase; and (4 daily NaF rinses only. Samples were re-transferred to the biofilm model and submitted to a cariogenic challenge. After six days, another quarter of each lesion was used to assess bacterial counts and the remaining sample was used to assess integrated mineral loss (ΔZ using microradiography. Results: ΔZ did not differ significantly between control (median (25th/75th percentiles: 9082 (7859/9782 vol % × µm, NaF (6704 (4507/9574 and SDF 7206 (5389/8082 (p < 0.05/Kruskal–Wallis test. CHX significantly reduced ΔZ (3385 (2447/4496 compared with all other groups (p < 0.05. Bacterial numbers did not differ significantly between control (1451 (875/2644 CFU/µg and NaF (750 (260/1401 (p > 0.05. SDF reduced bacterial counts (360 (136/1166 significantly compared with control (p < 0.05. CHX reduced bacterial counts (190 (73/517 significantly compared with NaF and control (p < 0.05. Conclusion: CHX varnish plus regular NaF rinses arrested root carious lesions most successfully.

  9. THE USE OF FLUORIDE AND ITS EFFECT ON HEALTH

    Directory of Open Access Journals (Sweden)

    Domen Kanduti

    2016-07-01

    Full Text Available Appropriate oral health care is fundamental for any individual’s health. Dental caries is still one of the major public health problems. The most effective way of caries prevention is the use of fluoride. Fluoride occurs naturally in our environment and is always present in our lives. However, the concentration differs from area to area. Exposure can occur through diet, respiration and fluoride supplements. During pregnancy, the placenta acts as a barrier. The fluoride, therefore, crosses the placenta in low concentrations. Drinking water in Slovenia is not fluoridated; the amount of naturally present fluoride is very low. Fluoride can be toxic in extremely high concentrations. The most important effect of fluoride on caries incidence is through its role in the process of remineralisation and demineralisation of tooth enamel. The European Academy of Paediatric Dentistry (EAPD recommends a preventive topical use of fluoride supplements because of their cariostatic effect. 

  10. Comparative proteomic analysis of fluoride treated rat bone provides new insights into the molecular mechanisms of fluoride toxicity.

    Science.gov (United States)

    Wei, Yan; Zeng, Beibei; Zhang, Hua; Chen, Cheng; Wu, Yanli; Wang, Nanlan; Wu, Yanqiu; Zhao, Danqing; Zhao, Yuxi; Iqbal, Javed; Shen, Liming

    2018-07-01

    Long-term excessive intake of fluoride (F) could lead to chronic fluorosis. To explore the underlying molecular mechanisms, present study is designed to elucidate the effect of fluoride on proteome expression of bone in sodium fluoride (NaF)-treated SD rats. Hematoxylin and eosin (H&E) staining was used to determine the severity of osteofluorosis, and bone samples were submitted for iTRAQ analysis. The results showed that the cortical thickness and trabecular area of femur bone in medium- and high-dose groups were higher than in control group. Contrary to this, trabecular area was reduced in the low-dose group, indicating that the bone mass was increased in medium- and high-dose groups, and decreased in the low-dose group. Thirteen (13), 35, and 34 differentially expressed proteins were identified in low-, medium-, and high-dose group, respectively. The medium- and high-dose groups shared a more similar protein expression pattern. These proteins were mainly associated with collagen metabolism, proteoglycans (PGs), matrix metalloproteinases (MMPs), etc. The results suggested that the effect of NaF on SD rats is in a dose-dependent manner. Some key proteins found here may be involved in affecting the bone tissues and bone marrow or muscle, and account for the complex pathology and clinical symptoms of fluorosis. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. The efficacy of amine fluoride/stannous fluoride in the suppression of morning breath odour.

    Science.gov (United States)

    Quirynen, Marc; Avontroodt, Pieter; Soers, Catherine; Zhao, Hong; Pauwels, Martine; Coucke, Wim; van Steenberghe, Daniel

    2002-10-01

    Breath odour is a complaint encountered worldwide, often linked to microbial overload in the oral cavity. This double blind, crossover, randomised study assessed the efficacy of several antiseptic mouthrinses or slurry vs. a control solution in the prevention of morning bad breath during an experimental period of 7 days without mechanical plaque control. Sixteen dental students with a healthy periodontium abolished, after a thorough professional cleaning, all means of mechanical plaque control during five experimental periods of 7 days, interleaved by washout periods of at least 3 weeks. During each experimental period, as the only oral hygiene measure, the students rinsed twice a day with one of the following formulations (in a randomised order): a 0.2% chlorhexidine-alcohol mouthrinse (CHX-Alc), a 0.05% CHX + 0.05% cetylpyridinium chloride + 0.14% zinc lactate mouthrinse (CHX-CPC-Zn), an amine fluoride/stannous fluoride (125 ppm F-/125 ppm F-) containing mouthrinse (AmF/SnF2Mr), a slurry of a tooth paste (AmF/SnF2Sl) containing amine fluoride (350 ppm F-) and stannous fluoride (1050 ppm F-) and a placebo solution (placebo). At days 0, 3 and 7, morning breath was scored via VSC level measurements of the mouth air, and organoleptic ratings of the mouth air and tongue coating. At the same visits both the degree of gingival inflammation and the de novo plaque formation were rated. At the end of each period a questionnaire for subjective ratings was completed and microbiological samples were taken from the tongue dorsum, the saliva and the supragingival plaque for anaerobic and aerobic culturing. Although oral hygiene during the experimental periods was limited to rinsing, bad breath parameters systematically improved (P bacterial load (aerobic & anaerobic) in the saliva (>or= 0.5 log reduction with a superiority (P bacterial load on the tongue dorsum could only be detected for the CHX-Alc solution (0.5 log). The antibacterial effect of the placebo solution and the

  12. [The influence of high fluoride exposure in drinking water on endocrine hormone in female].

    Science.gov (United States)

    Hou, Jia-xiang; Yang, Yue-jin; Gong, Biao; Li, Shi-hong; Ding, Zhong; Wen, Shi-bao; Li, Shi-qun; Cheng, Xue-min; Cui, Liu-xin; Ba, Yue

    2013-02-01

    To explore the influence of water fluoride exposure on reproductive hormones in female. Cross-sectional study was conducted in seven villages of a county in Henan province by using simple random sampling including high fluoride area, defluoridation project area and control area on April, 2011 based on the preliminary study results of fluoride concentration in drinking water. Women who were born and growth or lived in the village at least 5 years and aged 18-48 years old were recruited using cluster sampling. They were divided into high fluoride group (HFG, 116 subjects), defluoridation project group (DFPG, 132 subjects) and control group (CG, 227 subjects) in accordance with the above areas. All subjects accepted questionnaire and physical checkup. Fasting blood and morning urine samples were collected. The concentration of fluoride in urine was determined by fluoride ion selective electrode method. The serum level of GnRH was detected using enzyme linked immunosorbent assay (ELISA). The serum level of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T), estradiol (E2) were determined by chemiluminesence immunoassay (CLIA). The average age was (39.44 ± 7.34), (38.84 ± 8.03), (37.45 ± 7.70) years old in female from DFPG, HFG and CG respectively, there were no significant differences among the three groups (F = 3.02, P = 0.05). The urine fluoride levels were (1.34 ± 1.07), (2.59 ± 1.57), (0.92 ± 0.46) mg/ml in female from DFPG, HFG and CG respectively, there was a significant difference among three groups (F = 105.38, P 0.05). The serum levels of E2 in Ovulatory period were 67.73, 58.09, 84.96 pg/ml in female from DFPG, HFG and CG respectively. It was lower in HFG than that in CG (H = 4.00, P 0.05). The serum levels of GnRH in Luteal phase were 24.09, 20.16, 23.50 ng/ml in female from DFPG, HFG and CG respectively. It was lower in HFG than that in DFPG (H = 14.14, P 0.05 respectively). The abnormal rates of E2 level were 22.73 (30

  13. Community water fluoridation on the Internet and social media.

    Science.gov (United States)

    Mertz, Aaron; Allukian, Myron

    2014-01-01

    In the United States, 95 percent of teens and 85 percent of adults use the Internet. Two social media outlets, Facebook and Twitter, reach more than 150 billion users. This study describes anti-fluoridation activity and dominance on the Internet and social media, both of which are community water fluoridation (CWF) information sources. Monthly website traffic to major fluoridation websites was determined from June 2011 to May 2012. Facebook, Twitter, and YouTube fluoridation activity was categorized as "proCWF" or "anti-CWF." Twitter's anti-CWF tweets were further subcategorized by the argument used against CWF. Anti-CWF website traffic was found to exceed proCWF activity five- to sixty-fold. Searching "fluoride" and "fluoridation" on Facebook resulted in 88 to 100 percent anti-CWF groups and pages; "fluoridation" on Twitter and YouTube resulted in 64 percent anti-CWF tweets and 99 percent anti-CWF videos, respectively. "Cancer, " "useless, " and "poisonous" were the three major arguments used against fluoridation. Anti-fluoridation information significantly dominates the Internet and social media. Thousands of people are being misinformed daily about the safety, health, and economic benefits of fluoridation.

  14. FLUORIDE SORPTION USING MORRINGA INDICA-BASED ACTIVATED CARBON

    Directory of Open Access Journals (Sweden)

    G. Karthikeyan, S. Siva Ilango

    2007-01-01

    Full Text Available Batch adsorption experiments using activated carbon prepared from Morringa Indica bark were conducted to remove fluoride from aqueous solution. A minimum contact time of 25 min was required for optimum fluoride removal. The influence of adsorbent, dose, pH, co-ions (cations and anions on fluoride removal by the activated carbon has been experimentally verified. The adsorption of fluoride was studied at 30 C, 40 C and 50 C. The kinetics of adsorption and adsorption isotherms at different temperatures were studied. The fluoride adsorption obeyed both Langmuir and Freundlich isotherms and followed a pseudo first order kinetic model. The thermodynamic studies revealed that the fluoride adsorption by Morringa Indica is an endothermic process indicating an increase in sorption rate at higher temperatures. The negative values of G indicate the spontaneity of adsorption. SEM and XRD studies confirmed the surface morphological characteristics of the adsorbent and the deposition of fluoride on the surface of the material.

  15. Effect of titanium tetrafluoride, amine fluoride and fluoride varnish on enamel erosion in vitro

    NARCIS (Netherlands)

    Vieira, A; Ruben, JL; Huysmans, MCDNJM

    2005-01-01

    This study aimed at evaluating the effect of 1 and 4% titanium tetrafluoride (TiF4) gels, amine fluoride (AmF) 1 and 0.25% and a fluoride varnish (FP) on the prevention of dental erosion. Two experimental groups served as controls, one with no pretreatment and another one pre-treated with a

  16. Dental Fluorosis and Catalase Immunoreactivity of the Brain Tissues in Rats Exposed to High Fluoride Pre- and Postnatally.

    Science.gov (United States)

    Güner, Şirin; Uyar-Bozkurt, Süheyla; Haznedaroğlu, Eda; Menteş, Ali

    2016-11-01

    This study evaluated dental fluorosis of the incisors and immunoreactivity in the brain tissues of rats given chronic fluoride doses pre- and postnatally. Female rats were given drinking water with 0, 30 or 100 ppm fluoride ad libitum throughout gestation and the nursing period. In addition, 63 male offspring were treated with the same water regimens as the mothers after weaning and were followed for 1, 3 or 5 months. The upper and lower incisors were collected, and all teeth were examined under a stereomicroscope and scored by two blinded examiners using a modified rodent enamel fluorosis index. Cortical, hippocampal and cerebellar brain samples were evaluated morphologically and immunohistochemically. All fluoride-treated pups were born with low body weight (p = 0.001). All animals from the fluoride groups had enamel fluorosis with defects of various degrees. The increase in the dental fluorosis scores in the fluoride treatment groups was significant (p fluoride groups was significantly higher than that in the controls after 1, 3 and 5 months (p toxicity of fluoride.

  17. Fluoride-induced disruption of reproductive hormones in men

    International Nuclear Information System (INIS)

    Ortiz-Perez, Deogracias; Rodriguez-Martinez, Manuel; Martinez, Flavio; Borja-Aburto, V.H.; Castelo, Julio; Grimaldo, J.I.; Cruz, Esperanza de la; Carrizales, Leticia; Diaz-Barriga, Fernando

    2003-01-01

    Fluoride-induced reproductive effects have been reported in experimental models and in humans. However, these effects were found in heavily exposed scenarios. Therefore, in this work our objective was to study reproductive parameters in a population exposed to fluoride at doses of 3-27 mg/day (high-fluoride-exposed group--HFEG). Urinary fluoride levels, semen parameters, and reproductive hormones in serum (LH, FSH, estradiol, prolactin, inhibin-B, free and total testosterone) were measured. Results were compared with a group of individuals exposed to fluoride at lower doses: 2-13 mg/day (low-fluoride-exposed group-LFEG). A significant increase in FSH (P<0.05) and a reduction of inhibin-B, free testosterone, and prolactin in serum (P<0.05) were noticed in the HFEG. When HFEG was compared to LFEG, a decreased sensitivity was found in the FSH response to inhibin-B (P<0.05). A significant negative partial correlation was observed between urinary fluoride and serum levels of inhibin-B (r=-0.333, P=0.028) in LFEG. Furthermore, a significant partial correlation was observed between a chronic exposure index for fluoride and the serum concentrations of inhibin-B (r=-0.163, P=0.037) in HFEG. No abnormalities were found in the semen parameters studied in the present work, neither in the HFEG, nor in the LFEG. The results obtained indicate that a fluoride exposure of 3-27 mg/day induces a subclinical reproductive effect that can be explained by a fluoride-induced toxic effect in both Sertoli cells and gonadotrophs

  18. 4-phenylbutyrate Mitigates Fluoride-Induced Cytotoxicity in ALC Cells

    Directory of Open Access Journals (Sweden)

    Maiko Suzuki

    2017-05-01

    Full Text Available Chronic fluoride over-exposure during pre-eruptive enamel development can cause dental fluorosis. Severe dental fluorosis is characterized by porous, soft enamel that is vulnerable to erosion and decay. The prevalence of dental fluorosis among the population in the USA, India and China is increasing. Other than avoiding excessive intake, treatments to prevent dental fluorosis remain unknown. We previously reported that high-dose fluoride induces endoplasmic reticulum (ER stress and oxidative stress in ameloblasts. Cell stress induces gene repression, mitochondrial damage and apoptosis. An aromatic fatty acid, 4-phenylbutyrate (4PBA is a chemical chaperone that interacts with misfolded proteins to prevent ER stress. We hypothesized that 4PBA ameliorates fluoride-induced ER stress in ameloblasts. To determine whether 4PBA protects ameloblasts from fluoride toxicity, we analyzed gene expression of Tgf-β1, Bcl2/Bax ratio and cytochrome-c release in vitro. In vivo, we measured fluorosis levels, enamel hardness and fluoride concentration. Fluoride treated Ameloblast-lineage cells (ALC had decreased Tgf-β1 expression and this was reversed by 4PBA treatment. The anti-apoptotic Blc2/Bax ratio was significantly increased in ALC cells treated with fluoride/4PBA compared to fluoride treatment alone. Fluoride treatment induced cytochrome-c release from mitochondria into the cytosol and this was inhibited by 4PBA treatment. These results suggest that 4PBA mitigates fluoride-induced gene suppression, apoptosis and mitochondrial damage in vitro. In vivo, C57BL/6J mice were provided fluoridated water for six weeks with either fluoride free control-chow or 4PBA-containing chow (7 g/kg 4PBA. With few exceptions, enamel microhardness, fluorosis levels, and fluoride concentrations of bone and urine did not differ significantly between fluoride treated animals fed with control-chow or 4PBA-chow. Although 4PBA mitigated high-dose fluoride toxicity in vitro, a diet

  19. 4-phenylbutyrate Mitigates Fluoride-Induced Cytotoxicity in ALC Cells.

    Science.gov (United States)

    Suzuki, Maiko; Everett, Eric T; Whitford, Gary M; Bartlett, John D

    2017-01-01

    Chronic fluoride over-exposure during pre-eruptive enamel development can cause dental fluorosis. Severe dental fluorosis is characterized by porous, soft enamel that is vulnerable to erosion and decay. The prevalence of dental fluorosis among the population in the USA, India and China is increasing. Other than avoiding excessive intake, treatments to prevent dental fluorosis remain unknown. We previously reported that high-dose fluoride induces endoplasmic reticulum (ER) stress and oxidative stress in ameloblasts. Cell stress induces gene repression, mitochondrial damage and apoptosis. An aromatic fatty acid, 4-phenylbutyrate (4PBA) is a chemical chaperone that interacts with misfolded proteins to prevent ER stress. We hypothesized that 4PBA ameliorates fluoride-induced ER stress in ameloblasts. To determine whether 4PBA protects ameloblasts from fluoride toxicity, we analyzed gene expression of Tgf -β 1, Bcl2 / Bax ratio and cytochrome-c release in vitro . In vivo , we measured fluorosis levels, enamel hardness and fluoride concentration. Fluoride treated Ameloblast-lineage cells (ALC) had decreased Tgf -β 1 expression and this was reversed by 4PBA treatment. The anti-apoptotic Blc2 / Bax ratio was significantly increased in ALC cells treated with fluoride/4PBA compared to fluoride treatment alone. Fluoride treatment induced cytochrome-c release from mitochondria into the cytosol and this was inhibited by 4PBA treatment. These results suggest that 4PBA mitigates fluoride-induced gene suppression, apoptosis and mitochondrial damage in vitro . In vivo , C57BL/6J mice were provided fluoridated water for six weeks with either fluoride free control-chow or 4PBA-containing chow (7 g/kg 4PBA). With few exceptions, enamel microhardness, fluorosis levels, and fluoride concentrations of bone and urine did not differ significantly between fluoride treated animals fed with control-chow or 4PBA-chow. Although 4PBA mitigated high-dose fluoride toxicity in vitro , a diet rich

  20. Association between Urine Fluoride and Dental Fluorosis as a Toxicity Factor in a Rural Community in the State of San Luis Potosi

    OpenAIRE

    Jarquín-Yañez, Lizet; Mejía-Saavedra, José de Jesús; Molina-Frechero, Nelly; Gaona, Enrique; Rocha-Amador, Diana Olivia; López-Guzmán, Olga Dania; Bologna-Molina, Ronell

    2015-01-01

    Objective. The aim of this study is to investigate urine fluoride concentration as a toxicity factor in a rural community in the state of San Luis Potosi, Mexico. Materials and Methods. A sample of 111 children exposed to high concentrations of fluoride in drinking water (4.13?mg/L) was evaluated. Fluoride exposure was determined by measuring urine fluoride concentration using the potentiometric method with an ion selective electrode. The diagnosis of dental fluorosis was performed by clinica...

  1. Chronic fluoride toxicity: dental fluorosis.

    Science.gov (United States)

    Denbesten, Pamela; Li, Wu

    2011-01-01

    Dental fluorosis occurs as a result of excess fluoride ingestion during tooth formation. Enamel fluorosis and primary dentin fluorosis can only occur when teeth are forming, and therefore fluoride exposure (as it relates to dental fluorosis) occurs during childhood. In the permanent dentition, this would begin with the lower incisors, which complete mineralization at approximately 2-3 years of age, and end after mineralization of the third molars. The white opaque appearance of fluorosed enamel is caused by a hypomineralized enamel subsurface. With more severe dental fluorosis, pitting and a loss of the enamel surface occurs, leading to secondary staining (appearing as a brown color). Many of the changes caused by fluoride are related to cell/matrix interactions as the teeth are forming. At the early maturation stage, the relative quantity of amelogenin protein is increased in fluorosed enamel in a dose-related manner. This appears to result from a delay in the removal of amelogenins as the enamel matures. In vitro, when fluoride is incorporated into the mineral, more protein binds to the forming mineral, and protein removal by proteinases is delayed. This suggests that altered protein/mineral interactions are in part responsible for retention of amelogenins and the resultant hypomineralization that occurs in fluorosed enamel. Fluoride also appears to enhance mineral precipitation in forming teeth, resulting in hypermineralized bands of enamel, which are then followed by hypomineralized bands. Enhanced mineral precipitation with local increases in matrix acidity may affect maturation stage ameloblast modulation, potentially explaining the dose-related decrease in cycles of ameloblast modulation from ruffle-ended to smooth-ended cells that occur with fluoride exposure in rodents. Specific cellular effects of fluoride have been implicated, but more research is needed to determine which of these changes are relevant to the formation of fluorosed teeth. As further

  2. Modified zirconium-eriochrome cyanine R determination of fluoride

    Science.gov (United States)

    Thatcher, L.L.

    1957-01-01

    The Eriochrome Cyanine R method for determining fluoride in natural water has been modified to provide a single, stable reagent solution, eliminate interference from oxidizing agents, extend the concentration range to 3 p.p.m., and extend the phosphate tolerance. Temperature effect was minimized; sulfate error was eliminated by precipitation. The procedure is sufficiently tolerant to interferences found in natural and polluted waters to permit the elimination of prior distillation for most samples. The method has been applied to 500 samples.

  3. Comparison of fluoride uptake level by enamel from Iranian school brand and standard NaF mouthrinses

    Directory of Open Access Journals (Sweden)

    Gasem Ansari

    2009-03-01

    Full Text Available Background and aims. The use of fluoride mouthrinses has been proved to be one of the most effective ways to prevent tooth decay. A community based program using F+ rinse at school has also proved to be well-controlled and efficient. The aim of this investigation was to evaluate fluoride uptake level of a locally prepared NaF rinse used in Iran’s school program during 2005. Materials and methods. A total of 30 freshly extracted sound human premolars were collected and divided into two groups of 15. Each tooth then underwent two steps of sectioning; first the root was amputated from CEJ and then a longitudinal section was performed in bucco-lingual direction to provide two similar samples of the same tooth. A specific hemi-circular area on either of the experimental halves was treated by NaF rinse from USA or a locally prepared NaF used in school programs. Two subsequent biopsies were taken from each half using acid etch enamel biopsy technique. Fluoride and calcium content of the specimens were measured in order to evaluate fluoride uptake level and biopsy depth effect, respectively. Collected data were recorded in the forms provided and statistical analysis, mostly descriptive, was performed for comparison. Results. Based on the data collected, it appears that the use of F+ rinse would clearly improve enamel quality by a rise in fluoride concentration. Statistical analysis using a paired t-test and repeated measure method revealed that with 95% confidence fluoride concentration increases at both levels of biopsy with no statistically significant differences between the samples treated with two rinses. Conclusion. There seem to be reasonable potential for the clinical use of Iranian brand fluoride mouthrinse. There was no significant difference between the level of uptake from NaF from USA and the Iranian product in 2 layers of enamel biopsy.

  4. Health effects of fluoride pollution caused by coal burning

    Energy Technology Data Exchange (ETDEWEB)

    Ando, M.; Tadano, M.; Yamamoto, S.; Tamura, K.; Chen, X. [Regional Environment Division, National Institute for Environmental Studies, Tsukuba, 305-0083 Ibaraki (Japan); Asanuma, S. [Japan Institute of Rural Medicine, Usuda, Nagano (Japan); Watanabe, T. [Saku Central Hospital, Usuda, Nagano (Japan); Kondo, T. [Matsumoto Dental College, Shiojiri, Nagano (Japan); Sakurai, S. [Otsuma Women' s University, Tama, Tokyo (Japan); Ji, R.; Liang, C.; Cao, S. [Institute of Environmental Health and Engineering, Beijing (China); Hong, Z. [Shanxi Maternity and Children' s Hospital, Taiyuan (China)

    2001-04-23

    Recently a huge amount of fluoride in coal has been released into indoor environments by the combustion of coal and fluoride pollution seems to be increasing in some rural areas in China. Combustion of coal and coal bricks is the primary source of gaseous and aerosol fluoride and these forms of fluoride can easily enter exposed food products and the human respiratory tract. Major human fluoride exposure was caused by consumption of fluoride contaminated food, such as corn, chilies and potatoes. For each diagnostic syndrome of dental fluorosis, a log-normal distribution was observed on the logarithm of urinary fluoride concentration in students in China. Urinary fluoride content was found to be a primary health indicator of the prevalence of dental fluorosis in the community. In the fluorosis areas, osteosclerosis in skeletal fluorosis patients was observed with a high prevalence. A biochemical marker of bone resorption, urinary deoxypyridinoline content was much higher in residents in China than in residents in Japan. It was suggested that bone resorption was stimulated to a greater extent in residents in China and fluoride may stimulate both bone resorption and bone formation. Renal function especially glomerular filtration rate was very sensitive to fluoride exposure. Inorganic phosphate concentrations in urine were significantly lower in the residents in fluorosis areas in China than in non-fluorosis area in China and Japan. Since airborne fluoride from the combustion of coal pollutes extensively both the living environment and food, it is necessary to reduce fluoride pollution caused by coal burning.

  5. Evaluation of cryolite from pitinga (Amazonas-Brazil as a source of hydrogen fluoride

    Directory of Open Access Journals (Sweden)

    Jéssica F. Paulino

    2016-05-01

    Full Text Available This paper reports the use of cryolite from the Pitinga Mine (Amazonas state, Brazil as raw material in hydrogen fluoride production. Samples were initially characterized by chemical and mineralogical analyses. They presented low silica content (< 4 wt.%. After milling, cryolite samples were digested with concentrated sulfuric acid under stirring (200 rpm and variable temperature, time and liquid to solid ratio conditions. Under the best experimental conditions (140 °C, 3-5 h, 96 wt.% of fluorine was recovered as hydrogen fluoride. The application of a 23 full factorial design showed that temperature and reaction time were relevant parameters during leaching, whereas liquid to solid ratio was not statistically significant.

  6. Thermodynamic data-base for metal fluorides

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jae Hyung; Lee, Byung Gik; Kang, Young Ho and others

    2001-05-01

    This study is aimed at collecting useful data of thermodynamic properties of various metal fluorides. Many thermodynamic data for metal fluorides are needed for the effective development, but no report of data-base was published. Accordingly, the objective of this report is to rearrange systematically the existing thermodynamic data based on metal fluorides and is to use it as basic data for the development of pyrochemical process. The physicochemical properties of various metal fluorides and metals were collected from literature and such existing data base as HSC code, TAPP code, FACT code, JANAF table, NEA data-base, CRC handbook. As major contents of the thermodynamic data-base, the physicochemical properties such as formation energy, viscosity, density, vapor pressure, etc. were collected. Especially, some phase diagrams of eutectic molten fluorides are plotted and thermodynamic data of liquid metals are also compiled. In the future, the technical report is to be used as basic data for the development of the pyrochemical process which is being carried out as a long-term nuclear R and D project.

  7. Thermodynamic data-base for metal fluorides

    International Nuclear Information System (INIS)

    Yoo, Jae Hyung; Lee, Byung Gik; Kang, Young Ho and others

    2001-05-01

    This study is aimed at collecting useful data of thermodynamic properties of various metal fluorides. Many thermodynamic data for metal fluorides are needed for the effective development, but no report of data-base was published. Accordingly, the objective of this report is to rearrange systematically the existing thermodynamic data based on metal fluorides and is to use it as basic data for the development of pyrochemical process. The physicochemical properties of various metal fluorides and metals were collected from literature and such existing data base as HSC code, TAPP code, FACT code, JANAF table, NEA data-base, CRC handbook. As major contents of the thermodynamic data-base, the physicochemical properties such as formation energy, viscosity, density, vapor pressure, etc. were collected. Especially, some phase diagrams of eutectic molten fluorides are plotted and thermodynamic data of liquid metals are also compiled. In the future, the technical report is to be used as basic data for the development of the pyrochemical process which is being carried out as a long-term nuclear R and D project

  8. [Influence of water fluoride exposure on sex hormone binding globulin and testosterone in adult male].

    Science.gov (United States)

    Zhou, Tong; Yang, Rupu; Li, Shihong; Zheng, Guoqing; Xi, Yu; Cheng, Xuemin; Hou, Jiaxiang; Cui, Liuxin; Ba, Yue

    2013-03-01

    To explore the influence of water fluoride exposure on sex hormone binding globulin (SHBG) and testosterone in adult male. Cross-sectional study was conducted in three villages of Tongxu county including high fluoride group (HFG), defluoridation project group (DFPG) and control group (CG) based on the fluoride concentration in drinking water. Adult male who were born and raised in the village and aged 18 - 50 years old were recruited using cluster sampling. Fasting blood and morning urine samples were collected. The fluoride levels in drinking water and urine were detected by fluoride-ion selective electrode method. Serum SHBG level was determined using enzyme-linked immunosorbent assay (ELISA). The chemical luminescence immune analysis method was used to detect serum testosterone content. Serum SHBG level was 47.85 nmol/L in CG, 31.37 nmol/L in DFPG and 24.52 nmol/L in HFG respectively. There were significant difference among of three groups (P < 0.05). Serum testosterone level was 3.69 ng/ml in CG, 4.61 ng/ml in DFPG and 4.83 ng/ml in HFG respectively. Serum testosterone level in HFG was significantly higher than that in CG (P < 0.05). Serum SHBG level in HFG has positive correlation with serum testosterone (r = 0.230, P = 0.049), which has not been observed in DFPG and CG. Long-time fluorine exposure may affect serum SHBG and testosterone level in adult male.

  9. Focus on Fluoride and Fluorosis by Studying the Ground Water Quality in some Villages of Nalgonda, Nalgonda District, Andhra Pradesh

    OpenAIRE

    , Ishrath Aish; , B.L.P. Babu; , K. Sreenu

    2011-01-01

    The fluoride content of ground water was determined in eight villages of Shalsher vagu, Nalgonda district, Andhra Pradesh, where it is the only source for drinking water. Various water quality parameters such as Hydrogen potential, Electrical conductivity, Total dissolved solids, Total hardness, Total Alkalies and Fluoride were determined. The results indicated considerable variations among the analysed samples with respect to the above parameters the concentration of Fluoride in groundwater ...

  10. Mg-doped nano ferrihydrite - A new adsorbent for fluoride removal from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Mohapatra, M., E-mail: mamatamohapatra@yahoo.com [Institute of Minerals and Materials Technology, Bhubaneswar 751 013, Orissa (India); Hariprasad, D.; Mohapatra, L.; Anand, S.; Mishra, B.K. [Institute of Minerals and Materials Technology, Bhubaneswar 751 013, Orissa (India)

    2012-03-01

    The present study evaluates synthesized Mg-doped nano ferrihydrite powder as an adsorbent for F{sup -} removal from aqueous solutions. High surface area Mg-doped ferrihydrite was prepared by co-precipitation method under controlled conditions. Samples were prepared by varying Mg content in the range of 0.39-1.12%. Preliminary test work revealed that under similar conditions, with the increase in Mg content from 0.39 to 0.98% in doped ferrihydrite, % F{sup -} adsorption increased from 66 to 91%. Hence this sample was characterized by XRD, TEM, SAED and TG-DTA. Batch adsorption experiments were carried out by varying contact time (30-480 min), initial pH (1.0-10), initial fluoride concentration (10-150 mg/L), adsorbent dose (0.5-4 g/L), temperature (20-45 Degree-Sign C) and Cl{sup -} or SO{sub 4}{sup 2-} concentrations (nil to 50 mg/L). The results showed 0.98% Mg-doped ferrihydrite to be an excellent fluoride adsorbent giving maximum adsorption capacity of 64 mg/g. The time data fitted well to pseudo second order kinetic model. The isothermal data followed Langmuir model. Thermodynamic parameters confirmed the adsorption process to be spontaneous and endothermic. 89% of fluoride could be desorbed from loaded sample using 1 M NaOH.

  11. Metal fluoride complexes of Na,K-ATPase: characterization of fluoride-stabilized phosphoenzyme analogues and their interaction with cardiotonic steroids.

    Science.gov (United States)

    Cornelius, Flemming; Mahmmoud, Yasser A; Toyoshima, Chikashi

    2011-08-26

    The Na,K-ATPase belongs to the P-type ATPase family of primary active cation pumps. Metal fluorides like magnesium-, beryllium-, and aluminum fluoride act as phosphate analogues and inhibit P-type ATPases by interacting with the phosphorylation site, stabilizing conformations that are analogous to specific phosphoenzyme intermediates. Cardiotonic steroids like ouabain used in the treatment of congestive heart failure and arrhythmias specifically inhibit the Na,K-ATPase, and the detailed structure of the highly conserved binding site has recently been described by the crystal structure of the shark Na,K-ATPase in a state analogous to E2·2K(+)·P(i) with ouabain bound with apparently low affinity (1). In the present work inhibition, and subsequent reactivation by high Na(+), after treatment of shark Na,K-ATPase with various metal fluorides are characterized. Half-maximal inhibition of Na,K-ATPase activity by metal fluorides is in the micromolar range. The binding of cardiotonic steroids to the metal fluoride-stabilized enzyme forms was investigated using the fluorescent ouabain derivative 9-anthroyl ouabain and compared with binding to phosphorylated enzyme. The fastest binding was to the Be-fluoride stabilized enzyme suggesting a preformed ouabain binding cavity, in accord with results for Ca-ATPase where Be-fluoride stabilizes the E2-P ground state with an open luminal ion access pathway, which in Na,K-ATPase could be a passage for ouabain. The Be-fluoride stabilized enzyme conformation closely resembles the E2-P ground state according to proteinase K cleavage. Ouabain, but not its aglycone ouabagenin, prevented reactivation of this metal fluoride form by high Na(+) demonstrating the pivotal role of the sugar moiety in closing the extracellular cation pathway.

  12. Molten fluoride fuel salt chemistry

    International Nuclear Information System (INIS)

    Toth, L.M.; Del Cul, G.D.; Dai, S.; Metcalf, D.H.

    1995-01-01

    The chemistry of molten fluorides is traced from their development as fuels in the Molten Salt Reactor Experiment with important factors in their selection being discussed. Key chemical characteristics such as solubility, redox behavior, and chemical activity are explained as they relate to the behavior of molten fluoride fuel systems. Development requirements for fitting the current state of the chemistry to modern nuclear fuel system are described. It is concluded that while much is known about molten fluoride behavior which can be used effectively to reduce the amount of development required for future systems, some significant molten salt chemical questions must still be addressed. copyright American Institute of Physics 1995

  13. Milk fluoridation for the prevention of dental caries

    Directory of Open Access Journals (Sweden)

    Jolán Bánóczy

    2013-11-01

    Full Text Available The aim of this review is to give an overview of 55 years experience of milk fluoridation and draw conclusions about the applicability of the method. Fluoridated milk was first investigated in the early 1950s, almost simultaneously in Switzerland, the USA and Japan. Stimulated by the favourable results obtained from these early studies, the establishment of The Borrow Dental Milk Foundation (subsequently The Borrow Foundation in England gave an excellent opportunity for further research, both clinical and non-clinical, and a productive collaboration with the World Health Organization which began in the early 1980s. Numerous peer-reviewed publications in international journals showed clearly the bioavailability of fluoride in various types of milk. Clinical trials were initiated in the 1980s – some of these can be classed as randomised controlled trials, while most of the clinical studies were community preventive programmes. Conclusion. These evaluations showed clearly that the optimal daily intake of fluoride in milk is effective in preventing dental caries. The amount of fluoride added to milk depends on background fluoride exposure and age of the children: commonly in the range 0.5 to 1.0 mg per day. An advantage of the method is that a precise amount of fluoride can be delivered under controlled conditions. The cost of milk fluoridation programmes is low, about € 2 to 3 per child per year. Fluoridation of milk can be recommended as a caries preventive measure where the fluoride concentration in drinking water is suboptimal, caries experience in children is significant, and there is an existing school milk programme.

  14. Milk fluoridation for the prevention of dental caries.

    Science.gov (United States)

    Bánóczy, Jolán; Rugg-Gunn, Andrew; Woodward, Margaret

    2013-11-01

    The aim of this review is to give an overview of 55 years experience of milk fluoridation and draw conclusions about the applicability of the method. Fluoridated milk was first investigated in the early 1950s, almost simultaneously in Switzerland, the USA and Japan. Stimulated by the favourable results obtained from these early studies, the establishment of The Borrow Dental Milk Foundation (subsequently The Borrow Foundation) in England gave an excellent opportunity for further research, both clinical and non-clinical, and a productive collaboration with the World Health Organization which began in the early 1980s. Numerous peer-reviewed publications in international journals showed clearly the bioavailability of fluoride in various types of milk. Clinical trials were initiated in the 1980s - some of these can be classed as randomised controlled trials, while most of the clinical studies were community preventive programmes. These evaluations showed clearly that the optimal daily intake of fluoride in milk is effective in preventing dental caries. The amount of fluoride added to milk depends on background fluoride exposure and age of the children: commonly in the range 0.5 to 1.0 mg per day. An advantage of the method is that a precise amount of fluoride can be delivered under controlled conditions. The cost of milk fluoridation programmes is low, about € 2 to 3 per child per year. Fluoridation of milk can be recommended as a caries preventive measure where the fluoride concentration in drinking water is suboptimal, caries experience in children is significant, and there is an existing school milk programme. Copyright © 2013 by Academy of Sciences and Arts of Bosnia and Herzegovina.

  15. Poisoning by coal smoke containing arsenic and fluoride

    Energy Technology Data Exchange (ETDEWEB)

    An, D.; He, Y.G.; Hu, Q.X. [Guizhou Sanitary and Epidemiological Station, Guiyang (China)

    1997-02-01

    An investigation was made into a disease involving skin pigmentation, keratosis of the hands and feet, dental discoloration, and generalized bone and joint pain, stiffness and rigidity, in the village of Bazhi, Zhijin County, Ghizhou Province, People`s Republic of China. Measurements were made of the arsenic and fluoride levels of coal, water, air, food, urine and hair in Bazhi and a control village, Xinzhai, in which coal with a low arsenic content was used. Up to 188 people, including children, in Bazhi and 752 in Xinzhai, were examined for the presence of chronic arsenium, skeletal fluorosis, dental fluorosis and electrocardiogram abnormalities. The coal in Bazhi was found to contain high levels of arsenic and fluoride resulting, after burning in homes without an adequate chimney systems, in pollution of air and food with arsenic and fluoride. The coal in Xinzhai did not cause arsenic pollution but did produce a higher level of fluoride pollution. It was concluded that the endemic disease in Bazhi was caused by pollution by coal smoke containing arsenic and fluoride. It is suggested that arsenic may act synergistically with fluoride so that a lower level of fluoride may produce fluoride toxicity with dental and skeletal fluorosis.

  16. New Insight on the Response of Bacteria to Fluoride

    Science.gov (United States)

    Breaker, R.R.

    2012-01-01

    Fluoride has been used for decades to prevent caries and it is well established that this anion can inhibit the growth of bacteria. However, the precise effects that fluoride has on bacteria and the mechanisms that bacteria use to overcome fluoride toxicity have largely remained unexplored. Recently, my laboratory reported the discovery of biological systems that bacteria use to sense fluoride and reduce fluoride toxicity. These sensors and their associated genes are very widespread in biology, which has implications for a number of issues that are central to the use of fluoride for dental care. Below I provide a summary of our findings, comment on some of the key prospects for expanding our understanding of fluoride's effects on biology, and propose some future uses of this knowledge. PMID:22327376

  17. New insight on the response of bacteria to fluoride.

    Science.gov (United States)

    Breaker, R R

    2012-01-01

    Fluoride has been used for decades to prevent caries and it is well established that this anion can inhibit the growth of bacteria. However, the precise effects that fluoride has on bacteria and the mechanisms that bacteria use to overcome fluoride toxicity have largely remained unexplored. Recently, my laboratory reported the discovery of biological systems that bacteria use to sense fluoride and reduce fluoride toxicity. These sensors and their associated genes are very widespread in biology, which has implications for a number of issues that are central to the use of fluoride for dental care. Below I provide a summary of our findings, comment on some of the key prospects for expanding our understanding of fluoride's effects on biology, and propose some future uses of this knowledge. Copyright © 2012 S. Karger AG, Basel.

  18. Erosive potential of saliva stimulating tablets with and without fluoride in irradiated head and neck cancer patients

    International Nuclear Information System (INIS)

    Lajer, Christel; Buchwald, Christian; Nauntofte, Birgitte; Specht, Lena; Bardow, Allan; Jensdottir, Thorbjoerg

    2009-01-01

    Background: Patients irradiated in the head and neck region often suffer from severe dry mouth and use acidic saliva stimulating products, which may cause erosion of teeth. Purpose: To determine saliva stimulating effects and erosive potential (EP) of acidic saliva stimulating tablets (Xerodent TM ) with and without fluoride in irradiated head and neck cancer patients. Materials and method: Nineteen irradiated patients (median age 57 years) sucked Xerodent TM tablets with and without fluoride. Saliva collections were divided into three 10-min sessions in the sequence: unstimulated whole saliva, Xerodent TM stimulated saliva without fluoride, and with fluoride. Saliva pH was determined without loss of CO 2 and in combination with inorganic measures used to calculate the degree of saturation of hydroxyapatite (HAp) and fluorapatite (FAp). EP was determined directly in all saliva samples by monitored dissolution of HAp crystals. Results: Saliva flow rates increased significantly (15-fold) when sucking both tablets (p TM with and without fluoride were evaluated as non-erosive, however, for additional caries protection the fluoride variant is preferable.

  19. Solubility and fluoride release in ionomers and compomers.

    Science.gov (United States)

    Bertacchini, S M; Abate, P F; Blank, A; Baglieto, M F; Macchi, R L

    1999-03-01

    The degree of solubility and the fluoride release of glass-ionomer cements and "compomers" were determined as a function of time. Three conventional glass-ionomer cements, three hybrid ionomers, and two compomers were included in the study. Disk-shaped specimens were prepared and immersed in a lactic acid solution. Solubility was evaluated from determinations of loss of mass as a function of time. To evaluate fluoride release, similar specimens were immersed in 50 mL of deionized water to which 50 mL of buffer solution was added. A fluoride ion detector was used to read the concentration of fluoride ion in the overall solution at different times after immersion. Material and time factors had a significant influence on results. The compomers showed less corrosion and fluoride release than the ionomers. Some correlation was found between solubility and fluoride leakage values. Components of both the ionomers and compomers that were studied can dissolve in water. The materials leak fluoride ions in amounts that differ according to the characteristics of the individual products.

  20. Data on fluoride concentration levels in semi-arid region of Medak, Telangana, South India

    Directory of Open Access Journals (Sweden)

    Adimalla Narsimha

    2018-02-01

    Full Text Available According to the World Health Organization recommendation, the optimal fluoride concentration levels in drinking water have to be in the range of 0.5 and 1.5 mg/L since this permissible range is essential for normal mineralization of bones and teeth as well as for dental enamel formation in human's body Bell and budwig, 1970; Adimalla and Venkatayogi, 2017; Narsimha and Sudarshan, 2013, 2016; 2017 [1,2,4,5,6]. If continues intake of high fluoride (>1.5 water can severely cause dental and skeletal fluorosis. The investigated area people majorly depend on groundwater for drinking purposes and fluoride concentration ranged from 0.2 to 7.4 mg/L with mean concentration of 2.7 mg/L and data was compared with WHO guidelines for drinking purposes. Overall, data reveals that the 57% of groundwater samples data was not safe for drinking purposes. Therefore, distribution of fluoride in the groundwater of Medak region in Telangana was suggested to intake drinking water, which are below level of fluoride concentration in the groundwater and take care about health implications.

  1. The in vitro effect of fluoridated milk in a bacterial biofilm--enamel model.

    Science.gov (United States)

    Arnold, Wolfgang H; Forer, Stefan; Heesen, Joerg; Yudovich, Keren; Steinberg, Doron; Gaengler, Peter

    2006-07-01

    The purpose of this study was to investigate the effect of milk and fluoridated milk on bacterially induced caries-like lesions. Extracted impacted human molars were cut in half and covered with a varnish leaving a 4*4 mm window. The samples were coated with biofilm of S. sobrinus and were further divided into three experimental groups of S. sobrinus, S. sobrinus and milk and S. sobrinus and fluoridated milk. As negative controls served teeth incubated in saline. Of twenty tooth halves serial ground sections were cut through the lesions and investigated with polarization light microscopy (PLM) and scanning electron microscopy (SEM) and EDX element analysis. The PLM photographs were used for 3D reconstruction, volumetric assessment and determination of the extension of the lesion zones. Of eight tooth halves the biofilm on the enamel surface was studied with SEM and EDX element analysis. Volumetric assessment showed a statistically significant difference in the volume of the body of the lesion and the translucent zone between the milk group and fluoridated milk group. Quantitative element analysis demonstrated significant differences between sound enamel and the superficial layer in the fluoridated milk group. The biofilm on the enamel surface showed an increased Ca content in the milk group and fluoridated milk group. Milk as a common nutrient seems to play a complex role in in-vitro biofilm--enamel interactions stimulating bacterial demineralization on one hand, and, as effective fluoride carrier, inhibits caries-like demineralization.

  2. New Insight on the Response of Bacteria to Fluoride

    OpenAIRE

    Breaker, R.R.

    2012-01-01

    Fluoride has been used for decades to prevent caries and it is well established that this anion can inhibit the growth of bacteria. However, the precise effects that fluoride has on bacteria and the mechanisms that bacteria use to overcome fluoride toxicity have largely remained unexplored. Recently, my laboratory reported the discovery of biological systems that bacteria use to sense fluoride and reduce fluoride toxicity. These sensors and their associated genes are very widespread in biolog...

  3. Widespread genetic switches and toxicity resistance proteins for fluoride.

    Science.gov (United States)

    Baker, Jenny L; Sudarsan, Narasimhan; Weinberg, Zasha; Roth, Adam; Stockbridge, Randy B; Breaker, Ronald R

    2012-01-13

    Most riboswitches are metabolite-binding RNA structures located in bacterial messenger RNAs where they control gene expression. We have discovered a riboswitch class in many bacterial and archaeal species whose members are selectively triggered by fluoride but reject other small anions, including chloride. These fluoride riboswitches activate expression of genes that encode putative fluoride transporters, enzymes that are known to be inhibited by fluoride, and additional proteins of unknown function. Our findings indicate that most organisms are naturally exposed to toxic levels of fluoride and that many species use fluoride-sensing RNAs to control the expression of proteins that alleviate the deleterious effects of this anion.

  4. The Effect of Fluoridated and Non Fluoridated Mouth Washes on Color Stability of Different Aesthetic Arch Wires At Different Time Intervals (An in Vitro Study

    Directory of Open Access Journals (Sweden)

    Lubna Maky Hussein

    2018-01-01

    Full Text Available Background:The color stability of aesthetic arch wires is an important factor in the success of an aesthetic orthodontic treatment, but the color of these arch wires tends to change with time.This study was performed to assess the effect of two types of mouth washes on the color  stability of different types of aesthetic arch wires at different time intervals. Materials and methods:Four brands of nickel titanium coated aesthetic arch wires were used: epoxy coated (Orthotechnology and G&H and Teflon coated (Dany and Hubit.Thirty six samples were prepared, each sample contains ten halves of the aesthetic arch wires. They were divided into three groups according to the immersion media (distilled water as a control media, Listerine with fluoride and Listerine without fluoride and immersed for 30 seconds twice daily according to manufacturer's instructions to measure color change after 1 week, 3 weeks and 6 weeks by using spectrophotometer VITA Easyshade Compact according to Commission Internationale de l’Eclairage L*a*b* color space system. Results:It was found that there were highly significant differences in color change values of aesthetic arch wires among all immersion media at different time intervals and color change value increases as the time of immersion increases.Additionally, Listerine with fluoride mouth wash caused higher color change values of aesthetic arch wires than Listerine without fluoride and Hubit aesthetic arch wires were the least color stable while Orthotechnology aesthetic arch wires were the most color stable. Conclusions: We can conclude that the daily use of Listerine mouth washes could affect on the color stability of aesthetic arch wires. Although all tested aesthetic arch wires revealed color changes at variable degrees but some of these changes were not  visible and the others were clinically acceptable while the remaining were clinically unacceptable.

  5. Determination of boron, silica, fluoride, MBAS, phenols, cyanide and sulphide

    International Nuclear Information System (INIS)

    Smith, R.

    1982-01-01

    This study forms part of the NIWR's series of interlaboratory comparison studies involving southern African laboratories engaged in water and wastewater analysis, and is concerned with the analysis of synthetic water samples by 31 laboratories for boron, silica, fluoride, methylene blue active substances (MBAS), phenols, cyanide and sulphide. The results obtained are evaluated and discussed. Recognised standard methods, or modifications of these methods, were used for most of the determinations. Results from the boron, silica and fluoride determinations showed, in general, acceptable accuracy and precision. Results from the MBAS, phenols, cyanide and sulphide determinations were, however, somewhat widespread, and illustrated the difficulty in obtaining reliable results from the measurement of relatively low levels of these determinands

  6. Effects of different amine fluoride concentrations on enamel remineralization.

    Science.gov (United States)

    Naumova, E A; Niemann, N; Aretz, L; Arnold, W H

    2012-09-01

    The aim of this study was to investigate the effects of decreasing fluoride concentrations on repeated demineralizing challenges on human enamel. In 24 teeth, 3mm×3mm windows were prepared on the buccal and lingual sides and treated in a cycling demineralization-remineralization model. Remineralization was achieved with 100, 10 and 0.1 ppm fluoride from anime fluoride. Coronal sections were cut through the artificial lesions, and three sections per tooth were investigated using polarized light microscopy and scanning electron microscopy with quantitative element analysis. The morphology of the lesions was studied, and the extensions of the superficial layer and the body of the lesion were measured. Using element analysis, the Ca, P and F content were determined. The body of the lesion appeared remineralized after application of 100 ppm fluoride, while remineralization of the lesion was less successful after application of 10 and 0.1 ppm fluoride. The thickness of the superficial layer increased with decreasing fluoride concentrations, and also the extension of the body of the lesion increased. Ca and P content increased with increasing fluoride concentrations. The effectiveness of fluoride in enamel remineralization increased with increasing fluoride concentration. A consistently higher level of fluoride in saliva should be a goal in caries prevention. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Effect of dispersed particles of calcium fluoride on the molybdenum solubility in iron

    International Nuclear Information System (INIS)

    Shvejkin, G.P.; Antsiferov, V.N.; Postnikov, V.S.

    1981-01-01

    The results of the investigation of compositions containing 20 at% Mo and 12 vol.% CaF 2 are presented. The sample diffractograms of compositions Fe+20 at% Mo and (Fe+20 at% Mo)+12 vol.% CaF 2 are given. It is shown that the introduction of calcium fluoride results in formation of continuos series of solid solutions of molybdenum in iron. The results of X-ray diffraction investigations on exceeding solubility limit of molybdenum in iron in the presence of calcium fluoride are confirmed

  8. Antibacterial Effect of Silver Diamine Fluoride on Cariogenic Organisms.

    Science.gov (United States)

    Lou, Yali; Darvell, Brain W; Botelho, Michael G

    2018-05-01

    To screen the possible antimicrobial activity of a range of clinically used, silver-based compounds on cariogenic organisms: silver diamine fluoride (SDF), silver fluoride, and silver nitrate. Preliminary screening disk-diffusion susceptibility tests were conducted on Mueller-Hinton agar plates inoculated with Streptococcus mutans, Lactobacillus acidophilus, and Actinomyces naeslundii, organisms known to be cariogenic. In order to identify which component of the silver compounds was responsible for any antibacterial (AB) effect, and to provide controls, the following were also investigated at high and low concentrations: sodium fluoride, ammonium fluoride, ammonium chloride, sodium fluoride, sodium chloride, and sodium nitrate, as well as deionized water as control. A volume of 10 pL of a test solution was dispensed onto a paper disk resting on the inoculated agar surface, and the plate incubated anaerobically at 37°C for 48 hours. The zones of inhibition were then measured. Silver diamine fluoride, silver fluoride, silver nitrate, and ammonium fluoride had significant AB effect (p effect at low concentration; the remaining other compounds had no effect. Silver ions appear to be the principal AB agent at both high and low concentration; fluoride ions only have an AB effect at high concentration, while ammonium, nitrate, chloride and sodium ions have none. The anticaries effect of topical silver solutions appears restricted to that of the silver ions. Silver compounds, such as SDF, silver fluoride, and silver nitrate have AB effect against cariogenic organisms and these may have clinical impact in arresting or preventing dental decay. Sodium fluoride did not have AB effect under the conditions tested.

  9. High Fluoride Dentifrices for Elderly and Vulnerable Adults

    DEFF Research Database (Denmark)

    Ekstrand, Kim Rud

    2016-01-01

    The primary aim of this work is to present the available evidence that toothpastes containing >1,500 ppm fluoride (2,500-2,800 and 5,000 ppm F) provide an additional caries preventive effect on root caries lesions in elderly patients compared to traditional dentifrices (1,000-1,450 ppm F......). The secondary aim of this paper is to discuss why high fluoride dentifrices in general should perform better than traditional F-containing toothpaste. When examining the few studies that have considered the preventive benefits of high fluoride products on root caries the relative risk appears to be around 0.......5, and the risk can thus be halved by exchanging traditional F-containing toothpaste for toothpaste containing 5,000 ppm F. There is reasonable evidence that high fluoride dentifrices significantly increase the fluoride concentration in saliva during the day and the fluoride concentration in plaque compared...

  10. Approaches to the accurate characterization of high purity metal fluorides and fluoride glasses

    Science.gov (United States)

    Beary, E. S.; Paulsen, P. J.; Rains, T. C.; Ewing, K. J.; Jaganathan, J.; Aggarwal, I.

    1990-11-01

    The analytical challenges posed by the measurement of trace contaminants in high purity metal fluorides require that innovative chemical preparation procedures be used to enhance existing instrumental techniques. The instrumental techniques used to analyze these difficult matrices must be sensitive enough to detect extremely low levels of trace impurities, and the background interferences derived from the matrix (metal fluoride or glass) must be minimized. A survey of analytical techniques that have the necessary characteristics to analyze these materials will be given. In addition, means of controlling the chemical blank will be presented. Mass and atomic spectrometric techniques will be discussed, specifically graphite furnace atomic absorption spectrometry (GFAAS) and inductively coupled plasma-mass spectrometry (ICP-MS). Analytical procedures using GFAAS and ICP-MS have been developed to determine sub ppb (part per billion) levels of contaminants in high purity fluoride materials.

  11. Fluoride estimation and its correlation with other physicochemical parameters in drinking water of some areas of Balochistan, Pakistan.

    Science.gov (United States)

    Chandio, Tasawar Ali; Khan, Muhammad Nasiruddin; Sarwar, Anila

    2015-08-01

    The fluoride level in drinking water is an important parameter and has to be controlled in order to prevent dental and skeletal fluorosis. The objective of this study is to assess fluoride content and other water quality parameters in the samples taken from open wells, tube wells, and karezes of Mastung, Mangochar, and Pringabad areas of Balochistan province. A total number of 96 drinking water samples out of 150 were found unfit for human consumption. Area-wise analysis show that the samples from 39 sites from Mastung, 12 from Mangochar, and 13 from Pringabad were found in the risk of dental fluorosis of mild to severe nature. However, 12 sampling sites from Mastung, 8 from Mangochar, and 2 from Pringabad were identified as the risks of mottling and skeletal fluorosis or other bone abnormalities. The highest concentration of F(-) has been observed as 14 mg L(-1) in Mastung. Correlation analysis show that fluoride solubility in drinking water is pH dependent; and the salts of Ca(2+), Na(+), K(+), Cl(-), and SO4(2-) contribute to attain the favorable pH for dissolution of fluoride compounds in drinking water. Principal component analysis shows that the geochemical composition of the rocks is only responsible for groundwater contamination. On the basis of the results, defloridation of the identified sampling sites and continuous monitoring of drinking water at regular basis is recommended at government level to avoid further fluorosis risks.

  12. Effectiveness of early preventive intervention with semiannual fluoride varnish application in toddlers living in high-risk areas

    DEFF Research Database (Denmark)

    Anderson, Maria; Dahllöf, Göran; Twetman, Svante

    2016-01-01

    This study evaluated whether toddlers in an extended preventive program of semiannual fluoride varnish applications from 1 year of age had a lower incidence of caries than those undergoing a standard program. A cohort of 1-year-old children (n = 3,403) living in multicultural areas of low...... a standardized oral health program once yearly between 1 and 3 years of age. The children in the test group received the same standard program supplemented with topical applications of fluoride varnish every 6 months. We compared the test group and the reference group for the prevalence and increment of caries...... lesions (ICDAS II 3-6), with a mean increment of 0.5 (SD 2.4) in the test group and 0.6 (SD 2.2) in the reference group. In conclusion, semiannual professional applications of fluoride varnish, as a supplement to a standard oral health program, failed to reduce caries development in toddlers from high...

  13. Adsorption and exhaustion device for gaseoue uranium fluorides

    International Nuclear Information System (INIS)

    Kida, Yasuo; Nakamura, Yuichi.

    1984-01-01

    Purpose: To prevent gaseous uranium fluorides from passing through the adsorption layer upon exhausting the gaseous uranium, fluorides from a uranium fluoride processing facility through adsorption traps, by controlling the flow rate of the gaseous uranium fluorides passing through the layer constant. Constitution: An adsorption trap is connected by way of pipeways to a uranium fluoride processing facility, and a flow rate detector for detecting the flow rate of gaseous uranium fluorides and a pressure gauge for detecting the pressure at the inlet of the adsorption trap are disposed to the pipeways. The setting value for the pressure control is calculated from the detection value of the flow rate detector by the pressure control gage. Then, an operation amount for the pressure control valve is calculated based on the deviatoin between the setting value for the pressure control and the inlet pressure at the adsorption trap. This enables to control the flow rate of the gaseous uranium fluorides passing through the adsorption layer always constant thereby enabling to prevent excess increase in the flow rate which results in damages in the adsorption layer. (Moriyama, K.)

  14. The effective use of fluorides in public health

    DEFF Research Database (Denmark)

    Jones, Sheila; Burt, Brian A; Petersen, Poul Erik

    2005-01-01

    , systematic reviews summarizing these extensive databases have indicated that water fluoridation and fluoride toothpastes both substantially reduce the prevalence and incidence of dental caries. We present four case studies that illustrate the use of fluoride in modern public health practice, focusing on......Dental caries remain a public health problem for many developing countries and for underprivileged populations in developed countries. This paper outlines the historical development of public health approaches to the use of fluoride and comments on their effectiveness. Early research...

  15. Absorption, distribution and excretion of inhaled hydrogen fluoride in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Morris, J.B.

    1979-01-01

    Rats were subjected to whole body HF exposure for 6 hrs or to nose-only HF exposure for 1 hr. Total and/or ionic fluoride concentrations in selected tissues were determined at various times following exposure. In rats sacrificed 6 hrs after whole body exposure, dose-dependent increases in lung, plasma, and kidney total and ionic fluoride concentration occurred. Rats excreted more fluoride in the urine after whole body exposure than could be explained by the amount of HF inhaled. Considerable evidence suggests that airborne HF deposits on fur and is then ingested due to preening activity. Urinary fluoride excretion was increased by nose-only exposure. The urinary fluoride excretion accounted for approximately twice the fluoride estimated to be inhaled during exposure. Tissue fluoride concentrations were elevated immediately after nose-only exposure. Fluoride concentrations in lung and kidney returned to control levels within 12 hrs. Plasma fluoride concentration was slightly elevated 24 hrs after the start of the 1 hr exposure but was at control levels at 96 hrs. Immediately following nose-only exposure, lung ionic fluoride concentrations were less than plasma ionic fluoride concentrations suggesting that the fluoride in the lung had reached that site via plasma transport rather than by inhalation. A dose-dependent increase in plasma ionic fluoride concentration occurred after upper respiratory tract HF exposure providing strong evidence that fluoride is absorbed systemically from that site. The plasma ionic fluoride concentration after upper respiratory tract exposure was of sufficient magnitude to account for the plasma fluoride concentrations observed in intact nose-only exposed rats. (ERB)

  16. Fluoridation Basics

    Science.gov (United States)

    ... return on investment for community water fluoridation (including productivity losses) ranged from $4 in small communities of ... National Center for Chronic Disease Prevention and Health Promotion Email Recommend Tweet YouTube Instagram Listen Watch RSS ...

  17. Spectrophotometric determination of fluorides in water with Hach equipment; Determinacion espectrofotometrica de fluoruros en aguas con equipo Hach

    Energy Technology Data Exchange (ETDEWEB)

    Acosta L, E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: eal@nuclear.inin.mx

    1994-11-15

    The spectrophotometric method for the determination of the fluoride ion in water, demineralized water, raw waters, laundry waters and waters treated with ion exchange resins , using the technique and the SPADNS coloring indicated in the operation manual of the Hach equipment is described. This method covers the determination of the fluoride ion in the range from 0 to 2 mg/l on 25 ml. of radioactive base sample. These limits can be variable if the size of the used aliquot one is changed for the final determination of the fluoride ion. (Author)

  18. In vitro study of demineralization resistance and fluoride retention in dental enamel irradiated with Er,Cr: YSGG laser

    International Nuclear Information System (INIS)

    Ana, Patricia Aparecida da.

    2007-01-01

    This study aimed to establish irradiation conditions of Er,Cr:YSGG laser (λ of 2.79 μm) which could propitiate changes on human dental enamel and increase its resistance to demineralization, when associated or not with topical application of acidulated phosphate fluoride (APF). Fluences of 2,8 J/cm 2 , 5,6 J/cm 2 e 8,5 J/cm 2 were selected; they were associated or not with previous application of a photo absorber (coal paste) and then APF was applied or not after laser irradiation. In a first step, the morphological findings, the surface temperatures, and the pupal temperatures were evaluated during laser irradiation. After that, the treated samples were submitted to a a ten-day pH-cycling model. After producing the incipient white-spots lesions, the following aspects were evaluated: the mineral loss, the loosely bound fluoride and the firmly bound fluoride. All the demineralizing and remineralizing pH-cycling solutions were evaluated with respect to their calcium (Ca), inorganic phosphorous (Pi) and fluoride (F - ) concentrations. The data had their normality and homogeneity distribution statistically evaluated, and it was chosen an appropriated statistical test for each performed analysis according to the obtained results, considering 5% significant level. The fluences selected for this study created ablated surfaces; the fluences of 5.6 J/cm 2 and 8.5 J/cm 2 promoted increments in surface temperature above 110 deg C. The intrapupal temperature changes revealed that laser irradiation did not increase the pulpal temperatures above the critical threshold for induction of pulpitis. The coal paste did not promote any changes on surface morphology or in the intrapulpal temperature changes; however, this paste increased the surface temperatures during laser irradiation. Only laser irradiation at 8.5 J/cm 2 was able to decrease the mineral loss when compared to the no-treatment group; although the association of coal paste + laser at 2.8 J/cm 2 + APF application

  19. Tamarind (Tamarindus indica) fruit shell carbon: A calcium-rich promising adsorbent for fluoride removal from groundwater

    International Nuclear Information System (INIS)

    Sivasankar, V.; Rajkumar, S.; Murugesh, S.; Darchen, A.

    2012-01-01

    Highlights: ► The carbonization of Tamarind fruit shell improved its defluoridation efficiency. ► Calcium carbonate particles were involved in the defluoridation process. ► Adsorbent dose, pH, and fluoride concentration showed significant effects. ► Maximum adsorption of fluoride was achieved at pH 7–8. ► Prepared carbons were efficient in treating three natural waters. - Abstract: Tamarindus indica fruit shells (TIFSs) are naturally calcium rich compounds. They were impregnated with ammonium carbonate and then carbonized, leading to ammonium carbonate activated ACA-TIFS carbon. The resulting materials and carbon arising from virgin fruit shells V-TIFS were characterized and assayed as adsorbent for the removal of fluoride anions from groundwater. The fluoride scavenging ability of TIFS carbons was due to naturally dispersed calcium compounds. X-ray diffraction (XRD) showed that TIFS carbon contained a mixture of calcium oxalate and calcium carbonate. Batch studies on the fluoride removal efficiency of TIFS carbons with respect to contact time, pH, initial fluoride concentration, and co-ion interference were conducted. Applicability of various kinetic models (viz., pseudo-first-order, pseudo-second-order, intra-particle diffusion and Elovich) and sorption isotherms were tested for batch techniques. The fluoride removal capacity of TIFS carbons was found to be 91% and 83% at a pH of 7.05 for V-TIFS and ACA-TIFS carbons, respectively. The practical applicability of TIFS carbons using groundwater samples was approved. The fluoride removal was greater in groundwater without hydrogen carbonate ions than those containing these ions. The characterizations of fluoride unloaded and loaded TIFS carbons were done by SEM and XRD studies.

  20. Fluoride removal performance of phosphoric acid treated lime ...

    African Journals Online (AJOL)

    Fluoride in drinking water above permissible levels is responsible for dental and skeletal fluorosis. In this study, removal of fluoride ions from water using phosphoric acid treated lime was investigated in continuous and point-of-use system operations. In the continuous column operations, fluoride removal performance was ...

  1. Nutritional status and dental fluorosis among schoolchildren in communities with different drinking water fluoride concentrations in a central region in Mexico.

    Science.gov (United States)

    Irigoyen-Camacho, M E; García Pérez, A; Mejía González, A; Huizar Alvarez, R

    2016-01-15

    Poor water quality and under nutrition are important factors affecting the health of many communities in developing countries. The aims of this study were: i) to describe the fluoride water concentration and the hydrogeological conditions in a region of a state located in the central in Mexico ii) to measure the association between undernutrition and dental fluorosis in children living in communities with different drinking water fluoride concentrations in a state located in the central region of Mexico. Field work was performed in the region to identify the prevailing groundwater flow characteristics and water wells were sampled to analyze water fluoride concentration. Children were selected from three communities that had different drinking water fluoride concentrations (i.e., 0.56, 0.70 and 1.60 mg/l). Fluoridated salt was available in these communities. The Thylstrup-Fejerskov Index (TFI) was used to assess dental fluorosis. Categories four or higher of this index involve changes in the entire tooth surface (ITF ≥ 4). The weight and height of the children were measured. The assessment of undernutrition was based on the World Health Organization criteria: children were classified as being at risk of low-height (Height-for-Age Z score water captured by the wells is the result of a reaction with volcanic materials. The water fluoride concentration in the region ranged from 0.2 to 1.6 mg/l. A total of 734 schoolchildren participated in the study. The percentage of children in fluorosis categories (ITF ≥ 4) was 15.9%, 21.1% of the children were at risk of low height-for-age, and 8.0% had low height-for-age. The percentage of children with fluorosis (ITF ≥ 4) was 6.3%, 9.1% and 31.9% (p ˂ 0.001) and low high-for-age was 2.9%, 2.5% and 8.4% (p ˂ 0.001), for the communities with F concentrations of 0.56 mg/l, 0.70 mg/l and 1.6 mg/l, respectively. The logistic regression model showed an association between dental fluorosis (TFI ≥ 4) and low height-for-age (OR

  2. Fluoride uptake from restorative dental materials by human enamel

    International Nuclear Information System (INIS)

    Forsten, L.; Rytoemaa, I.; Anttila, A.; Keinonen, J.

    1976-01-01

    The purpose of the study was to determine the uptake in vitro of fluoride from restorative materials by tooth enamel and whether prior etching of the enamel causes a change of uptake. The outermost layer of the labial surface of extracted canines was removed by grinding and the enamel was covered with five different fluoride-containing materials ; a silicate, a composite resin, an amalgam, a silicophosphate, and a polycarboxylate luting cement. The material was either removed immediately or after storing the tooth in distilled water. The fluoride content was determined using a sensitive physical method based on the 19 F (p, αγ) 16 O reaction. In addition, the fluoride content of enamel after etching for different periods of time and of etched enamel which had been in contact with silicate cement was determined. The mean fluoride content of uncovered interior enamel was 226 parts 10 6 . All materials, except the composite, increased clearly the fluoride content of the underlying enamel. Etching of interior enamel also increased the fluoride values. No difference could be shown in fluoride uptake from silicate and composite resin between etched and unetched enamel. (author)

  3. Fluoride ion recognition by chelating and cationic boranes.

    Science.gov (United States)

    Hudnall, Todd W; Chiu, Ching-Wen; Gabbaï, François P

    2009-02-17

    Because of the ubiquity of fluoride ions and their potential toxicity at high doses, researchers would like to design receptors that selectively detect this anion. Fluoride is found in drinking water, toothpaste, and osteoporosis drugs. In addition, fluoride ions also can be detected as an indicator of uranium enrichment (via hydrolysis of UF(6)) or of the chemical warfare agent sarin, which releases the ion upon hydrolysis. However, because of its high hydration enthalpy, the fluoride anion is one of the most challenging targets for anion recognition. Among the various recognition strategies that are available, researchers have focused a great deal of attention on Lewis acidic boron compounds. These molecules typically interact with fluoride anions to form the corresponding fluoroborate species. In the case of simple triarylboranes, the fluoroborates are formed in organic solvents but not in water. To overcome this limitation, this Account examines various methods we have pursued to increase the fluoride-binding properties of boron-based receptors. We first considered the use of bifunctional boranes, which chelate the fluoride anion, such as 1,8-diborylnaphthalenes or heteronuclear 1-boryl-8-mercurio-naphthalenes. In these molecules, the neighboring Lewis acidic atoms can cooperatively interact with the anionic guest. Although the fluoride binding constants of the bifunctional compounds exceed those of neutral monofunctional boranes by several orders of magnitude, the incompatibility of these systems with aqueous media limits their utility. More recently, we have examined simple triarylboranes whose ligands are decorated by cationic ammonium or phosphonium groups. These cationic groups increase the electrophilic character of these boranes, and unlike their neutral analogs, they are able to complex fluoride in aqueous media. We have also considered cationic boranes, which form chelate complexes with fluoride anions. Our work demonstrates that Coulombic and chelate

  4. Formation of hydrogen fluoride by gamma and beta sterilisation in medical devices containing perfluoroheptane

    International Nuclear Information System (INIS)

    Zuendorf, Josef; Kremer, Stefan; Grueger, Thomas

    2008-01-01

    Infusion of hexadecafluoroheptane, a liquid perfluorocarbon released from repaired Althane dialysers was found to be the most probable reason for the deaths of 53 dialysis patients reported in the year 2001. This study focuses on toxic decomposition products generated due to gamma and beta sterilisation of hexadecafluoroheptane. The responsible dialysers were sterilised with a maximum dose of 45 kGy gamma irradiation. We investigated the influence of both 20-500 kGy gamma and beta irradiation on perfluoroheptane. Analysis of the irradiated samples verified the decomposition of perfluoroheptane in dependence on the dose of irradiation. Beta irradiation resulted in a higher degree of decomposition than the same dose of gamma irradiation. As decomposition products, hydrogen fluoride, CO 2 , and one saturated fluorinated hydrocarbon which could not be analysed exactly were identified. Even at 20 kGy gamma irradiation hydrogen fluoride was detectable. Our results provide evidence that hydrogen fluoride is generated as a highly toxic decomposition product when perfluoroheptane is sterilised with gamma irradiation as it was applied on the affected dialysers. There is no evidence of other toxic degradation products especially perfluoroisobutylene. Therefore, hydrogen fluoride or the dissociated fluoride ions might act as a toxic agent when medical devices containing liquid perfluorocarbons are sterilised by irradiation

  5. Fluoride reactions with dental enamel following different forms of fluoride supply

    International Nuclear Information System (INIS)

    Hellstroem, I.; Ericsson, Y.

    1976-01-01

    The reactions with dental enamel of NaF as tablets dissolved in different beverages or supplied with NaCl, simulating domestic salt fluoridation, were studied in tests with enamel surfaces and enamel powder. It was confirmed that powdered enamel can react quite differently from enamel surfaces under certain conditions. Enamel surfaces took up much more fluoride (F) from orange juice than from water or milk, and neither the low pH nor the citrate content of the juice increased the formation of unstable CaF 2 in the enamel, as judged from a KOH leaching test. The F uptake by enamel surfaces from 0.25 mM NaF in 175 mM NaCl, corresponding to a dish prepared with salt containing 500 parts/10 6 F, was about 80 percent greater than from the same NaF concentration in water. This NaCl concentration did not increase the formation of CaF 2 in the enamel, as judged from the KOH test, while 350 mM NaCl caused a moderate increase. The investigations support the administration of NaF tablets with orange juice and the plans for domestic salt fluoridation. (author)

  6. The influence of the unsaturated zone on the high fluoride contents in groundwater in the middle voltaian aquifers-the Gusghegu District, Northern Region

    International Nuclear Information System (INIS)

    Salifu, M.

    2012-01-01

    Elevated levels of fluoride have been reported to occur in some groundwater in the Gushegu district of the Northern region of Ghana leading to the closure of some boreholes in the area. Hydrochemical data from 21 water, soil and some rock samples were used to evaluate water quality, water types and to identify whether the unsaturated zone has influence on the elevated fluoride levels in groundwater as well as the processes that control fluoride level in the groundwater. Water samples were extracted from soil sample for flouride analysis using the cryogenic vacuum extraction set-up. Results of the water quality analysis showed that the groundwater in the study area were generally potable. A plot of Gibbs diagram revealed that rock weathering and rainfall were the major hydrogeochemical processes regulating the water chemistry of the study area. Two different water types were identified in the study area, namely: Na-HCO 3 - , which happened to be the major water type in the study area and Na-Ca-Mg-HCO 3 - water type. The fluoride concentration in the groundwater varied from 0.0 to 1.97 mg/L while that of the unsaturated zone ranged from 0.0 to 2.08 mg/L. The elevated fluoride levels in the groundwater strongly correlated with that of fluoride levels in the unsaturated zone (r 2 =0.76). Petrographic analysis of rock samples (siltstones) identified the minerals present to be muscovite, plagioclase feldspars, quartz, sericite and iron oxide. Other clay minerals such as montmorillonite, illite and chloride were identified. The elevated fluoride levels recorded in the groundwater may be due to leaching, as a result of the weathering and dissolution of muscovite, sericite as well as the presence of other clay minerals in the unsaturated zone. Application of phosphate fertilizers may also account for the the elevated fluoride concentrations recorded in the study area. Stable isotopic composition of the waters revealed that most of the groundwater were of meteoric origin

  7. Fluoride use in Controlling Dental Caries and Fluorosis

    Directory of Open Access Journals (Sweden)

    Gaurav Solanki

    2012-07-01

    Full Text Available Policy were introduced to control fluoride exposure and to reduce the prevalence of fluorosis. The study aimed of describing the prevalence, severity and risk factors for fluorosis, and to describe the trend of fluorosis among Indian children. The study also aimed of exploring the effect of the change in fluoride exposure on dental fluorosis and caries. Establishing an appropriate use of fluoride toothpaste could be successful in reducing fluorosis without a significant increase in caries experience. The use of fluorides for oral health has always involved a balance between the protective benefit against dental caries and the risk of developing fluorosis. The link between fluoride and dental health was established to determining the causes of dental fluorosis or enamel mottling. Fluorosis in Indian children was highly prevalent in the early 1990s.

  8. Parental preference for fluoride varnish: a new concept in a rapidly developing nation

    Directory of Open Access Journals (Sweden)

    Hendaus MA

    2016-07-01

    availability of the fluoride varnish in all clinics. Conclusion: The robust positive attitude of parents in this sample suggests that introducing fluoride varnish is feasible and acceptable in our community. Actions to augment fluoride varnish acceptability in the developing world, such as focusing on safety, could be important in the disseminated implementation of fluoride varnish. Keywords: fluoride, parents, varnish, Qatar

  9. Fluoride remediation using floating macrophytes

    Directory of Open Access Journals (Sweden)

    Naba Kumar Mondal

    2014-04-01

    Full Text Available Six aquatic macrophytes, such as Pistia stratiotes, Ceratophyllum demersum, Nymphoides indica, Lemna major, Azolla pinnata,and Eichhornia crassipes were considered for remove fluoride from aqueous solution. Five different concentrations (10, 30, 50, and 100 ppm of fluoride solution were taken in 1 L plastic container. Fixed weight (20 g of macrophytes along with 500 ml fluoride solution was taken in each plastic container for 72 hours observation. Results demonstrated all the macrophytes show highest fluoride removal during 24 h to 48 h, but after 72 h their efficiency reduced drastically. The species N. indica showed better removal efficiency than other experimental macrophytes. In general, pigment measurement data indicated higher concentration at 72 h. However, Pistia sp. showed higher concentration of pigmentation at intermediate time interval (48 h. Higher level of dry weight to fresh weight ratio was recorded for L. major and A. pinnata at all concentrations, excepting at 10 ppm. In addition, all macrophytes showed lower RGR at higher concentration. Isotherm study indicated that macrophyte C. demersum is a good fitted with Freundlich and Langmuir isotherm whereas L. major with Langmuir isotherm during 24 hours.

  10. Prenatal Fluoride Exposure and Cognitive Outcomes in Children at 4 and 6–12 Years of Age in Mexico

    Science.gov (United States)

    Thomas, Deena; Hu, Howard; Angeles Martinez-Mier, E.; Sanchez, Brisa N.; Basu, Niladri; Peterson, Karen E.; Ettinger, Adrienne S.; Wright, Robert; Zhang, Zhenzhen; Liu, Yun; Schnaas, Lourdes; Mercado-García, Adriana; María Téllez-Rojo, Martha; Hernández-Avila, Mauricio

    2017-01-01

    Background: Some evidence suggests that fluoride may be neurotoxic to children. Few of the epidemiologic studies have been longitudinal, had individual measures of fluoride exposure, addressed the impact of prenatal exposures or involved more than 100 participants. Objective: Our aim was to estimate the association of prenatal exposure to fluoride with offspring neurocognitive development. Methods: We studied participants from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) project. An ion-selective electrode technique was used to measure fluoride in archived urine samples taken from mothers during pregnancy and from their children when 6–12 y old, adjusted for urinary creatinine and specific gravity, respectively. Child intelligence was measured by the General Cognitive Index (GCI) of the McCarthy Scales of Children’s Abilities at age 4 and full scale intelligence quotient (IQ) from the Wechsler Abbreviated Scale of Intelligence (WASI) at age 6–12. Results: We had complete data on 299 mother–child pairs, of whom 287 and 211 had data for the GCI and IQ analyses, respectively. Mean (SD) values for urinary fluoride in all of the mothers (n=299) and children with available urine samples (n=211) were 0.90 (0.35) mg/L and 0.82 (0.38) mg/L, respectively. In multivariate models we found that an increase in maternal urine fluoride of 0.5mg/L (approximately the IQR) predicted 3.15 (95% CI: −5.42, −0.87) and 2.50 (95% CI −4.12, −0.59) lower offspring GCI and IQ scores, respectively. Conclusions: In this study, higher prenatal fluoride exposure, in the general range of exposures reported for other general population samples of pregnant women and nonpregnant adults, was associated with lower scores on tests of cognitive function in the offspring at age 4 and 6–12 y. https://doi.org/10.1289/EHP655 PMID:28937959

  11. Density and surface tension of melts of zirconium and hafnium fluorides with lithium fluoride

    International Nuclear Information System (INIS)

    Katyshev, S.F.; Artemov, V.V.; Desyatnik, V.N.

    1988-01-01

    A study was conducted to determine the temperature dependence of the density and surface tension of melts of LiF-ZrF 4 and LiF-HfF 4 . Density and surface tension were determined by the method of maximum pressure in an argon bubble. On the basis of experimental data over the entire concentration range the molar volumes and their relative deviations from the additive molar volumes were calculated for 1100 0 K. The positive deviations of the molar volumes from additivity in the LiF-HfF 4 system (22.45%) were greater than in the LiF-ZrF 4 system (15.75%). This indicated that the reaction with lithium fluoride is intensified with the switch to the hafnium fluoride. Results also demonstrated that the fluorides are surface-active components in the molten mixtures

  12. Influence of Surfactants and Fluoride against Enamel Erosion.

    Science.gov (United States)

    Zanatta, Rayssa Ferreira; Ávila, Daniele Mara da Silva; Miyamoto, Karen Mayumi; Torres, Carlos Rocha Gomes; Borges, Alessandra Bühler

    2018-06-06

    This study investigated the effect of surfactants associated with sodium fluoride (NaF) on enamel erosion prevention, using an erosion-remineralization in vitro model. Sodium lauryl sulfate (SLS), polysorbate 20 (P20), and cocoamidopropyl betaine (CAPB) were tested, at concentrations of 1.0 and 1.5%, and associated or not with NaF (275 ppm). The control groups were distilled water and the NaF solution. Bovine enamel samples (n = 12) were prepared and submitted to a 5-day cycling model: acid challenge (0.3% citric acid, pH 2.6, 4×/day), human saliva (2 h, 4×/day), and the treatment solutions (2 min, 2×/day). The protective potential of the agents against initial erosion was assessed by microhardness and the surface loss by profilometry. Enamel surface wettability was determined by goniometry, protein adsorption was measured by spectroscopy (FTIR), and the KOH-soluble fluoride was quantified. Goniometry showed that SLS and CAPB increased enamel wettability. No differences were found among the surfactants regarding protein adsorption. Microhardness showed that SLS reduced NaF protection. P20 (1 and 1.5%) and CAPB 1.5% presented a protective effect, but lower than the NaF solution. Profilometry showed that CAPB protected enamel, but no agent associated with NaF promoted a higher protection than the NaF solution alone. KOH-soluble fluoride analysis showed that all surfactants reduced the fluoride adsorption on the enamel surface. Therefore, the surfactants tested (except for P20) changed the enamel surface energy. The SLS decreased the protective potential of NaF on initial erosion, but no tested agent interfered with the protective effect of NaF on enamel erosive wear. © 2018 S. Karger AG, Basel.

  13. Changing use and knowledge of fluoride toothpaste by schoolchildren, parents and schoolteachers in Beijing, China

    DEFF Research Database (Denmark)

    Liu, Min; Zhu, Ling; Zhang, BoXue

    2007-01-01

    OBJECTIVE: To assess the oral hygiene practices, current use of and knowledge about fluoride toothpaste among schoolchildren, parents, and schoolteachers; to describe the attitudes of parents and schoolteachers in relation to improving schoolchildren's oral health. DESIGN: Cross-sectional study....... PARTICIPANTS: 1,557 schoolchildren, 1,132 parents, and 352 schoolteachers were recruited by multistage stratified sampling procedure in a district of Beijing, China. METHODS: Self-completed questionnaire. RESULTS: The percentage of schoolchildren, parents, and schoolteachers who actually used fluoride...... toothpaste was 88%, 86%, and 87%, respectively, and 74-78% of the respondent groups brushed their teeth twice a day or more. 64% of schoolchildren, 73% of parents, and 74% of schoolteachers confirmed the caries preventive effect of fluoride toothpaste. Toothpaste recommended by oral health professional...

  14. Coprecipitation of iron and silver with barium fluoride

    International Nuclear Information System (INIS)

    Kopilova, N.V.; Khamidov, B.O.; Kashina, Z.A.; Ikrami, D.D.

    1986-01-01

    Distribution of trace contaminants of iron and silver at coprecipitation of barium fluoride is studied in present work. It is defined that iron almost completely coprecipitated with barium fluoride in wide range of ph 5.5-12. Silver coprecipitated with barium fluoride in ph range 4-7. The value of coprecipitation varies from 94% to 100%.

  15. The effect of supplementation of calcium, vitamin D, boron, and increased fluoride intake on bone mechanical properties and metabolic hormones in rat.

    Science.gov (United States)

    Ghanizadeh, G; Babaei, M; Naghii, Mohammad Reza; Mofid, M; Torkaman, G; Hedayati, M

    2014-04-01

    Evidence indicates that optimal nutrition plays a role in bone formation and maintenance. Besides major components of mineralization such as calcium, phosphorus, and vitamin D, other nutrients like boron and fluoride have beneficial role, too. In this study, 34 male Wistar rats were divided into five groups: control diet, fluoride, fluoride + boron, fluoride + calcium + vitamin D, and fluoride + boron + calcium + vitamin D. Boron equal to 1.23 mg, calcium and vitamin D equal to 210 mg + 55 IU and fluoride equal to 0.7 mg/rat/day was added to their drinking water for 8 weeks. Plasma blood samples and bones were collected. Findings are evidence that fluoride + boron intake revealed significant positive effects on bone mechanical properties and bone metabolic hormones. These findings suggest that combined intake of these two elements has beneficial effects on bone stiffness and breaking strength comparing to even calcium + vitamin D supplementation. This evidence dealing with health problems related to bone and skeletal system in humans should justify further investigation of the role of boron and fluoride with other elements in relation to bone.

  16. Data on fluoride concentration level in villages of Asara (Alborz, Iran) and daily fluoride intake based on drinking water consumption.

    Science.gov (United States)

    Akhavan, Giti; Dobaradaran, Sina; Borazjani, Jaleh Mohajeri

    2016-12-01

    In the present data article, fluoride concentration levels of drinking water (with spring or groundwater sources) in 10 villages of Asara area located in Alborz province were determined by the standard SPADNS method using a spectrophotometer (DR/2000 Spectrophotometer, USA). Daily fluoride intakes were also calculated based on daily drinking water consumption. The fluoride content were compared with EPA and WHO guidelines for drinking water.

  17. ADSORPTIVE REMOVAL OF FLUORIDE FROM WATER USING ...

    African Journals Online (AJOL)

    Preferred Customer

    Currently available treatment methods for removal of excess fluoride from water are broadly divided into three ... the application of nanoparticles as sorbents for fluoride removal. Sundaram [26] studied the ... Characterization of adsorbent.

  18. Process development for treatment of fluoride containing wastes

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mahesh; Kanvinde, V Y [Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    Many chemical and metallurgical industries generate liquid wastes containing high values of fluorides in association of nitrates and other metals. Due to harmful effects of fluorides these type of wastes can not be disposed off in the environment without proper treatment. Bench-scale laboratory experiments were conducted to develop a process scheme to fix the fluorides as non-leachable solid waste and fluoride free treated liquid waste for their disposal. To optimize the important parameters, simulated synthetic and actual wastes were used. For this study, three waste streams were collected from Nuclear Fuel Complex, Hyderabad. (author). 6 tabs., 1 fig.

  19. Fluor determination by alkaline hydrolysis of the uranium and thorium fluorides; Determinacion de fluor por hidrolisis alcalina en fluoruros de uranio y torio

    Energy Technology Data Exchange (ETDEWEB)

    Barrachina Gomez, L; Gasco Sanchez, L

    1961-07-01

    The alkaline hydrolysis of the uranium and thorium fluorides is studded and a new method for the determination of the fluoride, on the basis of a indirect volumetric titration with standard soda, is proposed. The compounds that may influence the hydrolysis of the uranium fluoride and that may be occasionally found in it as impurities are also studied. the method can be applied to the uranium fluoride except when there is a great quantity of F{sub 2}UO{sub 2} or UO{sub 3} present in the sample. (Author) 20 refs.

  20. Chemically modified activated carbon with 1-acylthiosemicarbazide for selective solid-phase extraction and preconcentration of trace Cu(II), Hg(II) and Pb(II) from water samples.

    Science.gov (United States)

    Gao, Ru; Hu, Zheng; Chang, Xijun; He, Qun; Zhang, Lijun; Tu, Zhifeng; Shi, Jianping

    2009-12-15

    A new sorbent 1-acylthiosemicarbazide-modified activated carbon (AC-ATSC) was prepared as a solid-phase extractant and applied for removing of trace Cu(II), Hg(II) and Pb(II) prior to their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The separation/preconcentration conditions of analytes were investigated, including effects of pH, the shaking time, the sample flow rate and volume, the elution condition and the interfering ions. At pH 3, the maximum static adsorption capacity of Cu(II), Hg(II) and Pb(II) onto the AC-ATSC were 78.20, 67.80 and 48.56 mg g(-1), respectively. The adsorbed metal ions were quantitatively eluted by 3.0 mL of 2% CS(NH2)2 and 2.0 mol L(-1) HCl solution. Common coexisting ions did not interfere with the separation. According to the definition of IUPAC, the detection limits (3sigma) of this method for Cu(II), Hg(II) and Pb(II) were 0.20, 0.12 and 0.45 ng mL(-1), respectively. The relative standard deviation under optimum conditions is less than 4.0% (n=8). The prepared sorbent was applied for the preconcentration of trace Cu(II), Hg(II) and Pb(II) in certified and water samples with satisfactory results.

  1. Antioxidant status in oral subchronic toxicity of fipronil and fluoride co-exposure in buffalo calves.

    Science.gov (United States)

    Gill, Kamalpreet Kaur; Dumka, Vinod Kumar

    2016-02-01

    The effects of fipronil and fluoride co-exposure were investigated on antioxidant status of buffalo calves. A total of 24 healthy male buffalo calves divided into 4 groups were treated for 98 consecutive days. Group I, receiving no treatment, served as the control. Animals of groups II and III were orally administered with fipronil at the dosage of 0.5 mg/kg/day and sodium fluoride (NaF) at the dosage of 6.67 mg/kg/day, respectively, for 98 days. Group IV was coadministered with fipronil and NaF at the same dosages as groups II and III. Administration of fipronil alone produced significant elevation in lipid peroxidation (LPO) and decrease in the levels of nonenzymatic antioxidant glutathione (GSH). However, it did not produce any significant effect on the activities of enzymatic antioxidants including glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD). NaF exposure led to enhanced oxidative stress as shown by significant increase in the LPO and SOD activities while GPx and CAT activities and GSH levels were significantly decreased. Co-exposure to fipronil and NaF showed additive effects on LPO, GPx activity, and GSH levels. © The Author(s) 2013.

  2. Toxicity of fluoride to microorganisms in biological wastewater treatment systems.

    Science.gov (United States)

    Ochoa-Herrera, Valeria; Banihani, Qais; León, Glendy; Khatri, Chandra; Field, James A; Sierra-Alvarez, Reyes

    2009-07-01

    Fluoride is a common contaminant in a variety of industrial wastewaters. Available information on the potential toxicity of fluoride to microorganisms implicated in biological wastewater treatment is very limited. The objective of this study was to evaluate the inhibitory effect of fluoride towards the main microbial populations responsible for the removal of organic constituents and nutrients in wastewater treatment processes. The results of short-term batch bioassays indicated that the toxicity of sodium fluoride varied widely depending on the microbial population. Anaerobic microorganisms involved in various metabolic steps of anaerobic digestion processes were found to be very sensitive to the presence of fluoride. The concentrations of fluoride causing 50% metabolic inhibition (IC(50)) of propionate- and butyrate-degrading microorganisms as well as mesophilic and thermophilic acetate-utilizing methanogens ranged from 18 to 43 mg/L. Fluoride was also inhibitory to nitrification, albeit at relatively high levels (IC(50)=149 mg/L). Nitrifying bacteria appeared to adapt rapidly to fluoride, and a near complete recovery of their metabolic activity was observed after only 4d of exposure to high fluoride levels (up to 500 mg/L). All other microbial populations evaluated in this study, i.e., glucose fermenters, aerobic glucose-degrading heterotrophs, denitrifying bacteria, and H(2)-utilizing methanogens, tolerated fluoride at very high concentrations (>500 mg/L).

  3. Solid-phase zirconium and fluoride species in alkaline zircaloy cladding waste at Hanford.

    Science.gov (United States)

    Reynolds, Jacob G; Huber, Heinz J; Cooke, Gary A; Pestovich, John A

    2014-08-15

    The United States Department of Energy Hanford Site, near Richland, Washington, USA, processed plutonium between 1944 and 1987. Fifty-six million gallons of waste of various origins remain, including waste from removing zircaloy fuel cladding using the so-called Zirflex process. The speciation of zirconium and fluoride in this waste is important because of the corrosivity and reactivity of fluoride as well as the (potentially) high density of Zr-phases. This study evaluates the solid-phase speciation of zirconium and fluoride using X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). Two waste samples were analyzed: one waste sample that is relatively pure zirconium cladding waste from tank 241-AW-105 and another that is a blend of zirconium cladding wastes and other high-level wastes from tank 241-C-104. Villiaumite (NaF) was found to be the dominant fluoride species in the cladding waste and natrophosphate (Na7F[PO4]2 · 19H2O) was the dominant species in the blended waste. Most zirconium was present as a sub-micron amorphous Na-Zr-O phase in the cladding waste and a Na-Al-Zr-O phase in the blended waste. Some zirconium was present in both tanks as either rounded or elongated crystalline needles of Na-bearing ZrO2 that are up to 200 μm in length. These results provide waste process planners the speciation data needed to develop disposal processes for this waste. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Water fluoridation for the prevention of dental caries.

    Science.gov (United States)

    Iheozor-Ejiofor, Zipporah; Worthington, Helen V; Walsh, Tanya; O'Malley, Lucy; Clarkson, Jan E; Macey, Richard; Alam, Rahul; Tugwell, Peter; Welch, Vivian; Glenny, Anne-Marie

    2015-06-18

    Dental caries is a major public health problem in most industrialised countries, affecting 60% to 90% of school children. Community water fluoridation was initiated in the USA in 1945 and is currently practised in about 25 countries around the world; health authorities consider it to be a key strategy for preventing dental caries. Given the continued interest in this topic from health professionals, policy makers and the public, it is important to update and maintain a systematic review that reflects contemporary evidence. To evaluate the effects of water fluoridation (artificial or natural) on the prevention of dental caries.To evaluate the effects of water fluoridation (artificial or natural) on dental fluorosis. We searched the following electronic databases: The Cochrane Oral Health Group's Trials Register (to 19 February 2015); The Cochrane Central Register of Controlled Trials (CENTRAL; Issue 1, 2015); MEDLINE via OVID (1946 to 19 February 2015); EMBASE via OVID (1980 to 19 February 2015); Proquest (to 19 February 2015); Web of Science Conference Proceedings (1990 to 19 February 2015); ZETOC Conference Proceedings (1993 to 19 February 2015). We searched the US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization's WHO International Clinical Trials Registry Platform for ongoing trials. There were no restrictions on language of publication or publication status in the searches of the electronic databases. For caries data, we included only prospective studies with a concurrent control that compared at least two populations - one receiving fluoridated water and the other non-fluoridated water - with outcome(s) evaluated at at least two points in time. For the assessment of fluorosis, we included any type of study design, with concurrent control, that compared populations exposed to different water fluoride concentrations. We included populations of all ages that received fluoridated water (naturally or artificially

  5. Water Fluoridation Reporting System (Public Water Systems)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Water Fluoridation Reporting System (WFRS) has been developed to provide tools to assist states in managing fluoridation programs. WFRS is designed to track all...

  6. FLUORIDE CONTENT OF COMMERCIALLY AVAILABLE SOY MILK PRODUCTS IN THAILAND.

    Science.gov (United States)

    Rirattanapong, Opas; Rirattanapong, Praphasri

    2016-01-01

    Abstract. In Thailand, the consumption of soy milk products is common but there is limited data about their fluoride content. The purpose of this study was to es- timate the fluoride content of soy milk products available in Thailand. Fluoride content was determined for 76 brands of soy milk using a F-ion-specific electrode. The fluoride concentrations ranged from 0.01 to 3.78 μg/ml. The fluoride content was not related to sugar content, soy bean content or the sterilization process. Among 3 brands of soy milk containing tea powder extract, the fluoride content was high (1.25 to 3.78 μg/ml). Most brands of soy milk tested in our study had fluoride content below the optimal daily intake but brands containing tea powder extract if consumed by children may increase their risk for fluorosis.

  7. Alteration of paraoxonase, arylesterase and lactonase activities in people around fluoride endemic area of Tamil Nadu, India.

    Science.gov (United States)

    Arulkumar, Mani; Vijayan, Raji; Penislusshiyan, Sakayanathan; Sathishkumar, Palanivel; Angayarkanni, Jayaraman; Palvannan, Thayumanavan

    2017-08-01

    Toxicity due to excess fluoride concentration in drinking water is of great concern in people who rely only on the ground water as their water source in many region of the world. We collected samples and examined the toxicity of fluoride in a population residing at Salem, Dharmapuri and Krishnagiri districts of Tamil Nadu, India and measured HDL bound enzyme (PON1), erythrocyte membrane bound enzymes (acetylcholinesterase, AChE) and adenosine 5' triphosphatase (ATPases), plasma enzyme (butyrylcholinesterase, BChE) and rate limiting enzyme in heme biosynthesis (delta aminolevulinic acid dehydratase, δ-ALAD) activities. In fluorosis patients, formation of lipid peroxidation product was more in erythrocytes than in plasma. The observation further revealed that there was 50% reduction in the activity of HDL bound anti atherogenic enzyme-paraoxonase (PON1). The activities of membrane bound and signaling enzymes (acetylcholinesterase - AChE and adenosine 5' triphosphatase - ATPase) of erythrocyte were also diminished. These results suggested that there was defectiveness in the signaling and energy metabolism in fluorosis patients. Altered isoenzyme pattern of lactate dehydrogenase (LDH) in fluorosis samples was observed. Furthermore, the result suggested that both the heart (LDH 1) and liver (LDH 5) were most affected by fluoride toxicity. The study also provided reference values for tests which are used to predict the severity of fluoride toxicity. The toxic effect of fluoride was due to the collective effects on vital protective system rather than single factor. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Fluoride removal from water by nano filtration

    International Nuclear Information System (INIS)

    Bejaoui, Imen; Mnif, Amine; Hamrouni, Bechir

    2009-01-01

    As any oligo element, fluoride is necessary and beneficial for human health to low concentrations, but an excess amount of fluoride ions in drinking water has been known to cause undesirable effects, especially tooth and bones fluoro sis. The maximum acceptable concentration of fluoride in drinking water was fixed by the World Health Organization according to the climate in the range of 1 mg.L -1 to 1,2 mg.L -1 . Many methods have been used to remove fluoride from water such as precipitation, adsorption, electrocoagulation and membrane processes. Technologies using membrane processes are being used in many applications, particularly for brackish water desalination. Nano filtration seems to be the best process for a good selective defluorination of fluorinated waters. The main objective of this work was to investigate the retention of fluoride anions by nano filtration. The first part of this study deals with the characterisation of the NF HL2514TF membrane. The influence of various experimental parameters such as initial fluoride content, feed pressure, permeate flux, ionic strength, type of cation associated to fluoride and pH were studied in the second part. Results show that the retention order for the salts tested was TR(Na 2 SO 4 ) > TR(CaCl 2 ) > TR(NaCl), showing a retention sequence inversely proportional to the salt diffusion coefficients in water. It was also shown that charge effects could not be neglected, and a titration experiments confirmed that the NF membrane carry a surplus of negatively charged groups. Fluoride retention exceeds 60 pour cent, and increases with increasing concentration, where the rejection mechanism is related to the dielectric effects. Speigler-Kedem model was applied to experimental results in the aim to determine phenomenological parametersσand P s respectively, the reflexion coefficient of the membrane and the solute permeability of ions. The convective and diffusive parts of the mass transfer were quantified with

  9. Separation and preconcentration of lead(II), cobalt(II), and nickel(II) on EDTA immobilized activated carbon cloth prior to flame atomic absorption spectrometric determination in environmental samples

    OpenAIRE

    ALOTHMAN, ZEID ABDULLAH; YILMAZ, ERKAN; HABİLA, MOHAMED; SOYLAK, MUSTAFA

    2015-01-01

    The synthesis and characterization of ethylenediaminetetraacetic acid immobilized activated carbon cloth was performed in the present work. It was used for preconcentration-separation of lead(II), cobalt(II), and nickel(II) at trace levels as an adsorbent. Factors including pH, concentration and volume of eluent, sample and eluent flow rates, sample volume, and effect of coexisting ions on the solid phase extraction of analytes were examined. The preconcentration factor was 50. The detection ...

  10. Studies on the comparative effect of sodium fluoride on collagen ...

    African Journals Online (AJOL)

    Fluoride is an essential element for the normal development and growth of human beings. The main source of fluoride for humans is the intake of groundwater. At high levels, fluoride causes dental and skeletal fluorosis. In this study, control and sodium fluoride (NaF) treated groups of rats had significant (p < 0.05) higher ...

  11. Study of the thermoluminescence properties and kinetics of local natural calcium fluoride in Saudi Arabia

    International Nuclear Information System (INIS)

    Zarie, K.A.

    2006-01-01

    Thermoluminescence (TL) characteristics of local natural calcium fluoride that show light yellowish appearance obtained from a fluoride mine west of Saudi Arabia have been studied. TL glow peaks were observed at 160, 260 and 334 degree C. Thermal treatment and fading effects had been studied. The TL response was observed to increase with increasing dose, as expected, over the dose range used. The kinetic parameters were calculated to satisfy the feasibility of using the present sample as gamma -ray dosimetry

  12. Comparison of effects of diode laser and CO2 laser on human teeth and their usefulness in topical fluoridation.

    Science.gov (United States)

    González-Rodríguez, Alberto; de Dios López-González, Juan; del Castillo, Juan de Dios Luna; Villalba-Moreno, Juan

    2011-05-01

    Various authors have reported more effective fluoridation from the use of lasers combined with topical fluoride than from conventional topical fluoridation. Besides the beneficial effect of lasers in reducing the acid solubility of an enamel surface, they can also increase the uptake of fluoride. The study objectives were to compare the action of CO(2) and GaAlAs diode lasers on dental enamel and their effects on pulp temperature and enamel fluoride uptake. Different groups of selected enamel surfaces were treated with amine fluoride and irradiated with CO(2) laser at an energy power of 1 or 2 W or with diode laser at 5 or 7 W for 15 s each and compared to enamel surfaces without treatment or topical fluoridated. Samples were examined by means of environmental scanning electron microscopy (ESEM). Surfaces of all enamel samples were then acid-etched, measuring the amount of fluoride deposited on the enamel by using a selective ion electrode. Other enamel surfaces selected under the same conditions were irradiated as described above, measuring the increase in pulp temperature with a thermocouple wire. Fluorination with CO(2) laser at 1 W and diode laser at 7 W produced a significantly greater fluoride uptake on enamel (89 ± 18 mg/l) and (77 ± 17 mg/l) versus topical fluoridation alone (58 ± 7 mg/l) and no treatment (20 ± 1 mg/l). Diode laser at 5 W produced a lesser alteration of the enamel surface compared to CO(2) laser at 1 W, but greater pulp safety was provided by CO(2) laser (ΔT° 1.60° ± 0.5) than by diode laser (ΔT° 3.16° ± 0.6). Diode laser at 7 W and CO(2) laser at 2 W both caused alterations on enamel surfaces, but great pulp safety was again obtained with CO(2) (ΔT° 4.44° ± 0.60) than with diode (ΔT° 5.25° ± 0.55). Our study demonstrates that CO(2) and diode laser irradiation of the enamel surface can both increase fluoride uptake; however, laser energy parameters must be carefully

  13. Spectrophotometric determination of fluoride with alizarin complexone

    Energy Technology Data Exchange (ETDEWEB)

    Marczenko, Z; Lenarczyk, L [Politechnika Warszawska (Poland)

    1976-01-01

    The modification of direct spectrophotometric method of fluoride determination by alizarin complexone has been developed. It was shown that the lanthanum alizarin complexone chelate is more convenient than that of cerium (3). The influence of acetone, dioxane and dimethyl sulphoxide in water solution on the increase of sensitivity of the method and the rate of colour reaction has been determined. The optimal pH ranges for the reaction with lanthanum and cerium (3) have been estimated. Some amines having a large molecule are useful for extraction of blue fluoride complex with isobutanol. Dioctylamine was applied in a new extraction spectrophotometric procedure of fluoride determination. Conditions in reagent have been established. Both variants of the method have been applied to the fluoride determination in several chemicals. The obtained results show a good precision and accuracy.

  14. Removal of fluoride from water using aluminium containing compounds

    Institute of Scientific and Technical Information of China (English)

    M. Karthikeyan; K. P. Elango

    2009-01-01

    Batch adsorption studies were undertaken to assess the suitability of aluminium titanate (AT) and bismuth aluminate (BA) to remove fluoride ions from water.The effect of pH,dose of adsorbent,contact time,initial concentration,co-ions and temperature on fluoride removal efficiency were studied.The amounts of fluoride ions adsorbed,at 30℃ from 4 mg/L of fluoride ion solution,by AT and BA are 0.85 and 1.55 mg/g,respectively.The experimental data fitted well to the Freundlich and Langmuir isotherms.Thermodynamic parameters such as △H~0,△S~0 and △G~0 indicated that the removal of fluoride ions by AT is exothermic and non-spontaneous while that by BA is endothermic and spontaneous.Furrier transform infrared (FT-IR) analysis and X-ray diffraction (XRD) patterns of the adsorbent before and after adsorption indicated that fluoride ions are chemisorbed by these adsorbents.

  15. Synthesis and characterization of ruthenium fluorides and oxide fluorides with high oxidation states

    International Nuclear Information System (INIS)

    Meublat, L.

    1989-10-01

    The synthesis of ruthenium fluorides and oxide fluorides with high oxidation states was attempted from dioxide RuO 2 and tetroxide RuO 4 . Three fluorinating agents were used: fluorine, chlorine trifluoride and krypton difluoride. The reactions were achieved in anhydrous hydrogen fluoride at room temperature. Thus, the reaction of RuO 4 with CIF 3 enabled us to prepare chloryl hexafluororuthenate (V), CIO 2 + RuF 6 - , a new compound well identified by vibrational spectroscopy (infra-red and Raman), the structure of which was determined. The reaction of KrF 2 with RuO 4 gave the oxide tetrafluoride RuOF 4 , the previously published syntheses and properties of which were not in agreement with each other. This compound was definitely characterized here by chemical analysis, infra-red spectroscopy and X-ray powder diffraction. The product of thermal decomposition (70 0 C) of RuOF 4 is presumably RuF 4 since only oxygen is liberated during this decomposition. At last, the reaction of KrF 2 with RuO 2 probably leads to the formation of the new oxide fluoride RuO 2 F 4 . Indeed, no oxygen is given off during this reaction, the chemical analysis of the red-orange coloured solid residue is almost in agreement with the one proposed and its infra-red absorption spectrum indicates the presence of ruthenium-oxygen and ruthenium-terminal and bridging fluorine bonds [fr

  16. Synthesis and characterization of ruthenium fluorides and oxide fluorides with high oxidation states

    International Nuclear Information System (INIS)

    Meublat, L.

    1989-01-01

    The synthesis of ruthenium fluorides and oxide fluorides with high oxidation states was attempted from dioxide RuO 2 and tetroxide RuO 4 . Three fluorinating agents were used: fluorine, chlorine trifluoride and krypton difluoride. The reactions were achieved in anhydrous hydrogen fluoride at room temperature. Thus, the reaction of RuO 4 with CIF 3 enabled us to prepare chloryl hexafluororuthenate (V), ClO 2 + RuF 6 - , a new compound well idendified by vibrational spectroscopy (infra-red and Raman), the structure of which was determined. The reaction of KrF 2 with RuO 4 gave the oxide tetrafluoride RuOF 4 , the previously published syntheses and properties of which were not in agreement with each other. This compound was definitely characterized here by chemical analysis, infra-red spectroscopy and X-ray powder diffraction. The product of thermal decomposition (70 0 C) of RuOF 4 is presumably RuF 4 since only oxygen is liberated during this decomposition. At last, the reaction of KrF 2 with RuO 2 probably leads to the formation of the new oxide fluoride RuO 2 F 4 . Indeed, no oxygen is given off during this reaction, the chemical analysis of the red-orange coloured solid residue is almost in agreement with the one proposed and its infra-red absorption spectrum indicates the presence of ruthenium-oxygen and ruthenium-terminal and bridging fluorine bonds [fr

  17. Purification of Drinking Water from Fluorides by Reverse Osmosis

    Directory of Open Access Journals (Sweden)

    Aleksander A.

    2018-03-01

    Full Text Available Introduction: An important task in the sphere of sanitary and epidemiological welfare of the population of the Russian Federation is provision of drinking water. Tap water must not contain pathogenic bacteria and dangerous chemicals. Purification systems regulate the concentration of fluoride ions in drinking water. The aim of this paper is to study the possibility of purifying tap water from fluoride ions by reverse osmosis. Materials and Methods: We used the Alfa Laval PilotUnit 2.5 "RO/NF with a set of spiral-type membrane elements RO99-2517/48 to remove fluoride ions. We measured the concentration of fluoride ions by the potentiometric method using the Hanna HI 2211 (pH/mV/T. Fluoride-selective electrode ELIS 131 F was used as an indicator electrode and the standard chloride-silver electrode EVL-1M3 was used as a reference electrode. Both the calibration and buffer solutions were prepared from chemically pure reagents and A. R. purity for analysis reagents according to GOST 4386-89. Results: A single passage of water through the reverse osmosis membrane reduced the concentration of fluoride ions from 2.29 ± 0.02 to 0.240 ± 0.015 mg/l. Double passage of water reduced the concentration by a factor of two. As the concentration of fluoride ions increased in the retentate, the concentration in the filtrate slightly increased too. Purification of water reduced the concentration of fluoride ions from 20 mg/l, to 0.5 mg/l. Discussion and Conclusions: Thus, using the Alfa Laval PilotUnit 2.5" RO/NF with a set of spiral-type membrane elements RO99-2517/48 filters tap water of ions of fluoride to the maximum allowable concentration. This study opens the perspective of using reverse osmosis to purify tap water with high concentration of fluoride ions.

  18. Fluoride at non-toxic dose affects odontoblast gene expression in vitro

    International Nuclear Information System (INIS)

    Wurtz, Tilmann; Houari, Sophia; Mauro, Nicole; MacDougall, Mary; Peters, Heiko; Berdal, Ariane

    2008-01-01

    Elevated fluoride intake may lead to local tissue disturbances, known as fluorosis. Towards an understanding of this effect, fluoride-induced molecular responses were analyzed in MO6-G3 cultured odontoblasts cells. NaF at 1 mM changed expression of genes implicated in tissue formation and growth, without affecting cell proliferation or inducing stress factor RNAs. Up to 1 mM NaF, DNA accumulation was not inhibited, whereas at 3 mM, cells detached from their support and did not proliferate. Intracellular structures, characterized by EM, were normal up to 1 mM, but at 3 mM, necrotic features were evident. No sign of apoptotic transformation appeared at any NaF concentration. Fluoride-sensitive genes were identified by microarray analysis; expression levels of selected RNAs were determined by conventional and real-time RT-PCR. At 1 mM fluoride, RNAs encoding the extracellular matrix proteins asporin and fibromodulin, and the cell membrane associated proteins periostin and IMT2A were 10-fold reduced. RNA coding for signaling factor TNF-receptor 9 was diminished to one-third, whereas that for the chemokine Scya-5 was enhanced 2.5-fold. These RNAs are present in vivo in tooth forming cells. This was demonstrated by in situ hybridization and RT-PCR on RNA from dissected tissue samples; for the presence and functioning of fibromodulin in dentin matrix, a more comprehensive study has earlier been performed by others [Goldberg, M., Septier, D., Oldberg, A., Young, M.F., Ameye, L.G., 2006. Fibromodulin deficient mice display impaired collagen fibrillogenesis in predentin as well as altered dentin mineralization and enamel formation. J. Histochem. Cytochem. 54, 525-537]. Expression of most other RNA species, in particular of stress factor coding RNAs, was not altered. It was concluded that fluoride could influence the transcription pattern without inducing cell stress or apoptosis. In odontoblasts in vivo, aberrant expression of these fluoride-sensitive genes may impair the

  19. Clinical Usefulness of 18F-fluoride Bone PET

    International Nuclear Information System (INIS)

    Kang, Ji Yeon; Lee, Won Woo; Lee, Byung Chul; Kim, Sang Eun; So, Young

    2010-01-01

    18 F-fluoride bone positron emission tomography (PET) has been reported as a useful bone imaging modality. However, no clinical bone PET study had been performed previously in Korea. The authors investigated the usefulness of 18 F-fluoride bone PET in Korean patients with malignant or benign bone disease. Eighteen consecutive patients (eight women, ten men; mean age, 55±12 years) who had undergone 18 F-fluoride bone PET for the evaluation of bone metastasis (n=13) or benign bone lesions (n=5) were included. The interpretation of bone lesions on 18 F-fluoride bone PET was determined by consensus of two nuclear medicine physicians, and final results were confirmed using combination of all imaging studies and/or clinical follow-up. The analysis was performed on the basis of lesion group. Thirteen patients with malignant disease had 15 lesion groups, among which seven were confirmed as metastatic bone lesions and eight were confirmed as non-metastatic lesions. 18 F-fluoride bone PET correctly identified six of seven metastatic lesions (sensitivity, 86%), and seven of eight non-metastatic lesions (specificity, 88%). On the other hand, five patients with benign conditions had five bone lesion groups; four were confirmed as benign bone diseases and the other one was confirmed as not a bone lesion. 18 F-fluoride bone PET showed correct results in all the five lesion groups. 18 F-fluoride bone PET showed promising potential for bone imaging in Korean patients with malignant diseases as well as with various benign bone conditions. Therefore, further studies are required on the diagnostic performance and cost-effectiveness of 18 F-fluoride bone PET.

  20. Corrosion behavior of zirconia in acidulated phosphate fluoride

    Directory of Open Access Journals (Sweden)

    Anie Thomas

    2016-02-01

    Full Text Available ABSTRACT Objective The corrosion behavior of zirconia in acidulated phosphate fluoride (APF representing acidic environments and fluoride treatments was studied. Material and Methods Zirconia rods were immersed in 1.23% and 0.123% APF solutions and maintained at 37°C for determined periods of time. Surfaces of all specimens were imaged using digital microscopy and scanning electron microscopy (SEM. Sample mass and dimensions were measured for mass loss determination. Samples were characterized by powder X-ray diffraction (XRD to detect changes in crystallinity. A biosensor based on electrochemical impedance spectroscopy (EIS was used to detect ion dissolution of material into the immersion media. Results Digital microscopy revealed diminishing luster of the materials and SEM showed increased superficial corrosion of zirconia submerged in 1.23% APF. Although no structural change was found, the absorption of salts (sodium phosphate onto the surface of the materials bathed in 0.123% APF was significant. EIS indicated a greater change of impedance for the immersion solutions with increasing bathing time. Conclusion Immersion of zirconia in APF solutions showed deterioration limited to the surface, not extending to the bulk of the material. Inferences on zirconia performance in acidic oral environment can be elucidated from the study.

  1. Hydrogeochemical framework and factor analysis of fluoride contamination in Groundwater within the Savelugu-Nanton District, Northern Ghana

    International Nuclear Information System (INIS)

    Tay, Collins K.

    2017-01-01

    Fluoride contamination of groundwater within the Savelugu-Nanton District was assessed using hydrogeochemical framework and multivariate statistical approach. Eighty-one (No) boreholes were sampled for quality assessment in May and June 2008. The main objective of this study was to assess the fluoride levels in groundwater and delineate areas of low fluoride and high fluoride within the district. The study show that, 41.9% of the boreholes are within the safe limits of 0.5 –1.5 mg/L of fluoride for the protection of bones and teeth, 43.2% of the boreholes have fluoride levels below the lower safe limit (< 0.5 mg/L) and therefore vulnerable to dental caries, 10.8% of the boreholes have fluoride levels between 1.5 and 3.0 mg/Land therefore vulnerable to dental fluorosis and 4.1% of the boreholes have fluoride levels between 3.0 and 10 mg/L and therefore vulnerable to skeletal fluorosis. The results further show that, 14.9% of groundwater requires defluoridation, while, 43.2% of groundwater requires fluoride addition to the groundwaters. PCA using Varimax with Kaiser Normalization results in the extraction of three main principal components which delineates the factors that influence the principal components of the physico-chemical parameters. The three principal components have accounted for approximately 83% of the total variance. Component 1 delineates the main natural processes through which groundwater within the basin acquire its chemical characteristics. Component 2 delineates pollution sources principally fluoride and nitrate. Component 3 suggests mineralogical influence of fluoride with some major ions on the chemistry of groundwater. The loadings and score plots of the first two PCs which explains 71.52% of the total variance show grouping pattern which indicates the strength of the mutual relation amongst the hydrochemical variables. Biological defluoridation though not very well understood, is recommended as a best alternative to the conventional methods

  2. Titanium surface topography after brushing with fluoride and fluoride-free toothpaste simulating 10 years of use.

    Science.gov (United States)

    Fais, Laiza M G; Fernandes-Filho, Romeu B; Pereira-da-Silva, Marcelo A; Vaz, Luis G; Adabo, Gelson L

    2012-04-01

    To conduct a controlled study contrasting titanium surface topography after procedures that simulated 10 years of brushing using toothpastes with or without fluoride. Commercially pure titanium (cp Ti) and Ti-6Al-4V disks (6 mm Ø×4 mm) were mirror-polished and treated according to 6 groups (n=6) as a function of immersion (I) or brushing (B) using deionised water (W), fluoride-free toothpaste (T) and fluoride toothpaste (FT). Surface topography was evaluated at baseline (pretreatment) and post-treatment, using atomic force microscope in order to obtain three-dimensional images and mean roughness. Specimens submitted to immersion were submerged in the vehicles without brushing. For brushed specimens, procedures were conducted using a linear brushing machine with a soft-bristled toothbrush. Immersion and brushing were performed for 244 h. IFT and BFT samples were analysed under scanning electron microscope with Energy-Dispersive X-ray Spectroscopy (EDS). Pre and post-treatment values were compared using the paired Student T-test (α=.05). Intergroup comparisons were conducted using one-way ANOVA with Tukey post-test (α=.05). cp Ti mean roughness (in nanometers) comparing pre and post-treatment were: IW, 2.29±0.55/2.33±0.17; IT, 2.24±0.46/2.02±0.38; IFT, 2.22±0.53/1.95±0.36; BW, 2.22±0.42/3.76±0.45; BT, 2.27±0.55/16.05±3.25; BFT, 2.27±0.51/22.39±5.07. Mean roughness (in nanometers) measured in Ti-6Al-4V disks (pre/post-treatment) were: IW, 1.79±0.25/2.01±0.25; IT, 1.61±0.13/1.74±0.19; IFT, 1.92±0.39/2.29±0.51; BW, 2.00±0.71/2.05±0.43; BT, 2.37±0.86/11.17±2.29; BFT, 1.83±0.50/15.73±1.78. No significant differences were seen after immersions (p>.05). Brushing increased the roughness of cp Ti and of Ti-6Al-4V (p<.01); cp Ti had topographic changes after BW, BT and BFT treatments whilst Ti-6Al-4V was significantly different only after BT and BTF. EDS has not detected fluoride or sodium ions on metal surfaces. Exposure to toothpastes (immersion

  3. Protection From Dental Erosion: All Fluorides are Not Equal.

    Science.gov (United States)

    Faller, Robert V; Noble, Warden H

    2018-03-01

    All fluoride sources help strengthen teeth against bacterial acids that cause caries. However, excessive exposure to dietary acids, which can result in dental erosion, presents a more aggressive level of challenge compared to caries. Despite the fact that almost all toothpastes contain fluoride, both the incidence and prevalence of dental erosion appear to be on the rise. This article: (1) describes key differences between caries and dental erosion and the ability of different fluoride sources to help prevent erosion; (2) discusses the importance of the evaluation of patients for dental erosion at the earliest stages using the Basic Erosive Wear Examination scoring system to help assess and educate patients; and (3) provides evidence-based information for making specific recommendations to patients with dental erosion. The objective of this article is to assess the comparative ability of fluoride agents to protect against dental erosion. Though all fluorides are able to help strengthen teeth against cariogenic acids, not all available sources of fluoride provide the same level of erosion protection. Daily use of a stabilized stannous fluoride dentifrice has been shown to provide the most effective means of protecting teeth against the increasing risk of dental erosion and erosive tooth wear.

  4. Mesoporous zeolite and zeotype single crystals synthesized in fluoride media

    DEFF Research Database (Denmark)

    Egeblad, Kresten; Kustova, Marina; Klitgaard, Søren Kegnæs

    2007-01-01

    We report the synthesis and characterization of a series of new mesoporous zeolite and zeotype materials made available by combining new and improved procedures for directly introducing carbon into reaction mixtures with the fluoride route for conventional zeolite synthesis. The mesoporous...... materials were all prepared by hydrothermal crystallization of gels adsorbed on carbon matrices which were subsequently removed by combustion. The procedures presented here resulted in mesoporous zeolite and zeotypes materials with MFI, MEL, BEA, AFI and CHA framework structures. All samples were...... characterized by XRPD, SEM, TEM and N-2 physisorption measurements. For the zeolite materials it A as found that mesoporous MFI and MEL structured single crystals could indeed be crystallized from fluoride media using an improved carbon-templating approach. More importantly, it was found that mesoporous BEA...

  5. Chemical mechanism of the fluoride-inhibition of fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Warburg, O; Christian, W

    1941-08-01

    Among the fluoride-sensitive fermentation elements, enolase is the most sensitive. An investigation was made, quantitatively, of fluoride inhibition for chemically pure magnesium-enolase using an optical enolase test. Data show that the effective compound for fluoride inhibition is a complex magnesium-fluoro-phosphate and that the magnesium-fluoro-phosphate inhibits fermentation by combining proportionally to its concentration with the ferment-protein in a dissociating manner.

  6. Magnesium fluoride recovery method

    International Nuclear Information System (INIS)

    Gay, R.L.; McKenzie, D.E.

    1989-01-01

    A method of obtaining magnesium fluoride substantially free from radioactive uranium from a slag formed in the production of metallic uranium by the reduction of depleted uranium tetrafluoride with metallic magnesium in a retort wherein the slag contains the free metals magnesium and uranium and also oxides and fluorides of the metals. The slag having a radioactivity level of at least about 7,000 rhoCi/gm. The method comprises the steps of: grinding the slag to a median particle size of about 200 microns; contacting the ground slag in a reaction zone with an acid having a strength of from about 0.5 to 1.5 N for a time of from about 4 to about 20 hours in the presence of a catalytic amount of iron; removing the liquid product; treating the particulate solid product; repeating the last two steps at least one more time to produce a solid residue consisting essentially of magnesium fluoride substantially free of uranium and having a residual radioactivity level of less than about 1000 rhoCi/gm

  7. Performance of novel hydroxyapatite nanowires in treatment of fluoride contaminated water

    Energy Technology Data Exchange (ETDEWEB)

    He, Junyong; Zhang, Kaisheng [Nano-Materials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (China); Wu, Shibiao [Nano-Materials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Cai, Xingguo; Chen, Kai; Li, Yulian [Nano-Materials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (China); Sun, Bai; Jia, Yong; Meng, Fanli; Jin, Zhen [Nano-Materials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Kong, Lingtao, E-mail: ltkong@iim.ac.cn [Nano-Materials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Liu, Jinhuai [Nano-Materials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China)

    2016-02-13

    Highlights: • Novel ultralong hydroxyapatite (HAP) nanowires were developed for effective defluoridation. • High fluoride adsorption capacity, 40.65 mg/g at neutral pH. • The HAP nanowire membrane efficiently removed fluoride by dynamic adsorption. • The membrane could remove more than 98% fluoride, and filtered water amount reached 350 L/m{sup 2}. - Abstract: Novel ultralong hydroxyapatite (HAP) nanowires were successfully prepared for fluoride removal for the first time. The fluoride adsorption on the HAP nanowires was studied on a batch mode. The results revealed that the adsorption data could be well described by the Freundlich model, and the adsorption kinetic followed the pseudo-second-order model. The maximum of adsorption capacity was 40.65 mg/g at pH 7.0 when the fluoride concentration is 200 mg/L. The thermodynamic parameters suggested that the adsorption of fluoride was a spontaneous endothermic process. The FT-IR, XPS and Zeta potential analysis revealed that both anion exchange and electrostatic interactions were involved in the adsorption of fluoride. Furthermore, the HAP nanowires were made into HAP membrane through a simple process of suction filtration. Membrane filtration experiments revealed that the fluoride removal capabilities depended on the membrane thickness, flow rate and initial concentration of fluoride. The as-prepared membrane could remove fluoride efficiently through continues filtration. The filtered water amount could reach 350, 192, and 64 L/m{sup 2} when the fluoride concentrations were 4, 5 and 8 ppm, respectively, using the HAP membrane with only 150 μm thickness. The as-synthesized ultralong HAP nanowires were thus demonstrated to be very effective and biocompatible adsorbents for fluoride removal from contaminated water.

  8. Preparation and study of chlorine mono-fluoride and of chlorine oxi-fluorides; Preparation et etude du monofluorure et des oxyfluorures de chlore

    Energy Technology Data Exchange (ETDEWEB)

    Macheteau, Yves

    1969-07-01

    The objective of this engineering school report was to be a contribution to the study of a family of fluorine compounds: chlorine mono-fluoride (ClF), chlorine fluoride oxide (ClOF), chloryl fluoride (ClO{sub 2}F), perchloryl fluoride (ClO{sub 3}F) and perchloryl oxi-fluoride (ClO{sub 4}F). Such a study required very pure products to be obtained in order to be able to characterize them by different methods (infrared, micro-sublimation, and chromatography). The thermolysis of ClO{sub 2}F and ClO{sub 4}F has been particularly studied, and magnetic resonance has been used to establish a relationship between fluorine chemical displacement and the electro-negativity of the F-X bond where X represents the atom group to which fluorine is bonded.

  9. Sulfochlorphenol S as reagent for direct photometric determination of fluorides

    International Nuclear Information System (INIS)

    Dzhashi, D.O.; Dedkova, V.P.; Savvin, S.B.

    1978-01-01

    The system of zirconium-sulfochlorphenol S-fluoride was studied by the spectrophotometry method. The effect of pH, temperature and time on the formation of zirconium complexes with sulfochlorphenol S was investigated. A comparison of the above method of determining fluorides with other methods (using alizarinecomplexonate, quinalizarincomplexonate, cerium chelates, lanthanum, arsenazo 3) is presented. The sensitivity of determining fluorides with arsenazo 3 is lower than that with sulfochlorphenol S. The molar absorption coefficient is 3x10 4 , the reaction of determining fluorides with the aid of sulfochlorphenol S is highly selective. The method was used to determine fluorides in the supply water, zirconium solutions and electrolyzer cell. The range of concentration determination for fluorides is 0-3 μg/25 ml

  10. Fluoride loaded polymeric nanoparticles for dental delivery.

    Science.gov (United States)

    Nguyen, Sanko; Escudero, Carlos; Sediqi, Nadia; Smistad, Gro; Hiorth, Marianne

    2017-06-15

    The overall aim of the present paper was to develop fluoride loaded nanoparticles based on the biopolymers chitosan, pectin, and alginate, for use in dental delivery. First, the preparation of nanoparticles in the presence of sodium fluoride (NaF) as the active ingredient by ionic gelation was investigated followed by an evaluation of their drug entrapment and release properties. Chitosan formed stable, spherical, and monodisperse nanoparticles in the presence of NaF and tripolyphoshate as the crosslinker, whereas alginate and pectin were not able to form any definite nanostructures in similar conditions. The fluoride loading capacity was found to be 33-113ppm, and the entrapment efficiency 3.6-6.2% for chitosan nanoparticles prepared in 0.2-0.4% (w/w) NaF, respectively. A steady increase in the fluoride release was observed for chitosan nanoparticles prepared in 0.2% NaF both in pH5 and 7 until it reached a maximum at time point 4h and maintained at this level for at least 24h. Similar profiles were observed for formulations prepared in 0.4% NaF; however the fluoride was released at a higher level at pH5. The low concentration, but continuous delivery of fluoride from the chitosan nanoparticles, with possible expedited release in acidic environment, makes these formulations highly promising as dental delivery systems in the protection against caries development. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Fluoride Concentration of Drinking-Water of Qom, Iran

    Directory of Open Access Journals (Sweden)

    Ahmad Reza Yari

    2016-03-01

    Full Text Available Background and Purpose: Fluoride is a natural element essential for human nutrition due to its benefits for dental enamel. It is well-documented that standard amounts of fluoride in drinkingwater can decrease the rate of dental caries. This study was conducted with the aim of measuring fluoride concentration of drinking-water supplies and urban distribution system in Qom, Iran. Materials and Methods: Results were subsequently compared against national and international standards. All sources of drinking-water of rural and urban areas were examined. To measure fluoride, the standard SPADNS method and a DR/4000s spectrophotometer were used. Results: Results showed that the mean of fluoride concentration in rural areas, mainly supplied with groundwater sources, was 0.41 mg/L, that of the urban distribution system 0.82 mg/L, that of Ali-Abad station 0.11 mg/L, and that of the private water desalination system 0.24 mg/L. Due to the hot climate of Qom, fluoride concentration means of all sources were lower than the permissible standards set by Iranian Standards and the WHO guidelines (except those of some of the groundwater sources and urban distribution systems. Conclusion: It seems that in most of the drinking-water sources the average fluoride concentration is not enough to prevent dental caries or strengthen dental enamel. It is concluded that Qom’s drinkingwater would require at least 0.4 mg/L to reach the minimum desirable standard.

  12. Removal of fluoride from aqueous nitric acid

    International Nuclear Information System (INIS)

    Pruett, D.J.; Howerton, W.B.; Mailen, J.C.

    1981-06-01

    Several methods for removing fluoride from aqueous nitric acid were investigated and compared with the frequently used aluminum nitrate-calcium nitrate (Ca 2+ -Al 3+ ) chemical trap-distillation system. Zirconium oxynitrate solutions were found to be superior in preventing volatilization of fluoride during distillation of the nitric acid, producing decontamination factors (DFs) on the order of 2 x 10 3 (vs approx. 500 for the Ca 2+ -Al 3+ system). Several other metal nitrate systems were tested, but they were less effective. Alumina and zirconia columns proved highly effective in removing HF from HF-HNO 3 vapors distilled through the columns; fluoride DFs on the order of 10 6 and 10 4 , respectively, were obtained. A silica gel column was very effective in adsorbing HF from HF-HNO 3 solutions, producing a fluoride DF of approx. 10 4

  13. Fabrication of dense panels in lithium fluoride; Fabrication de panneaux denses en fluorure de lithium

    Energy Technology Data Exchange (ETDEWEB)

    Farcy, P.; Roger, J.; Pointud, R.

    1958-04-15

    The authors report a study aimed at the fabrication of large and dense lithium fluoride panels. This sintered lithium fluoride is then supposed to be used for the construction of barriers of protection against a flow of thermal neutrons. They briefly present the raw material which is used under the form of chamotte obtained through a pre-sintering process which is also described. Grain size measurements and sample preparation are indicated. Shaping, drying, and thermal treatment are briefly described, and characteristics of the sintered product are indicated.

  14. In vitro corrosion behavior of Ti-O film deposited on fluoride-treated Mg-Zn-Y-Nd alloy

    Energy Technology Data Exchange (ETDEWEB)

    Hou, S.S.; Zhang, R.R. [Materials Research Center, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002 (China); Guan, S.K., E-mail: skguan@zzu.edu.cn [Materials Research Center, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002 (China); Ren, C.X.; Gao, J.H.; Lu, Q.B.; Cui, X.Z. [Materials Research Center, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002 (China)

    2012-02-01

    In this paper, a new composite coating was fabricated on magnesium alloy by a two-step approach, to improve the corrosion resistance and biocompatibility of Mg-Zn-Y-Nd alloy. First, fluoride conversion layer was synthesized on magnesium alloy surface by immersion treatment in hydrofluoric acid and then, Ti-O film was deposited on the preceding fluoride layer by magnetron sputtering. FE-SEM images revealed a smooth and uniform surface consisting of aggregated nano-particles with average size of 100 nm, and a total coating thickness of {approx}1.5 {mu}m, including an outer Ti-O film of {approx}250 nm. The surface EDS and XRD data indicated that the composite coating was mainly composed of crystalline magnesium fluoride (MgF{sub 2}), and non-crystalline Ti-O. Potentiodynamic polarization tests revealed that the composite coated sample have a corrosion potential (E{sub corr}) of -1.60 V and a corrosion current density (I{sub corr}) of 0.17 {mu}A/cm{sup 2}, which improved by 100 mV and reduced by two orders of magnitude, compared with the sample only coated by Ti-O. EIS results showed a polarization resistance of 3.98 k{Omega} cm{sup 2} for the Ti-O coated sample and 0.42 k{Omega} cm{sup 2} for the composite coated sample, giving an improvement of about 100 times. After 72 h immersion in SBF, widespread damage and deep corrosion holes were observed on the Ti-O coated sample surface, while the integrity of composite coating remained well after 7 d. In brief, the data suggested that single Ti-O film on degradable magnesium alloys was apt to become failure prematurely in corrosion environment. Ti-O film deposited on fluoride-treated magnesium alloys might potentially meet the requirements for future clinical magnesium alloy stent application.

  15. In vitro corrosion behavior of Ti-O film deposited on fluoride-treated Mg-Zn-Y-Nd alloy

    International Nuclear Information System (INIS)

    Hou, S.S.; Zhang, R.R.; Guan, S.K.; Ren, C.X.; Gao, J.H.; Lu, Q.B.; Cui, X.Z.

    2012-01-01

    In this paper, a new composite coating was fabricated on magnesium alloy by a two-step approach, to improve the corrosion resistance and biocompatibility of Mg-Zn-Y-Nd alloy. First, fluoride conversion layer was synthesized on magnesium alloy surface by immersion treatment in hydrofluoric acid and then, Ti-O film was deposited on the preceding fluoride layer by magnetron sputtering. FE-SEM images revealed a smooth and uniform surface consisting of aggregated nano-particles with average size of 100 nm, and a total coating thickness of ∼1.5 μm, including an outer Ti-O film of ∼250 nm. The surface EDS and XRD data indicated that the composite coating was mainly composed of crystalline magnesium fluoride (MgF 2 ), and non-crystalline Ti-O. Potentiodynamic polarization tests revealed that the composite coated sample have a corrosion potential (E corr ) of -1.60 V and a corrosion current density (I corr ) of 0.17 μA/cm 2 , which improved by 100 mV and reduced by two orders of magnitude, compared with the sample only coated by Ti-O. EIS results showed a polarization resistance of 3.98 kΩ cm 2 for the Ti-O coated sample and 0.42 kΩ cm 2 for the composite coated sample, giving an improvement of about 100 times. After 72 h immersion in SBF, widespread damage and deep corrosion holes were observed on the Ti-O coated sample surface, while the integrity of composite coating remained well after 7 d. In brief, the data suggested that single Ti-O film on degradable magnesium alloys was apt to become failure prematurely in corrosion environment. Ti-O film deposited on fluoride-treated magnesium alloys might potentially meet the requirements for future clinical magnesium alloy stent application.

  16. Streptozotocin Aggravated Osteopathology and Insulin Induced Osteogenesis Through Co-treatment with Fluoride.

    Science.gov (United States)

    Yang, Chen; Zhang, Mengmeng; Li, Yagang; Wang, Yan; Mao, Weixian; Gao, Yuan; Xu, Hui

    2015-12-01

    The role of insulin in the mechanism underlying the excessive fluoride that causes skeletal lesion was studied. The in vitro bone marrow stem cells (BMSC) collected from Kunming mice were exposed to varying concentrations of fluoride with or without insulin. The cell viability and early differentiation of BMSC co-treated with fluoride and insulin were measured by using cell counting kit-8 and Gomori modified calcium-cobalt method, respectively. We further investigated the in vivo effects of varying dose of fluoride on rats co-treated with streptozotocin (STZ). Wistar rats were divided into six groups which included normal control, 10 mg fluoride/kg day group, 20 mg fluoride/kg day group, STZ control, STZ+10 mg fluoride/kg day group, and STZ+20 mg fluoride/kg day group. The rats were administered with sodium fluoride (NaF) by gavage with water at doses 10 and 20 mg fluoride/kg day for 2 months. In a period of one month, half of rats in every group were treated with streptozotocin (STZ) once through intraperitoneal injection at 52 mg/kg body weight. The serum glucose, HbA1c, and insulin were determined. Bone mineral content and insulin release were assessed. The results showed insulin combined with fluoride stimulated BMSC cell viability in vitro. The bone mineral content reduced in rats treated with higher dose of fluoride and decreased immensely in rat co-treated with fluoride and STZ. Similarly, a combination treatment of a high dose of fluoride and STZ decreased insulin sensitivity and activity. To sum up, these data indicated fluoride influenced insulin release, activity, and sensitivity. Furthermore, the insulin state in vivo interfered in the osteogenesis in turn and implied there was a close relation between insulin and bone pathogenesis in the mechanism of fluoride toxicity.

  17. Analysis of Ground Water Fluoride Content and its Association with Prevalence of Fluorosis in Zarand/Kerman: (Using GIS).

    Science.gov (United States)

    T, Malek Mohammadi; R, Derakhshani; M, Tavallaie; M, Raoof; N, Hasheminejad; Aa, Haghdoost

    2017-06-01

    The concentration of fluoride in water is usually higher in areas around the coal mines. Zarand region in the south-east of Iran is known for its coal mines. Some studies have shown the high prevalence of fluorosis and some studies reported high levels of fluoride in the region. This study aimed to use Geographic Information System (GIS) to assess the relationship between water fluoride content and the prevalence of fluorosis and its spatial distribution in Zarand region. This cross-sectional study aimed to recruit 550 people aged 7-40 years in Zarand. Dental examination for fluorosis was conducted based on the Dean's Index. The level of fluoride in the water was determined in samples of water taken from 35 areas. Information on fluorosis and fluoride content was mapped on GIS. Most participants lived in rural areas (87.25%) and had an educational status of high school level (66%). About 23% of the examined people had normal teeth, 10% had severe and 67% had mild to moderate fluorosis. Distribution of severe fluorosis was higher in areas with higher levels of fluoride in the water according to GIS map. GIS map clearly showed a positive relationship between the prevalence and severity of fluorosis with the level of fluoride in water in Zarand. The GIS analysis may be useful in the analysis of other oral conditions.

  18. PERBEDAAN TOPICAL FLUORIDE APPLICATION DAN FISSURE SEALANT DALAM MENCEGAH KARIES PADAGIGI MOLAR SATU

    Directory of Open Access Journals (Sweden)

    Pawarti Pawarti

    2017-07-01

    Full Text Available Abstract: Topical Fluoride Application And Fissure Sealant To Prevent Dental Caries Permanent First Molars. Anatomy pits and fissures of teeth are caries initiation vulnerable areas of the permanent molars that grow at the age of 6 years where children can not perform oral hygiene. Caries prevention can be done by closing the pits and fissures or application of fluoride (topical fluoride application on the surface of the teeth. The purpose of this study was to analyze the difference fissure sealants and topical application of fluoride to prevent dental caries of first permanent molars. This study was a quasi-experimental study with time series, a sample was taken by purposive 117-second grade students of SDN District of North Pontianak. Data were analyzed using t-test. The result showed that fissure sealant more effective in caries prevention of first permanent molar than topical fluoride application where there were none caries teeth after and month fissure sealant, 25% sealant partially off and 11% fully off. Teeth that have done fluoride after 6 months of 3.9% of dental caries, the eighth month of 5.4% of dental caries. There was a significant difference between the effectiveness of fissure sealants with topical application of fluoride to prevent dental caries in first permanent molars p-value < 0.05, after 6-month p-value: 0.004 and after 8-month p-value: 0.001. Abstrak: Topical Fluoride Application Dan Fissure Sealant Untuk Mencegah Karies Pada Gigi Molar Satu Permanen. Anatomi pit dan fisura gigi merupakan daerah rentan inisiasi karies gigi molar satu permanen yang tumbuh pada usia 6 tahun anak belum bisa melakukan kebersihan mulutnya. Pencegahan karies dapat dilakukan dengan cara menutup pit dan fissure atau pengolesan fluor (topical fluoride application pada permukaan gigi. Tujuan penelitian ini untuk menganalisis perbedaan efektivitas fissure sealant dan topical fluoride application untuk mencegah karies gigi molar satu permanen anak

  19. Validating a High Performance Liquid Chromatography-Ion Chromatography (HPLC-IC) Method with Conductivity Detection After Chemical Suppression for Water Fluoride Estimation.

    Science.gov (United States)

    Bondu, Joseph Dian; Selvakumar, R; Fleming, Jude Joseph

    2018-01-01

    A variety of methods, including the Ion Selective Electrode (ISE), have been used for estimation of fluoride levels in drinking water. But as these methods suffer many drawbacks, the newer method of IC has replaced many of these methods. The study aimed at (1) validating IC for estimation of fluoride levels in drinking water and (2) to assess drinking water fluoride levels of villages in and around Vellore district using IC. Forty nine paired drinking water samples were measured using ISE and IC method (Metrohm). Water samples from 165 randomly selected villages in and around Vellore district were collected for fluoride estimation over 1 year. Standardization of IC method showed good within run precision, linearity and coefficient of variance with correlation coefficient R 2  = 0.998. The limit of detection was 0.027 ppm and limit of quantification was 0.083 ppm. Among 165 villages, 46.1% of the villages recorded water fluoride levels >1.00 ppm from which 19.4% had levels ranging from 1 to 1.5 ppm, 10.9% had recorded levels 1.5-2 ppm and about 12.7% had levels of 2.0-3.0 ppm. Three percent of villages had more than 3.0 ppm fluoride in the water tested. Most (44.42%) of these villages belonged to Jolarpet taluk with moderate to high (0.86-3.56 ppm) water fluoride levels. Ion Chromatography method has been validated and is therefore a reliable method in assessment of fluoride levels in the drinking water. While the residents of Jolarpet taluk (Vellore distict) are found to be at a high risk of developing dental and skeletal fluorosis.

  20. Low-Cost, Robust, and Field Portable Smartphone Platform Photometric Sensor for Fluoride Level Detection in Drinking Water.

    Science.gov (United States)

    Hussain, Iftak; Ahamad, Kamal Uddin; Nath, Pabitra

    2017-01-03

    Groundwater is the major source of drinking water for people living in rural areas of India. Pollutants such as fluoride in groundwater may be present in much higher concentration than the permissible limit. Fluoride does not give any visible coloration to water, and hence, no effort is made to remove or reduce the concentration of this chemical present in drinking water. This may lead to a serious health hazard for those people taking groundwater as their primary source of drinking water. Sophisticated laboratory grade tools such as ion selective electrodes (ISE) and portable spectrophotometers are commercially available for in-field detection of fluoride level in drinking water. However, such tools are generally expensive and require expertise to handle. In this paper, we demonstrate the working of a low cost, robust, and field portable smartphone platform fluoride sensor that can detect and analyze fluoride concentration level in drinking water. For development of the proposed sensor, we utilize the ambient light sensor (ALS) of the smartphone as light intensity detector and its LED flash light as an optical source. An android application "FSense" has been developed which can detect and analyze the fluoride concentration level in water samples. The custom developed application can be used for sharing of in-field sensing data from any remote location to the central water quality monitoring station. We envision that the proposed sensing technique could be useful for initiating a fluoride removal program undertaken by governmental and nongovernmental organizations here in India.

  1. A health risk assessment for fluoride in Central Europe.

    Science.gov (United States)

    Fordyce, F M; Vrana, K; Zhovinsky, E; Povoroznuk, V; Toth, G; Hope, B C; Iljinsky, U; Baker, J

    2007-04-01

    Like many elements, fluorine (which generally occurs in nature as fluoride) is beneficial to human health in trace amounts, but can be toxic in excess. The links between low intakes of fluoride and dental protection are well known; however, fluoride is a powerful calcium-seeking element and can interfere with the calcified structure of bones and teeth in the human body at higher concentrations causing dental or skeletal fluorosis. One of the main exposure routes is via drinking water and the World Health Organisation currently sets water quality guidelines for the element. In Central Europe, groundwater resources that exceed the guideline value of 1.5 mg l-1 are widespread and effects on health of high fluoride in water have been reported. The aim of the current project was to develop a geographic information system (GIS) to aid the identification of areas where high-fluoride waters and fluorosis may be a problem; hence, where water treatment technologies should be targeted. The development of the GIS was based upon the collation and digitisation of existing information relevant to fluoride risk in Ukraine, Moldova, Hungary and Slovakia assembled for the first time in a readily accessible form. In addition, geochemistry and health studies to examine in more detail the relationships between high-fluoride drinking waters and health effects in the population were carried out in Moldova and Ukraine demonstrating dental fluorosis prevalence rates of 60-90% in adolescents consuming water containing 2-7 mg l-1 fluoride.

  2. Occurrence of fluoride in ground waters of Saudi Arabia

    Science.gov (United States)

    Alabdulaaly, Abdulrahman I.; Al-Zarah, Abdullah I.; Khan, Mujahid A.

    2013-09-01

    The presence of elevated levels of fluoride in groundwater is considered a global problem. Fluoride in water derives mainly from dissolution of natural minerals in the rocks and soils with which water interacts. The most common fluorine-bearing minerals are fluorite, apatite and micas. Anthropogenic sources of fluoride include agricultural fertilizers and combustion of coal. In the present research, a survey of wells ( n = 1,060) was undertaken in all the 13 regions of the Kingdom of Saudi Arabia to assess the contained fluoride (F) levels. The results indicated variation in fluoride levels from 0.10 to 5.4 mg/L as F throughout the kingdom. The average fluoride levels in milligrams per liter as F were as follows in descending order: 1.80 (Hadwood Shamalyah), 1.37 (Hail), 1.33 (Eastern Province), 1.16 (Al Jouf), 1.11 (Qassim), 1.01 (Riyadh), 0.90 (Madina Al Munnawara), 0.81 (Tabouk), 0.74 (Makkah Al- Mukaramma), 0.73 (Jizan), 0.66 (Asir), 0.64 (Najran), and 0.60 (Al Baha). The results indicated that fluoride levels exceeded the USEPA maximum contaminant limits for drinking water (4 mg/L) in several wells ( n = 7) in different regions of the kingdom and that 13.96 % of the wells exceeded the World Health Organization recommended levels (1.5 mg/L). The results were also compared with the secondary USEPA contaminant standards of 2.0 mg/L for fluorides.

  3. Association between urine fluoride and dental fluorosis as a toxicity factor in a rural community in the state of San Luis Potosi.

    Science.gov (United States)

    Jarquín-Yañez, Lizet; de Jesús Mejía-Saavedra, José; Molina-Frechero, Nelly; Gaona, Enrique; Rocha-Amador, Diana Olivia; López-Guzmán, Olga Dania; Bologna-Molina, Ronell

    2015-01-01

    The aim of this study is to investigate urine fluoride concentration as a toxicity factor in a rural community in the state of San Luis Potosi, Mexico. A sample of 111 children exposed to high concentrations of fluoride in drinking water (4.13 mg/L) was evaluated. Fluoride exposure was determined by measuring urine fluoride concentration using the potentiometric method with an ion selective electrode. The diagnosis of dental fluorosis was performed by clinical examination, and the severity of damage was determined using Dean's index and the Thylstrup-Fejerskov (TF) index. The range of exposure in the study population, evaluated through the fluoride content in urine, was 1.1 to 5.9 mg/L, with a mean of 3.14±1.09 mg/L. Dental fluorosis was present in all subjects, of which 95% had severe cases. Higher urine fluoride levels and greater degrees of severity occurred in older children. The results show that dental fluorosis was determined by the presence of fluoride exposure finding a high positive correlation between the severity of fluorosis and urine fluoride concentration and the years of exposure suggested a cumulative effect.

  4. Amelioration of chronic fluoride toxicity by calcium and fluoride-free water in rats.

    Science.gov (United States)

    Shankar, Priyanka; Ghosh, Sudip; Bhaskarachary, K; Venkaiah, K; Khandare, Arjun L

    2013-07-14

    The study was undertaken to explore the amelioration of chronic fluoride (F) toxicity (with low and normal Ca) in rats. The study was conducted in two phases. In phase I (6 months), seventy-six Wistar, weanling male rats were assigned to four treatment groups: normal-Ca (0·5 %) diet (NCD), Ca+F - ; low-Ca (0·25 %) diet (LCD), Ca - F - ; NCD +100 parts per million (ppm) F water, Ca+F+; LCD +100 ppm F water, Ca - F+. In phase II (reversal experiment, 3 months), LCD was replaced with the NCD. Treatment groups Ca+F+ and Ca - F+ were divided into two subgroups to compare the effect of continuation v. discontinuation along with Ca supplementation on reversal of chronic F toxicity. In phase I, significantly reduced food efficiency ratio (FER), body weight gain (BWG), faecal F excretion, serum Ca and increased bone F deposition were observed in the treatment group Ca - F+. Reduced serum 25-hydroxy-vitamin D3, increased 1,25-dihydroxy-vitamin D3 and up-regulation of Ca-sensing receptor, vitamin D receptor and S100 Ca-binding protein G (S100G) were observed in treatment groups Ca - F - and Ca - F+. In phase II (reversal phase), FER, BWG and serum Ca in treatment groups Ca - F+/Ca+F - and Ca - F+/Ca+F+ were still lower, as compared with other groups. However, other variables were comparable. Down-regulation of S100G was observed in F-fed groups (Ca+F+/Ca+F+ and Ca - F+/Ca+F+) in phase II. It is concluded that low Ca aggravates F toxicity, which can be ameliorated after providing adequate Ca and F-free water. However, chronic F toxicity can interfere with Ca absorption by down-regulating S100G expression irrespective of Ca nutrition.

  5. Fluoride removal from aqueous solution by pumice: case study on ...

    African Journals Online (AJOL)

    EJIRO

    conditions, the fluoride removal efficiency from Kuhbonan water by 2.8 mg/L fluoride was 74.64%. Eventually ... industrial wastewater containing fluoride is a key ..... solution using silica ceramic: Adsorption kinetics and equilibrium studies.

  6. Controlling the fluoride dosage in a patient with compromised salivary function.

    Science.gov (United States)

    Eichmiller, Frederick C; Eidelman, Naomi; Carey, Clifton M

    2005-01-01

    High-concentration topical fluorides are used commonly to with compromised salivary function due to irradiation and chemotherapy. The authors describe a 50-year-old man with previously treated cancer who was using tray-applied topical fluoride gel. He complained of gastric symptoms, difficulty in swallowing, leg muscle soreness and knee joint soreness. A computed tomographic scan revealed thickening of the esophageal walls. An upper endoscopy revealed abnormal motility. The motility test indicated high-amplitude peristalsis and hypertensive lower esophageal sphincter, and urine testing indicated high levels of systemic fluoride. The patient's fluoride regimen was altered, and within a short period his urinary fluoride levels returned to normal and his symptoms resolved. Clinicians prescribing home-applied high-concentration fluorides need to be cognizant of the symptoms of fluoride toxicity, carefully monitor the patient's compliance with the treatment regimen, and adjust the dosage or mode of application to control the total ingested dose of fluoride.

  7. Chronic Fluoride Toxicity: Dental Fluorosis

    OpenAIRE

    DenBesten, Pamela; Li, Wu

    2011-01-01

    Dental fluorosis occurs as a result of excess fluoride ingestion during tooth formation. Enamel fluorosis and primary dentin fluorosis can only occur when teeth are forming, and therefore fluoride exposure (as it relates to dental fluorosis) occurs during childhood. In the permanent dentition, this would begin with the lower incisors, which complete mineralization at approximately 2–3 years of age, and end after mineralization of the third molars. The white opaque appearance of fluorosed enam...

  8. Fluoride content and labelling of toothpastes marketed in India.

    Science.gov (United States)

    Thakkar, V P; Rao, A; Rajesh, G; Shenoy, R; Pai, M

    2015-09-01

    To enumerate the fluoride content and labelling practices of toothpastes marketed in India and to determine if the content is in accordance with the information provided on the packaging. In vitro analysis of total and free available fluoride in 5 adult and 5 children's fluoride toothpastes in India using fluoride ion electrode. Information on the tube and carton was checked to assess the labelling. The mean Total Fluoride concentrations (TF) in the toothpastes labelled 1,000 ppm, 500ppm and 458 ppm were 1,000, 500 and 449mg/L (sd values 3, 5 and 4mg/L) respectively. The toothpastes' Total Soluble Fluoride (TSF) concentration was generally slightly less than the TF concentration. Overall mean percentage of TSF concentration was 94% sd 9%. The mean percentage of TSF concentration in SMFP (sodium monofluorophosphate)/CaCO3 (calcium carbonate) containing toothpastes was 86% sd 16% while that in NaF (sodium fluoride)/Si (silica) based toothpastes was 98% sd 1% and 95% sd 1% in the remaining toothpastes with unknown abrasive. NaF/Si based toothpastes had more TSF concentration than the others (plabelled following the guidelines of the regulatory body of India, 3 of the 10 failed to mention the abrasive present.

  9. Photosynthesis of ammonium uranous fluoride

    International Nuclear Information System (INIS)

    El-Fekey, S.A.; Zaki, M.R.; Farah, M.Y.

    1975-01-01

    This study pertains to utilisation of solar energy for ethanol photosynthesis of ammonium uranous fluoride, that satisfies nuclear specifications needed for calcio- or magnesiothermy. Insolation in autumn using 4-10% ethanol in 5-20 g uranium/litre at initial pH 3.25 gave practically 99.8% yield in two hours, independant of 1.0 to 2.0 stoichiometric NH 4 F. With ultraviolet light, the yield varied between 30 and 60%, even after four hours irradiation. Stirring and heating to 60 0 C raised the tap density of the dried double fluorides from 1.48 at 30 0 C, to 1.85 g/cm 3 at 60 0 C. The texture increased also in fineness to 100% 50μ aggregates. The powders satisfy nuclear purity specifications. Thermograms indicated preferential decomposition of double fluoride at 375 0 C in controlled atmosphere to obtain nuclear pure anhydrous uranium tetrafluoride

  10. Identification of V-type nerve agents in vapor samples using a field-portable capillary gas chromatography/membrane-interfaced electron ionization quadrupole mass spectrometry instrument with Tri-Bed concentrator and fluoridating conversion tube.

    Science.gov (United States)

    Ohrui, Y; Nagoya, T; Kurimata, N; Sodeyama, M; Seto, Y

    2017-07-01

    A field-portable gas chromatography-mass spectrometry (GC-MS) system (Hapsite ER) was evaluated for the detection of nonvolatile V-type nerve agents (VX and Russian VX (RVX)) in the vapor phase. The Hapsite ER system consists of a Tri-Bed concentrator gas sampler, a nonpolar low thermal-mass capillary GC column and a hydrophobic membrane-interfaced electron ionization quadrupole mass spectrometer evacuated by a non-evaporative getter pump. The GC-MS system was attached to a VX-G fluoridating conversion tube containing silver nitrate and potassium fluoride. Sample vapors of VX and RVX were converted into O-ethyl methylphosphonofluoridate (EtGB) and O-isobutyl methylphosphonofluoridate (iBuGB), respectively. These fluoridated derivatives were detected within 10 min. No compounds were detected when the VX and RVX samples were analyzed without the conversion tube. A vapor sample of tabun (GA) was analyzed, in which GA and O-ethyl N,N-dimethylphosphoramidofluoridate were detected. The molar recovery percentages of EtGB and iBuGB from VX and RVX vapors varied from 0.3 to 17%, which was attributed to variations in the vaporization efficiency of the glass vapor container. The conversion efficiencies of the VX-G conversion tube for VX and RVX to their phosphonate derivatives were estimated to be 40%. VX and RVX vapors were detected at concentrations as low as 0.3 mg m -3 . Gasoline vapor was found to interfere with the analyses of VX and RVX. In the presence of 160 mg m -3 gasoline, the detection limits of VX and RVX vapor were increased to 20 mg m -3 . Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  11. Effect of Fluoride and Bentonite on Biochemical Aspects of Oxidative Stress in Pisum sativum L.

    Directory of Open Access Journals (Sweden)

    Martyna Śnioszek

    2018-03-01

    Full Text Available Fluoride is regarded as one of the strongest oxidants, which causes oxidative changes in cells of living organisms. It may both increase the content of reactive oxygen species and inhibit the activity of antioxidative enzyme. In recent years, many researchers successfully used the properties of clay minerals in the sorption of fluoride ion from water. This raises the question of the possibility of limiting the effect of fluorine on the negative changes in plants by adding bentonite to soil. A two-year pot experiment was carried out in the Greenhouse of West Pomeranian University of Technology in Szczecin, on loamy sand and sandy loam. Each sample of soil was mixed with three different concentrations of bentonite – 1, 5, 10% of dry weight (DW of the soil and then treated with 30 mmol of F- per 1 kg of dry weight of the soil in a form of NaF solution. A control series was prepared for each soil, to which no additives were added. The medium prepared in such way was transferred to plastic pots (3 kg each and seeded with 16 pea seeds of Pisum sativum. In three phases of pea development (4 leaves unfolded, flowering and development of fruit, fresh leaf samples were collected and the concentrations of ascorbic acid, reduced glutathione, total flavonoids and total polyphenols were measured. Sodium fluoride introduced to the soil changed the level of antioxidant parameters in the plant, which may suggest that fluoride is involved in the formation of reactive oxygen species, resulting in oxidative stress. Bentonite in a dosage of 10% reduced the toxic effects of fluoride on the oxidative balance and morphological changes in the plant, which was observed especially for loamy sand, naturally poor in clay minerals.

  12. Effect of Sodium Fluoride Mouthwash on the Frictional Resistance of Orthodontic Wires

    Directory of Open Access Journals (Sweden)

    Allahyar Geramy

    2017-12-01

    Full Text Available Objectives: The friction between the brackets and orthodontic wire during sliding mechanics inflicts difficulties such as decreasing the applied force and tooth movement and also the loss of anchorage. Therefore, many studies have focused on the factors that affect the friction. The purpose of this study was to assess the effect of 0.05% sodium fluoride mouthwash on the friction between orthodontic brackets and wire.Materials and Methods: Four types of orthodontic wires including rectangular standard stainless steel (SS, titanium molybdenum alloy (TMA, nickel-titanium (NiTi and copper-nickel-titanium (Cu-NiTi were selected. In each group, half of the samples were immersed in 0.05% sodium fluoride mouthwash and the others were immersed in artificial saliva for 10 hours. An elastomeric ligature was used for ligating the wires to brackets. The frictional test was performed in a universal testing machine at the speed of 10 mm/minute. Two-way ANOVA was used for statistical analysis of the friction rate.Results: The friction rate was significantly higher after immersion in 0.05% sodium fluoride mouthwash in comparison with artificial saliva (P=0.00. Cu-NiTi wire showed the highest friction value followed by TMA, NiTi and SS wires.  Conclusions: According to the results of the current study, 0.05% sodium fluoride mouthwash increased the frictional characteristics of all the evaluated orthodontic wires.

  13. Effect of xylitol, sodium fluoride and triclosan containing mouth rinse on Streptococcus mutans

    Directory of Open Access Journals (Sweden)

    Priya Subramaniam

    2011-01-01

    Full Text Available Introduction : Prevention of dental caries is one of the main strategies in contemporary pediatric dental practice. Mouth rinses are widely used as an adjunct to maintain oral hygiene. It is important for these products to be effective and safe for regular use in children. Objective : The aim of the study was to investigate the efficacy of a newly introduced xylitol, sodium fluoride and triclosan containing mouth rinse in reducing levels of plaque Streptococcus mutans and to compare it with that of a 0.12% chlorhexidine mouth rinse. Materials and Methods : Thirty children were randomly divided into two groups of 15 children each. Group I (study group was given a mouth rinse containing xylitol (5%, sodium fluoride (0.05% and triclosan (0.03% and Group II (control group was given a chlorhexidine (0.12% mouth rinse. Both mouth rinses were alcohol free. Mouth rinsing was carried out twice daily, half an hour after breakfast and half an hour following dinner, for a period of 21 days under the supervision of the investigator. Results: In both groups, there was a significant reduction in the mean S. mutans count at the end of 21 days (P < 0.001. No significant difference was observed between the two mouth rinses. Conclusion: The use of a low fluoride-xylitol based mouth rinse appears to be a suitable choice for regular use in children.

  14. Exposure to fluoride in drinking water and hip fracture risk: a meta-analysis of observational studies.

    Science.gov (United States)

    Yin, Xin-Hai; Huang, Guang-Lei; Lin, Du-Ren; Wan, Cheng-Cheng; Wang, Ya-Dong; Song, Ju-Kun; Xu, Ping

    2015-01-01

    Many observational studies have shown that exposure to fluoride in drinking water is associated with hip fracture risk. However, the findings are varied or even contradictory. In this work, we performed a meta-analysis to assess the relationship between fluoride exposure and hip fracture risk. PubMed and EMBASE databases were searched to identify relevant observational studies from the time of inception until March 2014 without restrictions. Data from the included studies were extracted and analyzed by two authors. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were pooled using random- or fixed-effects models as appropriate. Sensitivity analyses and meta-regression were conducted to explore possible explanations for heterogeneity. Finally, publication bias was assessed. Fourteen observational studies involving thirteen cohort studies and one case-control study were included in the meta-analysis. Exposure to fluoride in drinking water does not significantly increase the incidence of hip fracture (RRs, 1.05; 95% CIs, 0.96-1.15). Sensitivity analyses based on adjustment for covariates, effect measure, country, sex, sample size, quality of Newcastle-Ottawa Scale scores, and follow-up period validated the strength of the results. Meta-regression showed that country, gender, quality of Newcastle-Ottawa Scale scores, adjustment for covariates and sample size were not sources of heterogeneity. Little evidence of publication bias was observed. The present meta-analysis suggests that chronic fluoride exposure from drinking water does not significantly increase the risk of hip fracture. Given the potential confounding factors and exposure misclassification, further large-scale, high-quality studies are needed to evaluate the association between exposure to fluoride in drinking water and hip fracture risk.

  15. Exposure to fluoride in drinking water and hip fracture risk: a meta-analysis of observational studies.

    Directory of Open Access Journals (Sweden)

    Xin-Hai Yin

    Full Text Available Many observational studies have shown that exposure to fluoride in drinking water is associated with hip fracture risk. However, the findings are varied or even contradictory. In this work, we performed a meta-analysis to assess the relationship between fluoride exposure and hip fracture risk.PubMed and EMBASE databases were searched to identify relevant observational studies from the time of inception until March 2014 without restrictions. Data from the included studies were extracted and analyzed by two authors. Summary relative risks (RRs with corresponding 95% confidence intervals (CIs were pooled using random- or fixed-effects models as appropriate. Sensitivity analyses and meta-regression were conducted to explore possible explanations for heterogeneity. Finally, publication bias was assessed.Fourteen observational studies involving thirteen cohort studies and one case-control study were included in the meta-analysis. Exposure to fluoride in drinking water does not significantly increase the incidence of hip fracture (RRs, 1.05; 95% CIs, 0.96-1.15. Sensitivity analyses based on adjustment for covariates, effect measure, country, sex, sample size, quality of Newcastle-Ottawa Scale scores, and follow-up period validated the strength of the results. Meta-regression showed that country, gender, quality of Newcastle-Ottawa Scale scores, adjustment for covariates and sample size were not sources of heterogeneity. Little evidence of publication bias was observed.The present meta-analysis suggests that chronic fluoride exposure from drinking water does not significantly increase the risk of hip fracture. Given the potential confounding factors and exposure misclassification, further large-scale, high-quality studies are needed to evaluate the association between exposure to fluoride in drinking water and hip fracture risk.

  16. An In-Vitro Study on the Release of Fluoride from Two Restorative Materials and Their Rechargeability after Exposure to Daily 1000 ppm Fluoride

    Directory of Open Access Journals (Sweden)

    A. Kowsari

    2005-09-01

    Full Text Available Statement of Problem: Since the fluoride releases from materials with the property of releasing fluoride are decreasing gradually, it seems that probably the material rechargeability is more important than their long-term fluoride release.Purpose: the objective of this study was to asses the fluoride release and rechargeability of 2 types of fluoride releasing restorative materials, a resin modified glass ionomer(Vitremer and a compomer (Compoglass F, after exposure to daily NaF solutionscontaining 1000 ppm F, for 1 minute.Materials and Methods: Twelve discs ( 8 mm ×2 mm of each of the materials were fabricated, and divided into 2 groups (test and control. All discs were stored in 4 mL artificial saliva at 37°C. In group 1 (N=6, the specimens were immersed in artificialsaliva which was changed daily for 25 days. In group 2 (N=6, in addition to receiving the same treatment as group 1, the specimens were immersed in NaF solution (1000ppm F, ph=6.9 for 1 minute before daily saliva change. A potentiometer was used to determine the amount of fluoride released on days 1, 2, 3, 5, 10, 15, 20 and 25, after the daily saliva change, in all study groups. Data were analyzed by the t-student test after confirmation of the equality of variances by Leven’s test.Results: Both materials continued releasing fluoride throughout the whole study period. For each material, the release was highest on day one. During the first 3 days,glass ionomer released significantly higher amounts of fluoride as compared to compomer (p0.05. After exposure to NaF solution, none of the materials showed statistically significant rechargeability (p>0.05 and the amount of fluoride-releasecontinued to drop during the study period in similar patterns for both the test and the control groups.Conclusion: It may be concluded that rechargeability of glass ionomer and compomer,using daily neutral fluoride mouth rinses and toothpastes does not occur in reliable amounts.

  17. An In Vitro Study on the Effect of Amorphous Calcium Phosphate and Fluoride Solutions on Color Improvement of White Spot Lesions

    Directory of Open Access Journals (Sweden)

    Fahimeh Farzanegan

    2018-06-01

    Full Text Available The ability of remineralizing agents to improve the color of white spot lesions (WSL is an important aspect that should be investigated. The aim of this study was to evaluate the effects of 0.05% amorphous calcium phosphate (ACP, 0.5% ACP, and 0.05% fluoride solutions, as well as artificial saliva on the color improvement of white spot lesions (WSLs. In this in vitro study, 50 human premolar teeth were randomly classified into five groups. At baseline, all the samples were assessed by using a colorimeter (E0. Then, white spot lesions were induced on the surface of the teeth by means of a pH-cycling model, and the colorimeter was used again (E1. Afterwards, samples of the 1st and 2nd groups were kept in 0.05% ACP and 0.5% ACP solutions for 1 min/day, respectively. The 3rd group specimens were placed in 0.05% fluoride solution for 1 min/day. The other two groups were kept in artificial saliva and distilled in water separately. All the samples were assessed by the colorimeter for a third time (E2. We found no significant difference between the groups in ∆E1. There was also no significant difference among 0.05% ACP solution, 0.5% ACP solution, 0.05% fluoride solution, and artificial saliva considering ∆E2. However, a significant difference was noted between the above-mentioned solutions and distilled water in ∆E2. With respect to ∆E3, there were considerable differences between ACP solution and artificial saliva. The same results were obtained for the difference between fluoride solution and artificial saliva. However, no significant difference was found among 0.05% ACP, 0.5% ACP, and 0.05% fluoride solutions in terms of ∆E3. In Conclusion, ACP is as effective as fluoride in the color improvement of WSLs and the recommended treatment for this purpose is daily use of 0.05% ACP, 0.5% ACP or 0.05% fluoride solutions.

  18. Fluoride removal from diluted solutions by Donnan dialysis using full factorial design

    Energy Technology Data Exchange (ETDEWEB)

    Boubakri, Ali; Helali, Nawel; Tlili, Mohamed; Amor, Mohamed Ben [Center of Researches and Water Technologies, Soliman (Turkey)

    2014-03-15

    Excessive fluoride concentration in potable water can lead to fluorosis of teeth and bones. In the present study, Donnan dialysis (DD) is applied for the removal of fluoride ions from diluted sodium fluoride solutions. A four factor two level (2{sup 4}) full factorial design was used to investigate the influence of different physico-chemical parameters on fluoride removal efficiency (Y{sub F}) and fluoride flux (J{sub F}) through anion exchange membrane. The statistical design determines factors which have the important effects on Donnan dialysis performance and studies all interactions among the considered parameters. The four significant factors were initial fluoride concentration, feed flow rate, temperature and agitation speed. The experimental results and statistical analysis show that the temperature and agitation speed have positive effects on fluoride removal efficiency and the initial fluoride concentration has a negative effect. In the case of fluoride flux, feed flow rate and initial concentration are the main effect and all factors have a positive effect. The interaction between studied parameters was not negligible on two responses. A maximum fluoride removal of 75.52% was obtained under optimum conditions and the highest value of fluoride flux obtained was 2.4 mg/cm{sup 2}·h. Empirical regression models were also obtained and used to predict the flux and the fluoride removal profiles with satisfactory results.

  19. Performance of novel hydroxyapatite nanowires in treatment of fluoride contaminated water.

    Science.gov (United States)

    He, Junyong; Zhang, Kaisheng; Wu, Shibiao; Cai, Xingguo; Chen, Kai; Li, Yulian; Sun, Bai; Jia, Yong; Meng, Fanli; Jin, Zhen; Kong, Lingtao; Liu, Jinhuai

    2016-02-13

    Novel ultralong hydroxyapatite (HAP) nanowires were successfully prepared for fluoride removal for the first time. The fluoride adsorption on the HAP nanowires was studied on a batch mode. The results revealed that the adsorption data could be well described by the Freundlich model, and the adsorption kinetic followed the pseudo-second-order model. The maximum of adsorption capacity was 40.65 mg/g at pH 7.0 when the fluoride concentration is 200mg/L. The thermodynamic parameters suggested that the adsorption of fluoride was a spontaneous endothermic process. The FT-IR, XPS and Zeta potential analysis revealed that both anion exchange and electrostatic interactions were involved in the adsorption of fluoride. Furthermore, the HAP nanowires were made into HAP membrane through a simple process of suction filtration. Membrane filtration experiments revealed that the fluoride removal capabilities depended on the membrane thickness, flow rate and initial concentration of fluoride. The as-prepared membrane could remove fluoride efficiently through continues filtration. The filtered water amount could reach 350, 192, and 64 L/m(2) when the fluoride concentrations were 4, 5 and 8 ppm, respectively, using the HAP membrane with only 150 μm thickness. The as-synthesized ultralong HAP nanowires were thus demonstrated to be very effective and biocompatible adsorbents for fluoride removal from contaminated water. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Comparison of storage stability of odorous VOCs in polyester aluminum and polyvinyl fluoride tedlar bags

    Science.gov (United States)

    Whole air sampling using containers such as flexible bags or rigid canisters is commonly used to collect samples of volatile organic compounds (VOC) in air. The objective of this study was to compare the stability of polyester aluminum (PEA) and polyvinyl fluoride (PVF, brand name Tedlar®) bags for ...

  1. Solvents effects on electrochemical characteristics of graphite fluoride-lithium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Nobuatsu, W.; Hidekazu, T.; Rika, H.; Tsuyoshi, N.

    1982-11-01

    A study was made of the electrochemical characteristics of graphite fluoride-lithium batteries in various non-aqueous solvents. Two types of graphite fluorides (C/sub 2/F) /SUB n/ and (CF) /SUB n/ were used as cathode materials. The discharge characteristics of graphite fluorides were better in dimethylsulfoxide, ..gamma..-butyrolactone, propylene carbonate and sulfolane in that order. The relation between electrod potential of graphite fluoride and solvation energy of lithium ion with each solvent indicates that solvated lithium ion is intercalated into graphite fluoride layers by the electrode reaction. Both the difference in the overpotentials and in the rates of OCV recovery among these solvents further supports the proposed reaction mechanism.

  2. Beer as a Rich Source of Fluoride Delivered into the Body.

    Science.gov (United States)

    Styburski, D; Baranowska-Bosiacka, I; Goschorska, M; Chlubek, D; Gutowska, I

    2017-06-01

    Fluoride is an element which in the minimum amount is necessary for the proper construction of the teeth and bones. But on the other hand, it increases the synthesis of reactive oxygen species, inflammatory mediators, and impairs the action of enzymes. Beer is the most popular alcoholic beverage in the world. Due to its prevalence and volume of consumption, it should be considered as a potential source of F- and taken into account in designing a balanced diet. Therefore, the aim of this study was to analyze beer samples in terms of F- levels. The concentrations of fluoride were examined using ion-selective electrode Thermo Scientific Orion and statistical analysis was based on two-way ANOVA and t test. When compared to imported beers, Polish beers were characterized by the lowest mean F- concentration (0.089 ppm). The highest mean F- concentrations were recorded in beers from Thailand (0.260 ppm), Italy (0.238 ppm), Mexico (0.210 ppm), and China (0.203 ppm). Our study shows that beer is a significant source of fluoride for humans, which is mainly associated with the quality of the water used in beer production.

  3. Mie scattering in heavy-metal fluoride glasses

    International Nuclear Information System (INIS)

    Edgar, A.

    1996-01-01

    Heavy-metal fluoride glasses comprise mixtures of heavy-cation fluorides such as those of zirconium, barium, and lanthanum together with some stabilising fluorides such as AlF 3 . For particular relative proportions, the mixtures form a glass rather than a polycrystalline material when quenched from the melt. The particularly useful features of these glasses are the wide spectral region (∼200nm-8000nm) over which they are transparent, the low minimum attenuation at the centre of the spectral window, and the ease with which optically-active rare-earth ions can be incorporated, leading to potential applications in passive and active fibre optics. The minimal attenuation, which is potentially lower than for silica fibre, is generally limited by wavelength-independent scattering by particle and gas bubble inclusions. We have observed a new wavelength-dependent scattering effect in fluoride glass of the well-known composition ZLABN20. In this paper, we report on work in progress on the optical extinction and scattering spectrum of the fluoride glasses, and discuss the spectra in terms of Mie's scattering theory. The chemical nature of the scattering centres in these nominally 'pure' glasses is at present a puzzle, and relative merits of various possible models will be compared

  4. Effect of fluoride addition on the properties of dental alginate impression materials.

    Science.gov (United States)

    Lee, Yong-Keun; Lim, Bum-Soon; Kim, Cheol-We

    2004-03-01

    Fluoride-containing dental alginate impression materials can exert a considerable reduction in enamel solubility. The objective was to evaluate the effects of fluoride addition in the alginate impression materials on the properties and subsequent release of fluoride. Four experimental alginate impression materials were studied. Materials were mixed with distilled water (control) or 100-ppm fluoride solution. One or two percent NaF, or 1% SnF2 was added to the materials, which were mixed with distilled water. Fluoride release, flexibility, recovery from deformation, setting time, compressive strength and elastic modulus were determined in accordance with the ISO 1563 and ANSI/ADA Spec. 18. Fluoride release increased after addition of fluoride, and the released amount was 0.762-14.761 ppm. Addition of NaF or SnF2 resulted in higher fluoride release than the control group (p alginate impression material may result in effective release of fluoride without deteriorating the properties of material itself.

  5. Daya antibakteri obat kumur chlorhexidine, povidone iodine, fluoride suplementasi zinc terhadap, Streptococcus mutans dan Porphyromonas gingivalis (Antibacterial effect of mouth washes containing chlorhexidine, povidone iodine, fluoride plus zinc on Strep

    Directory of Open Access Journals (Sweden)

    Betadion Rizki Sinaredi

    2014-12-01

    Full Text Available Background: Dental Caries and periodontal disease prevalence in Indonesian children are still high. Some efforts can be done to overcome the problem; one of them is the use of mouthwash to decrease pathogen microorganisms. The mouthwashes that commercially available in market are chlorhexidine, povidone Iodine and Fluoride with Zinc supplementation. Purpose: The purpose of this study was to examine the anti bacterial effect of the mouthwashes chlorhexidine, povidone iodine and fluoride with zinc supplementation against mix bacteria that found in the plaque, Streptococcus mutans and Porphyromonas gingivalis. Methods: The antibacterial effect was measured using disk diffusion test. The bacteria samples (plaque polybacteria, S.mutans and P. gingivalis were inoculated and spread in the petridish containing MHA. Paper discs containing the mouthwashes were placed in the petridish and incubated for 24 hours at 37oC (anaerobe for P. gingivalis, aerobe for S. mutans and polybacteria. The diameter of inhibition zone surrounding the paper discs were measured and compared between each active ingredient contained in mouthwash. Results: Chlorhexidine had the strongest antibacterial effect than povidone iodine and fluoride. Chlorhexidine was more effective to inhibited the growth of S. mutans than to polybacteria or P.Gingivalis, while Povidone iodine and fluoride were more effective to inhibited the growth of polybacteria. Conclusion: The mouthwash chlorhexidine was more effective to inhibit the growth of plaque polybacteria, Streptoccous mutans and Porphyromonas gingivalis compared with povidone iodine and fluoride with zinc supplementation.Latar belakang: Prevalensi karies gigi dan penyakit periodontal masih tinggi pada anak Indonesia. Usaha mengatasi hal tersebut antara lain melalui melalui penggunaan obat kumur untuk mengurangi jumlah kuman pathogen. Kandungan obat kumur yang beredar di pasar diantaranya adalah chlorhexidine, povidone iodine dan fluoride

  6. Sirtuin1 and autophagy protect cells from fluoride-induced cell stress

    Science.gov (United States)

    Suzuki, Maiko; Bartlett, John D.

    2014-01-01

    Sirtuin1 (SIRT1) is an (NAD+)-dependent deacetylase functioning in the regulation of metabolism, cell survival and organismal lifespan. Active SIRT1 regulates autophagy during cell stress, including calorie restriction, endoplasmic reticulum stress and oxidative stress. Previously, we reported that fluoride induces endoplasmic reticulum (ER) stress in ameloblasts responsible for enamel formation, suggesting that ER-stress plays a role in dental fluorosis. However, the molecular mechanism of how cells respond to fluoride-induced cell stress is unclear. Here, we demonstrate that fluoride activates SIRT1 and initiates autophagy to protect cells from fluoride exposure. Fluoride treatment of ameloblast-derived cells (LS8) significantly increased Sirt1 expression and induced SIRT1 phosphorylation resulting in the augmentation of SIRT1 deacetylase activity. To demonstrate that fluoride exposure initiates autophagy, we characterized the expression of autophagy related genes (Atg); Atg5, Atg7 and Atg8/LC3 and showed that both their transcript and protein levels were significantly increased following fluoride treatment. To confirm that SIRT1 plays a protective role in fluoride toxicity, we used resveratrol (RES) to augmented SIRT1 activity in fluoride treated LS8 cells. RES increased autophagy, inhibited apoptosis, and decreased fluoride cytotoxicity. Rats treated with fluoride (0, 50 and 100 ppm) in drinking water for 6 weeks had significantly elevated expression levels of Sirt1, Atg5, Atg7 and Atg8/LC3 in their maturation stage enamel organs. Increased protein levels of p-SIRT1, ATG5 and ATG8/LC3 were present in fluoride-treated rat maturation stage ameloblasts. Therefore, the SIRT1/autophagy pathway may play a critical role as a protective response to help prevent dental fluorosis. PMID:24296261

  7. Sirtuin1 and autophagy protect cells from fluoride-induced cell stress.

    Science.gov (United States)

    Suzuki, Maiko; Bartlett, John D

    2014-02-01

    Sirtuin1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD(+))-dependent deacetylase functioning in the regulation of metabolism, cell survival and organismal lifespan. Active SIRT1 regulates autophagy during cell stress, including calorie restriction, endoplasmic reticulum (ER) stress and oxidative stress. Previously, we reported that fluoride induces ER-stress in ameloblasts responsible for enamel formation, suggesting that ER-stress plays a role in dental fluorosis. However, the molecular mechanism of how cells respond to fluoride-induced cell stress is unclear. Here, we demonstrate that fluoride activates SIRT1 and initiates autophagy to protect cells from fluoride exposure. Fluoride treatment of ameloblast-derived cells (LS8) significantly increased Sirt1 expression and induced SIRT1 phosphorylation resulting in the augmentation of SIRT1 deacetylase activity. To demonstrate that fluoride exposure initiates autophagy, we characterized the expression of autophagy related genes (Atg); Atg5, Atg7 and Atg8/LC3 and showed that both their transcript and protein levels were significantly increased following fluoride treatment. To confirm that SIRT1 plays a protective role in fluoride toxicity, we used resveratrol (RES) to augment SIRT1 activity in fluoride treated LS8 cells. RES increased autophagy, inhibited apoptosis, and decreased fluoride cytotoxicity. Rats treated with fluoride (0, 50, 100 and 125ppm) in drinking water for 6weeks had significantly elevated expression levels of Sirt1, Atg5, Atg7 and Atg8/LC3 in their maturation stage enamel organs. Increased protein levels of p-SIRT1, ATG5 and ATG8/LC3 were present in fluoride-treated rat maturation stage ameloblasts. Therefore, the SIRT1/autophagy pathway may play a critical role as a protective response to help prevent dental fluorosis. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Synthesis of metal-fluoride nanoparticles supported on thermally reduced graphite oxide

    Directory of Open Access Journals (Sweden)

    Alexa Schmitz

    2017-11-01

    Full Text Available Metal-fluoride nanoparticles, (MFx-NPs with M = Fe, Co, Pr, Eu, supported on different types of thermally reduced graphite oxide (TRGO were obtained by microwave-assisted thermal decomposition of transition-metal amidinates, (M{MeC[N(iPr]2}n or [M(AMDn] with M = Fe(II, Co(II, Pr(III, and tris(2,2,6,6-tetramethyl-3,5-heptanedionatoeuropium, Eu(dpm3, in the presence of TRGO in the ionic liquid (IL 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]. The crystalline phases of the metal fluorides synthesized in [BMIm][BF4] were identified by powder X-ray diffraction (PXRD to be MF2 for M = Fe, Co and MF3 for M = Eu, Pr. The diameters and size distributions of MFx@TRGO were from (6 ± 2 to (102 ± 41 nm. Energy-dispersive X-ray spectroscopy (EDX and X-ray photoelectron spectroscopy (XPS were used for further characterization of the MFx-NPs. Electrochemical investigations of the FeF2-NPs@TRGO as cathode material for lithium-ion batteries were evaluated by galvanostatic charge/discharge profiles. The results indicate that the FeF2-NPs@TRGO as cathode material can present a specific capacity of 500 mAh/g at a current density of 50 mA/g, including a significant interfacial charge storage contribution. The obtained nanomaterials show a good rate capacity as well (220 mAh/g and 130 mAh/g at a current density of 200 and 500 mA/g, respectively.

  9. Hepatocyte Growth Factor Inhibits Apoptosis by the Profibrotic Factor Angiotensin II via Extracellular Signal-regulated Kinase 1/2 in Endothelial Cells and Tissue Explants

    Science.gov (United States)

    2010-12-01

    1 mM sodium fluoride, 0.1 mM sodium orthovanadate, 1 mM tetrasodium pyrophosphate, 2 mM phenylmethylsulfonyl fluoride, 10 g/ml leupeptin, and 10 g...buffer [50 mM Tris-HCl, 1 mM EGTA, 1% (wt/vol) CHAPS, 10% glycerol, 50 mM sodium fluoride, 1 mM sodium orthovanadate, 2 mM phenylmethylsulfonyl fluoride...nucleus, nucleolin can be phosphorylated on serine res- idues by the cell cycle-regulated kinases casein kinase II and cell division cycle 2 protein

  10. The concentration data of fluoride and health risk assessment in drinking water in the Ardakan city of Yazd province, Iran.

    Science.gov (United States)

    Mirzabeygi Rad Fard, Majid; Yousefi, Mahmood; Soleimani, Hamed; Mohammadi, Ali Akbar; Mahvi, Amir Hossein; Abbasnia, Abbas

    2018-06-01

    According to the World Health Organization (WHO) reports, Iran is located in the global fluoride belts, so that is why carrying out extended research on this contaminant anion in water supplies must be considered. Due to the various industries in the Ardakan city, this region is severely suffering from fluoride contamination. This study was designed to investigate the fluoride concentration and its distribution pattern as well as related health risk assessment in groundwater resources of 28 villages of the Ardakan city in Yazd province using SPADNS method according to standard instructions. Our results show that, the average concentration of fluoride was 2.92 mg/l (range: 0.9-6 mg/l), also in half of the villages, the concentration range of this element was over than standard level (1.5 mg/l) given by WHO rules. In addition, risk assessment results showed that HQ value is higher than 1 in 46.4% of samples of groundwater resources in age groups of infants, children, teenagers and adults. Therefore, it is necessary to take measures to reduce fluoride concentration in drinking water in order to control resultant fluorosis. Actions should be implemented to enhance monitoring of fluoride levels to avoid the potential risk of high Fluoride concentration.

  11. Diffusion of fluoride in bovine enamel

    International Nuclear Information System (INIS)

    Flim, G.J.; Arends, J.; Kolar, Z.

    1976-01-01

    The uptake of 18 F and the penetration of both F and 18 F in bovine enamel was investigated. Sodium fluoride solutions buffered at pH 7 were employed. The uptake of 18 F was measured by a method described by R. Duckworth and M. Braden, Archs. Oral. Biol., 12(1967), pp. 217-230. The penetration concentration profiles of fluoride (F, 18 F) in the enamel were measured by a sectioning technique. The 18 F uptake in enamel was proportional to approximately tsup(3/4); t being the uptake time. The 18 F concentration as a function of the position in the enamel can be described by: c*(x,t) = c 0 *(t)exp[-α*(t)x]. After correction for the initial fluoride concentration in enamel, for unlabelled fluoride the same dependency is obtained. A model based on simultaneous diffusion and chemical reaction in the pores and diffusion into the hydroxyapatite crystallites will be presented. The results show that diffusion coefficients of the pores are approximately equal to 10 -10 cm 2 s -1 and in the apatite crystallites approximately equal to 10 -17 cm 2 s -1 . The limitations and the approximations of the model are discussed

  12. Chemico-therapeutic approach to prevention of dental caries. [using stannous fluoride gel

    Science.gov (United States)

    Shannon, I. L.

    1975-01-01

    The program of chemical preventive dentistry is based primarily upon the development of a procedure for stabilizing stannous fluoride in solution by forcing it into glycerin. New topical fluoride treatment concentrates, fluoride containing gels and prophylaxis pastes, as well as a completely stable stannous fluoride dentifrice are made possible by the development of a rather complicated heat application method to force stannous fluoride into solution in glycerin. That the stannous fluoride is clinically effective in such a preparation is demonstrated briefly on orthodontic patients.

  13. Press forging and optical properties of lithium fluoride

    Science.gov (United States)

    Ready, J. F.; Vora, H.

    1980-07-01

    Lithium fluoride is an important candidate material for windows on high power, short-pulse ultraviolet and visible lasers. Lithium fluoride crystals were press forged in one step over the temperature range 300 to 600 C to obtain fine grained polycrystalline material with improved mechanical properties. The deformation that can be given to a lithium fluoride crystal during forging is limited by the formation of internal cloudiness (veiling) with the deformation limit increasing with increasing forging temperature from about 40 percent at 400 C to 65 percent at 600 C. To suppress veiling, lithium fluoride crystals were forged in two steps over the temperature range 300 to 600 C, to total deformations of 69 to 76 percent, with intermediate annealing at 700 C. This technique yields a material which has lower scattering with more homogeneous microstructure than that obtained in one step forging. The results of characterization of various optical and mechanical properties of single crystal and forged lithium fluoride, including scattering, optical homogeneity, residual absorption, damage thresholds, environmental stability, and thresholds for microyield are described.

  14. Press forging and optical properties of lithium fluoride

    International Nuclear Information System (INIS)

    Ready, J.F.; Vora, H.

    1979-01-01

    Lithium fluoride is an important candidate material for windows on high-power, short-pulse ultraviolet and visible lasers. Lithium fluoride crystals have been press forged in one step over the temperature range 300 to 600 0 c to obtain fine-grained polycrystalline material with improved mechanical properties. The deformation that can be given to a lithium fluoride crystal during forging is limited by the formation of internal cloudiness (veiling) with the deformation limit increasing with increasing forging temperature from about 40% at 400 0 C to 65% at 600 0 C. To suppress veiling, lithium fluoride crystals were forged in two steps over the temperature range 300 to 600 0 C, to total deformations of 69-76%, with intermediate annealing at 700 0 C. This technique yields a material which has lower scattering with more homogeneous microstructure than that obtained in one-step forging. The results of characterization of various optical and mechanical properties of single-crystal and forged lithium fluoride, including scattering, optical homogeneity, residual absorption, damage thresholds, environmental stability, and thresholds for microyield are described

  15. Effects of fluorides on plants

    Energy Technology Data Exchange (ETDEWEB)

    Yamazoe, F

    1975-11-01

    Fluorine compounds known to be air pollutants, such as hydrogen fluoride and silicon tetrachloride, are highly poisonous to plants even at ppm - ppb levels. As solid microparticles, acidic sodium fluoride and cryolite cause problems by adhering to plant leaves and absorbing into plant bodies. Plants are classified by their susceptibility to hydrogen fluoride: gladiolus, apricot, buckwheat, turnip and Vaccinium vitis-idaea are most susceptible showing slight injury at less than 5 ppb for 7-9 days; maize, pepper, and dahlia are fairly susceptible, followed by azalea, rose, lilac, and alfalfa, then by oak and tomato. Gladiolus is used as an indicator plant. The exposure factor for one species was known. The symptoms of plants exposed to gaseous fluorine compounds are described in detail at various concentrations. The causal mechanism of the injuries due to fluorine compounds is described in detail, with the method of determining the fluorine content of plant parts. 7 references.

  16. SBIR-Long fluoride fiber

    Science.gov (United States)

    Jaeger, Raymond E.; Vacha, Lubos J.

    1987-08-01

    This report summarizes results obtained under a program aimed at developing new techniques for fabricating long lengths of heavy metal fluoride glass (HMFG) optical fiber. A new method for overcladding conventional HMFG preforms with a low melting oxide glass was developed, and improvements in the rotational casting method were made to increase preform length. The resulting composite glass canes consist of a fluoride glass overcoat layer to enhance strength and chemical durability. To show feasibility, prototype optical fiber preforms up to 1.6 cm in diameter with lengths of 22 cm were fabricated. These were drawn into optical fibers with lengths up to 900 meters.

  17. SITUATION OF FLUORIDES RATE IN WATERS AND MAJOR CONSUMED FOOD IN WILAYA EL-OUED

    Directory of Open Access Journals (Sweden)

    A. Zobeidi

    2015-08-01

    Full Text Available The effects of mineral salts in the drinking water, beneficial or harmful depending on their concentration, are known for many years and thus the problem posed                     by fluoride ions in the waters of the region (Fluorosis Dental and skeletal. This                  study proposes, the estimated daily intake of fluoride from its water distribution and           the main food consumed per capita in the region of El-Oued (dates, tea,                          couscous, lentils, carrots, potatoes, pumpkin ..., which has a significant content of fluoride in their composition. In addition to the arid climatic conditions, the air temperature is very high in summer, leads to a strong human perspiration. This preliminary result leads us to propose a standard fluoride-specific region of El-Oued. The results showed that the majority of water samples and analyzed the main foods of the region of El-Oued is charged fluoride ions and exceed the maximum dose recommended for adults from 0.05 to 0.07 mg / kg / day.

  18. IMPACT OF FLUORIDE ON DENTAL HEALTH QUALITY.

    Science.gov (United States)

    Medjedovic, Eida; Medjedovic, Senad; Deljo, Dervis; Sukalo, Aziz

    2015-12-01

    Fluoride is natural element that strengthens teeth and prevents their decay. Experts believe that the best way to prevent cavities is the use of fluoride from multiple sources. Studies even show that in some cases, fluoride can stop already started damage of the teeth. In children younger than 6 years fluoride is incorporated into the enamel of permanent teeth, making the teeth more resistant to the action of bacterial and acids in food. The aim of this study is to determine the effects of improving the health status of teeth after six months treatment with the use of topical fluoridation 0.5% NaF, and the level and quality of the impact of treatment with chemical 0.5% NaF on the dental health of children at age from 8 to 15 years, in relation to gender and chronological age. This study included school children aged 8 to 15 years who visited health and dental services dependent in Mostar. It is obvious that after the implementation of treatment with 5% NaF by the method of topical fluoridation, health status of subjects from the experimental group significantly improved, so that at the final review 89.71% or 61 subjects of the experimental group had healthy (cured teeth), tooth with dental caries only 5.88% or 4 respondents tooth with dental caries and filling 4.41% or 3 respondents, extracted baby tooth 14.71% or 10 respondents, while for 13.24% of respondents was identified state with still unerupted teeth. Our findings are indirectly confirmed that the six-month treatment of fluoridation with 5% NaF, contributed to statistically significant improvement in overall oral health of the experimental group compared to the control group which was not treated by any dental treatment. It can be concluded that there is a statistically significant difference in the evaluated parameters of oral health of children in the control group compared to the studied parameters of oral health the experimental group of children at the final dental examination.

  19. Fluoride caused thyroid endocrine disruption in male zebrafish (Danio rerio).

    Science.gov (United States)

    Jianjie, Chen; Wenjuan, Xue; Jinling, Cao; Jie, Song; Ruhui, Jia; Meiyan, Li

    2016-02-01

    Excessive fluoride in natural water ecosystem has the potential to detrimentally affect thyroid endocrine system, but little is known of such effects or underlying mechanisms in fish. In the present study, we evaluated the effects of fluoride on growth performance, thyroid histopathology, thyroid hormone levels, and gene expressions in the HPT axis in male zebrafish (Danio rerio) exposed to different determined concentrations of 0.1, 0.9, 2.0 and 4.1 M of fluoride to investigate the effects of fluoride on thyroid endocrine system and the potential toxic mechanisms caused by fluoride. The results indicated that the growth of the male zebrafish used in the experiments was significantly inhibited, the thyroid microtrastructure was changed, and the levels of T3 and T4 were disturbed in fluoride-exposed male fish. In addition, the expressional profiles of genes in HPT axis displayed alteration. The expressions of all studied genes were significantly increased in all fluoride-exposed male fish after exposure for 45 days. The transcriptional levels of corticotrophin-releasing hormone (CRH), thyroid-stimulating hormone (TSH), thyroglobulin (TG), sodium iodide symporter (NIS), iodothyronine I (DIO1), and thyroid hormone receptor alpha (TRα) were also elevated in all fluoride-exposed male fish after 90 days of exposure, while the inconsistent expressions were found in the mRNA of iodothyronineⅡ (DIO2), UDP glucuronosyltransferase 1 family a, b (UGT1ab), transthyretin (TTR), and thyroid hormone receptor beta (TRβ). These results demonstrated that fluoride could notably inhibit the growth of zebrafish, and significantly affect thyroid endocrine system by changing the microtrastructure of thyroid, altering thyroid hormone levels and endocrine-related gene expressions in male zebrafish. All above indicated that fluoride could pose a great threat to thyroid endocrine system, thus detrimentally affected the normal function of thyroid of male zebrafish. Copyright © 2015

  20. Contribution of chloride channel permease to fluoride resistance in Streptococcus mutans.

    Science.gov (United States)

    Murata, Takatoshi; Hanada, Nobuhiro

    2016-06-01

    Genes encoding fluoride transporters have been identified in bacterial and archaeal species. The genome sequence of the cariogenic Streptococcus mutans bacteria suggests the presence of a putative fluoride transporter, which is referred to as a chloride channel permease. Two homologues of this gene (GenBank locus tags SMU_1290c and SMU_1289c) reside in tandem in the genome of S. mutans The aim of this study was to determine whether the chloride channel permeases contribute to fluoride resistance. We constructed SMU_1290c- and SMU_1289c-knockout S. mutans UA159 strains. We also constructed a double-knockout strain lacking both genes. SMU_1290c or SMU_1289c was transformed into a fluoride transporter- disrupted Escherichia coli strain. All bacterial strains were cultured under appropriate conditions with or without sodium fluoride, and fluoride resistance was evaluated. All three gene-knockout S. mutans strains showed lower resistance to sodium fluoride than did the wild-type strain. No significant changes in resistance to other sodium halides were recognized between the wild-type and double-knockout strains. Both SMU_1290c and SMU_1289c transformation rescued fluoride transporter-disrupted E. coli cell from fluoride toxicity. We conclude that the chloride channel permeases contribute to fluoride resistance in S. mutans. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Influence of fluoride on aluminum toxicity to Atlantic salmon (Salmo salar)

    Science.gov (United States)

    Hamilton, Steven J.; Haines, Terry A.

    1995-01-01

    Atlantic salmon (Salmo salar) alevins were exposed to various aluminum (0–4700 μg/L) and four fluoride (0–500 μg/L) concentrations at two pH values (5.5 and 6.5) for 4- and 30-d periods. In the 4-d tests, aluminum with fluoride was less toxic at pH 6.5 than at pH 5.5, whereas without fluoride, pH had no effect. In the 30-d test, mortality in all treatments was 17–21% at pH 5.5, but only 3–7% at pH 6.5. Fish length and weight after 30 d were reduced in all fluoride–aluminum treatments at pH 5.5, but only in the 200-μg/L aluminum without fluoride treatment at pH 6.5. At pH 5.5 and 6.5 without aluminum, histomorphological examinations revealed no abnormalities in gill tissue. However, in aluminum exposure with no fluoride, gill filaments and secondary lamellae were swollen and thickened. Addition of fluoride at pH 6.5 alleviated some gill damage. At pH 5.5 and 200 μg/L aluminum, addition of 100 μg/L fluoride reduced swelling of gill lamellae, but 200 μg/L fluoride did not reduce swelling. Low fluoride concentrations (fluoride concentrations (> 100 μg/L) may not reduce aluminum-induced effects.

  2. The differences in healthcare utilization for dental caries based on the implementation of water fluoridation in South Korea.

    Science.gov (United States)

    Cho, Myung-Soo; Han, Kyu-Tae; Park, Sohee; Moon, Ki Tae; Park, Eun-Cheol

    2016-11-08

    There were some debates about the water fluoridation program in South Korea, even if the program had generally substantial effectiveness. Because the out-of-pocket expenditures for dental care were higher in South Korea than in other countries, an efficient solution was needed. Therefore, we examined the relationship between the implementation of water fluoridation and the utilization of dental care. We used the National Health Insurance Service National Sample Cohort. In this study, data finally included 472,250 patients who were newly diagnosed with dental caries during 2003-2013. We performed survival analysis using cox proportional hazard model, negative binomial-regression, and regression analyses using generalized estimating equation models. There were 48.49 % outpatient dental care visit during study period. Individuals with water fluoridation had a lower risk of dental care visits (HR = 0.949, 95 % CI = 0.928-0.971). Among the individuals who experienced a dental care visit, those with water fluoridation program had a lower number of dental care visits (β = -0.029), and the period of water fluoridation had an inverse association with the dental care expenditures. The implementation of water fluoridation programs and these periods are associated with reducing the utilization of dental health care. Considering these positive impacts, healthcare professionals must consider preventive strategies for activating water fluoridation programs, such as changes in public perception and relations, for the effective management of dental care in South Korea.

  3. Histopathological Effects of Varied Fluoride Concentration on Cerebrum in Albino Rats

    Directory of Open Access Journals (Sweden)

    Sajad Hamid

    2012-02-01

    Full Text Available Fluorides have been a cause of concern for scientists and environmentalists for the long because of their harmful effects on the human and animal life but the problem was highlighted during the twentieth century because of great increase in the human population and industrialization. Since fluorides accumulate in calcified and hard tissues of the body such as bone and teeth and can be detected easily in these tissues, so most of the previous studies focused on the effects of fluorides on these tissues. However, during the past decade researchers all over the world have felt that there is a need to study the effects of fluorides on various other tissues of the body including CNS as fluoride intake for prolonged period is known to cause abnormal behavioural pattern, grave implications for Alzheimer’s Disease, Dementia, Attention deficit disorder and reduced I.Q in children as the fluorides are known to cross blood brain barrier. Hence the present study has thrown light on the involvement of brain in chronic fluoride toxicity. The target organ of studied was cerebrum. In the Study, albino rats were exposed to 30 or 100 ppm fluoride (asNaF in drinking water for 3 months. Rats exposed to 30 ppm fluoride did not show any notable alterations in brain histology, whereas rats exposed to 100 ppm fluoride showed significant neurodegenerative changes in lhe motor cortex.Changes included decrease in size and number of neurons in all the regions, signs of chromatolysis and gliosis in the motor cortex. These histological changes suggest a toxic effect of high-fluoride intake & on chronic use. [J Interdiscipl Histopathol 2012; 1(1.000: 30-34

  4. Association between Urine Fluoride and Dental Fluorosis as a Toxicity Factor in a Rural Community in the State of San Luis Potosi

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    Lizet Jarquín-Yañez

    2015-01-01

    Full Text Available Objective. The aim of this study is to investigate urine fluoride concentration as a toxicity factor in a rural community in the state of San Luis Potosi, Mexico. Materials and Methods. A sample of 111 children exposed to high concentrations of fluoride in drinking water (4.13 mg/L was evaluated. Fluoride exposure was determined by measuring urine fluoride concentration using the potentiometric method with an ion selective electrode. The diagnosis of dental fluorosis was performed by clinical examination, and the severity of damage was determined using Dean’s index and the Thylstrup-Fejerskov (TF index. Results. The range of exposure in the study population, evaluated through the fluoride content in urine, was 1.1 to 5.9 mg/L, with a mean of 3.14 ± 1.09 mg/L. Dental fluorosis was present in all subjects, of which 95% had severe cases. Higher urine fluoride levels and greater degrees of severity occurred in older children. Conclusions. The results show that dental fluorosis was determined by the presence of fluoride exposure finding a high positive correlation between the severity of fluorosis and urine fluoride concentration and the years of exposure suggested a cumulative effect.

  5. Dental fluorosis and urinary fluoride concentration as a reflection of fluoride exposure and its impact on IQ level and BMI of children of Laxmisagar, Simlapal Block of Bankura District, W.B., India.

    Science.gov (United States)

    Das, Kousik; Mondal, Naba Kumar

    2016-04-01

    There has been growing public concern about intellectual performance of children at high levels of fluoride exposure. A cross-sectional study was conducted in Simlapal Block of Bankura District, West Bengal, to find out the relationship between fluoride (F) exposure as exposure dose (ED) with dental fluorosis (DF), urinary fluoride concentration (UF), intelligence quotient (IQ) and body mass index (BMI). Fifty groundwater samples were collected from the target area. One hundred forty-nine children belonging to age group 6 to 18 years were considered for this study. Experimental results reveal that mean F(-) concentration of that area is 2.11 mg/L (±SD 1.64). On the basis of F concentration in groundwater and water consumption pattern, ED was calculated to explore the impact of F(-) on DF, UF, IQ, and BMI. Paired t test results suggest that exposure rate of F does not show any significant differences ( severe > mild > very mild > questionable > normal conditions. The highest UF concentration was recorded as 17 mg/L, but the status of DF in the affected children was recorded as moderate. The results also reveal that ED has a positive correlation with DF (r = 0.299, P fluoride toxicity.

  6. Urinary fluoride as a monitoring tool for assessing successful intervention in the provision of safe drinking water supply in five fluoride-affected villages in Dhar district, Madhya Pradesh, India.

    Science.gov (United States)

    Srikanth, R; Gautam, Anil; Jaiswal, Suresh Chandra; Singh, Pavitra

    2013-03-01

    Endemic fluorosis was detected in 31 villages in the Dhar district of Madhya Pradesh, Central India. Out of the 109 drinking water sources that were analyzed, about 67 % were found to contain high concentration of fluoride above the permissible level of 1.0 mg/l. Dental fluorosis among the primary school children in the age between 8 and 15 served as primary indicator for fluoride intoxication among the children. Urinary fluoride levels among the adults were found to be correlated with drinking water fluoride in 10 villages affected by fluoride. Intervention in the form of alternate safe water supply in five villages showed significant reduction in the urinary fluoride concentration when compared to the control village. Urinary fluoride serves as an excellent marker for assessing the effectiveness of intervention program in the fluoride-affected villages.

  7. Combinatorial effects of arginine and fluoride on oral bacteria.

    Science.gov (United States)

    Zheng, X; Cheng, X; Wang, L; Qiu, W; Wang, S; Zhou, Y; Li, M; Li, Y; Cheng, L; Li, J; Zhou, X; Xu, X

    2015-02-01

    Dental caries is closely associated with the microbial disequilibrium between acidogenic/aciduric pathogens and alkali-generating commensal residents within the dental plaque. Fluoride is a widely used anticaries agent, which promotes tooth hard-tissue remineralization and suppresses bacterial activities. Recent clinical trials have shown that oral hygiene products containing both fluoride and arginine possess a greater anticaries effect compared with those containing fluoride alone, indicating synergy between fluoride and arginine in caries management. Here, we hypothesize that arginine may augment the ecological benefit of fluoride by enriching alkali-generating bacteria in the plaque biofilm and thus synergizes with fluoride in controlling dental caries. Specifically, we assessed the combinatory effects of NaF/arginine on planktonic and biofilm cultures of Streptococcus mutans, Streptococcus sanguinis, and Porphyromonas gingivalis with checkerboard microdilution assays. The optimal NaF/arginine combinations were selected, and their combinatory effects on microbial composition were further examined in single-, dual-, and 3-species biofilm using bacterial species-specific fluorescence in situ hybridization and quantitative polymerase chain reaction. We found that arginine synergized with fluoride in suppressing acidogenic S. mutans in both planktonic and biofilm cultures. In addition, the NaF/arginine combination synergistically reduced S. mutans but enriched S. sanguinis within the multispecies biofilms. More importantly, the optimal combination of NaF/arginine maintained a "streptococcal pressure" against the potential growth of oral anaerobe P. gingivalis within the alkalized biofilm. Taken together, we conclude that the combinatory application of fluoride and arginine has a potential synergistic effect in maintaining a healthy oral microbial equilibrium and thus represents a promising ecological approach to caries management. © International & American

  8. Impact of combined CO2 laser irradiation and fluoride on enamel and dentin biofilm-induced mineral loss.

    Science.gov (United States)

    Esteves-Oliveira, Marcella; El-Sayed, Karim Fawzy; Dörfer, Christof; Schwendicke, Falk

    2017-05-01

    The caries-protective effects of CO 2 laser irradiation on dental enamel have been demonstrated using chemical demineralization models. We compared the effect of CO 2 laser irradiation, sodium fluoride, or both on biofilm-induced mineral loss (∆Z) and Streptococcus mutans adhesion to enamel and dentin in vitro. Ground, polished bovine enamel, and dentin samples were allocated to four groups (n = 12/group): no treatment (C); single 22,600-ppm fluoride (F) varnish (5 % NaF) application; single CO 2 laser treatment (L) with short pulses (5 μs/λ = 10.6 μm); and laser and subsequent fluoride treatment (LF). Samples were sterilized and submitted to an automated mono-species S. mutans biofilm model. Brain heart infusion plus 5 % sucrose medium was provided eight times daily, followed by rinses with artificial saliva. After 10 days, bacterial numbers in biofilms were enumerated as colony-forming units/ml (CFU/ml) (n = 7/group). ∆Z was assessed using transversal microradiography (n = 12/group). Univariate ANOVA with post hoc Tukey honestly-significant-difference test was used for statistical analysis. Bacterial numbers were significantly higher on dentin than enamel (p  0.05). In dentin, only LF (163/227) significantly reduced ∆Z (p fluoride application was required to protect dentin.

  9. Caries and fluoridated water in two Brazilian municipalities with low prevalence of the disease

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    Mariângela Guanaes Bortolo da Cruz

    2018-04-01

    Full Text Available ABSTRACT OBJECTIVE To analyze the association between exposure to fluoridated water and dental caries in a context of widespread use of fluoride toothpaste in Brazil, in a scenario of low prevalence of the disease. METHODS This is a cross-sectional observational study, of the census type, in the form of a double population-based epidemiological survey carried out in two municipalities of the state of São Paulo in 2014. The sample consisted of adolescents aged 11 and 12 years, exposed (n = 184 or not exposed (n = 128 to fluoridated water for at least five years. The populations studied lived in communities of the same geographic region and had small demographic size and similar socioeconomic classification, differing only in the exposure (Silveiras or not exposure (São José do Barreiro to fluoridated water. The experience, magnitude, and degree of polarization of dental caries in these populations were analyzed using the DMFT and SiC indexes, and the association was tested using Pearson’s chi-square statistics and prevalence ratio between those not exposed and those exposed to fluoridated water. RESULTS Although caries experience (DMFT ≥ 1 was not associated with exposure to fluoridated water (chi-square = 1.78; p = 0.18; α = 5%, a significant difference was observed in the magnitude with which the disease reached the population: the means of DMFT were 1.76 in those exposed and 2.60 in those not exposed and the means of SiC were 4.04 and 6.16, respectively. The degree of polarization, indicated by the percentage of subjects with DMFT = 0, was different, being it higher (41.8% in subjects exposed and lower (34.3% in subjects not exposed. The prevalence ratio between those not exposed and those exposed was 1.13, indicating little expressiveness in prevalence difference. CONCLUSIONS Exposure to fluoridated water implied lower mean values for the DMFT and SiC indexes, even in the presence of the concomitant exposure to fluoridated toothpaste

  10. The protective effect of curcumin against sodium fluoride-induced oxidative stress in rat heart

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    Nabavi S.F.

    2011-01-01

    Full Text Available In the present study the cardioprotective effects of curcumin, a herbal polyphenolic compound, against sodium fluoride (NaF-induced toxicity in rat heart was evaluated. Fifty rats were divided into five experimental groups containing 10 rats each. Group I received standard water and diet and was used as a normal group; groups II and III were pretreated with curcumin intraperitoneally for 7 days prior to NaF intoxication. Group IV was pretreated with vitamin C, a standard antioxidant, intraperitoneally for 7 days prior to NaF intoxication and used as a positive control group. The animals in group V were intoxicated with NaF for the same time and used as a control group. There was a significant increase in lipid peroxidation along with a decrease in superoxide dismutase activity in the homogenates of tissues of the NaF-treated animals. Curcumin pretreatment in animals prior to fluoride intoxication normalized the levels of biochemical parameters measured.

  11. The Application of the Fluoride Reactivation Process to the Detection of Sarin and Soman Nerve Agent Exposures in Biological Samples

    National Research Council Canada - National Science Library

    Adams, T. K; Capacio, B. R; Smith, J. R; Whalley, C. E; Korte, W. D

    2004-01-01

    The fluoride reactivation process was evaluated for measuring the level of sarin or soman nerve agents reactivated from substrates in plasma and tissue from in vivo exposed guinea pigs (Cava porcellus...

  12. Pollution level and inhalation exposure of ambient aerosol fluoride as affected by polymetallic rare earth mining and smelting in Baotou, north China

    Science.gov (United States)

    Zhong, Buqing; Wang, Lingqing; Liang, Tao; Xing, Baoshan

    2017-10-01

    Airborne fluoride associated with total suspended particles (TSP) and respirable particulate (PM10) in the rare earth mining and smelting areas were analyzed during August 2012 and March 2013. In March, average concentrations of fluoride bound to TSP in the mining and smelting areas were 0.598 ± 0.626 μg/m3 and 3.615 ± 4.267 μg/m3, respectively, whereas that in August were 0.699 ± 0.801 μg/m3 and 1.917 ± 2.233 μg/m3, respectively. TSP samples were classified into four categories by different sampling periods and locations using Kohonen's self-organizing map, which demonstrates that high airborne fluoride concentrations in March in the smelting area were probably attributed to industrial emissions from smelting activities and wind-blown dust from tailings pond, influenced by meteorologic parameters such as temperature, relative humidity, precipitation and wind speed. The mean daily amount of fluoride inhaled in the mining and smelting areas were estimated to be in the range of 2.77-57.61 μg/day and 3.39-64.32 μg/day, respectively. These results indicate the high potential exposure level of fluoride inhaled for local residents in the polymetallic mining and smelting areas.

  13. Decomposição de amostras de solos assistida por radiação microondas: estratégia para evitar a formação de fluoretos insolúveis Microwave-assisted decomposition of soil samples: strategies to avoid formation of insoluble fluoride salts

    Directory of Open Access Journals (Sweden)

    Edivan Carvalho Vieira

    2005-07-01

    Full Text Available A decomposição de amostras que contêm elevados teores de Si, utilizando mistura com os ácidos nítrico e fluorídrico, pode provocar a precipitação de fluoretos de Al(III, Ca(II, Fe(III e Mg(II durante a digestão, impedindo a recuperação total desses elementos. Visando minimizar esse problema, foram testados quatro procedimentos aplicados a diferentes amostras de solos. O procedimento mais eficiente envolveu a decomposição assistida por radiação microondas, seguida pela separação do material sólido residual com elevado teor de Si do sobrenadante ácido. A fração residual foi solubilizada usando HF concentrado e, após complexação com ácido bórico, essa solução foi misturada à fase líquida do digerido. Os teores de metais nos digeridos foram determinados por espectrometria de emissão óptica em plasma induzido (ICP OES e a exatidão foi demonstrada aplicando o procedimento proposto em amostras provenientes do programa colaborativo International Soil-Analytical Exchange (ISE, Wegening Agricultural University, Holanda e em amostra certificada de solo proveniente do National Institute of Standard and Technology (NIST, SRM 2709, que apresentou respectivamente, os seguintes percentuais de recuperação: 100,0 ± 2,6; 99,5 ± 1,9; 108,5 ± 2,7; 94,6 ± 8,9; 92,2 ± 9,7; 95,7 ± 1,8; 96,7 ± 2,7; 95,2 ± 0,6; 103,6 ± 2,6 e 96,1 ± 1,6 para, Al, Ba, Ca, Cr, Cu, Fe, Mg, Mn, V e Zn.The use of pre-mixed nitric and hydrofluoric acids for the decomposition of samples containing high amounts of Si can cause the precipitation of Al(III, Ca(II, Fe(III, and Mg(II fluorides during digestion, reducing the total recovery of these elements. Four procedures were applied to certified soil samples in an attempt to circumvent this problem. The most efficient procedure was based on microwave-assisted acid digestion decomposition of the samples, followed by separation of the residual silicate compounds. This fraction was solubilized using

  14. Probability of foliar injury for Acer sp. based on foliar fluoride concentrations.

    Science.gov (United States)

    McDonough, Andrew M; Dixon, Murray J; Terry, Debbie T; Todd, Aaron K; Luciani, Michael A; Williamson, Michele L; Roszak, Danuta S; Farias, Kim A

    2016-12-01

    Fluoride is considered one of the most phytotoxic elements to plants, and indicative fluoride injury has been associated over a wide range of foliar fluoride concentrations. The aim of this study was to determine the probability of indicative foliar fluoride injury based on Acer sp. foliar fluoride concentrations using a logistic regression model. Foliage from Acer nedundo, Acer saccharinum, Acer saccharum and Acer platanoides was collected along a distance gradient from three separate brick manufacturing facilities in southern Ontario as part of a long-term monitoring programme between 1995 and 2014. Hydrogen fluoride is the major emission source associated with the manufacturing facilities resulting with highly elevated foliar fluoride close to the facilities and decreasing with distance. Consistent with other studies, indicative fluoride injury was observed over a wide range of foliar concentrations (9.9-480.0 μg F -  g -1 ). The logistic regression model was statistically significant for the Acer sp. group, A. negundo and A. saccharinum; consequently, A. negundo being the most sensitive species among the group. In addition, A. saccharum and A. platanoides were not statistically significant within the model. We are unaware of published foliar fluoride values for Acer sp. within Canada, and this research provides policy maker and scientist with probabilities of indicative foliar injury for common urban Acer sp. trees that can help guide decisions about emissions controls. Further research should focus on mechanisms driving indicative fluoride injury over wide ranging foliar fluoride concentrations and help determine foliar fluoride thresholds for damage.

  15. Combinatorial Effects of Arginine and Fluoride on Oral Bacteria

    OpenAIRE

    Zheng, X.; Cheng, X.; Wang, L.; Qiu, W.; Wang, S.; Zhou, Y.; Li, M.; Li, Y.; Cheng, L.; Li, J.; Zhou, X.; Xu, X.

    2015-01-01

    Dental caries is closely associated with the microbial disequilibrium between acidogenic/aciduric pathogens and alkali-generating commensal residents within the dental plaque. Fluoride is a widely used anticaries agent, which promotes tooth hard-tissue remineralization and suppresses bacterial activities. Recent clinical trials have shown that oral hygiene products containing both fluoride and arginine possess a greater anticaries effect compared with those containing fluoride alone, indicati...

  16. Structures and Heats of Formation of Simple Alkaline Earth Metal Compounds II: Fluorides, Chlorides, Oxides, and Hydroxides for Ba, Sr, and Ra.

    Science.gov (United States)

    Vasiliu, Monica; Hill, J Grant; Peterson, Kirk A; Dixon, David A

    2018-01-11

    Geometry parameters, vibrational frequencies, heats of formation, bond dissociation energies, cohesive energies, and selected fluoride affinities (difluorides) are predicted for the late alkaline earth (Sr, Ba, and Ra) oxides, fluorides, chlorides, and hydroxides at the coupled cluster theory CCSD(T) level. Additional corrections (scalar relativistic and pseudopotential corrections, vibrational zero-point energies, and atomic spin-orbit effects) were included to accurately calculate the total atomization energies and heats of formation following the Feller-Peterson-Dixon methodology. The calculated values are compared to the experimental data where available. In some cases, especially for Ra compounds, there are no experimental results, or the experimental energetics and geometries are not reliable or have very large error bars. All of the Sr, Ba, and Ra difluorides, dichlorides, and dihydroxides are bent structures with the OMO bond angles decreasing going down the group. The cohesive energies of bulk Be dihalides are predicted to be quite low, while those of Ra are relatively large. The fluoride affinities show that the difluorides are moderately strong Lewis acids and that such trifluorides may form under the appropriate experimental conditions.

  17. Indirect complexometric determination of thorium(IV) using sodium fluoride as masking agent

    International Nuclear Information System (INIS)

    Sreekumar, N.V.; Nazareth, R.A.; Narayana, B.; Hegde, P.; Manjunatha, B.R.

    2002-01-01

    A complexometric method for the determination of thorium(IV) in presence of other metal ions based on the selective masking ability of sodium fluoride towards thorium is described. Thorium(IV) present in a given sample solution is first complexed with a known excess of EDTA and the surplus EDTA is titrated against bismuth nitrate solution at pH 2-3 using xylenol orange as indicator. A known excess of sodium fluoride (5 %) is then added and the EDTA released from the Th-EDTA complex is titrated against standard bismuth nitrate solution. Reproducible and accurate results are obtained for 5 mg to 280 mg of thorium with relative errors ±0.65 % and standard deviations /leq 0.75 mg. The interference of various ions was studied. (author)

  18. Formulation of microemulsion propolis fluoride (PF) as varnish topical agent to stop activity of teeth caries

    Science.gov (United States)

    Sahlan, Muhamad; Prakoso, Chandra Dwi; Darwita, Risqa Rina; Hermansyah, Heri

    2017-02-01

    Topical fluoride is proven to have higher efficacy in preventing dental caries with low production cost and easy to apply. The objective of this research is to formulate alternative agent topical fluoride NH4F 5% mixed with extract ethanol propolis (EEP) in the micro-emulsion system that has high stability, antimicrobial activity, and remineralization capability to arrest teeth caries activity. By using total plate count (TPC) analysis, formulation 2.7% EEP; 6,3% surfactant; and 90,9% NH4F shows good perform to inhibit cariogenic bacteria development around 78-80%. Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray (EDX) result also showed that sample successfully remineralized enamel surface. In addition, sample showed good pH, flavonoid, and polyphenol stability for 40 days.

  19. Profile of Fluoride Release from a Nanohybrid Composite Resin

    Directory of Open Access Journals (Sweden)

    Raquel Assed Bezerra Silva

    2015-02-01

    Full Text Available The aim of this study was to evaluate in vitro the amount and profile of fluoride release from a fluoride-containing nanohybrid composite resin (Tetric® N-Ceram by direct potentiometry. Thirty specimens (5 mm diameter x 3 mm high; n=10/material were made of Tetric® N-Ceram, Vitremer® resin-modified glass ionomer cement (RMGIC (positive control or Filtek® Z350 nanofill composite resin (negative control. The specimens were stored individually in plastic tubes containing 1 mL of artificial saliva at 37°C, which was daily renewed during 15 days. At each renewal of saliva, the amount of fluoride ions released in the solution was measured using a fluoride ion-selective electrode with ion analyzer, and the values obtained in mV were converted to ppm (µg/mL. Data were analyzed statistically by ANOVA and Tukey’s post-hoc test at a significance level of 5%. The results showed that the resins Tetric® N-Ceram and Filtek® Z350 did not release significant amounts of fluoride during the whole period of evaluation (p>0.05. Only Vitremer® released significant amounts of fluoride ions during the 15 days of the experiment, with greater release in first 2 days (p0.05. In conclusion, the nanohybrid composite resin Tetric® N-Ceram did not present in vitro fluoride-releasing capacity throughout the 15 days of study.

  20. Comparison of the performance of different modified graphene oxide nanosheets for the extraction of Pb(II) and Cd(II) from natural samples

    International Nuclear Information System (INIS)

    Sayar, Omid; Mehrani, Kheirollah; Mehrani, Azadeh; Hoseinzadeh, Fatemeh; Sadeghi, Omid

    2014-01-01

    Graphene nanosheets were modified with amino groups and the resulting material was used as a sorbent for the extraction of cadmium and lead ions. The nanosheets were characterized by IR spectroscopy, transmission electron microscopy, thermal gravimetric analysis and elemental analysis. The effects of sample pH, eluent parameters (type, concentration and volume of eluent), flow rates (of both sample and eluent), and of a variety of other ions on the efficiency of the extraction of Cd(II) and Pb(II) were optimized. Following solid phase extraction, the elements were determined by FAAS. The limits of detection are <0.9 μg L −1 for Pb(II) and <5 ng L −1 for Cd(II). The relative standard deviations are <2.2 %. The method was validated by analyzing several certified reference materials and was then used for Pb(II) and Cd(II) determination in natural waters and vegetables. (author)

  1. Fluoride influences nickel-titanium orthodontic wires′ surface texture and friction resistance

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    Mona Aly Abbassy

    2016-01-01

    Full Text Available Objectives: The aim of this study was to investigate the effects exerted by the acidulated fluoride gel on stainless steel and nickel-titanium (Ni-Ti orthodontic wires. Materials and Methods: Sixty stainless steel and Ni-Ti orthodontic archwires were distributed into forty archwires used for in vitro study and twenty for in situ study. Fluoride was applied for 1 h in the in vitro experiment while it was applied for 5 min in the in situ experiment. The friction resistance of all wires with ceramic brackets before/after topical fluoride application was measured using a universal testing machine at 1 min intervals of moving wire. Moreover, surface properties of the tested wires before/after fluoride application and before/after friction test were examined by a scanning electron microscope (SEM. Dunnett′s t-test was used to compare frictional resistance of as-received stainless steel wires and Ni-Ti wires to the wires treated by fluoride in vitro and in situ (P < 0.05. Two-way ANOVA was used to compare the effect of fluoride application and type of wire on friction resistance in vitro and in situ (P < 0.05. Results: Ni-Ti wires recorded significantly high friction resistance after fluoride application when compared to stainless steel wires in vitro, P < 0.05. Fluoride application did not significantly affect the friction resistance of the tested wires in situ, P < 0.05. SEM observation revealed deterioration of the surface texture of the Ni-Ti wires after fluoride application in vitro and in situ. Conclusions: The in vitro fluoride application caused an increase in friction resistance of Ni-Ti wires when compared to stainless steel wires. In vitro and in situ fluoride application caused deterioration in surface properties of Ni-Ti wires.

  2. Preparation of Bioactive Titanium Surfaces via Fluoride and Fibronectin Retention

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    Carlos Nelson Elias

    2012-01-01

    Full Text Available Statement of Problem. The chemical or topographic modification of the dental implant surface can affect bone healing, promote accelerated osteogenesis, and increase bone-implant contact and bonding strength. Objective. In this work, the effects of dental implant surface treatment and fibronectin adsorption on the adhesion of osteoblasts were analyzed. Materials and Methods. Two titanium dental implants (Porous-acid etching and PorousNano-acid etching followed by fluoride ion modification were characterized by high-resolution scanning electron microscopy, atomic force microscopy, and X-ray diffraction before and after the incorporation of human plasma fibronectin (FN. The objective was to investigate the biofunctionalization of these surfaces and examine their effects on the interaction with osteoblastic cells. Results. The evaluation techniques used showed that the Porous and PorousNano implants have similar microstructural characteristics. Spectrophotometry demonstrated similar levels of fibronectin adsorption on both surfaces (80%. The association indexes of osteoblastic cells in FN-treated samples were significantly higher than those in samples without FN. The radioactivity values associated with the same samples, expressed as counts per minute (cpm, suggested that FN incorporation is an important determinant of the in vitro cytocompatibility of the surfaces. Conclusion. The preparation of bioactive titanium surfaces via fluoride and FN retention proved to be a useful treatment to optimize and to accelerate the osseointegration process for dental implants.

  3. Effect of fluoride mouthwash on tensile strength of stainless steel orthodontic archwires

    Science.gov (United States)

    Fatimah, D. I.; Anggani, H. S.; Ismah, N.

    2017-08-01

    Patients with orthodontic treatment are commonly recommended to use a fluoride mouthwash for maintaining their oral hygiene and preventing dental caries. However, fluoride may affect the characteristics of stainless steel orthodontic archwires used during treatment. The effect of fluoride mouthwash on the tensile strength of stainless steel orthodontic archwires is still unknown. The purpose of this study is to know the effect of fluoride mouthwash on the tensile strength of stainless steel orthodontic archwires. Examine the tensile strength of 0.016 inch stainless steel orthodontic archwires after immersion in 0.05%, 100 ml fluoride mouthwash for 30, 60, and 90 min. There is no statistically significant difference in the tensile strength of stainless steel orthodontic archwires after immersed in fluoride mouthwash. The p-values on immersion fluoride mouthwash for 30, 60, and 90 min consecutively are 0.790; 0.742; and 0.085 (p > 0.05). The use of fluoride mouthwash did not have an effect on the tensile strength of stainless Steel orthodontic archwires.

  4. Fluoride Consumption and Its Impact on Oral Health

    Directory of Open Access Journals (Sweden)

    Luis Fernando Jacinto-Alemán

    2011-01-01

    Full Text Available Objective. The purpose of this study was to evaluate caries and dental fluorosis among Mexican preschoolers and school-aged children in a non-endemic zone for fluorosis and to measure its biological indicators. Methods. DMFT, DMFS, dmft, dmfs, and CDI indexes were applied. Fluoride urinary excretion and fluoride concentrations in home water, table salt, bottled water, bottled drinks, and toothpaste were determined. Results. Schoolchildren presented fluorosis (CDI = 0.96 and dental caries (DMFT = 2.64 and DMFS = 3.97. Preschoolers presented dmft = 4.85 and dmfs = 8.80. DMFT and DMFS were lower in children with mild to moderate dental fluorosis (DF. Variable fluoride concentrations were found in the analyzed products (home water = 0.18–0.44 ppm F, table salt = 0–485 ppm F, bottled water = 0.18–0.47 ppm F, juices = 0.08–1.42 ppm F, nectars = 0.07–1.30 ppm F, bottled drinks = 0.10–1.70 ppm F, toothpaste = 0–2,053 ppm F. Mean daily fluoride excretion was 422 ± 176 µg/24 h for schoolchildren and 367 ± 150 µg/24 h for preschoolers. Conclusions. Data from our study show that, despite values of excretion within an optimal fluoride intake range, the prevalence of caries was significant in both groups, and 60% of the 11- to 12-year-old children presented with dental fluorosis. In addition, variable fluoride concentrations in products frequently consumed by children were found.

  5. Fluoride removal from aqueous solution by pumice: case study on ...

    African Journals Online (AJOL)

    The fluoride removal from synthetic water by pumice was studied at batch experiments in this study. The effect of pH, contact time, fluoride concentration and adsorbent dose on the fluoride sequestration was investigated. The optimum conditions were studied on Kuhbonan water as a case study. The results showed that ...

  6. Pilot-Scale Removal Of Fluoride From Legacy Plutonium Materials Using Vacuum Salt Distillation

    International Nuclear Information System (INIS)

    Pierce, R. A.; Pak, D. J.

    2012-01-01

    Between September 2009 and January 2011, the Savannah River National Laboratory (SRNL) and HB-Line designed, developed, tested, and successfully deployed a system for the distillation of chloride salts. In 2011, SRNL adapted the technology for the removal of fluoride from fluoride-bearing salts. The method involved an in situ reaction between potassium hydroxide (KOH) and the fluoride salt to yield potassium fluoride (KF) and the corresponding oxide. The KF and excess KOH can be distilled below 1000°C using vacuum salt distillation (VSD). The apparatus for vacuum distillation contains a zone heated by a furnace and a zone actively cooled using either recirculated water or compressed air. During a vacuum distillation operation, a sample boat containing the feed material is placed into the apparatus while it is cool, and the system is sealed. The system is evacuated using a vacuum pump. Once a sufficient vacuum is attaned, heating begins. Volatile salts distill from the heated zone to the cooled zone where they condense, leaving behind the non-volatile material in the feed boat. Studies discussed in this report were performed involving the use of non-radioactive simulants in small-scale and pilot-scale systems as well as radioactive testing of a small-scale system with plutonium-bearing materials. Aspects of interest include removable liner design considerations, boat materials, in-line moisture absorption, and salt deposition

  7. Application of Carrier Element-Free Co-precipitation Method for Ni(II), Cu(II) and Zn(II) Ions Determination in Water Samples Using Chrysin

    International Nuclear Information System (INIS)

    Layth Imad Abd Ali; Wan Aini Wan Ibrahim; Azli Sulaiman; Mohd Marsin Sanagi

    2015-01-01

    A co-precipitation method was developed to separate and pre-concentrate Ni(II), Cu(II) and Zn(II) ions using an organic co precipitant, chrysin without adding any carrier element termed as carrier element-free co-precipitation (CEFC). Analytes were determined using flame atomic absorption spectrometry (FAAS). The influence of analytical conditions, such as pH of the solution, quantity of co-precipitant, standing time, centrifugation rate and time, sample volume, and interference of concomitant ions were investigated over the recovery yields of the trace metals. The limit of detection, the limit of quantification and linearity range obtained from the FAAS measurements were found to be in the range of 0.64 to 0.86 μg L -1 , 2.13 to 2.86 μg L -1 and 0.9972 to 0.9989 for Ni(II), Cu(III) and Zn(II) ions, respectively. The precision of the method, evaluated as the relative standard deviation (RSD) obtained after analyzing a series of 10 replicates, was between 2.6 % to 3.9 % for the trace metal ions. The proposed procedure was applied and validated by analyzing river water reference material for trace metals (SLRS-5) and spiking trace metal ions in some water samples. The recoveries of the analyte metal ions were between 94.7-101.2 %. (author)

  8. The synthesis and structural characterization of novel transition metal fluorides

    Energy Technology Data Exchange (ETDEWEB)

    Casteel, W.J. Jr.

    1992-09-01

    High purity KMF[sub 6] and K[sub 2]MF[sub 6] salts (M = Mo,Re, Ru, Os, Ir, Pt) are obtained from reduction hexafluorides. A rhombohedral unit cell is observed for KReF[sub 6]. Fluoride ion capture by Lewis acids from the hexafluorometallate (IV) salts affords high purity tetrafluorides for M = Mo, Re, Ru, Os, and Pd. The structure of RuF[sub 4] is determined from X-ray synchrotron and neutron powder data. Unit cells based on theorthorhombic PdF[sub 4] type cell are derived from X-ray powder data for ReF[sub 4] and OsF[sub 4]. Fluoride ion capture from KAgF[sub 4] provides the thermally unstable trifluoride as a bright, red, diamagnetic solid. The structure solution of AgF[sub 3] and redetermination of the AuF[sub 3] structure from X-ray synchrotron and neutron powder data demonstrate that the two are isostnictural. Thermal decomposition product of AgF[sub 3] is the mixed valence compound Ag[sup II]Ag[sub 2][sup III]F[sub 8]. Several new salts containing the (Ag - F)[sub n][sup n+] chain cation are prepared. The first linear (Ag - F)[sub n][sup n+] chain is observed in AgF[sup +]BF[sub 4 [sup [minus

  9. The Impact of Selected Fluoridated Toothpastes on Dental Erosion in Profilometric Measurement.

    Science.gov (United States)

    Fita, Katarzyna; Kaczmarek, Urszula

    2016-01-01

    Some fluoridated toothpastes, available commercially, are described to have a protective effect against dental erosion. To evaluate the influence of the selected marketed toothpastes on the human enamel exposed to acid beverages. Enamel specimens from extracted human teeth were prepared (n = 40). Specimens were randomly divided into 10 experimental groups, 4 specimens each, which were subjected to acid challenge for 10 min using orange juice (pH 3.79) or Pepsi Cola (pH 2.58) and then immersed for 2 min into a slurry of five marketed toothpastes with distilled water (1 : 3 w/w). The tested toothpastes contained 1450 or 5000 ppm fluoride, CPP-ACP with 900 ppm fluoride, 1450 ppm fluoride with potassium nitrate 5%, all of them as sodium fluoride, and 700 ppm fluoride as amine and sodium fluoride with 3500 ppm SnCl2. Enamel roughness (Ra parameter) by contact profilometer at baseline and after exposure onto soft drinks and slurry was measured. Exposure to both beverages caused a similar increase of enamel surface roughness. After the specimens immersion into slurries of toothpastes with 1450 or 5000 ppm fluoride, 1450 ppm fluoride with potassium nitrate 5% and CPP-ACP with 900 ppm fluoride the significant decrease of Ra values were found, reaching the baseline values. However, toothpaste with 700 ppm fluoride and 3500 ppm SnCl2 did not cause any fall in Ra value, probably due to other mechanism of action. Within the limitation of the study we can conclude that the sodium fluoride toothpastes are able to restore the surface profile of enamel exposed shortly to acidic soft drinks.

  10. Fluoride in dental biofilm and saliva

    DEFF Research Database (Denmark)

    Larsen, Line Staun

    Dette ph.d.-projekt bidrager med ny viden om fordelingen af fluorid i dental biofilm og saliva. For at udforske koncentrationen af fluorid i naturlig (in vivo) biofilmvæske, biofilmsediment og i saliva, blev der udført to meget forskellige kliniske studier. Resultaterne fra tværsnitsstudiet (Studie...... I), hos en stor gruppe mennesker (n=42) der konsulterede en tandklinik for behandling, bekræfter tidligere viden, at der findes en naturlig biologisk variation i fluoridkoncentrationerne i biofilm fra forskellige intra-orale regioner samt mellem biofilmvæske, biofilmsediment og saliva...... fluoridkoncentrationer i underkæbefronten, intermediære koncentrationer i alle tre overkæberegioner og de laveste koncentrationer i underkæbemolarregionerne. Begge studier viser at biofilmsedimentet indeholder størstedelen af fluorid i biofilm. Set i et bredere perspektiv viser fundene at der er et omvendt forhold...

  11. Effect of atmospheric fluoride on plant metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Suketa, Y; Yamamoto, T

    1971-05-01

    Studies on the relationship between the exposure factor and foliar deposition of fluoride, or foliar burn, are introduced. Photosynthesis is adversely affected by atmospheric fluoride. The photosynthesis of a strawberry deteriorated by 50% when the strawberry was exposed to 48 ppb hydrofluoric acid for one hour. The effect of fluoride on the respiratory organs of plants is also reported. Soy beans exposed to 0.03 ppm HF had metabolic abnormalities. The total sugar quantity of leaves decreased from 242-253 mg/100 g to 111-141 mg/100 g and the non-reduced sugar/reduced sugar ratio decreased from 4.6-8.7 to 0.8-1.6. 30 references, 3 figures, 14 tables.

  12. Modelling of fluoride removal via batch monopolar electrocoagulation process using aluminium electrodes

    Science.gov (United States)

    Amri, N.; Hashim, M. I.; Ismail, N.; Rohman, F. S.; Bashah, N. A. A.

    2017-09-01

    Electrocoagulation (EC) is a promising technology that extensively used to remove fluoride ions efficiently from industrial wastewater. However, it has received very little consideration and understanding on mechanism and factors that affecting the fluoride removal process. In order to determine the efficiency of fluoride removal in EC process, the effect of operating parameters such as voltage and electrolysis time were investigated in this study. A batch experiment with monopolar aluminium electrodes was conducted to identify the model of fluoride removal using empirical model equation. The EC process was investigated using several parameters which include voltage (3 - 12 V) and electrolysis time (0 - 60 minutes) at a constant initial fluoride concentration of 25 mg/L. The result shows that the fluoride removal efficiency increased steadily with increasing voltage and electrolysis time. The best fluoride removal efficiency was obtained with 94.8 % removal at 25 mg/L initial fluoride concentration, voltage of 12 V and 60 minutes electrolysis time. The results indicated that the rate constant, k and number of order, n decreased as the voltage increased. The rate of fluoride removal model was developed based on the empirical model equation using the correlation of k and n. Overall, the result showed that EC process can be considered as a potential alternative technology for fluoride removal in wastewater.

  13. Prevention of dental caries through the effective use of fluoride

    DEFF Research Database (Denmark)

    Petersen, Poul Erik

    2016-01-01

    Background: The World Health Organization (WHO) emphasizes that dental caries is a severe public health problem across the world. The current global and regional patterns of dental caries reflect distinct risk profiles of countries which relate to the structure of the society, living conditions......, lifestyles, and the existence of preventive oral health programmes. Research conducted in high income countries documents that systematic use of fluoride reduces the burden of dental caries; such research is scarce in low and middle income countries. Objectives: This article reviews the evidence on effective...... use of fluoride, highlights the public health approach to fluoridation, and clarifies how automatic fluoridation contributes to breaking social inequities in dental caries. Data collection: Scientific publications on fluoride administration stored in PubMed/Medline and caries data from the WHO...

  14. Effect of various rinsing protocols after use of amine fluoride/stannous fluoride toothpaste on the bacterial composition of dental plaque

    NARCIS (Netherlands)

    van Loveren, C.; Gerardu, V.A.M.; Sissons, C.H.; van Bekkum, M.; ten Cate, J.M.

    2009-01-01

    This clinical study evaluated the effect of different oral hygiene protocols on the bacterial composition of dental plaque. After a 2-week period of using fluoride-free toothpaste, 30 participants followed three 1-week experimental protocols, each followed by 2-week fluoride-free washout periods in

  15. High fluoride and low calcium levels in drinking water is associated with low bone mass, reduced bone quality and fragility fractures in sheep.

    Science.gov (United States)

    Simon, M J K; Beil, F T; Rüther, W; Busse, B; Koehne, T; Steiner, M; Pogoda, P; Ignatius, A; Amling, M; Oheim, R

    2014-07-01

    Chronic environmental fluoride exposure under calcium stress causes fragility fractures due to osteoporosis and bone quality deterioration, at least in sheep. Proof of skeletal fluorosis, presenting without increased bone density, calls for a review of fracture incidence in areas with fluoridated groundwater, including an analysis of patients with low bone mass. Understanding the skeletal effects of environmental fluoride exposure especially under calcium stress remains an unmet need of critical importance. Therefore, we studied the skeletal phenotype of sheep chronically exposed to highly fluoridated water in the Kalahari Desert, where livestock is known to present with fragility fractures. Dorper ewes from two flocks in Namibia were studied. Chemical analyses of water, blood and urine were executed for both cohorts. Skeletal phenotyping comprised micro-computer tomography (μCT), histological, histomorphometric, biomechanical, quantitative backscattered electron imaging (qBEI) and energy-dispersive X-ray (EDX) analysis. Analysis was performed in direct comparison with undecalcified human iliac crest bone biopsies of patients with fluoride-induced osteopathy. The fluoride content of water, blood and urine was significantly elevated in the Kalahari group compared to the control. Surprisingly, a significant decrease in both cortical and trabecular bones was found in sheep chronically exposed to fluoride. Furthermore, osteoid parameters and the degree and heterogeneity of mineralization were increased. The latter findings are reminiscent of those found in osteoporotic patients with treatment-induced fluorosis. Mechanical testing revealed a significant decrease in the bending strength, concurrent with the clinical observation of fragility fractures in sheep within an area of environmental fluoride exposure. Our data suggest that fluoride exposure with concomitant calcium deficit (i) may aggravate bone loss via reductions in mineralized trabecular and cortical bone

  16. Effect of Enamel Caries Lesion Baseline Severity on Fluoride Dose-Response

    Directory of Open Access Journals (Sweden)

    Frank Lippert

    2017-01-01

    Full Text Available This study aimed to investigate the effect of enamel caries lesion baseline severity on fluoride dose-response under pH cycling conditions. Early caries lesions were created in human enamel specimens at four different severities (8, 16, 24, and 36 h. Lesions were allocated to treatment groups (0, 83, and 367 ppm fluoride as sodium fluoride based on Vickers surface microhardness (VHN and pH cycled for 5 d. The cycling model comprised 3 × 1 min fluoride treatments sandwiched between 2 × 60 min demineralization challenges with specimens stored in artificial saliva in between. VHN was measured again and changes versus lesion baseline were calculated (ΔVHN. Data were analyzed using two-way ANOVA (p<0.05. Increased demineralization times led to increased surface softening. The lesion severity×fluoride concentration interaction was significant (p<0.001. Fluoride dose-response was observed in all groups. Lesions initially demineralized for 16 and 8 h showed similar overall rehardening (ΔVHN and more than 24 and 36 h lesions, which were similar. The 8 h lesions showed the greatest fluoride response differential (367 versus 0 ppm F which diminished with increasing lesion baseline severity. The extent of rehardening as a result of the 0 ppm F treatment increased with increasing lesion baseline severity, whereas it decreased for the fluoride treatments. In conclusion, lesion baseline severity impacts the extent of the fluoride dose-response.

  17. The effect of dentifrice quantity and toothbrushing behaviour on oral delivery and retention of fluoride in vivo.

    Science.gov (United States)

    Creeth, Jonathan; Zero, Domenick; Mau, Melissa; Bosma, Mary Lynn; Butler, Andrew

    2013-12-01

    While toothpaste F(-) concentration and rinsing regimen have well-characterised impacts on fluoride's effectiveness, other aspects of brushing regimen have much less well-established effects, in particular, dentifrice quantity and brushing duration. An in vivo study (n = 42) of oral fluoride delivery (i.e. oral disposition post-brushing), and retention (i.e. concentration of F(-) in saliva post-brushing, a known efficacy predictor), was performed to compare effects observed with those of dentifrice F(-) concentration and rinsing regimen. Subjects brushed with a NaF-silica dentifrice (Aquafresh Advanced, 1,150 ppm F(-) ) or a control dentifrice (250 ppm F(-) , same base), for 45, 60, 120 or 180 seconds with 0.5 or 1.5 g dentifrice, and rinsed with 15 ml water once or three times in a cross-over design. The F(-) concentration was measured in post-brushing expectorate, rinse and toothbrush washing samples, and in saliva between 5-120 minutes after brushing. Using 1.5 g versus 0.5 g dentifrice increased F(-) in all samples: oral retention of F(-) was almost doubled by this increase. Increasing duration of brushing had more complex effects. The amount of F(-) in the expectorate increased but decreased in both rinse and toothbrush washing samples. Oral F(-) retention increased, but only in the period 30-120 minutes after brushing. Over the ranges investigated, the order of importance on oral F(-) retention was: dentifrice F(-) concentration > quantity > rinsing regimen > brushing duration. Hence, increasing dentifrice quantity and, to a lesser extent, the duration of brushing, can elevate oral fluoride post-brushing. Evidence is accumulating that the importance of these variables to fluoride efficacy may have been underestimated. © 2013 FDI World Dental Federation.

  18. Evaluation and Assessment of Fluoride in Drinking Water Wells Damavand Villages Zoning in GIS According to DMF Index

    Directory of Open Access Journals (Sweden)

    Kave Kheirkhah Rahimabad

    2016-09-01

    Full Text Available Background:Fluoride is one the vital anions and the drinking water is the main source of preparing it for the human body. Nonetheless, the aim of this paper is to investigate the Fluoride rate in water supplying wells by using GIS environment according to decay, missing or filled (DMF index.  Methods: This research is an analytic and cross-sectional descriptive study with sampling approach of 12 water supplying wells of Damavand villages in summer and autumn the year 2013. The Fluoride concentration was measured by standard method SPADNS using MN-Nano color 400 Photometer in laboratory of Rural Water and Wastewater Company of Tehran. Then DMF was investigated for local students and finally the obtained data were modeled in GIS. Results: The average of Fluoride concentration was 0.094 to 0.212 mg/L in summer and 0.137 to 3.48 mg/L in autumn. The DMF index was estimated around 5.46 for all evaluated students that the mentioned index was 7.635 and 3.29 for male and female pupils respectively which are statistically significant difference. Conclusion: The amounts of fluorine in drinking water supplies in rural Damavand villages are lower than the international water standards. According to the results of experiments and lack of fluorine ion in the villages of this town, required fluorine should be done by drinkable water fluoridation and continuities of implementation plan for fluoride ion among the schools until reaching the fluoride concentration to the standard threshold, Supplying required fluorine of body by mouth-wash materials for people of this region

  19. FLUORIDE LEVELS IN COMMERCIALLY AVAILABLE RICE IN ...

    African Journals Online (AJOL)

    Preferred Customer

    2013-05-05

    May 5, 2013 ... Rice is one of the commonly consumed cereals for more than half of the ... also used as flour, for making rice wine, as ingredient for beer and liquor, ... Fluoride is a necessary element to human health, and a moderate amount of fluoride intake ... For Ethiopian red rice (ERR) Fogera was selected to collect.

  20. Fluoride toothpaste utilization behaviour among preschool children in Perlis, Malaysia.

    Science.gov (United States)

    Tay, H L; Zainudin, I S; Jaafar, N

    2009-12-01

    Very mild fluorosis is quite prevalent in children and one of the sources may be attributed to poor fluoride toothpaste utilization habits. To investigate the frequency of toothbrushing, parental supervision, the person who usually applied the toothpaste, toothpaste swallowing and spitting habits, size of toothbrush, type of toothpaste used and amount of toothpaste used by shape and weight. Observational cross-sectional study of a representative random sample of 373 children aged 5-6 year-old. The children were interviewed using a structured close ended questionnaire. Direct observations were made on their toothpaste dispensing habit during a toothbrushing exercise. All children reported practising toothbrushing with 90% on a daily basis. Almost all used fluoridated toothpaste (91.4%). About one-half (50.7%) reported that their parents never supervised them. More than one-third of children used adult toothpaste and 60.1% of the toothpaste was flavoured. Most (92%) used toothbrush meant for children. About 40% applied a pea-sized amount of toothpaste. The mean weight of toothpaste applied was 0.43 g (SID + 0.35 g). The majority used the recommended child-sized toothbrush and toothpaste that contained fluoride but less than one-half of the parents supervised their children. Most children used flavoured children's toothpaste but a sizable proportion used toothpastes meant for adults. The amount applied by shape and weight exceeded the amount recommended by experts.

  1. Risk assessment of fluoride exposure in drinking water of Tunisia.

    Science.gov (United States)

    Guissouma, Wiem; Hakami, Othman; Al-Rajab, Abdul Jabbar; Tarhouni, Jamila

    2017-06-01

    The presence of fluoride in drinking water is known to reduce dental cavities among consumers, but an excessive intake of this anion might leads to dental and skeletal fluorosis. This study reports a complete survey of the fluoridated tap water taken from 100 water consumption points in Tunisia. The fluoride concentrations in tap water were between 0 and 2.4 mg L -1 . Risk assessment of Fluoride exposure was assessed depending on the age of consumers using a four-step method: hazard identification, toxicity reference values selection (TRVs), daily exposure assessment, and risk characterization. Our findings suggest that approximately 75% of the Tunisian population is at risk for dental decay, 25% have a potential dental fluorosis risk, and 20% might have a skeletal fluorosis risk according to the limits of fluoride in drinking water recommended by WHO. More investigations are recommended to assess the exposure risk of fluoride in other sources of drinking water such as bottled water. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. On the assessment of hydroxyapatite fluoridation by means of Raman scattering

    International Nuclear Information System (INIS)

    Campillo, M.; Valiente, M.; Lacharmoise, P. D.; Reparaz, J. S.; Goni, A. R.

    2010-01-01

    Hydroxyapatite is the main mineral component of bones and teeth. Fluorapatite, a bioceramic that can be obtained from hydroxyapatite by chemical substitution of the hydroxide ions with fluoride, exhibits lower mineral solubility and larger mechanical strength. Despite the widespread use of fluoride against caries, a reliable technique for unambiguous assessment of fluoridation in in vitro tests is still lacking. Here we present a method to probe fluorapatite formation in fluoridated hydroxyapatite by combining Raman scattering with thermal annealing. In synthetic minerals, we found that effectively fluoride substituted hydroxyapatite transforms into fluorapatite only after heat treatment, due to the high activation energy for this first order phase transition.

  3. On the assessment of hydroxyapatite fluoridation by means of Raman scattering

    Science.gov (United States)

    Campillo, M.; Lacharmoise, P. D.; Reparaz, J. S.; Goñi, A. R.; Valiente, M.

    2010-06-01

    Hydroxyapatite is the main mineral component of bones and teeth. Fluorapatite, a bioceramic that can be obtained from hydroxyapatite by chemical substitution of the hydroxide ions with fluoride, exhibits lower mineral solubility and larger mechanical strength. Despite the widespread use of fluoride against caries, a reliable technique for unambiguous assessment of fluoridation in in vitro tests is still lacking. Here we present a method to probe fluorapatite formation in fluoridated hydroxyapatite by combining Raman scattering with thermal annealing. In synthetic minerals, we found that effectively fluoride substituted hydroxyapatite transforms into fluorapatite only after heat treatment, due to the high activation energy for this first order phase transition.

  4. Biosorption of fluoride ion from water using the seeds of the ...

    African Journals Online (AJOL)

    Biosorption of fluoride ion from water using the seeds of the cabbage tree ( Moringa ... The maximum fluoride sorption capacity was found to be 1.32 mg.g-1 of dry weight ... Key words: Biosorption, chemisorption, desorption, fluoride, isotherm, ...

  5. Synthesis and characterization of lithium fluoride nano crystals doped with silver

    International Nuclear Information System (INIS)

    Rosario M, B. R.; Ramirez C, G.; Encarnacion E, E. K.; Sosa A, M. A.

    2017-10-01

    Thermoluminescence (Tl) is the emission of light by certain materials to be heated below its incandescence temperature, having previously been exposed to an exciting agent such as ionizing radiation. Lithium fluoride (LiF) is the thermoluminescent material used in the manufacture of Tl-100 dosimeters. What morphological characteristics (size, crystallinity) do the nano crystals of pure lithium fluoride (LiF) have when doped with silver (Ag) by the precipitation method? The objective of this study was to synthesize and characterize the LiF nano crystals doped with silver (Ag) in concentrations of 0.02, 0.04, 0.06, 0.08, 0.1 and 0.2%. The samples were synthesized using as reagents; distilled water, ammonium fluoride (NH 4 F), lithium chloride (LiCl), silver nitrate (AgNO 3 ); and materials such as: 0.1 mg precision balance, spatulas, test piece, magnetic stirrer, beaker, volumetric flask, burette, burette clamp, key and magnetic stirring wand. In the characterization process we used and X-ray diffractometer (XRD) with which we obtained the X-ray diffraction spectrum with well-defined peaks that are characteristic of LiF. Using the Scherrer equation we calculate the sizes of nano crystals. This study demonstrates that is possible to synthesize LiF using new dopant materials. (Author)

  6. Health impact of supplying safe drinking water containing fluoride below permissible level on flourosis patients in a fluoride-endemic rural area of West Bengal.

    Science.gov (United States)

    Majumdar, Kunal Kanti

    2011-01-01

    The problem of high fluoride concentration in groundwater resources has become one of the most important toxicological and geo-environmental issues in India. Excessive fluoride in drinking water causes dental and skeletal fluorosis, which is encountered in endemic proportions in several parts of the world. World Health Organization (WHO) guideline value and the permissible limit of fluoride as per Bureau of Indian Standard (BIS) is 1.5 mg/L. About 20 states of India, including 43 blocks of seven districts of West Bengal, were identified as endemic for fluorosis and about 66 million people in these regions are at risk of fluoride contamination. Studies showed that withdrawal of sources identified for fluoride often leads reduction of fluoride in the body fluids (re-testing urine and serum after a week or 10 days) and results in the disappearance of non-skeletal fluorosis within a short duration of 10-15 days. To determine the prevalence of signs and symptoms of suspected dental, skeletal, and non-skeletal fluorosis, along with food habits, addictions, and use of fluoride containing toothpaste among participants taking water with fluoride concentration above the permissible limit, and to assess the changes in clinical manifestations of the above participants after they started consuming safe drinking water. A longitudinal intervention study was conducted in three villages in Rampurhat Block I of Birbhum district of West Bengal to assess the occurrence of various dental, skeletal, and non-skeletal manifestations of fluorosis, along with food habits, addictions, and use of fluoride containing toothpaste among the study population and the impact of taking safe water from the supplied domestic and community filters on these clinical manifestations. The impact was studied by follow-up examination of the participants for 5 months to determine the changes in clinical manifestations of the above participants after they started consuming safe drinking water from supplied

  7. Advanced inorganic fluorides. Proceedings of the Second International Siberian workshop INTERSIBFLUORINE-2006

    International Nuclear Information System (INIS)

    Volkov, V.V.; Mit'kin, V.N.; Bujnovskij, A.S.; Sofronov, V.L.

    2006-01-01

    Proceedings of the Second International Siberian workshop ISIF-2006 on modern inorganic fluorides contain full author's texts of 82 plenary reports and posters on the main trends in chemistry and technology of inorganic fluorides and their various applications. The following new trends are reflected in the ISIF-2006 Proceedings versus the ISIF-2003 ones: production and use of of nano-sized systems and materials based on fluoride phases and fluorinating systems; chemistry of fluorofullerenes, fluorides of graphite and carbon materials; development of research and technical principles of economically viable process of depleted uranium hexafluoride conversion; vitrifying systems based on metal fluorides possessing valuable functional optical properties; mechanochemical processes and phenomena in chemistry of inorganic fluorides [ru

  8. Fluoride Removal From Drinking Water by Electrocoagulation Using Iron and Aluminum Electrodes

    Directory of Open Access Journals (Sweden)

    Takdastan

    2014-07-01

    Full Text Available Background Existence of fluoride in drinking water above the permissible level causes human skeletal fluorosis. Objectives Electrocoagulation by iron and aluminum electrodes was proposed for removing fluoride from drinking water. Materials and Methods Effects of different operating conditions such as treatment time, initial pH, applied voltage, type and number of electrodes, the spaces between aluminum and iron electrodes, and energy consumption during electrocoagulation were investigated in the batch reactor. Variable concentrations of fluoride solution were prepared by mixing proper amounts of sodium fluoride with deionized water. Results Experimental results showed that aluminum electrode is more effective in fluoride removal than iron, as in 40 minutes and initial pH of 7.5 at 20 V, the fluoride removal process reached to 97.86%. The final recommendable limit of fluoride (1.5 mg/L was obtained in 10 minutes at 20 V with the aluminum electrode. Conclusions In electrocoagulation with iron and aluminum electrodes, increase of voltage, number of electrodes and reaction time as well as decrease of the spaces between electrodes, enhanced the fluoride removal efficiency from drinking water. In addition the effect of pH and initial concentration of fluoride varied with types of electrodes.

  9. Removal of phosphorus, fluoride and metals from a gypsum mining leachate using steel slag filters.

    Science.gov (United States)

    Claveau-Mallet, Dominique; Wallace, Scott; Comeau, Yves

    2013-03-15

    The objective of this work was to evaluate the capacity of steel slag filters to treat a gypsum mining leachate containing 11-107 mg P/L ortho-phosphates, 9-37 mg/L fluoride, 0.24-0.83 mg/L manganese, 0.20-3.3 zinc and 1.7-8.2 mg/L aluminum. Column tests fed with reconstituted leachates were conducted for 145-222 days and sampled twice a week. Two types of electric arc furnace (EAF) slags and three filter sequences were tested. The voids hydraulic retention time (HRT(v)) of columns ranged between 4.3 and 19.2 h. Precipitates of contaminants present in columns were sampled and analyzed with X-ray diffraction at the end of tests. The best removal efficiencies over a period of 179 days were obtained with sequential filters that were composed of Fort Smith EAF slag operated at a total HRT(v) of 34 h which removed 99.9% of phosphorus, 85.3% of fluoride, 98.0% of manganese and 99.3% of zinc. Mean concentration at this system's effluent was 0.04 mg P/L ortho-phosphates, 4 mg/L fluoride, 0.02 mg/L manganese, 0.02 zinc and 0.5 mg/L aluminum. Thus, slag filters are promising passive and economical systems for the remediation of mining effluents. Phosphorus was removed by the formation of apatite (hydroxyapatite, Ca(5)(PO(4))(3)OH or fluoroapatite, Ca(5)(PO(4))(3)F) as confirmed by visual and X-ray diffraction analyses. The growth rate of apatite was favored by a high phosphorus concentration. Calcite crystals were present in columns and appeared to be competing for calcium and volume needed for apatite formation. The calcite crystal growth rate was higher than that of apatite crystals. Fluoride was removed by precipitation of fluoroapatite and its removal was favored by a high ratio of phosphorus to fluoride in the wastewater. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Fluoride Content of Bottled Drinking Waters in Qatar.

    Science.gov (United States)

    Almulla, Hessa Ibrahim; King, Nigel M; Alnsour, Hamza Mohammad; Sajnani, Anand K

    2016-12-01

    Fluoridation of drinking water has been recognized as one of the most effective ways of achieving community-wide exposure to the caries prevention effects of fluoride (F). A vast majority of people in Qatar use bottled water for drinking. Use of bottled water without knowing the F level may expose children to dental caries risk if the F level is lower than optimal or to dental fluorosis if the F level is too high. The aim of this study was to determine the F concentration of bottled water available in Qatar. A total of 32 brands of bottled water were evaluated. The F concentrations displayed on the labels were recorded. The F ion-selective electrode method was used to measure the F concentration in water samples, and three measurements were taken for every sample to ensure reproducibility. The p value was set at 0.05. The F concentration ranged from 0.06 to 3.0 ppm with a mean value of 0.8 ppm (±0.88). The F levels were provided by the manufacturers on the labels of 60 % of the samples, but this was significantly lower than the measured F levels (p < 0.0001). Moreover, bottled water that was produced in Saudi Arabia had significantly higher levels of F when compared to those produced in other countries (p < 0.05). There was a wide variation in the F levels in the different brands of bottled water. Furthermore, there was a significant disparity between the F levels which were measured and those that were provided on the labels.

  11. FLUORIDE: A REVIEW OF USE AND EFFECTS ON HEALTH

    OpenAIRE

    Kanduti, Domen; Sterbenk, Petra; Artnik, Barbara

    2016-01-01

    Introduction: Appropriate oral health care is fundamental for any individual?s health. Dental caries is still one of the major public health problems. The most effective way of caries prevention is the use of fluoride. Aim: The aim of our research was to review the literature about fluoride toxicity and to inform physicians, dentists and public health specialists whether fluoride use is expedient and safe. Methods: Data we used in our review were systematically searched and collected from web...

  12. Modification of radiation effect by sodium fluoride in Tradescantia

    International Nuclear Information System (INIS)

    Cebulska-Wasilewska, A.; Guminska, M.; Huczkowski, J.; Kuternozinska, W.

    1988-01-01

    Frequency of somatic mutations in the Tradescantia stamen hairs served as a measure of biological effect of gamma irradiation with single and split doses and of modifications caused by sodium fluoride. It was found that treatment of plants with fluoride before irradiation affects considerably radiation-induced mutations. The changed peak mutation frequency in plants treated with fluoride suggests that it vitally influences the repair processes of DNA and possibly modifies the mutation spectrum. 14 refs., 3 figs. (author)

  13. Effect of high fluoride concentration in drinking water on children’s intelligence

    Directory of Open Access Journals (Sweden)

    Seraj B

    2006-07-01

    Full Text Available Background and Aim: Human and animal studies linking fluoride with diminished intelligence have been published. Although adverse effects of high intake of fluoride on intelligence and mental acuity continue to be reported, they are still controversial. The aim of this research was to investigate the relationship between fluoride in drinking water and children's intelligence. Materials and Methods: In this cross sectional study, 41 children were selected from the high fluoride area with 2.5mg/l (ppm fluoride in the drinking water and 85 children were selected from low fluoride area with 0.4mg/l (ppm fluoride in the drinking water. The intelligence quotient (IQ of each child was measured by the Raven's test. The history of illnesses affecting the nervous system, head trauma, birth weight (2.5kg or  2.5kg, residental history, age and sex of children were investigated by questionnaires completed by the children's parents. Data were analyzed by Chi-Square test with p<0.05 as the limit of significance. Results: In the high fluoride area the mean IQ of children (87.911 was significantly lower than in the low fluoride area (98.912.9 (P=0.025. Conclusion: Based on the findings of this study, exposure of children to high levels of fluoride may carry the risk of impaired development of intelligence.

  14. Evaluation and Assessment of Fluoride in Drinking Water Wells Damavand Villages Zoning in GIS According to DMF Index

    OpenAIRE

    Kave Kheirkhah Rahimabad; Amir Hessam Hasani; Reza Saeedi; Mir Masoud Kheirkhah Zarkesh; Mojtaba Sayadi

    2016-01-01

    Background:Fluoride is one the vital anions and the drinking water is the main source of preparing it for the human body. Nonetheless, the aim of this paper is to investigate the Fluoride rate in water supplying wells by using GIS environment according to decay, missing or filled (DMF) index.  Methods: This research is an analytic and cross-sectional descriptive study with sampling approach of 12 water supplying wells of Damavand villages in summer and autumn the year 2013. The Fluor...

  15. Nutritional and water effect on fluoride uptake and respiration of bean seedlings. [Phaseolus vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Applegate, H G; Adams, D F

    1960-01-01

    Bean plants (Phaseolus vulgaris) were grown in an atmosphere containing 2.0 +/- 0.21 g F /mT (1.6 ppb). The effect of N, P, K, Fe, and Ca deficiencies and the effect of osmotic pressures of 0, 1.5, 3.0, 4.5, 6.0 and 7.5 pounds on fluoride uptake and fluoride-mediated respiration were studied. The data showed that P deficient plants took up more fluoride than plants deficient in any of the other elements studied. Fluoride-mediated respiration was phosphorous dependent, however. Plants low in Fe or K showed increased uptake of fluoride. Nitrogen had no effect on fluoride uptake under the conditions of this experiment. Plants low in Fe showed inhibition of oxygen uptake. This inhibition was accentuated by fluoride. The interactions of N, K and Ca with fluoride on respiration were complex. Neither fluoride uptake nor fluoride-mediated respiration appeared to be linked directly to the water economy of the plants. 14 references, 6 tables.

  16. Water fluoridation and the association of sugar-sweetened beverage consumption and dental caries in Australian children.

    Science.gov (United States)

    Armfield, Jason M; Spencer, A John; Roberts-Thomson, Kaye F; Plastow, Katrina

    2013-03-01

    We examined demographic and socioeconomic differences in the consumption of sugar-sweetened beverages (SSBs), its association with dental caries in children, and whether exposure to water fluoridation modifies this association. In a cross-sectional study, we used a stratified, clustered sampling design to obtain information on 16 508 children aged 5 to 16 years enrolled in Australian school dental services in 2002 to 2005. Dental staff assessed dental caries, and parents completed a questionnaire about their child's residential history, sources of drinking water, toothbrushing frequency, socioeconomic status (SES), and SSB consumption. Children who brushed their teeth less often and were older, male, of low SES, from rural or remote areas consumed significantly more SSBs. Caries was significantly associated with greater SSB consumption after controlling for potential confounders. Finally, greater exposure to fluoridated water significantly reduced the association between children's SSB consumption and dental caries. Consumption of SSBs should be considered a major risk factor for dental caries. However, increased exposure to fluoridated public water helped ameliorate the association between SSB consumption and dental decay. These results reconfirm the benefits of community water fluoridation for oral health.

  17. The Effects of Remineralization via Fluoride Versus Low-Level Laser IR810 and Fluoride Agents on the Mineralization and Microhardness of Bovine Dental Enamel

    Directory of Open Access Journals (Sweden)

    Edith Lara-Carrillo

    2018-01-01

    Full Text Available The objective of this study was to assess the mineralization and microhardness of bovine dental enamel surfaces treated with fluoride, tri-calcium phosphate, and infrared (IR 810 laser irradiation. The study used 210 bovine incisors, which were divided into six groups (n = 35 in each: Group A: Untreated (control, Group B: Fluoride (Durapath-Colgate, Group C: Fluoride+Tri-calcium phosphate (Clin-Pro White-3 M, Group D: Laser IR 810 (Quantum, Group E: Fluoride+laser, and Group F: Fluoride+tri-calcium phosphate+laser. Mineralization was measured via UV-Vis spectroscopy for phosphorus and via atomic absorption spectroscopy for calcium upon demineralization and remineralization with proven agents. Microhardness (SMH was measured after enamel remineralization. Mineral loss data showed differences between the groups before and after the mineralizing agents were placed (p < 0.05. Fluoride presented the highest remineralization tendency for both calcium and phosphate, with a Vickers microhardness of 329.8 HV0.1/11 (p < 0.05. It was observed that, if remineralization solution contained fewer minerals, the microhardness surface values were higher (r = −0.268 and −0.208; p < 0.05. This study shows that fluoride has a remineralizing effect compared with calcium triphosphate and laser IR810. This in vitro study imitated the application of different remineralizing agents and showed which one was the most efficient for treating non-cavitated injuries. This can prevent the progression of lesions in patients with white spot lesions.

  18. HOUSEHOLD PURIFICATION OF FLUORIDE CONTAMINATED MAGADI (TRONA)

    DEFF Research Database (Denmark)

    Nielsen, Joan Maj; Dahi, Elian

    1997-01-01

    Purification of fluoride contaminated magadi is studied using bone char sorption and calcium precipitation. The bone char treatment is found to be workable both in columns and in batches where the magadi is dissolved in water prior to treatment. The concentrations in the solutions were 89 g magadi....../L and 95 and 400 mg F/L respectively in natural and synthetic solutions. The fluoride removal capacities observed were 4.6 mg F/g bone char for the column system and 2.7 mg F/g bone char for the batch system in case of synthetic magadi solution. It is however concluded that the batch system is the best...... treatment method. A procedure for purification of fluoride contaminated magadi at household level is described....

  19. A Review on Adsorption of Fluoride from Aqueous Solution

    Science.gov (United States)

    Habuda-Stanić, Mirna; Ergović Ravančić, Maja; Flanagan, Andrew

    2014-01-01

    Fluoride is one of the anionic contaminants which is found in excess in surface or groundwater because of geochemical reactions or anthropogenic activities such as the disposal of industrial wastewaters. Among various methods used for defluoridation of water such as coagulation, precipitation, membrane processes, electrolytic treatment, ion-exchange, the adsorption process is widely used. It offers satisfactory results and seems to be a more attractive method for the removal of fluoride in terms of cost, simplicity of design and operation. Various conventional and non-conventional adsorbents have been assessed for the removal of fluoride from water. In this review, a list of various adsorbents (oxides and hydroxides, biosorbents, geomaterials, carbonaceous materials and industrial products and by-products) and its modifications from literature are surveyed and their adsorption capacities under various conditions are compared. The effect of other impurities on fluoride removal has also been discussed. This survey showed that various adsorbents, especially binary and trimetal oxides and hydroxides, have good potential for the fluoride removal from aquatic environments. PMID:28788194

  20. 199Hg Moessbauer measurements on mercury, alloys and Hg-fluorides

    International Nuclear Information System (INIS)

    Wurtinger, W.; Kankeleit, E.

    1979-01-01

    The Moessbauer effect on the 158 keV 5/2 - -1/2 - transition in 199 Hg, of the order of 10 ppm, has been studied using the current integration technique. The isomer shift between the Hg(I)- and Hg(II)-fluorides as well as the quadrupole splitting in Hg 2 Pt and Hg 2 F 2 are interpreted in terms of relativistic Hartree-Fock-Slater and Molecular Orbital calculations. The following nuclear parameters could be derived: Δ[r 2 ] = (3.2+-1.1) 10 -3 fm 2 and Q(5/2 - ) = (-0.8+-0.4)b. Evidence for an oblate triaxially deformed 199 Hg nucleus is derived from particle plus rotor calculations. (orig.)

  1. The use of 18F-fluoride and 18F-FDG PET scans to assess fracture healing in a rat femur model

    International Nuclear Information System (INIS)

    Hsu, W.K.; Feeley, B.T.; Krenek, L.; Stout, D.B.; Chatziioannou, A.F.; Lieberman, J.R.

    2007-01-01

    Currently available diagnostic techniques can be unreliable in the diagnosis of delayed fracture healing in certain clinical situations, which can lead to increased complication rates and costs to the health care system. This study sought to determine the utility of positron emission tomography (PET) scanning with 18 F-fluoride ion, which localizes in regions of high osteoblastic activity, and 18 F-fluorodeoxyglucose (FDG), an indicator of cellular glucose metabolism, in assessing bone healing in a rat femur fracture model. Fractures were created in the femurs of immunocompetent rats. Animals in group I had a fracture produced via a manual three-point bending technique. Group II animals underwent a femoral osteotomy with placement of a 2-mm silastic spacer at the fracture site. Fracture healing was assessed with plain radiographs, 18 F-fluoride, and 18 F-FDG PET scans at 1, 2, 3, and 4-week time points after surgery. Femoral specimens were harvested for histologic analysis and manual testing of torsional and bending strength 4 weeks after surgery. All fractures in group I revealed abundant callus formation and bone healing, while none of the nonunion femurs were healed via assessment with manual palpation, radiographic, and histologic evaluation at the 4-week time point. 18 F-fluoride PET images of group I femurs at successive 1-week intervals revealed progressively increased signal uptake at the union site during fracture repair. In contrast, minimal tracer uptake was seen at the fracture sites in group II at all time points after surgery. Data analysis revealed statistically significant differences in mean signal intensity between groups I and II at each weekly interval. No significant differences between the two groups were seen using 18 F-FDG PET imaging at any time point. This study suggests that 18 F-fluoride PET imaging, which is an indicator of osteoblastic activity in vivo, can identify fracture nonunions at an early time point and may have a role in the

  2. The use of 18F-fluoride and 18F-FDG PET scans to assess fracture healing in a rat femur model

    Science.gov (United States)

    Hsu, W. K.; Feeley, B. T.; Krenek, L.; Stout, D. B.; Chatziioannou, A. F.; Lieberman, J. R.

    2011-01-01

    Purpose Currently available diagnostic techniques can be unreliable in the diagnosis of delayed fracture healing in certain clinical situations, which can lead to increased complication rates and costs to the health care system. This study sought to determine the utility of positron emission tomography (PET) scanning with 18F-fluoride ion, which localizes in regions of high osteoblastic activity, and 18F-fluorodeoxyglucose (FDG), an indicator of cellular glucose metabolism, in assessing bone healing in a rat femur fracture model. Methods Fractures were created in the femurs of immuno-competent rats. Animals in group I had a fracture produced via a manual three-point bending technique. Group II animals underwent a femoral osteotomy with placement of a 2-mm silastic spacer at the fracture site. Fracture healing was assessed with plain radiographs, 18F-fluoride, and 18F-FDG PET scans at 1, 2, 3, and 4-week time points after surgery. Femoral specimens were harvested for histologic analysis and manual testing of torsional and bending strength 4 weeks after surgery. Results All fractures in group I revealed abundant callus formation and bone healing, while none of the nonunion femurs were healed via assessment with manual palpation, radiographic, and histologic evaluation at the 4-week time point. 18F-fluoride PET images of group I femurs at successive 1-week intervals revealed progressively increased signal uptake at the union site during fracture repair. In contrast, minimal tracer uptake was seen at the fracture sites in group II at all time points after surgery. Data analysis revealed statistically significant differences in mean signal intensity between groups I and II at each weekly interval. No significant differences between the two groups were seen using 18F-FDG PET imaging at any time point. Conclusion This study suggests that 18F-fluoride PET imaging, which is an indicator of osteoblastic activity in vivo, can identify fracture nonunions at an early time point

  3. Professionally applied fluoride gel in low-caries 10.5-year-olds.

    NARCIS (Netherlands)

    Truin, G.J.; Hof, M.A. van 't

    2005-01-01

    The question has been raised whether low-caries children regularly using fluoride toothpaste will benefit from the professional application of additional fluoride gel. To investigate the caries-reducing effect of semi-annually-applied neutral 1% sodium fluoride gel, we carried out a double-blind

  4. Sorption of fluoride using chemically modified Moringa oleifera leaves

    Science.gov (United States)

    Dan, Shabnam; Chattree, Amit

    2018-05-01

    Contamination of drinking water due to fluoride is a severe health hazard problem. Excess of fluoride (> 1.5 mg/L) in drinking water is harmful to human health. Various treatment technologies for removing fluoride from groundwater have been investigated. The present study showed that the leaves of Moringa oleifera, a herbal plant is an effective adsorbent for the removal of fluoride from aqueous solution. Acid treated Moringa oleifera leaves powder showed good adsorption capacity than alkali treated Moringa oleifera leaves powder. Batch sorptive defluoridation was conducted under the variable experimental condition such as pH, contact time, adsorbent dose and initial fluoride ion concentration. Maximum defluoridation was achieved at pH 1. The percentage of fluoride removal increases with adsorbent dose. The equilibrium sorption data were fitted into Langmuir, Freundlich and Temkin isotherms. Of the three adsorption isotherms, the R 2 value of Langmuir isotherm model was the highest. The maximum monolayer coverage ( Q max) from Langmuir isotherm model was determined to be 1.1441 mg/g, the separation factor indicating a favorable sorption experiment is 0.035. It was also discovered that the adsorption did not conform to the Freundlich adsorption isotherm. The heat of sorption process was estimated from Temkin Isotherm model to be - 0.042 J/mol which vividly proved that the adsorption experiment followed a physical process.

  5. Mechanisms of action of fluoride for caries control

    NARCIS (Netherlands)

    Buzalaf, M.A.R.; Pessan, J.P.; Honório, H.M.; ten Cate, J.M.; Buzalaf, M.A.R.

    2011-01-01

    Fluoride was introduced into dentistry over 70 years ago, and it is now recognized as the main factor responsible for the dramatic decline in caries prevalence that has been observed worldwide. However, excessive fluoride intake during the period of tooth development can cause dental fluorosis. In

  6. Sample problems for the novice user of the AMPX-II system

    International Nuclear Information System (INIS)

    Ford, W.E. III; Roussin, R.W.; Petrie, L.M.; Diggs, B.R.; Comolander, H.E.

    1979-01-01

    Contents of the IBM version of the APMX system distributed by the Radiation Shielding Information Center (APMX-II) are described. Sample problems which demonstrate the procedure for implementing AMPX-II modules to generate point cross sections; generate multigroup neutron, photon production, and photon interaction cross sections for various transport codes; collapse multigroup cross sections; check, edit, and punch multigroup cross sections; and execute a one-dimensional discrete ordinates transport calculation are detailed. 25 figures, 9 tables

  7. Dental fluorosis and urinary fluoride in 10-12 years old adolescents of Bushehr port

    Directory of Open Access Journals (Sweden)

    Giti Javan

    2006-02-01

    Full Text Available Background: Fluoride increases tooth resistance to dental caries, but mild toxicity due to excessive ingestion of fluoride can cause dental fluorosis. Drinking water naturally contains fluoride and is a major source of fluoride. In Bushehr port, drinking water is supplied from limestone springs with normal fluoride levels but dental fluorosis is observed. Methods: A total of 95 native school children (between the ages of 10-12 years old were randomly selected from four Bushehr port regions. Dental fluorosis, height and weight were examined. Probable attributing factors of dental fluorosis were also questioned. A 16 to 18 hours urinary fluoride concentration was measured with a fluoride ion selective electrode. Results: Dental fluorosis in four upper incisors was apparent in 52.6 % of the subjects. The urinary fluoride concentration was 2.18 mg/lit. Fluoride concentration in drinking water of schools ranged from 0.41 to 0.58 mg/lit. Forty percent of subjects were caries free. Conclusion: In spite of the normal range of fluoride concentration in the drinking water of Bushehr, dental fluorosis and urinary fluoride concentration are higher than the recommended ranges. Therefore, it is necessary to further investigate the amount and effects of fluoride ingestion in residents of Bushehr province.

  8. Effect of iron II on hydroxyapatite dissolution and precipitation in vitro.

    Science.gov (United States)

    Delbem, A C B; Alves, K M R P; Sassaki, K T; Moraes, J C S

    2012-01-01

    The aim of this study was to evaluate the effect of iron II on the dissolution and precipitation of synthetic hydroxyapatite (HA). HA powder was suspended in solutions of iron (0.84 µg/ml, Fe0.84; 18.0 µg/ml, Fe18; 70.0 µg/ml, Fe70), fluoride (1,100 µg/ml, F1,100), and deionized water and submitted to pH cycling. After pH cycling, the samples were analyzed by infrared spectroscopy and X-ray diffraction. The concentrations of fluoride, calcium, phosphorus, and iron were also analyzed. The data were submitted to ANOVA, and analyzed by Tukey's test (p iron. The intensity of the phosphate bands increased and that of the hydroxyl bands decreased in the group F1,100. It was observed that there was a higher concentration of Ca in the group F1,100, with no significant difference between the groups Fe18 and Fe70 (p > 0.05). There was an increase in Fe concentration in the HA directly related to the Fe concentration of the treatment solutions. Results show that the presence of Fe causes the precipitation of apatite with high solubility. Copyright © 2012 S. Karger AG, Basel.

  9. INTERACTION OF FLUORIDE COMPLEXES DERIVED FROM GLASS-IONOMER CEMENTS WITH HYDROXYAPATITE

    Directory of Open Access Journals (Sweden)

    Lewis S. M.

    2013-09-01

    Full Text Available A study has been undertaken of the interaction of complexed fluoride extracted from glass-ionomer dental cements with synthetic hydroxyapatite powder. Extracts were prepared from two commercial glass-ionomers (Fuji IX and ChemFlex under both neutral and acidic conditions. They were analysed by ICP-OES and by fluoride-ion selective electrode with and without added TISAB to decomplex the fluoride. The pH of the acid extracts was 4, conditions under which fluoride complexes with protons as HF or HF2-, it also complexes with aluminium, which was found to be present in higher amounts in the acid extracts. Fluoride was found to be almost completely complexed in acid extracts, but not in neutral extracts, which contained free fluoride ions. Exposure of these extracts to synthetic hydroxyapatite powder showed that fluoride was taken up rapidly (within 5 minutes, whether or not it was complexed. SEM (EDAX study of recovered hydroxyapatite showed only minute traces of aluminium taken up under all conditions. This showed that aluminium interacts hardly at all with hydroxyapatite, and hence is probably not involved in the remineralisation process.

  10. Preparation of rare earth fluorides from apatite concentrate

    International Nuclear Information System (INIS)

    Mulyarchuk, I.F.; Voloshchenko, M.V.; Zen'kovich, E.G.; Sumenkova, V.V.; AN Ukrainskoj SSR, Kiev. Inst. Problem Lit'ya)

    1980-01-01

    The processes of preparation of the rare earths element sum from apatite concentrate of the Khibins, connected with preliminary extraction of rare earth phosphates from nitric acid extract using solvent extraction or direct precipitation from the extract by solution of potassium and ammonium fluorides. The sequence of the processes of the first variant is the following: solvent extraction of rare earths by tributylphosphate from clarified nitric acid extract of apatite with subsequent reextraction of rare earths with water and precipitation of rare earth phosphates from aqueous solution during neutralization by ammonia. In case of fluoride preparation from rare earth phosphate the main attention is paid to precipitation and filtration of fluorides. Technological scheme and cost price of industry for the production of 1800 t of rare earth trifluorides a year are calculated. When taking account of TBP losses according to its solubility the industry cost price is 1O times lower the modern cost of rare earth fluorides

  11. State and National Water Fluoridation System (Public Water Systems)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Water Fluoridation Reporting System (WFRS) has been developed to provide tools to assist states in managing fluoridation programs. WFRS is designed to track all...

  12. Erosive potential of saliva stimulating tablets with and without fluoride in irradiated head and neck cancer patients

    DEFF Research Database (Denmark)

    Lajer, Christel; Buchwald, Christian; Nauntofte, Birgitte

    2009-01-01

    stimulated saliva without fluoride, and with fluoride. Saliva pH was determined without loss of CO(2) and in combination with inorganic measures used to calculate the degree of saturation of hydroxyapatite (HAp) and fluorapatite (FAp). EP was determined directly in all saliva samples by monitored dissolution......BACKGROUND: Patients irradiated in the head and neck region often suffer from severe dry mouth and use acidic saliva stimulating products, which may cause erosion of teeth. PURPOSE: To determine saliva stimulating effects and erosive potential (EP) of acidic saliva stimulating tablets (Xerodent...

  13. Recovery of fluoride ion selective electrode

    International Nuclear Information System (INIS)

    Monteiro, R.P.G.

    1988-01-01

    A recovery procedure of fluoride ion selective electrode based upon the body radiography of inactive electrode and introduction of suitable internal regeneration solution, is developed. The recovered electrode was tested in standard solutions of fluoride ions (10 sup5) to 10 -1M showing as good performance as the new one. The fluor determination by potentiometric measurements with selective electrode is used in nuclear fuel cycle for quality control of thorium and uranium mixed oxide pellets and pellets of uranium dioxides. (author) [pt

  14. Lipopolysaccharide and Lipoteichoic Acid Virulence Deactivation by Stannous Fluoride.

    Science.gov (United States)

    Haught, Chris; Xie, Sancai; Circello, Ben; Tansky, Cheryl S; Khambe, Deepa; Klukowska, Malgorzata; Huggins, Tom; White, Donald J

    2016-09-01

    Oral bacterial pathogens promote gingivitis and periodontal disease. Bacterial endotoxins, also known as lipopolysaccharides (LPSs) and lipoteichoic acids (LTAs), are known to enhance bacterial pathogenicity through binding with Toll-like receptors (TLRs), a group of pattern recognition receptors critical to the activation of innate immunity, that are expressed on host cells. Both LPS and LTA contain lipophilic domains and anionic charges that may be susceptible to reactivity with stannous fluoride, a commonly used ingredient clinically proven for the treatment and prevention of gingivitis. This study examined the effects of stannous fluoride on Toll-like receptor activation in response to bacterially derived LPS and LTA in select cell lines and secretion of inflammatory cytokines from human primary peripheral monocytes likewise exposed to LPS. TLR4 and TLR2 transfected HEK293 cells and THP1-Dual™ cells were exposed to bacterial LPS and LTA in the presence of increasing concentrations of stannous fluoride. Gene expression was assessed by measurement of secreted embryonic alkaline phosphatase (SEAP) reporter gene for HEK293 cells and SEAP and luciferase for THP-1 cells. Cell viability was confirmed using PrestoBlue. Human primary monocytes were treated with LPS with various concentrations of supplemented stannous fluoride, and cytokine expression was directly measured. Stannous fluoride inhibited gene expression response of TLR4 and TLR2 in HEK293 cells and THP1-Dual™ cells in a dose response fashion, producing complete inhibition at micromolar concentrations. The addition of stannous fluoride suppressed production of TNF-a, IFN-g, IL12p70, IL10, IL-1b, IL2, and IL-6, and also increased secretion of Il-8 in dose response fashion. Viability assays confirmed no effects of LPS or stannous fluoride on viability of HEK293, THP-1, and primary human monocytes. These results support the potential for stannous fluoride to provide clinical gingivitis benefits by directly

  15. Opinion of residents from the Gold Coast, Queensland, on community water fluoridation.

    Science.gov (United States)

    Kroon, Jeroen; Reid, Kate Emily; Cutting, Jenna Renae; Lalloo, Ratilal; Chiu, Kandy Chien

    2014-02-01

    To investigate opinions and concerns of Gold Coast residents regarding fluoridation of community water supplies. Anonymous data were collected in four major shopping centers from approximately 500 Gold Coast residents. Eighty-one percent of participants were aware of the addition of fluoride to the water supply. More than half obtained information on water fluoridation through the print and electronic media. Sixty percent of respondents supported water fluoridation. The majority preferred the public and/or health professionals to have made the decision on water fluoridation rather than the government. The percentage of residents supporting water fluoridation was lower than that found in other Queensland, Australian, and worldwide surveys. In this study, only age and the highest level of education attained were factors significantly related to levels of support for water fluoridation. The Queensland Government's decision to implement water fluoridation without a referendum caused disquiet amongst some Gold Coast residents. Future public health initiatives therefore may be assisted by more consultation with, and involvement from, health professionals in the relevant fields. Public health campaigns may benefit more from interaction with the community in order to address their specific concerns. © 2012 Wiley Publishing Asia Pty Ltd.

  16. Exposure to Fluoride in Smelter Workers in a Primary Aluminum Industry in India

    Directory of Open Access Journals (Sweden)

    AK Susheela

    2013-04-01

    Full Text Available Background: Fluoride is used increasingly in a variety of industries in India. Emission of fluoride dust and fumes from the smelters of primary aluminum producing industries is dissipated in the work environment and poses occupational health hazards. Objective: To study the prevalence of health complaints and its association with fluoride level in body fluids of smelter workers in a primary aluminum producing industry. Methods: In an aluminum industry, health status of 462 smelter workers, 60 supervisors working in the smelter unit, 62 non-smelter workers (control group 1 and 30 administration staff (control group 2 were assessed between 2007 and 2009. Their health complaints were recorded and categorized into 4 groups: 1 gastro-intestinal complaints; 2 non-skeletal manifestations; 3 skeletal symptoms; and (4 respiratory problems. Fluoride level in body fluids, nails, and drinking water was tested by an ion selective electrode; hemoglobin level was tested using HemoCue. Results: The total complaints reported by study groups were significantly higher than the control groups. Smelter workers had a significantly (p<0.001 higher urinary and serum fluoride level than non-smelter workers; the nail fluoride content was also higher in smelter workers than non-smelter workers (p<0.001. The smelter workers with higher hemoglobin level had a significantly (p<0.001 lower urinary fluoride concentration and complained less frequently of health problems. Only 1.4% of the smelter workers were consuming water with high fluoride concentrations. A high percentage of participants was using substances with high fluoride contents. Conclusions: Industrial emission of fluoride is not the only important sources of fluoride exposure—consumption of substance with high levels of fluoride is another important route of entry of fluoride into the body. Measurement of hemoglobin provides a reliable indicator for monitoring the health status of employees at risk of fluorosis.

  17. Preparation of bromine fluoride

    International Nuclear Information System (INIS)

    Domange, Pr; Duflo, J.

    1958-05-01

    This note addresses the preparation of bromine fluoride. It indicates the implemented process for the reaction, used products (fluorine and bromine), and column characteristics. It describes the operating mode. Apparatus drawing is provided

  18. Soil fluoride spiking effects on olive trees (Olea europaea L. cv. Chemlali).

    Science.gov (United States)

    Zouari, M; Ben Ahmed, C; Fourati, R; Delmail, D; Ben Rouina, B; Labrousse, P; Ben Abdallah, F

    2014-10-01

    A pot experiment under open air conditions was carried out to investigate the uptake, accumulation and toxicity effects of fluoride in olive trees (Olea europaea L.) grown in a soil spiked with inorganic sodium fluoride (NaF). Six different levels (0, 20, 40, 60, 80 and 100mM NaF) of soil spiking were applied through NaF to irrigation water. At the end of the experiment, total fluoride content in soil was 20 and 1770mgFkg(-1) soil in control and 100mM NaF treatments, respectively. The comparative distribution of fluoride partitioning among the different olive tree parts showed that the roots accumulated the most fluoride and olive fruits were minimally affected by soil NaF spiking as they had the lowest fluoride content. In fact, total fluoride concentration varied between 12 and 1070µgFg(-1) in roots, between 9 and 570µgFg(-1) in shoots, between 12 and 290µgFg(-1) in leaves, and between 10 and 29µgFg(-1) in fruits, respectively for control and 100mM NaF treatments. Indeed, the fluoride accumulation pattern showed the following distribution: roots>shoots>leaves>fruits. On the other hand, fluoride toxicity symptoms such as leaf necrosis and leaf drop appeared only in highly spiked soils (60, 80 and 100mM NaF). Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Preparation and Characterization of Rare Earth Doped Fluoride Nanoparticles

    Directory of Open Access Journals (Sweden)

    Timothy A. DeVol

    2010-03-01

    Full Text Available This paper reviews the synthesis, structure and applications of metal fluoride nanoparticles, with particular focus on rare earth (RE doped fluoride nanoparticles obtained by our research group. Nanoparticles were produced by precipitation methods using the ligand ammonium di-n-octadecyldithiophosphate (ADDP that allows the growth of shells around a core particle while simultaneously avoiding particle aggregation. Nanoparticles were characterized on their structure, morphology, and luminescent properties. We discuss the synthesis, properties, and application of heavy metal fluorides; specifically LaF3:RE and PbF2, and group IIA fluorides. Particular attention is given to the synthesis of core/shell nanoparticles, including selectively RE-doped LaF3/LaF3, and CaF2/CaF2 core/(multi-shell nanoparticles, and the CaF2-LaF3 system.

  20. Cloud point extraction and flame atomic absorption spectrometric determination of cadmium(II), lead(II), palladium(II) and silver(I) in environmental samples

    International Nuclear Information System (INIS)

    Ghaedi, Mehrorang; Shokrollahi, Ardeshir; Niknam, Khodabakhsh; Niknam, Ebrahim; Najibi, Asma; Soylak, Mustafa

    2009-01-01

    The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution was used for the extraction of cadmium(II), lead(II), palladium(II) and silver(I). The analytical procedure involved the formation of understudy metals complex with bis((1H-benzo [d] imidazol-2yl)ethyl) sulfane (BIES), and quantitatively extracted to the phase rich in octylphenoxypolyethoxyethanol (Triton X-114) after centrifugation. Methanol acidified with 1 mol L -1 HNO 3 was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The concentration of BIES, pH and amount of surfactant (Triton X-114) was optimized. At optimum conditions, the detection limits of (3 sdb/m) of 1.4, 2.8, 1.6 and 1.4 ng mL -1 for Cd 2+ , Pb 2+ , Pd 2+ and Ag + along with preconcentration factors of 30 and enrichment factors of 48, 39, 32 and 42 for Cd 2+ , Pb 2+ , Pd 2+ and Ag + , respectively, were obtained. The proposed cloud point extraction has been successfully applied for the determination of metal ions in real samples with complicated matrix such as radiology waste, vegetable, blood and urine samples.