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

PubMed

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.

Can we achieve a radionuclide radiation dose equal to or less than that of 99mTc-hydroxymethane diphosphonate bone scintigraphy with a low-dose 18F-sodium fluoride time-of-flight PET of diagnostic quality?

PubMed

Ohnona, Jessica; Michaud, Laure; Balogova, Sona; Paycha, Frédéric; Nataf, Valérie; Chauchat, Paul; Talbot, Jean-Noël; Kerrou, Khaldoun

2013-05-01

18F-Sodium fluoride is a bone tracer with a high signal-to-noise ratio, but its dosimetry is higher than that of 99mTc-labeled phosphonates at the recommended activities. The study's purpose was to determine whether the reduction by half of F-sodium fluoride-injected activity, mimicked by a short-timed reconstruction image, simulating a total dose less than or equal to that of 99mTc-hydroxymethane diphosphonate scintigraphy, had an impact on the accuracy of PET semiquantitative measurements and image quality. Whole-body time-of-flight 18F-sodium fluoride PET/computed tomography (CT) images were acquired prospectively from 40 adult patients for detection of bone metastases. 18F-Sodium fluoride was administered according to the European Association of Nuclear Medicine (EANM) and Society of Nuclear Medicine (SNM) practice guidelines. From the acquired 1 min/bed position list-mode data, 30-s reconstructions were extracted. Measurements of maximum standard uptake value were recorded with a region of interest applied to the same location on the 1-min and 30-s images, which were displayed side by side, and were analyzed using Bland-Altman plots. A masked reading was performed by two senior nuclear medicine physicians who counted the foci of visually increased uptake. Bland-Altman plots showed an excellent agreement between the maximum standard uptake value measurements of the 60- and 30-s images. The paired Wilcoxon test results between the corresponding 60- and 30-s images read by masked readers A and B were not significant (P=0.15 and 0.19, respectively). Reducing acquisition duration by half or injecting half of the activity recommended by the EANM and SNM practice guidelines can lead to 18F-sodium fluoride time-of-flight PET images of diagnostic quality, achieving a radiation dose less than or equal to that of 99mTc-labeled phosphonates.

40 CFR 415.550 - Applicability; description of the sodium fluoride production subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... sodium fluoride production subcategory. 415.550 Section 415.550 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Sodium Fluoride Production Subcategory § 415.550 Applicability; description of the sodium fluoride production subcategory. The provisions of this subpart are applicable to discharges and to the...

40 CFR 415.550 - Applicability; description of the sodium fluoride production subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... sodium fluoride production subcategory. 415.550 Section 415.550 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Sodium Fluoride Production Subcategory § 415.550 Applicability; description of the sodium fluoride production subcategory. The provisions of this subpart are applicable to discharges and to the...

Influence of sodium fluoride on the synthesis of hydroxyapatite by gel method

NASA Astrophysics Data System (ADS)

Kanchana, P.; Sekar, C.

2010-03-01

Hydroxyapatite (HA) is a good candidate for bone substitutes due to its chemical and structural similarity to bone mineral. Hydroxyapatite has been grown by the gel method using sodium fluoride (NaF) as additive. The growth was carried out at room temperature under the physiological pH of 7.4. The addition of NaF has significantly reduced growth rate and the yield was much less when compared to pure system. The samples of pure and fluoride doped HA were sintered at 600, 900 and 1200 °C in ambient atmosphere. Scanning electron microscopy (SEM), powder X-ray diffraction (XRD), thermogravimetric analysis (TG) and Fourier transform infrared spectroscopy (FTIR) were adopted to investigate the influence of NaF on the morphology, crystallinity, stability and phase purity of HA. EDAX and FTIR studies confirm that the fluoride is doped into the hydroxyapatite. Powder XRD and TGA results suggested that the incorporation of fluorine into the HA matrix improves the phase formation and crystallinity. SEM studies show that the microstructural morphology of HA changes from the fibers for pure to granular structure for the fluoride doped.

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

PubMed

Brar, Gurlal Singh; Arora, Amandeep Singh; Khinda, Vineet Inder Singh; Kallar, Shiminder; Arora, Karuna

2017-01-01

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. 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. 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. 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.

Effects of combined exogenous dextranase and sodium fluoride on Streptococcus mutans 25175 monospecies biofilms.

PubMed

Yang, Ying-Ming; Jiang, Dan; Qiu, Yuan-Xin; Fan, Rong; Zhang, Ru; Ning, Mei-Zhi; Shao, Mei-Ying; Zhang, Chao-Liang; Hong, Xiao; Hu, Tao

2013-10-01

To investigate the effects of exogenous dextranase and sodium fluoride on a S. mutans monospecies biofilm. S. mutans 25175 was grown in tryptone soya broth medium, and biofilm was formed on glass slides with 1.0% sucrose. Exogenous dextranase and sodium fluoride were added alone or together. The biofilm morphology was analyzed by confocal laser scanning microscopy. The effects of the drug on the adhesion and exopolysaccharide production by the biofilms were evaluated by scintillation counting and the anthrone method, respectively. In this study, we found that the structure of initial biofilm and mature biofilm were partly altered by dextranase and high concentrations of sodium fluoride separately. However, dextranase combined with a low concentration of sodium fluoride could clearly destroy the typical tree-like structure of the biofilm, and led to less bacterial adhesion than when the dextranase or fluoride were used alone (P < 0.05). The amounts of soluble and insoluble exopolysaccharide were significantly reduced by combining dextranase with a low concentration of sodium fluoride, much more than when they were used alone (P < 0.05). These data indicate that dextranase and a low concentration of sodium fluoride may have synergistic effects against S. mutans biofilm and suggest the application of a low concentration of sodium fluoride in anticaries treatment.

Exposure to Sodium Fluoride Produces Signs of Apoptosis in Rat Leukocytes

PubMed Central

Gutiérrez-Salinas, José; Morales-González, José A.; Madrigal-Santillán, Eduardo; Esquivel-Soto, Jaime; Esquivel-Chirino, César; González-Rubio, Manuel García-Luna y; Suástegui-Domínguez, Sigrit; Valadez-Vega, Carmen

2010-01-01

Fluoride is naturally present in the earth’s crust and can be found in rocks, coal, and clay; thus, it can be found in small quantities in water, air, plants, and animals. Therefore, humans are exposed to fluoride through food, drinking water, and in the air they breathe. Flouride is essential to maintain bone strength and to protect against dental decay, but if it is absorbed too frequently, it can cause tooth decay, osteoporosis, and damage to kidneys, bones, nerves, and muscles. Therefore, the present work was aimed at determining the effect of intake of sodium fluoride (NaF) as an apoptosis inducer in leukocytes of rats treated for eight weeks with 1 or 50 parts per million (ppm) NaF. Expression of p53, bcl-2, and caspade-3 were used as apoptotic and general metabolism indicators of leukocyte-like indicators of the (INT) oxidation system. Male rats were exposed to NaF (1 and 500 ppm) for eight weeks, and then sacrificed weekly to obtain blood samples. Expression of p53, bcl-2, and caspase-3 were determined in leukocytes by Western blot, and general metabolism of leukocytes was analyzed with a commercial kit. We found changes in the expression of the proteins described, especially when the animals received 50 ppm of NaF. These results indicate that NaF intoxication can be an apoptosis inducer in rat leukocytes treated with the compound for eight weeks. PMID:20957113

(18)F-sodium fluoride PET/CT for the in vivo visualization of Mönckeberg's sclerosis in a diabetic patient.

PubMed

Quirce, R; Martínez-Rodríguez, I; Banzo, I; de Arcocha-Torres, M; Jiménez-Bonilla, J F; Martínez-Amador, N; Ibáñez-Bravo, S; Ramos, L; Amado, J A; Carril, J M

2015-01-01

Diabetes is a major frequent cause of atherosclerosis vascular disease. Arterial calcification in diabetic patients is responsible for peripheral vascular involvement. Molecular imaging using (18)F-sodium fluoride ((18)F-NaF) positron emission tomography (PET)/computed tomography (CT) has been recently proposed as a marker to study the in vivo mineralization process in the atheroma plaque. A 69-year-old man with a history of type 2 diabetes and no clinical evidence of peripheral arterial disease underwent an (18)F-NaF PET/CT scan. A linear, well-defined (18)F-NaF uptake was detected along the femoral arteries. In addition, the CT component of the PET/CT identified an unsuspected "tram-track" calcification in his femoral arteries, suggestive of medial calcification (Mönckeberg's sclerosis). In other vascular territories, focal (18)F-NaF uptake was also detected in carotid and aorta atheroma plaques. Molecular imaging with (18)F-NaF PET/CT might provide new functional information about the in vivo vascular calcification process in diabetic patients. Copyright © 2015 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

Bioactivity of Sodium Free Fluoride Containing Glasses and Glass-Ceramics

PubMed Central

Chen, Xiaojing; Chen, Xiaohui; Brauer, Delia S.; Wilson, Rory M.; Hill, Robert G.; Karpukhina, Natalia

2014-01-01

The bioactivity of a series of fluoride-containing sodium-free calcium and strontium phosphosilicate glasses has been tested in vitro. Glasses with high fluoride content were partially crystallised to apatite and other fluoride-containing phases. The bioactivity study was carried out in Tris and SBF buffers, and apatite formation was monitored by XRD, FTIR and solid state NMR. Ion release in solutions has been measured using ICP-OES and fluoride-ion selective electrode. The results show that glasses with low amounts of fluoride that were initially amorphous degraded rapidly in Tris buffer and formed apatite as early as 3 h after immersion. The apatite was identified as fluorapatite by 19F MAS-NMR after 6 h of immersion. Glass degradation and apatite formation was significantly slower in SBF solution compared to Tris. On immersion of the partially crystallised glasses, the fraction of apatite increased at 3 h compared to the amount of apatite prior to the treatment. Thus, partial crystallisation of the glasses has not affected bioactivity significantly. Fast dissolution of the amorphous phase was also indicated. There was no difference in kinetics between Tris and SBF studies when the glass was partially crystallised to apatite before immersion. Two different mechanisms of apatite formation for amorphous or partially crystallised glasses are discussed. PMID:28788139

Sodium fluoride induces apoptosis in the kidney of rats through caspase-mediated pathways and DNA damage.

PubMed

Song, Guo Hua; Gao, Ji Ping; Wang, Chun Fang; Chen, Chao Yang; Yan, Xiao Yan; Guo, Min; Wang, Yu; Huang, Fu Bing

2014-09-01

Long-term excessive sodium fluoride (NaF) intake can cause many bone diseases and nonskeletal fluorosis. The kidneys are the primary organs involved in the excretion and retention of NaF. The objective of the present study was to determine the effects of NaF treatment on renal cell apoptosis, DNA damage, and the protein expression levels of cytosolic cytochrome C (Cyt C) and cleaved caspases 9, 8, and 3 in vivo. Male Sprague-Dawley rats were divided randomly into four groups (control, low fluoride, medium fluoride, and high fluoride) and administered 0, 50, 100, and 200 mg/L of NaF, respectively, via drinking water for 120 days. Histopathological changes in the kidneys were visualized using hematoxylin and eosin staining. Renal cell apoptosis was examined using flow cytometry, and renal cell DNA damage was detected using the comet assay. Cytosolic Cyt C and cleaved caspases 9, 8, and 3 protein expression levels were visualized using immunohistochemistry and Western blotting. The results showed that NaF treatment increased apoptosis and DNA damage. In addition, NaF treatment increased the protein expression levels of cytosolic Cyt C and cleaved caspases 9, 8, and 3. These results indicated that NaF induces apoptosis in the kidney of rats through caspase-mediated pathway, and DNA damage may be involved in this process.

Demons versus Level-Set motion registration for coronary 18F-sodium fluoride PET.

PubMed

Rubeaux, Mathieu; Joshi, Nikhil; Dweck, Marc R; Fletcher, Alison; Motwani, Manish; Thomson, Louise E; Germano, Guido; Dey, Damini; Berman, Daniel S; Newby, David E; Slomka, Piotr J

2016-02-27

Ruptured coronary atherosclerotic plaques commonly cause acute myocardial infarction. It has been recently shown that active microcalcification in the coronary arteries, one of the features that characterizes vulnerable plaques at risk of rupture, can be imaged using cardiac gated 18 F-sodium fluoride ( 18 F-NaF) PET. We have shown in previous work that a motion correction technique applied to cardiac-gated 18 F-NaF PET images can enhance image quality and improve uptake estimates. In this study, we further investigated the applicability of different algorithms for registration of the coronary artery PET images. In particular, we aimed to compare demons vs. level-set nonlinear registration techniques applied for the correction of cardiac motion in coronary 18 F-NaF PET. To this end, fifteen patients underwent 18 F-NaF PET and prospective coronary CT angiography (CCTA). PET data were reconstructed in 10 ECG gated bins; subsequently these gated bins were registered using demons and level-set methods guided by the extracted coronary arteries from CCTA, to eliminate the effect of cardiac motion on PET images. Noise levels, target-to-background ratios (TBR) and global motion were compared to assess image quality. Compared to the reference standard of using only diastolic PET image (25% of the counts from PET acquisition), cardiac motion registration using either level-set or demons techniques almost halved image noise due to the use of counts from the full PET acquisition and increased TBR difference between 18 F-NaF positive and negative lesions. The demons method produces smoother deformation fields, exhibiting no singularities (which reflects how physically plausible the registration deformation is), as compared to the level-set method, which presents between 4 and 8% of singularities, depending on the coronary artery considered. In conclusion, the demons method produces smoother motion fields as compared to the level-set method, with a motion that is physiologically

Demons versus level-set motion registration for coronary 18F-sodium fluoride PET

NASA Astrophysics Data System (ADS)

Rubeaux, Mathieu; Joshi, Nikhil; Dweck, Marc R.; Fletcher, Alison; Motwani, Manish; Thomson, Louise E.; Germano, Guido; Dey, Damini; Berman, Daniel S.; Newby, David E.; Slomka, Piotr J.

2016-03-01

Ruptured coronary atherosclerotic plaques commonly cause acute myocardial infarction. It has been recently shown that active microcalcification in the coronary arteries, one of the features that characterizes vulnerable plaques at risk of rupture, can be imaged using cardiac gated 18F-sodium fluoride (18F-NaF) PET. We have shown in previous work that a motion correction technique applied to cardiac-gated 18F-NaF PET images can enhance image quality and improve uptake estimates. In this study, we further investigated the applicability of different algorithms for registration of the coronary artery PET images. In particular, we aimed to compare demons vs. level-set nonlinear registration techniques applied for the correction of cardiac motion in coronary 18F-NaF PET. To this end, fifteen patients underwent 18F-NaF PET and prospective coronary CT angiography (CCTA). PET data were reconstructed in 10 ECG gated bins; subsequently these gated bins were registered using demons and level-set methods guided by the extracted coronary arteries from CCTA, to eliminate the effect of cardiac motion on PET images. Noise levels, target-to-background ratios (TBR) and global motion were compared to assess image quality. Compared to the reference standard of using only diastolic PET image (25% of the counts from PET acquisition), cardiac motion registration using either level-set or demons techniques almost halved image noise due to the use of counts from the full PET acquisition and increased TBR difference between 18F-NaF positive and negative lesions. The demons method produces smoother deformation fields, exhibiting no singularities (which reflects how physically plausible the registration deformation is), as compared to the level-set method, which presents between 4 and 8% of singularities, depending on the coronary artery considered. In conclusion, the demons method produces smoother motion fields as compared to the level-set method, with a motion that is physiologically

The effects of sodium fluoride and stannous fluoride on the surface roughness of intraoral magnet systems.

PubMed

Obatake, R M; Collard, S M; Martin, J; Ladd, G D

1991-10-01

Four types of intraoral magnets used for retention of overdentures and maxillofacial prostheses were exposed in vitro to SnF2 and NaF to determine the effects of fluoride rinses on surface roughness. The surface roughness (Ra) was measured, after simulated 1, 2, and 5 years' clinical exposure to fluoride (31, 62, and 155 hours). The mean change in Ra was calculated for each period of simulated exposure to fluoride for each magnet type. Two-way ANOVA was used to compare mean change in Ra between magnets within fluorides, and between fluorides within magnets. Paired t tests were used to compare mean change in Ra within fluorides within magnets. The mean change in Ra increased for all magnets after simulated 1, 2, and 5 years of exposure to SnF2 and NaF (p less than 0.03). Using the change in Ra as an indicator for corrosion, PdCo encapsulated SmCo5 magnets and their keepers demonstrated the least corrosion with either fluoride.

Erosion protection by calcium lactate/sodium fluoride rinses under different salivary flows in vitro.

PubMed

Borges, Alessandra B; Scaramucci, Taís; Lippert, Frank; Zero, Domenick T; Hara, Anderson T

2014-01-01

This study investigated the effect of a calcium lactate prerinse on sodium fluoride protection in an in vitro erosion-remineralization model simulating two different salivary flow rates. Enamel and dentin specimens were randomly assigned to 6 groups (n = 8), according to the combination between rinse treatments - deionized water (DIW), 12 mM NaF (NaF) or 150 mM calcium lactate followed by NaF (CaL + NaF) - and unstimulated salivary flow rates - 0.5 or 0.05 ml/min - simulating normal and low salivary flow rates, respectively. The specimens were placed into custom-made devices, creating a sealed chamber on the specimen surface connected to a peristaltic pump. Citric acid was injected into the chamber for 2 min, followed by artificial saliva (0.5 or 0.05 ml/min) for 60 min. This cycle was repeated 4×/day for 3 days. Rinse treatments were performed daily 30 min after the 1st and 4th erosive challenges, for 1 min each time. Surface loss was determined by optical profilometry. KOH-soluble fluoride and structurally bound fluoride were determined in specimens at the end of the experiment. Data were analyzed by 2-way ANOVA and Tukey tests (α = 0.05). NaF and CaL + NaF exhibited significantly lower enamel and dentin loss than DIW, with no difference between them for normal flow conditions. The low salivary flow rate increased enamel and dentin loss, except for CaL + NaF, which presented overall higher KOH-soluble and structurally bound fluoride levels. The results suggest that the NaF rinse was able to reduce erosion progression. Although the CaL prerinse considerably increased F availability, it enhanced NaF protection against dentin erosion only under hyposalivatory conditions.

Benefits of a silica-based fluoride toothpaste containing o-cymen-5-ol, zinc chloride and sodium fluoride.

PubMed

Newby, Craig S; Rowland, Joanna L; Lynch, Richard J M; Bradshaw, David J; Whitworth, Darren; Bosma, Mary Lynn

2011-08-01

Fluoride toothpastes in conjunction with tooth brushing are used to clean teeth, control plaque build-up and for anti-caries benefits. Toothpastes are designed with attractive flavours and appearances to encourage regular prolonged use to maximise these benefits. The incorporation of additional ingredients into toothpaste is a convenient way to provide supplementary protection that fits into people's everyday oral care routine. Such ingredients should not compromise the primary health benefits of toothpaste nor discourage its use. o-Cymen-5-ol and zinc chloride have been incorporated into a sodium fluoride (NaF)/silica toothpaste at 0.1%w/w and 0.6%w/w respectively to provide additional benefits. These include improved gingival health maintenance, in terms of the reduction of plaque, gingival index and bleeding, and an immediate and long lasting reduction in volatile sulfur compounds (VSCs) measured on breath. These benefits can be attributed to the antimicrobial and neutralisation actions of the toothpaste. The use of established fluoride models demonstrated no compromise in NaF bioavailability. The toothpaste was formulated without compromising product aesthetics. The combination of o-cymen-5-ol and zinc chloride in toothpaste gave superior maintenance of gingival health and reduction in malodour related VSCs without compromising the primary health benefits of the toothpaste or diminishing attributes preferred for the product's use. © 2011 FDI World Dental Federation.

The effect of increasing sodium fluoride concentrations on erosion and attrition of enamel and dentine in vitro.

PubMed

Austin, R S; Rodriguez, J M; Dunne, S; Moazzez, R; Bartlett, D W

2010-10-01

To investigate the effect of an aqueous sodium fluoride solution of increasing concentration on erosion and attrition of enamel and dentine in vitro. Enamel and dentine sections from caries-free human third molars were polished flat and taped (exposing a 3 mm x 3 mm area) before being randomly allocated to 1 of 5 groups per substrate (n=10/gp): G1 (distilled water control); G2 (225 ppm NaF); G3 (1450 ppm NaF); G4 (5000 ppm NaF); G5 (19,000 ppm NaF). All specimens were subjected to 5, 10 and 15 cycles of experimental wear [1 cycle=artificial saliva (2h, pH 7.0)+erosion (0.3% citric acid, pH 3.2, 5 min)+fluoride/control (5 min)+attrition (60 linear strokes in artificial saliva from enamel antagonists loaded to 300 g)]. Following tape removal, step height (SH) in mum was measured using optical profilometry. When the number of cycles increased the amount of tooth surface loss increased significantly in enamel and dentine after attrition and erosion and for dentine after attrition. Attrition and erosion resulted in greater surface loss than attrition alone after 15 cycles of experimental wear of enamel. 5000 ppm and 19,000 ppm sodium fluoride solutions had a protective effect on erosive and attritional enamel tooth wear in vitro, however no other groups showed significant differences. The more intensive the fluoride regime the more protection was afforded to enamel from attrition and erosion. However, in this study no such protective effect was demonstrated for dentine. Copyright 2010 Elsevier Ltd. All rights reserved.

[Adaptation of the (18)FDG module for the preparation of a sodium fluoride [(18)F] injection solution in agreement with the United States (USP 32) and European Pharmacopeia (PhEur 6)].

PubMed

Martínez, T; Cordero, B; Medín, S; Sánchez Salmón, A

2011-01-01

To establish an automated procedure for the preparation of sodium fluoride (18)F injection using the resources available in our laboratory for the preparation of (18)FDG and to analyze the repercussion of the conditioning column of the fluoride ion entrapment on the characteristics of the final product. The sequence of an (18)FDG synthesis module prepared so that it traps the fluoride ion from the cyclotron in ion-exchange resin diluted with 0.9% sodium chloride. The final solution was dosified and sterilized in a final vial in an automatized dispensing module. Three different column conditioning protocols within the process were tested. Quality controls were run according to USP 32 and EurPh 6, adding control of ethanol levels of residual solvent and quality controls of the solution at 8 h post-preparation. Activation of the resin cartridges with ethanol and water was the chosen procedure, with fluoride ion trapping > 95% and pH around 7. Ethanol levels were < 5.000 ppm. Quality controls at 8 h indicated that the solution was in compliance with the USP 32 and EurPh 6 specifications. This is an easy, low-cost, reliable automated method for sodium fluoride preparation in PET facilities with existing equipment for (18)FDG synthesis and quality control. Copyright © 2010 Elsevier España, S.L. y SEMNIM. All rights reserved.

[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].

PubMed

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 < 0.001). All groups exposed to NaF had significantly higher fluoride concentration

Orientational disorder in sodium cadmium trifluoride trihydrate, NaCdF{sub 3}.3H{sub 2}O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Robert W.; Mar, Arthur; Liu Jianjun

2006-03-09

Attempts to synthesize the hypothetical anhydrous fluoroperovskite NaCdF{sub 3}, which has been predicted to be stable, resulted instead in a hydrated fluoride of nominal composition NaCdF{sub 3}.3H{sub 2}O. It decomposes to sodium fluoride, cadmium fluoride, and water at 60deg. C. Its structure has been determined by single-crystal X-ray diffraction. Na{sub 0.92(2)}Cd{sub 1.08}F{sub 3.08}.2.92H{sub 2}O crystallizes in the cubic space group Fm3-bar m with a=8.2369(4)A and Z=4. The structure is based on the NaSbF{sub 6}-type (an ordered variant of the ReO{sub 3}-type) and features tilted sodium- and cadmium-centred octahedra that are linked by shared vertices to form a three-dimensional network. Substitutionalmore » disorder occurs on the nonmetal site, which is occupied by both F and O atoms, and on one of the metal sites, which is occupied by 92% Na and 8% Cd. A four-fold orientational disorder of the tilted octahedra is manifested as partial occupancy (25%) of the nonmetal site. A scheme to synthesize the anhydrous fluoride is presented.« less

Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen Ngoc, Tam Dan; Son, Young-Ok; Lim, Shin-Saeng

2012-03-15

Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G{sub 2}/M phase. The addition of NaFmore » induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45α. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-α or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ► The mode of NaF-induced cell death and the mechanisms involved were examined. ► NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ► NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ► JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ► ROS are the up-stream effector in NaF-mediated activation of JNK and p53

A randomised clinical study to measure the anti-erosion benefits of a stannous-containing sodium fluoride dentifrice

PubMed Central

West, Nicola; Seong, Joon; Macdonald, Emma; He, Tao; Barker, Matthew; Hooper, Susan

2015-01-01

Background: To compare the enamel protection efficacy of stannous-containing sodium fluoride and sodium monofluorophosphate (MFP)/triclosan dentifrices marketed in India in an in situ erosion model with acidic challenge. Materials and Methods: This randomised and controlled, in situ, supervised, double-blind clinical trial employed a two-treatment, four-period crossover design, wherein subjects wore an appliance fitted with human enamel samples 6 h/day during each 10 day treatment period and swished twice daily with their assigned dentifrice slurry: Oral-B® Pro-Health (maximum 1,000 ppm F as sodium fluoride with stannous chloride) or Colgate® Strong Teeth with Cavity Protection (maximum 1,000 F as sodium MFP and triclosan). Subjects swished with 250 ml of orange juice over a 10 min period after each treatment and twice daily for the acidic erosive challenge. Enamel samples were measured for tooth surface loss using contact profilometry at baseline and day 10. Results: A total of 34 subjects were randomised to treatment; 32 subjects completed the final visit. Baseline profilometry measurements of the specimen surfaces were near zero within ± 0.3 μm, and no statistically significant difference (P > 0.48) on average was observed between the two test dentifrices. At day 10, the stannous-containing dentifrice demonstrated 88% less erosion (P < 0.0001) relative to the MFP/triclosan dentifrice. Estimated medians (95% confidence intervals) were 0.21 μm (0.17, 0.25) for the stannous-containing dentifrice versus 1.66 μm (1.39, 1.99) for the MFP/triclosan dentifrice. Both dentifrices were well-tolerated. Conclusions: Compared with MFP/triclosan toothpaste, a stabilised stannous-containing sodium fluoride dentifrice gave statistically significantly greater protection against tooth enamel surface loss in situ following repeated acid erosive challenge. PMID:26015669

Sustained antibacterial actions of a new stabilized stannous fluoride dentifrice containing sodium hexametaphosphate.

PubMed

Ramji, Nivedita; Baig, Arif; He, Tao; Lawless, Michelle A; Saletta, Lisa; Suszcynsky-Meister, Elaine; Coggan, John

2005-09-01

Stannous fluoride has been used as a chemotherapeutic agent for years to improve oral health. The benefits of stannous fluoride in controlling caries, plaque, and gingivitis are directly associated with its antimicrobial actions. Recently, a novel dentifrice was developed that combines stannous fluoride with an anticalculus agent, sodium hexa. metaphosphate. A series of independent evaluations were conducted to assess the long-lasting antimicrobial activity of stannous fluoride in the new stannous fluoride/sodium hexametaphosphate dentifrice: an in vitro Live/Dead assay; an in vivo Plaque Glycolysis and Regrowth Model study; a rapid in vitro salivary bacteria metabolic activity study; and a 12-hour in vivo tin-retention study. In the Live/Dead study, the new stannous fluoride/sodium hexametaphosphate dentifrice killed approximately 90% to 99% of the salivary microbes 16 hours after a single exposure. Similarly, the stannous fluoride dentifrice produced statistically significant reductions in plaque acid production and plaque regrowth activity compared to plaque treated with a standard fluoride dentifrice at all time intervals measured after product exposure (15 and 45 minutes). Results from the final two studies collectively demonstrated the presence of total soluble tin, which serves as a marker for the active stannous fluoride, at levels above the minimum concentration for inhibition of salivary bacteria metabolic activity 12 hours posttreatment. These findings confirm the long-lasting antibacterial action of the new stannous fluoride dentifrice, which serves as a basis for its therapeutic benefits.

Evolving Role of Molecular Imaging with (18)F-Sodium Fluoride PET as a Biomarker for Calcium Metabolism.

PubMed

Raynor, William; Houshmand, Sina; Gholami, Saeid; Emamzadehfard, Sahra; Rajapakse, Chamith S; Blomberg, Björn Alexander; Werner, Thomas J; Høilund-Carlsen, Poul F; Baker, Joshua F; Alavi, Abass

2016-08-01

(18)F-sodium fluoride (NaF) as an imaging tracer portrays calcium metabolic activity either in the osseous structures or in soft tissue. Currently, clinical use of NaF-PET is confined to detecting metastasis to the bone, but this approach reveals indirect evidence for disease activity and will have limited use in the future in favor of more direct approaches that visualize cancer cells in the read marrow where they reside. This has proven to be the case with FDG-PET imaging in most cancers. However, a variety of studies support the application of NaF-PET to assess benign osseous diseases. In particular, bone turnover can be measured from NaF uptake to diagnose osteoporosis. Several studies have evaluated the efficacy of bisphosphonates and their lasting effects as treatment for osteoporosis using bone turnover measured by NaF-PET. Additionally, NaF uptake in vessels tracks calcification in the plaques at the molecular level, which is relevant to coronary artery disease. Also, NaF-PET imaging of diseased joints is able to project disease progression in osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis. Further studies suggest potential use of NaF-PET in domains such as back pain, osteosarcoma, stress-related fracture, and bisphosphonate-induced osteonecrosis of the jaw. The critical role of NaF-PET in disease detection and characterization of many musculoskeletal disorders has been clearly demonstrated in the literature, and these methods will become more widespread in the future. The data from PET imaging are quantitative in nature, and as such, it adds a major dimension to assessing disease activity.

Fluoride toothpastes and fluoride mouthrinses for home use.

PubMed

Rugg-Gunn, Andrew; Bánóczy, Jolán

2013-11-01

To provide a brief commentary review of fluoride-containing toothpastes and mouthrinses with emphasis on their use at home. Toothpastes and mouthrinses are just two of many ways of providing fluoride for the prevention of dental caries. The first investigations into incorporating fluoride into toothpastes and mouthrinses were reported in the middle 1940s. Unlike water fluoridation (which is 'automatic fluoridation'), fluoride-containing toothpastes and fluoridecontaining mouthrinses are, primarily, for home use and need to be purchased by the individual. By the 1960s, research indicated that fluoride could be successfully incorporated into toothpastes and clinical trials demonstrated their effectiveness. By the end of the 1970s, almost all toothpastes contained fluoride. The widespread use of fluoride- containing toothpastes is thought to be the main reason for much improved oral health in many countries. Of the many fluoride compounds investigated, sodium fluoride, with a compatible abrasive, is the most popular, although amine fluorides are used widely in Europe. The situation is similar for mouthrinses. Concentrations of fluoride (F), commonly found, are 1500 ppm (1500 μg F/g) for toothpastes and 225 ppm (225 μg F/ml) for mouthrinse. Several systematic reviews have concluded that fluoride-containing toothpastes and mouthrinses are effective, and that there is added benefit from their use with other fluoride delivery methods such as water fluoridation. Guidelines for the appropriate use of fluoride toothpastes and mouthrinses are available in many countries. Fluoride toothpastes and mouthrinses have been developed and extensive testing has demonstrated that they are effective and their use should be encouraged. Copyright © 2013 by Academy of Sciences and Arts of Bosnia and Herzegovina.

Comparative effect of a stannous fluoride toothpaste and a sodium fluoride toothpaste on a multispecies biofilm.

PubMed

Cheng, Xingqun; Liu, Jinman; Li, Jiyao; Zhou, Xuedong; Wang, Lijiang; Liu, Jiquan; Xu, Xin

2017-02-01

This paper aimed to compare the mode of action of a stannous fluoride-containing toothpaste with a conventional sodium fluoride-containing toothpaste on anti-biofilm properties. A three-species biofilm model that consists of Streptococcus mutans, Streptococcus sanguinis and Porphyromonas gingivalis was established to compare the anti-biofilm properties of a stannous fluoride-containing toothpaste (CPH), a conventional sodium fluoride-containing toothpaste (CCP) and a negative control (PBS). The 48h biofilms were subjected to two-minute episodes of treatment with test agents twice a day for 5 consecutive days. Crystal violet staining and XTT assays were used to evaluate the biomass and viability of the treated biofilm. Live/dead staining and bacteria/extracellular polysaccharides (EPS) double-staining were used to visualize the biofilm structure and to quantify microbial/extracellular components of the treated biofilms. Species-specific fluorescent in situ hybridization and quantitative polymerase chain reaction (qPCR) were used to analyze microbial composition of the biofilms after treatment. The biomass and viability of the biofilms were significantly reduced after CPH toothpaste treatment. The inhibitory effect was further confirmed by the live/dead staining. The EPS amounts of the three-species biofilm were significantly reduced by CCP and CPH treatments, and CPH toothpaste demonstrated significant inhibition on EPS production. More importantly, CPH toothpaste significantly suppressed S. mutans and P. gingvalis, and enriched S. sanguinis in the three-species biofilm. In all experiments CPH had a significantly greater effect than CCP (p<0.05) and CCP had a greater effect than PBS (p<0.05). Stannous fluoride-containing toothpaste not only showed better inhibitory effect against oral microbial biofilm, but was also able to modulate microbial composition within multi-species biofilm compared with conventional sodium fluoride-containing toothpaste. Copyright © 2016

Comparison of the toxicity of fluoridation compounds in the nematode Caenorhabditis elegans.

PubMed

Rice, Julie R; Boyd, Windy A; Chandra, Dave; Smith, Marjolein V; Den Besten, Pamela K; Freedman, Jonathan H

2014-01-01

Fluorides are commonly added to drinking water in the United States to decrease the incidence of dental caries. Silicofluorides, such as sodium hexafluorosilicate (Na2 SiF6 ) and fluorosilicic acid (H2 SiF6 ), are mainly used for fluoridation, although fluoride salts such as sodium fluoride (NaF) are also used. Interestingly, only the toxicity of NaF has been examined and not that of the more often used silicofluorides. In the present study, the toxicities of NaF, Na2 SiF6 , and H2 SiF6 were compared. The toxicity of these fluorides on the growth, feeding, and reproduction in the alternative toxicological testing organism Caenorhabditis elegans was examined. Exposure to these compounds produced classic concentration-response toxicity profiles. Although the effects of the fluoride compounds varied among the 3 biological endpoints, no differences were found between the 3 compounds, relative to the fluoride ion concentration, in any of the assays. This suggests that silicofluorides have similar toxicity to NaF. © 2013 SETAC.

18 F-sodium fluoride positron emission tomography of the equine distal limb: Exploratory study in three horses.

PubMed

Spriet, M; Espinosa, P; Kyme, A Z; Phillips, K L; Katzman, S A; Galuppo, L D; Stepanov, P; Beylin, D

2018-01-01

Positron emission tomography (PET) is a cross-sectional, functional imaging modality that has recently become available to the horse. The use of 18 F-sodium fluoride ( 18 F-NaF), a PET bone tracer, has not previously been reported in this species. To assess the feasibility of 18 F-NaF PET in the equine distal limb and explore possible applications in the horse in comparison with other imaging modalities. Exploratory descriptive study involving three research horses. Horses were placed under general anaesthesia prior to intravenous (i.v.) administration of 1.5 MBq/kg of 18 F-NaF. Positron emission tomography imaging of both front feet and fetlocks was performed using a portable scanner. Computed tomography (CT) of the distal limb was performed under a separate anaesthetic episode. Bone scintigraphy and magnetic resonance imaging (MRI) were subsequently performed under standing sedation. Images obtained from PET and other imaging modalities were independently assessed and the results correlated. Positron emission tomography images were obtained without complication. The radiation exposure rate was similar to equine bone scintigraphy. Positron emission tomography detected focal 18 F-NaF uptake in areas where other imaging modalities did not identify any abnormalities. This included sites of ligamentous attachment, subchondral compact bone plate and the flexor cortex of the navicular bone. 18 F-NaF uptake was identified in some, but not all, osseous fragments and areas of osseous formation, suggesting a distinction between active and inactive lesions. A small number of horses were included and histopathology was not available. 18 F-NaF PET imaging of the equine distal limb provides useful additional information when compared with CT, MRI and scintigraphy and has the potential for both research and clinical applications in the horse. The Summary is available in Chinese - see Supporting information. © 2017 EVJ Ltd.

Sodium fluoride and sulfur dioxide affected male reproduction by disturbing blood-testis barrier in mice.

PubMed

Zhang, Jianhai; Li, Zhihui; Qie, Mingli; Zheng, Ruibo; Shetty, Jagathpala; Wang, Jundong

2016-08-01

Fluoride and sulfur dioxide (SO2), two well-known environmental toxicants, have been implicated to have adverse effects on male reproductive health in humans and animals. The objective of this study to investigate if the BTB is one of the pathways that lead to reproductive toxicity of sodium fluoride and sulfur dioxide alone or in combination, in view of the key role of blood testis barrier (BTB) in testis. The results showed that a marked decrease in sperm quality, and altered morphology and ultrastructure of BTB in testis of mice exposure to fluoride (100 mg NaF/L in drinking water) or/and sulfur dioxide (28 mg SO2/m(3), 3 h/day). Meanwhile, the mRNA expression levels of some vital BTB-associated proteins, including occluding, claudin-11, ZO-1, Ncadherin, α-catenin, and connexin-43 were all strikingly reduced after NaF exposure, although only the reduction of DSG-2 was statistically significant in all treatment groups. Moreover, the proteins expressions also decreased significantly in claudin-11, N-cadherin, α-catenin, connexin-43 and desmoglein-2 in mice treated with fluoride and/or SO2. These changes in BTB structure and constitutive proteins may therefore be connected with the low sperm quality in these mice. The role of fluoride should deserves more attention in this process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Low glucose utilization and neurodegenerative changes caused by sodium fluoride exposure in rat's developmental brain.

PubMed

Jiang, Chunyang; Zhang, Shun; Liu, Hongliang; Guan, Zhizhong; Zeng, Qiang; Zhang, Cheng; Lei, Rongrong; Xia, Tao; Wang, Zhenglun; Yang, Lu; Chen, Yihu; Wu, Xue; Zhang, Xiaofei; Cui, Yushan; Yu, Linyu; Wang, Aiguo

2014-03-01

Fluorine, a toxic and reactive element, is widely prevalent throughout the environment and can induce toxicity when absorbed into the body. This study was to explore the possible mechanisms of developmental neurotoxicity in rats treated with different levels of sodium fluoride (NaF). The rats' intelligence, as well as changes in neuronal morphology, glucose absorption, and functional gene expression within the brain were determined using the Morris water maze test, transmission electron microscopy, small-animal magnetic resonance imaging and Positron emission tomography and computed tomography, and Western blotting techniques. We found that NaF treatment-impaired learning and memory in these rats. Furthermore, NaF caused neuronal degeneration, decreased brain glucose utilization, decreased the protein expression of glucose transporter 1 and glial fibrillary acidic protein, and increased levels of brain-derived neurotrophic factor in the rat brains. The developmental neurotoxicity of fluoride may be closely associated with low glucose utilization and neurodegenerative changes.

Silicon oxidation in fluoride solutions

NASA Technical Reports Server (NTRS)

Sancier, K. M.; Kapur, V.

1980-01-01

Silicon is produced in a NaF, Na2SiF6, and Na matrix when SiF4 is reduced by metallic sodium. Hydrogen is evolved during acid leaching to separate the silicon from the accompanying reaction products, NaF and Na2SiF6. The hydrogen evolution reaction was studied under conditions simulating leaching conditions by making suspensions of the dry silicon powder in aqueous fluoride solutions. The mechanism for the hydrogen evolution is discussed in terms of spontaneous oxidation of silicon resulting from the cooperative effects of (1) elemental sodium in the silicon that reacts with water to remove a protective silica layer, leaving clean reactive silicon, and (2) fluoride in solution that complexes with the oxidized silicon in solution and retards formation of a protective hydrous oxide gel.

Effect of Sodium Fluoride Ingestion on Malondialdehyde Concentration and the Activity of Antioxidant Enzymes in Rat Erythrocytes

PubMed Central

Morales-González, José A.; Gutiérrez-Salinas, José; García-Ortiz, Liliana; del Carmen Chima-Galán, María; Madrigal-Santillán, Eduardo; Esquivel-Soto, Jaime; Esquivel-Chirino, César; González-Rubio, Manuel García-Luna y

2010-01-01

Fluoride intoxication has been shown to produce diverse deleterious metabolic alterations within the cell. To determine the effects of sodium fluoride (NaF) treatment on malondialdehyde (MDA) levels and on the activity of antioxidant enzymes in rat erythrocytes, Male Wistar rats were treated with 50 ppm of NaF or were untreated as controls. Erythrocytes were obtained from rats sacrificed weekly for up to eight weeks and the concentration of MDA in erythrocyte membrane was determined. In addition, the activity of the enzymes superoxide, dismutase, catalase, and glutathione peroxidase were determined. Treatment with NaF produces an increase in the concentration of malondialdehyde in the erythrocyte membrane only after the eight weeks of treatment. On the other hand, antioxidant enzyme activity was observed to increase after the fourth week of NaF treatment. In conclusion, intake of NaF produces alterations in the erythrocyte of the male rat, which indicates induction of oxidative stress. PMID:20640162

Remineralizing Potential of a Low Fluoride Toothpaste with Sodium Trimetaphosphate: An in situ Study.

PubMed

Takeshita, Eliana M; Danelon, Marcelle; Castro, Luciene P; Cunha, Robson F; Delbem, Alberto C B

2016-01-01

To evaluate the effect of a low-fluoride (F) toothpaste supplemented with sodium trimetaphosphate (TMP) on enamel remineralization in situ. Bovine enamel blocks were selected on the basis of their surface hardness (SH) after caries-like lesions had been induced, and randomly divided into 4 treatment groups, according to the toothpastes used: without F or TMP (placebo); 500 ppm F; 500 ppm F plus 1% TMP; and 1,100 ppm F. The study design was blinded and crossover and performed in 4 phases of 3 days each. Eleven subjects used palatal appliances containing 4 bovine enamel blocks which were treated 3 times per day during 1 min each time, with natural slurries of saliva and toothpaste formed in the oral cavity during toothbrushing. After each phase, the percentages of surface (%SHR) and subsurface hardness recovery (%ΔKHNR) were calculated. F, calcium (Ca), and phosphorus (Pi) contents in enamel were also determined. Data were analyzed by 1-way, repeated-measures ANOVA, followed by the Student-Newman-Keuls test (p < 0.05). Toothpaste with 500 ppm F + TMP and 1,100 ppm F showed similar %SHR and %ΔKHNR as well as enamel F, Ca, and Pi concentrations. The addition of TMP to a low-fluoride toothpaste promoted a similar remineralizing capacity to that of a standard (1,100 ppm F) toothpaste in situ. © 2016 S. Karger AG, Basel.

Evaluation of standardized Bacopa monniera extract in sodium fluoride-induced behavioural, biochemical, and histopathological alterations in mice.

PubMed

Balaji, Bhaskar; Kumar, Ekambaram Prem; Kumar, Anil

2015-01-01

Effect of standardized Bacopa monniera (BM; family: Scrophulariaceae) extract (100 and 300 mg/kg) against sodium fluoride (NaF; 100 and 200 ppm)-induced behavioural, biochemical, and neuropathological alterations in mice was evaluated. Akinesia, rotarod (motor coordination), forced swim test (depression), open field test (anxiety), transfer latency (memory), cholinesterase (ChE), and oxidative stress (superoxide dismutase, catalase, glutathione peroxidase, and lipid peroxidation) were determined in mice treated with NaF for 30 days alone and in combination with BM. NaF induced motor incoordination, depression, and memory impairment, and these were prevented by coadministration of BM in mice. However, NaF did not alter the weight gain, feed/water consumption, and anxiety profile. Suppression of ChE levels and increased oxidative stress were observed in mice treated with NaF. Coadministration of BM significantly improved the memory, ChE levels, and antioxidant enzymes but failed to alter the fluoride levels in NaF-treated mice. Histopathological studies revealed that BM protected the neuropathological alterations induced by NaF. © The Author(s) 2012.

Effect of Sodium Fluoride Mouthwash on the Frictional Resistance of Orthodontic Wires.

PubMed

Geramy, Allahyar; Hooshmand, Tabassom; Etezadi, Tahura

2017-09-01

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. 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. 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. According to the results of the current study, 0.05% sodium fluoride mouthwash increased the frictional characteristics of all the evaluated orthodontic wires.

Minimally invasive monitoring of skeletal muscle hypermetabolism induced by the phosphodiesterase-III-inhibitor milrinone and sodium fluoride.

PubMed

Schuster, Frank; Johannsen, Stephan; Roewer, Norbert; Anetseder, Martin

2013-04-01

We hypothesized that the phosphodiesterase-III-inhibitor milrinone and the non-specific G-protein activator sodium fluoride increase the skeletal muscular lactate levels as a sign of a hypermetabolic response. With approval of the local animal care committee Sprague-Dawley rats were killed and artificially perfused either with Ringer's solution or sodium fluoride 110 mM, while milrinone 1.32 mM or Ringer's solution at 1 μl/min was applied via microdialysis probes in both hind limbs. Lactate was measured spectrophotometrically in the dialysate. Baseline lactate levels before drug application did not differ between hind limbs. Local infusion of milrinone via microdialysis did not significantly increase intramuscular lactate concentrations compared with the Ringer control group. Muscular perfusion with sodium fluoride resulted in a significant increase of lactate and was potentiated by combination with local milrinone. Phosphodiesterase-III-inhibition alone does not significantly influence the lactate levels in skeletal muscle of sacrificed rats. Sodium fluoride infusion leads to an intramuscular lactate increase, which was further potentiated by local inhibition of phosphodiesterase-III. The fluoride-mediated hypermetabolic response following sodium fluoride could be a possible explanation for the observed myotoxic adverse effects in individuals treated by fluoride-containing agents. © 2012 The Authors. JPP © 2012. Royal Pharmaceutical Society.

Pharmacokinetics of Fluoride in Toddlers After Application of 5% Sodium Fluoride Dental Varnish

PubMed Central

Taves, Donald M.; Kim, Amy S.; Watson, Gene E.; Horst, Jeremy A.

2014-01-01

The prevalence of dental caries (tooth decay) among preschool children is increasing, driven partially by an earlier age of onset of carious lesions. The American Academy of Pediatrics recommends application of 5% sodium fluoride varnish at intervals increasing with caries risk status, as soon as teeth are present. However, the varnishes are marketed for treatment of tooth sensitivity and are regulated as medical devices rather than approved by the US Food and Drug Administration for prevention of dental caries (tooth decay). The objective of this research is to examine the safety of use in toddlers by characterizing the absorption and distribution profile of a currently marketed fluoride varnish. We measured urinary fluoride for 5 hours after application of fluoride varnish to teeth in 6 toddlers aged 12 to 15 months. Baseline levels were measured on a separate day. The urine was extracted from disposable diapers, measured by rapid diffusion, and extrapolated to plasma levels. The mean estimated plasma fluoride concentration was 13 μg/L (SD, 9 μg/L) during the baseline visit and 21 μg/L (SD, 8 μg/L) during the 5 hours after treatment. Mean estimated peak plasma fluoride after treatment was 57 μg/L (SD, 22 μg/L), and 20 μg/kg (SD, 4 μg/L) was retained on average. Retained fluoride was 253 times lower than the acute toxic dose of 5 mg/kg. Mean plasma fluoride after placement of varnish was within an SD of control levels. Occasional application of fluoride varnish following American Academy of Pediatrics guidance is safe for toddlers. PMID:25136045

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

NASA Astrophysics Data System (ADS)

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.

Effect of Catalase and Sodium Fluoride on Human Enamel bleached with 35% Carbamide Peroxide

PubMed Central

Shigli, Anand L; Sharma, Divya S; Thakur, Gagan

2015-01-01

ABSTRACT Aim: To evaluate the effects of postbleaching antioxidant application fluoridation treatment on the surface morphology and microhardness of human enamel. Materials and methods: Ten freshly extracted human maxillary central incisors were cut at cementoenamel junction. Crown portion was sectioned into six slabs which were divided into five groups: group A – untreated controls; group B – 35% carbamide peroxide (CP); group C – 35% CP and catalase; group D – treatment with 35% CP and 5% sodium fluoride; group E – 35% CP, catalase and 5% sodium fluoride. Thirty-five percent carbamide peroxide application included two applications of 30 minutes each at a 5-day interval. After treatment, the slabs were thoroughly washed with water for 10 seconds and stored in artificial saliva at 37°C until the next treatment. Two percent sodium fluoride included application for 5 minutes. Three catalase included application for 3 minutes. Results: After 5 days, groups B and C showed significantly decreased enamel microhardness compared to control. Group D specimens showed relatively less reduction in enamel micro-hardness than group C specimens. There is a marked increase in enamel microhardness in group E specimens. Conclusions: Fluoride take up was comparatively enhanced after catalase application resulting in less demineralization and increased microhardness. How to cite this article: Thakur R, Shigli AL, Sharma DS, Thakur G. Effect of Catalase and Sodium Fluoride on Human Enamel bleached with 35% Carbamide Peroxide. Int J Clin Pediatr Dent 2015;8(1):12-17. PMID:26124575

Effect of Catalase and Sodium Fluoride on Human Enamel bleached with 35% Carbamide Peroxide.

PubMed

Thakur, Ruchi; Shigli, Anand L; Sharma, Divya S; Thakur, Gagan

2015-01-01

To evaluate the effects of postbleaching antioxidant application fluoridation treatment on the surface morphology and microhardness of human enamel. Ten freshly extracted human maxillary central incisors were cut at cementoenamel junction. Crown portion was sectioned into six slabs which were divided into five groups: group A - untreated controls; group B - 35% carbamide peroxide (CP); group C - 35% CP and catalase; group D - treatment with 35% CP and 5% sodium fluoride; group E - 35% CP, catalase and 5% sodium fluoride. Thirty-five percent carbamide peroxide application included two applications of 30 minutes each at a 5-day interval. After treatment, the slabs were thoroughly washed with water for 10 seconds and stored in artificial saliva at 37°C until the next treatment. Two percent sodium fluoride included application for 5 minutes. Three catalase included application for 3 minutes. After 5 days, groups B and C showed significantly decreased enamel microhardness compared to control. Group D specimens showed relatively less reduction in enamel micro-hardness than group C specimens. There is a marked increase in enamel microhardness in group E specimens. Fluoride take up was comparatively enhanced after catalase application resulting in less demineralization and increased microhardness. How to cite this article: Thakur R, Shigli AL, Sharma DS, Thakur G. Effect of Catalase and Sodium Fluoride on Human Enamel bleached with 35% Carbamide Peroxide. Int J Clin Pediatr Dent 2015;8(1):12-17.

40 CFR 721.10340 - Potassium zinc fluoride (KZnF3).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Potassium zinc fluoride (KZnF3). 721... Substances § 721.10340 Potassium zinc fluoride (KZnF3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as potassium zinc fluoride (KZnF3) (PMN P-04...

40 CFR 721.10340 - Potassium zinc fluoride (KZnF3).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Potassium zinc fluoride (KZnF3). 721... Substances § 721.10340 Potassium zinc fluoride (KZnF3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as potassium zinc fluoride (KZnF3) (PMN P-04...

40 CFR 721.10340 - Potassium zinc fluoride (KZnF3).

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Potassium zinc fluoride (KZnF3). 721... Substances § 721.10340 Potassium zinc fluoride (KZnF3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as potassium zinc fluoride (KZnF3) (PMN P-04...

Fluoride rinse effect on retention of CaF2 formed on enamel/dentine by fluoride application.

PubMed

Falcão, Amanda; Masson, Nadia; Leitão, Tarcísio Jorge; Botelho, Juliana Nunes; Ferreira-Nóbilo, Naiara de Paula; Tabchoury, Cínthia Pereira Machado; Tenuta, Livia Maria Andaló; Cury, Jaime Aparecido

2016-01-01

Calcium fluoride-like materials ("CaF2") formed on dental surfaces after professional fluoride application are unstable in the oral environment but can be retained longer with a daily NaF mouthrinse. We tested the effect of twice daily 0.05% NaF rinses on the retention of "CaF2" formed on enamel and dentine after applying acidulated phosphate fluoride (APF). "CaF2" formed on enamel/dentine by APF application significantly decreased after exposure to artificial saliva and the 0.05% NaF rinse was ineffective to avoid this reduction. These findings suggest that the combination of APF and 0.05% NaF is not clinically relevant, either for caries or dental hypersensitivity.

Development of a sustained fluoride delivery system.

PubMed

Baturina, Olga; Tufekci, Eser; Guney-Altay, Ozge; Khan, Shadeed M; Wnek, Gary E; Lindauer, Steven J

2010-11-01

To develop a novel delivery system by which fluoride incorporated into elastomeric rings, such as those used to ligate orthodontic wires, will be released in a controlled and constant manner. Polyethylene co-vinyl acetate (PEVA) was used as the model elastomer. Samples (N = 3) were prepared by incorporating 0.02 to 0.4 g of sodium fluoride (NaF) into previously prepared PEVA solution. Another group of samples prepared in the same manner were additionally dip-coated in PEVA to create an overcoat. Fluoride release studies were conducted in vitro using an ion selective electrode over a period of 45 days. The amount of fluoride released was compared to the optimal therapeutic dose of 0.7 microg F(-)/ring/d. Only coated samples with the highest fluoride content (group D, 0.4 g of NaF) were able to release fluoride at therapeutic levels. When fluoride release from coated and uncoated samples with the same amount of NaF were compared, it was shown that the dip-coating technique resulted in a fluoride release in a controlled manner while eliminating the initial burst effect. This novel fluoride delivery matrix provided fluoride release at a therapeutically effective rate and profile.

Comparison of in vitro fluoride uptake from whitening toothpastes and a conventional toothpaste in demineralised enamel.

PubMed

Altenburger, Markus J; Bernhart, Jasmin; Schicha, Thurid D; Wrbas, Karl-Thomas; Hellwig, Elmar

2010-01-01

Studies on the compatibility of abrasives and fluoride compounds deal exclusively with fluoride uptake and remineralization after storing the enamel specimens in a toothpaste-saliva mixture. The influence of brushing on the fluoride uptake when highly abrasive toothpastes are used has hardly been investigated so far. The aim of the present study was to investigate fluoride uptake in initially demineralised dental enamel after storage in, or brushing with, whitening toothpaste slurries, compared to a conventional toothpaste. For this purpose two widely available whitening toothpastes with ionically bound fluoride (sodium fluoride NaF), two with covalently-bound fluoride toothpastes (sodium monofluorophosphate, NaMFP) and a conventional amine fluoride toothpaste (AmF) were compared. The fluoride uptake after use of the AmF toothpaste was shown to be statistically significantly higher than that after application of the NaF toothpastes, which in turn was statistically significantly higher than the uptake resulting from NaMFP application. The fluoride uptake was slightly higher when the enamel samples were brushed with NaF toothpaste, rather than just stored in the respective toothpaste slurry. Brushing with highly abrasive toothpastes did not negatively influence fluoride uptake in demineralised dental enamel. The ionic form of the fluoride in toothpastes appears to be critical for increased fluoride uptake. The acidic components of the AmF toothpaste improved fluoride uptake compared to alkaline NaF toothpastes.

Altered sperm chromatin structure in mice exposed to sodium fluoride through drinking water.

PubMed

Sun, Zilong; Niu, Ruiyan; Wang, Bin; Wang, Jundong

2014-06-01

This study investigated the effects of sodium fluoride (NaF) on sperm abnormality, sperm chromatin structure, protamine 1 and protamine 2 (P1 and P2) mRNA expression, and histones expression in sperm in male mice. NaF was orally administrated to male mice at 30, 70, and 150 mg/l for 49 days (more than one spermatogenic cycle). Sperm head and tail abnormalities were significantly enhanced at middle and high doses. Similarly, sperm chromatin structure was also adversely affected by NaF exposure, indicating DNA integrity damage. Furthermore, middle and high NaF significantly reduced the mRNA expressions of P1 and P2, and P1/P2 ratio, whereas the sperm histones level was increased, suggesting the abnormal histone-protamine replacement. Therefore, we concluded that the mechanism by which F induced mice sperm abnormality and DNA integrity damage may involved in the alterations in P1, P2, and histones expression in sperm of mice. Copyright © 2012 Wiley Periodicals, Inc.

Comparison of the antimicrobial efficacy of chlorhexidine, sodium fluoride, fluoride with essential oils, alum, green tea, and garlic with lime mouth rinses on cariogenic microbes.

PubMed

Thomas, Ann; Thakur, Sneha; Mhambrey, Sanjana

2015-01-01

A number of natural mouth rinse formulations are being proposed as an alternative to the widely used chemical mouth rinses. To evaluate and compare the antimicrobial efficacy of chlorhexidine (0.2%), sodium fluoride (0.05%), fluoride with essential oils (0.05%), alum (0.02 M), green tea, and garlic with lime mouth rinses against Streptococcus mutans, lactobacilli, and Candida albicans. The three microbes were isolated from the saliva samples collected from children with severe early childhood caries. The zone of minimum inhibition was assessed using agar diffusion method. The data were statistically analyzed using SPSS software. Against S. mutans and lactobacilli, chlorhexidine mouth rinse was found to be the most effective as compared to sodium fluoride (P < 0.001, P < 0.001), fluoride with essential oils (P < 0.001, P < 0.001), alum (P < 0.001, P < 0.001), green tea (P < 0.001, P < 0.001), and garlic with lime (P < 0.001, P < 0.001) mouth rinses, respectively. But against C. albicans, garlic with lime mouth rinse was found to be the most effective as compared to chlorhexidine (P < 0.001), sodium fluoride (P < 0.001), fluoride with essential oils (P < 0.001), alum (P < 0.001), and green tea (P < 0.001) mouth rinses. Against S. mutans and lactobacilli, after chlorhexidine mouth rinse, garlic with lime mouth rinse was found to be significantly more effective than sodium fluoride (P = 0.053, P = 0.001), fluoride with essential oils (P < 0.001, P < 0.001), alum (P < 0.001, P < 0.001), and green tea (P < 0.001, P < 0.001) mouth rinses. As a natural mouth rinse, garlic with lime mouth rinse was found to be the most promising. However, further studies are needed in this field.

Effects of fluoridated milk on root dentin remineralization.

PubMed

Arnold, Wolfgang H; Heidt, Bastian A; Kuntz, Sebastian; Naumova, Ella A

2014-01-01

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.

18 F-Fluoride positron emission tomography/computed tomography for noninvasive in vivo quantification of pathophysiological bone metabolism in experimental murine arthritis

PubMed Central

2014-01-01

Introduction Evaluation of disease severity in experimental models of rheumatoid arthritis is inevitably associated with assessment of structural bone damage. A noninvasive imaging technology allowing objective quantification of pathophysiological alterations of bone structure in rodents could substantially extend the methods used to date in preclinical arthritis research for staging of autoimmune disease severity or efficacy of therapeutical intervention. Sodium 18 F-fluoride (18 F-NaF) is a bone-seeking tracer well-suited for molecular imaging. Therefore, we systematically examined the use of 18 F-NaF positron emission tomography/computed tomography (PET/CT) in mice with glucose-6-phosphate isomerase (G6PI)–induced arthritis for quantification of pathological bone metabolism. Methods F-fluoride was injected into mice before disease onset and at various time points of progressing experimental arthritis. Radioisotope accumulation in joints in the fore- and hindpaws was analyzed by PET measurements. For validation of bone metabolism quantified by 18 F-fluoride PET, bone surface parameters of high-resolution μCT measurements were used. Results Before clinical arthritis onset, no distinct accumulation of 18 F-fluoride was detectable in the fore- and hindlimbs of mice immunized with G6PI. In the course of experimental autoimmune disease, 18 F-fluoride bone uptake was increased at sites of enhanced bone metabolism caused by pathophysiological processes of autoimmune disease. Moreover, 18 F-fluoride signaling at different stages of G6PI-induced arthritis was significantly correlated with the degree of bone destruction. CT enabled identification of exact localization of 18 F-fluoride signaling in bone and soft tissue. Conclusions The results of this study suggest that small-animal PET/CT using 18 F-fluoride as a tracer is a feasible method for quantitative assessment of pathophysiological bone metabolism in experimental arthritis. Furthermore, the

Effect of fluoride sodium mouthwash solutions on cpTI: evaluation of physicochemical properties.

PubMed

Toniollo, Marcelo Bighetti; Galo, Rodrigo; Macedo, Ana Paula; Rodrigues, Renata Cristina Silveira; Ribeiro, Ricardo Faria; Mattos, Maria da Gloria Chiarello de

2012-01-01

The effects of fluoride, which is present in different oral hygiene products, deserve more investigation because little is known about their impact on the surface of titanium, which is largely used in Implantology. This study evaluated the surface of commercially pure titanium (cpTi) after exposure to different concentrations of sodium fluoride (NaF). The hypothesis tested in this study was that different concentrations of NaF applied at different time intervals can affect the titanium surface in different ways. The treatments resulted in the following groups: GA (control): immersion in distilled water; GB: immersion in 0.05% NaF for 3 min daily; GC: immersion in 0.2% NaF for 3 min daily; GD: immersion in 0.05% NaF for 3 min every 2 weeks; and GE: immersion in 0.2% NaF for 3 min every 2 weeks. The experiment lasted 60 days. Roughness was measured initially and every 15 days subsequently up to 60 days. After 60 days, corrosion analysis and anodic polarization were done. The samples were examined by scanning electron microscopy (SEM). The roughness data were analyzed by ANOVA and there was no significant difference among groups and among time intervals. The corrosion data (i(corr)) were analyzed by the Mann-Whitney test, and significant differences were found between GA and GC, GB and GC, GC and GD, GC and GE. SEM micrographs showed that the titanium surface exposed to NaF presented corrosion that varied with the different concentrations. This study suggests that the use of 0.05% NaF solution on cpTi is safe, whereas the 0.2% NaF solution should be carefully evaluated with regard to its daily use.

Longitudinal evaluation of fluoride levels in nails of 18-30-month-old children that were using toothpastes with 500 and 1100 μg F/g.

PubMed

Amaral, Jackeline G; Freire, Isabelle R; Valle-Neto, Eduardo F R; Cunha, Robson F; Martinhon, Cleide C R; Delbem, Alberto C B

2014-10-01

This study aimed to evaluate the fluoride concentration in the fingernails and toenails of children aged 18-30 months during use of fluoride-containing toothpastes supplemented with calcium glycerophosphate (CaGP) or sodium trimetaphosphate (TMP). According to the toothpaste used, children (n = 56) were randomly assigned into three groups: 500 μg F/g with 1% TMP, 500 μg F/g with 0.25% CaGP, and 1100 μg F/g. Fingernails and toenails were collected monthly over a period of 330 days, from the beginning of toothpaste use. Fluoride concentration in the water consumed by the volunteers and fluoride intake from diet and toothpaste were also determined. Fluoride analyses were performed with the electrode after hexamethyldisiloxane-facilitated diffusion or by the direct method, according to the samples. Data passed normality and homoscedasticity tests and were analyzed by 2-way analysis of variance (anova) and 1-way anova followed by Student-Newman-Keuls test (P < 0.05). Fluoride levels in the fingernails and toenails as well as fluoride intake from toothpaste were similar for the groups treated with 500 μg F/g with 1% TMP and 500 μg F/g with 0.25% CaGP toothpastes, but significantly lower than the 1100 μg F/g group (P < 0.05). No significant differences were noted among the groups regarding fluoride intake from diet and that by water consumed by the volunteers (P > 0.05). The results of the longitudinal study suggest that the level of fluoride present in nails was lower with the use of toothpastes with a low fluoride concentration. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Inhibitory Effect of Fluoride on Na+,K+ ATPase Activity in Human Erythrocyte Membrane.

PubMed

A, Shashi; G, Meenakshi

2015-12-01

The present study was performed to evaluate the role of long-term consumption of excessive fluoride on electrolyte homeostasis and their transporting mechanisms in erythrocytes of subjects afflicted with dental and skeletal fluorosis. A total of 620 adult (20-50 years) Indian residents participated in this study: 258 men and 242 women exposed to high concentrations of fluoride and 120 age and gender-matched control subjects. Erythrocytes were isolated from blood samples, washed, and used for the estimation of intraerythrocyte sodium and potassium concentrations. Na+,K+ ATPase activity was determined spectrophotometrically from a ghost erythrocyte membrane prepared by osmotic lysis. Erythrocyte analytes were correlated with the water and serum fluoride concentrations by Pearson's bivariate correlation and regression analysis. Results indicated a significant increase in intraerythrocyte sodium (F=14306.265, P<0.0001) in subjects from endemic fluorosis study groups as compared to controls. A significant (P<0.05) positive correlation of intracellular sodium was found with water and serum fluoride concentrations. Mean concentration of intraerythrocytic potassium ions showed significant reduction (F=9136.318, P<0.0001) in subjects exposed to fluoride. A significant (P<0.05) negative correlation of potassium ions was noted with water and serum fluoride concentrations. Na+,K+ ATPase activity was significantly declined (F=1572.763, P<0.0001) in subjects exposed to fluoride. A significant (P<0.05) inverse relationship of Na+,K+ ATPase activity was revealed with water and serum fluoride concentrations.

Taurine reverses sodium fluoride-mediated increase in inflammation, caspase-3 activity, and oxidative damage along the brain-pituitary-gonadal axis in male rats.

PubMed

Adedara, Isaac A; Olabiyi, Bolanle F; Ojuade, TeminiJesu D; Idris, Umar F; Onibiyo, Esther M; Farombi, Ebenezer O

2017-09-01

Excessive exposure to fluoride is associated with male reproductive dysfunction in humans and animals. Taurine (2-aminoethane sulfonic acid) is a free intracellular β-amino acid with antioxidant, anti-inflammatory, and neuroprotective properties. However, the effect of taurine on fluoride-induced reproductive toxicity has not been reported. The present study investigated the influence of taurine on sodium fluoride (NaF)-induced functional changes along the brain-pituitary-gonadal axis in male rats. NaF was administered singly in drinking water at 15 mg·L -1 alone or orally co-administered by gavage with taurine at 100 and 200 mg·(kg body mass) -1 for 45 consecutive days. Results showed that taurine significantly prevented NaF-induced increase in oxidative stress indices as well as augmented antioxidant enzymes activities and glutathione level in the brain, testes, and epididymis of the treated rats. Moreover, taurine reversed NaF-induced elevation in inflammatory biomarkers and caspase-3 activity as well as histological damage in the brain, testes, and epididymis of the treated rats. The significant reversal of NaF-induced decreases in testosterone level and testicular activities of acid phosphatase, alkaline phosphatase, and lactate dehydrogenase by taurine was accompanied by enhancement of sperm functional characteristics in the treated rats. Taurine may be a possible chemopreventive candidate against reproductive dysfunction resulting from fluoride exposure.

Prevention of disuse osteoporosis: Effect of sodium fluoride during five weeks of bed rest

NASA Technical Reports Server (NTRS)

Schneider, Victor S.

1987-01-01

An attempt was made to modify factors which promote disuse osteoporosis and thereby prevent it from occurring. Since fluoride is currently used to enhance bone formation in the treatment of low turnover osteoporosis, it was hypothesized that if the fluoride ion was available over a long period of time that it would slow the demonstrated loss of calcium by inhibiting bone resorption and enhancing bone formation. This study was used to determine whether oral medication with sodium F will modify or prevent 5 weeks of bed rest induced disuse osteoporosis, to determine the longitudinal effects of 5 weeks of bed rest on PTH, CT and calcitriol, to measure muscle volume changes and metabolic activity by magnetic resonance imaging and magnetic resonance spectroscopy during prolonged bed rest, to measure changes in peak muscle strength and fatigability, and to measure bone turnover in bone biopsies. Subjects were studied during 1 week of equilibration, 4 weeks of control ambulation, 5 weeks of bed rest, and 1 week of reambulation.

Evaluation of sodium fluoride toxicity in Schistosoma infected snails: assessment of antioxidants, antiapoptotic, hypoprotein and hypocholesterol activities.

PubMed

Koriem, Khaled M M; Shamsuri, Radziyah B; Ubaidillah, Asliza M

2016-12-01

The snails' tissues represents an intermediate or secondary host for Schistosoma sporocysts where, germ cells within the secondary sporocyst begin to divide to produce thousands of cercariae capable of infecting humans. The aim of the study was to evaluate the toxicity of sodium fluoride in Schistosoma snails' tissue homogenates. A total number of 264 different Schistosoma snails were collected from eight drainage water resources and divided into control uninfected and infected snails; where infected snails divided into four group; the first group without any treatment while second, third and fourth groups immersed in 25, 50 and 100 mg sodium fluoride/L during the period of 4 weeks then the snails' hemolymph and tissue homogenates were prepared to evaluate the snail' tissue antioxidants, protein content, lipid profile and apoptosis. The results obtained revealed that superoxide dismutase, glutathione- S -transferase, glutathione peroxidase, catalase, reduced glutathione, glutathione reductase levels were decreased while malondialdehyde, protein carbonyl, total protein, albumin, globulin, cholesterol, low density lipoprotein and triglycerides levels were increased in Schistosoma infected snails' tissues. Schistosoma also induced apoptosis in snails' tissues homogenates. Sodium fluoride restores all the above parameters to approach the control uninfected snails levels. In conclusion, sodium fluoride inhibits oxidative stress and apoptosis produced in Schistosoma infected snails and consequently it is be useful to be used in Schistosoma infection inhibition where sodium fluoride at higher dose was more effective than the lower two doses.

Influence of sodium fluoride (NaF) on the crystallization and spectral properties of L-tyrosine

NASA Astrophysics Data System (ADS)

Thenmozhi, M.; Suguna, K.; Sekar, C.

2011-12-01

L-Tyrosine (C 9H 11NO 3) is an essential amino acid in living organisms. It is also a building unit in protein, takes part in bio-synthesis of hormones, neurotransmitters, pigments and one of the organic chemical constituents of urinary stones. L-Tyrosine has been crystallized in silica gel by double diffusion technique with and without the addition of NaF. The crystals had rosette-like shape. In case of fluoride addition, two types of crystals have formed: rosette like crystallites, at the gel-solution interface and reticulate type crystallites beneath the interface. XRD results confirmed that both the products are of L-tyrosine with identical crystal structures. Crystal structure, morphology, thermal and spectral properties are analyzed using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric and differential thermal analysis (TG-DTA), Fourier transform infrared spectroscopy (FTIR) and UV-vis transmittance studies. The TG-DTA results suggest that the thermal stability of L-tyrosine has markedly improved due to fluoride doping. Optical band gap energy of NaF grown L-tyrosine crystallite is estimated as 4.28 eV. Second harmonic generation efficiency test indicates that L-tyrosine crystals can be used for application in nonlinear optical devices.

Quantification of 18F-Fluoride Kinetics: Evaluation of Simplified Methods.

PubMed

Raijmakers, Pieter; Temmerman, Olivier P P; Saridin, Carrol P; Heyligers, Ide C; Becking, Alfred G; van Lingen, Arthur; Lammertsma, Adriaan A

2014-07-01

(18)F-fluoride PET is a promising noninvasive method for measuring bone metabolism and bone blood flow. The purpose of this study was to assess the performance of various clinically useful simplified methods by comparing them with full kinetic analysis. In addition, the validity of deriving bone blood flow from K1 of (18)F-fluoride was investigated using (15)O-H2O as a reference. Twenty-two adults (mean age ± SD, 44.8 ± 25.2 y), including 16 patients scheduled for bone surgery and 6 healthy volunteers, were studied. All patients underwent dynamic (15)O-H2O and (18)F-fluoride scans before surgery. Ten of these patients had serial PET measurements before and at 2 time points after local bone surgery. During all PET scans, arterial blood was monitored continuously. (18)F-fluoride data were analyzed using nonlinear regression (NLR) and several simplified methods (Patlak and standardized uptake value [SUV]). SUV was evaluated for different time intervals after injection and after normalizing to body weight, lean body mass, and body surface area, and simplified measurements were compared with NLR results. In addition, changes in SUV and Patlak-derived fluoride influx rate (Ki) after surgery were compared with corresponding changes in NLR-derived Ki. Finally, (18)F-fluoride K1 was compared with bone blood flow derived from (15)O-H2O data, using the standard single-tissue-compartment model. K1 of (18)F-fluoride correlated with measured blood flow, but the correlation coefficient was relatively low (r = 0.35, P < 0.001). NLR resulted in a mean Ki of 0.0160 ± 0.0122, whereas Patlak analysis, for the interval 10-60 min after injection, resulted in an almost-identical mean Ki of 0.0161 ± 0.0117. The Patlak-derived Ki, for 10-60 min after injection, showed a high correlation with the NLR-derived Ki (r = 0.976). The highest correlation between Ki and lean body mass-normalized SUV was found for the interval 50-60 min (r = 0.958). Finally, changes in SUV correlated

The cytotoxic effect of TiF4 and NaF on fibroblasts is influenced by the experimental model, fluoride concentration and exposure time

PubMed Central

Salomão, Priscila Maria Aranda; de Oliveira, Flávia Amadeu; Rodrigues, Paula Danielle; Al-Ahj, Luana Polioni; Gasque, Kellen Cristina da Silva; Jeggle, Pia; Buzalaf, Marilia Afonso Rabelo; de Oliveira, Rodrigo Cardoso; Edwardson, John Michael

2017-01-01

Objective Titanium tetrafluoride (TiF4) has shown promising effect in preventing tooth lesions. Therefore, we compared the cytotoxicity of TiF4 with sodium fluoride (NaF) (already applied in Dentistry) considering different fluoride concentrations, pH values and experimental models. Materials and methods Step 1) NIH/3T3 fibroblasts were exposed to mediums containing NaF or TiF4 (from 0.15 to 2.45% F), both at native and adjusted pH, for 6 h. Step 2) NIH/3T3 were exposed to NaF or TiF4 varnishes with 0.95, 1.95 or 2.45% F (native pH), for 6, 12 or 24 h. We applied MTT (1st and 2nd steps) and Hoescht/PI stain (2nd step) assays. Step 3) NIH/3T3 were exposed to NaF or TiF4 varnish (2.45% F), at native pH, for 6 or 12 h. The cell stiffness was measured by atomic force microscopy (AFM). Results Step 1) All cells exposed to NaF or TiF4 mediums died, regardless of the F concentration and pH. Step 2) Both varnishes, at 1.90 and 2.45% F, reduced cell viability by similar extents (33–86% at 6 h, 35–93% at 12 h, and 87–98% at 24 h) compared with control, regardless of the type of fluoride. Varnishes with 0.95% F did not differ from control. Step 3) TiF4 and NaF reduced cell stiffness to a similar extent, but only TiF4 differed from control at 6 h. Conclusions Based on the results of the 3 experimental steps, we conclude that TiF4 and NaF have similar cytotoxicity. The cytotoxicity was dependent on F concentration and exposure time. This result gives support for testing the effect of TiF4 varnish in vivo. PMID:28614381

Magnetic Droplet Microfluidics as a Platform for the Concentration of [18F]Fluoride and Radiosynthesis of Sulfonyl [18F]Fluoride.

PubMed

Fiel, Somewhere A; Yang, Hua; Schaffer, Paul; Weng, Samuel; Inkster, James A H; Wong, Michael C K; Li, Paul C H

2015-06-17

The radioisotope 18F is often considered the best choice for positron emission tomography (PET) owing to its desirable chemical and radiochemical properties. However, nucleophilic 18F-fluorination of large, water-soluble biomolecules, based on C-F bond formation, has traditionally been difficult. Thus, several aqueous fluorination approaches that offer significant versatility in radiopharmaceutical synthesis with sensitive targeting vectors have been developed. Furthermore, because 18F decays rapidly, production of these 18F-labeled compounds requires an automated process to reduce production time, reduce radiation exposure, and minimize losses due to the transfer of reagents during tracer synthesis. Herein, we report the use of magnetic droplet microfluidics (MDM) as a means to concentrate [18F]fluoride from the cyclotron target solution, followed by the synthesis of an 18F-labeled compound on a microfluidic platform. Using this method, we have demonstrated 18F preconcentration in a small-volume droplet through the use of anion exchanging magnetic particles. By using MDM, the preconcentration step took approximately 5 min, and the [18F]fluoride solution was preconcentrated by 15-fold. After the preconcentration step, an 18F-labeling reaction was performed on the MDM platform using the S-F bond formation in aqueous conditions to produce an arylsulfonyl [18F]fluoride compound which can be used as a prosthetic group to label PET targeting ligands. The high radiochemical purity of 95±1% was comparable to the 96% previously reported using a conventional method. In addition, when MDM was used, the total synthesis time was improved to 15 min with lower reagent volumes (50-60 μL) used.

Fatal cases of acute suicidal sodium and accidental zinc fluorosilicate poisoning. Review of acute intoxications due to fluoride compounds.

PubMed

Lech, Teresa

2011-03-20

Fluoride, of all inorganic substances, is among the least likely to be identified by a routine toxicological analysis. Acute poisonings with salts of hydrofluoric or fluorosilicic acid, however, although relatively uncommon, may occur. Some fluorosilicates, salts of fluorosilicic acid (e.g. Al, Zn, Pb, Mg) are used as stone consolidants, others (e.g. sodium fluorosilicate)--in the production of enamel and milk glass, or as insecticide. In this paper, two fatal cases of poisonings are presented: a suicide involving sodium fluorosilicate of a 39-year-old male who died in his flat, without hospitalization, and an accidental ingestion of zinc fluorosilicate solution (probably due to mistaking it for mineral water) by a 38-year-old male at his workplace (building), who died about 3h after ingestion of the liquid, in spite of intensive care at hospitals. Post-mortem samples were examined by the use of the spectrophotometric method with lanthanum nitrate and alizarin complexone for fluorine (after isolation of fluoride compounds by the microdiffusion method) and using a flame atomic absorption spectrometry method for zinc (after mineralization of biological material by sulfuric and nitric acids). In the first case, the results were: blood--130 μg F/ml, stomach--1150 μg F/g, small intestine content --19.6 μg F/g, kidney--56.0 μg F/g, and urine--1940 μg F/ml. In the second case, the contents of fluorine and zinc in blood and internal organs were the following: blood--6.03 μg F/ml, 23.8 μg Zn/ml; brain--1.39 μg F/g, 7.54 μg Zn/g; stomach--152 μg Zn/g; stomach content--293 μg F/g, 84.4 μg Zn/g; small intestine--37.5 μg Zn/g; small intestine content--63.4 μg F/g, 19.6 μg Zn/g; liver--9.49 μg F/g, 81.0 μg Zn/g; kidney--29.6 μg F/g, 39.2 μg Zn/g; and exceeded the normal levels of these elements in biological material many times. In addition, in stomach and liver large amounts of silica were detected. In the paper, a review of acute intoxications with various

Anticaries Potential of a Sodium Monofluorophosphate Dentifrice Containing Calcium Sodium Phosphosilicate: Exploratory in situ Randomized Trial.

PubMed

Parkinson, Charles R; Siddiqi, Muhammad; Mason, Stephen; Lippert, Frank; Hara, Anderson T; Zero, Domenick T

2017-01-01

Calcium sodium phosphosilicate (CSPS) is a bioactive glass material that alleviates dentin hypersensitivity and is postulated to confer remineralization of caries lesions. This single-centre, randomized, single (investigator)-blind, placebo-controlled, crossover, in situ study explored whether the addition of 5% CSPS to a nonaqueous fluoride (F) such as sodium monofluorophosphate (SMFP)-containing dentifrice affects its cariostatic ability. Seventy-seven subjects wore 4 gauze-covered enamel specimens with preformed lesions (2 surface-softened and 2 subsurface) placed buccally on their mandibular bilateral dentures for up to 4 weeks. Subjects brushed twice daily with 1 of the 5 study dentifrices: 927 ppm F/5% CSPS, 927 ppm F/0% CSPS, 250 ppm F/0% CSPS, 0 ppm F/5% CSPS, or 0 ppm F/0% CSPS. Specimens were retrieved after either 21 (surface-softened lesions; analyzed by Knoop surface microhardness [SMH]) or 28 days (subsurface lesions; analyzed by transverse microradiography). The enamel fluoride uptake was determined for all specimens using a microbiopsy technique. The concentrations of fluoride and calcium in gauze-retrieved plaque were also evaluated. Higher dentifrice fluoride concentrations led to greater remineralization and fluoridation of both lesion types and increased plaque fluoride concentrations. CSPS did not improve the cariostatic properties of SMFP; there were no statistically significant differences between 927 ppm F/5% CSPS and 927 ppm F/0% CSPS in percent SMH recovery (p = 0.6788), change in integrated mineral loss (p = 0.5908), or lesion depth (p = 0.6622). Likewise, 0 ppm F/5% CSPS did not provide any benefits in comparison to 0 ppm F/0% CSPS. In conclusion, CSPS does not negatively impact nor does it improve the ability of an SMFP dentifrice to affect remineralization of caries lesions. © 2017 S. Karger AG, Basel.

Enhanced anticaries efficacy of a 0.243% sodium fluoride/10% xylitol/silica dentifrice: 3-year clinical results.

PubMed

Sintes, J L; Escalante, C; Stewart, B; McCool, J J; Garcia, L; Volpe, A R; Triol, C

1995-10-01

To evaluate the efficacy of a sodium fluoride (NaF)/silica/xylitol dentifrice compared with that of a positive control NaF/silica dentifrice on caries increments in school children over a 3-year period in an area without an optimal level of fluoride in the drinking water (mean level <0.1 ppm). A 3-year, double-blind clinical caries study was conducted in 2,630 children initially aged 8-10 years at 17 schools in the San Jose, Costa Rica metropolitan area. Clinical dental examinations were performed at participating schools utilizing portable dental equipment. Caries evaluations employed conventional tactile/visual methodology consisting of artificial light, dental mirrors and single-edge #23 explorers. Children accepted into the study were stratified by age and sex into two balanced groups within each school, and randomly assigned to use either a positive control dentifrice containing 0.243% NaF/silica or a test dentifrice containing 0.234% NaF/silica/10% xylitol. Children were instructed to brush with the assigned dentifrice twice daily. Caries evaluations were conducted at baseline, 2 years, and 3 years. After 3 years, subjects using the 0.234% NaF/silica/10% xylitol dentifrice had statistically significantly reduced decayed/filled surfaces (DFS; -12.3% reduction; P < or = 0.001) and decayed/filled buccal and lingual surfaces (DFS-BL; -10.5% reduction; P < or = 0/01).

Effect of the addition of nano-sized sodium hexametaphosphate to fluoride toothpastes on tooth demineralization: an in vitro study.

PubMed

Dalpasquale, Giovanna; Delbem, Alberto Carlos Botazzo; Pessan, Juliano Pelim; Nunes, Gabriel Pereira; Gorup, Luiz Fernando; Neto, Francisco Nunes Souza; de Camargo, Emerson Rodrigues; Danelon, Marcelle

2017-06-01

This study evaluated the effect of toothpastes containing 1100 ppm F associated with nano-sized sodium hexametaphosphate (HMPnano) on enamel demineralization in vitro using a pH-cycling model. Bovine enamel blocks (4 mm × 4 mm, n = 72) selected by initial surface hardness (SHi) were randomly allocated into six groups (n = 12), according to the test toothpastes: without fluoride or HMPnano (Placebo), 550 ppm F (550F), 1100 ppm F (1100F), 1100F plus HMPnano at concentrations of 0.25% (1100F/0.25%HMPnano), 0.5% (1100F/0.5%HMPnano), and 1.0% (1100F/1.0%HMPnano). Blocks were treated 2×/day with slurries of toothpastes and submitted to five pH cycles (demineralizing/remineralizing solutions) at 37 °C. Next, final surface hardness (SHf), integrated loss subsurface hardness (ΔKHN), integrated mineral loss (g HA p × cm -3 ), and enamel fluoride (F) concentrations were determined. Data were analyzed by ANOVA and Student-Newman-Keuls test (p < 0.001). Toothpaste with 1100F/0.5%HMPnano led to the lowest mineral loss and the highest mineral concentration among all groups, which were 26% (SHf) and 21% (ΔKHN) lower and ~58% higher (g HA p × cm -3 ) when compared to 1100F (p < 0.001). Similar values of enamel F were observed for all fluoridated toothpastes (p > 0.001). The addition of 0.5%HMPnano to a 1100 F toothpaste significantly enhances its effects against enamel demineralization when compared to its counterpart without HMPnano in vitro. Toothpaste containing 1100 ppm F associated with HMPnano has a higher potential to reduce the demineralization compared to 1100 ppm F. This toothpaste could be a viable alternative to patients at high risk of caries.

Sodium trimetaphosphate enhances the effect of 250 p.p.m. fluoride toothpaste against enamel demineralization in vitro.

PubMed

Missel, Emilene M C; Cunha, Robson F; Vieira, Ana E M; Cruz, Nathália V S; Castilho, Flavia C N; Delbem, Alberto C B

2016-08-01

This in vitro study investigated the effect of sodium trimetaphosphate (TMP), added to toothpaste containing 250 p.p.m. fluoride, on enamel demineralization. Bovine enamel blocks (n = 96) were subjected to five pH cycles over a 7-d period and treatment with suspensions of toothpastes containing 0, 250, 500, and 1,100 p.p.m. fluoride (as sodium fluoride), as well as with 250 p.p.m. fluoride containing TMP at 0.25, 0.5, 1.0, and 3.0%. Treatment with toothpaste suspensions was performed under agitation twice a day, for 1 min. Surface and cross-sectional hardness, and fluoride firmly bound to enamel, were quantified. Data were subjected to one-way anova, followed by Tukey's test. Low-fluoride toothpastes containing TMP at 0.25-1.0% resulted in enamel mineral loss similar to that seen for the toothpaste containing 1,100 p.p.m. fluoride. Also, the addition of TMP to the toothpaste containing 250 p.p.m. fluoride promoted enamel fluoride concentrations similar to those obtained for the 500 p.p.m. fluoride group. The toothpaste containing 250 p.p.m. fluoride and 0.25% TMP led to the lowest mineral loss among all groups. It was concluded that the addition of as little as 0.25% TMP to a toothpaste containing 250 p.p.m. fluoride can reduce enamel demineralization to levels similar to those seen for a conventional toothpaste containing 1,100 p.p.m. fluoride, in vitro. © 2016 Eur J Oral Sci.

Sodium fluoride mouthrinse used twice daily increased incipient caries lesion remineralization in an in situ model.

PubMed

Songsiripradubboon, Siriporn; Hamba, Hidenori; Trairatvorakul, Chutima; Tagami, Junji

2014-03-01

To investigate the remineralizing effects of fluoride mouthrinses used at different times and frequency in addition to fluoride toothpaste. A randomized crossover single blinded study comprised 4 experimental phases of 21 days each. Twelve orthodontic volunteers were fixed with an orthodontic bracket containing an artificial carious enamel slab, which was from the same tooth in all 4 phases, and were randomly assigned to the following groups: (1) brushing with F toothpaste 2× per day (F- brush), (2) F- brush+rinsing with 0.05% NaF (F- rinse) after lunch, (3) F- brush+F-rinse before bedtime, and (4) F- brush+F- rinse 2× per day. Mean mineral gain after each phase was determined from mineral density profiles obtained using Micro-CT. The mean mineral gain in all treatments with F- brush and F-rinse were significantly greater than those in F- brush (p<0.05). Moreover F- rinse 2× per day increased lesion remineralization more than F- rinse once a day. The twice-daily use of 0.05% NaF mouthrinse combined with twice-daily regular use of fluoride toothpaste resulted in the greatest remineralization of incipient caries. These data indicate that rinsing frequency is a factor affecting the effectiveness of fluoride mouthrinse. The rinsing frequency of NaF mouthrinse, when used with fluoride toothpaste, also affects the remineralization. This finding, if confirmed by a clinical study, would lead to a new recommendation for fluoride mouthrinse used in high caries risk patients who could benefit from using it twice a day. Copyright © 2014 Elsevier Ltd. All rights reserved.

Zero-gravity growth of a sodium chloride-lithium fluoride eutectic mixture

NASA Technical Reports Server (NTRS)

Yue, A. S.; Yeh, C. W.; Yue, B. K.

1982-01-01

Continuous and discontinuous lithium fluoride fibers embedded in a sodium chloride matrix were produced in space and on Earth, respectively. The production of continuous fibers in a eutectic mixture was attributed to the absence of convective current in the liquid during solidification in space. Image transmission and optical transmittance measurements of transverse sections of the space-grown and Earth-grown ingots were made with a light microscope and a spectrometer. It was found that better optical properties were obtained from samples grown in space. This was attributed to a better alignment of lithium fluoride fibers along the growth direction.

Effects of sodium fluoride on blood cellular and humoral immunity in mice.

PubMed

Guo, Hongrui; Kuang, Ping; Luo, Qin; Cui, Hengmin; Deng, Huidan; Liu, Huan; Lu, Yujiao; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Li, Yinglun; Wang, Xun; Zhao, Ling

2017-10-17

Exposure to high fluorine can cause toxicity in human and animals. Currently, there are no systematic studies on effects of high fluorine on blood cellular immunity and humoral immunity in mice. We evaluated the alterations of blood cellular immunity and humoral immunity in mice by using flow cytometry and ELISA. In the cellular immunity, we found that sodium fluoride (NaF) in excess of 12 mg/Kg resulted in a significant decrease in the percentages of CD3 + , CD3 + CD4 + , CD3 + CD8 + T lymphocytes in the peripheral blood. Meanwhile, serum T helper type 1 (Th1) cytokines including interleukin (IL)-2, interferon (IFN)-γ, tumor necrosis factor (TNF), and Th2 cytokines including IL-4, IL-6, IL-10, and Th17 cytokine (IL-17A) contents were decreased. In the humoral immunity, NaF reduced the peripheral blood percentages of CD19 + B lymphocytes and serum immunoglobulin A (IgA), immunoglobulin G (IgG) and immunoglobulin M (IgM). The above results show that NaF can reduce blood cellular and humoral immune function in mice, providing an excellent animal model for clinical studies on immunotoxicity-related fluorosis.

Sodium fluoride adversely affects ovarian development and reproduction in Drosophila melanogaster.

PubMed

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

2017-11-01

The study demonstrates the effects of chronic sub-lethal exposure of sodium fluoride (NaF) on reproductive structure and function of female Drosophila melanogaster. As a part of treatment, flies were maintained in food supplemented with sub-lethal concentrations of NaF (10-100 μg/mL). Fecundity, ovarian morphology, presence and profusion of viable cells from ovary and fat body were taken into consideration for evaluating changes in reproductive homeostasis. Wing length (a factor demonstrating body size and reproductive fitness) was also monitored after NaF exposure. Significant reduction in fecundity, alteration in ovarian morphology along with an increase in apoptosis was observed in treated females. Simultaneous decline in viable cell number and larval weight validates the result of MTT assay. Furthermore, altered ovarian Glucose-6-phosphate dehydrogenase and catalase activities together with increased rate of lipid peroxidation after 20 and 40 μg/mL NaF exposure confirmed the changes in reproduction related metabolism. Enhanced lipid peroxidation known for ROS generation might have induced genotoxicity which is confirmed through Comet assay. The enzyme activities were not dose dependent, rather manifested a bimodal response, which suggests a well-knit interaction among the players inducing stress and the ones that help establish physiological homeostasis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of Surfactants and Fluoride against Enamel Erosion.

PubMed

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.

Sulfonyl fluoride-based prosthetic compounds as potential 18F labelling agents.

PubMed

Inkster, James A H; Liu, Kate; Ait-Mohand, Samia; Schaffer, Paul; Guérin, Brigitte; Ruth, Thomas J; Storr, Tim

2012-08-27

Nucleophilic incorporation of [(18)F]F(-) under aqueous conditions holds several advantages in radiopharmaceutical development, especially with the advent of complex biological pharmacophores. Sulfonyl fluorides can be prepared in water at room temperature, yet they have not been assayed as a potential means to (18)F-labelled biomarkers for PET chemistry. We developed a general route to prepare bifunctional 4-formyl-, 3-formyl-, 4-maleimido- and 4-oxylalkynl-arylsulfonyl [(18)F]fluorides from their sulfonyl chloride analogues in 1:1 mixtures of acetonitrile, THF, or tBuOH and Cs[(18)F]F/Cs(2)CO(3(aq.)) in a reaction time of 15 min at room temperature. With the exception of 4-N-maleimide-benzenesulfonyl fluoride (3), pyridine could be used to simplify radiotracer purification by selectively degrading the precursor without significantly affecting observed yields. The addition of pyridine at the start of [(18)F]fluorination (1:1:0.8 tBuOH/Cs(2)CO(3(aq.))/pyridine) did not negatively affect yields of 3-formyl-2,4,6-trimethylbenzenesulfonyl [(18)F]fluoride (2) and dramatically improved the yields of 4-(prop-2-ynyloxy)benzenesulfonyl [(18)F]fluoride (4). The N-arylsulfonyl-4-dimethylaminopyridinium derivative of 4 (14) can be prepared and incorporates (18)F efficiently in solutions of 100 % aqueous Cs(2)CO(3) (10 mg mL(-1)). As proof-of-principle, [(18)F]2 was synthesised in a preparative fashion [88(±8) % decay corrected (n=6) from start-of-synthesis] and used to radioactively label an oxyamino-modified bombesin(6-14) analogue [35(±6) % decay corrected (n=4) from start-of-synthesis]. Total preparation time was 105-109 min from start-of-synthesis. Although the (18)F-peptide exhibited evidence of proteolytic defluorination and modification, our study is the first step in developing an aqueous, room temperature (18)F labelling strategy. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Soil fluoride spiking effects on olive trees (Olea europaea L. cv. Chemlali).

PubMed

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.

Fluoride loaded polymeric nanoparticles for dental delivery.

PubMed

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.

Fluoride glass starting materials - Characterization and effects of thermal treatment

NASA Technical Reports Server (NTRS)

Chen, William; Dunn, Bruce; Shlichta, Paul; Neilson, George F.; Weinberg, Michael C.

1987-01-01

The production of heavy metal fluoride (HMF) glasses, and the effects of thermal treatments on the HMF glasses are investigated. ZrF4, BaF2, AlF3, LaF3, and NaF were utilized in the synthesis of zirconium-barium-lanthanum-aluminum-sodium fluoride glass. The purity of these starting materials, in particular ZrF4, is evaluated using XRD analysis. The data reveal that low temperature heating of ZrF4-H2O is effective in removing the water of hydration, but causes the production of ZrF4 and oxyfluorides; however, dehydration followed by sublimation results in the production of monoclinic ZrFe without water or oxyfluoride contaminants.

Catalase and sodium fluoride mediated rehabilitation of enamel bleached with 37% hydrogen peroxide.

PubMed

Thakur, Ruchi; Shigli, Anand L; Sharma, Divya; Thakur, Gagan

2015-01-01

Bleaching agents bring about a range of unwanted changes in the physical structure of enamel which needs to be restored qualitatively and timely. Catalase being an antioxidant ensures the effective removal of free radicals and improvement in fluoride mediated remineralization from the enamel microstructure which if retained may harm the integrity and affect the hardness of enamel. Thirty freshly extracted incisors were sectioned to 6 slabs which were divided into 5 groups: Group A, control; Group B, treatment with 37% hydrogen peroxide (HP); Group C, treatment with 37% HP and catalase, Group D, treatment with 37% HP and 5% sodium fluoride application, Group E, treatment with 37% HP followed by catalase and 5% sodium fluoride. Scanning electron microscope and microhardness analysis were done for all slabs. One-way ANOVA test was applied among different groups. Vicker's microhardness number (VHN) of Group B and C was significantly lower. No significant difference between VHN of Group B and C. VHN of Group D was significantly higher than Group A, B, and C; but significantly lower than Group E. VHN of Group E was significantly higher than any other experimental group. One-way ANOVA revealed a highly significant P value (P = 0.0001) and so Tukey's post-hoc Test for the group comparisons was employed. Subsequent treatment of bleached enamel with catalase and fluoride varnish separately results in repairing and significantly increasing the microhardness.

Association of vascular fluoride uptake with vascular calcification and coronary artery disease.

PubMed

Li, Yuxin; Berenji, Gholam R; Shaba, Wisam F; Tafti, Bashir; Yevdayev, Ella; Dadparvar, Simin

2012-01-01

The feasibility of a fluoride positron emission tomography/computed tomography (PET/CT) scan for imaging atherosclerosis has not been well documented. The purpose of this study was to assess fluoride uptake of vascular calcification in various major arteries, including coronary arteries. We retrospectively reviewed the imaging data and cardiovascular history of 61 patients who received whole-body sodium [¹⁸F]fluoride PET/CT studies at our institution from 2009 to 2010. Fluoride uptake and calcification in major arteries, including coronary arteries, were analyzed by both visual assessment and standardized uptake value measurement. Fluoride uptake in vascular walls was demonstrated in 361 sites of 54 (96%) patients, whereas calcification was observed in 317 sites of 49 (88%) patients. Significant correlation between fluoride uptake and calcification was observed in most of the arterial walls, except in those of the abdominal aorta. Fluoride uptake in coronary arteries was demonstrated in 28 (46%) patients and coronary calcifications were observed in 34 (56%) patients. There was significant correlation between history of cardiovascular events and presence of fluoride uptake in coronary arteries. The coronary fluoride uptake value in patients with cardiovascular events was significantly higher than in patients without cardiovascular events. sodium [¹⁸F]fluoride PET/CT might be useful in the evaluation of the atherosclerotic process in major arteries, including coronary arteries. An increased fluoride uptake in coronary arteries may be associated with an increased cardiovascular risk.

Melatonin protect the development of preimplantation mouse embryos from sodium fluoride-induced oxidative injury.

PubMed

Zhao, Jiamin; Fu, Beibei; Peng, Wei; Mao, Tingchao; Wu, Haibo; Zhang, Yong

2017-09-01

Recently study shows that melatonin can protect embryos from the culture environment oxidative stress. However, the protective effect of melatonin on the mouse development of preimplantation embryos under sodium fluoride (NaF) induced oxidative stress is still unclear. Here, we showed that exposure to NaF significantly increased the reactive oxygen species (ROS) level, decreased the blastocyst formation rates, and increased the fragmentation, apoptosis and retardation of blastocysts in the development of mouse preimplantation embryos. However, the protective of melatonin remarkable increased the of blastocyst formation rates, maintained mitochondrial function and total antioxidant capacity by clearing ROS. Importantly the data showed that melatonin improved the activity of enzymatic antioxidants, including glutathione(GSH), superoxide dismutase(SOD), and malonaldehyde (MDA), and increased the expression levels of antioxidative genes. Taken together, our results indicate that melatonin prevent NaF-induced oxidative damage to mouse preimplantation embryo through down regulation of ROS level, stabilization of mitochondrial function and modulation of the activity of antioxidases and antioxidant genes. Copyright © 2017 Elsevier B.V. All rights reserved.

18F-Fluoride and 18F-Fluorodeoxyglucose Positron Emission Tomography After Transient Ischemic Attack or Minor Ischemic Stroke

PubMed Central

Jenkins, William S. A.; Irkle, Agnese; Moss, Alastair; Sng, Greg; Forsythe, Rachael O.; Clark, Tim; Roberts, Gemma; Fletcher, Alison; Lucatelli, Christophe; Rudd, James H. F.; Davenport, Anthony P.; Mills, Nicholas L.; Al-Shahi Salman, Rustam; Dennis, Martin; Whiteley, William N.; van Beek, Edwin J. R.; Dweck, Marc R.; Newby, David E.

2017-01-01

Background— Combined positron emission tomography (PET) and computed tomography (CT) can assess both anatomy and biology of carotid atherosclerosis. We sought to assess whether 18F-fluoride or 18F-fluorodeoxyglucose can identify culprit and high-risk carotid plaque. Methods and Results— We performed 18F-fluoride and 18F-fluorodeoxyglucose PET/CT in 26 patients after recent transient ischemic attack or minor ischemic stroke: 18 patients with culprit carotid stenosis awaiting carotid endarterectomy and 8 controls without culprit carotid atheroma. We compared standardized uptake values in the clinically adjudicated culprit to the contralateral asymptomatic artery, and assessed the relationship between radiotracer uptake and plaque phenotype or predicted cardiovascular risk (ASSIGN score [Assessing Cardiovascular Risk Using SIGN Guidelines to Assign Preventive Treatment]). We also performed micro PET/CT and histological analysis of excised plaque. On histological and micro PET/CT analysis, 18F-fluoride selectively highlighted microcalcification. Carotid 18F-fluoride uptake was increased in clinically adjudicated culprit plaques compared with asymptomatic contralateral plaques (log10standardized uptake valuemean 0.29±0.10 versus 0.23±0.11, P=0.001) and compared with control patients (log10standardized uptake valuemean 0.29±0.10 versus 0.12±0.11, P=0.001). 18F-Fluoride uptake correlated with high-risk plaque features (remodeling index [r=0.53, P=0.003], plaque burden [r=0.51, P=0.004]), and predicted cardiovascular risk [r=0.65, P=0.002]). Carotid 18F-fluorodeoxyglucose uptake appeared to be increased in 7 of 16 culprit plaques, but no overall differences in uptake were observed in culprit versus contralateral plaques or control patients. However, 18F-fluorodeoxyglucose did correlate with predicted cardiovascular risk (r=0.53, P=0.019), but not with plaque phenotype. Conclusions— 18F-Fluoride PET/CT highlights culprit and phenotypically high-risk carotid plaque

Characteristic of molten fluoride salt system LiF-BeF2 (Flibe) and LiF-NaF-KF (Flinak) as coolant and fuel carrier in molten salt reactor (MSR)

NASA Astrophysics Data System (ADS)

Bahri, Che Nor Aniza Che Zainul; Al-Areqi, Wadee'ah Mohd; Ruf, Mohd'Izzat Fahmi Mohd; Majid, Amran Ab.

2017-01-01

Interest of fluoride salts have recently revived due to the high temperature application in nuclear reactors. Molten Salt Reactor (MSR) was designed to operate at high temperature in range 700 - 800°C and its fuel is dissolved in a circulating molten fluoride salt mixture. Molten fluoride salts are stable at high temperature, have good heat transfer properties and can dissolve high concentration of actinides and fission product. The aim of this paper was to discuss the physical properties (melting temperature, density and heat capacity) of two systems fluoride salt mixtures i.e; LiF-BeF2 (Flibe) and LiF-NaF-KF (Flinak) in terms of their application as coolant and fuel solvent in MSR. Both of these salts showed almost same physical properties but different applications in MSR. The advantages and the disadvantages of these fluoride salt systems will be discussed in this paper.

Efficacy of calcium- and fluoride-containing materials for the remineralization of primary teeth with early enamel lesion.

PubMed

Memarpour, Mahtab; Soltanimehr, Elham; Sattarahmady, Naghmeh

2015-09-01

The aim of the study was to determine the efficacy of different products containing fluoride, calcium and phosphate for enamel remineralization in eroded primary teeth. A total of 90 sound primary canine teeth were randomly divided into 5 groups of 18 teeth each: 1) control (polished enamel), 2) 5% DuraShield sodium fluoride varnish, 3) 500 ppm fluoridated toothpaste, 4) casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) cream, and 5) Clinpro White varnish containing functionalized tri-calcium phosphate (fTCP). Enamel microhardness (EMH) was measured in all samples before and after demineralization and after 28 days of remineralization. Also 8 samples in groups 2 to 5 and four samples of sound and demineralized enamel were examined with atomic force microscopy (AFM). All data were analyzed with one-way ANOVA (p<0.05). Mean microhardness of demineralized enamel was significantly lower than in enamel at baseline (p<0.001). Remineralization significantly increased microharness in groups 2 to 5 compared to the control group (p<0.001). Percent EMH after remineralization with CPP-ACP was significantly higher than after fTCP (p=0.029), toothpaste (p< 0.001) or fluoride varnish (p<0.001); however, there was no significant difference between toothpaste and fluoride varnish (p=0.062). Microhardness increased more after fTCP treatment than after treatment with sodium fluoride varnish (p<0.001) or fluoridated toothpaste (p=0.045). AFM images showed that enamel roughness decreased most after treatment with fTCP, followed by CPP-ACP, toothpaste and fluoride varnish. The efficacy of CPP-ACP cream for remineralizing eroded enamel was greater than fluoride toothpaste, fluoride varnish or fTCP varnish. © 2015 Wiley Periodicals, Inc.

Digital Mammography Breast Dosimetry Using Copper-Doped Lithium Fluoride (LiF:MCP) Thermoluminescent Dosimeters (TLDs)

DTIC Science & Technology

2003-06-18

Mammography Breast Dosimetry Using Copper-Doped Lithium Fluoride (LiF:MCP) Thermoluminescent Dosimeters ( TLDs ) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...34Digital Mammography Breast Dosimetry Using Copper- Doped Lithium Fluoride (LiF:MCP) Thermoluminescent Dosimeters ( TLDs )" Author: LT John J. Tomon...Title of Thesis: " Digital Mammography Breast Dosimetry Using Copper-Doped Lithium Fluoride (LiF:MCP) Thermoluminescent

Materials corrosion in molten lithium fluoride-sodium fluoride-potassium fluoride eutectic salt

NASA Astrophysics Data System (ADS)

Olson, Luke Christopher

Static corrosion studies were undertaken to determine the compatibility of several candidate high temperature materials for a heat transfer loop in a molten alkali fluoride eutectic salt, LiF-NaF-KF: 46.5-11.5-42 mol % (commonly referred to as FLiNaK), as well as a molten chloride near eutectic salt, KCl-MgCl2: 68-32 mol %. Several high temperature alloys: Hastelloy-N, Hastelloy-X, Haynes-230, Inconel-617, and Incoloy-800H, Nb-1Zr, a nearly pure Ni alloy Ni-201, and a C/SiSiC ceramic were exposed to molten FLiNaK at 850°C for 500 h in sealed graphite crucibles under an argon cover gas. Corrosion occurred predominantly from dealloying of Cr from the Cr bearing alloys, an effect that was particularly pronounced at the grain boundaries. Corrosion was noted to occur from selective attack of the Si phase in the C/SiSiC ceramic. Alloy weight-loss/area due to molten fluoride salt exposure correlated with the initial Cr-content of the alloys, and was consistent with the Cr-content measured in the salts after corrosion tests. The alloys' weight-loss/area was also found to correlate to the concentration of carbon present in the nominally 20% Cr containing alloys, due to the formation of chromium carbide phases at the grain boundaries. The corrosion mechanisms for the chloride based salt were found to be similar to those observed in FLiNaK, but the chemical attack was found to be less aggressive. Sulfamate Ni electroplating and Mo plasma spraying of Fe-Ni-Cr alloy coupons was investigated to mitigate Cr dissolution. A chemical vapor deposited pyrolytic carbon and SiC coating was also investigated to protect the C/SiSiC composites. Results indicate that Ni-plating has the potential to provide protection against alloy corrosion in molten fluoride salts. Furthermore, the presence of a chromium-oxide interlayer at the interface of the Ni-plating and alloy substrate can further improve the efficacy of the Ni-plating. The pyrolytic carbon and SiC coating on the C/SiSiC composites

Fluoride intake of infants living in non-fluoridated and fluoridated areas.

PubMed

Zohoori, F V; Whaley, G; Moynihan, P J; Maguire, A

2014-01-01

Data on fluoride exposure of infants are sparse. This study aimed to estimate total daily fluoride intake (TDFI) of infants aged 1-12 months, living in non-fluoridated and fluoridated areas in north-east England. Daily dietary fluoride intake was assessed using a three-day food diary coupled with analysis of fluoride content of food/drink consumed, using a F-ISE and diffusion method. A questionnaire with an interview was used to collect information on toothbrushing habits. TDFI was estimated from diet, plus fluoride supplements and dentifrice ingestion where used. Thirty-eight infants completed the study; 19 receiving fluoridated water (mean 0.97 mgF/l) and 19 receiving non-fluoridated water (mean 0.19 mgF/l). Mean (SD) TDFI for the infants living in fluoridated and non-fluoridated areas was 0.107 (0.054) and 0.024 (0.015) mg/kg body weight per day, respectively. Diet was the only fluoride source for 87% of infants and none used fluoride supplements. For infants for whom mouth/teeth cleaning was undertaken, dentifrice contribution to TDFI ranged from 24 to 78%. Infants living in fluoridated areas, in general, may receive a fluoride intake, from diet only, of more than the suggested optimal range for TDFI. This emphasises the importance of estimating TDFI at an individual level when recommendations for fluoride use are being considered.

Biocompatible inorganic nanoparticles for [18F]-fluoride binding with applications in PET imaging

PubMed Central

Jauregui-Osoro, Maite; Williamson, Peter A.; Glaria, Arnaud; Sunassee, Kavitha; Charoenphun, Putthiporn; Green, Mark A.; Mullen, Gregory E. D.; Blower, Philip J.

2014-01-01

A wide selection of insoluble nanoparticulate metal salts was screened for avid binding of [18F]-fluoride. Hydroxyapatite and aluminium hydroxide nanoparticles showed particularly avid and stable binding of [18F]-fluoride in various biological media. The in vivo behaviour of the [18F]-labelled hydroxyapatite and aluminium hydroxide particles was determined by PET-CT imaging in mice. [18F]-labelled hydroxyapatite was stable in circulation and when trapped in various tissues (lung embolisation, subcutaneous and intramuscular), but accumulation in liver via reticuloendothelial clearance was followed by gradual degradation and release of [18F]-fluoride (over a period of 4 h) which accumulated in bone. [18F]-labelled aluminium hydroxide was also cleared to liver and spleen but degraded slightly even without liver uptake (subcutanenous and intramuscular). Both materials have properties that are an attractive basis for the design of molecular targeted PET imaging agents labelled with 18F. PMID:21394352

An in situ caries study on the interplay between fluoride dose and concentration in milk.

PubMed

Lippert, F; Martinez-Mier, E A; Zero, D T

2014-07-01

This randomized, cross-over in situ study investigated the impact of sodium fluoride dose and concentration in milk on caries lesion rehardening, fluoridation and acid resistance. Twenty-eight subjects wore two gauze-covered enamel specimens with preformed lesions placed buccally on their mandibular partial dentures for three weeks. Participants used fluoride-free dentifrice throughout the study and consumed once daily one of the five study treatments: no fluoride in 200 ml milk (0F-200), 1.5 or 3 mg fluoride in either 100 (1.5F-100; 3F-100) or 200 ml milk (1.5F-200; 3F-200). After three weeks, specimens were retrieved. Knoop hardness was used to determine rehardening and resistance to a secondary acid challenge. Enamel fluoride uptake (EFU) was determined using a microbiopsy technique. A linear fluoride dose-response was observed for all study variables which exhibited similar overall patterns. All the treatments resulted in rehardening, with 0F-200 inducing the least and 3F-100 the most. Apart from 1.5F-200, all the treatments resulted in statistically significantly more rehardening compared to 0F-200. The fluoride doses delivered in 100 ml provided directionally although not statistically significantly more rehardening than those delivered in 200 ml milk. EFU data exhibited better differentiation between treatments: all fluoridated milk treatments delivered more fluoride to lesions than 0F-200; fluoride in 100 ml demonstrated statistically significantly higher EFU than fluoride in 200 ml milk. Findings for acid resistance were also more discerning than rehardening data. The present study has provided further evidence for the anti-caries benefits of fluoridated milk. Both fluoride dose and concentration appear to impact the cariostatic properties of fluoride in milk. Copyright © 2014 Elsevier Ltd. All rights reserved.

Suppression of male reproduction in rats after exposure to sodium fluoride during early stages of development

NASA Astrophysics Data System (ADS)

Reddy, P. Sreedhar; Pushpalatha, T.; Reddy, P. Sreenivasula

2007-07-01

Sodium fluoride (NaF), a widespread natural pollutant was given to sperm-positive female rats throughout gestation and lactation at a dose of 4.5 and 9.0 ppm via drinking water. The neonates were allowed to grow up to 90 days on tap water, and then sperm parameters, testicular steroidogenic marker enzyme activity levels, and circulatory hormone levels were studied. The sperm count, sperm motility, sperm coiling (hypoosmotic swelling test), and sperm viability were decreased in experimental rats when compared with controls. The activity levels of testicular steroidogenic marker enzymes (3β hydroxysteroid dehydrogenase and 17β hydroxysteroid dehydrogenase) were significantly decreased in experimental animals indicating decreased steroidogenesis. The serum testosterone, follicle stimulating hormone and luteinizing hormone levels were also significantly altered in experimental animals. Our data indicate that exposure to NaF during gestation and lactation affects male reproduction in adult rats by decreasing spermatogenesis and steroidogenesis.

Effects of oral doses of fluoride on nestling European starlings

USGS Publications Warehouse

Fleming, W.J.; Grue, C.E.; Schuler, C.A.; Bunck, C.M.

1987-01-01

Nestling European starlings (Sturnus vulgaris), raised and fed by free-living adults, were given daily oral doses of either distilled water, 193 mg sodium as Na2CO3 per kg of body weight (sodium control group), or 6, 10, 13, 17,23, 30, 40, 80, 160 mg of the fluoride ion as NaF in distilled water per kg of body weight (mg/kg). Dosing began when nestlings were 24-48 hr old and continued for 16 days. The 24-hr LD50 of fluoride for day-old starlings was 50 mg/kg. The 16-day LD50 was 17 mg/kg. The sodium control group did not differ from the water control group with respect to any of the measured variables. Growth rates were significantly reduced in the 13 and 17 mg of fluoride/kg groups; weights of birds given higher dose levels were omitted from growth comparisons because of high, fluoride-induced mortality. Although pre-fledging weights for the 10, 13, and 17 mg of fluoride/kg groups averaged 3.6 to 8.6% less than controls at 17 days, this difference was not significant. Feather and bone growth of the fluoride and control groups were not different, except for keel length measured at 17 days of age which averaged less in the fluoride groups. Liver and spleen weights were not affected by fluoride treatments. No histological damage related to fluoride treatments was found in liver, spleen, or kidney. The logarithm of bone fluoride and magnesium concentration increased with the logarithm of increasing fluoride treatment levels and were significantly correlated with each other. Fluoride treatments had no effect on percent calcium or phosphorus in bone or plasma alkaline phosphatase activity. Oral doses of fluoride appear to be more toxic than equivalent dietary levels. Most birds probably acquire fluoride through their diet. Therefore, the results of the study may overestimate the potential effects of fluorides on songbirds living in fluoride-contaminated environments.

Effect of trimetaphosphate and fluoride association on hydroxyapatite dissolution and precipitation in vitro.

PubMed

Delbem, Alberto Carlos Botazzo; Souza, José Antonio Santos; Zaze, Ana Carolina Soares Fraga; Takeshita, Eliana Mitsue; Sassaki, Kikue Takebayashi; Moraes, João Carlos Silos

2014-01-01

The present study analyzed the action of sodium trimetaphosphate (TMP) and/or fluoride on hydroxyapatite. Hydroxyapatite powder was suspended in different solutions: deionized water, 500 µg F/mL, 1,100 µg F/mL, 1%TMP, 3%TMP, 500 µg F/mL plus 1%TMP and 500 µg F/mL plus 3%TMP. The pH value of the solutions was reduced to 4.0 and after 30 min, raised to 7.0 (three times). After pH-cycling, the samples were analyzed by X-ray diffraction and infrared spectroscopy. The concentrations of calcium fluoride, fluoride, calcium and phosphorus were also determined. Adding 1% or 3% TMP to the solution containing 500 µg F/mL produced a higher quantity of calcium fluoride compared to samples prepared in a 1,100 µg F/mL solution. Regarding the calcium concentration, samples prepared in solutions of 1,100 µg F/mL and 500 µg F/mL plus TMP were statistically similar and showed higher values. Using solutions of 1,100 µg F/mL and 500 µg F/mL plus TMP resulted in a calcium/phosphorus ratio close to that of hydroxyapatite. It is concluded that the association of TMP and fluoride favored the precipitation of a more stable hydroxyapatite.

Ab initio study of the diatomic fluorides FeF, CoF, NiF, and CuF.

PubMed

Koukounas, Constantine; Mavridis, Aristides

2008-11-06

The late-3d transition-metal diatomic fluorides MF = FeF, CoF, NiF, and CuF have been studied using variational multireference (MRCI) and coupled-cluster [RCCSD(T)] methods, combined with large to very large basis sets. We examined a total of 35 (2S+1)|Lambda| states, constructing as well 29 full potential energy curves through the MRCI method. All examined states are ionic, diabatically correlating to M(+)+F(-)((1)S). Notwithstanding the "eccentric" character of the 3d transition metals and the difficulties to accurately be described with all-electron ab initio methods, our results are, in general, in very good agreement with available experimental numbers.

Comparative uptake of ¹⁸F-FEN-DPAZn2, ¹⁸F-FECH, ¹⁸F-fluoride, and ¹⁸F-FDG in fibrosarcoma and aseptic inflammation.

PubMed

Liang, Xiang; Tang, Ganghua; Wang, Hongliang; Hu, Kongzhen; Tang, Xiaolan; Nie, Dahong; Sun, Ting; Huang, Tingting

2014-08-01

The aim of this study is to evaluate uptake of 2-(18)F-fluoroethyl-bis(zinc(II)-dipicolylamine) ((18)F-FEN-DPAZn2) as a promising cell death imaging agent, a choline analog (18)F-fluoroethylcholine ((18)F-FECH), (18)F-fluoride as a bone imaging agent, and a glucose analog 2-(18)F-fluoro-2-deoxy-d-glucose ((18)F-FDG) in the combined S180 fibrosarcoma and turpentine-induced inflammation mice models. The results showed that (18)F-FDG had the highest tumor-to-blood uptake ratio and tumor-to-muscle ratio, and high inflammation-to-blood ratio and inflammation-to-muscle ratio. (18)F -FECH showed moderate tumor-to-blood ratio and tumor-to-muscle ratio, and low inflammation-to-blood ratio and inflammation-to-muscle ratio. However, accumulation of (18)F FEN-DPAZn2 in tumor was similar to that in normal muscle. Also, (18)F-FEN-DPAZn2 and (18)F-fluoride exhibited the best selectivity to inflammation. (18)F-FECH positron emission tomography (PET) imaging demonstrates some advantages over (18)F-FDG PET for the differentiation of tumor from inflammation. (18)F FEN-DPAZn2 and (18)F-fluoride can be used for PET imaging of aseptic inflammation. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

PubMed

Norman, M; Twetman, S; Hultgren Talvilahti, A; Granström, E; Stecksén-Blicks, C

2017-03-01

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. Double-blind cross-over study. Nine healthy children, 2.5-4.5 years of age. In a randomized order, participants drank 1.5 dl milk once daily for 7 days with no fluoride added (control), 0.185 mg fluoride added and 0.375 mg fluoride added. The experiment was performed twice with (Part I) and without (Part II) parental tooth brushing with 1,000 ppm fluoride toothpaste. The fluoride content in the piped drinking water was 0.5 mg F/L. Urinary fluoride excretion. The 24-hour urinary fl uoride excretion/kg body weight varied from 0.014 mg F for the placebo intervention and non-fluoride toothpaste to 0.027 mg F for the 0.375 mg intervention with use of 1,000 ppm fluoride toothpaste. The difference compared with the placebo intervention was not statistically significant for any of the interventions when fluoride toothpaste was used (p⟩0.05) while it was statistically significantly different when non-fluoride toothpaste was used (p⟨0.05). All sources of fluoride must be considered when designing community programs. With 0.5 mg F/L in the drinking water and daily use of fluoride toothpaste, most children had a fluoride intake optimal for dental health. In this setting, additional intake of fluoride milk was within safe limits up to 0.185 mg/day while conclusions about the safety of 0.375 mg/day were uncertain. Copyright© 2017 Dennis Barber Ltd

Assessment of nickel titanium and beta titanium corrosion resistance behavior in fluoride and chloride environments.

PubMed

Kassab, Elisa J; Gomes, José Ponciano

2013-09-01

To assess the influence of fluoride concentration on the corrosion behavior of nickel titanium (NiTi) superelastic wire and to compare the corrosion resistance of NiTi with that of beta titanium alloy in physiological solution with and without addition of fluoride. NiTi corrosion resistance was investigated through electrochemical impedance spectroscopy and anodic polarization in sodium chloride (NaCl 0.15 M) with and without addition of 0.02 M sodium fluoride (NaF), and the results were compared with those associated with beta titanium. The influence of fluoride concentration on NiTi corrosion behavior was assessed in NaCl (0.15 M) with and without 0.02, 0.04, 0.05, 0.07, and 0.12 M NaF solution. Galvanic corrosion between NiTi and beta titanium were investigated. All samples were characterized by scanning electron microscopy. Polarization resistance decreased when NaF concentration was increased, and, depending on NaF concentration, NiTi can suffer localized or generalized corrosion. In NaCl solution with 0.02 M NaF, NiTi suffer localized corrosion, while beta titanium alloys remained passive. Current values near zero were observed by galvanic coupling of NiTi and beta titanium. There is a decrease in NiTi corrosion resistance in the presence of fluoride. The corrosion behavior of NiTi alloy depends on fluoride concentration. When 0.02 and 0.04 M of NaF were added to the NaCl solution, NiTi presented localized corrosion. When NaF concentration increased to 0.05, 0.07, and 0.12 M, the alloy presented general corrosion. NiTi corrosion resistance behavior is lower than that of beta titanium. Galvanic coupling of these alloys does not increase corrosion rates.

Clinical Relevance of 18F-Sodium Fluoride Positron-Emission Tomography in Noninvasive Identification of High-Risk Plaque in Patients With Coronary Artery Disease.

PubMed

Lee, Joo Myung; Bang, Ji-In; Koo, Bon-Kwon; Hwang, Doyeon; Park, Jonghanne; Zhang, Jinlong; Yaliang, Tong; Suh, Minseok; Paeng, Jin Chul; Shiono, Yasutsugu; Kubo, Takashi; Akasaka, Takashi

2017-11-01

18 F-sodium fluoride ( 18 F-NaF) positron-emission tomography has been introduced as a potential noninvasive imaging tool to identify plaques with high-risk characteristics in patients with coronary artery disease. We sought to evaluate the clinical relevance of 18 F-NaF uptake using optical coherence tomography (OCT), intravascular ultrasound (IVUS), and coronary computed tomography angiography in patients with coronary artery disease. The target population consisted of 51 prospectively enrolled patients (93 stenoses) who underwent 18 F-NaF positron-emission tomography before invasive coronary angiography. 18 F-NaF uptake was compared with IVUS- and OCT-derived plaque characteristics. In the coronary computed tomography angiography subgroup (46 lesions), qualitative lesion characteristics were compared between 18 F-NaF-positive and 18 F-NaF-negative plaques using adverse plaque characteristics. The plaques with 18 F-NaF uptake showed significantly higher plaque burden, more frequent posterior attenuation and positive remodeling in IVUS, and significantly higher maximum lipid arc and more frequent microvessels in OCT (all P <0.05). There were no differences in minimum lumen area and area of calcium between 18 F-NaF-positive and 18 F-NaF-negative lesions. Among 51 lesions with 18 F-NaF-positive uptake, 48 lesions (94.1%) had at least one of high-risk characteristics. The 18 F-NaF tissue-to-background ratio in plaques with high-risk characteristics was significantly higher than in those without (1.09 [95% confidence interval, 0.85-1.34] versus 0.62 [95% confidence interval, 0.42-0.82], P <0.001 for IVUS definition; 0.76 [95% confidence interval, 0.54-0.98] versus 0.42 [95% confidence interval, 0.21-0.62], P =0.014 for OCT definition). Among the 15 lesions that met both IVUS- and OCT-defined criteria for high-risk plaque, 14 (93.3%) showed 18 F-NaF-positive uptake. There was no difference in the prevalence of plaques with any adverse plaque characteristics between 18

Comparison of the incipient lesion enamel fluoride uptake from various prescription and OTC fluoride toothpastes and gels.

PubMed

Schemehorn, B R; DiMarino, J C; Movahed, N

2014-01-01

The objective of this in vitro study was to compare the fluoride uptake into incipient enamel lesions of a novel 970 ppm F- ion SnF2 over-the-counter (OTC) gel (Enamelon Preventive Treatment Gel) and a novel 1150 ppm F- ion OTC toothpaste (Enamelon), each delivering amorphous calcium phosphate (ACP), to the uptake from two different prescription strength, 5000 ppm F- ion dentifrices containing tri-calcium phosphate (TCP) and a prescription 900 ppm F- ion paste containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). The test procedure followed method #40 in the US-FDA Anticaries Drug Products for OTC Human Use, Final Monograph testing procedures. Eight sets of twelve incisor enamel cores were mounted in Plexiglas rods and the exposed surfaces were polished. The indigenous fluoride levels of each specimen were determined prior to treatment. The treatments were performed using slurries of a negative control (water) and the following products applied to a set of sound enamel cores: 5000 ppm F- ion, sodium fluoride (NaF) prescription (Rx) dentifrice "A" containing TCP; 5000 ppm F- ion, NaF Rx dentifrice "B" containing TCP; 900 ppm F- ion, NaF Rx paste with CPP-ACP; 1150 ppm F- ion, NaF OTC toothpaste; 1150 ppm F- ion, stannous fluoride (SnF2) OTC toothpaste delivering ACP (Enamelon); 1100 ppm F- ion, SnF2 OTC toothpaste; and 970 ppm F- ion, SnF2 OTC gel delivering ACP (Enamelon Preventive Treatment Gel). The twelve specimens of each group were immersed into 25 ml of their assigned slurry with constant stirring (350 rpm) for 30 minutes. Following treatment, one layer of enamel was removed from each specimen and analyzed for fluoride and calcium. The pre-treatment fluoride (indigenous) level of each specimen was subtracted from the post-treatment value to determine the change in enamel fluoride due to the test treatment. The increase in the average fluoride uptake for treated enamel cores was: 10,263 ± 295 ppm for the 970 ppm F- ion, Enamelon Preventive

Effect of topical applications of neutral sodium fluoride on dental careis in the rat.

PubMed

Poulsen, S; Larson, R H

1975-01-01

A study on various regimens by which the same total amount of neutral sodium fluoride is applied to the teeth of rats showed that greater effects were observed after frequent application of 0.2% solutions than after less frequent application of more concentrated solutions.

[Sodium fluoride in the therapy of osteoporosis].

PubMed

Krokowski, E

1979-10-04

Every form of osteoporosis--except the physiological involution osteoporosis--requires treatment. Osteoporosis is no disease by itself but a result or a concomitant phenomenon of various diseases. Therefore the primary disease has to be treated also. Only for the so-called idiopathic osteoporosis hitherto no cause is known. Today sodium fluoride is the only substance with an influence upon the bone which may induce re-ossification and re-stabilization. In the described series of investigations this compound, with which treatment by gradual dosage is possible, has proved its effectiveness. Osteoporosis is more than bone porosity, therefore additionally afflicted organic or functional system like the muscular apparatus, bone marrow, or the intraosseous blood supply, must be treated too. Psychological guidance of the patient is necessary as he must be motivated for activity.

Abnormal spermatogenesis following sodium fluoride exposure is associated with the downregulation of CREM and ACT in the mouse testis.

PubMed

Wang, Chong; Chen, Yan; Manthari, Ram Kumar; Wang, Jundong

2018-04-01

cAMP response element modulator (CREM) is involved in regulating gene expression in normal spermatogenesis. The transcriptional activity of CREM is partly regulated by activator of CREM in the testis (ACT). To investigate the effects of different concentrations of sodium fluoride (NaF) on the gene and protein expression of CREM and ACT in the mouse testis, sexually mature male Kunming mice were exposed to 50, 100, or 150 mg/L NaF in their drinking water for 90 days. NaF reduced the sperm count and viability and increased the percentage of malformed sperm in a dose-dependent manner. The mRNA expression of CREM and ACT was markedly downregulated in the NaF-treated groups. Furthermore, immunohistochemistry revealed that CREM and ACT proteins were decreased significantly in the 50, 100, and 150 mg/L NaF-treated groups compared to the control group. These findings indicate that the decreased gene and protein expression of CREM and ACT in the testis is associated with an impairment of reproductive functions by NaF.

Fluoride concentration in saliva after use of oral hygiene products.

PubMed

Campus, Guglielmo; Lallai, Maria Rosario; Carboni, Roberto

2003-01-01

The purpose of this in vivo, single-blind, randomized study was to compare fluoride concentrations in saliva of patients treated with oral hygiene products containing different fluoride salts. The study involved 104 students attending the University of Sassari. Participants were subdivided: group A used a sodium monofluorophosphate (NaMFP) toothpaste; groups B and C used an amine fluoride (AmF) toothpaste; group D used a toothpaste and a mouthwash both based on AmF, and group E used a toothpaste and a varnish both on an NaMFP base. Samples of unstimulated saliva were collected at baseline (t(0)), at the end of the 20 days' treatment phase (t(1)) and after 24 h, during which the volunteers refrained from any oral hygiene measure (t(2)). Saliva fluoride concentrations were measured using an ion-specific electrode. All measurements were made in triplicate and analysed statistically using ANOVA. In saliva, the mean fluoride concentration increased significantly in each treatment group. In conclusion, the fluoride concentration in saliva can be maintained to an optimal therapeutic level with the regular use of fluoridated products. Copyright 2003 S. Karger AG, Basel

Sodium fluoride affects zebrafish behaviour and alters mRNA expressions of biomarker genes in the brain: Role of Nrf2/Keap1.

PubMed

Mukhopadhyay, Debdip; Priya, Pooja; Chattopadhyay, Ansuman

2015-09-01

Sodium fluoride (NaF), used as pesticides and for industrial purposes are deposited in the water bodies and therefore affects its biota. Zebrafish exposed to NaF in laboratory condition showed hyperactivity and frequent surfacing activity, somersaulting and vertical swimming pattern as compared to the control group. Reactive oxygen species level was elevated and glutathione level was depleted along with increased malondialdehyde content in the brain. Levels of glutathione-s-transferase (GST), catalase (CAT) and superoxide dismutase were also elevated in the treatment groups. Expression of mRNA of nuclear factor erythroid 2 related factor 2 (Nrf2) and its inhibitor Kelch-like ECH-associated protein 1 (Keap1) during stress condition were observed along with Gst, Cat, NADPH: quinone oxidoreductase 1(Nqo1) and p38. Except Keap1, all other genes exhibited elevated expression. Nrf2/Keap1 proteins had similar expression pattern as their corresponding mRNA. The findings in this study might help to understand the molecular mechanism of fluoride induced neurotoxicity in fish. Copyright © 2015 Elsevier B.V. All rights reserved.

Remineralization Effect of Topical NovaMin Versus Sodium Fluoride (1.1%) on Caries-Like Lesions in Permanent Teeth

PubMed Central

Vahid Golpayegani, M.; Sohrabi, A.; Biria, M.; Ansari, G.

2012-01-01

Objective: NovaMin, a synthetic mineral composed of calcium, sodium, phosphorous and silica releases deposits of crystalline hydroxyl-carbonate apatite (HCA) structurally similar to tooth mineral composition. The aim of this investigation was to compare the potential remineralization effect of topical NovaMin and Sodium Fluoride gel on caries like lesions in permanent teeth. Materials and Methods: A total of 60 sound human freshly extracted teeth were subjected to a pH-cycling protocol. Specimens were randomly assigned to one of the two treatment groups with NovaMin contained dentifrice applied to group 1, while group 2 received a dentifrice containing 1.1% neutral Sodium Fluoride. Pastes were applied five times after the samples received a demineralization from an earlier cariogenic challenge. Specimens were then evaluated by a Surface Micro Hardness test (SMH, 25G, 5s). Post-treatment SMH measurements were conducted and Mann Whitney test was employed for statistical analysis. Results: Mean post lesion SMH values were 221.99±26.27 and 224.50±28.64 for the first and second groups, respectively. Post treatment SMH values were 232.52±24.34 for NovaMin and 232.03 ±24.46 for the fluoride group. Two way ANOVA test showed a highly significant difference between the two different treatment protocols (p<0.001). Conclusion: NovaMin dentifrice appears to have a greater effect on remineralization of carious-like lesions when compared to that of fluoride containing dentifrice in permanent teeth. PMID:22924104

Calculated high-pressure structural properties, lattice dynamics and quasi particle band structures of perovskite fluorides KZnF3, CsCaF3 and BaLiF3

NASA Astrophysics Data System (ADS)

Vaitheeswaran, G.; Kanchana, V.; Zhang, Xinxin; Ma, Yanming; Svane, A.; Christensen, N. E.

2016-08-01

A detailed study of the high-pressure structural properties, lattice dynamics and band structures of perovskite structured fluorides KZnF3, CsCaF3 and BaLiF3 has been carried out by means of density functional theory. The calculated structural properties including elastic constants and equation of state agree well with available experimental information. The phonon dispersion curves are in good agreement with available experimental inelastic neutron scattering data. The electronic structures of these fluorides have been calculated using the quasi particle self-consistent GW approximation. The GW calculations reveal that all the fluorides studied are wide band gap insulators, and the band gaps are significantly larger than those obtained by the standard local density approximation, thus emphasizing the importance of quasi particle corrections in perovskite fluorides.

Calculated high-pressure structural properties, lattice dynamics and quasi particle band structures of perovskite fluorides KZnF3, CsCaF3 and BaLiF3.

PubMed

Vaitheeswaran, G; Kanchana, V; Zhang, Xinxin; Ma, Yanming; Svane, A; Christensen, N E

2016-08-10

A detailed study of the high-pressure structural properties, lattice dynamics and band structures of perovskite structured fluorides KZnF3, CsCaF3 and BaLiF3 has been carried out by means of density functional theory. The calculated structural properties including elastic constants and equation of state agree well with available experimental information. The phonon dispersion curves are in good agreement with available experimental inelastic neutron scattering data. The electronic structures of these fluorides have been calculated using the quasi particle self-consistent [Formula: see text] approximation. The [Formula: see text] calculations reveal that all the fluorides studied are wide band gap insulators, and the band gaps are significantly larger than those obtained by the standard local density approximation, thus emphasizing the importance of quasi particle corrections in perovskite fluorides.

Reduction in fluoride-induced genotoxicity in mouse bone marrow cells after substituting high fluoride-containing water with safe drinking water.

PubMed

Podder, Santosh; Chattopadhyay, Ansuman; Bhattacharya, Shelley

2011-10-01

Treatment of mice with 15 mg l(-1) sodium fluoride (NaF) for 30 days increased the number of cell death, chromosomal aberrations (CAs) and 'cells with chromatid breaks' (aberrant cells) compared with control. The present study was intended to determine whether the fluoride (F)-induced genotoxicity could be reduced by substituting high F-containing water after 30 days with safe drinking water, containing 0.1 mg F ions l(-1). A significant fall in percentage of CAs and aberrant cells after withdrawal of F-treatment following 30 days of safe water treatment in mice was observed which was highest after 90 days, although their levels still remained significantly high compared with the control group. This observation suggests that F-induced genotoxicity could be reduced by substituting high F-containing water with safe drinking water. Further study is warranted with different doses and extended treatment of safe water to determine whether the induced damages could be completely reduced or not. Copyright © 2011 John Wiley & Sons, Ltd.

A new perspective on metals and other contaminants in fluoridation chemicals*

PubMed Central

Mullenix, Phyllis J

2014-01-01

Background: Fluoride additives contain metal contaminants that must be diluted to meet drinking water regulations. However, each raw additive batch supplied to water facilities does not come labeled with concentrations per contaminant. This omission distorts exposure profiles and the risks associated with accidents and routine use. Objectives: This study provides an independent determination of the metal content of raw fluoride products. Methods: Metal concentrations were analyzed in three hydrofluorosilicic acid (HFS) and four sodium fluoride (NaF) samples using inductively coupled plasma-atomic emission spectrometry. Arsenic levels were confirmed using graphite furnace atomic absorption analysis. Results: Results show that metal content varies with batch, and all HFS samples contained arsenic (4.9–56.0 ppm) or arsenic in addition to lead (10.3 ppm). Two NaF samples contained barium (13.3–18.0 ppm) instead. All HFS (212–415 ppm) and NaF (3312–3630 ppm) additives contained a surprising amount of aluminum. Conclusions: Such contaminant content creates a regulatory blind spot that jeopardizes any safe use of fluoride additives. PMID:24999851

Fluoride gastrointestinal absorption from Na2FPO3/CaCO3- and NaF/SiO2-based toothpastes.

PubMed

Falcão, A; Tenuta, L M A; Cury, J A

2013-01-01

Depending on toothpaste formulation, part of the fluoride is insoluble and would not be totally absorbable in the gastrointestinal tract, thus changing dental fluorosis risk estimation. This hypothesis was tested with formulations with either all fluoride in a soluble form (NaF/SiO2-based toothpaste, 1,100 µg F/g as labeled, 1,129.7 ± 49.4 µg F/g soluble fluoride as analyzed) or with around 20% of insoluble fluoride (Na2FPO3/CaCO3-based toothpaste, 1,450 µg F/g as labeled, 1,122.4 ± 76.4 µg F/g soluble fluoride as analyzed). Toothpastes were evaluated either fresh or after accelerated aging, which increased insoluble fluoride to 40% in the Na2FPO3/CaCO3-based toothpaste. In a blind, crossover clinical trial conducted in five legs, 20 adult volunteers ingested 49.5 µg of total fluoride/kg body weight from each formulation or purified water (control). Whole saliva and urine were collected as bioavailability indicators, and pharmacokinetics parameters calculated showed significantly (p < 0.05) lower fluoride bioavailability for Na2FPO3/CaCO3 toothpaste, which was reduced further after aging. A significant correlation between the amount of soluble fluoride ingested, but not total fluoride, and fluoride bioavailability was found (r = 0.57, p < 0.0001). The findings suggest that the estimated fluorosis risk as a result of ingestion of Na2FPO3/CaCO3-based toothpastes should be calculated based on the toothpaste's soluble rather than total fluoride concentration. Copyright © 2012 S. Karger AG, Basel.

Reduction of erosive wear in situ by stannous fluoride-containing toothpaste.

PubMed

Huysmans, M C D N J M; Jager, D H J; Ruben, J L; Unk, D E M F; Klijn, C P A H; Vieira, A M

2011-01-01

Stannous fluoride (SnF) has been suggested as a dental erosion-preventive agent. The aim of this single-centre, randomized, double-blind, in situ study was to evaluate the effect of toothpastes with SnF in the prevention of erosive enamel wear. A combined split-mouth (extra-oral water or toothpaste brushing) and crossover (type of toothpaste) set-up was used. Twelve volunteers wore palatal appliances containing human enamel samples. Three toothpastes were used, in three consecutive runs, in randomized order: two toothpastes containing SnF (coded M and PE) and one toothpaste containing only sodium fluoride (coded C). On day 1 of each run the appliances were worn for pellicle formation. On days 2-5 the samples were also brushed twice with a toothpaste-water slurry or only water (control). Erosion took place on days 2-5 extra-orally 3 times a day (5 min) in a citric acid solution (pH 2.3). Enamel wear depth was quantified by optical profilometry. The effect of toothpastes was tested using General Linear Modeling. Average erosive wear depth of control samples was 23 μm. Both SnF toothpastes significantly reduced erosive wear: M by 34% (SD 39%) and PE by 26% (SD 25%). The control toothpaste reduced erosive wear non-significantly by 7% (SD 20%). Both SnF-containing toothpastes significantly reduced erosive wear compared to the sodium fluoride toothpaste. We conclude that SnF-containing toothpastes are able to reduce erosive tooth wear in situ. Copyright © 2011 S. Karger AG, Basel.

Role of 18F-fluoride PET/CT in the assessment of multiple myeloma: initial experience.

PubMed

Nishiyama, Yuji; Tateishi, Ukihide; Shizukuishi, Kazuya; Shishikura, Ayako; Yamazaki, Etsuko; Shibata, Hiroto; Yoneyama, Tomohiro; Ishigatsubo, Yoshiaki; Inoue, Tomio

2013-01-01

The aim of this study was to report our early experience with (18)F-fluoride PET/CT for detecting lesions and evaluate the usefulness of this modality in the assessment of multiple myeloma (MM). (18)F-fluoride PET/CT and (99m)Tc-MDP bone scintigraphy (BS) studies from 7 myeloma patients (4 male and 3 female, mean age 55 years) diagnosed according to standard criteria were reviewed retrospectively. Two reviewers visually and quantitatively analyzed the images and recorded their findings after reaching a consensus. Diagnostic certainty regarding the presence or absence of myeloma lesions was evaluated according to the reference standard consisting of whole-body magnetic resonance imaging and whole-body X-ray. A total of 93 affected areas were definite according to the reference standard. Of these, 83 affected areas (89 %) were identified on (18)F-fluoride PET/CT, whereas 54 affected areas (58 %) were found on BS. Mean SUVmax in the affected areas was 9.8 ± 3.2 (standard deviation) ranging from 5.0 to 21.2. A total of s17 lesions with bone fracture were also detected by (18)F-fluoride PET/CT and 2 lesions (12 %) were negative on BS. Our result showed that (18)F-fluoride PET was a possible modality to detect areas of lesions in patients with MM.

[Mechanisms of nitroxide-ergic dysregulation in tissues of parodontium in rats under combined excessive sodium nitrate and fluoride intake].

PubMed

Богданов, Алексей В; Гришко, Юлия М; Костенко, Виталий А

2016-01-01

intake of inorganic nitrates is typically accompanied by production of excessive amount of nitric oxide (NO), which level is maintained by the mechanism of autoregulation known as the NO cycle. Hypothetically, this process may be disrupted with fluorides that are able to suppress arginase pathway of L-arginine metabolism, which competes with NO-synthase pathway. to study mechanisms of disregulation of oxidative (NO-synthase) and non-oxidative (arginase) metabolic pathways of L-arginine in the tissues of periodontium under combined excessive sodium nitrate and fluoride intake. these investigations were carried out on 90 white Wistar rats. Homogenates of parodontium soft tissues were used to assess spectrophotometrically the total activities of NO-synthase (NOS), arginase, ornithine decarboxylase as well as the peroxynitrite concentration. typical for the isolated sodium nitrate administration inhibition of total NOS activity varies under combined administration of nitrate and sodium fluoride and is usually manifested by its hyperactivation that is accompanied by an increase in peroxynitrite concentration. At this time arginase and ornithine decarboxylase activity is observed to be substantially reduced. The administration of aminoguanidine, an iNOS inhibitor, (20 mg/kg, twice a week during the experiment) increases arginase and ornithine decarboxylase activities, and the administration of L-arginine (500 mg/kg, twice a week) results in the increase of arginase activity. The administration of L-selenomethionine, a peroxynitrite scavenger (3 mg/kg, twice a week), and JSH-23 (4-methyl-N-(3-phenylpropyl) benzene-1,2-diamine, an inhibitor of NF-κB activation (1 mg/kg, twice a week) for modeling binary nitrate and fluoride intoxication reduces the total concentration of NOS activity and peroxynitrite concentration, and increases ornithine decarboxylase activity. the combined effect of nitrate and sodium fluoride for 30 days leads to disregulatory increased activity of NO

[Mechanisms of nitroxide-ergic dysregulation in tissues of parodontium in rats under combined excessive sodium nitrate and fluoride intake].

PubMed

Богданов, Алексей В; Гришко, Юлия М; Костенко, Виталий А

intake of inorganic nitrates is typically accompanied by production of excessive amount of nitric oxide (NO), which level is maintained by the mechanism of autoregulation known as the NO cycle. Hypothetically, this process may be disrupted with fluorides that are able to suppress arginase pathway of L-arginine metabolism, which competes with NO-synthase pathway. to study mechanisms of disregulation of oxidative (NO-synthase) and non-oxidative (arginase) metabolic pathways of L-arginine in the tissues of periodontium under combined excessive sodium nitrate and fluoride intake. these investigations were carried out on 90 white Wistar rats. Homogenates of parodontium soft tissues were used to assess spectrophotometrically the total activities of NO-synthase (NOS), arginase, ornithine decarboxylase as well as the peroxynitrite concentration. typical for the isolated sodium nitrate administration inhibition of total NOS activity varies under combined administration of nitrate and sodium fluoride and is usually manifested by its hyperactivation that is accompanied by an increase in peroxynitrite concentration. At this time arginase and ornithine decarboxylase activity is observed to be substantially reduced. The administration of aminoguanidine, an iNOS inhibitor, (20 mg/kg, twice a week during the experiment) increases arginase and ornithine decarboxylase activities, and the administration of L-arginine (500 mg/kg, twice a week) results in the increase of arginase activity. The administration of L-selenomethionine, a peroxynitrite scavenger (3 mg/kg, twice a week), and JSH-23 (4-methyl-N-(3-phenylpropyl) benzene-1,2-diamine, an inhibitor of NF-κB activation (1 mg/kg, twice a week) for modeling binary nitrate and fluoride intoxication reduces the total concentration of NOS activity and peroxynitrite concentration, and increases ornithine decarboxylase activity. the combined effect of nitrate and sodium fluoride for 30 days leads to disregulatory increased activity of NO

In Situ Study to Confirm the Anticaries Potential of a Sodium Monofluorophosphate Dentifrice Containing Calcium Sodium Phosphosilicate.

PubMed

Parkinson, C R; Siddiqi, M; Mason, S; Lippert, F; Hara, A T; Zero, D T

2017-06-01

A randomized, investigator-blind, five-treatment, crossover, non-inferiority study was conducted to investigate the effect of the addition of calcium sodium phosphosilicate (CSPS), an agent known to relieve dentin hypersensitivity, to a sodium monofluorophosphate (SMFP)-containing dentifrice on the enamel remineralization potential of fluoride (F), as assessed by percentage surface microhardness recovery (%SMHR) and enamel fluoride uptake (EFU) using a standard in situ caries model. Seventy-seven subjects wearing bilateral mandibular partial dentures holding partially demineralized bovine enamel specimens 24 hours/day brushed their teeth with their assigned randomized dentifrice containing either 1500 or 0 ppm F with 5% CSPS or 1500, 500, or 0 ppm F with 0% CSPS twice daily for 21 days. The success criterion was to observe a difference in % SMHR between dentifrices containing 1500 ppm F of six units or less in the upper bound of the two-sided 95% confidence interval (CI). Following 21 days of treatment, the upper bound CI of the %SMHR difference between the dentifrices containing 1500 ppm F was 1.66, thus within the non-inferiority limit. No statistically significant differences for %SMHR (p = 0.2601) and EFU (p = 0.2984) were noted between these two dentifrices. The present in situ caries study provides evidence demonstrating that the addition of the calcium-containing compound CSPS to a 1500 ppm F dentifrice does not interfere with the ability of fluoride to remineralize surface-softened enamel; i.e., CSPS neither impairs nor improves the potential cariostatic value of SMFP dentifrice.

Antibacterial Effect of Silver Diamine Fluoride on Cariogenic Organisms.

PubMed

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 < 0.05) on all three test organisms, although ammonium fluoride had no 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.

Epitaxial growth of lithium fluoride on the (1 1 1) surface of CaF 2

NASA Astrophysics Data System (ADS)

Klumpp, St; Dabringhaus, H.

1999-08-01

Growth of lithium fluoride by molecular beam epitaxy on the (1 1 1) surface of calcium fluoride crystals was studied by TEM and LEED for crystal temperatures from 400 to 773 K and impinging lithium fluoride fluxes from 3×10 11 to 3×10 14 cm -2 s -1. Growth starts, usually, at the <1 1 0> steps on the (1 1 1) surface of CaF 2. For larger step distances and at later growth stages also growth on the terraces between the steps is found. Preferably, longish, roof-like crystallites are formed, which can be interpreted by growth of LiF(2 0 1¯)[0 1 0] parallel to CaF 2(1 1 1)[ 1¯ 0 1]. To a lesser extent square crystallites, i.e. growth with LiF(0 0 1), and, rarely, three-folded pyramidal crystallites, i.e. growth with LiF(1 1 1) parallel to CaF 2(1 1 1), are observed. While the pyramidal crystallites show strict epitaxial orientation with LiF[ 1¯ 0 1]‖CaF 2[ 1¯ 0 1] and LiF[ 1¯ 0 1]‖CaF 2[1 2¯ 1], only about 80% of the square crystallites exhibit an epitaxial alignment, where LiF[1 0 0]‖CaF 2[ 1¯ 0 1] is preferred to LiF[1 1 0]‖CaF 2[ 1¯ 0 1]. The epitaxial relationships are discussed on the basis of theoretically calculated adsorption positions of the lithium fluoride monomer and dimer on the terrace and at the steps of the CaF 2(1 1 1) surface.

The Use of Backscattered Electron Imaging and Transmission Electron Microscopy to Assess Bone Architecture and Mineral Loci: Effect of Intermittent Slow-Release Sodium Fluoride Therapy

NASA Astrophysics Data System (ADS)

Zerwekh, Joseph E.; Bellotto, Dennis; Prostak, Kenneth S.; Hagler, Herbert K.; Pak, Charles Y. C.

1996-04-01

Backscattered electron imaging (BEI) and transmission electron microscopy (TEM) were used to examine the effects of treatment with intermittent slow-release sodium fluoride (SRNaF) and continuous calcium citrate on bone architecture and crystallinity. Examination was performed in nondecalcified biopsies obtained from patients following up to four years of therapy (placebo or SRNaF) and compared to pretreatment biopsies from each patient, as well as to bone from young, normal subjects. BEI images disclosed increased areas of recent bone formation following fluoride administration. There was no evidence of a mineralization defect in any biopsy and both cortical and trabecular architecture remained normal. TEM analysis demonstrated intrafibrillar platelike crystals and extrafibrillar needlelike crystals for both the pre- and post-treatment biopsies as well as for the bone from young normal subjects. There was no evidence of increased crystal size or of an increase in extrafibrillar mineral deposition. These observations suggest that intermittent SRNaF and continuous calcium therapy exerts an anabolic action on the skeleton not accompanied by a mineralization defect or an alteration of bone mineral deposition. The use of BEI and TEM holds promise for the study of the pathophysiology and treatment of metabolic bone diseases.

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

PubMed

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.

NiF2 Cathodes For Rechargeable Na Batteries

NASA Technical Reports Server (NTRS)

Bugga, Ratnakumar V.; Distefano, Salvador; Halpert, Gerald

1992-01-01

Use of NiF2 cathodes in medium-to-high-temperature rechargeable sodium batteries increases energy and power densities by 25 to 30 percent without detracting from potential advantage of safety this type of sodium battery offers over sodium batteries having sulfur cathodes. High-energy-density sodium batteries with metal fluoride cathodes used in electric vehicles and for leveling loads on powerlines.

Comparison of antimicrobial effects of titanium tetrafluoride, chlorhexidine, xylitol and sodium fluoride on streptococcus mutans: An in-vitro study.

PubMed

Eskandarian, Tahereh; Motamedifar, Mohammad; Arasteh, Peyman; Eghbali, Seyed Sajad; Adib, Ali; Abdoli, Zahra

2017-03-01

No studies have yet documented the bactericidal effects of TiF4, and its role in the treatment of dental caries, and no definite protocol has been introduced to regulate its use. The aim of this study was to determine the antimicrobial/bactericidal effects of TiF4 on Streptococcus Mutans ( S. Mutans ) and to compare it with chlorhexidine (Chx), sodium fluoride (NaF) and xylitol. This study was conducted at the Shiraz University of Medical Sciences microbiology laboratory during March 2015 to September 2015. In this in-vitro study, first a bacterial suspension was prepared and adjusted to a 0.5 McFarland standard (equivalent to 1×10 8 CFU/ml). The minimal inhibitory concentration (MIC) and minimal bactericidal concentrations (MBC) of TiF4, Chx, NaF and xylitol were assessed using broth microdilution assay and disk diffusion methods. In order to neutralize the acidic nature of TiF4, we used a sodium hydroxide preparation to obtain a pH of 7.2 and repeated all of the previous tests with the neutralized TiF4 solution. We reported the final results as percentages where appropriate. The MIC of TiF4, NaF and Chx for S. Mutans were 12.5%, 12.5% and 6.25%, respectively. At a concentration of 12.5% the inhibition zone diameters were 9 mm, 15mm and 14mm for TiF4, NaF and Chx, respectively. The MBC was 25%, 12.5% and 12.5% for TiF4, NaF and Chx, respectively. Xylitol failed to show any bactericidal or growth inhibitory effect in all of its concentrations. When we repeated the tests with an adjusted pH, identical results were obtained. TiF4 solutions have anti-growth and bactericidal effects on S. Mutans at a concentration of 12.5% which is comparable with chlorhexidine and NaF, indicating the possible use of this solution in dental practice as an anti-cariogenic agent, furthermore the antimicrobial activity is unaffected by pH of the environment.

Fluoride in groundwater: toxicological exposure and remedies.

PubMed

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 (<0.5 mg/L) is beneficial in promoting 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.

Comparative diagnostic value of 18F-fluoride PET-CT versus MRI for skull-base bone invasion in nasopharyngeal carcinoma.

PubMed

Le, Yali; Chen, Yu; Zhou, Fan; Liu, Guangfu; Huang, Zhanwen; Chen, Yue

2016-10-01

This study compared the diagnostic value of F-fluoride PET-computed tomography (PET-CT) and MRI in skull-base bone erosion in nasopharyngeal carcinoma (NPC) patients. A total of 93 patients with biopsy-confirmed NPC were enrolled, including 68 men and 25 women between 23 and 74 years of age. All patients were evaluated by both F-fluoride PET-CT and MRI, and the interval between the two imaging examinations was less than 20 days. The patients received no treatment either before or between scans. The studies were interpreted by two nuclear medicine physicians or two radiologists with more than 10 years of professional experience who were blinded to both the diagnosis and the results of the other imaging studies. The reference standard was skull-base bone erosion at a 20-week follow-up imaging study. On the basis of the results of the follow-up imaging studies, 52 patients showed skull-base bone erosion. The numbers of true positives, false positives, true negatives, and false negatives with F-fluoride PET-CT were 49, 4, 37, and 3, respectively. The numbers of true positives, false positives, true negatives, and false negatives with MRI were 46, 5, 36, and 6, respectively. The sensitivity, specificity, and crude accuracy of F-fluoride PET-CT were 94.23, 90.24, and 92.47%, respectively; for MRI, these values were 88.46, 87.80, and 88.17%. Of the 52 patients, 43 showed positive findings both on F-fluoride PET-CT and on MRI. Within the patient cohort, F-fluoride PET-CT and MRI detected 178 and 135 bone lesions, respectively. Both F-fluoride PET-CT and MRI have high sensitivity, specificity, and crude accuracy for detecting skull-base bone invasion in patients with NPC. F-fluoride PET-CT detected more lesions than did MRI in the skull-base bone. This suggests that F-fluoride PET-CT has a certain advantage in evaluating the skull-base bone of NPC patients. Combining the two methods could improve the diagnostic accuracy of skull-base bone invasion for NPC.

Fluoride mechanisms.

PubMed

ten Cate, J M; van Loveren, C

1999-10-01

This article discusses fluoride mechanisms in relation to dental caries. The authors specifically address firmly bound versus loosely bound fluoride; different fluoride active ingredients; fluoride and demineralization and remineralization; fluoride slow-release devices and F-releasing dental materials; antimicrobial effects of fluoride; the uptake of fluoride by oral bacteria; inhibition of enolase, protein-intruding ATPase and sugar transport; the various aspects of plaque as it relates to fluoride; and the rational use of fluoride.

Lead enhances fluoride influence on apoptotic processes in the HepG2 liver cell line.

PubMed

Gutowska, Izabela; Baranowska-Bosiacka, Irena; Siwiec, Ewa; Szczuko, Małgorzata; Kolasa, Agnieszka; Kondarewicz, Anna; Rybicka, Marta; Dunaj-Stańczyk, Małgorzata; Wiernicki, Ireneusz; Chlubek, Dariusz; Stachowska, Ewa

2016-03-01

Chronic long-term exposure to high levels of fluoride leads to fluorosis, manifested by skeletal fluorosis and damage to internal organs, including kidneys, liver, parathyroid glands, and brain. Excess fluoride can also cause DNA damage, trigger apoptosis, and change cell cycle. The effect of fluoride may be exacerbated by lead (Pb), a potent inhibitor of many enzymes and a factor causing apoptosis, still present in the environment in excessive amounts. Therefore, in this study, we investigated the effects of sodium fluoride (NaF) and/or lead acetate (PbAc) on development of apoptosis, cell vitality, and proliferation in the liver cell line HepG2. We examined hepatocytes from the liver cell line HepG2, incubated for 48 h with NaF, PbAc, and their mixture (NaF + PbAc), and used for measuring apoptosis, index of proliferation, and vitality of cells. Incubation of the hepatocytes with NaF or PbAc increased apoptosis, more when fluoride and Pb were used simultaneously. Vitality of the cells depended on the compound used and its concentration. Proliferation slightly increased and then decreased in a high fluoride environment; it decreased significantly after addition of Pb in a dose-dependent manner. When used together, fluoride inhibited the decreasing effect of Pb on cell proliferation. © The Author(s) 2013.

Influence of selenium and fluoride on blood antioxidant capacity of rats.

PubMed

Feng, Pei; Wei, Jun-ren; Zhang, Zi-gui

2012-09-01

This study is to explore the effect of selenium and fluoride on blood antioxidant capacity of rats, and try to find out the optimal level of selenium in drinking water against fluorosis. Animals were divided into control group, sodium fluoride treated group (NaF, 50 mg/L) and selenium+NaF treated group (sodium selenite 0.375, 0.75, 1.5 mg/L) in water were respectively administered to male rats, which were decapitated after 6 months. Their blood was collected for GSH-Px activity, plasma SOD activity, T-AOC assay, uric acid assay, sialic acid (SA) content and MDA content, and the fluidity of erythrocyte membrane by electron spin resonance (ESR) was analyzed. The results showed that, compared with the control group, the blood antioxidant capacity of the rats exposed to fluoride was down-regulated significantly (P<0.05, P<0.01), MDA content increased significantly (P<0.05), the fluidity of erythrocyte membrane decreased (P<0.05, P<0.01). Meanwhile, the treatments of selenium along with NaF compared with fluorosis group, SOD activity, GSH-Px activity and T-AOC assay increased respectively, MDA content decreased significantly (P<0.05) in NaF+Se (Se 0.75, 1.5 mg/L) treated groups, uric acid level was up-regulated, but had no statistical significant difference (P>0.05). The fluidity of erythrocyte membrane showed significant increase (P<0.05), the content of SA was lower. Fluorosis could induce the decline of blood antioxidant capacity and the fluidity of erythrocyte membrane, as evident in this study, and Se at different levels possess some antagonistic effects on blood induced by fluoride. However, high dose of selenium (1.5 mg/L) is the optimum concentration. Copyright © 2010 Elsevier GmbH. All rights reserved.

Mild hydrothermal crystal growth of new uranium(IV) fluorides, Na{sub 3.13}Mg{sub 1.43}U{sub 6}F{sub 30} and Na{sub 2.50}Mn{sub 1.75}U{sub 6}F{sub 30}: Structures, optical and magnetic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeon, Jeongho; Smith, Mark D.; Tapp, Joshua

Two new uranium(IV) fluorides, Na{sub 3.13}Mg{sub 1.43}U{sub 6}F{sub 30} (1) and Na{sub 2.50}Mn{sub 1.75}U{sub 6}F{sub 30} (2), were synthesized through an in situ mild hydrothermal route, and were structurally characterized by single crystal X-ray diffraction. The compounds exhibit complex crystal structures composed of corner- or edge-shared UF{sub 9} and MF{sub 6} (M=Mg, Mn) polyhedra, forming hexagonal channels in the three-dimensional framework, in which ordered or disordered divalent metal and sodium atoms reside. The large hexagonal voids contain the nearly regular M(II)F{sub 6} octahedra and sodium ions, whereas the small hexagonal cavities include M(II) and sodium ions on a mixed-occupied site.more » Magnetic susceptibility measurements yielded effective magnetic moments of 8.36 and 11.6 µ{sub B} for 1 and 2, respectively, confirming the presence and oxidation states of U(IV) and Mn(II). The large negative Weiss constants indicate the spin gap between a triplet and a singlet state in the U(IV). Magnetization data as a function of applied fields revealed that 2 exhibits paramagnetic behavior due to the nonmagnetic singlet ground state of U(IV) at low temperature. UV–vis diffuse reflectance and X-ray photoelectron spectroscopy data were also analyzed. - Graphical abstract: Two new quaternary U(IV) fluorides, Na{sub 3.13}Mg{sub 1.43}U{sub 6}F{sub 30} and Na{sub 2.50}Mn{sub 1.75}U{sub 6}F{sub 30}, were crystallized via an in situ reduction step of U(VI) to U(IV) under mild hydrothermal conditions. The compounds show complex crystal structures based on the 3-D building block of U{sub 6}F{sub 30}. Magnetic property measurements revealed that the U(IV) exhibits a nonmagnetic singlet ground state at low temperature with a spin gap. - Highlights: • Na{sub 3.13}Mg{sub 1.43}U{sub 6}F{sub 30} and Na{sub 2.50}Mn{sub 1.75}U{sub 6}F{sub 30} have been synthesized and characterized. • The U(IV) fluorides exhibit complex three-dimensional crystal structures. �

Fluoride induces apoptosis in H9c2 cardiomyocytes via the mitochondrial pathway.

PubMed

Yan, Xiaoyan; Wang, Lu; Yang, Xia; Qiu, Yulan; Tian, Xiaolin; Lv, Yi; Tian, Fengjie; Song, Guohua; Wang, Tong

2017-09-01

Numerous studies have shown that chronic excessive fluoride intake can adversely affect different organ systems. In particular, the cardiovascular system is susceptible to disruption by a high concentration of fluoride. The objectives of this study were to explore the mechanism of apoptosis by detecting the toxic effects of different concentrations of sodium fluoride (NaF) in H9c2 cells exposed for up to 96 h. NaF not only inhibited H9c2 cell proliferation but also induced apoptosis and morphological damage. With increasing NaF concentrations, early apoptosis of H9c2 cells was increased while the mitochondrial membrane potential was decreased. Compared with the control group, the mRNA levels of caspase-3, caspase-9, and cytochrome c all increased with increasing concentrations of NaF. In summary, these data suggest that apoptosis is involved in NaF-induced H9c2 cell toxicity and that activation of the mitochondrial pathway may occur. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thermal, optical, and dielectric properties of fluoride Rb2TaF7

NASA Astrophysics Data System (ADS)

Pogorel'tsev, E. I.; Mel'nikova, S. V.; Kartashev, A. V.; Gorev, M. V.; Flerov, I. N.; Laptash, N. M.

2017-05-01

The thermal, optical, and dielectric properties of fluoride Rb2TaF7 were investigated. It was observed that the variation in chemical pressure in fluorides A 2 +TaF7 caused by the cation substitution of rubidium for ammonium does not affect the ferroelastic nature of structural distortions, but leads to stabilization of the high- and low-temperature phases and enhancement of birefringence. The entropy of the phase transition P4/nmm ↔ Cmma is typical of the shift transformations, which is consistent with a model of the initial and distorted phase structures. The anisotropy of chemical pressure causes the change of signs of the anomalous strain and baric coefficient dT/ dp of Rb2TaF7 as compared with the values for its ammonium analog.

Fluoride geochemistry of thermal waters in Yellowstone National Park: I. Aqueous fluoride speciation

USGS Publications Warehouse

Deng, Y.; Nordstrom, D. Kirk; McCleskey, R. Blaine

2011-01-01

Thermal water samples from Yellowstone National Park (YNP) have a wide range of pH (1–10), temperature, and high concentrations of fluoride (up to 50 mg/l). High fluoride concentrations are found in waters with field pH higher than 6 (except those in Crater Hills) and temperatures higher than 50 °C based on data from more than 750 water samples covering most thermal areas in YNP from 1975 to 2008. In this study, more than 140 water samples from YNP collected in 2006–2009 were analyzed for free-fluoride activity by ion-selective electrode (ISE) method as an independent check on the reliability of fluoride speciation calculations. The free to total fluoride concentration ratio ranged from <1% at low pH values to >99% at high pH. The wide range in fluoride activity can be explained by strong complexing with H+ and Al3+ under acidic conditions and lack of complexing under basic conditions. Differences between the free-fluoride activities calculated with the WATEQ4F code and those measured by ISE were within 0.3–30% for more than 90% of samples at or above 10−6 molar, providing corroboration for chemical speciation models for a wide range of pH and chemistry of YNP thermal waters. Calculated speciation results show that free fluoride, F−, and major complexes (HF(aq)0">HF(aq)0, AlF2+, AlF2+">AlF2+and AlF30">AlF30) account for more than 95% of total fluoride. Occasionally, some complex species like AlF4-">AlF4-, FeF2+, FeF2+">FeF2+, MgF+ and BF2(OH)2-">BF2(OH)2- may comprise 1–10% when the concentrations of the appropriate components are high. According to the simulation results by PHREEQC and calculated results, the ratio of main fluoride species to total fluoride varies as a function of pH and the concentrations and ratios of F and Al.

Comparison of Fluoridated Miswak and Toothbrushing with Fluoridated Toothpaste on Plaque Removal and Fluoride Release.

PubMed

Baeshen, Hosam; Salahuddin, Sabin; Dam, Robel; Zawawi, Khalid H; Birkhed, Dowen

2017-04-01

Dental caries and periodontal diseases are all induced by oral biofilm (dental plaque). This study was conducted to evaluate if fluoride-impregnated miswak is as effective in plaque removal and fluoride release as toothbrushing with fluoride toothpaste. This single-blind, randomized, crossover study was conducted at the Department of Cariology, University of Gothenburg, Gothenburg, Sweden, from February 2010 to January 2011. Fifteen healthy subjects participated in this study. The participants were instructed to use the following: (1) 0.5% NaF-impregnated miswak, (2) nonfluoridated miswak, (3) toothbrush with nonfluoride toothpaste, and (4) toothbrush with 1450 ppm fluoride toothpaste. Each method was used twice a day for 1 week after which plaque amount and fluoride concentration in resting saliva were measured. There was a 1-week washout period between each method. No significant difference between miswak and tooth-brushing was found regarding plaque removal on buccal and lingual surfaces. A somewhat higher fluoride concentration in resting saliva was found after using impregnated miswak when compared with toothbrushing with fluoride toothpaste (p < 0.05). Miswak and toothbrushing showed the same plaque removing effect on buccal and lingual surfaces. Miswak impregnated with 0.5% NaF resulted in a higher concentration of fluoride in saliva than brushing with 1450 ppm fluoride toothpaste. Miswak impregnated with 0.5% NaF and toothbrushing results in comparable plaque removal and about the same fluoride concentration in saliva even it was somewhat higher for impregnated miswak.

Fluoride reduced the immune privileged function of mouse Sertoli cells via the regulation of Fas/FasL system.

PubMed

Sun, Zilong; Nie, Qingli; Zhang, Lianjie; Niu, Ruiyan; Wang, Jundong; Wang, Shaolin

2017-02-01

Previous investigations have demonstrated the adverse impacts of fluoride on Sertoli cells (SCs), such as oxidative stress and apoptosis. SCs are the crucial cellular components that can create the immune privileged environment in testis. However, the effect of fluoride on SCs immune privilege is unknown. In this study, mouse SCs were exposed to sodium fluoride with varying concentrations of 10 -5 , 10 -4 , and 10 -3  mol/L to establish the model of fluoride-treated SCs (F-SCs) in vitro. After 48 h of incubation, F-SCs were transplanted underneath the kidney capsule of mice for 21 days, or cocultured with spleen lymphocytes for another 48 h. Immunohistochemical analysis of GATA4 in SCs grafts underneath kidney capsule presented less SCs distribution and obvious immune cell infiltration in F-SCs groups. In addition, the levels of FasL protein and mRNA in non-cocultured F-SCs decreased with the increase of fluoride concentration. When cocultured with F-SCs, lymphocytes presented significantly high cell viability and low apoptosis in F-SCs groups. Protein and mRNA expressions of FasL in cocultured F-SCs and Fas in lymphocytes were reduced, and the caspase 8 and caspase 3 mRNA levels were also decreased in fluoride groups in a dose-dependent manner. These findings indicated that fluoride influenced the testicular immune privilege through disturbing the Fas/FasL system. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Transmetalation Reaction Enables the Synthesis of [ 18F]5-Fluorouracil from [ 18F]Fluoride for Human PET Imaging

DOE PAGES

Hoover, Andrew J.; Lazari, Mark; Ren, Hong; ...

2016-02-14

Translation of new 18F-fluorination reactions to produce radiotracers for human positron emission tomography (PET) imaging is rare because the chemistry must have useful scope and the process for 18F-labeled tracer production must be robust and simple to execute. The application of transition metal mediators has enabled impactful 18F-fluorination methods, but to date none of these reactions have been applied to produce a human-injectable PET tracer. In this article we present chemistry and process innovations that culminate in the first production from [ 18F]fluoride of human doses of [ 18F]5-fluorouracil, a PET tracer for cancer imaging in humans. Here, the firstmore » preparation of nickel σ-aryl complexes by transmetalation from arylboronic acids or esters was developed and enabled the synthesis of the [ 18F]5-fluorouracil precursor. Routine production of >10 mCi doses of [ 18F]5-fluorouracil was accomplished with a new instrument for azeotrope-free [ 18F]fluoride concentration in a process that leverages the tolerance of water in nickel-mediated 18F-fluorination.« less

A Transmetalation Reaction Enables the Synthesis of [18F]5-Fluorouracil from [18F]Fluoride for Human PET Imaging

PubMed Central

2016-01-01

Translation of new 18F-fluorination reactions to produce radiotracers for human positron emission tomography (PET) imaging is rare because the chemistry must have useful scope and the process for 18F-labeled tracer production must be robust and simple to execute. The application of transition metal mediators has enabled impactful 18F-fluorination methods, but to date none of these reactions have been applied to produce a human-injectable PET tracer. In this article we present chemistry and process innovations that culminate in the first production from [18F]fluoride of human doses of [18F]5-fluorouracil, a PET tracer for cancer imaging in humans. The first preparation of nickel σ-aryl complexes by transmetalation from arylboronic acids or esters was developed and enabled the synthesis of the [18F]5-fluorouracil precursor. Routine production of >10 mCi doses of [18F]5-fluorouracil was accomplished with a new instrument for azeotrope-free [18F]fluoride concentration in a process that leverages the tolerance of water in nickel-mediated 18F-fluorination. PMID:27087736

A Transmetalation Reaction Enables the Synthesis of [18F]5-Fluorouracil from [18F]Fluoride for Human PET Imaging.

PubMed

Hoover, Andrew J; Lazari, Mark; Ren, Hong; Narayanam, Maruthi Kumar; Murphy, Jennifer M; van Dam, R Michael; Hooker, Jacob M; Ritter, Tobias

2016-04-11

Translation of new 18 F-fluorination reactions to produce radiotracers for human positron emission tomography (PET) imaging is rare because the chemistry must have useful scope and the process for 18 F-labeled tracer production must be robust and simple to execute. The application of transition metal mediators has enabled impactful 18 F-fluorination methods, but to date none of these reactions have been applied to produce a human-injectable PET tracer. In this article we present chemistry and process innovations that culminate in the first production from [ 18 F]fluoride of human doses of [ 18 F]5-fluorouracil, a PET tracer for cancer imaging in humans. The first preparation of nickel σ-aryl complexes by transmetalation from arylboronic acids or esters was developed and enabled the synthesis of the [ 18 F]5-fluorouracil precursor. Routine production of >10 mCi doses of [ 18 F]5-fluorouracil was accomplished with a new instrument for azeotrope-free [ 18 F]fluoride concentration in a process that leverages the tolerance of water in nickel-mediated 18 F-fluorination.

A Transmetalation Reaction Enables the Synthesis of [ 18F]5-Fluorouracil from [ 18F]Fluoride for Human PET Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoover, Andrew J.; Lazari, Mark; Ren, Hong

Translation of new 18F-fluorination reactions to produce radiotracers for human positron emission tomography (PET) imaging is rare because the chemistry must have useful scope and the process for 18F-labeled tracer production must be robust and simple to execute. The application of transition metal mediators has enabled impactful 18F-fluorination methods, but to date none of these reactions have been applied to produce a human-injectable PET tracer. In this article we present chemistry and process innovations that culminate in the first production from [ 18F]fluoride of human doses of [ 18F]5-fluorouracil, a PET tracer for cancer imaging in humans. Here, the firstmore » preparation of nickel σ-aryl complexes by transmetalation from arylboronic acids or esters was developed and enabled the synthesis of the [ 18F]5-fluorouracil precursor. Routine production of >10 mCi doses of [ 18F]5-fluorouracil was accomplished with a new instrument for azeotrope-free [ 18F]fluoride concentration in a process that leverages the tolerance of water in nickel-mediated 18F-fluorination.« less

Fluoride availability in human saliva after dentifrice use: correlation with anticaries effects in rats.

PubMed

Afflitto, J; Schmid, R; Esposito, A; Toddywala, R; Gaffar, A

1992-04-01

Studies were conducted to determine fluoride availability in saliva after dentifrice use and to relate this parameter to cariostatic efficacy in rat caries experiments. Three dentifrices--two commercial formulations (Colgate Winterfresh Gel and Crest Dentifrice with Na-Sr-polyacrylate) and an Experimental dentifrice--were compared with respect to salivary fluoride availability. All of the dentifrices tested contained 1100 ppm F as sodium fluoride. It was observed that the Experimental dentifrice and Crest dentifrice with Sr-polyacrylate exhibited low salivary fluoride availability relative to the Colgate Winterfresh Gel. Salivary fluoride availability was assessed by means of two parameters: (a) the fluoride concentration in the dentifrice saliva slurry expectorated after brushing, and (b) the area under the curve of salivary F concentration vs. time for up to two hours after dentifrice use. In two rat caries experiments, it was observed that both the Experimental dentifrice and the Sr-polyacrylate dentifrice provided less cariostatic efficacy than the clinically validated Positive Control (Colgate Winterfesh Gel). Analysis of these data provides further evidence in support of the concept that fluoride availability in saliva following dentifrice use is an important parameter related to anticaries efficacy.

Preparation of Ti3C2 and Ti2C MXenes by fluoride salts etching and methane adsorptive properties

NASA Astrophysics Data System (ADS)

Liu, Fanfan; Zhou, Aiguo; Chen, Jinfeng; Jia, Jin; Zhou, Weijia; Wang, Libo; Hu, Qianku

2017-09-01

Here we reported the preparation of Ti3C2 MXene and Ti2C MXene by etching Ti3AlC2 and Ti2AlC with various fluoride salts in hydrochloric acid (HCl), including lithium fluoride (LiF), sodium fluoride (NaF), potassium fluoride (KF), and ammonium fluoride (NH4F). As-prepared Ti2C was further delaminated by urea, dimethylsulfoxide or ammonium hydroxide. Based on theoretical calculation and XPS results, the type of positive ions (Li+, Na+, K+, or NH4+) in etchant solution affect the surface structure of prepared MXene, which, in turn, affects the methane adsorption properties of MXene. The highest methane adsorption capacity is 8.5 cm3/g for Ti3C2 and 11.6 cm3/g for Ti2C. MXenes made from LiF and NH4F can absorb methane under high pressure and can keep methane under normal pressure, these MXenes may have important application on capturing methane or other hazardous gas molecules. MXenes made from NaF and KF can absorb methane under high pressure and release methane under low pressure. They can have important application in the adsorb storage of nature gas.

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

PubMed

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 < 0.05 with ≥90th percentile of control). High doses of ZnF2 also induced a significant Ccr decrease (p < 0.05 with ≤10th percentile of control). Low doses of NaF and mid-doses of ZnF2 induced polyuria (p < 0.05 with ≥90th percentile of control) while medium doses of NaF and low doses of KF also induced liver damage, as indicated by a high level of AST (p < 0.05 with ≥90th percentile of control). These findings suggest that oral administration of fluoride is a potential, dose-dependent risk factor of renal tubular damage.

18F-Fluoride PET/CT tumor burden quantification predicts survival in breast cancer.

PubMed

Brito, Ana E; Santos, Allan; Sasse, André Deeke; Cabello, Cesar; Oliveira, Paulo; Mosci, Camila; Souza, Tiago; Amorim, Barbara; Lima, Mariana; Ramos, Celso D; Etchebehere, Elba

2017-05-30

In bone-metastatic breast cancer patients, there are no current imaging biomarkers to identify which patients have worst prognosis. The purpose of our study was to investigate if skeletal tumor burden determined by 18F-Fluoride PET/CT correlates with clinical outcomes and may help define prognosis throughout the course of the disease. Bone metastases were present in 49 patients. On multivariable analysis, skeletal tumor burden was significantly and independently associated with overall survival (p < 0.0001) and progression free-survival (p < 0.0001). The simple presence of bone metastases was associated with time to bone event (p = 0.0448). We quantified the skeletal tumor burden on 18F-Fluoride PET/CT images of 107 female breast cancer patients (40 for primary staging and the remainder for restaging after therapy). Clinical parameters, primary tumor characteristics and skeletal tumor burden were correlated to overall survival, progression free-survival and time to bone event. The median follow-up time was 19.5 months. 18F-Fluoride PET/CT skeletal tumor burden is a strong independent prognostic imaging biomarker in breast cancer patients.

Kinetics of fluoride bioavailability in supernatant saliva and salivary sediment.

PubMed

Naumova, E A; Sandulescu, T; Bochnig, C; Gaengler, P; Zimmer, S; Arnold, W H

2012-07-01

The assessment of the fluoride kinetics in whole saliva as well as in the different salivary phases (supernatant saliva and sediment) is essential for the understanding of fluoride bioavailability. To assess the fluoride content, provided by sodium fluoride and amine fluoride, in the supernatant saliva and in salivary sediment. Seven trained volunteers were randomly attributed to 2 groups in a cross-over design and brushed their teeth in the morning for 3 min with a product containing either sodium fluoride or amine fluoride. Saliva was collected before, immediately after tooth brushing and 30, 120, and 360 min later and measured. The samples were centrifuged 10 min at 3024 × g. Fluoride content of the supernatant saliva and of the sediment was analysed using a fluoride sensitive electrode. All subjects repeated the study cycles 2 times, and statistical analyses were made using the nonparametric sign test for related samples, the Wilcoxon-Mann-Whitney-test for independent samples. There was a significant increase in fluoride immediately after tooth brushing in both groups in saliva and sediment. The distribution of fluoride between salivary sediment and supernatant saliva (ratio) varied considerably at the different collection times: decreased from 17.87 in baseline samples of saliva to 0.07 immediately and to 0.86 half an hour after tooth brushing in the sodium fluoride group and from 14.33 to 2.85 and to 3.09 in the amine fluoride group. Furthermore after 120 min and after 360 min after tooth brushing the ratio increased from 17.6 to 31.6 in the sodium fluoride group and from 20.5 to 25.76 in the amine fluoride group. No difference was found in the sediment-supernatant saliva ratio between the sodium fluoride and the amine fluoride groups 360 min after tooth brushing. For the assessment of fluoride kinetics in whole saliva it is necessary to pay attention to at least four factors: fluoride formulation, time after fluoride application, fluoride concentration in

Application of fluoridated hydroxyapatite thin film coatings using KrF pulsed laser deposition.

PubMed

Hashimoto, Yoshiya; Ueda, Mamoru; Kohiga, Yu; Imura, Kazuki; Hontsu, Shigeki

2018-06-08

Fluoridated hydroxyapatite (FHA) was investigated for application as an implant coating for titanium bone substitute materials in dental implants. A KrF pulsed excimer deposition technique was used for film preparation on a titanium plate. The compacts were ablated by laser irradiation at an energy density of 1 J/cm 2 on an area 1×1 mm 2 with the substrate at room temparature. Energydispersive spectrometric analysis of the FHA film revealed peaks of fluorine in addition to calcium and phosphorus. X-ray diffraction revealed the presence of crystalline FHA on the FHA film after a 10 h post annealing treatment at 450°C. The FHA film coating exhibited significant dissolution resistance to sodium phosphate buffer for up to 21 days, and favorable cell attachment of human mesenchymal stem cells compared with HA film. The results of this study suggest that FHA coatings are suitable for real-world implantation applications.

Oral fluoride retention after use of fluoride dentifrices.

PubMed

Duckworth, R M; Morgan, S N

1991-01-01

Fluoride is the only extensively clinically proven means of reducing dental caries. Despite a large body of epidemiological data on the effectiveness of fluoride, delivered in the form of dentifrices, mouthrinses, drinking water, etc., the precise mode of action of fluoride is not completely understood. The purpose of this paper is to report an investigation of the link between oral fluoride levels and applied fluoride dose from dentifrices. Human salivary fluoride clearance studies and equilibrium baseline studies of fluoride in saliva and plaque have been carried out with dentifrices which contained 1,000, 1,500 and 2,500 micrograms fluoride per gram as sodium monofluorophosphate. After a single brushing with a fluoride dentifrice, salivary fluoride decreased in two distinct phases: an initial rapid phase which lasted for 40-80 min, depending on the individual, and a second slow phase lasting for several hours. The latter phase is believed to be due to fluoride released from an oral fluoride reservoir. During regular repeated use of the test dentifrices, the equilibrium baseline fluoride concentration, attained in both saliva and plaque between one application and the next, increased significantly compared with placebo values. Such elevated baseline fluoride concentrations also increased with increasing Na2FPO3 content of the dentifrices. The present work supports the concept that labile fluoride, stored in an oral fluoride reservoir at the time of treatment application, may maintain a prolonged protective effect against dental caries.

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

PubMed

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.

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

USGS Publications Warehouse

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.

Lubricating Properties of Some Bonded Fluoride and Oxide Coatings for Temperature to 1500 F

NASA Technical Reports Server (NTRS)

Sliney, Harold E.

1960-01-01

The lubricating properties of some experimental ceramic coatings, diffusion-bonded fluoride coatings, and ceramic-bonded fluoride coatings were determined. The experiments were conducted in an air atmosphere at a sliding velocity of 430 feet per minute and at temperatures from 75 to 1500 F. Several ceramic coatings provided substantial reductions in friction coefficient and rider wear (compared with the unlubricated metals). For example, a cobaltous oxide (CoO) base coating gave friction coefficients of 0.24 to 0.36 within the temperature range of 75 to 1400 F; serious galling and welding of the metal surfaces were prevented. The friction coefficients were higher than the arbitrary maximum (0.2) usually considered for effective boundary lubrication. However, when a moderately high friction coefficient can be tolerated, this type of coating may be a useful antiwear composition. Diffusion-bonded calcium fluoride (CaF2) on Haynes Stellite 21 and on Inconel X gave friction coefficients of 0.1 to 0.2 at 1500 F. Endurance life was dependent on the thermal history of the coating; life improved with increased exposure time at elevated temperatures prior to running. Promising results were obtained with ceramic-bonded CaF2 on Inconel X. Effective lubrication and good adherence were obtained with a 3 to 1 ratio of CaF2 to ceramic. A very thin sintered and burnished film of CaF2 applied to the surface of this coating further improved lubrication, particularly above 1350 F. The friction coefficient was 0.2 at 500 F and decreased with increasing temperature to 0.06-at 1500 F. It was 0.25 at 75 F and 0.22 at 250 F.

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

PubMed

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.

Comparison of antimicrobial effects of titanium tetrafluoride, chlorhexidine, xylitol and sodium fluoride on streptococcus mutans: An in-vitro study

PubMed Central

Eskandarian, Tahereh; Motamedifar, Mohammad; Arasteh, Peyman; Eghbali, Seyed Sajad; Adib, Ali; Abdoli, Zahra

2017-01-01

Introduction No studies have yet documented the bactericidal effects of TiF4, and its role in the treatment of dental caries, and no definite protocol has been introduced to regulate its use. The aim of this study was to determine the antimicrobial/bactericidal effects of TiF4 on Streptococcus Mutans (S. Mutans) and to compare it with chlorhexidine (Chx), sodium fluoride (NaF) and xylitol. Methods This study was conducted at the Shiraz University of Medical Sciences microbiology laboratory during March 2015 to September 2015. In this in-vitro study, first a bacterial suspension was prepared and adjusted to a 0.5 McFarland standard (equivalent to 1×108 CFU/ml). The minimal inhibitory concentration (MIC) and minimal bactericidal concentrations (MBC) of TiF4, Chx, NaF and xylitol were assessed using broth microdilution assay and disk diffusion methods. In order to neutralize the acidic nature of TiF4, we used a sodium hydroxide preparation to obtain a pH of 7.2 and repeated all of the previous tests with the neutralized TiF4 solution. We reported the final results as percentages where appropriate. Results The MIC of TiF4, NaF and Chx for S. Mutans were 12.5%, 12.5% and 6.25%, respectively. At a concentration of 12.5% the inhibition zone diameters were 9 mm, 15mm and 14mm for TiF4, NaF and Chx, respectively. The MBC was 25%, 12.5% and 12.5% for TiF4, NaF and Chx, respectively. Xylitol failed to show any bactericidal or growth inhibitory effect in all of its concentrations. When we repeated the tests with an adjusted pH, identical results were obtained. Conclusion TiF4 solutions have anti-growth and bactericidal effects on S. Mutans at a concentration of 12.5% which is comparable with chlorhexidine and NaF, indicating the possible use of this solution in dental practice as an anti-cariogenic agent, furthermore the antimicrobial activity is unaffected by pH of the environment. PMID:28461883

Fluoride glass compositions

DOE Office of Scientific and Technical Information (OSTI.GOV)

El-Bayoumi, O.

1983-08-09

This invention relates to Fluoride-based glasses that exhibit a high degree of transparency throughout the near ultraviolet visible and mid infrared portions of the spectrum. The glasses are composed of MgF2 and ZnF2 as essential compositional ingredients together with at least two other metallic fluorides from the group of YbF3, ThF4, PbF2, A1F3 and MnF2.

Potential of nano-silver fluoride for tooth enamel caries prevention

NASA Astrophysics Data System (ADS)

Silva, Amitis V. C.; Mota, Cláudia C. B. O.; Teixeira, Joás. A.; Lins, Emery C.; Gomes, Anderson S. L.; Rosenblatt, Aronita

2018-02-01

This ex vivo study evaluated the efficiency of nano-silver fluoride (NSF) to enamel remineralization of deciduous teeth submitted to a high cariogenic challenge. 33 specimens of sound enamel were distributed into three groups: treated with sodium fluoride, with NSF, and deionized water. All specimens were submitted to microhardness test before chemical caries induction; post-induction of caries; and post-cariogenic challenge. The high cariogenic challenge was carried out in 14 daily cycles. There was no significant statistical difference (p=0.958) of enamel microhardness between NSFtreated and NaF-treated specimens. However, it presented significant difference between water-treated specimens and both NSF-treated and NaF-treated specimens (p=0.003).Furthermore, optical coherence tomography was employed for caries diagnosis, as it can be used in clinical environment.

Comparative Evaluation of Fluoridated Mouthwash and Sodium Bicarbonate in Management of Dentin Hypersensitivity: An In Vitro SEM Study.

PubMed

Rikame, Vasundhara; Doshi, Yogesh; Horowitz, Robert A; Kevadia-Shah, Vidhi; Shah, Mona

2018-01-01

Sodium bicarbonate (ie, baking soda) can be used as an adjunct to surgical periodontal therapy to reduce dentin hypersensitivity (DH). Sodium bicarbonate mouthwash has numerous appealing attributes, including high availability, low cost, low abrasivity, water solubility, buffering capability, and, in high concentrations, antimicrobial properties. It is also safe to use. The primary underlying cause of DH is open dentinal tubules from loss of either cementum or enamel. The aim of this in vitro study was to evaluate, through scanning electron microscopic examination, the effect of sodium bicarbonate on dentinal tubule occlusion and compare it with that of fluoridated mouthwash.

Fluoride-containing nanoporous calcium-silicate MTA cements for endodontics and oral surgery: early fluorapatite formation in a phosphate-containing solution.

PubMed

Gandolfi, M G; Taddei, P; Siboni, F; Modena, E; Ginebra, M P; Prati, C

2011-10-01

To test the chemical-physical properties and apatite-forming ability of experimental fluoride-doped calcium silicate cements designed to create novel bioactive materials for use in endodontics and oral surgery. A thermally treated calcium silicate cement (wTC) containing CaCl(2) 5%wt was modified by adding NaF 1%wt (FTC) or 10%wt (F10TC). Cements were analysed by environmental scanning electron microscopy with energy-dispersive X-ray analysis, IR and micro-Raman spectroscopy in wet conditions immediately after preparation or after ageing in a phosphate-containing solution (Dulbecco's phosphate-buffered saline). Calcium and fluoride release and pH of the storage solution were measured. The results obtained were analysed statistically (Tukey's HSD test and two-way anova). The formation of calcium phosphate precipitates (spherulites) was observed on the surface of 24 h-aged cements and the formation of a thick bone-like B-type carbonated apatite layer (biocoating) on 28 day-aged cements. The rate of apatite formation was FTC>F10TC>wTC. Fluorapatite was detected on FTC and F10TC after 1 day of ageing, with a higher fluoride content on F10TC. All the cements released calcium ions. At 5 and 24 h, the wTC had the significantly highest calcium release (P<0.001) that decreased significantly over the storage time. At 3-28 days, FTC and F10TC had significantly higher calcium release than wTC (P<0.05). The F10TC had the significantly highest fluoride release at all times (P<0.01) that decreased significantly over storage time. No significant differences were observed between FTC and wTC. All the cements had a strong alkalinizing activity (OH(-) release) that remained after 28 days of storage. The addition of sodium fluoride accelerated apatite formation on calcium silicate cements. Fluoride-doped calcium silicate cements had higher bioactivity and earlier formation of fluorapatite. Sodium fluoride may be introduced in the formulation of mineral trioxide aggregate cements to

Mild hydrothermal crystal growth of new uranium(IV) fluorides, Na3.13Mg1.43U6F30 and Na2.50Mn1.75U6F30: Structures, optical and magnetic properties

NASA Astrophysics Data System (ADS)

Yeon, Jeongho; Smith, Mark D.; Tapp, Joshua; Möller, Angela; zur Loye, Hans-Conrad

2016-04-01

Two new uranium(IV) fluorides, Na3.13Mg1.43U6F30 (1) and Na2.50Mn1.75U6F30 (2), were synthesized through an in situ mild hydrothermal route, and were structurally characterized by single crystal X-ray diffraction. The compounds exhibit complex crystal structures composed of corner- or edge-shared UF9 and MF6 (M=Mg, Mn) polyhedra, forming hexagonal channels in the three-dimensional framework, in which ordered or disordered divalent metal and sodium atoms reside. The large hexagonal voids contain the nearly regular M(II)F6 octahedra and sodium ions, whereas the small hexagonal cavities include M(II) and sodium ions on a mixed-occupied site. Magnetic susceptibility measurements yielded effective magnetic moments of 8.36 and 11.6 μB for 1 and 2, respectively, confirming the presence and oxidation states of U(IV) and Mn(II). The large negative Weiss constants indicate the spin gap between a triplet and a singlet state in the U(IV). Magnetization data as a function of applied fields revealed that 2 exhibits paramagnetic behavior due to the nonmagnetic singlet ground state of U(IV) at low temperature. UV-vis diffuse reflectance and X-ray photoelectron spectroscopy data were also analyzed.

Reusable electrochemical cell for rapid separation of [18F]fluoride from [18O]water for flow-through synthesis of 18F-labeled tracers

PubMed Central

Sadeghi, Saman; Liang, Vincent; Cheung, Shilin; Woo, Suh; Wu, Curtis; Ly, Jimmy; Deng, Yuliang; Eddings, Mark; van Dam, R. Michael

2015-01-01

A brass-platinum electrochemical micro flow cell was developed to extract [18F]fluoride from an aqueous solution and release it into an organic based solution, suitable for subsequent radio-synthesis, in a fast and reliable manner. This cell does not suffer electrode erosion and is thus reusable while operating faster by enabling increased voltages. By optimizing temperature, trapping and release potentials, flow rates, and electrode materials, an overall [18F]fluoride trapping and release efficiency of 84±5% (n=7) was achieved. X-ray photoelectron spectroscopy (XPS) was used to analyze electrode surfaces of various metal-metal systems and the findings were correlated with the performance of the electrochemical cell. To demonstrate the reactivity of the released [18F]fluoride, the cell was coupled to a flow-through reactor and automated synthesis of [18F]FDG with a repeatable decay-corrected yield of 56±4% (n=4) was completed in <15 min. A multi-human dose of 5.92 GBq [18F]FDG was also demonstrated. PMID:23474380

MOLTEN FLUORIDE NUCLEAR REACTOR FUEL

DOEpatents

Barton, C.J.; Grimes, W.R.

1960-01-01

Molten-salt reactor fuel compositions consisting of mixtures of fluoride salts are reported. In its broadest form, the composition contains an alkali fluoride such as sodium fluoride, zirconium tetrafluoride, and a uranium fluoride, the latter being the tetrafluoride or trifluoride or a mixture of the two. An outstanding property of these fuel compositions is a high coeffieient of thermal expansion which provides a negative temperature coefficient of reactivity in reactors in which they are used.

Emission beyond 4  μm and mid-infrared lasing in a dysprosium-doped indium fluoride (InF3) fiber.

PubMed

Majewski, Matthew R; Woodward, Robert I; Carreé, Jean-Yves; Poulain, Samuel; Poulain, Marcel; Jackson, Stuart D

2018-04-15

Optical emission from rare-earth-doped fluoride fibers has thus far been limited to less than 4 μm. We extend emission beyond this limit by employing an indium fluoride (InF 3 ) glass fiber as the host, which exhibits an increased infrared transparency over commonly used zirconium fluoride (ZBLAN). Near-infrared pumping of a dysprosium-doped InF 3 fiber results in broad emission centered around 4.3 μm, representing the longest emission yet achieved from a fluoride fiber. The first laser emission in an InF 3 fiber is also demonstrated from the 3 μm dysprosium transition. Finally, a frequency domain excited state lifetime measurement comparison between fluoride hosts suggests that multiphonon effects are significantly reduced in indium fluoride fiber, paving the way to more efficient, longer wavelength lasers compared to ZBLAN fibers.

Fluoride content of infant formulas prepared with deionized, bottled mineral and fluoridated drinking water.

PubMed

Buzalaf, M A; Granjeiro, J M; Damante, C A; de Ornelas, F

2001-01-01

Usually infant milk formula is the major source of fluoride in infancy. Fluoride concentrations in ten samples of powdered milk formulas, prepared with deionized, bottled mineral, and fluoridated drinking water were determined after HMDS-facilitated diffusion, using a fluoride ion specific electrode(Orion 9609). Fluoride concentrations ranged from 0.01 to 0.75 ppm; from 0.02 to 1.37 ppm and from 0.91 to 1.65 ppm for formulas prepared with deionized, bottled mineral (0.02 to 0.69 ppm F) and fluorinated drinking water (0.9 ppm F), respectively. Possible fluoride ingestion per Kg body mass ws estimated. With deionized water, only the soy-based- formulas should provide a daily fluoride intake of above the suggested threshold for fluorosis. With water containing 0.9 ppm F, however, all of them would provide it. Hence, to limit fluoride intakes to amounts <0.1 mg/kg/day, it is necessary to avoid use fo fluoridated water (around 1 ppm) to dilute powdered infant formulas.

Effect of the addition of MgF2 and NaF on the thermal, optical and magnetic properties of fluoride glasses for sensing applications

NASA Astrophysics Data System (ADS)

Wang, Yujie; Wang, Shuangbao; Deng, Saifu; Liu, Jianting; Zhang, Jiahui

2017-10-01

Optical glass was very important for the development of optical fiber sensor. In this paper, a new type fluoride glass of ZrF4-BaF2-AlF3-NaF-MgF2(ZBANM) was synthesized for sensing application which has low loss and high magneto-optical coefficient, and it was found that the glass system had at least 60% transmittance from 3.5 μm to 7 μm and smallest verdet constant of 4.628E-5/(rad A-1) at 632.8 nm. The relationship among the compositions of sample glass with its thermal property, optical absorptivity and magnetic-optical coefficients was respectively studied with Thermal Gravimetric-Differential Thermal Analyzer, Fourier Transform infrared spectroscopy and a home-made magneto optical bench. The study indicated that transmittance of fluoride glass structure had been obviously improved after moderate content of Mg2+ and Na+ was doped. Simultaneously, with the molar ratio of alkaline-earth ions Mg increased, the Verdet constant of fluoride glass was increased. And the glass structure with composition of 48%ZrF4-24%BaF2-6%AlF3-8%NaF-14%MgF2 exhibited a small molar absorptivity and the largest Verdet constant of 2.853E-4/(rad A-1).

The effect on human salivary fluoride concentration of consuming fluoridated salt-containing baked food items.

PubMed

Macpherson, L M; Stephen, K W

2001-10-01

Salt fluoridation is recognised world-wide as a proven and viable alternative means of consumer choice-related, community-based fluoridation where water fluoridation is either technically or politically impossible. However, as most salt consumed is contained within cooked food products, rather than sprinkled over prepared food at the table, the purpose of this study was to investigate the effects on salivary fluoride concentration of consuming baked food products prepared with 250 and 350 ppm fluoridated salt (as KF). Six food items were baked with (a) normal non-fluoridated salt, (b) 250 mg F/kg salt and (c) 350 mg F/kg salt. Eleven adult volunteers consumed these foodstuffs on separate occasions and salivary samples were collected for fluoride analyses before and at various time points (1-30 min) after eating. For most foodstuffs, small but significant increases in salivary fluoride concentration occurred for at least 5 min after ingestion of the fluoridated salt-containing items. Salivary fluoride concentrations peaked 1 or 2 min after eating, with highest values for the six test foods ranging from 0.16 to 0.25 ppm F, and from 0.18 to 0.44 ppm F for the 250 and 350 mg F/kg salt products, respectively. In all cases, salivary fluoride concentrations had returned to baseline by 20 min. The clinical significance of such small, short-term increases in salivary fluoride is uncertain, but the findings suggest that a more frequent intake of foods with fluoridated salt substituted for normal salt could help sustain slightly elevated salivary fluoride concentrations for more prolonged periods of the day, and might thus potentiate the cariostatic effects of saliva on tooth mineral.

Synthesis, structure and reactivity of a terminal magnesium fluoride compound, [TpBut,Me]MgF: hydrogen bonding, halogen bonding and C-F bond formation.

PubMed

Rauch, Michael; Ruccolo, Serge; Mester, John Paul; Rong, Yi; Parkin, Gerard

2016-01-01

The bulky tris(3- tert -butyl-5-pyrazolyl)hydroborato ligand, [Tp Bu t ,Me ], has been employed to obtain the first structurally characterized example of a molecular magnesium compound that features a terminal fluoride ligand, namely [Tp Bu t ,Me ]MgF, via the reaction of [Tp Bu t ,Me ]MgMe with Me 3 SnF. The chloride, bromide and iodide complexes, [Tp Bu t ,Me ]MgX (X = Cl, Br, I), can also be obtained by an analogous method using Me 3 SnX. The molecular structures of the complete series of halide derivatives, [Tp Bu t ,Me ]MgX (X = F, Cl, Br, I) have been determined by X-ray diffraction. In each case, the Mg-X bond lengths are shorter than the sum of the covalent radii, thereby indicating that there is a significant ionic component to the bonding, in agreement with density functional theory calculations. The fluoride ligand of [Tp Bu t ,Me ]MgF undergoes halide exchange with Me 3 SiX (X = Cl, Br, I) to afford [Tp Bu t ,Me ]MgX and Me 3 SiF. The other halide derivatives [Tp Bu t ,Me ]MgX undergo similar exchange reactions, but the thermodynamic driving forces are much smaller than those involving fluoride transfer, a manifestation of the often discussed silaphilicity of fluorine. In accord with the highly polarized Mg-F bond, the fluoride ligand of [Tp Bu t ,Me ]MgF is capable of serving as a hydrogen bond and halogen bond acceptor, such that it forms adducts with indole and C 6 F 5 I. [Tp Bu t ,Me ]MgF also reacts with Ph 3 CCl to afford Ph 3 CF, thereby demonstrating that [Tp Bu t ,Me ]MgF may be used to form C-F bonds.

Clinical evaluation of the efficacy of fluoride adhesive tape (F-PVA) in reducing dentin hypersensitivity.

PubMed

Lee, Sang-Ho; Lee, Nan-Young; Lee, In-Hwa

2013-06-01

To evaluate the in vivo effectiveness of an experimental 2.26% fluoride polyvinyl alcohol (F-PVA) tape in reducing dentin hypersensitivity. 30 healthy men and women (total of 79 teeth) in their third decade of life with dentin hypersensitivity were enrolled in this study. The subjects were divided into four groups: three experimental groups were treated with fluoride agents (F-PVA tape, Vanish varnish, and ClinPro XT varnish), and a control group was treated with gelatin as a placebo. Each fluoride agent was applied according to the manufacturer's instructions. Stimulation was applied to the subjects' teeth using compressed air and ice sticks before applying the agent, as well as at 3 days and 4, 8, and 12 weeks after applying the agent. The degree of pain was measured using a visual analogue scale (VAS). The VAS scores were significantly (P < 0.05) decreased at 3 days and at 4, 8, and 12 weeks from baseline in both the air stream and ice stick tests. The reduction in the VAS scores for the three fluoride agents was decreased 8 weeks after their application. The F-PVA tape was found to be more effective for dentin hypersensitivity than the Vanish varnish and ClinPro XT varnish at 4 and 8 weeks of the examination period.

Selective separation of phosphate and fluoride from semiconductor wastewater.

PubMed

Warmadewanthi, B; Liu, J C

2009-01-01

Hydrofluoric acid (HF) and phosphoric acid (H(3)PO(4)) are widely used in semiconductor industry for etching and rinsing purposes. Consequently, significant amount of wastewater containing phosphate and fluoride is generated. Selective separation of phosphate and fluoride from the semiconductor wastewater, containing 936 mg/L of fluoride, 118 mg/L of phosphate, 640 mg/L of sulfate, and 26.7 mg/L of ammonia, was studied. Chemical precipitation and flotation reactions were utilized in the two-stage treatment processes. The first-stage reaction involved the addition of magnesium chloride (MgCl(2)) to induce selective precipitation of magnesium phosphate. The optimal condition was pH 10 and molar ratio, [Mg(2 + )]/[(PO(4) (3-))], of 3:1, and 66.2% of phosphate was removed and recovered as bobierrite (Mg(3)(PO(4))(2).8H(2)O). No reaction was found between MgCl(2) and fluoride. Calcium chloride (CaCl(2)) was used in the second-stage reaction to induce precipitation of calcium fluoride and calcium phosphate. The optimum molar ratio, [Ca(2 + )]/[F(-)], was 0.7 at pH 10, and residual fluoride concentration of 10.7 mg/L and phosphate concentration of lower than 0.5 mg/L was obtained. Thermodynamic equilibrium was modeled with PHREEQC and compared with experimental results. Sodium dodecylsulfate (SDS) was an effective collector for subsequent solid-liquid removal via dispersed air flotation (DiAF). The study demonstrated that phosphate can be selectively recovered from the wastewater. Potential benefits include recovery of phosphate for reuse, lower required dosage of calcium for fluoride removal, and less amount of CaF(2) sludge.

An in vitro evaluation of a novel high fluoride daily mouthrinse using a combination of microindentation, 3D profilometry and DSIMS.

PubMed

Gracia, Louise H; Rees, Gareth D; Brown, Alan; Fowler, Christabel E

2010-11-01

Firstly, to evaluate the in vitro anti-erosion efficacy of a new mouthrinse formulation containing 450 ppm fluoride using profilometry and microindentation. Secondly, to compare fluoride uptake by erosive lesions from two mouthrinses containing different fluoride sources using dynamic secondary ion mass spectrometry (DSIMS). Sound human enamel was treated (60s) with mouthrinses containing different fluoride concentrations, then immersed in 1.0% citric acid pH 3.8 for either 300 s or 30 min (Studies 1 & 2 respectively). Surface roughness and erosion depth were determined profilometrically in Study 1, and surface microhardness monitored as a function of time in Study 2. Lesion rehardening was monitored following a 60 s rinse and immersion in artificial saliva for 48 h (Study 3), whilst Study 4 employed DSIMS to quantify fluoride uptake by lesions treated (60s) with rinses containing either sodium fluoride (NaF) or a NaF/Olaflur/stannous chloride combination. The test rinse (450 ppm fluoride) suppressed surface roughening and bulk tissue loss versus all comparators (p< 0.0001), except in the latter measure for the rinse containing 112 ppm fluoride. The test rinse significantly inhibited enamel surface softening versus the three rinses containing ≤112 ppm fluoride (as NaF) at 30 min (p<0.05), but was not statistically significantly different from the 225 ppm fluoride rinse. The test rinse conferred statistically superior lesion rehardening versus all comparators at both 24 and 48 h (p< 0.0001). DSIMS demonstrated statistically significantly higher fluoride uptake by incipient erosive lesions treated with the test rinse versus the NaF/Olaflur/stannous rinse. Anti-erosion efficacy was positively correlated with fluoride concentration. DSIMS showed significantly higher levels of fluoride uptake by incipient erosive lesions treated with the 450 ppm fluoride rinse versus the NaF/Olaflur/stannous rinse. Copyright © 2010 Elsevier Ltd. All rights reserved.

Mechanism of Electrophilic Fluorination with Pd(IV): Fluoride Capture and Subsequent Oxidative Fluoride Transfer†, ‡

PubMed Central

Brandt, Jochen R.; Lee, Eunsung; Boursalian, Gregory B.

2013-01-01

Electrophilic fluorinating reagents derived from fluoride are desirable for the synthesis of 18F-labeled molecules for positron emission tomography (PET). Here, we study the mechanism by which a Pd(IV)-complex captures fluoride and subsequently transfers it to nucleophiles. The intermediate Pd(IV)-F is formed with high rates even at the nano- to micromolar fluoride concentrations typical for radiosyntheses with 18F due to fast formation of an outer-sphere complex between fluoride and Pd(IV). The subsequent fluorine transfer from the Pd(IV)-F complex is proposed to proceed through an unusual SET/fluoride transfer/SET mechanism. The findings detailed in this manuscript provide a theoretical foundation suitable for addressing a more general approach for electrophilic fluorination with high specific activity 18F PET imaging. PMID:24376910

Bone formation in ankylosing spondylitis during anti-tumour necrosis factor therapy imaged by 18F-fluoride positron emission tomography

PubMed Central

Bruijnen, Stefan T G; Verweij, Nicki J F; van Duivenvoorde, Leonie M; Bravenboer, Nathalie; Baeten, Dominique L P; van Denderen, Christiaan J; van der Horst-Bruinsma, Irene E; Voskuyl, Alexandre E; Custers, Martijn; van de Ven, Peter M; Bot, Joost C J; Boden, Bouke J H; Lammertsma, Adriaan A; Hoekstra, Otto S H; Raijmakers, Pieter G H M; van der Laken, Conny J

2018-01-01

Abstract Objectives Excessive bone formation is an important hallmark of AS. Recently it has been demonstrated that axial bony lesions in AS patients can be visualized using 18F-fluoride PET-CT. The aim of this study was to assess whether 18F-fluoride uptake in clinically active AS patients is related to focal bone formation in spine biopsies and is sensitive to change during anti-TNF treatment. Methods Twelve anti-TNF-naïve AS patients [female 7/12; age 39 years (SD 11); BASDAI 5.5 ± 1.1] were included. 18 F-fluoride PET-CT scans were performed at baseline and in two patients, biopsies were obtained from PET-positive and PET-negative spine lesions. The remaining 10 patients underwent a second 18F-fluoride PET-CT scan after 12 weeks of anti-TNF treatment. PET scans were scored visually by two blinded expert readers. In addition, 18F-fluoride uptake was quantified using the standardized uptake value corrected for individual integrated whole blood activity concentration (SUVAUC). Clinical response to anti-TNF was defined according to a ⩾ 20% improvement in Assessment of SpondyloArthritis international Society criteria at 24 weeks. Results At baseline, all patients showed at least one axial PET-positive lesion. Histological analysis of PET-positive lesions in the spine confirmed local osteoid formation. PET-positive lesions were found in the costovertebral joints (43%), facet joints (23%), bridging syndesmophytes (20%) and non-bridging vertebral lesions (14%) and in SI joints (75%). After 12 weeks of anti-TNF treatment, 18F-fluoride uptake in clinical responders decreased significantly in the costovertebral (mean SUVAUC −1.0; P < 0.001) and SI joints (mean SUVAUC −1.2; P = 0.03) in contrast to non-responders. Conclusions 18F-fluoride PET-CT identified bone formation, confirmed by histology, in the spine and SI joints of AS patients and demonstrated alterations in bone formation during anti-TNF treatment. PMID:29329443

Bone formation in ankylosing spondylitis during anti-tumour necrosis factor therapy imaged by 18F-fluoride positron emission tomography.

PubMed

Bruijnen, Stefan T G; Verweij, Nicki J F; van Duivenvoorde, Leonie M; Bravenboer, Nathalie; Baeten, Dominique L P; van Denderen, Christiaan J; van der Horst-Bruinsma, Irene E; Voskuyl, Alexandre E; Custers, Martijn; van de Ven, Peter M; Bot, Joost C J; Boden, Bouke J H; Lammertsma, Adriaan A; Hoekstra, Otto S H; Raijmakers, Pieter G H M; van der Laken, Conny J

2018-04-01

Excessive bone formation is an important hallmark of AS. Recently it has been demonstrated that axial bony lesions in AS patients can be visualized using 18F-fluoride PET-CT. The aim of this study was to assess whether 18F-fluoride uptake in clinically active AS patients is related to focal bone formation in spine biopsies and is sensitive to change during anti-TNF treatment. Twelve anti-TNF-naïve AS patients [female 7/12; age 39 years (SD 11); BASDAI 5.5 ± 1.1] were included. 18 F-fluoride PET-CT scans were performed at baseline and in two patients, biopsies were obtained from PET-positive and PET-negative spine lesions. The remaining 10 patients underwent a second 18F-fluoride PET-CT scan after 12 weeks of anti-TNF treatment. PET scans were scored visually by two blinded expert readers. In addition, 18F-fluoride uptake was quantified using the standardized uptake value corrected for individual integrated whole blood activity concentration (SUVAUC). Clinical response to anti-TNF was defined according to a ⩾ 20% improvement in Assessment of SpondyloArthritis international Society criteria at 24 weeks. At baseline, all patients showed at least one axial PET-positive lesion. Histological analysis of PET-positive lesions in the spine confirmed local osteoid formation. PET-positive lesions were found in the costovertebral joints (43%), facet joints (23%), bridging syndesmophytes (20%) and non-bridging vertebral lesions (14%) and in SI joints (75%). After 12 weeks of anti-TNF treatment, 18F-fluoride uptake in clinical responders decreased significantly in the costovertebral (mean SUVAUC -1.0; P < 0.001) and SI joints (mean SUVAUC -1.2; P = 0.03) in contrast to non-responders. 18F-fluoride PET-CT identified bone formation, confirmed by histology, in the spine and SI joints of AS patients and demonstrated alterations in bone formation during anti-TNF treatment.

Arresting simulated dentine caries with adjunctive application of silver nitrate solution and sodium fluoride varnish: an in vitro study.

PubMed

Zhao, Irene Shuping; Mei, May Lei; Li, Quan-Li; Lo, Edward Chin Man; Chu, Chun-Hung

2017-08-01

The aim of this in vitro study was to assess the ability of silver nitrate solution, followed by sodium fluoride varnish, to arrest caries. Dentine slices were prepared and demineralised. Each slice was cut into three specimens for three groups (SF, SDF and W). Specimens of the SF group received topical application of 25% silver nitrate solution followed by 5% sodium fluoride varnish. The SDF group received topical application of 38% silver diamine fluoride solution (positive control). Specimens of the W group received deionised water (negative control). All specimens were subjected to pH cycling for 8 days. Dentine surface morphology, crystal characteristics, carious lesion depth and collagen matrix degradation were evaluated by scanning electron microscopy, X-ray diffraction, X-ray microtomography and spectrophotometry with a hydroxyproline assay. Scanning electron microscopy showed that dentine collagen was exposed in group W, but not in groups SF and SDF, while clusters of granular spherical grains were formed in groups SF and SDF. The mean lesion depths (±standard deviation) of groups SF, SDF and W were 128 ± 19, 135 ± 24 and 258 ± 53 μm, respectively (SF, SDF < W; P < 0.001). The X-ray diffraction analysis indicated that silver chloride was formed in groups SF and SDF. The concentration of hydroxyproline released from the dentine matrix was significantly lower in groups SF and SDF than in group W (P < 0.05). The results of this in vitro study indicate that the use of silver nitrate solution and sodium fluoride varnish is effective in inhibiting dentine demineralisation and dentine collagen degradation. © 2017 FDI World Dental Federation.

Fluoride varnishes containing calcium glycerophosphate: fluoride uptake and the effect on in vitro enamel erosion.

PubMed

Carvalho, Thiago S; Bönecker, Marcelo; Altenburger, Markus J; Buzalaf, Marília A R; Sampaio, Fabio C; Lussi, Adrian

2015-07-01

Calcium glycerophosphate (CaGP) was added to fluoride varnishes to analyze their preventive effect on initial enamel erosion and fluoride uptake: potassium hydroxide (KOH)-soluble and KOH-insoluble fluoride bound to enamel. This study was carried out in two parts. Part 1: 108 enamel samples were randomly distributed into six varnish groups: base varnish (no active ingredients); Duraphat® (2.26%NaF); Duofluorid® (5.63%NaF/CaF2); experimental varnish 1 (1%CaGP/5.63 NaF/CaF2); experimental varnish 2 (5%CaGP/5.63%NaF/CaF2); and no varnish. Cyclic demineralization (90 s; citric acid, pH = 3.6) and remineralization (4 h) was made once a day, for 3 days. Change in surface microhardness (SMH) was measured. Part 2: 60 enamel samples were cut in half and received no varnish (control) or a layer of varnish: Duraphat®, Duofluorid®, experimental varnishes 1 and 2. Then, KOH-soluble and KOH-insoluble fluoride were analyzed using an electrode. After cyclic demineralization, SMH decreased in all samples, but Duraphat® caused less hardness loss. No difference was observed between varnishes containing CaGP and the other varnishes. Similar amounts of KOH-soluble and insoluble fluoride was found in experimental varnish 1 and Duofluorid®, while lower values were found for experimental varnish 2 and Duraphat®. The addition of CaGP to fluoride varnishes did not increase fluoride bound to enamel and did not enhance their protection against initial enamel erosion. We observe that the fluoride varnishes containing CaGP do not promote greater amounts of fluoride bound to enamel and that fluoride bound to enamel may not be closely related to erosion prevention.

High-pressure synthesis and characterization of the first cerium fluoride borate CeB{sub 2}O{sub 4}F

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hinteregger, Ernst; Wurst, Klaus; Tribus, Martina

2013-08-15

CeB{sub 2}O{sub 4}F is the first cerium fluoride borate, which is exclusively built up of one-dimensional, infinite chains of condensed trigonal-planar [BO{sub 3}]{sup 3−} groups. This new cerium fluoride borate was synthesized under high-pressure/high-temperature conditions of 0.9 GPa and 1450 °C in a Walker-type multianvil apparatus. The compound crystallizes in the orthorhombic space group Pbca (No. 61) with eight formula units and the lattice parameters a=821.63(5), b=1257.50(9), c=726.71(6) pm, V=750.84(9) Å{sup 3}, R{sub 1}=0.0698, and wR{sub 2}=0.0682 (all data). The structure exhibits a 9+1 coordinated cerium ion, one three-fold coordinated fluoride ion and a one-dimensional chain of [BO{sub 3}]{sup 3−}more » groups. Furthermore, IR spectroscopy, Electron Micro Probe Analysis and temperature-dependent X-ray powder diffraction measurements were performed. - Graphical abstract: A new rare-earth fluoride borate CeB{sub 2}O{sub 4}F could be synthesized under high-pressure/high-temperature conditions of 0.9 °GPa and 1450 °Cin a Walker-type multianvil apparatus. The crystal structure represents a new structure type in the class of rare-earth fluoride borates. The structure exhibits a 9+1 coordinated cerium ion, one three-fold coordinated fluoride ion and a one-dimensional chain of [BO{sub 3}]{sup 3−} groups. A closer view on the ac-plane shows an interesting wave-like modulation of the borate chains. Highlights: • CeB{sub 2}O{sub 4}F is the first fluoride borate exclusively built up of one-dimensional, infinite chains of condensed trigonal-planar [BO{sub 3}]{sup 3−} groups. • CeB{sub 2}O{sub 4}F is the first cerium fluoride borate. • High-pressure conditions were necessary to synthesize CeB{sub 2}O{sub 4}F.« less

High-Dose Fluoride Impairs the Properties of Human Embryonic Stem Cells via JNK Signaling.

PubMed

Fu, Xin; Xie, Fang-Nan; Dong, Ping; Li, Qiu-Chen; Yu, Guang-Yan; Xiao, Ran

2016-01-01

Fluoride is a ubiquitous natural substance that is often used in dental products to prevent dental caries. The biphasic actions of fluoride imply that excessive systemic exposure to fluoride can cause harmful effects on embryonic development in both animal models and humans. However, insufficient information is available on the effects of fluoride on human embryonic stem cells (hESCs), which is a novel in vitro humanized model for analyzing the embryotoxicities of chemical compounds. Therefore, we investigated the effects of sodium fluoride (NaF) on the proliferation, differentiation and viability of H9 hESCs. For the first time, we showed that 1 mM NaF did not significantly affect the proliferation of hESCs but did disturb the gene expression patterns of hESCs during embryoid body (EB) differentiation. Higher doses of NaF (2 mM and above) markedly decreased the viability and proliferation of hESCs. The mode and underlying mechanism of high-dose NaF-induced cell death were further investigated by assessing the sub-cellular morphology, mitochondrial membrane potential (MMP), caspase activities, cellular reactive oxygen species (ROS) levels and activation of mitogen-activated protein kinases (MAPKs). High-dose NaF caused the death of hESCs via apoptosis in a caspase-mediated but ROS-independent pathway, coupled with an increase in the phospho-c-Jun N-terminal kinase (p-JNK) levels. Pretreatment with a p-JNK-specific inhibitor (SP600125) could effectively protect hESCs from NaF-induced cell death in a concentration- and time-dependent manner. These findings suggest that NaF might interfere with early human embryogenesis by disturbing the specification of the three germ layers as well as osteogenic lineage commitment and that high-dose NaF could cause apoptosis through a JNK-dependent pathway in hESCs.

Extracting Silicon From Sodium-Process Products

NASA Technical Reports Server (NTRS)

Kapur, V.; Sanjurjo, A.; Sancier, K. M.; Nanis, L.

1982-01-01

New acid leaching process purifies silicon produced in reaction between silicon fluoride and sodium. Concentration of sodium fluoride and other impurities and byproducts remaining in silicon are within acceptable ranges for semi-conductor devices. Leaching process makes sodium reduction process more attractive for making large quantities of silicon for solar cells.

Corrosive effects of fluoride on titanium under artificial biofilm.

PubMed

Fukushima, Azusa; Mayanagi, Gen; Sasaki, Keiichi; Takahashi, Nobuhiro

2018-01-01

This study aimed to investigate the effect of sodium fluoride (NaF) on titanium corrosion using a biofilm model, taking environmental pH into account. Streptococcus mutans cells were used as the artificial biofilm, and pH at the bacteria-titanium interface was monitored after the addition of 1% glucose with NaF (0, 225 or 900ppmF) at 37°C for 90min. In an immersion test, the titanium samples were immersed in the NaF solution (0, 225 or 900ppm F; pH 4.2 or 6.5) for 30 or 90min. Before and after pH monitoring or immersion test, the electrochemical properties of the titanium surface were measured using a potentiostat. The amount of titanium eluted into the biofilm or the immersion solution was measured using inductively coupled plasma mass spectrometry. The color difference (ΔE*ab) and gloss of the titanium surface were determined using a spectrophotometer. After incubation with biofilm, pH was maintained at around 6.5 in the presence of NaF. There was no significant change in titanium surface and elution, regardless of the concentration of NaF. After immersion in 900ppm NaF solution at pH 4.2, corrosive electrochemical change was induced on the surface, titanium elution and ΔE*ab were increased, and gloss was decreased. NaF induces titanium corrosion in acidic environment in vitro, while NaF does not induce titanium corrosion under the biofilm because fluoride inhibits bacterial acid production. Neutral pH fluoridated agents may still be used to protect the remaining teeth, even when titanium-based prostheses are worn. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Effects of polyphosphates and fluoride on hydroxyapatite dissolution: A pH-stat investigation.

PubMed

do Amaral, Jackeline Gallo; Delbem, Alberto Carlos Botazzo; Pessan, Juliano Pelim; Manarelli, Michele Mauricio; Barbour, Michele E

2016-03-01

This study investigated the immediate and sustained effect of sodium trimetaphosphate (TMP) and sodium hexametaphosphate (HMP) associated or not with fluoride (F) on hydroxyapatite (HA) dissolution using an erosion-like model, considering as well as the influence of salivary coating. Baseline dissolution rates were determined for HA discs using a pH-stat system. In the first set of experiments, HA discs were treated with 1100μgF/mL, 1% or 8% of HMP, 1% or 8% of TMP and 1100μgF/mL associated with 1% or 8% of HMP or TMP, totaling 9 groups (n=8). In a second phase, HA discs were kept in pooled human saliva at 37°C for 2h before treatment with deionised water and 1100μgF/mL associated with 1% or 8% of HMP or TMP, totaling 5 groups (n=8). The post-treatment dissolution rate was determined from three consecutive 30-min assays. Data were analysed using 2 and 3-way ANOVA followed by Fisher and Holm-Sidak methods, respectively (α=0.05). All test solutions promoted reduction in HA dissolution rate when compared to baseline control in the first post-treatment run (p<0.001). However, a synergistic effect was only observed between fluoride and 1% HMP. Moreover, the duration of inhibitory effect was greater when 8% HMP and 1 or 8% HMP associated with F were assessed (p<0.001). The presence of salivary coating led to higher protection for all groups when compared to discs without coating (p<0.001). The reduction of HA dissolution rate, as well as the duration of this effect were influenced by fluoride, type and concentration of phosphate salt and the presence of a salivary coating. Copyright © 2015 Elsevier Ltd. All rights reserved.

Role of the P-F bond in fluoride-promoted aqueous VX hydrolysis: an experimental and theoretical study.

PubMed

Marciano, Daniele; Columbus, Ishay; Elias, Shlomi; Goldvaser, Michael; Shoshanim, Ofir; Ashkenazi, Nissan; Zafrani, Yossi

2012-11-16

Following our ongoing studies on the reactivity of the fluoride ion toward organophosphorus compounds, we established that the extremely toxic and environmentally persistent chemical warfare agent VX (O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothioate) is exclusively and rapidly degraded to the nontoxic product EMPA (ethyl methylphosphonic acid) even in dilute aqueous solutions of fluoride. The unique role of the P-F bond formation in the reaction mechanism was explored using both experimental and computational mechanistic studies. In most cases, the "G-analogue" (O-ethyl methylphosphonofluoridate, Et-G) was observed as an intermediate. Noteworthy and of practical importance is the fact that the toxic side product desethyl-VX, which is formed in substantial quantities during the slow degradation of VX in unbuffered water, is completely avoided in the presence of fluoride. A computational study on a VX-model, O,S-diethyl methylphosphonothioate (1), clarifies the distinctive tendency of aqueous fluoride ions to react with such organophosphorus compounds. The facility of the degradation process even in dilute fluoride solutions is due to the increased reactivity of fluoride, which is caused by the significant low activation barrier for the P-F bond formation. In addition, the unique nucleophilicity of fluoride versus hydroxide toward VX, in contrast to their relative basicity, is discussed. Although the reaction outcomes were similar, much slower reaction rates were observed experimentally for the VX-model (1) in comparison to VX.

Plaque fluoride concentrations in a community without water fluoridation: effects of calcium and use of a fluoride or placebo dentifrice.

PubMed

Whitford, G M; Buzalaf, M A R; Bijella, M F B; Waller, J L

2005-01-01

The results of a recent study by Whitford et al. [Caries Res 2002;36:256-265] with subjects whose drinking water was fluoridated led to two major conclusions: (1) Compared to the use of a placebo dentifrice, plaque fluoride concentrations ([F]) throughout much of the day are not significantly increased by the use of an F dentifrice but (2) they are positively related to plaque [Ca] (p = 0.0001). The present double-blind, double-crossover study with 16 subjects used the same protocol and was done to: (1) determine the effects of the use of an F dentifrice on salivary and plaque [F] in a community without water fluoridation and (2) further examine the relationship between plaque [Ca] and [F]. Following the use of an F dentifrice or placebo for one week, whole saliva and plaque were collected 1.0 and 12 h after the last use of the products. The study was repeated to include rinsing with a 20 mmol/l CaCl(2) solution immediately before the use of the dentifrices. The CaCl(2) rinse had only minor effects on salivary [Ca] and [F] and none on the plaque concentrations. Unlike the results found in the fluoridated community, all salivary and plaque [F] associated with the use of the F dentifrice were significantly higher than those associated with the use of the placebo. The results suggest that the cariostatic effectiveness of an F dentifrice should be greater in areas without water fluoridation. As noted previously, plaque [F] were positively related to plaque [Ca] (p = 0.0001). Copyright (c) 2005 S. Karger AG, Basel.

One-Step Synthesis of Titanium Oxyhydroxy-Fluoride Rods and Research on the Electrochemical Performance for Lithium-ion Batteries and Sodium-ion Batteries.

PubMed

Li, Biao; Gao, Zhan; Wang, Dake; Hao, Qiaoyan; Wang, Yan; Wang, Yongkun; Tang, Kaibin

2015-12-01

Titanium oxyhydroxy-fluoride, TiO0.9(OH)0.9F1.2 · 0.59H2O rods with a hexagonal tungsten bronze (HTB) structure, was synthesized via a facile one-step solvothermal method. The structure, morphology, and component of the products were characterized by X-ray powder diffraction (XRD), thermogravimetry (TG), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), inductively coupled plasma optical emission spectroscopy (ICP-OES), ion chromatograph, energy-dispersive X-ray (EDX) analyses, and so on. Different rod morphologies which ranged from nanoscale to submicron scale were simply obtained by adjusting reaction conditions. With one-dimension channels for Li/Na intercalation/de-intercalation, the electrochemical performance of titanium oxyhydroxy-fluoride for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) was also studied. Electrochemical tests revealed that, for LIBs, titanium oxyhydroxy-fluoride exhibited a stabilized reversible capacity of 200 mAh g(-1) at 25 mA g(-1) up to 120 cycles in the electrode potential range of 3.0-1.2 V and 140 mAh g(-1) at 250 mA g(-1) up to 500 cycles, especially; for SIBs, a high capacity of 100 mAh g(-1) was maintained at 25 mA g(-1) after 115 cycles in the potential range of 2.9-0.5 V.

PET/CT study performed after an oral administration of 18F-fluoride.

PubMed

Zacchi, Samara Riguete; Valadares, Agnes Araújo; Duarte, Paulo Schiavom; Sapienza, Marcelo Tatit; Buchpiguel, Carlos Alberto

2013-12-01

A 52-year-old woman with right breast cancer was referred for 18F-fluoride whole-body PET/CT for the assessment of bone metastases. The peripheral i.v. access was not obtained after multiple attempts. The radiopharmaceutical was administered by oral route.

Fluoride bioavailability in saliva and plaque

PubMed Central

2012-01-01

Background Different fluoride formulations may have different effects on caries prevention. It was the aim of this clinical study to assess the fluoride content, provided by NaF compared to amine fluoride, in saliva and plaque. Methods Eight trained volunteers brushed their teeth in the morning for 3 minutes with either NaF or amine fluoride, and saliva and 3-day-plaque-regrowth was collected at 5 time intervals during 6 hours after tooth brushing. The amount of collected saliva and plaque was measured, and the fluoride content was analysed using a fluoride sensitive electrode. All subjects repeated all study cycles 5 times, and 3 cycles per subject underwent statistical analysis using the Wilcoxon-Mann-Whitney test. Results Immediately after brushing the fluoride concentration in saliva increased rapidly and dropped to the baseline level after 360 minutes. No difference was found between NaF and amine fluoride. All plaque fluoride levels were elevated after 30 minutes until 120 minutes after tooth brushing, and decreasing after 360 minutes to baseline. According to the highly individual profile of fluoride in saliva and plaque, both levels of bioavailability correlated for the first 30 minutes, and the fluoride content of saliva and plaque was back to baseline after 6 hours. Conclusions Fluoride levels in saliva and plaque are interindividually highly variable. However, no significant difference in bioavailability between NaF and amine fluoride, in saliva, or in plaque was found. PMID:22230722

APPLICATION OF VACUUM SALT DISTILLATION TECHNOLOGY FOR THE REMOVAL OF FLUORIDE AND CHLORIDE FROM LEGACY FISSILE MATERIALS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pierce, R.; Peters, T.

2011-11-01

Between September 2009 and January 2011, the Savannah River National Laboratory (SRNL) and the Savannah River Site (SRS) HB-Line Facility designed, developed, tested, and successfully deployed a production-scale system for the distillation of sodium chloride (NaCl) and potassium chloride (KCl) from plutonium oxide (PuO{sub 2}). Subsequent efforts adapted the vacuum salt distillation (VSD) technology for the removal of chloride and fluoride from less-volatile halide salts at the same process temperature and vacuum. Calcium chloride (CaCl{sub 2}), calcium fluoride (CaF{sub 2}), and plutonium fluoride (PuF{sub 3}) were of particular concern. To enable the use of the same operating conditions for themore » distillation process, SRNL employed in situ exchange reactions to convert the less-volatile halide salts to compounds that facilitated the distillation of halide without removal of plutonium. SRNL demonstrated the removal of halide from CaCl{sub 2}, CaF{sub 2} and PuF{sub 3} below 1000 C using VSD technology.« less

The cariostatic mechanisms of fluoride.

PubMed

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.

KINETIC MODEL OF FLUORIDE METABOLISM IN THE RABBIT

EPA Science Inventory

Sodium fluoride, in small doses, was given to rabbits intravenously or by stomach tube, and the appearance of fluoride in the blood and urine was then monitored frequently over the next 10 hours. Compartmental analysis of the data yielded a kinetic model of fluoride metabolism co...

Effect of Silver Nitrate and Sodium Fluoride with Tri-Calcium Phosphate on Streptococcus mutans and Demineralised Dentine.

PubMed

Yu, Ollie Yiru; Zhao, Irene Shuping; Mei, May Lei; Lo, Edward Chin-Man; Chu, Chun-Hung

2018-04-25

This study investigated the effect of 25% silver nitrate (AgNO₃) and 5% sodium fluoride (NaF) varnish with functionalized tri-calcium phosphate (fTCP) on a Streptococcus mutans ( S. mutans ) biofilm and dentine caries lesion. Demineralised dentine specimens were treated with 25% AgNO₃ and 5% NaF + fTCP (Group 1), 25% AgNO₃ and 5% NaF (Group 2), 25% AgNO₃ (Group 3), or water (Group 4). The specimens were subjected to a S. mutans biofilm challenge after treatment. The biofilm was then studied via scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and colony forming units (CFU). The specimens were assessed by micro-computed tomography, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). SEM and CLSM revealed less biofilm in Groups 1 to 3. The log 10 CFU of Groups 1 to 4 were 4.5 ± 0.7, 4.4 ± 0.9, 4.4 ± 0.9, and 6.7 ± 1.0, respectively (Groups 1, 2, 3 < 4, p < 0.001). The lesion depths of Groups 1 to 4 were 212.6 ± 20.1 µm, 280.8 ± 51.6 µm, 402.5 ± 61.7 µm, and 497.4 ± 67.2 µm, respectively (Groups 1 < 2 < 3 < 4, p < 0.001). XRD demonstrated silver chloride formation in Groups 1, 2, and 3. FTIR found the amide I: HPO₄ 2− values of the four groups were 0.22 ± 0.05, 0.25 ± 0.05, 0.41 ± 0.12, and 0.64 ± 0.14, respectively (Groups 1, 2 < 3 < 4; p < 0.001). In conclusion, this study revealed that AgNO₃ and NaF + fTCP reduced the damage of dentine caries by cariogenic biofilm.

Effect of fluoride on photosynthesis, growth and accumulation of four widely cultivated rice (Oryza sativa L.) varieties in India.

PubMed

Mondal, Naba Kumar

2017-10-01

Long-term use of fluoride contaminated groundwater to irrigate crops; especially paddy rice (Oryza sativa L.) has resulted in elevated soil fluoride levels in Eastern India. There is, therefore, growing concern regarding accumulation of fluoride in rice grown on these soils. A laboratory experiment was conducted to investigate the effect of F on germination and phytotoxicity of four varieties of rice (Orzya sativa L.) (MTU-1010; IET-4094; IET-4786 and GB-1) grown in petri dish in a green house with inorganic sodium fluoride (NaF). Three different levels (0, 5, 10 and 20mg/L) of NaF solution were applied. At the end of the experiment (28 days), biochemical analysis (pigment, sugar, protein, amino acid and phenol), lipid peroxidation, root ion leakage and catalase activity along with fluoride accumulation and fresh and dry weight of roots and shoots of four cultivars were measured. The results revealed that all the four studied varieties exhibited gradual decrease of germination pattern with increasing concentration of F. Pigment and growth morphological study clearly demonstrated that the variety IET-4094 was the least influenced by F compare to the other three varieties of rice. The translocation factor (TF) was recorded to be the highest for variety IET-4786 (0.215 ± 0.03) at 5mg/L F concentration. All the four varieties showed higher level of fluoride accumulation in root than in shoot. Variable results were recorded for biochemical parameters and lipid peroxidation. Catalase activity and relative conductivity (root ion leakage) gradually increased with increasing F concentration for all the four varieties. It is speculated that fluoride accumulation in rice straw at very high levels will affect the feeding cattle and such contaminated straw could be a direct threat to their health and also, indirectly, to human health via presumably contaminated meat and milk. Copyright © 2017. Published by Elsevier Inc.

COMPLEX FLUORIDES OF PLUTONIUM AND AN ALKALI METAL

DOEpatents

Seaborg, G.T.

1960-08-01

A method is given for precipitating alkali metal plutonium fluorides. such as KPuF/sub 5/, KPu/sub 2/F/sub 9/, NaPuF/sub 5/, and RbPuF/sub 5/, from an aqueous plutonium(IV) solution by adding hydrogen fluoride and alkali-metal- fluoride.

Synthesis of Actinide Fluoride Complexes Using Trimethyltin Fluoride as a Mild and Selective Fluorinating Reagent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kagan, Benjamin D.; Lichtscheidl, Alejandro G.; Erickson, Karla A.

Trimethyltin fluoride (Me₃SnF) is a mild and selective reagent for the installation of actinide fluoride bonds as demonstrated by the room temperature synthesis of a variety of organometallic and inorganic thorium(IV), uranium(IV), and uranium(V) fluoride complexes ((1,2,4-tBu₃C₅H₂)₂ThF₂, (C₅Me₅)₂U(F)(O-2,6-iPr₂C₆H₃), U(F)(O-2,6-tBu₂C₆H₃)₃, U(F)[N(SiMe₃)₂]₃ (C₅Me₅)₂UF₂(L) (L = O=PMe₃, O=PPh₃, O=PCy₃), and (C₅Me₅)₂U(F)(=N-2,6-iPr₂C₆H₃)) from their corresponding chloride, bromide, and iodide analogues. From these reactions, the new (C₅Me₅)₂UF₂(L) (L = O=PPh₃, O=PCy₃) uranium fluoride complexes were isolated and characterized by NMR spectroscopy and X-ray crystallography.

Synthesis of Actinide Fluoride Complexes Using Trimethyltin Fluoride as a Mild and Selective Fluorinating Reagent

DOE PAGES

Kagan, Benjamin D.; Lichtscheidl, Alejandro G.; Erickson, Karla A.; ...

2017-11-07

Trimethyltin fluoride (Me₃SnF) is a mild and selective reagent for the installation of actinide fluoride bonds as demonstrated by the room temperature synthesis of a variety of organometallic and inorganic thorium(IV), uranium(IV), and uranium(V) fluoride complexes ((1,2,4-tBu₃C₅H₂)₂ThF₂, (C₅Me₅)₂U(F)(O-2,6-iPr₂C₆H₃), U(F)(O-2,6-tBu₂C₆H₃)₃, U(F)[N(SiMe₃)₂]₃ (C₅Me₅)₂UF₂(L) (L = O=PMe₃, O=PPh₃, O=PCy₃), and (C₅Me₅)₂U(F)(=N-2,6-iPr₂C₆H₃)) from their corresponding chloride, bromide, and iodide analogues. From these reactions, the new (C₅Me₅)₂UF₂(L) (L = O=PPh₃, O=PCy₃) uranium fluoride complexes were isolated and characterized by NMR spectroscopy and X-ray crystallography.

Retention of long-term interim restorations with sodium fluoride enriched interim cement

NASA Astrophysics Data System (ADS)

Strash, Carolyn

Purpose: Interim fixed dental prostheses, or "provisional restorations", are fabricated to restore teeth when definitive prostheses are made indirectly. Patients undergoing extensive prosthodontic treatment frequently require provisionalization for several months or years. The ideal interim cement would retain the restoration for as long as needed and still allow for ease of removal. It would also avoid recurrent caries by preventing demineralization of tooth structure. This study aims to determine if adding sodium fluoride varnish to interim cement may assist in the retention of interim restorations. Materials and methods: stainless steel dies representing a crown preparation were fabricated. Provisional crowns were milled for the dies using CAD/CAM technology. Crowns were provisionally cemented onto the dies using TempBond NE and NexTemp provisional cements as well as a mixture of TempBond NE and Duraphat fluoride varnish. Samples were stored for 24h then tested or thermocycled for 2500 or 5000 cycles before being tested. Retentive strength of each cement was recorded using a universal testing machine. Results: TempBond NE and NexTemp cements performed similarly when tested after 24h. The addition of Duraphat significantly decreased the retention when added to TempBond NE. NexTemp cement had high variability in retention over all tested time periods. Thermocycling for 2500 and 5000 cycles significantly decreased the retention of all cements. Conclusions: The addition of Duraphat fluoride varnish significantly decreased the retention of TempBond NE and is therefore not recommended for clinical use. Thermocycling significantly reduced the retention of TempBond NE and NexTemp. This may suggest that use of these cements for three months, as simulated in this study, is not recommended.

Biochemical alterations induced by oral subchronic exposure to fipronil, fluoride and their combination in buffalo calves.

PubMed

Gill, Kamalpreet Kaur; Dumka, Vinod Kumar

2013-11-01

The effects of various pesticides and minerals on biochemical parameters have been explored in different species, but hardly any data exist regarding the combined toxicological effect of pesticides and minerals on these parameters in animals. The present study investigated the effects of fipronil and fluoride co-exposure on biochemical parameters in buffalo calves. Twenty-four healthy male buffalo calves divided into four 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 @ 0.5mg/kg/day and sodium fluoride (NaF) @ 6.67 mg/kg/day, respectively, for 98 days. An additional group IV was co-administered fipronil and NaF at the same dosages as groups II and III. Administration of fipronil alone produced mild toxic signs, significant elevation in plasma proteins, blood glucose, blood urea nitrogen (BUN) and significant decline in the plasma cholesterol levels. NaF exposure produced toxic signs specifically of muscle weakness and brown and black discoloration of teeth. Significant elevation was seen in whole blood cholinesterase, BUN and creatinine levels. However, it produced significant decline in blood glucose, cholesterol and plasma protein levels. Combined exposure to fipronil and sodium fluoride produced toxic signs with greater intensity while biochemical alterations produced were similar to those that were produced by their individual exposures. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of perinatal fluoride exposure on the expressions of miR-124 and miR-132 in hippocampus of mouse pups.

PubMed

Wang, Jixiang; Zhang, Yuliang; Guo, Zhenzhen; Li, Rui; Xue, Xingchen; Sun, Zilong; Niu, Ruiyan

2018-04-01

To investigate the effects of perinatal fluoride exposure on learning and memory ability of mouse offspring, ICR female mice were received different doses of sodium fluoride (0, 25, 50, 100 mg/L NaF) from pregnant day 7 to lactational day 21. Pups were exposed to fluoride through the cord blood and breast milk. Open field test showed that compared to the control group, perinatal fluoride exposure significantly decreased the number of entries into the center zone in 100 mg/L NaF group. In the eight-arm maze test, the number of working memory errors, reference memory errors, and the total arm entries were significantly increased in fluoride treatment groups, compared to the control group. Additionally, 100 mg/L NaF significantly elevated the expression levels of miR-124, miR-132, and DiGeorge syndrome chromosomal region 8 (DGCR8) in hippocampus of mouse pups at postnatal day (PND) 21. Contrarily, methyl CpG binding protein 2 (MeCP2) were dramatically reduced in 50 and 100 mg/L NaF groups, while cAMP-response element binding protein (CREB) mRNA level was significantly decreased in all fluoride groups. These findings suggested that the impairment of learning and memory in mouse offspring induced by perinatal fluoride exposure may partly result from the enhanced miR-124 and miR-132 and the alterations of their target genes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of lead fluoride incorporation on the structure and luminescence properties of tungsten sodium phosphate glasses

NASA Astrophysics Data System (ADS)

Nardi, Rachel Prado Russo Delorenzo; Braz, Celso Eduardo; de Camargo, Andrea S. S.; Ribeiro, Sidney J. L.; Rocha, Lucas A.; Cassanjes, Fábia Castro; Poirier, Gael

2015-11-01

Tungsten phosphate glasses are known to be promising materials for several applications in optics such as non linear optical properties, lower phonon energy or photochromic effects related with tungsten oxide incorporation inside the phosphate network. In this study, lead fluoride has been incorporated in a 60NaPO3-40WO3 glass composition according to the ternary molar compositions (100 - x)[0.6NaPO3-0.4WO3]-xPbF2 with x varying from 0 to 60 mol%. The structural changes as a function of composition were investigated by thermal analysis, UV-visible absorption, Raman spectroscopy, X-ray diffraction of the crystallized samples, and Eu3+ emission in the visible. While DSC analyzes points out a strong decrease in the glass network connectivity and higher crystallization tendency with increasing PbF2 contents, Raman spectra clearly identify a progressive incorporation of PbF2 in the phosphate network with the formation of terminal Psbnd F and Wsbnd F bonds. These results are also in agreement with the crystallization of β-PbF2 observed for the most lead fluoride concentrated samples. Investigation of Eu3+ emission data in the visible showed longer 5D0 excited state lifetime values and higher quantum efficiencies. These results are discussed in terms of the assumption of higher local symmetry around Eu3+ with increasing PbF2 contents.

Estimated fluoride doses from toothpastes should be based on total soluble fluoride.

PubMed

Oliveira, Maria José L; Martins, Carolina C; Paiva, Saul M; Tenuta, Livia M A; Cury, Jaime A

2013-11-01

The fluoride dose ingested by young children may be overestimated if based on levels of total fluoride (TF) rather than levels of bioavailable fluoride (total soluble fluoride-TSF) in toothpaste. The aim of the present study was to compare doses of fluoride intake based on TF and TSF. Fluoride intake in 158 Brazilian children aged three and four years was determined after tooth brushing with their usual toothpaste (either family toothpaste (n = 80) or children's toothpaste (n = 78)). The estimated dose (mg F/day/Kg of body weight) of TF or TSF ingested was calculated from the chemical analysis of the toothpastes. Although the ingested dose of TF from the family toothpastes was higher than that from the children's toothpastes (0.074 ± 0.007 and 0.039 ± 0.003 mg F/day/Kg, respectively; p < 0.05), no difference between types of toothpaste was found regarding the ingested dose based on TSF (0.039 ± 0.005 and 0.039 ± 0.005 mg F/day/Kg, respectively; p > 0.05). The fluoride dose ingested by children from toothpastes may be overestimated if based on the TF of the product. This finding suggests that the ingested dose should be calculated based on TSF. Dose of TSF ingested by children is similar whether family or children's toothpaste is used.

Lack of deleterious effect of slow-release sodium fluoride treatment on cortical bone histology and quality in osteoporotic patients

NASA Technical Reports Server (NTRS)

Zerwekh, J. E.; Antich, P. P.; Sakhaee, K.; Prior, J.; Gonzales, J.; Gottschalk, F.; Pak, C. Y.

1992-01-01

We evaluated the effects of intermittent slow-release sodium fluoride (SRNaF) and continuous calcium citrate therapy on cortical bone histology, reflection ultrasound velocity (material strength) and back-scattered electron image analysis (BEI) in 26 osteoporotic patients before and following therapy. All measurements were made on transiliac crest bone biopsies obtained before and following 2 years of therapy in each patient. For all 26 patients there were no significant changes in cortical bone histomorphometric parameters. In 15 patients in whom bone material quality was assessed by reflection ultrasound, there was no change in velocity (4000 +/- 227 SD to 4013 +/- 240 m/s). BEI disclosed no mineralization defects or the presence of woven bone. Mean atomic number (density) of bone increased slightly, but significantly (9.261 +/- 0.311 to 9.457 +/- 0.223, P = 0.031). While these changes are less marked than those observed for cancellous bone, they indicate that this form of therapy does not adversely affect cortical bone remodelling.

Repeatability of quantitative parameters of 18F-fluoride PET/CT and biochemical tumour and specific bone remodelling markers in prostate cancer bone metastases.

PubMed

Wassberg, Cecilia; Lubberink, Mark; Sörensen, Jens; Johansson, Silvia

2017-12-01

18F-fluoride PET/CT exhibits high sensitivity to delineate and measure the extent of bone metastatic disease in patients with prostate cancer. 18F-fluoride PET/CT could potentially replace traditional bone scintigraphy in clinical routine and trials. However, more studies are needed to assess repeatability and biological uptake variation. The aim of this study was to perform test-retest analysis of quantitative PET-derived parameters and blood/serum bone turnover markers at the same time point. Ten patients with prostate cancer and verified bone metastases were prospectively included. All underwent two serial 18F-fluoride PET/CT at 1 h post-injection. Up to five dominant index lesions and whole-body 18F-fluoride skeletal tumour burden were recorded per patient. Lesion-based PET parameters were SUVmax, SUVmean and functional tumour volume applying a VOI with 50% threshold (FTV 50% ). The total skeletal tumour burden, total lesion 18F-fluoride (TLF), was calculated using a threshold of SUV of ≥15. Blood/serum biochemical bone turnover markers obtained at the time of each PET were PSA, ALP, S-osteocalcin, S-beta-CTx, 1CTP and BAP. A total of 47 index lesions and a range of 2-122 bone metastases per patient were evaluated. Median time between 18F-fluoride PET/CT was 7 days (range 6-8 days). Repeatability coefficients were for SUVmax 26%, SUVmean 24%, FTV 50% for index lesions 23% and total skeletal tumour burden (TLF) 35%. Biochemical bone marker repeatability coefficients were for PSA 19%, ALP 23%, S-osteocalcin 18%, S-beta-CTx 22%, 1CTP 18% and BAP 23%. Quantitative 18F-fluoride uptake and simultaneous biochemical bone markers measurements are reproducible for prostate cancer metastases and show similar magnitude in test-retest variation.

76 FR 6144 - Positron Emission Tomography; Notice of Public Meeting; Request for Comments

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-03

... injection, and sodium fluoride F 18 injection used in positron emission tomography (PET) imaging. By... be submitted for FDG F 18 injection, ammonia N 13 injection, and sodium fluoride F 18 injection used..., ammonia N 13 injection, and sodium fluoride F 18 injection. FDA will present information designed to...

Melatonin-mediated upregulation of Sirt3 attenuates sodium fluoride-induced hepatotoxicity by activating the MT1-PI3K/AKT-PGC-1α signaling pathway.

PubMed

Song, Chao; Zhao, Jiamin; Fu, Beibei; Li, Dan; Mao, Tingchao; Peng, Wei; Wu, Haibo; Zhang, Yong

2017-11-01

Mitochondrial reactive oxygen species (ROS) production has been implicated in the pathogenesis of fluoride toxicity in liver. Melatonin, an indolamine synthesized in the pineal gland, was previously shown to protect against sodium fluoride (NaF)-induced hepatotoxicity. This study investigated the protective effects of melatonin pretreatment on NaF-induced hepatotoxicity and elucidates the potential mechanism of melatonin-mediated protection. Reducing mitochondrial ROS by melatonin substantially attenuated NaF-induced NADPH oxidase 4 (Nox4) upregulation and cytotoxicity in L-02 cells. Melatonin exerted its hepatoprotective effects by upregulating Sirtuin 3 (Sirt3) expression level and its activity. Melatonin increased the activity of manganese superoxide dismutase (SOD2) by promoting Sirt3-mediated deacetylation and promoted SOD2 expression through Sirt3-regulated DNA-binding activity of forkhead box O3 (FoxO3a), thus inhibiting the production of mitochondrial ROS induced by NaF. Notably, increased peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α) by melatonin activated the Sirt3 expression, which was regulated by an estrogen-related receptor (ERR) binding element (ERRE) mapped to Sirt3 promoter region. Analysis of the cell signaling pathway profiling systems and specific pathway inhibition indicated that melatonin enhances PGC-1α expression by activating the PI3K/AKT signaling pathway. Importantly, inhibition of melatonin receptor (MT)-1 blocked the melatonin-activated PI3K/AKT-PGC-1α-Sirt3 signaling. Mechanistic study revealed that the protective effects of melatonin were associated with down-regulation of JNK1/2 phosphorylation. Our findings provided a theoretical basis that melatonin mitigated NaF-induced hepatotoxicity, which, in part, was mediated through the activation of the Sirt3 pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

The MMP-9/TIMP-1 System is Involved in Fluoride-Induced Reproductive Dysfunctions in Female Mice.

PubMed

Wang, Hong-Wei; Zhao, Wen-Peng; Tan, Pan-Pan; Liu, Jing; Zhao, Jing; Zhou, Bian-Hua

2017-08-01

A total of 84 healthy female mice were kept with various concentrations of sodium fluoride (F) (0, 50, 100, 150 mg F - /L in drinking water for 90 days) and were then mated with healthy male mice for 1 week to study the effect of excessive fluoride on female reproductive function, particularly in embryo implantation. The rate of pregnancy, litter size, and the birth weight of female mice were evaluated. Ultrastructural changes of uteri tissues were observed by transmission electron microscopy (TEM). The mRNA expression levels of MMP-9 and TIMP-1 were determined by quantitative real-time PCR. The protein expression levels of MMP-9 and TIMP-1 were analyzed by western blotting. Results showed a significant decrease of litter size in mice exposed to fluoride. TEM images of uteri tissue of mice that underwent a 150 mg/L F - treatment for 90 days showed a vague nucleus, reduced microvilli, increased lysosomes, a dilated endoplasmic reticulum, and a vacuolization mitochondrion when compared with the control group. Following the damage of the structure, the expression levels of MMP-9 and TIMP-1 in uteri tissues were significantly unregulated in the F 150 group. These results show that MMP-9/TIMP-1 system disturbance and changes of histological structure in uteri tissue are involved in fluoride-induced reproductive dysfunctions.

Effectiveness of a Toothpaste with Low Fluoride Content Combined with Trimetaphosphate on Dental Biofilm and Enamel Demineralization in situ.

PubMed

Takeshita, Eliana M; Danelon, Marcelle; Castro, Luciene P; Sassaki, Kikue T; Delbem, Alberto C B

2015-01-01

The aim of the present study was to evaluate in situ whether a toothpaste with low fluoride associated with sodium trimetaphosphate (TMP) would provide similar effect to that of a 1,100 ppm F toothpaste. This crossover double-blind study consisted of 4 phases (14 days each), during which 10 volunteers wore oral appliances containing 4 enamel bovine blocks. The cariogenic challenge was performed by the application of a 20% sucrose solution (6×/day). The toothpaste treatments (2×/day) were: placebo, 500 ppm F, 500 ppm F plus 1% TMP, and 1,100 ppm F. At the end, enamel mineral loss and biofilm composition were analyzed. The toothpaste with 500 ppm F plus 1% TMP showed the lowest mineral loss (p < 0.05). Regarding the fluoride and calcium concentrations in the enamel and in the biofilm, there were no significant differences between 500 ppm F plus 1% TMP, and 1,100 ppm F toothpastes (p > 0.569), but they were significantly different when compared to toothpaste with 500 ppm F (p < 0.050). The addition of 1% TMP to a low-fluoride toothpaste reduces enamel demineralization in situ similar to a 1,100 ppm F toothpaste. © 2015 S. Karger AG, Basel.

Evaluation of different fluoridated dentifrice formulations using an in situ erosion remineralization model.

PubMed

Barlow, A P; Sufi, F; Mason, S C

2009-01-01

The objective of these three clinical in situ studies was to investigate the relative performance of commercially available and experimental dentifrice formulations, having different fluoride sources and excipient ingredients, at remineralizing a bovine enamel surface previously softened by a dietary acid challenge. Each study utilized the same randomized, placebo-controlled, single-blind, crossover design. Subjects undertook single brushings of their natural teeth, with an in situ appliance in place, using different dentifrices in a randomly assigned order. Study A involved 58 subjects with the following dentifrices: Sensodyne Pronamel (1450 ppm F as NaF/5% KNO3); Blend-a-Med Classic (1450 ppm F as NaF); and a matched (Pronamel) placebo control (0 ppm F). Study B involved 56 subjects with the following dentifrices: Sensodyne Pronamel (1150 ppm F as NaF/5% KNO3); Crest Cavity Protection (1100 ppm F as NaF); Crest Pro-Health (0.454% SnF2 [1100 ppm F]/sodium hexametaphosphate); and a matched (Pronamel) placebo control (0 ppm F). Study C involved 56 subjects with the following dentifrices: Sensodyne Pronamel (1150 ppm F as NaF/5% KNO3); Sensodyne Pronamel Gentle Whitening (1150 ppm F as NaF/5% KNO3); Colgate Sensitive Multi Protection (1000 ppm F as NaMFP/5.53% potassium citrate/2% zinc citrate); and a matched (Pronamel) placebo control (0 ppm F). Subjects wore their palatal appliances holding eight bovine enamel blocks, previously exposed for 25 minutes to an in vitro erosive challenge with grapefruit juice, for the duration of the experiment. Five minutes after appliance insertion, subjects undertook a supervised, 90-second brush/rinse regimen with their assigned dentifrice. Surface microhardness (SMH) of the specimens was determined prior to the erosive challenge (baseline), after the in vitro erosive challenge, and were remeasured after four hours in situ remineralization following the tooth brushing event. Finally, SMH values were determined after a second in

Fluoride and calcium concentrations in the biofilm fluid after use of fluoridated dentifrices supplemented with polyphosphate salts.

PubMed

Nagata, Mariana Emi; Delbem, Alberto Carlos Botazzo; Hall, Kevin Bruce; Buzalaf, Marília Afonso Rabelo; Pessan, Juliano Pelim

2017-04-01

The present study evaluated fluoride (F) and calcium (Ca) concentrations in the biofilm fluid formed in situ under cariogenic challenge after using F dentifrices supplemented or not with sodium trimetaphosphate (TMP) or calcium glycerophosphate (CaGP). Volunteers (n = 12) were randomly divided into 5 groups according to the toothpastes used: placebo (without F, CaGP or TMP), 1100 ppm F (1100F) and low-fluoride dentifrice (LFD, 550 ppm F) with no supplementation (550F) or supplemented with 1 % TMP (550F-TMP) or 0.25 % CaGP (550F-CaGP). In each phase, volunteers wore palatal appliances containing 4 bovine enamel blocks. Cariogenic challenge was performed with 30 % sucrose solution, 6 times/day. On the morning of the eigth day, biofilm samples were collected 12 h and 1 h after brushing and cariogenic challenge. F and Ca analyses in the biofilm fluid were performed with the inverted electrode after buffering with TISAB III and using the Arsenazo III method, respectively. Data were submitted to two-way ANOVA (repeated measures) and Student-Newman-Keuls test (p < 0.05). A dose-response relationship was verified between F concentrations in the dentifrices and in the biofilm fluid. Significant differences were observed among placebo, 550F, and 1100F only 1 h after brushing, without statistical differences among 550F, 550F-TMP, and 550F-CaGP. No defined trend was observed among the groups regarding Ca concentrations, with the highest values seen for placebo and 550F-CaGP. The anticaries effect of LFDs supplemented with CaGP or TMP cannot be related to an increased availability of F and Ca in the biofilm fluid. The better performance of LFDs containing CaGP or TMP shown in previous studies should be attributed to their ability to interact with tooth enamel and with the biofilm, rather to their effect on the biofilm fluid.

Contribution of chloride channel permease to fluoride resistance in Streptococcus mutans.

PubMed

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.

Towards optimization of odonto/osteogenic bioengineering: in vitro comparison of simvastatin, sodium fluoride, melanocyte-stimulating hormone.

PubMed

Zijah, Vahid; Salehi, Roya; Aghazadeh, Marziyeh; Samiei, Mohammad; Alizadeh, Effat; Davaran, Soodabeh

2017-06-01

Tissue engineering has emerged as a potential therapeutic option for dental problems in recent years. One of the policies in tissue engineering is to use both scaffolds and additive factors for enhancing cell responses. This study aims to evaluate and compare the effect of three types of biofactors on poly-caprolactone-poly-ethylene glycol-poly caprolactone (PCL-PEG-PCL) nanofibrous scaffold on human dental pulp stem cell (hDPSCs) engineering. The PCL-PEG-PCL copolymer was synthesized with ring opening polymerization method, and its nanofiber scaffold was prepared by electrospinning method. Nanofibrous scaffold-seeded hDPSCs were treated with sodium fluoride (NaF), melanocyte-stimulating hormone (MSH), or simvastatin (SIM). Non-treated nanofiber seeded cells were utilized as control. The viability, biocompatibility, adhesion, proliferation rate, morphology, osteo/odontogenic potential, and the expression of tissue-specific genes were studied. The results showed that significant higher results demonstrated significant higher adhesive behavior, viability, alizarin red activity, and dentin specific gene expression in MSH- and SIM-treated cells (p < 0.05). This study is unique; in that, it compares the effects of different treatments for optimization of dental tissue engineering.

Remineralization ability of sodium fluoride on the microhardness of enamel, dentin, and dentinoenamel junction: An in vitro study

PubMed Central

Sivapriya, Elangovan; Sridevi, Krishnamoorthy; Periasamy, Ravishankar; Lakshminarayanan, Lakshmikanthanbharathi; Pradeepkumar, Angambakkam Rajasekaran

2017-01-01

Aim: Dental tissues such as enamel, dentinoenamel junction (DEJ), dentin, and root dentin can react differently to demineralization and remineralization. The aim of this study was to evaluate the remineralization ability of sodium fluoride on the microhardness of enamel, dentin, and dentinoenamel junction. Materials and Methods: Ten extracted third molar teeth were sectioned mesiodistally to form control and test groups. For the test group, initial demineralization was done with acetic acid for 24 h followed by remineralization for 28 days by application of sodium fluoride (226 ppm) for 2 min twice a day. Vickers microhardness test was done to control and test groups at different sites after initial demineralization and on the 3rd, 5th, 7th, 14th, and 28th day of remineralization. Statistical Analysis Used: Data were analyzed with one-way analysis of variance and post hoc test with a significance level of P < 0.001 with SPSS (21) software. Results: Microhardness values in the demineralization group were significantly lower than controls (P < 0.001). Evaluation of remineralization samples showed that microhardness similar to control values were achieved at the 3rd day in root predentin and on the 5th day in coronal dentin and coronal predentin. On the 7th day, remineralization coronal predentin was significantly higher than the control (P < 0.001). On the 14th day, DEJ axial zone and root dentin were similar to control and coronal dentin was significantly higher than the control (P < 0.001). Enamel was similar to control on the 28th day. Microhardness of DEJ-cusp tip and DEJ-center of the fissure was significantly lower than control even at the 28th day (P < 0.001). Conclusion: Long-term repeated application of sodium fluoride (226 ppm) can improve the microhardness of demineralized dental tissues on enamel, dentin, and DEJ-axial zone, except in the DEJ-cusp tip and DEJ-center of fissure. PMID:28855756

Extraosseus uptake of F-18 fluoride in the primary malignancy and cerebral metastasis in a case of non-small-cell lung cancer.

PubMed

Li, Yuxin; Tafti, Bashir A; Shaba, Wisam; Berenji, Gholam R

2011-07-01

A 68-year-old man with history of heavy smoking was admitted for increasing falls during the past 4 weeks. Chest x-ray revealed a right upper lobe mass. Biopsy demonstrated poorly differentiated non-small-cell carcinoma. F-18 fluoride positron emission tomography/computer tomography (PET/CT) was performed to evaluate bone metastasis. Review of the sectional PET images demonstrated extraosseous fluoride uptake in the primary lung mass, as well as ring-shaped fluoride uptake in the cerebral metastatic lesion. Neither of these lesions demonstrated calcifications on CT images. The patient received radiation treatment of the brain metastasis after F-18 fluoride PET/CT study.

Impact of ¹⁸F-fluoride PET-CT on implementing early treatment of painful bone metastases with Sm-153 EDTMP.

PubMed

Storto, Giovanni; Gallicchio, Rosj; Pellegrino, Teresa; Nardelli, Anna; De Luca, Serena; Capacchione, Daniela; Sirignano, Cesare; Pace, Leonardo

2013-05-01

This study evaluated the diagnostic impact of using skeletal (18)F-fluoride PET/CT on patients with painful bone metastases to schedule an early palliative radionuclide treatment. The skeletal involvement from prostate cancer metastases was assessed by both (99m)Tc-diphosphonate bone scan (BS) and (18)F-fluoride PET/CT within four weeks in 24 patients (67.7 ± 5.1 years) suffering from a borderline degree of bone pain for which radionuclide palliation was not shortly planned for administration. The BS and (18)F-fluoride PET/CT results were compared, assessing the number and extension of the skeletal sites involved. Afterward, the patients were randomly assigned either to the study group (N=12) receiving radionuclide therapy (Samarium-153 EDTMP) or to the control group (N=12) not receiving radionuclide therapy. The short-term results from the radionuclide palliation group (evaluated with a visual analogue scale) were compared with the controls. Overall, at BS, 7.6 ± 1.4 sites were considered metastatic, involving at least 5 ± 1 body regions. At (18)F-fluoride PET/CT, 116 ± 19 sites presented metastatic involvement with 12/12 body regions concerned. No differences were found in regards to either the number of metastatic sites or regions at both BS and (18)F-fluoride PET/CT between the study group and controls (p=ns). At CT, 88 blastic metastases were identified, whereas 110 were mainly lytic. Most of mainly lytic lesions were not detectable at BS. The reduction in total discomfort and bone pain in the study group was significantly greater than in the controls (p<0.0001). Sm-153 EDTMP therapy should be considered for patients with early bone pain from prostate cancer even if their BS only indicates a few metastases before the initiation of a severe pain syndrome. (18)F-fluoride PET/CT may be helpful in deciding if the implementation of bone pain palliation using bone-seeking radionuclides at pain onset is necessary. Copyright © 2013 Elsevier Inc. All rights

Solubility of aluminum in the presence of hydroxide, fluoride, and sulfate

USGS Publications Warehouse

Roberson, Charles Elmer; Hem, John David

1969-01-01

The total concentration of aqueous dissolved species of aluminum that will be present in equilibrium with microcrystalline gibbsite at various levels of complexing ligand concentration are shown graphically. The graphs can be used to estimate aluminum solubility, at 25?C and 1 atmosphere total pressure, when the pH of the solution, its ionic strength, and the total sulfate and fluoride concentrations are known. The standard free energy of formation of cryolite calculated from solubility experiments is --745.4 ? 1.0 kcal per mole at 25?C. Diagrams are included showing the solubility of cryolite in terms of aluminum, fluoride, and sodium concentrations. The stability fields of cryolite and microcrystalline gibbsite and their solubilities also are shown on pH-[F] diagrams.

The role of the IRE1 pathway in excessive iodide- and/or fluoride-induced apoptosis in Nthy-ori 3-1 cells in vitro.

PubMed

Liu, Hongliang; Zeng, Qiang; Cui, Yushan; Zhao, Liang; Zhang, Lei; Fu, Gang; Hou, Changchun; Zhang, Shun; Yu, Linyu; Jiang, Chunyang; Wang, Zhenglun; Chen, Xuemin; Wang, Aiguo

2014-01-30

Excessive iodide and fluoride coexist in the groundwater in many regions, causing a potential risk to the human thyroid. To investigate the mechanism of iodide- and fluoride-induced thyroid cytotoxicity, human thyroid follicular epithelial cells (Nthy-ori 3-1) were treated with different concentrations of potassium iodide (KI), with or without sodium fluoride (NaF). Cell morphology, viability, lactate dehydrogenase (LDH) leakage, apoptosis, and expression of inositol-requiring enzyme 1 (IRE1) pathway-related molecules were assessed. Results showed 50 mM of KI, 1 mM of NaF, and 50 mM of KI +1 mM of NaF changed cellular morphology, decreased viability, and increased LDH leakage and apoptosis. Elevated expression of binding protein (BiP), IRE1, and C/EBP homologous protein (CHOP) mRNA and protein, as well as spliced X-box-binding protein-1 (sXBP-1) mRNA, were observed in the 1 mM NaF and 50 mM KI +1 mM NaF groups. Collectively, excessive iodide and/or fluoride is cytotoxic to the human thyroid. Although these data do not manifest iodide could induce the IRE1 pathway, the cytotoxicity followed by exposure to fluoride alone or in combination with iodide may be related to IRE1 pathway-induced apoptosis. Furthermore, exposure to the combination of excessive iodide and fluoride may cause interactive effects on thyroid cytotoxicity. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Bioavailability of fluoride in drinking water: a human experimental study.

PubMed

Maguire, A; Zohouri, F V; Mathers, J C; Steen, I N; Hindmarch, P N; Moynihan, P J

2005-11-01

It has been suggested that systemic fluoride absorption from drinking water may be influenced by the type of fluoride compound in the water and by water hardness. Using a human double-blind cross-over trial, we conducted this study to measure c(max), T(max), and Area Under the Curve (AUC) for plasma F concentration against time, following the ingestion of naturally fluoridated hard and soft waters, artificially fluoridated hard and soft waters, and a reference water. Mean AUC over 0 to 8 hours was 1330, 1440, 1679, 1566, and 1328 ng F.min.mL(-1) for naturally fluoridated soft, naturally fluoridated hard, artificially fluoridated soft, artificially fluoridated hard, and reference waters, respectively, with no statistically significant differences among waters for AUC, c(max), or T(max). Any differences in fluoride bioavailability between drinking waters in which fluoride is present naturally or added artificially, or the waters are hard or soft, were small compared with large within- and between-subject variations in F absorption. Abbreviations used: F, fluoride; AUC, Area under the Curve for plasma F concentration against time; AUC(0-3), Area under the Curve for plasma F concentration against time for 0 to 3 hours following water ingestion; AUC(0-8), Area under the Curve for plasma F concentration against time for 0 to 8 hours following water ingestion; c(max), maximum plasma F concentration corrected for baseline plasma F and dose (i.e., F concentration of individual waters); T(max), time of c(max).

Protective effect of lycopene on fluoride-induced ameloblasts apoptosis and dental fluorosis through oxidative stress-mediated Caspase pathways.

PubMed

Li, Weishan; Jiang, Binghua; Cao, Xianglin; Xie, Yongjiang; Huang, Ting

2017-01-05

Fluoride is an environmental toxicant and induces dental fluorosis and oxidative stress. Lycopene (LYC) is an effective antioxidant that is reported to attenuate fluoride toxicity. To determine the effects of LYC on sodium fluoride (NaF) -induced teeth and ameloblasts toxicity, rats were treated with NaF (10 mg/kg) and/or LYC (10 mg/kg) by orally administration for 5 weeks; ameloblasts were treated with NaF (5 mM) and/or LYC (2 μM) for 6 h. We found that the concentrations of fluoride, malondialdehyde (MDA) and reactive oxygen species (ROS), gene expressions and activities of Caspase-9 and Caspase-3, and the gene expressions of Bax were significantly decreased, while the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX), the gene expression of Bcl-2 were significantly increased in the LYC + NaF-treated rats group; concentrations of MDA and ROS, gene expressions and activities of Caspase-9 and Caspase-3, and the gene expression of Bax, and ameloblasts apoptosis rate were significantly decreased, while the activities of SOD and GPX, the gene expression of Bcl-2 were significantly increased in the LYC + NaF-treated ameloblasts group. These results suggest that LYC significantly combated NaF-induced ameloblasts apoptosis and dental fluorosis by attenuation oxidative stress and down-regulation Caspase pathway. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Matrix infrared spectroscopy and quantum-chemical calculations for the coinage-metal fluorides: comparisons of Ar-AuF, Ne-AuF, and Molecules MF2 and MF3.

PubMed

Wang, Xuefeng; Andrews, Lester; Brosi, Felix; Riedel, Sebastian

2013-01-21

The reactions of laser-ablated Au, Ag, and Cu atoms with F(2) in excess argon and neon gave new absorptions in the M-F stretching region of their IR spectra, which were assigned to metal-fluoride species. For gold, a Ng-AuF bond was identified in mixed neon/argon samples. However, this bonding was much weaker with AgF and CuF. Molecules MF(2) and MF(3) (M=Au, Ag, Cu) were identified from the isotopic distribution of the Cu and Ag atoms, comparison of the frequencies for three metal fluorides, and theoretical frequency calculations. The AuF(5) molecule was characterized by its strongest stretching mode and theoretical frequency calculations. Additional evidence was observed for the formation of the Au(2) F(6) molecule. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Clinical effectiveness of some fluoride-containing toothpastes*

PubMed Central

1982-01-01

Comparisons were made of the clinical effectiveness of two small groups of fluoride-containing toothpastes on the basis of published and unpublished information available to the group. One comparison showed that particular sodium fluoride/silica and stannous fluoride/calcium pyrophosphate formulations were effective in reducing the incidence of dental caries in schoolchildren and that the former toothpaste was more effective than the latter. A separate comparison showed that certain toothpastes containing sodium monofluorophosphate formulated with either an alumina or an insoluble metaphosphate abrasive were also effective in reducing and controlling caries. The group recommended that there was a need for additional field trials in which direct comparisons could be made between a wide variety of formulations, and that further research should be carried out to develop improved formulations. Extension of the use of adequately formulated fluoride-containing toothpastes is recommended as a valuable public health measure to reduce the incidence of dental caries. PMID:6291796

Excessive ER stress and the resulting autophagic flux dysfunction contribute to fluoride-induced neurotoxicity.

PubMed

Niu, Qiang; Chen, Jingwen; Xia, Tao; Li, Pei; Zhou, Guoyu; Xu, Chunyan; Zhao, Qian; Dong, Lixin; Zhang, Shun; Wang, Aiguo

2018-02-01

Fluoride is capable of inducing neurotoxicity, but its mechanisms remain elusive. This study aimed to explore the roles of endoplasmic reticulum (ER) stress and autophagy in sodium fluoride (NaF)-induced neurotoxicity, focusing on the regulating role of ER stress in autophagy. The in vivo results demonstrated that NaF exposure impaired the learning and memory capabilities of rats, and resulted in histological and ultrastructural abnormalities in rat hippocampus. Moreover, NaF exposure induced excessive ER stress and associated apoptosis, as manifested by elevated IRE1α, GRP78, cleaved caspase-12 and cleaved-caspase-3, as well as defective autophagy, as shown by increased Beclin1, LC3-II and p62 expression in hippocampus. Consistently, the in vitro results further verified the findings of in vivo study that NaF induced excessive ER stress and defective autophagy in SH-SY5Y cells. Notably, inhibition of autophagy in NaF-treated SH-SY5Y cells with Wortmannin or Chloroquine decreased, while induction of autophagy by Rapamycin increased the cell viability. These results were correlated well with the immunofluorescence observations, thus confirming the pivotal role of autophagic flux dysfunction in NaF-induced cell death. Importantly, mitigation of ER stress by 4-phenylbutyrate in NaF-treated SH-SY5Y cells inhibited the expressions of autophagy markers, and decreased cell apoptosis. Taken together, these data suggest that neuronal death resulted from excessive ER stress and autophagic flux dysfunction contributes to fluoride-elicited neurotoxicity. Moreover, the autophagic flux dysfunction was mediated by excessive ER stress, which provided novel insight into a better understanding of fluoride-induced neurotoxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Streptozotocin Aggravated Osteopathology and Insulin Induced Osteogenesis Through Co-treatment with Fluoride.

PubMed

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.

Effectiveness of probiotic, chlorhexidine and fluoride mouthwash against Streptococcus mutans – Randomized, single-blind, in vivo study

PubMed Central

Jothika, Mohan; Vanajassun, P. Pranav; Someshwar, Battu

2015-01-01

Aim: To determine the short-term efficiency of probiotic, chlorhexidine, and fluoride mouthwashes on plaque Streptococcus mutans level at four periodic intervals. Materials and Methods: This was a single-blind, randomized control study in which each subject was tested with only one mouthwash regimen. Fifty-two healthy qualified adult patients were selected randomly for the study and were divided into the following groups: group 1- 10 ml of distilled water, group 2- 10 ml of 0.2% chlorhexidine mouthwash, group 3- 10 ml of 500 ppm F/400 ml sodium fluoride mouthwash, and group 4- 10 ml of probiotic mouthwash. Plaque samples were collected from the buccal surface of premolars and molars in the maxillary quadrant. Sampling procedure was carried out by a single examiner after 7 days, 14 days, and 30 days, respectively, after the use of the mouthwash. All the samples were subjected to microbiological analysis and statistically analyzed with one-way analysis of variance (ANOVA) and post-hoc test. Results: One-way ANOVA comparison among groups 2, 3, and 4 showed no statistical significance, whereas group 1 showed statistically significant difference when compared with groups 2, 3, and 4 at 7th, 14th, and 30th day. Conclusion: Chlorhexidine, sodium fluoride, and probiotic mouthwashes reduce plaque S. mutans levels. Probiotic mouthwash is effective and equivalent to chlorhexidine and sodium fluoride mouthwashes. Thus, probiotic mouthwash can also be considered as an effective oral hygiene regimen. PMID:25984467

Estimated Fluoride Doses from Toothpastes Should be Based on Total Soluble Fluoride

PubMed Central

Oliveira, Maria José L.; Martins, Carolina C.; Paiva, Saul M.; Tenuta, Livia M. A.; Cury, Jaime A.

2013-01-01

The fluoride dose ingested by young children may be overestimated if based on levels of total fluoride (TF) rather than levels of bioavailable fluoride (total soluble fluoride—TSF) in toothpaste. The aim of the present study was to compare doses of fluoride intake based on TF and TSF. Fluoride intake in 158 Brazilian children aged three and four years was determined after tooth brushing with their usual toothpaste (either family toothpaste (n = 80) or children’s toothpaste (n = 78)). The estimated dose (mg F/day/Kg of body weight) of TF or TSF ingested was calculated from the chemical analysis of the toothpastes. Although the ingested dose of TF from the family toothpastes was higher than that from the children’s toothpastes (0.074 ± 0.007 and 0.039 ± 0.003 mg F/day/Kg, respectively; p < 0.05), no difference between types of toothpaste was found regarding the ingested dose based on TSF (0.039 ± 0.005 and 0.039 ± 0.005 mg F/day/Kg, respectively; p > 0.05). The fluoride dose ingested by children from toothpastes may be overestimated if based on the TF of the product. This finding suggests that the ingested dose should be calculated based on TSF. Dose of TSF ingested by children is similar whether family or children’s toothpaste is used. PMID:24189183

Fluoride-elicited developmental testicular toxicity in rats: Roles of endoplasmic reticulum stress and inflammatory response

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Shun; Jiang, Chunyang; Department of Thoracic Surgery, Tianjin Union Medicine Centre, 190 Jieyuan Road, Hongqiao District, Tianjin 300121, Tianjin

Long-term excessive fluoride intake is known to be toxic and can damage a variety of organs and tissues in the human body. However, the molecular mechanisms underlying fluoride-induced male reproductive toxicity are not well understood. In this study, we used a rat model to simulate the situations of human exposure and aimed to evaluate the roles of endoplasmic reticulum (ER) stress and inflammatory response in fluoride-induced testicular injury. Sprague–Dawley rats were administered with sodium fluoride (NaF) at 25, 50 and 100 mg/L via drinking water from pre-pregnancy to gestation, birth and finally to post-puberty. And then the testes of malemore » offspring were studied at 8 weeks of age. Our results demonstrated that fluoride treatment increased MDA accumulation, decreased SOD activity, and enhanced germ cell apoptosis. In addition, fluoride elevated mRNA and protein levels of glucose-regulated protein 78 (GRP78), inositol requiring ER-to-nucleus signal kinase 1 (IRE1), and C/EBP homologous protein (CHOP), indicating activation of ER stress signaling. Furthermore, fluoride also induced testicular inflammation, as manifested by gene up-regulation of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in a nuclear factor-κB (NF-κB)-dependent manner. These were associated with marked histopathological lesions including injury of spermatogonia, decrease of spermatocytes and absence of elongated spermatids, as well as severe ultrastructural abnormalities in testes. Taken together, our results provide compelling evidence that ER stress and inflammation would be novel and significant mechanisms responsible for fluoride-induced disturbance of spermatogenesis and germ cell loss in addition to oxidative stress. - Highlights: • We used a rat model to simulate the situations of human fluoride (F) exposure. • Developmental F exposure induces testicular damage related with oxidative

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

PubMed

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 < 10 -5 -10 -9 ), results consistent with a substantial spatial variance of 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

Coronary fluorine-18-sodium fluoride uptake is increased in healthy adults with an unfavorable cardiovascular risk profile: results from the CAMONA study.

PubMed

Blomberg, Björn A; Thomassen, Anders; de Jong, Pim A; Lam, Marnix G E; Diederichsen, Axel C P; Olsen, Michael H; Mickley, Hans; Mali, Willem P T M; Alavi, Abass; Høilund-Carlsen, Poul F

2017-11-01

Coronary artery fluorine-18-sodium fluoride (F-NaF) uptake reflects coronary artery calcification metabolism and is considered to be an early prognostic marker of coronary heart disease. This study evaluated the relationship between coronary artery F-NaF uptake and cardiovascular risk in healthy adults at low cardiovascular risk. Study participants underwent blood pressure measurements, blood analyses, and coronary artery F-NaF PET/CT imaging. In addition, the 10-year risk for the development of cardiovascular disease, on the basis of the Framingham Risk Score, was estimated. Multivariable linear regression evaluated the dependence of coronary artery F-NaF uptake on cardiovascular risk factors. We recruited 89 (47 men, 42 women) healthy adults aged 21-75 years. Female sex (0.34 kBq/ml; P=0.009), age (0.16 kBq/ml per SD; P=0.002), and BMI (0.42 kBq/ml per SD; P<0.001) were independent determinants of increased coronary artery F-NaF uptake (adjusted R=0.21; P<0.001). Coronary artery F-NaF uptake increased linearly according to the number of cardiovascular risk factors present (P<0.001 for a linear trend). The estimated 10-year risk for the development of cardiovascular disease was on average 2.4 times higher in adults with coronary artery F-NaF uptake in the highest quartile compared with those in the lowest quartile of the distribution (8.0 vs. 3.3%, P<0.001). Our findings indicate that coronary artery F-NaF PET/CT imaging is feasible in healthy adults at low cardiovascular risk and that an unfavorable cardiovascular risk profile is associated with a marked increase in coronary artery F-NaF uptake.

Fluoride exposure changed the structure and the expressions of HSP related genes in testes of pubertal rats.

PubMed

Zhao, Yangfei; Zhao, Jun; Wang, Jinming; Wang, Jundong

2017-10-01

Previous studies have indicated that fluoride exposure damaged the male reproductive function; however, the cellular mechanism of fluoride-induced testicular toxicity is still unclear. In this study, twenty-two female pregnant Wistar rats were allotted randomly to two groups: control (deionized water) and sodium fluoride (NaF, contain F - : 67.86 mg/L) groups. After delivery, the dosage was continued for 15 weeks for puppies. Twelve rats in each group were tested at 6 and 9 (pubertal); 12 and 15 (mature) weeks of age. Our results suggested that organ coefficient of epididymis was significantly decreased in the mature (12 and 15 week-old) rats. Epididymal sperm abnormality and femur fluoride concentration were increased with the concomitant decrease in sperm motility and concentration in these experimental periods. Compared to the control, in the NaF group, the seminiferous tubules of each age were reduced in terms of diameter and thickness. The sperm cells were lost and shedding and finally disappeared after 9 weeks. mRNA and protein levels of HSP27 and 90 were decreased with a concomitant increase in HSP70 and HSF mRNA and protein levels in NaF exposed rats. The mRNA and protein levels of HSP27 and HSF (only mRNA) were significantly increased in NaF treated rats at 9 and 15 weeks of age, respectively. In summary, these results emphasize that NaF induces testicular and sperm abnormalities through the involvement of HSPs especially during the pubertal period. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

PubMed

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; P<0.05), properly increased TSH level 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.

Mechanochemical synthesis, structure and properties of lead containing alkaline earth metal fluoride solid solutions MxPb1-xF2 (M = Ca, Sr, Ba)

NASA Astrophysics Data System (ADS)

Heise, M.; Scholz, G.; Düvel, A.; Heitjans, P.; Kemnitz, E.

2018-03-01

The paper deals with the mechanochemical synthesis of lead containing alkaline earth metal fluoride solid solutions MxPb1-xF2 (M = Ca, Sr, Ba) by high-energy ball milling. Several metal precursors and fluorinating agents were tested for synthesizing M0.5Pb0.5F2. Metal acetates and ammonium fluoride as precursors show the most promising results and were therefore used for the formation of MxPb1-xF2 with different metal cationic ratios. The characterization of the local fluorine coordination and the crystal structure was performed by 19F MAS NMR spectroscopy and X-ray diffraction. Additional calculations of 19F chemical shifts using the superposition model allow a deeper insight into the local structure of the compounds. The fluoride ion conductivity was followed by temperature dependent DC conductivity measurements. Significantly higher conductivities were found in comparison with those of the corresponding binary fluorides. The highest values were observed for samples with high lead content M0.25Pb0.75F2, bearing in mind the much higher conductivity of PbF2 compared to MF2.

DELAYED TOOTH REPLANTATION AFTER ROOT SURFACE TREATMENT WITH SODIUM HYPOCHLORITE AND SODIUM FLUORIDE: HISTOMORPHOMETRIC ANALYSIS IN RATS

PubMed Central

Sottovia, André Dotto; Sonoda, Celso Koogi; Poi, Wilson Roberto; Panzarini, Sônia Regina; Lauris, José Roberto Pereira

2006-01-01

In cases of delayed tooth replantation, non-vital periodontal ligament remnants have been removed with sodium hypochlorite in an attempt to control root resorption. Nevertheless, reports of its irritating potential in contact with the alveolar connective tissue have been described. Therefore, this study evaluated the healing process on delayed replantation of rat teeth, after periodontal ligament removal by different treatment modalities. Twenty-four rats, assigned to 3 groups (n=8), had their upper right incisor extracted and left on the workbench for desiccation during 60 min. Afterwards, the teeth in group I were immersed in saline for 2 min. In group II, root surfaces were scrubbed with gauze soaked in saline for 2 min; and in group III, scrubbing was done with gauze soaked in 1% sodium hypochlorite solution. Thereafter, root surfaces were etched with 37% phosphoric acid and immersed in 2% acidulate-phosphate sodium fluoride solution, at pH 5.5. Root canals were filled with a calcium hydroxide-based paste and the teeth were replanted. The animals were sacrificed 60 days postoperatively and the pieces containing the replanted teeth were processed and paraffin-embedded. Semi-serial transversally sections were obtained from the middle third of the root and stained with hematoxylin and eosin for histomorphometric analysis. Data were analyzed statistically using Kruskal-Wallis and Dunn's tests. The results showed that root structure and cementum extension were more affected by resorption in group III (p<0.05). All groups were affected by root resorption but the treatment performed in group III was the least effective for its control. The treatment accomplished in groups I and II yielded similar results to each other. PMID:19089038

Delayed tooth replantation after root surface treatment with sodium hypochlorite and sodium fluoride: histomorphometric analysis in rats.

PubMed

Sottovia, André Dotto; Sonoda, Celso Koogi; Poi, Wilson Roberto; Panzarini, Sônia Regina; Lauris, José Roberto Pereira

2006-04-01

In cases of delayed tooth replantation, non-vital periodontal ligament remnants have been removed with sodium hypochlorite in an attempt to control root resorption. Nevertheless, reports of its irritating potential in contact with the alveolar connective tissue have been described. Therefore, this study evaluated the healing process on delayed replantation of rat teeth, after periodontal ligament removal by different treatment modalities. Twenty-four rats, assigned to 3 groups (n=8), had their upper right incisor extracted and left on the workbench for desiccation during 60 min. Afterwards, the teeth in group I were immersed in saline for 2 min. In group II, root surfaces were scrubbed with gauze soaked in saline for 2 min; and in group III, scrubbing was done with gauze soaked in 1% sodium hypochlorite solution. Thereafter, root surfaces were etched with 37% phosphoric acid and immersed in 2% acidulate-phosphate sodium fluoride solution, at pH 5.5. Root canals were filled with a calcium hydroxide-based paste and the teeth were replanted. The animals were sacrificed 60 days postoperatively and the pieces containing the replanted teeth were processed and paraffin- embedded. Semi-serial transversally sections were obtained from the middle third of the root and stained with hematoxylin and eosin for histomorphometric analysis. Data were analyzed statistically using Kruskal-Wallis and Dunn's tests. The results showed that root structure and cementum extension were more affected by resorption in group III (p<0.05). All groups were affected by root resorption but the treatment performed in group III was the least effective for its control. The treatment accomplished in groups I and II yielded similar results to each other.

Fluorides and non-fluoride remineralization systems.

PubMed

Amaechi, Bennett T; van Loveren, Cor

2013-01-01

Caries develops when the equilibrium between de- and remineralization is unbalanced favoring demineralization. De- and remineralization occur depending on the degree of saturation of the interstitial fluids with respect to the tooth mineral. This equilibrium is positively influenced when fluoride, calcium and phosphate ions are added favoring remineralization. In addition, when fluoride is present, it will be incorporated into the newly formed mineral which is then less soluble. Toothpastes may contain fluoride and calcium ions separately or together in various compounds (remineralization systems) and may therefore reduce demineralization and promote remineralization. Formulating all these compounds in one paste may be challenging due to possible premature calcium-fluoride interactions and the low solubility of CaF2. There is a large amount of clinical evidence supporting the potent caries preventive effect of fluoride toothpastes indisputably. The amount of clinical evidence of the effectiveness of the other remineralization systems is far less convincing. Evidence is lacking for head to head comparisons of the various remineralization systems. Copyright © 2013 S. Karger AG, Basel.

The Impact of Selected Fluoridated Toothpastes on Dental Erosion in Profilometric Measurement.

PubMed

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.

The effects of fluoride on neuronal function occurs via cytoskeleton damage and decreased signal transmission.

PubMed

Chen, Lingli; Ning, Hongmei; Yin, Zhihong; Song, Xiaochao; Feng, Yongchao; Qin, Hao; Li, Yi; Wang, Jundong; Ge, Yaming; Wang, Wenkui

2017-10-01

It has been reported that fluoride exposure may cause serious public health problems, particularly neurotoxicity. However, the underlying mechanisms remain unclear. This study used Neuro-2A cells to investigate the effects of fluoride on the cytoskeleton. The Neuro-2A cells were exposed to 0, 1, 2, 4 and 6 mM sodium fluoride (NaF) for 24 h. Cell viability and lactate dehydrogenase (LDH) release were examined. It was observed that exposure to NaF reduced cell viability, disrupted cellular membrane integrity, and high levels of LDH were released. The observed changes occurred in a dose response manner. Morphologic observations showed that cell became rounded and were loosely adherent following exposure to NaF. Axon spines and normal features disappeared with high dose NaF treatment. The expression of MAP2 and synaptophysin decreased, particularly at 4 mM and 6 mM (P < 0.05) for MAP2. These results corroborate the morphologic observations. The content of glutamate and NMDAR (glutamate receptor) protein were assessed to help understand the relationship between synapses and neurotransmitter release using ELISA and Western-blot. Compared with the control, glutamate and NMDAR expression declined significantly at 4 mM and 6 mM (P < 0.05) group. Finally, the ultrastructural changes observed with increasing doses of NaF were: disappearance of synapses, mitochondrial agglutination, vacuole formation, and cellular edema. Taken together, NaF exposure disrupted cellular integrity and suppressed the release of neurotransmitters, thus effecting neuronal function. These findings provide deeper insights into roles of NaF in neuron damage, which could contribute to a better understanding of fluoride-induced neurotoxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

NMR parameters in column 13 metal fluoride compounds (AlF₃, GaF₃, InF₃ and TlF) from first principle calculations.

PubMed

Sadoc, Aymeric; Biswal, Mamata; Body, Monique; Legein, Christophe; Boucher, Florent; Massiot, Dominique; Fayon, Franck

2014-01-01

The relationship between the experimental (19)F isotropic chemical shift and the (19)F isotropic shielding calculated using the gauge including projector augmented-wave (GIPAW) method with PBE functional is investigated in the case of GaF3, InF3, TlF and several AlF3 polymorphs. It is shown that the linear correlation between experimental and DFT-PBE calculated values previously established on alkali, alkaline earth and rare earth of column 3 basic fluorides (Sadoc et al., Phys. Chem. Chem. Phys. 13 (2011) 18539-18550) remains valid in the case of column 13 metal fluorides, indicating that it allows predicting (19)F solid state NMR spectra of a broad range of crystalline fluorides with a relatively good accuracy. For the isostructural α-AlF3, GaF3 and InF3 phases, PBE-DFT geometry optimization leads to noticeably overbended M-F-M bond angles and underestimated (27)Al, (71)Ga and (115)In calculated quadrupolar coupling constants. For the studied compounds, whose structures are built of corner shared MF6 octahedra, it is shown that the electric field gradient (EFG) tensor at the cationic sites is not related to distortions of the octahedral units, in contrast to what previously observed for isolated AlF6 octahedra in fluoroaluminates. Copyright © 2014 Elsevier Inc. All rights reserved.

Drinking water quality and fluoride concentration.

PubMed

Frazão, Paulo; Peres, Marco A; Cury, Jaime A

2011-10-01

This paper aimed to analyze the fluoride concentration in drinking water, taking into account the balance between the benefits and risks to health, in order to produce scientific backing for the updating of the Brazilian legislation. Systematic reviews studies, official documents and meteorological data were examined. The temperatures in Brazilian state capitals indicate that fluoride levels should be between 0.6 and 0.9 mg F/l in order to prevent dental caries. Natural fluoride concentration of 1.5 mg F/l is tolerated for consumption in Brazil if there is no technology with an acceptable cost-benefit ratio for adjusting/removing the excess. Daily intake of water with a fluoride concentration > 0.9 mg F/l presents a risk to the dentition among children under the age of eight years, and consumers should be explicitly informed of this risk. In view of the expansion of the Brazilian water fluoridation program to regions with a typically tropical climate, Ordinance 635/75 relating to fluoride added to the public water supply should be revised.

PROCESS FOR TREATING VOLATILE METAL FLUORIDES

DOEpatents

Rudge, A.J.; Lowe, A.J.

1957-10-01

This patent relates to the purification of uranium hexafluoride, made by reacting the metal or its tetrafluoride with fluorine, from the frequently contained traces of hydrofluoric acid. According to the present process, UF/sub 6/ containing as an impurity a small amount of hydrofluoric acid, is treated to remove such impurity by contact with an anhydrous alkali metal fluoride such as sodium fluoride. In this way a non-volatile complex containing hydrofluoric acid and the alkali metal fluoride is formed, and the volatile UF /sub 6/ may then be removed by distillation.

Fluoride metabolism.

PubMed

Buzalaf, Marília Afonso Rabelo; Whitford, Gary Milton

2011-01-01

Knowledge of all aspects of fluoride metabolism is essential for comprehending the biological effects of this ion in humans as well as to drive the prevention (and treatment) of fluoride toxicity. Several aspects of fluoride metabolism - including gastric absorption, distribution and renal excretion - are pH-dependent because the coefficient of permeability of lipid bilayer membranes to hydrogen fluoride (HF) is 1 million times higher than that of F(-). This means that fluoride readily crosses cell membranes as HF, in response to a pH gradient between adjacent body fluid compartments. After ingestion, plasma fluoride levels increase rapidly due to the rapid absorption from the stomach, an event that is pH-dependent and distinguishes fluoride from other halogens and most other substances. The majority of fluoride not absorbed from the stomach will be absorbed from the small intestine. In this case, absorption is not pH-dependent. Fluoride not absorbed will be excreted in feces. Peak plasma fluoride concentrations are reached within 20-60 min following ingestion. The levels start declining thereafter due to two main reasons: uptake in calcified tissues and excretion in urine. Plasma fluoride levels are not homeostatically regulated and vary according to the levels of intake, deposition in hard tissues and excretion of fluoride. Many factors can modify the metabolism and effects of fluoride in the organism, such as chronic and acute acid-base disturbances, hematocrit, altitude, physical activity, circadian rhythm and hormones, nutritional status, diet, and genetic predisposition. These will be discussed in detail in this review. Copyright © 2011 S. Karger AG, Basel.

Fluoride-induced iron overload contributes to hepatic oxidative damage in mouse and the protective role of Grape seed proanthocyanidin extract.

PubMed

Niu, Qiang; He, Ping; Xu, Shangzhi; Ma, Ruling; Ding, Yusong; Mu, Lati; Li, Shugang

2018-01-01

Emerging evidence has demonstrated that iron overload plays an important role in oxidative stress in the liver. This study aimed to explore whether fluoride-induced hepatic oxidative stress is associated with iron overload and whether grape seed proanthocyanidin extract (GSPE) alleviates oxidative stress by reducing iron overload. Forty Kunming male mice were randomly divided into 4 groups and treated for 5 weeks with distilled water (control), sodium fluoride (NaF) (100 mg/L), GSPE (400 mg/kg bw), or NaF (100 mg/L) + GSPE (400 mg/kg bw). Mice exposed to NaF showed typical poisoning changes of morphology, increased aspartate aminotransferase and alanine aminotransferase activities in the liver. NaF treatment also increased MDA accumulation, decreased GSH-Px, SOD and T-AOC levels in liver, indicative of oxidative stress. Intriguingly, all these detrimental effects were alleviated by GSPE. Further study revealed that NaF induced disorders of iron metabolism, as manifested by elevated iron level with increased hepcidin but decreased ferroportin expression, which contributed to hepatic oxidative stress. Importantly, the iron dysregulation induced by NaF could be normalized by GSPE. Collectively, these data provide a novel insight into mechanisms underlying fluorosis and highlight the potential of GSPE as a naturally occurring prophylactic treatment for fluoride-induced hepatotoxicity associated with iron overload.

Influence of bioadhesive polymers on the protective effect of fluoride against erosion.

PubMed

Ávila, Daniele Mara da Silva; Zanatta, Rayssa Ferreira; Scaramucci, Tais; Aoki, Idalina Vieira; Torres, Carlos Rocha Gomes; Borges, Alessandra Bühler

2017-01-01

This study investigated if the incorporation of the bioadhesive polymers Carbopol 980, Carboxymethyl cellulose (CMC), and Aristoflex AVC in a fluoridated solution (NaF-900ppm) would increase the solution's protective effect against enamel erosion. Enamel specimens were submitted to a 5-day de-remineralization cycling model, consisting of 2min immersions in 0.3% citric acid (6x/day), 1min treatments with the polymers (associated or not with fluoride), and 60min storage in artificial saliva. Ultrapure water was used as the negative control and a 900ppm fluoride solution as positive control. The initial Knoop microhardness (KHN1) was used to randomize the samples into groups. Another two microhardness assessments were performed after the first (KHN2) and second (KHN3) acid immersions, to determine initial erosion in the first day. The formula: %KHN alt =[(KHN3-KHN2)/KHN2]*100 was used to define the protective effect of the treatments. After the 5-day cycling, surface loss (SL, in μm) was evaluated with profilometry. Data were analyzed with 2-way ANOVA and Tukey's tests (p<0.05). For %KHN alt , the polymers alone did not reduce enamel demineralization when compared to the negative control, but Carbopol associated with NaF significantly improved its protective effect. The profilometric analysis showed that Carbopol, associated or not with NaF, exhibited the lowest SL, while CMC and Aristoflex did not exhibit a protective effect, nor were they able to improve the protection of NaF. It is concluded that Carbopol enhanced NaF's protection against initial erosion. Carbopol alone or associated with NaF was able to reduce SL after several erosive challenges. Carbopol by itself was able to reduce the erosive wear magnitude to the same extent as the sodium fluoride, therefore, is a promising agent to prevent or control enamel erosion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Boosting the oxidase mimicking activity of nanoceria by fluoride capping: rivaling protein enzymes and ultrasensitive F- detection

NASA Astrophysics Data System (ADS)

Liu, Biwu; Huang, Zhicheng; Liu, Juewen

2016-07-01

Nanomaterial-based enzyme mimics (nanozymes) are currently a new forefront of chemical research. However, the application of nanozymes is limited by their low catalytic activity and low turnover numbers. Cerium dioxide nanoparticles (nanoceria) are among the few with oxidase activity. Herein, we report an interesting finding addressing their limitations. The oxidase activity of nanoceria is improved by over 100-fold by fluoride capping, making it more close to real oxidases. The turnover number reached 700 in 15 min, drastically improved from ~15 turnovers for the naked particles. The mechanism is attributed to surface charge modulation and facilitated electron transfer by F- capping based on ζ-potential and free radical measurements. Ultrasensitive sensing of fluoride was achieved with a detection limit of 0.64 μM F- in water and in toothpastes, while no other tested anions can achieve the activity enhancement.Nanomaterial-based enzyme mimics (nanozymes) are currently a new forefront of chemical research. However, the application of nanozymes is limited by their low catalytic activity and low turnover numbers. Cerium dioxide nanoparticles (nanoceria) are among the few with oxidase activity. Herein, we report an interesting finding addressing their limitations. The oxidase activity of nanoceria is improved by over 100-fold by fluoride capping, making it more close to real oxidases. The turnover number reached 700 in 15 min, drastically improved from ~15 turnovers for the naked particles. The mechanism is attributed to surface charge modulation and facilitated electron transfer by F- capping based on ζ-potential and free radical measurements. Ultrasensitive sensing of fluoride was achieved with a detection limit of 0.64 μM F- in water and in toothpastes, while no other tested anions can achieve the activity enhancement. Electronic supplementary information (ESI) available: Methods, TMB oxidation kinetics and control experiments. See DOI: 10.1039/c6nr02730j

The role of fluoride and chlorhexidine in preserving hardness and mineralization of enamel and cementum after gamma irradiation.

PubMed

Abdalla, Rowida; Niazy, Maha A; Jamil, Wael E; Hazzaa, Hala A; Elbatouti, Amal A

2017-05-01

The purpose of this study was to evaluate the effect of 0.05% sodium fluoride and 0.12% chlorhexidine mouthwashes on the micro-hardness of tooth enamel and cementum that was exposed to therapeutic doses of gamma radiation. Sixty extracted human teeth were divided into two groups, one was irradiated, the other was not irradiated. The two groups were further subdivided into three subgroups, which were each treated either with 0.05% sodium fluoride or with 0.12% chlorhexidine; the third subgroup served as a control. After demineralization-remineralization cycling, teeth from the irradiated groups showed a significantly lower micro-hardness when compared to those from the non-irradiated groups. Both in the irradiated and non-irradiated groups, teeth from the control subgroups showed a significantly lower micro-hardness, as compared to teeth treated with sodium fluoride and chlorhexidine. For non-irradiated enamel samples, those treated with chlorhexidine showed a significantly less micro-hardness compared to those treated with sodium fluoride. In contrast, irradiated enamel showed no significant difference in micro-hardness, whatever treatment (chlorhexidine or sodium fluoride) was applied. For cementum, treatment with chlorhexidine resulted in a significantly lower micro-hardness compared to sodium fluoride, both for the irradiated and non-irradiated groups. It is concluded that gamma irradiation with therapeutic doses typically used for head and neck carcinoma treatment has a direct effect in reducing micro-hardness of tooth enamel and cementum. Mouthwash protocols including, for example, application of 0.05% sodium fluoride or 0.12% chlorhexidine three times per day for 6 weeks, can protect enamel and cementum against the reduction in hardness and demineralization caused by gamma irradiation. Sodium fluoride offers more protection compared to chlorhexidine.

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

PubMed

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.

Quantitative studies of bone using (18)F-fluoride and (99m)Tc-methylene diphosphonate: evaluation of renal and whole-blood kinetics.

PubMed

Park-Holohan, S J; Blake, G M; Fogelman, I

2001-09-01

We report a study of the renal and whole-blood kinetics of (18)F-fluoride and (99m)Tc-methylene diphosphonate ((99m)Tc-MDP) and their effect on the evaluation of the skeletal kinetics of the two bone tracers. Data were obtained during an investigation of postmenopausal women taking hormone replacement therapy who were compared with untreated, age-matched controls. After intravenous injection of 18F-fluoride (1 MBq), (99m)Tc-MDP (1 MBq), (51)Cr-ethylenediaminetetraacetic acid (51Cr-EDTA) (3 MBq) and (125)I-human serum albumin ((125)I-HSA) (0.25 MBq), multiple blood samples and urine collections were taken between 0 and 4 h after injection. (51)Cr-EDTA data were used to evaluate the glomerular filtration rate (GFR) and the completeness of each timed urine collection. (125)I-HSA data were used to evaluate the plasma volume and the red cell uptake of the other three tracers. At 4 h, the cumulative urine excretions (and standard deviations, SDs) were: (99m)Tc-MDP, 58.2% (4.8%); (18)F-fluoride, 36.1% (5.7%); (51)Cr-EDTA, 81.5% (4.5%). Plots of the renal clearance of (18)F-fluoride against urine volume showed that urine flow rates greater than 5 ml.min-1 were necessary to ensure a constant renal clearance of (18)F and hence stable conditions for the evaluation of bone tracer kinetics. In contrast, a low urine flow rate had no effect on the renal kinetics of (99m)Tc-MDP. For MDP, the evaluation of skeletal kinetics requires data on protein binding so that calculations can be performed for free MDP. In the present study, protein binding of MDP was evaluated from the ratio of total (99m)Tc-MDP renal clearance to GFR based on the principle that free (99m)Tc-MDP is a GFR tracer. Between 0 and 4 h after injection, the fractional protein binding of MDP increased linearly with time, changing from 21+/-5% immediately after injection to 58+/-5% at 4 h. Although red cell uptake of (99m)Tc-MDP was negligible, for (18)F-fluoride around 30% of circulating tracer was transported in red

A clinical investigation of the efficacy of a dentifrice containing 1.5% arginine and 1450 ppm fluoride, as sodium monofluorophosphate in a calcium base, on primary root caries.

PubMed

Hu, D Y; Yin, W; Li, X; Feng, Y; Zhang, Y P; Cummins, D; Mateo, L R; Ellwood, R P

2013-01-01

The purpose of this six-month study was to assess the ability of a new dentifrice containing 1.5% arginine, an insoluble calcium compound, and 1450 ppm fluoride, as sodium monofluorophosphate, to arrest and reverse primary root caries lesions in adults. Three test groups used dentifrices which contained either: 1) 1.5% arginine and 1450 ppm fluoride as sodium monofluorophosphate in a calcium base (experimental); 2) 1450 ppm fluoride as sodium fluoride in a silica base (positive control); or 3) no fluoride in a calcium base (negative control). The study participants were residents of the city of Chengdu, Sichuan Province, China. In order to take part, subjects had to have at least one non-cavitated primary root caries lesion. A total of 412 subjects completed the study. They were aged from 50 to 70 years (mean age 64 +/- 4.1 years) and 53.6% were female. Efficacy for arresting and reversal of primary root caries was assessed by clinical hardness measures and through the use of the Electrical Caries Monitor. After three months of product use, clinical hardness measures showed that 27.7%, 24.6%, and 13.1% of lesions had improved in the experimental, positive, and negative control groups, respectively, and 0.7%, 4.5%, and 16.8% had become worse, respectively. The differences in the distribution of lesion change between the negative control group and both the experimental (p < 0.001) and positive control (p = 0.001) were statistically significant. The Electrical Caries Monitor was also used as an objective measure of lesion severity. The end values increased from baseline to the three-month examinations, but none of the differences between the groups attained statistical significance. After six months, clinical hardness measures showed that only one lesion (0.7%) was worse than at the baseline examination-in the experimental group compared to 9.0% and 18.2% in the positive and negative control groups, respectively. In addition, 61.7%, 56.0%, and 27.0%, respectively

Water fluoridation and osteoporotic fracture.

PubMed

Hillier, S; Inskip, H; Coggon, D; Cooper, C

1996-09-01

Osteoporotic fractures constitute a major public health problem. These fractures typically occur at the hip, spine and distal forearm. Their pathogenesis is heterogeneous, with contributions from both bone strength and trauma. Water fluoridation has been widely proposed for its dental health benefits, but concerns have been raised about the balance of skeletal risks and benefits of this measure. Fluoride has potent effects on bone cell function, bone structure and bone strength. These effects are mediated by the incorporation of fluoride ions in bone crystals to form fluoroapatite, and through an increase in osteoblast activity. It is believed that a minimum serum fluoride level of 100 ng/ml must be achieved before osteoblasts will be stimulated. Serum levels associated with drinking water fluoridated to 1 ppm are usually several times lower than this value, but may reach this threshold at concentrations of 4 ppm in the drinking water. Animal studies suggest no effect of low-level (0-3 ppm) fluoride intake on bone strength, but a possible decrease at higher levels. Sodium fluoride has been used to treat established osteoporosis for nearly 30 years. Recent trials of this agent, prescribed at high doses, have suggested that despite a marked increase in bone mineral density, there is no concomitant reduction in vertebral fracture incidence. Furthermore, the increase in bone density at the lumbar spine may be achieved at the expense of bone mineral in the peripheral cortical skeleton. As a consequence, high dose sodium fluoride (80 mg daily) is not currently used to treat osteoporosis. At lower doses, recent trials have suggested a beneficial effect on both bone density and fracture. The majority of epidemiological evidence regarding the effect of fluoridated drinking water on hip fracture incidence is based on ecological comparisons. Although one Finnish study suggested that hip fracture rates in a town with fluoridated water were lower than those in a matching town

Fluorescent Sensing of Fluoride in Cellular System

PubMed Central

Jiao, Yang; Zhu, Baocun; Chen, Jihua; Duan, Xiaohong

2015-01-01

Fluoride ions have the important roles in a lot of physiological activities related with biological and medical system, such as water fluoridation, caries treatment, and bone disease treatment. Great efforts have been made to develop new methods and strategies for F- detection in the past decades. Traditional methods for the detection of F- including ion chromatography, ion-selective electrodes, and spectroscopic techniques have the limitations in the biomedicine research. The fluorescent probes for F- are very promising that overcome some drawbacks of traditional fluoride detection methods. These probes exhibit high selectivity, high sensitivity as well as quick response to the detection of fluoride anions. The review commences with a brief description of photophysical mechanisms for fluorescent probes for fluoride, including photo induced electron transfer (PET), intramolecular charge transfer (ICT), fluorescence resonance energy transfer (FRET), and excited-state intramolecular proton transfer (ESIPT). Followed by a discussion about common dyes for fluorescent fluoride probes, such as anthracene, naphalimide, pyrene, BODIPY, fluorescein, rhodamine, resorufin, coumarin, cyanine, and near-infrared (NIR) dyes. We divide the fluorescent probes for fluoride in cellular application systems into nine groups, for example, type of hydrogen bonds, type of cleavage of Si-O bonds, type of Si-O bond cleavage and cylization reactions, etc. We also review the recent reported carriers in the delivery of fluorescent fluoride probes. Seventy-four typical fluorescent fluoride probes are listed and compared in detail, including quantum yield, reaction medium, excitation and emission wavelengths, linear detection range, selectivity for F-, mechanism, and analytical applications. Finally, we discuss the future challenges of the application of fluorescent fluoride probes in cellular system and in vivo. We wish that more and more excellent fluorescent fluoride probes will be developed

High pressure synthesis and properties of ternary titanium (III) fluorides in the system KF-TiF 3 containing regular pentagonal bipyramids [TiF 7

NASA Astrophysics Data System (ADS)

Yamanaka, Shoji; Yasuda, Akira; Miyata, Hajime

2010-01-01

Titanium trifluoride TiF 3 has the distorted ReO 3 structure composed of corner sharing TiF 6 octahedra linked with Ti-F-Ti bridges. Potassium fluoride KF was inserted into the bridges using high-pressure and high-temperature conditions (5 GPa, 1000-1200 °C). When the molar ratio KF/TiF 3≥1, a few low dimensional compounds were obtained forming non-bridged F ions. At the composition KF/TiF 3=1/2, a new compound KTi 2F 7 was formed, which crystallizes with the space group Cmmm and the lattice parameters of a=6.371(3), b=10.448(6), c=3.958(2) Å, consisting of edge-sharing pentagonal bipyramids [TiF 7] forming ribbons running along the a axis. The ribbons are linked by corners to construct a three-dimensional framework without forming non-bridged F ions. The compound is antiferromagnetic with the Néel temperature T N=75 K, and the optical band gap was 6.4 eV. A new fluoride K 2TiF 5 (KF/TiF 3=2) with the space group Pbcn and the lattice parameters of a=7.4626(2), b=12.9544(4) and c=20.6906(7) Å was also obtained by the high pressure and high temperature treatment (5 GPa at 1000 °C) of a molar mixture of 2 KF+TiF 3. The compound contains one-dimensional chains of corner-sharing TiF 6 octahedra.

Sol-Gel-Synthesis of Nanoscopic Complex Metal Fluorides

PubMed Central

Rehmer, Alexander; Scheurell, Kerstin; Scholz, Gudrun; Kemnitz, Erhard

2017-01-01

The fluorolytic sol-gel synthesis for binary metal fluorides (AlF3, CaF2, MgF2) has been extended to ternary and quaternary alkaline earth metal fluorides (CaAlF5, Ca2AlF7, LiMgAlF6). The formation and crystallization of nanoscopic ternary CaAlF5 and Ca2AlF7 sols in ethanol were studied by 19F liquid and solid state NMR (nuclear magnetic resonance) spectroscopy, as well as transmission electron microscopy (TEM). The crystalline phases of the annealed CaAlF5, Ca2AlF7, and LiMgAlF6 xerogels between 500 and 700 °C could be determined by X-ray powder diffraction (XRD) and 19F solid state NMR spectroscopy. The thermal behavior of un-annealed nanoscopic ternary and quaternary metal fluoride xerogels was ascertained by thermal analysis (TG/DTA). The obtained crystalline phases of CaAlF5 and Ca2AlF7 derived from non-aqueous sol-gel process were compared to crystalline phases from the literature. The corresponding nanoscopic complex metal fluoride could provide a new approach in ceramic and luminescence applications. PMID:29099086

Fluoride Binding to Dental Biofilm Bacteria: Synergistic Effect with Calcium Questioned.

PubMed

Nóbrega, Diego Figueiredo; Leitão, Tarcísio Jorge; Cury, Jaime Aparecido; Tenuta, Livia Maria Andaló

2018-06-06

It has been suggested that fluoride binding to dental biofilm is enhanced when more bacterial calcium binding sites are available. However, this was only observed at high calcium and fluoride concentrations (i.e., when CaF2 precipitation may have occurred). We assessed fluoride binding to Streptococcus mutans pellets treated with calcium and fluoride at concentrations allowing CaF2 precipitation or not. Increasing calcium concentration resulted in a linear increase (p < 0.01) in fluoride concentration only in the pellets in which CaF2 precipitated. The results suggest that CaF2 precipitation, rather than bacterially bound fluoride, is responsible for the increase in fluoride binding to dental biofilm with the increase in calcium availability. © 2018 S. Karger AG, Basel.

[Fluoride toxicity].

PubMed

Giachini, M; Pierleoni, F

2004-04-01

Many years have passed since domestic water fluoridation was adopted to reduce the incidence of caries in developed countries; however, since there is an additional dose of fluorides ingested with foods and drinks prepared with such waters, the problem has emerged of possible adverse effects on health associated to them, so that in some countries fluorine integrator selling is allowed only with preventive medical prescription. Owing to the affinity for calcifited tissues, fluorine has a powerful effect on bone cellular order (mediated by growth factors' upregulation system IGF-2, TGF-beta, PDGF, bFGF, EGF, BMP-2 and PTH), on function and length, since it can provoke chronic joints-pain, ligaments-calcification, osteosclerosis. Moreover, sodium-fluoride may cause adverse effects on testicular activity (connected to oxidative-stress depending on increased activity of peroxidases and catalases) due to inhibition of 2 androgenesis-regulator enzymes DELTA(5)b-HSD and 17beta-HSD. Furthermore, insoluble gut formed calcium-fluoride may be responsible for hypocalcemia inducing a secondary hyperparathyroidism with bone matrix resorption, osteoporosis, osteomalacia and, perhaps, lowered level of phosphorus. At encephalic level, then, high doses of fluorine cause the onset of neurological symptoms and of a decreased spontaneous motor activity due to a reduction in the number of nicotinic acetylcholine receptors. Nevertheless, epidemiological studies about fluoride toxicity have established that such oligoelement may be safely used at odontoiatric dosages.

[18F]-NaF PET/CT imaging in cardiac amyloidosis.

PubMed

Van Der Gucht, Axel; Galat, Arnault; Rosso, Jean; Guellich, Aziz; Garot, Jérôme; Bodez, Diane; Plante-Bordeneuve, Violaine; Hittinger, Luc; Dubois-Randé, Jean-Luc; Evangelista, Eva; Sasanelli, Myriam; Chalaye, Julia; Meignan, Michel; Itti, Emmanuel; Damy, Thibaud

2016-08-01

Cardiac amyloidosis (CA) is recognized as a common cause of restrictive cardiomyopathy and heart failure due to the deposition of insoluble proteins in the myocardial interstitium. We emphasize the role of [18F]-sodium fluoride (NaF) PET/CT as a potential noninvasive tool to identify and differentiate the transthyretin-related cardiac amyloidosis from the light-chain cardiac amyloidosis. We report cases of a 73-year-old man and a 75-year-old woman followed in our center for congestive heart failure with marked alteration of the left ventricular ejection fraction due to familial transthyretin Val122Ile cardiac amyloidosis and light-chain cardiac amyloidosis, respectively, confirmed on endomyocardial biopsy.

Preparation of high density heavy metal fluoride glasses with extended ultraviolet and infra red ranges, and such high density heavy metal fluoride glasses

NASA Technical Reports Server (NTRS)

Martin, Steven W. (Inventor); Huebsch, Jesse (Inventor)

2001-01-01

A heavy metal fluoride glass composition range (in mol percent) consisting essentially of: (16-30)BaF.sub.2.(8-26)HfF.sub.4.(6-24)InF.sub.3 or GaF.sub.3.(4-16)CdF.sub.2.(6-24)YbF.sub.3.(4-22)ZnF.sub.2. In an alternative embodiment, a heavy metal fluoride glass composition range (in mol percent) comprises (16-30)BaF.sub.2.(8-26)HfF.sub.4.(6-24) of (0-24)InF.sub.3, (0-24)GaF.sub.3 and (0-19)AlF.sub.3.(1-16)CdF.sub.2.(6-24)YbF.sub.3.(4-26)ZnF.sub.2. A preferred heavy metal fluoride glass produced in accordance with the present invention comprises a composition (in mol %) and comprises about 26BaF.sub.2.18HfF.sub.4.7InF.sub.3.5GaF.sub.3.10CdF.sub.2.18YbF.sub.3. 16ZnF.sub.2. A preferred heavy metal fluoride glass has maximum thickness of most preferably about 3 mm. Another preferred heavy metal fluoride glass comprises a composition (in mol %) and comprises about 26BaF.sub.2.18HfF.sub.4.12AlF.sub.3.10CdF.sub.2.18YbF.sub.3.16ZnF.sub.2.

New Fluoride-arsenide Diluted Magnetic Semiconductor (Ba,K)F(Zn,Mn)As with Independent Spin and Charge Doping

NASA Astrophysics Data System (ADS)

Chen, Bijuan; Deng, Zheng; Li, Wenmin; Gao, Moran; Liu, Qingqing; Gu, C. Z.; Hu, F. X.; Shen, B. G.; Frandsen, Benjamin; Cheung, Sky; Lian, Liu; Uemura, Yasutomo J.; Ding, Cui; Guo, Shengli; Ning, Fanlong; Munsie, Timothy J. S.; Wilson, Murray Neff; Cai, Yipeng; Luke, Graeme; Guguchia, Zurab; Yonezawa, Shingo; Li, Zhi; Jin, Changqing

2016-11-01

We report the discovery of a new fluoride-arsenide bulk diluted magnetic semiconductor (Ba,K)F(Zn,Mn)As with the tetragonal ZrCuSiAs-type structure which is identical to that of the “1111” iron-based superconductors. The joint hole doping via (Ba,K) substitution & spin doping via (Zn,Mn) substitution results in ferromagnetic order with Curie temperature up to 30 K and demonstrates that the ferromagnetic interactions between the localized spins are mediated by the carriers. Muon spin relaxation measurements confirm the intrinsic nature of the long range magnetic order in the entire volume in the ferromagnetic phase. This is the first time that a diluted magnetic semiconductor with decoupled spin and charge doping is achieved in a fluoride compound. Comparing to the isostructure oxide counterpart of LaOZnSb, the fluoride DMS (Ba,K)F(Zn,Mn)As shows much improved semiconductive behavior that would be benefit for further application developments.

Impacts of sodium hydroxide and sodium hypochlorite aging on polyvinylidene fluoride membranes fabricated with different methods.

PubMed

Wu, Qilong; Zhang, Xihui; Cao, Guodong

2018-05-01

This study compared the effects of chemical aging on the polyvinylidene fluoride (PVDF) membranes fabricated with the methods of non-solvent induced phase separation (NIPS) (named NIPS-PVDF) and thermally induced phase separation (TIPS) (named TIPS-PVDF). The chemical solutions of sodium hypochlorite (NaClO) and sodium hydroxide (NaOH) were chosen at the concentration of 5000mg/L. The equivalence of 5 and 10years was respectively selected as the time of aging. The physicochemical evolutions of membrane aging are characterized on the base of morphology analysis, chemical components, permeation ability and mechanical properties. The aging of NIPS-PVDF membrane led to the elimination of surface hydrophilic additives, while NaOH focused on the dehydrofluorination process resulting in the formation of conjugated chains of polyene on the skeleton structure. The chemical components of the surface of TIPS-PVDF membrane were removed continuously during the aging processes of both NaClO and NaOH, which was caused by the saponification of surface additives and the chain scissions of skeleton structure, but without producing any obvious conjugated chains of polyene. All the aging processes led to the increase of contact angle and the decrease of mechanical properties, and the permeability was reduced first and increased later due to the enlargement of surface membrane pores and membrane block. With the influence of membrane aging, selectivity of membrane was decreased (except coliform bacteria). At the beginning of filtration, the turbidity and particle count were at relatively high levels and declined with the filtration process. Copyright © 2017. Published by Elsevier B.V.

Sodium fluoride-assisted modulation of anodized TiO₂ nanotube for dye-sensitized solar cells application.

PubMed

Yun, Jung-Ho; Ng, Yun Hau; Ye, Changhui; Mozer, Attila J; Wallace, Gordon G; Amal, Rose

2011-05-01

This work reports the use of sodium fluoride (in ethylene glycol electrolyte) as the replacement of hydrofluoric acid and ammonium fluoride to fabricate long and perpendicularly well-aligned TiO₂ nanotube (TNT) (up to 21 μm) using anodization. Anodizing duration, applied voltage and electrolyte composition influenced the geometry and surface morphologies of TNT. The growth mechanism of TNT is interpreted by analyzing the current transient profile and the total charge density generated during anodization. The system with low water content (2 wt %) yielded a membrane-like mesoporous TiO₂ film, whereas high anodizing voltage (70 V) resulted in the unstable film of TNT arrays. An optimized condition using 5 wt % water content and 60 V of anodizing voltage gave a stable array of nanotube with controllable length and pore diameter. Upon photoexcitation, TNTs synthesized under this condition exhibited a slower charge recombination rate as nanotube length increased. When made into cis-diisothiocyanato-bis(2,2̀-bipyridyl-4,4̀-dicarboxylato) ruthenium(II) bis (tetrabutyl-ammonium)(N719) dye-sensitized solar cells, good device efficiency at 3.33 % based on the optimized TNT arrays was achieved with longer electron time compared with most mesoporous TiO₂ films.

Potassium permanganate-glutaraldehyde chemiluminescence system catalyzed by gold nanoprisms toward selective determination of fluoride.

PubMed

Abolhasani, Jafar; Hassanzadeh, Javad; Ghorbani-Kalhor, Ebrahim

2016-02-01

Gold and silver nanoparticles (NPs) are shown to exert a positive effect on the chemiluminescence (CL) reaction of permanganate aldehydes. Interestingly, between various shapes examined, Au nanoprisms have the highest beneficial effect. This effect is even more notable in the presence of sodium dodecyl sulfate (SDS) surfactant. UV-vis spectra and transmission electron microscopy were used to characterize the NP shapes and sizes. Furthermore, it was observed that iron(III) ions can slightly increase CL emission of this system. This intensification is very effective in the presence of fluoride ions (F(-)). These observations form the basis of the method for the high sensitive determination of F(-) in the 6-1200 nmol L(-1) concentration range, with a detection limit of 2.1 nmol L(-1). The proposed method has good precision and was satisfactorily used in the selective determination of low concentrations of fluoride ion in real samples. Copyright © 2015 John Wiley & Sons, Ltd.

Protective effects of selenium on fluoride induced alterations in certain enzymes in brain of mice.

PubMed

Reddy, K Pratap; Sailaja, G; Krishnaiah, Chirumari

2009-09-01

This study reports the protective effects of selenium on fluoride induced alterations in the activities of pro-oxidative (xanthine oxidase (XOD), lipid peroxidation (LPO) free radical scavenging, [catalase, superoxide dismutase (SOD), glutathione-s-transferase (GST), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione) and metabolic (glucose-6-phosphate dehydrogenase, alanine amino transferase (ALAT), aspartate aminotransferase (AAT), creatine phosphokinase (CPK), acid phosphatase (AP), alkaline phosphatase (ALP)] enzymes along with fluoride and selenium levels in brain of mice. Animals were divided into control, NaF treated group (20 mg kg(-1) body wt.(-1) intraperitonial) and Selenium+NaF treated group (sodium selenite, 5 microg of selenium/0.2 ml distilled water kg(-1) body wt.(-1) day) and were maintained for 14 days on respective treatments. The decreased bodyweight (-11.35%) as well as organosomatic index (-15.1%) of brain in NaF group were recovered in treatment of selenium along with NaF. The increased accumulation of fluoride (32.1%) in brain observed in NaF treated group compared to control was diminished in selenium+NaF treated group. Selenium levels (3.03%) increased in selenium+NaF treated group in compared to decrement in NaF treatment. The SOD (-16.6%), Catalase (-21.5%), GST(-13.72%), GPX (-19.16%), GR (-44.97%) activities and Glutathione (-23%) content in NaF treated group were decreased significantly compared to controls, which were significantly (p < 0.01) recovered in selenium+NaF group. Increased XOD (10.85%) and LPO (8.61%) levels observed in brain of NaF treated mice were reversed with selenium treatment. Glucose-6-phosphate dehydrogenase (-46.98%), ALAT (-10.44%), AAT (-10.21%), CPK (-27.98%) were decreased and alkaline phosphatase (10.6%), acid phosphatase (24.09%) increased in brain of mice after administration of NaF. All metabolic enzymes were significantly (p < 0.01) reversed after administration of selenium to the NaF

Fluoride varnishes with calcium glycerophosphate: fluoride release and effect on in vitro enamel demineralization.

PubMed

Carvalho, Thiago Saads; Peters, Bianca Glerean; Rios, Daniela; Magalhães, Ana Carolina; Sampaio, Fabio Correia; Buzalaf, Marília Afonso Rabelo; Bönecker, Marcelo José Strazzeri

2015-01-01

The aims of this study were (1) to assess the amount of fluoride (F) released from varnishes containing calcium glycerophosphate (CaGP) and (2) to assess the effect of the experimental varnishes on in vitro demineralization. Six test groups using 5 varnishes: base varnish (no active ingredients); Duraphat® (2.26% NaF); Duofluorid® (5.63% NaF/CaF2); experimental varnish 1 (1% CaGP/5.63% NaF/CaF2); experimental varnish 2 (5% CaGP/5.63% NaF/CaF2); and no varnish were set up. In stage 1, 60 acrylic blocks were randomly distributed into 6 groups (n = 10). Then 300 µg of each varnish was applied to each block. The blocks were immersed in deionized water, which was changed after 1, 8, 12, 24, 48 and 72 hours. Fluoride concentration in the water was analyzed using a fluoride electrode. In stage 2, 60 bovine enamel samples were distributed into 6 groups (n = 10), and treated with 300 µg of the respective varnish. After 6 h the varnish was removed and the samples were subjected to a 7-day in vitro pH cycle (6 h demineralization/18 h remineralization per day). The demineralization was measured using surface hardness. The results showed that both experimental varnishes released more fluoride than Duofluorid® and Duraphat® (p < 0.05), but Duraphat® showed the best preventive effect by decreasing enamel hardness loss (p < 0.05). Therefore, we conclude that even though (1) the experimental varnishes containing CaGP released greater amounts of F, (2) they did not increase in the preventive effect against enamel demineralization.

The Role of Calcium in Ameliorating the Oxidative Stress of Fluoride in Rats.

PubMed

Mohamed, N E

2016-03-01

The present study was carried out to investigate the effects of fluoride toxicity on some biochemical, hormonal, and histological parameters of female rats and the protective role of calcium against such effects. Adult female albino rats were divided into five groups; control group received distilled water for 60 days, calcium group received calcium carbonate with dose of 50 mg/kg three times per week for 60 days, fluoride group received sodium fluoride with dose of 20 mg/kg three times per week for 60 days, calcium + fluoride group received calcium carbonate (50 mg/kg) then after 2 h received sodium fluoride (20 mg/kg) three times per week for 60 days, and fluoride + calcium group received sodium fluoride (20 mg/kg) three times per week for 30 days then received calcium carbonate (50 mg/kg) three times per week for another 30 days. The results showed that the levels of thiobarbituric acid reactive substances, urea, creatinine, alkaline phosphatase, triiodothyronine, thyroxine, parathormone, phosphorous, magnesium, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and gamma glutamyl transferase were significantly increased in rats treated with fluoride while serum estradiol, calcium, and organ glutathione were significantly decreased. The histological examination of the femur bone revealed that fluoride treatment induced thinning of bone trabeculae with wilding of marrow space, demineralization, and loss of trabeculae interconnections. Also, the histological examination of hepatic and renal tissues of fluoride-treated rats showed some damages in these tissues while administration of calcium carbonate for 30 or 60 days during fluoride treatment minimized such damages. It could be concluded that administration of calcium to female rats can ameliorate the hazardous effects of fluoride observed in the biochemical, hormonal, and histological parameters.

A hybrid approach for treating fluorided water and biogeophysical monitoring of treatment processes

NASA Astrophysics Data System (ADS)

Singh, K. P.

2016-12-01

A laboratory experiment has been conducted for investigating the possibility of development of novel techniques for treating fluoride contamination and monitoring of physico-chemical alterations caused by biogeochemical processes in the media. In the present study, high adsorption capacity and ion-exchange property of natural zeolites have been utilized in treating fluoride contamination. The preset goals are achieved by designing and constructing experimental setup consisting of three columns, first one is filled with 450 ppm fluorided water prepared by dissolving sodium fluoride in deionized water, the second is filled with zeolite and fluorided water, and the third is filled with zeolite, fluorided water, sodium lactate and the bacterial seed. The first and the second columns were poisoned with sodium azide for preventing the growth of microorganisms. The self-potential (SP) signals associated with physico-chemical alterations in natural zeolite induced by biogeochemical processes are measured by using Cu-CuSO4 gel electrodes. Liquid-phase analysis of samples from column two and three show the reduced concentrations of fluoride and aluminum and it indicates the possibility of precipitation of insoluble aluminum fluoride. This is further confirmed by the presence of fluoride and aluminum in the solid samples as detected by energy dispersive X-ray analysis. The distinct SP of the order of -50 mV and 200 mV have been associated with biostimulated fluoride remediation and geochemical fluoride remediation processes respectively. Thus, there is a possibility of non-invasive monitoring of fluoride remediation processes driven by both microbes and chemical processes. It is found that after thirty-day nitrate and sulfate is introduced in column two due chemical interaction between water and natural zeolite. Furthermore, this study demonstrates that a hybrid approach, a combination of ion exchange and adsorption properties of natural zeolite and the bioremediation is more

In vitro effect of calcium-containing prescription-strength fluoride toothpastes on bovine enamel erosion under hyposalivation-simulating conditions.

PubMed

Scaramucci, Taís; Borges, Alessandra B; Lippert, Frank; Zero, Domenick T; Hara, Anderson T

2015-02-01

To evaluate the ability of calcium-containing prescription-strength fluoride (F) toothpastes in preventing enamel erosion under low salivary flow simulating conditions. Enamel and dentin bovine specimens were assigned to the following groups: A - placebo; B - 1,100 ppm F/NaF (Aquafresh Advanced); C - 5,000 ppm F/NaF (Prevident 5000 Booster); D - 5000 ppm F/NaF+calcium sodium phosphosilicate (Topex Renew); and E - 5,000 ppm F/NaF+tri-calcium phosphate (Clinpro 5000). Specimens were positioned in custom-made devices, creating a sealed chamber on the surface, connected to peristaltic pumps. Citric acid was injected into the chamber for 2 minutes, followed by artificial saliva (0.05 ml/minute), for 60 minutes, 4x/day, for 3 days. Aquafresh was also tested under normal salivary flow (0.5 ml/minute), as reference (Group F). Specimens were exposed to the toothpastes for 2 minutes, 2x/day. After cycling, surface loss (SL) and concentration of loosely- and firmly-bound F were determined. Data were analyzed by ANOVA. Results: Group A (placebo) presented highest surface loss (SL), while Group F had the lowest, for both substrates. For enamel, none of the dentifrices differed from Group B or among each other. For dentin, none of the dentifrices differed from Group B, but Group E showed greater protection than Group C. Group E presented the highest F concentrations for both substrates, only matched by Group D for firmly-bound fluoride on enamel. All fluoridated dentifrices tested reduced SL, with no additional benefit from higher F concentrations. Some formulations, especially Clinpro 5000, increased F availability on the dental substrates, but no further erosion protection was observed.

A comparative evaluation to assess the efficacy of 5% sodium fluoride varnish and diode laser and their combined application in the treatment of dentin hypersensitivity

PubMed Central

Suri, Isha; Singh, Poonam; Shakir, Quaid Johar; Shetty, Arvind; Bapat, Ranjeet; Thakur, Roshani

2016-01-01

Background: Dentin hypersensitivity (DH) is an age old complaint with a great number of treatment modalities, but none of these are totally effective till date. Lasers being one of the latest treatment options in periodontics, a study was conducted to test the efficacy of diode laser (DL) in DH alone and in comparison with 5% sodium fluoride (NaF) varnish. Aim: The aim of the present study was to compare the effectiveness of 5% topical NaF varnish and 980 nm gallium aluminum arsenide (GaAlAs) DL alone and combination of 5% NaF + 980 nm GaAlAs DL in the management of DH. Materials and Methods: The study was conducted on 120 teeth in thirty patients with DH assessed by tactile and air blast (AB) stimuli measured by visual analog scale (VAS). Teeth were randomly divided into Group 1 (P) placebo-treated control group, Group 2 (NaF) treated by 5% NaF varnish, Group 3 (DL) treated with 980 nm DL, and Group 4 (NaF + DL) treated with both 5% NaF varnish and 980 nm DL (combination group). Results: There was a significant reduction in DH. The VAS reduction percentages were calculated, and there was a significant decrease in DH above all in G4 (NaF + DL) than G3 (DL) and G2 (NaF). Conclusion: Even though all the three groups (2, 3, and 4) showed improvement in terms of DH reduction, 5% NaF varnish with DL showed the best results among all the groups. PMID:27563205

Effect of Fluoride on Nickel-Titanium and Stainless Steel Orthodontic Archwires: An In-Vitro Study

PubMed Central

Heravi, Farzin; Moayed, Mohamad Hadi; Mokhber, Nima

2015-01-01

Objectives: The commonly used Nickel-Titanium (NiTi) archwires in orthodontic treatment are often exposed to fluoride-containing mouthwashes. The aim of this in-vitro study was to evaluate and compare the corrosion resistance of three commercially available NiTi archwires exposed to 0.05 wt% and 0.2 wt% fluoride mouthwashes. Materials and Methods: Three different types of NiTi archwires, 0.016″ in diameter, from Dentaurum, Global, and GAC, and a stainless steel archwire from Dentaurum were examined to assess their corrosion resistance in Fusayama-Meyer artificial saliva and in two other artificial saliva containing 0.05 wt% and 0.2 wt% sodium fluoride (NaF). After the primary setup of wires, they were tested by potentiodynamic and potentiostatic polarization and corrosion potential/time analyses. Their surfaces were evaluated using a scanning electronic microscope (SEM). Results: The results showed that all the wires were passive in artificial saliva. In contrast, by adding fluoride ions to the solution, the decrease in the archwires’ corrosion resistance was in direct proportion to the increase in fluoride concentration. Conclusion: The NiTi wires experienced deterioration of their corrosion properties under the effect of fluoride but not as much as the stainless steel archwires. PMID:26005454

Fluoride Consumption and Its Impact on Oral Health

PubMed Central

Jiménez-Farfán, María Dolores; Hernández-Guerrero, Juan Carlos; Juárez-López, Lilia Adriana; Jacinto-Alemán, Luis Fernando; de la Fuente-Hernández, Javier

2011-01-01

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. PMID:21318021

Comparing the antiplaque efficacy of 0.5% Camellia sinensis extract, 0.05% sodium fluoride, and 0.2% chlorhexidine gluconate mouthwash in children.

PubMed

Hambire, Chaitali U; Jawade, Rashmi; Patil, Amol; Wani, Vaibhav R; Kulkarni, Ankur A; Nehete, Parag B

2015-01-01

Dental caries is a multifactorial disease which requires a susceptible host, a cariogenic microflora, and a suitable substrate that must be present for a sufficient length of time. Tea is prepared by the infusion of dried leaves of the tea plant, Camellia sinensis, which contains bioactive compounds like polyphenols, flavonoids, and catechins that are thought to be responsible for the health benefits that have traditionally been attributed to tea. These compounds have multidimensional effects such as antibacterial action, inhibitory action on the bacterial and salivary amylase, and inhibition of acid production. The aim of this study is to compare the antiplaque efficacy of 0.5% C. sinensis extract, 0.05% sodium fluoride, and 0.2% chlorhexidine gluconate mouthwash in children. A randomized blinded controlled trial with 60 healthy children of age group 9-14 years was carried out. The subjects were randomly assigned to three groups, i.e. group A - 0.2% chlorhexidine gluconate, group B - 0.05% sodium fluoride, and group C - 0.5% C. sinensis extract, with 20 subjects per group. Plaque accumulation and gingival condition were recorded using plaque index and gingival index. Oral hygiene was assessed by simplified oral hygiene index (OHIS). Salivary pH was assessed using indikrom pH strips. Plaque, gingival, and simplified OHI scores as well as salivary pH were recorded at baseline, immediately after first rinse, after 1 week, and in the 2(nd) week. The data were analyzed using a computer software program (SPSS version 17). Analysis of variance (ANOVA) tests were used to identify significant differences between the means of the study groups. Finally, paired t-tests were used to assess the significance of changes within each group between time periods. Critical P values of significance were set at 0.05 and the confidence level set at 95%. Mean plaque and gingival scores were reduced over the 2-week trial period in the experimental groups. Antiplaque effectiveness was

Effect of oral calcium and calcium + fluoride treatments on mouse bone properties during suspension

NASA Technical Reports Server (NTRS)

Simske, S. J.; Luttges, M. W.; Allen, K. A.; Spooner, B. S. (Principal Investigator)

1992-01-01

The bone effects of oral dosages of calcium chloride with or without supplementary sodium fluoride were assessed in antiorthostatically suspended mice. Two calcium dosages were used to replace half (3.1 mM) or all(6.3 mM) of the dietary calcium lost due to reduced food intake by the suspended mice. Two groups of 6.3 mM CaCl2-treated mice were additionally treated with 0.25 or 2.5 mM NaF. The results indicate that supplementation of the mouse drinking water with calcium salts prevents bone changes induced by short-term suspension, while calcium salts in combination with fluoride are less effective as fluoride dosage increases. However, the calcium supplements change the relationship between the femur mechanical properties and the mineral composition of the bone. Because of this, it appears that oral calcium supplements are effective through a mechanism other than simple dietary supplementation and may indicate a dependence of bone consistency on systemic and local fluid conditions.

Ab initio investigation of the ground and low-lying states of the diatomic fluorides TiF, VF, CrF, and MnF

NASA Astrophysics Data System (ADS)

Koukounas, Constantine; Kardahakis, Stavros; Mavridis, Aristides

2004-06-01

The electronic structure of the ground and low-lying states of the diatomic fluorides TiF, VF, CrF, and MnF was examined by multireference and coupled cluster methods in conjunction with extended basis sets. For a total of 34 states we report binding energies, spectroscopic constants, dipole moments, separation energies, and charge distributions. In addition, for all states we have constructed full potential curves. The suggested ground state binding energies of TiF(X 4Φ), VF(X 5Π), CrF(X 6Σ+), and MnF(X 7Σ+) are 135, 130, 110, and 108 kcal/mol, respectively, with first excited states A 4Σ-, A 5Δ, A 6Π, and a 5Σ+ about 2, 3, 23, and 19 kcal/mol higher. In essence all our numerical findings are in harmony with experimental results. For all molecules and states studied it is clear that the in situ metal atom (M) shows highly ionic character, therefore the binding is described realistically by M+F-.

Ab initio investigation of the ground and low-lying states of the diatomic fluorides TiF, VF, CrF, and MnF.

PubMed

Koukounas, Constantine; Kardahakis, Stavros; Mavridis, Aristides

2004-06-22

The electronic structure of the ground and low-lying states of the diatomic fluorides TiF, VF, CrF, and MnF was examined by multireference and coupled cluster methods in conjunction with extended basis sets. For a total of 34 states we report binding energies, spectroscopic constants, dipole moments, separation energies, and charge distributions. In addition, for all states we have constructed full potential curves. The suggested ground state binding energies of TiF(X (4)Phi), VF(X (5)Pi), CrF(X (6)Sigma(+)), and MnF(X (7)Sigma(+)) are 135, 130, 110, and 108 kcal/mol, respectively, with first excited states A (4)Sigma(-), A (5)Delta, A (6)Pi, and a (5)Sigma(+) about 2, 3, 23, and 19 kcal/mol higher. In essence all our numerical findings are in harmony with experimental results. For all molecules and states studied it is clear that the in situ metal atom (M) shows highly ionic character, therefore the binding is described realistically by M(+)F(-). (c) 2004 American Institute of Physics.

Dental caries and dental fluorosis at varying water fluoride concentrations.

PubMed

Heller, K E; Eklund, S A; Burt, B A

1997-01-01

The purpose of this study was to investigate the relationships between caries experience and dental fluorosis at different fluoride concentrations in drinking water. The impact of other fluoride products also was assessed. This study used data from the 1986-87 National Survey of US School-children. Fluoride levels of school water were used as an indicator of the children's water fluoride exposure. The use of fluoride drops, tablets, professional fluoride treatments, and school fluoride rinses were ascertained from caregiver questionnaires. Only children with a single continuous residence (n = 18,755) were included in this analysis. The sharpest declines in dfs and DMFS were associated with increases in water fluoride levels between 0 and 0.7 ppm F, with little additional decline between 0.7 and 1.2 ppm F. Fluorosis prevalence was 13.5 percent, 21.7 percent, 29.9 percent, and 41.4 percent for children who consumed < 0.3, 0.3 to < 0.7, 0.7 to 1.2, and > 1.2 ppm F water. In addition to fluoridated water, the use of fluoride supplements was associated with both lower caries and increased fluorosis. A suitable trade-off between caries and fluorosis appears to occur around 0.7 ppm F. Data from this study suggest that a reconsideration of the policies concerning the most appropriate concentrations for water fluoridation might be appropriate for the United States.

FLUORIDE CONTENT OF COMMERCIALLY AVAILABLE BOTTLED DRINKING WATER IN BANGKOK, THAILAND.

PubMed

Rirattanapong, Praphasri; Rirattanapong, Opas

2016-09-01

The use of bottled drinking water may be a source of fluoride and could be a risk factor for fluorosis among infants and young children. The aim of this study was to evaluate the fluoride content of commercially available bottled drinking water in Bangkok, Thailand. Forty-five water samples (15 samples of plain water and 30 samples of mineral water) were purchased from several supermarkets in Bangkok, Thailand. Three bottles of each water sample were purchased, and the fluoride content of each sample was measured twice using a combination fluoride-ion selective electrode. The average reading for each sample was then calculated. Data were analyzed by descriptive statistics. Differences between mineral and plain water samples were determined by Student’s t-test. The mean (±SD) fluoride content for all the water samples was 0.17 (±0.17) mg F/l (range: 0.01-0.89 mg F/l). Six brands (13%) tested stated the fluoride content on the label. The actual fluoride content in each of their brands varied little from the label. Eight samples (18%) had a fluoride content >0.3 mg F/l and two samples (4%) had a fluoride content >0.6 mg F/l. The mean mineral water fluoride concentration was significantly higher than the mean fluoride concentration of plain water (p=0.001). We found commercially sold bottled drinking water in Bangkok, Thailand contained varying concentrations of fluoride; some with high concentrations of fluoride. Health professions need to be aware this varying fluoride content of bottled drinking water and educate the parents of infants and small children about this when prescribing fluoride supplements. Consideration should be made to have fluoride content put on the label of bottled water especially among brands with a content >0.3 mg F/l.

Rates and mechanism of fluoride and water exchange in UO(2)F(5)(3-) and [UO(2)F(4)(H(2)O)](2-) studied by NMR spectroscopy and wave function based methods.

PubMed

Vallet, Valérie; Wahlgren, Ulf; Szabó, Zoltán; Grenthe, Ingmar

2002-10-21

The reaction mechanism for the exchange of fluoride in UO(2)F(5)(3-) and UO(2)F(4)(H(2)O)(2-) has been investigated experimentally using (19)F NMR spectroscopy at -5 degrees C, by studying the line broadening of the free fluoride, UO(2)F(4)(2-)(aq) and UO(2)F(5)(3-), and theoretically using quantum chemical methods to calculate the activation energy for different pathways. The new experimental data allowed us to make a more detailed study of chemical equilibria and exchange mechanisms than in previous studies. From the integrals of the different individual peaks in the new NMR spectra, we obtained the stepwise stability constant K(5) = 0.60 +/- 0.05 M(-1) for UO(2)F(5)(3-). The theoretical results indicate that the fluoride exchange pathway of lowest activation energy, 71 kJ/mol, in UO(2)F(5)(3-) is water assisted. The pure dissociative pathway has an activation energy of 75 kJ/mol, while the associative mechanism can be excluded as there is no stable UO(2)F(6)(4-) intermediate. The quantum chemical calculations have been made at the SCF/MP2 levels, using a conductor-like polarizable continuum model (CPCM) to describe the solvent. The effects of different model assumptions on the activation energy have been studied. The activation energy is not strongly dependent on the cavity size or on interactions between the complex and Na(+) counterions. However, the solvation of the complex and the leaving fluoride results in substantial changes in the activation energy. The mechanism for water exchange in UO(2)F(4)(H(2)O)(2-) has also been studied. We could eliminate the associative mechanism, the dissociative mechanism had the lowest activation energy, 39 kJ/mol, while the interchange mechanism has an activation energy that is approximately 50 kJ/mol higher.

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

PubMed

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.

The effect of a fluoride dentifrice containing an anticalculus agent on dental caries in children.

PubMed

Lu, K H; Yen, D J; Zacherl, W A; Ruhlman, C D; Sturzenberger, O P; Lehnhoff, R W

1985-01-01

In this double-blind caries study, 1160 Taiwanese children (ages 8-15) completed a program using a test dentifrice containing 1.243 percent sodium fluoride and soluble pyrophosphates, or a control dentifrice without these agents. The average reduction of new carious tooth surfaces was 39 percent with the sodium fluoride dentifrice.

The fractional urinary fluoride excretion of adults consuming naturally and artificially fluoridated water and the influence of water hardness: a randomized trial.

PubMed

Villa, A; Cabezas, L; Anabalón, M; Rugg-Gunn, A

2009-09-01

To assess whether there was any significant difference in the average fractional urinary fluoride excretion (FUFE) values among adults consuming (NaF) fluoridated Ca-free water (reference water), naturally fluoridated hard water and an artificially (H2SiF6) fluoridated soft water. Sixty adult females (N=20 for each treatment) participated in this randomized, double-blind trial. The experimental design of this study provided an indirect estimation of the fluoride absorption in different types of water through the assessment of the fractional urinary fluoride excretion of volunteers. Average daily FUFE values (daily amount of fluoride excreted in urine/daily total fluoride intake) were not significantly different between the three treatments (Kruskal-Wallis; p = 0.62). The average 24-hour FUFE value (n=60) was 0.69; 95% C.I. 0.65-0.73. The results of this study suggest that the absorption of fluoride is not affected by water hardness.

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

PubMed

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 < 0.0001) and after meal ingestion (p < 0.04; salt > 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.

Necessity to review the Brazilian regulation about fluoride toothpastes

PubMed Central

Cury, Jaime Aparecido; Caldarelli, Pablo Guilherme; Tenuta, Livia Maria Andaló

2015-01-01

The aim of this study was to evaluate the adequacy of the Brazilian legislation about fluoride toothpaste. A search was conducted in LILACS, Medline and SciELO databases about the fluoride concentration found in Brazilians toothpastes, using descriptors on health. Publications since 1981 have shown that some Brazilian toothpastes are not able to maintain, during their expiration time, a minimum of 1,000 ppm F of soluble fluoride in the formulation. However, the Brazilian regulation (ANVISA, Resolution 79, August 28, 2000) only sets the maximum total fluoride (0.15%; 1,500 ppm F) that a toothpaste may contain but not the minimum concentration of soluble fluoride that it should contain to have anticaries potential, which according to systematic reviews should be 1,000 ppm F. Therefore, the Brazilian regulation on fluoride toothpastes needs to be revised to assure the efficacy of those products for caries control. PMID:26487295

Investigation of effect of fluoride on corrosion of 2S-0 aluminum and 347 stainless steel in fuming nitric acid at 170 F

NASA Technical Reports Server (NTRS)

Feiler, Charles E; Morrell, Gerald

1954-01-01

The effect of small additions of fluoride on the corrosion of 2S-0 aluminum and 347 stainless steel by fuming nitric acid at 170 degrees F has been evaluated quantitatively by the determination of the weight loss of metal specimens immersed in the acid. The ratio of metal surface area to volume of acid was approximately 7.5 inch (superscript)-1 in all cases. It was found that for acids containing no fluorides the weight loss of aluminum was approximately 1/5 that of stainless steel. Addition of 1 percent fluoride ion to the acid reduced the weight loss of both metals to practically zero even after 26 days of exposure to the acid at 170 degrees F. The minimum quantity of fluoride ion required to inhibit corrosion was found to be approximately 0.25 and 0.5 percent for aluminum and stainless steel, respectively, in white fuming nitric acid and 0.5 and 1 percent in red fuming nitric acid (18 percent nitrogen dioxide). These fluoride percentages were based on the total weight of acid. Provided the concentration of fluoride ion was sufficient to inhibit corrosion, the source of these ions was immaterial. Additional information concerning the effect of fluorides on corrosion was obtained by measuring the electrode potentials of the metals against a platinum reference electrode.

Solid electrolytes for fluoride ion batteries: ionic conductivity in polycrystalline tysonite-type fluorides.

PubMed

Rongeat, Carine; Reddy, M Anji; Witter, Raiker; Fichtner, Maximilian

2014-02-12

Batteries based on a fluoride shuttle (fluoride ion battery, FIB) can theoretically provide high energy densities and can thus be considered as an interesting alternative to Li-ion batteries. Large improvements are still needed regarding their actual performance, in particular for the ionic conductivity of the solid electrolyte. At the current state of the art, two types of fluoride families can be considered for electrolyte applications: alkaline-earth fluorides having a fluorite-type structure and rare-earth fluorides having a tysonite-type structure. As regard to the latter, high ionic conductivities have been reported for doped LaF3 single crystals. However, polycrystalline materials would be easier to implement in a FIB due to practical reasons in the cell manufacturing. Hence, we have analyzed in detail the ionic conductivity of La(1-y)Ba(y)F(3-y) (0 ≤ y ≤ 0.15) solid solutions prepared by ball milling. The combination of DC and AC conductivity analyses provides a better understanding of the conduction mechanism in tysonite-type fluorides with a blocking effect of the grain boundaries. Heat treatment of the electrolyte material was performed and leads to an improvement of the ionic conductivity. This confirms the detrimental effect of grain boundaries and opens new route for the development of solid electrolytes for FIB with high ionic conductivities.

Synthesis of Multicolor Core/Shell NaLuF4:Yb3+/Ln3+@CaF2 Upconversion Nanocrystals

PubMed Central

Li, Hui; Hao, Shuwei; Yang, Chunhui; Chen, Guanying

2017-01-01

The ability to synthesize high-quality hierarchical core/shell nanocrystals from an efficient host lattice is important to realize efficacious photon upconversion for applications ranging from bioimaging to solar cells. Here, we describe a strategy to fabricate multicolor core @ shell α-NaLuF4:Yb3+/Ln3+@CaF2 (Ln = Er, Ho, Tm) upconversion nanocrystals (UCNCs) based on the newly established host lattice of sodium lutetium fluoride (NaLuF4). We exploited the liquid-solid-solution method to synthesize the NaLuF4 core of pure cubic phase and the thermal decomposition approach to expitaxially grow the calcium fluoride (CaF2) shell onto the core UCNCs, yielding cubic core/shell nanocrystals with a size of 15.6 ± 1.2 nm (the core ~9 ± 0.9 nm, the shell ~3.3 ± 0.3 nm). We showed that those core/shell UCNCs could emit activator-defined multicolor emissions up to about 772 times more efficient than the core nanocrystals due to effective suppression of surface-related quenching effects. Our results provide a new paradigm on heterogeneous core/shell structure for enhanced multicolor upconversion photoluminescence from colloidal nanocrystals. PMID:28336867

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

PubMed

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.

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

PubMed Central

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

2013-01-01

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, 18F, 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. PMID:24173035

Methyl fluoride-13C in nematic liquid crystals: Anisotropy of the indirect 13C-19F spin-spin coupling and of the 1H, 13C, and 19F chemical shieldings

NASA Astrophysics Data System (ADS)

Jokisaari, J.; Hiltunen, Y.; Lounila, J.

1986-09-01

The anisotropy of the indirect 13C-19F spin-spin coupling tensor of methyl fluoride-13C in the liquid crystals ZLI 1167, EBBA, their mixtures, phase IV, and phase 1221 was studied by applying 1H and 19F NMR spectroscopy. The relative anisotropy ΔJCF/JCF gets values between -4.3 (in ZLI 1167) and +30.7 (in EBBA) when determined in the conventional way from the experimental dipolar coupling constants taking into account only harmonic vibrational corrections. The inclusion of the deformational corrections in both the direct and indirect C-F coupling tensors leads to a constant, solvent independent relative anisotropy of -2.5±0.2. This result is also obtained when a mixture of the liquid crystals ZLI 1167 and EBBA is used which mixture gives an undistorted geometry for methyl fluoride. The chemical shielding anisotropies ΔσH, ΔσC, and ΔσF for methyl fluoride were determined by applying the method of mixing two thermotropic nematogens (ZLI 1167 and EBBA) with opposite anisotropies of diamagnetic susceptibility. The results ΔσH =+5.2±0.2 ppm, ΔσC =+87±4 ppm, and ΔσF =-90±4 ppm are in fair agreement with theoretical calculations.

Fluoride therapy for osteoporosis: characterization of the skeletal response by serial measurements of serum alkaline phosphatase activity.

PubMed

Farley, S M; Wergedal, J E; Smith, L C; Lundy, M W; Farley, J R; Baylink, D J

1987-03-01

Optimum use of fluoride therapy for osteoporosis requires a sensitive and convenient index of the skeletal response to fluoride. Since previous studies had shown that serum alkaline phosphatase activity (SALP) was increased in response to fluoride therapy, we examined serial measurements of SALP in 53 osteoporotics treated with 66 to 110 mg of sodium fluoride (NaF) for 12 to 91 months. SALP was increased in 87% of the subjects during therapy with fluoride. The increase in SALP was thought to reflect the osteogenic action of fluoride based on the findings that SALP correlated with both trabecular bone area (r = .81, P less than .001) and osteoid length (r = .67, P less than .01) in iliac crest biopsies, predicted increased bone density on spinal radiographs in response to fluoride therapy with an 87% accuracy, and predicted decreased back pain in response to fluoride with a 91% accuracy. In addition, the SALP response to fluoride was seen earlier than other therapeutic responses as indicated by the findings that the tau 1/2 for the SALP response (ie, time for 1/2 of the patients to show a significant response) was significantly less (1.2 +/- 0.3 yr) than that for the pain response (1.6 +/- 0.3 yr, P less than .05) or that for the radiographic response (3.7 +/- 0.5 yr, P less than .001). Although most patients responded to fluoride with an increase in SALP, evaluation of the kinetics of the SALP response to fluoride revealed marked interpatient variation.(ABSTRACT TRUNCATED AT 250 WORDS)

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

PubMed

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.

Kagomé lattices as cathode: Effect of particle size and fluoride substitution on electrochemical lithium insertion in sodium- and ammonium Jarosites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sandineni, Prashanth; Yaghoobnejad Asl, Hooman; Choudhury, Amitava, E-mail: choudhurya@mst.edu

Highly crystalline sodium and ammonium Jarosites, NaFe{sub 3}(SO{sub 4}){sub 2}(OH){sub 6} and NH{sub 4}Fe{sub 3}(SO{sub 4}){sub 2}(OH){sub 6}, have been synthesized employing hydrothermal synthesis routes. The structures consist of anionic layers of vertex-sharing FeO{sub 6} octahedra and SO{sub 4} tetrahedral units with interlayer space occupied by Na and ammonium ions, respectively. The corner-sharing FeO{sub 6} octahedral units form six and three rings similar to hexagonal tungsten bronze sheets also known as kagomé lattice. These sodium and ammonium Jarosites are thermally stable up to 400 °C and undergo facile electrochemical lithium insertion through the reduction of Fe{sup 3+} to Fe{sup 2+}.more » Galvanostatic charge–discharge indicates that up to 2.25 and 2 lithium ions per formula unit can be inserted at an average voltage of 2.49 and 2.26 V to the sodium and the ammonium Jarosites, respectively, under slow discharge rate of C/50. The cycle-life and experimental achievable capacity show strong dependence on particle sizes and synthesis conditions. A small amount of fluoride substitution improves both achievable capacity and average voltage. - Graphical abstract: Discharge capacity of jarosite phases as a function of particle size and fluoride substitution. - Highlights: • Synthesis of natro- and ammonium Jarosites. • Jarosites as cathodes for lithium ion batteries. • Li-ion electrochemistry of Jarosites. • Mössbauer spectroscopy of Jarosites.« less

Multiferroic fluoride BaCoF4 Thin Films Grown Via Molecular Beam Epitaxy

NASA Astrophysics Data System (ADS)

Borisov, Pavel; Johnson, Trent; García-Castro, Camilo; Kc, Amit; Schrecongost, Dustin; Cen, Cheng; Romero, Aldo; Lederman, David

Multiferroic materials exhibit exciting physics related to the simultaneous presence of multiple long-range orders, in many cases consisting of antiferromagnetic (AF) and ferroelectric (FE) orderings. In order to provide a new, promising route for fluoride-based multiferroic material engineering, we grew multiferroic fluoride BaCoF4 in thin film form on Al2O3 (0001) substrates by molecular beam epitaxy. The films grow with the orthorhombic b-axis out-of-plane and with three in-plane structural twin domains along the polar c-axis directions. The FE ordering in thin films was verified by FE remanent hysteresis loops measurements at T = 14 K and by room temperature piezoresponse force microscopy (PFM). An AF behavior was found below Neel temperature TN ~ 80 K, which is in agreement with the bulk properties. At lower temperatures two additional magnetic phase transitions at 19 K and 41 K were found. First-principles calculations demonstrated that the growth strain applied to the bulk BaCoF4 indeed favors two canted spin orders, along the b- and a-axes, respectively, in addition to the main AF spin order along the c-axis. Supported by FAME (Contract 2013-MA-2382), WV Research Challenge Grant (HEPC.dsr.12.29), and DMREF-NSF 1434897.

Comparative evaluation of the remineralizing efficacy of calcium sodium phosphosilicate agent and fluoride based on quantitative and qualitative analysis.

PubMed

Mony, Saranya; Rao, Arathi; Shenoy, Ramya; Suprabha, Baranya Srikrishna

2015-01-01

Calcium sodium phosphosilicate (NovaMin) is an agent that is claimed to release calcium and phosphate ions intraorally to help the self-repair process of enamel. It is used extensively as a desensitizing agent, but the chemical reactions that occur may promote apatite formation enhancing remineralization. The present study was undertaken to evaluate the ability of NovaMin to remineralize an experimentally induced demineralized lesion. The evaluation was done based on the quantitative and qualitative analysis of enamel over the period of 15 and 30 days. A sample of 120 noncarious premolar teeth extracted for orthodontic reasons were used for the study. Baseline data for hardness, Ca/PO 4 , and surface characteristics before and after demineralization process was obtained. All the teeth were brushed twice daily at 12 h interval with the test agents using a powered toothbrush for 2 min. The samples were tested on the 15 th and 30 th day. Calcium phosphate ratio and hardness in both the groups improved during the study period. Fluoride group showed higher values for Ca/PO 4 and hardness but was not statistically significant with the P > 0.05. Scanning electron microscope pictures showed that the deposition of the material over the decalcified enamel is more smoother and uniform with NovaMin and more irregular with fluoride. NovaMin is found to be as effective in improving the Ca/PO 4 ratio and hardness in a demineralized enamel as fluoride. Hence, it can be a new alternate material for remineralization of enamel with less toxic effects compared to fluorides.

Atomic layer deposition of magnesium fluoride via bis(ethylcyclopentadienyl)magnesium and anhydrous hydrogen fluoride

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hennessy, John, E-mail: hennessy@caltech.edu; Jewell, April D.; Greer, Frank

2015-01-15

A new process has been developed to deposit magnesium fluoride (MgF{sub 2}) thin films via atomic layer deposition (ALD) for use as optical coatings in the ultraviolet. MgF{sub 2} was deposited in a showerhead style ALD reactor using bis(ethylcyclopentadienyl)magnesium and anhydrous hydrogen fluoride (HF) as precursors at substrate temperatures from 100 to 250 °C. The use of HF was observed to result in improved morphology and reduced impurity content compared to other reported MgF{sub 2} ALD approaches that use metal fluoride precursors as the fluorine-containing chemistry. Characterization of these films has been performed using spectroscopic ellipsometry, atomic force microscopy, and x-raymore » photoelectron spectroscopy for material deposited on silicon substrates. Films at all substrate temperatures were transparent at wavelengths down to 190 nm and the low deposition temperature combined with low surface roughness makes these coatings good candidates for a variety of optical applications in the far ultraviolet.« less

Luminescence properties and warm white LED application of a ternary-alkaline fluoride red phosphor K2NaAlF6:Mn4+ .

PubMed

Wang, L Y; Song, E H; Deng, T T; Zhou, Y Y; Liao, Z F; Zhao, W R; Zhou, B; Zhang, Q Y

2017-08-14

Herein, a Mn 4+ ion doped complex ternary-alkaline fluoride red phosphor K 2 NaAlF 6 :Mn 4+ has been synthesized through a facile two-step co-precipitation method at room temperature. The crystal structure, morphological properties and influence of the dopant concentration, temperature and humidity on luminescence properties as well as the performance of the as-synthesized phosphor used in white light emitting diodes (WLEDs) were investigated carefully. Intense absorption in the blue region (∼460 nm) and bright narrow-band red emission (∼630 nm) with high color purity were observed from this resultant powder. Temperature-dependent investigation and reliability examination in a HTHH environment (85 °C high temperature and 85% high humidity) indicate that the obtained ternary-alkaline fluoride phosphor K 2 NaAlF 6 :Mn 4+ presents more exceptional thermal quenching behavior and longevity compared to some other binary-alkaline fluorides. Moreover, using K 2 NaAlF 6 :Mn 4+ as a red light component, a warm WLED with a preferable color rendering index (R a = 85.5) and luminous efficacy (LE = 91.2 lm W -1 ) as well as a low corresponding color temperature (CCT = 3650 K) is easily achieved, further revealing the great potential of the as-prepared ternary-alkaline fluoride red phosphor K 2 NaAlF 6 :Mn 4+ for WLED applications.

Fluoride in the diet of 2-years-old children.

PubMed

Martinez-Mier, E A; Spencer, Kathryn L; Sanders, Brian J; Jones, James E; Soto-Rojas, Armando E; Tomlin, Angela M; Vinson, LaQuia A; Weddell, James A; Eckert, George J

2017-06-01

This study aimed to calculate the fluoride concentrations of commonly consumed foods and beverages for 2-years-old children utilizing market basket information for the US Midwest region. Total Diet Study food lists were cross-referenced with National Health and Nutrition Examination Survey-What We Eat in America data to determine the foods and beverages to be included. Fluoride concentrations were determined using a modification of the hexamethyldisiloxane microdiffusion technique. Fluoride concentrations were summarized for each of the food categories. Daily dietary fluoride intake was estimated using a simulation analysis. Food and beverage fluoride concentrations varied widely, ranging from nondetectable for some oils and dairy products to more than 3.0 μgF/g food for some processed meats, fish and fruits. The estimated mean (±SD) daily dietary fluoride intake, excluding dentifrice and supplements, was 412±114 μgF/d. The estimated average ingestion for a 2-years-old weighing 12.24 kg was 0.034±0.009 mg/kg/d. A diet based on foods and beverages in the fifth percentile of fluoride intake distribution for an average child would result in 247 μgF/d or 0.020 mg/kg/d, while a diet with foods and beverages in the 95th percentile would result in a total intake of 622 μgF/d or 0.051 mg/kg/d. The fluoride concentrations of foods and beverages vary widely, and, if items in the 95th percentile of fluoride intake distribution are ingested, children could consume more fluoride than the recommended 0.05 mg/kg/d. Fluoride intake calculated in this study was higher than historically reported dietary levels. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparing three toothpastes in controlling plaque and gingivitis: A 6-month clinical study.

PubMed

Triratana, Terdphong; Kraivaphan, Petcharat; Amornchat, Cholticha; Mateo, Luis R; Morrison, Boyce M; Dibart, Serge; Zhang, Yun-Po

2015-04-01

To investigate the clinical efficacy of three toothpastes in controlling established gingivitis and plaque over 6 months. 135 subjects were enrolled in a single-center, double-blind, parallel group, randomized clinical study. Subjects were randomly assigned to one of three treatments: triclosan/copolymer/fluoride dentifrice containing 0.3% triclosan, 2.0% copolymer and 1,450 ppm F as sodium fluoride in a silica base; herbal/bicarbonate dentifrice containing herbal extract and 1,400 ppm F as sodium fluoride in a sodium bicarbonate base; or fluoride dentifrice containing 450 ppm F as sodium fluoride, and 1,000 ppm F as sodium monofluorophosphate. Subjects were instructed to brush their teeth twice daily for 1 minute for 6 months. After 6 months, subjects assigned to the triclosan/copolymer/fluoride group exhibited statistically significant reductions in gingival index scores and plaque index scores as compared to subjects assigned to the herbal/bicarbonate group by 35.4% and 48.9%, respectively. There were no statistically significant differences in gingival index and plaque index between subjects in the herbal/ bicarbonate group and those in the fluoride group. The triclosan/copolymer/fluoride dentifrice was statistically significantly more effective in reducing gingivitis and dental plaque than the herbal/bicarbonate dentifrice, and this difference in efficacy was clinically meaningful.

APPLICATION OF VACUUM SALT DISTILLATION TECHNOLOGY FOR THE REMOVAL OF FLUORIDE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pierce, R.; Pak, D.

2011-08-10

Vacuum distillation of chloride salts from plutonium oxide (PuO{sub 2}) and simulant PuO{sub 2} has been previously demonstrated at Department of Energy (DOE) sites using kilogram quantities of chloride salt. The apparatus for vacuum distillation contains a zone heated using 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 attained, heating begins. Volatile salts distill frommore » the heated zone to the cooled zone where they condense, leaving behind the non-volatile materials in the feed boat. The application of vacuum salt distillation (VSD) is of interest to the HB-Line Facility and the MOX Fuel Fabrication Facility (MFFF) at the Savannah River Site (SRS). Both facilities are involved in efforts to disposition excess fissile materials. Many of these materials contain chloride and fluoride salt concentrations which make them unsuitable for dissolution without prior removal of the chloride and fluoride salts. 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. Subsequent efforts are attempting to adapt the technology for the removal of fluoride. Fluoride salts of interest are less-volatile than the corresponding chloride salts. Consequently, an alternate approach is required for the removal of fluoride without significantly increasing the operating temperature. HB-Line Engineering requested SRNL to evaluate and demonstrate the feasibility of an alternate approach using both non-radioactive simulants and plutonium-bearing materials. Whereas the earlier developments targeted the removal of sodium chloride (NaCl) and potassium chloride (KCl), the

Registration of F1025, F1026, and F1027 sugarbeet germplasm with low concentrations of sodium, potassium, or amino-nitrogen

USDA-ARS?s Scientific Manuscript database

F1025 (Reg. No. GP-xxx, PI xxxxxx), F1026 (Reg. No. GP-xxx, PI xxxxxx), and F1027 (Reg. No. GP-xxx, PI xxxxxx) sugarbeet (Beta vulgaris L.) germplasm lines, selected for low concentrations of sodium, potassium, and amino-nitrogen, respectively, in the roots, were released by the USDA-ARS and the Nor...

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

PubMed

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 (p<0.05). Groups 7 and 9 provided similar results to group 2, but the results of those groups were different when compared with groups 8 and 10. The use of 6% HP and 10% CP associated with daily or weekly fluoridation regimens did not increase the susceptibility of enamel 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.

An alternate technique of care using silver fluoride followed by stannous fluoride in the management of root caries in aged care.

PubMed

Deutsch, Alan

2016-01-01

An alternate technique of care to prevent, arrest and manage root caries using aqueous silver fluoride followed by stannous fluoride (AgF+SnF2) in aged care is demonstrated by three case studies. With increasing age, the inability to maintain ones own oral care from dementia, illness or frailty and polypharmacy induced salivary gland hypofunction will result in dental caries becoming a progessively greater burden for the elderly. Future generations of elders will live longer and need to maintain many more teeth longer than earlier generations. Both silver diamine fluoride (SDF)and AgF+SnF2 arrest and prevent caries and are easy to use in residential aged care facilities. Clinical differences between SDF and AgF+SnF2 are discussed. However, in aged care, AgF+SnF2 may offer advantages over SDF. AgF+SnF2 used to arrest and prevent caries in children can be modified to provide effective but minimally invasive care for an ageing and frail population. These techniques are rapid, inexpensive and nonthreatening suited to treat frail elders, dementia patients exhibiting challenging behaviours and patients with multiple rapidly progressing decay. Silver fluoride, applied before placing glass-ionomer cement (GIC) restorations is an important adjunct to the atraumatic restorative technique and may retard caries reactivation more than GIC used alone. © 2015 Special Care Dentistry Association and Wiley Periodicals, Inc.

Zinc, copper, and nitrogen balances during bed rest and fluoride supplementation in healthy adult males

NASA Technical Reports Server (NTRS)

Krebs, J. M.; Schneider, V. S.; LeBlanc, A. D.

1988-01-01

The effects of bed rest and fluoride supplementation on zinc, copper, and nitrogen balances and Zn and Cu serum levels were measured in 15 healthy males. Subjects aged 19-54 y remained on a metabolic research ward for 10 wk. During weeks 1-5, subjects were ambulatory. During wks 6-10 they remained in continuous bed rest. During weeks 3-10 nine subjects received 10 or 20 mg F/d as sodium fluoride. Daily urine and weekly fecal composites were made and biweekly fasting blood samples were taken. Dietary intakes were 1.40 +/- 0.17 mg Cu/d (22.0 +/- 2.7 mumol Cu/d), 10.82 +/- 0.49 mg Zn/d (165.6 +/- 7.6 mumol Zn/d), and 14.27 +/- 0.23 g N/d (1019 +/- 16 mmol N/d). Bed rest increased urinary Zn and N excretions and fecal Zn excretions and decreased Zn balance (p less than 0.05) whereas Cu balance was unchanged. During bed rest, F supplementation increased Zn and N balances compared with untreated control subjects (p less than 0.05). These results are compatible with bone and muscle atrophy during bed rest and increased bone formation with F supplementation.

A{sub 5}RE{sub 4}X[TO{sub 4}]{sub 4} crystal growth: Fluoride flux synthesis of Na{sub 5}Ln{sub 4}F[GeO{sub 4}]{sub 4} (Ln=Pr, Nd), the first quaternary germanate oxyfluorides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Latshaw, Allison M.; Wilkins, Branford O.; Morrison, Gregory

Crystals of Na{sub 5}Pr{sub 4}F[GeO{sub 4}]{sub 4} and Na{sub 5}Nd{sub 4}F[GeO{sub 4}]{sub 4} were synthesized using a eutectic sodium fluoride, sodium chloride flux. Both compounds crystallize in the tetragonal space group I-4 with lattice parameters of a=12.1173(4) Å and c=5.6795(2) Å (Pr) and of a=12.0642(17) Å and c=5.6674(11) Å (Nd). The structure of the reported compounds is three-dimensional with face and corner sharing lanthanide polyhedra which edge and corner share with isolated germanium tetrahedra. These novel compositions represent the first example of quaternary germanium containing oxyfluorides. - Graphical abstract: Structural image of the first examples of quaternary germanate oxyfluorides. Displaymore » Omitted - Highlights: • Molten flux growth of crystals of two lanthanide germanate oxyfluorides. • Expansion of the A{sub 5}RE{sub 4}X[TO{sub 4}]{sub 4} family into germanate oxyfluorides. • Synthesis of Na{sub 5}Nd{sub 4}F[GeO{sub 4}]{sub 4} and Na{sub 5}Pr{sub 4}F[GeO{sub 4}]{sub 4}.« less

Solvothermal indium fluoride chemistry: Syntheses and crystal structures of K{sub 5}In{sub 3}F{sub 14}, beta-(NH{sub 4}){sub 3}InF{sub 6} and [NH{sub 4}]{sub 3}[C{sub 6}H{sub 21}N{sub 4}]{sub 2}[In{sub 4}F{sub 21}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jayasundera, Anil C.A.; Goff, Richard J.; Li Yang

2010-02-15

The solvothermal syntheses and crystal structures of three indium fluorides are presented. K{sub 5}In{sub 3}F{sub 14} (1) and beta-(NH{sub 4}){sub 3}InF{sub 6} (2) are variants on known inorganic structure types chiolite and cryolite, respectively, with the latter exhibiting a complex and apparently novel structural distortion. [NH{sub 4}]{sub 3}[C{sub 6}H{sub 21}N{sub 4}]{sub 2}[In{sub 4}F{sub 21}] (3) represents a new hybrid composition displaying a unique trimeric metal fluoride building unit. - Graphical abstract: Solvothermal synthesis has been used to prepare three indium fluorides, including a novel hybrid material containing a unique [In{sub 3}F{sub 15}] trimer templated by tren.

Chronologic Trends in Studies on Fluoride Mechanisms of Action.

PubMed

Oh, H J; Oh, H W; Lee, D W; Kim, C H; Ahn, J Y; Kim, Y; Shin, H B; Kim, C Y; Park, S H; Jeon, J G

2017-11-01

Fluoride has been widely used for the prevention of dental caries since the mid-20th century. The aim of this study was to investigate the chronologic trends in studies on fluoride mechanisms of action against dental caries during the years 1950 to 2015. To this aim, queries such as "fluoride," "fluoride and demineralization," "fluoride and remineralization," "fluoride and (plaque or biofilms)," and "fluoride and (bacteria or microbials)" were submitted to PubMed to collect research article information, including titles, abstracts, publication dates, author affiliations, and publication journals. The article information that PubMed produced was then collected by an automatic web crawler and examined through informetrics and linguistic analyses. We found that the number of articles concerned with fluoride mechanisms of action against dental caries was 6,903 and gradually increased over time during the years 1950 to 2015. They were published by 1,136 journals-most notably, Caries Research and Journal of Dental Research. Of the articles published, those related to bacteria/microbials had a higher percentage (44%) than those dealing with plaque/biofilms, demineralization, and remineralization. With regard to the geographic distribution of authors, Europe and North America accounted for 65% of the articles during the years 1987 to 2015, although the number of authors in Asia sharply increased in recent years. Among the fluoride compounds, NaF was mentioned more frequently than SnF 2 , Na 2 PO 3 F, amine fluoride, and acidulated phosphate fluoride during the years 1986 to 2015. Water fluoridation received the most attention among the various fluoride application methods (toothpastes, mouthwashes, fluoride varnishes, and fluoride gels) during the same period. These results, obtained from employing informetrics and linguistic analyses, suggest that in studies on fluoride mechanisms of action, 1) the unbalanced geographic distribution of articles and 2) the heavy

Clinical evaluation of the intraoral fluoride releasing system in radiation-induced xerostomic subjects. Part 2: Phase I study.

PubMed

Chambers, Mark S; Mellberg, James R; Keene, Harris J; Bouwsma, Otis J; Garden, Adam S; Sipos, Tibor; Fleming, Terence J

2006-10-01

significantly more radiation than those in the test group (68Gy vs. 60Gy; p=0.047). No marked differences in follow-up new and recurrent caries were found between the stannous fluoride gel control and IFRS groups during the study period. The rate of new or recurrent carious lesions in the group treated with the fluoride gel was slightly lower than in the IFRS group, based on carious lesions at the baseline examination (Poisson mean number of new or recurrent carious lesions for the control group=0.55 per year vs. 0.83 per year for the study group, p=0.705; odds ratio of the occurrence of any new or recurrent caries during follow-up for control group vs. the study group=0.80; p=0.781). This pilot study revealed that the IFRS was well-tolerated and safe in this study population associated with minimal complications during the duration of this study and was comparable in efficacy to a SnF(2) gel in preventing caries development. The IFRS provided similar rates of control for caries formation to a fluoride-gel-containing tray. The IFRS is designed to release a daily dose of 0.12mg of sodium fluoride, which can be evenly distributed throughout the oral cavity for a single application of 4 months. It would be more convenient than the daily home application of a tray of 0.4% stannous fluoride or 1.1% sodium fluoride gel, and avoids the problem of variable patient compliance.

Effect of fluoride toothpaste with nano-sized trimetaphosphate on enamel demineralization: An in vitro study.

PubMed

Danelon, Marcelle; Pessan, Juliano Pelim; Souza-Neto, Francisco Nunes; de Camargo, Emerson Rodrigues; Delbem, Alberto Carlos Botazzo

2017-06-01

This study evaluated the effect of toothpastes containing 1100ppm F associated or not with micrometric or nano-sized sodium trimetaphosphate (TMP) on enamel demineralization in vitro, using a pH cycling model. Bovine enamel blocks (4mm×4mm, n=96) were randomly allocated into eight groups (n=12), according to the test toothpastes: Placebo (without fluoride or TMP); 1100ppm F (1100F); 1100F plus micrometric TMP at concentrations of 1%, 3% or 6%; and 1100F plus nanosized TMP at 1%, 3% or 6%. Blocks were treated 2×/day with slurries of toothpastes and submitted to a pH cycling regimen for five days. Next, final surface hardness (SHf), integrated hardness loss (IHL), differential profile of integrated hardness loss (ΔIHL) and enamel fluoride (F) concentrations were determined. Data were analyzed by ANOVA and Student-Newman-Keuls' test (p<0.05). The use of 1100F/3%TMPnano led to SHf 30% higher (p<0.001) and IHL∼80% lower (p<0.001) when compared to 1100F. This toothpaste also resulted in ∼64% reduction of mineral loss (ΔIHL) when compared to 1100F. Moreover, the addition of nano-sized TMP promoted increases in enamel F uptake of 90%, 160% and 100%, respectively for the concentrations of 1%, 3% and 6%, when compared to 1100F (p<0.001). The addition of nano-sized TMP at 3% to a conventional toothpaste significantly decreased enamel demineralization when compared to its counterparts without TMP or supplemented with micrometric TMP. Copyright © 2017 Elsevier Ltd. All rights reserved.

Factors Affecting the Plasticity of Sodium Chloride, Lithium Fluoride, and Magnesium Oxide Single Crystals. 1

NASA Technical Reports Server (NTRS)

Stearns, Carl A.; Pack, Ann E.; Lad, Robert A.

1959-01-01

A study was made of the relative magnitude of the effects of various factors on the ductility of single crystals of sodium chloride (NaCl), lithium fluoride (LiF), and magnesium oxide (MgO). Specimen treatments included water-polishing, varying cleavage rate, annealing, quenching, X-irradiation, surface coating, aging, and combinations of some of these treatments. The mechanical behavior of the crystals was studied in flexure and in compression, the latter study being performed at both constant strain rate and constant load. Etch-pit studies were carried out to provide some pertinent information on the results of pretreatment on the dislocation concentration and distribution in the vicinity of the surface. The load deformation curves for these ionic single crystals show an initial region of very low slope which proved to be due to anelastic deformation. The extent of initial anelastic deformation is modified by specimen pretreatment in a way that suggests that this deformation is the result of expansion of cleaved-in dislocation loops, which can contract on the removal of the stress. The effects of the various pretreatments on the load and deflection at fracture are in accord with the prediction one might make with regard to their effect on the nucleation of fatal surface cracks. For NaCl, increases in ductility are always accompanied by increases in strength. The creep constants for NaCl are a function of treatments which affect the bulk structure but are not a function of treatments which only affect the surface.

Assigning crystallographic electron densities with free energy calculations—The case of the fluoride channel Fluc

PubMed Central

2018-01-01

Approximately 90% of the structures in the Protein Data Bank (PDB) were obtained by X-ray crystallography or electron microscopy. Whereas the overall quality of structure is considered high, thanks to a wide range of tools for structure validation, uncertainties may arise from density maps of small molecules, such as organic ligands, ions or water, which are non-covalently bound to the biomolecules. Even with some experience and chemical intuition, the assignment of such disconnected electron densities is often far from obvious. In this study, we suggest the use of molecular dynamics (MD) simulations and free energy calculations, which are well-established computational methods, to aid in the assignment of ambiguous disconnected electron densities. Specifically, estimates of (i) relative binding affinities, for instance between an ion and water, (ii) absolute binding free energies, i.e., free energies for transferring a solute from bulk solvent to a binding site, and (iii) stability assessments during equilibrium simulations may reveal the most plausible assignments. We illustrate this strategy using the crystal structure of the fluoride specific channel (Fluc), which contains five disconnected electron densities previously interpreted as four fluoride and one sodium ion. The simulations support the assignment of the sodium ion. In contrast, calculations of relative and absolute binding free energies as well as stability assessments during free MD simulations suggest that four of the densities represent water molecules instead of fluoride. The assignment of water is compatible with the loss of these densities in the non-conductive F82I/F85I mutant of Fluc. We critically discuss the role of the ion force fields for the calculations presented here. Overall, these findings indicate that MD simulations and free energy calculations are helpful tools for modeling water and ions into crystallographic density maps. PMID:29771936

Crystallographic nature of fluoride in enameloids of fish.

PubMed

LeGeros, R Z; Suga, S

1980-01-01

X-ray diffraction studies on calcified tissues (teeth and/or scales) of fish and of shark showed that the presence of fluoride affects the crystallite size and lattice parameters of the apatite phase. An inverse correlation between F contents (ranging from 0.2 to 3.8 wt% F) and alpha-axis dimensions (9.441 to 9.375 +/- 0.003 A) exists for both synthetic and enameloid apatites and is consistent with the F-for-OH substitution in the apatite, idealized as Ca10(PO4)6(OH)2 and Ca10(PO4)6F2, for fluoride-free and maximum fluoride-substituted apatite, respectively. In synthetic systems, the incorporation of F is found to be dependent on the F concentration of the media from which the apatite formed. This dependency is also observed between F content of the dentine apatites and the F concentration of the water from which the fish can (i.e., less than 0.08 ppmF in fresh water, about 1.3 ppm in seawater). However, no such dependency was observed between the F incorporation in fish enameloid apatite and the F concentration in the water of origin. In some cases, the F incorporated in the enameloid apatite is much in excess of what can be expected from the F concentration of water. These observations suggest that in some fish, a fluoride-concentrating mechanism is operative during the formation of the enameloid but not during the formation of the dentine, and this mechanism appears to be specie-related.

Water Atomization of Barium Fluoride: Calcium Fluoride for Enhanced Flow Characteristics of PS304 Feedstock Powder Blend

NASA Technical Reports Server (NTRS)

Stanford, Malcolm K.; DellaCorte, Christopher

2003-01-01

PS304 is a plasma spray deposited solid lubricant coating with feedstock composed of NiCr, Cr2O3, Ag, and BaF2-CaF2 powders. The effects of rounded BaF2-CaF2 particles on the gravity-fed flow characteristics of PS304 feedstock have been investigated. The BaF2-CaF2 powder was fabricated by water atomization using four sets of process parameters. Each of these powders was then characterized by microscopy and classified by screening to obtain 45 to 106 micron particles and added incrementally from 0 to 10 wt% to the other constituents of the PS304 feedstock, namely nichrome, chromia, and silver powders. The relationship between feedstock flow rate, measured with the Hall flowmeter, and concentration of fluorides was found to be linear in each case. The slopes of the lines were between those of the linear relationships previously reported using angular and spherical fluorides and were closer to the relationship predicted using the rule of mixtures. The results offer a fluoride fabrication technique potentially more cost-effective than gas atomization processes or traditional comminution processes.

Effects of sodium fluoride on immune response in murine macrophages.

PubMed

De la Fuente, Beatriz; Vázquez, Marta; Rocha, René Antonio; Devesa, Vicenta; Vélez, Dinoraz

2016-08-01

Excessive fluoride intake may be harmful for health, producing dental and skeletal fluorosis, and effects upon neurobehavioral development. Studies in animals have revealed effects upon the gastrointestinal, renal and reproductive systems. Some of the disorders may be a consequence of immune system alterations. In this study, an in vitro evaluation is made of fluoride immunotoxicity using the RAW 264.7 murine macrophage line over a broad range of concentrations (2.5-75mg/L). The results show that the highest fluoride concentrations used (50-75mg/L) reduce the macrophage population in part as a consequence of the generation of reactive oxygen and/or nitrogen species and consequent redox imbalance, which in turn is accompanied by lipid peroxidation. A decrease in the expression of the antiinflammatory cytokine Il10 is observed from the lowest concentrations (5mg/L). High concentrations (50mg/L) in turn produce a significant increase in the proinflammatory cytokines Il6 and Mip2 from 4h of exposure. In addition, cell phagocytic capacity is seen to decrease at concentrations of ≥20mg/L. These data indicate that fluoride, at high concentrations, may affect macrophages and thus immune system function - particularly with regard to the inflammation autoregulatory processes, in which macrophages play a key role. Copyright © 2016 Elsevier B.V. All rights reserved.

Recommendations for fluoride limits in drinking water based on estimated daily fluoride intake in the Upper East Region, Ghana.

PubMed

Craig, Laura; Lutz, Alexandra; Berry, Kate A; Yang, Wei

2015-11-01

Both dental and skeletal fluorosis caused by high fluoride intake are serious public health concerns around the world. Fluorosis is particularly pronounced in developing countries where elevated concentrations of naturally occurring fluoride are present in the drinking water, which is the primary route of exposure. The World Health Organization recommended limit of fluoride in drinking water is 1.5 mg F(-) L(-1), which is also the upper limit for fluoride in drinking water for several other countries such as Canada, China, India, Australia, and the European Union. In the United States the enforceable limit is much higher at 4 mg F(-) L(-1), which is intended to prevent severe skeletal fluorosis but does not protect against dental fluorosis. Many countries, including the United States, also have notably lower unenforced recommended limits to protect against dental fluorosis. One consideration in determining the optimum fluoride concentration in drinking water is daily water intake, which can be high in hot climates such as in northern Ghana. The results of this study show that average water intake is about two times higher in Ghana than in more temperate climates and, as a result, the fluoride intake is higher. The results also indicate that to protect the Ghanaian population against dental fluorosis, the maximum concentration of fluoride in drinking water for children under 6-8 years should be 0.6 mg F(-) L(-1) (and lower in the first two years of life), and the limit for older children and adults should be 1.0 mg F(-) L(-1). However, when considering that water treatment is not cost-free, the most widely recommended limit of 1.5 mg F(-) L(-1) - which is currently the limit in Ghana--may be appropriate for older children and adults since they are not vulnerable to dental fluorosis once the tooth enamel is formed. Copyright © 2015 Elsevier B.V. All rights reserved.

Fluoride penetration from toothpastes into incipient enamel erosive lesions investigated using dynamic secondary ion mass spectrometry.

PubMed

Fowler, C E; Gracia, L; Edwards, M I; Brown, A; Rees, G D

2009-01-01

The primary aim of this study was to assess the utility of dynamic secondary ion mass spectrometry (DSIMS) as a convenient and sensitive technique for determining fluoride uptake and distribution into incipient human enamel erosive lesions in vitro. A secondary aim was to correlate the extent of lesion rehardening following treatment with a toothpaste slurry, with relative fluoride uptake determined by DSIMS. The final aim was to compare fluoride uptake by incipient lesions treated with toothpastes containing different sources of fluoride using DSIMS. Relative fluoride uptake into the surface and body of enamel erosive lesions was monitored by DSIMS as a function of fluoride concentration in a series of formulation-matched experimental pastes. Fluoride uptake into lesions that had been subjected to treatment with different toothpaste slurries in a single-treatment enamel lesion rehardening model was also determined, and its relationship with regard to the extent of rehardening and also the fluoride source investigated. Fluoride uptake by incipient erosive lesions treated with toothpastes containing NaF was quantitatively compared by DSIMS and found to be directly proportional to the fluoride concentration over the studied range (0-1400 ppm). Lesion repair observed in a single-treatment lesion rehardening model was positively correlated with the extent of fluoride uptake by the treated lesions. DSIMS was also able to show differences between commercial toothpastes containing different sources of fluoride and their ability to deliver the fluoride into the body of the lesion. The detrimental effect of sodium hexametaphosphate (NaHMP) present in Crest Pro-Health formulations previously reported in the single-treatment lesion rehardening model was also evident from the DSIMS elemental line scans obtained from the lesion cross-sections. DSIMS has been shown to be a powerful selective technique for quantifying relative fluoride uptake into enamel erosive lesions, and

Comparison of residual salivary fluoride retention using amine fluoride toothpastes in caries-free and caries-prone children.

PubMed

Nazzal, H; Duggal, M S; Kowash, M B; Kang, J; Toumba, K J

2016-06-01

This was to compare the salivary fluoride levels following tooth brushing with amine fluoride toothpastes containing three different concentrations of F (250 ppm F, 500 ppm F and 1250 ppm F) and to evaluate the effect of rinsing with water on the oral fluoride levels up to 90 min. A double blind randomised six-arm crossover study was conducted with 32 child participants. Patients were divided into two groups depending on their caries experience with caries-free group (n = 17, mean age = 72.9 months) and caries-prone group (n = 15, mean age = 69.6 months, mean dmfs = 12.3). Each participant brushed their teeth with a smear of dentifrice containing (250 ppm, 500 ppm and 1250 ppm F toothpastes) for 60 s. After spitting out the dentifrice/saliva slurry, participants either rinsed with water or did not rinse at all. Samples of whole mixed unstimulated saliva were collected at 0 (baseline), 1, 15, 30, 45, 60 and 90 mins post-brushing/rinsing. After completing the study on residual fluoride concentration it was found that caries was not a significant variable (p = 0.567) while every other variable was (all p values <0.001). Time, toothpaste F concentration and rinse had significant effects (p < 0.001). In general, higher residual salivary F concentrations were found with increased F concentration in toothpastes and when no rinsing was performed after brushing. The results of this study support the current recommendation of using toothpastes with >1000 ppm F concentration in children with an increased caries risk in addition to spitting excess toothpaste with no rinsing following brushing.

Double cross-polarization MAS NMR in the assignment of abundant-spin resonances: ¹⁹F-{²⁹Si}-¹⁹F FBCP/MAS NMR of fluoride ions incorporated in calcium silicate hydrate (C-S-H) phases.

PubMed

Tran, Thuan T; Bildsøe, Henrik; Jakobsen, Hans J; Skibsted, Jørgen

2012-08-01

A new version of the double cross-polarization MAS NMR experiment, which transfers polarization Forth and Back (FBCP) between high- and low-γ spin nuclei, is presented. The pulse sequence is demonstrated by ¹⁹F-{²⁹Si}-¹⁹F and ¹⁹F-{¹³C}-¹⁹F FBCP NMR spectra of a mixture of cuspidine (Ca₄Si₂O₇F₂) and Teflon (-CF₂-)(n). The experiment is useful for assignment of the high-γ spin resonances, as demonstrated by ¹⁹F-{²⁹Si}-¹⁹F FBCP NMR of a fluoride-containing calcium-silicate-hydrate (C-S-H) phase, where the ¹⁹F resonance from fluoride ions incorporated in the interlayer structure of the C-S-H phase is identified. Copyright © 2012 Elsevier Inc. All rights reserved.

[Fluoride release and recharge properties of six restorative materials].

PubMed

Gui, Yajie; Zhao, Xinyi; Li, Shibao; Tang, Lihui; Gong, Xu

2015-01-01

To evaluate the F(-) releasing and recharging properties of six dental restorative materials. Disc specimens 10 mm in diameter and 1 mm in thickness were prepared from 6 different dental restorative materials: Fuji VII [glass ionomer cement (GIC)], Fuji II LC (light-curing, GIC), Beautifil (giomer), Compoglass F (compomer), Charisma (composite) and Experimental I (a fluoride releasing composite), with 10 discs for each material. Specimens were dipped in 5 ml deionized water and F(-) release was detected using a fluoride-specific ion electrode every day from 1-7 days and every three days from 8-28 days. On day 28, specimens were exposed to a fluoride foam for 4 min and then dipped in water, then the F(-) concentration was detected every day for a week. The specimens were exposed to fluoride foam and fluoride release was detected repeatedly for three times. All materials presented the highest F(-) release on the first day after dipping and the F(-) release sharply decreased after 24 h and slowly decreased after 3 days. On the first day, Fuji VII presented the highest F(-) release[(99.68±15.21) µg×cm(-2)×d(-1)], followed by Fuji II LC [(37.12±1.67) µg×cm(-2)×d(-1)], Experimental I [(22.93±1.53) µg×cm(-2)×d(-1)], Compoglass F[(15.28±0.70) µg×cm(-2)×d(-1)], Beautifil[(2.40±0.52) µg×cm(-2)×d(-1)] and Charisma[(0.11±0.02) µg×cm(-2)×d(-1)]. Within 28 days of dipping, both Fuji VII and Fuji II LC released more F(-) than other materials did(P < 0.05), followed by Compoglass F and Experimental I, and Beautifil and Charisma released the least F(-)(P < 0.01). After F(-) uptake, all materials released the highest F- on the first day and presented sharply decrease after 24 h and slowly decrease after 2 days. On the first day after F(-) uptake, Fuji VII presented the highest F(-) release (>40 µg×cm(-2) ×d(-1)), much more than other materials(P < 0.01), followed by Fuji II LC(>25 µg×cm(-2) ×d(-1)). Beautifil, Compoglass F and Experimental I were close

Determination of total fluoride in HF/HNO3/H2SiF6 etch solutions by new potentiometric titration methods.

PubMed

Weinreich, Wenke; Acker, Jörg; Gräber, Iris

2007-03-30

In the photovoltaic industry the etching of silicon in HF/HNO(3) solutions is a decisive process for cleaning wafer surfaces or to produce certain surface morphologies like polishing or texturization. With regard to cost efficiency, a maximal utilisation of etch baths in combination with highest quality and accuracy is strived. To provide an etch bath control realised by a replenishment with concentrated acids the main constituents of these HF/HNO(3) etch solutions including the reaction product H(2)SiF(6) have to be analysed. Two new methods for the determination of the total fluoride content in an acidic etch solution based on the precipitation titration with La(NO(3))(3) are presented within this paper. The first method bases on the proper choice of the reaction conditions, since free fluoride ions have to be liberated from HF and H(2)SiF(6) at the same time to be detected by a fluoride ion-selective electrode (F-ISE). Therefore, the sample is adjusted to a pH of 8 for total cleavage of the SiF(6)(2-) anion and titrated in absence of buffers. In a second method, the titration with La(NO(3))(3) is followed by a change of the pH-value using a HF resistant glass-electrode. Both methods provide consistent values, whereas the analysis is fast and accurate, and thus, applicable for industrial process control.

Prior fluoridation in childhood affects dental caries and tooth wear in a south east Queensland population.

PubMed

Teo, C; Young, W G; Daley, T J; Sauer, H

1997-04-01

Fluoride exposure in early life has an effect on dental caries experience, but does it affect tooth wear in later life? Ninety-six South East Queensland subjects were studied. Their histories revealed three groups; a fluoride (F-) in water supply, a F- by supplement, and a non-fluoridated (non F-) group. Significantly higher caries experience was found in the non-F- group compared with F- in water group and the F- supplement group. No statistically significant difference in caries experience was found between the F- in water and F- supplement groups. Overall, tooth wear affected more sextants of the dentitions of non-fluoridated, high-caries subjects than of fluoridated low-caries subjects. Comparisons of wear patterns on sextants of the dentitions, between the fluoridated and non-fluoridated groups, revealed that in sextants where attrition was present no marked differences were discernible between the two groups. However, in most sextants where incisal, palatal, occlusal or non-occlusal erosion was found, this type of wear was commoner in non-fluoridated subjects. The exceptions were the mandibular molar sextants, where prior fluoride-exposure did not appear to protect against occlusal erosion patterns. This study showed that fluoride exposure during the first 12 years of life, which reduced dental caries in this population, may also protect teeth from wear to some extent.

Ion release from, and fluoride recharge of a composite with a fluoride-containing bioactive glass.

PubMed

Davis, Harry B; Gwinner, Fernanda; Mitchell, John C; Ferracane, Jack L

2014-10-01

Materials that are capable of releasing ions such as calcium and fluoride, that are necessary for remineralization of dentin and enamel, have been the topic of intensive research for many years. The source of calcium has most often been some form of calcium phosphate, and that for fluoride has been one of several metal fluoride or hexafluorophosphate salts. Fluoride-containing bioactive glass (BAG) prepared by the sol-gel method acts as a single source of both calcium and fluoride ions in aqueous solutions. The objective of this investigation was to determine if BAG, when added to a composite formulation, can be used as a single source for calcium and fluoride ion release over an extended time period, and to determine if the BAG-containing composite can be recharged upon exposure to a solution of 5000ppm fluoride. BAG 61 (61% Si; 31% Ca; 4% P; 3% F; 1% B) and BAG 81 (81% Si; 11% Ca; 4% P; 3% F; 1% B) were synthesized by the sol-gel method. The composite used was composed of 50/50 Bis-GMA/TEGDMA, 0.8% EDMAB, 0.4% CQ, and 0.05% BHT, combined with a mixture of BAG (15%) and strontium glass (85%) to a total filler load of 72% by weight. Disks were prepared, allowed to age for 24h, abraded, then placed into DI water. Calcium and fluoride release was measured by atomic absorption spectroscopy and fluoride ion selective electrode methods, respectively, after 2, 22, and 222h. The composite samples were then soaked for 5min in an aqueous 5000ppm fluoride solution, after which calcium and fluoride release was again measured at 2, 22, and 222h time points. Prior to fluoride recharge, release of fluoride ions was similar for the BAG 61 and BAG 81 composites after 2h, and also similar after 22h. At the four subsequent time points, one prior to, and three following fluoride recharge, the BAG 81 composite released significantly more fluoride ions (p<0.05). Both composites were recharged by exposure to 5000ppm fluoride, although the BAG 81 composite was recharged more than the BAG

Influence of magnesium fluoride (MgF2) layer on a conventional surface plasmon resonance sensor

NASA Astrophysics Data System (ADS)

Mohapatra, Saswat; Moirangthem, Rakesh S.

2018-05-01

In this work, a numerical study of Surface Plasmon Resonance (SPR) sensor has been done by using Magnesium Fluoride (MgF2) layer on a conventional Kretschmann configuration. The prism was coated with smooth gold thin film of thickness 50 nm followed by MgF2 layer. To obtain the maximum reflection dips in the SPR modes, the thickness of MgF2 layer is optimized by varying it from 200-800 nm. Our calculations also reveal that SPR modes corresponding to gold-MgF2 layer are very sensitive to the changes in the surrounding medium as compared to the traditional SPR device. The sensing performance of the proposed nano-plasmonic sensor is theoretically calculated using bulk refractive index sensing. Such bilayer device (gold-MgF2) is expected to take an important role on the field of chemical and biological sensing.

Fluoride and arsenic exposure affects spatial memory and activates the ERK/CREB signaling pathway in offspring rats.

PubMed

Zhu, Yu-Peng; Xi, Shu-Hua; Li, Ming-Yan; Ding, Ting-Ting; Liu, Nan; Cao, Fu-Yuan; Zeng, Yang; Liu, Xiao-Jing; Tong, Jun-Wang; Jiang, Shou-Fang

2017-03-01

Fluoride and arsenic are inorganic contaminants that occur in the natural environment. Chronic fluoride and/or arsenic exposure can induce developmental neurotoxicity and negatively influence intelligence in children, although the underlying molecular mechanisms are poorly understood. This study explored the effects of fluoride and arsenic exposure in drinking water on spatial learning, memory and key protein expression in the ERK/CREB signaling pathway in hippocampal and cerebral cortex tissue in rat offspring. Pregnant rats were divided into four groups. Control rats drank tap water, while rats in the three exposure groups drank water with sodium fluoride (100mg/L), sodium arsenite (75mg/L), and a sodium fluoride (100mg/L) and sodium arsenite (75mg/L) combination during gestation and lactation. After weaning, rat pups drank the same solution as their mothers. Spatial learning and memory ability of pups at postnatal day 21 (PND21) and postnatal day 42 (PND42) were measured using a Morris water maze. ERK, phospho-ERK (p-ERK), CREB and phospho-CREB (p-CREB) protein expression in the hippocampus and cerebral cortex was detected using Western blot. Compared with the control pups, escape latencies increased in PND42 pups exposed to arsenic and co-exposed to fluoride and arsenic, and the short-term and long-term spatial memory ability declined in pups exposed to fluoride and arsenic, both alone and in combination. Compared with controls, ERK and p-ERK levels decreased in the hippocampus and cerebral cortex in pups exposed to combined fluoride and arsenic. CREB protein expression in the cerebral cortex decreased in pups exposed to fluoride, arsenic, and the fluoride and arsenic combination. p-CREB protein expression in both the hippocampus and cerebral cortex was decreased in pups exposed to fluoride and arsenic in combination compared to the control group. There were negative correlation between the proteins expression and escape latency periods in pups. These data

Effects of gaseous fluoride on Delicious and Golden Delicious apples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, M.J.

1973-01-01

Atmospheric fluorides were monitored in apple and other fruit orchards around two adjacent sources of fluoride emissions. Delicious and Golden Delicious trees were fumigated with low (4.6-4.7 micrograms F/cu m) fluoride levels once, twice, or three times a week. However, both methods were adequate in the determination of the fluoride distribution pattern in the study area. Considerably higher levels of fluoride were detected at sampling sites downwind of the emission sources. Fluoride-induced tip necrosis on apple leaves was observed in one orchard where a mean seasonal limed filter paper value of 82.4 micrograms F/d sq m/mo and 22.5 F inmore » the washed foliage were recorded. Tip necrosis increased as the F level and frequency of exposure increased. Leaf respiration was inhibited at the lower but not the higher F fumigation level. Fruit respiration was stimulated to equal levels by the two F concentrations used. A trend toward increased inhibition of fruit ethylene production at lower exposure factors (concentration times time) was observed. The loss of green color in the skin of treated fruits was retarded relative to an increase in the F level and the exposure frequency. With the exception of leaf respiration, where an inverse relationship was found, the degree of response with respect to leaf injury, fruit respiration, and color were directly affected by the exposure factor used. Within the scope of this study, fruit shape, firmness, and soluble solids were not affected by the treatments.« less

Unusual hydrogen bonding in L-cysteine hydrogen fluoride.

PubMed

Minkov, V S; Ghazaryan, V V; Boldyreva, E V; Petrosyan, A M

2015-08-01

L-Cysteine hydrogen fluoride, or bis(L-cysteinium) difluoride-L-cysteine-hydrogen fluoride (1/1/1), 2C3H8NO2S(+)·2F(-)·C3H7NO2S·HF or L-Cys(+)(L-Cys···L-Cys(+))F(-)(F(-)...H-F), provides the first example of a structure with cations of the 'triglycine sulfate' type, i.e. A(+)(A···A(+)) (where A and A(+) are the zwitterionic and cationic states of an amino acid, respectively), without a doubly charged counter-ion. The salt crystallizes in the monoclinic system with the space group P2(1). The dimeric (L-Cys···L-Cys(+)) cation and the dimeric (F(-)···H-F) anion are formed via strong O-H···O or F-H···F hydrogen bonds, respectively, with very short O···O [2.4438 (19) Å] and F···F distances [2.2676 (17) Å]. The F···F distance is significantly shorter than in solid hydrogen fluoride. Additionally, there is another very short hydrogen bond, of O-H···F type, formed by a L-cysteinium cation and a fluoride ion. The corresponding O···F distance of 2.3412 (19) Å seems to be the shortest among O-H···F and F-H···O hydrogen bonds known to date. The single-crystal X-ray diffraction study was complemented by IR spectroscopy. Of special interest was the spectral region of vibrations related to the above-mentioned hydrogen bonds.

Effect of fluoride on major organs with the different time of exposure in rats.

PubMed

Perera, Thanusha; Ranasinghe, Shirani; Alles, Neil; Waduge, Roshitha

2018-05-16

High fluoride levels in drinking water in relation to the prevalence of chronic kidney disease of unknown etiology (CKDu) in Sri Lanka were investigated using rats as an experimental model. The effects of fluoride after oral administration of Sodium fluoride (NaF) at levels of 0, 0.5, 5 and 20 ppm F - were evaluated in adult male Wistar rats. Thirty-six rats were randomly divided into 4 groups (n = 9), namely, control, test I, II, and III. Control group was given daily 1 ml/rat of distilled water and test groups I, II, and III were treated 1 ml/rat of NaF doses of 0.5, 5, and 20 ppm, respectively, by using a stomach tube. Three rats from the control group and each experimental group were sacrificed after 15, 30, and 60 days following treatment. Serological and histopathological investigations were carried out using blood, kidney, and liver. No significant differences were observed in body weight gain and relative organ weights of the liver and kidney in fluoride-treated groups compared to control group. After 60 days of fluoride administration, group I showed a mild portal inflammation with lytic necrosis while multiple areas of focal necrosis and various degrees of portal inflammation were observed in groups II and III. This was further confirmed by increased serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) activities. As compared with control and other treated groups, group III showed a significantly higher serum AST activity (p < 0.05) and ALT activity (p < 0.05) after 60 days and ALP activity with a significant difference (p < 0.05) after 15, 30, and 60 days. The renal histological analysis showed normal histological features in all groups with the elevated serum creatinine levels in group III compared to those in the groups I and II (p < 0.05) after 60 days. Significantly elevated serum fluoride levels were observed in group II of 30 and 60 days and group III after 15, 30, and

Antibacterial effects of fluoride varnish compared with chlorhexidine plus fluoride in disabled children.

PubMed

Baygin, Ozgul; Tuzuner, Tamer; Kusgoz, Adem; Senel, Ahmet Can; Tanriver, Mehmet; Arslan, Ipek

2014-01-01

To evaluate the effects of fluoride varnish vs a combination of chlorhexidine-thymol varnish plus a gel containing chlorhexidine and fluoride on oral hygiene and caries prevention in disabled children. Ninety patients aged 3-17 years who were treated under general anaesthesia were randomly assigned into three groups as follows: group 1: Fluor Protector (0.1% fluoride varnish); group 2: Cervitec Plus (1% chlorhexidine- 1% thymol varnish) + Cervitec Gel (0.2% chlorhexidine-0.2% sodium fluoride); group 3: control (toothbrushing only). Mutans streptococci (MS) and lactobacilli (LB) levels, visible plaque index (VPI) and gingival bleeding index (GBI) were evaluated at four stages: T0, before general anaesthesia; T1, one month after treatment; T2, six months after treatment; T3, twelve months after treatment. The data were evaluated using Kruskal-Wallis and Mann-Whitney U-tests (P < 0.05). Groups 1 and 2 showed significantly lower scores than group 3 for all parameters at T1 and T2. No statistically significant difference was detected among any of the the groups at T3 (P > 0.05). The use of materials that include both fluoride and chlorhexidine as routine treatment of children with disability may increase the success of restorations by improving oral hygiene, reduce the need for future restorative treatments and thus the need for general anaesthesia.

The effect of fluoridation and its discontinuation on fluoride profiles in the alveolar bone of rat.

PubMed

Ohmi, Kyohei; Nakagaki, Haruo; Tsuboi, Shinji; Okumura, Akihiro; Sugiyama, Tomoko; Thuy, Tran Thu; Robinson, Colin

2005-10-01

We investigated the effect of fluoridation and its discontinuation on fluoride content in the alveolar portion of the mandible in rats. Drinking water with three different fluoride contents (0, 50, 100 ppmF) was given to rats for three different periods (4, 13 and 25 weeks). Fluoride concentrations were measured in the crest, the middle, and the apical parts of the alveolar bone and in the body of the mandible. Furthermore, after fluoridated drinking water was given to rats for 4 or 13 weeks, distilled water was given to them for 21 or 12 weeks respectively; and the effect of the discontinuation on fluoride profiles was investigated. Layer samples were analyzed by abrasive microsampling. Fluoride and phosphorus concentrations were determined by ion-specific electrode and colorimetric procedures, respectively. There was an increase in fluoride concentrations in the mandible in proportion to the fluoride content in the drinking water and the duration of fluoridation. After fluoridation was discontinued, fluoride concentrations in the surface layers of the mandible presented a decrease. Among the four different parts of the mandible, the upper part of the alveolar bone and the alveolar crest part presented the highest rates of reduction. The relative reduction rate of fluoride concentration was closely related to the duration of discontinuation. The alveolar crest was affected most by the discontinuation of fluoridation, presenting the greatest reduction.

Combinatorial effects of arginine and fluoride on oral bacteria.

PubMed

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

Combinatorial Effects of Arginine and Fluoride on Oral Bacteria

PubMed Central

Zheng, X.; Cheng, X.; Wang, L.; Qiu, W.; Wang, S.; Zhou, Y.; Li, M.; Li, Y.; Cheng, L.; Li, J.; Zhou, 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, 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. PMID:25477312

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

PubMed Central

Maleki, Afshin; Daraei, Hiua; Mohammadi, Elham; Zandi, Shiva; Teymouri, Pari; Mahvi, Amir Hossien; Gharibi, Fardin

2016-01-01

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). However, the additives had no significant effect on the fluoride release into the infusions (P > 0.05). Finally, drinking of the studied green teas cannot make a significant contribution to the daily dietary intake of F for consumers. PMID:27042093

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

PubMed

Maleki, Afshin; Daraei, Hiua; Mohammadi, Elham; Zandi, Shiva; Teymouri, Pari; Mahvi, Amir Hossien; Gharibi, Fardin

2016-01-01

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). However, the additives had no significant effect on the fluoride release into the infusions (P > 0.05). Finally, drinking of the studied green teas cannot make a significant contribution to the daily dietary intake of F for consumers.

The efficacy of an intraoral fluoride-releasing system in irradiated head and neck cancer patients: a preliminary study.

PubMed

Meyerowitz, C; Watson, G E

1998-09-01

This study compared the anticaries effectiveness of an intraoral fluoride-releasing system, or IFRS, with a standard regimen of daily application of a 1.1 percent neutral sodium fluoride gel in custom trays. Caries protection in subjects in the IFRS group was comparable to that in subjects in the 1.1 percent neutral sodium fluoride group. The subjects all had head or neck cancer and had received radiation therapy, but no more recently than three months before taking part in the study. Overall, IFRS devices were well-tolerated and patient satisfaction was high. The IFRS appears to offer several advantages over the daily application of fluoride gels in custom trays.

Effect of discontinuation of fluoride intake from water and toothpaste on urinary excretion in young children.

PubMed

Martins, Carolina C; Paiva, Saul M; Cury, Jaime A

2011-06-01

As there is no homeostatic mechanism for maintaining circulating fluoride (F) in the human body, the concentration may decrease and increase again when intake is interrupted and re-started. The present study prospectively evaluated this process in children exposed to F intake from water and toothpaste, using F in urine as a biomarker. Eleven children from Ibiá, Brazil (with sub-optimally fluoridated water supply) aged two to four years who regularly used fluoridated toothpaste (1,100 ppm F) took part in the study. Twenty-four-hour urine was collected at baseline (Day 0, F exposure from water and toothpaste) as well as after the interruption of fluoride intake from water and dentifrice (Days 1 to 28) (F interruption) and after fluoride intake from these sources had been re-established (Days 29 to 34) (F re-exposure). Urinary volume was measured, fluoride concentration was determined and the amount of fluoride excreted was calculated and expressed in mg F/day. Urinary fluoride excretion (UFE) during the periods of fluoride exposure, interruption and re-exposure was analyzed using the Wilcoxon test. Mean UFE was 0.25 mg F/day (SD: 0.15) at baseline, dropped to a mean of 0.14 mg F/day during F interruption (SD: 0.07; range: 0.11 to 0.17 mg F/day) and rose to 0.21 (SD: 0.09) and 0.19 (SD: 0.08) following F re-exposure. The difference between baseline UFE and the period of F interruption was statistically significant (p<0.05), while the difference between baseline and the period of F re-exposure was non-significant (p>0.05). The findings suggest that circulating F in the body of young children rapidly decreases in the first 24 hours and again increases very fast after discontinuation and re-exposure of F from water and toothpaste.

Effect of Discontinuation of Fluoride Intake from Water and Toothpaste on Urinary Excretion in Young Children

PubMed Central

Martins, Carolina C.; Paiva, Saul M.; Cury, Jaime A.

2011-01-01

As there is no homeostatic mechanism for maintaining circulating fluoride (F) in the human body, the concentration may decrease and increase again when intake is interrupted and re-started. The present study prospectively evaluated this process in children exposed to F intake from water and toothpaste, using F in urine as a biomarker. Eleven children from Ibiá, Brazil (with sub-optimally fluoridated water supply) aged two to four years who regularly used fluoridated toothpaste (1,100 ppm F) took part in the study. Twenty-four-hour urine was collected at baseline (Day 0, F exposure from water and toothpaste) as well as after the interruption of fluoride intake from water and dentifrice (Days 1 to 28) (F interruption) and after fluoride intake from these sources had been re-established (Days 29 to 34) (F re-exposure). Urinary volume was measured, fluoride concentration was determined and the amount of fluoride excreted was calculated and expressed in mg F/day. Urinary fluoride excretion (UFE) during the periods of fluoride exposure, interruption and re-exposure was analyzed using the Wilcoxon test. Mean UFE was 0.25 mg F/day (SD: 0.15) at baseline, dropped to a mean of 0.14 mg F/day during F interruption (SD: 0.07; range: 0.11 to 0.17 mg F/day) and rose to 0.21 (SD: 0.09) and 0.19 (SD: 0.08) following F re-exposure. The difference between baseline UFE and the period of F interruption was statistically significant (p < 0.05), while the difference between baseline and the period of F re-exposure was non-significant (p > 0.05). The findings suggest that circulating F in the body of young children rapidly decreases in the first 24 hours and again increases very fast after discontinuation and re-exposure of F from water and toothpaste. PMID:21776221

Fluoride release, recharge and mechanical property stability of various fluoride-containing resin composites.

PubMed

Naoum, S; Ellakwa, A; Martin, F; Swain, M

2011-01-01

To determine the fluoride release and recharge of three fluoride-containing resin composites when aged in deionized water (pH 6.5) and lactic acid (pH 4.0) and to assess mechanical properties of these composites following aging. Three fluoride-containing resin composites were analyzed in this study; a new giomer material named Beautifil II, Gradia Direct X, and Tetric EvoCeram. A glass ionomer cement, Fuji IX Extra, was also analyzed for comparison. Specimens were fabricated for two test groups: group 1 included 10 disc specimens initially aged 43 days in deionized water (five specimens) and lactic acid (five specimens). The fluoride release from these specimens was measured using a fluoride-specific electrode on nine specific test days during the aging period. Following 49 days of aging, each specimen was recharged in 5000 ppm neutral sodium fluoride solution for 5 minutes. Specimen recharge was then repeated on a weekly basis for 3 weeks. The subsequent fluoride rerelease was measured at 1, 3, and 7 days after each recharge episode. Group 2 included six disc specimens aged for 3 months in deionized water (three specimens) and lactic acid (three specimens). The hardness and elastic modulus of each specimen was measured using nano-indentation at intervals of 24 hours, 1 month, and 3 months after fabrication. Two-way factorial analysis of variance (ANOVA) and post-hoc (Tukey) testing was used to assess the influence of storage media (two levels) and composite type (three levels) on the fluoride release, fluoride rerelease, hardness, and elastic modulus of the assessed materials. The level of significance was set at p=0.05. All three composites demonstrated fluoride release and recharge when aged in both deionized water and lactic acid. The cumulative fluoride released from Beautifil II into both media was substantially greater than the fluoride released from Gradia Direct X and Tetric EvoCeram after 43 days aging and was significantly (p<0.05, ANOVA, Tukey test

Investigation on the role of Spirulina platensis in ameliorating behavioural changes, thyroid dysfunction and oxidative stress in offspring of pregnant rats exposed to fluoride.

PubMed