• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.682-688
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• 2013

In this study, we investigated about cell toxicity and oxidative stress of HepG2 cell by treatment of sodium fluoride (NaF) and fluoride extracts from krill Euphausia superba meat, shell, whole body and krill meal. The cell toxicity showed significant at 300 and $500{\mu}g/mL$ NaF treatment group. But krill (Euphausia superba) fluoride extract (KFE) treatment in all groups were not toxic. The superoxide radical production increased significantly in NaF treated group, but there was no significant change in KFE treated group. The superoxide dismutase activity was a significant increase 21.5% at $100{\mu}g/mL$ and 24.7% at $300{\mu}g/mL$ treatment group of fluoride extracts from krill meat, and 8.7% at $300{\mu}g/mL$ in krill meals, compared to the control group. However, hydroxy radical flux and catalase and glutathione peroxidase activity of fluoride extracts from krill meat did not change. As a result, for a short period of time, NaF treatment in HepG2 cells affect the cell toxicity and oxidative stress, but in the case of KFE, these were not recognized. Thus, depending on the type of food ingested with fluoride, cell toxicity and oxidative stress was found to be different.

• The korean journal of orthodontics
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• v.21 no.1 s.33
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• pp.97-111
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• 1991

It is the aim of this study to investigate the effects of sodium fluoride and sodium orthovanadate upon the proliferation and activity of the osteoblast (MC3T3-E1 cells). MC3T3-E1 cells were cultured in $\alpha-MEM$ containing $10\%$ FBS and various concentration of sodium fluoride and sodium orthovanadate was appended to serum free media. DNA synthesis was examined through the $[^3H]$ thymidine incorporation into DNA. Collagen synthesis was examined through the $[^3H]$ proline incorporation into collagenase digestible protein and noncollagen protein. The following results were drawn; 1. Sodium fluoride stimulated the DNA synthesis of osteoblast significantly in dose-dependent manner within the concentration from $2{\mu}M$ to $10{\mu}M$ (P < 0.005). 2. Sodium orthovanadate stimulated the DNA synthesis of osteoblast significantly in dose-dependent manner within the concentration from $2{\mu}M\;to\;8{\mu}M$, however showed diminution at $10{\mu}M$ (P < 0.001). 3. Sodium fluoride and sodium orthovanadate stimulated the percent collagen synthesis of osteoblast significantly in dose-dependent manner within the concentration from $5{\mu}M$ to $10{\mu}M$ (P < 0.001). 4. Sodium fluoride and sodium orthovanadate stimulated the noncollagen synthesis of osteoblast significantly in dose-dependent manner within the concentration from $5{\mu}M\;to\;10{\mu}M$ (P < 0.001). In conclusion, sodium fluoride and sodium orthovanadate stimulate the proliferation and activity of osteoblast by stimulation of DNA synthesis and collagen and noncollagen synthesis in osteoblast.

• Restorative Dentistry and Endodontics
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• v.43 no.4
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• pp.45.1-45.11
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• 2018

Objectives: This study was conducted to evaluate fluoride release and the micro-shear bond strength of resin-modified glass ionomer cement (RMGIC) in casein phosphopeptide-amorphous calcium phosphate (CPP-ACP)-remineralized caries-affected dentin (CAD). Materials and Methods: Exposed dentin surfaces of 30 human third molar teeth were divided into 2 equal groups for evaluating fluoride release and the micro-shear bond strength of RMGIC to CAD. Each group was subdivided into 3 equal subgroups: 1) control (sound dentin); 2) artificially demineralized dentin (CAD); 3) CPP-ACP remineralized dentin (remineralized CAD). To measure fluoride release, 15 disc-shaped specimens of RMGIC (4 mm in diameter and 2 mm in thickness) were bonded on one flat surface of the dentin discs of each group. Fluoride release was tested using ion chromatography at different intervals; 24 hours, 3, 5, 7 days. RMGIC micro-cylinders were built on the flat dentin surface of the 15 discs, which were prepared according to the assigned group. Micro-shear bond strength was measured after 24 hours water storage. Data were analyzed using 1- and 2-way analysis of variance and the post hoc least significant difference test (${\alpha}=0.05$). Results: Fluoride detected in solutions (at all intervals) and the micro-shear bond strength of RMGIC bonded to CPP-ACP-remineralized dentin were significantly higher than those bonded to artificial CAD (p < 0.05). Conclusions: Demineralized CAD consumes more fluoride released from RMGIC into the solution for remineralization than CPP-ACP mineralized dentin does. CPP-ACP increases the micro-shear bond strength of RMGIC to CAD.

• Journal of the Korean Ceramic Society
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• v.32 no.2
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• pp.183-188
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• 1995

The properties of the glasses are not dominantly dependent on the chemical composition, temperature, and pressure but also on the thermal history. For example, electrical, thermal, optical, and mechanical properties are all known to be strongly dependent on the thermal history. Fluoride glasses have received a great deal of attention as candidate materials for an infra-red transmitting medium. A series of fluoride glasses and fibers were prepared under a nitrogen atmosphere. Thermal history effects of the fluoride glass fibers associated with the fast cooling rate employed during the fiber drawing process were discussed in terms of the glass temperatures and the fictive temperatures on the basis of the results obtained from the Differential Scanning Calorimeter (DSC) measurements of the fiber and bulk forms of the same chemical composition.

• Journal of the Korean Ceramic Society
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• v.26 no.5
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• pp.601-608
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• 1989

Electrical properties of ZrF4-based heavy metla fluoride glasses were measured by the ac complex impedance method. The effects of alkali and chloride ions addition into fluoro zirconate glasses on the electrical conductivity were examined. The electrical conductivities of fluoride glasses show Arrhenian behavior in the temperature range of the experiment and were decreased by the addition of sodium fluoride up to 15mol%. Mixed alkali substitution resulted in conductivity minimum at intermediate composition which is commonly observed as mixed alkali effect' in alkali oxide glasses. Chloride ion substituted for fluoride ion was found to lower the conductivity.

• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.1
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• pp.1-5
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• 2006

The major dominant fluoride-endurance (Dfe) gene was introduced into the commercial varieties by crossing and pedigree selection to breed silkworm races that could normally develop in the area that polluted by fluoride. After backcrossed for two generations, the Dfe gene was made homozygous, and individuals with good economic characters were selected to generate next generation. After 8 generations of selection, their characters became stable, and the silkworm variety which is resistant to fluoride, Huayuan${\times}$Dongsheng, for spring rearing were bred.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.919-925
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• 2010

The features of precipitating reaction of fluoride have been examined by employing waste gypsum as a precipitant. The major component of waste gypsum was examined to be CaO with minor components of $SO_3$, $SiO_2$. In the experimental condition, the precipitating reaction of fluoride progressed rapidly within a few minutes after the reaction started and reached its equilibrium in 10 minutes. Kinetic analysis showed that the precipitating reaction of fluoride generally followed a first Oder and second Oder with decreasing rate constant with the initial dosage of precipitant. XRD analysis showed that the crystalline structure of precipitate was mainly $CaF_2$ with partly $Ca_5(PO_4)_3(OH)$.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.286-288
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• 2005

This study was conducted to compare the fluoride concentrations in urine of preschool children aged 3${\sim}$6 years between residing in community water fluoridation area(Kwangju City) and non-fluoridation area(Sungnam City). The acid-diffusible fluoride in the urine and drinking water was isolated by the acid-diffusion technique and measured with a fluoride electrode. The mean daily fluoride excretion to urine of children residing in Kwangju and Sungnam were $1.27{\pm}0.75mgF^-$/g creatinine and $0.87{\pm}47 mgF^-$/g creatinine, respectively. It is concluded from this investigation that the $F^-$concentration in urine sample of kindergarten and drinking water of children living in Kwanju(fluoridated areas) were significantly higher than that of children living in Sungnam(non-fluoridated areas).

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.1
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• pp.11-14
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• 2003

NF733xin, the near allele line was obtained by means of crossing and backcrossing the silkworm race T6, which contained fluoride resistance major gene, to race 733xin, which was highly susceptible to fluoride toxicity. Two hundred RAPD random primers were used in the RAPD analysis of these 3 strains. Two molecular markers, OPB-08850 and OPB-10917, were obtained. OPB-10917 was used to detect the backcross generations. It was found that all the fluoride resistant individuals in each backcross generation had the same special band. These results proved that this marker was reliable.

• Journal of Technologic Dentistry
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• v.20 no.1
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• pp.139-143
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• 1998

This study was carried out to collect basic dates on fluoride intake from drinking water, and the apperance of mottled teeth after taking samples form 5 selected waterways from Iksan region's reservoir to the filtration plant for examination of the fluoride content. The results are as follows. 1. It indicatied that from Hoojung reservoir $2.17{\pm}0.95ppm$, Bulsan reservoir $1.93{\pm}0.23ppm$ and Yoolso reservoir $2.19{\pm}0.10ppm$. 2. Significances were found between Shinhung reservoir $2.57{\pm}1.22ppm$ and Uhwoo reservoir $0.80{\pm}0.55ppm$. 3. Except for the Uhwoo reservoir, the remaining 4 reservoir exceeded the standard fluoride content of 0.50-1.00ppm. For the residents in the region where they use natural water with fluoride content exceeding the standard 1.00ppm as their drinking water and the apperance of mottled teeth should be carried out.