• 한국물환경학회지
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• 제25권6호
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• pp.916-921
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• 2009

This study was aimed to both enhance the fluoride removal and to reduce the phosphorus removal in treating semiconductor wastewater using $Ca(OH)_2$ at low pH so as to facilitate struvite crystallization reaction. The struvite crystallization could be introduced after fluoride removal by retaining the phosphorus source. As the results, the method applied in this study achieved high fluoride removal efficiency (about 91%) with retardation of phosphorus removal at pH 4, compared to conventional methods where the removal of fluoride and phosphorus were done at pH 11. Therefore, the fluoride removal at low pH would contribute to the enhancement of nitrogen and phosphorus removals in a consecutive struvite crystallization reactor. Treatment of semiconductor wastewater at low pH using $Ca(OH)_2$ also had lower (about 20%) water content of precipitated sludge compared to conventional method. As the molar ratio of Ca to F increased the removal efficiencies of fluoride and phosphorus increased. Although the amount of seed dosage didn't affect the removal of fluoride and phosphorus, its increase reduced the water content of precipitated matter. Finally, considering consecutive struvite reaction, the optimum condition for the removal of fluoride and phosphorus was as follow: pH: 4, the molar ratio of Ca:F: 1:1.

• 한국치위생학회지
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• 제12권1호
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• pp.113-122
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• 2012

Objectives : This study was carried out to investigate the caries resistant effect of fluoride by dental polishing prior to fluoride application in vitro. Methods : Artificial caries lesion was made on the surface of specimen enamel taken from cow's permanent cuspid on the part of labial surface after resin embedding and polishing. Artificial dental plaque was formed on the 72 dental specimen 25~45 VHN(Vickers Hardness Number) which were divided into three groups(fluoride varnish, APF gel, control) with dental polishing and without polishing respectively. Fluoride varnish and APF gel group with 20 second polishing or without polishing were immersed in the artificial saliva respectively. Control group with or without polishing were immersed in the artificial saliva. Results : 1. Significant difference was not found by fluoride varnish between polishing group and non polishing group (p>0.01). 1) polishing group. The changes of Vickers Hardness Number(VHN) were $14.49{\pm}13.73$. 2) non-polishing group. The changes of VHN were $11.67{\pm}5.39$. 2. Significant difference was not found by APF gel between polishing group and non polishing group (p>0.01). 1) polishing group. The changes of VHN were $8.48{\pm}8.37$. 2) non-polishing group. The changes of VHN were $5.32{\pm}2.59$. Conclusions : Showed no significant difference between polishing group and non-polishing group regardless of fluoride materials (fluoride varnish, APF gel).

• 대한소아치과학회지
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• 제25권3호
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• pp.635-648
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• 1998

The clinical use of fluoride with a well known osteogenic action in osteoporotic patients is rational, because this condition is characterized by impaired bone formation. However, its anabolic effect has not been demonstrated well in vitro. The purpose of this study was to investigate the effects of sodium fluoride on the physiological role of osteoblastic cell. Osteoblastic cells were isolated from fetal rat calvaria. The results were as follows : 1. Mineralized nodules were shown in osteoblastic cell cultures, which had been maintained in the presence of ascorbic acid and ${\beta}-glycerophosphate$ up to 21 days. When cultures were treated with pulses of 48 hr duration before apparent mineralization was occurring, 2-fold increased in their number was detected. 2. Alkaline phosphatase activity of osteoblastic cells was inhibited by sodium fluoride in dose dependent manner. 3. The effect of sodium fluoride on the osteoblastic cell proliferation was measured by the incorporation of $[^3H]$-thymidine into DNA. As a result, sodium fluoride at $1{\sim}100{\mu}M$ increased the $[^3H]$-thymidine incorporation into DNA in a dose dependent manner. 4. The signaling mechanism activated by sodium fluoride dose-dependently enhanced the tyrosine phosphorylation of the adaptor molecule $Shc^{p66}$ and their association with Grb2, one of earlier events in a MAP kinase activation pathway cascade used by a significant subset of G protein-coupled receptors. 5. The phosphorylation of CREB(cAMP response element binding protein)was inhibited by the sodium fluoride in MC3T3E1 cells. In conclusion, the results of this study suggested that the mitogenic effect of the sodium fluoride in MC3T3E1 cell was stimulated in a dose-dependent manner and suggested "an important role for the interaction between She and Grb2" in controlling the proliferation of osteoblasts.

• 분석과학
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• 제37권2호
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• pp.87-97
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• 2024

The appropriate intake of fluoride (F^-) is beneficial to human health; however, the over-consumption can result in various potentially harmful effects. This study compared different colorimetric reagents, i.e., aluminium-xylenol orange (Al-XO), zirconium-xylenol orange (Zr-XO), and zirconium-alizarin red S (Zr-ARS), for fluoride measurements by the UV-Vis, in terms of reaction mechanisms, method sensitivity, and interferences from aluminium and ferric ions. The colorimetric procedures were optimized, and the analytical methods were evaluated. The goodness of linearity (R² > 0.998) was obtained for all three assays within the concentration range of 1.0-20.0 mg/L fluoride in deionized water, in which the method sensitivity followed the descending order of Zr-XO > Al-XO > Zr-ARS. The Zr-XO was applied for determining the fluoride in different tea extracts in water (90 ℃ and 60-minute-brewing) and black tea demonstrated the highest fluoride content (3.0-3.6 mg/L). The effects of brewing time and temperature on the release of fluoride in the tea extracts were also investigated, indicating these are critical factors for the fluoride extraction. This study highlighted the application potentials of the UV-Vis measurement as a simple, convenient, and cheap analytical approach and discussed different colorimetric reagents used for fluoride determination in tea extracts in the context that the UV-Vis spectrophotometers are commonly equipped in most laboratories.

• 대한소아치과학회지
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• 제51권2호
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• pp.132-139
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• 2024

This study aimed to compare the fluoride-releasing ability and degree of microbial attachment of a newly developed glass-hybrid restorative material (GH) with those of a high-viscosity glass ionomer (HvGIC), resin-modified glass ionomer (RMGI), and composite resin (CR). In addition, the correlation between fluoride-releasing ability and microbial attachment between materials was evaluated. Specimens were prepared in a disc shape and divided into 4 groups according to the materials (GH, HvGIC, RMGI, and CR). The fluoride release experiments were performed in each group (n = 15). The amount of fluoride released was measured on days 1, 3, 7, 14, 28, and 42 after storage. For the microbial attachment experiment, 12 specimens were produced per group using Mutans Streptococci (S.mutans ), a cariogenic microorganism. S. mutans was cultured on the specimens for 24 hours, and the number of bacteria was measured. GH had the highest cumulative fluoride release and showed a significant difference when compared with RMGI (p = 0.001) and CR (p < 0.0001). Microbial attachment was the lowest in GH; however, no significant difference was observed between the materials (p = 0.169). There was no significant correlation between fluoride release from materials and microbial attachment (p > 0.05). From this perspective, remineralization of low-mineralized areas could be expected due to the high fluoride release of GH, and the effect of delaying the progression of dental caries could be predicted from the low cariogenic microbial attachment. Therefore, GH might be a useful restorative material for treating immature permanent teeth with hypomineralized enamel. However, further studies are needed about the degree of remineralization of hypomineralized areas after restoration and the capacity to recharge fluoride.

• 핵의학기술
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• 제13권3호
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• pp.24-30
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• 2009

국내의 암 발생 변화 추이를 고려해보면, 현재 남성에게 발생하는 전립선암의 비중이 나날이 증가하고 있다. 전립선 암의 경우 림프절이나 뼈에 전이가 되면 90% 이상 사망에 이른다. 따라서 최근 핵의학 분야에서는 전립선 암의 뼈 전이를 보다 정확하게 진단하기 위해 여러 영상기법과 방사성 의약품의 개발이 진행, 소개되고 있다. 본 연구에서는 전립선 암세포의 뼈 전이에 대한 보다 정밀한 영상을 획득하여 진단능을 향상시키는 $^{18}F$-Fluoride PET/CT의 유용성을 알아보고자 한다. 본 연구는 총 33명의 전립선암으로 진단된 환자로서, 평균 $67.8{\pm}10.2$세의 남자를 대상으로 하였다. 동일한 환자에게 각각 전신 뼈 검사(Whole Body Bone Scan; WBBS)와 뼈 양전자 방출 컴퓨터 단층 촬영(18F-Fluoride Positron Emission Tomography/Computed Tomography; $^{18}F$-Fluoride PET/CT)을 시행하였으며, 각 검사에서 나타난 병변을 확인하여 ROC곡선(Receiver Operating Characteristic Curve)을 통해 AUROC (The Area Under an ROC)분석하였다. 또한 두 검사의 민감도와 특이도, 양성예측률과 음성예측률 그리고 두 검사의 정확도를 비교 분석하였다. 총 33명 중 22명의 환자(66.6%)에게서 뼈 전이가 있었으며, $^{18}F$-Fluoride PET/CT에서 모두 우수한 결과치가 나타났다. WBBS의 민감도는 63.6%, 특이도는 81.8%였고, $^{18}F$-Fluoride PET/CT에서는 민감도 100%, 특이도 90.9%로 나타났으며, AUROC를 비교한 결과 WBBS에서 0.778, $^{18}F$-Fluoride PET/CT는 0.942로 분석되었다. $^{18}F$-Fluoride PET/CT는 WBBS에 비하여 높은 민감도와 특이도를 보였으며, 3D 영상 구현으로 암세포의 뼈에 대한 전이성 병소를 더욱 정확하고 명확하게 발견할 수 있었다. 또한 WBBS의 장시간 검사에 비하여 $^{18}F$-Fluoride PET/CT는 상대적으로 단시간에 뼈의 생리적인 변화에 대한 정확한 영상을 얻을 수 있어 환자의 불편함을 최소화 할 수 있었다. 고가 검사비용에 대한 부담을 줄일 수 있다면 $^{18}F$-Fluoride PET/CT를 통해 더욱 정확한 영상을 제공하여 임상에서의 진단능을 향상 시킬 수 있을 것으로 사료된다.

• 구강회복응용과학지
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• 제22권4호
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• pp.349-365
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• 2006

State of problem : A number of investigation about increase of surface area via various surface treatments and modification of surface constituent have been carried out. Purpose : The surface characteristics and stability of implants treated with anodic oxidation, fluoride ion incorporation, and groups treated with both methods were evaluated. Material and method : Specimens were divided into six groups, group 1 was the control group with machined surface implants, groups 2 and 3 were anodic oxidized implants (group 2 was treated with 1M $H_2SO_4$ and 185V, group 3 was treated with 0.25M $H_2SO_4$ and $H_3PO_4$ and 300V). Groups 4, 5 and 6 were treated with fluoride. Group 4 was machined implants treated with 0.1% HF, and groups 5 and 6 were groups 2 and 3 treated with 10% NaF respectively. Using variable methods, implant surface characteristics were observed, and the implant stability was evaluated on rabbit tibia at 0, 4, 8 and 12 weeks. Result : 1. In comparison of the surface characteristics of anodic oxidized groups, group 2 displayed delicate and uniform oxidation layer with small pore size containing Ti, C, O and showed mainly rutile, but group 3 displayed large pore size and irregular oxidation layer with many crators. 2. In comparison of the surface characteristics of fluoride treated groups 4, 5, 6 and non-fluoride treated groups 1, 2, 3, the configurations were similar but the fluoride treated groups displayed rougher surfaces and composition analysis revealed fluoride in groups 4, 5, 6. 3. The fluoride incorporated anodic oxidized groups showed the highest resonance frequency values and removal torque values, and the values decreased in the order of anodic oxidized groups, fluoride treated group, control group. 4. According to implant stability tests, group 2 and 3 showed significantly higher values than the control group (P<.05). The fluoride treated groups showed relatively higher values than the non fluoride treated groups and there were significant difference between group 4 and group 1 (P<.05). Conclusion : From the results above, it can be considered that the anodic oxidation method is an effective method to increase initial bone stability and osseointegration and fluoride containing implant surfaces enhance new bone formation. Implants containing both of these methods should increase osseointegration, and reduce the healing period.

• 농촌의학ㆍ지역보건
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• 제21권2호
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• pp.221-230
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• 1996

This study was purposed to develop the fluoride mouthrinsing project through the public health system in a rural area. This project was performed under the management of the public health dentist for the 3rd grade students selected from the 5 primary schools at Goksunggun in Chonnam area. Fluoride mouthrinsing was executed with 0.2% neutral sodium fluoride solution once a week. After 1 year's fluoride mouthrinsing project, DMFT index, DMF rate frequencies of toothbrushing, simplified oral hygiene index, and the responses to fluoride mouthrinsing project of the school children participated were examined. The results obtained from this study were as follows: 1. The fluoride mouthrinsing project for school children was performed average 10 times a year by the public health dentist. They were relatively little active to perform this project. 2. There was no significant difference in the increasement of DMFT index and DMF rate during 1 year between control and fluoride mouthrinsing group. 3. Control group was increased higher than fluoride mouthrinsing group in simplified oral hygiene index. 4. Toothbrushing frequencies increased in both groups. 5. 80.4% of school children participated in fluoride mouthrinsing project was responded to like it, and 78.2% among them was responded the project to be beneficial for their dental health. 6. 39.2% of school children was responded to have water-like taste for fluoride solution. But 34.0% of them was done to have strange taste. On consideration of above findings, this fluoride mouthrinsing project was not well performed by the public health dentists and also the oral health status of school children participated was not significantly improved by this project. Therefore, to perform continually this project well, it was recommended that this project should be performed by other person such as dental hygienist rather than public health dentist.

• 대한소아치과학회지
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• 제40권2호
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• pp.89-97
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• 2013

연구의 목적은 인체 안정성이 입증된 고분자제제인 폴리비닐알코올(PVA, polyvinyl alcohol)로 얇은 박막을 제조하고 불화나트륨(NaF)을 첨가하여 불소를 함유한 고분자 접착 테이프(NaF-PVA)를 개발하여 피실험자의 구강 내에 도포 후 잔류하는 불소농도를 측정하였다. 이를 통해 제제 도포 전후의 타액 내 불소농도를 분석하여 불소를 함유한 고분자 접착 테이프의 치아우식증 예방효과를 간접적으로 평가하였다. 불소겔(60seconds taste$^{(R)}$, Group 1), 불소바니쉬(FluoroDose$^{(R)}$ varnish, Group 2)와 불소를 함유한 고분자 접착 테이프(NaF-PVA, Tiral product, Group 3)를 각각 15명씩 상악 치아 12개의 순면에 도포 후, 1시간, 3시간, 6시간, 12시간, 24시간, 48시간 후 비자극성 타액 내 불소농도를 불소이온전극을 이용하여 측정하였다. 도포 후 3시간까지 세 군 모두 불소제제 도포 전 농도보다 유의하게 높은 불소농도를 보였으며 3군의 경우 도포 후 6시간에서도 불소제제 도포 전 농도보다 유의하게 높은 불소농도를 보였다(p < 0.05). 도포 후 6시간에서 3군은 1군과 2군보다 유의하게 높은 불소농도를 보였고 (p < 0.05), 1군과 2군 사이의 유의한 차이는 없었다(p > 0.05).

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2004년도 International Conference Global Environmental Problems and their Health Consequences
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• pp.213-216
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• 2004

This work was based on the hypotheses that fingernail clippings can be used as a biomarker for the subchronic exposure to fluoride. This study was conducted to prove the hypotheses and fingernail clippings were collected form 120 preschool children aged $3{\sim}6$ residing in Jumunjin(community water fluoridation area) and Kangnung(non-fluoridation area). The acid-diffusible fluoride in the fingernail clipping was isolated by the acid-diffusion technique and measured with a fluoride electrode. The mean fingernail fluoride as the children's living area were 4.49ug/g(SD 2.43) to Jumunjin and 2.68ug/g(SD 1.13) to Kangnung. As would be expected, the fluoride concentration in fingernail clippings were significantly different between the two geographical groups(p<0.001) determined by t-test.