• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.57-64
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• 2008

It is well established that fluoride products play an important role in the prevention and remineralization of carious lesion. Fluoride varnish is a concentrated topical fluoride and varnishes adhere to tooth surface, permitting prolonged fluoride exposure and uptake. In this study, the artificial initial enamel caries was caused on the sound human enamel and divided 60 specimens into three groups. Group 1 and group 2 were treated with the topical application of fluoride varnish and stored in artificial saliva for 1 and 2 weeks. Group 3 was stored in artificial saliva for 2 weeks, which acted as control group. Changes in mineral contents were analysed with the confocal laser scanning microscope. The following results were obtained: 1. In group 1 and group 2, the total fluorescence of the lesion(TFL) was reduced in remineralized area compared to in demineralized area(p<0.05). 2. The total fluorescence of the lesion of remineralized area was more reduced in group 2 than in group 1(p<0.05). 3. The total fluorescence of the lesion was more reduced in group 2 than in control group(p<0.05). 4. Confocal laser scanning microscope can be used in quantitative analysis of remineralization by fluoride varnish.

• Restorative Dentistry and Endodontics
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• v.13 no.1
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• pp.23-38
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• 1988

In order to investigate the material formed by application of fluoride on human dentin, exposed dentin of tooth cervix and sound dentin powder was treated by several fluoride solutions. The former was observed by scanning electron microscope and the latter was analysed by x-ray diffractometer and infrared spectrophotometer. The results obtained were as follows: 1. Application with NaF, $SnF_2$ and $Na_2PO_3F$ on exposed dentin of tooth cervix formed mineralized materials covered. 2. The amount of mineralized materials increased with time intervals of applying the fluorides. 3. The density of mineralized materials was highest in $Na_2PO_3F$ treatment group, and NaF treatment group was higher than $SnF_2$ treatment group. 4. $SnF_2$ remained in covering of mineralized materials. 5. Application with NaF and $Na_2PO_3F$ formed mineralized materials characterized apatitic crystals. 6. The crystallinity of mineralized materials was higher prominently in $Na_2PO_3F$ treatment group.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.613-622
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• 2007

The purpose of this study was to evaluate the effect of fluoride varnish on prevention of enamel demineralization. Eighty bovine enamel blocks were divided randomly into 4 groups of 20 specimens: Group I served as the control with no topical application of fluoride. Group II was treated with APF gel for 4 minutes. Group III was treated with Fluor $Protector^{(R)}$. Group IVV was treated with $CavityShield^{TM}$. After 24 hours of treatment, samples were brushed with a soft bristled tooth brush to stimulate normal mechanical wear of varnish. Early caries lesions were produced by placing each specimen into demineralization solution at pH 4.0 for 48 hours. Then the optical density of the lesions was measured by light fluorescence induced by plasma light and the surface microhardness were measured by the vicker's hardness test. The results were as follows: 1. The optical densities of group III, IV were significantly higher than that of group II, but no significant difference was noted between group III and IV. 2. The surface microhardness of group IV was the highest, followed by group III, II, and I(p<0.05). 3. There were no significant differences between group III and IV in optical density. However, the surface microhardness of group IV was significantly higher than that of group III. The results of present study indicate that the fluoride varnish is more effective than APF gel for prevention of dental caries.

• Restorative Dentistry and Endodontics
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• v.9 no.1
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• pp.115-119
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• 1983

The purpose of this study was to compare the solubility of enamel and dentin to an etchant after fluoride application. Specimens were collected from extracted anterior and bicuspid and each tooth was cut into several pieces. These specimen were allocated in 7 group; 1%, 2%, 3% NaF, 1%, 8%, 20% $SnF_2$, and control group. Five specimens in each group was exposed to pre-determined fluoride solution for 3 minutes, and washed with running water. These specimens were etched by Hipol (commercial label) etchant for 30 seconds. Following are the findings obtained through S.E.M. 1. All specimens with acid etching revealed preferential removal of prism periphery leaving prism core. 2. Specimens treated with 1%, 2% NaF solution showed that the shape of prism tip was thin and sharp like a needle. The case of 3% NaF showed rather round shape at prism end. 3.1% of $SnF_2$ case showed similar findings with the control group but 8% and 20% $SnF_2$ case revealed needle shape at the prism and was less clear than NaF case. Preferential removal of prism periphery was partialy observed and un decalcified area is fused to prism forming reidge. 4. Dentine treated by fluoride compound in low concentration showed the orifice of dentinal tubule was clearly enlarged whereas in high concentration the orifice was not widened.

• The Journal of the Korea Contents Association
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• v.13 no.12
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• pp.893-899
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• 2013

This study was to determine the efficacy in the remineralization on premary teeth following the application of toothpaste with and without sodium fluoride. All tooth were checked using microhardness tester and the calcium (Ca) and phosphorous (P) concentration by electron probe microanalyzer (EPMA) analysis for the 4 weeks. The collected data was analysed using the statistical software program SPSS, 20.0. The applied enamel of premary teeth with 0.243% fluoridated toothpaste resulted in significant differences in the microhardness values (p>0.05). The Ca and P concentrations of applied premary teeth with fluoridated toothpaste were also significant difference in norm wt% (p>0.05). As a results, a increasing the surface microhardness of the premary teeth and providing a remineralizing effect by increased Ca and P concentrations.

• Journal of the Korea Convergence Society
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• v.8 no.6
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• pp.139-145
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• 2017

The aim of this study was to measure the remineralization effect of APF gel and fluride varnish on artificial enamel caries using CLSM in vitro. The samples were divided into 3 groups: control, 1.23% APF gel, 5% NaF varnish. The specimen surfaces were observed by CLSM and measured average fluorescence of the lesion(AFL). The results were analyzed using one-way ANOVA and Pearson's correlation analysis at a significance level off 0.05(PSWA 18.0, SPSS Inc., USA). There were significant differences between AFL at baseline and 1 day after fluoride application(p<0.05) but there are no significant differences between ${\Delta}$ AFL of all groups (p=0.222). Result of Pearson's correlation analysis, there are no significant correlation between VHN and AFL, but there were significant correlation between AFL at baseline and 1 day after fluoride application(r=0.811, p<0.001). Although AFL decreased after fluoride application, but there was no difference between the groups. In the future, it is necessary to test the oral environment model or in situ experiment supplemented the limitations of this study.

• Restorative Dentistry and Endodontics
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• v.25 no.3
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• pp.338-358
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• 2000

The effect of bench drying or removal of the periodontal ligament with NaOCl upon periodontal healing and root resorption after replantation of molars was studied in rats. A total of 40 Sprague-Dawley female rats were used and fed a powdered purina rat chow diet containing 0.4% beta-aminoproprionitrile. The maxillary first molars were extracted and the periodontal ligaments were removed either by bench drying for 15 minutes or by immersion in 2.5% NaOCl solution. The rats were sacrificed at 5, 10, and 21 days by heart infusion. In order to observe the effect of 0.5% stannous fluoride, $10^{-4}M$, $10^{-2}M$, and 1M etidronate disodium on the early stage of periodontal healing, the periodontal ligament was removed with 2.5% NaOCl followed by immersion of the molar in the respective solutions for 5 minutes. The rats were sacrificed after 10 days and the following results were obtained. 1. The removal of the periodontal ligament with 2.5% NaOCl seemed to be more effective than bench drying, since the resorption area in the NaOCl treated group showed a gradual increase whereas a decline in resorption area from 5 days to 21 days was observed in the bench dried group. 2. The application of 0.5% stannous fluoride seemed to enhance the periodontal ligament attachment and active migration of fibroblasts could be observed. 3. The application of $10^{-4}M$, $10^{-2}M$, and 1M etidronate disodium led to a good periodontal ligament attachment. No evident areas of root resorption were found. 4. The use of ${\beta}$-APN made it possible to extract the maxillary first molar with all five roots intact.

• The Journal of the Korean dental association
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• v.23 no.12 s.199
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• pp.1067-1072
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• 1985

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5602-5609
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• 2014

This study examined the remineralization effect of CPP-ACFP according to the etching time and the frequency of application. A CPP-ACFP paste was formed from a combination of CPP-ACP paste and fluorine. The remineralization effect of CPP-ACFP was measured according to the etching time and the frequency of applications of CPP-ACFP. The microhardness of 64 teeth was measured as the sound sample and observed by scanning electron microscopy. As a result, the effect on remineralization of the enamel increased with increasing etching time and frequency of application. Therefore, a CPP-ACP paste combination to fluorine in the tooth mineral CPP-ACFP paste fluoride application can be supplied with the material-advisable enamel remineralization.

• Polymer(Korea)
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• v.25 no.3
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• pp.367-374
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• 2001

The electromagnetic interference (EMI) shielding effectiveness (SE) of poly(vinylidene fluoride) (PVDF) composites was investigated using carbon nanofiber fillers prepared by catalytic chemical vapor deposition of various carbon-containing gases over Ni and Ni-Cu catalysts. The electrical conductivity of carbon nanofiber which was regarded as the key property of filler for the application of EMI shielding ranged from 4.2 to 22.4 S/cm at a pressure of 10000 psi. The electrical conductivity of carbon nanofiber/PVDF composites ranged from 0.22 to 2.46 S/cm and the EMI SE of those was in the range of 2∼13 dB. The electrical conductivity of carbon nanofibers increased with the increase in heat treatment temperature and time, while the electrical conductivity of the composites increased rapidly at the initial heat treatment and then approached a certain value with the further increase of heat treatment. The SE of the composites showed a maximum at the medium heat treatment and was proportional to the electrical conductivity of the composites. It was concluded that the specific surface area of carbon nanofibers decreased with the continual heat treatment and the specific surface area of filler was an important factor for the SE of the composites.