• International Journal of Clinical Preventive Dentistry
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• v.14 no.4
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• pp.209-215
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• 2018

In recent years, the numbers of the orthodontic dental patients have been rapidly increased in adolescent or young adult aged generation. It has been well known that it would be very hard to control the oral hygiene cares for orthodontic applied dental patient because of the complexity of the appliance. So the caries prevalence of the orthodontic dental patients would be higher than non-appliance persons, and it might be easy to cause the dental caries especially on the labial or buccal surface of the tooth through equipping the fixed type appliance with a long period, even though the alignment of the teeth would be arranged well. So, the massive preventive program for preventive dentistry should be needed for the dental patients for orthodontic treatment, in order to protect the dental caries and the periodontal disease for them. But, lots of the dentists or dental hygienists sometimes neglect of this point for preventive dental cares orthodontic dental patients, or do not know the importance and how to manage the skill for the preventive dental works in clinical. In this article, it will be introduced the basic theories and skills for preventive cares as tooth-brushing instruction, fluoride topical application and pit and fissure sealant, scaling and professional mechanical tooth cleansing and the diet control, for the dental patients with the fixed type of the orthodontic appliance, in case by case.

• 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.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.1
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• pp.82-90
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• 2010

This study examined the effect of adhesive tape supplemented with sodium fluoride on the prevention of dental erosion in vitro. Sound bovine tooth samples were selected and divided randomly into the following 4 groups according to the material treatments: group 1, APF gel; group 2, fluoride varnish; and groups 3 and 4, fluoride tape supplemented with 5% NaF in either a methyl cellulose or poly vinyl acetate carrier, respectively. All specimens were submitted to alternate cycles of acid exposure in a cola beverage (pH 4.3) and artificial saliva for $6\;{\times}\;5\;min/day$ over a 5 day period. The micro-hardness was recorded each day and the lesion depth was measured after 5 days. The micro-hardness of the experimental sides of groups 2, 3 and 4 were significantly higher than that of their control sides and the experimental side of group 1 during the experimental period (p<0.05) except on the 5th day. The enamel surfaces of treatment groups 2, 3 and 4 showed significantly higher resistance to mineral loss in terms of the erosion depth (p<0.05) than group 1 and their control sides. There was no statistically significant difference among group 2, 3 and 4, indicating that the fluoride varnish and tapes produce similar results. Fluoride adhesive tapes are effective in reducing the progression of erosion and can be recommended for young patients who are more susceptible to dental erosion.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.4
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• pp.361-369
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• 2008

The purpose of this study is to make porous oxide film on the surfaces of pure Ti through anodic spark discharge in electrolytic solution containing calcium and phosphate ions, to improve osseointergration by treating fluoride agent. In addition, it is to evaluate the fluoride modified effect on the surface. Commercial pure Ti plate with $20{\times}10{\times}2mm$ and Ti wire with a diameter of 1.5mm and a total length of 15mm were used. After making titanium oxide films converted by anodic spark discharge, anodizing was performed. Fluoride was spreaded to titanium laboratory plate and maintained for 30 minutes after anodizing breakdown. Fluoride ion discharge amount was measured per 24 hours after dipping titanium plate into saline (10ml) and sustaining 90rpm in a pyrostat. Some plates and wires were dipped in Hanks solutions for a month to examine biocompatibility using SEM and XRD. $TiO_2$ film formed by anodic discharge technique showed great roughness and uniform pores which were $1{\sim}3{\mu}m$ in a diameter. Roughness of the films treated with anodic discharge after blasting were higher than the turned ones(P<0.05). Rapid surface activity was observed in the samples treated with $TiF_3$ agent, which immersed in Hanks solution for 30 days. Taking the results into consideration, the fluoride modified implant with anodic discharge demonstrates that it makes uniformly porous oxide film on the surface of implant and properly increase roughness for osseointegration. The implants will achieve greater bone integration after short healing time by improving surface activity.

• Applied Microscopy
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• v.29 no.2
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• pp.189-193
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• 1999

The response of ameloblast to long term (3 weeks) exposure to fluoride was examined in continuously erupting mandibular incisors of pregnancy rats as compared to control rats receiving a similar diet (Teklad L-356) but no sodium fluoride in there drinking water. Rats were started on water containing 0 ppm, 100 ppm, 200 ppm, and 300 ppm NaF at the beginning of pregnancy. To examine on the ultrastructural changes of the ameloblast, electron microscopy was used. The results indicated that rat incisors expressed two major changes in normal amelogenesis that could be attributed to chronic fluoride treatment. The fluoride produces marked alteration in the fine structure of ameloblast from teeth of young rats, such as large confluent distensions of the endoplasmic reticulum and swelling of isolated mitochondria, in particular on the morphology of the rough-surfaced endoplasmic reticulum. A graded series of alterations to these organelles were produced, and the severity of the changes would seem to be dependent on dose and time. This experimental data suggested that exposure prolonged of animal to high level of fluoride appears to induce morphological changes in the normal appositional growth and initial mineralization of enamel created during amelogenesis.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.467-475
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• 2021

The purpose of this study was to compare the effect of sodium fluoride(NaF) varnish and potassium iodide(KI) on remineralization efficacy of silver diamine fluoride(SDF) by measuring microhardness and evaluating surface morphology by scanning electron microscope(SEM). Artificial caries lesions were induced on extracted primary molars and vickers microhardness was measured. Specimens were randomly separated into 4 groups for treatment. The specimens in group I were treated with SDF, group II with NaF varnish after SDF, group III with KI after SDF and group IV with distilled water. After 8 days of pH cycling, vickers microhardness was measured and difference before and after treatment was calculated. For SEM, 2 samples were evaluated respectively after enamel polishing, lesion formation and after pH cycling. Group III showed highest increase in microhardness. Group I showed higher increase in microhardness than Group II but without statistical difference. Group IV showed lowest increase in microhardness value among 4 groups. On SEM image, group I, II and III showed smoother and less irregular surface compared to group IV. Amorphous crystal pellicles were observed in group III. In conclusion, SDF, SDF and NaF, SDF and KI groups showed smoother surface and increase in microhardness suggesting the possibility that remineralization effect might take place in oral conditions. In addition, in limited conditions of this study, applying NaF varnish after SDF did not increase the remineralization efficacy of SDF while KI significantly increased the remineralization efficacy of SDF. However, additional study considering various conditions that might affect demineralization and remineralization in clinical situations need to be conducted.

• The korean journal of orthodontics
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• v.42 no.5
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• pp.263-269
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• 2012

Objective: To evaluate the antimicrobial effect of different frequencies of brushing with fluoride toothpaste on the levels of salivary mutans streptococci and lactobacilli in children undergoing fixed orthodontic treatment. Methods: The study included 22 patients scheduled for fixed orthodontic therapy distributed between 2 groups with different hygiene regimes. All the subjects received identical braces, bands, and brackets bonded with the same material. Stimulated saliva samples were obtained before placement of the appliance and at 6, 12, and 18 weeks during the therapy. Saliva samples were cultured on selective microbial agar for the detection of microorganisms. Results: Salivary mutans streptococci were significantly suppressed throughout the experimental period in the group that brushed 4 times a day as compared to the group that brushed twice a day. Salivary lactobacilli were not significantly affected by the frequency of brushing with 0.32% sodium fluoride (NaF) toothpaste. Conclusions: The use of 0.32% NaF-containing toothpaste more than 3 times a day has effective antimicrobial activity on mutans streptococci but not lactobacilli in the saliva of children with fixed orthodontic appliances.

• Journal of Plant Biology
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• v.27 no.3
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• pp.139-147
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• 1984

This in vitro study was employed to clarify the effects of several pollutants i.e. $SO_2$, fluoride, cadmium(Cd), aluminum(Al) and NaCl, on the organogenesis and growth responses of shoot-tip, stem and multiple-buds segments derived from hypocotyl or cotyledon culture of petunia seedlings. ${Na_2}{SO_3}$levels of more than 200$\mu{g}$/ml had significantly reduced organogenesis, growth, and chlorophyll content. The injuries caused by ${Na_2}{SO_3}$, concentration of more than 400$\mu{g}$/ml were alleviated by increasing hydrogenion concentration of medium, indicating some relationship between two factors. Organogenesis was not affected by the fluoride concentration up to 100ppm in the media, but the growth and chlorophyll content were greatly reduced by the fluoride. The effect of Cd depended on the explant sources used for the culture; 1.0ppm was effective for fresh weight increase in shoot tip culture, and 3.0ppm in stem segments culture. Organogenesis and growth were greatly reduced by more than 10.0 Cd treatment. Growth and formation of shoots were better with Na conc. of 0.3% compared to control, but those of roots were inhibited. Na concentration goes over 1.0%, organogenesis and subsequent growth were inhibited, and chlorophyll synthesis was drastically reduced. Chlorophyll content was increased on the medium supplemented with Al 50$\mu{g}$/ml compared to control. However the formation and growth of shoots were greatly inhibited with more than 400$\mu{g}$/ml and roots were not produced at all.

• Membrane Journal
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• v.25 no.5
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• pp.391-397
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• 2015

The porous support polyvinylidene fluoride (PVDF) with a salting out based on the hollow fiber membrane polyethyleneimine (PEI) and polyvinylsulfonic acid (PVSA) by coating with by phase separated and pressurization (PSP) method to produce a multilayer membrane. The resulting membranes were characterized under the various conditions, such as the heat treatment temperature, coating concentration, feed concentration, cross-linking time and cross-link agent concentration in terms of flux and rejection rate for NaCl 100 ppm solution at 4 atm. The best results were PEI 20,000 ppm and PVSA 1,000 ppm, PEI 15% with a 2% malic acid aqueous solution coated by PSP method the hollow fiber membrane heat-treated for 1 minute showed flux 24.3 LMH, the rejection of 82.1%.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.1
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• pp.48-53
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• 2019

A bone metastasis is an important factor for prognosis and treatment of breast or prostate cancer patients. [$^{18}F$]Sodium fluoride ([$^{18}F$]NaF) is a PET radiopharmaceutical that can detect bone metastasis. Conventional [$^{18}F$]NaF production process included radioactive metal impurities because the product was prepared by adding saline after beam irradiation to $[^{18}O]H_2O$. In this study, we apply the method of removing radionuclidic impurities. To meet the criteria prescribed by GMP in quality control, we designed the custom-made [$^{18}F$]NaF automatic module. The mean radiochemical yield was $82.1{\pm}4.4%$ (n = 32) productions for 3 years) and the total preparation time was 4 min. The final produced [$^{18}F$]NaF solution meets the USP criteria for quality control. Thus, this fully automated system is validated for clinical use.