• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.367-375
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• 2021

This study evaluated the fluoride release of alkasite restorative material (ARM) and giomer penetrating the dentin adhesive layer. Twenty specimens were prepared for each restorative material, and dentin adhesive with uniform thickness was applied to half of them. The prepared specimens were placed in a polyethylene tube containing 2.0 mL of deionized water and deposited in a 37.0℃ water bath for the study duration. The amount of fluoride release was measured on the 1^st, 3^rd, 7^th, 14^th, 21^st, and 28^th days after deposition. The dentin adhesive applied to the ARM and giomer could not completely block the fluoride release; however, it significantly reduced its amount. The cumulative amount of fluoride release of the ARM after 28 days was higher than that of the giomer regardless of the application of dentin adhesive.

• Journal of the korean academy of Pediatric Dentistry
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• v.11 no.1
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• pp.169-179
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• 1984

The purpose of this study was to observe the effect of dental varnish applied with fluoride to dental pulp by comparing the groups of commercial fluoride product $Duraphat^{(R)}$, $Copalite^{(R)}$ after 1 Mole sodium fluoride application, Cavity $Sealer^{(R)}$ after 1 Mole sodium fluoride application with the control group not applied the dental varnish. After Cl V Cavity form was prepared on the buccal surface of the crowns with the total 75 teeth by using 5 dogs, average weight of 13.2Kg, dental varnish and silver analgram were placed. This study was performed by 3, 7, 21, 28, 56 days each. The dogs were sacrificed to extract the teeth, cut at the apical one fourth, and prepared histologic examination by fixing with 10% buffered formalin perfusion at sacrifice and decalcification in 10% nitric acid. The specimens were embedded in paraffin, stained with Hematoxylin and Eosin, and serially sectioned with 6 ${\mu}$width each. Microscopic evaluation of serial sections at the various time periods among the different groups revealed the following results: 1. In the control group, the marked change of the odontoblastic layer was showed on the 3 days group, and it was decreased gradually. Healing response, such as hyperplasia, was seen on the 28 days group and it was continued to the 56 days group. 2. In the experimental group with Cavity $Sealer,^{(R)}$ a slight hemorrhage was seen in the odontoblastic layer on the 3 days group, and the healing response with the hyperplasia of the odontoblast was showed on the 21, 28 days group. It was completely healed on the 56 days group. 3. In the Duraphat R group, a slight hemorrhage showed on the 3 days group and the disarrangement of the Odontoblastic layer was seen on the 7, 21, 28 days group. Odontoblasts showed hyperplasia on the 28 days group, and healed completely on the 56 days group. 4. In the $Copalite^{(R)}$ group, the 7 days group showed remarkable hemorrhage in the odontoblastic layer and stroma, and also it showed reticular degeneration with the disarrangement of the odontoblastic layer and congestion. Each group showed disarrangement. Healing ability of this group was greater than that of the control group, but less than that of the $Duraphat^{(R)}$ and Cavity $Sealer^{(R)}$ group.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.381-390
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• 2004

The purpose of this in vitro study was to investigate the effects of Nd:YAG laser irradiation and fluorides on acid drink demineralized enamel. The materials were 30 freshly extracted permanent premolars with intact smooth enamel surfaces. They were demineralized with Coca-cola at $37^{\circ}C$ for 12hours and then irradiated by Nd:YAG laser with 6W power, $50mJ/cm^2$ energy density, and 20Hz pulse repetition. After laser irradiation, teeth were treated by three kinds of fluorides; (1)0.05% NaF fluoride solution (2)1.23% APF gel and (3)0.1%F fluoride varnish, microhardness(VHN) and Diagnodent scores were measured and the surfaces of each treated specimens were also observed with SEM under 1500 magnification. The results were as follows: 1. In the change of microhardness(VHN), it decreased to 34.68% from the initial micrhardness, increased to 78.37% after laser irradiation and increased to 82.62% after fluoride treatment, there were significant differences except when it was irradiated and treated with fluoride(P<0.05). 2. In the change of Diagnodent scores, it was decreased to 28.08% from the initial scores after demineralization, and then increased to 59.81% after laser irradiation, and increased to 82.17% after fluoride treatment. Scores were different significantly between the scores of initial, demineralization, laser irradiation and fluoride treatment(P<0.05). All the scores were not different significantly between fluoride types. 3. SEM observation showed that the lased enamel surfaces after demineralization were thermally degenerated and showed molten lava-like appearance and crater with cracks and many microholes.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.3
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• pp.469-476
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• 2008

This study was performed to compare the fluoride release pattern and compressive strength of recently developed resin-modified glass ionomers($Ketac^{TM}$ N 100 and Fuji Fil LC) with those of conventional glass ionomer restorative material(Fuji II LC). Fifteen sample discs(6 mm diameter and 1 mm height) were prepared for each tested material. The fluoride release was measured by pH/ISE meter(750P, Istek, Korea) for 31 days. For compressive strength experiment, fifteen cylindrical specimens were prepared for each tested material. Each specimen was submitted to compressive strength testing in an universal testing machine(Kyung-sung Testing Machine Co., Korea) at crosshead speed of 5.0mm/min until failure. The results can be summarized as follows; 1. Fuji Fil LC released the highest amount of fluoride, followed by Fuji II LC and $Ketac^{TM}$ N 100(p<0.05). 2. The compressive strength of Fuji Fil LC was the lowest(p<0.05). However, no significant difference was found from Fuji II LC and $Ketac^{TM}$ N 100(p>0.05). By considering the above results, careful case selection and accurate clinical application is recommended when using $Ketac^{TM}$ N 100 and Fuji Fil LC.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.4
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• pp.406-415
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• 2020

Silver diamine fluoride (SDF) is an effective and efficient agent for arresting dental caries. It can be useful in treating children with behavioral or medical limitations. The purpose of this study was to evaluate the antimicrobial effect of SDF by using salivary biofilm. Pellicle-like saliva coated structure was prepared by using unstimulated saliva. For developing cariogenic biofilm, Streptococcus mutans was added to the mixture of pooled saliva and inoculated into a saliva coated glass or chamber. SDF was applied to cariogenic biofilm to evaluate the antimicrobial effect of SDF. As time passed, total bacteria and S. mutans were reduced after application of SDF (p < 0.000). Confocal laser scanning microscope also showed the increment of the ratio of dead cell. As a result of experiment using enamel and dentin of primary teeth, it was confirmed that the growth of cariogenic biofilm was inhibited when the SDF was treated (p = 0.029 each). This study showed excellent anti-microbial effect of SDF. And anti-caries effect in clinical practice can be expected.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.595-603
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• 2018

This study was conducted to understand the growth of attached microbial community in small and medium streams of Gyeonggi-do and the removal efficiency of fluoride with changes in growth. The sites monitoring were carried out for 12 weeks at the P1 and P2(P1 is the point where the discharge water flows. P2 is the downstream point of about 2 km flow), and investigated the water quality and the biomass analysis of the attached microbial community. The growth of the attached microbial community increased up to the 7th investigation, and it was observed that detachment phenomenon occurred. Influencing factors about growth of the attached microbial community were flow rate, velocity, and organic material(T-N & T-P). Meanwhile, fluoride content of attached microbial community also tended to increase until the 7th investigation, and decrease from the 8th. It is assumed that fluoride content has also be reduced with the detachment phenomenon of the attached microbial community. It is expected that this will contribute to the evaluation and management of the use of attached microbial community as a means of stream management. The application of techniques using the attached microbial community should include basic investigation of factors that may affect the growth of the attached microbial community and replacement of the attachment plate according to the time of removal.

• Journal of Korean society of Dental Hygiene
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• v.11 no.6
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• pp.1005-1016
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• 2011

Objectives : The purpose of this study was to examine the awareness of mothers on their children's oral health and their concern for that by socio-demographic characteristics and the relationship of their awareness of methods of dental-caries prevention to their practice of the methods. Methods : The subjects in this study were 337 guardians of preschoolers at kindergartens and daycare centers. A self-administered survey was conducted from April 25 to May 27, 2011, and the collected data were analyzed by the statistical package SPSS 18.0. Results : 1.Self-rated concern for children's oral health, 87.7 percent and 12.1 percent replied, "So-so." Whether they were working or not and whether they were mainly responsible for child rearing made significant differences to that(p<.05). 2. As to subjective awareness of their children's oral health, the largest group of the mothers answered "So-so." (44.9%) The second replied that their children were in good oral health(40.5%), and the third group in poor oral health(14.2%). 3. The relationship between self-rated concern for their children's oral health and awareness of methods of caries prevention, statistically significant differences were found according to toothbrushing education and sealant(p<.05). There were no statistically significant differences in practice, but application of fluoride was the least. 4. The relationship between self-rated awareness for their children's oral health and awareness of the preventive methods of caries, there were statistically significant gaps in awareness of toothbrushing education(p<.05). In practice, statistically significant gaps were found in practice of toothbrushing education and sugar-intake restriction(p<.01). 5. In regard to the correlation between awareness and practice of the preventive methods of caries, awareness of all the factors involving toothbrushing education, sealant, application of fluoride and restriction of sugar intake had a significant positive correlation to practice of them. Better awareness led to better practice. Conclusions : In order to ensure children's successful oral health care, more authentic education of how to prevent dental caries should be offered by experts such as dental hygienists and dentists. Especially, detailed information on application of fluoride, restriction of sugar intake and pit and sealant should be provided for mothers to help their children to stay away from dental caries.

• Journal of dental hygiene science
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• v.16 no.3
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• pp.249-255
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• 2016

The Ministry of Health and Welfare in Korea has enforced the oral health promotion program for elderly in Korea. There are the denture delivery program and the fluoride application-scaling program for elderly. Donggu Public Health Center in Daejeon has delivered the fluoride application-scaling program for elderly since the demonstration project in 2009. The official dental hygienists had a prior consultation with Dong-gu branch of Korean Senior Citizens Association in Daejeon. We expanded the program through government office, welfare centers, and nursing homes. The participants were satisfied with the public relations (95.2%), scaling (99.7%), fluoride application (91.5%), toothbrushing education (98.6%), and denture cleaning education (96.6%). After a medial accident with persistent bleeding, the pre-inspection survey about systemic disease and medication was reinforced. The official dental hygienists have agonized over the low participation of the low-income group and the overlap benefit with health insurance benefit of scaling. We suggested it be needed the assessment of the public oral health program to overlap with health insurance benefit.

• Membrane Journal
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• v.23 no.3
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• pp.220-225
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• 2013

Hydrophilic monomers were polymerized for lamination on polyvinylidene fluoride (PVDF) membrane surface for hydrophilization of the membranes. Hydrophilization reduced the contact angle from $95^{\circ}$ to $55^{\circ}$ and enhanced the water flux by 10 times while it reduced the bovine serum albumin (BSA) adsorption amount to 1/4 level. Thermal polymerization process was optimized by examining several operation parameters. Dimethyl oxobuthyl acrylamide (DOAA) showed the best effect due to its better hydrophilicity than others. Increase of amount of monomer enhanced the performance until the optimum concentration of 30 wt%, beyond which excess amount of monomer resulted in homopolymerization to deteriorate the performance. Azobis (isobutyronitrile)(AIBN) initiator has greater activation temperature range than benzoyl peroxide (BPO) and it showed better hydrophilation performance. Two stage lamination process, application of initiator followed by monomer addition, was more effective than one stage process, addition of initiator and monomer at once, which still reduced the contact angle but also reduced the water flux by pore blocking phenomena.

• Restorative Dentistry and Endodontics
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• v.18 no.2
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• pp.341-356
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• 1993

In the prevention of root surface caries, antimicrobial therapy for the control of subgingival and supragingival plaque is seriously considered as a long term suppression of pathogenic microflora. Recently, varnishes containing antimicrobial agents have been developed to control the supragingival microflora. The purpose of this study was to determine the antimicrobial effects of 20% chlorhexidine varnish and 2.6% silane fluoride varnish with sealant. In clinical experiments, 12 subjects were selected from the periodontally treated patient and divided into 3 groups. After a dental prophylaxis, the subjects were treated with single application of placebo varnish (group I), 20% chlorhexidine varnish (group II), and 2.6% silane fluoride varnish (group III). Root surface plaque samples were taken before (baseline) and one, two, four, and 8 weeks after the treatments. Microbiological examinations of root surface plaque were performed with culture study and indirect immunoflorescence (I.I.F.) study, and immunological examination of gingival crevicular fluid antibody titers was performed with ELISA study. The results were as follows: 1. Pathogenic microflora on the root surface including S. mutans, S. sanguis, S. mitis, A. naeslundii, A. viscosus were 24 - 37% on I.I.F. study. 2. S. mutans, S. sanguis, S. mitis, A. naeslundii, A. viscosus of the root surface plaque was significantly reduced from 1 week to 8 weeks after antimicrobial varnish treatment, but showed generally increasing tendency in control group. 3. Gingival crevicular fluid antibody titers were significantly reduced from 1 or 2 weeks to 4 weeks after antimicrobial varnish treatment.