• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.1
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• pp.70-77
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• 2020

The present study is aimed to assess the effect of antimicrobial photodynamic therapy (aPDT) on Streptococcus mutans biofilm through teeth whitening light emitting diode (LED). Planktonic and dynamic biofilm state cultures of S. mutans were used. Erythrosine 20 μM/L was used as the photosensitizer. Irradiation was performed by exposing cultures to clinic and homecare whitening LEDs for 15 minutes. The viability was measured through Colony Forming Unit counts and confocal laser scanning microscopy. aPDT using whitening LEDs and erythrosine significantly decreased the CFU count of S. mutans compared to that in the control group. Dynamic biofilm group showed more resistant features to aPDT compared with planktonic state. Clinic and homecare whitening LED device showed similar antimicrobial effect. The whitening LED, which could irradiate the entire oral arch, showed a significant photodynamic effect on cariogenic S. mutans biofilm. aPDT mediated by erythrosine and LEDs used for teeth whitening exhibited promising antimicrobial activity.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.4
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• pp.397-405
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• 2020

The aim of this study is to compare cariogenic characteristics of fluoride-sensitive Streptococcus mutans [fluoride-sensitive (FS) S. mutans ] and fluoride-resistant Streptococcus mutans [fluoride-resistant (FR) S. mutans] in the presence of sucrose, and to evaluate its effect on cariogenic biofilm formation. S. mutans ATCC 25175 was continuously cultured in trypticase soy broth (TSB) containing NaF (70 ppm) for 40 days to generate FR S. mutans. FS and FR S. mutans were inoculated in TSB with or without 2% sucrose, and optical density and pH were measured every hour. An oral biofilm was formed using saliva bacteria and analyzed through confocal laser scanning microscopy and CFU count. Finally, the expression of glucosyltransferases genes of both S. mutans was investigated through RT-PCR. FR S. mutans exhibited slower growth and lower acidogenicity in the presence of sucrose compared to FS S. mutans . Both cariogenic and single species biofilm formation was lower in the presence of FR S. mutans, along with reduced number of bacteria. FR S. mutans showed significantly low levels of gtfB, gtfC, and gtfD expression compared to FS S. mutans . On the basis of results, FR S. mutans may be less virulent in the induction of dental caries.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.522-530
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• 2009

The purpose of this study was to evaluate the clinical effectiveness of new streptococcus detection system which used monoclonal antibody against Streptococcus mutans. 92 children aged between 2 and 8 were involved in this experiment and their saliva samples were collected for testing. Streptococcus mutans were measured by both monoclonal antibody-based detecting system (Saliva-$check^{TM}$ Mutans) and dip slide detecting system($Dentocult^{TM}$-SM). The results showed that Saliva-$check^{TM}$ Mutans levels had a significant correlation with dfs rate of subjects and the two test kits, Saliva-$check^{TM}$ Mutans and $Dentocult^{TM}$-SM were shown to have a good correlation although they were based on different mechanism.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.206-213
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• 2013

This study aims at finding which change there is of oral health promotion as investigating the oral health status in quality, diagnosing which effects knowledge and attitude of oral health has before and after the oral health education as developing and conducting the oral health education program for international marriage migrant women to form their oral health belief for improving oral health. This study consisted of each 51 of the experimental group and the controlled group at the multi-cultural family support center from $26^{th}$ of March, 2012 to $30^{th}$ of June, 2012 as the subjects, and pre-to-post investigated knowledge of oral and cognition. Also as it took follow-up examination of the clients who visited to the dentist with changing of their cognition, conducted matched-pair sample t-test and analysis of repeated measure variance. As the result, there were always the changes at the field of knowledge about oral, periodontal disease and toothbrush in awareness of oral health, and at the field of periodontal disease, dental caries, toothbrush, fluorine and bad breath in knowledge of oral health. The change of DMFT index, DT index has been reduced and FT index has been increased. As the result above, the oral health education program for international marriage migrant women has led to change awareness of oral health and knowledge, and the change of knowledge has influenced to a behavior, so there were the changes of periodontal status and DMFT index as well. This has been showing the importance of the program for oral health of international marriage migrant women. Moreover, while the oral health education program is developed in various aspects by offering the information for developing the oral health education program in future, it needs to run parallel prevention with treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.2
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• pp.140-148
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• 2022

This study aimed to evaluate the effect of silver diamine fluoride (SDF) and potassium iodide (KI) on the formation of cariogenic biofilm and surface roughness in vitro. A total of 48 bovine dentin specimens with artificially induced caries were prepared and divided into 3 groups of 16: untreated control, SDF-treated, and SDF-treated followed by KI (SDFKI). Ten specimens from each group were used to observe microbial adhesion. Multispecies cariogenic biofilms including Streptococcus mutans, Lactobacillus casei, and Candida albicans were cultured on the specimens. Microbes were cultured for 24 hours, and the colony-forming unit was calculated. The remaining specimens were observed by atomic force microscope and scanning electron microscope (SEM). The number of bacteria was significantly lower in the SDF and SDFKI groups. KI did not inhibit the antibacterial activity of SDF significantly. SEM images showed particles generated after SDF and SDFKI application were deposited on the dentin, but there was no significant difference in surface roughness between the 3 groups. This study confirmed that SDF and SDFKI application did not have a significant effect on the surface roughness of dentin, but effectively inhibited the formation of the early cariogenic bacterial film after 24 hours compared to the control.

• Journal of dental hygiene science
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• v.12 no.4
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• pp.303-309
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• 2012

This study was designed to provide basic data for developing a standardized caries potentiality index to help to choose snack foods with a low score on the index by investigating adolescents' snack intakes and measuring them in total saccharinity, pH, and acidogenic potential and glucosidase activity of Streptococcus mutans (S. mutans). Total 28 snack foods were selected and measured for total saccharinity (Pocket refractometer PAL-1, ATAGO) and pH with a pH meter (Mentor, Seoul, Korea). Artificial saliva was added to each sample. The experiment group was administered with S. mutans (ATCC 3692), cultured in a constant temperature incubator at $37^{\circ}C$, and measured for pH changes over five times including after 10 minutes, 30 minutes, 1 hour, and 24 hours. Each sample of 0.3 ml was added to tubes containing sucrose, galactose, or glucose to measure the glucosidase activity of S. mutans. They were then observed for glucosidase activity with colorimetry after 24 hours of culture in a constant temperature incubator at $37^{\circ}C$. The mean pH by the acidogenic potential of S. mutans was pH 5.33. The experiment group dropped in pH more than the control group due to the increasing acidogenic potential of S. mutans by glucosidase activity, recording pH 5.27 after 10 minutes, pH 5.21 after 30 minutes, pH 5.15 after 1 hour, and pH 4.80 after 24 hours. The observation results of glucosidase activity of S. mutans with colorimetry show that most of the samples were positive in orange and yellow with glucose, sucrose, and glactose recording activity of 78.58%, 75%, and 71.42%, respectively.

• 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.31 no.3
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• pp.506-515
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• 2004

The objective of this study was to compare the rate of in vitro demineralization of bovine permanent (BP), human deciduous (HD) and human permanent (HP) enamel. Twenty aye flattened and polished enamel samples for each group (BP, HD, HP) were immersed in a demineralizing solution (0.1 mol/L lactic acid, 0.2% Carbopol 907, and 50% saturated hydroxyapatite) for 1, 2, 4 or 8 days. All 25 samples from each group were subjected to Quantitative light induced fluorescence analysis (QLF) and 5 samples from each group were randomly selected for Transverse Microradiography analysis (TMR). Integrated mineral loss (IML) and lesion depth (LD) were determined by TMR. The fluorescence radiance (FR) of sound enamel $(FR_S)$, demineralized enamel $(FR_D)$ were determined by QLF and FR ratio $(FR_D/FR_S)$ was calculated. Bovine enamel samples showed significant correlation between FR ratio and lesion depth(p<0.05) and deciduous enamel samples does not showed significant correlation between FR ratio and lesion depth(p>0.05). Permanent enamel samples showed significant correlation between FR ratio and lesion depth(p<0.05) The constant of demineralization time between FR ratio from regression analysis were as follows: bovine enamel was -4.643(p<0.05) deciduous enamel was -5.421(p<0.05) and permanent enamel was -4.435(p<0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.3
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• pp.298-305
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• 2017

This study aimed to compare chair-side test results for caries risk assessment and evaluate how well the tests reflect caries experience. The study was conducted on children aged < 6 years in primary dentition. Dental examination of children was conducted to determine the dmft index and subjects were divided into two groups : group I (dmft < 6), group II (dmft > 6). This study used four kinds of test kits (Plaque-check PH kit, Saliva-check buffer kit, Saliva-check mutans kit, Cytoperio analysis system). Saliva buffer capacity was significantly low in the high caries experience group (dmft > 6) and correlated with dmft index. Saliva pH level correlated significantly with saliva buffer capacity. The results showed that plaque pH and saliva pH levels had no correlation with dmft index. The Streptococcus mutans level measured by using the Saliva-check mutans and Cytoperio analysis system did not correlate with dmft index.

• Journal of dental hygiene science
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• v.7 no.3
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• pp.197-200
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• 2007

This study was carried out to assess anticariogenic activity from natural products. The hexane extracts of 11 medicinal plants were tested for the antimicrobial activities against a cariogenic bacterium, S. sobrinus B13. The hexane extracts of 11 medicinal plants such as Alisma orientale, Cyperus rotundus, Saussurea lappa, Atractylodes japonica, Kalopanax pictus, Angelica gigas, Salvia miltorrhiza, Lonicera japonica, Gardenia jasmoides, Aurantii nobilis percarpium and Bupleurum lorgiradiatum were used for this study, and S. sobrinus B13 was cultured with 0.5% extracts of the medicinal plants, in trypticase soy broth medium under 5% $CO_2$ for 0, 6, 12, 24 hours at $37^{\circ}C$. The obtained results were as follows. Immediately after culturing for inoculation, Kalopanax pictus and Cyperus rotundus showed better antimicrobial activities than those of others. After culturing for 6 hours, the order of effective antimicrobial activity was Salvia miltorrhiza, Angelica gigas. After incubation for 12 hours, Salvia miltorrhiza showed the best antimicrobial activity. After incubation for 24 hours Salvia miltorrhiza, Cyperus rotundus, Saussurea lappa, Atractylodes japonica had better antimicrobial activity than others. In conclusion, among Hexane extracts of 11 medicinal plants, Cyperus rotundus, Saussurea lappa, Atractylodes japonica showed effective antimicrobial activity.