• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.625-631
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• 2002

The effect of combinations of 8 antimicrobial agents on the growth of Streptococcus mutans and Streptococcus sobrinus was investigated with the minimum inhibitory concentration and fractional inhibitory concentration(FIC) and ${\Sigma}FIC$ index. According to the ${\Sigma}FIC$ values by. The American Society for Microbiology and Berenbaum, Approximately 34% and 82% of the combinations were synergistic respectively. Partial synergy described by Isenberg was also observed in the half of the combinations. There was a tendency for additive antimicrobial effect against cariogenic bacteria though the test results showed difference according to the applied values. It may be beneficial to use combined antimicrobial agents that have various activities against an ecosystem and metabolism of bacteria than using individual agents.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.618-624
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• 2002

Effect of the roasted barley tea in commercial markets on the adherence to the saliva-coated hydroxyapatite(HA) beads and the cell surface hydrophobicity of Streptococcus mutans and Streptococcus sobrinus as cariogenic microorganism was examined in vitro. Adherence activity and hydrophobicity in bacteria tested in all the barley tea samples decreased and the values were different according to the type of tea and the type of treatment. The inhibition of bacterial adsorption to HA beads suggest that barley tea active molecules as catechins and melanoidins may adsorb to a host surface, preventing the tooth receptor from interacting with any bacterial adhesions. The obtained results showed that the barley tea may inhibit bacterial adherence, the first step of the pathogenesis of dental caries in which these microorganism are involved.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.2
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• pp.195-202
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• 2018

The purpose of this study is to analyze the cariogenicity of vitamin supplements for children by the Caries Potentiality Index (CPI), pH drop capacity, proliferation rate of Streptococcus mutans. Four vitamin supplements were selected - Noma (NM), Cenovis Kids (CK), Animal Parade (AP), and Character Vitamin (CV). CPI value decreased in the order of AP, CV, CK, and NM. Initial values of all experimental groups showed acidity below pH 7.0. Analysis of the colony forming units of Streptococcus mutans showed that NM and CV resulted a higher proliferation rate (p < 0.05) than CK and AP (p < 0.05). Bacterial activity of the control group was lower than other groups when observed with a confocal laser scanning microscope. Considering the bacterial activity and acidity of vitamin supplements, it is necessary to pay close attention when children taken the vitamin supplements for their oral health.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.247-255
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• 2004

The purpose of this study was to examine the effects of resin composite monomers (Bis-GMA, TEGDMA, EGDMA, UDMA, HEMA, Camphorquinone) on the growth of the two cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus. We obtained the following results : 1. The growth rate of S. mutans and S. sobrinus was decreased significantly in the group of all composite resin monomer at a concentration of 0.03mmo1/L(P<0.01). 2. The growth rate of S. mutars in the group of UDMA at a concentration of 0.01 mmol/L and the group of CQ at a concentration of 0.005 mmol/L, 0.01 mmol/L was decreased significantly compared to the control group(P<0.01). 3. The growth rate of S. sobrinus in the group of HEMA, UDMA at a concentration of 0.01 mmol/L and the group of CQ at a concentration of 0.005mmol/L. 0.01mmo1/L was decreased significantly compared to the control group (P<0.01). 4. The growth rate of S. sobrinus in the group of EGDMA at a concentration of 0.001, 0.01, 0.03mmo1/L was decreased significantly compared to the control group(P<0.01) and were showed to be statistically significant difference between experimental groups(P<0.01).

• Journal of dental hygiene science
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• v.13 no.1
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• pp.45-52
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• 2013

Antimicrobial activity of extract from some traditional oriental medicinal plants were evaluated for their antimicrobial activity against six oral pathogens, Streptococcus salivarius, Streptococcus oralis, Streptococcus mutans, Streptococcus sanguinis, Lactobacillus acidophilus and Lactobacillus casei, which are associated with caries disease. The antimicrobial activity was examined by determining the inhibition zone using the disc diffusion assay. In antibacterial activity test, extracts of Scutellaria baicalensis, Chrysanthemum indicum, Kochia scoparia, Hydnocarpus anthelmintica and Caesalpinia sappan showed inhibitory effects (40 mg/ml) against tested caries bacteria. Especially, the C. sappan extract showed the strongest activity on S. oralis (40 mm), L. casei (35 mm) and S. mutans (28 mm). Thus, this result suggests that C. sappan may be applicable to preventing dental caries.

• 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 the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.83-91
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• 2008

Dental caries which is one of the most common chronic disease complexly developed by the action of oral bacteria, diet, and host factor. Various prevention program enhance resistance of demineralization and reduce the acidogenecity of oral bacteria have been introduced, representative material is fluoride and chlorhexidine. The purpose of the study was to evaluate and compare effectiveness of fluoride varnish and chlorhexidine varnish in vivo. Bovine tooth specimens were implanted in the lower space maintainers and applied with fluoride varnish and chlorhexidine varnish. After seven days in oral environment, metal mesh was covered to make similar condition of plaque accumulation and induce caries. All specimens were analysed by EPMA to evaluate quantitative change of Ca, P and by polarized microscope to identify histological changes. The results were as follows : After initial artificial caries induction in the mouth, there were remarkable enamel caries lesion in the control group under polarized light microscopy. The highest amount of mineral decrease were showed in control group. No statistically significant mineral decrease were showed in fluoride varnish group, while chlorhexidine varnish group showed only significant decrease of P(P<0.05). In conclusion both fluoride varnish and chlorhexidine varnish seemed to be effective for protecting enamel surface from caries activity, although fluoride varnish has more anticariogenic effect than chlorhexidine varnish.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.289-294
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• 2010

Salvia miltiorrhiza Bunge (S. miltiorrhiza) is a traditional Korean medicine that is commonly used for the treatment of inflammatory diseases such as edema, arthritis, and hepatitis. The present study investigated the antimicrobial activity of methanol (MeOH) extract of S. miltiorrhiza roots against oral bacteria using broth the microdilution method and the checkerboard and time-kill methods evaluated the synergistic effects of treatment with antibiotics. The MeOH extract was demonstrated as a higher antibacterial activity (MICs, 8 to $64\;{\mu}g/mL$; MBCs, 16 to $64\;{\mu}g/mL$) against all tested oral bacteria. Additionally, the extract was observed to have a synergistic effect with ampicillin or gentamicin. A time-kill study evaluating the effects of the extract indicated that the extract treatment in combination with ampicillin or gentamicin showed rapid bactericidal activity. The results suggest that MeOH extract of S. miltiorrhiza could be employed as a natural antibacterial agent against dental caries.

• Journal of dental hygiene science
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• v.13 no.2
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• pp.182-190
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• 2013

Composition of oral microbial flora is suggested to play a role in the maintenance of oral health. Among them, Streptococcus mutans plays an essential role in the formation of dental plaque and it is being noticed as incipient infective bacteria of dental caries. The purpose of this study was to prepare the basic data about distribution of Streptococcus mutans detected from saliva by measuring colony density. It is well known that smoking as well as drinking is a factor of dental caries, however there are few investigations about distribution of Streptococcus mutans either smoking or drinking. The materials of this study were collected from students of dentistry college with general characteristics obtained by self-administered questionnaires. Students were asked to gently chew the paraffin to get saliva for 1 minute. Bacitracin disc in the culture medium was activated for 15 minutes, and then sample was incubated in the activated medium at $37^{\circ}C$ incubator for 48 hours. Streptococcus mutans colonization per 1 ml saliva was measured by the number of criteria. The severe levels of dental caries activity were significantly increased in the case of smoking (from 5.6% to 10%) or drinking (form 0% to 7%), respectively. Also, dental caries activity increased according to smoking and drinking periods longer. However, using the SPSS analytical process (Mann-Whitney's U), no significant differences were observed between the smoking and the non-smoking or the drinking and non-drinking, respectively. These results obtained from dental caries activity of saliva suggest that distribution of Streptococcus mutans following smoking or drinking can be used as a significant information for oral health.

• Journal of Korean society of Dental Hygiene
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• v.21 no.5
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• pp.527-533
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• 2021

Objectives: Electrolyzed water has been proven to have antibacterial effects against various microorganisms. However, there are only a few studies about effects of electrolyzed water on oral bacteria. The purpose of this study was to examine the antibacterial effect of electrolyzed water on Streptococcus mutans in vitro. Methods: S. mutans KCOM 1054 was treated with electrolyzed water for 1 or 3 minutes and plated on Mitis Salivarius agar with 15% sucrose and bacitracin. After incubation for 48 hours, colony forming units (CFU) were counted, and dental plaque was quantified by crystal violet staining. Results: The growth of S. mutans was significantly inhibited by electrolyzed water (p<0.001). In addition, the dental plaque formation by S. mutans was decreased in a time-dependent manner by exposure to electrolyzed water (p<0.001). Conclusions: Our results suggest that electrolyzed water can effectively prevent dental caries by inhibiting growth of (and the formation of dental plaque by) S. mutans.