• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.71-95
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• 1995

Bacteria have been regarded as a one of major etiologic factors in root canal infections. In endodontic treatment the effective removal of pathogenic microorganisms in the root canal is the key to successful outcome. Bacterial cell wall components may play an important role in the development of pulpal and periapical disease. The purpose of this study was to evaluate the effect of sonic extracts of Streptococcus spp. on cultured L929 cells and to characterize cell wall protein profiles of Streptococcus spp. Streptococcus spp. were isolated from infected root canals and identified with Vitek Systems(Biomeriux, USA). Five streptococci, namely S. sanguis, S. mitis, S uberis, S. mutans (ATCC 10449) and S. faecalis (ATCC 19433) weere enriched in brain heart infusion broth. Cell pellets were sonicated and cell wall extracts were dialyzed and membrane filtered. Prepared cell wall proteins were applied to cultured L929 cell. The cell reaction were evaluated by monitoring DNA synthesis, cell numbers and the change of cell morphology. The total cell wall protein profiles of microorganisms were characterized by sodium dodecyl sulfate polyacrylamide-gel eledruphoresis(SDS-PAGE). DNA synthesis of L929 cells were reduced by the increasing concentration of sonic extracts. DNA synthesis was significantly suppressed in more than $50{\mu}g$/ml of sonic extract conentration in five streptococci. S. nutans (ATCC 10449) showed stronger suppression on DNA synthesis than remaining four streptococci, which had the similar effect on DNA synthesis. Analysis of DNA synthesis measured by [$^3H$]-thymidine uptake was more sensitvie method than cell counting. Sonic extracts affected the microscopic findings of L929 cells. The protein profiles indicated that all five strains shared two major proteins with molecular masses of 70.8 and 57.5 kD respectively. S. uberis and S. mutans shared common minor proteins of which molecular weights were 147.9 and 112.2 kD respectively. However some minor proteins were unique for S. mitis, S. uberis and S. faecalis.

• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.170-180
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• 1997

Cariogenicity of the bacteria is attributed to their binding capacity to the teeth. Bacterial attachment to oral surfaces is an essential step for colonization and subsequently infection. Therefore, it is conceivable that caries prevention can be achieved fundamentally by inhibition of bacterial attachment. The rationale for caries prevention through the use of sugar substitutes or limited use of sugar has been revealed. Among many sugar substitutes, xylitol has been shown to exhibit the most profound cariostatic effect, inhibiting glucose metabolism and possibly binding of mutans streptococci. The purpose of this study was to examine the effect of xylitol on binding of different species of oral bacteria. The effect of xylitol on binding of [$^3H$]-labeled oral bacteria to hydroxyapatite coated with human saliva(SHA) as a model for the pellicle-coated tooth surfaces was investigated. The strains of oral bacteria used in this study were A. viscosus T14V, A. viscosus WVU627, P. gingivaiis 2561, P. gingivalis A7Al-28, S. gordonii G9B, S. gordonii Challis, S. sobrinus 6715, S. mutans UA101, S. mutans KPSK -2, S. mutans T8, and S. mutans UA130. The obtained results were as follows: 1. P. gingivalis A7 Al-28, S. mutans UA130, S. mutans T8 grown with xylitol showed greater binding to SHA than the organism grown without xylitol. Among these, S. mutans T8 showed the greatest rate of increase in its binding to SHA ; 8-fold increase in its binding with xylitol. 2. S. mutans KPSK -2 grown with xylitol showed 2 times lesser binding to SHA than the organism grown without xylitol. 3. Binding ability of the remaining strains grown with xylitol to SHA was almost same as that of the organisms grown without xylitol. The overall results suggest that use of xylitol in the oral cavity may affect the complex oral bacterial ecosystem.

• International Journal of Oral Biology
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• v.45 no.4
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• pp.143-151
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• 2020

Streptococcus mutans and Streptococcus sobrinus play important roles in dental caries. Coptis chinensis is a natural product with antimicrobial activity against enterobacteria; however, its effects on oral streptococci are still unknown. Therefore, the effects of C. chinensis on the growth and biofilm formation of the representative cariogenic bacteria S. mutans and S. sobrinus were investigated for the possible use of C. chinensis as an anticaries agent. The C. chinensis extract was diluted with sterile distilled water, and 0.1-2.5% of the extract was used in the experiment. The effects of the C. chinensis extract on the growth and glucan formation of S. mutans and S. sobrinus were measured by viable cell counting and spectrophotometry at 650 nm absorbance, respectively. Crystal violet staining was also carried out to confirm the C. chinensis extract's inhibitory effect on biofilm formation. The C. chinensis extract significantly inhibited the growth of S. mutans and S. sobrinus at concentrations of ≥ 0.3% as compared with the control group. The viable cell count of colonies decreased by 1.7-fold and 1.2-fold at 2.5% and 1.25%, respectively, compared with the control group. The biofilm formation of S. mutans and S. sobrinus was inhibited by > 20-fold at C. chinensis extract concentrations of ≥ 1.25% as compared with the control group. In summary, the C. chinensis extract inhibited the growth and biofilm and glucan formation of S. mutans and S. sobrinus. Therefore, C. chinensis might be a potential candidate for controlling dental caries.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.2
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• pp.187-193
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• 2014

Dental caries are one of the most common oral diseases and Streptococcus mutans (S. mutans) plays an important role in the initiation and progression of dental caries. Oral malodor is primarily the result of microbial metabolism such as Porphyromonas gingivalis (P. gingivalis) that produce volatile sulfur compounds (VSCs), causing oral malodor. Prevotella intermedia (P. intermedia) is known as typical periodontopathic bacteria, and periodontal disease is chronic inflammatory disease that leads to damage of gingival connective tissue and alveolar bone, eventually loss of teeth. In this study, we investigated antimicrobial effect of mouthwash containing cetylpyridinium chloride (CPC), sodium fluoride (NaF), green tea water extract and pine needles water extract against cariogenic and periodontopathic bacteria sucn as S. mutans, P. gingivalis and P. intermedia. As a result, the reduction ratios of S. mutans and P. gingivalis were 4.00 Log and 4.68 Log reduction for 30 s, and P. intermedia were 2.40 Log reduction for 30 s and 2.70 Log reduction for 60 s. Dentocult SM Strip mutans (SM Strip) provides easy detection of visual data showing a significant inhibition on S. mutans. In conclusion, we expected that mouthwash containing CPC, NaF, green tea water extract and pine needles water extract could help preventing the dental disease like dental caries and oral malodor.

• The Korea Journal of Herbology
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• v.31 no.5
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• pp.7-13
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• 2016

Objectives : Camellia sinensis (Theaceae) possesses a various beneficial effects such as free radical-scavenging, inactivation of urokinase in cancer cell proliferation, antibacterial, and hypotensive. Dental caries is one of the most common oral infectious disease in a human. Oral microorganisms play a significant role in the etiology of dental caries. An aberration to this ecology due to dietary habits, improper oral hygiene or systemic factors lead to an increase in cariogenic microorganisms. Cariogenic microorganisms like Streptococcus mutans and Streptococcus sobrinus encourage the accumulation and adherence of plaque biofilm by metabolizing sucrose into glucans. The purpose of this study was to investigate the antimicrobial activity of phenolic compounds of Camellia sinensis and R-carvone, monoterpenes, is can be found naturally in numerous essential oils, on Streptococcus mutans and Streptococcus sobrinus .Methods : The antimicrobial activity of these compounds was determined by the broth microdilution method and checkerboard dilution assay to investigate the potential synergistic effects of each five compounds of Camellia sinensis (C. sinensis) and R-carvone.Results : C. sinensis-isolated compounds and R-carvone were determined with MIC of more than 1,000 ㎍/mL. However, the combination test showed significant synergism against S. mutans and S. sobrinus, implicated in the lowered MICs.Conclusions : These results suggest that combinatory application of phenolic five compounds (theophyllin, l-theanine, epicatechin, epicatechin gallate, and caffeine) from C. sinensis and R-carvone has a potential synergistic effect and thus may be useful as a mouthrinse in helping control cariogenic microorganism.

• Journal of dental hygiene science
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• v.10 no.2
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• pp.123-129
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• 2010

To examine whether the effects of chewing gum containing xylitol are purely based on xylitol itself rather than the preventive effects on dental caries based on other constituents or factors, gargling was done using xylitol solution which was diluted in a distilled water. Then, attempts were made to perform an experiment for the bacterial activity of S. mutans depending on the amount of xylitol. Gargling was done using solutions containing xylitol at an amount of 30, 50, 60, 70, 80 and 90% with the same methods after 48 hours. When gargling was done using a solution containing xylitol at a volume of 60% in those who experienced dental caries, the bacterial activity of S. mutans was decreased by 35% as compared with the control group. When gargling was done using a solution containing xylitol at a volume of 70%, the bacterial activity of S. mutans was decreased by 80% as compared with the control group. These results indicate that there was a significant difference between the two groups (p<0.05). Besides, similar result appeared in those who did not experience dental caries(p<0.05). Based on the above results, under the hypothesis that the effects of xylitol contained in a chewing gum were not associated with other constituents, it is presumed that the amount of xylitol at a ratio of > 70% is effective in reducing the bacterial activity of S. mutans with no respect to experiences of dental caries. But we need an another experiment to confirm whether this result is due to xylitol's effect or not.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.549-576
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• 1995

Bacteria are one of the most important causative agents of the pulpal and periapical diseases. Streptococci are one of the most frequently isolated facultative anarerobic bacteria in the infected root canals. Bacterial cell wall components have a direct effect in the pathogenesis of the pulpal and periapical infections. Hyaluronidase produced by bacteria has been implicated in dissemination of the diseases. The purpose of this study was to evaluate the effect of cell wall extract of streptococci on the L929 cells using inverted microscope and the transmission electron microscopy (TEM). Hyaluronidase production of streptococcal strains were investigated to determine the correlation between the severity of cell damage and the activity of enzymes. Bacterial cell wall extracts of S. sanguis, S. mitis and S. uberis isolated from infected root canals and ATCC type strains of S. mutans (ATCC 10449) and E. faecalis (ATCC 19433) were prepared by sonication and confirmed with SDS-PAGE. Silver stain of SDS-PAGE of sonic extract was efficient at $100{\mu}g$/ml concentration of cell wall protein, while Coomasie blue stain was efficient at $100{\mu}g$/ml concentration. Inverted microscope showed that sonic extract-treated L929 cells were round and detached from the substratum while others lost their fibroblastic shapes. Transmission electron microscopic examination revealed that streptococcal extracts induced death of L929 cells. Sonic extracts of streptococci had variable effect on microstructure of L929 cells. significant chromatin condensation was observed in the nucleus of the cells. Disappearance of cell surface microvilli and nuclear fragments with dense chromatin were observed. The cell nucleus had an irregular shape and numerous large vacuoles were seen in the cytoplasm and some breaks of the cell membrane could be seen. Cell organelles were in various stages of destruction and cristae of mitochondria were disoriented or disappeared. Eighteen strains of streptococci did not produce hyaluronidase.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.505-513
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• 2009

Streptococcus mutans plays a major role in the formation of dental plaque and it is considered one of the important pathogens in the development of dental caries. Established dental plaque can be more resistant to antimicrobial agents and offers nutrient rich and relatively stable cariogenic conditions for bacteria. Thus bacteria growing in dental plaque have strong resistance to antimicrobial agents and they are not removed easily by the flow of saliva. Many researchers have been performed using natural materials, especially herbal extracts to prevent dental plaque. However, the strains of mutans streptococci used in the researches were not from Koreans. Therefore, it would be necessary to evaluate the antimicrobial activity of herbal extracts against clinical isolates of Streptococcus mutans isolated from saliva of Koreans living in Jeollabuk-do. For this study four clinical isolates were isolated from saliva samples of seventeen Korean people to investigate whether essential oils of Artemisia spp. have antimicrobial activity against them including four reference strains of Streptococcus mutans. Minimum inhibitory concentrations, Minimum bactericidal concentrations and time kill studies were performed and the results showed that Artemisia lavandulaefolia DC, Artemisia scoparia, and Artemisia capillaries have antimicrobial activity against the Streptococcus mutans clinical isolates and reference strains.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.2
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• pp.247-254
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• 2007

Mutans streptococci have been reported to be implicated in dental caries. Of these streptococcal species, Streptcoccus mutans and Streptococcus sobrinus are most commonly found in human dental caries. Prevalence of these bacterial species in dental caries is found to be varied in different races and countries. Therefore, importance of these bacteria in dental caries remains to be determined The present study was performed to find out correlation S. mutans and S. sobrinus with dental caries in 125 Korean children with mixed dentition between 6 to 11 years of age. They were classified as group A(6-8 years) and group B(9-11 years) by age. For the study, stimulated saliva samples were collected from each subject. The vials containing saliva specimens were serially diluted (1:10) in saline and plated in duplicate on tryptone-yeast extract-cysteine with sucrose and bacitracin (TYCSB) for S. mutans and S. sobrinus. After genomic DNA was extracted from the samples, polymerase chain reaction (PCR) amplification was performed for identification using universal primers and specific primers to S. mutans and S. sobrinus. Data of microbial variables were compared to caries status of the subjects. According to this study, the result were as follows : 1. S. mutans versus S. sobrinus were moderate positive linear correlated in both group A(r=0.70) and group B(r=0.50). 2. Between S. mutans and dental caries there were weak positive linear correlation in both group A(r= 0.25) and group B(r=0.34). 3. S. sobrinus versus dental caries were not correlated in group A but slightly correlated in group B(r=0.21). 4. Between S. mutans and age, there were not correlation in both group. 5. S. sobrinus versus age were weak correlated in group A(r=0.32) but not correlated in group B.

• International Journal of Oral Biology
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• v.31 no.1
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• pp.7-10
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• 2006

Mitis-salivarius sucrose bacitracin(MSB) medium is widely used in the selective isolation of mutans streptococci(MS), a designation for a group of oral cariogenic species. Recently, we have isolated three bacterial strains grown on MSB agar from human dental plaques. The three strains exhibited biochemical characteristics similar to those of the biotype IV of MS, with the exception that they manifested a positive reaction for arginine deaminase. The objective of this study was to identify and characterize these three clinical isolates. The bacteria were identified with biochemical tests as well as by 16S rDNA cloning and sequencing. In order to compare the antibiotics susceptibility of the clinical isolates with that of type strain, the minimum inhibitory concentrations of 9 antibiotics were determined using broth dilution assays. The results identified all of our three clinical isolates as Enterococcus faecalis. All E. faecalis strains were found to be susceptible to penicillin G, amoxicillin, augmentin, and vancomycin, but were resistant to ciprofloxacin, cefuroxim axetil, and clindamycin. Our findings indicate that E. faecalis is capable of growing on MSB agar, and suggest that the MSB medium be improved so that only MS should be recoverable on the medium, as originally devised for their selection.