• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.267-279
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• 1996

Microorganisms are implicated the endodontic treatment failures. Persistent endodontic infection may be the result of retention of microorganisms in the dentin of the root canal walls. Dentinal tubules of the root canal walls have been shown to harbor microorganisms. The purpose of this study was to investigate the invasion of microorganism into the root dentin and dentinal tubules. The effects of irrigation solutions and smear layer on bacterial colonization of root canal were evaluated using a scanning electron microscopy. Canals of extracted human teeth with single and straight canals were stepback prepared using normal saline. Tooth samples were divided into four groups according to the irrigation solutions -5 % sodium hypochlorite and normal saline-and smear layer treatment. The smear layer was removed by 5% NaOCl and 20% EDTA for 10 min respectively. After sterilization, they were incubated with each strains of Streptococcus sanguis, Enterococcus faecalis, Staphylococcus aureus and Escherichia coli. Sodium hypochlorite solution reduced the adhesion of microorganisms effectively compared to normal saline. The smear layer inhibited colonization of E. faecalis, S. aureus and E. coli in the root canals due to their blocking of dentianl tubules. But S. sanguis invaded dentinal tubules in the root canals without smear layer. It was suggested that bacterial attachment might be different according to the strains. Sodium hypochlorite inhibited bacterial attachment in the dentinal tubules dramatically. The absence or presence of smear layer affected bacterial invasion of the dentinal tubules.

• The korean journal of orthodontics
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• v.27 no.2
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• pp.173-180
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• 1997

The purpose of this study was to evaluate the effectiveness of chlorhexidine varnish treatment in the prevention of dental caries in orthodontic patients by observing microbial change in dental plaque after varnish treatment. The sample consisted of 26 patients who were classified into an experimental group and a control group, 13 patients each. The experimental group was treated with chlorhexidine varnish once a week for 4 weeks. The control group was treated with placebo varnish using the same procedure, The microbial change was analysed by indirect immunofluorescene technique before treatment and 4 weeks, 8 weeks after treatment. The results were as follows. 1. Streptococcus mutans were strongly suppressed until 8 weeks after chlorhexidine varnish treatment(p<0.01). 2 The proportion of Streptococcus sanguis increased temporarily 4 weeks after chlorhexidine varnish treatment(p<0.05), decreased to original level after 8 weeks. 3. Streptococcus mitts, Actinomyces viscosus, Actinomyces naeslundii did not show significant change after chlorhexidine varnish treatment.

• Journal of Periodontal and Implant Science
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• v.30 no.3
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• pp.661-676
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• 2000

Gingivitis and periodontitis are infectious diseases in that microorganisms are the primary extrinsic cause of the diseases. the occurrence of gingivitis has been associated clearly with the presence of microorganisms at the disease site, and the histologic nature of the tissue involved is indicative of an inflammatory response induced by microorganisms. additional evidence for the microbial etiology of periodontal disease is that numerous antimicrobial agents are effective in reducing plaque accumulation and periodontal diseases. the purpose of this article is to analyze the antimicrobial effects of Pulsatilla koreana. Well-dried Pulsatilla koreana purchased from herbs distributor was ground and extracted into methanol(MeOH), ethylacetate(EtoAc), chlorform($CHCl_3$) and Butyl alcohol(BuOH). we have then applied each solution to the bacteria samples(Bacteroides forsythus, Streptococcus mutans, Streptococcus sanguis, Porphylomonas gingivalis, Actinobacillus actinomycetemcomitans, Eikenella corrodens, Prevotella intermedia, Actinomyces viscosus, Prevotella nigrescens , Rothia dentocariosa, Fusobacterium nucleatum, Pseudomonas aeruginosa, Staphylococcus aureus) collected from several organizations. To conduct susceptibility test(Kirby-Bauer method), plate contained each periodontopathic bacteria is spread extracted into methanol(MeOH), ethylacetate(EtoAc), chlorform($CHCl_3$) and Butyl alcohol(BuOH) and to measure the minimum inhibition concentration(MIC) of the bacteria against the solutions to ultimately determine antimicrobial effects of the solutions, insert bacteria sample into $20{\mu\ell}/{m\ell}$, $10{\mu\ell}/{m\ell}$, $5{\mu\ell}/{m\ell}$, $2.5{\mu\ell}/{m\ell}$ of each solution and control group(not contained solution) 1. Solution extracted into methanol did not show clear zone against all bacteria samples. Only P.nigrescens, S. mutans and S. sanguis in solution extracted into ethylacetate, S. mutans and S. anguis in solutions extracted into chlorform and Butyl alcohol showed clear zone against all bacteria samples. Solution extracted into Butyl alcohol showed clear zone against 13 types of bacteria, excluding P. gingivalis. 2. In Solution extracted into methanol, the bacteria samples grew in the highest concentrated plate, showing minimal variation from control group. 3. In Solution extracted into Butyl alcohol, S. aureus, P. intermedia, E. corrodens, A. actinomycetemcomitans, B. forsythus, P. gingivalis et al. showed decreased growth in the highest concentrated plate. P. auruginosa, R. dentocariosa, A. viscosus, P. nigrescens, S. mutans et al. showed decreased growth at MIC $20{\mu\ell}/{m\ell}$ and S. sanguis showed decreased growth at MIC $10{\mu\ell}/{m\ell}$. 4. By analyzing the MIC level through considering the results from Kirby-Bauer method, Solution extracted into methanol did not reveal any antimicrobial effects and Solution extracted into Butyl alcohol showed the highest antimicrobial effects In conclusion, it can be used the extracts of Pulsatilla koreana as wide spectrum antimicrobial agent.

• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.393-398
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• 2015

Aptamers are composed of single-stranded oilgonucleotides that can selectively bind desired molecules. It has been reported that RNA or DNA could act as not only a genetic messenger but also a catalyst in metabolic pathways. RNA aptamers (average sizes 40-50 bp) are smaller than antibodies and have strong binding capacities to target molecules, similar to antigenantibody interactions. Once an aptamer was selected, it can be readily produced in large quantities at low cost. The objectives of this study are to screen and develop aptamers specific to oral pathogens such as Porphyromonas gingivalis, Treponema denticola, and Streptococcus mutans. The bacterial cell pellet was fixed with formaldehyde as a target molecule for the screening of aptamers. The SELEX method was used for the screening of aptamers and a modified western blot analysis was used to verify their specificities. Through SELEX, 40 kinds of aptamers were selected and the specificity of the aptamers to the bacterial cells was confirmed by modified western blot analysis. Through the SELEX method, 40 aptamers that specifically bind to oral pathogens were screened and isolated. The aptamers showed possibility as effective candidates for the detection agents of oral infections.

• 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.18 no.2
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• pp.377-386
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• 1993

The purpose of this study was to evaluate the disinfection efficacy of root canal irrigation method and irrigation solution in infected root canals. Access cavity were prepared in single-rooted extracted human teeth and each canals were prepared with step-back method and sterilized with ethylene oxide gas. Prepared teeth were experimentally inoculated in the canals for 30 minutes with four aerobes(Streptococcus mutans, Stapylococcus aures, Streptococcus sanguis, and E. coli) and two anaerobes(Streptoccus intermedius, and Clostrium perfringens). Normal saline, 3% $H_2O_2$, and 3% NaOCl were used as irrgation solutions. And root canals were irrigated with each irrigation solutions manually with disposible syringe or ultrasonic instument. (Apoza Uitrasonc, Taiwan). The irrigation effect on the eradication of S. aures and S. intermedius with normal saline was not similar between manual method and ultrasonic method. No significant differences were observed in the eradication of E. coli and C. perfringens among the irrigation solution and irrespective of the irrigation methods. In S. aurues and S. mutans, there was somewhat different eradication effect according to irrigation solutions, but there was no significant difference between manual method and ultrasonic methods. These results suggest that ultrasonic irrigation method with saline is more effective in some strains than manual irrigation.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.556-560
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• 2009

Xanthorrhizol, a sesquiterpene isolated from Curcuma xanthorrhiza Roxb., was used to investigate its effect on reducing the saliva and multi-species oral biofilms consisting of Streptococcus mutans, Streptococcus sanguis, and Actinomyces viscosus by anti-biofilm and confocal laser scanning microscopy (CLSM) assays. Xanthorrhizol exhibited significant antibiofilm activity in the dose- and time-dependent manners. Exposure to 2 and $5{\mu}g/mL$ xanthorrhizol for 30 min remained <50% of saliva and multi-species biofilms formed for 24 hr. In addition, exposure to $10{\mu}g/mL$ xanthorrhizol for 30 min reduced 65 and 77% of 24 hr saliva and multi-species oral biofilms, respectively. CLSM results visually demonstrated that xanthorrhizol reduced bacterial viability in the saliva and multi-species oral biofilms. These results suggest that C. xanthorrhiza Roxb. containing xanthorrhizol with strong anti-biofilm activity can be employed as a plant source for oral care functional foods.

• Restorative Dentistry and Endodontics
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• v.16 no.1
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• pp.236-244
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• 1991

Numerous studies have been focused on the immunologic aspects of inflamed pulp and periapical tissues. The purpose of this study was to evaluate levels of serum IgG and IgM in patients of acute pulpitis and acute apical abscess using Enzyme-Linked Immunosorbent Assay. Streptococcus mutans, Streptococcus sanguis, Bacteroides intermedius and Bacteroides gingivalis were grown for use as antigen and they were harvested by centrifugation. The patients were divided into 3 groups; patients of acute apical abecess, acute pulpitis and normal control 5 patients of each group were selected and their blood was obtained via intravenous puncture. Sera were prepared by centrifugation of each blood samples. Then serum antibodies were measured by modified ELISA. The following results were obtained; 1. Serum IgM levels of patients with acute pulpitis and acute apical abscess seemed to be slightly higher than those of normal control 2. Serum IgG levels of patients with acute apical abscess were slightly higher than those of normal control 3. Serum IgG and IgM levels of acute apical abscess patients and serum IgM levels of acute pulpitis were highest to Bacteroides gingivalis.

• Restorative Dentistry and Endodontics
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• v.25 no.2
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• pp.212-218
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• 2000

The recruitment of leukocytes to a site of inflammation is dependent on a complex interplay of a number of cytokines. Monocyte chemoattractant protein-1 (MCP-1) is a potent chemoattractant for monocytes, whereas interleukin-8 (IL-8) has chemotactic activity for neutrophils, lymphocytes, and basophils. The purpose of this study was to determine the effects of several microbes found in infected root canal systems on the production of inflammatoy cytokines, interleukin 8 and monocyte chemoattractant protein-1 from human peripheral blood mononuclear cells (PBMC). Monocytes isolated from peripheral blood were stimulated by group A streptococci (GAS, ATCC 19615), Enterococcus faecalis (ATCC 29212), Streptococcus mutans (ATCC 10449), Streptococcus sanguis (clinical isolate), and Candida albicans (ATCC 90029) respectively. Each of these bacteria induced dose-dependent induction in IL-8 and MCP-1 determined by ELISA. IL-8 production by each bacteria was decreased in the range of the microbe-to-PBMC ratios of 0.1-1.0. Group A streptococci was the week inducer of MCP-1 production. These results suggest that different oral pathogens induce specific dose-dependent patterns of cytokine release. Such patterns may provide a means of control of the type of immune celles particularly with regard to inflammatory leukocyte recruitment.

• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.557-566
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• 1996

It is known that some natural extracts from plants have a various range of antimicrobial and antiinflammatory activity. There are lots of clinical trials to develop toothpastes containing natural extracts for prevention of dental caries and gingival inflammation. The purpose of this study was to evaluate antimicrobial and antiinflammatory activity of magnolol containing toothpastes and other commercial toothpastes. Eleven kinds oftoothpastes were used. They include magnolol, sanguinarine, Myrrha, Mori radicis cortex,Cimicifugae rhizoma, sodium fluoride, aminocaprolactic acid etc. Six strains of bacteria were used for this test, ego Porphylomonas gingivalis, Prevotellain-termedia, Actinobacillus actinomy cetemcomitans, Streptococcus mutans, Stretococcus sanguis, and Actinomyces species. Antimicrobial activity was determined by an agar dillution method and a broth microdillution method. Antiinflammatory activity was assessed by the inhibition of $PGE_2$ production from gingival fibroblast with the addition of rHIL-1 and centrifuged solution of toothpastes. Control group was only rHIL-1 additive sample. $PGE_2$ enzyme immunoassay systemfAmersham, In. Buckinghamshire, U.K). $PGE_2$ level was measured by ELISA reader with 450 nm, The results from the study revealed that toothpastes containing natural extracts generally had high antimicrobial and antiinflammatory activity. Especially magnolol containing toothpaste showed higher antimicrobial activity than other toothpastes, and sanguinarine containing toothpaste showed particularly high antimicrobial activity in A. actinomicetemcomitans and A. viscosus. In some degree all toothpastes inhibited $PGE_2$ production, but magnolol containing toothpaste was potent inhibitor of $PGE_2$. Sodium chloride containing toothpaste had also effective result. The results suggested that toothpastes containing natural extracts were promising in plaque control and prevention of dental caries and gingivitis.