• Restorative Dentistry and Endodontics
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• v.28 no.2
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• pp.178-183
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• 2003

The purpose of this study was to investigate the frequency of 7 putative pathogens in endodontic infections. The specimens were collected from infected pulpal tissue of patients who were referred for root canal treatment to the department of conservative dentistry, Chosun University Samples were collected aseptically using a barbed broach and a paper point. The cut barbed broaches and paper points were transferred to an eppendorf tube containing 500 ml of 1 X PBS. DNAs were extracted from the samples by direct DNA extraction method using lysis buffer (0.5% EDTA, 1% Triton X-100). Identification of 7 putative pathogens was performed by PCR based on 16S rDNA. The target species were as follows : Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Bacteroides forsythus, Actinobacillus actinomycetemcomitans, and Treponema denticola. Our data revealed that the prevalence of P. endodontalis was found in 88.6% (39/54), P. ginivalis 52.3% (23/44), P. nigrescens 18.2% (8/44), P intermedia 15.9% (7/44) B. forsythus 18.2% (8/44), A. actinomycetemcomitans 3.3% (1/44), T. denticola 25% (l1/44) of the samples. The high prevalence of P. endodontalis and P. ginivalis suggests that they may play an important role in the etiology of endodontic infections.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.845-851
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• 2008

TolC is an outer membrane porin protein and an essential component of drug efflux and type-I secretion systems in Gram-negative bacteria. TolC comprises a periplasmic $\alpha$-helical barrel domain and a membrane-embedded $\beta$-barrel domain. TdeA, a functional and structural homolog of TolC, is required for toxin and drug export in the pathogenic oral bacterium Actinobacillus actinomycetemcomitans. Here, we report the expression of the periplasmic domain of TdeA as a soluble protein by substitution of the membrane-embedded domain with short linkers, which enabled us to purify the protein in the absence of detergent. We confirmed the structural integrity of the TdeA periplasmic domain by size-exclusion chromatography, circular dichroism spectroscopy, and electron microscopy, which together showed that the periplasmic domain of the TolC protein family fold correctly on its own. We further demonstrated that the periplasmic domain of TdeA interacts with peptidoglycans of the bacterial cell wall, which supports the idea that completely folded TolC family proteins traverse the peptidoglycan layer to interact with inner membrane transporters.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.3
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• pp.447-456
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• 2006

In this study, the antimicrobial effects of Horseradish (Armoracia rusticana) root extracts against oral pathogens were investigated, and also compared with that of chlorhexidine. The following 7 microorganisms were used in this study, Streptococcus mutans ATCC 25175, Streptococcus sobrinus(d) ATCC 27607, Lactobacillus casei ATCC 393, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Actinobacillus actinomycetemcomitans ATCC 29522. Candida albicans ATCC 10261. Horseradish root extracts and chlorhexidine were tested to determine their minimum inhibitory concentration(MIC) and minimum bactericidal concentration(MBC). The results of this study can be summarized as follows : 1. Horseradish root extracts showed antimicrobial effect against the tested oral pathogens. MIC and MBC of this extracts were 30-125, 125-500ppm, respectively. Especially, it was the most effective against C. albicans of other tested microorganisms. 2. Chlorhexidine also showed antimicrobial effect against the tested oral pathogens. MIC of chlorhexidine range between 0.15 and 2.5%, MBC are 0.4-2.5%. In conclusion, it was suggested that AIT had similar antimicrobial effects in the lower concentration, compared with that of chlorhexidine.

• 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 Periodontal and Implant Science
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• v.27 no.4
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• pp.723-737
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• 1997

본 연구의 목적은 조직유도재생술의 초기치유시에 구강양치액으로 사용되어지는 0.1% 클로르헥시딘과 0.2% 클로르헥시딘을 사용했을 경우, 양치액을 사용하지 않았을 경우의 세균감염 정도를 비교하는 것이다. 30명의 성인형 치주염에 이환되어진 사람을 대상으로 하였다. 초기치료(Scaling/Root planing/Oral hygiene instruction)를 시행한 후에 한 사람에 한 군데씩 선정하여 2급이나 3급의 치근이개부를 가지고 임상적으로 혹은 방사선학적으로 치간골내낭을 보이지 않는 치아에 통법에 따라 Gore-TexTM를 위치시켰다. 술후 5일간 항생제 (UnasynTM 375mg tablet p.o.tid)를 투여하고 차폐막을 제거할 때까지(4주 혹은 6주) 10명의 환자에게는 0.1% 클로르헥시딘을, 다른 10명의 환자에게는 0.2% 클로르헥시딘으로 구강양치를 하게 하고, 또 다른 10명의 환자에게는 구강양치액을 사용하지 않도록 하였다. 또 1주일에 한번씩 전문가구강위생술식을 실시하였다. 4주나 6주 후에 차폐막을 제거하고 주사전자현미경, 혐기성 세균배양을 이용하여 세균감염정도를 비교하였다. 1. 주사전자현미경으로 관찰시에 0.1% 클로르헥시딘을 사용했을 경우와 0.2% 클로르헥시딘을 사용했을 경우, 클로르헥시딘을 사용하지 않은 경우에 별 차이를 발견할 수 없었다. 2. 혐기성 세균배양시에 0.2% 클로르헥시딘을 사용했을 경우, 0.1%클로르헥시딘을 사용했을 경우보다 적은 수의 세균 수를 보였으나 통계적으로 유의할 만한 차이는 보이지 않았다. 클로르헥시딘을 사용하지 않은 경우에는 다른 두 경우에 비해 통계적으로 유의할 만한 차이를 보였다.(P<0.05) 3. Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia를 인지한 경우에는 세 경우 모두 비슷한 비율로 발견되었다.

• Journal of Microbiology
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• v.43 no.3
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• pp.260-265
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• 2005

The objective of this study was to detect and compare the presence of periodontopathogens in the subgingival plaques of gingivitis lesions in adults who wore fixed orthodontic appliances, as opposed to adults who did not wear any orthodontic appliances. Thirty-six individuals participated in this study. Ninteen of these subjects did not wear any orthodontic appliances, and these subjects comprised the control group. The other 17 individuals had been wearing fixed orthodontic appliances for at least 3 months each. After a periodontal examination, we collected subgingival plaque samples from the gingivitis lesions of each patient. Using PCR based on 168 rDNA, we detected the presence of 6 putative periodontopathogenic species, Treponema denticola, Porphyromonas gingivalis, Tannerella forsythia (formerly Bacteroides forsythus), Prevotella nigrescens, Prevotella intermedia, and Actinobacillus actinomycetemcomitans. With regard to the presence of individual periodontopathogens, we found that T. forsythia, T. denticola, and P. nigrescens were significantly more common in the samples obtained from the orthodontic patients than in the samples obtained from the non-orthodontic patient controls. Our results indicate that the local changes associated with the wearing of fixed orthodontic appliances may affect the prevalence of periodontopathogens in subgingival dental plaques.

• Restorative Dentistry and Endodontics
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• v.28 no.4
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• pp.303-313
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• 2003

It has been documented that periodontopathic bacteria are also implicated in endodontic infections. 168 rDNA gene-directed PCR was to examine the prevalence of periodontopathic bacteria including Actinobacillus actinomycetemcomitans (Aa), Prevotella intermedia (Pi), Prevotella nigrescens (Pn), Porphyromonas gingivalis (Pg), Porphyromonas endodontalis (Pe), and Treponema denticola (Td) in the root canals of 36 endodontically infected teeth having apical lesions with or without clinical symptoms like pain, swelling, and fistula. 1. In 36 infected root canals, most frequently detected bacterial species was Pg (61.1%), followed by Td (52.8%) and Pe (38.9%). 2. Of 36 infected root canals, Aa was detected in 6 canals (16.7%) of the teeth, all of which showed clinical symptoms. 3. Of 36 infected root canals, Pi and Pn were found in 4 03.9%) and 5 (33.3%), respectively. Notably, prevalence of Pn in the symptomatic teeth was 50.0%. 4. One of black-pigmented anaerobic bacteria (BPB) including Pi, Pn, Pe, and Pg was detected in all of the teeth that showed pain or especially swelling but not fistula. It was, however, found that prevalence of BPB in the asymptomatic teeth or the teeth with fistula was only 40%. 5. Pe and Pg were detected in the teeth regardless of the presence or absence of symptoms. 6. Td was detected in the teeth regardless of the presence or absence of symptoms. High prevalence of BPB in the symptomatic teeth but low in the asymptomatic teeth suggests that BPB may play an important role in the pathogenesis of periapical lesions.

• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.249-255
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• 2002

Zea Mays L. has been known to be effective for improving tissue health and Magnoliae cortex to have effective antibacterial and antimicrobial activity against pathogenic microbes. The purpose of this study was to examine the antimicrobial effects of Zea Mays L. and Magnoliae cortex extract mixtures on periodontal pathogens(Prevotella intermedia, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Streptococcus mutans )and to examine the effects on human gingival fibroblast cellular activity. Zea Mays L. and Magnoliae cortex extracts and their mixtures were prepared with various mixing ratios (0.5:1, 1:1, 1.5:1, 2:1). These extracts were loaded to periodontal pathogen cultured petri dish for antimicrobial test and also loaded to cultured human gingival fibroblast for cellular activity test. Each test was repeated 3 times and data were analyzed by one-way ANOVA with 95% confidence level. Mixture of these two extracts showed greater amount of inhibition area on periodontal pathogen and more improved gingival fibroblast activity as Zea Mays L. ratio reduced. So, mixture ratio 0.5:1 (Zea Mays L. : Magnoliae cortex) group showed statistical significance in antimicrobial activity and cellular activity among various mixtures(p < 0.05). In conclusion, 0.5:1 (Zea Mays L. : Magnoliae cortex) mixture possessed best gingival fibroblast cellular activity and antimicrobial activity toward periodontal pathogens.

• Journal of Periodontal and Implant Science
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• v.40 no.2
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• pp.61-68
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• 2010

Purpose: The present study was performed to clarify the relationship between periodontal disease severity and selected immunological parameters consisting of serum IgG titer against periodontopathogenic bacteria, the expression of the helper T-cell cytokine by gingival mononuclear cells, and patients' immunoreactivity to cross-reactive heat shock protein (HSP) epitope peptide from P. gingivalis HSP60. Methods: Twenty-five patients with moderate periodontitis had their gingival connective tissue harvested of gingival mononuclear cells during an open flap debridement procedure and peripheral blood was drawn by venipuncture to collect serum. The mean level of interproximal alveolar bone was calculated to be used as an index for periodontal disease severity for a given patient. Each of selected immunologic parameters was subject to statistical management to seek their correlations with the severity of periodontal disease. Results: A significant correlation could not be identified between serum IgG titers against specific bacteria (Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, and Streptococcus mutans) and the severity of periodontal disease. Expression of interleukin (IL)-10 by gingival mononuclear cells was statistically significant in the group of patients who had higher levels of alveolar bone height. However, a similar correlation could not be demonstrated in cases for IL-4 or interferon-$\gamma$. Patients' serum reactivity to cross-reactive epitope peptide showed a significant correlation with the amount of alveolar bone. Conclusions: It was concluded that expression of IL-10 by gingival mononuclear cells and patients' sero-reactivity to the cross-reactive HSP peptide of P. gingivalis HSP60 were significantly correlated with alveolar bone height.

• Journal of Periodontal and Implant Science
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• v.35 no.2
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• pp.401-411
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• 2005

The aim of this study was to determine the minimal inhibitory concentration(MIC) of cefixime, which is a 3rd generation of cefalosporin, against 6 species of putative periodontopathogens; Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, Prevotella intermedia, Prevotella nigrescens, Tannerella forsythia and Porphyromonas gingivalis. The efficacy of cefixime was examined by comparing it with that of several antibiotics(amoxicillin, $Augmentin^{(R)}$ ciprofloxacin, metronidazole, and tetracycline), which were used as the control. The MIC was measured using a microdilution method. The MIC of cefixime against the putative periodotopathogens, as a single use regimen, was relatively lower than that of the other antibiotics. The MIC of cefixime/metronidazole against P. intermedia ChDC KB14, P. nigrescens ChDC KB50, F. nucleatum ChDC PV-F37, F. nucleatum ChDC F130, and F. nucleatum ChDC F175, as a simultaneous regimen, was lower than that of the other antibiotics. The concentration of cefixime in the crevicular fluid of volunteers who received 250mg every 12 hours for 3 days was $9{\mu}g/ml$ after 9 hours. In conclusion, cefixime showed good antimicrobial activity in a single treatment or as a combined therapy with amoxicillin, $Augmentin^{(R)}$ or metronidazole against 6 periodontopathogens.