• Journal of Korean society of Dental Hygiene
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• v.20 no.5
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• pp.743-752
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• 2020

Objectives: The objectives of this study were to investigate the distribution and level of periodontopathic bacteria with the general characteristics and oral health condition of the elderly. Methods: A total of 335 elderly individuals aged 65 years or older who lived in Ganghwa-gun, Incheon, were included in the study. Oral examination, investigation through a questionnaire, and collection of saliva were carried out. The collected saliva was analyzed for the distribution and levels of bacteria (red and orange complex bacteria) by real-time polymerase chain reaction. Statistical analyses were performed using chi-square test, t-test, one-way analysis of variance, and Pearson's correlation coefficient with SAS statistical software version 9.4. Results: Among the general characteristics, there were significant differences in the distribution of Porphyromonas gingivalis, Treponema denticola, and Parvimonas micra depending on sex, age, and dental visits (p<0.05). The number of remaining teeth and denture use were related to the distribution of periodontopathic bacteria, except T. denticola (p<0.05). Additionally, periodontitis was related to the distribution of P. gingivalis (p<0.05). As the number of remaining teeth increased, the copy number of red and orange complex bacteria also increased (p<0.05). Those individuals who did not use dentures and had periodontal disease had more periodontopathic bacteria (p<0.05). Conclusions: The distribution and copy number of periodontopathic bacteria in the elderly were more related to oral health condition than to general characteristics. In particular, the distribution and copy number of periodontopathic bacteria were higher in subjects with multiple remaining teeth, no dentures, and periodontal disease.

• Journal of Periodontal and Implant Science
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• v.34 no.2
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• pp.243-253
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• 2004

최근의 레이저 기술의 발전은 치의화영역에서 많은 가능성을 제시해 주고 있으며, 레이저를 이용한 외과적 치료의 기전과 안전성은 많은 분야에서 입증되어 있다. 근래에는 치주학적 분야에도 레이저를 적용하려는 노력이 계속되어 왔으며, 치석의 제거나 치근면의 세균제거 등에서 효과를 제시한 연구들이 있었다. 본 연구의 목적은 $CO_2$ 레이저를 통상적 치은연하소파술과 병용하였을때의 임상적 효과를 임상 지수의 측정을 통하여 평가하는 것이다. 만성 중둥도-고도의 치주염으로 진단된 12명의 환자가 본 임상연구에 포함되었다. 한 환자에서 각각 2부위의 사분악을 선택하여 임의로 2가지 치료군에 다음과 같이 나누어 포함시켰다: 1) 치은연하 소파술만을 적용한 사분악을 대조군 2) 치은연하 소파술과 0.8W의 에너지 수준을 갖는 $CO_2$ 레이저를 병용하여 적용한 사분악을 Laser 군으로 포함하였다. 치주낭 탐침 깊이, 임상 부착 수준, 치은 퇴축 및 탐침시 출혈풍의 임상지수를 치료전과 술후 각각 1, 3, 6개월 경과시에 측정하여 다음과 같은 결과를 얻었다. 치주낭 탐침 깊이, 임상 부착 수준, 치은 퇴축 및 탐침시 출혈 등의 모든 측정한 임상지수에서 치료전 ${\cdot}$ 후를 비교하였을 때 통계적으로 유의한 개선을 보였다. 그러나 실험군과 대조군간의 비교에서는 치주낭 탐침 깊이, 임상 부착 수준에서는 통계적으로 유의한 차이를 보이지 않았다. 탐침시 출혈은 술후 6개월시에 Laser군에서 대조군에 비하여 통계적으로 유의성있는 차이를 보이며 감소하였다(p<0.05). 결론적으로 $CO_2$ laser를 비외과적 치주 치료에 부가적으로 적용하였을 때 염증 감소에 기여할 가능성이 있을 것으로 사료된다.

• Journal of Periodontal and Implant Science
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• v.28 no.4
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• pp.659-678
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• 1998

In the present study, oligonucleotide probes based on 16S rRNA were taken to investigate the diversity of oral spirochetes without culture method. This is the first study that revealed oral spirochetes of both presently cultivable and uncultured oral spirochetes in Korean adult periodontitis patients. Subgingival plaque samples were taken from diseased sites(probing depth ${\geq}6\;mm$, experimental group, n=116) and healthy sites(probing depth${\leq}3mm$, control 1 group, n=28) in 29 patients with adult periodontitis, and from 20 periodontally healthy subjects(probing depth${\leq}3mm$, control 2 group, n=100). Following being examined under phase-contrast microscope, all samples were submitted to dot-blot hybridization after polymerase chain reacton with eubacterial primers. 5 species-specific probes(TVIN, TDEN, TMAL, TSOC, and TPEC) and 7 group-specific probes(TRE I, TRE II, TRE III, TRE IV, TRE V, TRE VI, and TRE VII) were used one by one for the identification of both cultivable and so far uncultivable oral spirochetes. All probes were labeled with digoxigenin(DIG)-ddUTP and detected by chemilumininescence. The following results were obtained. 1. Under phase-contrast microscope, 91.37% and 14.28% of oral spirochetes were observed in the experimental and control 1 groups, respectively. None of oral spirochetes were observed in control 2 group. 2. With universal probe, 98.27%, 46.42%, and 22.0% of oral spirochetes were observed in experimental, control 1, and control 2 groups, respectively. 3. With specific probe, 95.68%, 35.71%, and 19.0% of oral spirochetes were observed in experimental, control 1, and control 2 groups, respectively. 4. With species-specific probes, T. socranskii were recovered in a high percentage of sites(81.89%) examined, followed by T. maltophilum(50.0%), T. vincentii(36.20%), T. denticola(13.79%), respectively. With group- specific probes, TRE IV was recovered in a high percentage of sites(85.34%) examined, followed by TRE II(77.58%), TRE I(56.89%), TRE III(25.86%), TRE VI(5.17%), and TRE V(2.58%), respectively. 5. T. vincentii were only observed in the diseased sites, not in the healthy sites. 6. Neither T. pectinovorum nor group VII oral spirochetes were observed in any sites. The findings warrant further investgations of the recovered spirochetes to elucidate the possible associations of oral spirochetal prevalence in race and types of periodontitis, pathogenesis of T. vincentii and the possible distributional change of oral spirochetes before and after treatments.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.126-128
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• 2017

Cutibacterium acnes (formerly Propionibacterium acnes) is an anaerobic, Gram-positive rod and that is a normal flora of human skin and mucosal surface as well as an opportunistic pathogen related to acnes vulgaris, sarcoidosis, brain abscess, endocarditis, periodontitis, and endodontic infections. C. acnes KCOM 1861 (= ChDC B594) was isolated from a human jaw osteomyelitis lesion. Here, we present the complete genome sequence of C. acnes KCOM 1861.

• The Journal of the Korean Society for Microbiology
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• v.21 no.4
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• pp.487-501
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• 1986

Previous studies from our laboratory suggested that Korean LJP patients might habor A. actinomycetemcomitans of different serotype from Caucasian LJP patients in whom serotype b was predominant. In order to observe the prevalence and serotype distribution of A. actinomycetemcomitans in localized juvenile periodontitis patients and to evaluate leukotoxic activity of oral isolates, this study was performed. A. actinomycetemcomitans was isolated by using a selective medium(tryptic soy agar supplemented with 10% serum, $75{\mu}g$ of bacitracin and $5{\mu}g$ of vancomycin per ml). Using immunoabsorbed, ammonium sulfate-fractionated serotype-specific antisera, a total of 69 strains were serologically categorized by ELISA. Leukotoxicity was monitored biochemically by measuring lactate dehydrogenase indicator of cell viability in culture supernatant of PMNL plus viable A. actinomycetemcomitans mixture. The results were as follows: 1. A. actinomycetemcomitans was detected in 75% of 16 LJP patients, and 71% in the LJP lesions and 6% in the control sites. 2. Presence or absence of A. actinomycetemcomitans in the sampled disease sites has no in fluence on clinical measurements. 3. Three serotypes were approximately equally distributed in overall 9 patients. Three patients harbored 2 different serotypes of A. actinomycetemcomitans in the same disease site or different disease sites. 4. The proportion of leukotoxic oral isolates was 22% of a total of 46 strains and the prevalence was 69% in 13 sampled sites. The same disease site could harbor both leukotoxic and nonleukotoxic strains. 5. Distribution of leukotoxic strains in 3 serotypes were not different.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.691-698
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• 2008

Purpose: Periodontal pathogens can invade the host tissue. Morphologic studies have revealed bacteria within the pocket epithelium, gingival connective tissues, alveolar bone, and oral epithelium. The objective of this study was to visualize and evaluate presence of Porphyromonas gingivalis and Tannerella forsythia in crevicular epithelial cells of periodontally healthy subjects and chronic periodontitis patients. Materials and Methods: A total of 666 crevicular epithelial cells in the samples obtained from 27 chronic periodontitis patients and 9 healthy volunteers were examined. Specific probes for P. gingivalis and T. forsythia and a universal probe for detection of all eubacteria targeting 168 rRNA for fluorescence in situ hybridization was used in conjunction with confocal laser scanning microscopy. Results: 98.99% of sulcular epithelial cells from healthy volunteers and 84.40% of pocket epithelial cells from periodontitis patients were found to harbor bacteria. P. gingivalis and T. forsythia were discovered more often in crevicular epithelial cells from periodontitis patients. Conclusion: P. gingivalis and T. forsythia can invade crevicular epithelial cells and intracellular bacteria may act as a source of bacteria for persistent infection.

• Journal of Periodontal and Implant Science
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• v.30 no.4
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• pp.725-736
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• 2000

It is becoming increasingly apparent that periodontitis consists of mixture of diseases, most of which respond favorably to traditional mechanical therapy. Among these variants of the disease, some appear to be associated with unusual microbial infections and defective host defenses. Many of these fail to respond to conventional treatment. The recognition that some forms of periodontitis are refractory to standard periodontal therapy has given rise to a new classification of peridontitis. A series of 1692 subgingival microbial samples sent to a diagnostic microbiology laboratory included 738 samples that could be identified as compatible with a clinical diagnosis of refractory or recurrent periodontitis. In descending order of prevalence the associated microbiota included Bacteroides forsythus(85%) ,Fusobacterium species(78%), Spirochetes(67%), Campylobacter rectus(64%), Porphyromonas gingivalis(59%), Peptostreptococcus micros(58%), motile rods(46%), Prevotella intermedia(33%), Eikenella corrodens(13%), Capnocytophaga species(12%) ,and Actinobacillus actinomycetemcomitans(6%). Antibiotic resistance to tetracycline, penicillin G, or metronidazole was particularly noticeable for Fusobacterium species, Capnocytophaga species, and Actinobacillus actinomycetemcomitans. It was largely absent for Campylobacter rectus. No antibiotic data were obtained for Porphyromonas gingivalis or Bacteroides forsythus, as these species were detected by immunofluorescence. The results indicate that a substantial number of microorganisms associated with refractory periodontitis are variably resistant to commonly-used antibiotics. Diagnostic microbiology must be considered an essential adjunct to the therapist faced with periodontal lesions refractory to conventional treatment.

• Restorative Dentistry and Endodontics
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• v.30 no.5
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• pp.409-422
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• 2005

The aim of this study was to identify the bacteria isolated from acute endodontic lesions by cell culture and 16S rDNA sequencing. The necrotic pulpal tissue was collected from 17 infected root canals, which were diagnosed as being either an acute pulpitis or acute periapical abscess. Samples were collected aseptically from the infected pulpal tissue of the infected root canals using a barbed broach and a paper point. The cut barbed broaches and paper points were transferred to an eppendorf tube containing 500 ul of 1 XPBS. The sample solution was briefly mixed and plated onto a BHI-agar plate containing $5\%$ sheep blood. The agar plates were incubated in a $37^{\circ}C$ anaerobic chamber for 7 days. The bacteria growing on the agar plate were identified by 16S rRNA coding gene (rDNA) cloning and sequencing at the species level. Among the 71 colonies grown on the agar plates, 56 strains survived and were identified. In dental caries involving the root canals, Streptococcus spp. were mainly isolated. Actinomyces, Clostridia, Bacteroides and Fusobacteria were isolated in the periapical lesion without dental caries. Interestingly, two new Actinomyces spp. (ChDC B639 and ChDC B631) were isolated in this study. These results showed that there was diversity among the species in endodontic lesions, This suggests that an endodontic infection is a mixed infection with a polymicrobial etiology. These results may offer the bacterial strains for pathogenesis studies related to an endodontic infection.

• Journal of dental hygiene science
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• v.9 no.2
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• pp.249-255
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• 2009

This study was carried out for the purpose of comparing bacterial culture method, single PCR, and multiplex PCR for identification of F. nucleatum and A. actinomycetemcomitans in subgingival plaque of adult periodontitis. Targeting 20 patients with adult periodontitis, the subgingival plaque was collected in teeth, respectively, for #16, #36, #44. A bacillus was cultivated by painting it over the solid selective media of F. nucleatum and A. actinomycetemcomitans. Bacterial species were detected in 0 tooth with 12 pieces, respectively. Through single PCR and multiplex PCR, the positive reaction was indicated in 43 teeth with 45 pieces, respectively, as for F. nucleatum, and in 1 tooth with 4 pieces, respectively, as for A. actinomycetemcomitans. In the comparative analysis between bacterial identification methods. F. nucleatum showed the more statistically significant difference(p=0.0(0) in comparison between single PCR and multiplex PCR. Even A. actinomycetemcomitans was indicated significantly(p=0.067) in a case that is based on 0.1 in significant level in the comparison between single PCR and multiplex PCR. In conclusion, as a result of comparing the bacterial identification methods, the detection frequency was indicated to be higher in PCR than in bacterial culture method. Single PCR and multiplex PCR showed the mutually similar detection frequency. Accordingly, given thinking of economic efficiency, quickness, and reduction in labor force, it is thought to be more efficient method to use single PCR as the bacterial identification method.

• Journal of Periodontal and Implant Science
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• v.33 no.2
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• pp.247-257
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• 2003

The purpose of this study was to evaluate the difference of subgingival bacterial compositions between periodontally healthy and diseased sites. Subgingival plaque samples were obtained from 100 sites in 20 untreated adult periodontitis patients(experimental group), and 100 sites in healthy individuals(contro1 group). Before sampling, probing pocket depth(PPD) and clinical level of attachment(CAL), Plaque Index(PI), and Sulcus Bleeding Index(SBI) were recorded for each sampled sites. Microbial samples were collected from the bases of gingival sulci or periodontal pockets with sterile curettes. The samples were examined under darkfield microscope(${\times}$400). At least 150 bacteria were evaluated and categorized on the basis of bacterial morphology and motility, i.e. cocci, non-motile rods, motile rods, and spirochetes. In control group, subgingival microbial flora consisted of 73.7% of cocci, 20.0% of non-motile rods, 4.3% of motile rods, and 2.0% of spirochetes. The microbial samples from experimental group consisted of 51.5% of cocci, 19.4% of non-motile rods, 17.6% of motile rods, and 11.6% of spirochetes. The proportion of cocci was higher in control group than in experimental group. Proportions of motile rods and spirochetes were higher in experimental group than in control group. The proportion of nonmotile rods in experimental group and control group was not significantly different. Sulcus Bleeding Index and Plaque Index showed high correlation with the bacterial composition. These findings suggests that examination of subgingival bacterial proportion may serve as more sensitive mirror of the local periodontal status than clinical parameters.