• International Journal of Oral Biology
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• v.46 no.3
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• pp.111-118
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• 2021

Periodontitis and periimplantitis are caused as a result of dental biofilm formation. This biofilm is composed of multiple species of pathogens. Therefore, controlling biofilm formation is critical for disease prevention. To inhibit biofilm formation, sugars can be used to interrupt lectin-involving interactions between bacteria or between bacteria and a host. In this study, we evaluated the effect of D-Arabinose on biofilm formation of putative periodontal pathogens as well as the quorum sensing activity and whole protein profiles of the pathogens. Crystal violet staining, confocal laser scanning microscopy, and scanning electron microscopy revealed that D-Arabinose inhibited biofilm formation of Porphyromonas gingivalis, Fusobacterium nucleatum, and Tannerella forsythia. D-Arabinose also significantly inhibited the activity of autoinducer 2 of F. nucleatum and the expression of representative bacterial virulence genes. Furthermore, D-Arabinose treatment altered the expression of some bacterial proteins. These results demonstrate that D-Arabinose can be used as an antibiofilm agent for the prevention of periodontal infections.

• Journal of Korean Academy of Dental Administration
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• v.10 no.1
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• pp.42-52
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• 2022

This study aimed to investigate the association of lifestyle with the copy number of periodontal pathogens. This retrospective study collected electronic health records of 102 subjects with periodontitis, including reports of bacterial genetic tests and lifestyle questionnaires. The five pathogens were analyzed as follows: Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, and Fusobacterium nucleatum. The lifestyle questionnaire included age, sex, oral hygiene management, smoking, drinking, exercise, dietary, snacks, water intake, and sleeping time. An independent t-test or ANOVA was performed to compare the copy number of periodontal pathogens according to lifestyle (α=0.05). The copy numbers of P. gingivalis and F. nucleatum were significantly higher than those of other strains. The copy number of T. forsythia in patients who exercised was 54% lower than in those who did not (p=0.009). Other lifestyle factors did not affect the number of bacteria. Exercise habits among the lifestyles showed a association with the number of specific oral bacteria. This result suggests that a lifestyle questionnaire is essential in clinical situation and necessary to prevent and treat the periodontal disease effectively.

• Journal of Korean society of Dental Hygiene
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• v.17 no.1
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• pp.77-87
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• 2017

Objectives: This study attempted to provide basic data necessary for a prevention promotion program for oral health management in college students. Methods: This study investigated general characteristics and subjective periodontal health status using a structured questionnaire and examined the distribution of bacteria related to periodontal disease in oral cavity by real-time PCR in subjects composed of 57 male and female college students. Results: It was statistically significant that P. gingivalis was detected more frequently in smokers with 25% compared to non-smokers with 6.1%, not detected in subjects that engaged in tooth brushing more than three times a day, and was detected in subjects that engaged in tooth brushing fewer than three times a day with 21.1%. Pathogens in saliva had significant correlations with each other (p<0.05, p<0.01, p<0.001). P. gingivalis showed positive correlations with T. forsythia, T. denticola, P. intermedia, and A. actinomycetemocmitans, and T. forsythia with P. intermedia, and A. actinomycetemocmitans. P. intermedia had a positive correlation with A. actinomycetemocmitans, and F. nucleatum with P. intermedia. Conclusions: Bacteria related to periodontal disease in oral cavities in college students were distributed in various ways, and smoking and the frequency of daily toothbrushing were found to be risk factors for the detection of bacteria.

• International Journal of Oral Biology
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• v.39 no.2
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• pp.115-120
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• 2014

Minimal inhibitory concentration (MIC) is the lowest concentration of antibiotics that inhibits the visible growth of a microorganism. It has been reported that sub-MIC of antibiotics may result in morphological alterations along with biochemical and physiological changes in bacteria. The purpose of this study was to examine morphological changes of periodontal pathogens after treatment with sub-MIC antibiotics. Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis were used in this study. The MIC for amoxicillin, doxycycline, metronidazole, penicillin, and tetracycline were determined by broth dilution method. The bacterial morphology was observed with bright field microscope after incubating with sub-MIC antibiotics. The length of A. actinomycetemcomitans and F. nucleatum were increased after incubation with metronidazole; penicillin and amoxicillin. P. gingivalis were increased after incubating with metronidazole and penicillin. However, F. nucleatum showed decreased length after incubation with doxycycline and tetracycline. In this study, we observed that sub-MIC antibiotics can affect the morphology of periodontal pathogens.

• Journal of Periodontal and Implant Science
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• v.43 no.1
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• pp.3-11
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• 2013

Periodontitis is a chronic inflammation of periodontal tissue caused by subgingival plaque-associated bacteria. Periodontitis has long been understood to be the result of an excessive host response to plaque bacteria. In addition, periodontal pathogens have been regarded as the causative agents that induce a hyperinflammatory response from the host. In this brief review, host-microbe interaction of nonperiodontopathic versus periodontopathic bacteria with innate immune components encountered in the gingival sulcus will be described. In particular, we will describe the susceptibility of these microbes to antimicrobial peptides (AMPs) and phagocytosis by neutrophils, the induction of tissue-destructive mediators from neutrophils, the induction of AMPs and interleukin (IL)-8 from gingival epithelial cells, and the pattern recognition receptors that mediate the regulation of AMPs and IL-8 in gingival epithelial cells. This review indicates that true periodontal pathogens are poor activators/suppressors of a host immune response, and they evade host defense mechanisms.

• Journal of Korean society of Dental Hygiene
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• v.24 no.2
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• pp.91-98
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• 2024

Objectives: This case study aimed to evaluate changes in periodontal pathogens and systemic disease indicators following the adjunctive use of probiotics for periodontal treatment. Methods: Two adults, a 64-year-old male and 71-year-old female, were selected with ethical approval and underwent comprehensive oral and systemic health assessments before and after probiotic intake with periodontal debridement. Results: There was a significant reduction in the periodontal pathogens, particularly Porphyromonas gingivalis and Treponema forsythia, and no adverse systemic indicators were observed. Moreover, a trend toward improved lipid profiles was noted, suggesting a potential positive impact on systemic health. Conclusions: This study shows the potential role of probiotics in enhancing oral health and preventing systemic diseases, thus highlighting the need for further research and clinical trials.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.1
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• pp.8-16
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• 2016

Early colonization of periodontal pathogens has been related as a risk indicator for the subsequent development of periodontal disease. Such colonization can be easily detected with mediums like saliva and plaque. This study aimed to evaluate the prevalence of the bacteria associated with periodontal disease in saliva and plaque in healthy children and adolescents. The experiment was conducted using 90 samples from subjects consisting of thirty elementary school students, thirty high school students and thirty adults. PCR was used to detect the prevalence and distribution of five periodontal pathogens in the collected saliva and plaque. The detected periodontal pathogens are as follows: A. actinomycetemcomitans, P. gingivalis, T. forsythia, F. nucleatum and P. intermedia. Periodontal pathogens were prevailed in a higher number of adolescents than the number of children. A. actinomycetemcomitans and P. intermedia were detected the most in the adolescents group. T. forsythia and F. nucleatum were detected the most in the children group. The overall result showed that saliva is more a useful medium than supragingival plaque. The detection of high risk periodontal pathogens in children and adolescents without clinical signs of periodontal disease can emphasize the importance of the early diagnosis and preventive approach.

• International Journal of Oral Biology
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• v.43 no.4
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• pp.171-175
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• 2018

Quorum sensing (QS) is a cell density-dependent communication mechanism between bacteria through small signaling molecules. When the number of QS signaling molecules reaches a threshold, they are transported back into the cells or recognized by membrane-bound receptors, triggering gene expression which affects various phenotypes including bioluminescence, virulence, adhesion, and biofilm formation. These phenotypes are beneficial for bacterial survival in harsh environments. This review summarizes the application of QS inhibitors for control of biofilm formation and virulence expression of periodontal pathogens.

• International Journal of Oral Biology
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• v.43 no.4
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• pp.193-200
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• 2018

The purpose of this study is to determine if natural extracts could be used as an additive in oral health food made with Weissella cibaria CMU (oraCMU). Natural extracts of green tea, mulberry leaf, licorice, and propolis, which are reported to have antimicrobial activities, were selected and used in this study. The minimum inhibitory concentrations (MIC) of extracts on periodontal pathogens such as Fusobacterium nucleatum and Porphyromonas gingivalis and their synergy effects with oraCMU by the fractional inhibitory concentrations methods were measured. From the results obtained, all the extracts showed no effect on the growth of oraCMU. Green tea extract showed the best antibacterial activity with MIC of 1.8 mg/ml against both F. nucleatum and P. gingivalis. In addition, green tea extract had a synergistic effect with oraCMU against F. nucleatum. Therefore, these results suggested that green tea extract is available as an additive in oral health food made with oraCMU.

• Journal of Periodontal and Implant Science
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• v.33 no.2
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• pp.159-166
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• 2003

The purpose of this study was to investigate and compare the frequence of 4 periodontal pathogens in the supra- and subgingival plaque in periodontally healthy subjects. Twenty adult individuals aged 22 to 28 years (mean age 23.65 years) participated in this study. All subjects had no pocket sites more than 3 mm deep, and the sites selected for sampling were all negative for bleeding. After drying and isolation of the sites with cotton rolls, supragingival plaque was sampled using sterile periodontal curette. Each plaque sample was placed in individual tubes containing 500 ml of 1X PBS. After removal of the supragingival sample and any remaining supragingival plaque, subgingival plaque samples were taken from the same sites using sterile curette and placed in similar individual tubes. Identification of 4 putative periodontal pathogens from the samples was performed by polymerase chain reaction based on 16S rDNA. Chi-square test was employed to identify significant explanatory variables for the presence of the 4 periodontal pathogens. The data show that Actinobacillus actinmycetemcomitans, Porphyromonanas gingivalis, Bacteroides forsythus, and Fusobacterium nucleatum occurred in 16.9%, 14.4%, 52.5%, and 80.6%, respectively. No significant differences were noted in the periodontal pathogens between supra- and subgingival plaques according to the kind of teeth. However, the incisors were at higher risk for harboring F. nucleatum (p <0.05). Conclusion: These results reveal that anaerobic periodontal pathogens can be detected in supragingival plaques. Supragingival plaque may function as a reservoir of peri-odotopathogens.