• International Journal of Clinical Preventive Dentistry
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• v.14 no.4
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• pp.264-270
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• 2018

Objective: This study performed a quantitative analysis using the real-time polymerase chain reaction technique to examine the oral microbial prevalence in adults and intended to examine the correlations between risk factors of periodontal disease and oral bacteria and correlation between oral test scores and oral microorganisms. Methods: We examined papillary marginal attached (PMA) index, modified patient hygiene performance (M-PHP) index, probing depth (PD), modified gingival index, and oral bacteria counts and surveyed 117, 20 years or older adult males and females who visited dental clinics in the Daejeon region to analyze the prevalence and oral health. Results: The prevalence was 100% for Fusobacterium nucleatum, meaning it was observed in all examined subject, 85.5% for Parvimonas micra, 76.1% for Prevotella intermedia, and 72.6% for Tannerella forsythia. The averages of P. gingivalis and T. forsythia increased as the examined subjects were older, and there was a statistically significant difference between T. forsythia and E. nodatum in relation to medical history, between P. intermedia and P. micra in relation to gender, and between P. intermedia and E. corrodens in relation to smoking (p<0.05). For a correlation between the oral test scores and oral microorganisms, P. gingivalis and F. nucleatum was highly correlated with PD (correlation coefficient of 0.51 and 0.41) (p<0.01) while P. gingivalis, P. micra, C. rectus, and E. nodatum were significantly correlated with M-PHP index, gingival index, PD, and PMA index (p<0.01, p<0.05). Conclusion: For oral health management of adults, the age, systemic disease, and smoking are closely related to oral bacteria, and P. gingivalis, T. forsythia, F. nucleatum, P. intermedia, P. micra, C. rectus, E. corrodens, and E. nodatum are considered to be the oral microorganisms that indicate periodontal health.

• International Journal of Oral Biology
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• v.45 no.4
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• pp.204-210
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• 2020

Excessive intake of sodium caused by high salt diet promotes the expression of inflammatory cytokines and differentiation of helper T cells resulting in inflammatory responses. High-glucose diet also contributes to the pathogenesis of periodontitis by inducing changes in the oral microbiome and reducing salivation. However, the effect of a high-salt and glucose diet (HSGD) on the prognosis of periodontitis remains unclear. In this study, a rat model of experimental periodontitis was established by periodic insertion of absorbable sutures containing Porphyromonas gingivalis and Fusobacterium nucleatum strains into the right gingival sulcus to analyze the effect of HSGD on the incidence and progression of periodontitis. The alveolar bone heights (ABH) was measured with microcomputed tomography imaging of the HSGD- and general diet (GD)-treated groups. The right ABH was significantly decreased compared to the left in both groups at 4 weeks after induction of inflammation; however, no significant difference was noted between the groups. Notably, the ABH in the HSGD-treated group was significantly decreased at 8 weeks after induction of inflammation, whereas in the GD-treated group, an increase in the ABH was observed; a significant difference of the ABH was noted between the two groups (p < 0.05). At 12 weeks, recovery of the alveolar bone was observed in both groups, with no significant differences in ABH between the two groups. These findings indicate that the intake of excessive sodium attenuates the recovery rate of the alveolar bone even after the local infectant is removed. In addition, this study demonstrates the use of HSGD in establishing a new animal model of periodontitis.

• Journal of dental hygiene science
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• v.22 no.2
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• pp.99-107
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• 2022

Background: Obesity weakens acquired immunity and causes infection. This study aimed to investigate the relationship between the inflammatory markers in the gingival crevicular fluid and serum and periodontal bacteria in saliva through obesity control for 4 weeks. Methods: Forty-six subjects with a body mass index (BMI) of ≥23 kg/m² stayed in the camp for 4 weeks, followed by exercise and a low salt-low fat diet. Body size measurements, oral examinations, blood, saliva, and gingival crevicular fluid were collected before and after the program. C-reactive protein (CRP) in serum, matrix metalloproteinase (MMP)-8, MMP-9, and interleukin (IL)-1β in the gingival sulcus fluid were measured. After extracting bacterial genomic DNA from saliva, the presence of periodontal bacteria were detected using Taq probe. The relationship of each index before and after the program was analyzed through paired t-test and partial correlation analysis. Results: Campylobacter rectus (Cr) increased after the program, and there was no significant change in other bacteria. Serum CRP and Fusobacterium nucleatum (Fn), Aggregatibacter actinomycetemcomitans, Cr, ratio of Fn, and ratio of Cr had a positive relationship at baseline; however, the relationship was not significant after the program. Ratio of Prevotella intermedia had a positive relationship with MMP-9, MMP-8, IL-1β at baseline. Moreover, the ratio of Treponema denticola and the ratio of Tannerella forsythia showed a positive relationship with MMP-8, MMP-9, and IL-1β. The relationship between the ratio of Porphyromonas gingivalis and IL-1β showed a constant positive relationship at baseline and after the program. Conclusion: Obesity control program in subjects with a BMI of ≥23 kg/m² accompanied by diet and exercise did not affect the changes in periodontal bacteria itself, but changes in the relationship between periodontal bacteria and serum CRP, the relationship between the inflammatory index in the gingival crevicular fluid and periodontal bacteria was observed.

• 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 Periodontal and Implant Science
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• v.52 no.1
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• pp.77-87
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• 2022

Purpose: This pilot study assessed the immediate in vivo effect of high peak pulse power neodymium-doped yttrium aluminum garnet (Nd:YAG) laser monotherapy on selected red/orange complex periodontal pathogens in deep human periodontal pockets. Methods: Twelve adults with severe periodontitis were treated with the Laser-Assisted New Attachment Procedure (LANAP®) surgical protocol, wherein a free-running, digitally pulsed, Nd:YAG dental laser was used as the initial therapeutic step before mechanical root debridement. Using a flexible optical fiber in a handpiece, Nd:YAG laser energy, at a density of 196 J/cm² and a high peak pulse power of 1,333 W/pulse, was directed parallel to untreated tooth root surfaces in sequential coronal-apical passes to clinical periodontal probing depths, for a total applied energy dose of approximately 8-12 joules per millimeter of periodontal probing depth at each periodontal site. Subgingival biofilm specimens were collected from each patient before and immediately after Nd:YAG laser monotherapy from periodontal pockets exhibiting ≥6 mm probing depths and bleeding on probing. Selected red/orange complex periodontal pathogens (Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia/nigrescens, Fusobacterium nucleatum, Parvimonas micra, and Campylobacter species) were quantified in the subgingival samples using established anaerobic culture techniques. Results: All immediate post-treatment subgingival biofilm specimens continued to yield microbial growth after Nd:YAG laser monotherapy. The mean levels of total cultivable red/orange complex periodontal pathogens per patient significantly decreased from 12.0% pretreatment to 4.9% (a 59.2% decrease) immediately after Nd:YAG laser monotherapy, with 3 (25%) patients rendered culture-negative for all evaluated red/orange complex periodontal pathogens. Conclusions: High peak pulse power Nd:YAG laser monotherapy, used as the initial step in the LANAP® surgical protocol on mature subgingival biofilms, immediately induced significant reductions of nearly 60% in the mean total cultivable red/orange complex periodontal pathogen proportions per patient prior to mechanical root instrumentation and the rest of the LANAP® surgical protocol.

• Journal of Periodontal and Implant Science
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• v.52 no.2
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• pp.141-154
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• 2022

Purpose: C57BL/6 mice, which are among the most common backgrounds for genetically engineered mice, are resistant to the induction of periodontitis by oral infection with periodontal pathogens. This study aimed to develop a periodontitis model in C57BL/6 mice using coaggregation between human pathogens and the mouse oral commensal Streptococcus danieliae (Sd). Methods: The abilities of Porphyromonas gingivalis ATCC 33277 (Pg33277), P. gingivalis ATCC 49417 (Pg49417), P. gingivalis KUMC-P4 (PgP4), Fusobacterium nucleatum subsp. nucleatum ATCC 25586 (Fnn), and F. nucleatum subsp. animalis KCOM 1280 (Fna) to coaggregate with Sd were tested by a sedimentation assay. The Sd-noncoaggregating Pg33277 and 2 Sd-coaggregating strains, PgP4 and Fna, were chosen for animal experiments. Eighty C57BL/6 mice received oral gavage with Sd once and subsequently received vehicle alone (sham), Fna, Pg33277, PgP4, or Fna+PgP4 6 times at 2-day intervals. Mice were evaluated at 5 or 8 weeks after the first gavage of human strains. Results: Fnn, Fna, and PgP4 efficiently coaggregated with Sd, but Pg33277 and Pg49417 did not. Alveolar bone loss was significantly higher in the PgP4 group at both time points (weeks 5 and 8) and in all experimental groups at week 8 compared with the sham group. The PgP4 group presented greater alveolar bone loss than the other experimental groups at both time points. A higher degree of alveolar bone loss accompanied higher bacterial loads in the oral cavity, the invasion of not only PgP4 but also Sd and Fna, and the serum antibody responses to these bacteria. Conclusions: Periodontitis was successfully induced in C57BL/6 mice by oral infection with a P. gingivalis strain that persists in the oral cavity through coaggregation with a mouse oral commensal bacterium. This new model will be useful for studying the role of human oral bacteria-host interactions in periodontitis using genetically engineered mice.

• Journal of Periodontal and Implant Science
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• v.51 no.6
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• pp.409-421
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• 2021

Purpose: The aim of this study was to compare the prevalence and bacterial load of 6 main periodontal pathogens between pairs of periodontal patients with and without type 2 diabetes mellitus. Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans genotypes were also investigated. Methods: Twenty patients affected by chronic periodontitis and type 2 diabetes were retrospectively selected and matched to 20 patients without diabetes on the basis of the degree and severity of periodontal disease. Microbiological data of subgingival biofilms were analysed and compared for the examined pathogens: A. actinomycetemcomitans, P. gingivalis, Prevotella intermedia, Treponema denticola, Fusobacterium nucleatum, and Tannerella forsythia. Results: The pairs were balanced in terms of demographic and clinical parameters, except for bleeding on probing and suppuration. In the microbiological test sites (4 for each patient), the mean probing pocket depth was 6.34±1.63 mm in patients with diabetes and 6.41±1.78 mm in patients without diabetes. No significant difference between pairs in the prevalence of P. gingivalis or the distribution of its genotypes was recorded. Patients with diabetes had a significantly greater amount of total bacterial load, P. gingivalis, T. denticola, T. forsythia, and F. nucleatum (P<0.05). Moreover, patients with diabetes had a higher number of sites with a greater cell count than patients without diabetes. When compared to the total bacterial load, only T. forsythia maintained its relative load in patients with diabetes (P=0.001). Conclusions: This retrospective matched study supports the hypothesis that microbiological differences exist among periodontal patients with and without diabetes mellitus.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.97-102
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• 2022

In this study, the antibacterial effect of silkworm extract and Momordica charantia extract on S. mutans and F. nucleatum was investigated. S. mutans or F. nucleatum and 0%, 2%, 4%, 8% concentration of silkworm powder or Momordica charantia powder extract were added to the BHI liquid medium and cultured, and the sample was measured at an optical density of 600nm. As a result, S. mutans, the absorbance value was significantly decreased only in 8% of the silkworm extract, and the absorbance value was significantly decreased in all concentrations in the Momordica charantia extract. The absorbance of F. nucleatum was significantly decreased in a concentration-dependent manner in both the silkworm extract and the Momordica charantia extract. This suggests the possibility that silkworm extract and Momordica charantia extract can be used as materials for the prevention and treatment of oral diseases.

• Journal of Periodontal and Implant Science
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• v.53 no.2
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• pp.110-119
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• 2023

Purpose: This study aimed to investigate the proper wavelengths for safe levels of light-emitting diode (LED) irradiation with bactericidal and photobiomodulation effects in vitro. Methods: Cell viability tests of fibroblasts and osteoblasts after LED irradiation at 470, 525, 590, 630, and 850 nm were performed using the thiazolyl blue tetrazolium bromide assay. The bactericidal effect of 470-nm LED irradiation was analyzed with Streptococcus gordonii, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, and Tannerella forsythia. Levels of nitric oxide, a proinflammatory mediator, were measured to identify the anti-inflammatory effect of LED irradiation on lipopolysaccharide-stimulated inflammation in RAW 264.7 macrophages. Results: LED irradiation at wavelengths of 470, 525, 590, 630, and 850 nm showed no cytotoxic effect on fibroblasts and osteoblasts. LED irradiation at 630 and 850 nm led to fibroblast proliferation compared to no LED irradiation. LED irradiation at 470 nm resulted in bactericidal effects on S. gordonii, A. actinomycetemcomitans, F. nucleatum, P. gingivalis, and T. forsythia. Lipopolysaccharide (LPS)-induced RAW 264.7 inflammation was reduced by irradiation with 525-nm LED before LPS treatment and irradiation with 630-nm LED after LPS treatment; however, the effects were limited. Conclusions: LED irradiation at 470 nm showed bactericidal effects, while LED irradiation at 525 and 630 nm showed preventive and treatment effects on LPS-induced RAW 264.7 inflammation. The application of LED irradiation has potential as an adjuvant in periodontal therapy, although further investigations should be performed in vivo.

• Journal of Oral Medicine and Pain
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• v.47 no.1
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• pp.10-26
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• 2022

Purpose: The purpose of this study was to investigate whether various saliva collection methods affect the observed salivary microbiome and whether microbiomes of stimulated and unstimulated saliva and plaque differ in richness and diversity. Methods: Seven sampling methods for unstimulated saliva, stimulated saliva, and plaque samples were applied to six orally and systemically healthy participants. Bacterial 16S ribosomal RNA genes of 10 major oral bacterial species, namely, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Prevotella intermedia, Prevotella nigrescens, Streptococcus mitis, Streptococcus sobrinus, and Lactobacillus casei, were analyzed by real-time polymerase chain reaction. We comprehensively examined the dependence of the amount of bacterial ribosomal DNA (rDNA), bacterial-community composition, and relative abundance of each species on sample collection methods. Results: There were significant differences in the bacterial rDNA copy number depending on the collection method in three species: F. nucleatum, P. nigrescens, and S. mitis. The species with the highest richness was S. mitis, with the range from 89.31% to 100.00%, followed by F. nucleatum, P. nigrescens, T. denticola, T. forsythia, and P. intermedia, and the sum of the proportions of the remaining five species was less than 1%. The species with the lowest observed richness was P. gingivalis (<0.1%). The Shannon diversity index was the highest in unstimulated saliva collected with a funnel (4.449). The Shannon diversity index was higher in plaque samples (3.623) than in unstimulated (3.171) and stimulated (3.129) saliva and in mouthwash saliva samples (2.061). Conclusions: The oral microbial profile of saliva samples can be affected by sample collection methods, and saliva differs from plaque in the microbiome. An easy and rapid technique for saliva collection is desirable; however, observed microbial-community composition may more accurately reflect the actual microbiome when unstimulated saliva is assayed.