• Journal of Periodontal and Implant Science
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• v.43 no.2
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• pp.72-78
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• 2013

Purpose: The purpose of this study was to compare the phototoxic effects of blue light exposure on periodontal pathogens in both planktonic and biofilm cultures. Methods: Strains of Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis, in planktonic or biofilm states, were exposed to visible light at wavelengths of 400.520 nm. A quartz-tungsten-halogen lamp at a power density of $500mW/cm^2$ was used for the light source. Each sample was exposed to 15, 30, 60, 90, or 120 seconds of each bacterial strain in the planktonic or biofilm state. Confocal scanning laser microscopy (CSLM) was used to observe the distribution of live/dead bacterial cells in biofilms. After light exposure, the bacterial killing rates were calculated from colony forming unit (CFU) counts. Results: CLSM images that were obtained from biofilms showed a mixture of dead and live bacterial cells extending to a depth of $30-45{\mu}m$. Obvious differences in the live-to-dead bacterial cell ratio were found in P. gingivalis biofilm according to light exposure time. In the planktonic state, almost all bacteria were killed with 60 seconds of light exposure to F. nucleatum (99.1%) and with 15 seconds to P. gingivalis (100%). In the biofilm state, however, only the CFU of P. gingivalis demonstrated a decreasing tendency with increasing light exposure time, and there was a lower efficacy of phototoxicity to P. gingivalis as biofilm than in the planktonic state. Conclusions: Blue light exposure using a dental halogen curing unit is effective in reducing periodontal pathogens in the planktonic state. It is recommended that an adjunctive exogenous photosensitizer be used and that pathogens be exposed to visible light for clinical antimicrobial periodontal therapy.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.717-725
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• 2005

It is widely known that individuals with Down's syndrome(DS) often develop early onset severe periodontal diseases. In this study, We examined the prevalence of periodontopathic bacteria in DS patients to compare controls with mental disabilities(MD) The subjects were 27 DS patients (7 to 19 years old) and 27 age-matched controls with MD. Plaque index and gingival index were measured. And 5 pathogens, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, were surveyed in subgingival plaque samples using a polymerase chain reaction. No significant difference in plaque index and gingival index were observed between the DS and control group. The prevalence in DS was 96.3% for F. nucleatum, 74.1% for T. forsythia, 63.0% for P. gingivalis, 55.6% for A. actinomycetemcomitans. 40.7% for T. denticola. No significant differences were observed in the prevalence of periodontopathic bacterias between the DS and control. Prevalence of P.g(16.7%) at age $7{\sim}10$ is lower than other age group in DS, but its prevalence increased with age. Prevalence of A.a(83.3%) is peak at age $7{\sim}10$ in DS. These results suggest that various periodontopathic pathogens can colo nize in the very early childhood of DS and MD patients. But no significant difference was observed in the prevalence of periodontopathic bacterias between the DS and control.

• Journal of Periodontal and Implant Science
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• v.24 no.2
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• pp.238-254
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• 1994

Cyclosporine A is an immunosuppressant commonly used for patients receiving organ transplants. Gingival overgrowth is an adverse side-effect seen in about 8-26% of patients taking cyclosporine A which have been shown to increase the DNA synthesis of gingival fibroblast at the concentration of $10^{-9}g/ml$ in vitro. Glycyrrhetinic acid is the active pharmacological ingredients of licorice which exerts steroid-like action and anti-viral activity. Oleanolic acid, which were isolated from Glechoma hederacea, has been shown to act as inhibitors of tumor promotion in vivo and to be less cytotoxic retinoic acid. This study has been performed to evaluate the effects of glycyrrhetinic acid and oleanolic acid on cyclosporine A induced cell activity in vitro. Human gingival fibroblasts were isolated from explant cultures of healthy gingiva of orthodontic patients. Gingival fibroblasts were trypsinized and transferred to the walls of microtest plates. Fibroblasts were cultured in growth medium added $10^{-9}g/ml$ cyclosporineA and $50{\mu}l/ml$ lipopolysaccharides. Cells between the 4th and 6th transfer in culture were used for this study. The morphology of gingival fibroblst were examined by inverted microscope. The effects of cyclosporine A on the time course of DNA sythesis by human gingival fibroblasts were assessed by $[^3H]-thymidine$ uptake assays. Cyclosporine A was found to stimulate DNA synthesis of human gingival fibroblast at a concentration of $10^{-9}g/ml$. In the presence of lipopolysaccharide derived from Fusobacterium nucleatum, addition of cyclosporine A results in reversal of inhibition at the concentration which normally inhibits gingival fibroblast proliferation. The cell acitivities in the presence of glycyrrhetinic acid and oleanolic acid were decreased, and increased cell acitivities by cyclosporine A were decreased by glycyrrhetinic acid and oleanolic acid at the concentration of $200{\mu}g/ml$. These results suggested that the increased cell activities by cyclosporine A modulated by glycyrrhetinic acid and oleanolic acid.

• Restorative Dentistry and Endodontics
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• v.27 no.5
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• pp.530-534
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• 2002

최근 치근단 와동 형성 시 초음파 또는 음파 기구를 이용하는 것이 보편화되어 있고 여러 측면에서 평가되어져 왔다. 본 연구의 목적은 혐기성 세균을 이용한 미세 누출 모델을 이용하여 초음파와 음파 기구를 사용, 치근단 와동 형성을 하였을 때 두 기구의 사용이 충전된 치근단 와동의 미세 누출에 미치는 영향을 비교 평가하는 것이다. 48개의 단근치의 근관을 crown-down방법을 이용 Profile로 .06 black까지 근관 성형을 시행하고 수직 가압법을 사용하여 gutta-percha와 AH26 sealer를 이용하여 근관 충전을 시행하였다. 각 충전된 시편의 치근단 3mm를 절제하였다. 각 시편은 이미로 4군으로 나누었으며 1군에서는 치근단 와동을 초음파 기구로 형성하였고 2군에서는 음파 기구로 형성하였다. 3군은 음성대조군으로 4군은 양성대조군으로 분류하였다. 형성된 치근단 와동은 공기 분사침을 이용하여 건조 후 super EBA 시멘트로 충전하였으며 Anaerobic chamber에서 Fusobacterium nucleatum (VPI 10197)을 사용한 혐기성 세균 미세누출 모델을 이용하여 30일간 미세 누출을 관찰한 결과, 초음파 기구를 사용한 군에서는 80%에서 음파 기구를 사용한 군에서는 75%에서 미세누출이 나타났으나 통계적으로 유의성 있는 차이는 보이지 않았다.

• Journal of Periodontal and Implant Science
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• v.44 no.6
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• pp.280-287
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• 2014

Purpose: The purpose of this randomized single-blind controlled trial was to elucidate the clinical and antimicrobial effects of daily phototherapy (PT) as an adjunct to scaling and root planing (SRP) in patients with chronic periodontitis. Methods: The study was conducted from December 2013 to May 2014 at Ewha Womans University Mokdong Hospital, Seoul, Korea. Forty-one patients with mild to moderate chronic periodontitis were randomly divided into two therapeutic groups in a 1:1 ratio: SRP+PT and SRP (control) groups. All participants underwent full-mouth SRP. PT was performed thrice a day for a month by using electric toothbrushes with embedded light-emitting diodes. Plaque index, gingival index, probing pocket depth (PPD), clinical attachment level (CAL), and bleeding on probing were assessed before (baseline) and four weeks after (follow-up) the treatment. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, Fusobacterium nucleatum, Parvimonas micra, Campylobacter rectus, Eikenella corrodens, Streptococcus mutans, and Streptococcus sobrinus levels were detected by a real-time polymerase chain reaction at the same points in time. Results: The clinical parameters improved in both the groups. At the follow-up assessment, PPD was significantly decreased in the SRP+PT group (P=0.00). Further, PPD and CAL showed significantly greater changes in the SRP+PT group than in the SRP group (PPD, P=0.03; CAL, P=0.04). P. gingivalis and T. forsythia levels decreased in this group, but no significant intergroup differences were noted. Conclusions: Adjunctive PT seems to have clinical benefits, but evidence of its antimicrobial effects is not sufficient. Long-term studies are necessary to develop the most effective PT protocol and compare the effectiveness of PT with and without exogenous photosensitizers.

• 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.51 no.5
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• pp.316-328
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• 2021

Purpose: This study aimed to examine the prevalence and abundance of 9 representative periodontal pathogens in the saliva samples of periodontally healthy subjects (PH) and patients with periodontitis who underwent supportive periodontal therapy (SPT). The age-specific distribution of these pathogens in periodontally healthy individuals was also analyzed. Methods: One hundred subjects (aged >35 years) were recruited (50 each in the PH and SPT groups) between August 2016 and April 2019. The prevalence and abundance of periodontal pathogens in the PH group were compared with those in periodontally healthy young subjects (94 subjects; aged <35 years), who were included in our previous study. DNA copy numbers of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), Campylobacter rectus (Cr), Peptostreptococcus anaerobius (Pa), and Eikenella corrodens (Ec) were analyzed using real-time polymerase chain reaction. Results: The detection frequencies of all pathogens, except Aa, were high in the PH and SPT groups. The ranking order of pathogen DNA copy numbers was similar in both groups. In both groups, Fn had the highest abundance, Aa had the lowest abundance. Additionally, Td was significantly more abundant in men than in women in both groups (P<0.05). Compared with the PH group, the SPT group exhibited significantly lower total bacteria and Fn abundance and higher Pg abundance (P<0.05). The age-specific pathogen distribution analysis revealed a significantly low Aa abundance and high Tf and Cr abundance in the PH group. Conclusions: The clinical parameters and microbial profiles were similar between the SPT and PH groups. However, patients with periodontitis require supportive care to prevent recurrence. As the abundance of some bacteria varied with age, future studies must elucidate the correlation between age-related physiological changes and periodontal bacterial composition.

• Journal of Periodontal and Implant Science
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• v.50 no.6
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• pp.358-367
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• 2020

Purpose: The aim of this study was to investigate the efficacy and validity of subgingival bacterial sampling using a retraction cord, and to evaluate how well this sampling method reflected changes in periodontal conditions after periodontal therapy. Methods: Based on clinical examinations, 87 subjects were divided into a healthy group (n=40) and a periodontitis group (n=47). Clinical measurements were obtained from all subjects including periodontal probing depth (PD), bleeding on probing (BOP), clinical attachment loss (CAL), and the plaque index. Saliva and gingival crevicular fluid (GCF) as a subgingival bacterial sample were sampled before and 3 months after periodontal therapy. The salivary and subgingival bacterial samples were analyzed by reverse-transcription polymerase chain reaction to quantify the following 11 periodontal pathogens: Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythus (Tf), Treponema denticola (Td), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), Pavimonas micra (Pm), Campylobacter rectus (Cr), Prevotella nigrescens (Pn), Eikenella corrodens (Ec), and Eubacterium nodatum (En). Results: Non-surgical periodontal therapy resulted in significant decreases in PD (P<0.01), CAL (P<0.01), and BOP (P<0.05) after 3 months. Four species (Pg, Tf, Pi, and Pm) were significantly more abundant in both types of samples in the periodontitis group than in the healthy group. After periodontal therapy, Cr was the only bacterium that showed a statistically significant decrease in saliva, whereas statistically significant decreases in Cr, Pg, and Pn were found in GCF. Conclusions: Salivary and subgingival bacterial sampling with a gingival retraction cord were found to be equivalent in terms of their accuracy for differentiating periodontitis, but GCF reflected changes in bacterial abundance after periodontal therapy more sensitively than saliva.

• 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.