• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.1
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• pp.16-23
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• 2016

Purpose: The aim of this study was to evaluate whether fluorides at various pH cause changes in the surface roughness of titanium implants that alter the adherence of bacterial biofilms. Materials and Methods: The titanium disks were assigned randomly to the following seven groups according to the fluoride agents and application time (1 minute or 30 minute) used: control (no treatment); group 1 (1.23% acidulated phosphate fluoride [APF] at pH 3.5 for 1 minute); group 2 (1.23% APF at pH 3.5 for 30 minute); group 3 (1.23% APF at pH 4.0 for 1 minute); group 4 (1.23% APF at pH 4.0 for 30 minute); group 5 (2% NaF gel at pH 7.0 for 1 minute); group 6 (2% NaF gel at pH 7.0 for 30 minute). The surface roughness of the titanium disks and the amount of adherent bacteria were measured. Results: Group 2 showed a significantly greater surface roughness than the control group (P < 0.0001). No significant differences in the amount of surface bacteria were observed between the treated samples and the controls. In addition, there were no significant differences in bacterial adherence relative to the incubation period between the treated samples and the controls. Conclusion: The surface roughness of the titanium disks was significantly greater after treatment with APF at pH 3.5 for 30 min compared with that of the controls. In addition, we found that the amount of Porphyromonas gingivalis, Fusobacterium nucleatum, and Aggregatibactor actinomycetemcomitans was similar among all groups

• Restorative Dentistry and Endodontics
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• v.29 no.1
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• pp.51-57
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• 2004

본 연구는 에폭시레진계 봉함제 (AH26)과 두 가지의 상아질 접착제와 함께 근관충전을 시 행하였을 때와 에폭시레진계 봉함제 단독으로 사용하였을 때의 미세누출을 혐기성 세균모델을 이용하여 평가하였다. 52개의 단근치를 이용하여 .04, .06 taper Profile (Dentsply-Maillefer, Ballaigues, Swiss)을 사용하여 변형된 crown-down pressureless법으로 근관형성 하였다. 형성된 치근을 12개씩 무작위로 나누어 4개의 실험군으로 하였으며, 나머지 치아 중 2개를 양성대조군에, 2개는 음성대조군으로 사용하였다. 제1군은 All Bond 2(Bisco, Itasca, IL, USA)를 적용하고 거타퍼쳐와 AH26 (Dentsply, Konstanz, Germany)을 이용하여 continuous wave of condensation technique으로 근관충전 하였으며, 제 2군은Prime ＆ Bond NT (Dentsply, Konstanz, Germany)를 적용 후 거타퍼쳐와 AH26을 이용하여 충전하였으며, 제3군은 17％ EDTA를 적용하여 도말층을 제거한 후 거터퍼쳐 와 AH26을 사용하여 충전하였다. 제4군은 17％ EDTA를 적용하지 않고 거터퍼쳐와 AH26을 사용하여 충전하였다. Fusobacterium nucleatum (VPI 10197)을 추적자로 이용한 혐기성세균모델을 사용하여 혐기성배양기에서 배양시키면서 60일 동안 각군에 대한 미세누출 여부를 관찰하였다. 매일 배양액의 혼탁도와 색상변화를 관찰하여 기록하였다. 제4군에서 통계학적으로 유의할만한 미세누출을 가장 많이 보였으며(p<0.0005) 나머지 3개의 실험군에서는 서로간의 통계학적으로 유의할 만한 차이를 보이지 않았다. 주사전자현미경 관찰 시 제 1군과 제2군의 상아질 접착제가 상아세관으로 침투한 소견을 관찰 할 수 있었다.

• International Journal of Oral Biology
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• v.39 no.4
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• pp.201-206
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• 2014

This study investigated the antimicrobial activity of methanol extract of mulberry leaf against 16 strains of mutans streptococci and four species of periodontopathogens: Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Aggregatibacter actinomycetemcomitans. The antimicrobial activities of the crude extracts or silica gel chromatography fractions of methanol-extracted mulberry leaf were evaluated by determining minimal inhibitory concentrations using an established microdilution method. The cytotoxicity of the extracts of mulberry leaf on KB cells was tested by the methyl thiazolyl tetrazolium assay. Chromatography fraction 12 displayed the most potent antimicrobial activity against all 16 strains of mutans streptococci, P. gingivalis, and P. intermedia. No KB cell cytotoxicity was evident up to $128{\mu}g/ml$ of fraction 12. The methanol extract had no antimicrobial activity against F. nucleatum and A. actinomycetemcomitans. These results suggest chromatography fraction 12 methanol extract of mulberry leaf could be useful in the development of oral hygiene products, such as dentifrice and oral hygiene solution, for the prevention of dental caries.

• Restorative Dentistry and Endodontics
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• v.25 no.2
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• pp.235-242
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• 2000

The purpose of this in vitro study was to evaluate the sealing ability of three sealers(Sealapex, Pulp canal sealer, AH26) used with continuous wave method using an anaerobic bacterial leakage model. 53 extracted human teeth with straight and single canals were prepared with crown-down pressureless technique using .04, .06 taper Profile(Maillefer, Swiss). Master apical file was maintained as #35 K-file. All canals of the experimental teeth were obturated with continuous wave method using System B(Analytic technology, U.S.A.) The teeth were randomly divided into three experimental groups of 15 and two control groups of 4. Experimental group 1 was obturated with Sealapex and group 2 with Pulp canal sealer, and group 3 with AH26. A dual chamber anaerobic bacterial leakage model was assembled. Brain heart infusion with yeast extract, hemin, menadion, and the chromogenic indicator bromocresol purple was used as the culture broth for Fusobacterium nucleatum(VPI 10197), The specimens were incubated in anaerobic chamber at $37^{\circ}C$ and were observed every 2 to 3 clays, The coronal leakage was evaluated through the color change of culture broth in lower chamber for 60 days. The results were as follows: 1. The incidence of bacterial leakage in group 1 (Sealapex group was 80%, 53% in group 2 (Pulp canal sealer), 27% in group 3 (AH26). 2. There were statistically significant differences in leakage scores between group 1 and group 2, and between group 1 and group 3, respectively. (P<0.05) 3. There was no significantly difference in leakage score between group 2 and group 3. (P>0 05)

• 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.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 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 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.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.2
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• pp.237-244
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• 2009

When the symptom of periapical infection is not released by mechanical instrumentation. anti-microbial agents including antibiosis become necessary in order to remove microorganisms from the root canal. Since anti-microbial agents of natural origins are currently popular, more natural remedies are being sought out. As it turns out, it is well known isothiocyanates (ITCs) in horseradish root extract have anti-microbial activity from many studies. In this research, anti-microbial effects of horseradish root extract and chlorhexidine, a typical anti-microbial agent, were investigated and compared against two kinds of obligate anaerobes. Fusobacterium nucleatum and Prevotella nigrescens, that are often discovered in infected root canal, and Clostridium perfringens, which is resistant to antibiotics and frequently used as a control strain for antibacterial studies 1. The MIC and MBC of horseradish root extract were ranged from 87 to 470 ppm and from 156 to 625 ppm against three kinds of obligate anaerobes, respectively. Horseradish root extract showed the strongest anti-bacterial activity (MBC, 156 ppm) against F. nucleatum and also showed anti-bacterial activity against antibiotic resistant obligate anaerobes. C. perfringens. 2. The MIC and MBC of chlorhexidine were ranged from 3.12 to 6.25 ppm and 10.94 ppm against three kinds of obligate anaerobes, respectively. 3. The MIC with 87-470 ppm of horseradish root exact has the same growth inhibiting effect as the one of 3.12-6.25 ppm of chlorhexidine. Likewise, the MBC with 156-625 ppm of horseradish has the similar bactericidal effect as 10.94 ppm of chlorhexidine.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.305-308
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• 2000

This study was observed to the effect of the feeding Platycodon grandiflorum A. DC (3 years) extract on the bronchus diseases bacteria ( C. diphtheriae, S. aureus, Mycobacterium sp., F. nucleatum, S. pygogenes, K. pneumoniae and N. gonorrhoeae) and fungi(A. fumicatus). Platycodon grandiflorum A. DC was extracted ethanon, water, ethyl ether and petroleum ether. The extraction rate of Platycodon grandiflorum A. DC to the extract solution was identified 71.8%, 100%, 15.4% and 14.1%. Each extract solution was injected culture media into several concentrations and then investigated the bacteria cell growth during 32 hours. As a result antimicrobial activity was excellent an extract by ethyl ether and petroleum ether. Among several concentrations, bacteria cell growth inhibition was observed from 0.06% to 0.14%. The rate of antimicrobial activity was over 70%. The cell growth inhibition rate of each bacteria was appeared in order of ethyl ether > petroleum ether > water > ethanol.