• Restorative Dentistry and Endodontics
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• 제20권2호
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• pp.549-576
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• 1995

Bacteria are one of the most important causative agents of the pulpal and periapical diseases. Streptococci are one of the most frequently isolated facultative anarerobic bacteria in the infected root canals. Bacterial cell wall components have a direct effect in the pathogenesis of the pulpal and periapical infections. Hyaluronidase produced by bacteria has been implicated in dissemination of the diseases. The purpose of this study was to evaluate the effect of cell wall extract of streptococci on the L929 cells using inverted microscope and the transmission electron microscopy (TEM). Hyaluronidase production of streptococcal strains were investigated to determine the correlation between the severity of cell damage and the activity of enzymes. Bacterial cell wall extracts of S. sanguis, S. mitis and S. uberis isolated from infected root canals and ATCC type strains of S. mutans (ATCC 10449) and E. faecalis (ATCC 19433) were prepared by sonication and confirmed with SDS-PAGE. Silver stain of SDS-PAGE of sonic extract was efficient at $100{\mu}g$/ml concentration of cell wall protein, while Coomasie blue stain was efficient at $100{\mu}g$/ml concentration. Inverted microscope showed that sonic extract-treated L929 cells were round and detached from the substratum while others lost their fibroblastic shapes. Transmission electron microscopic examination revealed that streptococcal extracts induced death of L929 cells. Sonic extracts of streptococci had variable effect on microstructure of L929 cells. significant chromatin condensation was observed in the nucleus of the cells. Disappearance of cell surface microvilli and nuclear fragments with dense chromatin were observed. The cell nucleus had an irregular shape and numerous large vacuoles were seen in the cytoplasm and some breaks of the cell membrane could be seen. Cell organelles were in various stages of destruction and cristae of mitochondria were disoriented or disappeared. Eighteen strains of streptococci did not produce hyaluronidase.

• The Journal of Advanced Prosthodontics
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• 제11권1호
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• pp.41-47
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• 2019

PURPOSE. Surface finishing of a zirconia restoration is essential after clinical adjustment. Herein, we investigated the effects of a surface finishing protocol for monolithic zirconia on final roughness and bacterial adherence. MATERIALS AND METHODS. Forty-eight disk-shaped monolithic zirconia specimens were fabricated and divided into four groups (n = 12) based on initial surface treatment, finishing, and polishing protocols: diamond bur+polishing bur (DP group), diamond bur+stone grinding bur+polishing bur (DSP group), no diamond bur+polishing bur (NP group), and no diamond bur+stone grinding bur+polishing bur (NSP group). Initial and final surface roughness was measured with a profilometer, and shown using scanning electron microscope. Bacterial adhesion was evaluated by quantifying Streptococcus mutans in the biofilm. Kruskal-Wallis and Mann-Whitney U tests were used to compare results among groups, and two-way analysis of variance was used to evaluate the effects of grinding burs on final roughness (${\alpha}=.05$). RESULTS. The DP group had the highest final Ra value, followed by the DSP, NP, and NSP groups. Use of the stone grinding bur as a coarse-finishing step significantly decreased final Ra values when a diamond bur was used (P<.001). Omission of the stone grinding bur increased biofilm formation on specimen surfaces. Combining a stone grinding bur with silicone polishing burs produced the smallest final biofilm values, regardless of the use of a diamond bur in initial surface treatment. CONCLUSION. Coarse finishing of monolithic zirconia with a stone grinding bur significantly decreased final Ra values and bacterial biofilm formation when surfaces had been roughened by a diamond bur.

• 디지털융복합연구
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• 제17권6호
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• pp.315-326
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• 2019

본 연구는 프로바이오틱스의 특성과 관련 연구에 대한 종설이다. 프로바이오틱스는 면역질환 개선 효과, 유당불내증 완화 효과, 변비 및 설사 개선 효과, 항암 및 항종양 효과, 심혈관계 질환 예방 효과, 항당뇨 효과, 항산화 효과, 항균효과, 유용 대사산물의 생산 등의 기능성을 입증하였다. 구강 프로바이오틱스는 젖산을 생성하여 충치의 원인이 되는 뮤탄스균과 잇몸 질환을 일으키는 진지발리스균을 비롯한 유해균이 서식하기 어려운 환경을 만들어 구강 생태계 조성과 구취 제거에 효과적이라는 연구가 입증되었다. 그 결과 질환 완화는 물론 건강한 구강 밸런스를 관리하는 예방법으로 주목받고 있다. 일부 제한점에도 불구하고 현재 유용한 임상연구가 진행되고 있으며, 본 연구는 치아우식증과 치주염, 칸디다의 집락화 등 구강상태를 개선하기 위한 프로바이오틱스의 근거가 될 수 있을 것이다.

• The Journal of Advanced Prosthodontics
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• 제12권6호
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• pp.369-375
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• 2020

PURPOSE. This study evaluated the availability of multi-directionally forged (MDF) titanium (Ti) as a component of removable partial dentures (RPDs). MDF-Ti remarkably improved the mechanical properties of RPDs due to its ultrafine-grained structure. MATERIALS AND METHODS. The wear resistance, plaque adhesion, and machinability of MDF-Ti were tested. As controls, commercially pure (CP) titanium was used for wear, plaque adhesion, and machinability tests. For wear resistance, the volume losses of the titanium teeth before and after wear tests were evaluated. Plaque adhesion was evaluated by the assay of Streptococcus mutans. In the machinability test, samples were cut and ground by a steel fissure bur and carborundum (SiC) point. An unpaired t-test was employed for the analysis of the significant differences between MDF-Ti and the control in the results for each test. RESULTS. Wear resistance and plaque adherence of MDF-Ti similar to those of CP-Ti (P>.05) were indicated. MDF-Ti exhibited significantly larger volume loss than CP-Ti in all conditions except 100/30,000 g/rpm in machinability tests (P<.05). CONCLUSION. Although the wear resistance and plaque adherence of MDF-Ti were comparable to those of controls, MDF-Ti showed better machinability than did CP-Ti. MDF-Ti could be used as a framework material for RPDs.

• Journal of Microbiology and Biotechnology
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• 제31권5호
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• pp.705-709
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• 2021

Porphyromonas gingivalis (P. gingivalis) is a major bacterial pathogen that causes periodontitis, a chronic inflammatory disease of tissues around the teeth. Periodontitis is known to be related to other diseases, such as oral cancer, Alzheimer's disease, and rheumatism. Thus, a precise and sensitive test to detect P. gingivalis is necessary for the early diagnosis of periodontitis. The objective of this study was to optimize a rapid visual detection system for P. gingivalis. First, we performed a visual membrane immunoassay using 3,3',5,5'-tetramethylbenzidine (TMB; blue) and coating and detection antibodies that could bind to the host laboratory strain, ATCC 33277. Antibodies against the P. gingivalis surface adhesion molecules RgpB (arginine proteinase) and Kgp (lysine proteinase) were determined to be the most specific coating and detection antibodies, respectively. Using these two selected antibodies, the streptavidin-horseradish peroxidase (HRP) reaction was performed using a nitrocellulose membrane and visualized with a detection range of 10³-10⁵ bacterial cells/ml following incubation for 15 min. These selected conditions were applied to test other oral bacteria, and the results showed that P. gingivalis could be detected without cross-reactivity to other bacteria, including Streptococcus mutans and Escherichia fergusonii. Furthermore, three clinical strains of P. gingivalis, KCOM 2880, KCOM 2803, and KCOM 3190, were also recognized using this optimized enzyme immunoassay (EIA) system. To conclude, we established optimized conditions for P. gingivalis detection with specificity, accuracy, and sensitivity. These results could be utilized to manufacture economical and rapid detection kits for P. gingivalis.

• Journal of Microbiology and Biotechnology
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• 제33권7호
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• pp.964-972
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• 2023

Bacteriophage endolysins are peptidoglycan hydrolases composed of cell binding domain (CBD) and an enzymatically active domain. A phage endolysin CBD can be used for detecting bacteria owing to its high specificity and sensitivity toward the bacterial cell wall. We aimed to develop a method for detection of Enterococcus faecalis using an endolysin CBD. The gene encoding the CBD of ECP3 phage endolysin was cloned into the Escherichia coli expression vector pET21a. A recombinant protein with a C-terminal 6-His-tag (CBD) was expressed and purified using a His-trap column. CBD was adsorbed onto epoxy magnetic beads (eMBs). The bacterial species specificity and sensitivity of bacterial binding to CBD-eMB complexes were determined using the bacterial colony counting from the magnetic separations after the binding reaction between bacteria and CBD-eMB complexes. E. faecalis could bind to CBD-eMB complexes, but other bacteria (such as Enterococcus faecium, Staphylococcus aureus, Escherichia coli, Acinetobacter baumannii, Streptococcus mutans, and Porphyromonas gingivalis) could not. E. faecalis cells were fixed onto CBD-eMB complexes within 1 h, and >78% of viable E. faecalis cells were recovered. The E. faecalis recovery ratio was not affected by the other bacterial species. The detection limit of the CBD-eMB complex for E. faecalis was >17 CFU/ml. We developed a simple method for the specific detection of E. faecalis using bacteriophage endolysin CBD and MBs. This is the first study to determine that the C-terminal region of ECP3 phage endolysin is a highly specific binding site for E. faecalis among other bacterial species.

• 생약학회지
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• 제54권1호
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• pp.27-37
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• 2023

This research was conducted to investigate the comprehensive effects of methanol extract of Coptidis rhizoma (MECR) against oral pathogen. We studied the antibacterial, anti-biofilm, anti-gingipain and anti-inflammatory activity of MECR. The minimum bactericidal concentration (MBC) of MECR was 100 ㎍/mL against several oral pathogens. The formation of biofilm of Streptococcus mutans was reduced to 8.93~24.12% in the presence of 25 ㎍/mL of MECR. The gingipain activity of Porphyromonas gingivalis were reduced to 3.91~6.23% in case of Kgp and 5.73~7.78% in case of Rgp in the presence of 10 mg/mL of MECR. The expression of fadA mRNA, virulence factor of Fusobacterium nucleatum (F. nucleatum) was 3 folds decreased in the presence of 25 ㎍/mL of MECR. In case of YD-38 cells challenged with F. nucleatum, RQ values of IL-8 and IL-6 were reduced about 12 folds and 5.45 folds in the presence of 2 ㎍/mL of MECR. In case of RAW 264.7 murine cell challenged with F. nucleatum, RQ values of IL-1β and IL-6 were 2.52 folds and 2.55 folds reduced in the presences of 2 ㎍/mL of MECR. Conclusively, MECR showed potent antibacterial and anti-inflammatory effects against oral pathogenic bacteria.

• 대한치과교정학회지
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• 제53권6호
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• pp.374-392
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• 2023

Objective: Assess and evaluate the different indicators of oral health-related quality of life (OHRQoL) among patients treated with clear aligners (CAs) versus those treated with conventional fixed orthodontics (FAs). Methods: An electronic search was performed on the database is Web of Science, Scopus, and Embase databases. Randomized and non-randomized control trials, cross-sectional, prospective cohort and retrospective trials were included. Quality was assessed with risk of bias tool and risk of bias in non-randomised studies. Meta-analyses were performed with random effects models, estimating the standardized and non-standardized mean differences, odds ratio and risk ratio as the measure of effect. The effect on time was determined using a meta-regression model. Results: Thirty one articles were included in the qualitative synthesis and 17 in the meta-analysis. CAs had a significantly lower negative impact on QoL, with an "important" effect size, while the influence of time was not significant. Periodontal indicators plaque index (PI), gingival index (GI), probing depth (PD), and bleeding on probing show significantly better values in patients treated with CAs, with moderate to large effect sizes. PI and GI have a significant tendency to improve over time. In microbiological indicators, CAs present a lower biofilm mass without differences in the percentage of patients with high counts of Streptococcus mutans and Lactobacilli bacteria. The risk of white spot lesion onset is ten times lower in carriers of CAs. Conclusions: Patients wearing CAs show better periodontal indicators, less risk of white spot development, less biofilm mass and a better QoL than patients with FAs.

• 대한치위생과학회지
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• 제1권1호
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• pp.57-63
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• 2018

The coffee demand market in Korea is growing every year, and the adults drink an average of one cup of coffee every day. In order to investigate the effect of coffee on oral malodor, 15 Korean subjects were recruited. There were no significant differences in the values of oral malodor using BB checker(Taiyo, Japan) in the factors of sex, smoking, drinking, feeling oral malodor by themselves, feeling oral malodor by others, periodic scaling, activity of Streptococcus mutans, bleeding on probing, and coffee drinking habits. Patient hygiene performance index, calculus index, index of coat on the tongue, toothbrushing time, toothbrushing frequency had no correlation with oral malodor. The difference between before and after drinking coffee with syrup(17.93±16.54) was significant, but the difference between before and after drinking coffee without syrup(1.13±14.75) was not significant. We suggested the cause of oral malodor after drinking coffee was syrup, but not coffee.

• 한국식품영양과학회지
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• 제43권9호
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• pp.1380-1387
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• 2014

본 연구에서는 발효 한약재를 사용하여 한방구강세척제를 개발하고자 후박, 감초, 천궁, 박하 및 정향을 상황버섯균사체로 고체발효 하였다. 후박, 감초 천궁은 수분을 30% 첨가한 조건에서 고체발효에 성공하였으며, 박하는 30% 수분과 현미가루 10%를 영양성분으로 제공하였을 때 고체발효가 진행되었다. 그러나 정향은 진균류에 대한 항균활성이 강하여 상황버섯균사체를 이용한 고체발효에 성공하지 못하였다. 고체발효 한약재 에탄올 추출물의 총 페놀 함량 및 DPPH 소거능은 발효 후 유의적으로 상승하였으며 항균효과 역시 상승하였다. 구강질환 균인 Staphylococcus epidermis, Streptococcus pyogenes, Candida albicans 또는 Streptococcus mutans에 대해 후박, 감초 및 천궁이 항균활성을 보였으며, 항균활성은 고체발효에 의해 약 100배 정도 증가하였다. 한방구강세척제 조성비를 확립하기 위하여 발효한 후박, 감초 및 천궁의 에탄올 추출물을 5:3:2로 혼합하였을 때 가장 높은 항균활성을 나타내었다. 이들 발효 한약재 에탄올 추출물 혼합액 0.075%를 유효성분으로 하고 박하와 정향 열수 추출물(100:15, v/v) 83.64%를 베이스로 하는 한방구강세척제 조성을 관능검사에 의거 결정하고 시제품을 제조하였다. 본 연구에서 개발한 발효 한방구강세척제와 시판하고 있는 한방구강세척제에 대한 소비자 선호도 조사(n=30)를 실시하였을 때 본 연구에서 개발한 제품이 종합적인 평가 점수에서 유의적으로 높았으며 구강세척제 사용 후 지속 효과를 구취 측정계로 측정하여 시간을 산출하였을 때 유의적인 차이는 없었으나 발효 한방구강세척제의 지속 효과가 다소 길었다.