자일리톨 처리 농도에 따른 자일리톨 감성균주와 내성균주의 독력 비교

임상욱 ( Sang Uk Im ),안상헌 ( Sang Hun Ahn ),송근배 ( Keun Bae Song ) 한국치위생과학회 2011 치위생과학회지 Vol.11 No.5

Streptococcus mutans (S. mutans) is the major causative bacteria in dental caries. Xylitol is effective anticarious natural sugar substitute by inhibiting the virulence of S. mutans. However, long-term xylitol consumption leads to the emergence of the xylitol-resistant (XR) strains which means xylitol is no more inhibited their growth. We therefore confirmed the general characteristics and the virulence factors of the xylitol-sensitive (XS) and XR S. mutans for different concentrations of xylitol. S. mutans KCTC 3065 was maintained in TYE medium containing 0.4% glucose with 1% xylitol during 30 days at 37oC, 10% CO2 to form XR strain. The strains were transferred to new medium every 24 hr and the same procedures without xylitol were repeated for the formation of XS S. mutans. Both XS and XR were cultured in different concentrations of xylitol (0%, 0.1% and 1%) then, cell growth, acid production and mRNA expression of gtf genes were analyzed. Xylitol reduced the cell growth of XS S. mutans in dose-dependent manner, but not reduced that of XR. Xylitol inhibited acid production of XS in dose-dependent manner, but not inhibited that of XR. Xylitol reduced the gtfB and gtfD mRNA expression of XS S. mutans which genes synthesized soluble and insoluble extracellular polysaccharides, but not reduced that of XR. These results indicate that the virulence of XR S. mutans is different characters of XS strains, which suggests XR strains may have different cariogenicity of XS strains. Further study is needed to explain the mechanism related to extracellular polysaccharide in the XR strains.

자일리톨 처리농도에 따른 자일리톨 감성균주와 내성균주의 gtf 유전자 발현과 부착력 비교

임상욱 ( Sang Uk Im ),안서영 ( Seo Young An ),최연희 ( Youn Hee Choi ),송근배 ( Keun Bae Song ) 대한예방치과·구강보건학회 2012 大韓口腔保健學會誌 Vol.36 No.2

Objectives: Xylitol is an effective anticarious natural sugar substitute, by inhibiting the virulence of Streptococcus mutans (S. mutans). However, long-term xylitol consumption leads to an emergence of the xylitol-resistant (XR) strains. This study aimed to confirm the general characteristics, mRNA expression of gtf genes, and adhesive ability of the xylitol-sensitive (XS) and XR S. mutans, by xylitol-treated concentrations. Methods: S. mutans KCTC3065 was maintained in TYE medium, containing 0.4% glucose with 1% xylitol for 30 days at 37oC, 10% CO2 to form XR strain and the same procedures, without xylitol, were repeated for the formation of XS S. mutans. Both XS and XR were cultured by xylitol-treated concentrations (0%, 0.1% and 1%), then, general characteristics, such as growth and acid production, mRNA expression of gtf genes and adhesive ability were analyzed. Results: Xylitol reduced the cell growth of XS S. mutans in a dose-dependent manner, but did not reduce the XR. Xylitol inhibited acid production of XS in a dose-dependent manner. However, it did not inhibit that of XR. Xylitol reduced the gtfB and gtfD mRNA expression of the XS S. mutans, which the genes synthesized soluble and insoluble extracellular polysaccharides, but not reduced that of the XR. By a microtiter plate assay, biofilm formation was more reduced in the XR strains, which means biofilm`s adhesive ability of XR S. mutans was lower than that of the XS. Conclusions: These results indicate that a lower level of adhesive ability for XR S. mutans is related with mRNA expression level of gtf genes, which suggested that the XR strains may be less cariogenic than that of the XS.

포도당배지에서 DNA chip을 이용한 자일리톨 감성균주와 내성균주의 유전자 발현 비교

임상욱 ( Sang Uk Im ),안상헌 ( Sang Hun Ahn ),박동옥 ( Dong Ok Park ),최연희 ( Youn Hee Choi ),송근배 ( Keun Bae Song ) 대한구강보건학회 2012 大韓口腔保健學會誌 Vol.36 No.4

Objectives: Streptococcus mutans (S. mutans) is the major causative bacteria in dental caries. Xylitol is an effective anticarious natural sugar substitute by inhibiting the virulence of S. mutans. However, longterm xylitol consumption leads to the emergence of the xylitol-resistant S. mutans (XR). The aim of this study is to analyze the difference of gene expression profile of xylitol-sensitive S. mutans (XS) and XR in 0.5% glucose containing TYE media, using a DNA chip. Methods: S. mutans KCTC3065 was maintained in 0.5% glucose and 1% xylitol containing TYE media, during 30 days at 37oC 10% CO2 to form XR. The same procedures without xylitol were repeated for the formation of XS. Both XS and XR were cultured in 0.5% glucose with or without 1% xylitol containing TYE media overnight and total RNA was extracted. RNA from XS was labeled with Cy-3 dye as control, and XR were labeled with Cy-5 as references. DNA chip was hybridized for 18-20 h at 42oC. Results: A total of 277 genes of DNA chip data were significantly increased or decreased in XR. There is a total of 174 XR up-regulated genes in 0.5% glucose and 1% xylitol containing TYE media, and a total of 103 down-regulated genes. For compare with results of DNA chip, 11 in up-regulated genes and 10 in down-regulated were verified by RT-PCR. The most abundant increased genes in XR were related to cell envelope, cellular processes, DNA metabolism, transcription, and protein folding and stabilization. The decreased genes in XR were related to amino acid biosynthesis, toxin production and resistance, energy metabolism, ribosomal proteins synthesis, and signal transduction. Conclusions: These results indicate that the difference of gene expression profile of XS and XR may be in existence. In particular, results of this study for XR up-regulated genes have a lot of similarities with the already published xylitol-related researches and other functional studies.

다양한 채취 방법에 따른 구강미생물의 정량적 비교연구: 예비연구

임상욱 ( Sang-uk Im ),김지혜 ( Ji-hye Kim ),송근배 ( Keun-bae Song ),최연희 ( Youn-hee Choi ) 대한예방치과·구강보건학회 2023 大韓口腔保健學會誌 Vol.47 No.4

Objectives: This study aimed to compare each strain’s number of microorganisms found in oral samples collected using various collection methods. Methods: Twenty-two adults aged 40 and above participated in the study. Oral samples were collected from subjects using three different methods (stimulated saliva, oral biofilm, and calculus), and the collected samples were analyzed using the multiplex real-time Polymerase chain reaction (PCR) method. Results: The study included 22 subjects (2 men, 20 women) with an age range of 40-75 years. Healthy oral condition was observed in 10 subjects, while the remaining 12 had periodontitis. The saliva and biofilm collection methods for oral microorganisms detected Porphyromonas gingivalis (Pg), Tannerella forsynthesis (Tf), and Fusobacterium nucleatum (Fn), which are the causative bacteria of periodontal disease, more effectively compared with the calculus group. In addition, the saliva group showed a better ability to detect Streptococcus mutans (Sm) which causes dental caries, compared with the biofilm and calculus groups. Comparisons based on the presence or absence of periodontitis and the collection method revealed a statistically significant difference in the number of oral microorganisms only in case of Sm strain. Conclusions: The frequency of expression of certain strains varies according to the method of collection of oral microorganisms. Further, the saliva and biofilm methods of collecting oral microorganisms are more suitable for quantitative analysis of bacteria causing periodontal disease.

치면열구전색재와 충전재료에 대한 우식유발 세균의 부착특성 비교

강재민(Jae-Min Kang),임상욱(Sang-Uk Im),조화영(Jae-Min Kang),마재경(Jae-Kyung Ma),김정숙(Jeong-Sook Kim),김교한(Kyo-Han Kim),송근배(Keun-Bae Song),최연희(Youn-Hee Choi) 대한치과재료학회 2015 대한치과재료학회지 Vol.42 No.3

Primer를 함께 사용하는 자가미백 부착대의 임상적 효과

신해은 ( Hae Eun Shin ),임상욱 ( Sang Uk Im ),김은경 ( Eun Kyung Kim ),김종훈 ( Jong Hun Kim ),안재현 ( Jae Hyun Ahn ),최연희 ( Youn Hee Choi ),송근배 ( Keun Bae Song ) 대한예방치과·구강보건학회 2016 大韓口腔保健學會誌 Vol.40 No.1

Objectives: The purpose of this study was to evaluate the efficacy of a 2.9% hydrogen peroxide (HP) whitening strip with a desensitizing agent as a primer. Methods: This study was approved by the Institutional Review Board of Kyungpook National University Hospital. A total of 144 subjects (mean age: 21.7 years) were recruited after they provided informed consent for participation in the study. All participants used the whitening strip and primer for 1.5 h a day for 14 days. ShadeEye-NCC and Vita classical shade guide were used to determine the color changes, with respect to baseline, after 1, 3, 5, 7, and 14 days. A self-administered questionnaire was used to collect data on satisfaction after bleaching and irritating symptoms during the 14 days. All collected data were analyzed with repeated measures ANOVA and one-way ANOVA using SPSS 20.0 for windows. Results: Brightness (ΔL*) was significantly higher in groups 2 and 3 than in the control group after 3 days of the experiment. Chroma (Δb*) started to decrease in groups 2 and 3, compared to control, after 1 day. Perceived symptoms of irritation were significantly lower in groups using the strip combined with the desensitizing primer than in the control group. Satisfaction after bleaching was higher in the experimental groups than in control. Conclusions: The HP whitening strip with a desensitizing agent as a primer is clinically effective in bleaching human enamel after 3 days of use. It also reduces the prevalence of gingival irritation.

감껍질, 여주, 작두콩 추출물이 Streptococcus mutans의 우식유발 관련특성에 미치는 영향

김동운 ( Dong-woon Kim ),이동익 ( Dong-ik Lee ),임상욱 ( Sang-uk Im ),최연희 ( Youn-hee Choi ),송근배 ( Keun-bae Song ) 대한예방치과·구강보건학회 2019 大韓口腔保健學會誌 Vol.43 No.3

Objectives: The purpose of this study is to determine methods of dental caries prevention by investigating the use of compounds of Diospyros kaki (D. kaki) peel, Momordica charantia (M. charantia), and Canavalia gladiata (C. gladiata) extracts to limit the cariogenic traits of Streptococcus mutans (S. mutans), such as their ability to proliferate and adhere to the tooth surface. Methods: Broth microdilution and the agar spreading assay were used to determine the antimicrobial effect and minimum inhibitory concentration (MIC) of S. mutans extracts. In order to identify the adhesive ability of S. mutans at varying concentrations, culture plates were first stained with 1 ml of 0.01% crystal violet for 15 minutes at room temperature, and then eluted with 1 ml of EtOH:Acetone (8:2) solution for 15 minutes in a 37℃ incubator. Eluted solutions were then evaluated by use of a spectrophotometer at 575 nm. Results: Experiments were conducted in order to investigate the effectiveness of D. kaki peel, M. charantia, and C. gladiata extracts on limiting the proliferation of S. mutans. The MIC was measured as an indication of whether the antibacterial activity of D. kaki peel, M. charantia, and C. gladiata extracts had a significant bacteriostatic effect on S. mutans. M. charantia extract was effective for growth inhibition on S. mutans at a minimum concentration of 0.25%. From the adhesion ability assay, M. charantia extract had an anti-adhesive effect. Conclusions: These results indicate that M. charantia extract demonstrates antibacterial activity and has an anti-adhesive effect on S. mutans. Due to these properties, M. charantia extract may be used to prevent dental caries.

치주염유발세균 복합체의 분포에 따른 구강건강상태

김지혜 ( Ji-hye Kim ),이동익 ( Dong-ik Lee ),임상욱 ( Sang-uk Im ),전은숙 ( Eun-suk Jeon ),송근배 ( Keun-bae Song ),최연희 ( Youn-hee Choi ) 대한예방치과·구강보건학회 2020 大韓口腔保健學會誌 Vol.44 No.1

Objectives: The purpose of this study was to evaluate the association between the distribution of periodontopathic bacteria and oral conditions. Methods: Stimulated saliva was collected from 162 adults aged 60 years and above. The prevalence and amount of periodontopathic bacteria in the saliva were analyzed using real-time PCR. Pocket depth and clinical attachment loss were examined to evaluate the oral conditions of the subjects. Patients who had at least one tooth surface involved, with a pocket depth ≥4 mm or clinical attachment loss ≥5 mm were classified as having periodontal disease. Results: The detection rates of most bacteria in the orange and green complexes were more than 90%, while those of P. gingivalis and T. forsythia in the red complex were 58.6% and 61.7%, respectively. The number of bacteria in the red complex positively correlated with each other. There were no significant differences in the number of types of red complex bacteria in the saliva and the distribution of residual number of teeth and periodontal disease (P>0.05). On the other hand, the number of remaining teeth in subjects with higher bacterial density were more than those with lesser bacterial density. In addition, the occurrence of dental disease differed significantly depending on the number of P. gingivalis and T. forsythia. Conclusions: The relative amount of periodontopathic bacteria is important in the occurrence of periodontal disease, and the number of these bacteria positively correlated with each other.

어린이의 구강 내 아말감 노출이 요중 수은농도에 미치는 영향

전은숙 ( Eun Suk Jeon ),진혜정 ( Hye Jung Jin ),김은경 ( Eun Kyong Kim ),임상욱 ( Sang Uk Im ),송근배 ( Keun Bae Song ),최연희 ( Youn Hee Choi ) 한국치위생과학회 2014 치위생과학회지 Vol.14 No.1

구강 내 아말감 충전물에 의해 인체에 유리되는 수은이 요중 수은농도에 미치는 영향에 대하여 관련성을 평가하고자 하였다. 이 연구는 대도시 일부지역의 2개 초등학교 1∼4학년 학생 317명을 대상으로 6개월 간격으로 총 4번의 구강검진과 소변검사를 실시하였으며, 자료를 수합하여 분석한 결과 다음과 같은 결론을 얻었다. 각 조사 시점별 아말감 충전 여부에 따라 요중 수은농도를 비교한 결과, 모든 연구시기에서 아말감 충전한 대상자에서 아말감 비충전군에 비해 요중 수은농도가 높게 나타났으며, 2차 추적조사와 3차 추적조사는 통계적으로 유의한 차이가 있었다. 혼합모형 분석한 결과 아말감 한 치면이 증 가할수록 현재 요중 수은농도에서 0.028 μg/g creatinine 증가하였다(p<0.001). 남학생에 비해 여학생에서 0.065 μg/g creatinine (p<0.001), 생선섭취 빈도에서 일주일에 3회 이상 섭취군에서 0.099 μg/g creatinine 증가하였다(p=0.001). 누적 요중 수은농도에서 아말감 한 치면이 증가할수록 누적 요중 수은농도에서 0.017 μg/g creatinine 증가하였다(p<0.001). 남학생에 비해 여학생에서 0.071 μg/g creatinine (p<0.001), 생선섭취 빈도에서 일주일에 3회 이상 섭취군에서 0.110 μg/g creatinine 증가하였다(p<0.001). 구강 내 아말감 충전물은 미량이라도 수은을 유리시켜 체내 요중 수은농도의 변화에 영향을 미치므로 이 연구결과를 토대로 구강 내 수은흡수를 최소화할 수 있는 기준이나 방안이 마련되어야 할 것이다. This study aims to evaluate the impact of varying exposure to dental amalgam on urinary mercury levels in children by measuring the number ofamalgam-filled teeth and the variance of mercury concentration in urine over a period of 2 years. A total of 317 (male 158, female 159) elementaryschool children (1st∼4th graders) attending 2 schools in urban regions participated in this study. At 6-month intervals, 4 oral examinations wereconducted to check any variance in the conditions of dental caries and the status of dental fillings. Also, urine tests were conducted followed bya questionnaire survey. To elucidate the factors potentially affecting the mercury concentration in urine, t-test, ANOVA, chi-square test and a mixedmodel were used for the analysis. Regarding the status of dental fillings in line with examination time periods, deciduous teeth had moreamalgam-filled surfaces than those filled with resin, whereas permanent teeth had more resin-filled surfaces than those filled with amalgam. Asignificant relevance was found between the exposure to dental amalgam and urinary mercury levels. Specifically, subjects whose teeth surfaceshad been filled with dental amalgam showed higher urinary mercury levels than those who had no dental amalgam fillings. Based on the analysisusing the mixed model, the increase in the number of teeth surfaces filled with amalgam was found to be the factor affecting the increase in urinarymercury levels. The urinary mercury levels were found to be highly associated with the exposure to dental amalgam. The more the teeth surfacesfilled with amalgam, the higher the urinary mercury levels. Hence, even a trace of dental amalgam fillings can liberate mercury, affecting the variancein the urinary mercury levels. These findings suggest that some criteria or measures should be developed to minimize the exposure to dentalamalgam. Moreover, relevant further studies are warranted.

Polycan-Calcium Gluconate 복합제에 의한 염증인자의 감소 효과

김지혜 ( Ji Hye Kim ),김기림 ( Ki Rim Kim ),진혜정 ( Hye Jung Jin ),임상욱 ( Sang Uk Im ),송근배 ( Keun Bae Song ),최연희 ( Youn Hee Choi ) 한국치위생과학회 2014 치위생과학회지 Vol.14 No.2

The aim of this study was to examine the effect of polycan-calcium gluconate complex on the levels of immune and inflammatory mediators in gingival crevicular fluid and serum from patients with periodontitis. A total of 39 patients with periodontitis took placebo (placebo group) or polycan-calcium gluconate complex (treatment group) twice a day for 4 weeks. At baseline and 4 weeks, gingival crevicular fluid (GCF) and blood was collected from each subjects. The secretion level of interleukin (IL)-1β in GCF was measured by enzyme-linked immunosorbent assay (ELISA). Western blot analysis was conducted to determine the expression of matrix metalloproteinase (MMP)-8 and tumor necrosis factor (TNF)-α in GCF. Serum samples were analysed for MMP-8 by ELISA and C-reactive protein (CRP) by turbidimetric immuno assay. MMP-8 and TNF-α were significantly decreased in the treatment group at 4 weeks. The level of IL-1β in the treatment group was significantly lower than those of the placebo group. No differences were observed in CRP levels. Taken together, these data indicate that taking of polycan-calcium gluconate complex led to reduction of inflammatory biomarkers in serum and GCF of periodontitis patients.