Inhibition of post-bleach stain by dentifrice containing nano-carbonate apatite

강시묵 ( Si Mook Kang ),권호근 ( Ho Keun Kwon ),김백일 ( Baek Il Kim ) 대한구강보건학회 2007 大韓口腔保健學會誌 Vol.31 No.-

새로운 색지표를 이용한 우식활성검사법 개발

강시묵 ( Si Mook Kang ),정회인 ( Hoi In Jung ),정승화 ( Seung Hwa Jeong ),권호근 ( Ho Keun Kwon ),김백일 ( Baek Il Kim ) 대한예방치과·구강보건학회 2010 大韓口腔保健學會誌 Vol.34 No.1

Objectives. The aim of this study was to develop a new caries activity test based on colorimetric changes that could better reflect the amount of acid produced by oral bacteria as a broad spectrum of color than the previous test. The optimal candidates were combinations of pH indicators, and these were evaluated in pH buffering solutions and using dental plaque. Methods. Six pH indicators, Bromocresol-purple (BCP), Bromocresol-green (BCG), Methyl-red (MR), Methyl-orange (MO), Resazurin (R), and Naphthyl-red (NR), were selected to show different colors at various pH environments (range pH 3.0~7.0). BCP and BCG are pH indicators that are already used in the Cariostat(R), and they can show color changes from blue to yellow. This study tried to broaden the color change spectrum from blue to red to give a more distinct differentiation at various pHs. Four pH indicators (MR, MO, R and NR) were blended with BCP and BCG. Each combination of the three indicators was assessed in different pH buffer systems: pH 7.0, 6.0, 5.0, 4.0, and 3.0. The selected combinations of pH indicators were applied to human dental plaque from 11 subjects (mean age: 27) to confirm the reproducibility of the in vitro results. Results. According to the in vitro buffer system, the mixture of BCP, BCG and MR did not show any differences between pH 4.0 and pH 3.0. On the other hand, the mixtures of BCP-BCG-MO (ratio 2:1:1.5), BCP-BCG-R (1.5:1:0.5) and BCP-BCG-NR (2:1:1.5) showed distinguishable color changes from pH 7.0 to pH 3.0. Among the three candidates, the BCP-BCG-NR mixture showed the best color differences in the buffer solution and the human dental plaque cultivated solutions at various pHs. Conclusions. This study evaluated a new colorimetric caries activity test that used a combination of several pH indicators. The new system can easily detect various pH environments from organic acid fermentation by using a wider range of colors (blue-dark green-green-orange-red).

TiO₂ 농도 및 여기광에 따른 광촉매 반응이Streptococcus mutans의 생장에 미치는 영향

강시묵 ( Si Mook Kang ),이해나 ( Hae Na Lee ),김희은 ( Hee Eun Kim ),김백일 ( Baek Il Kim ) 한국치위생과학회 2014 치위생과학회지 Vol.14 No.3

The aim of this study was to evaluate influences of titanium dioxide (TiO2) concentrations and irradiation times on growth of Streptococcus mutans when irradiated by visible light (405 nm wavelength) and by ultraviolet light (254 nm wavelength). To find the optimal antibacterial concentration ofTiO2, 0.01, 0.1, 1.0, and 10.0 mg/ml TiO2 suspension was prepared with sterilized distilled water. S. mutans cultured media was added to TiO2solution to set the final cell count to 104 CFU/ml. The photo catalytic reaction was induced by irradiating 254 nm and 405 nm lights for 10 minutes. To compare the bactericidal activities according to irradiation times, all photo catalytic reaction was carried out with 0.1 mg/ml TiO2 for 0, 10, 20, 30, and 40 minutes with both lights. After the photo catalytic reaction, 100 μm of the reaction mixture was immediately plated on brain heart infusion agar. These plates were placed at 5% CO2, 37oC, for 24 hours and the bacterial colonies were counted. All experiments were performed in quintuplicate. One-way ANOVA was used to determine whether there were any significant differences between the TiO2 concentrations or the irradiation times. The most effective concentration of TiO2 for its photo catalytic bactericidal effect on S. mutans was 0.1 mg/ml when irradiated with254 nm and 405 nm lights. The longer the irradiation time, the bigger the bactericidal effect for both wavelengths. Over 99% of bacteria in theinoculum were killed after irradiation with 254 nm for 20 minutes and with 405 nm for 40 minutes. In conclusion, a photo catalytic reaction of TiO2induced by visible light of 405 nm constitutes the bactericidal effect on S. mutans.

QLF-D, ICDAS, DIAGNOdent를 이용한 발거된 치아의 교합면 우식증의 정량화 비교

강시묵 ( Si Mook Kang ),민지현 ( Ji Hyun Min ),김한나 ( Han Na Kim ),김백일 ( Baek Il Kim ),김진범 ( Jin Bom Kim ),정승화 ( Seung Hwa Jeong ) 대한예방치과·구강보건학회 2014 大韓口腔保健學會誌 Vol.38 No.2

Objectives: To compare the QLF-D method and the ICDAS and DIAGNOdent techniques for in vitro quantification of occlusal caries and to assess the histological features of the caries. Methods: One hundred and twenty-two extracted permanent teeth were selected, and the site of interest on the occlusal surface was examined using each detection method. The occlusal sites were classified according to the ICDAS II criteria based on the decision taken by two investigators, who have taken the ICDAS E-learning course. The examined site was then measured using the DIAGNOdent, and the peak value was recorded. In addition, by using the QLF-D, the occlusal site was photographed to obtain the ΔFmax value. After all assessments were performed, the occlusal sites were vertically sectioned in order to assess the histological features. This was considered the gold standard. The histological criteria were graded using a 4-point scale as follows: S=sound (n=21), E1=limited enamel caries (n=27), E2=caries extending to the dento-enamel junction (n=49), D=caries involving the dentine (n=25). Results: An ICDAS code between 0 and 4 was assigned to all the occlusal sites, and this revealed the QLF-D value, which was between ―95 to 0. The DIAGNOdent value was between 8 and 99. The correlation values of QLF-D, ICDAS, and DIAGNOdent with the histological features were 0.68, 0.58, and 0.46, respectively (P<0.01). A highly significant correlation was observed between QLF-D and the gold standard, which showed a moderate correlation and an acceptable correlation was observed with ICDAS (r=0.75, P<0.01). A statistically significant difference was observed in the average QLF-D values of each histological grade i.e., ―28.5 (S), ―53.7 (E1), ―68.1 (E2), and ―84.4 (D). Conclusions: The QLF-D showed a significant correlation with the ICDAS and histological features. Therefore, visual inspection with QLF-D would improve the detection accuracy and ensure early diagnosis of dental caries.nt

예방치과학 분야 : 원저 ; 전문가 미백 처치 후 나노 탄산 아파타이트 함유 치약에 의한 재 착색 방지 효과

강시묵 ( Si Mook Kang ),김희은 ( Hee Eun Kim ),권호근 ( Ho Keun Kwon ),김백일 ( Baek Il Kim ) 대한구강보건학회 2008 大韓口腔保健學會誌 Vol.32 No.1

국내 시판 일부 구강 양치액의 Streptococcus mutans 바이오필름 형성 억제 효과

이은송 ( Eun Song Lee ),강시묵 ( Si Mook Kang ),김은우 ( Eunu Kim ),권호근 ( Ho Keun Kwon ),김백일 ( Baek Il Kim ) 대한예방치과·구강보건학회 2011 大韓口腔保健學會誌 Vol.35 No.3

Objectives. The aim of this in vitro study was to evaluate the inhibitory effects of several commercially available antibacterial oral rinses on S. mutans biofilm formation. Methods. In this study, four commercial oral rinses produced in Korea containing different antibacterial substances (benzethonium chloride, cetylpyridinium chloride, chlorhexidine, and essential oil) were selected for assessment. Sterile distilled water and 0.1% chlorhexidine solution were used as a negative and a positive control, respectivery The planktonic S. mutans (107 CFU/ml) was mixed with the experimental oral rinses for 1 minute and the live cells were counted as a colonies forming unit (CFU). Also, the antibacterial effect of oral rinses were tested by a S. mutans biofilm model with the artificial saliva, THYE medium, and hydroxyapatite (HA) discs. The S. mutans biofilm was formed on an HA disc coated with artificial saliva for 64 hours. The medium was replaced every 24 hours, and the cultured biofilm was treated with each oral rinse for either 1 or 5 minutes, 3 times a day for two days. Also, the number of live cells in the biofilm were counted and denoted as CFU. Results. All four commercial oral rinses elicited significant antibacterial effects on planktonic S. mutans, showing more than 99% of CFU reduction. However, only Hexamedine oral rinse primarily composed of chlorhexidine exhibited a significant antibacterial effect on S. mutans biofilm. Conclusions. The antibacterial effects of the commercial oral rinses were less pronounced in biofilm than in the planktonic cells, and they varied among different products.

계면활성제를 첨가한 잔토리졸의 항균효과

김해선 ( Hae Sun Kim ),강시묵 ( Si Mook Kang ),권호근 ( Ho Keun Kwon ),김백일 ( Baek Il Kim ) 대한예방치과·구강보건학회 2011 大韓口腔保健學會誌 Vol.35 No.1

Objectives. The aim of this study was to evaluate the antibacterial effect caused by a combination of Xanthorrhizol (Xan) and several surfactants on planktonic and biofilm of S. mutans. An additional aim was to confirm the safety of a combined solution as a MTT cell viability assay. Methods. The Xan, isolated from Indonesian folk medicinal plants, was used at concentrations of 12.5 and 25 ppm. Ethanol (12.5%) was used as a solvent, while sodium lauryl sulfate (SLS; 200, 250 ppm) and sodium methyl cocoyl taurate (Tau; 250, 300 ppm) were used as surfactants. The planktonic S. mutans ATCC 25175 (2×107 CFU/ml) was mixed with Xan containing surfactant and ethanol for 5 minutes, and counted as colonies of live cells. The antibacterial effect of Xan was tested by a biofilm model with S. mutans, which was used with the saliva-media, hydroxyapatite (HA) disc and BHI broth. The cultured biofilm on HA disc was exposed to the treatment solutions mixed with Xan, surfactants, and ethanol for 5 minutes. This process was repeated at 16, 40, 64 hours later. MTT assays were carried out to evaluate cell viability and cell proliferation after exposure of Xan. Results. Antibacterial effect of Xan on planktonic S. mutans significantly increased when applied with 200 ppm SLS and 300 ppm Tau (p<0.05). The formation of S. mutans biofilm was inhibited by 25 ppm Xan mixed with 250 ppm SLS or 300 ppm Tau. In addition, the cytotoxicity of Xan was similar to that of 0.2% chlorhexidine oral rinse. Conclusions. The solutions of Xanthorrhizol with surfactants such as SLS and Tau showed significant antimicrobial effect on planktonic and biofilm cells of S. mutans (p<0.05). These solutions also exhibited biological safety similar to chlorhexidine oral rinse.

치약 내 불소의 생리적 가용능 평가

고혜연 ( Hae Youn Ko ),강시묵 ( Si Mook Kang ),권호근 ( Ho Keun Kwon ),김백일 ( Baek Il Kim ) 대한예방치과·구강보건학회 2015 大韓口腔保健學會誌 Vol.39 No.2

Objectives: The aims of this study were to determine the total fluoride concentration and bioavailable fluoride concentration in different toothpastes, based on a newly suggested method by the International Organization for Standardization (ISO), and to compare the measured concentrations with the concentrations written on the packaging. Methods: The concentrations of total fluoride (TF) and bioavailable fluoride (BF) were measured in six toothpastes. For the TF measurement, 1 g of each toothpaste was mixed with dipotassium hydrogen phosphate (K2HPO4), and hydrogen chloride (HCl) was placed. After 24 hours, the samples were centrifuged and total ionic strength adjustment buffer (TISAB) solution was added. For the BF measurement, the toothpaste was mixed with K2HPO4 for only 1 minute. The samples were centrifuged, and then HCl was placed and allowed to stand for 24 hours. The TISAB solution was added subsequently. The concentration of fluoride ions was measured using a fluoride ion-selective electrode and calculated against a standard curve. Results: The six toothpastes were composed of different fluoride compounds and abrasives. The measured TF concentration ranged from 624.99 ppm to 1,353.00 ppm, and the similarity to the declared fluoride concentration ranged from 53.48% to 93.31%. The measured BF concentration ranged from 587.61 ppm to 1,360.05 ppm, and the similarity to the expected fluoride concentration ranged from 41.97% to 93.80%. Two samples were clearly separated when the samples were centrifuged, whereas the remaining four samples had unclear supernatants. The clearly separated toothpastes (i.e., toothpastes 5 and 6) had BF concentrations that were similar to or lower than the declared fluoride concentrations and the measured TF concentrations. However, the unclearly separated toothpastes showed inconsistent relationships between the measured TF and BF concentrations. Conclusions: The measured TF and BF concentrations of the six toothpastes did not reach the expected fluoride concentration. This finding resulted from the different compositions and forms of the toothpastes. Therefore, the properties of toothpastes need to be considered when measuring their fluoride concentrations.

법랑질 병소 회복율 평가를 위한 QLF 기술의 적용

김경민(Gyung-Min Kim),구혜민(Hye-Min Ku),이은송(Eun-Song Lee),강시묵(Si-Mook Kang),Elbert de Josselin de Jong,권호근(Ho-Keun Kwon),김백일(Baek-Il Kim) 대한치과의사협회 2017 대한치과의사협회지 Vol.55 No.2

Purpose: The aim of this in vitro study was to assess changes in remineralization by stimulated human saliva over a short period of 48 hours with quantitative light-induced fluorescence (QLF) technology. Materials and Methods: Bovine incisor surfaces were demineralized for 10 days. Two types of stimulated saliva were collected from 7 healthy persons. 24 hours after tooth brushing (Stimulated saliva group) and immediately after tooth brushing with 1,000 ppm NaF dentifrice (Dentifrice saliva group). The specimens were immersed in saliva and fluorescence images were obtained by QLF-digital (QLF-D biluminator<SUP>TM</SUP>‚) at 2, 4, 6, 12, 24, and 48 hours fluorescence loss (⊿F%) of the lesions. A paired t-test was performed to assess fluorescence differences between before (⊿Fbaseline) and after (⊿Ftreatment time) the remineralization process. Results: Before the remineralization, the mean ⊿Fbaseline of the initial demineralized specimens was -18.42±0.15 (%). In both groups, the ⊿F values obtained at baseline and after 2 hours were statistically significant (P < 0.001), indicating recovery of the lesions by approximately 40% after 2 hours. After 48 hours, remineralization rates were slightly higher (49%) for the stimulated saliva group than for the dentifrice saliva group (41%), but the difference was not statistically significant. Conclusions: With QLF minute degrees of remineralization by saliva can be measured in periods as short as 2 hours. Additionally no significantly higher effects of remineralization were observed in the dentifrice saliva group when compared to the stimulated saliva group.

치주 건강 상태에 따른 치면세균막의 산 생성능력 평가에 대한 연구

민지현 ( Ji Hyun Min ),윤홍철 ( Hong Cheol Yoon ),김종관 ( Jong Kwan Kim ),강시묵 ( Si Mook Kang ),김백일 ( Baek Il Kim ) 한국치위생과학회 2015 치위생과학회지 Vol.15 No.2

The aim of this retrospective study was to evaluate the relationship between periodontal health condition and the results of a new method such as Cariview which could evaluate the acidity of dental biofilms. Fifty four subjects more than 20 years old were selected for the candidates of this study. The periodontal health conditions of the candidates were divided into 4 groups according to the assessment of X-ray and Quantitative Light-induced Fluorescence-Digital (QLF-D; Inspektor Research Systems BV) images; gingivitis, slight periodontitis, moderate periodontitis, severe periodontitis. The biofilm acidogenicity of each subject was examined using Cariview (All in ONE BIO) according to manufacturer`s instruction, and the Cariview score was calculated. The mean differences of Cariview score between 4 groups of periodontal health condition were examined by ANCOVA test with the covariance of decayed, missing, and filled teeth (DMFT) index. As a result, the mean Cariview score was different, however it was not significantly different from the 4 groups (p=0.12). The mean score was the lowest in the gingivitis group (40.54±11.01), and the highest in slight periodontitis group (57.26±20.51). In conclusion, the significant mean differences were not confirmed in Cariview score according to the periodontal health condition.