• 한국식품과학회지
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• 제34권5호
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• pp.787-791
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• 2002

수입자유화이후 유입량이 급증한 농산물중 하나인 율무의 원산지 판별을 위하여 CE의 적용가능성을 검토하였다. 분석을 위한 지표물질의 추출을 위해 30% ethanol을 사용하였으며, $50\;{\mu}m\;I.D.{\times}27\;cm$(20 cm inlet to detector)의 capillary를 이용하여 $45^{\circ}C$, 15 kV로 200 nm에서 detect 하였다. 분석 buffer는 0.1 M phosphate buffer(pH 2.5)에 30% methanol과 26 mM HSA를 첨가하였으며, pressure injection 20초, detector rise time 0.1초로 하였다. 분석시 초기에 증류수와 0.1 M phosphate buffer(pH 2.5)로 각 5분씩 capillary를 rinse하고 분석 buffer로 10분간 equilibration 시킨 후 30분간 분석하고 다시 1 M phosphoric acid로 14분간 rinse하여 다음 시료 분석시의 오차를 줄였다. 이 조건으로 2000년 및 2001년의 국산 및 수입산 율무 총 240점을 분석한 결과 서로를 구분하는 peak JT5의 도출이 가능하였으며 이 peak JT5에 의한 국산 및 수입산 율무의 판별율은 2000년 시료에서는 국산이 총 47점 중 39점(판별율 약 83%), 수입산은 총 48점 중 39점(판별율 약 81%), 2001년 시료는 국산 총 74점 중 60점(판별율 약 81%), 수입산은 총 71점 중 59점(판별율 약 83%)이었으며 전체적으로 약 82%의 판별율을 나타내었다.

• Restorative Dentistry and Endodontics
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• 제37권1호
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• pp.9-15
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• 2012

Objectives: This study evaluated the effect of 2% chlorhexidine digluconate (CHX) with different application times on microtensile bonds strength (MTBS) to dentin in class I cavities and intended to search for ideal application time for a simplified bonding protocol. Materials and Methods: Flat dentinal surfaces with class I cavities ($4mm{\times}4mm{\times}2mm$) in 40 molar teeth were bonded with etch-and-rinse adhesive system, Adper Single Bond 2 (3M ESPE) after: (1) etching only as a control group; (2) etching + CHX 5 sec + rinsing; (3) etching + CHX 15 sec + rinsing; (4) etching + CHX 30 sec + rinsing; and (5) etching + CHX 60 sec + rinsing. Resin composite was builtup with Z-250 (3M ESPE) using a bulk method and polymerized for 40 sec. For each condition, half of the specimens were immediately submitted to MTBS test and the rest of them were assigned to thermocycling of 10,000 cycles between $5^{\circ}C$ and $55^{\circ}C$ before testing. The data were analyzed using two-way ANOVA, at a significance level of 95%. Results: There was no significant difference in bond strength between CHX pretreated group and control group at the immediate testing period. After thermocycling, all groups showed reduced bond strength irrespective of the CHX use. However, groups treated with CHX maintained significantly higher MTBS than control group (p < 0.05). In addition, CHX application time did not have any significant influence on the bond strength among groups treated with CHX. Conclusion: Application of 2% CHX for a short time period (5 sec) after etching with 37% phosphoric acid may be sufficient to preserve dentin bond strength.

• 치위생과학회지
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• 제11권5호
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• pp.397-404
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• 2011

최근 구강관리에 대한 관심이 증가하면서 시판되고 있는 구강양치용액의 종류도 다양해지고 있고 휴대가 간편하여 쉬운 사용방법으로 활용이 급진적으로 증가하고 있다. 본 연구에서는 시판 중인 구강양치용액의 pH를 측정하여 고유 산도가 법랑질 표면의 색조변화, 미세경도, 미세구조 변화, 거칠기 측정 등에 관한 실험방법을 통하여 구강양치용액의 효과를 평가하였다. 1. 색조변화는 Nextcare와 Listerine에서 light-dark를 나타내는 $L^*$값은 0에 가깝게 어두워졌으며 yellow-blue를 나타내는 $b^*$값은 초기값과 비교하여 채도가 낮아졌다. 특히 Listerine에서 ${\Delta}L^*$, ${\Delta}b^*$ 각각 -6.70, -7.20으로 가장 큰 변화를 보였다. 2. 표면경도 측정에서는 Nextcare와 Listerine에서 모두 통계적으로 유의한 감소를 보였다(p<0.05). 또한 표면의 형상과 거칠기에서도 Nextcare와 Listerine에서 다른 실험군과 비교하여 법랑질 표면의 붕괴 및 침식양상과 함께 거칠기가 매우 높아졌음을 알 수 있었다. 결론적으로, 현재 시판 중인 구강양치용액의 pH를 측정하여 고유 산도가 치아 경조직에 미치는 영향에 대해 알아본 결과, 산성의 pH를 가진 구강양치용액을 장기간 사용시 치면 착색 및 법랑질 표면의 영향을 줄 수 있으므로 적절한 사용법을 숙지하여 단기간 사용하는 것이 안전할 것으로 사료된다.

• 디지털융복합연구
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• 제17권12호
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• pp.393-398
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• 2019

본 연구에서는 잇솔질 후 헹굼 횟수에 따른 흡광도 및 pH 변화를 조사하여 구강 내 잔여 치약의 양을 확인하고 이를 통하여 적정 헹굼 횟수를 제시하고자 하였다. 연구대상자는 대전, K대학 대학생 중 일생생활에 지장이 없는 건강한 신체를 가진 학생 총 14명을 선정하였으며, 연구대상자는 잇솔질 후 0회부터 12회까지 40ml의 물로 입울 헹구었다. 각 헹굼액은 수거하여 흡광도 및 pH를 측정하였다. 헹굼액의 흡광도 값을 측정한 결과, 잇솔질 후 6 ~ 7회의 헹굼액부터 흡광도 값이 일정한 수치를 보이며 통계적으로 유의한 결과가 나타났다(p<0.05). 1g, 1.5g, 2g으로 달리한 치약의 양에 따라서는 차이가 없었다. 향후 이러한 결과를 바탕으로 세치제 사용에 관한 교육과 구강 내 잔여 세치제가 구강에 미치는 영향에 대한 다양한 연구가 필요할 것으로 사료된다.

• 대한치과의사협회지
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• 제55권2호
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• pp.180-188
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• 2017

Introduction : Inadequate oral health control is a major risk of oral diseases. Regular home-based care is essential to maintain good oral hygiene. In particular, mouthrinses can support conventional tooth brushing in reducing accumulation of oral plaque. Effect : Antimicrobial mouthrinses are used as part of daily oral care to reduce plaque and gingivitis. Mouthrinses contains fluoride could help remineralization of enamel and dentin. The most common molecules contained in mouthrinses are chlorhexidine, essential oils, cetyl pyridinium chloride, triclosan, hyaluronic acid. Currently, chlorhexidine is the most efficacious compound, with both antiplaque and antibacterial activities. Similar results are reported for essential oils and cetyl pyridinium chloride, although with a somewhat reduced efficacy. Considering the adverse effects of chlorhexidine and its time-related characteristics, this molecule may best be indicated for acute/short term use, while essential oils and cetyl pyridinium chloride may be appropriate for long-term, maintenance treatment. Conclusion and suggestion : Antimicrobial mouthrinses are safe and effective, and when used in conjunction with brushing and flossing, they are an important method of reducing plaque and gingivitis. To improve compliance, dental health care professionals should adapt oral health care recommendations to fit patients' specific needs.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3279-3281
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• 1999

This paper describes a method of direct wafer bonding using surfaces activated by a radio-frequency hydrogen plasma. The hydrogen plasma cleaning of silicon in the RIE mode was investigated as a pretreatment for silicon direct bonding. The cleaned silicon surface was successfully terminated by hydrogen, The hydrogen-terminated surfaces were rendered hydrophilic, which could be wetted by Dl water rinse. Two wafers of silicon and silicon dioxide were contacted to each other at room temperature and postannealed at $300{\sim}1100^{\circ}C$ in an $N_2$ atmosphere for 2 h. From the AFM results, it was revealed that the surface became rougher with the increased plasma exposure time and power. The effect of the plasma treatment on the surface chemistry was investigated by the AES analysis. It was shown that the carbon contamination at the surface could be reduced below 5 at %. The interfacial energy measured by the crack propagation method was 122 $mJ/m^2$ and 384 $mJ/m^2$ for RCA cleaning and hydrogen plasm, respectively.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.89-89
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• 2009

높은 소수반송자 수명(life-time)을 가지는 고품위 실리콘 기판은 고효율 실리콘 이종접합 태양전지 제작을 위한 중요 요소 기술 중 하나이다. 본 연구에서는 n-type c-Si 기판을 이용한 고효율 실리콘 이종접합 태양전지제작을 위해 hot water oxidation(HWO) 공정을 이용하여 고품위 실리콘 기판을 제작하였다. 실리콘 기판의 특성 분석은 Qusi-steady state photoconductance (QSSPC)를 이용하여 소수반송자 수명을 측정하였으며, 기판의 면저항 및 wetting angle을 측정하여 공정에 따른 특성변화를 분석하였다. Saw damage etching 된 기판을 웨이퍼 표면으로부터 particle, 금속 불순물, 유기물 등의 오염을 제거하기 위해 $60{\sim}85^{\circ}C$로 가열된 Ammonia수, 과산화수소수($NH_4OH/H_2O_2/H_2O$), 염산 과산화수소수($HCL/H_2O_2/H_2O$) 및 실온 희석불산(DHF) 중에 기판을 각각 10분 정도씩 침적하여, 각각의 약액 처리 후에 매회 10분 정도씩 순수(DI water)에서 rinse하여 RCA 세정을 진행한 후 HWO 공정을 통해 기판 표면에 얇은 산화막 을 형성시켜 패시베이션 해주었다. HF를 이용하여 자연산화막을 제거시 HWO 공정을 거친 기판은 매끄러운 표면과 패시베이션 영향으로 기판의 소수 반송자 수명이 증가하며, 태양전지 제작시 접촉저항을 감소시켜 효율을 증가 시킬수 있다. HWO 공정은 반응조 안의 DI water 온도와 반응 시간에 따라 life-time을 측정하여 진행하였으며, 이후 PE-CVD법으로 증착된 a-Si:H layer 및 투명전도 산화막, 금속전극을 증착하여 실리콘 이종접합 태양전지를 제작하였다.

• Restorative Dentistry and Endodontics
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• 제40권3호
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• pp.202-208
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• 2015

Objectives: This study determined the effect of the air-stream application time and the bonding technique on the dentin bond strength of adhesives with different solvents. Furthermore, the content and volatilization rate of the solvents contained in the adhesives were also evaluated. Materials and Methods:Three adhesive systems with different solvents (Stae, SDI, acetone; XP Bond, Dentsply De Trey, butanol; Ambar, FGM, ethanol) were evaluated. The concentrations and evaporation rates of each adhesive were measured using an analytical balance. After acid-etching and rinsing, medium occlusal dentin surfaces of human molars were kept moist (conventional) or were treated with 10% sodium hypochlorite for deproteinization. After applying adhesives over the dentin, slight air-stream was applied for 10, 30 or 60 sec. Composite cylinders were built up and submitted to shear testing. The data were submitted to ANOVA and Tukey's test (${\alpha}=0.05$). Results: Stae showed the highest solvent content and Ambar the lowest. Acetone presented the highest evaporation rate, followed by butanol. Shear bond strengths were significantly affected only by the factors of 'adhesive' and 'bonding technique' (p < 0.05), while the factor 'duration of air-stream' was not significant. Deproteinization of dentin increased the bond strength (p < 0.05). Stae showed the lowest bond strength values (p < 0.05), while no significant difference was observed between XP Bond and Ambar. Conclusions: Despite the differences in content and evaporation rate of the solvents, the duration of air-stream application did not affect the bond strength to dentin irrespective of the bonding technique.

• Restorative Dentistry and Endodontics
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• 제47권2호
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• pp.21.1-21.11
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• 2022

Objectives: This study aimed to investigate the bonding effects of cleaning protocols on dentin impregnated with endodontic sealer residues using ethanol (E) or xylol (X). The effects of dentin acid etching immediately (I) or 7 days (P) after cleaning were also evaluated. For bonding to dentin, universal adhesive (Scotchbond Universal; 3M ESPE) was used. The persistence of sealer residues, hybrid layer formation and microshear bond strength were the performed analysis. Materials and Methods: One hundred and twenty bovine dentin specimens were allocated into 4 groups (n = 10): G1 (E+I); G2 (X+I); G3 (E+P); and G4 (X+P). The persistence of sealer residues was evaluated by SEM. Confocal laser scanning microscopy images were taken to measure the formed hybrid layer using the Image J program. For microshear bond strength, 4 resin composite cylinders were placed over the dentin after the cleaning protocols. ANOVA followed by Tukey test and Kruskal-Wallis followed by Dunn test were used for parametric and non-parametric data, respectively (α = 5%). Results: G2 and G4 groups showed a lower persistence of residues (p < 0.05) and thicker hybrid layer than the other groups (p < 0.05). No bond strength differences among all groups were observed (p > 0.05). Conclusions: Dentin cleaning using xylol, regardless of the time-point of acid etching, provided lower persistence of residues over the surface and thicker hybrid layer. However, the bond strength of the universal adhesive system in etch-and-rinse strategy was not influenced by the cleaning protocols or time-point of acid etching.

• 한국학교보건학회지
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• 제14권1호
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• pp.107-114
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• 2001

The purpose of this study was to collect basic data for the development of oral health education program of parents and to encourage their actual interest and participation in school oral health program. The authors surveyed parents' awareness and behaviors about the oral health of their children. The subjects in this study were 193 parents of elementary school children in Seoul. The collected data were analyzed, the obtained results were as follows: 1. Thirty-five percent of the parents investigated paid a regular visit to a dental clinic. The most common tooth brushing time among them was after dinner, the second was after breakfast, and this was followed by before bedtime and before breakfast 2. Ninety-four percent of the parents responded that prevention is necessary, 92.2% had a plan to visit a dental clinic to prevent dental caries, and 60.1% experienced receiving pit and fissure sealants. Ninety-seven percent responded that they did check their children's dental caries. 54.9% checked their children's oral status after tooth brushing. The parents who visit a dental clinic on a regular basis were more likely to check their children's teeth after tooth brushing than those who don't(P<0.05). 3. Eighty eight percent of respondents wanted to keep the fluoride mouth rinse program. 4. It is recommended that an oral health education program be developed for parents to visit dental clinics on a regular basis, to educate as to the right tooth brushing time, and to check out their children's oral status after tooth brushing.