• Restorative Dentistry and Endodontics
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• 제27권3호
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• pp.249-256
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• 2002

The use of flowable composite resins as liners in class II packable composite restoration has been suggested by some manufacturers. However, the contributions of this technique are unproven. The purpose of this study was to compare the gingival microleakage in class II packable composite restorations with or without the use of flowable composite resins as liners. Slot cavities were prepared on both proximals of 80 extracted human molars and randomly assigned to 8 groups of 20 each. The gingival margins were located at 1mm above CEJ in 80 cavities (group1-4) and 1mm below CEJ in 80 cavities (group5-8). The prepared teeth were mounted in the customized tray with adjacent teeth to simulate clinical conditions and metallic matrix band (Sectional matrix) and wooden wedges were applied. After acid etching and application of Single Bond, each group was restored with the following materials using incremental placement technique: Group 1,5 (Filtek P60), group 2, 3, 4 and group 6, 7, 8 (AeliteFlo, TetricFlow, Revolution/ Filtek P60). All specimens were thermocycled 500 times between 5$^{\circ}C$ and 55$^{\circ}C$ with 1 mimute dwell time, immersed 2% methylene blue dye for 24 hours and then rinsed with tab water. The specimens were embedded in clear resin and sectioned longitudinally through the center of restoration with a low speed diamond saw. Dye penetration at gingival margin was viewed at 20 magnification and analyzed on a scale of 0 to 4. Kruscal-Wallis One way analysis and Mann-Whitney Rank sum test were used to analyze the results. The results of this study were as follows. 1. The leakage values seen at the enamel margin were significantly lower than those seen at the dentin margin(P<0.05). 2. On the enamel margin, packable composite resins with flowable liners showed lower leakage than those without flowable liners, but there were no significant differences among the four groups(P>0.05). 3. On the dentin margin, four groups demonstrated moderate to severe leakage, and there were no significant differences in leakage values(P>0.05).

• Restorative Dentistry and Endodontics
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• 제27권3호
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• pp.232-238
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• 2002

연구목적 : Cytokine은 유해 미생물에 대한 숙주의 방어기전으로서의 염증반응에서 숙주세포 상호간의 작용을 매개해 주는 역할을 하며, 인간의 치수조직에서도 그 존재가 확인된 바 있다. Interleukin-6와 Interleukin-10은 염증의 초기에 작용하는 cytokine으로 알려져 있으나, 치수 및 치근단 질환에서의 역할과 상호작용에 대해서는 잘 알려져 있지 않다. 본 연구에서는 치수염의 원인균으로 알려진 Prevotella nigrescens를 이용하여 백서의 치수염을 유도한 후 시간의 변화에 따른 Interleukin-6, Interleukin-10의 농도의 변화를 측정하여 이들의 치수염에서의 작용을 알아보는 것을 목적으로 한다. 방법 : 실험적으로 치수의 염증반응을 일으키기 위하여 치수염의 원인균으로 알려진 Prevotella nigrescens를 이용하였다. 실험동물의 하악절치의 incisal tip부분을 절단한 후(n=120), 치수강을 개방시켰다. 실험군에서는 Prevotella nigrescens를 멸균된 면구에 묻혀서 개방된 치수강 내에 접종하였으며, 대조군에서는 균을 접종하지 않고 멸균된 면구만을 개방된 치수강 내에 위치시켰다. 그 후 1, 2, 5일이 경과되었을 때 실험에 사용된 치아를 발치하여, 치수조직을 적출하였다. Amersham사의 ELISA kit를 사용하여 적출된 치수조직내의 Interleukin-6와 Interleukin-10의 양을 측정하였으며 그 결과를 Mann-Whitney rank sum test를 사용하여 통계학적 유의성을 검증하였다. 조직학적 검사를 위해서는 발치된 치아를 nitric acid를 사용하여 탈회시킨 후 헤마톡실린-에오신 염색을 시행한 후 관찰하였다. 결과 : 1) Interleukin-6의 농도는 균접종 후 1일, 2일, 5일 모두에서 실험군에서 대조군보다 높게 나타났으며, 균접종 1일째의 결과는 통계적 유의성이 있었다(P<0.05). 2) Interleukin-10의 농도는 균접종 후 1일, 2일, 5일 모두에서 실험군에서 대조군보다 높게 나타났으며, 균접종 1일째의 결과는 통계적 유의성이 있었다(P<0.05). 3) Interleukin-10/1nterleukin-6 ratio는 실험군과 대조군 모두에서 1일보다 2일째의 결과에서 더 높은 값을 보였으며 대조군에서는 통계적 유의성을 보였다(P<0.05). 4)조직학적 관찰결과 균접종 후 2일째의 조직표본에서는 림프구의 침윤과 부분적인 조직의 괴사 등 염증반응의 양상을 관찰할 수 있었으며, 균접종 5일째의 조직표본에서는 염증의 정도가 감소되는 양상을 확인할 수 있었다.

• Journal of the Korean Data and Information Science Society
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• 제28권2호
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• pp.339-348
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• 2017

전통적인 통계적 공정관리에서 품질특성치의 위치모수와 척도모수의 변화를 탐지하는 것은 주된 관심사였고, 이를 위해 일반적으로 두 개의 관리도를 병행하여 사용한다. 그러나 하나의 관리도를 사용하여 두 모수의 변화를 동시에 탐지하는 절차에 대한 연구도 많이 진행되어 왔다. 하나 또는 두 개의 관리도를 사용할 때, 제1국면 (phase I)을 통하여 모수를 추정하여 관리한계를 설정하여 제2국면(phase II)의 관리도를 운영하는데 이때 정규성 가정의 만족 여부는 아주 중요한 점검 사항이다. 실제 공정에서는 종종 분포에 대한 가정을 하기 어렵거나 정규분포를 따른다고 가정하기 어려운 경우가 있는데, 이러한 경우에는 비모수적 관리도를 사용할 수 있다. 이 논문에서는 비모수적 관리도이면서, 하나의 관리도를 사용하여 위치모수와 척도모수의 변화를 탐지하는 Shewhart-Lepage 관리도를 소개하고, 위치모수와 척도모수가 동시에 변화할 때 진단 단계에서 변화의 원인을 가장 정확하게 진단할 수 있는 최적의 진단한계를 모의실험을 통해 제시하고 그 효율에 대해 연구하였다.

• Journal of Korean Dental Science
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• 제5권1호
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• pp.7-12
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• 2012

Purpose: To examine the antibacterial effectiveness of silver nanoparticles (SNP) mixed with commercial orthodontic adhesives. Materials and Methods: SNP was prepared by dissolving silver perchlorate in an organic solvent and reducing it with ultraviolet radiation. SNP was then mixed with four commercial orthodontic adhesives (Light Bond, Blugloo, Transbond XT, and Fuji Ortho LC) (0.05 wt %), which were then formed into disc-shape specimens ($8.0mm{\times}3.0mm$). Commercial orthodontic adhesives containing no SNP were used as the control groups. Specimens of the four experimental and four control groups were incubated with streptococcus mutans and the medium turbidity was assessed at 3, 6, 9, 12, and 24 hours after incubation. The agar diffusion test was also performed to examine the growth inhibition zone of these groups. The data were statistically analyzed using a Wilcoxon rank sum test and t-test with a Bonferroni's correction (P<0.05). Result: The SNP containing groups had a superior antibacterial effect compared to the control groups. In the agar diffusion test, the control groups without SNP did not produce an inhibition zone, whereas the SNP containing groups showed inhibition zone of 10~13 mm. Conclusion: The incorporation of SNP into orthodontic adhesives can inhibit cariogenic bacterial growth.

• 분석과학
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• 제24권1호
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• pp.38-44
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• 2011

본 연구는 제주지역에서 생산되는 세 종류의 물과 서울지역에서 사용되고 있는 수돗물 등 네 종류의 물을 전탕용수로 하여 중요 한약재인 대황으로부터 활성성분을 추출하고 용수 중의 미네랄이 대황활성성분 추출에 미치는 효과에 대하여 비교 분석하였다. 유도결합플라즈마방출분광기와 유도결합플라즈마질량분석기를 이용하여 30여종의 미네랄과 다수의 음이온을 분석하였다. 각 전탕용수로 대황을 추출하고 그 추출액의 일부를 증발시켜 총 추출량을 구하고, 또한 HPLC를 이용하여 추출액으로부터 대황의 생리활성 성분을 분석하였다. 용수 간 총 추출량과 대황 성분함량의 차이 검정을 위하여 Kruskal-Wallis 검정을 시행하였고, 미네랄, 음이온, 총 추출량 및 성분함량과의 관계분석을 위하여 다중요인분석을 시행하였다. 분석결과 용수 중의 미네랄 함량은 대황의 총 추출량 및 성분 추출량과 높은 상관관계가 있는 것으로 나타났다.

• Restorative Dentistry and Endodontics
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• 제25권1호
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• pp.123-132
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• 2000

To overcome problems of conventional glass ionomers, resin components have been added to glass ionomers. On a continuum between glass ionomers and composites are a variety of blends, employing different proportions of acid-base and free radical reactions to bring about cure. Popular groups defined between the ends are resin-modified glass-ionomers(RMGIs), polyacid-modified composite resins(Compomers) and ionomer modified resins. These groups show different clinical properties, and in selecting these materials for a restoration, one should sufficiently understand these different setting properties. In this study, some difference in the setting characteristics of different groups of hybrid ionomers were examined. Two RMGIs (Fuji2 LC,GC / Vitremer, 3M), three Compomers (Dyract AP, Dentsply / F2000, 3M / Elan, Kerr) were involved in this study. The identification of the setting characteristics of different groups was achieved by a two-stage study. First, thermal analysis was performed by a differential scanning calorimeter, and then the hardness of each group at different depth and time were measured by a micro-hardness tester. Thermal analysis was performed to identify the inorganic filler content and to record the heat change during setting process. The setting process was progressed for each material by chemical set mode and light-cured mode. In the hardness test, samples of materials were prepared with a 6mm-diameter metal ring, and the hardness was measured at the top, and 1mm, 2.5mm, 4mm below at just after a 40 second-cure, and after 10 minutes, 24 hours, and 7 days. Statistical analysis was performed by Mann-Whitney rank sum test to assess significant differences between set modes and types of materials, and by ANOVA and T-test to evaluate the statistical meanings of data at different times and depths of each materials. Followings are findings and conclusions derived from this study. Thermal analysis; 1. Compomers show no evidence of chemical setting while RMGIs exhibit heat output during the process of chemical setting. 2. Heat of cure of RMGIs exceed Compomers. 3. The net heat output of RMGIs through light-cured mode is higher than through chemically set mode. Hardness test; 1. Initial hardness of RMGIs immediately after light cure is relatively low, but the hardness increases as time goes by. On the contrary, Comomers do not show evident increase of the hardness following time. 2. Compomers show a marked decrease of setting degree as the depth of the material increases. In RMGIs, the setting degree at different depths does not significantly differ.

• 치위생과학회지
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• 제16권2호
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• pp.134-141
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• 2016

이번 연구는 치위생학과 교육과정에서 이론과 실습으로 구성된 효과적인 치과의료커뮤니케이션의 교육과정을 개발하기 위한 목적으로 운영되었으며, 다음과 같은 결론을 얻었다. '관계 형성하기', '대화 열기', '정보 수집하기', '상대방의 시각 이해하기', '정보 공유하기', '의견일치 보기', '마무리짓기' 등 7가지 평가항목에서 교육 전보다 교육 후 모든 점수가 상승되었다. 이 중 '정보 수집하기'의 자가평가 수준은 수업 후 통계적으로 유의한 변화가 있었다(p=0.008). 치과의료커뮤니케이션 수업에 참여한 학생들은 교과목에 대한 중요성과 필요성에 대해 수업운영 전보다 후에 높게 인식하는 것으로 조사되었는데, '치과의료커뮤니케이션 수업은 치과위생사의 전문성을 키우는 데 중요하다고 생각하나요', '치과의료커뮤니케이션 수업이 교육과정에서 필요하다고 생각하나요' 라는 항목에서는 수업 전후 각각 통계적 유의한 차이를 보였다(p=0.019, p=0.016). 이러한 결과로 볼 때 치과위생사에게 필요한 핵심역량인 치과의료커뮤니케이션 역량을 향상시킬 수 있는 교육과정은 치위생(학) 교육과정으로 반드시 포함되어야 한다. 치과의료커뮤니케이션 역량은 교육과 학습을 통해 계발 및 향상될 수 있다. 따라서 치과의료현장에서 필요한 치과의료커뮤니케이션 요소들을 보다 구체적으로 정리하고, 이론 교육만이 아닌 실습 교육을 포함한 체계적이고, 학년 간 연계 가능한 교육과정의 개발이 시급한 것으로 판단된다. 또한 연구 대상자 수를 늘리고, 자가수준의 평가가 아닌 학생들의 커뮤니케이션 역량을 객관적으로 측정할 수 있는 평가도구 개발과 표준화된 치과의료커뮤니케이션 교육과정이 필요할 것으로 본다.

• 한국가족관계학회지
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• 제21권1호
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• pp.77-98
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• 2016

Objectives: The aim of this study was to explore perceived meanings of dating and marriage among well-educated Korean couples who were in optimal marriageable ages. Particularly, an emphasis was placed on finding out where the traditional gender norms and post-modern contexts intersect on the couples' course of dating and marriage. Method: We undertook a qualitative analysis of 8 couples (age: 26-34) dating. Participants were limited to university graduates of upper-middle rank universities in Seoul, South Korea. The rationale for choosing such sample was based on the idea that characteristics of class is inherent in the act of dating and marriage, and that such characteristics lead to different contextual experiences in dating and marriage. This study was based on interviews conducted over a three-month time span. The interviews were first transcribed into research text and then subjects and key categories were drawn from the transcripts for analysis. Results: Participants sought meanings of joy, learning, and self-improvement in dating, and they were free from traditional gender norms in their romantic relationships. They viewed marriage as having a permanent companionship with their partner, becoming independent from their parents, and/or a social norm to be followed. Participants reported mixed perceptions about marriage in such fashion that they described their parents' relationship in terms of a gendered leader-supporter relationship, while viewing their own relationship as being genderless partners. In transition to parenthood, however, they regressed to traditional gender norms dichotomized as women being a homemaker and men being a breadwinner. In sum, participants displayed expectations that were inconsistent with regard to dating and marriage over the study period. That is, during the course of dating and early marriage, they did not hold separated gender norms; however, when transitioning from being a newly married couple to giving their first childbirth, expectations shifted to traditional gender norms and values. Conclusion: This suggests that it is not marriage, but the experience of childbirth and motherhood, which strengthen traditional gendered norms, engendering regeneration of the gender norms in families. The results indicate that there is a need to promote co-parenting behavior among the newly-married couples and to educate gender equality about parent roles or for parents in South Korea so that they can overcome traditional gendered norms in family.

• 한방재활의학과학회지
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• 제29권3호
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• pp.87-101
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• 2019

Objectives The purpose of this study is to investigate characteristics of low back pain patients and trends of Korean medicine conservative treatment effects of low back pain patients by registry data. Methods A total of 78 patients were analyzed, statistical analysis was performed using a generalized linear model. The comparison between groups was performed using independent two samples t-test or Wilcoxon rank sum test according to the distribution of normality. Before and after the treatment effects, ANOVA and Kruskal-Wallis method were used for the comparison, Sheffe method was used for the post test. Results The average age of hospitalized patients was 31.8 years old and out-patient department (OPD) patients was 44.9 years old. Lots of OPD patients and hospitalized patients were classified to 'Lumbago due to Coexist Qu Stagnation and Bloos Stasis'. Both OPD patients and hospitalized patients classified to 'Lumbago due to Coexist Qu Stagnation and Bloos Stasis' showed statistically significant decrease in RMDQ (Roland-Morris disability questionnaire) and NRS (numeric rating scale) on 1 month and 3 month after clinical research start date. Comparing the treatment effects of Chuna manual therapy, both Chuna group and non-Chuna group showed statistically significant decrease in RMDQ and NRS on discharge date, 1 month and 3 month after clinical research start date. Conclusions We expect that a larger scale registry study will be carried out to provide a higher level of basis for the Korean medical treatment of low back pain.

• Journal of Korean Neurosurgical Society
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• 제64권1호
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• pp.78-87
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• 2021

Objective : Intraoperative neurophysiological monitoring (IONM) has been widely used during spine surgery to reduce or prevent neurologic deficits, however, its application to the surgical management for cervical myelopathy remains controversial. This study aimed to assess the success rate of IONM in patients with cervical myelopathy and to investigate the factors associated with successful baseline monitoring and the effect of increasing the stimulation intensity by focusing on motor evoked potentials (MEPs). Methods : The data of 88 patients who underwent surgery for cervical myelopathy with IONM between January 2016 and June 2018 were retrospectively reviewed. The success rate of baseline MEP monitoring at the initial stimulation of 400 V was investigated. In unmonitorable cases, the stimulation intensity was increased to 999 V, and the success rate final MEP monitoring was reinvestigated. In addition, factors related to the success rate of baseline MEP monitoring were investigated using independent t-test, Wilcoxon rank-sum test, chi-squared test, and Fisher's exact probability test for statistical analysis. The factors included age, sex, body mass index, diabetes mellitus, smoking history, symptom duration, Torg-Pavlov ratio, space available for the cord (SAC), cord compression ratio (CCR), intramedullary increased signal intensity (SI) on magnetic resonance imaging, SI length, SI ratio, the Medical Research Council (MRC) grade, the preoperative modified Nurick grade and Japanese Orthopedic Association (JOA) score. Results : The overall success rate for reliable MEP response was 52.3% after increasing the stimulation intensity. No complications were observed to be associated with increased intensity. The factors related to the success rate of final MEP monitoring were found to be SAC (p<0.001), CCR (p<0.001), MRC grade (p<0.001), preoperative modified Nurick grade (p<0.001), and JOA score (p<0.001). The cut-off score for successful MEP monitoring was 5.67 mm for SAC, 47.33% for the CCR, 3 points for MRC grade, 2 points for the modified Nurick grade, and 12 points for the JOA score. Conclusion : Increasing the stimulation intensity could significantly improve the success rate of baseline MEP monitoring for unmonitorable cases at the initial stimulation in cervical myelopathy. In particular, the SAC, CCR, MRC grade, preoperative Nurick grade and JOA score may be considered as the more important related factors associated with the success rate of MEP monitoring. Therefore, the degree of preoperative neurological functional deficits and the presence of spinal cord compression on imaging could be used as new detailed criteria for the application of IONM in patients with cervical myelopathy.