• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.611-620
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• 1994

The purpose of this study was to evaluate the effect of post space preparation on apical sealing according to the methods and time of gutta percha removal. Forty six extracted single rooted teeth were selected for this study. Forty teeth were used as experimental groups and six teeth as control groups. Forty teeth were routinely prepared by step-back method and obturated with gutta percha cones and zinc oxide-eugenol cement using lateral condensation. All obturated teeth were divided into 4 groups of 10 teeth each. In each group of 1, 2, 3, heated plugger, gate glidden drill and chloroform and K-file were used respectively for post space preparation by removing the gutta percha immediately after obturation. In group 4, post space were prepared with gate glidden drill one week after obturation. In all experimental groups, the post space were prepared so that 4mm of apical gutta percha remained. After post space preparation, apical leakage were measured with electrochemical method for 28 days and analyzed statistically. The following results were obtained ; 1. No statistically significant differences in apical leakage were occured among the experimental groups using heated plugger, gate glidden drill and chloroform and K-file to remove the gutta percha immediately after obturation. 2. No significant difference in apical leakage was found between the teeth prepared post space immediately after obturation and those prepared 1 week after obturation. 3. In all experimental groups, the apical leakage was increased with time passage regardless of the post space preparation time and the gutta percha removal techniques.

• 한국심리학회지 : 문화 및 사회문제
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• 제22권2호
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• pp.137-163
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• 2016

본 연구의 목적은 계획된 행동 이론(Theory of Planned Behavior; Ajzen, 1991)에 입각하여 중고령 근로자의 활동적 노년과 생산적 노년을 고찰하는 것으로, 노년기 행동에 대한 참여 과정에 대한 동기화 과정을 비교하였다. 이러한 동기화 요소로 활동적 노년과 생산적 노년 각각에 대한 태도, 주관적 규범, 행동 통제감을 연구하였으며, 이 세 요소가 노후준비라는 행동의도에 영향을 주는지 검증하였다. 또한, 노후준비의 세부요소가 활동적 노년과 생산적 노년 각각에 미치는 영향이 어떻게 다른지를 함께 검증하였다. 50~69세의 중고령 근로자 192명에게 설문조사를 통해 자료를 수집하였다. 분석 결과, 활동적 노년에 대해서는 주로 태도와 행동 통제감이 노후준비를 통해서 활동적 노년에 영향을 미치는 것으로 나타났다. 반면 생산적 노년에 대해서는 규범과 행동 통제감이 노후준비를 매개로 생산적 노년에 영향을 미치는 것으로 나타났다. 세부적인 분석 결과, 활동적 노년에 대해서는 사회적 노후준비를 매개 변인으로 했을 때 간접효과가 유의미했으며, 생산적 노년에 대해서는 정서적 및 사회적 노후준비를 매개변인으로 했을 때 간접효과가 유의미한 것으로 나타났다. 연구 결과를 바탕으로 중고령 근로자의 활동적 노년과 생산적 노년에 대한 시사점을 제시하였다.

• Restorative Dentistry and Endodontics
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• 제42권1호
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• pp.27-33
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• 2017

Objectives: To determine the optimal timing for post space preparation of root canals sealed with epoxy resin-based AH Plus sealer in terms of its polymerization and influence on apical leakage. Materials and Methods: The epoxy polymerization of AH Plus (Dentsply DeTrey) as a function of time after mixing (8, 24, and 72 hours, and 1 week) was evaluated using Fourier transform infrared (FTIR) spectroscopy and microhardness measurements. The change in the glass transition temperature ($T_g$) of the material with time was also investigated using differential scanning calorimetry (DSC). Fifty extracted human single-rooted premolars were filled with gutta-percha and AH Plus, and randomly separated into five groups (n = 10) based on post space preparation timing (immediately after root canal obturation and 8, 24, and 72 hours, and 1 week after root canal obturation). The extent of apical leakage (mm) of the five groups was compared using a dye leakage test. Each dataset was statistically analyzed by one-way analysis of variance and Tukey's post hoc test (${\alpha}=0.05$). Results: Continuous epoxy polymerization of the material with time was observed. Although the $T_g$ values of the material gradually increased with time, the specimens presented no clear $T_g$ value at 1 week after mixing. When the post space was prepared 1 week after root canal obturation, the leakage was significantly higher than in the other groups (p < 0.05), among which there was no significant difference in leakage. Conclusions: Poor apical seal was detected when post space preparation was delayed until 1 week after root canal obturation.

• 한국식품조리과학회지
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• 제2권2호
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• pp.76-83
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• 1986

Time and temperature, pH and Aw, and microbiological evaluation were made to identify critical control points during various phases in product flow of chicken soup preparation in a university foodservice establishment. The results are summarised as follows: 1) Time and temperature data indicated that the phases of cooling after cooking, post-preparation, and holding ingredients at room temperature before assembly were critical. 2) pH and Aw values were in favorable for microbial growth. 3) Microbiological data indicated that the phases of basic ingredients. post-preparation and holding ingredients before assembly were critical. 4) Critical control points identified were; basic ingredients, cooling after cooking, post-preparation, holding before assembly and service, and assembly and service. 5) Several guidelines were suggested for the effective qualitly control program.

• Restorative Dentistry and Endodontics
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• 제45권2호
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• pp.19.1-19.8
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• 2020

Objective: This study aimed to evaluate the effect of ultrasonic cleaning of the intracanal post space on the bond strength of fiber posts in oval canals filled with a premixed bioceramic (Bio-C Sealer [BIOC]) root canal sealer. Materials and Methods: Fifty premolars were endodontically prepared and divided into 5 groups (n = 10), based on the type of root canal filling material used and the post space cleaning protocol. A1: gutta-percha + AH Plus (AHP) and post space preparation with ultrasonic cleaning, A2: gutta-percha + BIOC and post space preparation with ultrasonic cleaning, B1: gutta-percha + AHP and post space preparation, B2: gutta-percha + BIOC and post space preparation, C: control group. Fiber posts were cemented with a self-adhesive luting material, and 1 mm thick slices were sectioned from the middle and cervical third to evaluate the remaining filling material microscopically. The samples were subjected to a push-out test to analyze the bond strength of the fiber post, and the results were analyzed with the Shapiro-Wilk, Bonferroni, Kruskal-Wallis, and Mann-Whitney tests (p < 0.05). Failure modes were evaluated using optical microscopy. Results: The results showed that the fiber posts cemented in canals sealed with BIOC had lower bond strength than those sealed with AHP. The ultrasonic cleaning of the post space improved the bond strength of fiber posts in canals sealed with AHP, but not with BIOC. Conclusions: BIOC decreased the bond strength of fiber posts in oval canals, regardless of ultrasonic cleaning.

• 대한소아치과학회지
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• 제35권1호
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• pp.11-17
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• 2008

본 연구는 Er:YAG laser에 의한 치수의 초기 조직반응과 calcitonin gene-related peptide (CGRP) 함유 신경섬유의 발현을 비교 평가하고자 시행하였다. Er:YAG laser와 conventional bur를 이용하여 상악 제1대구치의 교합면에 와동을 형성하였다. 와동형성 후 48시간 후에 조직을 처리하여 hematoxylin-eosin 염색과 CGRP 면역조직화학을 시행한 후 다음과 같은 결과를 얻었다. 1. Conventional bur를 이용하여 삭제한 경우, 상아질 바닥면은 균열이 없는 평면의 균일한 모양을 보였으며, Er:YAG laser의 경우에는 상아질의 면은 bur에 비해서 파동형의 불규칙적인 형태와 바닥면에서 상아세관의 주행방향을 따라 미세한 균열을 보였다. 2. Er:YAG laser에 의해 손상 받은 치수에서는 혈관확장과 노출된 치수의 손상부위를 따라 bur에서 손상 받은 치수보다 더 많은 염증세포의 침윤과 상아모세포층의 파괴를 보였다. 3. 노출손상 후에 치수신경 말단에서 CGRP 발현은 bur와 laser군 모두에서 손상을 받지 않은 정상 치수에 비해서 증가된 양상을 보였으며, 그 증가된 정도는 laser의 경우에서 더 강하였다. 위의 결과들을 종합하면, Er:YAG laser가 치수손상을 최소화하여 적용되면 치아우식 제거와 와동형성과 같은 여러 수복치료 시 유용하게 사용될 수 있으리라 사료된다.

• 가족자원경영과 정책
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• 제28권3호
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• pp.1-16
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• 2024

본 연구에서는 일본의 은퇴자 조사 자료를 이용해서 은퇴 전후의 노후불안, 노후생활 준비, 노후 생활지원 요구를 파악하고, 이런 요소들이 은퇴 후의 생활만족도에 어떠한 영향을 미치는지를 분석하였다. 본 연구에서 이용한 분석 자료는 일본 전국 60세 이상 74세의 은퇴자를 대상으로 조사된 것이며 분석에는 1,257명의 데이터가 사용되었다. 분석결과는 다음과 같다. 첫째, 노후불안 요인 중 남성과 여성 모두 수입과 저축, 생활비 부족 등의 경제적인 면에서의 노후불안이 다른 노후불안 요소보다 높은 수준인 것으로 나타났는데, 이러한 경향은 특히 남성에서 더 두드러지는 것으로 나타났다. 둘째, 수입과 저축, 생활비 부족 등의 경제적인 면에서의 노후불안 수준이 높을수록 남성과 여성의 은퇴 후 생활만족도 수준이 낮아지는 것으로 나타났다. 셋째, 노후생활 준비의 측면을 보면 남성과 여성 모두 경제적 기반에 대한 준비 점수가 클수록 은퇴 후 생활만족도가 큰 것으로 나타났다. 넷째, 은퇴 후 노후 생활지원 요구의 영향에 대해서는 남성의 경우에, 은퇴 후 재고용 및 재취업 기회가 필요하다고 생각할수록 은퇴 후 생활만족도가 낮아지는 것으로 확인되었다. 이를 토대로 은퇴 이후의 시기에 생활만족도를 높이는 방안으로, 지역사회참여 프로그램 및 취업연계 프로그램의 필요성을 제시하였다.

• 디지털융복합연구
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• 제12권8호
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• pp.493-499
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• 2014

본 연구는 베이비부머(실험집단 11명, 통제집단 12명)을 대상으로 하여, 생애설계 교육 프로그램의 효과성을 검증하는데 목적이 있다. 충남 A지역에서 주2회 각 2시간씩 총 36시간의 프로그램이 시행되었다. 그 결과 첫째, 실험집단 베이비부머의 프로그램 효과성 분석을 위해 사전-사후검사간의 Wilcoxon의 조합기호 순위검증법을 실시한 결과 실험집단 베이비부머는 노후준비의식에서 자원봉사준비 의식이 향상된 것으로 나타났고, 통제 집단은 사전-사후 유의미한 차이가 나타나지 않았다. 둘째, 프로그램의 만족도는 교육과정, 교육내용, 교육자료, 교육방법, 강사, 교육환경에 대한 만족도는 모두 5점 만점에 3.5점 이상으로 나타났다.

• Restorative Dentistry and Endodontics
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• 제13권1호
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• pp.151-158
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• 1988

The purpose of this study was to evaluate the effect of canal filling methods and post-space preparation time on the apical seal of endodontically treated teeth. Seventy-six single-rooted human teeth were divided into 6 groups and each tooth was obturated and prepared post-space according to the purpose of this study. After all specimens were immersed in Indian ink, decalcified and cleared, the degree of dye penetration into the root canals observed by magnifying glass (X20) and measured by caliper. The results were as follows: 1. In the thermatic condensation, no significant difference in ink penetration occured when the post-spaces were created immediately after obturation or when they were made a week later. 2. In the lateral condensation, no significant difference in ink penetration existed between teeth whose post-space were prepared immediately or delayed. 3. In comparison of experimental groups and control groups, no significant difference showed when the groups were obturated with McSpadden compactor but when the teeth were laterally condensed, the experimental groups showed less ink penetration than controls. 4. Thermatic condensed teeth with McSpadden compactor were less ink penetration thn laterally condensed teeth.

• 한국재료학회지
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• 제16권1호
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• pp.11-18
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• 2006

[ $Co_3O_4$ ] particles with non-aggregation characteristics were prepared by various conditions such as preparation temperature, flow rate of carrier gas, and concentration of spray solution using spray pyrolysis. The morphology and crystallinity of the preformed particles obtained by spray pyrolysis at various conditions affected the mean size and morphology of the post-treated $Co_3O_4$ particles. The preformed particles with hollow and porous morphology obtained from spray solution with citric acid and ethylene glycol turned to $Co_3O_4$ particles with nano size, regular morphology and non-aggregation characteristics after post-treatment at $800^{\circ}C$. On the other hand, the preformed particles obtained by the preparation conditions of short residence time of particles inside hot wall reactor and high reactor temperature turned to $Co_3O_4$ particles with aggregated morphology after post-treatment. The mean crystallite size and particle size of the $Co_3O_4$ particles prepared from optimum preparation conditions were 47 nm and 210 nm at post-treatment temperature of $800^{\circ}C$.