• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.473-484
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• 1994

To investigate the effect of resin cement, which had been known to increase the adhesive capacity of the cast gold inlay, on the gingival marginal fit and whether the tin-planting of the beveled area affects the marginal fit, Class II cast gold inlays were made on the 25 sound molars. Control group(ZPC goup) was cemented with the ZPC by conventional method. Experimental groups were cemented with the resin cement(Super-hond & $Panavia_{EX}$) and subdivided further by the existence or nonexistence of the tin-plating of the beveled area(ST & PT groups: with plating, SNT & PNT groups: without plating). So, each group was consisted of 5 teeth and the gingival margin of each specimen was mesiodistally sectioned by 3 times and the marginal and internal gap were evaluated by the Stereo Microscope (${\times}180$) and the Scanning Electron Micrascope(${\times}5,000$) was used for examining the adhesive relationship of the resin cement to the cavity wall and to the cast gold surface. The results were as follows : 1. Marginal gap was less than internal gap in all groups. 2. ZPC and SNT(bevel without tin-plating) groups showed the least gap and gap in PNT(bevel without tin-plating) group, ST(bevel with tin-plating) group, PT(bevel with tin-plating) group showed the greater value in order in evaluation of the both internal gap and marginal gap. 3. With the exception of the relationships between ZPC and SNT groups, ST and PNT groups, relationships between any other groups showed the statistical significance in the internal gap(p<0.05). 4. In the marginal gap, all relationships between groups showed the statistical significance (p<0.05) except the relationships between ZPC and SNT groups, ST and PNT groups, ZPC and PNT groups. 5. ZPC group showed more soluble phenamena than the resin groups(ST, SNT, PT, PNT). 6. Resin cement showed the void spaces in spite of good penetration into the micro-irregularities on both the tooth surface and the cast surface. The void was shown more in PT and PNT groups than in the ST and SNT groups. 7. After the treatment of heat and desiccation for SEM specimen, resin cements were detached more easily from the tooth surface than from the cast surface.

• 대한치과기공학회지
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• 제41권4호
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• pp.271-278
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• 2019

Purpose: To quantify the effect of the crystallization process on lithium disilicate ceramic crowns that are fabricated using a computer-aided design/computer-aided manufacturing(CAD/CAM) system, and to determine whether they are clinically acceptable by comparing values before and after the crystallization process. Methods: The maxillary first molar was selected as the abutment for the experiments. Ten working models were prepared. Marginal and internal gap of 4 groups of lithium disilicate crowns(n=10) fabricated with conventional method. Comparison was performed using the silicone replica technique and 3D superimposition analysis. The marginal and internal gaps of the restoration were measured before and after the crystallization process of this prosthesis. The average value of each part(the average of values measured before and after the crystallization) was statistically analyzed using paired t-test(α=0.05). Results: The results from the second phase of this research, which compared the average value of the gap between the marginal and internal fits of the lithium disilicate single crown before and after the crystallization process, indicated that the marginal gap was larger and the internal gap was smaller after the crystallization process, and this difference was statistically significant (P<0.05) in all the parts evaluated. Conclusion: While the shrinkage that occurs during crystallization does affect the marginal and internal fit of the prosthesis, it cannot be concluded to be a major effect because the resultant distortion was within the clinically acceptable range.

• The Journal of Advanced Prosthodontics
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• 제12권4호
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• pp.225-232
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• 2020

PURPOSE. This study aimed to fabricate provisional crowns at varying build directions using the digital light processing (DLP)-based 3D printing and evaluate the marginal and internal fit of the provisional crowns using the silicone replica technique (SRT). MATERIALS AND METHODS. The prepared resin tooth was scanned and a single crown was designed using computer-aided design (CAD) software. Provisional crowns were printed using a DLP-based 3D printer at 6 directions (120°, 135°, 150°, 180°, 210°, 225°) with 10 crowns in each direction. In total, sixty crowns were printed. To measure the marginal and internal fit, a silicone replica was fabricated and the thickness of the silicone impression material was measured using a digital microscope. Sixteen reference points were set and divided into the following 4 groups: marginal gap (MG), cervical gap (CG), axial gap (AG), and occlusal gap (OG). The measurements were statistically analyzed using one-way ANOVA and Dunnett T3. RESULTS. MG, CG, and OG were significantly different by build angle groups (P<.05). The MG and CG were significantly larger in the 120° group than in other groups. OG was the smallest in the 150° and 180° and the largest in the 120° and 135° groups. CONCLUSION. The marginal and internal fit of the 3D-printed provisional crowns can vary depending on the build angle and the best fit was achieved with build angles of 150° and 180°.

• 대한치과기공학회지
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• 제44권1호
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• pp.1-7
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• 2022

Purpose: The purpose of this in vitro study is to evaluate the clinical acceptability of the marginal discrepancies and internal spacing of multi-layered zirconia prothesis by speed sintering. Methods: The two specimen types come from the same manufacturer but differ in the ingredients in layered zirconia and indication, that is anterior and posterior. The designs of both specimens were full contour crowns, and a total of 20 pieces were repeatedly fabricated, 10 for each group. The specimens were divided into two subgroups (n=10) and sintered with various total times (4 hours, 8 hours) at the maximum temperature (1,530℃). The gap between the two groups of multi-layered zirconia prostheses was measured using a silicone replica technique of 2D analysis method. The independent sample t-test was then used to compare and analyze the data obtained from the two groups (α=0.05). Results: The marginal and internal gap was superior in the 8-hour compared to the 4-hour group, and the results exhibited significant differences (p<0.05). All specimens showed that using the speed sintering schedule does not exceed the clinically permitted value of 120 ㎛, meaning zirconia prothesis using the speed sintering was adequate. Conclusion: The sintering condition is shown to affect the marginal and internal gaps of multi-layered zirconia restoration.

• 대한한방내과학회지
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• 제30권2호
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• pp.375-387
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• 2009

Objective : Gyehyuldeung (GHD) has been widely used in oriental medicine for the treatments of cardiovascular and neurological disorders. Thus, its potential facilitatory activity on axonal regeneration was investigated in the rats. Methods: Sprague-Dawley rats were given crush injury at the sciatic nerve and the changes of axon growth after nerve injury on each nerve injury model were investigated with anti-NF-200 antibody, DiI, GAP-43 protein and Cdc2 protein Results : GHD-mediated enhancement of axonal regeneration after crush injury was measured in both qualitative and quantitative ways by immunofluorescence staining with anti-NF-200 antibody and retrograde tracing of fluorescence dye DiI. GAP-43 protein levels were elevated by GHD treatments in the distal injured sciatic nerve and DRG sensory neurons. The neurite outgrowth of DRG sensory neurons was facilitated by GHD treatment when co-cultured with Schwann cells and astrocytes prepared from injured sciatic nerves and injured spinal cord tissues, respectively. It was observed that Cdc2 protein was up-regulated in co-cultured Schwann cells or astrocytes and Cdc2 protein signals were co-localized to a certain extent with those of phospho-vimentin protein. Conclusions : These results suggest that GHD may play a facilitatory role in axonal regeneration by acting on the injured axons and adjacent non-neuronal cells. The current findings may be useful for the development of therapeutic targets through more specific explorations on molecular interactions between herbal components and endogenous factors.

• 대한한방내과학회지
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• 제19권1호
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• pp.373-384
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• 1998

• 대한한방내과학회지
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• 제32권1호
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• pp.68-74
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• 2011

Objectives : The present study was conducted to determine whether Jerksukji-san and Tangnisodok-eum have an effect on treatment of burn. Methods : 24 male rats were randomly divided into 4 groups. Burns were created by scalding on the skin surface. Immediately after being burned, the rats of group 1 were applied with silver sulfadiazine ointment topically on the burn wound. The rats of group 2 were applied with Jerksukji-san ointment topically and administrated Tangnisodok-eum orally. The rats of group 3 were applied with Jerksukji-san ointment topically. The rats of group 4 were cleaned with saline solution. All treatments were applied twice a day. After 3 and 7 days the inflammatory cellularinfiltration and epidermal gap were measured. Data were analyzed by one-way ANOVA and Kruskal-Wallis test. Results : The rats of groups 1 and 2 showed a statistically narrow epithelial gap compared with those of groups 3 and 4 on the third and on seventh days (p<0.05). Group 3 showed a statistically narrow epithelial gap compared with group 4 on the third and seventh days (p<0.05). The decrease of inflammatory cellularinfiltration observed in group 2 was bigger than in the other groups (group 2>1>3>4) on the third and seventh days. Conclusions : These results demonstrate that Tangnisodok-eum and Jerksukji-san ointment are effective to treat burn, and it is necessary for clinical study to better ascertain this method.

• 한국초등수학교육학회지
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• 제19권3호
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• pp.371-386
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• 2015

비의 값과 비율 용어 사용에 관한 다양한 방안이 제안되어 왔다. 이 논문에서는 비의 값과 비율 용어에 관한 선행 연구에 내재된 상이한 관점들을 추출하고, 이 관점들과 최근 수학 교과서의 비의 값 및 비율 용어 사용 방식의 관련성을 분석하였다. 분석 결과는 비의 값과 비율 용어 사용에 관한 상이한 관점들이 경합해 왔음을 보여준다. 이와 같은 혼란이 어디에 기인하는 것인지를 명확히 하고자, 비의 값과 비율 용어를 맥락과 기준량에 초점을 맞추어 종합적으로 분석하였다. 이 분석에 기초하여 기존 문헌에서 추출한 관점들을 자리매김하고, 비의 값과 비율 용어 사용에 관한 몇 가지 시사점을 도출하였다.

• 대한치과보철학회지
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• 제48권2호
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• pp.135-142
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• 2010

연구목적: 최근CAD/CAM으로 제작한 지르코니아 코어의 변연적합도에 관한 연구가 많이 진행되었지만, 여러 종의CAD/CAM 시스템의 변연 뿐만 아니라 내면적합도까지 상호 비교한 연구는 아직 미흡한 실정이다. 따라서 본 연구에서는 3종의CAD/CAM 시스템으로 제작한 전치부 단일 치아 지르코니아 코어의 변연 및 내면적합도를 Replica technique을 이용해 평가하고자 하였다. 연구 재료 및 방법:3종의CAD/CAM 시스템 (Cerasys $system^{(R)}$, KaVo $Everest^{(R)}$, $LAVA^{TM}$)을 이용하여, 시스템 별로 5개씩의 단일치아 지르코니아 코어를 제작하였다. 제작된 지르코니아 코어를 레플리카 테크닉 (Replica Technique)을 이용해 복제하고 복제된 시편을 협설, 근원심으로 정중앙을 절단하여 변연 및 내면의 간격을 측정하였다. Measuring microscope ($AXIO^{(R)}$)를 이용하여 50배 확대하여 촬영하고 $I-Solution^{(R)}$을 이용하여 측정하였고, ANOVA를 이용하여 통계적으로 분석하였다. 결과:지르코니아코어의 평균 변연간격은 $Cerasys^{(R)}$가 $84.74{\pm}27.57{\mu}m$, KaVo $Everest^{(R)}$가 $80.23{\pm}21.07{\mu}m$, $Lava^{TM}$가 $96.37{\pm}11.45{\mu}m$이었고 평균내면간격은각각 $Cerasys^{(R)}$는 $94.99{\pm}18.74{\mu}m$, KaVo $Everest^{(R)}$는 $92.31{\pm}25.18{\mu}m$, $LAVA^{TM}$는 $94.99{\pm}18.74{\mu}m$이었으며, 세 시스템간의 변연 및 내면간격의 평균적인 적합도에서 통계적 유의차는 없었다. 변연 및 내면간격의 비교에서는 KaVo $Everest^{(R)}$가 $LAVA^{TM}$보다 전반적으로 내면간격이 작은 것으로 보였다 (P< .05). 내면간격 중 절단부위의 간격은 세 시스템에서 공통적으로 다른 부위보다 크게 나타났다. 결론:본 연구에서 $Cerasys^{(R)}$, KaVo $Everest^{(R)}$, $LAVA^{TM}$시스템의 변연적합도는 차이가 없었고, 내면적합도는 KaVo $Everest^{(R)}$가 $LAVA^{TM}$ 보다 적었으나 세 시스템에서 공통적으로 절단부위 간격이 크게 나타났다. 세 시스템 모두 변연적합도 및 내면적합도가 임상적으로 허용범위 내에 있었다.

• 대한영양사협회학술지
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• 제3권2호
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• pp.123-140
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• 1997

The purpose of this study were to assess main management components that can lead to successful university foodservice operations. Specifically, it was intended to develop the tool which assesses the service quality, management, to assess the difference between customer importance from and perceptions of service quality, to compare management perceptions of customer importances with actual service delivery, and to identify internal problems which affect service quality with the use of gap model. Three types of questionnaires were developed and implemented for customers, foodservice personals and foodservice manager. Assessment tools were developed based on the literature review, SERVQUAL, GAP model, and the pilot study. Through the validity and reliability test, the questionnaires were revised. Questionnaires were distributed to 900 university students, 207 foodservice personnels, and 54 foodservice manager respectively. 831 university students, 177 foodservice personnels, and 48 foodservice manager were responded with a response rate of 92.3%, 85.5%, and 88.8% respectively. Statistical data analysis was completed using the SPSS programs for descriptive analysis, ANOVA. and SNK test. The results of this study can be summarized as follows : 1. In quality service management components, 31 quality service attributes were categorized and named into primary quality, secondary quality, hygiene, empathy, tangibles, reliability, responsiveness, and price by the factor analysis. 2. Importance mean score of customers was 4.02 out of 5, but perception mean score of customers was 2.55. So there was a relative big gap(1.47) between importance and perception scores, especially in three dimensions of responsiveness, primary quality, and hygiene. 3. It showed that customers' mean scores of perceived service quality by dimensions were the following order : price > reliability > secondary quality > hygiene > tangibles > primary quality > responsiveness > empathy. And the perception mean score of rented(2.59) or contracted(2.58) management was significantly higher than that of self-operated(2.48). 4. Customers' importances mean score which internal customers recognize was 4.23 out of 5, but service delivery mean score was 3.85. So there was a little gap(0.39) between management perceptions of customer importances and actual service delivery. 5. In gap model, SERVQUAL score showed -1.47, Gap 1 positive 0.15, gap 2 negative 0.61, and gap 3 was positive 0.19. 6. The internal problems were as follows : (1) The managers of University foodservice perceived well enough the customers' expectation value but their management competency was lacked in terms of responding customer needs, (2) The foodservice staff perceived service performance more highly than service quality specifications.