• 대한치과보철학회지
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• 제49권1호
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• pp.80-86
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• 2011

임플란트 인접치아가 심한 치아우식이나 파절 등으로 인해 치관부의 잔존 치질이 손상된 경우 인위적 맹출술을 이용한 치관연장술은 임플란트와 인접한 치조골과 치간 유두의 보존으로 심미적인 보철 치료를 가능하게 한다. 54세 남자 환자분이 상악 전치부 고정성 보철물의 탈락으로 새로운 보철 치료를 주소로 내원하셨다. 상악 우측 중절치는 경도의 치아우식만 보였고 상악 우측 견치는 치관부 치질이 대부분 소실되어 있었다. 상악 우측 측절치의 결손부는 골 이식을 동반한 임플란트 식립을 시행하였고, 상악 우측 견치는 1달간 인위적 맹출술을 통한 치관연장술을 시행하였다. 임플란트 식립 5개월 후 2차 수술을 시행하였고, 임시치아의 단계적 수정을 통한 치은 성형 후 상악 우측 중절치, 상악 우측 측절치, 상악 우측 견치 각각 금속-도재관으로 수복하여 만족할 만한 임상결과를 얻을 수 있었다.

• 대한심미치과학회지
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• 제27권2호
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• pp.75-81
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• 2018

본 연구의 목적은 기존의 다른 포스트-코어 재료와의 유한요소분석(FEA)의 비교를 통한 치과용 포스트-코어 재료로서의 고성능 폴리머 PEKK의 생체역학 및 장기 안전성을 평가하는 데 있다. 상악 중절치를 모델링 하였으며, 구개 표면에서 치아의 장축에 $45^{\circ}$의 각도로 50N의 반복 하중을 가했다. 전통적으로 사용 된 포스트 코어 재료와 비교하기 위해 3가지 재료 (금, 유리 섬유 및 PEKK)를 시뮬레이션하여 결과를 상호 비교 해 보았다. 상아질보다 낮은 탄성 계수를 갖는 PEKK는 종래의 포스트 코어 재료보다 비교적 치근에 유리한 응력 분포를 보여 주었다. 그러나, PEKK 포스트-코어 시스템은 금속 또는 유리 섬유 포스트-코어 시스템보다 장기간의 반복하중에 대해 타락 및 크라운 파손의 가능성이 더 높을 가능성이 있다.

• The Journal of Advanced Prosthodontics
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• 제15권1호
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• pp.44-54
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• 2023

PURPOSE. To assess the clinical performance of monolithic CAD-CAM lithium disilicate glass-ceramic (LDGC) crowns and metal-ceramic (MC) crowns provided by predoctoral students. This study also assessed the effects of patient and provider-related factors on their clinical performance as well as patient preference for these types of crowns. MATERIALS AND METHODS. Twenty-five patients who received 50 crowns (25 LDGC CAD-CAM and 25 MC) provided by predoctoral students were retrospectively examined. LDGC CAD-CAM crowns were milled in-house using the CEREC Bluecam system and cemented with either RelyX Unicem or Calibra Esthetic resin cements. MC crowns were cemented with RelyX Unicem cement. Clinical assessment of the crowns and the supporting periodontal structures were performed following the modified California Dental Association (CDA) criteria. Patients' preference was recorded using a visual analog scale (VAS). The results were statistically analyzed using log-rank test, Pearson Chi-squared test and Kaplan-Meier survival analysis. RESULTS. Twelve complications were observed in the MC crown group (9-esthetic, 2-technical and 1-biological). In comparison, 2 complications in the LDGC CAD-CAM crown group were observed (1-technical and 1-esthetic). The 6-year cumulative survival rates for MC crowns and LDGC CAD-CAM were 90.8% and 96%, respectively, whereas the success rates were 83.4% and 96%, respectively. Overall, patients preferred the esthetic outcomes of LDGC CAD-CAM crowns over MC crowns. CONCLUSION. The high survival and success rates, low number of complications, and the high level of patients' acceptance of monolithic LDGC CAD-CAM crowns lend them well as predictable and viable alternatives to the "gold standard" MC crowns.

• 복식문화연구
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• 제17권3호
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• pp.383-395
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• 2009

The purpose of this study was to provide a formative charateristics by analyzing aesthetic charateristics of Egypt costume expressed in contemporary fashion. The result of this study obtained through this process were as follows. Aesthetic characteristics were expressed as a primative-retro characteristics, and a erotic-retro characteristics and a decorative-retro characteristics. Based on these trends, this study analyzed formative charateristics in an aspect of form, color, material, and decoration. In the modern fashion, unlike the H-line silhouette given by a natural fit in the primitive retro, the erotic retro was characterized in the shape by a tight H-line silhouette. For the color, peach, yellow green, gold, light blue, red, and black were used as the main color. For the material, see-through, gauze, mesh, organdy, and tight vinyl were utilized to emphasize an erotic image and expose a body secretly. For the decoration, the characteristic of erotic retro using the simple or same colors frequently was the use of similar accessories colors matched with material colors. The decorative retro was characterized in the shape by a H-line silhouette connected as a part of clothing which applied passium and a greatly modified silhouette from an Egyptian simple style which was well-matched with splendid accessories. For the color, the broadest range of color changes was found from light pastel such as white, yellow, light pink, burnt orange, blue, purple, silver, gold, and red to strong vivid tones. For the material, modern materials such as organdy, tulle, leather, and furs were often used. For the decoration, passium, an eagle pattern, scarab earrings, a crown, a sneak-shaped coronet, and pictograph printed on the fabric were frequently used.

• 대한치과보철학회지
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• 제33권3호
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• pp.397-412
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• 1995

The purpose of this study was to analyze the stress distribution in the dentin and post structures by the various post core materials and the amount of remaining coronal tooth structures. The 2-dimensional finite element models of mandibular 2nd premolars was divided into seven types according to the various amount of remaining coronal tooth structures. All types were modeled using equal length, diameter and shape of the post. 2 types of post and core materials were used : 1) cast gold post and core 2) stainless steel post and compsite resin core 10 Newton force was applied as follows 1) vertical force on occlusal fossa 2) $45^{\circ}$ oblique force on buccal surface of buccal cusp tip The results were as follows : 1. There was no apparent difference in the pattern of stress distribution according to the amount of remaining coronal tooth structure. 2. There was no apparent difference in the pattern of stress distribution within the dentin according to the post and core materials. A cast gold post and core generated lower dentin stress than a stainless steel post and resin core. 3. Max. dentinal stress resulting from vertical force was observed in the lingual side of dentin around the crown margin.This stress resulting from oblique force was observed in the lingual root surface of alveolar bone crest level.

• 대한가정학회지
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• 제44권1호
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• pp.131-138
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• 2006

The yanggwan is a striped headpiece for civil and military officials worn with jebok, a costume for the royal ancestral worship ceremony, or jobok, a ceremonial costume for the courtier. It was called a jegwan when it was worn with a jebok. The geumgwan and jegwan are of the same style but the geumgwan has a gilded band and backside and the jegwan is mostly lacquered. The yanggwan was worn first with the jebok by the officials, both of which were received from the Chinese Ming dynasty in the 19th year of the King Gongmin's reign during the Goryeo period. The royal crown and court clothing system was two grades lower than the standard clothing code of the Ming dynasty of China. In the Joseon dynasty, the oyanggwan worn by the highest grade officials had five-stripes but was later replaced during the Daehan Empire by the seven-striped chilyanggwan used by Ming dynasty officials. Oyanggwans make up the majority of the surviving examples of these headpieces, with the exception of the six-striped yukyanggwan of Chung In-hak (1839-1919), the Minister of Justice, which originated in the Daehan Empire and whose owner is definitively known. The gilt portion of this yukyanggwan is finely engraved in relief with a bird, flower and tendril motif. The yukyanggwan is topped by a decorative bird ornament, called a jeongkkot. EDSS spectrum analysis of the gold plating reveals a composition of 51.32% gold and 10.34% silver. The yanggwan is composed of bamboo, mulberry paper and silk crepe. The black portions are lacquered. The individual yang is made with twisted mulberry paper.

• 대한치과의사협회지
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• 제52권2호
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• pp.96-104
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• 2014

The aim of this study was to investigate the frequency of positive patch test reaction to dental materials in patients with oral mucosal diseases. Epicutaneous patch test was performed in 110 patients with oral mucosal diseases; 41 patients with oral lichen planus(OLP), 44 patients with burning mouth syndrome(BMS), 25 patients with other oral mucosal diseases including recurrent aphthous ulcer and mucous membrane pemphigoid. The obtained results were as follows: Oral gold restorations were most common in patents with oral mucosal diseases and porcelain fused metal crown, implant appeared in the order. 33 of 110 patients did not appear skin reactions (negative, 30%) and 77 patients (positive, 70%) had skin reactions including redness, rash, blisters. Dental materials causing positive reaction to patch test were mainly as gold-sodium-thiosulfate (26.7%), nickel sulfate(Ni) (22.7%), cobalt chloride(Co) (14.7%), palladium chloride(Pd) (11.9%), potassium dichromate (10.7%) in order, respectively. In conclusion, old metal restorations could be the cause of oral mucosal diseases and epicutaneous patch test could be used as a tool to improve the oral conditions.

• Restorative Dentistry and Endodontics
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• 제23권1호
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• pp.163-174
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• 1998

The purpose of this study is to evaluate the distribution of stress in the root end resected teeth. The finite element method was used to compare stresses along the root and retrograde filling material in seven two-dimensional models of mandibular 2nd premolar. Each model was endodontic treatment and gold crown' restoration. Each model divided with amagam core restoration or gold casting post restoration. Thus each model divided with shape of root end resection, depth of retropreparation and exposure length of root in the bony cavity. The seven models were classified as in the table 1 below. A load of 500N was applied $45^{\circ}$ diagonally on the lingual slope of the buccal cusp. These mode were analyzed with two dimensional finite element methods. The results of this study were as follows : 1. The maximum tensile stress along the inner canal wall was shown on the model 7. 2. When the model 1 was compared with the model 5, the maximum tensile stress along the inner canal wall showed the model 1. 3. Less equivalent stress was shown on the model 6 and more equivalent stress was shown on the model 4. 4. More shear stress was shown on the retrograde filling material of the model 7. 5. The models with increased length of exposed root in the bony cavity demonstrated a gradual increase to the tensile stress in X direction which occurred approximately a boundary between the bone and exposed root in' the bony cavity. 6. The model which had a case of matching the apex of post and a boundary between the bone and exposed root in the bony cavity demonstrated more increase tensile stress in X direction than other models.

• 구강회복응용과학지
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• 제24권4호
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• pp.317-324
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• 2008

이 논문의 목적은 전부주조관에서 교합점의 위치와 교합력의 방향이 합착용 시멘트층 내의 응력에 미치는 영향에 대해서 알아보는 것이다. 하악 제 1대구치상에서 서로 다른 9 개의 교합점과 3가지 교합력 방향을 가진 27가지 조합의 유한요소 모델을 상정하였다. 금관의 소재는 제 3형 금합금이고, 변연의 형태는 chamfer이다. 합착용 시멘트로는 전 층에서 균일하게 $70{\mu}m$의 두께를 가지는 글라스 아이오노머 시멘트가 사용되었다. 금관에는 100N의 하중을 적용하였다. 협측과 설측 변연의 근접도에 따라서 시멘트층 내 응력은 다른 양상을 나타내었다. 협측은 변연으로부터 약 0.5 mm, 설측은 변연으로부터 약 1 mm 내측에서 최대 응력 값을 가졌다. 하중 방향이 치축에 대해 경사가 클수록, 하중점이 교두첨에 근접해 있을수록 더 큰 응력이 발생하였다.

• 대한치과보철학회지
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• 제33권2호
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• pp.177-197
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• 1995

The endodontically treated tooth is generally restored with post & core, owing to the brittleness and the loss of large amount of tooth structure. Although there have been lots of studies about the endodontically treated teeth, the three-dimensional quantitative studies about the strees distribution of them are in rare cases. In this study, it was assumed that the coronal portion of the upper incisou had severely damaged. After the root canal therapy it was post cored, and restored with PFM crown, for this experiment nine types of model were constructed : 1); long, 2); medium, 3); short gold post for the roots supported with a narmal alveolar bone, 4); long, 5); medium, 6); short gold post for the roots supported with an alveolar bone resorbed to its 1/3 of root length, 7); long, 8); medium, 9); short base metal post for the roots supported with an alveolar bone resorbed to its 1/3 of root length. Force was applied from two directions. One was functional maximum bite force(300N) applied to the spot just lingual to the incisal edge with the angle of 45 degrees to the long axis of the tooth, and the other one was horizontal force(300N) applied to the labial surface. The results analyzed with three-dimensional finite element method were as follows : 1. Stress was concentrated on the middle portion of the labial side dentin of the root and the lingual portion of the apical dentin of the root. Stress in the post showed maximum value at 2 mm above the post apex. 2. In case of the long post and base metal post, strees was concentrated on the apex of the root and the post. 3. In case of the longer post, the displacement on the post-cement interface was lessened. The gold post was more displaceable than the base metal post. 4. In case of the alveolar bone resorption, stress concentrated on the root and the post and displacement on the post-cement interface were increased.