• 대한기관식도과학회지
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• 제7권2호
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• pp.128-139
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• 2001

The purpose of this study was to review the literatures of experimental tracheal reconstruction. Although there have been significant advancements in the surgical treatment of the long circumferential tracheal injuries, there still has been a difficult problem with high morbidity and mortality. The method for tracheal reconstruction after circumferential resection is preferred end-to-end anastomosis for defects up to 6 cm in length, but larger tracheal defects require the use of tracheal allograft, various artificial prosthesis or autogenous organs. The tracheal allotransplantation has been widely used as there was significantly improved the method of surgical technique, preservation and immunosuppression. But it has been limited by a number of factors such as few donor, limited use of immunosuppressant, delayed revascularization and re-epitheliazation. Experimental studies on the tracheal prosthesis have a long history and they tried to use silicone, polytetrafluoroethylene, polypropylene mesh, Dacron, Marlex mesh, external or internal stents. Other experimental studies were reported the use of autogenous tissues that were cartilage. jejunum, aorta, skin, muscle, periostium or esophagus. But a great variety of these protheses have been resulted unsatisfactory in a significant Proportion of cases. Alternatively, the tissue-engineering technique has showed a new approach to reconstruct trachea and much progress in tissue-engineering bas been made recently. In conclusion, although the tracheal allotransplantation and the use of prosthesis and allograft have been reported a lot of limitation to overcome, we could sooner expect good result of ideal tracheal prosthesis.

• 대한치과보철학회지
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• 제34권4호
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• pp.833-849
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• 1996

The material of choice for functional and esthetic reconstruction of maxillofacial defects is silicone. Silicone has appropriate physical properties for maxillofacial prosthesis but it has weak edge strength. Therefore, a proper combination of silicone and polyurethane sheet is recommended to improve this weakness. Various primers are also used to enhance the adhesive strength between silicone and polyurethane sheet. The purpose of this study was to determine the adhesive strength of silicone and polyurethane sheet. Silicone elastomer mixture was made by admixing MDX4-4210 elastomer (40%) and Silastic Medical Adhesive Type A(60%). This silicone elastomer mixture was attached to polyurethane sheet, using one of three different primers(1205, S-2260, or A-304), treated for 1, 2, 4, 6, and 8 hours. These were then polymerized in room temperature, dry-heat oven or microwave oven. Six specimens per each group, a total of 270 specimens were prepared for final test. The differences of T-peel bonding strengths were then determined by a test. The differences of T-peel bonding strengths were then determined by a test method that was recommended by American Society for Testing and Materials C794-80. The results were statistically analyzed using the ANOVA and Mutiple Range Tests(Tukey' HSD). The reults were as follow. 1. Type of primer, primer reaction time, and methods of polymerization showed significant correlation on the T-peel bonding strengths in adhesiveness between silicone and polyurethane sheet. 2. A-304 primer showed statistically higher in T-peel bonding strength than otehr type of primers except for the polymerization in microwave oven with reaction times of 2, 6 hours(p<0.05). 3. No significant differences in T-peel bonding strength were observed among the polymerization methods. 4. The effect of reaction time by the primer type and polymerization method showed statistically significant differences in bonding strength among different reaction times. And in most cases, reaction time of 1 or 2 hours showed higher T-peel bonding strength.

• The Journal of Advanced Prosthodontics
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• 제9권5호
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• pp.358-363
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• 2017

PURPOSE. The purpose of this study was to evaluate the reliability of computer-aided replica technique (CART) by calculating its agreement with the replica technique (RT), using statistical agreement analysis. MATERIALS AND METHODS. A prepared metal die and a metal crown were fabricated. The gap between the restoration and abutment was replicated using silicone indicator paste (n = 25). Gap measurements differed in the control (RT) and experimental (CART) groups. In the RT group, the silicone replica was manually sectioned, and the marginal and occlusal gaps were measured using a microscope. In the CART group, the gap was digitized using optical scanning and image superimposition, and the gaps were measured using a software program. The agreement between the measurement techniques was evaluated by using the 95% Bland-Altman limits of agreement and concordance correlation coefficients (CCC). The least acceptable CCC was 0.90. RESULTS. The RT and CART groups showed linear association, with a strong positive correlation in gap measurements, but without significant differences. The 95% limits of agreement between the paired gap measurements were 3.84% and 7.08% of the mean. The lower 95% confidence limits of CCC were 0.9676 and 0.9188 for the marginal and occlusal gap measurements, respectively, and the values were greater than the allowed limit. CONCLUSION. The CART is a reliable digital approach for evaluating the fit accuracy of fixed dental prostheses.

• 한국임상수의학회지
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• 제32권1호
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• pp.108-111
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• 2015

7개월령 수컷 말티즈견이 1.5개월 동안 오른쪽 눈의 녹내장으로 치료를 받던 중에 내원하였다. 안검사에서 우안, 각막 천공, 홍채 탈출, 각막부종 및 혈관화가 관찰되었다. 안압은 오른쪽 눈이 33 mmHg, 왼쪽 눈이 19 mmHg이었다. 오른쪽 눈은 만성 녹내장, 각막 천공 및 홍채 탈출로 진단되었다. 그 눈은 실명하였으며 안구를 보존하기 위해 안내 보철물 삽입과 결막 플랩을 함께 적용하기로 하였다. 수술 후에 결막 플랩은 각막 천공 부위를 막고 안내 보철물을 적절하게 유지하였다. 수술 15개월 후에도 아무런 합병증 없었으며 보호자는 매우 만족하였다. 그러므로 안내 보철물과 결막 플랩의 병용 적용은 각막 천공으로 인한 녹내장의 치료에 이용될 수 있을 것이다.

• 대한치과기공학회지
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• 제41권3호
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• pp.187-193
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• 2019

Purpose: The purpose of this study was to compare two-dimensional fitness of the monolithic zirconia prosthesis by using different type of scanner. Methods: No. 26 abutment tooth of FDI system was selected for the study. Using the extraoral scanner and intraoral scanner, the abutment tooth was scanned 10 times and the scanned files were saved as STL files. CAD/CAM system was used to produce the monolithic zirconia prosthesis. marginal and internal gap of the monolithic zirconia prosthesis were measured by digital microscope(x160) and applied silicone replica technique was applied. t-test, a statistical software, was used to perform data analysis. Results: Marginal gap $mean{\pm}SD$ of the monolithic zirconia prosthesis was $33{\pm}7.5{\mu}m$ with extra oral scanner and $34.7{\pm}11.1{\mu}m$ with intraoral scanner. axial gap mean was $40.5{\pm}3.5{\mu}m$ with extra oral scanner and $44.6{\pm}11.6{\mu}m$ with intraoral scanner. occlusal gap mean was $110.1{\pm}25.4{\mu}m$ with extra oral scanner and $64{\pm}9.7{\mu}m$ with intraoral scanner. Conclusion: In this study, fabricating zirconia prosthesis with different type of scanner was clinically applicable.

• 한국임상수의학회지
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• 제27권5호
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• pp.610-613
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• 2010

체중 7.9 kg, 나이 8세의 수컷견이 좌측 안구의 돌출과 각막 부종 증세로 건국대학교 수의과대학 부속 동물병원에 내원하였다. 3년 전 좌안에 백내장 수술을 받은 병력이 있었다. 안과 검사상에서 좌안의 안압은 매우 높았으며 (47 mmHg), 눈부심반사는 음성이었다. 환축은 속발성 녹내장에 준하여 전신 및 국소적 약물 처치를 받았다. 약물 처치 후, 각막 부종은 감소되었으나, 좌안의 안압은 30-35 mmHg로 여전히 높은 상태를 보였다. 17개월 후, 환축은 우발적인 외상으로 인하여 전안방 출혈, 상공막 충혈과 각막 부종 상태를 보여 다시 내원하였다. 안구 외형을 보존하고 싶어하는 보호자의 요청에 따라 안구내 실리콘 보철물 삽입이 안구내용적출술을 통하여 실시되었다. 수술 3개월 후 좌안에 각막궤양이 발생하였으나, 약물 처치 후 호전되었다. 이후 1년까지 환축은 다른 합병증 없이 안정적인 상태를 보였다.

• 구강회복응용과학지
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• 제33권2호
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• pp.63-70
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• 2017

임상적으로 고정성보철물의 적합도는 성공적인 수복을 위해 필수적인 요소이다. 보철물의 적합도는 크게 변연적합도와 내면적합도로 분류되며, 이를 평가하기 위한 방법으로는 현미경 변연 측정법, 절단면 측정법, 실리콘 복제법, 3차원 스캔데이터 중첩법, 무게 측정법, 마이크로 CT 측정법 등 다양한 방법들이 소개되고 있다. 이에 본 연구에서는 기존의 문헌들을 바탕으로 각 방법들의 장, 단점을 비교분석함으로써 디지털환경에서 보다 편리하고 정확한 측정법을 제시하고자 한다.

• 대한두개안면성형외과학회지
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• 제17권1호
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• pp.20-24
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• 2016

Background: Midface concavity is a relatively common facial feature in East Asian populations. Paranasal augmentation is becoming an increasingly popular procedure for patients with mild concavity and normal occlusion. In this study, we evaluate clinical outcomes following a series of paranasal augmentation. Methods: A retrospective review was performed for patients with Class I occlusion who had undergone bilateral paranasal augmentation using custom-made silicone implants, between October 2005 and September 2013. Patient charts were reviewed for demographic information, concomitant operations, and postoperative complications. Preoperative and postoperative (1-month) photographs were used to evaluate operative outcome. Results: The review identified a total of 93 patients meeting study criteria. Overall, aesthetic outcomes were satisfactory. Five-millimeter thick silicone implant was used in 81 cases, and the mean augmentation was 4.26 mm for this thickness. Among the 93 patients, 2 patients required immediate implant removal due to discomfort. An additional 3 patients experienced implant migration without any extrusion. Nine patients complained of transient paresthesia, which had resolved by 2 weeks. There were no cases of hematoma or infection. All patients reported improvement in their lateral profile and were pleased at follow-up. Complications that arose postoperatively included 9 cases of numbness in the upper lip and 3 cases of implant migration. All cases yielded satisfactory results without persisting complications. Sensations were fully restored postoperatively after 1 to 2 weeks. Conclusion: Paranasal augmentation with custom-made silicone implants is a simple, safe, and inexpensive method that can readily improve the lateral profile of a patient with normal occlusion. When combined with other aesthetic procedures, paranasal augmentation can synergistically improve outcome and lead to greater patient satisfaction.

• 대한치과기공학회지
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• 제42권3호
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• pp.228-233
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• 2020

Purpose: This study aimed to assess and compare the marginal fit of ceramic-based hybrid resin restoration (HYB) and zirconia restoration (ZIR) for dental computer-aided design/computer-aided manufacturing systems. Methods: A stainless steel master model was produced. The impression was first made with silicone, and then stone working models were produced. A total of twenty restorations were fabricated with two different materials: ZIR and HYB. The silicone film thickness of the marginal gap was measured using a digital microscope; digital photos were taken at a magnification of ×160, and then analyzed using a measurement software. The values of the result were evaluated with the independent-sample t-test (α=0.05). All statistical analyses were performed with a statistical software. Results: The mean values for the marginal gap was 37.14±2.96 ㎛ for HYB, compared with 40.37±5.26 ㎛ for ZIR. No significant difference was found between ZIR and HYB (p=0.107). Conclusion: As a result, the marginal fit of the restoration fabricated using the hybrid resin was better than that of the restoration fabricated using zirconia. Also, the marginal fit of all groups was below the clinical acceptable range of 120 ㎛. Thus, HYB for dental CAD/CAM system in this study is expected to be suitable for clinical use in dentistry.

• 대한치과기공학회지
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• 제41권1호
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• pp.1-7
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• 2019

Purpose: The objectives of this study was to evaluate clinical adaptation of dental prostheses printed by 3 dimensional(3D) printing technology. Methods: Ten study models were prepared. Ten specimens of experimental group were printed by 3D printing(3DP group). As a control group, 10 specimens were fabricated by casting method on the same models. Marginal gaps of all specimens were measured to evaluate clinical adaptation. Marginal adaptations were measured using silicone replica technique and measured at 8 sites per specimen. Wilcoxon's signed-ranks test was used for statistical analysis(${\alpha}=0.05$). Results: Means of marginal adaptations were $95.1{\mu}m$ for 3DP group and $75.9{\mu}m$ for CAST group(p < 0.000). Conclusion : However, the mean of the 3DP group was within the clinical tolerance suggested by the previous researchers. Based on this, dental prosthesis fabricated by 3D printing technology is considered to be clinically acceptable.