• Restorative Dentistry and Endodontics
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• 제22권2호
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• pp.702-709
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• 1997

To compare the marginal leakage of CAD/CAM-fabricated ceramic inlay, gold inlay and amalgam, forty extracted caries-free premolars were prepared with Class II MO cavity design. The teeth were divided into four groups of ten samples each. Group 1 was restored with CAD/CAM-fabricated ceramic inlays cemented with Scotchbond Resin Cement / Scotchbond Multi-purpose plus. Group 2 was restored with gold inlays cemented with Scotchbond Resin Cement / Scotchbond Multi-purpose plus. Group 3 was restored with gold inlays cemented with zinc phosphate cement. And, Group 4 was restored with amalgam. All samples were thermocycled, and stored in 1 % methylene blue. Marginal leakage was examined at four margins, that is, occlusal distal, priximal gingival, occlusal facial and occlusal lingual margins from sectioned samples under stereomicroscope(x15). The results were as follows : 1. Group 1 and 2 showed no statistically significant difference among marginal leakage at all four examined margins(p>0.05). 2. Group 3 and 4 showed significant marginal leakage at proximal gingival margin compared with other margins(p<0.05). 3. Significantly increased marginal leakage at priximal gingival, occlusal facial and occlusal lingual margins in group 3 were observed compared with other groups (p<0.05).

• 대한치과의사협회지
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• 제50권3호
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• pp.110-117
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• 2012

Dental computer-aided design (CAD) and computer-aided manufacturing (CAM) technology have rapidly progressed over the past 30 years. The technology, which can be used in the dental laboratory, the dental office and the form of production centers, has become more common in recent years. This technology is now applied to inlays, onlays, crowns, fixed partial dentures, removable partial denture frameworks, complete dentures, templates for implant installation, implant abutments, and even maxillofacial prostheses. Dentists and dental technicians, who want to use these techniques, should have certain basic knowledge about that. This article gives an overview of CAD/CAM technologies, histories and how it applies in prosthetic dentistry.

• 대한조선학회지
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• 제30권4호
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• pp.33-36
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• 1993

본 과제는 의장설계 분야의 기본설계, 기능설계, 상세설계 및 생산설계 단계를 전산화하여 설계 생산성을 향상시키고 우수한 품질의 생산정보 및 생산관리 기초정보를 적기에 제공할 수 있는 의장설계일관시스템(Fig. 8.1)의 구축을 최종 목표로 하고 있으며, 다음과 같이 3개의 세부과제로 분담, 수행되었다. .CSDP-의장설계시스템 개발 : KRISO의장설계 일관시스템의 설계 및 관련 요소시스템의 통합 화를 위한 기반시스템의 개발'5' .CSDP-의장CAD응용기술 개발 : 현대중공업 범용 CAD시스템의 조선 전용화를 위한 의장설계 각 분야별 요구기능의 분석 및 정의'12' .CSDP-배관배치모델링기법 개발 : 대우조선 범용 CAD시스템을 토대로 한 배관설계시스템의 초기 계? 단계의 배치모델링 기법 개발'15' 본 고에서는 의장설계 일관시스템의 기본개념, 범용 CAD시스템을 중심으로한 분야별 일관시스 템의 구축을 위한 기능분석 및 기법 개발, 시스템 통합환경 구축, 그리고 향후 조선CIMS를 목 표로한 제품모델 개념의 생산지향 의장시스템 모델에 관한 개념설계 결과를 중심으로 서술하 였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.970-974
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• 1993

This paper is concerned with an automatic generation of BOM (Bill Of Material) for a bicycle frame set using a knowledge based system. The major components module system includes : (1) Part information retrieval in CAD drawing, (2) BOM code generation rule, and (3) Database interface. The knowledge based system includes a rule base and a fact base. The fact base consists of basic, variant, and optional components of the standard BOMs of frame sets. The rule contains rules for generating new BOM code in case that the specified is not in the database. The system was implemented on a SUN workstation under Open Windows environments. AutoCAD for CAD drawing was also used.

• 한국CDE학회논문집
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• 제18권1호
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• pp.28-35
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• 2013

Product Life cycle Management (PLM) is an indispensable tool for manufactures to develop competitive products in an efficient way. This enlarges the number of participants for product development who should understand PLM for their supporting activities. However, burdens for developing example products, maintaining complex PLM systems and training prerequisite skills for engineering tools such as CAD systems prohibit an efficient introductory course to PLM. This paper proposes a comprehensive introductory course to PLM that bases on general product development process. In addition, it enables participants to build their example products with familiar Lego blocks and to construct 3D CAD assembly models by using predefined 3D elements. The PLM system for the course provides an intuitive and simple user environment for participants to specify their parts lists, associated 3D CAD models, and product structure of example products. Experiences on a class of the course show it is a valid and efficient education and training method for the PLM introduction.

• The Journal of Advanced Prosthodontics
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• 제14권1호
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• pp.22-31
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• 2022

PURPOSE. The purpose of this study was to investigate the misfit and screw preload at the implant abutment connection of implant supported fixed dental prosthesis with cantilever (ICFDP) manufactured using different digital manufacturing techniques and to compare the screw preload before and after cyclic loading. MATERIALS AND METHODS. Mandibular jaw model with four intra-foraminal implants was scanned using digital scanner. Stereolithography file was used to design a framework with nonengaging (NE) abutments and 10 mm cantilever distal to one terminal implant. Five frameworks were constructed using combined digital-conventional techniques (CAD-cast), and five frameworks were constructed using three-dimensional printing (3DP). Additional CAD-cast framework was constructed in a way that ensures passive fit (PF) to use as control. Scanning electron microscope (SEM) measured the implant abutment connection misfit. Sixty screws were used on the corresponding frameworks. Screws were torqued and pre-cyclic loading reverse torque value (RTV) was recorded. Frameworks were subjected to 200,000 loading cycles with a loading point 9 mm from the center of terminal implants adjacent to the cantilever and post-cyclic loading RTVs were recorded. RESULTS. Microscopic readings showed significant differences between frameworks. PF demonstrated the lowest measurements of 16.04 (2.6) ㎛ while CAD-cast demonstrated the highest measurements of 29.2 (3.1) ㎛. In all groups, RTVs were significantly lower than the applied torque. Post-cyclic loading RTV was significantly lower than pre-cyclic loading RTV in PF and 3DP frameworks. Differences in RTVs between the three manufacturing techniques were insignificant. CONCLUSION. Although CAD-cast and three-dimensionally printed (3DP) both produce frameworks with clinically acceptable misfit, 3DP might not be the technique of choice for maintaining screw's preload stability under an aggressive loading situation.

• 한국지반환경공학회 논문집
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• 제15권1호
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• pp.69-77
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• 2014

본 연구의 목적은 소하천 유역에 대한 홍수범람해석 모형을 비교하는 것이다. 검청천을 대상으로 1차원 수리모형인 HEC-RAS와 범람해석을 위한 HEC-GeoRAS, RAS Mapper, RiverCAD 모형을 적용하여 홍수범람해석을 수행하였다. 실측 강우량과 빈도별 홍수량을 적용하여 3가지 모형에 따른 홍수범람해석을 모의하였으며, 해석결과와 당시 조사된 침수흔적도를 비교하고 각 모형들의 빈도별, 침수심별에 따라 홍수범람면적을 비교하였다. 실측 강우량을 적용하여 해석된 홍수범람면적은 HEC-GeoRAS 모형의 결과가 침수흔적도와 비교적 유사하게 나타났다. 또한, 빈도별 설계홍수량을 적용하여 해석된 범람면적은 RAS Mapper 모형이 가장 크게 나타났으며, 3가지 모형의 전체 범람면적 차이가 10% 이내로 비교적 유사한 결과를 나타내었다. 침수심별 범람면적을 비교한 결과 침수심 2.0 m 이하 구간에서는 3가지 모형의 결과가 비교적 유사하게 나타났으며, 침수심 2.0 m 이상의 구간에서 RiverCAD 모형의 범람면적이 비교적 큰 차이를 나타내었다.

• 디자인학연구
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• 제17권1호
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• pp.289-298
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• 2004

패션텍스타일 산업의 미래를 제시할 수 있는 패션텍스타일 전용 CAD 시스템의 개발은 디지털 기술의 발달과 함께 가속화되고 있다. 이러한 디지털 문화 기반의 구축은 패션텍스타일 산업에서도 고부가가치의 상품개발과 신속한 생산체제의 변화가 요구되며, 이런 욕구에 충족할 수 있는 전용 프로그램들이 개발되고 있다. 본 연구에서는 디지털 패션텍스타일의 변화와 디자인 시스템의 구성과 특징을 고찰하고 디지털 패션텍스타일 디자인 전개방법을 비교분석하였다. 또한 기존 그래픽프로그램과 차별화되어 개발되고 있는 창의적인 디지털 패턴디자인의 전개와 변형, 적합한 직물 텍스츄어의 표현, 3D모델링을 통한 시뮬레이션효과를 체계적으로 정립하였다. 패션텍스타일 CAD시스템의 활용을 디자인적 측면과 생산적인 측면으로 나누어 패션텍스타일 디자인 전용 CAD의 활용 가치를 높이는데 중점을 두었다.

• 대한치과기공학회지
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• 제39권1호
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• pp.1-7
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• 2017

Purpose: The purpose of this in vitro study compared to evaluation of repeatability of scanning abutment tooth stone model and impression applied CAD/CAM ISO standard in dentistry. Methods: To evaluate repeatability of scanning abutment tooth stone model, were repeatedly scanned to obtain 11 data via 3D stereolithography (STL) files. 10 data (STL files) were compared with the first 3D data (STL file), and the error sizes were measured by using 3D superimposing software(n=10). Also, the repeatability of scanning abutment tooth impression was evaluated with the same procedure. Independent t test was performed to evaluate the repeatability of scanning abutment tooth stone model versus impression through root mean square(RMS) and standard deviation(SD)(${\alpha}=0.05$). Results: $RMS{\pm}SD$ with regard to repeatability were $14.7{\pm}2.5{\mu}m$, $17.1{\pm}4.0{\mu}m$, respectively, with scanning abutment tooth stone model and impression(p=0.129). Conclusion: This study results showed a little different repeatability of scanning abutment tooth stone model and impression applied CAD/CAM ISO standard in dentistry, will suggest futures good studies and clinical advantages.

• 대한치과보철학회지
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• 제46권3호
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• pp.269-279
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• 2008

STATEMENT OF PROBLEM: Recently, various all-ceramic crowns fabricated with CAD/CAM systems have come into wide use in dental clinic. However, there are only few domestic studies on CAD/CAM restorations. PURPOSE: Purpose of this study was to compare the fidelity (absolute marginal discrepancy and internal gap) between various cores fabricated with different CAD/CAM systems (Procera system, Lava system, Cerec inLab system) and conventional metal cast core. MATERIALS AND METHODS: 10 cores per each system were fabricated. The absolute marginal discrepancies were measured using measuring microscope and digital counter. The internal gaps were calculated using a silicone paste. The results were statistically analyzed using the one-way ANOVA test and Tukey's HSD test. RESULTS: Within the limits of this study the results were as follows. 1. The absolute marginal discrepancies were $32.5{\pm}3.7\;{\mu}m$ for metal cast core, $72.2{\pm}7.0\;{\mu}m$ for Procera core, $40.8{\pm}5.4\;{\mu}m$ for Lava core, and $55.3{\pm}8.7\;{\mu}m$ for Cerec inLab core. The internal gaps were $38.4{\pm}5.7\;{\mu}m$ for metal cast core, $71.4{\pm}5.3\;{\mu}m$ for Procera core, $45.9{\pm}7.3\;{\mu}m$ for Lava core, and $51.8{\pm}6.2\;{\mu}m$ for Cerec inLab core. 2. The fidelity of metal cast core showed the smallest gaps, followed by Lava core, Cerec inLab core, and Procera core. CONCLUSION: The fidelities of 4 core groups were all within the clinically acceptable range ($120\;{\mu}m$).