• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.296-303
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• 2019

In edentulous patient, not only mastication and pronunciation but also esthetics are compromised. By restoring an edentulous patient with complete dentures, masticatory function and esthetics can be rehabilitated. The advantages of the dentures using CAD/CAM are that they can be reconstructed ubiquitously with stored data, and the strength and density of CAD/CAM material are clinically acceptable. In this clinical report, interocclusal record was taken in a conventional manner and then two lab processing procedures were performed: conventional method and CAD/CAM method. Two types of processing procedures were compared and evaluated. Fair clinical results were obtained in both ways, satisfying the patient.

• The Journal of Advanced Prosthodontics
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• v.15 no.1
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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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1146-1149
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• 1995

The CAD/CAM System for deep drawing transfer die in mechanical press proess has been developed. The developed CAD system can generate the drawing of drawing of transfer die in mechanical press. Using these results from CAD system, it can generate the NC data to machine die's elements on the CAD system. This system can reduce design man-hours and human errors. In order to construct the system, it is used to automate the design process using knowledge base system. The developed system is based on the knowledge base system which is involved a lot of expert's technology in the practice filed. Using AutoLISP language under the AutoCAD system, CTK customer language of SmartCAM is used as the overall CAD/CAM environment. Results of this system will be provide effective aids to the designer and mannufacturer in this field.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.617-628
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• 1995

본 논문에서는 상용화된 이 기종 CAD/CAM 시스템간의 CAD 데이타 교환기능을 가지는 IGES Translator 시스템의 구조를 제안한다. 제품생산의 여러 단계에서 CAD/CAM의 사용이 보편화되어감에 따라 상용 CAD/CAM 시스템들은 응용분야에 맞는 특수한 도구로 사용되는 경향이 생겨났다. 예를 들어, ALIAS는 주로 스타일링 디자인에, I-DEAS와 PRO/ENGINEER는 엔지니어링 디자인에, EUCLID는 금형 디자인에, 그리고 OMEGA와 Z-MASTER는 NC 공구경로생성에 주로 사용되고 있다. CAD 데이타 교환을 위해 제안된 중립파일형식(Neutral File Format)중에서, IGES(Initial Graphics Exchange Specification)는 대부분의 상용 CAD/CAM 시스템에서 지원을 하고 있으며 가장 널리 쓰이는 파일형식이다. 그런데, IGES를 통한 CAD 데이타 교환은 다음과 같은 문제점들을 가지고 있다. 즉, patch의 사라짐, 경계곡선의 왜곡, patch의 overlap 또는 gap, trimming error, 곡면각의 꺾임각도 등이 그것이다. 이 논문의 목적은 이러한 문제점들을 해결할 수 있는 범용 IGES Translator를 개발하는데 있다. 이 논문의 주요한 기여 내용은 다음과 같다. 1) 주요 상용 CAD/CAM 시스템의 IGES Interface 기능의 비교 분석, 2) 주요 상용 IGES Translator의 기능 분석, 3) 사용자의 기능적 요구사항의 분석, 4) 사용자 관점 및 시스템 관점에서의 IGES Translator의 구조 제안, 5) Prototype IGES Translator의 개발 및 테스트 결과 제시.

• Journal of Technologic Dentistry
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• v.37 no.1
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• pp.9-15
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• 2015

Purpose: The purpose of this study was to compare the accuracy of the maxillary three-unit fixed dental prosthesis (FDPs) made using two CAD/CAM milling machines : DCM Group(Dentaim CAD/CAM milling machine), WCM Group(Wieland CAD/CAM milling machine). Methods: Each of 10 duplicate models was scanned by blue light scanner(Identica, Medit, Korea), and the three-unit FDPs (STL file) was designed using DelcamCAD. A total of 20 three-unit FDPs was fabricated, comprising 2 groups of 10 specimens each (shrinkage ratio is 1:1). The first three-unit FDPs STL file was used as a CAD reference model (CRM). Obtained STL files by scanning the inner surface of three-unit FDPs were convened into the point clouds-ASC II files. Discrepancies between the point clouds and CRM were measured by superimposition software. Statistical methods to analyze the data were used non-parametric method. The mean (SD) values were compared by a Mann-Whitney U-test. Type one error rate was set at 0.05. Results: WCM group had small discrepancies with $2.17{\mu}m$ of mean value compared to $4.44{\mu}m$ in DCM group. The accuracy values between the two groups showed a sratistically significant difference (Table 2, p<.05). Conclusion: The accuracy of the three-unit fixed dental prosthesis(FDPs) made of two CAD/CAM milling machines were statistically different. Accuracy with which the prosthesis made of WCM group was superior.

• The Journal of the Korean dental association
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• v.50 no.11
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• pp.660-669
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• 2012

We describes the process of 3D virtual treatment planning and of CAD/CAM for surgical splint in orthognathic surgery. The potential benefits and disadvantages of 3D virtual approach and the use of CAD/CAM system for the treatment of the patient with a maxillofacial deformity are discussed. For the more convenient applications,3D software should be improved.

• Journal of the KSME
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• v.23 no.5
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• pp.326-334
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• 1983

1980년대에서는 생산성이 세계 제조업자들에게 특히 중요하게 된다. 이 기간 중에, 보호관세가 낮아져서 외국사람의 접근이 증가하게 되고, 국내 및 국외시장에서 경쟁 역시 증가될 것이다. 동 시에 전세계적인 산업자동화의 물결이, 급속히 증가하고 있는 컴퓨터와 산업용 로봇들을 근거로 제조업에 거세게 일 것이며, 이 기술변환의 지표로서, CAD/CAM에 관한 약 1,000개의 논문 및 서적과 기사가 매년 출판 발표되고 있다. 이러한 변화의 물결 중에서, 가장 급속히 진보하고 있는 2개의 첨단기술은, 컴퓨터응용설계를 위한 그래픽시스템의 사용이며, 생산기계류와 수치로 제어 되는 기계공구 사용과 더불어 부품과 공구취급을 위한 산업용 로봇의 사용이다. CAD/CAM이, 기업이나 산업국가에게 위협을 줄런지 또는 행운을 가져다 줄런지 결정하는 CAD/CAM 그 자 체가 아니라, CAD/CAM에 대한 기업이나 산업국가의 반응 및 그 활용에 있겠다.

• Journal of Technologic Dentistry
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• v.33 no.2
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• pp.137-145
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• 2011

Purpose: To evaluate the accuracy of zirconia copings in terms of clinical verified for the clinical application of CAD/CAM. Methods: Zirconia copings (n=5) were prepared using CAD/CAM system and were sintered using the relevant electrical induction furnace, which uses a 2h sintering program with a maximum temperature of $1500^{\circ}C$. The copings placed at the models and the interval values were measured. Results: The meas interval values between the die and the zirconia copings were $44.14{\mu}m$(A), $44.57{\mu}m$(B), $44.72{\mu}m$(C). 51.05 ${\mu}m$(D). Conclusion: The maximum interval values between the die and the zirconia copings were $51.3{\mu}m$ which is acceptable for clinical use. ${\mu}m$ Proper understanding of the test conditions will help enhancing the accuracy of zirconia coping.

• Journal of the KSME
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• v.33 no.4
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• pp.330-342
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• 1993

CAD/CAM이 국내에 도입되기 시작한 것은 70년대 후반이나, 본격적으로 보급되어 사용되기 시작한 것은 80년대 초부터라 하겠다. 도입초기에는 설계의 획기적인 변화를 약속해주는 새로운 기술로 각광을 받아오고, 또한 몇몇 분야에서는 그만한 가능성을 보여주기도 하였으나, 설계실 에서 컴퓨터가 제도판을 밀어내기 시작한지 약 10년이 지난 이 시점에서 돌이켜보건대 과연 CAD/CAM이 초기의 커다란 기대에 부응하는 성과를 올리고 있는 가에는 의문이 가는 것도 부 인할 수 없는 사실이다. 이는, 여러 가지 해석이 있을 수 있겠으나 필자의 견해로는 다음의 4가 지에 주로 기인한다. 1) CAD/CAM시스템 자체의 기능 및 성능 부족 2) 이기종 시스템간의 인터페이스 기술의 부족 3) 산업현장의 설계표준, 정보관리체계 등의 기반환경 미비 4) 적용 대상에의 전용화(customizing)기술의 부족 이 글에서는 이러한 원인들의 부분적인 해결을 위해서 필자가 속해있는 회사에서 수행한 노력 들을 몇 가지 사례를 통하여 소개하고자 한다.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.298-301
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• 2007

Computational speed plays key role in background subtraction and shadow detection, because those are only preprocessing steps of a moving object segmentation, tracking and activity recognition. A color intensity variation based approach fastly detect a moving object and extract shadow in a image sequences. The moving object is subtracted from background using meanmax, meanmin thresholds and shadow is detected by decrease limit and correspondence thresholds. The proposed approach relies on the ability to represent shadow cast impact by offline experiment dataset on sub grouped RGB color space.