• 한국정밀공학회지
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• 제23권11호
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• pp.126-134
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• 2006

In this study, the effect of stem-end design on contact pressure and stress distribution in revision TKR was investigated using finite element method. The finite element model of tibia, including the cortical bone, the cancellous bone and canal, was developed based on CT images. The implant models with various stem lengths, diameters, friction coefficients, and press-fit effects were considered. The results showed that the longer stem length, the stronger press-fit, the bigger stem diameter, and the higher friction coefficient increased both peak contact pressure and Von-Mises stress distributions. The results supported the clinical hypothesis that peak contact pressure and stress are related to the stem end pain. The results of this study will be useful to design the stem and reduce the end-of-stem pain in revision TKR.

• Archives of Plastic Surgery
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• 제39권4호
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• pp.309-316
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• 2012

Computer aided design and manufacturing (CAD/CAM) technology today is the standard in manufacturing industry. The application of the CAD/CAM technology, together with the emerging 3D medical images based virtual surgical planning (VSP) technology, to craniomaxillofacial reconstruction has been gaining increasing attention to reconstructive surgeons. This article illustrates the components, system and clinical management of the VSP and CAD/CAM technology including: data acquisition, virtual surgical and treatment planning, individual implant design and fabrication, and outcome assessment. It focuses primarily on the technical aspects of the VSP and CAD/CAM system to improve the predictability of the planning and outcome.

• 대한치과보철학회지
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• 제55권3호
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• pp.279-285
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• 2017

구강암에 대한 외과적 처치로 구강 내 광범위한 경조직, 연조직을 제거한 환자는 저작, 연하, 발음 등의 기능적 문제와 치열, 안모의 심미적 문제를 갖게 된다. 악골 재건 후에도 치조골 등 합병증으로 인해 가철성 보철물의 유지 및 지지를 받는데 제한적이다. 임플란트 지지 고정성 보철물은 이러한 환자들에게 적절한 보철수복 방법이 되어 왔다. 본 증례는 하악 재건 후 computer-aided design과 computer-aided manufacturing을 이용하여 지르코니아 프레임워크 상부에 단일 구조 지르코니아 크라운을 제작하여 현재 치열의 기능적, 심미적 회복을 하여 이에 보고하고자 한다.

• 대한치과보철학회지
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• 제62권2호
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• pp.157-164
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• 2024

진단, 수술, 인상, 보철물 제작 등 임플란트 치료 전 과정에서 디지털 기술이 활용되고 있다. 본 증례에서는 디지털 수술 가이드를 이용하여 합병증 없이 상악동 거상술을 시행하고, 계획된 위치에 임플란트를 식립하였다. 골유착을 위한 치유 기간 이후, CAD-CAM(Computer-aided design/Computer-aided Manufacturing)으로 맞춤형 지대주 및 임시 보철물을 제작하여 장착하고, 환자의 적응도와 교합을 평가하였다. 임시 보철물상에서 교합 변화가 관찰되어, 광중합형 컴포지트 레진으로 수리하였다. 최종 보철물 제작 시, 지대주의 수직 침하, 임시 보철물의 형태와 적응된 교합 관계를 반영하기 위해, 이중 스캔과 지대주 수준의 디지털 인상을 채득하였다. 치은 압배 없이 치은 연하 변연을 인기하기 위해, CAD-CAM 소프트웨어상에서 라이브러리화된 지대주 데이터를 중첩하고, 지르코니아 최종보철물 제작하여 장착하였다. 구치부 임플란트 수복 시, 디지털 시스템을 이용하여 전통적인 방법에서 겪는 어려움을 줄이고, 수술부터 보철물 제작까지 효율적인 치료 과정과 안정적이고 예지성 있는 결과를 얻어 보고하는 바이다.

• 한국실내디자인학회논문집
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• 제15권3호
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• pp.126-135
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• 2006

The concept of the Hospital run for medical treatment changing to the forms of theme complex hospital with design by the impact of a boutique design. Especially, this design's element emboss with strongly to form a ring around the special hospital as the dentistry, dermatology and plastic surgery, the woman hospital of a lying-in hospital etc. that is the higher value-added industrial among groups of medical, even general hospital that is not depend on the design relatively, the application of the interior design is extending farther. Also, this special hospital shape up become bigger, form a group and competition for admission to medical industry. For dentistry, the more departmentalize and definite service as implant, children dental clinic holding an absolute dominant position about management, and effective environmental exchange can be essential element for the most profits. Accordingly, In this study I would like to see about the space composition of the dentistry that changing with the times, suggest direction from now on the bigger, specialization and a characteristic of a space focused on recently dentistry project.

• 대한의용생체공학회:의공학회지
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• 제20권4호
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• pp.495-502
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• 1999

본 연구에서는 내이의 손상에 의한 감각성 난청환자들의 청력회복을 위한 청각보철장치내의 가장 중요한 부분인 어음발췌기의 음성신호처리 알고리즘 및 하드웨어를 개발하였다. 증폭, 저역통과 필터, AGC의 역할을 수행하는 외이 및 중이는 아날로그 시스템으로 모델링하였고, 시간 지연된 다중 필터 및 변환기의 역할을 수행하는 내이는 실시간 처리가 가능한 고속 DSP 회로로 구현되었다. 특히 내이의 기저막특성은 비선형 자중 필터뱅크로 모델링한후, 피치와 동기화된 다중 스펙트럼을 출력할 수 있는 (pitch-synchronous multi-spectra : PSMS) 전략을 이용함으로서 청각계의 tonotopy와 periodicity를 만족시킬 수 있었다. 또한 주요, 음성신호처리의 대부분이 S/W로 수행되므로 다양한 실험을 위한 시스템 수정이 용이하며, C 언어로 프로그램이 개발되었기 때문에 다른 프로세스를 사용하는 H/W에도 쉽게 이식될 수 있다는 장점을 가진다.

• Journal of Periodontal and Implant Science
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• 제41권5호
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• pp.211-217
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• 2011

Purpose: The marginal bone levels around implants following restoration are used as a reference for evaluating implant success and survival. Two design concepts that can reduce crestal bone resorption are the microthread and platform-switching concepts. The aims of this study were to analyze the placement of microthreaded and platform-switched implants and their short-term survival rate, as well as the level of bone around the implants. Methods: The subjects of this study were 27 patients (79 implants) undergoing treatment with microthreaded and platform-switched implants between October 2008 and July 2009 in the Dental Hospital of Yonsei University Department of Periodon-tology. The patients received follow-up care more than 6 months after the final setting of the prosthesis, at which time periapical radiographs were taken. The marginal bone level was measured from the reference point to the lowest observed point of contact between the marginal bone and the fixture. Comparisons were made between radiographs taken at the time of fixture installation and those taken at the follow-up visit. Results: During the study period (average of 11.8 months after fixture installation and 7.4 months after the prosthesis delivery), the short-term survival rate of microthreaded and platform-switched implants was 100% and the marginal bone loss around implants was $0.16{\pm}0.08$ mm, the latter of which is lower than the previously reported values. Conclusions: This short-term clinical study has demonstrated the successful survival rates of a microthread and platform-switched implant system, and that this system is associated with reduced marginal bone loss.

• 대한치과교정학회지
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• 제47권4호
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• pp.229-237
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• 2017

Objective: The aim of this study was to compare the initial stability as insertion and removal torque and the clinical applicability of novel orthodontic zirconia micro-implants made using a powder injection molding (PIM) technique with those parameters in conventional titanium micro-implants. Methods: Sixty zirconia and 60 titanium micro-implants of similar design (diameter, 1.6 mm; length, 8.0 mm) were inserted perpendicularly in solid polyurethane foam with varying densities of 20 pounds per cubic foot (pcf), 30 pcf, and 40 pcf. Primary stability was measured as maximum insertion torque (MIT) and maximum removal torque (MRT). To investigate clinical applicability, compressive and tensile forces were recorded at 0.01, 0.02, and 0.03 mm displacement of the implants at angles of $0^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$, and $40^{\circ}$. The biocompatibility of zirconia micro-implants was assessed via an experimental animal study. Results: There were no statistically significant differences between zirconia micro-implants and titanium alloy implants with regard to MIT, MRT, or the amount of movement in the angulated lateral displacement test. As angulation increased, the mean compressive and tensile forces required to displace both types of micro-implants increased substantially at all distances. The average bone-to-implant contact ratio of prototype zirconia micro-implants was $56.88{\pm}6.72%$. Conclusions: Zirconia micro-implants showed initial stability and clinical applicability for diverse orthodontic treatments comparable to that of titanium micro-implants under compressive and tensile forces.

• 구강회복응용과학지
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• 제25권3호
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• pp.243-253
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• 2009

임플란트 술식에서 방사선 영상 기술, 컴퓨터 소프트웨어의 발전으로 정확한 진단 및 surgical guide의 제작이 가능해졌다. 본 증례는 양악 무치악 환자에서 고정성 임플란트 보철을 위해 CAD/CAM technique을 이용하여 수술을 하고 즉시 하중을 가한 증례이다. Planning software program을 이용하여 해부학적 구조물과 단면상을 고려하여 상 하악에 각각 6개씩의 임플란트를 최적의 위치에 계획하였다. 정밀한 surgical guide 이용하여 미리 계획된 위치와 방향으로 무절개 임플란트 식립 수술을 시행하였다. 즉시 사용 가능한 고정성 임시 보철물을 미리 제작해 수술 직후 장착하여 환자의 만족도를 높였으며, 이를 6개월간 평가하여 심미적이며, 기능적으로 안정적인 최종 보철물을 제작할 수 있었다.

• 한국신뢰성학회지:신뢰성응용연구
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• 제17권1호
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• pp.50-57
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• 2017

Purpose : This paper is a comparative analysis results of the fatigue test for dental implants and accelerated life test by using a static type loading device commonly used in Korea and a dynamic type loading device (universal-joint) recommended by FDA. Methods : Fatigue tests of dental implant is based on ISO 14801 and classified into static load test and dynamic load test. The tests were carried out on three test specimens by four load stress steps under each loading device. For analysis on failure mode such as crack, fracture and permanent deformation of test specimens, we used X-ray three-dimensional computed tomography on test specimens before and after the fatigue tests. The design of the accelerated life test was based on the analysis results of the fatigue life data obtained from the dynamic load test and the statistical analysis software (Minitab ver.15) was used to analyze the appropriate life distribution. Results : As a result of the fatigue tests and the accelerated life tests at same acceleration condition under each test method, the fatigue life under the dynamic type loading device (universal-joint) was shorter than when static type loading device was applied. Conclusion : This paper can be used as a reference when the universal-joint type loading device for implants fatigue test is applied as ISO 14801.