• The Journal of Advanced Prosthodontics
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• 제12권1호
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• pp.38-48
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• 2020

PURPOSE. The objective of this literature review was to analyze the cumulative survival rates (CSRs) of rigid and non-rigid double-crown-retained removable dental prostheses. MATERIALS AND METHODS. Screening of the literature published from January 1995 to December 2019 was performed by using electronic data base (Pubmed) and manual search. The CSRs of rigid and non-rigid double crown removable dental prostheses were investigated. RESULTS. A total of 403 articles were reviewed and 56 relevant articles of them were selected. Subsequently, 25 articles were included for data extraction. These articles were classified according to rigid and non-rigid type double crowns and further subdivided into teeth, implants, and teeth-implant combination types. The CSRs of rigid type double crown ranged from 68.9% to 95.1% of 5 to 10 years in tooth abutments, 94.02% to 100% over a 3-year mean observation periods in implant abutments, and 81.8% to 97.6% in tooth-implant combination. Non-rigid type double crowns had various CSR ranges from 34% to 94% maximum during 10 years observation in teeth abutment. The CSRs of non-rigid type had over 98% in implant abutments, and ranged from 85% to 100% in tooth-implant combination. CONCLUSION. The CSRs of double crowns varies according to types. With accurate evaluation of the remaining teeth and plan of the strategic implant placement, it could be successful treatment alternatives for partially or completely edentulous patients.

• 대한치과보철학회지
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• 제54권1호
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• pp.21-27
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• 2016

국소의치 수복에서는 의치 장착에 의한 잔존 조직의 위해를 최소한으로 억제하는 것이 중요하다. 잔존 구강조직에 위해를 가하는 첫 번째 요인은 잔존치 및 치조제의 기능력 부담이며 두 번째는 구강 위생관리 부족에 의한 영향이다. 이중관을 활용한 국소의치는 rigid support를 통해 치조제에 미치는 부담을 경감시킬 수 있으며, 외관과 의치부에 부착되는 치태 및 침착물을 구강 외에서 쉽고 확실하게 관리할 수 있다. 또한 내관인 지대치 역시 모든 방향에서 청소가 용이해 변연 치은의 건강에 유리하다. 본 증례에서는 심한 치조골 흡수 및 불량한 구강 위생관리를 보이는 부분 무치악 환자에서 이중관을 이용한 국소의치로 상, 하악을 수복하여 기능과 심미, 구강 위생 관리 측면에서 만족할 만한 결과를 얻을 수 있었다.

• Structural Engineering and Mechanics
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• 제56권4호
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• pp.667-694
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• 2015

The suspended dome system is a new structural form that has become popular in the construction of long-span roof structures. Suspended dome is a kind of new pre-stressed space grid structure that has complex mechanical characteristics. In this paper, an optimum topology design algorithm is performed using the enhanced colliding bodies optimization (ECBO) method. The length of the strut, the cable initial strain, the cross-sectional area of the cables and the cross-sectional size of steel elements are adopted as design variables and the minimum volume of each dome is taken as the objective function. The topology optimization on lamella dome is performed by considering the type of the joint connections to determine the optimum number of rings, the optimum number of joints in each ring, the optimum height of crown and tubular sections of these domes. A simple procedure is provided to determine the configuration of the dome. This procedure includes calculating the joint coordinates and steel elements and cables constructions. The design constraints are implemented according to the provision of LRFD-AISC (Load and Resistance Factor Design-American Institute of Steel Constitution). This paper explores the efficiency of lamella dome with pin-joint and rigid-joint connections and compares them to investigate the performance of these domes under wind (according to the ASCE 7-05), dead and snow loading conditions. Then, a suspended dome with pin-joint single-layer reticulated shell and a suspended dome with rigid-joint single-layer reticulated shell are discussed. Optimization is performed via ECBO algorithm to demonstrate the effectiveness and robustness of the ECBO in creating optimal design for suspended domes.