• The Journal of Advanced Prosthodontics
• /
• 제8권6호
• /
• pp.439-448
• /
• 2016

PURPOSE. The purposes of this study are to evaluate the internal and marginal adaptation of two widely used CAD/CAM systems and to study the effect of porcelain press veneering process on the prosthesis adaptation. MATERIALS AND METHODS. Molar of a lower jaw typodont resin model was prepared by adjusting a 1.0 mm circumferential chamfer, an occlusal reduction of 2.0 mm, and a $5^{\circ}$ convergence angle and was duplicated as an abrasion-resistant master die. The monolithic crowns and copings were fabricated with two different CAD/CAM system-Ceramil and Zirkonzahn systems. Two kinds of non-destructive analysis methods are used in this study. First, weight technique was used to determine the overall fitting accuracy. And, to evaluate internal and marginal fit of specific part, replica technique procedures were performed. RESULTS. The silicone weight for the cement space of monolithic crowns and copings manufactured with Ceramil system was significantly higher than that from Zirkonzahn system. This gap might cause the differences in the silicone weight because the prostheses were manufactured according to the recommendation of each system. Marginal discrepancies of copings made with Ceramil system were between 106 and $117{\mu}m$ and those from Zirkonzahn system were between 111 and $115{\mu}m$. Marginal discrepancies of copings made with Ceramil system were between 101 and $131{\mu}m$ and those from Zirkonzahn system were between 116 and $131{\mu}m$. CONCLUSION. Marginal discrepancy was relatively lower in Ceramil system and internal gap was smaller in Zirkonzahn system. There were significant differences in the internal gap of monolithic crown and coping among the 2 CAD/CAM systems. Marginal discrepancy produced from the 2 CAD/CAM systems were within a reported clinically acceptable range of marginal discrepancy.

• 대한치과기공학회지
• /
• 제37권1호
• /
• pp.9-15
• /
• 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.

• International Journal of Precision Engineering and Manufacturing
• /
• 제6권4호
• /
• pp.8-13
• /
• 2005

Interoperability has been the problem of CAD/CAM systems. Starting from 1980's, national and international organizations have addressed the issue through development and release of standards for the exchange of geometric and nongeometric design data. To CAD/CAM vendors, the task of interpreting and implementing these standards falls into their products. This task is a balancing action between users' needs, available development resources, and the technical specifications of standards. This paper explores an area of CAD/CAM systems development, particularly the implementation of the effective exchange files translators'. A new approach is introduced, which proposes to enclose all the translation operations concerning each exchange format to a separate DLL, thus making a 'plug-in.' Then, this plug-in could be used together with the CAD/CAM system or with specialized translation software. This approach allows to create new translators rapidly and to gain the reliable, high-efficiency, and reusable program code. The second part of the paper concerns the possible problems of translators' development. These difficulties often come from the exchange standards' misunderstanding or ambiguity in standards. All examples come from the authors' practice experiences of dealing with CAD/CAM systems.

• Asian Pacific Journal of Cancer Prevention
• /
• 제17권4호
• /
• pp.2277-2284
• /
• 2016

Ribosome-inactivating protein (RIP) from Mirabilis jalapa L. leaves has cytotoxic effects on breast cancer cell lines but is less toxic towards normal cells. However, it can easily be degraded after administration so it needs to be formulated into nanoparticles to increase its resistance to enzymatic degradation. The objectives of this study were to develop a protein extract of M. jalapa L. leaves (RIP-MJ) incorporated into nanoparticles conjugated with Anti-EpCAM antibodies, and to determine its cytotoxicity and selectivity in the T47D breast cancer cell line. RIP-MJ was extracted from red-flowered M. jalapa L. leaves. Nanoparticles were formulated based on polyelectrolyte complexation using low viscosity chitosan and alginate, then chemically conjugated with anti-EpCAM antibody using EDAC based on carbodiimide reaction. RIP-MJ nanoparticles were characterised for the particle size, polydispersity index, zeta potential, particle morphology, and entrapment efficiency. The cytotoxicity of RIP-MJ nanoparticles against T47D and Vero cells was then determined with MTT assay. The optimal formula of RIP-MJ nanoparticles was obtained at the concentration of RIP-MJ, low viscosity chitosan and alginate respectively 0.05%, 1%, and 0.4% (m/v). RIP-MJ nanoparticles are hexagonal with high entrapment efficiency of 98.6%, average size of 130.7 nm, polydispersity index of 0.380 and zeta potential +26.33 mV. The $IC_{50}$ values of both anti-EpCAM-conjugated and non-conjugated RIP-MJ nanoparticles for T47D cells (13.3 and $14.9{\mu}g/mL$) were lower than for Vero cells (27.8 and $33.6{\mu}g/mL$). The $IC_{50}$ values of conjugated and non-conjugated RIP-MJ for both cells were much lower than $IC_{50}$ values of non-formulated RIP-MJ (>$500{\mu}g/mL$).

• 한국안전학회지
• /
• 제8권4호
• /
• pp.54-60
• /
• 1993

The purpose of this study is to develop a CAD/CAM system for automatic creation and manufacturing of three dimension objects. The computer system used in this study made RAM 2M, CPU 80386, VGA graphic card. The results in this paper are as follows ; 1. By interconnect PC(personal computer) and NC(numerical control) milling machine with RS232C connector, we was constructed with CAD/CAM system. 2. The developed algorithm in this study is able to be design of three dimension object on the computer CRT and manufacturing of NC milling machine. 3. Because of design and modifying on the PC of objects, we can be saving time, cost and improvable precision of objects. 4. Essentially, we expect industrial accident to reduse according as we takes advantage of CAD/CAM system.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2006년도 추계학술대회 논문집
• /
• pp.269-270
• /
• 2006

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2023년도 추계학술발표대회
• /
• pp.479-480
• /
• 2023

생성형 인공지능은 학습의 기준을 파악하기 어려운 모델이다. 그 중 DCGAN을 분석하여 판별자를 통해 생성자의 학습 기준을 판단할 수 있는 하나의 방법을 제안하고자 한다. 그 과정에서 XAI 기법인 Grad-CAM을 활용하여 학습 시에 모델이 중요시하는 부분을 분석하여 적합한 학습과 학습에 적합하지 않은 데이터를 분석하는 방법을 소개하고자 한다.

• The Journal of Advanced Prosthodontics
• /
• 제2권2호
• /
• pp.33-38
• /
• 2010

PURPOSE. Marginal fit is a very important factor considering the restoration's long-term success. However, adding porcelain to copings can cause distortion and lead to an inadequate fit which exposes more luting material to the oral environment and causes secondary caries. The purpose of this study was to compare the marginal fit of 2 different all-ceramic crown systems before and after porcelain veneering. This study was also intended to verify the marginal fit of crowns originated from green machining of partially sintered blocks of zirconia (Lava CAD/CAM system) and that of crowns obtained through machining of fully sintered blocks of zirconia (Digident CAD/CAM system). MATERIALS AND METHODS. 20 crowns were made per each system and the marginal fit was evaluated through a light microscope with image processing (Accura 2000) at 50 points that were randomly selected. Each crown was measured twice: the first measurement was done after obtaining a 0.5 mm coping and the second measurement was done after porcelain veneering. The means and standard deviations were calculated and statistical inferences among the 2 groups were made using independent t-test and within the same group through paired t-test. RESULTS. The means and standard deviations of the marginal fit were $61.52{\pm}2.88{\mu}m$ for the Digident CAD/CAM zirconia ceramic crowns before porcelain veneering and $83.15{\pm}3.51{\mu}m$ after porcelain veneering. Lava CAD/CAM zirconia ceramic crowns showed means and standard deviations of $62.22{\pm}1.78{\mu}m$ before porcelain veneering and $82.03{\pm}1.85{\mu}m$ after porcelain veneering. Both groups showed significant differences when analyzing the marginal gaps before and after porcelain veneering within each group. However, no significant differences were found when comparing the marginal gaps of each group before porcelain veneering and after porcelain veneering as well. CONCLUSION. The 2 all-ceramic crown systems showed marginal gaps that were within a reported clinically acceptable range of marginal discrepancy.

• 농업과학연구
• /
• 제25권2호
• /
• pp.235-246
• /
• 1998

지반의 압밀에 따른 변형 거동을 분석하고 입력정수들의 영향을 알아보기 위해서 쌍곡선 모델과 수정 Cam-Clay 모델을 사용하여 수치해석하고 실측자료와 비교한 결과 다음과 같은 결과를 얻었다. 1. 압밀계수 산정밥법에 대한 신뢰성을 평가한 결과, 정규압밀영역에서는 모두 유사한 값을 나타냈으나, 과압밀영역에서는 변화 폭이 커서 적합한 압밀계수를 산정하는데 문제점이 있는 것으로 나타났다. 2. 수치해석에 의하여 전반적인 수평변위의 거동을 파악할 수 있으며, 현장 실측치를 기초로 성토하중에 의한 연약지반의 단기적인 안정성을 파악하는데는 쌍곡선 방법을 적용하는 것이 적합하다. 3. 수평변위의 영향범위(L)는 성토체의 선단으로부터 전체연약층(H)의 L=(0.7~1.4)H 범위까지 미치는 것으로 나타났으며, 최대수평변위는 성토체의 선단하부 G.L.-10m지점으로 전체 연약층 깊이의 1/3지점에서 발생하였다. 4. 쌍곡선 모델과 수정 Cam-Clay 모델을 이용하여 연약지반의 침하량을 비교분석한 결과 침하량의 크기는 Curve fitting 방법, 수정 Cam-Clay 모델, 쌍곡선모델 순으로 나타났다. 5. 쌍곡선 모델과 수정 Cam-Clay 모델에서 입력변수의 영향을 알아보기 위해서 각각의 입력변수들을 변화시켜 침하량과 수평변위의 변화를 비교한 결과, 쌍곡선모델에서는 K값의 영향이 가장 크게 나타났고, 수정 Cam-Clay 모델에서는 침하량은 ${\Gamma}$값의 영향이 가장 크고, 측방변위는 M값의 영향이 가장 크게 나타났다.

• The Journal of Advanced Prosthodontics
• /
• 제5권3호
• /
• pp.219-225
• /
• 2013

PURPOSE. Few studies have investigated the marginal accuracy of 3-unit zirconia fixed partial dentures (FPDs) fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM) system. The purpose of this study was to compare the marginal fit of zirconia FPDs made using two CAD/CAM systems with that of metal-ceramic FPDs. MATERIALS AND METHODS. Artificial resin maxillary central and lateral incisors were prepared for 3-unit FPDs and fixed in yellow stone. This model was duplicated to epoxy resin die. On the resin die, 15 three-unit FPDs were fabricated per group (45 in total): Group A, zirconia 3-unit FPDs made with the Everest system; Group B, zirconia 3-unit FPDs made with the Lava system; and Group C, metal-ceramic 3-unit FPDs. They were cemented to resin dies with resin cement. After removal of pontic, each retainer was separated and observed under a microscope (Presize 440C). Marginal gaps of experimental groups were analyzed using one-way ANOVA and Duncan test. RESULTS. Mean marginal gaps of 3-unit FPDs were $60.46{\mu}m$ for the Everest group, $78.71{\mu}m$ for the Lava group, and $81.32{\mu}m$ for the metal-ceramic group. The Everest group demonstrated significantly smaller marginal gap than the Lava and the metal-ceramic groups (P<.05). The marginal gap did not significantly differ between the Lava and the metal-ceramic groups (P>.05). CONCLUSION. The marginal gaps of anterior 3-unit zirconia FPD differed according to CAD/CAM systems, but still fell within clinically acceptable ranges compared with conventional metal-ceramic restoration.