• The Journal of Advanced Prosthodontics
• /
• 제5권2호
• /
• pp.118-125
• /
• 2013

PURPOSE. The purpose of this study was to evaluate the effect of the span length on the fit of zirconia framework fabricated using CAD/CAM system. MATERIALS AND METHODS. Abutments for single, 4-unit and 6-unit fixed partial prostheses were fabricated. Ten zirconia frameworks were fabricated for each group. The marginal and internal gap were presented by means of replica technique and measured by measuring microscope ($AXIO^{(R)}$, Carl Zeiss, Rochester, NY) and software (I-$solution^{(R)}$, IMT i-solution Inc., Vancouver, BC, Canada). The results were statistically analyzed by multivariate analysis test and Dunnett T3 test for post hoc test (${\alpha}$=.05). RESULTS. There were statistically significant differences at 2, 4, 7, 8 points (mesio-distal section) and b, d, e, f, g (labio-lingual section). In some marginal reference points of 6-unit group (P<.05), the marginal gap were larger than 120 ${\mu}m$. CONCLUSION. Span length of zirconia core may have an influence on marginal and internal fit. Within the limitation of this study, the increase of span length of zirconia framework of 6 or more-unit fixed partial denture may decrease the marginal and internal fit.

• 대한한의학회지
• /
• 제43권3호
• /
• pp.16-26
• /
• 2022

Objectives: Traditional Korean medicine (TKM) has been supplied as part of a national health care system in South Korea under a dual medical system, however it has been difficult to mix western medicine and TKM medical practices in existing hospitals. For the objective of innovative integration between them, Comprehensive and Integrative Medicine Hospital were founded in Daegu, South Korea. Here, we discussed the clinical outcomes of cancer patients who received integrative cancer treatment (ICT). Methods: A total of 678 patients previously diagnosed with cancer were retrospectively checked in our institution for 2 years. After applying inclusion/exclusion criteria, 573 patients were eligible for the final analysis. The overall survival (OS) of these patients in the aftercare period were determined. We looked at how clinical factors and treatments including chemotherapy, complementary and alternative medicine (CAM), and TKM affected the OS. Results: At the first visit, 212 subjects had no evidence of disease after tumor resection and 355 ones with advanced cancer, who receiving ICT including chemotherapy, CAM, and TKM showed better OS compared to the CAM including TKM or the best supportive care (median OS = 216, 78, and 46 days, respectively). The median OS was not reached in TKM only, even though the sample size was small (N=12). Even after adjusting for clinical factors associated to liver, renal, and hematologic manifestation, ICT still remained significant. Conclusions: We demonstrated that ICT might be beneficial for advanced cancer regardless of the performance status, liver and renal function, since it positively affected the OS.

• 한국지반공학회논문집
• /
• 제21권2호
• /
• pp.47-55
• /
• 2005

본 연구에서는 점토지반에서 수평력을 받는 군말뚝과 단말뚝의 수평저항력을 파악하기 위하여 유한요소 해석프로그램인 ABAQUS를 이용하여 수치해석을 행하였다. 수치해석은 말뚝직경(1.0, 0.5m), 말뚝길이(7, 10m) 그리고 두부조건(두부자유와 말뚝캡을 적용한 두부구속조건)을 변수로 하여 실시하였다. 수평력 작용시 선말뚝(leading pile)의 캡에 의한 영향과,군말뚝내의 각각의 말뚝에 대한수평저항력의 크기와 분포를 평가하기 위하여 1$\times$3 군말뚝을 사용하였다. 점토지반은 Cam-clay 모델을 사용하였고, 말뚝은 원형의 콘크러트로 탄성모델을 사용하여 3차원 해석을 수행하였다. 해석결과 말뚝캡의 크기는 단말뚝의 수평저항력에 영향을 미치는 것으로 나타났으며, 군말뚝내의 선말뚝은 군말뚝의 효과에 의해 수평저항력이 증가하면서 Brown이 제안한p-multiplier 값이 1보다 크게 평가되었다.

• The Journal of Advanced Prosthodontics
• /
• 제11권2호
• /
• pp.120-127
• /
• 2019

PURPOSE. To determine wear amount of single molar crowns, made from four different restoratives, and opposing natural teeth through computerized fabrication techniques using 3D image alignment. MATERIALS AND METHODS. A total of 24 single crowns (N = 24 patients, age range: 18 - 50) were made from lithium disilicate (IPS E-max CAD), lithium silicate and zirconia based (Vita Suprinity CAD), resin matrix ceramic material (Cerasmart, GC), and dual matrix (Vita Enamic CAD) blocks. After digital impressions (Cerec 3D Bluecam, DentsplySirona), the crowns were designed and manufactured (Cerec 3, DentsplySirona). A dualcuring resin cement was used for cementation (Variolink Esthetic DC, Ivoclar). Then, measurement and recording of crowns and the opposing enamel surfaces with the intraoral scanner were made as well as at the third and sixth month follow-ups. All measurements were superimposed with a software (David-Laserscanner, V3.10.4). Volume loss due to wear was calculated from baseline to follow-up periods with Siemens Unigraphics NX 10 software. Statistical analysis was accomplished by Repeated Measures for ANOVA (SPSS 21) at = .05 significance level. RESULTS. After 6 months, insignificant differences of the glass matrix and resin matrix materials for restoration/enamel wear were observed (P>.05). While there were no significant differences between the glass matrix groups (P>.05), significant differences between the resin matrix group materials (P<.05) were obtained. Although Cerasmart and Enamic were both resin matrix based, they exhibited different wear characteristics. CONCLUSION. Glass matrix materials showed less wear both on their own and opposing enamel surfaces than resin matrix ceramic materials.

• 대한치과기공학회지
• /
• 제41권4호
• /
• pp.279-285
• /
• 2019

Purpose: The dental CAD / CAM system has been popular with the development of the digital dental industry. Zirconia is a typical material in dental CAD / CAM systems. Zirconia crowns are classified into single layer and double layer. This study is about the double layer crown of zirconia. The surface roughness, bond strength and fracture patterns of the zirconia surface were observed. Methods: Zirconia blocks were cut using a low speed cutter. Sintered to form a plate shape (6mm × 6mm × 3mm). The prepared specimens were surface treated in four ways. Surface roughness and bond strength were measured. And the fracture pattern was observed. Results: Result of surface treatment of zirconia. The surface roughness test results were as ET 2.87 ㎛, ST 2.67 ㎛, LT 2.44 ㎛, AT 2.41 ㎛, CN 2.08 ㎛ order. Bond Strength results were as LT 25.09 MPa, AT 23.27 MPa, ST 21.27 MPa, ET 21.09 MPa, CN 16.12 MPa order. Fracture patterns showed cohesive failure of 25-50% of the bond area. Conclusion: Surface roughness, bond strength and fracture pattern of the zirconia surface were observed. Etching the surface treatment of zirconia materials has been shown to affect the surface roughness. Zirconia special binder treatment has been shown to affect the bond strength improvement.

• International Journal of CAD/CAM
• /
• 제8권1호
• /
• pp.21-28
• /
• 2009

In the present work, an attempt has been made to construct branching surface from 2-D contours, which are given at different layers and may have branches. If a layer having more than one contour and corresponds to contour at adjacent layers, then it is termed as branching problem and approximated by adding additional points in between the layers. Firstly, the branching problem is converted to single contour case in which there is no branching at any layer and the final branching surface is obtained by skinning. Contours are constructed from the given input points at different layers by energy-based B-Spline approximation. 3-D curves are constructed after adding additional points into the contour points for all the layers having branching problem by using energy-based B-Spline formulation. Final 3-D surface is obtained by skinning 3-D curves and 2-D contours. There are three types of branching problems: (a) One-to-one, (b) One-to-many and (c) Many-to-many. Oneto-one problem has been done by plethora of researchers based on minimizations of twist and curvature and different tiling techniques. One-to-many problem is the one in which at least one plane must have more than one contour and have correspondence with the contour at adjacent layers. Many-to-many problem is stated as m contours at i-th layer and n contours at (i+1)th layer. This problem can be solved by combining one-to-many branching methodology. Branching problem is very important in CAD, medical imaging and geographical information system(GIS).

• 한국정보기술학회 영문논문지
• /
• 제10권2호
• /
• pp.167-175
• /
• 2020

In this paper, we propose a traffic accident detection on vehicle-mounted camera. In the proposed method, the minimum bounding box coordinates the central coordinates on the bird's eye view and motion vectors of each vehicle object, and ego-motions of the vehicle equipped with dash-cam are extracted from the dash-cam video. By using extracted 4 kinds features as the input of Bi-LSTM (bidirectional LSTM), the accident probability (score) is predicted. To investigate the effect of each input feature on the probability of an accident, we analyze the performance of the detection the case of using a single feature input and the case of using a combination of features as input, respectively. And in these two cases, different detection models are defined and used. Bi-LSTM is used as a cascade, especially when a combination of the features is used as input. The proposed method shows 76.1% precision and 75.6% recall, which is superior to our previous work.

• 대한화학회지
• /
• 제61권1호
• /
• pp.16-24
• /
• 2017

본 연구는 그래핀과 유사한 2차원 붕소-질소(BN)와 알루미늄-질소(AlN) 시트에 여러 대기 유해 가스($CO_x$, $NO_x$, $SO_x$)가 흡착될 때의 구조적 특징과 결합에너지를 밀도 범함수 이론(DFT)과 MP2 방법을 사용하여 연구하였다. 분자 구조는 $B3LYP/6-31G^{**}$와 $CAM-B3LYP/6-31G^{**}$이론 수준에서 최적화하고, 진동 주파수를 계산하여 열역학적으로 가장 안정한 분자 구조를 확인하였다. 결합에너지는 $MP2/6-31G^{**}$ 이론 수준에서 한 점(single point) 에너지를 계산하고, 영점 진동에너지(ZPVE)와 바탕집합 중첩에러(BSSE)를 모두 보정하였다. BN 시트에 가스의 흡착은 모두 물리흡착으로 예측되었으며, AlN 시트에 대한 가스 흡착은 $CO_x$나 $NO_x$에 대해서는 물리흡착이 그리고 $SO_x$에 대해서는 화학 흡착이 일어날 것으로 예측되었다.

• The Journal of Advanced Prosthodontics
• /
• 제9권4호
• /
• pp.239-243
• /
• 2017

PURPOSE. The purpose of this study is to compare single and three-unit metal frameworks that are produced by micro-stereolithography. MATERIALS AND METHODS. Silicone impressions of a selected molar and a premolar were used to make master abutments that were scanned into a stereolithography file. The file was processed with computer aided design software to create single and three-unit designs from which resin frameworks were created using micro-stereolithography. These resin frameworks were subjected to investment, burnout, and casting to fabricate single and three-unit metal ones that were measured under a digital microscope by using the silicone replica technique. The measurements were verified by means of the Mann-Whitney U test (${\alpha}=.05$). RESULTS. The marginal gap was $101.9{\pm}53.4{\mu}m$ for SM group and $104.3{\pm}62.9{\mu}m$ for TUM group. The measurement of non-pontics in a single metal framework was $93.6{\pm}43.9{\mu}m$, and that of non-pontics in a three-unit metal framework was $64.9{\pm}46.5{\mu}m$. The dimension of pontics in a single metal framework was $110.2{\pm}61.4{\mu}m$, and that of pontics in a three-unit metal framework was $143.7{\pm}51.8{\mu}m$. CONCLUSION. The marginal gap was smaller for the single metal framework than for the three-unit one, which requires further improvement before it can be used for clinical purposes.

• Restorative Dentistry and Endodontics
• /
• 제45권2호
• /
• pp.15.1-15.7
• /
• 2020

This clinical report describes designing and fabricating a single-retainer resin-bonded fixed dental prosthesis with a chair-side computer-aided design/computer-aided manufacturing system. The whole procedure, from tooth extraction to final placement of the prosthesis, was completed in one day, and a single clinic visit. No clinical complications were found at the 2-year follow-up after placement of the restoration, and satisfactory functional and esthetic results were achieved.