Duplication of complete dentures using general-purpose handheld optical scanner and 3-dimensional printer: Introduction and clinical considerations

2017 ◽  
Vol 61 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Kosuke Kurahashi ◽  
Takashi Matsuda ◽  
Takaharu Goto ◽  
Yuichi Ishida ◽  
Teruaki Ito ◽  
...  
Author(s):  
Tom C. Johnson ◽  
Judy M. Vance

Abstract Virtual reality (VR) provides the ability to work with digital models in an environment that provides 3 dimensional interaction. This technology can be used to evaluate how humans interact with products before costly physical prototypes are built. One of the advantages of using VR technology in design evaluation is the ability to easily explore many different “what-if” design scenarios. One of the areas of current research in the use of VR is in assembly methods planning. As a result of prior work performed at Iowa State University, it became clear that collision detection is an important component in the development of virtual assembly methods planning applications. This paper describes the use of the Voxmap Pointshell method of collision detection as it is applied to a general purpose virtual assembly planning application.


Author(s):  
Tae-Hyun Park ◽  
Young-Woo Lee ◽  
Hyun-Ho Lee ◽  
Hyun-Soo Shin

Long duration numerical sloshing simulations and model tests have been carried out to assess membrane LNG cargo containment system design. In the sloshing model tests, resonance periods of the tank were taken into consideration for the selection of critical sea states in viewpoint of sloshing loads. For the sloshing scenario of the most probable highest extreme impact pressure used in sloshing model tests, impact pressures were calculated and statistically post-processed for critical locations in a cargo hold of LNG carrier using full scale 5-hour numerical simulations. In the numerical simulations, violent sloshing behaviors could be reproduced using a general-purpose commercial CFD code which uses PLIC VOF method to capture the free surface evolutions. For validation of the numerical calculations, 2-dimensional sloshing simulation was first performed for a rectangular tank and a good agreement with experimental data was shown. For use in the assessment of the tank design, 3-dimensional numerical sloshing simulations were performed using four degrees of freedom irregular ship motions and the statistically processed impact pressures were compared with those of the sloshing model tests. The comparison showed that the 3-dimensional long duration numerical sloshing simulation can be a qualitative computational tool for use in the assessment of the membrane LNG cargo containment system design.


2019 ◽  
Author(s):  
Ryan N. Hughes ◽  
Glenn D.R. Watson ◽  
Elijah Petter ◽  
Namsoo Kim ◽  
Konstantin I. Bakhurin ◽  
...  

SummaryThe Ventral Tegmental Area (VTA) is a midbrain region implicated in a variety of motivated behaviors. However, the function of VTA GABAergic (Vgat+) neurons remains poorly understood. Here, using 3D motion capture, in vivo electrophysiology and calcium imaging, and optogenetics, we demonstrate a novel function of VTAVgat+ neurons. We found three distinct populations of neurons, each representing head angle about a principal axis of rotation: pitch, roll, and yaw. For each axis, opponent cell groups were found that increase firing when the head moves in one direction, and decrease firing in the opposite direction. Selective excitation and inhibition of VTAVgat+ neurons generate opposite rotational movements. The relationship between these neurons and head angle is degraded only at the time of reward consumption, at which point all head-angle related neuronal subpopulations show indistinguishable reward-related responses. Thus, VTAVgat+ neurons serve a critical role in the control of rotational kinematics while pursuing a moving target. This general-purpose steering function can guide animals toward desired spatial targets in any motivated behavior.


2012 ◽  
Vol 38 (5) ◽  
pp. 603-609 ◽  
Author(s):  
Oguz Ozan ◽  
Emre Seker ◽  
Sevcan Kurtulmus-Yilmaz ◽  
Ahmet Ersan Ersoy

The success of implant-supported restorations depends on the treatment planning and the transfer of planning through the surgical field. Recently, new computer-aided design and manufacturing (CAD/CAM) techniques, such as stereolithographic (SLA) rapid prototyping, have been developed to fabricate surgical guides to improve the precision of implant placement. The objective of the present case is to introduce a recently developed SLA surgical guide system into the rehabilitation of a 62-year-old male patient with mandibular edentulism. After obtaining a cone-beam computerized tomography (CBCT) scan of the mandible with a radiographic template, the images were transferred into a 3-dimensional (3D) image-based software for implant planning. The StentCad Beyond SLA surgical guide system, which is a combination of a currently used surgical template with pilot hollows and a surgical handpiece guidance apparatus, was designed to transfer a preoperatively defined implant position onto the surgical site without any drill-surgical guide contact. For the fabrication of this system, a surgical handpiece was scanned by a laser optical scanner and a mucosa-supported surgical guide was designed according to the patient's 3D model, which was attained from the CBCT images. Four dental implants were inserted through the SLA surgical guide system by a torque-controlled surgical handpiece to the interforaminal region via a flapless surgical procedure. Implants were assessed 3 months after surgery, and an implant-retained mandibular overdenture was fabricated. The present case emphasizes that CAD/CAM SLA surgical guides, along with CBCT images and scanning data, may help clinicians plan and place dental implants.


Author(s):  
Osamu Watanabe

Making a finite element model for pressure vessel and piping is laborious work and time-consuming. General purpose programs have a special mesh generation tool, which produces finite element model to be used in the analysis of structure, where automatic meshes are generated based on geometrical properties. Obtained mesh shape is generally irregular for complex structures. The present paper shows a development method of finite element model by assembling finite element models for structural component to the whole structure, as is seen in the procedure of actual structures. The finite element component models are prepared for cylindrical shell, spherical shell and nozzle etc., and finite elements for these components are connected to each other to build a whole structure. The present paper presents an application of 3D FE modeling by the proposed method, to show the features and mesh examples.


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