A three-dimensional dental model restoration method based on tooth feature contours

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shuai Yang ◽  
Wenjie Zhao ◽  
Yongzhen Ke ◽  
Jiaying Liu ◽  
Yongjiang Xue

Purpose Due to the inability to directly apply an intra-oral image with esthetic restoration to restore tooth shape in the computer-aided design system, this paper aims to propose a method that can use two-dimensional contours obtained from the image for the three-dimensional dental mesh model restoration. Design/methodology/approach First, intra-oral image and smiling image are taken from the patient, then teeth shapes of the images are designed based on esthetic restoration concepts and the pixel coordinates of the teeth’s contours are converted into the vertex coordinates in the three-dimensional space. Second, the dental mesh model is divided into three parts – active part, passive part and fixed part – based on the teeth’s contours of the mesh model. Third, the vertices from the teeth’s contours of the dental model are matched with ones from the intra-oral image and with the help of matching operation, the target coordinates of each vertex in the active part can be calculated. Finally, the Laplacian-based deformation algorithm and mesh smoothing algorithm are performed. Findings Benefitting from the proposed method, the dental mesh model with esthetic restoration can be quickly obtained based on the intra-oral image that is the result of doctor-patient communication. Experimental results show that the quality of restoration meets clinical needs, and the typical time cost of the method is approximately one second. So the method is both time-saving and user-friendly. Originality/value The method provides the possibility to design personalized dental esthetic restoration solutions rapidly.

2019 ◽  
Vol 25 (5) ◽  
pp. 857-863
Author(s):  
Fusong Yuan ◽  
Yao Sun ◽  
Lei Zhang ◽  
Yuchun Sun

Purpose The purpose of this paper is to establish a chair-side design and production method for a tooth-supported fixed implant guide and to evaluate its accuracy. Design/methodology/approach Three-dimensional (3D) data of the alveolar ridge, adjacent teeth and antagonistic teeth were acquired from models of the edentulous area of 30 patients. The implant guides were then constructed using self-developed computer-aided design software and chair-side fused deposition modelling 3D-printing and positioned on a dental model. A model scanner was used to acquire 3D data of the positioned implant guides, and the overall error was then evaluated. Findings The overall error was 0.599 ± 0.146 mm (n = 30). One-way ANOVA revealed no statistical differences among the 30 implant guides. The gap between the occlusal surface of the teeth covering and the tissue surface of the implant guide was measured. The maximum gap after positioning of the implant guide was 0.341 mm (mean, 0.179 ± 0.019 mm). The implanted axes of the printed implant guide and designed guide were compared in terms of overall, lateral and angular error, which were 0.104 ± 0.004 mm, 0.097 ± 0.003 mm, and 2.053° ± 0.017°, respectively. Originality/value The results of this study demonstrated that the accuracy of a new chair-side tooth-supported fixed implant guide can satisfy clinical requirements.


2019 ◽  
Vol 31 (3) ◽  
pp. 339-349 ◽  
Author(s):  
Yeonghoon Kang ◽  
Sungmin Kim

Purpose The purpose of this paper is to develop the core module of computer-aided three-dimensional garment pattern design system. Design/methodology/approach A progressive mesh cutting algorithm and mesh reshaping algorithm have been developed to cut a single mesh into multiple patches. A flat projection algorithm has been developed to project 3D patches into 2D patterns. Findings The software developed in this study is expected to enable its users to design complex garment patterns without the in-depth knowledge of pattern design process. Research limitations/implications The mesh model used in this study was a fixed model. It will be extended to a deformable garment model that can be resized according to the underlying body model Practical implications The software developed in this study is expected to reduce the time required for time-consuming and trial-and-error-based pattern design process. Social implications Fashion designers will be able to design complex patterns by themselves and the dependence upon expert patterners could be reduced Originality/value The progressive mesh cutting algorithm developed in this study can cut a mesh model using arbitrary lines. The mesh reshaping algorithm can improve the mesh quality of divided patches to increase the numerical stability during subsequent pattern flattening process. The flip removal algorithm can effectively remove the partially flipped mesh elements.


2017 ◽  
Vol 23 (6) ◽  
pp. 1136-1145 ◽  
Author(s):  
Yunbo Zhang ◽  
Tsz Ho Kwok

Purpose The purpose of this paper is to establish new computer-aided-design (CAD) framework to design custom product that is fabricated additive manufacturing (AM), which can produce complex three-dimensional (3D) object without additional tool or fixture. Additive manufacturing (AM) enables the fabrication of three-dimensional (3D) objects with complex shapes without additional tools and refixturing. However, it is difficult for user to use traditional computer-aided design tools to design custom products. Design/methodology/approach In this paper, the authors presented a design system to help user design custom 3D printable products based on some reference freeform shapes. The user can define and edit styling curves on the reference model using the interactive geometric operations for styling curve. Incorporating with the reference models, these curves can be converted into 3D printable models through the fabrication interface. Findings The authors tested their system with four design applications including a hollow patterned bicycle helmet, a T-rex with skin frame structure, a face mask with Voronoi patterns and an AM-specific night dress with hollow patterns. Originality/value The executable prototype of the presented design framework used in the customization process is publicly available.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yongzhen Ke ◽  
Wenjie Zhao ◽  
Shuai Yang ◽  
Kai Wang ◽  
Jiaying Liu

Purpose This paper aims to obtain a texture dental model with real images and improve the rendering effect of the dental model. Design/methodology/approach The paper proposes a semiautomatic method to construct a realistic dental model with real images based on two-dimensional/three-dimensional (2D/3D) registration. First, a 3D digital dental model and three intraoral images are obtained by a 3D scanner and digital single-lens reflex camera. Second, the camera projection poses for every intraoral images are calculated by using the single-objective optimization algorithm. Third, with camera poses, the preliminary projection texture mapping is performed; besides, the seam between two textures is marked. Finally, the marked regions are fused based on the image pyramid to eliminate obvious seams. Findings The paper provides a method to construct a realistic dental model. The method can map three intraoral images to the dental model. The experimental results show that the textured dental model without obvious distortion, dislocation and seams is constructed with simple interactions. Originality/value The proposed method can be applied to the digital smile design system to improve the communication efficiency between doctors, patients and technicians.


2015 ◽  
Vol 35 (3) ◽  
pp. 269-280 ◽  
Author(s):  
Hu Qiao ◽  
Rong Mo ◽  
Ying Xiang

Purpose – The purpose of this paper is to establish an adaptive assembly, to realize the adaptive changing of the models and to improve the flexibility and reliability of assembly change. For a three-dimensional (3D) computer-aided design (CAD) assembly in a changing process, there are two practical problems. One is delivering parameters’ information not smoothly. The other one is to easily destroy an assembly structure. Design/methodology/approach – The paper establishes associated parameters design structure matrix of related parts, and predicts possible propagation paths of the parameters. Based on the predicted path, structured storage is made for the affected parameters, tolerance range and the calculation relations. The study combines structured path information and all constrained assemblies to build the adaptive assembly, proposes an adaptive change algorithm for assembly changing and discusses the extendibility of the adaptive assembly. Findings – The approach would improve the flexibility and reliability of assembly change and be applied to different CAD platform. Practical implications – The examples illustrate the construction and adaptive behavior of the assembly and verify the feasibility and reasonability of the adaptive assembly in practical application. Originality/value – The adaptive assembly model proposed in the paper is an original method to assembly change. And compared with other methods, good results have been obtained.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wiktoria Maria Wojnarowska ◽  
Jakub Najowicz ◽  
Tomasz Piecuch ◽  
Michał Sochacki ◽  
Dawid Pijanka ◽  
...  

Purpose Chicken orthoses that cover the ankle joint area are not commercially available. Therefore, the main purpose of this study is to fabricate a customised temporary Ankle–Foot Orthosis (AFO) for a chicken with a twisted ankle using computer-aided design (CAD) and three-dimensional (3D) printing. The secondary objective of the paper is to present the specific application of Additive Manufacturing (AM) in veterinary medicine. Design/methodology/approach The design process was based on multiple sketches, photos and measurements that were provided by the owner of the animal. The 3D model of the orthosis was made with Autodesk Fusion 360, while the prototype was fabricated using fused deposition modelling (FDM). Evaluation of the AFO was performed using the finite element method. Findings The work resulted in a functional 3D printed AFO for chicken. It was found that the orthosis made with AM provides satisfactory stiffen and a good fit. It was concluded that AM is suitable for custom bird AFO fabrication and, in some respects, is superior to traditional manufacturing methods. It was also concluded that the presented procedure can be applied in other veterinary cases and to other animal species and other parts of their body. AM provides veterinary with a powerful tool for the production of well-fitted and durable orthoses for animals. Research limitations/implications The study does not include the chicken's opinion on the comfort or fit of the manufactured AFO due to communication issues. Evaluation of the final prototype was done by the researchers and the animal owner. Originality/value No evidence was found in the literature on the use of AM for chicken orthosis, so this study is the first to describe such an application of AM. In addition, the study demonstrates the value of AM in veterinary medicine, especially in the production of devices such as orthoses.


2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771038 ◽  
Author(s):  
Isad Saric ◽  
Adil Muminovic ◽  
Mirsad Colic ◽  
Senad Rahimic

This article presents architecture of integrated intelligent computer-aided design system for designing mechanical power-transmitting mechanisms (IICADkmps). The system has been developed in C# program environment with the aim of automatising the design process. This article presents a modern, automated approach to design. Developed kmps modules for calculation of geometrical and design characteristics of mechanical power-transmitting mechanisms are described. Three-dimensional geometrical parameter modelling of mechanical power-transmitting mechanisms was performed in the computer-aided design/computer-aided manufacturing/computer-aided engineering system CATIA V5. The connection between kmps calculation modules and CATIA V5 modelling system was established through initial three-dimensional models – templates. The outputs from the developed IICADkmps system generated final three-dimensional virtual models of mechanical power-transmitting mechanisms. Testing of the developed IICADkmps system was performed on friction, belt, cogged (spur and bevel gears) and chain transmitting mechanisms. Also, connection of the developed IICADkmps system with a device for rapid prototyping and computer numerical control machines was made for the purpose of additional testing and verification of practical use. Physical prototypes of designed characteristic elements of mechanical power-transmitting mechanisms were manufactured. The selected test three-dimensional virtual prototypes, obtained as an output from the developed IICADkmps system, were manufactured on the device for rapid prototyping (three-dimensional colour printer Spectrum Z510) and computer numerical control machines. Finally, at the end of the article, conclusions and suggested possible directions of further research, based on theoretical and practical research results, are presented.


Author(s):  
Baptiste Ristagno ◽  
Dominique Giraud ◽  
Julien Fontchastagner ◽  
Denis Netter ◽  
Noureddine Takorabet ◽  
...  

Purpose Optimization processes and movement modeling usually require a high number of simulations. The purpose of this paper is to reduce global central processing unit (CPU) time by decreasing each evaluation time. Design Methodology Approach Remeshing the geometry at each iteration is avoided in the proposed method. The idea consists in using a fixed mesh on which functions are projected to represent geometry and supply. Findings Results are very promising. CPU time is reduced for three dimensional problems by almost a factor two, keeping a low relative deviation from usual methods. CPU time saving is performed by avoiding meshing step and also by a better initialization of iterative resolution. Optimization, movement modeling and transient-state simulation are very efficient and give same results as usual finite element method. Research Limitations Implications The method is restricted to simple geometry owing to the difficulty of finding spatial mathematical function describing the geometry. Moreover, a compromise between imprecision, caused by the boundary evaluation, and time saving must be found. Originality Value The method can be applied to optimize rotating machines design. Moreover, movement modeling is performed by shifting functions corresponding to moving parts.


2019 ◽  
Vol 85 (18) ◽  
Author(s):  
Yutaka Yawata ◽  
Tatsunori Kiyokawa ◽  
Yuhki Kawamura ◽  
Tomohiro Hirayama ◽  
Kyosuke Takabe ◽  
...  

ABSTRACT Here we analyzed the innate fluorescence signature of the single microbial cell, within both clonal and mixed populations of microorganisms. We found that even very similarly shaped cells differ noticeably in their autofluorescence features and that the innate fluorescence signatures change dynamically with growth phases. We demonstrated that machine learning models can be trained with a data set of single-cell innate fluorescence signatures to annotate cells according to their phenotypes and physiological status, for example, distinguishing a wild-type Aspergillus nidulans cell from its nitrogen metabolism mutant counterpart and log-phase cells from stationary-phase cells of Pseudomonas putida. We developed a minimally invasive method (confocal reflection microscopy-assisted single-cell innate fluorescence [CRIF] analysis) to optically extract and catalog the innate cellular fluorescence signatures of each of the individual live microbial cells in a three-dimensional space. This technique represents a step forward from traditional techniques which analyze the innate fluorescence signatures at the population level and necessitate a clonal culture. Since the fluorescence signature is an innate property of a cell, our technique allows the prediction of the types or physiological status of intact and tag-free single cells, within a cell population distributed in a three-dimensional space. Our study presents a blueprint for a streamlined cell analysis where one can directly assess the potential phenotype of each single cell in a heterogenous population by its autofluorescence signature under a microscope, without cell tagging. IMPORTANCE A cell’s innate fluorescence signature is an assemblage of fluorescence signals emitted by diverse biomolecules within a cell. It is known that the innate fluoresce signature reflects various cellular properties and physiological statuses; thus, they can serve as a rich source of information in cell characterization as well as cell identification. However, conventional techniques focus on the analysis of the innate fluorescence signatures at the population level but not at the single-cell level and thus necessitate a clonal culture. In the present study, we developed a technique to analyze the innate fluorescence signature of a single microbial cell. Using this novel method, we found that even very similarly shaped cells differ noticeably in their autofluorescence features, and the innate fluorescence signature changes dynamically with growth phases. We also demonstrated that the different cell types can be classified accurately within a mixed population under a microscope at the resolution of a single cell, depending solely on the innate fluorescence signature information. We suggest that single-cell autofluoresce signature analysis is a promising tool to directly assess the taxonomic or physiological heterogeneity within a microbial population, without cell tagging.


Author(s):  
Guy Phuong ◽  
Sylvester Abanteriba ◽  
Paul Haley ◽  
Philippe Guillerot

Volutes are widely used in centrifugal compressors for industrial processes, refrigeration systems, small gas turbines and gas pipelines. However, large costs associated with the volute design and analysis process can be reduced with the introduction of a software design system that ties together both geometry creation and mesh generation having the ultimate intent of improving stage efficiency. Computational Fluid Dynamics (CFD) has become an integral part of engineering design. High quality grids need to be produced as part of the analysis process. Engineers of different expertise may be required to determine volute design constraints and parameters, produce the geometry, and generate a high quality grid. The current research aims to develop and demonstrate a volute design tool that allows design engineers the ability to easily and efficiently generate volute geometry and automate grid generation by means of geometrical constraints using functional relationships. The approach was outlined in [1]. Visualization of volute geometry can be in two-dimensional (2D) or three-dimensional (3D) modes. Control of the diffuser upstream of the scroll, the scroll itself and the conic are totally integrated in the design system. The user can position the conic anywhere in space and control the shape of the conic centroid curve, therefore having complete control over the development of the tongue region. The program will output data for automated grid generation where user can control resulting grid properties. Once the desired design configuration has been determined, the users can output the geometry surfaces and wireframes to a Computer Aided Design (CAD) package for production. Every little detail is also incorporated into the software from volute draft angle, discharge conic centroid shape, to cross section fillet radii. Upon entering all the required constraints and parameters of the volute, the geometry is created in seconds. Grids can be generated in minutes accommodating geometrical changes thus reducing the bottlenecks associated with geometry/grid generation for CFD applications.


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