Algorithm for the boundary detection of dental crowns for 3D dental model segmentation

There are many steps in fabrication of dental crowns and bridges at which an error can occur, and a technician can only fabricate a quality restoration if the impression itself is of adequate quality. All dental practitioners should have the ability to evaluate the quality of dental impression before sending to the laboratory. Elastomeric silicones (polysiloxane) are the most utilised impression materials in dental practice. The present study deal with the deficiencies of silicones dental impressions sent to commercial dental laboratories for fabrication of single crowns and bridges.

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An Efficient Shot Boundary Detection Using Data-cube Searching Technique

Recent Advances in Computer Science and Communications ◽

10.2174/2213275912666190830141628 ◽

2020 ◽

Vol 13 (4) ◽

pp. 798-807

Author(s):

J. Kavitha ◽

P. Arockia Jansi Rani ◽

P. Mohamed Fathimal ◽

Asha Paul

Keyword(s):

Texture Features ◽

Boundary Detection ◽

Data Cube ◽

Multimedia Data ◽

Shot Boundary Detection ◽

Gradual Transition ◽

Detection Rates ◽

Effective Manner ◽

Shot Boundary ◽

Shot Transitions

Background:: In the internet era, there is a prime need to access and manage the huge volume of multimedia data in an effective manner. Shot is a sequence of frames captured by a single camera in an uninterrupted space and time. Shot detection is suitable for various applications such that video browsing, video indexing, content based video retrieval and video summarization. Objective:: To detect the shot transitions in the video within a short duration. It compares the visual features of frames like correlation, histogram and texture features only in the candidate region frames instead of comparing the full frames in the video file. Methods: This paper analyses candidate frames by searching the values of frame features which matches with the abrupt detector followed by the correct cut transition frame with in the datacube recursively until it detects the correct transition frame. If they are matched with the gradual detector, then it will give the gradual transition ranges, otherwise the algorithm will compare the frames within the next datacube to detect shot transition. Results:: The total average detection rates of all transitions computed in the proposed Data-cube Search Based Shot Boundary Detection technique are 92.06 for precision, 96.92 for recall and 93.94 for f1 measure and the maximum accurate detection rate. Conclusion:: Proposed method for shot transitions uses correlation value for searching procedure with less computation time than the existing methods which compares every single frame and uses multi features such as color, edge, motion and texture features in wavelet domain.

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Rule-based scene boundary detection for semantic video segmentation

5th International Conference on Visual Information Engineering (VIE 2008) ◽

10.1049/cp:20080397 ◽

2008 ◽

Author(s):

Yue Feng ◽

R. Ren ◽

J. Jose

Keyword(s):

Video Segmentation ◽

Boundary Detection ◽

Rule Based

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Direct 3D model extraction method for color volume images

Technology and Health Care ◽

10.3233/thc-218014 ◽

2021 ◽

Vol 29 ◽

pp. 133-140

Author(s):

Bin Liu ◽

Shujun Liu ◽

Guanning Shang ◽

Yanjie Chen ◽

Qifeng Wang ◽

...

Keyword(s):

3D Model ◽

Clinical Medicine ◽

Three Dimensional ◽

Laplacian Matrix ◽

Segmentation Method ◽

Human Organs ◽

Model Segmentation ◽

Treatment Objective ◽

Organ Models ◽

Different Parts

BACKGROUND: There is a great demand for the extraction of organ models from three-dimensional (3D) medical images in clinical medicine diagnosis and treatment. OBJECTIVE: We aimed to aid doctors in seeing the real shape of human organs more clearly and vividly. METHODS: The method uses the minimum eigenvectors of Laplacian matrix to automatically calculate a group of basic matting components that can properly define the volume image. These matting components can then be used to build foreground images with the help of a few user marks. RESULTS: We propose a direct 3D model segmentation method for volume images. This is a process of extracting foreground objects from volume images and estimating the opacity of the voxels covered by the objects. CONCLUSIONS: The results of segmentation experiments on different parts of human body prove the applicability of this method.

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Scanning Accuracy of Bracket Features and Slot Base Angle in Different Bracket Materials by Four Intraoral Scanners: An In Vitro Study

Materials ◽

10.3390/ma14020365 ◽

2021 ◽

Vol 14 (2) ◽

pp. 365

Author(s):

Seon-Hee Shin ◽

Hyung-Seog Yu ◽

Jung-Yul Cha ◽

Jae-Sung Kwon ◽

Chung-Ju Hwang

Keyword(s):

Stainless Steel ◽

In Vitro Study ◽

Sem Images ◽

Polycrystalline Alumina ◽

Base Angle ◽

Accurate Expression ◽

Dental Model ◽

Alumina Composite ◽

The Difference

The accurate expression of bracket prescription is important for successful orthodontic treatment. The aim of this study was to evaluate the accuracy of digital scan images of brackets produced by four intraoral scanners (IOSs) when scanning the surface of the dental model attached with different bracket materials. Brackets made from stainless steel, polycrystalline alumina, composite, and composite/stainless steel slot were considered, which have been scanned from four different IOSs (Primescan, Trios, CS3600, and i500). SEM images were used as references. Each bracket axis was set in the reference scan image, and the axis was set identically by superimposing with the IOS image, and then only the brackets were divided and analyzed. One-way analysis of variance (ANOVA) was used to compare the differences. The difference between the manufacturer’s nominal torque and bracket slot base angle was 0.39 in SEM, 1.96 in Primescan, 2.04 in Trios, and 5.21 in CS3600 (p < 0.001). The parallelism, which is the difference between the upper and lower angles of the slot wall, was 0.48 in SEM, 7.00 in Primescan, 5.52 in Trios, 6.34 in CS3600, and 23.74 in i500 (p < 0.001). This study evaluated the accuracy of the bracket only, and it must be admitted that there is some error in recognizing slots through scanning in general.

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Effect of frame design and veneering material on biomechanical behavior of zirconia dental crowns veneered with overpressing ceramics

Dental Materials Journal ◽

10.4012/dmj.2016-096 ◽

2017 ◽

Vol 36 (3) ◽

pp. 275-281 ◽

Cited By ~ 1

Author(s):

Liliana POROJAN ◽

Florin TOPALĂ ◽

Sorin POROJAN ◽

Cristina SAVENCU

Keyword(s):

Frame Design ◽

Biomechanical Behavior ◽

Dental Crowns

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