Three-Dimensional Digitalized Surface and Volumetric Analysis of Posterior Prefabricated Zirconia Crowns for Children

2019 ◽  
Vol 43 (4) ◽  
pp. 231-238 ◽  
Author(s):  
Hyeonjong Lee ◽  
Yong Kwon Chae ◽  
Hyo-Seol Lee ◽  
Sung Chul Choi ◽  
Ok Hyung Nam
Keyword(s):  
Stainless Steel ◽  
Three Dimensional ◽  
Volumetric Analysis ◽  
Occlusal Surface ◽  
Tooth Surface ◽  
Zirconia Crowns ◽  
Tooth Preparation ◽  
3D Software ◽  
Surface Morphologies ◽  
Axial Surface

Objectives: This study was designed to compare the surface morphologies and volumes of posterior prefabricated zirconia crowns and posterior stainless steel crowns (SSCs) using digitalized three-dimensional (3D) reconstructed images. Study design: We tested prefabricated zirconia crowns (NuSmile ZR; Orthodontic Technologies, Houston, TX, USA) and SSCs (Kids Crown; Shinhung, Seoul, Korea) used to restore left maxillary and mandibular molars. A Rainbow scanner (Dentium, Seoul, Korea) was used to digitise the inner and outer surface morphologies of all crowns. The data were superimposed and evaluated using 3D software. The differences between the outer and inner surfaces and inner volume were measured. Results: The differences between the two types of crowns differed by tooth surface. At the occlusal surface, the differences were greater at the cusp tip than the fossa. At the axial level, the differences decreased toward the gingival margins. Also, relative volumetric ratios varied. Conclusions: Tooth preparation prior to placement of prefabricated zirconia crowns requires special consideration. Greater amounts of tooth reduction are necessary for posterior zirconia crowns than for SSCs. The occlusal surface requires more tooth reduction than the axial surface and the gingival margin.

scholarly journals Feasibility of 3-Dimensional Visual Guides for Preparing Pediatric Zirconia Crowns: An In Vitro Study

2020 ◽  
Vol 17 (16) ◽  
pp. 5732
Author(s):  
Ho Yeon Kang ◽  
Hyeonjong Lee ◽  
Yong Kwon Chae ◽  
Seoung-Jin Hong ◽  
Yun Yeong Jeong ◽  
...  
Keyword(s):  
Three Dimensional ◽  
In Vitro Study ◽  
Mixed Dentition ◽  
Preparation Time ◽  
Second Molar ◽  
Significant Difference ◽  
Distal Surface ◽  
Zirconia Crowns ◽  
Tooth Preparation

This study evaluated the feasibility of a tooth preparation guide for prefabricated zirconia crowns (PZCs). Three-dimensional surface data for PZCs of the left maxillary primary first molar and left mandibular primary second molar were obtained using a model scanner. The tooth preparation data were digitally designed to harmonize with the adjacent teeth on the mixed dentition model and visualized using a color-coded map, which presents the required amount of tooth reduction. Twenty participants were recruited for preparing teeth with and without using the tooth preparation guide. The following three parameters were evaluated: tooth preparation time, harmony score, and amount of tooth reduction. The preparation time when using the guide was significantly reduced (p < 0.05), and a significant difference was observed in the harmony scores for the maxillary primary first molar preparation. Furthermore, the amount of tooth reduction was significantly different for both maxillary and mandibular primary molars (p < 0.05) in terms of the occlusal distal surface and buccal line angle in the maxillary primary first molars, and the smooth surfaces, proximal surfaces, and mesial line angles in the mandibular primary second molars. Thus, the results suggest that a tooth preparation guide could facilitate better tooth preparation for PZCs.

The Extrusion Behavior of Mg Alloys Interpenetrating with Stainless Steel Wire

2014 ◽  
Vol 906 ◽  
pp. 289-292
Author(s):  
Ping Li ◽  
Shou Ren Wang ◽  
Yong Wang ◽  
Guang Ji Xue
Keyword(s):  
Stainless Steel ◽  
Basal Plane ◽  
Deformation Behavior ◽  
Steel Wire ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
Stainless Steel Wire ◽  
3D Software ◽  
Deform 3D ◽  
Magnesium Composites

The interpenetrating magnesium composites reinforced by three-dimensional braided stainless steel wire reinforcement were fabricated. And, the deformation behavior of materials was analyzed in four extrusion velocities by DEFORM-3D software. The results show that with the increases of extrusion velocities, the equivalent stress values exhibit a gradually increasing and then decreasing trend. Owing to the effect of three dimensional reinforcement, the basal plane orientation occur tilt. And, the microstructure turns refined.

A three‐dimensional evaluation of tooth preparation forms in paediatric zirconia crowns: an in‐vitro study

2021 ◽  
Author(s):  
Yong Kwon Chae ◽  
Hyeonjong Lee ◽  
Hong‐Keun Hyun ◽  
Hyo‐Seol Lee ◽  
Sung Chul Choi ◽  
...  
Keyword(s):  
Three Dimensional ◽  
In Vitro Study ◽  
Vitro Study ◽  
Zirconia Crowns ◽  
Tooth Preparation

scholarly journals Assessment of Tooth Preparations Submitted to Dental Laboratories for Fabrication of Monolithic Zirconia Crowns

2021 ◽  
Vol 9 (10) ◽  
pp. 112
Author(s):  
Ramtin Sadid-Zadeh ◽  
Hadjer Sahraoui ◽  
Brian Lawson ◽  
Robert Cox
Keyword(s):  
Three Dimensional ◽  
Finish Line ◽  
Posterior Teeth ◽  
3D Images ◽  
Line Angle ◽  
Zirconia Crowns ◽  
Monolithic Zirconia ◽  
Tooth Preparation ◽  
Line Design

Purpose: The objective of this study was to assess the quality of posterior teeth prepared for monolithic zirconia crowns. Materials and Methods: A total of 392 STL-files of posterior preparations for monolithic zirconia crowns were evaluated in this study. Three-dimensional (3D) images were evaluated using a software (3D Viewer; 3Shape A/S, Copenhagen, Denmark) for finish line design, finish line width, occluso-cervical dimension, total occlusal convergence (TOC), intercuspal angulation, finish line quality, line angle form, and presence or absence of undercut at the axial wall and unsupported lip of enamel. The assessment was performed by two calibrated evaluators. Then, data were descriptively analyzed. Data for occluso-cervical dimension and TOC were descriptively analyzed according to their location. Results: Thirty-nine percent of premolars, 77% of first molars, and 91% of second molars had an average occluso-cervical dimension of less than 3 mm (premolars) and 4 mm (molars), with most of the preparations having a TOC of more than 20 degrees. More than 50% of preparations had undercut, unsupported enamel and/or unacceptable finish line quality. Conclusions: The quality of tooth preparation including finish line quality, absence of unsupported enamel and undercut at the axial wall should be evaluated when preparing monolithic zirconia crowns.

scholarly journals A Web-Based Rendering Application for Communicating Dental Conditions

Healthcare ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 960
Author(s):  
Hudson D. Spangler ◽  
Miguel A. Simancas-Pallares ◽  
Jeannie Ginnis ◽  
Andrea G. Ferreira Zandoná ◽  
Jeff Roach ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Latent Class ◽  
Real Life ◽  
Tooth Surface ◽  
Caries Experience ◽  
Visual Aids ◽  
Web Based ◽  
Surface Level ◽  
Ceramic Crowns ◽  
Dental Conditions

The importance of visual aids in communicating clinical examination findings or proposed treatments in dentistry cannot be overstated. Similarly, communicating dental research results with tooth surface-level precision is impractical without visual representations. Here, we present the development, deployment, and two real-life applications of a web-based data visualization informatics pipeline that converts tooth surface-level information to colorized, three-dimensional renderings. The core of the informatics pipeline focuses on texture (UV) mapping of a pre-existing model of the human primary dentition. The 88 individually segmented tooth surfaces receive independent inputs that are represented in colors and textures according to customizable user specifications. The web implementation SculptorHD, deployed on the Google Cloud Platform, can accommodate manually entered or spreadsheet-formatted tooth surface data and allows the customization of color palettes and thresholds, as well as surface textures (e.g., condition-free, caries lesions, stainless steel, or ceramic crowns). Its current implementation enabled the visualization and interpretation of clinical early childhood caries (ECC) subtypes using latent class analysis-derived caries experience summary data. As a demonstration of its potential clinical utility, the tool was also used to simulate the restorative treatment presentation of a severe ECC case, including the use of stainless steel and ceramic crowns. We expect that this publicly available web-based tool can aid clinicians and investigators deliver precise, visual presentations of dental conditions and proposed treatments. The creation of rapidly adjustable lifelike dental models, integrated to existing electronic health records and responsive to new clinical findings or planned for future work, is likely to boost two-way communication between clinicians and their patients.

scholarly journals An “Animated Spatial Time Machine” in Co-Creation: Reconstructing History Using Gamification Integrated into 3D City Modelling, 4D Web and Transmedia Storytelling

2021 ◽  
Vol 10 (7) ◽  
pp. 460
Author(s):  
Mario Matthys ◽  
Laure De Cock ◽  
John Vermaut ◽  
Nico Van de Weghe ◽  
Philippe De Maeyer
Keyword(s):  
Public Space ◽  
Low Cost ◽  
Three Dimensional ◽  
Physical Situation ◽  
Time Machine ◽  
Transmedia Storytelling ◽  
Spatial Reconstruction ◽  
3D Software ◽  
The City ◽  
City Models

More and more digital 3D city models might evolve into spatiotemporal instruments with time as the 4th dimension. For digitizing the current situation, 3D scanning and photography are suitable tools. The spatial future could be integrated using 3D drawings by public space designers and architects. The digital spatial reconstruction of lost historical environments is more complex, expensive and rarely done. Three-dimensional co-creative digital drawing with citizens’ collaboration could be a solution. In 2016, the City of Ghent (Belgium) launched the “3D city game Ghent” project with time as one of the topics, focusing on the reconstruction of disappeared environments. Ghent inhabitants modelled in open-source 3D software and added animated 3D gamification and Transmedia Storytelling, resulting in a 4D web environment and VR/AR/XR applications. This study analyses this low-cost interdisciplinary 3D co-creative process and offers a framework to enable other cities and municipalities to realise a parallel virtual universe (an animated digital twin bringing the past to life). The result of this co-creation is the start of an “Animated Spatial Time Machine” (AniSTMa), a term that was, to the best of our knowledge, never used before. This research ultimately introduces a conceptual 4D space–time diagram with a relation between the current physical situation and a growing number of 3D animated models over time.

scholarly journals Marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation of four finish line locations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Keunbada Son ◽  
Young-Tak Son ◽  
Ji-Min Lee ◽  
Kyu-Bok Lee
Keyword(s):  
Three Dimensional ◽  
Clinical Situation ◽  
Intraoral Scanner ◽  
Replica Technique ◽  
Finish Line ◽  
Marginal Fit ◽  
Tooth Preparation ◽  
The Right ◽  
Internal Fit ◽  
Marginal Region

AbstractThis study evaluated the marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation scanned at four finish line locations. The right maxillary first molar tooth preparation model was fabricated using a ceramic material and placed in four finish line locations (supragingival, equigingival, subgingival, and subgingival with a cord). Intraoral scanning was performed. Crowns were designed based on the scanned area. Interim crowns were fabricated using a stereolithography three-dimensional (3D) printer (N = 16 per location). Marginal and internal fit were evaluated with a silicone replica technique. Intaglio surface trueness was evaluated using a 3D inspection software. One-way analysis of variance and Tukey HSD test were performed for comparisons (α = 0.05). The marginal and internal fit showed significant differences according to locations (P < 0.05); the marginal fit showed the best results in the supragingival finish line (P < 0.05). Intaglio surface trueness was significantly different in the marginal region, with the highest value in the subgingival location (P < 0.05). Crowns fabricated on the subgingival finish line caused inaccurate marginal fit due to poor fabrication reproducibility of the marginal region. The use of an intraoral scanner should be decided on the clinical situation and needs.

scholarly journals Volumetric Analysis and Three-Dimensional Glucose Metabolic Mapping of the Striatum and Thalamus in Patients With Autism Spectrum Disorders

2006 ◽  
Vol 163 (7) ◽  
pp. 1252-1263 ◽  
Author(s):  
M. Mehmet Haznedar ◽  
Monte S. Buchsbaum ◽  
Erin A. Hazlett ◽  
Elizabeth M. LiCalzi ◽  
Charles Cartwright ◽  
...  
Keyword(s):  
Autism Spectrum Disorders ◽  
Three Dimensional ◽  
Volumetric Analysis ◽  
Autism Spectrum ◽  
Metabolic Mapping ◽  
Spectrum Disorders

scholarly journals On the Fluctuation Induced Excess Conductivity in Stainless Steel Sheathed MgB2 Tapes

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Suchitra Rajput ◽  
Sujeet Chaudhary
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Stainless Steel ◽  
Coherence Length ◽  
Three Dimensional ◽  
Excess Conductivity ◽  
Scaling Functions ◽  
Critical Fluctuations ◽  
Scaling Models

We report on the analyses of fluctuation induced excess conductivity in the - behavior in the in situ prepared MgB2 tapes. The scaling functions for critical fluctuations are employed to investigate the excess conductivity of these tapes around transition. Two scaling models for excess conductivity in the absence of magnetic field, namely, first, Aslamazov and Larkin model, second, Lawrence and Doniach model, have been employed for the study. Fitting the experimental - data with these models indicates the three-dimensional nature of conduction of the carriers as opposed to the 2D character exhibited by the HTSCs. The estimated amplitude of coherence length from the fitted model is ~21 Å.

Optimized Attachment to Achieve Different Buccolingual Movement of Maxillary Molars in Clear Aligner Orthodontic System: Biomechanical Analysis

2020 ◽  
Vol 12 (11) ◽  
pp. 1249-1254
Author(s):  
Long Qin ◽  
Qiao Wang ◽  
Dongliang Zhang ◽  
Xin He ◽  
Binbin Wu
Keyword(s):  
Tooth Movement ◽  
Biomechanical Analysis ◽  
Occlusal Surface ◽  
Tooth Surface ◽  
Force System ◽  
Maxillary Molars ◽  
Clear Aligner

The different positions and angles of attachment affecting the buccolingual movement of the maxillary molars, especially lingual tipping and negative torque movements, were biomechanically analyzed in order to determine how to better control and prevent unwanted movement of clear aligners. The aligner can be designed and placed appropriately to improve expected tooth movement. Based on mechanical principles, the force system of attachment was analyzed, and the optimum attachment position and angle for tipping and negative torque movement was determined. Attachment close to the enamel-cementum junction (ECJ) was found to achieve the best F (M/L) during negative torque movement; however, the angle should also be adjusted. Attachment close to the occlusal surface achieved greater tipping force at specific angles. When more tipping movement is required, it is recommended to place the attachment 3–5 mm from the ECJ. The angle of the attachment should be 110–120 degrees from the tooth surface. When place the attachment 4–5 mm from the ECJ, the angle of the attachment should be between 145 and 146.5 degrees.

Sign in / Sign up

Export Citation Format

Share Document