scholarly journals Comparison of reconstruction of cement space in resin copings fabricated with the use of a 3D printer in single- and three-unit restorations

2019 ◽  
Vol 9 (3) ◽  
pp. 3919-3925
Keyword(s):  
Mixed Models ◽  
Single Unit ◽  
Statistical Significance ◽  
3D Printer ◽  
Printing Technique ◽  
Molar Teeth ◽  
Jaw Model ◽  
Internal Fit ◽  
Die Spacer ◽  
3D Printing Technique

Marginal and internal gaps are very important factors in fixed prosthetic restorations. The marginal fit is affected by the cementing process of the restoration. One of the techniques used to create the required space between the prepared tooth and the crown is to use a die spacer. The aim of the current study was to assess the accuracy of reconstruction of the cement space in the resin copings of extracoronal restorations fabricated with the use of the 3D printing technique and compare it in single- and three-unit restorations. After taking impressions from the left maxillary first premolar and first molar teeth of a jaw model, a total of 20 models were prepared with the use of a 3D printer for single-unit and three-unit groups (a total of 120 samples) and cemented on their relevant dies. The samples were sectioned buccolingually. The images of the internal gaps were prepared under a light microscope and evaluated. The values in different groups were compared in relation to marginal and internal fit and analyzed with ANOVA (mixed models). Statistical significance was set at P<0.05. Comparison of the accuracy of reconstruction of the cement space in resin copings fabricated with the use of a 3D printer showed that in the single-unit premolar tooth with a presumptive cement space of 45 µm the cement space was 30.45±20.01 µm (P>0.001) at the margin and 36.01±13.52 µm (P>0.001) in the internal area; in the reconstruction of the three-unit molar tooth with a presumptive cement space of 25 µm, the cement space at the margin was 105.97±33.7 µm (P>0.964), with 120.09±63.15 µm (P>0.005) in the internal area. It was concluded from the results of the present study that the accuracy of reconstruction of the cement space in resin copings fabricated with the use of a 3D printer in samples with a larger presumptive cement space was higher than that in samples with a smaller presumptive cement space. The accuracy of the reconstruction of the cement space in resin copings fabricated using a 3D printer in single-unit restorations was higher than that in three-unit restorations.

scholarly journals Fabrication of Porous Hydrogenation Catalysts by a Selective Laser Sintering 3D Printing Technique

ACS Omega ◽  
2019 ◽  
Vol 4 (7) ◽  
pp. 12012-12017 ◽  
Author(s):  
Elmeri Lahtinen ◽  
Lotta Turunen ◽  
Mikko M. Hänninen ◽  
Kalle Kolari ◽  
Heikki M. Tuononen ◽  
...  
Keyword(s):  
3D Printing ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Hydrogenation Catalysts ◽  
Printing Technique ◽  
3D Printing Technique

Evaluation of skin displacement in the equine neck

2014 ◽  
Vol 10 (3) ◽  
pp. 181-186 ◽  
Author(s):  
A. Bergh ◽  
A. Egenvall ◽  
E. Olsson ◽  
M. Uhlhorn ◽  
M. Rhodin
Keyword(s):  
Mixed Models ◽  
Sagittal Plane ◽  
Cervical Vertebrae ◽  
Statistical Significance ◽  
Longitudinal Axis ◽  
Joint Motion ◽  
Skin Marker ◽  
Significant Difference ◽  
Axis Parallel ◽  
Kinematic Studies

Kinematic studies, using reflective skin markers, are commonly used to investigate equine joint motion in equitation science and for rehabilitation purposes. In order to interpret the registrations accurately, the degree of skin displacement has been described for the limbs and back, but not yet for the neck. The aim of the present study was to measure sagittal plane skin displacement in the equine neck. Radiopaque skin markers were applied to the skin over the first six cervical vertebrae of six healthy horses. Latero-lateral radiographs were taken in three standardised neck positions in the sagittal plane: control (horizontal neck), ‘on the bit’ and ‘nose to carpus’. The scales of the images were normalised and calculation of skin displacement was done by use of a coordinate system, dividing the displacement along an x-axis parallel to the vertebra's longitudinal axis and a y-axis perpendicular to the x-axis. Mixed models analysis was employed to study the differences in distances in x- and y-directions, and statistical significance was set to PÃ0.05. Between control and ‘nose to carpus’ positions, there were significant differences in skin marker locations, relative to the underlying vertebrae, in the x-direction for C1-6, and in y-direction for C3-6. Between normal and ‘on the bit’ positions, there were significant difference in both x- and y-directions for C6. Differences in marker locations along x- and y-axes, respectively, were 3±9 mm and 44±14 mm. The outcome of this study indicates that skin displacement should be considered when investigating equine neck motion with skin marker methodology.

scholarly journals Comparison of the internal fit of metal crowns fabricated by traditional casting, computer numerical control milling, and three-dimensional printing

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257158
Author(s):  
Wei-Ting Chou ◽  
Chuan-Chung Chuang ◽  
Yi-Bing Wang ◽  
Hsien-Chung Chiu
Keyword(s):  
3D Printing ◽  
Minimum Distance ◽  
Statistical Significance ◽  
Three Dimensional ◽  
Reference Points ◽  
Numerical Control ◽  
Maximum Distance ◽  
Cnc Milling ◽  
Low Viscosity ◽  
Internal Fit

This experimental study aimed to compare the internal fit (marginal fit and internal discrepancy) of metal crowns fabricated by traditional casting and digital methods (computer numerically controlled (CNC) milling and three-dimensional [3D] printing). Thirty standard master abutment models were fabricated using a 3D printing technique with digital software. Metal crowns were fabricated by traditional casting, CNC milling, and 3D printing. The silicon replica method was used to measure the marginal and internal fit. A thin layer of low-viscosity polyvinyl siloxane material was placed inside each crown and on the die (like a seat) until the material was set. Replicas were examined at four reference points under a microscope: the central pit (M1), cusp tip (M2), axial wall (M3), and margin (M4). The measured data were analyzed using a one-way analysis of variance (ANOVA) to verify statistical significance, which was set at p < 0.05. In the traditional casting group, the minimum distance measured was at M3 (90.68 ± 14.4 μm) and the maximum distance measured was at M1 (145.12 ± 22 μm). In the milling group, the minimum distance measured was at M3 (71.85 ± 23.69 μm) and the maximum distance measured was at M1 (108.68 ± 10.52 μm). In the 3D printing group, the minimum distance measured was at M3 (100.59 ± 9.26 μm) and the maximum distance measured was at M1 (122.33 ± 7.66 μm). The mean discrepancy for the traditional casting, CNC milling, and 3D printing groups was 120.20, 92.15, and 111.85 μm, respectively, showing significant differences (P < 0.05). All three methods of metal crown fabrication, that is, traditional casting, CNC milling, and 3D printing, had values within the clinically acceptable range. The marginal and internal fit of the crown was far superior in the CNC milling method.

Controlled Release of Bi-Layered Malvidin Tablets Using 3D Printing Techniques

2021 ◽  
pp. 70-78
Author(s):  
Tejinder Kaur ◽  
Suruchi Singh
Keyword(s):  
Controlled Release ◽  
3D Printing ◽  
Fruits And Vegetables ◽  
Physical And Mechanical Properties ◽  
3D Printer ◽  
Anti Cancer ◽  
Printing Cost ◽  
3D Printed ◽  
Cost Efficient ◽  
3D Printing Technique

Malvidin belongs to the class of anthocyanidin, a pigment compound present in fruits and vegetables like the colored berries, flowers, and vegetables which have pigments on it and it is available commercially as malvidin chloride. Malvidin is known to possess many medicinal characteristics like anti-microbial, anti-diabetic, anti-inflammatory, anti-obesity, and anti-cancer. In this research paper, a 3D printing technique is used which evolves a 3D printer based on desktop that extrudes tablets comprising the active drug which here is malvidin our main ingredient and the other excipients which are used as binders and disintegrants. Methods which are adapted here for the formulation of 3D printed tablet make the tablets appropriate for immediate and sustained release with its definite physical and mechanical properties like hardness, friability, and weight. Tablets that are extruded by the 3D printer are controlled release bi-layer tablets. Due to involvement of 3D printer, printing cost for the bi-layered tablets found very low that makes our method as cost efficient.

Combustion of toluene over cobalt-modified MFI zeolite dispersed on monolith produced using 3D printing technique

2020 ◽  
Author(s):  
Anna Rokicińska ◽  
Marek Drozdek ◽  
Elżbieta Bogdan ◽  
Adam Węgrzynowicz ◽  
Piotr Michorczyk ◽  
...  
Keyword(s):  
3D Printing ◽  
Mfi Zeolite ◽  
Printing Technique ◽  
3D Printing Technique

scholarly journals Production of ERCP training model using a 3D printing technique (with video)

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Chang-Il Kwon ◽  
Yeonsun Shin ◽  
Jaeok Hong ◽  
Minje Im ◽  
Guk Bae Kim ◽  
...  
Keyword(s):  
3D Printing ◽  
Training Model ◽  
Printing Technique ◽  
3D Printing Technique

Engineering Design for Robot Aesthetics

2015 ◽  
Author(s):  
Wenchang Zhang ◽  
Annan Dai ◽  
Yiming Rong
Keyword(s):  
Panel Discussion ◽  
Physical Models ◽  
Analysis Method ◽  
Design Evolution ◽  
Component Design ◽  
Printing Technique ◽  
Technical Function ◽  
Overall Evaluation ◽  
The Aesthetic ◽  
3D Printing Technique

This paper presents a show case of aesthetic robot design considering technical function constraints and using engineering performance analysis method. First a project goal was determined based on a robot aesthetic analysis. Decision matrices were used to evaluate the aesthetic satisfaction in both component and assembly levels of the design while the scores were assigned subjectively through panel discussion. 3D printing technique was used to get the physical models for rapid verification of the design and to facilitate the design evolution. Examples are given for robot component design as well as the overall evaluation of the robot aesthetics.

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