scholarly journals The effect of different confluence confirmation strategies on the obturation of Vertucci type II canal: micro-CT analysis

2021 ◽  
Vol 46 (1) ◽  
Author(s):  
Seungjae Do ◽  
Min-Seock Seo
Keyword(s):  
Type Ii ◽  
Micro Ct ◽  
Author(s):  
Melissa R. Requist ◽  
Yantarat Sripanich ◽  
Tim Rolvien ◽  
Amy L. Lenz ◽  
Alexej Barg

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1995
Author(s):  
Mirko Sinico ◽  
Suraj Dinkar Jadhav ◽  
Ann Witvrouw ◽  
Kim Vanmeensel ◽  
Wim Dewulf

Recently, the use of novel CuCr1 surface-modified powder for reliable laser powder-bed fusion (LPBF) manufacturing has been proposed, enabling a broader LPBF processing window and longer powder storage life. Nevertheless, virgin CuCr1 powder is also LPBF processable, on the condition that a high-energy density is employed. In this work, we compare two dense specimens produced from virgin and surface-modified CuCr1 powder. Furthermore, a third sample fabricated from surface-modified powder is characterized to understand an abnormal porosity content initially detected through Archimedes testing. Utilizing high-resolution micro-CT scans, the nature of the defects present in the different samples is revealed. Pores are analyzed in terms of size, morphology and spatial distribution. The micro-CT data reveal that the virgin CuCr1 dense specimen displays keyhole pores plus pit cavities spanning multiple layer thicknesses. On the other hand, the sample fabricated with the surface-modified CuCr1 powder mainly contains small and spherical equi-distributed metallurgical defects. Finally, the CT analysis of the third specimen reveals the presence of a W contamination, favoring lack-of-fusion pores between subsequent LPBF layers. The LPBF melting mode (keyhole or conductive), the properties of the material, and the potential presence of contaminants are connected to the different porosity types and discussed.


Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 408
Author(s):  
Anna Stepien

This paper describes the use of glass sand in the production of autoclaved bricks. Traditional autoclaved materials consist of SiO2, CaO, and H2O. The purpose of the tests is to analyze the possibility of using glass sand in autoclaved materials and to determine their properties and durability. Depending on the structure, building materials can have porosities ranging from 0% (glass, metals) to over 90% (thermal insulation materials such as aerated concrete). Porosity of materials is directly related to the strength of materials and their density, and further to the thermal and acoustic insulation properties of products used especially for external wall construction, i.e., bricks, concrete, and aerated concrete. This type of silicate brick is formed at a temperature of 203 °C, therefore the dominant phase forming the microstructure is tobermorite, in contrast to the C-S-H phase, which dominates in concretes and which is characterized by a larger specific surface. The nature of pores, their number, appearance and arrangement in the material can be studied using computer techniques (SEM, XRD, computed tomography, porosimetry). Computed tomography (micro-CT analysis) showed that the number of voids in the material modified by glass sand is about 20% in relation to the weight of the product. The density of the product with glass sand was determined to be 2.2 kg/dm3.


2018 ◽  
Vol 221 (4) ◽  
pp. 1831-1842 ◽  
Author(s):  
Adriano Losso ◽  
Andreas Bär ◽  
Birgit Dämon ◽  
Christian Dullin ◽  
Andrea Ganthaler ◽  
...  

2019 ◽  
Vol 31 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Ken Nakahara ◽  
Maiko Haga‐Tsujimura ◽  
Kensuke Igarashi ◽  
Eizaburo Kobayashi ◽  
Benoit Schaller ◽  
...  

2010 ◽  
Vol 30 (2) ◽  
pp. 129-135
Author(s):  
Shoichi HIGASHI ◽  
Mitsuori MAYAHARA ◽  
Tetsuo KODAKA ◽  
Kaoru EGAWA ◽  
Masanori NAKAMURA ◽  
...  

2015 ◽  
Vol 345 ◽  
pp. 141-144 ◽  
Author(s):  
Yi-Jie Kuo ◽  
Yung-Kai Huang ◽  
Hsiu-Chu Chou ◽  
Man-Hui Pai ◽  
Ai-Wei Lee ◽  
...  
Keyword(s):  
Micro Ct ◽  
Tof Sims ◽  

2018 ◽  
Vol 43 (6) ◽  
pp. 656-664 ◽  
Author(s):  
J Nie ◽  
AU Yap ◽  
XY Wang

SUMMARY This study determined the influence of shrinkage and viscosity of flowable composite liners on the cervical microleakage of Class II restorations using micro-CT. Seven composites of varying viscosities were selected and included five giomers (Shofu Beautifil II [BF], Flow Plus F00 and F03 [F00 and F03], Flow F02 and F10 [F02 and F10]) and 2 nano-filled composites (3M-ESPE Filtek Z350 [Z350] and Filtek Z350 Flowable [Z350F]). Polymerization shrinkage (n=7) was assessed with the Acuvol volumetric shrinkage analyzer while complex viscosity was determined with the advanced rheometric expansion system at 25°C. Standardized Class II restorations incorporating 1-mm horizontal layers of different flowable liners and 3-mm oblique layers of BF or Z350 were subjected to a silver nitrate test for 24 hours and examined using micro-CT. Microleakage was determined at 0.1-mm intervals from the buccal to lingual surfaces providing 30 sites per specimen and scored accordingly. Statistical analysis was performed with the one-way ANOVA, Kruskal-Wallis test, and Spearman's rho correlation at a significance level of p<0.05. Mean volumetric shrinkage ranged from 5.33±0.17% to 2.35±0.02% for F02 to Z350, respectively. The flowable materials had significantly higher shrinkage than did their sculptable counterparts (BF and Z350). Complex viscosities ranged from 9.65 to 4.20 (Z350 and F10, respectively) at a frequency of 10 rad/s and from 8.16 to 3.28 (Z350 and F03, respectively) for 100 rad/s. Giomer restorations had significantly less leakage than did those restored with nano-filled composites. No microleakage was observed with restorations lined with F02 or F10. The use of flowable liners reduced cervical microleakage of Class II restorations. Interfacial integrity of Class II restorations was significantly correlated with liner viscosity, filler volume, and shrinkage.


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