scholarly journals Influence of Implant Connection, Abutment Design and Screw Insertion Torque on Implant-Abutment Misfit

2020 ◽  
Vol 9 (8) ◽  
pp. 2365
Author(s):  
Jorge Vélez ◽  
Jesús Peláez ◽  
Carlos López-Suárez ◽  
Rubén Agustín-Panadero ◽  
Celia Tobar ◽  
...  
Keyword(s):  
Insertion Torque ◽  
Scanning Electron Microscopy Data ◽  
Test Results ◽  
Tightening Torque ◽  
Screw Insertion ◽  
Electron Microscopy Data ◽  
Implant Abutment ◽  
External Connection ◽  
Microscopy Data ◽  
One Way Anova

Background: An accurate fit at the implant-abutment interface is an important factor to avoid biological and mechanical complications. The aim of this study was to evaluate the marginal misfit at the implant-abutment interface on external and Morse taper connection, with straight and angulated abutments under different insertion torque loads. Materials and Methods: A total of 120 implants were used, 60 with external connection (EC) and 60 with Morse taper connection (IC). Straight (SA) (n = 60) and angulated abutments (AA) (n = 60) were randomly screwed to each connection at different torque levels (n = 10 each): 10, 20 and 30 Ncm. All specimens were subjected to thermal and cyclic loading and the misfit was measured by scanning electron microscopy. Data were analyzed with one-way ANOVA, t-test and Kruskal-Wallis test. Results: Significant differences (p < 0.001) were found between connections and abutments regardless of the torque applied. Morse taper connections with straight and angulated abutments showed the lowest misfit values (0.6 µm). Misfit values decreased as torque increased. Conclusions: The misfit was affected by the type of connection. The type of abutment did not influence the fit in the Morse taper connection. The higher the tightening torque applied the increase in the fit of the implant-abutment interface.

Fractographic Regularities in Fatigue Failure of 17Mn1Si Steel

2014 ◽  
Vol 1040 ◽  
pp. 230-235
Author(s):  
Pavlo Maruschak ◽  
Sergey Panin ◽  
Ilya Vlasov ◽  
Iryna Danyliuk ◽  
Roman Bishchak
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Scanning Electron Microscopy Data ◽  
Structural Level ◽  
Deformation And Failure ◽  
Leading Role ◽  
Electron Microscopy Data ◽  
Microscopy Data ◽  
Scanning Electron

Using the scanning electron microscopy data the main regularities of the fatigue crack propagation in the 17Mn1Si steel were studied. Based on fracture surface observation and analysis one can testify that the transition of the leading role of deformation and failure from the lower structural level to the higher one has the ordered pattern.

scholarly journals Evaluation of permeability of root dentin after different irrigation protocols

2018 ◽  
Vol 146 (9-10) ◽  
pp. 492-497 ◽  
Author(s):  
Ljiljana Bjelovic ◽  
Jelena Krunic ◽  
Nikola Stojanovic ◽  
Jelena Eric ◽  
Tatjana Kanjevac
Keyword(s):  
New Combination ◽  
Control Group ◽  
Scanning Electron Microscopy Data ◽  
Test Results ◽  
Dye Penetration ◽  
Dentin Permeability ◽  
Significant Difference ◽  
Root Dentin ◽  
Microscopy Data ◽  
And Control

Introduction/Objective. This study was aimed at evaluating dentin permeability after irrigation with sodium hypochlorite (NaOCl) and final rinse with chlorhexidine (CHX), ethylenediamine tetraacetic acid (EDTA) + CHX, and new combination products: QMiX or MTAD. Methods. Roots of 60 maxillary incisors were randomly divided into five groups (n = 12) before instrumentation and irrigation with NaOCl according to the final irrigation regimen: CHX (2% CHX), EDTA + CHX (17% EDTA + 2% CHX), QMiX, MTAD, and control group (distilled water). After final irrigation, ten roots of each group were horizontally sectioned and dye penetration was evaluated in the coronal, middle, and apical thirds. Remaining samples were subjected to scanning electron microscopy. Data were analyzed with ANOVA/Tukey?s test. Results. Less dye penetration was found in CHX group compared with control as well as with QMiX and MTAD group in all thirds (p < 0.05). A significant difference between the control and EDTA + CHX, QMiX or MTAD group was observed only in the apical root third (p < 0.05). Conclusion. Dentin permeability was significantly reduced after final irrigation with CHX, but not after use of other final irrigation solutions, except in the apical third of the root canal.

scholarly journals Structural resistance of orthodontic mini-screws inserted for extra-alveolar anchorage

2021 ◽  
Vol 34 (1) ◽  
pp. 27-34
Author(s):  
Carlos Vieira ◽  
Francyelle Pires ◽  
Wallisen Hattori ◽  
Cleudmar de Araújo ◽  
Marcelo Garcia-Junior ◽  
...  
Keyword(s):  
Stainless Steel ◽  
In Vivo Studies ◽  
Scanning Electron Microscopy Data ◽  
Insertion Angle ◽  
Electron Microscopy Data ◽  
Alloy Type ◽  
Structural Resistance ◽  
Microscopy Data ◽  
Post Hoc

The risk of fracture or strain in mini-screws is higher if diameter, length, type of alloy or insertion angle is selected inappropriately. The aims of this study were to test the structural resistance of two types of orthodontic mini-screws –one made of stainless steel and another of titanium– from an international brand and to evaluate the efficacy of two other titanium miniscrews of Brazilian origin, during an extra-alveolar anchorage procedure. The mini-screws analyzed were: Bomei stainless steel and Bomei titanium / Taiwan, Morelli titanium and Neodent titanium/ Brazil. Experiments were conducted on pig mandibles to simulate the process of extra-alveolar anchorage. Two insertion processes were used: Direct at 30º, and Indirect, starting at 60º and ending at 30º with gradual continuous movement. Strain was evaluated using Optical and Scanning Electron Microscopy. Data were evaluated using Kruskal-Wallis non-parametric statistical analysis and post hoc Tamhane test. Significant statistical differences in strain were observed among the mini-screws used in the extra-alveolar insertions, both for the direct and indirect procedures. In the indirect insertion tests, both stainless steel and titanium mini-screws suffered deformation, showing that angling can be an important factor in mini-screw failure rates. The change in angle during the insertion movement increased deformation rates independently of alloy type, increasing the risk of failure. These results could help orthodontists in choosing mini-screws for extra-alveolar anchorage, which can be performed with direct or indirect insertion. In vivo studies should be conducted to confirm the findings of this study.

scholarly journals Creating a virtual device for processing the results of sorption measurements in the study of zinc oxide nanorods

2020 ◽  
Vol 7 (4) ◽  
pp. 154-158
Author(s):  
E. V. Maraeva ◽  
N. V. Permiakov ◽  
Y. Y. Kedruk ◽  
L. V. Gritsenko ◽  
Kh. A. Abdullin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Zinc Oxide ◽  
Zinc Oxide Nanorods ◽  
Scanning Electron Microscopy Data ◽  
Virtual Device ◽  
Electron Microscopy Data ◽  
Oxide Nanorods ◽  
Microscopy Data ◽  
Scanning Electron

The work is devoted to the creation of a virtual device (computer program) for processing the results of sorption analysis of nanomaterials, including for estimating the size of nanoparticles based on the specific surface area. The obtained evaluation results were compared with the scanning electron microscopy data. Photocatalytically active zinc oxide samples were chosen as the object of the study.

scholarly journals Tryblionella persuadens comb. nov. (Bacillariaceae, Diatomeae): new observations on frustule morphology of a seldom recorded diatom

2013 ◽  
Vol 85 (4) ◽  
pp. 1419-1426
Author(s):  
KAOLI P. CAVALCANTE ◽  
PRISCILA I. TREMARIN ◽  
EDUARDO G. FREIRE ◽  
THELMA A.V. LUDWIG
Keyword(s):  
Northeastern Brazil ◽  
Scanning Electron Microscopy Data ◽  
Freshwater Environment ◽  
Brackish Waters ◽  
Electron Microscopy Data ◽  
Venetian Lagoon ◽  
Microscopy Data ◽  
First Time ◽  
Frustule Morphology ◽  
Scanning Electron

ABSTRACT The species originally described from brackish waters of the Venetian Lagoon as Nitzschia persuadens is a diatom rarely cited in the literature since its proposition and it is here recorded for the first time in a freshwater environment in South America. Morphological features of this species, such valve slightly panduriform, with a longitudinal straight fold of the valve face, poroidal areolae, and strongly eccentric raphe system clearly assign this species to Tryblionella, and the transfer was made. Here we present new observations on the frustule morphology and comparisons with related species. Light and scanning electron microscopy data of Tryblionella persuadens comb. nov. from Cachoeira River, Northeastern Brazil are documented.

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