scholarly journals Influence of the Geometrical Cross-Section Design on the Dynamic Cyclic Fatigue Resistance of NiTi Endodontic Rotary Files—An In Vitro Study

2021 ◽  
Vol 10 (20) ◽  
pp. 4713
Author(s):  
Vicente Faus-Llácer ◽  
Nirmine Hamoud-Kharrat ◽  
María Teresa Marhuenda Ramos ◽  
Ignacio Faus-Matoses ◽  
Álvaro Zubizarreta-Macho ◽  
...  
Keyword(s):  
Cross Section ◽  
Fatigue Resistance ◽  
Niti Alloy ◽  
Rectangular Cross Section ◽  
Study Groups ◽  
Cyclic Fatigue ◽  
Triangular Cross Section ◽  
Geometrical Cross Section ◽  
Section Design ◽  
Shaped Cross Section

The aim of this study was to analyze and compare the influence of the geometrical cross-section design on the dynamic cyclic fatigue resistance of NiTi endodontic rotary files. Materials and Methods: Forty sterile endodontic rotary files were selected and distributed into the following study groups: A: 25.06 double S-shaped cross-section NiTi alloy endodontic rotary files (Mtwo) (n = 10); B: 20.04 rectangular cross-section NiTi alloy endodontic rotary files (T Pro E1) (n = 10); C: 25.04 convex triangular cross-section NiTi alloy endodontic rotary files (T Pro E2) (n = 10); and D: 25.06 triangular cross-section NiTi alloy endodontic rotary files (T Pro E4) (n = 10). A cyclic fatigue device was used to conduct the static cyclic fatigue tests with stainless steel artificial root canal systems with 200 µm and 250 µm apical diameter, 60° curvature angle, 3 mm radius of curvature, 20 mm length, and 4% and 8% taper. The results were analyzed using the ANOVA test and Weibull statistical analysis. Results: All the pairwise comparisons presented statistically significant differences between the time to failure and number of cycles to failure for the cross-section design study groups (p < 0.001). Conclusions: the double S-shaped cross-section of Mtwo NiTi endodontic files shows higher cyclic fatigue resistance than the rectangular cross-section of T Pro E1 NiTi endodontic files, the convex triangular cross-section of T Pro E2 NiTi endodontic files, and the triangular cross-section of T Pro E4 NiTi endodontic files.

scholarly journals The Influence of NiTi Alloy on the Cyclic Fatigue Resistance of Endodontic Files

2020 ◽  
Vol 9 (11) ◽  
pp. 3755
Author(s):  
Celia Ruiz-Sánchez ◽  
Vicente Faus-Llácer ◽  
Ignacio Faus-Matoses ◽  
Álvaro Zubizarreta-Macho ◽  
Salvatore Sauro ◽  
...  
Keyword(s):  
Fatigue Resistance ◽  
Niti Alloy ◽  
Study Groups ◽  
Gold Wire ◽  
Cyclic Fatigue ◽  
Fatigue Tests ◽  
Radius Of Curvature ◽  
Time To Failure ◽  
Root Canals ◽  
Vortex Blue

Background: The aim of this study was to analyze the influence of NiTi alloy in endodontic rotary instruments on cyclic fatigue resistance. Methods: One hundred and sixty-four (164) sterile endodontic rotary files were selected and distributed into the following study groups: A: 25.08 F2 ProTaper Universal (PTU) (n = 41); B: 25.06 X2 ProTaper Next (PTN) (n = 41); C: 25.08 F2 ProTaper Gold (PTG) (n = 41), and D: 25.06 ProFile Vortex Blue (PVB) (n = 41). A cyclic fatigue device was designed to conduct the static cyclic fatigue tests with stainless steel artificial root canals systems with 250 µm apical diameter, 60° curvature angle, 5 mm radius of curvature, 20 mm length, and 6% (25.06) and 8% taper (25.08). Failure of the endodontic rotary instrument was detected by a single operator through direct observation and was also filmed to allow measurement of the exact time to failure. Results were analyzed using the ANOVA test and Weibull statistical analysis. Results: All pairwise comparisons presented statistically significant differences between the time to failure for the NiTi alloy study groups (p < 0.001), except between the PTN and PVB study groups (p = 0.379). In addition, statistically significant differences between the number of cycles to failure for the NiTi alloy study groups (p < 0.001) were also observed. Conclusions: The NiTi CM-Gold wire alloy of the ProTaper Gold endodontic rotary files resulted in greater resistance to cyclic fatigue than ProFile Vortex Blue, ProTaper Next, and ProTaper Universal endodontic rotary files.

scholarly journals Penilaiankebersihansepertigaapikaldindingsaluranakardarismearlayer dengan menggunakan rotary instrument dengan disain convex triangular dan rectangular cross section (Hygiene assessment on apical third of root canal wall of smear layer using rotary instrument design convex triangular and rectangular cross section)

2015 ◽  
Vol 14 (1) ◽  
pp. 65
Author(s):  
Nurni Amda ◽  
Juni Jekti N ◽  
Aries Chandra Trilaksana ◽  
Christine Anastasia Rovani ◽  
Nurhayaty Natsir ◽  
...  
Keyword(s):  
Cross Section ◽  
Root Canal ◽  
Rectangular Cross Section ◽  
Instrument Design ◽  
Smear Layer ◽  
Root Canal Preparation ◽  
Triangular Cross Section ◽  
Rotary Instruments ◽  
Section Design ◽  
Rotary Instrument

This study aim to compare the smear layer clearance on the apical third of the root canal walls instrumented withconvex triangular cross- section designed hand instruments, rectangular cross-section and convex triangular crosssectiondesigned rotary instruments. Mandibular premolars that met the inclusion criteria were divided into 3 groupsof 10 samples, and prepared using convex triangular cross section design hand instruments, convex triangular crosssectionandrectangularcross-section design rotary instruments. After preparation and drainage, the sample was cutinto halves using a stainless steel chisel, a section was randomly selected and examined using SEM with 1000 X. Thisstudy showed that the smear layer clearance of hand instrument group was the lowest compared to other two groups, the rotary instruments with rectangular cross-section design showed the highest percentage smear layer clearanceamong the three groups.It was concluded that root canal preparation using a rotary instrument design convextriangular cross section produces hygiene apical third of the canal walls of the smear layer significantly compared tomanual instruments designed convex triangular cross section and root canal preparation with a rotary instrument designof rectangular cross section produces hygiene apical third of the wall root canal of the smear layer significantlycompared convex design of triangular cross section.

scholarly journals Influence of nickel-titanium rotary systems with varying cross-sectional, pitch, and rotational speed on deflection and cyclic fatigue: a finite element analysis study

2021 ◽  
Vol 41 ◽  
pp. 05005
Author(s):  
Wignyo Hadriyanto ◽  
Lukita Wardani ◽  
Christina Nugrohowati ◽  
Ananto Alhasyimi ◽  
Rachmat Sriwijaya ◽  
...  
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Rotational Speed ◽  
Cyclic Fatigue ◽  
Nickel Titanium ◽  
Element Analysis ◽  
Cross Sectional ◽  
Rotary Instruments ◽  
Section Design ◽  
Sectional Shape

The effectiveness of endodontic file preparation depends, among others, on the material, geometric shape, and the drive system. This study aimed to analyze the effect of cross-sectional, pitch, and rotational speed on cyclic fatigue and deflection of NiTi files using finite element analyses. A total of 18 NiTi endodontic rotary instruments ProTaper Gold F2 #25.08 and Hyflex CM #25.04 (n=9) modeling were designed using Autodesk software. Subjects were divided into two groups, the design group of square and convex triangles. Static simulation was then carried out to each group with force on the instrument’s tip by 1N, 2N, and 3N. The file’s cycling fatigue was analyzed at rotating speeds of 200 rpm, 300 rpm, and 400. The data were analyzed by using the three-way Analysis of variance (ANOVA) test followed by LSD (p< 0.05). The results showed the cross-sectional shape and force effect on the deflection value and cyclic fatigue received by the endodontic files (p< 0.05). The convex triangle design presented the lowest cyclic fatigue than square. The convex triangular cross-section design showed a higher deflection value than the square cross-section design.

scholarly journals Assessment of the role of cross section on fatigue resistance of rotary files when used in reciprocation

2016 ◽  
Vol 10 (04) ◽  
pp. 541-545 ◽  
Author(s):  
Vadhana Sekar ◽  
Ranjith Kumar ◽  
Suresh Nandini ◽  
Suma Ballal ◽  
Natanasabapathy Velmurugan
Keyword(s):  
Cross Section ◽  
Fatigue Resistance ◽  
Fatigue Testing ◽  
Dynamic Testing ◽  
Cyclic Fatigue ◽  
Reciprocating Motion ◽  
Continuous Rotation ◽  
Significant Difference ◽  
Post Hoc

ABSTRACT Objective: The purpose of this study was to assess the role of cross section on cyclic fatigue resistance of One Shape, Revo-S SU, and Mtwo rotary files in continuous rotation and reciprocating motion in dynamic testing model. Materials and Methods: A total of 90 new rotary One Shape, Revo-S SU, and Mtwo files (ISO size 25, taper 0.06, length 25 mm) were subjected to continuous rotation or reciprocating motion. A cyclic fatigue testing device was fabricated with 60° angle of curvature and 5 mm radius. The dynamic testing of these files was performed using an electric motor which permitted the reproduction of pecking motion. All instruments were rotated or reciprocated until fracture occurred. The time taken for each instrument to fracture was recorded. All the fractured files were analyzed under a scanning electron microscope (SEM) to detect the mode of fracture. Statistical analysis was performed using one-way ANOVA, followed by Tukey's honestly significant difference post hoc test. Results: The time taken for instruments in reciprocating motion to fail under cyclic loading was significantly longer when compared with groups in continuous rotary motion. There was a statistically significant difference between Mtwo rotary and the other two groups in both continuous and reciprocating motion. One Shape rotary files recorded significantly longer duration to fracture resistance when compared with Revo-S SU files in both continuous and reciprocating motion. SEM observations showed that the instruments of all groups had undergone a ductile mode of fracture. Conclusion: Reciprocating motion improved the cyclic fatigue resistance of all tested groups.

scholarly journals Fatigue resistance of endodontic instruments manufactured in NiTi CM Wire and in conventional NiTi alloy with eletrochemical treatment

2018 ◽  
Vol 66 (2) ◽  
pp. 111-116
Author(s):  
Inês de Fátima de Azevedo Jacinto INOJOSA ◽  
Hélio Pereira LOPES ◽  
Phillip Lucas Ricardo PEREIRA ◽  
Diogo Lopes do NASCIMENTO ◽  
Carlos Nelson ELIAS ◽  
...  
Keyword(s):  
Cross Section ◽  
Fatigue Resistance ◽  
Manufacturing Process ◽  
Fracture Resistance ◽  
Niti Alloy ◽  
Fatigue Behavior ◽  
Morphological Characteristics ◽  
Static Fatigue ◽  
Number Of Cycles ◽  
Fractured Surface

ABSTRACT Objective: This study compared the fatigue behavior of endodontic instruments manufactured with conventional NiTi alloy electropolishing, RaCe (FKG Dentaire, LaChauxdeFonds, Switzerland), with instruments manufactured with NiTi CM Wire subjected to thermomechanical treatment, in the manufacturing process, HyFlex CM (Coltène Whaledent, Cuyahoga Falls, Ohio, USA), both with similar geometry and dimensions in order to determine the influence of the manufacturing process in the fatigue resistance. Methods: The methodoly consisted of twenty HyFlex CM and RaCe instruments with D0 0.25 mm, taper 0.06 mm / mm, 25 mm length, both with triangular cross section. The fracture resistance was evaluated by static fatigue test, using a stainless artificial canal with 5mm of radius (86°), recording the time and calculating the number of cycles until fracture occurs (NCF). For statistical analysis the Student t test was used The fractured instruments surface was analyzed by SEM. Results: The NCF was significantly higher for HyFlex CM instruments in comparison with RaCe files (P˂0.05) being 1336% more resistant to fatigue. The analysis of the fractured surface by SEM showed ductile-kind morphological characteristics for both instruments and the absence of plastic deformation. Conclusion: HyFlex CM instruments present higher values of NCF. Thus, it can be concluded that the thermal treatment to which these instruments with CM Wire alloy are submitted makes them more resistant to fracture than Race instruments manufactured with conventional NiTi alloy electropolishing.

scholarly journals Effectivity of convex triangular and rectangular cross section instruments on decreasing the amount of root canal enterococcus faecalis bacteria colonies

2016 ◽  
Vol 1 (2) ◽  
pp. 120
Author(s):  
Meilina Goenawan ◽  
Juni J. Nugroho ◽  
Christine R. Anastasia ◽  
Aries C. Trilaksana ◽  
Nurhayaty Natsir ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Cross Section ◽  
Root Canal ◽  
Rectangular Cross Section ◽  
Bacterial Count ◽  
Bacterial Reduction ◽  
Root Canals ◽  
Triangular Cross Section ◽  
Rotary Instruments ◽  
Significant Difference

This study aims to evaluate effectiveness difference between convex triangular and rectangular cross section rotary  instruments on root canal Enterococcus faecalis bacteria colonies. Samples mandibular premolar teeth with one narrow and straight root canal divided into 3 groups : instrumented with convex triangular cross section rotary instruments, rectangular cross section rotary instruments, and convex triangular cross section manual  instruments. Each group consisted of 9 samples. Standardized teeth length, instrumented to #15 K-file  and sterilized. E. faecalis suspension in BHIB was standardized then 27 root canals contaminated. Root canals were incubated for 21 days. Every 48 hours root canals added with BHIB. Initial samples were collected, plated in agar culture medium and incubated for bacterial count. and then bacterial count was performed again. Data were collected and analysed using Paired T-test and ANOVAThe results showed there are significant  difference on Enterococcus faecalis bacteria colonies amount before and after preparation with all instruments that was used and bacterial reduction amount in root canals were greater on convex triangular cross section instruments than on rectangular cross section instruments even there was no significant difference.

scholarly journals Improvement of prt-9 constructive system on the basis of frame elements strength balance

2020 ◽  
Vol 100 (4) ◽  
pp. 40-45
Author(s):  
Taras Dovbush ◽  
Nadia Khomyk ◽  
Hanna Tson ◽  
Anatoliy Dovbush
Keyword(s):  
Cross Section ◽  
Rectangular Cross Section ◽  
Organic Fertilizer ◽  
Experimental Investigations ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Strength Uniformity ◽  
Shaped Cross Section ◽  
Main Frame

Analytical and experimental investigations of the most loaded elements of the base frame of PRT-9 solid organic fertilizer spreader are carried out in this paper. The residual operation life of the central beam of the paired Z-shaped profile, as well as the lateral spars of the Z-shaped cross section are determined. According to the results of studies, it was found that the residual operation life of these system elements differ significantly. In order to achieve strength uniformity of the main frame elements, it is decided to weaken the central beam by replacing the paired Z-shaped profile with a thin-walled tube of rectangular cross-section and strengthen the lateral spars by replacing Z-shaped profile with a channel profile with the same height.

scholarly journals High-Throughput, Label-Free Isolation of White Blood Cells From Whole Blood Using Parallel Spiral Microchannels With U-Shaped Cross-Section

2021 ◽  
Author(s):  
Amirhossein Mehran ◽  
Peyman Rostami ◽  
Mohammad Said Saidi ◽  
Bahar Firoozabadi ◽  
Navid Kashaninejad
Keyword(s):  
Cross Section ◽  
High Throughput ◽  
Whole Blood ◽  
Blood Cells ◽  
High Efficiency ◽  
Rectangular Cross Section ◽  
White Blood Cells ◽  
Label Free ◽  
Entire Cross Section ◽  
Shaped Cross Section

Rapid isolation of white blood cells (WBCs) from whole blood is an essential part of any WBC examination platform. However, most conventional cell separation techniques are labor-intensive and low throughput, require large volumes of samples, need extensive cell manipulation, and have low purity. To address these challenges, we report the design and fabrication of a passive, label-free microfluidic device with a unique U-shaped cross-section to separate WBCs from whole blood using hydrodynamic forces that exist in a microchannel with curvilinear geometry. It is shown that the spiral microchannel with a U-shaped cross-section concentrates larger blood cells (e.g., WBCs) in the inner cross-section of the microchannel by moving smaller blood cells (e.g., red blood cells (RBCs) and platelets) to the outer microchannel section and preventing them from returning to the inner microchannel section. Therefore, it overcomes the major limitation of a rectangular cross-section where secondary Dean vortices constantly enforce particles throughout the entire cross-section and decrease its isolation efficiency. Under optimal settings, more than 95% of WBCs can be isolated from whole blood under high-throughput (6 ml/min), high-purity (88%), and high-capacity (180 ml of sample in 1 hour) conditions. High efficiency, fast processing time, and non-invasive WBC isolation from large blood samples without centrifugation, RBC lysis, cell biomarkers, and chemical pre-treatments make this method an ideal choice for downstream cell study platforms.

scholarly journals Lateral Torsional Buckling of Steel Beams under Transverse Impact Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
Wenna Zhang ◽  
Feng Liu ◽  
Feng Xi
Keyword(s):  
Numerical Simulation ◽  
Dynamic Response ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Steel Beams ◽  
Minor Effect ◽  
Transverse Impact ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Shaped Cross Section

This study employs experiments and numerical simulation to analyze the dynamic response of steel beams under huge-mass impact. Results show that lateral torsional buckling (LTB) occurs for a narrow rectangular cross-section steel beam under transverse impact. The experiments were simulated using LS-DYNA. The numerical simulation is in good agreement with experimental results, thus indicating that the LTB phenomenon is the real tendency of steel beams under impact. Meanwhile, the study shows that LS-DYNA can readily predict the LTB of steel beams. A numerical simulation on the dynamic response of H-shaped cross-section steel beams under huge-mass impact is conducted to determine the LTB behavior. The phenomenon of dynamic LTB is illustrated by displacement, strain, and deformation of H-shaped steel beams. Thereafter, a parametric study is conducted to investigate the effects of initial impact velocity and momentum on LTB. The LTB of H-shaped cross-section steel beams under transverse impact is primarily dependent on the level of impact kinetic energy, whereas impact momentum has a minor effect on LTB mode.

scholarly journals Novel Electronic Device to Quantify the Cyclic Fatigue Resistance of Endodontic Reciprocating Files after Using and Sterilization

2020 ◽  
Vol 10 (14) ◽  
pp. 4962 ◽  
Author(s):  
Álvaro Zubizarreta-Macho ◽  
Óscar Alonso-Ezpeleta ◽  
Alberto Albaladejo Martínez ◽  
Vicente Faus Matoses ◽  
Javier Caviedes Brucheli ◽  
...  
Keyword(s):  
Fatigue Resistance ◽  
Computer Aided Design ◽  
Electronic Device ◽  
Light Emitting Diode ◽  
Study Groups ◽  
Cyclic Fatigue ◽  
Time To Failure ◽  
Cyclic Resistance ◽  
Computer Aided ◽  
Number Of Cycles

Background: The aim of this study was to analyze the effects of the time of use (TU) and sterilization cycles (SC) of endodontic reciprocating files on cyclic fatigue resistance. Methods: One-hundred-and-twenty (120) Procodile NiTi endodontic reciprocating instruments were selected at random and distributed into the following study groups: A: 0 sterilization cycles/0s time of use (n = 10); B: 0/60 (n = 10); C: 0/120 (n = 10); D: 1/0 (n = 10); E: 1/60 (n = 10); F: 1/120 (n = 10); G: 5/0 (n = 10); H: 5/60 (n = 10); I: 5/120 (n = 10); J: 10/0 (n = 10); K: 10/60 (n = 10); and L: 10/120 (n = 10). A dynamic cyclic fatigue device was designed using computer-aided design/computer-aided engineering (CAD/CAE) technology and created with a 3D printer to simulate the pecking motion performed by the clinician. Failure of the endodontic rotary instrument was detected by a light-emitting diode-light-dependent resistor (LED-LDR) system controlled by an Arduino driver complex and management software. The results were analyzed using the ANOVA test. Results: All pairwise comparisons presented statistically significant differences between the time to failure, number of cycles to failure and number of cycles of in-and-out movement for the time of use study groups (p < 0.001), but not in the number of sterilization cycles (p > 0.05). Conclusions: The time of use of NiTi endodontic reciprocating files negatively affects dynamic cyclic fatigue resistance. Dynamic cyclic resistance is not affected by the number of sterilization cycles.

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