scholarly journals Effect of autoclave cycles on cyclic fatigue resistance of control memory NiTi files observed by scanning electron microscopy.

2017 ◽  
Vol 74 (1) ◽  
pp. 23
Author(s):  
Victor Talarico Leal Vieira ◽  
Hélio Pereira Lopes ◽  
Carlos Nelson Elias ◽  
Leticia Chaves de Souza ◽  
Emmanuel João Nogueira Leal da Silva ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Fatigue Test ◽  
Crack Formation ◽  
Cyclic Fatigue ◽  
Radius Of Curvature ◽  
Sem Images ◽  
Significant Difference ◽  
Group 2 ◽  
Niti Instruments ◽  
Number Of Cycles

Objective: Hyflex CM instruments were developed for debridement of the root canal system. The control-memory alloy recovers its shape on sterilization, thereby allowing instrument reuse. This study investigated the effect of shape recovery by sterilization on the fatigue life and crack formation of Hyflex CM NiTi instruments. Material and Methods: the cyclic fatigue test was performed in two groups: In the first, it was continuously performed to establish the fatigue life (group 1, n = 10); in the second, it was performed with outages of 30s to evaluate cracks’ nucleation and propagation (group 2, n = 10). The test was performed using a stainless steel canal that was 1.5mm in diameter and 3.5mm in depth, with an arc of 9.42mm and radius of curvature of 6mm. The instruments were driven at 300 rpm. The fatigue time was recorded using a digital stopwatch (Technos). An electronic microscope (Quanta 250) was used to observe the crack formation and growth during the cyclic fatigue. Results: the autoclaved instruments endured 1196.67+214.63 cycles, and the non-autoclaved endured 1000+199.42 cycles until the occurrence of fracture. The t-student test (?=5%) revealed a significant difference. The cyclic fatigue test with pauses demonstrated a significantly longer cyclic fatigue life than the continuous cyclic fatigue test (p<0.05). Conclusion: as revealed by SEM images, cracks grow with an increase in the number of cycles to fracture (NCF). It can be concluded that the shape of Hyflex CM instruments recovered by autoclaving withstood significantly more NCF than non-autoclaved instruments (p<0.05), demonstrating an improvement of approximately 16%.

scholarly journals Comparison of Cyclic Fatigue Resistance of Heat-Treated Nickel-Titanium Reciprocating Instruments at the Intracanal Temperature

2021 ◽  
Vol 25 (2) ◽  
pp. 87-91
Author(s):  
Neslihan Büşra Keskin ◽  
Gürkan Güneç
Keyword(s):  
Fatigue Resistance ◽  
Cyclic Fatigue ◽  
Radius Of Curvature ◽  
Heat Treated ◽  
Significant Difference ◽  
Number Of Cycles ◽  
The Moment ◽  
The One ◽  
Post Hoc ◽  
Different Characteristics

Summary Background/Aim: The aim of the present study was to compare the cyclic fatigue resistance of NiTi files running with reciprocal motion and having different characteristics (RPC Blue, WOG, EndoArt Wise Reciproc Gold, EndoArt Wise Reciproc Blue) at the intracanal temperature (35°C) by using NaOCl irrigation solution. Material and Methods: Totally 60 WaveOne GOLD (Dentsply-Sirona, Ballaigues, Switzerland), Reciproc Blue (VDW, Munich, Germany), EndoArt Wise Reciproc Gold, and EndoArt Wise Blue (Inci Dental Productions Co, Istanbul, Turkey) (n= 15) files were used. Each of the rotary files were tested at the intracanal temperature (35°C) using a dynamic model in a stainless-steel artificial canal with an inner diameter of 1.5 mm, 60° angle of curvature, and 2mm radius of curvature until fracture occurred. The device automatically stopped at the moment of fracture and the number of cycles to the fracture was calculated as per second. The lengths of fractured parts were measured using a digital microcaliper. The One-Way Analysis of Variance (ANOVA) and Tukey’s post-hoc tests were used for intergroup comparisons. Results: In 2 mm Radius of curvature, the EndoArt Wise Reciproc Blue group had a significantly higher time to fracture followed by the EndoArt Wise Reciproc Gold, Resiproc Blue, WaveOne Gold. No significant difference was found between EndoArt Wise Reciproc Gold and Resiproc Blue groups (P>0.05). Among the groups, there was no statistically significant difference in the lengths of fractured parts of the instruments (P> 0.05). Conclusions: EndoArt Wise Reciproc Blue files exhibited significantly higher cyclic fatigue resistance compared with other files tested in a 2-mm radius of curvature and a 60° angle in an artificial canal at the intracanal temperature.

scholarly journals Cyclic Fatigue of Dental NiTi Instruments after Plasma Nitriding

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2155
Author(s):  
Michal Bumbalek ◽  
Zdenek Joska ◽  
Zdenek Pokorny ◽  
Josef Sedlak ◽  
Jozef Majerik ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Low Temperature ◽  
Plasma Nitriding ◽  
Cyclic Fatigue ◽  
Nitriding Process ◽  
Radius Of Curvature ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Dental Instruments ◽  
Niti Instruments

This study investigated the possibility of nitride NiTi instruments using low-temperature plasma nitriding technology in a standard industrial device. Changes in the properties and fatigue life of used NiTi instruments before and after low-temperature nitriding application were investigated and compared. Nontreated and two series of plasma-nitrided NiTi instruments, designed by Mtwo company with tip sizes of 10/.04 taper, 15/.05 taper, and 20/.06 taper, were experimentally tested in this study. All these instruments were used and discarded from clinical use. The instruments were tested in an artificial canal made of stainless steel with an inner diameter of 1.5 mm, a 60° angle of curvature, and a radius of curvature of 3 mm. A low-temperature plasma nitriding process was used for the surface treatment of dental files using two different processes: 550 °C for 20 h, and 470 °C for 4 h. The results proved that it is possible to nitride dental instruments made of NiTi with a low-temperature plasma nitriding process. Promising results were achieved in trial testing by NiTi instruments nitrided at a higher temperature. Plasma-nitrided files were found to have, in some cases, significantly higher values than nontreated files in terms of fatigue life. The results showed that the nitriding process offers promising possibilities for suitably modified surface properties and quality of surface layer of NiTi instruments. Within the limitations of the present study, the cyclic fatigue life of plasma-nitrided NiTi dental files can be increased using this surface technology.

scholarly journals Cyclic fatigue resistance of 2Shape, Twisted File and EndoSequence Xpress nickel-titanium rotary files at intracanal temperature

2018 ◽  
Vol 12 (4) ◽  
pp. 283-287 ◽  
Author(s):  
Gülşah Uslu ◽  
Taha Özyürek ◽  
Mustafa Gündoğar ◽  
Koray Yılmaz
Keyword(s):  
Fatigue Resistance ◽  
Statistical Significance ◽  
Cyclic Fatigue ◽  
Nickel Titanium ◽  
Bonferroni Correction ◽  
Significant Difference ◽  
Inner Diameter ◽  
The Difference ◽  
Number Of Cycles ◽  
Analyze Data

Background. The aim of this study was to compare the cyclic fatigue resistance of 2Shape, Twisted File (TF) and EndoSequence Xpress (ESX) nickel-titanium rotary files at intracanal temperature (35°C). Methods. Twenty 2Shape TS1 (25/.04), 20 TF (25/.04) and 20 ESX (25/.04) files were tested for cyclic fatigue at intracanal temperature (35°C). All the instruments were rotated in artificial canals which were made of stainless steel with an inner diameter of 1.5 mm, 60° angle of curvature and a radius curvature of 5 mm until fracture occurred; the time to fracture was recorded in seconds using a digital chronometer and the number of cycles to fracture (NCF) for each file was calculated. Kruskal-Wallis test with Bonferroni correction was performed to statistically analyze data using SPSS 21.0. Statistical significance was set at P<0.05. Results. NCF values revealed that the 2Shape had significantly the highest cyclic fatigue resistance, followed by TF and ESX at intracanal temperature (P<0.05). The difference was significant between the TF and ESX groups (P<0.05). There was no significant difference among the 2Shape, TF and ESX files with respect to the lengths of the fractured file fragments (P>.05). Conclusion. Within the limitations of present study, it was concluded that the cyclic fatigue resistance of 2Shape files at the intracanal temperature is higher than that of TF and ESX files.

scholarly journals Comparison of cyclic fatigue of a reciprocating file system at different angles of rotation

2021 ◽  
Vol 11 (Suppl. 1) ◽  
pp. 67-73
Author(s):  
Ahmet Akay ◽  
Özkan Adıgüzel ◽  
Seda Erkan Akay ◽  
Sadullah Kaya
Keyword(s):  
Analysis Of Variance ◽  
Fatigue Resistance ◽  
File System ◽  
Cyclic Fatigue ◽  
Curvature Radius ◽  
Two Samples ◽  
Significant Difference ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Aim: The purpose of this in vitro study is to compare the cyclic fatigue resistance of Reciproc Nickel-Titanium (Ni-Ti) rotary files while operating root canals using in three different reciprocal angles. Methodology: Forty-five pieces of Reciproc R25 canal files were tested using artificial canals with a 60° angle of curvature, 5 mm curvature radius, and 1.5 mm diameter carved into a stainless steel block. The Ni-Ti files were checked with a stereomicroscope and then randomly separated into 3 groups. Group 1 consisted of reciprocal angles CCW 150°–CW 30°, Group 2 consisted of CCW 180°–CW 60°, and Group 3 consisted of CCW 210°–CW 90°. The duration of the cyclic fatigue being measured, elapsed time until a file fractured was determined with a chronometer. The lengths of the fractured pieces were measured with a digital caliper. After the cyclic fatigue test, two samples from each group were examined with a Scanning Electron Microscope (SEM) to determine the signs of cyclic fatigue. Results: One-way analysis of variance (ANOVA) was applied to the normally distributed groups (p<0,05). Since there was a significant statistical difference of file’s cyclic fatigue resistance (p=0,001) between the groups, Tukey’s honestly significant difference (HSD) post-hoc pairwise comparison test were used for determine to between which groups. While there were statistically significant differences between Group 1 and Group 2 (p=0,001), and between Group 1 and Group 3 (p=0,001), there was no significant difference between Group 2 and Group 3 (p=0,376). Group 1 displayed the highest resistance to cyclic fatigue. There were no statistically significant differences between the lengths of the fractured files within the three groups according to the one-way analysis of variance (p=0,847). Conclusion: In our study, it was observed that the reciprocal angles of CCW 150°–CW 30°, which were also suggested by the file manufacturer firms, had the highest fracture resistance against cyclic fatigue.   How to cite this article: Akay A, Adıgüzel Ö, Erkan Akay S, Kaya S. Comparison of cyclic fatigue of a reciprocating file system at different angles of rotation. Int Dent Res 2021;11(Suppl.1):67-72. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.11   Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.  

scholarly journals Comparison of cyclic fatigue resistance of XP-endo Shaper, HyFlex CM, FlexMaster and Race instruments

2018 ◽  
Vol 12 (3) ◽  
pp. 208-212 ◽  
Author(s):  
Mehmet Adiguzel ◽  
Ipek Isken ◽  
Ismail Ilker Pamukcu
Keyword(s):  
Body Temperature ◽  
Fatigue Resistance ◽  
Cyclic Fatigue ◽  
Radius Of Curvature ◽  
Rotary Instruments ◽  
Recorded Data ◽  
The Difference ◽  
Number Of Cycles ◽  
Cycles To Failure ◽  
One Way Anova

Background. The aim of this study was to compare the cyclic fatigue resistance of XP-endo Shaper, HyFlex CM, FlexMaster and Race rotary instruments at body temperature (37±1°C). Methods. Twenty XP-endo Shaper (#30/.01), 20 HyFlex CM (#30/.04), 20 FlexMaster (#30/.04) and 20 Race (#30/.04) instruments were tested at body temperature (n=20). The instruments were evaluated in artificial canals with a 3-mm radius of curvature and 60° angle of curvature to the center of the 1.5-mm-wide canal. Each instrument was rotated until fracture occurred and the number of cycles to failure (NCF) recorded. Data were analyzed using one-way ANOVA and Tukey HSD tests (P<0.05). Results. The difference in the NCF of all the instruments was statistically significant (P<0.05). The order of the instruments from the highest to the lowest NCF was as follows: XP-endo Shaper (3064.0±248.1), HyFlex CM (1120.5±106.1), FlexMaster (569.8±48.4) and Race (445.5±53.5). Conclusion. Under the limitations of the present study, XP-endo Shaper instruments were more resistant to cyclic fatigue than the #30/.04 nickel-titanium rotary instruments immersed in water at simulated body temperature.

scholarly journals Evaluation of Cyclic Fatigue of Hyflex EDM, Twisted Files, and ProTaper Gold Manufactured with Different Processes: An In Vitro Study

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Pooja D. Khandagale ◽  
Prashant P. Shetty ◽  
Saleem D. Makandar ◽  
Pradeep A. Bapna ◽  
Mohmed Isaqali Karobari ◽  
...  
Keyword(s):  
Fatigue Resistance ◽  
Root Canal ◽  
File Systems ◽  
In Vitro Study ◽  
Cyclic Fatigue ◽  
Segment Length ◽  
Significant Difference ◽  
Number Of Cycles ◽  
Post Hoc

Introduction. The main aims of root canal instrumentation are to provide an environment that will lead to healing and to provide a root canal shape that is comfortable to clean and seal. When working with rotary endodontic instruments, the most significant concerns are that the instrument might fracture in the root canal, thus affecting the treatment outcome. Hence, it is of immense importance to know which file systems have more cyclic fatigue resistance. Methodology. This study evaluated the effect of the curved segment length of the artificial canal (the arch), and the number of cycles necessary in fracture of Hyflex EDM, Twisted files, and ProTaper Gold were recorded. Sixty NiTi rotary instruments of 25 mm length (Hyflex EDM (20), Twisted files (20), and ProTaper Gold (20)) were tested in a metal block with simulated canal having 90° angle of curvature. The study was performed with a specific radius and degree of curvature, i.e., 8 mm radius and 90⁰ angle of curvature, and data obtained were subsequently subjected to statistical evaluation using one-way analysis of variance and Tukey’s post hoc test. Result. The Hyflex EDM (774.29) exhibited the maximum cyclic fatigue resistance compared to Twisted files (654.875) and ProTaper Gold (375.575). A statistically significant difference was observed between the tested groups. Conclusion. The Hyflex EDM files showed the highest cyclic fatigue resistance, followed by Twisted files and ProTaper Gold files.

scholarly journals Cyclic fatigue resistance of four different nickel-titanium instruments in an artificial canal

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 800
Author(s):  
Khoa Van Pham
Keyword(s):  
Stainless Steel ◽  
Cyclic Fatigue ◽  
Nickel Titanium ◽  
Primary System ◽  
Group 4 ◽  
Group 3 ◽  
The Mean ◽  
Group 2 ◽  
Number Of Cycles ◽  
Electronic Microscope

Introduction: The objective of this study was to measure the number of cycles to fracture of four continuous or reciprocating rotary nickel-titanium instruments in different materials. Methods: A total of 40 nickel-titanium instruments were used for the present study. Instruments were divided into four groups (n=10): group 1, Revo-S SU; group 2, ProTaper Next X2; group 3, Reciproc R25; group 4, WaveOne Gold Primary. An artificial stainless-steel was used to test the cyclic fatigue of the instruments. The instruments were introduced into the stainless-steel canal, one at a time, until they reached the other end, then they were rotated inside the canal without in-out motion. The time from the beginning of instrument rotation until the occurrence of breakage was recorded. The number of rotated cycles to fracture of the instrument were calculated based on the revolutions per minute (rpm) of each instrument and the recorded rotated time. The mean number of cycles to fracture and standard deviations were calculated and statistically analysed. Results: The number of cycles to fracture of the Revo-S SU was the lowest, and that of the WaveOne Gold Primary was highest. Scanning electronic microscope images of fracture surfaces revealed the characteristics of fatigue. Conclusions: The number of cycles to fracture of the reciprocating WaveOne Gold Primary system was the highest amongst the tested instruments.

Combination of Cyclic Fatigue Testing and Materials Characterisation to Investigate Ageing of Elastomers

2017 ◽  
Vol 44 (4) ◽  
pp. 1-8 ◽  
Author(s):  
T. Kroth ◽  
D. Lellinger ◽  
I. Alig ◽  
M. Wallmichrath
Keyword(s):  
Fatigue Life ◽  
Molecular Mass ◽  
Fatigue Testing ◽  
Cyclic Fatigue ◽  
Chain Scission ◽  
Thermal Ageing ◽  
Fatigue Tests ◽  
Additive Package ◽  
Number Of Cycles ◽  
Cycles To Failure

Cyclic fatigue testing and elastomer characterisation were combined to study changes in material properties and network structure of elastomers during thermal ageing. Natural rubber containing a typical additive package with carbon black was studied as a model material. The samples were aged at different temperatures in air or under a nitrogen atmosphere. The fatigue life in number of cycles to failure (S-N curves) was determined from force- and displacement-controlled fatigue tests on tensile bar specimens after different thermal ageing times. Changes in mechanical properties and crosslink density were studied by tensile tests, dynamic mechanical analysis, stress relaxation experiments, compression set measurements, swelling measurements and solid-state NMR. Changes in network density during thermal ageing are related to the interplay between the formation of new crosslinks and chain scission. The average molecular mass of the network chains was found to be a suitable parameter for comparing different characterisation methods. An initial decrease in the molecular mass between two crosslinking points due to post-curing is followed by an increase due to chain scission. A similar trend was found for fatigue life in number of cycles to failure (N) in force-controlled fatigue tests: an increase in N for short ageing times is followed by a decrease after longer ageing times.

scholarly journals Fracture Resistance of K3 Nickel-Titanium Files Made from Different Thermal Treatments

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
JinWook Choi ◽  
Soram Oh ◽  
Yu-Chan Kim ◽  
Kwang-Koo Jee ◽  
KeeYeon Kum ◽  
...  
Keyword(s):  
Cyclic Fatigue ◽  
Nickel Titanium ◽  
Torsional Angle ◽  
Thermal Treatments ◽  
Heat Treated ◽  
Significant Difference ◽  
Number Of Cycles ◽  
Torsional Fracture ◽  
One Way Anova ◽  
Angle Of Rotation

The purpose of this study was to compare fracture resistances of K3 nickel-titanium files made from different thermal treatments. K3 (SybronEndo, Orange, CA), K3XF (SybronEndo), and experimentally heat treated K3 (K3H) were used. For the cyclic fatigue test, the samples were rotated with up-and-down motion in the artificial canal with the curvature of 60 degrees until the fracture occurred. The number of cycles to fracture (NCF) was measured. For the torsional fracture test, the samples were tightly bound and rotated until the fracture occurred. Elastic modulus (EM), ultimate torsional strength (UTS), and angle of rotation to fracture (ARF) were measured. The results were statistically analyzed by one-way ANOVA. The NCF of K3H was higher than those of K3 and K3XF (P<0.05). The EM of K3XF and K3H was lower than that of K3 (P<0.05). There was no significant difference in UTS. The ARF of K3XF was higher than that of K3 (P<0.05). K3XF and K3H showed more flexibility than K3. The maximum torsional angle of K3XF was higher than that of K3, but there was no significant difference on the UTS in all three groups.

Sign in / Sign up

Export Citation Format

Share Document