scholarly journals Evaluation of the Cyclic Fatigue of Two Single Files at Body and Room Temperature with Different Radii of Curvature

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2256
Author(s):  
Giusy Rita Maria La Rosa ◽  
Valeria Shumakova ◽  
Gaetano Isola ◽  
Francesco Indelicato ◽  
Calogero Bugea ◽  
...  

Background: To compare the influence of different temperatures and curvature radii on the cyclic fatigue resistance of F6 SkyTaper (F6ST) and One Curve (OC) single file nickel-titanium rotary instruments. Methods: A total of 120 instruments of F6ST and OC #25.06 were evaluated in 5 mm and 3 mm curvature radii at two temperatures (20 °C ± 1 °C and 37 °C ± 1 °C) in 16 mm stainless steel artificial canals associated with a curvature of 60°. The cyclic fatigue of tested files was assessed by employing a customized testing apparatus and expressed as times to fracture (TtF). A statistical analysis was performed with the significance level set at 95%. Results: All instruments decreased their TtF at 37 °C except for OC in the 3 mm radius, in which no significant difference was detected between 20 °C and 37 °C. A 3 mm curvature radius negatively affected TtF of all tested instruments, except for F6ST at 20 °C. F6ST had higher TtF than OC in the 3 mm radius at 20 °C, with no significant difference between them in the other tested conditions. Conclusions: Under the limits of the present in vitro study, body temperature impaired cyclic fatigue resistance of all files, except for OC in the 3 mm curvature radius. All instruments exhibited lower times to fracture in the 3 mm radius, excluding F6ST at 20 °C.

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Pooja D. Khandagale ◽  
Prashant P. Shetty ◽  
Saleem D. Makandar ◽  
Pradeep A. Bapna ◽  
Mohmed Isaqali Karobari ◽  
...  

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.


2012 ◽  
Vol 18 (6) ◽  
pp. MT41-MT45 ◽  
Author(s):  
Gianluca Plotino ◽  
Dina Al-Sudani ◽  
Stefano Pulino ◽  
Nicola M. Grande ◽  
Piero Alessandro Marcoli ◽  
...  

2021 ◽  
Vol 24 (4) ◽  
Author(s):  
Marco Seracchiani ◽  
Orlando Donfrancesco ◽  
Michela Relucenti ◽  
Rodolfo Reda ◽  
Alessio Zanza ◽  
...  

Objective: Aim of the present study is to evaluate mechanical properties of a newly developed rotary file, AF Rotary (Fanta Dental, Shanghai, China), and to compare these features with a worldwide spread rotary file, Protaper Gold F2 (PTG F2; Dentsply Maillefer, Ballaigues, Switzerland). Material and Methods: 60 AF Rotary 25.06 and 60 PTG F2 were divided in three groups of 20 files each. A group underwent to cyclic fatigue resistance tests, second group underwent to torsional resistance tests, third group underwent to bending tests. The statistical analysis was performed using t student test with significance level set at 95% (p < 0.05). Results: AF Rotary showed significantly higher torsional resistance and cyclic fatigue resistance (p < 0.05) when compared to the PTG F2. AF Rotary also showed significantly lower bending resistance (p < 0.05) when compared to the PTG F2. Conclusion: Therefore, within the limitations of this study, the results show better performances for AF Rotary compared to PTG F2 regarding the cyclic fatigue test, the torsional test and the bending test. Since the PTG F2 is a commonly used and widely investigated instrument it could be possible to state that the AF Rotary exhibits remarkable in vitro performances.   Keywords AF Rotary; Protaper gold; NiTi rotary instruments; Cyclic fatigue; Torsional resistance.


Author(s):  
Anil K Tomer ◽  
Vanita Verma ◽  
Nitin Bhateja ◽  
Pudu Tirupathi ◽  
Sushma Kumari

Aim:  To compare and evaluate the cyclic fatigue resistance of three NiTi rotary file system Materials and Methods: Three NiTi rotary system (Hyflex EDM, Protaper Gold and One curve) were used in study . All files were tested in simulated constructed apparatus with angle of curvature 60o and radius of curvature 5mm.The rotary files were used in endomotor X smart (Densply) .All the instruments were utilized until fracture occurred, and then the number of cycles to failure (NCF) was calculated. The data were analyzed statistically using Annova test. The statistical significance level was set at P < 0.05. Result: HEDM instruments had the highest cyclic fatigue resistance among all the other instruments (P < 0.05). The one curve instruments had a significantly higher fatigue resistance than the Protaper gold instruments (P < 0.05). Conclusion: Within the limitations of this in vitro study, it was found that the cyclic fatigue resistance was higher for the HEDM instruments than for the, Protaper gold and one curve instruments. Keywords: Cyclic fatigue resistance, heat‑treated NiTi instruments, HyFlex EDM, OneCurve


2021 ◽  
Vol 11 (Suppl. 1) ◽  
pp. 67-73
Author(s):  
Ahmet Akay ◽  
Özkan Adıgüzel ◽  
Seda Erkan Akay ◽  
Sadullah Kaya

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.  


Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Ayca Yilmaz ◽  
Dilek Helvacioglu-Yigit ◽  
Cansu Gur ◽  
Handan Ersev ◽  
Gullu Kiziltas Sendur ◽  
...  

The purpose of this study was to compare the incidence and longitudinal propagation of dentin defects after gutta-percha removal with hand and rotary instruments using microcomputed tomography. Twenty mandibular incisors were prepared using the balanced-force technique and scanned in a 19.9 μm resolution. Following filling with the lateral compaction technique, gutta-percha was removed with ProTaper Universal Retreatment (PTUR) or hand instruments. After rescanning, a total of 24,120 cross-sectional images were analyzed. The numbers, types, and longitudinal length changes of defects were recorded. Defects were observed in 36.90% of the cross sections. A total of 73 defects were comprised of 87.67% craze lines, 2.73% partial cracks, and 9.58% fractures. No significant difference in terms of new defect formation was detected between the retreatment groups. The apical and middle portions of the roots had more dentin defects than the coronal portions. Defects in three roots of the PTUR instrument group increased in length. Under the conditions of this in vitro study, gutta-percha removal seemed to not increase the incidence of dentin defect formation, but the longitudinal defect propagation finding suggests possible cumulative dentinal damage due to additional endodontic procedures. Hand and rotary instrumentation techniques caused similar dentin defect formation during root canal retreatment.


2021 ◽  
Vol 58 (1) ◽  
pp. eUJ3657
Author(s):  
Germano Brandão ◽  
◽  
Liliana Ávila Maltagliati ◽  
Ana Carla Raphaelli Nahás-Scocate ◽  
Murilo Matias ◽  
...  

The objective of this in vitro study was to assess and compare the shear bond strength of conventional and modified orthodontic tubes bonded to the surface of dry and saliva-contaminated enamel. The sample consisted of 40 human teeth, which were randomly divided into four groups according to attachment base and presence or absence of saliva contamination as follows: Group CB, conventional orthodontic tubes without salivary contamination; Group CB-S, conventional orthodontic tubes with salivary contamination; Groups BM, orthodontic tubes modified by welding a metal mesh to their base without salivary contamination; and Group BM-S, modified orthodontic tubes with salivary contamination. Shear bond strength test was performed in a universal testing machine and analysis of the adhesive remnant index (ARI) by optical microscopy. Two-way ANOVA was used, followed by Tukey’s test at a statistical significance level of 5%. The ARI results were analysed descriptively. There was statistically significant difference between the groups regarding the shear bond strength values, with conventional tubes presenting significantly higher values (P < 0.05). In addition, the presence of salivary contamination interfered negatively with the behaviour of conventional tubes only (P < 0.05). Shear bond strength was not improved by increasing the area of the orthodontic tubes. Moreover, salivary contamination influenced negatively the SBS values, but only when conventional tubes were used.


2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
Thalita Miranda Vieira ◽  
Ryhan Menezes Cardoso ◽  
Nayane Chagas Carvalho Alves ◽  
Silvio Emanuel Acioly Conrado de Menezes ◽  
Shirley Machado Batista ◽  
...  

The main aim is to evaluate the cyclic fatigue resistance of blue heat-treated instruments with different kinematics. Twenty-four endodontic instruments of the same brand were used for each of three experimental groups: VB (Vortex Blue 40/0.04), RB (RECIPROC Blue 40/0.06), and XB (X1 Blue 40/0.06). The instruments were randomly distributed and subjected to temperatures of 20°C and 37°C. The fatigue test was performed using a stainless steel device. Data were analysed using the Shapiro–Wilk test, Student’s t-test, the F test, and Tukey’s and Tamhane tests at significance level P = 0.05 . The instruments’ cyclic fatigue resistance at both temperatures differed significantly for each instrument type ( P < 0.001 ). The RB instruments displayed greater cyclic fatigue resistance at the tested temperatures compared with the VB and XB instruments ( P < 0.001 ). Reciprocating kinematics positively influenced cyclic fatigue resistance. Blue heat-treated instruments showed decreased cyclic fatigue resistance as the temperature increased ( P < 0.001 ).


2020 ◽  
pp. 232020682095394
Author(s):  
Özgecan S¸ivet ◽  
Özlem Malkondu ◽  
Sercan Küçükkurt ◽  
Ender Kazazoglu

Aim: To evaluate the changes in the temperature of zirconia during grinding under different clinical conditions. Materials and Methods: A total of 60 zirconia framework specimens were fabricated and divided into groups of 10 specimens each. Two different handpieces, namely, a high-speed handpiece (HSH) and a low-speed handpiece (LSH), were used for grinding with and without water cooling. Fine- and coarse-grit diamond burrs were used with the HSH, separately. The following six groups were created: (a) HSH fine-grit with water cooling, (b) HSH coarse grit with water cooling, (c) HSH fine grit without water cooling, (d) HSH coarse grit without water cooling, (e) LSH with water cooling, and (f) LSH without water cooling. Each zirconia framework was ground until 1 mm3 of the material was removed. Temperature values corresponding to the grinding techniques were compared and statistically analyzed. One-way analysis of variance was used to compare the group parameters, while the Tukey honest significant difference test was used to detect significant differences between the groups. The significance level was set at P <.05. Results: The highest mean temperature was measured in the case of grinding with the LSH without water cooling (54.7 °C ± 11.6 °C), while the lowest mean temperature was observed in the case of grinding with the HSH using the coarse-grit diamond rotary instrument under water cooling (22.6 °C ± 0.6 °C). Conclusions: The grinding of zirconia must be performed with an HSH under water cooling. Further, when water cooling is used, neither the type of handpiece nor the grain type of the rotary instrument used as it has a significant effect on the temperature.


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