scholarly journals Effect of Autoclaving Cycles on the Cyclic Fatigue Resistance of Race and Race Evo Nickel-Titanium Endodontic Rotary Files: An In Vitro Study

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1947
Author(s):  
Rahaf A. Almohareb ◽  
Reem Barakat ◽  
Aroob Albakri ◽  
Manal Altamimi

Objective: The aim of this study was to evaluate the influence of autoclave sterilization on the resistance to cyclic fatigue of two nickel-titanium (NiTi) endodontic files of identical design and taper, but with different NiTi alloy treatments: the newly introduced heat-treated Race Evo and the electropolished Race files. Materials and methods: Fifteen Race (25/0.06) files and fifteen Race Evo (25/0.06) files (n = 30 in total) were randomly assigned to five sub-groups each consisting of three files of the same NiTi alloy treatment. One group served as a control with files unautoclaved. The four remaining groups were sterilized in a steam sterilizer for 1, 3, 5, and 10 autoclave cycles, respectively. Files then underwent cyclic fatigue testing in a simulated metal canal block. A scanning electron microscope was used to inspect the surface of the fractured instruments. Statistical analysis was conducted using independent t-test and multi-factorial analysis of variance with significance set at a p value of ≤0.05. Results: Both Race Evo and Race files showed no significant difference between the different autoclaving cycles in terms of the number of cycles to fracture (p = 0.232 and p = 0.359). Despite rotating at a higher speed, the number of cycles to fracture of heat-treated Race Evo files was significantly higher than that of Race files (p ≤ 0.0001). Conclusion: Autoclave sterilization has no significant effect on the resistance to cyclic fatigue of heat-treated Race Evo or electropolished Race files. However, Race Evo files showed superior resistance to cyclic fatigue irrespective of autoclaving cycles.

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.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
JinWook Choi ◽  
Soram Oh ◽  
Yu-Chan Kim ◽  
Kwang-Koo Jee ◽  
KeeYeon Kum ◽  
...  

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Reham Sharroufna ◽  
Mohammed Mashyakhy

Objective. The purpose of this study was to evaluate the effect of repeated autoclave sterilization on the cyclic fatigue resistance of heat-treated NiTi rotary endodontic instruments. Materials and Methods. Three NiTi rotary endodontic instruments (EdgeFile X7, EFX7 0.30/0.4; Vortex Blue, VB 0.30/0.4; and TRUShape, TS 0.30/0.6) were selected. Each group ( n = 24 each) was divided into 2 subgroups ( n = 12 each): sterilized instruments and nonsterilized instruments. The sterilized instruments were subjected to 10 cycles of autoclave sterilization. Twelve instruments from each different subgroups were tested for cyclic fatigue resistance, and the number of cycles to failure (NCF) was calculated. Means and standard deviations were calculated for each group, and data were statistically analyzed using the SPSS program ( P < 0.05 ). Results. Sterilized and nonsterilized EFX7 files showed the highest NCF compared with other file subgroups. Comparing the results between sterilized and nonsterilized instruments for each type of files, there was a statistically significant difference ( P < 0.05 ) only between sterilized and nonsterilized EFX7 files (1198 versus 755 NCF). The other instruments did not show significant differences ( P > 0.05 ) in the mean NCF as a result of sterilization cycles (VB, 606 versus 568 NCF; TS, 487 versus 442 NCF). Conclusion. Repeated cycles of autoclave sterilization increased the NCF of the new heat-treated files, with EFX7 showing statistically significant superior results compared with other files tested.


2018 ◽  
Vol 12 (4) ◽  
pp. 283-287 ◽  
Author(s):  
Gülşah Uslu ◽  
Taha Özyürek ◽  
Mustafa Gündoğar ◽  
Koray Yılmaz

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.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Suhad Jabbar Hamed Al-Nasrawi ◽  
Zuha Ayad Jaber ◽  
Nibrass Talib Al-Quraine ◽  
Abtesam Imhemed Aljdaimi ◽  
Sattar Jabbar Abdul-Zahra Al-Hmedat ◽  
...  

Peracetic acid (PAA) is widely used as a sterilizing/disinfecting agent, and, in endodontics, it has been introduced as a promising irrigant in root canal treatment. It has been used at different concentrations to achieve various functions. However, endodontic instruments in contact with PAA of a certain concentration may affect their fatigue resistance. Therefore, the aim of this study was to investigate the impact of PAA on the cyclic fatigue resistance of three commercial heat-treated nickel-titanium (NiTi) rotary files. Three types of heat-treated NiTi rotary files were selected: One Curve (OC), ProTaper Gold (PTG), and Wave One Gold (WOG). Each type was divided into three subgroups (n = 6 for each file type): (1) untreated instruments; (2) files immersed in 0.002% PAA; and (3) files immersed in 0.35% PAA. The performance of each file type was tested in a simulated canal. The number of cycles to fracture (NCF) was determined to assess cyclic fatigue resistance of the files. Independent sample t-test was applied to compare each treated file within a subgroup with its respective control group, and one-way ANOVA was used for comparison among the main groups. All types of tested files revealed a significant decline in the cyclic fatigue resistance after exposure to 0.002% PAA except the PTG ( P = 0.209 ). After exposure of the files to a higher concentration (0.35% PAA), a dramatic reduction was demonstrated by all the groups. Before and after exposure of the files to PAA, PTG displayed the highest cyclic fatigue resistance, followed by the WOG, while the OC showed the lowest resistance. Exposure of heated-treated NiTi files to PAA in a relatively high or low concentration adversely affects the cyclic fatigue resistance. The PTG files demonstrated the best performance among the tested types and can be disinfected with 0.002% PAA for clinical purpose.


2021 ◽  
Vol 25 (2) ◽  
pp. 87-91
Author(s):  
Neslihan Büşra Keskin ◽  
Gürkan Güneç

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.


2017 ◽  
Vol 11 (02) ◽  
pp. 157-161 ◽  
Author(s):  
Bertan Kesim ◽  
Burak Sagsen ◽  
Tugrul Aslan

ABSTRACT Objective: The aim of this study was to compare the incidence of root cracks after root canal instrumentation with thermomechanically processed nickel-titanium (Ni-Ti) files with different instrumentation kinematics. Materials and Methods: A total of 150 extracted mandibular premolars with mature apices and straight root canals were divided into five groups and used in this study. In Group 1, 30 teeth were prepared using hand K-files and assigned to control group, Group 2 was instrumented using K3XF Rotary files (SybronEndo, Glendora, CA, USA) with continuous rotary motion. The teeth in Group 3 were instrumented by ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland) rotary files which make asymmetric rotary motion, In Group 4, teeth were instrumented by RECIPROC (VDW, Munich, Germany) with reciprocation motion and in Group 5, teeth were instrumented by Twisted File (TF) Adaptive (SybronEndo, Orange, CA, USA) files that use combination of continuous rotation and reciprocation motion (n = 30/per group). All the roots were horizontally sectioned 3, 6, and 9 mm from the apex with a low speed saw under water cooling. Then, the slices were examined through a stereomicroscope to determine the presence of dentinal microcracks.Results: For the apical (3-mm) and coronal (9-mm) sections, the ProTaper Next and TF Adaptive produced significantly more cracks than the hand files, RECIPROC, and K3XF (P < 0.05). There was no significant difference between the experimental groups and control group at the 6-mm level (P > 0.05). Conclusions: Within the limitations of this in vitro study, all thermal-treated Ni-Ti instruments and hand files caused microcracks in root canal dentin.


2006 ◽  
Vol 30 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Muhammad Faisal Khattak ◽  
John Patrick Conry ◽  
Ching-Chang Ko

The purpose of this in vitro study was to evaluate the short and long-term effectiveness of fluoride varnish and compare it with the two most commonly used topical fluorides, i.e., fluoride gel and foam.A second purpose of the study was to compare the effectiveness of these preparations on primary and permanent teeth. Enamel slabs with a thickness of 500 microns were obtained from caries free primary molars and premolars. They were divided into four groups: control, foam (F), gel (G) and varnish (V). Fluorides were applied to the enamel slabs according to the manufacturer's instructions and were placed in a 5.1 pH acidic gel for one week. The amount of demineralization from the enamel was measured by calculating the amount of light reflected from these surfaces. This was done by using a Charged Couple Device attached to a high resolution microscope with image processing software, Optima 5.22. The enamel slabs were placed in a freshly prepared acidic gel for a second week without application of fluorides. This was done to mimic a situation where fluoride is eventually brushed away from teeth. Reflective images were recorded under the previously described conditions. A two-way analysis of covariance was used to compare the treatments. The results showed no statistically significant difference (with Bonferroni correction) in the effectiveness of different fluoride preparations over the short-term (Week I comparison; p-values: F vs. G 0.079, F vs.V 0.030, G vs.V 0.44). However, the long-term protection provided by fluoride varnish was far more than fluoride gel and foam (Week II comparison; p-values: F vs. G 9X10-5 , F vs.V 7X10-8, G vs.V 1X10-4). Fluorides were equally effective for both primary and permanent enamels (p-value 0.24). The results of this study suggest that fluoride varnish is beneficial for use with white spot lesions, newly erupted permanent teeth and early decalcification in primary dentition.


Author(s):  
Deebah Choudhary

Introduction: Microleakage is a major setback to restorative dentistry. Leakage at the tooth/restoration interface may lead to numerous problems like postoperative sensitivity, recurrent caries, marginal sealing and later total failure of restoration. Aim: To determine the sealing ability (microleakage) of a new hydraulic calcium silicate cement (Biodentine) as a base material and a bulk filling material. Materials and Methods: An in-vitro study was conducted with ten freshly extracted maxillary molars from March 2019 to June 2019. Standardised Class II cavities were prepared on mesial and distal proximal surfaces. The twenty prepared samples were randomly divided into two groups (n=10)- G1 (BiodentineTM group) and G2 (BiodentineTM + Tetric N-Ceram group). The samples were subjected to thermocycling, followed by 1% methylene blue dye immersion. They were subsequently sectioned both buccolingually and mesiodistally in order to separate to proximal restorations (mesial and distal) and appreciate the amount of dye penetration at tooth/restoration interface respectively. Microleakage was evaluated by observing the samples under a stereomicroscope (30x). The data obtained was analysed using one-way ANOVA test and compared using Post-hoc test. p-value <0.05 to be considered significant. Results: Biodentine showed no significant difference between the sealing ability as a bulk filling and a base material. Group G2 (0.35) indicated comparatively less microleakage as compared to Group G1 (0.6) but the difference in microleakages in both groups was insignificant (p-value 0.083467). Conclusion: BiodentineTM exhibits microleakage when used as a bulk filling material and as a dentin substitute in Class II cavities since there is no significant difference in both the groups.


Sign in / Sign up

Export Citation Format

Share Document