|
 
 |
| ORIGINAL RESEARCH |
|
| Year : 2022 | Volume
: 14
| Issue : 6 | Page : 551-560 |
|
Comparative evaluation of cutting efficiency, cyclic fatigue, corrosion resistance, and autoclave cycle effects of three different file systems: An in-vitro micro-CT and metallurgy analysis
Kondas V Venkatesh, Eldho J Varghese
Department of Conservative Dentistry and Endodontics, SRM Kattankulathur Dental College and Hospital, SRM Institute of Science and Technology, SRM Nagar, Kattankulathur, 603203 Kanchipuram, Tamil Nadu, India
| Date of Submission | 26-Apr-2022 |
| Date of Acceptance | 11-Aug-2022 |
| Date of Web Publication | 30-Dec-2022 |
Correspondence Address:
Dr. Eldho J Varghese
Department of Conservative Dentistry and Endodontics, SRM Kattankulathur Dental College and Hospital, SRM Institute of Science and Technology, SRM Nagar, Kattankulathur, 603203 Kanchipuram, Tamil Nadu
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/jioh.jioh_91_22
Aim: To compare the cutting efficiency, cyclic fatigue, corrosion resistance, and autoclave cycle effects of ProTaper Gold, TruNatomy, and WaveOne Gold file systems. Materials and Methods: Thirty mesiobuccal roots of extracted maxillary first molars were randomly divided into three groups (10 specimens each) for testing cutting efficiency: Groups A, B, and C: ProTaper Gold, TruNatomy-Prime, and WaveOne Gold-Primary, respectively. Root canal instrumentation was carried out in each root accordingly. Specimens’ weights were measured and micro-computed tomography was used to scan the samples before and after root canal preparation. For cyclic-fatigue, corrosion-resistance, and autoclave-cycle-effects testing, 30 files were allocated into three groups at random, Groups A, B, and C: ProTaper Gold-F2, TruNatomy-Prime, and WaveOne Gold-Primary (10 specimens each). For cyclic-fatigue testing, the instruments were firmly held in a stainless steel block with an artificial canal without pressure. The time (s) was calculated until fracture. For the corrosion-resistance test, SEM surface-topographical analysis was carried out in response to 5.25% NaOCl, 2% CHX, and 17% EDTA. For evaluation of autoclave cycle effects, SEM surface-topographical analysis was carried out for 1, 5, and 10 autoclave cycles. Data were analyzed statistically using one-way analysis of variance followed by multiple comparisons with Bonferroni’s test at P<0.05. Results: TruNatomy was the most resistant to cyclic fatigue and ProTaper Gold the least. WaveOne Gold removed significantly more dentin and had the least corrosion resistance and highest autoclave cycle effects. Conclusion: TruNatomy can be considered as a better file system compared with WaveOne Gold and has comparable efficiency with that of ProTaper Gold. Keywords: Autoclave Cycle Effects, Corrosion Resistance, Cutting Efficiency, Cyclic Fatigue, TruNatomy
How to cite this article:
Venkatesh KV, Varghese EJ. Comparative evaluation of cutting efficiency, cyclic fatigue, corrosion resistance, and autoclave cycle effects of three different file systems: An in-vitro micro-CT and metallurgy analysis. J Int Oral Health 2022;14:551-60 |
How to cite this URL:
Venkatesh KV, Varghese EJ. Comparative evaluation of cutting efficiency, cyclic fatigue, corrosion resistance, and autoclave cycle effects of three different file systems: An in-vitro micro-CT and metallurgy analysis. J Int Oral Health [serial online] 2022 [cited 2023 Nov 30];14:551-60. Available from: https://www.jioh.org/text.asp?2022/14/6/551/366439 |
| Introduction | |  |
Over time, there has been a consistent interest in NiTi instrument research. Walia and co-workers introduced nickel–titanium (NiTi) files to endodontics for the first time in 1988. NiTi alloy was initially proposed as a material for hand and rotary instruments by Civjan et al.[1] Compared with stainless steel hand files, rotary NiTi instruments can clean and shape root canals more precisely and with fewer procedural errors. The tool’s flexibility and cutting effectiveness determine its capacity to sculpt the root canal. These instruments, however, have a tendency to disintegrate suddenly. The instrument ultimately shatters torsionally when it reaches an irreversible plastic deformation condition as a result of the frequent loading and unloading of NiTi files during instrumentation.[2]
NiTi rotary file systems have been created to promote flexibility and to reduce iatrogenic mistakes. These systems use special alloys, varied cross-sectional designs, cutting edges, and different tapers. Another manufacturing method for enhancing mechanical performance is thermal treatment of NiTi alloys, which controls the microstructure of the alloy while changing the transition temperature. In other words, heat-treated NiTi alloys mostly include the more flexible R-phase or martensite rather than the more common austenite seen in ordinary NiTi alloys. Compared with regular NiTi files, heat-treated NiTi files are substantially more flexible and resistant to cyclic fatigue. After the files are machined, gold heat-treated instruments are heated to eliminate machining process flaws and alter the crystalline phase structure. On May 2, 2014, DENTSPLY Tulsa Dental Specialities in California released the first ProTaper GOLD instruments. These files, according to the maker, have undergone a particular heat treatment that boosts their elasticity and makes them more resistant to cycle fatigue. The same company later published WaveOne GOLD files in 2011, which had a modified parallelogram cross-section with two cutting edges.[2] With a novel file design and heat treatment that allows better flexibility and effective shaping while only removing dentin when clinically appropriate, the DENTSPLY Tulsa released the TruNatomy file systems in 2019.[3]
Using scanning electron microscopy (SEM) and micro-computed tomography (micro-CT) analysis, this study assesses the surface topographical analysis of the aforementioned file systems. The study gives a thorough explanation of the effects of corrosion and autoclave on the instruments’ cross-sections. Utilizing different chemical irrigants during the cleaning and shaping of root canal instrumentation has the potential to harm the instruments’ surfaces. Additionally, the autoclave cycles used to sterilize the instruments can alter their surface.[3]
No study has compared the effects of ProTaper GOLD, TruNatomy, and WaveOne GOLD on cutting effectiveness, cyclic fatigue, corrosion resistance, and autoclave cycle. Therefore, the purpose of this study was to perform a thorough analysis of metallurgy by evaluating all four of the ProTaper GOLD, TruNatomy, and WaveOne GOLD parameters in vitro. The null hypothesis was that there would be no statistically significant changes in cutting efficiency, cyclic fatigue, corrosion resistance, or autoclave cycle impacts between the ProTaper GOLD, TruNatomy GOLD, and WaveOne GOLD systems.
| Materials and Methods | | |
This study is an in-vitro metallurgy analysis.
Methodology for cutting efficiency
Sample collection
Inclusion criteria include
intact, crack-free, and non-treated mesiobuccal roots.
Exclusion criteria include
infected mesiobuccal roots, treated mesiobuccal roots, fractured mesiobuccal roots, and calcified mesiobuccal roots.
Sample size calculation
The sample size was calculated with probability (power) 0.9 according to a previous study.[4],[5] Three experimental groups were to be studied to reject the null hypothesis. To compensate for any loss of sample drop out, the sample size was increased to become by 30% (n=10) for each group. The type I error probability associated with this test of null hypothesis is 0.5.
Specimen’s preparation for cutting efficiency testing
For this investigation, 30 extracted human maxillary molars with complete, uncracked, and untreated mesiobuccal roots measuring at least 11 mm in length were employed. The highest frequency of instrument separation and curvatures occurs in mesiobuccal roots. These molars had their palatal and distal roots removed and discarded. Then, utilizing Endo access and Endo Z burs, canals were accessible (Dentsply, Maillefer, Ballaigues, Switzerland). Using ISO 10 and later 15 K data, mesial canals were discovered and navigated to the apical foramen (Dentsply, Maillefer, Ballaigues, Switzerland). The Schneider idea was used to calculate the curvatures of the root canals. To ensure that the weights of all the roots were comparable, they were weighed.
Grouping of the specimen and study design for cutting efficiency testing
This in-vitro study involved three main cutting efficiency testing groups (10 specimens each) Groups A, B, and C: ProTaper Gold, TruNatomy-Prime, and WaveOne Gold-Prime preparations, respectively. The random sampling method was used.
Evaluation for cutting efficiency
Hyposol, a 3% solution of sodium hypochlorite, was used for irrigation. Micro-CT was used to scan the samples both before and after root canal preparation. Comparing and evaluating scanned images for root dentin loss and canal integrity are shown in [Figure 1]. Additionally, the weights of the specimens were determined using the AUW220D before beginning the root canal preparation for the groups (Shimadzu, Kyoto, Japan). After instrumentation, the specimens were weighed on the AUW220D scale. The division of specimen weight loss for the duration of root canal preparation led to the cutting efficiency (240S).[4],[5] From the micro-CT images, it is clear that TruNatomy files preserved the root canal’s maximum integrity and shape, whereas the other two file systems gave the root canal anatomy a new shape.
Grouping of the specimen and study design for cyclic fatigue, corrosion resistance, and autoclave cycle effects testing
This in-vitro study involved three main file groups to test cyclic fatigue, corrosion resistance, and autoclave cycle effects Group A, B, and C: ProTaper Gold-F2, TruNatomy-Prime, and WaveOne Gold-Primary (10 specimens each). The random sampling method was used.
Evaluation of cyclic fatigue
An X-Smart Plus endo motor (Dentsply, Maillefer, Ballaigues, Switzerland) was used to spin the instruments at the manufacturer-recommended speed and torque. In a stainless steel block containing an artificial canal with the following dimensions: 600 curvature, radius of curvature 3.5 mm, length 21 mm, width 2 mm, and depth 3 mm, the instruments were secured using a clamping mechanism with passive adjustment and without pressure. The model’s attributes matched those of the block used by Gambarini et al.[6] and Champa et al.[7] [Figure 2]. After each filing, glycerin was used to lubricate the canal. The number of seconds (s) till fracture was computed. (Resistance (s) × Speed)/60 was used to compute the number of cycles to fracture (NCF).[8]
Evaluation of corrosion resistance
For evaluation of corrosion resistance, surface topographical analysis was carried out using high-resolution SEM. The surfaces of the instruments were initially subjected to scanning followed by surface treatment using 5.25% NaOCl, 2% CHX, and 17% EDTA for 10 min at 37°C. Immediately after removing from the immersion, all the files were rinsed with distilled water to neutralize the effect of irrigation and dried. Surface roughness (sum of pixels showing grooves and bumps) was evaluated after the treatment using SEM [Figure 3].[9],[10]
Evaluation of autoclave cycle effects
For evaluation of autoclave cycle effects, high-resolution SEM surface topographical analysis was carried out for 1, 5, and 10 autoclave cycles. The surfaces of the files of each group were scanned initially using SEM and then the files were subjected to 1, 5, and 10 autoclave cycles. The scanning was performed after 1, 5, and 10 autoclave cycles, and then the surface roughness (sum of pixels showing grooves and bumps) was evaluated [Figure 4].[10]
| Results | | |
Statistical analysis
Data were collected and entered into Microsoft Excel and analyzed using IBM SPSS Statistics for Windows, Version 20 (IBM Corp., Armonk, NY, USA). Data were explored for normality using the Kolmogorov–Smirnov test, which showed normally distributed data. Cutting efficiency, cyclic fatigue, corrosion effects, and autoclave cycle effects (1, 5, and 10 cycles) across three groups were analyzed using one-way analysis of variance (ANOVA) followed by multiple comparisons with the Bonferroni test (α=0.05). The level of statistical significance was determined at P≤0.05.
[Table 1] depicts the cutting efficiency of the tested files; Group A ProTaper Gold removed the least amount of dentin, whereas Group C WaveOne Gold removed the maximum amount of dentin. [Table 2] depicts cyclic fatigue resistance of the tested files; Group B TruNatomy showed maximum cyclic fatigue resistance, whereas Group A ProTaper Gold showed the least cyclic fatigue resistance. Corrosion effects, when subjected to chlorhexidine and EDTA solutions, were insignificant. [Table 3] depicts the effects of sodium hypochlorite on the surface of the tested files; Group C WaveOne Gold showed the least corrosion resistance to NaOCl solution. [Table 4][Table 5][Table 6] depict the effects of autoclave cycles on file surfaces after 1, 5, and 10 cycles, respectively; Group C WaveOne Gold showed the least resistance to autoclave cycles. | Table 1: Comparison of cutting efficiency and post hoc analysis using Bonferroni test regarding cutting efficiency between the groups
Click here to view |
 | Table 2: Comparison of resistance to cyclic fatigue and post hoc analysis using the Bonferroni test regarding resistance to cyclic fatigue between the three groups
Click here to view |
 | Table 3: Comparison of corrosion effects of NaOCl and post hoc analysis using the Bonferroni test regarding corrosion effects of NaOCl between the groups
Click here to view |
 | Table 4: Comparison of 1 autoclave cycle effects and post hoc analysis using the Bonferroni test regarding 1 autoclave cycle effects between the three groups
Click here to view |
 | Table 5: Comparison of 5 autoclave cycle effects and post hoc analysis using the Bonferroni test regarding 5 autoclave cycle effects between the three groups
Click here to view |
 | Table 6: Comparison of 10 autoclave cycle effects and post hoc analysis using the Bonferroni test regarding 10 autoclave cycle effects between the three groups
Click here to view |
| Discussion | | |
This study evaluated the effects of ProTaper Gold, TruNatomy, and WaveOne GOLD file systems on cutting effectiveness, cyclic fatigue, corrosion resistance, and autoclave cycle. The study’s findings revealed statistically significant differences in all of the parameters compared among the three experimental groups, rejecting the null hypothesis.
Cutting efficiency
Cutting efficiency refers to the capacity to remove a regular funnel-shaped channel from the root canal walls, which simplifies the subsequent filling operation. Some of the elements that impact the cutting effectiveness of NiTi instruments include the cross-sectional design, helical and rake angles, angle incidence between the instrument and sample, hardness of the alloy as a consequence of electropolishing or heat treatments, and instrument motion.[3],[11]
The instrument’s ability to advance into the root canal is inversely correlated with its cutting capacity. A favorable blade rake angle enhances the cutting action of the instrument while reducing obstruction and torsional load risks. An instrument with a positive rake angle will cut more effectively than one with a neutral or negative rake angle, which will grind the root canal walls and increase the risk of torsional fracture and excessive pressing forces. Additionally, a number of studies have found that when it comes to root canal cleaning, instruments with actively cutting blades outperform files with radial lands. A higher cutting efficiency, however, might cause the instrument to wear out more quickly and remove more dentine, decreasing the root’s resistance to vertical fracture. There is no method that is generally accepted for figuring out how well endodontic instruments cut. In this study, both conventional weight loss comparison technique and the advanced micro-CT analysis were used to determine the cutting efficiency. Due to its distinct offset parallelogram-shaped cross-section, WaveOne Gold demonstrated maximum cutting efficiency in this study. The square cross-section of TruNatomy files has an off-center design. Convex triangular cross-sectional files are available for ProTaper Gold. ProTaper Gold files were not as effective at cutting as TruNatomy files. This is consistent with earlier literary research.[3],[11],[12],[13],[14]
Cycle fatigue
Rotary devices need to rotate significantly more often within the canal, which increases their risk of fracture due to torsion and/or flexion. When the instrument’s tip gets stuck in the root canal and the file keeps turning, torsional fatigue develops. Flexural fatigue develops when the instrument spins too quickly in the area of maximum curvature of a curved root canal. Manufacturers have added the reciprocating motion and novel alloys, such M-wire and R-phase NiTi files, which have shown higher cycle fatigue resistance than conventional files, to increase the fracture resistance of rotary NiTi files. To complete a full rotational cycle, the device spins in one direction and then in the other way.[2],[15],[16],[17],[18]
In terms of the time needed to create a curved root canal, cutting effectiveness, and cycle fatigue resistance, reciprocating motion is more effective than continuous rotation. However, there is still disagreement on the relative merits of reciprocating vs. continuous movements and how they affect cycle fatigue. In this work, the number of cycles to fracture for each instrument was determined. Continuous and reciprocating systems were compared, and an apparatus was built using the Gambarini et al.[6] and Champa et al. block.[7] In comparison to WaveOne Gold files, TruNatomy files were more resilient to cycle fatigue. The least resilient files to cyclic wear were ProTaper Gold files. This is consistent with earlier literary research.[13],[16],[17],[19] This can be explained by the thin wire technology of TruNatomy, which makes it more flexible and resistant to cyclic fatigue, in contrast to WaveOne Gold files, which are superior to the ProTaper Gold file system but flexible and less resistant to cyclic fatigue due to their stress-induced martensite phase (R phase) state.[2],[15],[17],[18]
Effects of corrosion resistance and autoclave cycle
In the course of instrumentation, endodontic files in the pulp chamber and root canal will come into contact with root canal irrigants, another factor that could affect the physical characteristics of NiTi files. The impact of root canal irrigation on the surface topography of various types of NiTi rotary instruments has been the subject of numerous studies. In contrast to EDTA, which is a chelating and lubricating agent used to treat canals that are too narrow or too calcified, NaOCl is an antibacterial agent with tissue-dissolving properties. The most effective method for destroying tissue and disinfecting root canals is to use NaOCl and EDTA solutions. As a result, these solutions come into contact with NiTi instruments during chemomechanical preparation or cleaning operations. In order to identify the surface deformations brought on by the treatment in this study, SEM analysis was carried out on each instrument after it had been exposed to an irrigant solution. SEM was also used to analyze how autoclaving affected the surface topography. It was decided to conduct a quantitative analysis of surface imperfections in the form of grooves and bumps. Compared with WaveOne Gold, TruNatomy demonstrated better resistance to corrosion and autoclave cycle effects. ProTaper Gold demonstrated the greatest resistance to the effects of autoclave cycles and corrosion. The NiTi precipitates that develop on the surface of these instruments can be used to explain this. Comparing WaveOne Gold with the other experimental groups in the research, the rate of formation is greater.[2],[12],[19],[20],[21],[22],[23]
Bruker micro-CT analysis
The study was completed using MicroCT SKYSCAN 1176. A 0.5 mm aluminum filter was used. From the scan pictures, it is clear that the TruNatomy file instrumentation was more centrally located and maintained the integrity of the canal architecture, in contrast to the ProTaper Gold and WaveOne Gold, which failed to do so. The approach used was comparable to other research using micro-CT analysis.[15],[24],[25],[26]
WaveOne Gold, TruNatomy, and ProTaper GOLD have an off-centered parallelogram cross-section and progressive taper; they all have a convex triangle cross-section. The thin NiTi wire used in TruNatomy has a regressive taper and a maximum flute diameter of 0.8 mm.
WaveOne Gold is the end result of a unique heat treatment that takes place both before and after the files are created. The SE NiTi alloy is put through a special heat treatment at 410–440°C with a constant load of between 3 and 15 kg. The working section of the file is machined, and then the completed instrument is heat-treated a second time at a temperature between 120°C and 260°C. Temperatures in the Af (austenite finish) vary from 40°C to 60°C. The extra heat treatment that creates finely distributed Ti3Ni4 precipitates in the austenitic matrix may be the cause of the surface roughness. For the alloy to develop martensite, more cooling is required.
With the use of a certain heat treatment, TruNatomy becomes more malleable and is better able to center canals while maintaining tooth integrity. Thin NiTi wire and an off-centered parallelogram cross-sectional design may have been used to increase cycle fatigue resistance.[2],[3],[27],[28],[29],[30],[31]
The need for specialized electric motors for reciprocation action with set angles, speeds, and torque is one of this study’s limitations. There is never a reliable methodology for in-vitro testing. The evaluation of four clinically significant parameters across three distinct file systems was compiled in this study. Regarding the compilation of all these tested parameters in a single study, there is no literature. To test all the other parameters that were not tested in this study, additional research is imperative.
| Conclusion | | |
Within the limitations of the study, TruNatomy can be considered as a better file system compared with WaveOne Gold and has comparable efficiency with ProTaper Gold.
Acknowledgement
The SRM Kattankulathur Dental College and Hospital, SRMIST Universit, Chennai, Tamil Nadu, India is acknowledged by the authors. This study was attributed to Dental Faculty, SRM Kattankulathur Dental College and Hospital, SRMIST University, Chennai, Tamil Nadu, India.
Financial support and sponsorship
Financial needs for performing the study was undertaken by the corresponding author himself and the article processing fee was shared by the two authors themselves.
Conflicts of interest
There are no conflicts of interest.
Authors’ contributions
Manuscript preparation, editing and review by Dr. Eldho Jijy Varghese. Study concept by Dr. K. Vijay Venkatesh. Statistical analysis by Dr. Varsha. Experimental procedures by Dr. Eldho Jijy Varghese.
Ethical policy and Institutional Review Board statement
This experimental study was approved by the The SRM Kattankulathur Dental College and Hospital, SRMIST University, Chennai, Tamil Nadu, India.
Patient declaration of consent
Not applicable.
Data availability statement
Not applicable.
| References | | |
| 1. | Civjan S, Huget EF, DeSimon LB Potential applications of certain nickel–titanium (Nitinol) alloys. J Dent Res 1975;54:89-96.  |
| 2. | Srivastava S, Alghadouni MA, Alotheem HS Current strategies in metallurgical advances of rotary NiTi instruments: A review. J Dent Health Oral Disord Ther 2018;9:72-7. |
| 3. | HyeWon K, Su-Jin J, Min-Seock S Comparison of the shaping ability of ProTaper GOLD, WaveOne GOLD, and TruNatomy in simulated double curved canals. BMC Oral Health 2021;21:533. |
| 4. | Van Pham K, Nguyen NQ Cutting efficiency and dentinal defects using two single-file continuous rotary nickel–titanium instruments. Saudi Endod J 2020;10:56-60. |
| 5. | Vinothkumar TS, Miglani R, Lakshminarayananan L Influence of deep dry cryogenic treatment on cutting efficiency and wear resistance of nickel–titanium rotary endodontic instruments. J Endod 2007;33:1355-8. |
| 6. | Gambarini G, Miccoli G, Seracchiani M, Morese A, Piasecki L, Gaimari G, et al. Fatigue resistance of new and used nickel–titanium rotary instruments: A comparative study. Clin Ter 2018;169:e96-e101. |
| 7. | Champa C, Divya V, Srirekha A, Karale R, Shetty A, Sadashiva P An analysis of cyclic fatigue resistance of reciprocating instruments in different canal curvatures after immersion in sodium hypochlorite and autoclaving: An in vitro study. J Conserv Dent 2017;20:194-8. |
| 8. | Rubio J, Zarzosa JI, Pallarés A. A comparative study of cyclic fatigue of 10 different types of endodontic instruments: An in vitro study. Acta Stomatol Croat 2019;53:28-36. |
| 9. | Nóvoa XR, Martin-Biedma B, Varela-Patinõ P, Collazo A, Macías-Luaces A, Cantatore G, et al. The corrosion of nickel–titanium rotary endodontic instruments in sodium hypochlorite. Int Endod J 2007;40:36-44. |
| 10. | Razavian H, Iranmanesh P, Mojtahedi H, Nazeri R Effect of autoclave cycles on surface characteristics of s-file evaluated by scanning electron microscopy. Iran Endod J 2016;11:29-32. |
| 11. | Pedullà E, Leanza G, La Rosa GRM, Gueli AM, Pasquale S, Plotino G, et al. Cutting efficiency of conventional and heat-treated nickel–titanium rotary or reciprocating glide path instruments. Int Endod J 2020;53:376-84. |
| 12. | Cai JJ, Tang XN, Ge JY Effect of irrigation on surface roughness and fatigue resistance of controlled memory wire nickel–titanium instruments. Int Endod J 2017;50:718-24. |
| 13. | Van der Vyver PJ, Vorster M, Peters O A. Minimally invasive endodontics using a new single-file rotary system. Int Dent Afr Ed 2019;9:6-20. |
| 14. | Peters OA, Arias A, Choi A Mechanical properties of a novel nickel–titanium root canal instrument: Stationary and dynamic tests. J Endod 2020;46:994-1001. |
| 15. | Ferreira F, Adeodato C, Barbosa I, Aboud L, Scelza P, Zaccaro Scelza M Movement kinematics and cyclic fatigue of NiTi rotary instruments: A systematic review. Int Endod J 2017;50:143-52. |
| 16. | Mustafa R, Al Omari T, Al-Nasrawi S, Al Fodeh R, Dkmak A, Haider J Evaluating in vitro performance of novel nickel–titanium rotary system (TruNatomy) based on debris extrusion and preparation time from severely curved canals. J Endod 2021;47:976-81. |
| 17. | Pérez Morales MLN, González Sánchez JA, Olivieri JG, Elmsmari F, Salmon P, Jaramillo DE, et al. Micro-computed tomographic assessment and comparative study of the shaping ability of 6 nickel–titanium files: An in vitro study. J Endod 2021;47:812-9. |
| 18. | Gündoğar M, Uslu G, Özyürek T, Plotino G Comparison of the cyclic fatigue resistance of Vdw. Rotate, TruNatomy, 2Shape, and HyFlex Cm nickel–titanium rotary files at body temperature. Restor Dent Endod 2020;45:e37. |
| 19. | Khandagale PD, Shetty PP, Makandar SD, Bapna PA, Karobari MI, Marya A, et al. Evaluation of cyclic fatigue of HyFlex EDM, twisted files, and ProTaper gold manufactured with different processes: An in vitro study. Int J Dent 2021;2021:7402658. |
| 20. | Riyahi AM, Bashiri A, Alshahrani K, Alshahrani S, Alamri HM, Al-Sudani D Cyclic fatigue comparison of TruNatomy, twisted file, and ProTaper next rotary systems. Int J Dent 2020;2020:3190938. |
| 21. | Yılmaz Çırakoglu N, Özbay Y Apically extruded debris associated with ProTaper next, ProTaper gold and TruNatomy systems: An in vitro study. J Dent Res Dent Clin Dent Prospects 2021;15:30-4. |
| 22. | Elnaghy AM, Elsaka SE, Mandorah AO In vitro comparison of cyclic fatigue resistance of TruNatomy in single and double curvature canals compared with different nickel–titanium rotary instruments. BMC Oral Health 2020;20:38. |
| 23. | Mustafa R, Al Omari T, Al-Nasrawi S, et al. Evaluating in-vitro performance of novel nickel–titanium rotary system (TruNatomy) based on debris extrusion and preparation time from severely curved canals. J Endod 2021;1:1-6. |
| 24. | Stringheta CP, Bueno CES, Kato AS, Freire LG, Iglecias EF, Santos M, et al. Micro-computed tomographic evaluation of the shaping ability of four instrumentation systems in curved root canals. Int Endod J 2019;52:908-16. |
| 25. | Arican B, Atav Atesx A, Fisxekçio_glu E Cone-beam computed tomographic analysis of shaping ability of XP-endo Shaper and ProTaper Next in large root canals. J Endod 2020;46:437-43. |
| 26. | Velozo C, Silva S, Almeida A, Romeiro K, Vieira B, Dantas H, et al. Shaping ability of XP-endo shaper and ProTaper Next in long oval-shaped canals: A micro-computed tomography study. Int Endod J 2020;53:998-1006. |
| 27. | Singh S, Abdul MSM, Sharma U, Sainudeen S, Jain C, Kalliath JT An in vitro comparative evaluation of volume of removed dentin, canal transportation, and centering ratio of 2Shape, WaveOne gold, and ProTaper gold files using cone-beam computed tomography. J Int Soc Prev Community Dent 2019;9:481-5. |
| 28. | Al-Dhbaan AA, Al-Omari MA, Mathew ST, Baseer MA Shaping ability of ProTaper gold and WaveOne gold nickel–titanium rotary file in different canal configurations. Saudi Endod J 2018;8: 202-7. |
| 29. | Kwak SW, Lee CJ, Kim SK, et al. Comparison of screw-in forces during movement of endodontic files with different geometries, alloys, and kinetics. Materials (Basel) 2019;12:1506. |
| 30. | Van der Vyver PJ, Vorster MPO Minimally invasive endodontics using a new single-file rotary system. Int Dent Afr Ed 2019;9:6-20. |
| 31. | Drukteinis S, Peciuliene V, Dummer PMH, Hupp J Shaping ability of BioRace, ProTaper Next and Genius nickel–titanium instruments in curved canals of mandibular molars: A micro-CT study. Int Endod J 2019;52:86-93. |
[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]
|
Search Pubmed for