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Agrawal PR, Chandak M, Nikhade PP, Patel AS, Bhopatkar JK. Revolutionizing endodontics: Advancements in nickel-titanium instrument surfaces. JOURNAL OF CONSERVATIVE DENTISTRY AND ENDODONTICS 2024; 27:126-133. [PMID: 38463467 PMCID: PMC10923218 DOI: 10.4103/jcde.jcde_248_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 11/19/2023] [Accepted: 12/05/2023] [Indexed: 03/12/2024]
Abstract
Nickel-titanium (NiTi) instruments have become the backbone of endodontics due to their exceptional properties, superelasticity, and shape memory. However, challenges such as unexpected breakage, poor cutting efficiency, and corrosion have prompted researchers to explore innovative surface modifications to enhance their performance. This comprehensive review discusses the latest advancements in NiTi metallurgy and their impact on rotary NiTi file systems. Various surface treatment techniques, including ion implantation, cryogenic treatment (CT), thermal nitridation, electropolishing, and physical or chemical vapor deposition, have been investigated to minimize defects, boost surface hardness, and improve cyclic fatigue resistance. Ion implantation has shown promise by increasing wear resistance and cutting efficiency through nitrogen ion incorporation. Thermal nitridation has successfully formed titanium nitride (TiN) coatings, resulting in improved corrosion resistance and cutting efficiency. CT has demonstrated increased cutting efficiency and overall strength by creating a martensite transformation and finer carbide particles. Electropolishing has yielded mixed results, providing smoother surfaces but varying impacts on fatigue resistance. Physical or chemical vapor deposition has proven effective in forming TiN coatings, enhancing hardness and wear resistance. Furthermore, the concept of surface functionalization with silver ions for antibacterial properties has been explored. These advancements present an exciting future for endodontic procedures, offering the potential for enhanced NiTi instruments with improved performance, durability, and patient outcomes.
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Affiliation(s)
- Paridhi Rajesh Agrawal
- Department of Conservative Dentistry and Endodontics, DMIHER, Sharad Pawar Dental College and Hospital, Wardha, Maharashtra, India
| | - Manoj Chandak
- Department of Conservative Dentistry and Endodontics, DMIHER, Sharad Pawar Dental College and Hospital, Wardha, Maharashtra, India
| | - Pradnya Prashant Nikhade
- Department of Conservative Dentistry and Endodontics, DMIHER, Sharad Pawar Dental College and Hospital, Wardha, Maharashtra, India
| | - Aditya Satyawansingh Patel
- Department of Conservative Dentistry and Endodontics, DMIHER, Sharad Pawar Dental College and Hospital, Wardha, Maharashtra, India
| | - Jay Kailas Bhopatkar
- Department of Conservative Dentistry and Endodontics, DMIHER, Sharad Pawar Dental College and Hospital, Wardha, Maharashtra, India
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2
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Chan WS, Gulati K, Peters OA. Advancing Nitinol: From heat treatment to surface functionalization for nickel–titanium (NiTi) instruments in endodontics. Bioact Mater 2023; 22:91-111. [PMID: 36203965 PMCID: PMC9520078 DOI: 10.1016/j.bioactmat.2022.09.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 09/04/2022] [Accepted: 09/09/2022] [Indexed: 11/27/2022] Open
Abstract
Nickel-titanium (NiTi) alloy has been extensively researched in endodontics, particularly in cleaning and shaping the root canal system. Research advances have primarily focused on the design, shape, and geometry of the NiTi files as well as metallurgy and mechanical properties. So far, extensive investigations have been made surrounding surface and thermomechanical treatments, however, limited work has been done in the realm of surface functionalization to augment its performance in endodontics. This review summarizes the unique characteristics, current use, and latest developments in thermomechanically treated NiTi endodontic files. It discusses recent improvements in nano-engineering and the possibility of customizing the NiTi file surface for added functionalization. Whilst clinical translation of this technology has yet to be fully realized, future research direction will lie in the use of nanotechnology. Nitinol (Nickel Titanium alloy) is widely used to clean/shape root canal system in endodontics. To enhance its performance, various thermo-mechanical and nano-engineering modifications have been performed. This comprehensive review summarizes the latest advances and future trends relating to functionalized NiTi endodontic files.
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El Abed R, Al Raeesi D, Alshehhi A, Alkhatib Z, Khamis AH, Jamal M, Kim HC. Effect from Autoclave Sterilization and Usage on the Fracture Resistance of Heat-Treated Nickel-Titanium Rotary Files. MATERIALS (BASEL, SWITZERLAND) 2023; 16:2261. [PMID: 36984141 PMCID: PMC10056662 DOI: 10.3390/ma16062261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/03/2023] [Accepted: 03/08/2023] [Indexed: 06/18/2023]
Abstract
This study aimed to assess the effect of mechanical loading and heating on the cyclic fatigue and torsional fracture resistances of heat-treated nickel-titanium files after usage and autoclaving. Sixty files (One Curve) were tested for cyclic fatigue and torsional fracture resistances using customized devices. The files were divided into three groups according to the test conditions (n = 10); new (group-N), used for simulated canal shaping (group-U), and sterilized after use (group-S). For cyclic fatigue resistances, the files were freely rotated in a curved metal canal under body temperature; the time elapsed to fracture was recorded and the numbers of cycles to fracture (NCF) were calculated. For the torsional resistances, the file tip was fixed and rotated until the file fractured. The maximum torsional load and distortion angle were recorded. The toughness was calculated. Fracture fragments were examined with a scanning electron microscope. Data were analyzed using a one-way analysis of variance and Tukey's post hoc test at the significance level of 95%. Group-U showed significantly higher NCF than group-S (p < 0.05). However, there was no significant differences between groups-N and -S in the NCF (p > 0.05). Group-N showed a significantly bigger distortional angle and higher torsional toughness than groups-U and -S, but the ultimate torsional strength did not have significant difference between the groups. Under the limitation of this study, autoclave sterilization after single-usage did not improve the fracture resistance of heat-treated One Curve nickel-titanium files.
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Affiliation(s)
- Rashid El Abed
- Endodontic Department, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai 505055, United Arab Emirates
| | - Dana Al Raeesi
- Endodontic Department, Emirates Health Services Establishment, Dubai, United Arab Emirates
| | - Aisha Alshehhi
- Endodontic Department, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai 505055, United Arab Emirates
| | - Zuhair Alkhatib
- Endodontic Department, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai 505055, United Arab Emirates
- Emirates Endodontic Society, Dubai, United Arab Emirates
| | - Amar H. Khamis
- Biostatistics Department, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai 505055, United Arab Emirates
| | - Mohamed Jamal
- Endodontic Department, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai 505055, United Arab Emirates
| | - Hyeon-Cheol Kim
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Pusan National University, Yangsan 50612, Republic of Korea
- Dental and Life Science Institute, Pusan National University, Yangsan 50612, Republic of Korea
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Jiang J, Sun J, Huang Z, Bi Z, Yu G, Yang J, Wang Y. The state of the art and future trends of root canal files from the perspective of patent analysis: a study design. Biomed Eng Online 2022; 21:90. [PMID: 36566212 PMCID: PMC9789667 DOI: 10.1186/s12938-022-01060-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 12/14/2022] [Indexed: 12/25/2022] Open
Abstract
The goal of this review is to present a detailed and comprehensive description of the published work from the past decade regarding methods of improved material, geometric design, and additional functions in root canal files. The main improved methods of files and the most common technologies were further addressed, underlining their advantages and main limitations. Online databases (the Derwent Innovations Index) were consulted on this topic. Published work from 2010 to 2022 was collected and analyzed the relevant papers were chosen for inclusion in this review. The patent map classified the latest phase of the root canal files based on the analysis of the number of patents. The performance of the root canal files, such as materials. Directly affects the quality of the root canal therapy. We provided a thorough review of advances in the field of root canal files. In particular, three categories of improved methods were examined and compared, including material-based methods, geometry-based methods, and those based on additional functions. To understand this state of the art of different improved methods of root canal files, we conducted a literature analysis and a series of comparisons between different methods. The features and limitations of each method of root canal files were further discussed. Finally, we identified promising research directions in advancing the methods for the improved performance of root canal files. There is no perfect technology for all material/geometric design/additional functions, capable alone of fulfilling all the specificity and necessities of every patient. Although it is very promising, the material of the files remains understudied, and further work is required to make material science a pervasive technology in root canal therapy, and contribute to endodontic and periapical diseases by assisting in the subsequent development of root canal files.
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Affiliation(s)
- Jingang Jiang
- grid.411994.00000 0000 8621 1394Key Laboratory of Advanced Manufacturing and Intelligent Technology, Ministry of Education, Harbin University of Science and Technology, Harbin, 150080 Heilongjiang People’s Republic of China ,grid.19373.3f0000 0001 0193 3564State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin, 150001 Heilongjiang People’s Republic of China
| | - Jianpeng Sun
- grid.411994.00000 0000 8621 1394Key Laboratory of Advanced Manufacturing and Intelligent Technology, Ministry of Education, Harbin University of Science and Technology, Harbin, 150080 Heilongjiang People’s Republic of China
| | - Zhiyuan Huang
- grid.19373.3f0000 0001 0193 3564State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin, 150001 Heilongjiang People’s Republic of China
| | - Zhuming Bi
- grid.503846.c0000 0000 8951 1659Department of Civil and Mechanical Engineering, Purdue University Fort Wayne, West Lafayette, 46805 USA
| | - Guang Yu
- grid.12527.330000 0001 0662 3178Department of Mechanical Engineering, Tsinghua University, Beijing, 100084 People’s Republic of China
| | - Jingwen Yang
- grid.11135.370000 0001 2256 9319National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School of Stomatology, Beijing, 100081 People’s Republic of China ,grid.11135.370000 0001 2256 9319Peking University School of Stomatology, Beijing, 100081 People’s Republic of China
| | - Yong Wang
- grid.11135.370000 0001 2256 9319National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School of Stomatology, Beijing, 100081 People’s Republic of China ,grid.11135.370000 0001 2256 9319Peking University School of Stomatology, Beijing, 100081 People’s Republic of China
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A Novel Technique for Identification of Wear Values at Different Lengths after Multiple Clinical Use of Different File Systems. Medicina (B Aires) 2022; 58:medicina58081117. [PMID: 36013584 PMCID: PMC9416307 DOI: 10.3390/medicina58081117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 07/30/2022] [Accepted: 08/16/2022] [Indexed: 11/16/2022] Open
Abstract
Introduction The purpose of this research is to assess the wearing of the rotary file system (Protaper Next) and reciprocating file systems (Reciproc Blue and WaveOne Gold) at different lengths using a novel technique after in vivo clinical use. Materials and Methods Twelve different unused samples from each brand were accepted as reference values. For three different brands, the diameters of the files were measured by taking 12 samples used once, 12 samples used twice, and 12 samples used three times. Images were taken with a USB Micron Microscope, and file diameters were measured by determining limit values with Autocad. Result Reciproc Blue system was the most worn at apical 1 mm, and WaveOne Gold system was the most worn at apical 3 mm. PTN system exhibited the least wearing at any length. Moreover, less wearing was observed in the rotation motion than in the reciprocating motion. Conclusion In clinical practice, for the guttapercha to be fully adapted to the apical construction prepared according to the determined WL, the file should not undergo any wearing and volume reduction. Wearing—especially in the apical parts of the file—causes less preparation, and this situation could lead to apically obturation failure.
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What meaningful information are the instruments mechanical testing giving us? A comprehensive review. J Endod 2022; 48:985-1004. [PMID: 35667567 DOI: 10.1016/j.joen.2022.05.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/21/2022] [Accepted: 05/26/2022] [Indexed: 11/22/2022]
Abstract
Instruments mechanical strength and flexibility are traditionally tested by running cyclic fatigue, torsional, bending, buckling and microhardness tests. Several cyclic fatigue test models have been used in endodontics, all capable of providing a curved trajectory for the instrument to rotate. The cyclic fatigue testing allowed to identify conditions that may affect the fatigue strength outcomes, such as canal radius and degree of curvature, handpiece static vs dynamic motions, test temperature, kinematics, instrument previously wear and sterilization cycles, or instrument's size and metal alloy features. Due to the international test specifications for both torsional and bending tests, the variations of their models are not as many as for cyclic fatigue. These tests have also identified conditions capable of affecting the outcomes, such as kinematics, instrument's preloading, cross-sectional diameters, or alloy heat treatments. Buckling and microhardness are less common, with the metal alloy being considered to have a major influence on the results. Instruments mechanical testing, having all these individual conditions as independent variables, allowed to understand them and moulded the way the technical procedures are performed clinically. Even though the artificiality and simplicity of these tests will hardly mimic real working situations, and independently of being capable of producing cornerstone knowledge, these tests are also associated with inconsistency, lack of reproducibility and low external validity. Several attempts have been made to increase the generalizability of the outcomes by adding test settings that intend to mimic the clinical condition. Although pertinent, these settings may also add variabilities inherent to their concepts and practical applications in the laboratory environment. Although the actual studies should be seen as laboratory mechanical tests that measure very specific parameters under very particular conditions and that by far do not mimic the clinical condition, the lower validity drawback seems to be possible to be minimized when achieving a comprehensive understanding of the instrument behaviour. A Finite Elements Method and/or a multimethod research approach may lead to superior data collection, analysis, and results' interpretation, which when associated with a reliable confounding factors control and proper study designs may be helpful tools and strategies in order to increase the reliability of the outcomes.
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Pedullà E, La Rosa GRM, Romano G, Leanza G, Rapisarda S, Isola G, Ferlito S, Neelakantan P, Generali L. Influence of kinematics and incidence angles on the cutting efficiency of two single-file nickel-titanium rotary instruments. AUST ENDOD J 2022; 48:58-64. [PMID: 34258843 PMCID: PMC9290840 DOI: 10.1111/aej.12543] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 06/15/2021] [Accepted: 06/26/2021] [Indexed: 02/05/2023]
Abstract
To compare the cutting efficiency of F6 Sky Taper (F6ST) and One Curve (OC) with different kinematics and cutting inclinations. Cutting efficiency of 80 new F6ST and OC was tested at 90° and 70° inclination in relation to the sample, in continuous rotation and reciprocation, against standardised gypsum samples for 120 seconds using a customised device. Data expressed as weight loss and length of the sample cut were analysed using two-way analysis of variance and Tukey t-test (P<.05). F6ST showed significantly higher cutting efficiency in reciprocation, while OC in continuous rotation. Regardless of inclination, F6ST showed statistically higher values than OC in reciprocation, while OC exhibited higher cutting ability in continuous rotation. The 70° inclination significantly improved the cutting efficiency of both files. Reciprocation improved the cutting efficiency of F6ST while continuous rotation enhanced cutting ability of OC. An inclined insertion improved the cutting ability, independently from the movement.
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Affiliation(s)
- Eugenio Pedullà
- Department of General Surgery and Medical ‐ Surgical SpecialtiesUniversity of CataniaCataniaItaly
| | - Giusy Rita Maria La Rosa
- Department of General Surgery and Medical ‐ Surgical SpecialtiesUniversity of CataniaCataniaItaly
| | - Giuseppe Romano
- Department of General Surgery and Medical ‐ Surgical SpecialtiesUniversity of CataniaCataniaItaly
| | - Giuseppe Leanza
- Department of General Surgery and Medical ‐ Surgical SpecialtiesUniversity of CataniaCataniaItaly
| | - Silvia Rapisarda
- Department of General Surgery and Medical ‐ Surgical SpecialtiesUniversity of CataniaCataniaItaly
| | - Gaetano Isola
- Department of General Surgery and Medical ‐ Surgical SpecialtiesUniversity of CataniaCataniaItaly
| | - Sebastiano Ferlito
- Department of General Surgery and Medical ‐ Surgical SpecialtiesUniversity of CataniaCataniaItaly
| | - Prasanna Neelakantan
- Discipline of EndodontologyFaculty of DentistryThe University of Hong KongThe Prince Philip Dental HospitalHong Kong SARChina
| | - Luigi Generali
- Endodontic SectionDepartment of Surgery, MedicineDentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO)School of DentistryUniversity of Modena and Reggio EmiliaModenaItaly
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8
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Abstract
A very extensive literature review presents the possibilities and needs of using, in endodontics, the alloys commonly known as nitinol. Nitinol, as the most modern group of engineering materials used to develop root canals, is equilibrium nickel and titanium alloys in terms of the elements’ atomic concentration, or very similar. The main audience of this paper is engineers, tool designers and manufacturers, PhD students, and students of materials and manufacturing engineering but this article can also certainly be used by dentists. The paper aims to present a full material science characterization of the structure and properties of nitinol alloys and to discuss all structural phenomena that determine the performance properties of these alloys, including those applied to manufacture the endodontic tools. The paper presents the selection of these alloys’ chemical composition and processing conditions and their importance in the endodontic treatment of teeth. The results of laboratory studies on the analysis of changes during the sterilization of endodontic instruments made of nitinol alloys are also included. The summary of all the literature analyses is an SWOT analysis of strengths, weaknesses, opportunities, and threats, and is a forecast of the development strategy of this material in a specific application such as endodontics.
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Smutný M, Kopeček M, Bezrouk A. An Investigation of the Accuracy and Reproducibility of 3D Printed Transparent Endodontic Blocks. ACTA MEDICA (HRADEC KRALOVE, CZECH REPUBLIC) 2022; 65:59-65. [DOI: 10.14712/18059694.2022.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Due to a broad spectrum of endodontic rotary instruments on the market and no standardised protocol for comparing their mechanical properties, it can be challenging for clinician to choose proper instruments. In vitro studies using resin blocks with artificial canals can offer many valuable information because of their uniformity compared to studies performed on extracted teeth. To improve precision and reproducibility of artificial canals, 3D printing was used in this study to manufacture endodontic test block samples. 20 commercially available endodontic blocks Endo-Training-Bloc-J by Dentsply Sirona were tested. The mean values of the measured parameters were used for a 3D CAD model of their replicas. 20 copies of the endodontic training blocks were printed from acrylic resin (VeroClear-RGD810, Stratasys, Eden Prairie, USA) using the 3D printer Objet30 Pro (Stratasys, Eden Prairie, USA). The key dimensions of the commercial blocks and the 3D printed blocks were measured under and compared using t – test and Levene’s test for equality of variances. The profiles of the 3D printed artificial canals showed significantly lower dimensional variability when compared with the commercial blocks. 3D polyjet printing proved to be a precise and reproducible method for production of blocks for testing endodontic rotary instruments.
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10
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Schäfer E, Bürklein S, Donnermeyer D. A critical analysis of research methods and experimental models to study the physical properties of NiTi instruments and their fracture characteristics. Int Endod J 2021; 55 Suppl 1:72-94. [PMID: 34862796 DOI: 10.1111/iej.13673] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 12/03/2021] [Indexed: 11/27/2022]
Abstract
The aim of this review is to provide a critical overview of the physical properties (surface hardness, cutting efficiency, bending properties, flexibility and cyclic fatigue resistance) of NiTi instruments. Frequently used experimental models regarding these aspects will be presented and discussed with regard to their strengths and weaknesses. For all these aspects, a plethora of experimental models have been described. Based on a critical appraisal and especially taking the appropriate translation of experimental findings to clinical endodontics into account, suggestions for future research based on clearly defined and valid experimental methodologies will be provided. Up to now, very few attempts have been made to assess which particular physical properties of NiTi instruments exert an impact on the clinical outcome of root canal treatment. Departure from merely focusing on physical properties and fracture characteristics towards more biological aspects in terms of treatment outcome is essential.
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Affiliation(s)
- Edgar Schäfer
- Central Interdisciplinary Ambulance in the School of Dentistry, Münster, Germany
| | - Sebastian Bürklein
- Central Interdisciplinary Ambulance in the School of Dentistry, Münster, Germany
| | - David Donnermeyer
- Department of Periodontology and Operative Dentistry, Westphalian Wilhelms-University, Münster, Germany
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Qualitative Assessment of the Surface Topographic Changes of XP-endo Shaper and TruNatomy files after exposure to Sodium Hypochlorite and Ethylenediaminetetraacetic Acid. Eur Endod J 2021; 6:197-204. [PMID: 34650015 PMCID: PMC8461496 DOI: 10.14744/eej.2021.10437] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVE TruNatomy and XP-endo Shaper are recently introduced file systems showing increased fatigue resistance rate. The present study aims to evaluate the surface topographic changes and nickel (Ni) and titanium (Ti) elemental loss of XP-endo Shaper (XPS) and TruNatomy (TN) files on exposure to conventionally used root canal irrigants; [5.25% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA)] at a 10 minute time frame using atomic force microscopy (AFM) and energy dispersion X-ray spectroscopy (EDX) analytical techniques. METHODS Twelve samples for each of XPS (30/.04 taper) and TN (26/.04 taper; prime) instruments were dynamically exposed to 5.25% NaOCl, 17% EDTA separately for 10 minutes and in combination of 5.25% NaOCl (8 minutes)+17% EDTA (2 minutes) for a total of 10 minutes. Post exposure, the files were subjugated to AFM and EDX analysis. Independent t test and one-way ANOVA were used for statistical analysis, and the level of significance was set at 0.05. RESULTS XPS and TN showed a significant increase of surface roughness (Ra) and roughness mean square (RMS) on exposure to various irrigants (P<0.05) using AFM analysis. Increased overall roughness was observed with TN in comparison to XPS (P<0.05). Elements Ni and Ti loss was found in both XPS and TN files using EDX analysis. Both files exhibited Ni and Ti loss with the loss of Ni content higher for TN after exposure to 17% EDTA. Loss of Ti was seen for both files on exposure to a combination of 5.25% NaOCl+17% EDTA. CONCLUSION After exposure to root canal irrigants, the surface roughness was lesser in XPS compared to TN files. 17% EDTA caused significantly higher surface roughness in both file systems when compared to 5.25% NaOCl. TN exhibited overall higher elemental (Ni and Ti) loss on exposure to 17% EDTA and 5.25% NaOCl+17% EDTA in comparison to XPS files.
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12
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Current technology in endodontic instrumentation: advances in metallurgy and manufacture. Br Dent J 2021; 231:49-57. [PMID: 34244648 DOI: 10.1038/s41415-021-3170-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 10/14/2020] [Indexed: 11/08/2022]
Abstract
Since the introduction of nickel-titanium endodontic instruments, there have been a myriad of developments which can be confusing and sometimes contradictory. This article seeks to review and articulate these advances, and allow the reader to better understand the benefits and the limitations of the systems available. Ultimately, this helps clinicians to engage more confidently with trade and have a more informed choice of the most appropriate file to use for each individual endodontic case. All this should facilitate more predictable endodontic outcomes.
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13
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Nino-Barrera J, Sanchez-Aleman J, Acosta-Humanez M, Gamboa-Martinez L, Cortes-Rodriguez C. Shot peening increases resistance to cyclic fatigue fracture of endodontic files. Sci Rep 2021; 11:12961. [PMID: 34155287 PMCID: PMC8217493 DOI: 10.1038/s41598-021-92382-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 06/09/2021] [Indexed: 11/09/2022] Open
Abstract
The objective of this study was to assess the resistance to fatigue fracture of conventional nickel–titanium files after undergoing shot peening. Forty NITIFLEX endodontic files, number 30, were divided into two groups; one was submitted to shot peening treatment and the other was not. All instruments were tested for fatigue fracture in simulated canals with a TRI-AUTO ZX endodontic motor. One file of each group was subjected to a residual stress analysis by XRD. Finally, the fractured surface was observed and elemental analysis performed by means of SEM and EDX. Roughness analysis was made by focal variation microscope. The shot peening group showed greater resistance to fatigue fracture; there was no difference in the length of the fractured fragments. XRD results showed the presence of residual compression stresses in the file submitted to shot peening, a decrease in the interplanar spacing, and an increase in the full-width-at-half-maximum and the microstrains. SEM and EDX showed a ductile fracture with zones of fatigue and an equiatomic ratio between the nickel and titanium. Surface roughness increased after the file was subjected to the shot peening procedure. In conclusion, shot peening increases the resistance to fatigue fracture due to the presence of residual compression stresses in files manufactured from a conventional nickel–titanium alloy.
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Affiliation(s)
- Javier Nino-Barrera
- Faculty of Dentistry, Endodontics Program, Universidad Nacional de Colombia, Building 210, Office 301, Bogotá, Colombia.
| | - Jose Sanchez-Aleman
- Faculty of Dentistry, Endodontics Program, Universidad Nacional de Colombia, Building 210, Office 301, Bogotá, Colombia
| | | | - Luis Gamboa-Martinez
- School of Dentistry, Endodontics Program, Universidad El Bosque, Bogotá, Colombia
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14
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Pedullà E, La Paglia P, La Rosa GRM, Gueli AM, Pasquale S, Jaramillo DE, Forner L, Lo Savio F, La Rosa G, Rapisarda E. Cutting efficiency of heat-treated nickel-titanium single-file systems at different incidence angles. AUST ENDOD J 2020; 47:20-26. [PMID: 33169440 DOI: 10.1111/aej.12462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 08/08/2020] [Accepted: 10/21/2020] [Indexed: 11/28/2022]
Abstract
Cutting efficiency of Reciproc R25 (REC) and Reciproc blue R25 (REB) at different inclinations was evaluated. Sixty new files were tested at 90°, 70° and 45° of inclination in relation to the sample (n = 10), using a customised machine. All files were activated in reciprocation against standardised gypsum blocks for 120 s. Cutting efficiency was determined by measuring the block weight loss with an analytical balance and measuring the length of the block surface cut using a digital calliper. Data were statistically analysed (two-way ANOVA, Bonferroni t-test) with the significance level set at P < 0.05. There was no difference for REC among the tested angles. REB had no statistical difference between 90° and 70°; however, its cutting efficiency significantly increased at 45°. There was a significant difference between REC and REB at 45° only. Under these conditions, increased file inclination to 45° and blue heat treatment improved cutting efficiency of reciprocating files.
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Affiliation(s)
- Eugenio Pedullà
- Department of General Surgery and Medical - Surgical Specialties, University of Catania, Catania, Italy
| | - Pietro La Paglia
- Department of General Surgery and Medical - Surgical Specialties, University of Catania, Catania, Italy
| | - Giusy Rita Maria La Rosa
- Department of General Surgery and Medical - Surgical Specialties, University of Catania, Catania, Italy
| | - Anna Maria Gueli
- Department of Physics and Astronomy, PH3DRA (Physics for Dating Diagnostics Dosimetry Research and Applications) Laboratories, University of Catania & INFN, Catania, Italy
| | - Stefania Pasquale
- Department of Physics and Astronomy, PH3DRA (Physics for Dating Diagnostics Dosimetry Research and Applications) Laboratories, University of Catania & INFN, Catania, Italy
| | - David E Jaramillo
- Department of Endodontics, School of Dentistry, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Leopoldo Forner
- Department of Stomatology, University of Valencia, Valencia, Spain
| | - Fabio Lo Savio
- Department of Industrial Engineering, University of Catania, Catania, Italy
| | - Guido La Rosa
- Department of Industrial Engineering, University of Catania, Catania, Italy
| | - Ernesto Rapisarda
- Department of General Surgery and Medical - Surgical Specialties, University of Catania, Catania, Italy
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15
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Keskin C, Sivas Yilmaz Ö, Keleş A, Inan U. Comparison of cyclic fatigue resistance of Rotate instrument with reciprocating and continuous rotary nickel-titanium instruments at body temperature in relation to their transformation temperatures. Clin Oral Investig 2020; 25:151-157. [PMID: 32542583 DOI: 10.1007/s00784-020-03346-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 05/15/2020] [Indexed: 01/25/2023]
Abstract
OBJECTIVE The aim of this study was to compare the cyclic fatigue resistance at body temperature and phase transformation behaviors of novel Rotate instrument (25.06) with rotating Mtwo (25.06) and reciprocating Reciproc Blue (25.08) and Reciproc (25.08) instruments. MATERIALS AND METHODS The Rotate, Reciproc Blue, Reciproc, and Mtwo instruments free of visible deformations were collected and tested in a static cyclic fatigue test method, which has a ceramic block containing an artificial canal with 60° angle of curvature and a 5-mm radius of curvature at 37 °C (n = 16). All instruments were operated until fracture occurred, and both time to fracture (TF) and the lengths of the fractured fragments were recorded. TF data was analyzed with one-way ANOVA followed by post hoc Tukey tests and Weibull analysis, and fractured fragment length data were subjected to one-way ANOVA and post hoc Tukey tests (P < 0.05). Two unused instruments from each brand were also subjected to differential scanning calorimetry (DSC) analysis to determine their phase transformation temperatures. RESULTS The Reciproc Blue instruments showed significantly higher TF values and reliability than the other groups (P < 0.05). Rotate instruments exhibited greater cyclic fatigue resistance than the Reciproc and Mtwo instruments (P < 0.05). No significant difference was detected among the fractured fragment lengths (P > 0.05). The lowest austenite finish temperature was exhibited by the Mtwo, which presented a single transformation peak, followed by the Rotate, Reciproc Blue, and Reciproc instruments which all presented two peaks during transformation. CONCLUSIONS Cyclic fatigue resistance of instruments manufactured from thermally treated Blue wire instruments was superior to those of the Mtwo and Reciproc, whereas reciprocating the Blue wire showed the highest resistance. CLINICAL RELEVANCE The present study compared the cyclic fatigue resistance of the novel Rotate instrument with similar instruments manufactured from conventional nickel-titanium, m-wire, and Blue wire at body temperature and reported that Blue-treated instruments exhibited superior cyclic fatigue resistance.
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Affiliation(s)
- Cangül Keskin
- Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, 55400, Samsun, Turkey.
| | - Özlem Sivas Yilmaz
- Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, 55400, Samsun, Turkey
| | - Ali Keleş
- Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, 55400, Samsun, Turkey
| | - Uğur Inan
- Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, 55400, Samsun, Turkey
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16
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Ramyadharshini T, Anand Sherwood I, Vigneshwar VS, Ernest Prince P, Vaanjay M. Influence of glide path size and operating kinetics on time to reach working length and fracture resistance of Twisted File adaptive and Endostar E3 nickel-titanium file systems. Restor Dent Endod 2020; 45:e22. [PMID: 32483539 PMCID: PMC7239674 DOI: 10.5395/rde.2020.45.e22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/25/2019] [Accepted: 11/21/2019] [Indexed: 11/11/2022] Open
Abstract
Objectives This study investigated the influence of glide path size and operating kinetics on the time to reach the working length and the fracture resistance of Twisted File (TF) and Endostar E3 files. Materials and Methods A total of 120 mandibular single-rooted premolars were selected. Two methods of kinetic motion (TF adaptive and continuous rotary motion) and file systems (TF and Endostar E3) were employed. The files were used in root canals prepared to apical glide path sizes of 15, 20, and 25. The time taken to reach the working length and the number of canals used before the instrument deformed or fractured were noted. Fractured instruments were examined with scanning electron microscopy. Results The TF system took significantly more time to reach the working length than the Endostar E3 system. Both systems required significantly more time to reach the working length at the size 15 glide path than at sizes 20 and 25. A greater number of TFs than Endostar E3 files exhibited deformation, and a higher incidence of instrument deformation was observed in adaptive than in continuous rotary motion; more deformation was also observed with the size 15 glide path. One TF was fractured while undergoing adaptive motion. Conclusions No significant difference was observed between continuous rotary and adaptive motion. The TF system and adaptive motion were associated with a higher incidence of deformation and fracture. Apical glide path sizes of 20 and 25 required significantly less time to reach the working length than size 15.
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Affiliation(s)
| | - Inbaraj Anand Sherwood
- Department of Conservative Dentistry and Endodontics, CSI College of Dental Sciences, Madurai, TN, India
| | - V Shanmugham Vigneshwar
- Department of Conservative Dentistry and Endodontics, CSI College of Dental Sciences, Madurai, TN, India
| | - Prakasam Ernest Prince
- Department of Conservative Dentistry and Endodontics, CSI College of Dental Sciences, Madurai, TN, India
| | - Murugadoss Vaanjay
- Department of Conservative Dentistry and Endodontics, CSI College of Dental Sciences, Madurai, TN, India
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17
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Pedullà E, Leanza G, La Rosa GRM, Gueli AM, Pasquale S, Plotino G, Rapisarda E. Cutting efficiency of conventional and heat‐treated nickel–titanium rotary or reciprocating glide path instruments. Int Endod J 2019; 53:376-384. [DOI: 10.1111/iej.13224] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Accepted: 09/25/2019] [Indexed: 11/29/2022]
Affiliation(s)
- E. Pedullà
- Department of General Surgery and Medical Surgical Specialties University of Catania Catania Italy
| | - G. Leanza
- Department of General Surgery and Medical Surgical Specialties University of Catania Catania Italy
| | - G. R. M. La Rosa
- Department of General Surgery and Medical Surgical Specialties University of Catania Catania Italy
| | - A. M. Gueli
- PH3DRA (Physics for Dating Diagnostics Dosimetry Research and Applications) Laboratories Department of Physic and Astronomy INFN University of Catania Catania Italy
| | - S. Pasquale
- PH3DRA (Physics for Dating Diagnostics Dosimetry Research and Applications) Laboratories Department of Physic and Astronomy INFN University of Catania Catania Italy
| | | | - E. Rapisarda
- Department of General Surgery and Medical Surgical Specialties University of Catania Catania Italy
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18
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Keskin NB, Inan U. Cyclic fatigue resistance of rotary NiTi instruments produced with four different manufacturing methods. Microsc Res Tech 2019; 82:1642-1648. [PMID: 31254483 DOI: 10.1002/jemt.23330] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/20/2019] [Accepted: 06/13/2019] [Indexed: 11/09/2022]
Abstract
The aim of this study was to compare the cyclic fatigue resistance of rotary NiTi files, produced with four different manufacturing methods on specially designed dynamic models that simulated clinical conditions. In this study, 120 files, consisting of 30 files for Typhoon, ProTaper Next, RaCe, and Twisted Files nickel titanium rotary systems were used. The 30 files of each group were divided into three subgroups to be used in artificial canals with a 60° angle of curvature and radii of curvature of 2, 5, and 8 mm (n = 10). All files were rotated in the artificial canals until fracture occurred and the number of cycles to fracture was calculated. The data were analyzed using one- and two-way analyses of variance and Tamhane multiple comparison tests. In all three groups, Typhoon instruments had the highest number of cycles to failure than the RaCe, ProTaper Next, and Twisted Files instruments, and the difference statistically significant (p < .05). There were no significant differences between the RaCe, ProTaper Next, and Twisted Files groups (p > .05). The CM wire Typhoon system was significantly more resistant to cyclic fatigue compared to the other file systems in all three artificial canals. When the fracture resistance of an instrument in three different artificial canals was compared, the mean NCFs decreased as the radius of the curvature of the canal decreased from 8 to 2 mm. Manufacturing method is one of the most important factors on cyclic fatigue resistance, also the radius of curvature effects the cyclic fatigue.
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Affiliation(s)
- Neslihan B Keskin
- Department of Endodontics, Faculty of Dentistry, Yıldırım Beyazıt University, Ankara, Turkey
| | - Uğur Inan
- Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey
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19
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Alqedairi A, Alfawaz H, Abualjadayel B, Alanazi M, Alkhalifah A, Jamleh A. Torsional resistance of three ProTaper rotary systems. BMC Oral Health 2019; 19:124. [PMID: 31226984 PMCID: PMC6588856 DOI: 10.1186/s12903-019-0820-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 06/12/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of this study is to compare the torsional resistance of the available ProTaper rotary systems, namely, ProTaper Universal (PTU), ProTaper Next (PTN), and ProTaper Gold (PTG). METHODS A total of 195 files from the three systems distributed into 13 groups (PTU-S1, PTU-S2, PTU-F1, PTU-F2, PTU-F3, PTG-S1, PTG-S2, PTG-F1, PTG-F2, PTG-F3, PTN-X1, PTN-X2 and PTN-X3) were subjected to torsional fatigue until failure. The torsional test was performed according to ISO 3630-1, where each file was placed in a straight position to eliminate the influence of cyclic fatigue. The Kruskal-Wallis test was conducted to compare the mean maximum torques and angular deflections at fracture for the groups, and the Mann-Whitney test was performed for pairwise comparisons. The significance level was set at 0.05 and the fractured surfaces were examined under a scanning electron microscope. RESULT Among the tested files, PTG-S1 had the lowest torsional fatigue resistance, whereas PTU-F2 and PTU-F3 had the highest torsional resistance. The scanning electron microscope showed typical features of torsional failure. CONCLUSION The new ProTaper systems (PTG and PTN) did not show improved torsional resistance in comparison with PTU.
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Affiliation(s)
- Abdullah Alqedairi
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Hussam Alfawaz
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Bader Abualjadayel
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Mohammad Alanazi
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Ahmad Alkhalifah
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Ahmed Jamleh
- King Abdullah International Medical Research Centre, Restorative and Prosthetic Dental Sciences, College of Dentistry, Ministry of National Guard Health Affairs, King Saud bin Abdulaziz University for Health Sciences, P.O. Box 22490, Riyadh, 11426, Saudi Arabia.
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20
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Zupanc J, Vahdat-Pajouh N, Schäfer E. New thermomechanically treated NiTi alloys - a review. Int Endod J 2018; 51:1088-1103. [DOI: 10.1111/iej.12924] [Citation(s) in RCA: 166] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 03/16/2018] [Indexed: 11/29/2022]
Affiliation(s)
- J. Zupanc
- Department of Periodontology and Operative Dentistry; Westphalian Wilhelms-University; Münster Germany
| | - N. Vahdat-Pajouh
- Department of Periodontology and Operative Dentistry; Westphalian Wilhelms-University; Münster Germany
| | - E. Schäfer
- Central Interdisciplinary Ambulance in the School of Dentistry; Münster Germany
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21
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Cyclic fatigue resistance of R-Pilot, WaveOne Gold Glider, and ProGlider glide path instruments. Clin Oral Investig 2018; 22:3007-3012. [DOI: 10.1007/s00784-018-2391-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 02/09/2018] [Indexed: 11/26/2022]
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22
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Ounsi HF, Nassif W, Grandini S, Salameh Z, Neelakantan P, Anil S. Evolution of Nickel-titanium Alloys in Endodontics. J Contemp Dent Pract 2017; 18:1090-1096. [PMID: 29109327 DOI: 10.5005/jp-journals-10024-2181] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
UNLABELLED To improve clinical use of nickel-titanium (NiTi) endodontic rotary instruments by better understanding the alloys that compose them. A large number of engine-driven NiTi shaping instruments already exists on the market and newer generations are being introduced regularly. While emphasis is being put on design and technique, manufacturers are more discreet about alloy characteristics that dictate instrument behavior. Along with design and technique, alloy characteristics of endodontic instruments is one of the main variables affecting clinical performance. Modification in NiTi alloys is numerous and may yield improvements, but also drawbacks. Martensitic instruments seem to display better cyclic fatigue properties at the expense of surface hardness, prompting the need for surface treatments. On the contrary, such surface treatments may improve cutting efficiency but are detrimental to the gain in cyclic fatigue resistance. Although the design of the instrument is vital, it should in no way cloud the importance of the properties of the alloy and how they influence the clinical behavior of NiTi instruments. CLINICAL SIGNIFICANCE Dentists are mostly clinicians rather than engineers. With the advances in instrumentation design and alloys, they have an obligation to deal more intimately with engineering consideration to not only take advantage of their possibilities but also acknowledge their limitations.
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Affiliation(s)
- Hani F Ounsi
- Department of Endodontics, Faculty of Dental Medicine Lebanese University, Beirut, Lebanon; Department of Endodontics and Restorative Dentistry, Siena University, Siena, Italy, e-mail:
| | - Wadih Nassif
- Department of Prosthodontics, Faculty of Dental Medicine Lebanese University, Beirut, Lebanon
| | - Simone Grandini
- Department of Endodontics and Restorative Dentistry, Siena University, Siena, Italy
| | - Ziad Salameh
- Department of Research, Faculty of Dental Medicine, Lebanese University, Beirut, Lebanon
| | - Prasanna Neelakantan
- Department of Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong
| | - Sukumaran Anil
- Department of Dental Health, Dental Biomaterials Research Chair, College of Applied Medical Sciences, King Saud University Riyadh, Kingdom of Saudi Arabia
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23
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Alfouzan K, Jamleh A. Fracture of nickel titanium rotary instrument during root canal treatment and re-treatment: a 5-year retrospective study. Int Endod J 2017; 51:157-163. [PMID: 28796346 DOI: 10.1111/iej.12826] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 08/06/2017] [Indexed: 11/27/2022]
Abstract
AIM To evaluate retrospectively the incidence of K3 nickel titanium rotary instrument fracture in referred cases during root canal treatment and re-treatment. METHODOLOGY Clinical and radiographic reports of 12 867 endodontic cases treated at the King Abdulaziz medical city between January 2010 and November 2015 were reviewed to obtain information on intracanal fractured instruments with respect to the treatment performed, tooth type and the size and at what level the instrument fractured (coronal, middle or apical). The degree of canal curvature was classified into mild (<10° ), moderate (10-25° ) or severe (>25° ). Logistic regression was used to test the incidence of instrument fracture in relation to the root canal treatment performed and tooth type. Chi-square tests were used to analyse the fracture incidence in the treated teeth in respect to fracture level and fractured file diameter. The level of significance was set at 0.05. RESULTS Root canal treatment was performed on 8946 cases, whilst re-treatment was performed on 3921 cases. The fracture incidence was higher during re-treatment cases (2.96%) than in primary root canal treatment (0.74%) (P < 0.001) with a 1.41% incidence overall. There was a trend for more fractures in maxillary (1.68%) and mandibular (1.35%) molar teeth. Moreover, 56.6% of the fractured instruments occurred in severely curved canals, and the apical third of the root canal was the most common site for instrument fracture (85.7%), followed by middle (13.2%), and coronal (1.1%) thirds, mostly with file sizes 20 and 25 (59.9% and 25.27%, respectively). CONCLUSION The fracture incidence of K3 instruments was significantly greater during root canal re-treatment than root canal treatment, mainly with small instruments and in the apical third of the canals.
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Affiliation(s)
- K Alfouzan
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Restorative and Prosthetic Dental Sciences, College of Dentistry, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - A Jamleh
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Restorative and Prosthetic Dental Sciences, College of Dentistry, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
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24
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Vasconcelos RA, Arias A, Peters OA. Lateral and axial cutting efficiency of instruments manufactured with conventional nickel-titanium and novel gold metallurgy. Int Endod J 2017; 51:577-583. [DOI: 10.1111/iej.12822] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 07/20/2017] [Indexed: 11/30/2022]
Affiliation(s)
- R. A. Vasconcelos
- Department of Endodontics; Arthur A Dugoni School of Dentistry; University of the Pacific; San Francisco CA USA
- Department of Restorative Dentistry; Sao Jose dos Campos School of Dentistry; Institute of Science and Technology Sao Jose dos Campos ICT/UNESP; Sao Jose dos Campos SP Brazil
| | - A. Arias
- Department of Endodontics; Arthur A Dugoni School of Dentistry; University of the Pacific; San Francisco CA USA
- Department of Conservative Dentistry; School of Dentistry; Complutense University; Madrid Spain
| | - O. A. Peters
- Department of Endodontics; Arthur A Dugoni School of Dentistry; University of the Pacific; San Francisco CA USA
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25
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Cyclic Fatigue Resistance of Reciproc Blue, Reciproc, and WaveOne Gold Reciprocating Instruments. J Endod 2017; 43:1360-1363. [DOI: 10.1016/j.joen.2017.03.036] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 03/19/2017] [Accepted: 03/23/2017] [Indexed: 11/21/2022]
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26
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Keskin C, Inan U, Demiral M. Effect of interrupted motion on the cyclic fatigue resistance of reciprocating nickel-titanium instruments. Int Endod J 2017; 51:549-555. [DOI: 10.1111/iej.12790] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/27/2017] [Indexed: 11/28/2022]
Affiliation(s)
- C. Keskin
- Department of Endodontics; Faculty of Dentistry; Ondokuz Mayıs University; Samsun, Istanbul Turkey
| | - U. Inan
- Department of Endodontics; Faculty of Dentistry; Ondokuz Mayıs University; Samsun, Istanbul Turkey
| | - M. Demiral
- Cekmekoy Oral and Dental Health Center; Istanbul Turkey
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27
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The Effect of Hydrofluoric Acid Surface Treatment on the Cyclic Fatigue Resistance of K3 NiTi Instruments. Bioinorg Chem Appl 2017; 2017:3189729. [PMID: 28539854 PMCID: PMC5433420 DOI: 10.1155/2017/3189729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 03/19/2017] [Accepted: 04/11/2017] [Indexed: 11/26/2022] Open
Abstract
The aim of this study was to investigate the effect of 50% hydrofluoric acid (HF) surface treatment on the cyclic fatigue resistance (CFR) of K3 NiTi instruments. Twenty as-received and twenty HF-treated K3 NiTi instruments were compared in CFR. The surface texture and fracture surface of two instrument groups were examined with a scanning electron microscope (SEM). Additionally, any change of Ni and Ti composition from both instrument groups was investigated using energy dispersive spectrometry. The results were analyzed with t-test. The HF-treated K3 group showed statistically higher cyclic fatigue resistance than as-received K3 group (P < 0.05). HF-treated K3 instruments showed smoother and rounded surface compared to as-received K3 under SEM observation. The fracture surfaces of both groups showed typical patterns of cyclic fatigue fracture. There was no difference in surface Ni and Ti composition between two groups. HF treatment of K3 instruments smoothed the file surface and increased the cyclic fatigue resistance, while it had no effect on surface ion composition and the file fracture pattern.
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28
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Pedullà E, Corsentino G, Ambu E, Rovai F, Campedelli F, Rapisarda S, La Rosa GR, Rapisarda E, Grandini S. Influence of continuous rotation or reciprocation of Optimum Torque Reverse motion on cyclic fatigue resistance of nickel-titanium rotary instruments. Int Endod J 2017; 51:522-528. [DOI: 10.1111/iej.12769] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 03/18/2017] [Indexed: 11/30/2022]
Affiliation(s)
- E. Pedullà
- Department of General Surgery and Surgical - Medical Specialties; University of Catania; Catania Italy
| | - G. Corsentino
- Department of Endodontics and Restorative Dentistry; University of Siena; Siena Italy
| | - E. Ambu
- Department of Endodontics and Restorative Dentistry; University of Siena; Siena Italy
| | - F. Rovai
- Private Practition; Perugia Italy
| | - F. Campedelli
- Department of Endodontics and Restorative Dentistry; University of Siena; Siena Italy
| | - S. Rapisarda
- Department of General Surgery and Surgical - Medical Specialties; University of Catania; Catania Italy
| | - G. R. La Rosa
- Department of General Surgery and Surgical - Medical Specialties; University of Catania; Catania Italy
| | - E. Rapisarda
- Department of General Surgery and Surgical - Medical Specialties; University of Catania; Catania Italy
| | - S. Grandini
- Department of Endodontics and Restorative Dentistry; University of Siena; Siena Italy
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29
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Chi CW, Lai EHH, Liu CY, Lin CP, Shin CS. Influence of heat treatment on cyclic fatigue and cutting efficiency of ProTaper Universal F2 instruments. J Dent Sci 2017; 12:21-26. [PMID: 30895019 PMCID: PMC6395258 DOI: 10.1016/j.jds.2016.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 06/06/2016] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND/PURPOSE Heat pretreatment can improve the cyclic fatigue life of nickel-titanium (NiTi) instruments. This study evaluated the effects of two different heat treatments on the cyclic fatigue resistance and cutting efficiency of ProTaper Universal F2 files. MATERIALS AND METHODS The files were divided into three groups: no treatment (control), heat treatment at 400°C (HT400) and heat treatment at 600°C (HT600). The phase transformation of the files was evaluated by differential scanning calorimetry. In cyclic fatigue tests, the differences in file performance in four simulated canals among the three groups were assessed. The cutting efficiency was tested at four cutting portions (3 mm, 6 mm, 9 mm, and 12 mm) from the tip of the file. RESULTS Differential scanning calorimetry showed a prolonged phase transformation of the files only after 600°C treatment. At 3 mm cutting portion, 400°C heat-treated files had significantly better cutting ability than those in the control group. However, the files in the HT600 group had significantly lower cutting efficiency than those in the other two groups at the four tested positions. In the cyclic fatigue test, fatigue lives of the files after 400°C and 600°C treatment were prolonged from 2.1 to 2.8 times and from 1.7 to 5.5 times, respectively. CONCLUSION Although 600°C treatment increased resistance to cyclic fatigue, it reduced the cutting efficiency of the files. The 400°C treatment maintained the cutting ability and prolonged the cyclic fatigue life of the files. Therefore, for clinical use of ProTaper Universal F2 files, 400°C pretreatment is a better choice than 600°C pretreatment.
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Affiliation(s)
- Chih-Wen Chi
- Graduate Institute of Clinical Dentistry, School of Dentistry and National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Eddie Hsiang-Hua Lai
- Graduate Institute of Clinical Dentistry, School of Dentistry and National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chao-Yuan Liu
- Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan
| | - Chun-Pin Lin
- Graduate Institute of Clinical Dentistry, School of Dentistry and National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.,School of Dentistry, China Medical University and China Medical University Hospital, Taichung, Taiwan
| | - Chow-Shing Shin
- Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan
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30
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Chang SW, Shim KS, Kim YC, Jee KK, Zhu Q, Perinpanayagam H, Kum KY. Cyclic fatigue resistance, torsional resistance, and metallurgical characteristics of V taper 2 and V taper 2H rotary NiTi files. SCANNING 2016; 38:564-570. [PMID: 26792574 DOI: 10.1002/sca.21301] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Revised: 12/31/2015] [Accepted: 01/07/2016] [Indexed: 06/05/2023]
Abstract
The aim of this study was to compare the cyclic fatigue resistance, torsional resistance, and metallurgical characteristics of conventional NiTi wire (V taper 2, V2) and CM wire (V taper 2H, V2H)-based files. Cyclic fatigue and torsional resistance of V2 and V2H were investigated by measuring the number of cycles to fracture, maximum torque at fracture, and maximum angle at fracture. The typical patterns of fatigue and torsional fractures were investigated using a scanning electron microscope (SEM). The metallurgical characteristics were investigated by differential scanning calorimetry (DSC) from -100 °C to 100 °C. The austenite finishing temperature (Af) of each instrument was also measured. The microstructures of the instruments were investigated by a transmission electron microscope (TEM) along with selected area diffraction pattern analysis. The results were statistically analyzed by Mann-Whitney U-test (p = 0.05). V2H showed significantly higher cyclic fatigue resistance and torsional resistance than V2. SEM images of the fractured surfaces showed typical patterns of fatigue and torsional fracture. The DSC analysis of V2 showed one small peak in both the heating and cooling curves. The Af of V2 was -0.32 °C. V2H showed two remarkable peaks in the heating curve and one remarkable peak in the cooling curve. The Af of V2H was 33.25 °C. The TEM analysis showed that both V2 and V2H are mainly composed of austenite. In conclusion, V2H showed higher cyclic fatigue resistance and torsional resistance than V2. The superior properties of V2H could be attributed to the annealing effect and possibly the martensite phase. SCANNING 38:564-570, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- S W Chang
- Department of Conservative Dentistry, School of Dentistry, Kyung Hee University, Seoul, Korea
| | - K S Shim
- Department of Conservative Dentistry, School of Dentistry, Kyung Hee University, Seoul, Korea
| | - Y C Kim
- Biomedical Research Institute, Korea Institute of Science and Technology, Seoul, Korea
| | - K K Jee
- Future Convergence Research Division, Korea Institute of Science and Technology, Seoul, Korea
| | - Q Zhu
- Division of Endodontology, Department of Oral Health and Diagnostic Sciences, School of Dental Medicine, University of Connecticut Health Center, Farmington, Connecticut
| | - H Perinpanayagam
- Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - K Y Kum
- Department of Conservative Dentistry, Dental Research Institute and BK21 Program, Seoul National University Dental Hospital, Seoul National, University School of Dentistry, Seoul, Korea
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Wang Z, Zhang W, Zhang X. Cyclic Fatigue Resistance and Force Generated by OneShape Instruments during Curved Canal Preparation. PLoS One 2016; 11:e0160815. [PMID: 27513666 PMCID: PMC4981425 DOI: 10.1371/journal.pone.0160815] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 06/22/2016] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES To evaluate the cyclic fatigue resistance and the force generated by OneShape files during preparation of simulated curved canals. METHODS Six OneShape files (the test) and six ProTaper F2 files (the control) were subject to the bending ability test. Another thirty files of each type were used to prepare artificial canals (n = 60), which were divided into 3 groups according to respective curvatures of the canals (30°, 60°, and 90°). The numbers of cycles to fatigue (NCF) as well as the positive and negative forces that were generated by files during canal preparation were recorded. The scanning electron microscopy was applied to detect the fracture surfaces. RESULTS Compared with ProTaper F2 files, the bending loads of OneShape files were significantly lower at deflections of 45°(P < .05), 60° (P < .05) and 75° (P < .01). No significant difference was found at 30°. OneShape files presented a higher NCF in both 60° and 90° canals than the control (P < .01). No significant difference of NCF was found between OneShape and ProTaper files in 30° canals. During the preparation of 30° canals by both files, the negative forces were dominant. With the increase of the curvature, more positive forces were observed. When the OneShape Files were compared with the control, significant different forces were found at D3 and D2 (P < .05) in 30° canals, at D2 (P < .05), D1 (P < .01) and D0 (P < .01) in 60° canals, and at D4 and D3 (P < .01) in 90° canals. CONCLUSIONS OneShape files possessed a reliable flexibility and cyclic fatigue resistance. According to the assessments of the forces generated by files, OneShape instruments performed in a more fatigue-resistant way during curved canal preparation, compared with the ProTaper F2 files.
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Affiliation(s)
- Zhuyu Wang
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
- Department of Periodontology and Endodontology, Graduate School of Dentistry, Tohoku University, Sendai, Japan
| | - Wen Zhang
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Xiaolei Zhang
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
- * E-mail:
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Lopes HP, Elias CN, Vieira MVB, Vieira VTL, de Souza LC, Dos Santos AL. Influence of Surface Roughness on the Fatigue Life of Nickel-Titanium Rotary Endodontic Instruments. J Endod 2016; 42:965-8. [PMID: 27080117 DOI: 10.1016/j.joen.2016.03.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 03/01/2016] [Accepted: 03/04/2016] [Indexed: 11/19/2022]
Abstract
INTRODUCTION The goal of the present study was to evaluate the influence of surface grooves (peaks and valleys) resulting from machining during the manufacturing process of polished and unpolished nickel-titanium BR4C endodontic files on the fatigue life of the instruments. METHODS Ten electropolished and 10 unpolished endodontic files were provided by the manufacturer. Specimens were from the same batch, but the unpolished instruments were removed from the production line before surface treatment. The instruments were evaluated with a profilometer to quantify the surface roughness on the working part of the instruments. Then the files were subjected to rotating bending fatigue tests. RESULTS Analysis with the profilometer showed that surface grooves were deeper on the unpolished instruments compared with their electropolished counterparts. In the rotating bending fatigue test, the mean and standard deviation for the number of cycles until fracture (NCF) were greater for instruments with less pronounced grooves. Student t test revealed significant differences in all tests (P < .05). CONCLUSIONS The results from the present study showed that the depth of the surface grooves on the working part affected the NCF of the instruments tested; the smaller the groove depth, the greater the NCF.
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Affiliation(s)
- Hélio P Lopes
- Department of Endodontics, School of Dentistry, Estácio de Sá University, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carlos N Elias
- Materials Science Department, Instituto Militar de Engenharia, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Márcia V B Vieira
- Advanced Education Program in Endodontics, Funorte, Governador Valadares, Minas Gerais, Brazil.
| | - Victor T L Vieira
- Department of Endodontics, Grande Rio University, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Letícia Chaves de Souza
- Materials Science Department, Instituto Militar de Engenharia, Rio de Janeiro, Rio de Janeiro, Brazil
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Constant Insertion Rate Methodology for Measuring Torque and Apical Force in 3 Nickel-Titanium Instruments with Different Cross-sectional Designs. J Endod 2015. [DOI: 10.1016/j.joen.2015.05.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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ELSAKA SE, ELNAGHY AM. Cyclic fatigue resistance of OneShape and WaveOne instruments using different angles of curvature. Dent Mater J 2015; 34:358-63. [DOI: 10.4012/dmj.2014-252] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Shaymaa E. ELSAKA
- Department of Dental Biomaterials, Faculty of Dentistry, Mansoura University
- Department of Restorative Dental Sciences, Al-Farabi College of Dentistry and Nursing
| | - Amr M. ELNAGHY
- Department of Conservative Dentistry and Endodontics, Faculty of Dentistry, Mansoura University
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Kim BH, Ha JH, Lee WC, Kwak SW, Kim HC. Effect from surface treatment of nickel-titanium rotary files on the fracture resistance. SCANNING 2015; 37:82-87. [PMID: 25488324 DOI: 10.1002/sca.21182] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 10/31/2014] [Indexed: 06/04/2023]
Abstract
This study was aimed to compare the cyclic fatigue resistance and torsional resistance of rotary instruments with and without surface treatment. G6 A2 (Group A2) with and G6 A2 without surface treatment after machining (Group AN) were compared in this study. ProTaper F2 (Group F2) which has similar dimension and shape was also used for comparison. To evaluate the torsional resistance, ultimate torsional strength and distortion angle until fracture were recorded, and the toughness was calculated. The cyclic fatigue resistance was compared by evaluating the number of cycles to failure in a simulated canal. Statistical analysis was performed by one-way analysis of variance and Tukey post hoc test (p = 0.05). After torsional and cyclic fatigue tests, all fracture fragments were observed under a scanning electron microscope. Group A2 showed higher cyclic fatigue resistance than the groups AN and F2 (p < 0.05). Although group A2 demonstrated lower ultimate torsional strength than the others, there were no significant differences in toughness among the groups. While obvious machining grooves were seen in groups AN and F2, group A2 showed smooth surface resulting from the surface treatment. The specimens of fracture fragments showed typical features of cyclic failure such as micro-cracks, overloaded fast fracture zone, and torsional fracture such as unwinding helix, circular abrasion marks and dimples. Under the conditions of this study, the surface treated instruments may improve cyclic fatigue resistance while maintaining the torsional resistances and mechanical properties.
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Affiliation(s)
- Bo Hoon Kim
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Pusan National University, Yangsan, Korea
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36
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Comparison of Conventional and New-generation Nickel-Titanium Files in Regard to Their Physical Properties. J Endod 2014; 40:1824-9. [DOI: 10.1016/j.joen.2014.06.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 06/22/2014] [Accepted: 06/24/2014] [Indexed: 11/18/2022]
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37
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Park SK, Kim YJ, Shon WJ, You SY, Moon YM, Kim HC, Lee W. Clinical efficiency and reusability of the reciprocating nickel-titanium instruments according to the root canal anatomy. SCANNING 2014; 36:246-251. [PMID: 23630105 DOI: 10.1002/sca.21096] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 03/20/2013] [Accepted: 03/25/2013] [Indexed: 06/02/2023]
Abstract
The application of the single-file technique using the reciprocating motion is gaining concern in root canal preparation. The purpose of this research is to compare the efficiency of the reciprocating motion-employing files (RECIPROC and WaveOne) by measuring the working time for complete canal shaping, and to evaluate their reusability under scanning examinations. One hundred curved root canals of the extracted molars were used. The working length was determined and the glide path was confirmed using a #15 K-file. Canals shaping was completed to the length either with RECIPROC R25 file (n = 50), or with WaveOne Primary file (n = 50). The time taken for the file to reach the working length was also measured. Each file was repeatedly used in a maximum of 10 canals for comparing the change of the efficiency (shaping time) according to the working length, canal curvature, and number of file re-use. The deformations or surface defects of the files after the in vitro use were observed using a scanning electron microscope (SEM). There was no difference under the SEM between the 2 file groups with no initiation of micro-cracks until they were re-used up to 5 canals. WaveOne Primary file showed significantly shorter working time than RECIPROC R25 (p < 0.05). There was a statistically significant correlation between the working time and three variables. As the working length and the curvature of the canal increased, the shaping time was increased in both file systems. Reusability of these reciprocating instruments might be maximum 5 canals with minimal surface deformations.
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Affiliation(s)
- Sung-Kyung Park
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Seoul National University, Seoul, Korea
| | - Young-Jae Kim
- Department of Pediatric Dentistry, School of Dentistry, Dental Research Institute, Seoul National University, Seoul, Korea
| | - Won-Jun Shon
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Seoul National University, Seoul, Korea
| | - Sung-Yeop You
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Seoul National University, Seoul, Korea
| | - Young-Mi Moon
- Department of Conservative Dentistry, School of Dentistry, Daejeon Hospital, WonKwang University, Daejeon, Korea
| | - Hyeon-Cheol Kim
- Department of Conservative Dentistry, School of Dentistry, Pusan National University, Yangsan, Korea
| | - WooCheol Lee
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Seoul National University, Seoul, Korea
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38
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Cutting Efficiency of Conventional and Martensitic Nickel-Titanium Instruments for Coronal Flaring. J Endod 2013; 39:1634-8. [DOI: 10.1016/j.joen.2013.08.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 08/04/2013] [Accepted: 08/05/2013] [Indexed: 11/30/2022]
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40
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Fayyad DM, Mahran AH. Atomic force microscopic evaluation of nanostructure alterations of rotary NiTi instruments after immersion in irrigating solutions. Int Endod J 2013; 47:567-73. [DOI: 10.1111/iej.12189] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Accepted: 08/31/2013] [Indexed: 11/29/2022]
Affiliation(s)
- D. M. Fayyad
- Department of Endodontics; Faculty of Dentistry; Suez Canal University; Ismailia Egypt
| | - A. H. Mahran
- Department of Endodontics; Faculty of Dentistry; Ain Shams University; Cairo Egypt
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41
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da Silva MAC, Ponciano Gomes JADC, Ormiga F. Influence of electrochemical polishing on the mechanical behaviour of nickel-titanium rotary files. AUST ENDOD J 2013; 39:73-7. [PMID: 23890263 DOI: 10.1111/j.1747-4477.2011.00308.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The purpose of this study was to evaluate the influence of electrochemical polishing on the cyclic fatigue, cutting efficiency and surface topography of Miltex nickel-titanium rotary files. A group of files were submitted to electrochemical polishing. New files and polished files were tested for flexural fatigue and for cutting efficiency. Scanning electron microscopy observations of all files were carried out to compare the surface morphologies of polished and new files. The t-test was used to compare the groups for cutting efficiency. Scanning electron microscopy analysis indicated that the polishing resulted in more regular surfaces in relation to the new files. Electropolished files attained a significantly higher number of cycles to fracture than new unpolished files. No statistical difference exists between the groups in relation to the cutting efficiency (t-test, P < 0.05). The polished files keep their integrity for a significantly higher number of cycles to fracture than the new files, without compromising cutting efficiency.
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Affiliation(s)
- Marcio A C da Silva
- Department of Metallurgy and Materials, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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42
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Plotino G, Testarelli L, Al-Sudani D, Pongione G, Grande NM, Gambarini G. Fatigue resistance of rotary instruments manufactured using different nickel–titanium alloys: a comparative study. Odontology 2012; 102:31-5. [DOI: 10.1007/s10266-012-0088-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 09/13/2012] [Indexed: 11/30/2022]
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43
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Yamamura B, Cox TC, Heddaya B, Flake NM, Johnson JD, Paranjpe A. Comparing Canal Transportation and Centering Ability of EndoSequence and Vortex Rotary Files by Using Micro–Computed Tomography. J Endod 2012; 38:1121-5. [DOI: 10.1016/j.joen.2012.04.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 04/25/2012] [Accepted: 04/27/2012] [Indexed: 11/25/2022]
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44
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dos Santos M, Gavini G, Siqueira EL, da Costa C. Effect of Nitrogen Ion Implantation on the Flexibility of Rotary Nickel-Titanium Instruments. J Endod 2012; 38:673-5. [DOI: 10.1016/j.joen.2012.01.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 01/13/2012] [Accepted: 01/30/2012] [Indexed: 10/28/2022]
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45
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JAMLEH A, KOBAYASHI C, YAHATA Y, EBIHARA A, SUDA H. Deflecting load of nickel titanium rotary instruments during cyclic fatigue. Dent Mater J 2012; 31:389-93. [DOI: 10.4012/dmj.2011-233] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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46
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Gutmann JL, Gao Y. Alteration in the inherent metallic and surface properties of nickel-titanium root canal instruments to enhance performance, durability and safety: a focused review. Int Endod J 2011; 45:113-28. [PMID: 21902705 DOI: 10.1111/j.1365-2591.2011.01957.x] [Citation(s) in RCA: 132] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The expanded use of nickel-titanium (NiTi) rotary instruments in root canal procedures has led to the development of a wide variety of shapes, designs and applications. Root canal anatomy has not changed, however, and the same challenges exist in both initial treatment and the revision of unacceptable treatment. These challenges include application with high levels of achievement and low to no levels of adverse effects, such as instrument fracture, root canal wall ledging, dentine wall perforation and so forth. To that end, many manufacturers have been seeking ways to alter the presently available and wide range of root canal instrument designs, with a focus on altering the surface of the alloy or altering the alloy microstructure with post-machining or post-twisting heat treatment. This focused review will address the impact that these modifications have had on instrument flexibility, resistance to cyclic fatigue and cutting efficiency.
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Affiliation(s)
- J L Gutmann
- Baylor College of Dentistry, Texas A&M Health Science Center, Dallas, TX, USA.
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47
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Cheung GSP, Zhang EW, Zheng YF. A numerical method for predicting the bending fatigue life of NiTi and stainless steel root canal instruments. Int Endod J 2011; 44:357-61. [PMID: 21219364 DOI: 10.1111/j.1365-2591.2010.01838.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
AIM To evaluate the bending fatigue lifetime of nickel-titanium alloy (NiTi) and stainless steel (SS) endodontic files using finite element analysis. METHODOLOGY The strain-life approach was adopted and two theoretical geometry profiles, the triangular (TR) and the square cross-sections, were considered. Both low-cycle fatigue (LCF) lifetime and high-cycle fatigue (HCF) lifetime were evaluated. RESULTS The bending fatigue behaviour was affected by the material property and the cross-sectional configuration of the instrument. Both the cross-section factor and material property had a substantial impact on fatigue lifetime. The NiTi material and TR geometry profiles were associated with better fatigue resistance than that of SS and square cross-sections. CONCLUSIONS Within the limitations of this study, finite element models were established for endodontic files to prejudge their fatigue lifetime, a tool that would be useful for dentist to prevent premature fatigue fracture of endodontic files.
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Affiliation(s)
- G S P Cheung
- Area of Endodontics, Comprehensive Dental Care, Faculty of Dentistry, the University of Hong Kong, Hong Kong, Hong Kong Special Administrative Region
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48
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Lopes HP, Elias CN, Vieira VT, Moreira EJ, Marques RV, Machado de Oliveira JC, Debelian G, Siqueira JF. Effects of Electropolishing Surface Treatment on the Cyclic Fatigue Resistance of BioRace Nickel-Titanium Rotary Instruments. J Endod 2010; 36:1653-7. [DOI: 10.1016/j.joen.2010.06.026] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Revised: 06/26/2010] [Accepted: 06/28/2010] [Indexed: 10/19/2022]
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49
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Oh SR, Chang SW, Lee Y, Gu Y, Son WJ, Lee W, Baek SH, Bae KS, Choi GW, Lim SM, Kum KY. A comparison of nickel-titanium rotary instruments manufactured using different methods and cross-sectional areas: ability to resist cyclic fatigue. ACTA ACUST UNITED AC 2010; 109:622-8. [PMID: 20303058 DOI: 10.1016/j.tripleo.2009.12.025] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 11/27/2009] [Accepted: 12/03/2009] [Indexed: 02/02/2023]
Abstract
OBJECTIVE This study examined the effect of the manufacturing methods (ground, electropolished, and twisted) and the cross-sectional area (CSA) of nickel-titanium (NiTi) rotary instruments on their cyclic fatigue resistance. STUDY DESIGN A total of 80 NiTi rotary instruments (ISO 25/.06 taper) from 4 brands (K3, ProFile, RaCe, and TF) were rotated in a simulated root canal with pecking motion until fracture. The number of cycles to failure (NCF) was calculated. The CSA at 3 mm from the tip of new instruments of each brand was calculated. The correlation between the CSA and NCF was evaluated. All fractured surfaces were analyzed using a scanning electron microscope to determine the fracture mode. RESULTS The TF instruments were the most resistant to fatigue failure. The resistance to cyclic failure increased with decreasing CSA. All fractured surfaces showed the coexistence of ductile and brittle properties. CONCLUSION The CSA had a significant effect on the fatigue resistance of NiTi rotary instruments.
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Affiliation(s)
- So-Ram Oh
- Department of Conservative Dentistry, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
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50
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Condorelli GG, Bonaccorso A, Smecca E, Schäfer E, Cantatore G, Tripi TR. Improvement of the fatigue resistance of NiTi endodontic files by surface and bulk modifications. Int Endod J 2010; 43:866-73. [DOI: 10.1111/j.1365-2591.2010.01759.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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