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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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Abutayyem H, Alam MK, Kanwal B, Alswairki HJ, Alogaibi YA. Metallurgy in orthodontic-A systematic review and meta-analysis on the types of metals used. J Orthod Sci 2023; 12:50. [PMID: 37881657 PMCID: PMC10597363 DOI: 10.4103/jos.jos_52_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 04/27/2023] [Accepted: 04/27/2023] [Indexed: 10/27/2023] Open
Abstract
A variety of metals and alloys are employed in the field of orthodontics, primary of which happen to be the construction of wires. Through this systematic review, we aimed to assess the various metallurgical characteristics of the said metals and alloys. Four hundred and eighty-two documents in total were found after a thorough search of the online journals, and 169 of the papers were initially chosen. Ultimately, 16 documents were selected that satisfied the necessary inclusion and exclusion criteria, primarily in vitro studies, literature reviews, and comparative analyses. NiTi alloy was found to be the most commonly used alloy in construction of orthodontic wires across all the studies that we had selected for our review. It also had better performance and consistency in terms of its usage as depicted by the meta-analysis performed, with stainless steel wires being a close second primarily due to its lesser cost compared to the former. Metallurgy and orthodontics are inextricably linked with one another. The various components of orthodontics such as wires, pliers, and other instruments utilize the metallurgical characteristics of metals and alloys that are specially prepared for the challenges of this field. PROSPERO Registration Number: CRD42022378444.
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Affiliation(s)
- Huda Abutayyem
- Department of Clinical Sciences, Center of Medical and Bio-Allied Health Sciences Research, College of Dentistry, Ajman University, Ajman, United Arab Emirates
| | - Mohammad Khursheed Alam
- Orthodontic Division, Preventive Dentistry Department, Orthodontic Division, College of Dentistry, Jouf University, Sakaka 72345, Saudi Arabia
- Department of Dental Research Cell, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu, India
- Department of Public Health, Faculty of Allied Health Sciences, Daffodil lnternational University, Dhaka, Bangladesh
| | - Bushra Kanwal
- Specialist, Practicing in Dental Clinic, AlBaha, Saudi Arabia
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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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Nino-Barrera JL, Aldana-Ojeda L, Gamboa-Martinez LF, Acosta-Humanez M, Silva-Castellanos C, Cortes-Rodriguez CJ. Comparison of Mechanical and Structural Properties of Nickel-titanium Alloy with Titanium-molybdenum Alloy and Titanium-niobium Alloy as Potential Metals for Endodontic Files. IRANIAN ENDODONTIC JOURNAL 2021; 16:49-55. [PMID: 36704415 PMCID: PMC9709876 DOI: 10.22037/iej.v16i1.24048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/21/2020] [Accepted: 12/06/2020] [Indexed: 01/28/2023]
Abstract
Introduction The objective of this study was to compare the mechanical and structural properties of the nickel-titanium (Ni-Ti) alloy already used in endodontics with titanium-molybdenum (Ti-Mo) and titanium-niobium (Ti-Nb) alloys to determine if these can be suggested in the manufacture of endodontic files. Methods and Materials Orthodontic wires made of the different alloys were used. The previously mentioned alloys were characterized by energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and torsion tests. Cyclic fatigue tests were performed on a simulated canal with a curvature of 86° to 375 rpm. The fractured surfaces of the wires were observed by means of scanning electron microscopy (SEM). A Kruskal-Wallis test and U Mann Whitney test were used to determine significant differences in cyclic fatigue between groups. Results In the mechanical tests, similar values of torsion were found for the three alloys. In XRD, the Ti-Nb showed less structural changes. In the cyclic fatigue test, Ti-Nb was found to be significantly more resistant with respect to Ni-Ti and Ti-Mo. Conclusion Based on our in vitro study, Ti-Nb is suggested as a possible alloy for the manufacture of rotary files due to its impressive properties.
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Affiliation(s)
- Javier Laureano Nino-Barrera
- Universidad Nacional de Colombia, Department of Basic Sciences and Oral Medicine, School of Dentistry, Bogota, Colombia;,Universidad el Bosque, School of Dentistry, Bogota, Colombia; ,Corresponding author: Javier Laureano Nino-Barrera, Bogota, Colombia, Calle 135 #58b-21 Interior 2 Apartamento 302. Bogotá, 111111, Colombia
| | - Laura Aldana-Ojeda
- Universidad Nacional de Colombia, Department of Basic Sciences and Oral Medicine, School of Dentistry, Bogota, Colombia;
| | | | - Manuel Acosta-Humanez
- Universidad Nacional de Colombia, Department of Mechanics and Mechatronics, School of Engineering, Bogota, Colombia
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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: 5] [Impact Index Per Article: 1.3] [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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Sabet Y, Shahsiah S, Yazdizadeh M, Baghamorady S, Jafarzadeh M. Effect of deep cryogenic treatment on cyclic fatigue resistance of controlled memory wire nickel-titanium rotary instruments. Dent Res J (Isfahan) 2020; 17:300-305. [PMID: 33282157 PMCID: PMC7688033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
BACKGROUND Cryogenic methods have been used to increase the wear, abrasion, corrosion resistance and to improve the strength of metals. The aim of this study was to evaluate the effect of cryogenic treatment on the cyclic fatigue resistance of rotary nickel-titanium (NiTi) instruments. MATERIALS AND METHODS In this in vitro study, 20 Hyflex (Coltene, Altstätten, Switzerland) nickel-titanium instruments, size 25, 0.06 taper, were randomly divided into two groups as follows: untreated NiTi rotary files (Group A) and cryotreated NiTi rotary files (Group B). The instruments of Group A were completely immersed in a cryocan containing liquid nitrogen (-196°C) for 24 h. After 24 h, the instruments were removed from the bath and were allowed to return to room temperature gradually. All files were used (at a speed of 500 rpm and a torque of 2.5 Ncm) in an artificial canal with a 60° curvature until fracture. Time to failure was recorded with a stopwatch in seconds and subsequently converted to number of cycles to fracture (NCF). Groups were compared using the independent-samples t-test. The level of statistical significance was set at 0.05. RESULTS Mean NFCs in Group A and B were 1576 and 1395, respectively. However, statistical analysis showed that there was no significant difference between the groups (P = 0.2). CONCLUSION Deep cryotherapy of NiTi endodontic files cannot improve the cyclic fatigue resistance of HyFlex files, but further studies are required to evaluate these cryogenically treated NiTi files clinically.
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Affiliation(s)
- Yazdan Sabet
- Department of Endodontics, Faculty of Dentistry, Lorestan University of Medical Sciences, Lorestan, Iran,Address for correspondence: Dr. Yazdan Sabet, Lorestan University of Medical Sciences, Anooshirvan Rezaei Square, Khorramabad, Lorestan, Iran. E-mail:
| | - Samira Shahsiah
- Department of Endodontics, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mohammad Yazdizadeh
- Department of Endodontics, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | | | - Mansour Jafarzadeh
- Department of Endodontics, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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Cryotherapy: A New Paradigm of Treatment in Endodontics. J Endod 2020; 46:936-942. [DOI: 10.1016/j.joen.2020.03.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/27/2020] [Accepted: 03/15/2020] [Indexed: 02/08/2023]
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Singh P, Pungotra H, Kalsi NS. Parametric optimization of deep cryogenic treatment for the wear response of implant material UNS R56700: Taguchi’s approach. Proc Inst Mech Eng H 2019; 234:61-73. [DOI: 10.1177/0954411919884775] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Using the Taguchi’s robust design of experiments methodology, this article presents the systematic identification and optimization of most influential parameters of deep cryogenic treatment process to minimize the specific wear rate of UNS R56700 (Ti6Al7Nb). In addition to the different soaking durations (0–96 h) at 77 K and different tempering temperatures (room temperature, 403–523 K), three commonly used variables of pin-on-disk test, namely, sliding speed (1.047–2.723 ms−1), contact pressure (0.641–1.282 MPa), and sliding time (600–2280 s) were chosen to conduct the tests. During dry sliding conditions, pin-on-disk tribo-tests were performed to slide Ti6Al7Nb on the surface of UNS 52986 (En31) material as per standardized ASTM G99 guidelines. Experimentally measured wear rate values were converted to signal–noise ratio to statistically analyze the influence of five control variables using pooled analysis of variance and F-test. Statistically found influential control variables are confirmed experimentally. The results show that sliding speed, contact pressure and soaking duration are the most significant factors influencing the wear rate. In contrast, the parameters, that is, tempering temperature and sliding time, exhibit a lower level of influence. Microstructural characterizations done using optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction techniques suggested that deep cryogenic treatment favors the refinement of grain size of present phases with reduction in β-stabilization (β-phase) in Ti6Al7Nb. The possible reasons for the improvement in wear rate of Ti6Al7Nb underlying the morphological alterations have been explained.
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Affiliation(s)
- Paramjit Singh
- Research Scholar, I. K. Gujral Punjab Technical University, Kapurthala, India
| | - Harish Pungotra
- Department of Mechanical Engineering, Beant College of Engineering and Technology, Gurdaspur, India
| | - Nirmal S Kalsi
- Department of Mechanical Engineering, Beant College of Engineering and Technology, Gurdaspur, India
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Effects of Cryogenic Treatment after Annealing of Ti-6Al-4V Alloy Sheet on Its Formability at Room Temperature. METALS 2018. [DOI: 10.3390/met8050295] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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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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Yazdizadeh M, Skini M, Hoseini Goosheh SM, Jafarzadeh M, Shamohammadi M, Rakhshan V. Effect of Deep Cryogenic Treatment on Cyclic Fatigue of Endodontic Rotary Nickel Titanium Instruments. IRANIAN ENDODONTIC JOURNAL 2017; 12:216-219. [PMID: 28512489 PMCID: PMC5431711 DOI: 10.22037/iej.2017.42] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Introduction: Cyclic fatigue is the common reason for breakage of rotary instruments. This study was conducted to evaluate the effect of cryogenic treatment (CT) in improving the resistance to cyclic fatigue of endodontic rotary instruments. Methods and Materials: In this in vitro study, 20 RaCe and 20 Mtwo files were randomly divided into two groups of negative control and CT. CT files were stored in liquid nitrogen at -196°C for 24 h, and then were gradually warmed to the room temperature. All files were used (at torques and speeds recommended by their manufacturers) in a simulated canal with a 45° curvature until breakage. The time to fail (TF) was recorded and used to calculate the number of cycle to fail (NCF). Groups were compared using independent-samples t-test. Results: Mean NCFs were 1248.2±68.1, 1281.6±78.6, 4126.0±179.2, and 4175.4±190.1 cycles, for the Mtwo-control, Mtwo-CT, RaCe-control, and RaCe-CT, respectively. The difference between the controls and their respective CT groups were not significant (P>0.3). The difference between the systems was significant. Conclusion: Deep CT did not improve resistance to cyclic fatigue of the evaluated rotary files.
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Affiliation(s)
- Mohammad Yazdizadeh
- Department of Endodontics, Dental School, Ahvaz Jundishapur University of Medical Science, Ahvaz, Iran
| | - Masoumeh Skini
- Department of Orthodontics, Dental School, Ahvaz Jondishapoor University of Medical Science, Iran
| | | | - Mansour Jafarzadeh
- Department of Endodontics, Dental School, Ahvaz Jundishapur University of Medical Science, Ahvaz, Iran
| | - Milad Shamohammadi
- Department of Orthodontics, Dental School, Ahvaz Jondishapoor University of Medical Science, Iran
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Vinothkumar TS, Kandaswamy D, Prabhakaran G, Rajadurai A. Effect of dry cryogenic treatment on Vickers hardness and wear resistance of new martensitic shape memory nickel-titanium alloy. Eur J Dent 2016; 9:513-517. [PMID: 26929689 PMCID: PMC4745232 DOI: 10.4103/1305-7456.172626] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES The aim of this study is to investigate the role of dry cryogenic treatment (CT) temperature and time on the Vickers hardness and wear resistance of new martensitic shape memory (SM) nickel-titanium (NiTi) alloy. The null hypothesis tested was that there is no difference in Vickers hardness and wear resistance between SM NiTi alloys following CT under two soaking temperatures and times. MATERIALS AND METHODS The composition and the phase transformation behavior of the alloy were examined by X-ray energy dispersive spectroscopy and differential scanning calorimetry, respectively. Fifteen cylindrical specimens and 50 sheet specimens were subjected to different CT conditions: Deep cryogenic treatment (DCT) 24 group: -185°C, 24 h; DCT six group: -185°C, 6 h; shallow cryogenic treatment (SCT) 24 group: -80°C, 24 h; SCT six group: -80°C, 6 h; and control group. Wear resistance was assessed from weight loss before and after reciprocatory wet sliding wear. RESULTS The as-received SM NiTi alloy contained 50.8 wt% nickel and possessed austenite finish temperature (Af) of 45.76°C. Reduction in Vickers hardness of specimens in DCT 24 group was highly significant (P < 0.01; Tukey's honest significant difference [HSD]). The weight loss was significantly higher in DCT 24 group (P < 0.05; Tukey's HSD). CONCLUSION Deep dry CT with 24 h soaking period significantly reduces the hardness and wear resistance of SM NiTi alloy.
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Affiliation(s)
- Thilla Sekar Vinothkumar
- Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences of Sri Ramachandra University, Chennai, Tamil Nadu, India
| | - Deivanayagam Kandaswamy
- Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences of Sri Ramachandra University, Chennai, Tamil Nadu, India
| | | | - Arunachalam Rajadurai
- Department of Production Technology, MIT Campus, Anna University, Chennai, Tamil Nadu, India
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Vinothkumar TS, Kandaswamy D, Prabhakaran G, Rajadurai A. Microstructure of cryogenically treated martensitic shape memory nickel-titanium alloy. J Conserv Dent 2015; 18:292-6. [PMID: 26180413 PMCID: PMC4502124 DOI: 10.4103/0972-0707.159727] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 04/19/2015] [Accepted: 05/28/2015] [Indexed: 11/08/2022] Open
Abstract
Context: Recent introduction of shape memory (SM) nickel-titanium (NiTi) alloy into endodontics is a major breakthrough. Although the flexibility of these instruments was enhanced, fracture of rotary endodontic instruments during instrumentation is an important challenge for the operator. Implementation of supplementary manufacturing methods that would improve the fatigue life of the instrument is desirable. Aim: The purpose of this study was to investigate the role of dry cryogenic treatment (CT) conditions on the microstructure of martensitic SM NiTi alloy. Materials and Methods: Experiments were conducted on Ni-51 wt% Ti-49 wt% SM alloy. Five cylindrical specimens and five sheet specimens were subjected to different CT conditions: Deep CT (DCT) 24 group: −185°C; 24 h, DCT 6 group: −185°C; 6 h, shallow CT (SCT) 24 group: −80°C, 24 h, SCT 6 group: −80°C, 6 h and control group. Microstructure of surface was observed on cylindrical specimens with an optical microscope and scanning electron microscope at different magnifications. Subsurface structure was analyzed on sheet specimens using X-ray diffraction (XRD). Results: Microstructures of all SM NiTi specimens had equiaxed grains (approximately 25 μm) with well-defined boundaries and precipitates. XRD patterns of cryogenically treated specimens revealed accentuation of austenite and martensite peaks. The volume of martensite and its crystallite size was relatively more in DCT 24 specimen. Conclusions: DCT with 24 h soaking period increases the martensite content of the SM NiTi alloy without altering the grain size.
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Affiliation(s)
- Thilla Sekar Vinothkumar
- Department of Restorative Dental Sciences, College of Dentistry, Jazan Universtiy, Jazan, Kingdom of Saudi Arabia
| | - Deivanayagam Kandaswamy
- Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, Sri Ramachandra University, Chennai, Tamil Nadu, India
| | | | - Arunachalam Rajadurai
- Department of Production Technology, MIT Campus, Anna University, Chennai, Tamil Nadu, India
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14
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Tocci L, Plotino G, Al-Sudani D, Rubini AG, Sannino G, Piasecki L, Putortì E, Testarelli L, Gambarini G. Cutting efficiency of instruments with different movements: a comparative study. J Oral Maxillofac Res 2015; 6:e6. [PMID: 25937877 PMCID: PMC4414237 DOI: 10.5037/jomr.2014.6106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 02/09/2015] [Indexed: 11/24/2022]
Abstract
OBJECTIVES The aim of the present study was to evaluate the cutting efficiency of two new reciprocating instruments, Twisted File Adaptive and WaveOne Primary. MATERIAL AND METHODS 10 new Twisted File Adaptive (TF Adaptive) (SybronEndo, Glendora, CA, USA) and 10 new WaveOne Primary files (Dentsply Maillefer, Ballaigues, Switzerland) were activated using a torque-controlled motor, respectively TFA motor (SybronEndo, Glendora, CA, USA) and Silver motor (VDW, Munich, Germany). The device used for the cutting test consisted on a mainframe to which a mobile plastic support for the hand-piece is connected and a stainless-steel block containing a Plexiglas block against which the cutting efficiency of the instruments was tested. The length of the block cut in 1 minute was measured in a computerized program with a precision of 0.1 mm. Mean and standard deviations of each group were calculated and data were statistically analyzed with one-way ANOVA and Bonferroni t test (P < 0.05). RESULTS TF Adaptive displayed significantly greater maximum penetration depth than WaveOne Primary (P < 0.05). In fact, TF Adaptive instruments (Group 1) cut the Plexiglas block to a mean depth of 8.7 (SD 0.5) mm, while WaveOne Primary instruments cut the Plexiglas block to a mean depth of 6.4 (SD 0.3) mm. CONCLUSIONS Twisted File Adaptive instruments demonstrated statistically higher cutting efficiency than WaveOne instruments.
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Affiliation(s)
- Luigi Tocci
- Department of Endodontics, "Sapienza" University of RomeItaly
| | | | - Dina Al-Sudani
- Department of Endodontics, "Sapienza" University of RomeItaly
| | | | | | - Lucila Piasecki
- Department of Endodontics, "Sapienza" University of RomeItaly
| | - Ermanno Putortì
- Department of Endodontics, "Sapienza" University of RomeItaly
| | - Luca Testarelli
- Department of Endodontics, "Sapienza" University of RomeItaly
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15
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Cutting efficiency of nickel–titanium rotary and reciprocating instruments after prolonged use. Odontology 2014; 104:77-81. [DOI: 10.1007/s10266-014-0183-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 10/16/2014] [Indexed: 10/24/2022]
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16
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Cutting Efficiency of Reciproc and WaveOne Reciprocating Instruments. J Endod 2014; 40:1228-30. [DOI: 10.1016/j.joen.2014.01.041] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Revised: 01/21/2014] [Accepted: 01/25/2014] [Indexed: 11/21/2022]
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17
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Rubini AG, Plotino G, Al-Sudani D, Grande NM, Putorti E, Sonnino G, Cotti E, Testarelli L, Gambarini G. A new device to test cutting efficiency of mechanical endodontic instruments. Med Sci Monit 2014; 20:374-8. [PMID: 24603777 PMCID: PMC3948890 DOI: 10.12659/msm.890119] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Accepted: 12/17/2013] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND The purpose of the present study was to introduce a new device specifically designed to evaluate the cutting efficiency of mechanically driven endodontic instruments. MATERIAL AND METHODS Twenty new Reciproc R25 (VDW, Munich, Germany) files were used to be investigated in the new device developed to test the cutting ability of endodontic instruments. The device consists of a main frame to which a mobile plastic support for the hand-piece is connected and a stainless-steel block containing a Plexiglas block against which the cutting efficiency of the instruments was tested. The length of the block cut in 1 minute was measured in a computerized program with a precision of 0.1mm. The instruments were activated by using a torque-controlled motor (Silver Reciproc; VDW, Munich, Germany) in a reciprocating movement by the "Reciproc ALL" program (Group 1) and in counter-clockwise rotation at 300 rpm (Group 2). Mean and standard deviations of each group were calculated and data were statistically analyzed with a one-way ANOVA test (P<0.05). RESULTS Reciproc in reciprocation (Group 1) mean cut in the Plexiglas block was 8.6 mm (SD=0.6 mm), while Reciproc in rotation mean cut was 8.9 mm (SD=0.7 mm). There was no statistically significant difference between the 2 groups investigated (P>0.05). CONCLUSIONS The cutting testing device evaluated in the present study was reliable and easy to use and may be effectively used to test cutting efficiency of both rotary and reciprocating mechanical endodontic instruments.
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Affiliation(s)
| | - Gianluca Plotino
- Department of Endodontics, “Sapienza” University of Rome, Rome, Italy
| | - Dina Al-Sudani
- Department of Restorative, King Saud University, Riyadh, Saudi Arabia
| | - Nicola M. Grande
- Department of Endodontics, “Sapienza” University of Rome, Rome, Italy
| | - Ermanno Putorti
- Department of Endodontics, “Sapienza” University of Rome, Rome, Italy
| | | | - Elisabetta Cotti
- Department of Endodontics, University of Cagliari, Cagliari, Italy
| | - Luca Testarelli
- Department of Endodontics, “Sapienza” University of Rome, Rome, Italy
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18
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Gu K, Wang J, Zhou Y. Effect of cryogenic treatment on wear resistance of Ti–6Al–4V alloy for biomedical applications. J Mech Behav Biomed Mater 2014; 30:131-9. [DOI: 10.1016/j.jmbbm.2013.11.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 10/31/2013] [Accepted: 11/02/2013] [Indexed: 11/30/2022]
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19
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Mohammadi Z, Soltani MK, Shalavi S, Asgary S. A Review of the Various Surface Treatments of NiTi Instruments. IRANIAN ENDODONTIC JOURNAL 2014; 9:235-40. [PMID: 25386201 PMCID: PMC4224758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Revised: 07/01/2014] [Accepted: 07/15/2014] [Indexed: 12/01/2022]
Abstract
Since the introduction of engine-driven nickel-titanium (NiTi) instruments, attempts have been made to minimize or eliminate their inherent defects, increase their surface hardness/flexibility and also improve their resistance to cyclic fatigue and cutting efficiency. The various strategies of enhancing instrument surface include ion implantation, thermal nitridation, cryogenic treatment and electropolishing. The purpose of this paper was to review the metallurgy and crystal characteristics of NiTi alloy and to present a general over review of the published articles on surface treatment of NiTi endodontic instruments.
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Affiliation(s)
- Zahed Mohammadi
- Iranian Center for Endodontic Research, Research Institute of Dental Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran;
| | | | | | - Saeed Asgary
- Iranian Center for Endodontic Research, Research Institute of Dental Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran;,Corresponding author: Saeed Asgary, ICER, Research Institute of Dental Sciences, Evin, Tehran, Iran. Tel:+98-21 22413897, Fax: +98-21 22427753, E-mail:
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20
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Zhou H, Peng B, Zheng YF. An overview of the mechanical properties of nickel-titanium endodontic instruments. ACTA ACUST UNITED AC 2013. [DOI: 10.1111/etp.12045] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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21
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Abstract
The effect of cryogenic treatment on the microstructure and properties of Ti-6Al-4V has been studied in this paper. The program controlled SLX cryogenic box was used to conduct the cryogenic treatment and the subsequent low temperature temper. The scanning electron microscope was used to study the morphology of microstructure and fracture surface. As the results show that the cryogenic treatment increases the elongation of Ti-6Al-4V from 16.5 percent to 24.5 percent, at the same time, the strength increases slightly, this indicates that cryogenic treatment can improve the comprehensive mechanical properties. The microstructure measurement revealed that there is a tendency of reduction in the precipitated particles after cryogenic treatment. The cross section is flat and the size of dimples is more uniform. It is concluded that the change in the precipitation particle had a great influence in the mechanical properties.
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22
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Balasubramanian S, Gupta MK, Singh KK. Cryogenics and its application with reference to spice grinding: a review. Crit Rev Food Sci Nutr 2012; 52:781-94. [PMID: 22698269 DOI: 10.1080/10408398.2010.509552] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Cryogenics is the study of very low temperature and its application on different materials including biological products. Cryogenics has numerous applications in space science, electronics, automobiles, the manufacturing industry, sports and musical instruments, biological science and agriculture, etc. Cryogenic freezing finds pivotal application in food, that is, spices and condiments. Although there is a wide range of cryogens to produce the desired low temperature, generally liquid nitrogen (LN₂) is used in food grinding. The application of low temperature shows a promising pathway to produce higher quality end product with higher flavor and volatile oil retention. Cryogenic grinders generally consist of precoolers and grinder with the cryogen distribution system. In such grinding systems, cryogens subject the raw material up to or lower than glass transition temperature before it is ground, thus eliminating much of the material and quality hassles of traditional grinding. At present, the capital investment including cryogen and handling costs escalate the final cost of the product. Thus, for large-scale production, a proper design to optimize and make it feasible is the need of the hour and understanding the behavior of different food materials at these low temperature conditions. This article reviews the scenario and application of cryogenics in different sectors, especially to spice grinding.
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Affiliation(s)
- S Balasubramanian
- Central Institute of Post Harvest Engineering and Technology, P.O. P.A.U. Campus, Ludhiana, Punjab, India.
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23
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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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24
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Testarelli L, Plotino G, Al-Sudani D, Vincenzi V, Giansiracusa A, Grande NM, Gambarini G. Bending Properties of a New Nickel-Titanium Alloy with a Lower Percent by Weight of Nickel. J Endod 2011; 37:1293-5. [PMID: 21846552 DOI: 10.1016/j.joen.2011.05.023] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 05/20/2011] [Accepted: 05/21/2011] [Indexed: 10/18/2022]
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25
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Gavini G, Pessoa OF, Barletta FB, Vasconcellos M, Caldeira CL. Cyclic Fatigue Resistance of Rotary Nickel-Titanium Instruments Submitted to Nitrogen Ion Implantation. J Endod 2010; 36:1183-6. [DOI: 10.1016/j.joen.2010.03.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 03/09/2010] [Accepted: 03/11/2010] [Indexed: 10/19/2022]
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26
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Zinelis S, Eliades T, Eliades G. A metallurgical characterization of ten endodontic Ni-Ti instruments: assessing the clinical relevance of shape memory and superelastic properties of Ni-Ti endodontic instruments. Int Endod J 2010; 43:125-34. [PMID: 20078701 DOI: 10.1111/j.1365-2591.2009.01651.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S Zinelis
- Department of Biomaterials, School of Dentistry, University of Athens, Athens, Greece.
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27
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Zinelis S, Akhtar R, Tsakiridis P, Watts DC, Silikas N. In-depth hardness profiles of Stainless Steel and Ni-Ti endodontic instrument cross-sections by nano-indentation. Int Endod J 2008; 41:747-54. [DOI: 10.1111/j.1365-2591.2008.01426.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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28
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Three-dimensional Analysis of Cutting Behavior of Nickel-Titanium Rotary Instruments by Microcomputed Tomography. J Endod 2008; 34:606-10. [DOI: 10.1016/j.joen.2008.02.025] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2007] [Revised: 02/18/2008] [Accepted: 02/25/2008] [Indexed: 11/23/2022]
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29
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Vinothkumar TS, Miglani R, Lakshminarayananan L. Influence of Deep Dry Cryogenic Treatment on Cutting Efficiency and Wear Resistance of Nickel–Titanium Rotary Endodontic Instruments. J Endod 2007; 33:1355-8. [DOI: 10.1016/j.joen.2007.07.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Revised: 06/21/2007] [Accepted: 07/15/2007] [Indexed: 10/22/2022]
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30
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Parashos P, Messer HH. Rotary NiTi Instrument Fracture and its Consequences. J Endod 2006; 32:1031-43. [PMID: 17055902 DOI: 10.1016/j.joen.2006.06.008] [Citation(s) in RCA: 316] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2006] [Revised: 06/08/2006] [Accepted: 06/08/2006] [Indexed: 11/26/2022]
Abstract
The fracture of endodontic instruments is a procedural problem creating a major obstacle to normally routine therapy. With the advent of rotary nickel-titanium (NiTi) instruments this issue seems to have assumed such prominence as to be a considerable hindrance to the adoption of this major technical advancement. Considerable research has been undertaken to understand the mechanisms of failure of NiTi alloy to minimize its occurrence. This has led to changes in instrument design, instrumentation protocols, and manufacturing methods. In addition, factors related to clinician experience, technique, and competence have been shown to be influential. From an assessment of the literature presented, we derive clinical recommendations concerning prevention and management of this complication.
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Affiliation(s)
- Peter Parashos
- School of Dental Science, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia.
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