1
|
Kimura S, Ebihara A, Maki K, Kyaw MS, Kasuga Y, Omori S, Okiji T. Phase transformation behavior and mechanical properties of HyFlex EDM nickel-titanium endodontic rotary instrument: Evaluation at body temperature. J Dent Sci 2024; 19:929-936. [PMID: 38618130 PMCID: PMC11010611 DOI: 10.1016/j.jds.2023.07.039] [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: 06/29/2023] [Revised: 07/31/2023] [Indexed: 04/16/2024] Open
Abstract
Background/purpose Temperature-dependent phase compositional changes influence the mechanical properties of heat-treated nickel-titanium (NiTi) rotary instruments. This study evaluated the phase composition, bending properties, and cyclic fatigue resistance of HyFlex EDM NiTi rotary instruments against differently heat-treated and non-heat-treated NiTi instruments at body temperature (BT). Materials and methods HyFlex EDM OneFile (EDM) instruments, heat-treated HyFlex CM (CM) and Twisted File (TF) instruments, and non-heat-treated K3 instruments (size #25/.08) were subjected to differential scanning calorimetry, and the martensitic, R-phase, and reverse transformation starting and finishing temperatures were determined. A cantilever bending test and a cyclic fatigue test were conducted at BT (37 °C ± 1.0 °C), and the bending load and number of cycles to failure (NCF) were recorded. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U tests (α = 0.05). Results TF and K3 had reverse transformation finishing temperatures lower than BT, while those for EDM and CM were higher than BT. The bending loads at a 0.5 mm deflection were in the order of EDM < TF < CM < K3 (P < 0.05), and those at a 2.0 mm deflection were EDM < CM and TF < K3 (P < 0.05). EDM had the highest NCF among the four instruments (P < 0.05). Conclusion The EDM instrument had a reverse transformation finishing temperature higher than BT indicating its martensite/R-phase composition at BT. The EDM instrument had superior flexibility and greater resistance to cyclic fatigue than the CM, TF, and K3 instruments at BT.
Collapse
Affiliation(s)
- Shunsuke Kimura
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Arata Ebihara
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Keiichiro Maki
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Moe Sandar Kyaw
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Yuka Kasuga
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Satoshi Omori
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Takashi Okiji
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| |
Collapse
|
2
|
Srivastava S. Root Canal Instrumentation: Current Trends and Future Perspectives. Cureus 2024; 16:e58045. [PMID: 38738101 PMCID: PMC11088362 DOI: 10.7759/cureus.58045] [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] [Accepted: 04/11/2024] [Indexed: 05/14/2024] Open
Abstract
The evolution of root canal instrumentation techniques has significantly impacted the field of endodontics, enhancing both the efficiency and outcomes of treatments. This review outlines the transition from manual to mechanical and rotary instruments, highlighting the role of nickel-titanium (NiTi) alloys and smart technologies in advancing procedural precision and reducing patient discomfort. Key historical developments and technological innovations, such as digital imaging and navigation systems, are explored for their contributions to improved clinical outcomes and patient satisfaction. Additionally, the review addresses the challenges presented by the complex anatomy of the root canal system and the advent of current instrumentation techniques. The potential of emerging trends, including artificial intelligence and advances in materials science, is discussed in the context of future endodontic practices. Despite the progress, challenges related to using advanced instrumentation methods, ethical considerations, and the cost factor of new technologies persist. The present review underscores the ongoing need for research and development to further refine root canal instrumentation techniques, ensuring that advancements in endodontic care remain patient-centered and accessible.
Collapse
Affiliation(s)
- Swati Srivastava
- Department of Conservative Dental Sciences, College of Dentistry, Qassim University, Buraidah, SAU
| |
Collapse
|
3
|
Yi Ği T Eİ, Çetinkaya İ. Effect of Temperature on the Cyclic Fatigue Resistance and Phase Transformation Behavior of Three Different NiTi Endodontic Instruments. Cureus 2024; 16:e52916. [PMID: 38406139 PMCID: PMC10893821 DOI: 10.7759/cureus.52916] [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] [Accepted: 01/22/2024] [Indexed: 02/27/2024] Open
Abstract
Background This study aims to analyze the phase transformation behavior and evaluate the effect of different temperatures on the fracture strength of files. Methodology A total of 108 files were used, and cyclic fatigue tests were performed on HyFlex EDM, VDW.ROTATE, and TruNatomy at three different temperatures (+4°C, +35°C, and +60°C) The time to fracture of files was measured, and the number of cycles was calculated. In addition, the fractured fragment lengths were measured. The Kruskal-Wallis test was used to compare the data that were not normally distributed according to groups. The Mann-Whitney U test was performed for comparisons. P-values <0.05 were considered statistically significant. Results As the temperature increased for all files, the number of cycles to fracture (NCF) decreased. NCF was significantly higher for ROTATE at 4°C and 60°C and HyFlex EDM at 35°C. Conclusions The resistance to cyclic fatigue in all files decreased significantly as the temperature increased.
Collapse
|
4
|
Belladonna FG, Guimarães TDM, Silva EJNL, Vieira EDO, Lee JK, Rodrigues EDA, Souza EM, Versiani MA. Exploring the Efficacy of 6 Preparation Systems for Achieving Minimal Root Canal Transportation: A Micro-CT Investigation. J Endod 2023; 49:1722-1732. [PMID: 37717910 DOI: 10.1016/j.joen.2023.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/02/2023] [Accepted: 09/07/2023] [Indexed: 09/19/2023]
Abstract
INTRODUCTION This study aimed to assess the canal transportation with 6 preparation systems. METHODS Sixty curved mesial roots of mandibular molars were scanned, and their root canals (n = 20 per group) were prepared with XP-endo Shaper, BioRace, ProTaper Next, Twisted File Adaptive, Reciproc, or Reciproc Blue systems. After preparation, a new scan was conducted, and transportation was determined by comparing the geometric center of the canal in 13,542 cross-sectional slices. The transport direction frequencies were recorded, and linear transport were compared using a Univariate GLM model and Tukey honestly significant difference tests (α = 5 %). RESULTS Transportation was affected by the preparation system and root third (P < .05), with no significant effect observed for the root canal (P > .05). The Twisted File Adaptive had the highest transport (P < .05), and the lowest transports were observed with XP-endo Shaper, ProTaper Next, and BioRace (P < .05). Reciproc Blue and Reciproc showed intermediate results (P < .05). The apical and coronal third exhibited the lowest and highest transportation, respectively (P < .05). A significant interaction was observed between the preparation system and root third (P < .05). In the coronal third, transportation was mostly toward the disto-inside direction, whereas in the middle and apical thirds, transportation was predominantly toward the mesio-outside direction. CONCLUSIONS XP-endo Shaper had the lowest mean linear transportation followed by the ProTaper Next, BioRace, Reciproc Blue, and Reciproc systems. The Twisted File Adaptive system had the worst performance. The direction of transportation was generally toward the inner aspect of the canal at the coronal third and toward the outer aspect of the curve at the middle and apical thirds.
Collapse
Affiliation(s)
| | | | - Emmanuel João Nogueira Leal Silva
- Department of Endodontics, Fluminense Federal University, Rio de Janeiro, Brazil; Department of Endodontics, Grande Rio University (UNIGRANRIO), Rio de Janeiro, Brazil
| | | | - Jong-Ki Lee
- Private Practice, Changwon, Republic of Korea
| | | | - Erick Miranda Souza
- Department of Dentistry II, Federal University of Maranhão, São Luís, Maranhão
| | | |
Collapse
|
5
|
Kasuga Y, Kimura S, Maki K, Unno H, Omori S, Hirano K, Ebihara A, Okiji T. Phase transformation and mechanical properties of heat-treated nickel-titanium rotary endodontic instruments at room and body temperatures. BMC Oral Health 2023; 23:825. [PMID: 37904159 PMCID: PMC10614384 DOI: 10.1186/s12903-023-03550-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 10/18/2023] [Indexed: 11/01/2023] Open
Abstract
BACKGROUND The aim of this study was to evaluate the phase composition, phase transformation temperatures, bending property, and cyclic fatigue resistance of different heat-treated nickel-titanium (NiTi) rotary instruments with the same tip diameter and taper at room (RT; 25 ± 1 °C) and body (BT; 37 ± 1 °C) temperatures. METHODS Five heat-treated NiTi rotary instruments, HyFlex EDM (EDM), HyFlex CM (CM), Vortex Blue (VB), RE file CT (RE) and JIZAI, and a non-heat-treated NiTi rotary instrument (Mtwo) with a size 40, 0.04 taper were investigated. Temperature-dependent phase transformation was examined with differential scanning calorimetry (DSC). The bending loads of the instruments at RT and BT were evaluated using a cantilever-bending test. Cyclic fatigue resistance at RT and BT was measured using a dynamic test, during which the instruments were rotated in combination with a 2-mm back-and-forth motion in an artificial curved canal, and the number of cycles to failure (NCF) was determined. The results were analyzed using two-way repeated measures analysis of variance, a simple main effect test, and the Bonferroni test (α = 0.05). RESULTS DSC results indicated that EDM and Mtwo were primarily composed of martensite/R-phase and austenite, respectively, while the other heat-treated instruments were composed of a mix of martensite/R-phase and austenite at the tested temperatures. Regardless of the temperature setting, the bending loads of heat-treated instruments were significantly lower than those of Mtwo (p < 0.05). EDM showed the lowest bending loads and highest NCF at both temperatures (p < 0.05). CM, VB, and JIZAI showed significantly higher bending loads at BT than at RT (p < 0.05). The NCF of all the heat-treated instruments, except VB, was lower at BT than at RT (p < 0.05). At BT, the NCF of CM, VB, RE, and JIZAI were not significantly higher than that of Mtwo (p > 0.05). CONCLUSIONS Heat-treated NiTi instruments exhibited lower bending loads and higher NCF values than Mtwo. However, this tendency was less pronounced at BT than at RT, especially in the NCF values of instruments with a mixture of martensite/R-phase and austenite phases at the tested temperatures.
Collapse
Affiliation(s)
- Yuka Kasuga
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan
| | - Shunsuke Kimura
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan.
| | - Keiichiro Maki
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan
| | - Hayate Unno
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan
| | - Satoshi Omori
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan
| | - Keiko Hirano
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan
| | - Arata Ebihara
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan
| | - Takashi Okiji
- Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan
| |
Collapse
|
6
|
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.
Collapse
|
7
|
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.
Collapse
|
8
|
Endodontic Rotary Files, What Should an Endodontist Know? Medicina (B Aires) 2022; 58:medicina58060719. [PMID: 35743982 PMCID: PMC9230915 DOI: 10.3390/medicina58060719] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/18/2022] [Accepted: 05/25/2022] [Indexed: 11/17/2022] Open
Abstract
Clinicians should be aware of all the characteristics and capacities of the instruments that are possible to use when conducting a root canal treatment. The wide variety of nickel–titanium (Ni-Ti) rotary systems on the market and the lack of standardisation of this type of instrument makes the choice in each specific case difficult. Therefore, this review is intended to summarize the characteristics that should be taken into account when choosing one instrument over another. It will be essential to know characteristics, of alloy from which the instrument is made. Moreover, the geometry of the instrument will determine its behaviour, being the mass, the one that marks its resistance to a greater extent. The movement performed by the file is another of the fundamental keys to understand rotary instruments. In conclusion, when performing root canal treatment, the characteristics of the instrument and the tooth must be taken into account, and the operator’s own limitations should be known. This paper provides the key points to keep in mind when making this type of treatment.
Collapse
|
9
|
Guillory M, Vall P. Past, Present, and Future Trends of Nickel Titanium Rotary Instrumentation. J Vet Dent 2022; 39:257-268. [PMID: 35585702 DOI: 10.1177/08987564221098566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This article reviews the historical development, properties, and trends of nickel titanium rotary instrumentation use for the veterinary endodontist.
Collapse
Affiliation(s)
| | - Patrick Vall
- Animal Dental Care and Oral Surgery, Colorado Springs, CO
| |
Collapse
|
10
|
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.
Collapse
|
11
|
Zanza A, D’Angelo M, Reda R, Gambarini G, Testarelli L, Di Nardo D. An Update on Nickel-Titanium Rotary Instruments in Endodontics: Mechanical Characteristics, Testing and Future Perspective-An Overview. Bioengineering (Basel) 2021; 8:bioengineering8120218. [PMID: 34940371 PMCID: PMC8698980 DOI: 10.3390/bioengineering8120218] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 12/21/2022] Open
Abstract
Since the introduction of Nickel-Titanium alloy as the material of choice for the manufacturing of endodontic rotary instruments, the success rate of the root canal therapies has been significantly increased. This success mainly arises from the properties of the Nickel-Titanium alloy: the biocompatibility, the superelasticity and the shape memory effect. Those characteristics have led to a reduction in time of endodontic treatments, a simplification of instrumentation procedures and an increase of predictability and effectiveness of endodontic treatments. Nevertheless, the intracanal separation of Nickel-Titanium rotary instruments is still a major concern of endodontists, with a consequent possible reduction in the outcome rate. As thoroughly demonstrated, the two main causes of intracanal separation of endodontic instruments are the cyclic fatigue and the torsional loads. As results, in order to reduce the percentage of intracanal separation research and manufacturers have been focused on the parameters that directly or indirectly influence mechanical properties of endodontic rotary instruments. This review describes the current state of the art regarding the Nickel-Titanium alloy in endodontics, the mechanical behavior of endodontic rotary instruments and the relative stresses acting on them during intracanal instrumentation, highlighting the limitation of the current literature.
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Kwak SW, Shen Y, Liu H, Wang Z, Kim HC, Haapasalo M. Heat Treatment and Surface Treatment of Nickel–Titanium Endodontic Instruments. FRONTIERS IN DENTAL MEDICINE 2021. [DOI: 10.3389/fdmed.2021.769977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Knowledge and thorough understanding of the characteristics of endodontic nickel–titanium (NiTi) files is paramount for dentists performing root canal treatments to patients. Understanding the behavior of the NiTi files guides the clinicians in choosing the correct instruments for different clinical and anatomical situations. This review focuses on the metallurgical properties of endodontic NiTi files, with a special emphasis on recent developments and improvements in metallurgy and the effects of heat treatment and surface treatment. In this study, the impact that such developments have on the properties of endodontic NiTi files is discussed.
Collapse
|
14
|
Van Pham K. Differential scanning calorimetric investigations of three rotary nickel-titanium instrument systems before and after simulated clinical uses. BMC Oral Health 2021; 21:488. [PMID: 34600503 PMCID: PMC8487136 DOI: 10.1186/s12903-021-01857-w] [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: 07/05/2021] [Accepted: 09/28/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The transformation temperatures were important values, influencing the mechanical properties and clinical performance of nickel-titanium instruments. The aim of this study was to determine the transformation temperatures of three rotary nickel-titanium (NiTi) instruments: Reciproc, HyFlex CM Pro, and Neoniti before and after simulated clinical uses. METHODS Ninety new NiTi instruments of three single-file instruments: Reciproc, HyFlex CM Pro, and Neoniti were divided into three groups. Thirty instruments of each group were divided into 3 subgroups (10 instruments for each subgroup): new, one-time simulated clinical used and sterilised, and three times simulated clinical used and sterilized subgroups. The instruments were in the as-received condition for the new subgroups, one time used in the plastic endo-training blocks and sterilised for the one-time subgroups, and three times used in the plastic endo-training blocks and sterilised for the three times subgroups. Each instrument in subgroups was cut into four small segments of 4-5 mm. All segments of instruments were analysed using Differential Scanning Calorimetry (DSC). Data was collected and analysed using SPSS version 20.0 with ANOVA test or Kruskal-Wallis test at the significant level of 0.05. RESULTS There was not significant difference between before and after simulated clinical use with sterilised procedure in three NiTi instrument systems. The austenite-finish (Af) temperatures of three instrument systems were higher than that of the human body (37 °C), of these, the Af temperature of Neoniti was highest and that of HyFlex CM Pro was lowest. CONCLUSIONS The austenite-finish (Af) temperatures of three NiTi instruments were higher than that of human body temperature, therefore, material was in the phase transformation from martensite to austenite, gives the instruments more flexibility when used in the clinical situation.
Collapse
Affiliation(s)
- Khoa Van Pham
- Department of Operative Dentistry and Endodontics, Faculty of Odonto-Stomatology, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, 700000, Vietnam.
| |
Collapse
|
15
|
In-Depth Metallurgical and Microstructural Analysis of Oneshape and Heat Treated Onecurve Instruments. Eur Endod J 2021; 6:90-97. [PMID: 33762534 DOI: 10.14744/eej.2021.63634] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVE To define surface, mechanical, microstructural and metallurgical features of conventional One-Shape (OShape) and heat-treated OneCurve (OCurve) nickel-titanium instruments. METHODS Instruments were analysed by scanning electron microscopy (SEM) on new instruments and after simulated clinical use (SCU). Cyclic fatigue testing was performed and the number of cycles to fracture (NCF) and the length of the fractured instruments were measured (Mann-Whitney test). Fractured instruments during cyclic fatigue testing were then inspected by SEM fractographic analysis. Field emission gun scanning scanning electron microscopy (FEG-SEM), energy-dispersive X-ray spectroscopy (EDX) and micro-Raman spectroscopy were used to assess alloy surface chemistry. Focused ion beam (FIB) was performed to analyse the oxide layer on the surface of OCurve before and after SCU. X-Ray diffraction (XRD), metallographic evaluation and differential scanning calorimetry (DSC) were used to determine martensitic/austenitic phase transformation temperatures. RESULTS SEM observations on new instruments revealed a smooth regular surface with flattened milling grooves. No wear features were detected after SCU. OCurve exhibited a higher cyclic fatigue resistance (P<0.05), slower crack propagation and a surface layer of TiO2. Metallographic analysis and XRD showed the prevalence of martensitic grains on OCurve instruments that were stable at body temperature as confirmed by DSC analysis. Furthermore, DSC demonstrated a shift in the temperature transformation ranges suggesting an increase of martensite phase in autoclaved OCurve instruments. CONCLUSION Heat treatment processes were confirmed as a valid enhancement of the properties of the new generation NiTi instruments. OCurve presented a significant improvement over OShape regarding both mechanical and metallurgical characteristics.
Collapse
|
16
|
Arslan H, Doğanay Yıldız E, Taş G, Karataş E, Tepecik E. Effects of continuous irrigation at room temperature or +4ºC on the cyclic fatigue resistance of K3XF instruments. J Dent Res Dent Clin Dent Prospects 2021; 14:153-157. [PMID: 33408819 PMCID: PMC7770397 DOI: 10.34172/joddd.2020.038] [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: 01/11/2020] [Accepted: 07/31/2020] [Indexed: 11/09/2022] Open
Abstract
Background. The present study aimed to evaluate the impact of continuous irrigation with saline solution at room temperature or +4°C on the cyclic fatigue resistance of K3XF files.
Methods. Forty-eight new K3XF files (#30, .04 taper) were randomly assigned to three groups: control group (no irrigation), continuous irrigation with saline solution at room temperature, and continuous irrigation with saline solution at +4°C. The instruments were tested in an artificial, stainless steel root canal with a double curvature at body temperature (37±1°C). Time to fracture was converted to the number of cycles to fracture (NCF). The lengths of the fractured fragments were recorded. Kruskal–Wallis H test and one-way ANOVA were used to analyze data.
Results. K3XF files’ cyclic fatigue resistance was significantly higher in the continuous irrigation groups than in the control group. Continuous irrigation with saline solution at +4°C resulted in higher cyclic fatigue resistance than continuous irrigation with saline solution at room temperature. There were no significant differences between the groups in terms of the fractured fragments’ length.
Conclusion. Within this study’s limitations, continuous irrigation with saline solution increased the NCF of NiTi instruments; decreasing the saline solution’s temperature increased this effect.
Collapse
Affiliation(s)
- Hakan Arslan
- Department of Endodontics, Faculty of Dentistry, Health Sciences University, İstanbul, Turkey
| | - Ezgi Doğanay Yıldız
- Department of Endodontics, Faculty of Dentistry, Bursa Uludağ University, Bursa, Turkey
| | - Gizem Taş
- Çorlu Oral and Dental Health Hospital, Tekirdağ, Turkey
| | - Ertuğrul Karataş
- Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey
| | - Ebru Tepecik
- Private Practice, Dental Clinic, İstanbul, Turkey
| |
Collapse
|
17
|
Hou XM, Yang YJ, Qian J. Phase transformation behaviors and mechanical properties of NiTi endodontic files after gold heat treatment and blue heat treatment. J Oral Sci 2020; 63:8-13. [PMID: 33281148 DOI: 10.2334/josnusd.19-0331] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
WaveOne Gold, ProTaper Gold, Reciproc Blue, ProTaper Next, WaveOne and ProTaper files were selected to compare the phase transformation behaviors and mechanical properties of nickel-titanium (NiTi) rotary files after gold heat and blue heat treatments. The reverse transformation finishing point temperatures of WaveOne Gold, ProTaper Gold, ProTaper Next and WaveOne were higher than those of the other two instruments investigated. At a deflection of 0.5 mm, the loads were significantly varied except for ProTaper Next and ProTaper Gold. At a deflection of 3.0 mm, the loads of Reciproc Blue and WaveOne Gold were significantly varied compared to WaveOne and ProTaper. Cycles to failure were reduced in the order of WaveOne Gold, Reciproc Blue, ProTaper Gold, ProTaper Next, WaveOne and ProTaper. NiTi instruments after gold heat and blue heat treatments exhibited significantly higher bending properties and cyclic fatigue resistances, representing an improved performance over traditional and M-wire instruments.
Collapse
Affiliation(s)
- Xiao-Mei Hou
- The Second Dental Center of Peking University School of Stomatology
| | - Yin-Jie Yang
- Department of Stomatology, Beijing Xicheng District Xinjiekou Community Health Service Center
| | - Jun Qian
- The Second Dental Center of Peking University School of Stomatology
| |
Collapse
|
18
|
Generali L, Malovo A, Bolelli G, Borghi A, La Rosa GRM, Puddu P, Lusvarghi L, Rota A, Consolo U, Pedullà E. Mechanical Properties and Metallurgical Features of New Green NiTi Reciprocating Instruments. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E3736. [PMID: 32847048 PMCID: PMC7503947 DOI: 10.3390/ma13173736] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/05/2020] [Accepted: 08/21/2020] [Indexed: 11/16/2022]
Abstract
To evaluate the properties of two nickel-titanium (NiTi) reciprocating endodontic instruments (commercially known as Procodile and Reziflow), a total of 40 size 25 and 0.06 taper new Procodile and Reziflow instruments (n = 20) were subjected to cyclic fatigue tests (60° angle of curvature, 5-mm radius) at 20 °C and 37 °C and a torsional test based on ISO 3630-1. The fracture surface of each fragment was examined. The morphological, mechanical, chemical, thermal, and phase composition characteristics of the files were investigated by field-emission gun scanning electron microscopy (FEG-SEM) equipped with an energy-dispersive X-ray (EDX) detector, focused ion beam analysis (FIB), micro-Raman spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Auger electron spectroscopy (AES). Reziflow showed higher cyclic fatigue resistance than Procodile at 37 °C (p < 0.05). The maximum torsional strength of Procodile was lower than that of Reziflow (p < 0.05). No difference was found between their angular rotations to fracture (p > 0.05). SEM, FIB, Micro-Raman, and AES analyses revealed the presence of an Nb/Nb2O5 coating on the Procodile surface. DSC and XRD analysis confirmed that both files consist of an almost austenitic phase structure at 37 °C. The cyclic fatigue resistance of Procodile and Reziflow significantly decreases upon exposure to body temperature.
Collapse
Affiliation(s)
- Luigi Generali
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), University of Modena and Reggio Emilia, 41124 Modena, Italy; (A.M.); (A.B.); (U.C.)
| | - Anastasiya Malovo
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), University of Modena and Reggio Emilia, 41124 Modena, Italy; (A.M.); (A.B.); (U.C.)
| | - Giovanni Bolelli
- Department of Engineering “Enzo Ferrari” (DIEF), University of Modena and Reggio Emilia, 41125 Modena, Italy; (G.B.); (P.P.); (L.L.)
- InterMech—MO.RE. Centro Interdipartimentale per la Ricerca Applicata e i Servizi nel Settore della Meccanica Avanzata e della Motoristica, University of Modena and Reggio Emilia, 41125 Modena, Italy
- Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (INSTM), Local Unit: University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Alessia Borghi
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), University of Modena and Reggio Emilia, 41124 Modena, Italy; (A.M.); (A.B.); (U.C.)
| | - Giusy Rita Maria La Rosa
- Department of General Surgery and Surgical-Medical Specialties, University of Catania, 95124 Catania, Italy; (G.R.M.L.R.); (E.P.)
| | - Pietro Puddu
- Department of Engineering “Enzo Ferrari” (DIEF), University of Modena and Reggio Emilia, 41125 Modena, Italy; (G.B.); (P.P.); (L.L.)
| | - Luca Lusvarghi
- Department of Engineering “Enzo Ferrari” (DIEF), University of Modena and Reggio Emilia, 41125 Modena, Italy; (G.B.); (P.P.); (L.L.)
- InterMech—MO.RE. Centro Interdipartimentale per la Ricerca Applicata e i Servizi nel Settore della Meccanica Avanzata e della Motoristica, University of Modena and Reggio Emilia, 41125 Modena, Italy
- Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (INSTM), Local Unit: University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Alberto Rota
- Department of Physics, Computer Science and Mathematics, University of Modena and Reggio Emilia, 41125 Modena, Italy;
| | - Ugo Consolo
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), University of Modena and Reggio Emilia, 41124 Modena, Italy; (A.M.); (A.B.); (U.C.)
| | - Eugenio Pedullà
- Department of General Surgery and Surgical-Medical Specialties, University of Catania, 95124 Catania, Italy; (G.R.M.L.R.); (E.P.)
| |
Collapse
|
19
|
Peters OA, Arias A, Choi A. Mechanical Properties of a Novel Nickel-titanium Root Canal Instrument: Stationary and Dynamic Tests. J Endod 2020; 46:994-1001. [DOI: 10.1016/j.joen.2020.03.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 03/03/2020] [Accepted: 03/13/2020] [Indexed: 10/24/2022]
|
20
|
Elnaghy AM, Elsaka SE, Mandorah AO. In vitro comparison of cyclic fatigue resistance of TruNatomy in single and double curvature canals compared with different nickel-titanium rotary instruments. BMC Oral Health 2020; 20:38. [PMID: 32019522 PMCID: PMC7001210 DOI: 10.1186/s12903-020-1027-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 01/29/2020] [Indexed: 11/16/2022] Open
Abstract
Background The purpose of this study was to compare the cyclic fatigue resistance of newly developed TruNatomy instruments (TRN) in single and double (S-shaped) curvature canals with HyFlex CM (HCM), Vortex Blue (VB) and RaCe (RC) instruments. Methods Size 20/.04 taper and size 25/0.04 of HCM, VB and RC were used. For TRN instruments, size 20/.04 taper (small) and size 26/.04 taper (prime) were used. The instruments were tested in artificial canals with double curvature (coronal curve; 60° curvature, 5 mm radius and apical curve; 70° curvature and 2 mm radius) and single curvature (60° curvature, 5 mm radius). The number of cycles to failure (NCF) was recorded. Data were statistically analyzed by Kruskal-Wallis and Dunn’s multiple comparison tests. Weibull analysis was performed on NCF data. Statistical significant was set at p < 0.05. Results TRN and HCM revealed higher NCF compared with the other instruments for both tested sizes in single and double curvature canals (p < 0.05). TRN and HCM showed no statistically significant difference in the NCF (p > 0.05). The probability of survival was higher for HCM and TRN instruments than VB and RC instruments. Conclusions HCM and TRN instruments were more resistant to cyclic fatigue than VB and RC instruments in single and double curvature canals. HCM and TRN instruments were anticipated to survive with higher number of cycles than the other tested instruments. RC instrument had the lowest fatigue resistance than the other instruments.
Collapse
Affiliation(s)
- Amr M Elnaghy
- Department of Endodontics, Faculty of Dentistry, Mansoura University, Mansoura, PC, 35516, Egypt.
| | - Shaymaa E Elsaka
- Department of Dental Biomaterials, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.,Department of Restorative Science, Alfarabi Private College for Dentistry and Nursing, Jeddah, Saudi Arabia
| | - Ayman O Mandorah
- Department of Restorative and Dental Materials, Faculty of Dentistry, Taif University, Taif, Saudi Arabia
| |
Collapse
|
21
|
Generali L, Puddu P, Borghi A, Brancolini S, Lusvarghi L, Bolelli G, Consolo U, Pedullà E. Mechanical properties and metallurgical features of new and
ex vivo
used Reciproc Blue and Reciproc. Int Endod J 2019; 53:250-264. [DOI: 10.1111/iej.13214] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 08/30/2019] [Indexed: 11/26/2022]
Affiliation(s)
- L. Generali
- Department of Surgery, Medicine Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO) University of Modena and Reggio Emilia Modena Italy
| | - P. Puddu
- Department of Engineering “Enzo Ferrari” (DIEF) University of Modena and Reggio Emilia Modena Italy
| | - A. Borghi
- Department of Surgery, Medicine Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO) University of Modena and Reggio Emilia Modena Italy
| | - S. Brancolini
- Department of Surgery, Medicine Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO) University of Modena and Reggio Emilia Modena Italy
| | - L. Lusvarghi
- Department of Engineering “Enzo Ferrari” (DIEF) University of Modena and Reggio Emilia Modena Italy
| | - G. Bolelli
- Department of Engineering “Enzo Ferrari” (DIEF) University of Modena and Reggio Emilia Modena Italy
| | - U. Consolo
- Department of Surgery, Medicine Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO) University of Modena and Reggio Emilia Modena Italy
| | - E. Pedullà
- Department of General Surgery and Surgical‐Medical Specialties University of Catania Catania Italy
| |
Collapse
|
22
|
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.
Collapse
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
| |
Collapse
|
23
|
Generali L, Borghi A, Lusvarghi L, Bolelli G, Veronesi P, Vecchi A, Consolo U, Becce C, Bertoldi C, Sassatelli P. Evaluation of the usage-induced degradation of Genius and Reciproc nickel-titanium reciprocating instruments. Odontology 2019; 107:473-481. [PMID: 30924034 DOI: 10.1007/s10266-019-00423-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 01/31/2019] [Indexed: 11/30/2022]
Abstract
The aim of this study was to characterize the main features and the usage-induced degradation of the Genius file after four severely curved root canal instrumentations and to compare their properties to the Reciproc files. Brand new and ex vivo used files were analysed by scanning electron microscopy (SEM) with energy-dispersive X-ray spectrometry (EDS), differential scanning calorimetry (DSC), X-ray diffraction (XRD), optical metallography, and nano-indentation to disclose their morphological, chemical, mechanical, thermal, and phase composition features. Nano-indentation data were statistically analysed using the Student's t test for normal distribution or the Kolmogorov-Smirnov test for not-normal distributions. SEM analysis showed the presence of micro-cracks near the tip on both files after ex vivo usage test. EDS analysis confirmed that both files are manufactured from an almost equiatomic NiTi alloy. DSC analysis revealed that the transition temperature of the Genius is below 20 °C, while that of the Reciproc is above 20 °C. XRD analysis of Genius files identified cubic B2 austenite with minor peaks of residual monoclinic B19 martensite, while the contemporaneous presence of martensite, austenite and hexagonal R-phase was observed in the Reciproc files. Significant differences in nanohardness and modulus of elasticity (P < .05) were observed in both Genius and Reciproc files before and after use. The collected results showed that both instruments can be safely used as single-use files.
Collapse
Affiliation(s)
- Luigi Generali
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), University of Modena and Reggio Emilia, Modena, Italy.
| | - Alessia Borghi
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), University of Modena and Reggio Emilia, Modena, Italy
| | - Luca Lusvarghi
- Department of Engineering Enzo Ferrari (DIEF), University of Modena and Reggio Emilia, Modena, Italy
| | - Giovanni Bolelli
- Department of Engineering Enzo Ferrari (DIEF), University of Modena and Reggio Emilia, Modena, Italy
| | - Paolo Veronesi
- Department of Engineering Enzo Ferrari (DIEF), University of Modena and Reggio Emilia, Modena, Italy
| | | | - Ugo Consolo
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), University of Modena and Reggio Emilia, Modena, Italy
| | | | - Carlo Bertoldi
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), University of Modena and Reggio Emilia, Modena, Italy
| | - Paolo Sassatelli
- Department of Engineering Enzo Ferrari (DIEF), University of Modena and Reggio Emilia, Modena, Italy
| |
Collapse
|
24
|
Pedullà E, Ambu E, Rovai F, Chang SW, Campedelli F, Corsentino G, Rapisarda S, La Rosa GRM, Grandini S. Influence of proper or reciprocating optimum torque reverse kinematics on cyclic fatigue of four single files. ACTA ACUST UNITED AC 2019; 10:e12409. [PMID: 30848100 DOI: 10.1111/jicd.12409] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 10/19/2018] [Indexed: 11/30/2022]
Abstract
AIM The aim of the present study was to evaluate the resistance to cyclic fatigue of heat-treated single files used in proper or in reciprocating optimum torque reverse motions. METHODS Ninety-six HyFlex electrical discharge machining (EDM), Reciproc R25 (Rec), WaveOne Primary (WO), and WaveOne Gold (WOG) Primary were used. Resistance to cyclic fatigue was determined by recording time to fracture in a stainless steel artificial canal. Differential scanning calorimetric analysis was performed. Data were analyzed by two-way analysis of variance and Bonferroni post-hoc tests at 0.05. RESULTS In both movements, HyFlex EDM showed higher time to fracture than other files (P < 0.0001). Rec showed higher time to fracture than WO (P < 0.0001), while WOG showed higher cyclic fatigue resistance than Rec and WO with both movements (P < 0.005). CONCLUSIONS Reciprocating optimum torque reverse motion improved significantly cyclic fatigue resistance of gold and controlled memory wire single files.
Collapse
Affiliation(s)
- Eugenio Pedullà
- Department of General Surgery and Surgical-Medical Specialties, University of Catania, Catania, Italy
| | - Emanuele Ambu
- Department of Endodontics and Restorative Dentistry, University of Siena, Siena, Italy
| | | | - Seok-Woo Chang
- Department of Conservative Dentistry, Kyung Hee University, Seoul, Korea
| | - Federico Campedelli
- Department of Endodontics and Restorative Dentistry, University of Siena, Siena, Italy
| | - Giacomo Corsentino
- Department of Endodontics and Restorative Dentistry, University of Siena, Siena, Italy
| | - Silvia Rapisarda
- Department of General Surgery and Surgical-Medical Specialties, University of Catania, Catania, Italy
| | - Giusy R M La Rosa
- Department of General Surgery and Surgical-Medical Specialties, University of Catania, Catania, Italy
| | - Simone Grandini
- Department of Endodontics and Restorative Dentistry, University of Siena, Siena, Italy
| |
Collapse
|
25
|
Fu HY, Wang FF, Hou XM. [Construction and mechanical analysis of finite element model for bending property of controlled memory wire nickel-titanium rotary file]. JOURNAL OF PEKING UNIVERSITY. HEALTH SCIENCES 2019; 51:131-135. [PMID: 30773557 DOI: 10.19723/j.issn.1671-167x.2019.01.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To construct a model for a controlled memory (CM) nickel-titanium (NiTi) file and another M-wire NiTi file with the same geometry by using finite element analysis. To evaluate the flexibility of a CM NiTi file by using three dimensional finite element method and to compare its mechanical responses with that M-wire NiTi. METHODS Based on the reverse engineering, the 21 mm long, 25#/08 taper Hyflex NT NiTi file and Hyflex CM NiTi file were fixed by the cantilever bending model at a distance of 9.5 mm from the tip of the file. The mechanical tester's indenter was loaded/unloaded at a distance of 3 mm from the tip of the file. The maximum displacement was 3 mm, the load displacement curve was obtained. Subsequently, by using a micro-CT to scan (layer spacing of 8 μm) NiTi files, and ABAQUS (6.10) was introduced to construct a geometric model. Hyflex NT was considered as a shapememory alloy constitutive model, Hyflex CM was considered as a power-hardening plastic constitutive model, respectively. Comparing the load-displacement curve of cantilever bending in the three-dimensional finite element model with the load-displacement curve in the experiment. RESULTS Two tetrahedral element models were constructed, the total number of nodes was 99 353 and the total number of cells was 63 744. When the loading displacement was 1 mm, the stress distribution of the cross section at 6.1 mm from the tip of the file was observed. The upper and lower surfaces were subjected to the maximum bending stress and entered the phase transformation yield stage. The finite element simulation could clearly show the deformation of the file. Various information such as deformation characteristics and stress distribution in the process were well fitted to the actual experimental curve. CONCLUSION The constitutive behavior of the material has a significant effect on the mechanical behavior of NiTi file. The finite element model established for the NiTi file of the CM wire can accurately capture the characteristics of various deformation processes of the NiTi root canal file, and it has a good fit with the actual experimental curve. The finite element model can be used for study on bending properties of CM wire.
Collapse
Affiliation(s)
- H Y Fu
- Department of Stomatology, Peking University First Hospital, Beijing 100034, China
| | - F F Wang
- Department of Stomatology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - X M Hou
- Second Clinical Division, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100101, China
| |
Collapse
|
26
|
Gil J, Rupérez E, Velasco E, Aparicio C, Manero JM. Mechanism of fracture of NiTi superelastic endodontic rotary instruments. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2018; 29:131. [PMID: 30088100 DOI: 10.1007/s10856-018-6140-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 07/26/2018] [Indexed: 06/08/2023]
Abstract
The aim is to investigate the premature catastrophic fracture produced for different periods during clinical endodontic treatment of two brands of NiTi endodontic rotary instruments. 3 samples as-received, 6 samples used with patients for 2 and 7 h and 5 samples fractured were studied for each brand of endodontic NiTi rotary instruments. Transformation temperatures (Ms, Mf, As and Af) and enthalpies of transformation were determined by calorimetry. Critical stresses until fracture (σβ→SIM, σSIM→β) were obtained using an electromechanical testing machine. The samples were also visualized by Scanning Electron Microscopy. Calorimetric studies have shown an increase of the Ms and As transformation temperatures with time of use as well as a decrease of their stress transformations. Moreover, reverse transformation enthalpies decreased along the time. The enthalpies of transformation decreased because martensitic plates were anchored, which prevented their transformation to austenite; thus losing its superelastic effect. The stabilisation of the martensitic plates induced the collapse of the structure and so the main cause for the fracture. The heat treatment proposed has been increased the life in service of NiTi superelastic endodontic instruments recovering theirs superelastic effect.
Collapse
Affiliation(s)
- Javier Gil
- School of Dentistry, Universitat Internacional de Catalunya, Barcelona, Spain.
| | - Elisa Rupérez
- Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgy, Technical University of Catalonia (UPC), Barcelona, Spain
| | - Eugenio Velasco
- Faculty of Odontology, University of Seville, Seville, Spain
| | - Conrado Aparicio
- MDRCBB-Minnesota Dental Research Center for Biomaterials and Biomechanics, Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, USA
| | - José María Manero
- Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgy, Technical University of Catalonia (UPC), Barcelona, Spain
| |
Collapse
|
27
|
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
| |
Collapse
|
28
|
Mechanical and Metallurgical Properties of Various Nickel-Titanium Rotary Instruments. BIOMED RESEARCH INTERNATIONAL 2017; 2017:4528601. [PMID: 29318149 PMCID: PMC5727669 DOI: 10.1155/2017/4528601] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/27/2017] [Accepted: 11/02/2017] [Indexed: 11/26/2022]
Abstract
The aim of this study was to investigate the effect of thermomechanical treatment on mechanical and metallurgical properties of nickel-titanium (NiTi) rotary instruments. Eight kinds of NiTi rotary instruments with sizes of ISO #25 were selected: ProFile, K3, and One Shape for the conventional alloy; ProTaper NEXT, Reciproc, and WaveOne for the M-wire alloy; HyFlex CM for the controlled memory- (CM-) wire; and TF for the R-phase alloy. Torsional fracture and cyclic fatigue fracture tests were performed. Products underwent a differential scanning calorimetry (DSC) analysis. The CM-wire and R-phase groups had the lowest elastic modulus, followed by the M-wire group. The maximum torque of the M-wire instrument was comparable to that of a conventional instrument, while those of the CM-wire and R-phase instruments were lower. The angular displacement at failure (ADF) for the CM-wire and R-phase instruments was higher than that of conventional instruments, and ADF of the M-wire instruments was lower. The cyclic fatigue resistance of the thermomechanically treated NiTi instruments was higher. DSC plots revealed that NiTi instruments made with the conventional alloy were primarily composed of austenite at room temperature; stable martensite and R-phase were found in thermomechanically treated instruments.
Collapse
|
29
|
Miccoli G, Gaimari G, Seracchiani M, Morese A, Khrenova T, Di Nardo D. In vitro resistance to fracture of two nickel-titanium rotary instruments made with different thermal treatments. ANNALI DI STOMATOLOGIA 2017; 8:53-58. [PMID: 29299189 DOI: 10.11138/ads/2017.8.2.059] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Aim Aim of the study was to evaluate effectiveness of different heat treatments in improving Ni-Ti endodontic rotary instruments' resistance to fracture. Methods 24 new NiTi instruments similar in length and shape: 12 M3 instruments, tip size 25 and .06 taper (United Dental, Shanghai, China), and 12 M3 Pro Gold instruments tip size 25 and .06 taper (United Dental, Shanghai, China), were tested in a 60° curved artificial root canal. Each group received a different heat treatment. Cycles to fracture were calculated for each instrument. Differences among groups were evaluated with an analysis of variance test (significance level was set at P<0.05.). Results Statistical analysis found significant differences (p<0.0213) between groups. The M3 Pro Gold instruments were significantly more resistant to fatigue (mean values = 1012, SD +/- 77) than M3 instruments (mean values = 748, SD +/- 62). No statistically significant differences were found between fragments' lengths (p>0,05). Conclusions An increased flexibility and the reduction of internal defects produced by heat treatments during or after manufacturing processes, may be responsible for improving resistance to cyclic fatigue and flexural stresses.
Collapse
Affiliation(s)
- Gabriele Miccoli
- Department of Oral and Maxillo-Facial Sciences, "Sapienza" University of Rome, Rome, Italy
| | - Gianfranco Gaimari
- Department of Oral and Maxillo-Facial Sciences, "Sapienza" University of Rome, Rome, Italy
| | - Marco Seracchiani
- Department of Oral and Maxillo-Facial Sciences, "Sapienza" University of Rome, Rome, Italy
| | - Antonio Morese
- Department of Oral and Maxillo-Facial Sciences, "Sapienza" University of Rome, Rome, Italy
| | - Tatyana Khrenova
- Department of Oral and Maxillo-Facial Sciences, "Sapienza" University of Rome, Rome, Italy
| | - Dario Di Nardo
- Department of Oral and Maxillo-Facial Sciences, "Sapienza" University of Rome, Rome, Italy
| |
Collapse
|
30
|
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.
Collapse
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
| |
Collapse
|
31
|
Iacono F, Pirani C, Generali L, Bolelli G, Sassatelli P, Lusvarghi L, Gandolfi MG, Giorgini L, Prati C. Structural analysis of HyFlex EDM instruments. Int Endod J 2016; 50:303-313. [DOI: 10.1111/iej.12620] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 02/08/2016] [Indexed: 11/29/2022]
Affiliation(s)
- F. Iacono
- Endodontic Clinical Section; Department of Biomedical and Neuromotor Sciences (DIBINEM); University of Bologna; Bologna Italy
| | - C. Pirani
- Endodontic Clinical Section; Department of Biomedical and Neuromotor Sciences (DIBINEM); University of Bologna; Bologna Italy
| | - L. Generali
- Endodontic Section; Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery; Oncology and Regenerative Medicine Relevance (CHIMOMO); School of Dentistry; University of Modena and Reggio Emilia; Modena Italy
| | - G. Bolelli
- Department of Engineering “Enzo Ferrari” (DIEF); University of Modena and Reggio Emilia; Modena Italy
| | - P. Sassatelli
- Department of Engineering “Enzo Ferrari” (DIEF); University of Modena and Reggio Emilia; Modena Italy
| | - L. Lusvarghi
- Department of Engineering “Enzo Ferrari” (DIEF); University of Modena and Reggio Emilia; Modena Italy
| | - M. G. Gandolfi
- Endodontic Clinical Section; Department of Biomedical and Neuromotor Sciences (DIBINEM); University of Bologna; Bologna Italy
| | - L. Giorgini
- Department of Industrial Chemistry “Toso Montanari” and INSTM UdR-Bologna; University of Bologna; Bologna Italy
| | - C. Prati
- Endodontic Clinical Section; Department of Biomedical and Neuromotor Sciences (DIBINEM); University of Bologna; Bologna Italy
| |
Collapse
|
32
|
Phase Transformation Behavior and Resistance to Bending and Cyclic Fatigue of ProTaper Gold and ProTaper Universal Instruments. J Endod 2015; 41:1134-8. [DOI: 10.1016/j.joen.2015.02.030] [Citation(s) in RCA: 146] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 02/19/2015] [Accepted: 02/22/2015] [Indexed: 11/19/2022]
|
33
|
Shen Y, Zhou H, Coil JM, Aljazaeri B, Buttar R, Wang Z, Zheng YF, Haapasalo M. ProFile Vortex and Vortex Blue Nickel-Titanium Rotary Instruments after Clinical Use. J Endod 2015; 41:937-42. [DOI: 10.1016/j.joen.2015.02.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 01/31/2015] [Accepted: 02/03/2015] [Indexed: 11/26/2022]
|
34
|
Ha JH, Kim SK, Cheung GSP, Jeong SH, Bae YC, Kim HC. Effect of alloy type on the life-time of torsion-preloaded nickel-titanium endodontic instruments. SCANNING 2015; 37:172-178. [PMID: 25676195 DOI: 10.1002/sca.21195] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 01/03/2015] [Accepted: 01/09/2015] [Indexed: 06/04/2023]
Abstract
This study was aimed to evaluate the effect of torsional preloads on the cyclic fatigue life of nickel-titanium (NiTi) instruments with different history of heat treatments by manufacturers. WaveOne (Primary) made of M-wire, K3XF (#30/0.06) of R-phase, and ProTaper (F2) of conventional NiTi alloy was used. Each file was preloaded at four conditions (nil, 25, 50, and 75% of their mean ultimate torsional strength) before fatigue testing. The torsional preloads 10-, 30-, or 50-times were applied by securing 5 mm of the file tip, rotating it until the preset torque was attained before returning to the origin. Then, the number of cycles to failure (NCF) was evaluated by rotational bending in a simulated canal. Data were analyzed using multiple linear regression analysis and two-way ANOVA. Fractured instruments were examined under scanning electron microscope (SEM). SEM showed that most WaveOne after 75% preloading, regardless of repetitions, showed some longitudinal cracks parallel to the long axis of the file, which were rare for K3XF. Regression analysis revealed that the brand of instrument was the most critical factor. At up to 75% preloading, ProTaper and K3XF did not show any significant decline in NCF. For 30-repetition groups of WaveOne, the 50 and 25% torsion preloaded groups showed a significantly higher NCF than the 0 and 75% groups. Within the limitations of this study, the alloy type of NiTi instrument have a significant effect on the phenomenon that a certain amount of torsional preload may improve the cyclic fatigue resistance of NiTi rotary instruments.
Collapse
Affiliation(s)
- Jung-Hong Ha
- Department of Conservative Dentistry, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Sung Kyo Kim
- Department of Conservative Dentistry, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Gary Shun-Pan Cheung
- Area of Endodontics, Faculty of Dentistry, University of Hong Kong, Hong Kong SAR, China
| | - Seong Hwa Jeong
- Faculty of Health Science, Daegu Haany University, Gyeongsan, Korea
| | - Yong Chul Bae
- Department of Oral Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Hyeon-Cheol Kim
- Department of Conservative Dentistry, School of Dentistry, Pusan National University, Dental Research Institute, Yangsan, Korea
| |
Collapse
|
35
|
Pagliosa A, Sousa-Neto MD, Versiani MA, Raucci-Neto W, Silva-Sousa YTC, Alfredo E. Computed tomography evaluation of rotary systems on the root canal transportation and centering ability. Braz Oral Res 2015; 29:S1806-83242015000100240. [PMID: 25715038 DOI: 10.1590/1807-3107bor-2015.vol29.0039] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 11/09/2014] [Indexed: 11/22/2022] Open
Abstract
The endodontic preparation of curved and narrow root canals is challenging, with a tendency for the prepared canal to deviate away from its natural axis. The aim of this study was to evaluate, by cone-beam computed tomography, the transportation and centering ability of curved mesiobuccal canals in maxillary molars after biomechanical preparation with different nickel-titanium (NiTi) rotary systems. Forty teeth with angles of curvature ranging from 20° to 40° and radii between 5.0 mm and 10.0 mm were selected and assigned into four groups (n = 10), according to the biomechanical preparative system used: Hero 642 (HR), Liberator (LB), ProTaper (PT), and Twisted File (TF). The specimens were inserted into an acrylic device and scanned with computed tomography prior to, and following, instrumentation at 3, 6 and 9 mm from the root apex. The canal degree of transportation and centering ability were calculated and analyzed using one-way ANOVA and Tukey's tests (α = 0.05). The results demonstrated no significant difference (p > 0.05) in shaping ability among the rotary systems. The mean canal transportation was: -0.049 ± 0.083 mm (HR); -0.004 ± 0.044 mm (LB); -0.003 ± 0.064 mm (PT); -0.021 ± 0.064 mm (TF). The mean canal centering ability was: -0.093 ± 0.147 mm (HR); -0.001 ± 0.100 mm (LB); -0.002 ± 0.134 mm (PT); -0.033 ± 0.133 mm (TF). Also, there was no significant difference among the root segments (p > 0.05). It was concluded that the Hero 642, Liberator, ProTaper, and Twisted File rotary systems could be safely used in curved canal instrumentation, resulting in satisfactory preservation of the original canal shape.
Collapse
Affiliation(s)
- André Pagliosa
- Faculty of Dentistry, Universidade de Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | - Manoel Damião Sousa-Neto
- Restorative Dentistry Department, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Marco Aurélio Versiani
- Restorative Dentistry Department, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Walter Raucci-Neto
- Faculty of Dentistry, Universidade de Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | | | - Edson Alfredo
- Faculty of Dentistry, Universidade de Ribeirão Preto, Ribeirão Preto, SP, Brazil
| |
Collapse
|
36
|
Assessment of the Mechanical Properties of ProTaper Next Nickel-Titanium Rotary Files. J Endod 2014; 40:1830-4. [DOI: 10.1016/j.joen.2014.06.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Revised: 06/03/2014] [Accepted: 06/06/2014] [Indexed: 11/19/2022]
|
37
|
Jamleh A, Sadr A, Nomura N, Ebihara A, Yahata Y, Hanawa T, Tagami J, Suda H. Endodontic instruments after torsional failure: nanoindentation test. SCANNING 2014; 36:437-443. [PMID: 24610598 DOI: 10.1002/sca.21139] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 01/24/2014] [Indexed: 06/03/2023]
Abstract
This study aimed to evaluate effects of torsional loading on the mechanical properties of endodontic instruments using the nanoindentation technique. ProFile (PF; size 30, taper 04; Dentsply Maillefer, Switzerland) and stainless steel (SS; size 30, taper 02; Mani, Japan) instruments were subjected to torsional test. Nanoindentation was then performed adjacent to the edge of fracture (edge) and at the cutting part beside the shank (shank). Hardness and elastic modulus were measured under 100-mN force on 100 locations at each region, and compared to those obtained from the same regions on new instruments. It showed that PF and SS instruments failed at 559 ± 67 and 596 ± 73 rotation degrees and mean maximum torque of 0.90 ± 0.07 and 0.99 ± 0.05 N-cm, respectively. Hardness and elastic modulus ranged 4.8-6.7 and 118-339 GPa in SS, and 2.7-3.2 and 52-81 GPa in PF. Significant differences between torsion-fractured and new instruments in hardness and elastic modulus were detected in the SS system used. While in PF system, the edge region after torsional fracture had significantly lower hardness and elastic modulus compared to new instruments. The local hardness and modulus of elasticity of endodontic instruments adjacent to the fracture edge are significantly reduced by torsional loading.
Collapse
Affiliation(s)
- Ahmed Jamleh
- Department of Endodontics, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, National Guard Health Affairs, Riyadh, Saudi Arabia
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Effect of Fatigue on Torsional Failure of Nickel-Titanium Controlled Memory Instruments. J Endod 2014; 40:562-5. [DOI: 10.1016/j.joen.2013.12.035] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Revised: 12/19/2013] [Accepted: 12/30/2013] [Indexed: 11/22/2022]
|
39
|
Shen Y, Zhou H, Campbell L, Wang Z, Wang R, Du T, Haapasalo M. Fatigue and nanomechanical properties of K3XF nickel-titanium instruments. Int Endod J 2014; 47:1160-7. [DOI: 10.1111/iej.12265] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 02/06/2014] [Indexed: 11/26/2022]
Affiliation(s)
- Y. Shen
- Division of Endodontics; Department of Oral Biological and Medical Sciences; Faculty of Dentistry; The University of British Columbia; Vancouver BC Canada
- Department of Materials Engineering; The University of British Columbia; Vancouver BC Canada
| | - H. Zhou
- Center for Biomedical Materials and Engineering; College of Material Science and Chemical Engineering; Harbin Engineering University; Harbin China
| | - L. Campbell
- Division of Endodontics; Department of Oral Biological and Medical Sciences; Faculty of Dentistry; The University of British Columbia; Vancouver BC Canada
| | - Z. Wang
- Division of Endodontics; Department of Oral Biological and Medical Sciences; Faculty of Dentistry; The University of British Columbia; Vancouver BC Canada
| | - R. Wang
- Department of Materials Engineering; The University of British Columbia; Vancouver BC Canada
| | - T. Du
- Department of Stomatology; Tongji Hospital; Tongji Medical College; Huazhong University of Science and Technology; Wuhan China
| | - M. Haapasalo
- Division of Endodontics; Department of Oral Biological and Medical Sciences; Faculty of Dentistry; The University of British Columbia; Vancouver BC Canada
| |
Collapse
|
40
|
Kim KW, Cho KM, Park SH, Choi KY, Karabucak B, Kim JW. A comparison of dimensional standard of several nickel-titanium rotary files. Restor Dent Endod 2014; 39:7-11. [PMID: 24516823 PMCID: PMC3916510 DOI: 10.5395/rde.2014.39.1.7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Accepted: 11/06/2013] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES The aim of this study was to compare the dimensional standard of several nickel-titanium (Ni-Ti) rotary files and verify the size conformity. MATERIALS AND METHODS ProFile (Dentsply Maillefer), RaCe (FKG Dentaire), and TF file (SybronEndo) #25 with a 0.04 and 0.06 taper were investigated, with 10 in each group for a total of 60 files. Digital images of Ni-Ti files were captured under light microscope (SZX16, Olympus) at 32×. Taper and diameter at D1 to D16 of each files were calculated digitally with AnalySIS TS Materials (OLYMPUS Soft Imaging Solutions). Differences in taper, the diameter of each level (D1 to D16) at 1 mm interval from (ANSI/ADA) specification No. 101 were statistically analyzed using one-way ANOVA and Scheffe's post-hoc test at 95% confidence level. RESULTS TF was the only group not conform to the nominal taper in both tapers (p < 0.05). All groups except 0.06 taper ProFile showed significant difference from the nominal diameter (p < 0.05). CONCLUSIONS Actual size of Ni-Ti file, especially TF, was different from the manufacturer's statements.
Collapse
Affiliation(s)
- Ki-Won Kim
- Department of Conservative Dentistry, Gangneung-Wonju National University College of Dentistry, Gangneung, Korea
| | - Kyung-Mo Cho
- Department of Conservative Dentistry, Gangneung-Wonju National University College of Dentistry, Gangneung, Korea
| | - Se-Hee Park
- Department of Conservative Dentistry, Gangneung-Wonju National University College of Dentistry, Gangneung, Korea
| | - Ki-Yeol Choi
- Department of Dental Biomaterials, Gangneung-Wonju National University College of Dentistry, Gangneung, Korea
| | - Bekir Karabucak
- Department of Endodontics, University of Pennsylvania, Philadelphia School of Dental Medicine, USA
| | - Jin-Woo Kim
- Department of Conservative Dentistry, Gangneung-Wonju National University College of Dentistry, Gangneung, Korea
| |
Collapse
|
41
|
MIYARA K, YAHATA Y, HAYASHI Y, TSUTSUMI Y, EBIHARA A, HANAWA T, SUDA H. The influence of heat treatment on the mechanical properties of Ni-Ti file materials. Dent Mater J 2014; 33:27-31. [DOI: 10.4012/dmj.2013-196] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
42
|
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]
|
43
|
|
44
|
Haapasalo M, Shen Y. Evolution of nickel-titanium instruments: from past to future. ACTA ACUST UNITED AC 2013. [DOI: 10.1111/etp.12049] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
45
|
Comparison of the Mechanical Behavior between Controlled Memory and Superelastic Nickel-Titanium Files via Finite Element Analysis. J Endod 2013; 39:1444-7. [DOI: 10.1016/j.joen.2013.07.030] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 07/25/2013] [Accepted: 07/28/2013] [Indexed: 11/20/2022]
|
46
|
Marzouk AM, Ghoneim AG. Computed Tomographic Evaluation of Canal Shape Instrumented by Different Kinematics Rotary Nickel-Titanium Systems. J Endod 2013; 39:906-9. [DOI: 10.1016/j.joen.2013.04.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 03/26/2013] [Accepted: 04/03/2013] [Indexed: 10/26/2022]
|
47
|
Shen Y, Zhou HM, Wang Z, Campbell L, Zheng YF, Haapasalo M. Phase transformation behavior and mechanical properties of thermomechanically treated K3XF nickel-titanium instruments. J Endod 2013; 39:919-23. [PMID: 23791264 DOI: 10.1016/j.joen.2013.04.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 03/13/2013] [Accepted: 04/03/2013] [Indexed: 02/02/2023]
Abstract
INTRODUCTION The bending and torsional properties of thermomechanically treated K3XF (SybronEndo, Orange, CA) nickel-titanium instruments in relation to their phase transformation behavior were evaluated. METHODS NiTi instruments K3 (SybronEndo) and K3XF, both in sizes 25/.04 and 40/.04, were examined by differential scanning calorimetry and X-ray diffraction. The metal composition was determined by scanning electron microscopy with X-ray energy-dispersive spectrometric analyses. The bending property of K3 and K3XF instruments was measured in a cantilever-bending test with a maximum deflection of 4.00 mm. A torsional test of the instruments was evaluated according to the American National Standards Institute/American Dental Association Specification No. 28. RESULTS K3 and K3XF instruments had approximately the same chemical composition with a nickel content of 48-49 atomic %. The differential scanning calorimetry analyses showed that each segment of the K3XF instruments (24.89°C ± 1.98°C) had a higher austenite finish temperature than the K3 instruments (17.63°C ± 1.76°C) (P < .05). The bending load values were significantly lower for K3XF than for K3 in the superelastic ranges (P < .05). There was no statistically significant difference between K3 and K3XF in the maximum torque or maximum angular deflection before failure. The torque at fracture values of K3 and K3XF increased significantly with the diameter (P < .05). CONCLUSIONS K3XF exhibited different phase transformation behavior and flexibility when compared with K3, which may be attributed to the special heat treatment history of K3XF instruments.
Collapse
Affiliation(s)
- Ya Shen
- Division of Endodontics, Department of Oral Biological and Medical Sciences, Faculty of Dentistry, The University of British Columbia, Vancouver, Canada
| | | | | | | | | | | |
Collapse
|
48
|
Zhao D, Shen Y, Peng B, Haapasalo M. Micro–Computed Tomography Evaluation of the Preparation of Mesiobuccal Root Canals in Maxillary First Molars with Hyflex CM, Twisted Files, and K3 Instruments. J Endod 2013; 39:385-8. [DOI: 10.1016/j.joen.2012.11.030] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 11/11/2012] [Accepted: 11/12/2012] [Indexed: 12/01/2022]
|
49
|
Shen Y, Zhou HM, Zheng YF, Peng B, Haapasalo M. Current Challenges and Concepts of the Thermomechanical Treatment of Nickel-Titanium Instruments. J Endod 2013; 39:163-72. [DOI: 10.1016/j.joen.2012.11.005] [Citation(s) in RCA: 294] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 11/03/2012] [Accepted: 11/06/2012] [Indexed: 11/17/2022]
|
50
|
Shen Y, Coil JM, Zhou H, Zheng Y, Haapasalo M. HyFlex nickel-titanium rotary instruments after clinical use: metallurgical properties. Int Endod J 2013; 46:720-9. [PMID: 23330612 DOI: 10.1111/iej.12049] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 12/12/2012] [Indexed: 12/30/2022]
Abstract
AIM To analyse the type and location of defects in HyFlex CM instruments after clinical use in a graduate endodontic programme and to examine the impact of clinical use on their metallurgical properties. METHODOLOGY A total of 468 HyFlex CM instruments discarded from a graduate endodontic programme were collected after use in three teeth. The incidence and type of instrument defects were analysed. The lateral surfaces of the defect instruments were examined by scanning electron microscopy. New and clinically used instruments were examined by differential scanning calorimetry (DSC) and x-ray diffraction (XRD). Vickers hardness was measured with a 200-g load near the flutes for new and clinically used axially sectioned instruments. Data were analysed using one-way anova or Tukey's multiple comparison test. RESULTS Of the 468 HyFlex instruments collected, no fractures were observed and 16 (3.4%) revealed deformation. Of all the unwound instruments, size 20, .04 taper unwound the most often (n = 5) followed by size 25, .08 taper (n = 4). The trend of DSC plots of new instruments and clinically used (with and without defects) instruments groups were very similar. The DSC analyses showed that HyFlex instruments had an austenite transformation completion or austenite-finish (Af ) temperature exceeding 37 °C. The Af temperatures of HyFlex instruments (with or without defects) after multiple clinical use were much lower than in new instruments (P < 0.05). The enthalpy values for the transformation from martensitic to austenitic on deformed instruments were smaller than in the new instruments at the tip region (P < 0.05). XRD results showed that NiTi instruments had austenite and martensite structure on both new and used HyFlex instruments at room temperature. No significant difference in microhardness was detected amongst new and used instruments (with and without defects). CONCLUSIONS The risk of HyFlex instruments fracture in the canal is very low when instruments are discarded after three cases of clinical use. New HyFlex instruments were a mixture of martensite and austenite structure at body temperature. Multiple clinical use caused significant changes in the microstructural properties of HyFlex instruments. Smaller instruments should be considered as single-use.
Collapse
Affiliation(s)
- Y Shen
- Division of Endodontics, Department of Oral Biological & Medical Sciences, Faculty of Dentistry, The University of British Columbia, Vancouver, BC, Canada
| | | | | | | | | |
Collapse
|