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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.
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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
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Tyagi G, Kumar P, Kumari A, Shakarwal P, Singh A, Kusum P. Comparing the EdgeFile X3, GenEndo, HeroGold, and ProTaper Gold Rotary Instruments Regarding the Effect of Different Concentrations and Temperature of NaOCl on Cyclic Fatigue Resistance. J Contemp Dent Pract 2023; 24:715-721. [PMID: 38152947 DOI: 10.5005/jp-journals-10024-3515] [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] [Indexed: 12/29/2023]
Abstract
AIM This research was carried out with the objective of comparison between GenEndo, Protaper Gold, Hero Gold and EdgeFile X3 regarding the effect of different concentrations of NaOCl. MATERIALS AND METHODS About 720 study specimens were included in the study. They were divided into four groups. Each group consisted of 180 files. Group A: GenEndo, Group B: Protaper Gold, Group C: Hero Gold, Group D: EdgeFile X3. Each group of instruments were further subdivided into nine subgroups (n = 20 for each subgroup). Testing of the cyclic fatigue was carried out in artificial canals which were prepared inside the blocks of stainless steel. The stainless steel blocks with artificial canals were established in a receiver that was packed with experimental solutions like distilled water, 5.25% NaOCl and 2.5% NaOCl. The adjustment of temperature was done at 25, 37, and 60°C. The rotation of the instrument was carried out inside the artificial canal as per the instructions of the manufacturer. The instrument was rotated until it got fractured. The time taken by the instrument to fracture was recorded in seconds. The number of cycles to fracture (NCF) was analyzed with the help of the equation (NCF = time to fracture × rpm/60). Surfaces at the site of fracture were examined with the help of a scanning electron microscope (EVOLS10, ZEISS) at magnification (300x and 2000x). RESULTS It was noticed that there was a statistically significant increase in cyclic fatigue when sodium chloride was used as an endodontic irrigant instead of distilled water. The increase in cyclic fatigue was also observed when 5.25% sodium chloride was used instead of 2.5% sodium hypochlorite. Cyclic fatigue increased on change in temperature from 25 to 37°C and from 37 to 60°C. The difference was statistically significant (p < 0.05). It was observed that resistance against cyclic fatigue on treatment with different irrigation solutions at different temperatures was in the order of GenEndo > Protaper Gold > Hero Gold > EdgeFile X3. CONCLUSION The resistance against cyclic fatigue in new NiTi rotary files can be affected significantly by different concentrations of sodium hypochlorite irrigant solution and the GenEndo rotary endodontic instrument has the maximum resistance against cyclic fatigue. CLINICAL SIGNIFICANCE Irrigation of the root canal with irrigants, such as sodium hypochlorite (NaOCl) has been recommended strongly. NaOCl is used in the range of 0.5 and 6.5% concentration owing to its antimicrobial activity and tissue dissolution activities, particularly at higher temperatures. It has been postulated that fatigue of rotary endodontic instruments can be influenced by adjoining medium and their concentration.
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Affiliation(s)
- Garima Tyagi
- Department of Conservative Dentistry and Endodontics, Kothiwal Dental College & Research Centre, Moradabad, Uttar Pradesh, India
| | - Prakash Kumar
- Department of Conservative Dentistry and Endodontics, Mithila Minority Dental College and Hospital, Darbhanga, Bihar, Phone: +91 6205229036, e-mail:
| | - Annu Kumari
- Department of Conservative Dentistry and Endodontics, Mithila Minority Dental College and Hospital, Darbhanga, Bihar, India
| | - Parul Shakarwal
- Department of Conservative Dentistry and Endodontics, Sardar Patel Post Graduate Institute of Dental and Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Aditya Singh
- Department of Conservative Dentistry and Endodontics, Sardar Patel Post Graduate Institute of Dental and Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Pallavi Kusum
- Department of Orthodontics and Dentofacial Orthopedics, Buddha Institute of Dental Sciences & and Hospital, Patna, Bihar, India
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Alfawaz H, Alqedairi A, Alhamdan M, Alkhzim N, Alfarraj S, Jamleh A. Effect of NaOCl and EDTA irrigating solutions on the cyclic fatigue resistance of EdgeTaper Platinum instruments. BMC Oral Health 2022; 22:195. [PMID: 35599316 PMCID: PMC9125847 DOI: 10.1186/s12903-022-02215-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 05/06/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND To compare the solution on the cyclic fatigue resistance of EdgeTaper Platinum (ETP) instruments with that of ProTaper Gold (PTG) in the presence of ethylenediaminetetraacetic acid (EDTA) or sodium hypochlorite (NaOCl) irrigating solutions. METHODS Sixty PTG and 60 ETP instruments with the same size (#25) and taper (8%) were tested under 17% EDTA, 5.25% NaOCl, or distilled water (n = 20 each). Cyclic fatigue was tested using artificial canals that were milled in stainless steel blocks using a laser micromachining technique. The canals had a curvature angle of 60 and a curvature radius of 5 mm. The center of maximum curvature was set at 5 mm from the instrument tip. The block of artificial canals was stabilized inside a container that was filled with one of the tested solutions. The temperature was fixed at 37 °C with a tolerance limit of 1 °C. The number of cycles to fracture (NCF) was calculated and the fractured surfaces were examined using a scanning electron microscope. All statistical analyses were performed using SPSS software Version 20 (IBM-SPSS Inc., Chicago, IL) at a confidence level of 95%. RESULTS ETP showed higher NCF than PTG in any of the tested solutions (P < 0.05). Within each group, NaOCl drastically decreased the NCF compared to water and EDTA (P < 0.05) and changing the solution from distilled water to EDTA did not affect the fatigue resistance (P > 0.05). CONCLUSIONS ETP showed improved cyclic fatigue performance compared to PTG in all tested irrigating solutions. EDTA can be used in combination with NiTi instruments during canal instrumentation without compromising the cyclic fatigue resistance of PTG and ETP instruments. However, NaOCl drastically decreased the NCF.
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Affiliation(s)
- Hussam Alfawaz
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh, 11545, Saudi Arabia.
| | - Abdullah Alqedairi
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh, 11545, Saudi Arabia
| | - Maha Alhamdan
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh, 11545, Saudi Arabia
| | - Najla Alkhzim
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh, 11545, Saudi Arabia
| | - Shatha Alfarraj
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh, 11545, Saudi Arabia
| | - Ahmed Jamleh
- Department of Restorative and Prosthetic Sciences, College of Dentistry, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
- King Abdullah International Medical Research Center, Ministry of National Guard-Health Affairs, Riyadh, Saudi Arabia
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Alqedairi A, Alfawaz H, Abualjadayel B, Alanazi M, Alkhalifah A, Jamleh A. Torsional resistance of three ProTaper rotary systems. BMC Oral Health 2019; 19:124. [PMID: 31226984 PMCID: PMC6588856 DOI: 10.1186/s12903-019-0820-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 06/12/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of this study is to compare the torsional resistance of the available ProTaper rotary systems, namely, ProTaper Universal (PTU), ProTaper Next (PTN), and ProTaper Gold (PTG). METHODS A total of 195 files from the three systems distributed into 13 groups (PTU-S1, PTU-S2, PTU-F1, PTU-F2, PTU-F3, PTG-S1, PTG-S2, PTG-F1, PTG-F2, PTG-F3, PTN-X1, PTN-X2 and PTN-X3) were subjected to torsional fatigue until failure. The torsional test was performed according to ISO 3630-1, where each file was placed in a straight position to eliminate the influence of cyclic fatigue. The Kruskal-Wallis test was conducted to compare the mean maximum torques and angular deflections at fracture for the groups, and the Mann-Whitney test was performed for pairwise comparisons. The significance level was set at 0.05 and the fractured surfaces were examined under a scanning electron microscope. RESULT Among the tested files, PTG-S1 had the lowest torsional fatigue resistance, whereas PTU-F2 and PTU-F3 had the highest torsional resistance. The scanning electron microscope showed typical features of torsional failure. CONCLUSION The new ProTaper systems (PTG and PTN) did not show improved torsional resistance in comparison with PTU.
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Affiliation(s)
- Abdullah Alqedairi
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Hussam Alfawaz
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Bader Abualjadayel
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Mohammad Alanazi
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Ahmad Alkhalifah
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Ahmed Jamleh
- King Abdullah International Medical Research Centre, Restorative and Prosthetic Dental Sciences, College of Dentistry, Ministry of National Guard Health Affairs, King Saud bin Abdulaziz University for Health Sciences, P.O. Box 22490, Riyadh, 11426, Saudi Arabia.
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Alfawaz H, Alqedairi A, Alsharekh H, Almuzaini E, Alzahrani S, Jamleh A. Effects of Sodium Hypochlorite Concentration and Temperature on the Cyclic Fatigue Resistance of Heat-treated Nickel-titanium Rotary Instruments. J Endod 2018; 44:1563-1566. [DOI: 10.1016/j.joen.2018.07.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/10/2018] [Accepted: 07/05/2018] [Indexed: 11/28/2022]
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Alfouzan K, Jamleh A. Fracture of nickel titanium rotary instrument during root canal treatment and re-treatment: a 5-year retrospective study. Int Endod J 2017; 51:157-163. [PMID: 28796346 DOI: 10.1111/iej.12826] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 08/06/2017] [Indexed: 11/27/2022]
Abstract
AIM To evaluate retrospectively the incidence of K3 nickel titanium rotary instrument fracture in referred cases during root canal treatment and re-treatment. METHODOLOGY Clinical and radiographic reports of 12 867 endodontic cases treated at the King Abdulaziz medical city between January 2010 and November 2015 were reviewed to obtain information on intracanal fractured instruments with respect to the treatment performed, tooth type and the size and at what level the instrument fractured (coronal, middle or apical). The degree of canal curvature was classified into mild (<10° ), moderate (10-25° ) or severe (>25° ). Logistic regression was used to test the incidence of instrument fracture in relation to the root canal treatment performed and tooth type. Chi-square tests were used to analyse the fracture incidence in the treated teeth in respect to fracture level and fractured file diameter. The level of significance was set at 0.05. RESULTS Root canal treatment was performed on 8946 cases, whilst re-treatment was performed on 3921 cases. The fracture incidence was higher during re-treatment cases (2.96%) than in primary root canal treatment (0.74%) (P < 0.001) with a 1.41% incidence overall. There was a trend for more fractures in maxillary (1.68%) and mandibular (1.35%) molar teeth. Moreover, 56.6% of the fractured instruments occurred in severely curved canals, and the apical third of the root canal was the most common site for instrument fracture (85.7%), followed by middle (13.2%), and coronal (1.1%) thirds, mostly with file sizes 20 and 25 (59.9% and 25.27%, respectively). CONCLUSION The fracture incidence of K3 instruments was significantly greater during root canal re-treatment than root canal treatment, mainly with small instruments and in the apical third of the canals.
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Affiliation(s)
- K Alfouzan
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Restorative and Prosthetic Dental Sciences, College of Dentistry, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - A Jamleh
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Restorative and Prosthetic Dental Sciences, College of Dentistry, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
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Atmeh AR, Watson TF. Root dentine and endodontic instrumentation: cutting edge microscopic imaging. Interface Focus 2016; 6:20150113. [PMID: 27274802 DOI: 10.1098/rsfs.2015.0113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cutting of the dental hard tissues is an integral part of restorative dentistry. Cutting of the root dentine is also needed in preparation prior to endodontic treatment, with significant commercial investment for the development of flexible cutting instruments based around nickel titanium (NiTi) alloys. This paper describes the evolution of endodontic cutting instruments, both in materials used, e.g. the transition from stainless steel to NiTi, and the design of the actual instruments themselves and their method of activation-by hand or motor driven. We have been examining tooth-cutting interactions microscopically for over 25 years using a variety of microscopic techniques; in particular, video-rate confocal microscopy. This has given a unique insight into how many of the procedures that we take for granted are achieved in clinical practice, by showing microscopic video images of the cutting as it occurs within the tooth. This technology has now been extended to allow imaging of the endodontic instrument and the root canal wall for the first time. We are able to image dentine distortion and crack propagation during endodontic filing of the root canal space. We are also able to visualize the often claimed, but seldom seen action of contemporary endodontic instruments.
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Affiliation(s)
- Amre R Atmeh
- Department of Restorative Dental Science , College of Dentistry, University of Dammam , Dammam , Kingdom of Saudi Arabia
| | - Timothy F Watson
- Tissue Engineering and Biophotonics Division , King's College London Dental Institute , Floor 17, Guy's Tower, Guy's Hospital, London SE1 9RT , UK
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