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Jeong HY, Ha JH, Sigurdsson A, Peters OA, Kim HC, Kwak SW. Effects of Side Flattening on Torsional and Cyclic Fracture Resistance of Nickel-Titanium File. J Endod 2024; 50:1011-1016. [PMID: 38642733 DOI: 10.1016/j.joen.2024.04.008] [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: 01/18/2024] [Revised: 04/02/2024] [Accepted: 04/10/2024] [Indexed: 04/22/2024]
Abstract
INTRODUCTION The purpose of this study was to evaluate the effect of side flattening of cutting flutes on the cyclic resistance and torsional resistance of nickel-titanium files. METHODS Both novel flattened Platinum V.EU (PL) and standard nonflattened CC Premium V.EU (CC) rotaries were tested. For cyclic fatigue tests, all the files were rotated in an artificial root canal with a curvature of 45° and a radius of 6.06 mm at 300 rpm (n = 15 in each group). The number of cycles to failure (NCF) was calculated. For torsional tests, the files were rotated at 2 rpm clockwise until fracture occurred. The maximum torque value at fracture was measured and the toughness and distortion angle were computed. Subsequently, 5 fragments were randomly selected in each experiment, the cross-section and longitudinal direction of the fragments were photographed using a scanning electron microscope. An unpaired t-test was performed at a significance level of 95%. RESULTS There was a statistically significant difference in NCF between CC and PL (P < .05). CC showed higher NCF than PL. There was no statistically significant difference between CC and PL with regards to the parameters related to torsional resistance (distortion angle, ultimate strength, and toughness) (P > .05). CONCLUSION Within the limitations of this study, side flattening of the file did not improve cyclic resistance or torsional resistance of the files. As side flattening may reduce a file's cyclic resistance, such files should be used with caution in clinical practice.
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Affiliation(s)
- Hee-Yoon Jeong
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Dental and Life Science Institute, Pusan National University, Yangsan, South Korea
| | - Jung-Hong Ha
- Department of Conservative Dentistry, College of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Asgeir Sigurdsson
- Department of Endodontics, New York University College of Dentistry, New York University, New York, New York
| | - Ove A Peters
- School of Dentistry, The University of Queensland, Herston, Queensland, Australia
| | - Hyeon-Cheol Kim
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Dental and Life Science Institute, Pusan National University, Yangsan, South Korea
| | - Sang Won Kwak
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Dental and Life Science Institute, Pusan National University, Yangsan, South Korea.
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Omori S, Ebihara A, Hirano K, Kasuga Y, Unno H, Nakatsukasa T, Kimura S, Maki K, Hanawa T, Okiji T. Effect of Rotational Modes on Torque/Force Generation and Canal Centering Ability during Rotary Root Canal Instrumentation with Differently Heat-Treated Nickel-Titanium Instruments. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6850. [PMID: 36234189 PMCID: PMC9571549 DOI: 10.3390/ma15196850] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/18/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
This study aimed to evaluate how various rotational modes influence the torque/force production and shaping ability of ProTaper Universal (PTU; non-heat-treated) and ProTaper Gold (PTG; heat-treated) nickel−titanium instruments. J-shaped resin canals were instrumented with PTU or PTG using an automated instrumentation device operated with reciprocating rotation [150° clockwise and 30° counterclockwise (R150/30) or 240° clockwise and 120° counterclockwise (R240/120)], optimum torque reverse motion (OTR), or continuous rotation (CR) (n = 10 each). Maximum force and torque were recorded, and canal centering ratios were calculated. Statistical analysis was performed with two-way ANOVA and a Bonferroni test (α = 0.05). The results were considered with reference to previous studies on the microstructure of the instruments. The upward force generated by R240/120 and OTR was smaller than that generated by R150/30 and CR in PTG (p < 0.05). The clockwise torque produced by OTR was lower than that produced by R150/30 in PTU and R240/120 and CR in PTG (p < 0.05). R240/120 and OTR induced less canal deviation compared to CR in PTU at 0 mm from the apex (p < 0.05). In conclusion, R240/120 and OTR reduced the screw-in force in PTG and improved the canal centering ability in PTU, which may be associated with the heat treatment-induced microstructural difference of the two instruments.
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Affiliation(s)
- 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
| | - 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
| | - 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
| | - 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
| | - 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
| | - Taro Nakatsukasa
- 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
| | - Takao Hanawa
- Department of Metallic Biomaterials, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, 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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Matoug-Elwerfelli M, Abdou A, Almutairi W, Alhuthayli M, Aloyaynaa S, Almohareb R. Radiographic assessment of endodontic mishaps in an undergraduate student clinic: a 2-year retrospective study. PeerJ 2022; 10:e13858. [PMID: 35945941 PMCID: PMC9357366 DOI: 10.7717/peerj.13858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 07/17/2022] [Indexed: 01/18/2023] Open
Abstract
Objectives The aim of this study was to compare the occurrence of instrumentation and obturation related endodontic procedural mishaps following the use of either, stainless steel hand or engine-driven rotary instrumentation techniques. Methods From a computerized hospital database, a total of 730 dental patient records who had received endodontic treatment by undergraduate dental students between August 2018 to September 2020 were retrieved. The inclusion criteria were primary (non-surgical) endodontic treatment on permanent teeth with complete radiographic records. Following record screening, a final sample of n = 475 dental records were included. Radiographic records were evaluated for both instrumentation and obturation related mishaps. The data was analysed using multiple logistic regression analysis (α = 0.05). Results Engine-driven rotary instrumentation resulted in a significant decrease in the overall occurrence of instrumentation related endodontic mishaps by 40% compared to hand instrumentation (Odds Ratio = 0.59 [0.36-0.97], p = 0.04). In particular, rotary instrumentation decreased ledge formation, perforation and obturation related mishaps, with minimal effect on the limitation of zipping. Conclusion The use of rotary instrumentation techniques may reduce the incidence of instrumentation and obturation endodontic mishaps in the undergraduate dental clinic.
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Affiliation(s)
| | - Ahmed Abdou
- Prosthetic Dentistry Department, Division of Biomaterials, Faculty of Dentistry, King Salman International University, El Tur, South Sinai, Egypt
| | - Wejdan Almutairi
- College of Dentistry, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Malak Alhuthayli
- College of Dentistry, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Shaikhah Aloyaynaa
- College of Dentistry, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Rahaf Almohareb
- Department of Clinical Dental Sciences, College of Dentistry, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
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Uslu O, Haznedaroglu F, Keskin C. Comparison of mechanical resistance and standardisation between original brand and replica-like endodontic systems. AUST ENDOD J 2022; 49:149-158. [PMID: 35703893 DOI: 10.1111/aej.12639] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 04/11/2022] [Accepted: 05/16/2022] [Indexed: 11/30/2022]
Abstract
This study compared the original (ProTaper Next and Reciproc) endodontic systems with their replica-like brands (X File and Only One File) in terms of standardisation, design, phase-transformation behaviour, composition and mechanical behaviour. X File showed greater taper values than ProTaper Next, while Only One File had the greatest tip diameter. Both replica-like files had an active tip and greater dimensions than their reports. There were also significant differences between the original and replica-like systems in terms of their phase-transformation behaviour and the precision of the measurement lines. Only One File showed significantly lower cyclic fatigue and torsional resistance than Reciproc (p < 0.05). There were no significant differences in the cyclic fatigue, torsional resistance and composition of NiTi between X File and ProTaper Next (p > 0.05). Although replica systems show mechanical properties that can be acceptable, they are not consistent in terms of standardisation and design.
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Affiliation(s)
- Orkun Uslu
- Department of Endodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey.,Institute of Graduate Studies in Health Sciences, Istanbul University, Istanbul, Turkey
| | - Faruk Haznedaroglu
- Department of Endodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - Cangül Keskin
- Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey
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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: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 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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Martins JNR, Silva EJNL, Marques D, Pereira MR, Vieira VTL, Arantes-Oliveira S, Martins RF, Braz Fernandes F, Versiani M. Design, Metallurgical Features, and Mechanical Behaviour of NiTi Endodontic Instruments from Five Different Heat-Treated Rotary Systems. MATERIALS 2022; 15:ma15031009. [PMID: 35160955 PMCID: PMC8840527 DOI: 10.3390/ma15031009] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/23/2022] [Accepted: 01/25/2022] [Indexed: 12/24/2022]
Abstract
The current study aimed to compare the F1 endodontic instruments from five different heat-treated rotary systems regarding their design, metallurgical properties, and mechanical performance. Five F1 root canal shaping instruments (ProTaper Gold [PTG], Premium Taper Gold, Go-Taper Flex, EdgeTaper Platinum, and Super Files Blue)—plus, a conventional ProTaper Universal (PTU)—which were evaluated regarding their design, nickel/titanium ratio, phase transformation temperatures, microhardness, cyclic fatigue, and torsional and bending strengths. Mood's median test was used for the statistical comparison with a significance set at 5%. The instruments were similar regarding the nickel/titanium ratio and overall design. Go-Taper Flex had the closest transformation temperatures to PTG. PTU and Go-Taper Flex had the highest microhardness (408.3 and 410.5 HVN). The time to fracture of Super Files Blue was three and seven times higher than PTG and PTU, respectively. No difference was observed in the maximum torque to fracture among PTG (1.30 N·cm) and the other systems, except for the Premium Taper Gold (1.05 N·cm) and Go-Taper Flex (1.10 N·cm). Significantly lower bending loads than PTG (269.2 gf) were observed for the EdgeTaper Platinum (158.3 gf) and Premium Taper Gold (103.5 gf) instruments. Super Files Blue outperformed PTG in the cyclic fatigue test, while EdgeTaper Platinum and Premium Taper Gold were more flexible. Premium Taper Gold and Go-Taper Flex showed lower torsional strength.
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Affiliation(s)
- Jorge N. R. Martins
- Faculdade de Medicina Dentária, Universidade de Lisboa, 1600-277 Lisboa, Portugal; (D.M.); (M.R.P.); (S.A.-O.)
- Grupo de Investigação em Bioquimica e Biologia Oral, Unidade de Investigação em Ciências Orais e Biomédicas (UICOB), 1600-277 Lisboa, Portugal
- Centro de Estudo de Medicina Dentária Baseada na Evidência (CEMDBE), 1600-277 Lisboa, Portugal
- Correspondence:
| | - Emmanuel J. N. L. Silva
- Department of Endodontics, Grande Rio University (UNIGRANRIO), Rio de Janeiro 21210-623, Brazil; (E.J.N.L.S.); (V.T.L.V.)
- Department of Endodontics, Fluminense Federal University, Niterio, Rio de Janeiro 24220-900, Brazil
| | - Duarte Marques
- Faculdade de Medicina Dentária, Universidade de Lisboa, 1600-277 Lisboa, Portugal; (D.M.); (M.R.P.); (S.A.-O.)
- Grupo de Investigação em Bioquimica e Biologia Oral, Unidade de Investigação em Ciências Orais e Biomédicas (UICOB), 1600-277 Lisboa, Portugal
- Centro de Estudo de Medicina Dentária Baseada na Evidência (CEMDBE), 1600-277 Lisboa, Portugal
- LIBPhys-FCT UID/FIS/04559/2013, 1600-277 Lisboa, Portugal
| | - Mário Rito Pereira
- Faculdade de Medicina Dentária, Universidade de Lisboa, 1600-277 Lisboa, Portugal; (D.M.); (M.R.P.); (S.A.-O.)
| | - Victor T. L. Vieira
- Department of Endodontics, Grande Rio University (UNIGRANRIO), Rio de Janeiro 21210-623, Brazil; (E.J.N.L.S.); (V.T.L.V.)
| | - Sofia Arantes-Oliveira
- Faculdade de Medicina Dentária, Universidade de Lisboa, 1600-277 Lisboa, Portugal; (D.M.); (M.R.P.); (S.A.-O.)
- LIBPhys-FCT UID/FIS/04559/2013, 1600-277 Lisboa, Portugal
- BIOMAT, Laboratório de Biomateriais, Unidade de Investigação em Ciências Orais e Biomédicas (UICOB), 1600-277 Lisboa, Portugal
| | - Rui F. Martins
- UNIDEMI, Department of Mechanical and Industrial Engineering, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal;
| | - Francisco Braz Fernandes
- CENIMAT/I3N, Department of Materials Science, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal;
| | - Marco Versiani
- Dental Specialty Center, Brazilian Military Police, Belo Horizonte 30350-190, Brazil;
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Jamleh A, Almedlej R, Alomar R, Almayouf N, Alfadley A, Alfouzan K. Evidence for reduced torsional resistance of rotary files under curved position. Saudi Dent J 2021; 33:614-619. [PMID: 34803309 PMCID: PMC8589599 DOI: 10.1016/j.sdentj.2020.07.005] [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: 05/18/2020] [Revised: 07/08/2020] [Accepted: 07/23/2020] [Indexed: 11/24/2022] Open
Abstract
Objectives The aim of this in vitro study was to investigate the torsional fatigue resistance of different rotary files in straight and curved positions at a simulated intracanal temperature. Methods Forty-eight size #25 files from ProTaper Universal (PTU), ProTaper Next (PTN) and ProTaper Gold (PTG) were tested for torsional resistance in both straight and curved (90 degrees) positions (n = 8 each). The experiment was conducted at a simulated intracanal temperature of 35 ± 1 °C. The torque gauge was reset before every use, and uniform torsional stress was applied by rotating the file clockwise at a speed of 40 rpm until fracture. Torque failure values were recorded, and fractured surfaces were tested using a scanning electron microscopy (SEM). Statistical analysis of the data was completed using one-way ANOVA and post-hoc test (LSD) in order to compare between the tested systems in each file position. Student’s t-test was also performed to compare between the two positions in each rotary system, and significance level was set at 5%. Results In the straight position, torsional resistance of PTN was significantly lower than that of PTU and PTG (p < 0.001), while the PTU and PTG had comparable results (p > 0.05). In the curved position, torsional resistance was found to be comparable among all systems (p > 0.05). Within each system, the curved position resulted in a significantly lower torsional resistance when compared to the straight position (p < 0.001). SEM examination revealed similar torsional failure behavior for all files tested under both positions. Conclusions Our study identified that placing files in a curved position was associated with a significant decrease in torsional resistance of all systems, and this necessitates reconsidering the torque settings proposed by the manufacturers. Whether these effects can be translated into in vivo studies remains to be investigated, and thus future studies are essential to provide confirming evidence.
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Affiliation(s)
- Ahmed Jamleh
- Restorative and Prosthetic Dental Sciences, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, National Guard Health Affairs, Riyadh, Saudi Arabia.,King Abdullah International Medical Research Centre, National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Raghad Almedlej
- Restorative and Prosthetic Dental Sciences, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, National Guard Health Affairs, Riyadh, Saudi Arabia.,King Abdullah International Medical Research Centre, National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Rasha Alomar
- Restorative and Prosthetic Dental Sciences, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, National Guard Health Affairs, Riyadh, Saudi Arabia.,King Abdullah International Medical Research Centre, National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Nouf Almayouf
- Restorative and Prosthetic Dental Sciences, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, National Guard Health Affairs, Riyadh, Saudi Arabia.,King Abdullah International Medical Research Centre, National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Abdulmohsen Alfadley
- Restorative and Prosthetic Dental Sciences, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, National Guard Health Affairs, Riyadh, Saudi Arabia.,King Abdullah International Medical Research Centre, National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Khalid Alfouzan
- Restorative and Prosthetic Dental Sciences, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, National Guard Health Affairs, Riyadh, Saudi Arabia.,King Abdullah International Medical Research Centre, National Guard Health Affairs, Riyadh, Saudi Arabia
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8
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Kalyoncuoğlu E, Keskin C, Keleş A, Aydemir H. Metallurgical characterisation and torsional resistance of blue thermomechanically treated nickel titanium instruments after simulated ex vivo retreatment procedure. AUST ENDOD J 2021; 48:121-130. [PMID: 34670014 DOI: 10.1111/aej.12584] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 09/06/2021] [Accepted: 10/06/2021] [Indexed: 12/29/2022]
Abstract
To compare used and unused Reciproc Blue and Reciproc after retreatment, the instruments were used in the mesiobuccal canals of maxillary molars with curvature. The torsional resistances were tested and then unused instruments were subjected to XRD, DSC and microhardness tests. Student's t, ANOVA and Tukey's tests were performed (α-level 0.05). The torsional strength of used Reciproc Blue was not significantly different than unused ones (P > .05), while torsional strength of Reciproc decreased significantly (P < .05). DSC and XRD indicated that Reciproc Blue exhibited prominent transformation peaks corresponding austenite to R-phase. Microhardness of Reciproc was significantly higher (P < .05). A second reuse of Reciproc Blue for retreatment could be considered safe in terms of torsional strength. Blue treatment also decreased surface microhardness of the instrument and changed phase composition by increasing the R-phase.
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Affiliation(s)
- Elif Kalyoncuoğlu
- Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey
| | - Cangül Keskin
- Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey
| | - Ali Keleş
- Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey
| | - Hikmet Aydemir
- Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey
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9
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Martins JNR, Silva EJNL, Marques D, Belladonna F, Simões-Carvalho M, Camacho E, Braz Fernandes FM, Versiani MA. Comparison of design, metallurgy, mechanical performance and shaping ability of replica-like and counterfeit instruments of the ProTaper Next system. Int Endod J 2021; 54:780-792. [PMID: 33300121 DOI: 10.1111/iej.13463] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 12/06/2020] [Accepted: 12/07/2020] [Indexed: 11/30/2022]
Abstract
AIM To compare the ProTaper Next (PTN) system with a replica-like and a counterfeit system regarding design, metallurgy, mechanical performance and shaping ability. METHODOLOGY Replica-like (X-File) and counterfeit (PTN-CF) instruments were compared to the PTN system regarding design (microscopy), phase transformation temperatures (differential scanning calorimetry), nickel-titanium ratio (energy-dispersive X-ray spectroscopy), cyclic fatigue, torsional resistance, bending strength, and untouched canal areas in extracted mandibular molars (micro-CT). anova, post hoc Tukey's and Kruskal-Wallis tests were used according to normality assessment (Shapiro-Wilk test) with the significance level set at 5%. RESULTS Overall similarities in design and nickel-titanium (Ni/Ti) ratio were observed amongst instruments with the X-File having a smoother surface finish. PTN and PTN-CF had mixed austenite plus R-phase (R-phase start approximately at 45 ºC and near 30 ºC, respectively), whilst X-File instruments were austenitic (R-phase started at approximately at 17 ºC) at room temperature (20 ºC). PTN-CF had the greatest inconsistency in the phase transformation temperatures. Time to fracture of PTN-CF X2 and X3 was significantly shorter than PTN and X-File instruments (P < 0.05), whilst no difference was noted in maximum torque to fracture amongst the tested systems (P > 0.05). X-Files and PTN-CF had a stress-induced phase change during bending load. Mean unprepared surface areas of root canals were 25.8% (PTN), 31.1% (X-File) and 32.5% (PTN-CF) with no significant difference amongst groups (P > 0.05). CONCLUSION Similarities amongst the systems were noted in the Ni/Ti ratio and maximum torque to fracture, whilst differences were observed in the design, phase transformation temperatures and mechanical behaviour. The ProTaper Next counterfeit instruments could be considered as the less secure system considering its low-cyclic fatigue resistance. Apart from these differences, the unprepared canal surface areas, obtained with the tested systems, were similar.
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Affiliation(s)
- J N R Martins
- Department of Endodontics, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal.,Unidade de Investigação em Ciências Orais e Biomédicas (UICOB), Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal.,Centro de Estudo de Medicina Dentária Baseada na Evidência (CEMDBE), Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal
| | - E J N L Silva
- Department of Endodontics, School of Dentistry, Grande Rio University (UNIGRANRIO), Rio de Janeiro, Rio de Janeiro, Brazil.,Department of Endodontics, Fluminense Federal University, Niteroi, Rio de Janeiro, Brazil
| | - D Marques
- Centro de Estudo de Medicina Dentária Baseada na Evidência (CEMDBE), Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal.,LIBPhys-FCT UID/FIS/04559/2013, Lisboa, Portugal
| | - F Belladonna
- Department of Endodontics, Fluminense Federal University, Niteroi, Rio de Janeiro, Brazil
| | - M Simões-Carvalho
- Department of Endodontics, Fluminense Federal University, Niteroi, Rio de Janeiro, Brazil
| | - E Camacho
- CENIMAT/I3N, Department of Materials Science, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal
| | - F M Braz Fernandes
- CENIMAT/I3N, Department of Materials Science, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal
| | - M A Versiani
- Dental Specialty Center, Brazilian Military Police, Minas Gerais, Brazil
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Advancement of Mechanical Properties of Nickel-Titanium Rotary Endodontic Instruments by Spring Machining on the File Shaft. MATERIALS 2020; 13:ma13225246. [PMID: 33233623 PMCID: PMC7699742 DOI: 10.3390/ma13225246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 11/17/2022]
Abstract
Nickel-titanium (NiTi) endodontic rotary instruments are used extensively in root canal procedures by both general dentists and specialists. However, their vulnerability to fracture is the major reason for clinicians' concern regarding their use. The objective of this study was to investigate the potential effects of spring machining of the file shaft on the fatigue and torsional resistances of NiTi rotary instruments. Three types of NiTi rotary systems with (S) and without (NS) spring machining were used in this study (n = 15 each): a spring file (SPR; #25/.06, SPR-S, SPR-NS), a ProTaper Next X2 (PTN; #25/variable taper, PTN-S, PTN-NS), and a ProTaper Gold F2 (PTG; #25/variable taper, PTG-S, PTG-NS). Spring machining was adjusted on the 6 mm of each file system's shaft via a laser cutting process. The number of rotation cycles until fracture (i.e., cyclic fatigue resistance), ultimate torsional strength, the distortion angle, and the toughness of each subgroup were estimated with specially designed devices. The results were analyzed using a paired t-test at a significance level of 95%. NiTi rotary instruments with spring machining exhibited a higher cyclic fatigue resistance than instruments without spring machining. The groups with spring machining exhibited a higher toughness and larger distortion angle than the groups without it (p < 0.05). In conclusion, spring machining on the shank of NiTi instruments may provide a stress-bearing area and attenuate the torsional and cyclic fatigue of NiTi rotary instruments.
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Gambarini G, Miccoli G, Nardo DD, Giudice AD, Mazzoni A, Seracchiani M, Testarelli L. Torsional Resistance of Two New Heat Treated Nickel Titanium Rotary Instruments: An in Vitro Evaluation. PESQUISA BRASILEIRA EM ODONTOPEDIATRIA E CLÍNICA INTEGRADA 2020. [DOI: 10.1590/pboci.2020.156] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Reda R, Zanza A. A Comprehensive In Vitro Comparison of Mechanical Properties of Two Rotary Endodontic Instruments. ACTA ACUST UNITED AC 2020. [DOI: 10.5005/jp-journals-10015-1729] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Isik V, Kwak SW, Abu-Tahun IH, Ha JH, Kayahan MB, Kim HC. Effect of Shaft Length on the Torsional Resistance of Rotary Nickel-titanium Instruments. J Endod 2019; 46:295-300. [PMID: 31812358 DOI: 10.1016/j.joen.2019.10.019] [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: 09/16/2019] [Revised: 10/20/2019] [Accepted: 10/25/2019] [Indexed: 12/01/2022]
Abstract
INTRODUCTION This study was conducted to evaluate the effect of file length on the torsional resistance of nickel-titanium rotary files. METHODS Forty-five new files with a #25 tip size and variable taper for ProTaper Next (PTN; Dentsply Sirona, York PA), ProTaper Gold (PTG, Dentsply Sirona), and HyFlex CM (HCM; Coltene-Whaledent, Allstetten, Switzerland) were divided into 3 subgroups (n = 15) according to the file length (21, 25, and 31 mm). Torsional tests were performed using a custom-made device (AEndoS; DMJ System, Busan, Korea). The maximum torsional load and distortion angle were measured until file fracture occurred. The toughness was calculated using these data. All data were statistically analyzed using 2-way analysis of variance at a confidence level of 95%. One-way analysis of variance and Duncan post hoc comparison were also conducted to assess the difference among the independent variables, shaft length, and file system. RESULTS A statistically significant interaction was observed between the file system and instrument length with respect to the maximum torsional load (P < .05). The 31-mm shaft length of HCM showed higher maximum torsional load than that of the 25- and 21-mm shaft length in the HCM groups (P < .05). Among the instrument systems, PTG showed the significantly highest maximum torsional load followed by PTN and HCM (P < .05). The 31-mm shaft length of PTG showed significantly higher toughness than that of the 21- and 25-mm shaft lengths (P < .05), whereas PTN and HCM did not show any difference in relation to the shaft length. CONCLUSIONS Within the limitations of this study, the instrument with a longer shaft may have higher maximum torsional load or toughness than that with a shorter shaft.
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Affiliation(s)
- Vasfiye Isik
- Department of Endodontics, Division of Clinical Sciences, Faculty of Dentistry, Okan University, Istanbul, Turkey
| | - Sang Won Kwak
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Pusan National University, Yangsan, Korea
| | - Ibrahim H Abu-Tahun
- Department of Conservative Dentistry, School of Dentistry, The University of Jordan, Amman, Jordan
| | - Jung-Hong Ha
- Department of Conservative Dentistry, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Mehmet Baybora Kayahan
- Department of Endodontics, Division of Clinical Sciences, Faculty of Dentistry, Okan University, Istanbul, Turkey.
| | - Hyeon-Cheol Kim
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Pusan National University, Yangsan, Korea.
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