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Chien PY, Walsh LJ, Peters OA. The extended finite element method in endodontics: A scoping review and future directions for cyclic fatigue testing of nickel-titanium instruments. Clin Exp Dent Res 2024; 10:e893. [PMID: 38770579 PMCID: PMC11106644 DOI: 10.1002/cre2.893] [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: 12/12/2023] [Revised: 04/02/2024] [Accepted: 04/24/2024] [Indexed: 05/22/2024] Open
Abstract
OBJECTIVES The present study reviews the current literature regarding the utilization of the extended finite element method (XFEM) in clinical and experimental endodontic studies and the suitability of XFEM in the assessment of cyclic fatigue in rotary endodontic nickel-titanium (NiTi) instruments. MATERIAL AND METHODS An electronic literature search was conducted using the appropriate search terms, and the titles and abstracts were screened for relevance. The search yielded 13 hits after duplicates were removed, and four studies met the inclusion criteria for review. RESULTS No studies to date have utilized XFEM to study cyclic fatigue or crack propagation in rotary endodontic NiTi instruments. Challenges such as modelling material inputs and fatigue criteria could explain the lack of utilization of XFEM in the analysis of mechanical behavior in NiTi instruments. CONCLUSIONS The review showed that XFEM was seldom employed in endodontic literature. Recent work suggests potential promise in using XFEM for modelling NiTi structures.
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Affiliation(s)
- Philip Yuan‐Ho Chien
- The University of Queensland, School of Dentistry, UQ Oral Health CentreHerstonQLDAustralia
| | - Laurence James Walsh
- The University of Queensland, School of Dentistry, UQ Oral Health CentreHerstonQLDAustralia
| | - Ove Andreas Peters
- The University of Queensland, School of Dentistry, UQ Oral Health CentreHerstonQLDAustralia
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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.
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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
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Diaconu CT, Diaconu AE, Tuculina MJ, Mihai LL, Gheorghiță M, Gheorghiță LM, Mărășescu P, Gliga A, Diaconu OA. Assessment of the Cyclic Fatigue Performance of the Novel Protaper Ultimate File System Used in Different Kinematics: An In Vitro Study. J Funct Biomater 2024; 15:85. [PMID: 38667542 PMCID: PMC11051539 DOI: 10.3390/jfb15040085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 03/06/2024] [Accepted: 03/27/2024] [Indexed: 04/28/2024] Open
Abstract
This in vitro study aims to assess the cyclic fatigue resistance of the Protaper Ultimate (PTU) files compared to the Protaper Gold (PTG) and the M3 UDG (M3) files using various motion kinematics in simulated canals. As far as the authors are aware, no study has previously compared the three file systems before this current investigation. Therefore, closing this information gap is the goal of the current research. Methods: A total of (60 new endodontic files were randomly divided into 6 groups (10 files per group); groups 1, 3, and 5 used continuous rotation (CR), while groups 2, 4, and 6 used forward reciprocating motion (FRM). A manufactured stainless-steel artificial canal was used to perform the cyclic fatigue testing. The results were analyzed using Student's t-test and two-way ANOVA. All pairwise comparisons revealed statistically significant differences in the time to failure (TTF) for every study group (p < 0.001), with the exception of the PTG and M3 files, which performed similarly using both CR and FRM. Conclusions: The PTU files performed better than the PTG and M3 files in terms of the TTF and number of cycles to failure (NCF) using both CR and FRM.
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Affiliation(s)
- Cezar Tiberiu Diaconu
- Faculty of Dental Medicine, Department of Endodontics, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (C.T.D.); (A.E.D.); (L.M.G.); (O.A.D.)
| | - Anca Elena Diaconu
- Faculty of Dental Medicine, Department of Endodontics, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (C.T.D.); (A.E.D.); (L.M.G.); (O.A.D.)
| | - Mihaela Jana Tuculina
- Faculty of Dental Medicine, Department of Endodontics, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (C.T.D.); (A.E.D.); (L.M.G.); (O.A.D.)
| | - Laurența Lelia Mihai
- Faculty of Dental Medicine, University Titu Maiorescu of Bucharest, 031593 Bucharest, Romania
| | - Mircea Gheorghiță
- Faculty of Dental Medicine, Department of Oral and Maxillofacial Surgery, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania;
| | - Lelia Mihaela Gheorghiță
- Faculty of Dental Medicine, Department of Endodontics, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (C.T.D.); (A.E.D.); (L.M.G.); (O.A.D.)
| | - Petre Mărășescu
- Faculty of Dental Medicine, Department of Dental Prothesis Technology, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania;
| | - Alexandru Gliga
- Faculty of Dental Medicine, Department of Operative Dentistry, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania;
| | - Oana Andreea Diaconu
- Faculty of Dental Medicine, Department of Endodontics, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (C.T.D.); (A.E.D.); (L.M.G.); (O.A.D.)
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La Rosa GRM, Canova FS, Generali L, Pedullà E. The Role of Pecking Motion Depths in Dynamic Cyclic Fatigue Resistance: In Vitro Study. Int Dent J 2024:S0020-6539(24)00040-6. [PMID: 38350803 DOI: 10.1016/j.identj.2024.01.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 01/09/2024] [Accepted: 01/22/2024] [Indexed: 02/15/2024] Open
Abstract
OBJECTIVE This is the first study evaluating the impact of different pecking motion depths on dynamic cyclic fatigue resistance of different endodontic instruments. METHODS Four nickel-titanium systems (Hyflex EDM OneFile 25/. ∼; Rotate 25/0.6; Mtwo 25/0.6; Reciproc Blue R25) were tested. Forty instruments from each group were subjected to 4 different pecking movements to evaluate their cyclic fatigue resistance. The distances for the pecking motion were 3-mm forward and backward, 1-mm (3-mm forward and 2-mm backward), 2-mm (4-mm forward and 2-mm backward), and 3-mm (5-mm forward and 2-mm backward). Speeds were 100 and 200 mm/min for the descending and ascending motion, respectively. The times to fracture (TtF) in seconds were recorded for each instrument. Data were statistically analysed by using 2-way ANOVA and Bonferroni multiple comparison post hoc test (P < .05). RESULTS All instruments had a significant increase in cyclic fatigue resistance during the forward dynamic motion compared with the axial continuous. Overall, the heat-treated instruments reported higher fatigue strength than the untreated files (P < .05). Reciproc Blue and Hyflex EDM showed higher TtF in the forward movements of 1-/2-mm and 2-mm (P < .05), respectively while Mtwo 25.06 and Rotate 25.06 in the forward movement of 3-mm (P < .05). CONCLUSIONS Within the limits of this in vitro study, the pecking motion depths had varying impacts on the cyclic fatigue resistance of instruments. Reciproc Blue and Hyflex EDM performed significantly better with pecking motions of 1-and 2-mm. Improving endodontic instrument durability through specific pecking depths has the potential for improving clinical performance and reducing instrument failures.
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Affiliation(s)
- Giusy Rita Maria La Rosa
- Department of General Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy.
| | - Francesco Saverio Canova
- Department of General Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy
| | - Luigi Generali
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance, University of Modena and Reggio Emilia, Modena, Italy
| | - Eugenio Pedullà
- Department of General Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy
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Bürklein S, Maßmann P, Schäfer E, Donnermeyer D. Cyclic Fatigue of Different Reciprocating Endodontic Instruments Using Matching Artificial Root Canals at Body Temperature In Vitro. MATERIALS (BASEL, SWITZERLAND) 2024; 17:827. [PMID: 38399077 PMCID: PMC10890344 DOI: 10.3390/ma17040827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/05/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024]
Abstract
Reciprocating motion expands the lifetime of endodontic instruments during the preparation of severely curved root canals. This study aimed to investigate the time to fracture (TTF) and number of cycles to failure (NCF) of different reciprocating instruments (n = 20 in each group) at body temperature using a dynamic testing model (amplitude = 3 mm). Reciproc Blue (RPB), size 25/.08, WaveOne Gold (WOG) 25/.07, Procodile (Proc) 25/.06, R-Motion (RM_06) 25/.06 and R-Motion (RM_04) 30/.04 instruments were tested in their specific reciprocating motion in artificial matching root canals (size of the instrument ± 0.02 mm; angle of curvature 60°, radius 5.0 mm, and centre of curvature 5.0 mm from apical endpoint). The number of fractured instruments, TTF, NCF, the and lengths of the fractured instruments were recorded and statistically analysed using the Chi-Square or Kruskal-Wallis test. Both TTF (median 720, 643, 562, 406, 254 s) and the NCF (3600, 3215, 2810, 2032, 1482 cycles) decreased in the following order RM_06 > RPB > RM_04 > Proc > WOG with partially significant differences. During testing, only six RM_06 instruments fractured, whereas 16/20 (RPB), 18/20 (Proc), and 20/20 (RM_04, WOG) fractures were recorded (p < 0.05). Within the limitations of the present study, blue-coloured RPB and RM instruments exhibited a significantly superior cyclic fatigue resistance compared to SE-NiTi and Gold-wire instruments. Heat treatment, cross-sectional design and core mass significantly influenced the longevity of reciprocating instruments in cyclic dynamic testing.
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Affiliation(s)
- Sebastian Bürklein
- Central Interdisciplinary Ambulance in the School of Dentistry, University of Münster, 48149 Münster, Germany; (S.B.); (P.M.); (E.S.)
| | - Paul Maßmann
- Central Interdisciplinary Ambulance in the School of Dentistry, University of Münster, 48149 Münster, Germany; (S.B.); (P.M.); (E.S.)
| | - Edgar Schäfer
- Central Interdisciplinary Ambulance in the School of Dentistry, University of Münster, 48149 Münster, Germany; (S.B.); (P.M.); (E.S.)
| | - David Donnermeyer
- Department of Periodontology and Operative Dentistry, University of Münster, 48149 Münster, Germany
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Langaliya A, Patel N, Pallipurath A, Parmar G, Kothari A, Jhala K. Analysis of cyclic fatigue resistance of different endodontic nickel-titanium rotary instruments: An in vitro study. JOURNAL OF CONSERVATIVE DENTISTRY AND ENDODONTICS 2024; 27:95-99. [PMID: 38389747 PMCID: PMC10880468 DOI: 10.4103/jcde.jcde_204_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/10/2023] [Accepted: 12/06/2023] [Indexed: 02/24/2024]
Abstract
Aims The aim of this in vitro study was to compare the cyclic fatigue resistance of three different endodontic nickel-titanium rotary instruments using a dynamic testing device. Materials and Methods Ten files each of ProTaper Gold (PG), Hyflex Electro-discharge Machining (HEDM), and TruNatomy (TN) were tested in a custom-fabricated dynamic cyclic fatigue testing device at 60° curvature having a radius of curvature of 5 mm. The number of cycles to the fracture (NCF) of each instrument was calculated and three continuous groups were compared by the Kruskal-Wallis test and Dunn post hoc test was used for pairwise comparison. Results Cyclic fatigue resistance of HEDM was the highest, followed by TN. PG had the lowest among the three. Conclusion Within the limitations of the present in vitro results, it can be concluded that HEDM files appeared to be suitable for shaping complex canals with the greater number of cycles before it fractures.
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Affiliation(s)
- Akshayraj Langaliya
- Department of Conservative Dentistry and Endodontics, AMC Dental College and Hospital, Ahmedabad, Gujarat, India
| | - Neeta Patel
- Department of Conservative Dentistry and Endodontics, AMC Dental College and Hospital, Ahmedabad, Gujarat, India
| | - Athulya Pallipurath
- Department of Conservative Dentistry and Endodontics, AMC Dental College and Hospital, Ahmedabad, Gujarat, India
| | - Girish Parmar
- Department of Conservative Dentistry and Endodontics, Government Dental College and Hospital, Ahmedabad, Gujarat, India
| | - Anjali Kothari
- Department of Conservative Dentistry and Endodontics, AMC Dental College and Hospital, Ahmedabad, Gujarat, India
| | - Kairavi Jhala
- Department of Conservative Dentistry and Endodontics, AMC Dental College and Hospital, Ahmedabad, Gujarat, India
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Dos Reis FAS, Abu Hasna A, Ragozzini G, de Moura FB, Campos TMB, de Martin AS, Carvalho CAT, Bueno CES. Assessing the cyclic fatigue resistance and sterilization effects on replica-like endodontic instruments compared to Reciproc Blue. Sci Rep 2023; 13:22956. [PMID: 38151487 PMCID: PMC10752872 DOI: 10.1038/s41598-023-50096-2] [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: 08/24/2023] [Accepted: 12/15/2023] [Indexed: 12/29/2023] Open
Abstract
This study aimed to evaluate the effect of the number of uses and autoclave sterilization on the cyclic fatigue resistance of four replica-like instruments RC Blue; Only One File Blue; Recip One Blue; and Micro Blue compared to the original system Reciproc Blue (VDW, Munich, Germany). The instruments were analyzed by scanning electron microscope (SEM) before being used in root canal instrumentation (baseline). Fifty molars were instrumented by ten instruments (n=10). After sterilization in an autoclave, the instruments were analyzed by SEM. This procedure was repeated twice more using different molars, totaling 3 rounds of instrumentation, sterilization and SEM analysis. Then, ten different instruments from each brand were tested for cyclic fatigue resistance. Number of uses data were analyzed using Chi-squared analysis, and cyclic fatigue data were analyzed by one-way Anova followed by Tukey's test as the data had normal distribution. The fracture times for all systems had no significant difference, but Micro Blue had significantly lower values than the other systems (p < 0.05). The SEM analysis showed distortions in the instruments after the 3rd use. Therefore, all tested instruments except of Micro Blue have similar resistance to cyclic fatigue, and all are reliable for use in up to 2-cases.
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Affiliation(s)
| | - Amjad Abu Hasna
- Department of Restorative Dentistry, Endodontics Division, Institute of Science and Technology, São Paulo State University (UNESP), Av. Eng. Francisco José Longo Avenue 777, São José dos Campos, SP, CEP 12245-000, Brazil.
- School of Dentistry, Universidad Espíritu Santo, Samborondón, Ecuador.
| | - Gustavo Ragozzini
- Faculdade São Leopoldo Mandic, Instituto de Pesquisas São Leopoldo Mandic, Endodontia, Campinas, SP, Brazil
| | - Felipe Bernardo de Moura
- Department of Restorative Dentistry, Endodontics Division, Institute of Science and Technology, São Paulo State University (UNESP), Av. Eng. Francisco José Longo Avenue 777, São José dos Campos, SP, CEP 12245-000, Brazil
| | | | | | - Cláudio Antonio Talge Carvalho
- Department of Restorative Dentistry, Endodontics Division, Institute of Science and Technology, São Paulo State University (UNESP), Av. Eng. Francisco José Longo Avenue 777, São José dos Campos, SP, CEP 12245-000, Brazil
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dos Reis FAS, Abu Hasna A, Ragozzini G, de Moura FB, Campos TMB, de Martin AS, Carvalho CAT, Bueno CES. Assessing the cyclic fatigue resistance and sterilization effects on replica-like endodontic instruments compared to Reciproc Blue. Sci Rep 2023; 13:22956. [DOI: https:/doi.org/10.1038/s41598-023-50096-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 12/15/2023] [Indexed: 01/17/2024] Open
Abstract
AbstractThis study aimed to evaluate the effect of the number of uses and autoclave sterilization on the cyclic fatigue resistance of four replica-like instruments RC Blue; Only One File Blue; Recip One Blue; and Micro Blue compared to the original system Reciproc Blue (VDW, Munich, Germany). The instruments were analyzed by scanning electron microscope (SEM) before being used in root canal instrumentation (baseline). Fifty molars were instrumented by ten instruments (n=10). After sterilization in an autoclave, the instruments were analyzed by SEM. This procedure was repeated twice more using different molars, totaling 3 rounds of instrumentation, sterilization and SEM analysis. Then, ten different instruments from each brand were tested for cyclic fatigue resistance. Number of uses data were analyzed using Chi-squared analysis, and cyclic fatigue data were analyzed by one-way Anova followed by Tukey’s test as the data had normal distribution. The fracture times for all systems had no significant difference, but Micro Blue had significantly lower values than the other systems (p < 0.05). The SEM analysis showed distortions in the instruments after the 3rd use. Therefore, all tested instruments except of Micro Blue have similar resistance to cyclic fatigue, and all are reliable for use in up to 2-cases.
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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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Silva EJNL, Alcalde MP, Martins JNR, Vieira VTL, Vivan RR, Duarte MAH, Belladonna FG, Braz-Fernandes FM, Versiani MA. To flat or not to flat? Exploring the impact of flat-side design on rotary instruments using a comprehensive multimethod investigation. Int Endod J 2023; 56:1301-1315. [PMID: 37594701 DOI: 10.1111/iej.13960] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 07/28/2023] [Accepted: 07/31/2023] [Indexed: 08/19/2023]
Abstract
AIM To assess the influence of a flat-side design on the geometry, metallurgy, mechanical performance and shaping ability of a novel nickel-titanium rotary instrument. METHODOLOGY Sixty-five new 25-mm flat-side rotary instruments (size 25, taper 0.04) and their nonflat-side prototypes (n = 65) were assessed for major deformations and examined regarding macroscopic and microscopic design, determination of nickel and titanium elements ratio, measurement of phase transformation temperature and evaluation of mechanical performance parameters including time/cycles to fracture, maximum torque, angle of rotation, maximum bending and buckling strengths and cutting ability. Additionally, unprepared canal areas, volume of hard tissue debris and percentage reduction of dentine thickness were calculated for each tested instrument after preparing mesial canals of mandibular molars (n = 12), using micro-CT imaging. Statistical analyses were performed using the U-Mann-Whitney test and independent Student t-test (α = 5%). RESULTS The number of spirals (n = 8) and blade direction (clockwise) were similar between both flat and nonflat instruments, whilst the helical angles were equivalent (⁓25°). Flat-instruments showed inconsistencies in the homogeneity of the gold colour on the flat-side surface, blade discontinuity, and incomplete and variable S-shaped cross-sections. The titanium-to-nickel ratios were equivalent, but significant differences in the R-phase finish and austenitic start phase transformation temperatures were observed between the flat and nonflat-side instruments. The flat-side instruments demonstrated superior cutting ability compared to the nonflat instruments, as well as, significantly lower values for time to fracture, rotation to fracture and maximum torque to fracture (p < .001). No statistical difference was observed between tested instruments regarding angle of rotation (p = .437), maximum bending (p = .152) and buckling load (p = .411). Preparation protocols using flat and nonflat instruments did not show any statistically significant differences (p > .05). All flat-side instruments exhibited deformation after shaping procedures. CONCLUSIONS The flat-side instrument showcased enhanced cutting ability compared to its nonflat counterpart. However, it exhibited inferior performance in terms of time, rotation and maximum torque to fracture, along with distinct phase transformation temperatures. No differences were observed in the titanium-to-nickel ratios, angle of rotation, maximum bending, buckling load, preparation time, percentage of untouched canal walls, volume of hard tissue debris and percentage reduction of dentine thickness.
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Affiliation(s)
- Emmanuel J N L Silva
- Department of Endodontics, Fluminense Federal University, Rio de Janeiro, Brazil
- Department of Endodontics, State University of Rio de Janeiro, Rio de Janeiro, Brazil
- Department of Endodontics, Grande Rio University, Rio de Janeiro, Brazil
| | - Murilo P Alcalde
- Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Jorge 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
| | - Victor T L Vieira
- Department of Endodontics, Grande Rio University, Rio de Janeiro, Brazil
| | - Rodrigo R Vivan
- Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Marco A H Duarte
- Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Felipe G Belladonna
- Department of Endodontics, Fluminense Federal University, Rio de Janeiro, Brazil
| | - Francisco Manuel Braz-Fernandes
- CENIMAT/I3N, Department of Materials Science, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Marco A Versiani
- Dental Specialty Center, Brazilian Military Police, Minas Gerais, Brazil
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11
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Elsewify T, Elhalabi H, Eid B. Dynamic Cyclic Fatigue and Differential Scanning Calorimetry Analysis of R-Motion. Int Dent J 2023; 73:680-684. [PMID: 36631389 PMCID: PMC10509393 DOI: 10.1016/j.identj.2022.12.007] [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: 10/31/2022] [Revised: 12/14/2022] [Accepted: 12/18/2022] [Indexed: 01/11/2023] Open
Abstract
INTRODUCTION The aim of this study was to assess the dynamic cyclic fatigue resistance of an R-Motion file at simulated body temperature and document corresponding phase transformations compared to OneCurve and HyFlex EDM (HFEDM). METHODS R-Motion (25/.06), OneCurve (25/.06), and HFEDM (25/.06) files were selected and divided into 3 groups (n = 9) according to the file type. Dynamic cyclic fatigue testing was done with a custom-made artificial stainless-steel canal that had a 90° angle of curvature and a 5-mm radius of curvature. Files were operated continuously at body temperature until fracture in the artificial canal. The time to fracture was calculated. Statistical analysis was performed, and significance was set at 5%. Phase transformation temperatures for 2 instruments of each group were analysed by differential scanning calorimetry (DSC) analysis. RESULTS The highest mean time to fracture value was measured in the HFEDM group (277.84 ± 2.51), followed by the R-Motion group (115.09 ± 0.01), whilst the lowest value was found in the OneCurve group (44.28 ± 3.63). Post hoc pairwise comparisons were all statistically significant (P < .001). DSC heating curves show austinite start temperatures to be 33.94 °C and 43.32 °C and austinite finish temperatures to be 35.09 °C and 50 °C for R-Motion and HFEDM, respectively. DSC cooling curves show martensite start temperatures to be 27.54 °C and 44.52 °C and martensite finish temperatures to be 29.13 °C and 37.68 °C for R-Motion and HFEDM, respectively. DSC curves of OneCurve failed to demonstrate transformation temperatures within the tested heat range. CONCLUSIONS Crystalline arrangement of Ni and Ti atoms within the NiTi alloys greatly affects the dynamic cyclic fatigue resistance of the file.
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Affiliation(s)
- Tarek Elsewify
- Endodontic Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt; Restorative Dental Sciences Department, College of Dentistry, Gulf Medical University, Ajman, UAE.
| | - Hisham Elhalabi
- Endodontic Department, Faculty of Dentistry, Assuit University, Assuit, Egypt
| | - Bassem Eid
- Restorative Dental Sciences Department, College of Dentistry, Gulf Medical University, Ajman, UAE
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12
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Chan WS, Gulati K, Peters OA. Advancing Nitinol: From heat treatment to surface functionalization for nickel–titanium (NiTi) instruments in endodontics. Bioact Mater 2023; 22:91-111. [PMID: 36203965 PMCID: PMC9520078 DOI: 10.1016/j.bioactmat.2022.09.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 09/04/2022] [Accepted: 09/09/2022] [Indexed: 11/27/2022] Open
Abstract
Nickel-titanium (NiTi) alloy has been extensively researched in endodontics, particularly in cleaning and shaping the root canal system. Research advances have primarily focused on the design, shape, and geometry of the NiTi files as well as metallurgy and mechanical properties. So far, extensive investigations have been made surrounding surface and thermomechanical treatments, however, limited work has been done in the realm of surface functionalization to augment its performance in endodontics. This review summarizes the unique characteristics, current use, and latest developments in thermomechanically treated NiTi endodontic files. It discusses recent improvements in nano-engineering and the possibility of customizing the NiTi file surface for added functionalization. Whilst clinical translation of this technology has yet to be fully realized, future research direction will lie in the use of nanotechnology. Nitinol (Nickel Titanium alloy) is widely used to clean/shape root canal system in endodontics. To enhance its performance, various thermo-mechanical and nano-engineering modifications have been performed. This comprehensive review summarizes the latest advances and future trends relating to functionalized NiTi endodontic files.
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13
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Thu M, Ebihara A, Maki K, Nishijo M, Kimura S, Nakatsukasa T, Kyaw MS, Okiji T. Effect of different axial speed patterns on cyclic fatigue resistance of rotary nickel-titanium instruments. BMC Oral Health 2022; 22:617. [PMID: 36529721 PMCID: PMC9761994 DOI: 10.1186/s12903-022-02639-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 11/30/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND To evaluate the effect of pecking motions with faster upward speed on the dynamic cyclic fatigue resistance of nickel-titanium rotary instruments with different metallurgy. METHODS Forty each of ProTaper Universal F3 (PTU) and ProTaper Gold F3 (PTG) instruments (size #30/.09) were equally divided into four groups. The test was performed using an 18-mm-long stainless steel artificial canal with a 5-mm radius of curvature, a 45° canal curvature and a 2-mm canal diameter. A downward speed of 100 mm/min was employed, while the upward speed was set at 100, 150, 200 or 300 mm/min. Time to failure (Tf), number of cycles to failure (Nf) and number of pecking motions to failure (Np) were recorded. Statistical analysis was performed using Kruskal Wallis and Mann-Whitney U tests for Tf, Nf, and Np (α = 0.05). RESULTS The 100/300 mm/min group showed significantly higher Np values than the 100/100 mm/min group (p < 0.05), whereas there were no significant differences in Tf and Nf among the tested speed groups (p < 0.05) in either PTU or PTG. PTG exhibited significantly higher Tf, Nf, and Np than PTU (p < 0.05). CONCLUSIONS Under the tested conditions, the fastest upward speed group showed significantly higher cyclic fatigue resistance, as demonstrated by larger Np, than the same speed group. PTG had significantly higher cyclic fatigue resistance than PTU in all groups.
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Affiliation(s)
- Myint Thu
- grid.265073.50000 0001 1014 9130Division of Oral Health Sciences, Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 5-45, Yushima 1-chome, Bunkyo-ku, Tokyo, 113-8549 Japan
| | - Arata Ebihara
- grid.265073.50000 0001 1014 9130Division of Oral Health Sciences, Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 5-45, Yushima 1-chome, Bunkyo-ku, Tokyo, 113-8549 Japan
| | - Keiichiro Maki
- grid.265073.50000 0001 1014 9130Division of Oral Health Sciences, Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 5-45, Yushima 1-chome, Bunkyo-ku, Tokyo, 113-8549 Japan
| | - Miki Nishijo
- grid.265073.50000 0001 1014 9130Division of Oral Health Sciences, Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 5-45, Yushima 1-chome, Bunkyo-ku, Tokyo, 113-8549 Japan
| | - Shunsuke Kimura
- grid.265073.50000 0001 1014 9130Division of Oral Health Sciences, Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 5-45, Yushima 1-chome, Bunkyo-ku, Tokyo, 113-8549 Japan
| | - Taro Nakatsukasa
- grid.265073.50000 0001 1014 9130Division of Oral Health Sciences, Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 5-45, Yushima 1-chome, Bunkyo-ku, Tokyo, 113-8549 Japan
| | - Moe Sandar Kyaw
- grid.265073.50000 0001 1014 9130Division of Oral Health Sciences, Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 5-45, Yushima 1-chome, Bunkyo-ku, Tokyo, 113-8549 Japan
| | - Takashi Okiji
- grid.265073.50000 0001 1014 9130Division of Oral Health Sciences, Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 5-45, Yushima 1-chome, Bunkyo-ku, Tokyo, 113-8549 Japan
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14
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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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15
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What meaningful information are the instruments mechanical testing giving us? A comprehensive review. J Endod 2022; 48:985-1004. [PMID: 35667567 DOI: 10.1016/j.joen.2022.05.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/21/2022] [Accepted: 05/26/2022] [Indexed: 11/22/2022]
Abstract
Instruments mechanical strength and flexibility are traditionally tested by running cyclic fatigue, torsional, bending, buckling and microhardness tests. Several cyclic fatigue test models have been used in endodontics, all capable of providing a curved trajectory for the instrument to rotate. The cyclic fatigue testing allowed to identify conditions that may affect the fatigue strength outcomes, such as canal radius and degree of curvature, handpiece static vs dynamic motions, test temperature, kinematics, instrument previously wear and sterilization cycles, or instrument's size and metal alloy features. Due to the international test specifications for both torsional and bending tests, the variations of their models are not as many as for cyclic fatigue. These tests have also identified conditions capable of affecting the outcomes, such as kinematics, instrument's preloading, cross-sectional diameters, or alloy heat treatments. Buckling and microhardness are less common, with the metal alloy being considered to have a major influence on the results. Instruments mechanical testing, having all these individual conditions as independent variables, allowed to understand them and moulded the way the technical procedures are performed clinically. Even though the artificiality and simplicity of these tests will hardly mimic real working situations, and independently of being capable of producing cornerstone knowledge, these tests are also associated with inconsistency, lack of reproducibility and low external validity. Several attempts have been made to increase the generalizability of the outcomes by adding test settings that intend to mimic the clinical condition. Although pertinent, these settings may also add variabilities inherent to their concepts and practical applications in the laboratory environment. Although the actual studies should be seen as laboratory mechanical tests that measure very specific parameters under very particular conditions and that by far do not mimic the clinical condition, the lower validity drawback seems to be possible to be minimized when achieving a comprehensive understanding of the instrument behaviour. A Finite Elements Method and/or a multimethod research approach may lead to superior data collection, analysis, and results' interpretation, which when associated with a reliable confounding factors control and proper study designs may be helpful tools and strategies in order to increase the reliability of the outcomes.
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16
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Multimethod Assessment of Design, Metallurgical, and Mechanical Characteristics of Original and Counterfeit ProGlider Instruments. MATERIALS 2022; 15:ma15113971. [PMID: 35683270 PMCID: PMC9182015 DOI: 10.3390/ma15113971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 05/31/2022] [Accepted: 05/31/2022] [Indexed: 11/17/2022]
Abstract
A multimethod study was conducted to assess the differences between original (PG-OR) and counterfeit (PG-CF) ProGlider instruments regarding design, metallurgical features, and mechanical performance. Seventy PG-OR and PG-CF instruments (n = 35 per group) were evaluated regarding the number of spirals, helical angles, and measuring line position by stereomicroscopy, while blade symmetry, cross-section geometry, tip design, and surface were assessed by scanning electron microscopy. Energy-dispersive X-ray spectroscopy and differential scanning calorimetry were used to identify element ratio and phase transformation temperatures, while cyclic fatigue, torsional, and bending testing were employed to assess their mechanical performance. An unpaired t-test and nonparametric Mann−Whitney U test were used to compare instruments at a significance level of 5%. Similarities were observed in the number of spirals, helical angles, blade symmetry, cross-sectional geometries, and nickel−titanium ratios. Measuring lines were more reliable in the original instrument, while differences were noted in the geometry of the tips (sharper tip for the original and rounded for the counterfeit) and surface finishing with PG-CF presenting more surface irregularities. PG-OR showed significantly more time to fracture (118 s), a higher angle of rotation (440°), and a lower maximum bending load (146.3 gf) (p < 0.05) than PG-CF (p < 0.05); however, maximum torque was similar for both instruments (0.4 N.cm) (p > 0.05). Although the tested instruments had a similar design, the original ProGlider showed superior mechanical behavior. The results of counterfeit ProGlider instruments were unreliable and can be considered unsafe for glide path procedures.
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17
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Zanza A, Russo P, Di Matteo P, Reda R, Di Nardo D, Gambarini G, Testarelli L. Mechanical properties and metallurgical features of two similar endodontic rotary instruments with different heat treatments (FireWire™ and Gold). Sci Prog 2022; 105:368504221103763. [PMID: 35656775 PMCID: PMC10364944 DOI: 10.1177/00368504221103763] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The aim of this study was to explain the mechanical differences between EdgeTaper Platinum (ETP) and ProTaper Gold (PTG) determining the transition temperatures and the composition of the alloy of ETP, since no data are present in literature. A total of 130 instruments were selected: 65 ETP F2 and 65 PTG F2. 20 instruments per type were submitted to each mechanical tests. The cyclic fatigue and torsional tests were performed at a pre-set temperature of 35 °C ± 1 °C. During the cyclic fatigue test, Time to fracture, number of cycles to fracture (NCF) and the fragment length (FL) were recorded. During the static torsional, Torque to Fracture (TtF) and FL were recorded. The fracture surface of 5 randomly selected fragments from each test was examined through a Scanning Electron Microscopy (SEM) and an EDX analysis was performed. 20 instruments per type were submitted to a bending test The force generated (grams) to bend each was recorded. Recorded data of mechanical and metallurgical tests were statistically analyzed using a one-way analysis of variance (ANOVA) test with significance set to a 95% confidence level. ETP F2 showed a higher cyclic fatigue resistance and bending ability than PTG F2, with a statistically significant difference (p < 0.05). PTG showed a higher torsional resistance with a statistically significant difference (p < 0.05). DSC analysis of 5 samples for each instrument type pointed out that the austenite finish temperature of PTG was higher than the ETP, respectively of 49.99 ± 3.31 (°C) and 38.92 ± 1.75 (°C). EDX analysis confirmed the near-equiatomic composition of the Ni-Ti alloys, with a presence of a third component recognized as rubidium in the ETP samples. ETP showed higher flexibility in comparison with PTG, despite the latter is characterized by a more martensitic characterization. since its Af temperature is higher than the ETP.
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Affiliation(s)
- Alessio Zanza
- Department of Oral and Maxillo-Facial Sciences, Sapienza University of Rome, via Caserta 6, 00161 Rome, Italy
| | - Paola Russo
- Department of Chemical Engineering, Materials, Environment DICMA, La Sapienza University of Rome, via Scarpa, 00161 Rome, Italy
| | - Paola Di Matteo
- Department of Chemical Engineering, Materials, Environment DICMA, La Sapienza University of Rome, via Scarpa, 00161 Rome, Italy
| | - Rodolfo Reda
- Department of Oral and Maxillo-Facial Sciences, Sapienza University of Rome, via Caserta 6, 00161 Rome, Italy
| | - Dario Di Nardo
- Department of Oral and Maxillo-Facial Sciences, Sapienza University of Rome, via Caserta 6, 00161 Rome, Italy
| | - Gianluca Gambarini
- Department of Oral and Maxillo-Facial Sciences, Sapienza University of Rome, via Caserta 6, 00161 Rome, Italy
| | - Luca Testarelli
- Department of Oral and Maxillo-Facial Sciences, Sapienza University of Rome, via Caserta 6, 00161 Rome, Italy
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18
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Martins JNR, Marques D, Vasconcelos I, Arantes-Oliveira S, Caramês J, Braz Fernandes FM. Multimethod Assessment of the Cyclic Fatigue Strength of ProGlider, Edge Glide Path and R-Pilot Endodontic Instruments. Dent J (Basel) 2022; 10:dj10020030. [PMID: 35200255 PMCID: PMC8870709 DOI: 10.3390/dj10020030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/11/2022] [Accepted: 02/15/2022] [Indexed: 12/03/2022] Open
Abstract
Background: The aim of this study was to comprehensively evaluate the cyclic fatigue strength of ProGlider, Edge Glide Path, and R-Pilot instruments. Methods: Sixty-three instruments were submitted to a multimethod evaluation. Their design was analyzed by stereomicroscopy and scanning electron microscopy, including the number of blades, helical angle means, cross-sectional design, surface finishing, and symmetry. Energy-dispersive X-ray spectroscopy was used determine the nickel/titanium elements ratio, and differential scanning calorimetry determined the instruments’ phase transformation temperatures. The cyclic fatigue tests were conducted in an artificial canal with a 6 mm radius and 86 degrees of curvature. The Mood’s median test and one-way ANOVA were used to determine differences, with the significance level set at 0.05. Results: The ProGlider presented the highest number of blades (n = 21), while R-Pilot had the highest helical angles (26.4°). Differences were noted in the instruments’ cross-sections and surface finishing. The ProGlider and R-Pilot showed some similarities regarding the phase transformation temperatures but differed from the Edge Glide Path. All alloys showed an almost equiatomic nickel/titanium ratio. The R-Pilot instruments showed a significantly higher (p < 0.05) time to fracture than both the other files. Conclusion: Reciprocating R-Pilot instruments showed a higher cyclic fatigue time to fracture than the ProGlider and Edge Glide Path rotary files.
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Affiliation(s)
- Jorge N. R. Martins
- Faculdade de Medicina Dentária, Universidade de Lisboa, 1600-277 Lisboa, Portugal; (D.M.); (I.V.); (S.A.-O.); (J.C.)
- Centro de Estudo de Medicina Dentária Baseada na Evidência (CEMDBE), 1600-277 Lisboa, Portugal
- Implantology Institute, 1070-064 Liaboa, Portugal
- Correspondence:
| | - Duarte Marques
- Faculdade de Medicina Dentária, Universidade de Lisboa, 1600-277 Lisboa, Portugal; (D.M.); (I.V.); (S.A.-O.); (J.C.)
- Centro de Estudo de Medicina Dentária Baseada na Evidência (CEMDBE), 1600-277 Lisboa, Portugal
- Implantology Institute, 1070-064 Liaboa, Portugal
- LIBPhys-FCT UID/FIS/04559/2013, 1600-277 Lisboa, Portugal
| | - Isabel Vasconcelos
- Faculdade de Medicina Dentária, Universidade de Lisboa, 1600-277 Lisboa, Portugal; (D.M.); (I.V.); (S.A.-O.); (J.C.)
- Center for Rapid and Sustainable Product Development, Polytechnic Institute of Leiria, 2411-901 Leiria, Portugal
| | - Sofia Arantes-Oliveira
- Faculdade de Medicina Dentária, Universidade de Lisboa, 1600-277 Lisboa, Portugal; (D.M.); (I.V.); (S.A.-O.); (J.C.)
- LIBPhys-FCT UID/FIS/04559/2013, 1600-277 Lisboa, Portugal
| | - João Caramês
- Faculdade de Medicina Dentária, Universidade de Lisboa, 1600-277 Lisboa, Portugal; (D.M.); (I.V.); (S.A.-O.); (J.C.)
- Implantology Institute, 1070-064 Liaboa, Portugal
- LIBPhys-FCT UID/FIS/04559/2013, 1600-277 Lisboa, Portugal
| | - Francisco Manuel Braz Fernandes
- CENIMAT/I3N, Department of Materials Science, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal;
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19
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Nickel–Titanium Rotary Instruments: Mechanical and Metallurgical Characteristics. Clin Pract 2022; 12:94-96. [PMID: 35200263 PMCID: PMC8870687 DOI: 10.3390/clinpract12010012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 02/10/2022] [Indexed: 02/04/2023] Open
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20
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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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Sharma S, Savitha S, Kumar V, Chawla A, Vanamail P, Logani A. Effect of body temperature on the cyclic fatigue resistance of the nickel”titanium endodontic instruments: A systematic review and meta-analysis of in vitro studies. J Conserv Dent 2022; 25:338-346. [PMID: 36187856 PMCID: PMC9520645 DOI: 10.4103/jcd.jcd_55_22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/18/2022] [Accepted: 05/03/2022] [Indexed: 11/27/2022] Open
Abstract
Aim: The aim of this systematic review was to compare the effect of body temperature (I) on the cyclic fatigue resistance (O) of nickel–titanium (NiTi) endodontic instruments (P) to that of room temperature (C). Methods: The study was registered in the PROSPERO database (CRD42020204286). A systematic search in PubMed, Scopus, Web of Science, Google Scholar, and OpenGrey was conducted in English until December 31, 2021. In vitro studies comparing the cyclic fatigue resistance of NiTi instruments at the body (35°C ± 2°C) and room temperature (20°C–25°C) were included. Eligible studies were evaluated for risk of bias and meta-analyzed to estimate the effects. Results: Twenty-one studies out of 347 met the criteria for inclusion. The meta-analysis included six studies (n = 215) with comparative study parameters. The overall effect sizes (5.49; 95% confidence interval [CI]: 4.04–6.93) were significantly different (P < 0.001), indicating that the mean values at room temperature were significantly (P < 0.001) higher. The effect sizes for full rotary motion (standardized mean difference [SMD]: 4.80; 95% CI: 3.04–6.56) and reciprocating motion (SMD: 6.37; 95% CI: 3.63–9.11) were not significantly different (P = 0.346). Heterogeneity was high (I2 = 94%). Sensitivity analysis revealed that the SMD values were not significantly different (P > 0.05) from the overall effect size, indicating that none of the studies had an effect on the overall effect size. Conclusions: Within the limitation of the study, the cyclic fatigue resistance of heat-treated NiTi endodontic files is significantly reduced at body temperature when compared to room temperature. Cyclic fatigue testing should be conducted at simulated body temperature.
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MESQUITA ML, BUENO CEDS, DE MARTIN AS, PELEGRINE RA, FONTANA CE. Influência do hipoclorito de sódio na resistência à fadiga cíclica em instrumentos rotatórios endodônticos de memória controlada de NiTi: uma avaliação experimental. REVISTA DE ODONTOLOGIA DA UNESP 2022. [DOI: 10.1590/1807-2577.04622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Resumo Introdução É importante saber se o hipoclorito de sódio (NaOCl) influencia a resistência à fadiga cíclica das limas de níquel-titânio (NiTi). Objetivo Avaliar a influência de NaOCl 2,5% na resistência à fadiga cíclica de dois sistemas de NiTi. Material e método: 40 instrumentos rotatórios – 20 TruNatomy® (TRU, Dentsply Sirona, Maillefer, Ballaigues, Suíça) e 20 Prodesing Logic2® (PDL2, Bassi, Belo Horizonte, Minas Gerais, Brasil) – foram aleatoriamente distribuídos em 4 grupos experimentais (n = 10) imersos em água destilada (H2O) e NaOCl 2,5% em temperatura a 37°C. Foram submetidos a testes de fadiga cíclica mensurando o número de ciclos para fratura (NCF) e análise dessas superfícies pós-teste em microscópio eletrônico por varredura. Para a análise estatística entre os grupos, foi aplicada a análise de variância (ANOVA), complementada com o pós-teste de Tukey. Resultado Houve diferença estatística em todos os grupos (P < 0,05). Os instrumentos PDL2 obtiveram maior resistência à fratura nas condições em H2O e em NaOCl 2,5% comparados aos instrumentos TRU. Na análise de grupos de instrumentos nas soluções de NaOCl e H2O, foi observado que o NaOCl 2,5% diminuiu o NCF. Conclusão A resistência à fadiga cíclica dos instrumentos TRU e PDL2 diminuiu com NaOCl 2,5%. Os instrumentos PDL2 foram mais resistentes à fratura em relação aos instrumentos TRU.
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Schäfer E, Bürklein S, Donnermeyer D. A critical analysis of research methods and experimental models to study the physical properties of NiTi instruments and their fracture characteristics. Int Endod J 2021; 55 Suppl 1:72-94. [PMID: 34862796 DOI: 10.1111/iej.13673] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 12/03/2021] [Indexed: 11/27/2022]
Abstract
The aim of this review is to provide a critical overview of the physical properties (surface hardness, cutting efficiency, bending properties, flexibility and cyclic fatigue resistance) of NiTi instruments. Frequently used experimental models regarding these aspects will be presented and discussed with regard to their strengths and weaknesses. For all these aspects, a plethora of experimental models have been described. Based on a critical appraisal and especially taking the appropriate translation of experimental findings to clinical endodontics into account, suggestions for future research based on clearly defined and valid experimental methodologies will be provided. Up to now, very few attempts have been made to assess which particular physical properties of NiTi instruments exert an impact on the clinical outcome of root canal treatment. Departure from merely focusing on physical properties and fracture characteristics towards more biological aspects in terms of treatment outcome is essential.
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Affiliation(s)
- Edgar Schäfer
- Central Interdisciplinary Ambulance in the School of Dentistry, Münster, Germany
| | - Sebastian Bürklein
- Central Interdisciplinary Ambulance in the School of Dentistry, Münster, Germany
| | - David Donnermeyer
- Department of Periodontology and Operative Dentistry, Westphalian Wilhelms-University, Münster, Germany
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Hülsmann M. A critical appraisal of research methods and experimental models for studies on root canal preparation. Int Endod J 2021; 55 Suppl 1:95-118. [PMID: 34800299 DOI: 10.1111/iej.13665] [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: 07/05/2021] [Accepted: 11/17/2021] [Indexed: 01/02/2023]
Abstract
It is the aim of this review to present a critical overview and summary on the contemporary possibilities, limitations and challenges of research related to root canal preparation. Frequently used research tools and contemporary research designs will be presented and discussed critically focussing on shortcomings and benefits with special regard to clinical relevance and scientific evidence. A plethora of experimental set-ups for assessing the shaping of root canals have been described in the endodontic literature using a considerable number of techniques and instruments. Nevertheless, it can be stated that scientific evidence demonstrating the clinical impact of many investigated topics is questionable or even missing. Instead of technical, radiographic and geometrical parameters, further research should focus on biological aspects and clinical evidence of the impact of root canal preparation on the outcome of root canal treatment.
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Affiliation(s)
- Michael Hülsmann
- Clinic of Conservative and Preventive Dentistry, University of Zurich, Zurich, Switzerland
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Deniz N, Orhan EO. Development of a multi-criteria decision-making-based assessment model for dental material selection: Engine-driven nickel-titanium instruments case study. Clin Oral Investig 2021; 26:2645-2659. [PMID: 34750681 DOI: 10.1007/s00784-021-04234-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 10/15/2021] [Indexed: 11/25/2022]
Abstract
OBJECTIVES The aims of this study are (i) to propose specific selection criteria related to NiTi instruments for dental practitioners and (ii) to objectively assess the NiTi instruments. MATERIALS AND METHODS The steps of the methodology are as follows: Step 1: "Delphi method" was employed to reach a consensus on criteria defined according to the literature review and a group of panelists. Step 2: "Smart pairwise comparisons" were employed to rank the proposed criteria. Step 3: "Borda voting" was employed to determine the weights of the proposed criteria. Step 4: To determine assessment scores, "Simple Additive Weighting" was employed. Step 5: Reliability and validity checks were made by "simulation." RESULTS Specific criteria classified under dimensions were proposed and weighted for the NiTi instrument assessment. In this context, an assessment model was proposed and validated. CONCLUSIONS The proposed assessment model for NiTi instruments could aid to make the decision-making process as systematic, transparent, and reproducible as possible not only for dental practitioners but also for healthcare professionals. Also, this proposed model can represent a reference framework for further MCDM studies which can rank or classify materials in medical science. CLINICAL RELEVANCE The model proposed in this study can be used to aid decision-making in clinical practice by means assessing the NiTi instrumentation system alternatives for practitioners.
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Affiliation(s)
- Nurcan Deniz
- Department of Business Administration, Faculty of Economics and Administrative Sciences, Eskişehir Osmangazi University, 26040, Eskişehir, Turkey.
| | - Ekim Onur Orhan
- Department of Endodontics, Faculty of Dentistry, Eskişehir Osmangazi University, 26040, Eskişehir, Turkey.,Translational Medicine Research and Clinical Center, Eskisehir Osmangazi University, 26040, Eskisehir, Turkey
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Bürklein S, Zupanc L, Donnermeyer D, Tegtmeyer K, Schäfer E. Effect of Core Mass and Alloy on Cyclic Fatigue Resistance of Different Nickel-Titanium Endodontic Instruments in Matching Artificial Canals. MATERIALS 2021; 14:ma14195734. [PMID: 34640131 PMCID: PMC8510035 DOI: 10.3390/ma14195734] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 11/16/2022]
Abstract
Instrument failure during root canal preparation is still a concern among endodontists. However, it remains unclear whether the use of more martensitic alloys or the cross-sectional design parameters (i.e., core mass) significantly improve fracture resistance. The aim of the study was to evaluate the impact of core mass and alloy on dynamic cyclic fatigue resistance of nickel-titanium endodontic instruments in matching artificial canals at body temperature. Two groups were tested. (A) taper 0.04: F360 (Komet, Lemgo, Germany), Twisted file (Sybron Endo, Glendora, CA, USA) (=TF), JIZAI (Mani, Tochigi, Japan) (=J_04) (all size #25) and the variable tapered TruNatomy (Dentsply, Ballaigues, Switzerland) (size #26) (=TN). (B) size #25; taper 0.06: (Mtwo (VDW, Munich, Germany), JIZAI (Mani) (=J_06), and variable tapered Hyflex EDM OneFile (Coltene Whaledent, Altstätten, Switzerland) (=HF). Time, number of cycles to fracture (NCF), and number and length of fractured fragments were recorded and statistically analysed using ANOVA Student-Newman-Keuls, Kruskal–Wallis or Chi-square test (significance level = 0.05). (A) TN showed the significantly shortest time until fracture, followed by TF, F360 and J_04 which also differed significantly, while NCF showed the following order: F360 < TN < TF < J_04 (p < 0.05). Only one J_04 but all instruments of the other groups fractured within the test-limit of 10 min. (B) Mtwo was significantly inferior concerning time until fracture and NCF, compared to J_06 and HF (p < 0.05), which did not differ significantly (p > 0.05). While all Mtwo instruments fractured, only four instruments failed in the other groups (p < 0.05). Within the limitations of this study, alloy and cross-sectional design (i.e., core mass) were critical factors regarding instrument failure, but none of these factors could be determined as a main parameter for increased or decreased time, and cycles to fracture. Rather, it seemed to be the interaction of multiple factors (e.g., longitudinal and cross-sectional design, alloy, and rotational speed) that was responsible for differences in the time and cycles to fracture. Nonetheless, all instruments had lifetimes that allow safe clinical use. However, the superiority or inferiority of an instrument with regard to cyclic fatigue based on laboratory results—even when identical trajectories are guaranteed—may be considered questionable, as the characteristics and design parameters of the instruments vary considerably, and the experimental setups lack additional clinical parameters and thus clinical relevance.
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Affiliation(s)
- Sebastian Bürklein
- Albert-Schweitzer-Campus 1, Central Interdisciplinary Ambulance in the School of Dentistry, Westphalian Wilhelms-University, Building W 30, 48149 Münster, Germany;
- Correspondence: ; Tel.: +49-251-834-7051; Fax: +49-251-834-7894
| | | | - David Donnermeyer
- Albert-Schweitzer-Campus 1, Department of Periodontology and Operative Dentistry, Westphalian Wilhelms-University, Building W 30, 48149 Münster, Germany; (D.D.); (K.T.)
| | - Karsten Tegtmeyer
- Albert-Schweitzer-Campus 1, Department of Periodontology and Operative Dentistry, Westphalian Wilhelms-University, Building W 30, 48149 Münster, Germany; (D.D.); (K.T.)
| | - Edgar Schäfer
- Albert-Schweitzer-Campus 1, Central Interdisciplinary Ambulance in the School of Dentistry, Westphalian Wilhelms-University, Building W 30, 48149 Münster, Germany;
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Peters OA, Chien PYH, Armitt K, Macorra JC, Arias A. Testing Cyclic Fatigue Resistance of Nickel Titanium Rotary Endodontic Instruments: A Validation Study for a Minimum Quality Criterion in a Standardized Environment. FRONTIERS IN DENTAL MEDICINE 2021. [DOI: 10.3389/fdmed.2021.744809] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Introduction: Cyclic fatigue resistance of rotary endodontic instruments has been extensively studied in the last two decades, yet with no standardization. While new low-cost instruments are now manufactured, a standard is lacking to guarantee a minimum quality. This study aimed to validate a new model for CF testing through a fixture proposed for ISO Specification 3630-1 and to establish a minimum quality standard based on testing conditions and material characteristics.Materials and methods: Size 25/0.06 instruments of ProFile Vortex (PF) and Vortex Blue (VB) were run until failure in curved metallic fixtures (5 or 7.5 mm radius) built according to a proposal for an additional test for the ISO 3630-1 standard. High resolution videos were recorded, number of cycles to failure (NCF) registered and apical fragments measured with a digital caliper. Surface strain was determined from test dimensions and fragment lengths. Mean life, β and η parameters were calculated with Weibull analysis. NCF data were compared using student's t-tests and referenced to a minimum required cycles at fracture (Cmin) based on austenite finish temperatures, testing temperature and deformation.Results: VB instruments were statistically more resistant than PF in both 7.5 mm radius curve (p = 0.001) and 5 mm radius curve (p = 0.002) simulated canals. Weibull probability plots showed higher mean life for VB than PV. NCF for both instruments were higher than Cmin.Conclusions: The NCF results in this study support the findings of previous studies where VB and PF were compared. The novel test design appears a suitable addition to ISO 3630-1.
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28
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Martins JNR, Silva EJNL, Marques D, Pereira MR, Arantes-Oliveira S, Martins RF, Braz Fernandes FM, Versiani MA. Evaluation of Design, Metallurgy, Microhardness, and Mechanical Properties of Glide Path Instruments: A Multimethod Approach. J Endod 2021; 47:1917-1923. [PMID: 34537227 DOI: 10.1016/j.joen.2021.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 08/18/2021] [Accepted: 09/02/2021] [Indexed: 02/01/2023]
Abstract
INTRODUCTION This study aims to compare the design, metallurgy, microhardness, and mechanical properties of 3 glide path nickel-titanium (NiTi) instruments. METHODS A total of 132 ProGlider (Dentsply Sirona, Ballaigues, Switzerland), Edge Glide Path (EdgeEndo, Johnson City, TN), and R-Pilot instruments (VDW, Munich, Germany) (44 per group) were selected. Design was assessed through stereomicroscopy (blades, helical angle, measuring lines, and deformation) and scanning electron microscopy (symmetry, cross section, tip, and surface finishing). NiTi ratios were measured by energy-dispersive X-ray spectroscopy and phase transformation temperatures by differential scanning calorimetry. Microhardness and mechanical performance (torsion, bending, and buckling resistance tests) were also evaluated. Statistical analyses were performed with the Mood median test with a significance set at 5%. RESULTS The Edge Glide Path had the lowest number of blades and the R-Pilot the greatest helical angle. All instruments had an almost equiatomic NiTi ratio, while showing different cross sections and tip geometries. The Edge Glide Path had a smoother surface finishing. The R-Pilot showed martensitic characteristics at room temperature, whereas mixed austenite plus R-phase was observed in the other instruments. The R-Pilot had higher results on the microhardness (436.8 hardness Vickers number), maximum torsion (0.9 Ncm), and buckling load (0.7 N) tests (P < .05), whereas the Edge Glide Path had a superior angle of rotation (683.5°) and the ProGlider was more flexible (144.1 gf) (P < .05). CONCLUSIONS Differences in the design of the instruments and the phase transformation temperatures accounted for their mechanical behavior. The R-Pilot showed the highest torque, buckling, and microhardness, whereas the ProGlider instrument was the most flexible.
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Affiliation(s)
- Jorge N R Martins
- Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal; Grupo de Investigação em Bioquimica e Biologia Oral, Unidade de Investigação em Ciências Orais e Biomédicas, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal; Centro de Estudo de Medicina Dentária Baseada na Evidência, Cochrane Portugal, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal.
| | - Emmanuel João Nogueira Leal Silva
- School of Dentistry, Grande Rio University, Rio de Janeiro, Rio de Janeiro, Brazil; Fluminense Federal University, Niteroi, Rio de Janeiro, Brazil
| | - Duarte Marques
- Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal; Grupo de Investigação em Bioquimica e Biologia Oral, Unidade de Investigação em Ciências Orais e Biomédicas, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal; Centro de Estudo de Medicina Dentária Baseada na Evidência, Cochrane Portugal, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal; LIBPhys-FCT UID/FIS/04559/2013, Lisbon, Portugal
| | - Mário Rito Pereira
- Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal
| | - Sofia Arantes-Oliveira
- Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal; Grupo de Investigação em Bioquimica e Biologia Oral, Unidade de Investigação em Ciências Orais e Biomédicas, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal; LIBPhys-FCT UID/FIS/04559/2013, Lisbon, Portugal
| | - Rui F Martins
- UNIDEMI, Department of Mechanical and Industrial Engineering, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Francisco Manuel Braz Fernandes
- CENIMAT/I3N, Department of Materials Science, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal
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Jo HJ, Kwak SW, Kim HC, Kim SK, Ha JH. Torsional Resistance of Heat-Treated Nickel-Titanium Instruments under Different Temperature Conditions. MATERIALS 2021; 14:ma14185295. [PMID: 34576520 PMCID: PMC8470266 DOI: 10.3390/ma14185295] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/06/2021] [Accepted: 09/11/2021] [Indexed: 11/16/2022]
Abstract
This study compared the torsional resistance of heat-treated nickel-titanium (NiTi) instruments under different temperature conditions. Four thermomechanically treated single-use NiTi rotary instruments were selected for this study: OneShape (OS), OneCurve (OC), WaveOne Gold (WOG) and HyFlex EDM (HFE). Each instrument was further subdivided by temperature into 2 subgroups. Maximum torque and the distortion angle until fracture occurred were evaluated. Differential scanning calorimetry analysis was performed to measure the phase transformation temperature. Statistical analysis was performed using a two-way ANOVA and t-test (p < 0.05). Fractured fragments were observed using scanning electron microscopy (SEM). The two-way ANOVA showed no significant differences for different temperature conditions. At both room (RT) and body temperature (BT), OS was predominantly austenite while HFE was martensite. OC and WOG were predominantly martensite at RT and mixed phase at BT. At BT, more than half of WOG was martensite, while half of OC was austenite. SEM examination showed no topographical differences between instruments in different temperature groups. In relation to a limitation of this study, there was no difference in torsional resistance of NiTi rotary instruments between the BT and RT conditions. This implies that clinicians do not need to consider a decrease of torsional resistance of heat-treated NiTi instruments at BT.
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Affiliation(s)
- Hyo Jin Jo
- Department of Conservative Dentistry, School of Dentistry, Kyungpook National University, Daegu 41940, Korea; (H.J.J.); (S.K.K.)
| | - Sang Won Kwak
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Pusan National University, Yangsan 50612, Korea; (S.W.K.); (H.-C.K.)
| | - Hyeon-Cheol Kim
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Pusan National University, Yangsan 50612, Korea; (S.W.K.); (H.-C.K.)
| | - Sung Kyo Kim
- Department of Conservative Dentistry, School of Dentistry, Kyungpook National University, Daegu 41940, Korea; (H.J.J.); (S.K.K.)
| | - Jung-Hong Ha
- Department of Conservative Dentistry, School of Dentistry, Kyungpook National University, Daegu 41940, Korea; (H.J.J.); (S.K.K.)
- Correspondence: ; Tel.: +82-53-600-7624
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30
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Evaluation of Cyclic Fatigue of Hyflex EDM, Twisted Files, and ProTaper Gold Manufactured with Different Processes: An In Vitro Study. Int J Dent 2021; 2021:7402658. [PMID: 34367289 PMCID: PMC8346304 DOI: 10.1155/2021/7402658] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 07/20/2021] [Indexed: 11/17/2022] Open
Abstract
Introduction The main aims of root canal instrumentation are to provide an environment that will lead to healing and to provide a root canal shape that is comfortable to clean and seal. When working with rotary endodontic instruments, the most significant concerns are that the instrument might fracture in the root canal, thus affecting the treatment outcome. Hence, it is of immense importance to know which file systems have more cyclic fatigue resistance. Methodology. This study evaluated the effect of the curved segment length of the artificial canal (the arch), and the number of cycles necessary in fracture of Hyflex EDM, Twisted files, and ProTaper Gold were recorded. Sixty NiTi rotary instruments of 25 mm length (Hyflex EDM (20), Twisted files (20), and ProTaper Gold (20)) were tested in a metal block with simulated canal having 90° angle of curvature. The study was performed with a specific radius and degree of curvature, i.e., 8 mm radius and 90⁰ angle of curvature, and data obtained were subsequently subjected to statistical evaluation using one-way analysis of variance and Tukey's post hoc test. Result The Hyflex EDM (774.29) exhibited the maximum cyclic fatigue resistance compared to Twisted files (654.875) and ProTaper Gold (375.575). A statistically significant difference was observed between the tested groups. Conclusion The Hyflex EDM files showed the highest cyclic fatigue resistance, followed by Twisted files and ProTaper Gold files.
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Nino-Barrera J, Sanchez-Aleman J, Acosta-Humanez M, Gamboa-Martinez L, Cortes-Rodriguez C. Shot peening increases resistance to cyclic fatigue fracture of endodontic files. Sci Rep 2021; 11:12961. [PMID: 34155287 PMCID: PMC8217493 DOI: 10.1038/s41598-021-92382-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 06/09/2021] [Indexed: 11/09/2022] Open
Abstract
The objective of this study was to assess the resistance to fatigue fracture of conventional nickel–titanium files after undergoing shot peening. Forty NITIFLEX endodontic files, number 30, were divided into two groups; one was submitted to shot peening treatment and the other was not. All instruments were tested for fatigue fracture in simulated canals with a TRI-AUTO ZX endodontic motor. One file of each group was subjected to a residual stress analysis by XRD. Finally, the fractured surface was observed and elemental analysis performed by means of SEM and EDX. Roughness analysis was made by focal variation microscope. The shot peening group showed greater resistance to fatigue fracture; there was no difference in the length of the fractured fragments. XRD results showed the presence of residual compression stresses in the file submitted to shot peening, a decrease in the interplanar spacing, and an increase in the full-width-at-half-maximum and the microstrains. SEM and EDX showed a ductile fracture with zones of fatigue and an equiatomic ratio between the nickel and titanium. Surface roughness increased after the file was subjected to the shot peening procedure. In conclusion, shot peening increases the resistance to fatigue fracture due to the presence of residual compression stresses in files manufactured from a conventional nickel–titanium alloy.
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Affiliation(s)
- Javier Nino-Barrera
- Faculty of Dentistry, Endodontics Program, Universidad Nacional de Colombia, Building 210, Office 301, Bogotá, Colombia.
| | - Jose Sanchez-Aleman
- Faculty of Dentistry, Endodontics Program, Universidad Nacional de Colombia, Building 210, Office 301, Bogotá, Colombia
| | | | - Luis Gamboa-Martinez
- School of Dentistry, Endodontics Program, Universidad El Bosque, Bogotá, Colombia
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32
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Martins JNR, Silva EJNL, Marques D, Belladonna F, Simões-Carvalho M, Vieira VTL, Antunes HS, Braz Fernandes FMB, Versiani MA. Design, metallurgical features, mechanical performance and canal preparation of six reciprocating instruments. Int Endod J 2021; 54:1623-1637. [PMID: 33829516 DOI: 10.1111/iej.13529] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 04/05/2021] [Indexed: 11/28/2022]
Abstract
AIM To compare six reciprocating instruments regarding their geometric design, metallurgical characteristics, mechanical behaviour and ability to prepare root canals. METHODOLOGY A total of 246 new 25-mm NiTi instruments (41 per group) from six reciprocating systems (Reciproc, Reciproc Blue, One Files, One Files Blue, Reverso Silver, and WaveOne Gold) were evaluated throughout a multimethod approach regarding their design using stereomicroscopy (number of blades and helix angle) and scanning electron microscopy (blades symmetry, cross section and surface finishing), nickel-titanium composition, phase transformation temperatures, mechanical performance (cyclic fatigue, torsional and bending resistance) and unprepared canal surface area on anatomically matched mandibular molars assessed by micro-CT. One-way ANOVA and post hoc Tukey's or Mood's median tests were selected depending on sample distribution with significance level set at 5%. RESULTS The instruments had similarities regarding their metal composition and unprepared canal area, whilst differences in phase transformation temperatures and geometric design (number of blades, surface finishing and tip geometry) were observed. Overall, no difference was observed regarding the maximum torque values (P > 0.05), whilst One Files (72 s) and One Files Blue (414 s) had the shortest and longest times to fracture, respectively (P < 0.05). Similar angles of rotation were observed in Reciproc (310°), One Files (285°) and Reverso Silver (318°) instruments (P > 0.05), which were significantly lower than Reciproc Blue (492°), One Files Blue (456°) and WaveOne Gold (492°; P < 0.05). Maximum bending load demonstrated that Reciproc Blue (201.3 gf) was significantly more flexible that the other instruments (P < 0.05). CONCLUSION Although there were similarities in metal composition and percentage of unprepared canal surface, the instruments had differences in the overall geometric design, phase transformation temperatures and in the four mechanical resistance parameters (time to fracture, maximum torque, angle of rotation and maximum bending load).
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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, Brazil.,Department of Endodontics, Fluminense Federal University, Niteroi, Brazil
| | - D Marques
- 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.,LIBPhys-FCT UID/FIS/04559/2013, Lisboa, Portugal
| | - F Belladonna
- Department of Endodontics, Fluminense Federal University, Niteroi, Brazil
| | - M Simões-Carvalho
- Department of Endodontics, Fluminense Federal University, Niteroi, Brazil
| | - V T L Vieira
- Department of Endodontics, School of Dentistry, Grande Rio University (UNIGRANRIO), Rio de Janeiro, Brazil
| | - H S Antunes
- Department of Endodontics, School of Dentistry, Grande Rio University (UNIGRANRIO), Rio de Janeiro, Brazil
| | - F M B 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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Iacono F, Pirani C, Gatto MR, Prati C, Peters OA. Combining apical torsional load and cyclic fatigue resistance of NiTi instruments: New approach to determine the effective lifespan of rotary instruments. AUST ENDOD J 2021; 47:429-434. [PMID: 33650137 DOI: 10.1111/aej.12495] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/28/2020] [Accepted: 02/12/2021] [Indexed: 11/29/2022]
Abstract
In the described proof-of-principle experiments, we introduced a novel testing device to investigate how different concurrent torsional loads influence the cyclic fatigue (CF) resistance of a nickel-titanium (NiTi) instrument. The device was designed to test CF resistance of NiTi files with a standardized load on the apical 5 mm; a movable cylinder controlled by a lever provided a uniform real-time load. Thirty-three NiTi instruments 25.04 (F360, Komet, Lemgo, Germany) were rotated until fracture at 30° curvature under three different torsional loads (n = 11 each); Group A: 2.5 Ncm; Group B: 5 Ncm; Group C: 10 Ncm. anova, multiple comparisons Tamhane tests, regression and Kaplan-Meyer analysis were performed to contrast means. Resistance to cyclic fatigue differed significantly among groups (P = 0.0001). Increased torsional loads led to a decrease in time to failure. An inverse correlation (r = -0.721, P = 0.001) was observed between time and torsional load, with higher torsional loads correlated to shorter times to fracture.
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Affiliation(s)
- Francesco Iacono
- Endodontic Clinical Section, School of Dentistry, Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Chiara Pirani
- Endodontic Clinical Section, School of Dentistry, Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Maria Rosaria Gatto
- Endodontic Clinical Section, School of Dentistry, Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Carlo Prati
- Endodontic Clinical Section, School of Dentistry, Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Ove A Peters
- School of Dentistry, University of Queensland, Herston, Queensland, Australia.,University of the Pacific, Arthur A. Dugoni School of Dentistry, San Francisco, California, USA
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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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Tobón-Arroyave S, Restrepo-Restrepo F, Holguín-Vásquez V, Cañas-Jiménez S, Villa-Machado P, Ochoa-Soto S, Ossa-Orozco C. Microstructural, microchemical, and mechanical changes associated with the clinical reuse of two nickel–titanium endodontic instruments. Dent Res J (Isfahan) 2021. [DOI: 10.4103/1735-3327.318943] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Stošić N, Popović J, Anđelković-Apostolović M, Mitić A, Nikolić M, Barac R. Ultrastructural analysis of the surface changes on the nickel-titanium endodontic instruments after multiple use. ACTA FACULTATIS MEDICAE NAISSENSIS 2021. [DOI: 10.5937/afmnai38-29386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
One of the primary goals in endodontics is efficient cleaning and shaping of the root canal while maintaining its original configuration. Numerous studies highlight the advantage of using nickel-titanium instruments and the most important is their high flexibility and the ability to penetrate the curved canals. The aim of this study was to analyze the ultrastructure of the surface of nickel-titanium endodontic files before and after use. Eighty-four instruments were included in this study. The instruments were used one, three and six times for root canal preparation on extracted upper premolars. The analysis was performed based on the number of uses and the size of the instruments. Changes on flat surfaces in the grooves of the instruments, defects of the cutting edges and fractures were evaluated. The surface ultrastructure was analyzed on a scanning electron microscope (SEM). SEM analysis showed irregularities on the surfaces of the new instruments. Surface defects and damage of the cutting edges were present after the first use. After three uses, the damage was more evident in instruments of all sizes. After six uses, all instruments showed damage of the cutting edges, and a significant number of fractures were observed. Irregularities on the working parts are already noticed on the new endodontic instruments and originate from the production process. The first signs of damage appear after the first use. In order to prevent errors in clinical work during root canal preparation, it is recommended that the number of instruments uses should be limited.
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Abstract
OBJECTIVE The aim of this study was to evaluate the cyclic fatigue, torsional behavior and bending resistance of EdgeTaper Platinum [ETP (tip 25, taper 0.06)], Flex Gold [FG (tip 25, taper 0.08)], Pro-T [PT (tip 25, taper 0.08)] and ProTaper Gold [PTG (tip 25, taper 0.08)] systems. METHODS Rotary instruments of ETP, PT, FG, and PTG were used (n=30). Cyclic fatigue tests were performed using an artificial stainless-steel canal with a 60o angle and a 5-mm radius of curvature at body temperature (35°±1°C). The time and number of cycles to fracture (NCF) was recorded. The torsional test evaluated the torque and angle of rotation to failure at 3 mm from the tip according to ISO 3630-1. The fractured surface of each fragment was observed by using scanning electron microscopy (SEM). The bending test evaluated the torque required to bend the instruments at an angular deflection of 60°. Data were analyzed using one-way ANOVA and Tukey tests, and the level of significance was set at 5%. RESULTS The ETP had highest time until fracture and NCF than all the groups (P<0.05). The PTG had the highest torsional strength, followed by FG (P<0.05). The ETP had the highest angular rotation, followed by PT and PTG (P<0.05). The FG showed the highest bending resistance, followed by the PTG (P<0.05). CONCLUSION In conclusion, the ETP and PT exhibited higher cyclic fatigue resistance, higher angular deflection values and lower bending force than FG and PTG. The PTG instruments showed the highest torsional strength and the lowest cyclic fatigue resistance.
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Drukteinis S, Peciuliene V, Bendinskaite R, Brukiene V, Maneliene R, Rutkunas V. Shaping and Centering Ability, Cyclic Fatigue Resistance and Fractographic Analysis of Three Thermally Treated NiTi Endodontic Instrument Systems. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E5823. [PMID: 33371244 PMCID: PMC7766619 DOI: 10.3390/ma13245823] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 12/16/2020] [Accepted: 12/18/2020] [Indexed: 11/26/2022]
Abstract
The better understanding of the clinically important behavioral features of new instrument systems has an important significance for the clinical endodontics. This study aimed to investigate the shaping and centering ability as well as cyclic fatigue resistance of HyFlex CM (CM), HyFlex EDM (EDM) and EdgeFile (EF) thermally treated nickel-titanium (NiTi) endodontic instrument systems. Sixty curved root canals of the mesial roots of mandibular molars were randomly assigned into three groups (n = 20) and shaped using CM, EDM and EF files up to the size 40 and taper 04 of the instruments. µCT scanning of the specimens before and after preparation was performed and the morphometric 2D and 3D parameters were evaluated in the apical, middle and coronal thirds of root canals. In each group, 40.04 instruments (n = 20) were subjected to the cyclic fatigue resistance test in artificial root canals at 37 °C temperature until fractures occurred, and the number of cycles to failure (NCF) was calculated. The fractographic analysis was performed using a scanning electron microscope, evaluating topographic features and surface profiles of the separated instruments. The one-way analysis of variance with post hoc Tuckey's test was used for statistical analysis of the data; the significance level was set at 5%. All systems prepared the comparable percentage of root canal surface with the similar magnitude of canal transportation in all root thirds (p > 0.05), but demonstrated significantly different resistance to cyclic fatigue (p < 0.05). The most resistant to fracture was EF, followed by EDM and CM. The length of the fractured fragments was not significantly different between the groups, and fractographic analysis by SEM detected the typical topographic features of separated thermally treated NiTi instrument surfaces.
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Affiliation(s)
- Saulius Drukteinis
- Institute of Dentistry, Faculty of Medicine, Vilnius University, Zalgirio 115, LT-08217 Vilnius, Lithuania; (V.P.); (R.B.); (V.B.); (R.M.); (V.R.)
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Weissheimer T, Heck L, Calefi PHS, Alcalde MP, Rosa RA, Vivan RR, Duarte MAH, Só MVR. Evaluation of the mechanical properties of different nickel–titanium retreatment instruments. AUST ENDOD J 2020; 47:265-272. [DOI: 10.1111/aej.12474] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/27/2020] [Accepted: 11/21/2020] [Indexed: 11/27/2022]
Affiliation(s)
- Theodoro Weissheimer
- Department of Conservative Dentistry Federal University of Rio Grande do Sul Porto Alegre Brazil
| | - Luana Heck
- Department of Conservative Dentistry Federal University of Rio Grande do Sul Porto Alegre Brazil
| | - Pedro Henrique Souza Calefi
- Department of Operative Dentistry Endodontics and Dental Materials Bauru School of Dentistry University of São Paulo São Paulo Brazil
| | | | - Ricardo Abreu Rosa
- Department of Conservative Dentistry Federal University of Rio Grande do Sul Porto Alegre Brazil
| | - Rodrigo Ricci Vivan
- Department of Operative Dentistry Endodontics and Dental Materials Bauru School of Dentistry University of São Paulo São Paulo Brazil
| | - Marco Antonio Hungaro Duarte
- Department of Operative Dentistry Endodontics and Dental Materials Bauru School of Dentistry University of São Paulo São Paulo Brazil
| | - Marcus Vinícius Reis Só
- Department of Conservative Dentistry Federal University of Rio Grande do Sul Porto Alegre Brazil
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Martins JN, Silva EJ, Marques D, Pereira MR, Ginjeira A, Silva RJ, Braz Fernandes FM, Versiani MA. Mechanical Performance and Metallurgical Features of ProTaper Universal and 6 Replicalike Systems. J Endod 2020; 46:1884-1893. [DOI: 10.1016/j.joen.2020.08.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/25/2020] [Accepted: 08/29/2020] [Indexed: 11/29/2022]
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Root Canal Transportation after Root Canal Preparation with ProTaper Next, WaveOne Gold, and Twisted Files. J Clin Med 2020; 9:jcm9113661. [PMID: 33202555 PMCID: PMC7696375 DOI: 10.3390/jcm9113661] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 11/10/2020] [Accepted: 11/12/2020] [Indexed: 11/16/2022] Open
Abstract
Background: Root canal preparation during endodontic treatment may be associated with various complications, including a change in the original pathway of the root canal lumen. The aim of our study was to determine whether files of similar sizes that use various movement kinematics (rotary, reciprocal, adaptive motion) cause root canal transportation, and whether the differences between such systems are statistically significant. Methods: The degree of root canal transportation (DT) was calculated with the use of computed tomography scans for 3 groups of teeth (for each group: n = 20) in which the root canals were prepared using either rotary (ProTaper Next—PTN), reciprocal (WaveOne Gold—WOG), or adaptive movement (Twisted Files—TF) instruments. Results: For rotary ProTaper Next instruments, the mean value of the DT index was 0.0795 (SD = 0.0179) for 3 mm from the apex, 0.09 (SD = 0.0262) for 6 mm from the apex, and 0.106 (SD = 0.0221) for 9 mm from the apex. For reciprocal WaveOne Gold Primary instruments, the mean value of the DT index was 0.0355 (SD = 0.015) for 3 mm from the apex, 0.061 (SD = 0.02) for 6 mm from the apex, and 0.08 (SD = 0.25) for 9 mm from the apex. For Twisted Files, the mean value of the DT index was 0.05 (SD = 0.03) for 3 mm from the apex, 0.092 (SD = 0.17) for 6 mm from the apex, and 0.08 (SD = 0.02) for 9 mm from the apex. Conclusions: The use of PTN, WOG, and TF files resulted in root canal transportation to a different degree. The use of rotary PTN files produced the most transported preparation, whereas the use of WOG files produced the conservative root canal preparation that allowed the retention of the original shape of the root canal.
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Effects of Simultaneous Liquid or Gel Sodium Hypochlorite Irrigation on the Cyclic Fatigue of Two Single-File Nickel-Titanium Instruments. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10196666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
To evaluate the effect of simultaneous liquid or gel sodium hypochlorite (NaOCl) irrigation on cyclic fatigue of F6 SkyTaper (F6ST) and OneCurve (OC) single files, 180 new 25/0.06 F6ST and OC files were divided into 6 groups (n = 15) for each brand. Groups 1 and 4 included new instruments not exposed to NaOCl at 20 °C and 37 °C, respectively. Groups 2 and 5 included files activated with liquid NaOCl at 20 °C and 37 °C, respectively. Groups 3 and 6 consisted of instruments tested with NaOCl gel at 20 °C and 37 °C, respectively. Instruments were subjected to a fatigue test using a novel customized device. Data were expressed as time to fracture (TtF) and statistically analyzed (p < 0.05) after checking their normality through the Shapiro–Wilk test. Because they were normally distributed, 2-way analyses of variance (ANOVA) and the Tukey multiple comparison post-hoc test were used. Time to fracture of all tested instruments decreased at 37 °C (p < 0.05). At 20 °C, NaOCl improved TtF of F6ST and OC (p < 0.05). NaOCl liquid increased TtF of F6ST (p < 0.05) in comparison with gel, while there was no difference between the two formulations for OC. At 37 °C, both NaOCl formulations had no significant influence on TtF for F6ST, while they increased TtF of OC (p < 0.05). NaOCl improved the cyclic fatigue resistance of OC, independently of the temperature, while for F6ST the negative impact of higher temperature reduced the irrigant benefits.
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Orhan EO, Ertuğrul İF, Tosun S. Monotonic torsional resistance and fatigue resistance of novel SCOPE RS instruments. Microsc Res Tech 2020; 84:62-70. [PMID: 32790124 DOI: 10.1002/jemt.23565] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/14/2020] [Accepted: 07/14/2020] [Indexed: 11/07/2022]
Abstract
To evaluate monotonic torsional resistance and fatigue resistance of novel SCOPE RS instruments and to compare ROTATE, Hyflex CM, OneCurve, and ProTaper Next instruments as a counterpart. The instrument groups were as follows: SCOPE RS; ROTATE; HyflexCM; OneCurve; ProTaperNext. The cyclic fatigue resistance of unused instruments was tested at both room and body temperatures (n = 10). The time to fracture, the mean number of cycles until failure, and the length of the fractured fragments were analyzed. The monotonic torsional resistance of new instruments was measured in accordingly American National Standards/American Dental Association No. 28 and International Organization for Standardization 3630-1:2008 specifications (n = 10). The maximum torque and angular deflection at break were recorded. The fractographic examination was performed by scanning electron microscope. Energy-dispersive X-ray spectroscopy was used to investigate the microstructure of NiTi instruments. One-way ANOVA with Games-Howell Post Hoc multiple comparisons tests were used (p < .05). The ROTATE had superior cyclic fatigue resistance than other groups in both temperature conditions (p < .01). However, it exhibited lower torsional resistance than SCOPE RS (p < .01). SCOPE RS had superior torsional resistance than other groups (p < .01). Micrographs revealed typical features of fatigue behaviors in all groups. Weight percentages of the Ni and Ti revealed similarity for all instruments. The novel SCOPE RS instruments presented superior monotonic torsional resistance but failed to show any improvement in the cyclic fatigue resistance compared with its counterparts, ROTATE, HyflexCM, and OneCurve.
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Affiliation(s)
- Ekim Onur Orhan
- Department of Endodontics, Faculty of Dentistry, Eskişehir Osmangazi University Eskişehir, Turkey
| | - İhsan Furkan Ertuğrul
- Department of Endodontics, Faculty of Dentistry, Pamukkale University, Denizli, Turkey
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Martins JN, Nogueira Leal Silva EJ, Marques D, Ginjeira A, Braz Fernandes FM, De Deus G, Versiani MA. Influence of Kinematics on the Cyclic Fatigue Resistance of Replicalike and Original Brand Rotary Instruments. J Endod 2020; 46:1136-1143. [DOI: 10.1016/j.joen.2020.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/16/2020] [Accepted: 05/01/2020] [Indexed: 10/24/2022]
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Novel Electronic Device to Quantify the Cyclic Fatigue Resistance of Endodontic Reciprocating Files after Using and Sterilization. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10144962] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background: The aim of this study was to analyze the effects of the time of use (TU) and sterilization cycles (SC) of endodontic reciprocating files on cyclic fatigue resistance. Methods: One-hundred-and-twenty (120) Procodile NiTi endodontic reciprocating instruments were selected at random and distributed into the following study groups: A: 0 sterilization cycles/0s time of use (n = 10); B: 0/60 (n = 10); C: 0/120 (n = 10); D: 1/0 (n = 10); E: 1/60 (n = 10); F: 1/120 (n = 10); G: 5/0 (n = 10); H: 5/60 (n = 10); I: 5/120 (n = 10); J: 10/0 (n = 10); K: 10/60 (n = 10); and L: 10/120 (n = 10). A dynamic cyclic fatigue device was designed using computer-aided design/computer-aided engineering (CAD/CAE) technology and created with a 3D printer to simulate the pecking motion performed by the clinician. Failure of the endodontic rotary instrument was detected by a light-emitting diode-light-dependent resistor (LED-LDR) system controlled by an Arduino driver complex and management software. The results were analyzed using the ANOVA test. Results: All pairwise comparisons presented statistically significant differences between the time to failure, number of cycles to failure and number of cycles of in-and-out movement for the time of use study groups (p < 0.001), but not in the number of sterilization cycles (p > 0.05). Conclusions: The time of use of NiTi endodontic reciprocating files negatively affects dynamic cyclic fatigue resistance. Dynamic cyclic resistance is not affected by the number of sterilization cycles.
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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]
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Sobotkiewicz T, Huang X, Haapasalo M, Mobuchon C, Hieawy A, Hu J, Zhou H, Wang Z, Shen Y. Effect of canal curvature location on the cyclic fatigue resistance of reciprocating files. Clin Oral Investig 2020; 25:169-177. [PMID: 32488488 DOI: 10.1007/s00784-020-03348-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 05/15/2020] [Indexed: 10/24/2022]
Abstract
OBJECTIVES To determine the effect of the location of the canal curvature on the fatigue resistance of WaveOne (WO), WaveOne Gold (WOG), Reciproc (Rec), and Reciproc Blue (RecB) files, and to examine the phase transformation behaviors of the reciprocating file systems. MATERIAL AND METHODS The instruments were subjected to fatigue testing in five artificial canals with a curvature of 60° angle and a 3-mm radius. The location of the curvature was unique for each canal. Each file was inserted 16 mm into the canal and operated until fracture occurred. The time to fracture was recorded and the length of the fragment was measured. Differential scanning calorimetry was used to characterize the thermal behavior of the files. The number of cycles to failure was analyzed using two-way analysis of variance and the post hoc Tukey test. The Kruskal-Wallis test was used to compare the mean fragment lengths between groups. RESULTS The instruments had significantly lower fatigue resistance in canals with curvatures in the middle and coronal canals compared with those with apical curvatures (p < 0.05). At all tested curvature locations, RecB had superior fatigue resistance compared with WO and Rec (p < 0.05). There were no significant differences between WOG and Rec in canals with curvatures in the middle and coronal canals. The DSC thermograms for RecB exhibit a single exothermic peak during cooling but double endothermic peaks during heating indicating that a two-step phase transformation from martensite to R-phase to austenite takes place. CONCLUSIONS The reciprocating instruments experience decreased cyclic fatigue resistance when operated in canals with coronal- and middle-third curvatures when compared with curvatures in the apical-third. Instrumenting coronally positioned curvatures with reciprocating files needs to be performed with caution. CLINICAL RELEVANCE The location of the root canal's curvature influences the fracture resistance of rotary files that are used with reciprocating movements. Therefore, caution needs to be exercised when using reciprocating instruments in canals with coronal or middle curvatures.
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Affiliation(s)
- Tyler Sobotkiewicz
- Division of Endodontics, Faculty of Dentistry, The University of British Columbia (UBC), 2199 Wesbrook Mall, Vancouver, V6T1Z3, Canada
| | - Xiangya Huang
- Department of Conservative Dentistry & Endodontics, Guanghua School of Stomatology, Guangdong Province Key Laboratory of Stomatology, Sun Yat-Sen University Guangzhou, Guangzhou, China
| | - Markus Haapasalo
- Division of Endodontics, Faculty of Dentistry, The University of British Columbia (UBC), 2199 Wesbrook Mall, Vancouver, V6T1Z3, Canada
| | | | - Ahmed Hieawy
- Division of Endodontics, Faculty of Dentistry, The University of British Columbia (UBC), 2199 Wesbrook Mall, Vancouver, V6T1Z3, Canada
| | - Jinghao Hu
- Division of Endodontics, Faculty of Dentistry, The University of British Columbia (UBC), 2199 Wesbrook Mall, Vancouver, V6T1Z3, Canada
| | - Huimin Zhou
- Center for Biomedical Materials and Engineering, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin, China
| | - Zhejun Wang
- Division of Endodontics, Faculty of Dentistry, The University of British Columbia (UBC), 2199 Wesbrook Mall, Vancouver, V6T1Z3, Canada
| | - Ya Shen
- Division of Endodontics, Faculty of Dentistry, The University of British Columbia (UBC), 2199 Wesbrook Mall, Vancouver, V6T1Z3, Canada.
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Velozo C, Silva S, Almeida A, Romeiro K, Vieira B, Dantas H, Sousa F, De Albuquerque DS. Shaping ability of XP‐endo Shaper and ProTaper Next in long oval‐shaped canals: a micro‐computed tomography study. Int Endod J 2020; 53:998-1006. [DOI: 10.1111/iej.13301] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 03/23/2020] [Indexed: 11/28/2022]
Affiliation(s)
- C. Velozo
- Department of Restorative Dentistry and Endodontics Dental College of Pernambuco University of Pernambuco Camaragibe Brazil
| | - S. Silva
- Department of Restorative Dentistry and Endodontics Dental College of Pernambuco University of Pernambuco Camaragibe Brazil
| | - A. Almeida
- Department of Restorative Dentistry and Endodontics Dental College of Pernambuco University of Pernambuco Camaragibe Brazil
| | - K. Romeiro
- Department of Restorative Dentistry and Endodontics Dental College of Pernambuco University of Pernambuco Camaragibe Brazil
| | - B. Vieira
- Department of Morphology Health Science Center Federal University of Paraíba Paraíba Brazil
| | - H. Dantas
- Department of Morphology Health Science Center Federal University of Paraíba Paraíba Brazil
| | - F. Sousa
- Department of Morphology Health Science Center Federal University of Paraíba Paraíba Brazil
| | - D. S. De Albuquerque
- Department of Restorative Dentistry and Endodontics Dental College of Pernambuco University of Pernambuco Camaragibe Brazil
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Pedullà E, La Rosa GRM, Virgillito C, Rapisarda E, Kim HC, Generali L. Cyclic Fatigue Resistance of Nickel-titanium Rotary Instruments according to the Angle of File Access and Radius of Root Canal. J Endod 2020; 46:431-436. [PMID: 31911005 DOI: 10.1016/j.joen.2019.11.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 11/13/2019] [Accepted: 11/23/2019] [Indexed: 10/25/2022]
Abstract
INTRODUCTION The aim of this study was to compare the influences from different access angles and curvature radii on cyclic fatigue resistance of nickel-titanium rotary files. METHODS Two file systems (2Shape [TS; MicroMega, Besançon, France] and HyFlex CM [HCM; Coltène/Whaledent, Allstätten, Switzerland]) were used. A total of 192 instruments of TS #25/.04 (TS1), TS #25/.06 (TS2), HCM #25/.04, and HCM #25/.06 were evaluated at 3 insertion angles (0°, 10°, and 20°) and 2 radii (5 mm and 3 mm) in 16-mm stainless steel artificial canals with a 60° curvature. Cyclic fatigue resistance was determined by the number of cycles to failure (NCF) using a customized testing device. Data were analyzed statistically with the significance level established at 95%. RESULTS In the 3-mm radius canal, the instruments showed lower cyclic fatigue resistance than in the 5-mm radius canal (P < .05). HCM #25/.06 and all .04 taper instruments had a significant NCF reduction at 20° and 10° in the 3-mm radius canal (P < .05), whereas TS2 showed no significant differences. In the 5-mm radius of curvature, although .06 taper instruments had no significant NCF reduction for each angle tested, .04 taper files exhibited significant NCF reduction when tested at 20° (P < .05). Comparing the same size instruments, HCM had higher NCF than TS (P < .05). Instruments with a .04 taper exhibited higher NCF than the .06 ones with the same heat treatment (P < .05). CONCLUSIONS An inclined insertion into the canals decreased cyclic fatigue resistance of thermal-treated instruments with a .04 taper at all radii of curvature tested. The synergistic effect of a small radius of curvature and access angulation of heat-treated instruments decreases their fatigue resistance.
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Affiliation(s)
- Eugenio Pedullà
- Department of General Surgery and Surgical-Medical Specialties, University of Catania, Catania, Italy
| | - Giusy Rita Maria La Rosa
- Department of General Surgery and Surgical-Medical Specialties, University of Catania, Catania, Italy
| | - Chiara Virgillito
- Department of General Surgery and Surgical-Medical Specialties, University of Catania, Catania, Italy
| | - Ernesto Rapisarda
- Department of General Surgery and Surgical-Medical Specialties, University of Catania, Catania, Italy
| | - Hyeon-Cheol Kim
- Department of Conservative Dentistry, School of Dentistry, Dental and Life Science Institute, Dental Research Institute, Pusan National University, Yangsan, Korea.
| | - 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
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Zubizarreta-Macho Á, Mena Álvarez J, Albaladejo Martínez A, Segura-Egea JJ, Caviedes Brucheli J, Agustín-Panadero R, López Píriz R, Alonso-Ezpeleta Ó. Influence of the Pecking Motion Frequency on the Cyclic Fatigue Resistance of Endodontic Rotary Files. J Clin Med 2019; 9:jcm9010045. [PMID: 31878217 PMCID: PMC7020062 DOI: 10.3390/jcm9010045] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Revised: 12/19/2019] [Accepted: 12/20/2019] [Indexed: 11/08/2022] Open
Abstract
Purpose: To analyze the influence of the pecking motion frequency on the cyclic fatigue resistance of endodontic rotary files. Material and Methods: Sixty PlexV 25.06 endodontic rotary files were selected and distributed into three groups: 30 movements/min (n = 20), 60 movements/min (n = 20), and 120 movements/min (n = 20). A dynamic cyclic fatigue device was designed using Computer Aided Design/ Computer Aided Engineering (CAD/CAE) technology and manufactured by 3D impressions to simulate the pecking motion performed by an operator. Failures of the endodontic rotary files were detected by a Light-Emitting Diode (LED)/Light-Dependent Resistor (LDR) system controlled by an Arduino-Driver complex and management software. Endodontic rotary files were tested on an artificial root canal manufactured by wire electrical discharge machining (EDM), with similar dimensions to those of the instrument under examination. Endodontic rotary files were used following the manufacturer’s recommendations. The results were analyzed by ANOVA and Weibull statistics. Results: All pairwise comparisons revealed statistically significant differences in all three variables, except for the difference in the number of cycles between the groups with 60 and 120 movements/min (p = 0.298). The scale distribution parameter of Weibull statistics showed statistically significant differences in all three variables, except for the differences in the number of cycles between groups with 30 and 60 movements/min (p = 0.0722). No statistically significant differences in the three variables were observed for the shape distribution parameter. Conclusion: A low frequency of pecking motion is recommended to reduce the risk of failure of endodontic rotary files associated with cyclic fatigue.
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Affiliation(s)
- Álvaro Zubizarreta-Macho
- Department of Endodontics, Faculty of Health Sciences, Alfonso X el Sabio University, 28691 Madrid, Spain;
- Correspondence:
| | - Jesús Mena Álvarez
- Department of Endodontics, Faculty of Health Sciences, Alfonso X el Sabio University, 28691 Madrid, Spain;
| | | | | | - Javier Caviedes Brucheli
- Centro de Investigaciones Odontológicas (CIO) Pontificia, Universidad Javeriana, Bogotá 1101, Colombia;
| | - Rubén Agustín-Panadero
- Department of Stomatology, Faculty of Medicine and Dentistry, University of Valencia, 46010 Valencia, Spain;
| | - Roberto López Píriz
- Institute of Materials Science of Madrid, Superior Council of Scientific Investigations, 28222 Madrid, Spain;
| | - Óscar Alonso-Ezpeleta
- Department of Endodontics, School of Health Sciences, University of Zaragoza, 22006 Aragorn, Spain;
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