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Yum HW, Oh S, Perinpanayagam H, Gu Y, Chang SW, Yoo YJ, Kum KY. Phase Transformation and Mechanical Behaviour of Different Heat-Treated Nickel-Titanium Rotary Instruments. Int Dent J 2024:S0020-6539(24)01403-5. [PMID: 39138098 DOI: 10.1016/j.identj.2024.07.1211] [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: 04/27/2024] [Revised: 07/10/2024] [Accepted: 07/22/2024] [Indexed: 08/15/2024] Open
Abstract
OBJECTIVES This study evaluated the phase composition, phase transformation behaviour, and mechanical properties of five heat-treated NiTi instruments. METHODS ProTaper NEXT (M-wire, PTN), ProTaper Gold (Gold-wire, PTG), One Curve (C-wire, OC), EdgeTaper Platinum (Fire-wire, ETP), NeoNiTi (electrical discharge machining-wire, NNA), and ProTaper Universal (conventional wire, PTU, control) with #25-tip size were tested (n = 12/group) for cyclic fatigue resistance (number of cycles to failure; NCF) and torsional resistance (angle of rotation to fracture and maximum torque at fracture [ultimate torsional strength]). The geometry and fracture surfaces of the tested instruments were examined by scanning electron microscopy. The phase transformation temperature and phase composition of the instruments were evaluated using differential scanning calorimetry and X-ray diffraction. Data were statistically analysed using one-way ANOVA and Tukey's post hoc test, with the significance level set at 5%. RESULTS PTG showed the highest NCF (P < .05) at 37°C, while ETP exhibited the highest angle of rotation to fracture, ultimate torsional strength, and stiffness (P < .05). Scanning electron microscopy demonstrated typical clusters of fatigue striations and numerous cracks after cyclic fatigue fracture, whereas there was a concentric abrasion pattern with a dimple and microvoids at the centre after torsional fracture. In differential scanning calorimetry curves, austenite-finishing temperatures of heat-treated instruments were higher than 37°C, whereas that of PTU was lower than 37°C. PTU showed strong peaks of austenite at 25 and 37°C, whereas ETP showed a strong peak of R-phase at 25°C, but mostly austenite phase at 37°C in X-ray diffraction. CONCLUSIONS Geometry, alloy type, and phase transformation temperatures of NiTi instruments affected their mechanical behaviour. CLINICAL RELEVANCE PTG showed the highest NCF, suitable for markedly curved canals. ETP had the highest torsional resistance, appropriate for narrow and constricted canals.
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Affiliation(s)
- Hee-Won Yum
- Department of Conservative Dentistry, Dental Research Institute, Seoul National University Dental Hospital, Seoul National University School of Dentistry, Seoul, Republic of Korea
| | - Soram Oh
- Department of Conservative Dentistry, Kyung Hee University Dental Hospital, Seoul, Republic of Korea
| | - Hiran Perinpanayagam
- Division of Endodontics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Yu Gu
- Department of Endodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University, Shandong, China
| | - Seok-Woo Chang
- Department of Conservative Dentistry, Kyung Hee University Dental Hospital, Seoul, Republic of Korea
| | - Yeon-Jee Yoo
- Department of Conservative Dentistry, Dental Research Institute, Seoul National University Dental Hospital, Seoul National University School of Dentistry, Seoul, Republic of Korea.
| | - Kee-Yeon Kum
- Department of Conservative Dentistry, Dental Research Institute, Seoul National University Dental Hospital, Seoul National University School of Dentistry, Seoul, Republic of Korea.
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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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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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Só GB, Siocheta G, Calefi P, Alcalde M, Vivan RR, Duarte MAH, Só MVR, da Rosa RA. Cyclic and torsional fatigue resistance of a new rotary file on a rotary and reciprocating motion. Microsc Res Tech 2023; 86:1635-1641. [PMID: 37587834 DOI: 10.1002/jemt.24399] [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: 03/09/2023] [Revised: 06/17/2023] [Accepted: 08/06/2023] [Indexed: 08/18/2023]
Abstract
This study evaluated the cyclic and torsional fatigue resistance of a new nickel-titanium (Flat File 25.04) instrument on the continuous and reciprocating motion. Sixty instruments of the ProDesign Logic2 25.03 and 25.05 (Easy Equipamentos Odontológicos, Belo Horizonte, Brazil), and MK Flat File 25.04 (n = 20) (MK Life, Porto Alegre, Brazil) were used. For the cyclic fatigue test, an artificial stainless steel simulated canal with an angle of 60° and a radius of curvature of 5 mm located 5 mm from its tip was used. The torque and rotation angle at the instruments' failure on the torsional fatigue test was based on the ISO 3630-1 protocol, in which the 3 mm tip of each instrument was fixed and connected to an electric motor and a load cell. The fractured surface of each fragment was examined by scanning electron microscopy. Data were analyzed using a 1-way analysis of variance and Tukey's test with a significance level of 5%. Flat File 25.04 had lower cyclic fatigue in both kinematics than the Logic instruments (p < .05). Reciprocating motion improved the cyclic fatigue of the tested instruments (p < .05). Flat File 25.04 had similar torque to Logic2 25.05 (p > .05), and both were superior to Logic2 25.03 (p < .05). The angular deflection values were different for the three tested instruments (p < .05), in the decreasing order: Logic2 25.03, 25.05, and Flat File 25.04. Flat File presented good resistance to cyclic and torsional fatigue resistance. Reciprocating motion improved the cyclic fatigue resistance of the instruments and can be considered when using programmable motors. RESEARCH HIGHLIGHTS: Scanning electron microscopy evaluation of different endodontic rotary file and fatigue resistance tests.
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Affiliation(s)
- Gabriel Barcelos Só
- Department of Conservative Dentistry, School of Dentistry, Rio Grande do Sul Federal University (UFRGS), Porto Alegre, Brazil
| | - Giovana Siocheta
- Department of Conservative Dentistry, School of Dentistry, Rio Grande do Sul Federal University (UFRGS), Porto Alegre, Brazil
| | - Pedro Calefi
- Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Murilo Alcalde
- Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Rodrigo Ricci Vivan
- Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Marco Antônio H Duarte
- Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Marcus Vinicius Reis Só
- Department of Conservative Dentistry, School of Dentistry, Rio Grande do Sul Federal University (UFRGS), Porto Alegre, Brazil
| | - Ricardo Abreu da Rosa
- Department of Conservative Dentistry, School of Dentistry, Rio Grande do Sul Federal University (UFRGS), Porto Alegre, Brazil
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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: 4] [Impact Index Per Article: 4.0] [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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Osaki RB, Bramante CM, Vivan RR, Alcalde MP, Calefi PHS, Duarte MAH. Influence of temperature on the torsional properties of two thermally treated NiTi rotary instruments. Braz Dent J 2023; 34:12-18. [PMID: 36888838 PMCID: PMC10027105 DOI: 10.1590/0103-6440202305094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 01/02/2023] [Indexed: 03/08/2023] Open
Abstract
This study aimed to evaluate the influence of temperature on torsional strength and angular deflection of two experimental NiTi rotary instruments manufactured from Blue and Gold thermal treatments and with identical cross-sections. A total of 40 experimental NiTi instruments 25.06 and with a triangular cross-section and manufactured from Blue and Gold thermal treatments were used (n=20). The torsional test was performed in the 3 mm from the tip of the instrument according to ISO 3630-1. The torsional test evaluated the torsional strength and angular deflection to failure at room temperature (21°C ± 1° C) and body temperature (36°C ±1°C). The fractured surface of each fragment was observed by using scanning electron microscopy (SEM). Data were analyzed using an unpaired t test for inter and intra-group comparison and the level of significance was set at 5%. The results showed that the body temperature did not affect the torsional strength and angular deflection of the instruments when compared with room temperature (P>0.05). However, at body temperature, the Blue NiTi instruments presented significantly lower angular deflection in comparison with Gold NiTi instruments (P<0.05). There was no significant difference regarding the torsional strength of the instruments at body temperature (P>0.05). The temperature did not affect the torsional strength of the instruments manufactured from Blue and Gold technology. However, the Blue NiTi instruments presented significantly lower angular deflection than Gold instruments at 36°C temperature.
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Affiliation(s)
- Roberto Barreto Osaki
- Department of Dentistry, Endodontics and Dental Materials, Bauru Dental School, University of São Paulo, Bauru, SP, Brazil
| | - Clovis Monteiro Bramante
- Department of Dentistry, Endodontics and Dental Materials, Bauru Dental School, University of São Paulo, Bauru, SP, Brazil
| | - Rodrigo Ricci Vivan
- Department of Dentistry, Endodontics and Dental Materials, Bauru Dental School, University of São Paulo, Bauru, SP, Brazil
| | - Murilo Priori Alcalde
- Department of Dentistry, Endodontics and Dental Materials, Bauru Dental School, University of São Paulo, Bauru, SP, Brazil
| | - Pedro Henrique Souza Calefi
- Department of Dentistry, Endodontics and Dental Materials, Bauru Dental School, University of São Paulo, Bauru, SP, Brazil
| | - Marco Antonio Hungaro Duarte
- Department of Dentistry, Endodontics and Dental Materials, Bauru Dental School, University of São Paulo, Bauru, SP, Brazil
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Oh S, Seo JY, Lee JE, Kim HJ, Jang JH, Chang SW. Evaluation of design, mechanical properties, and torque/force generation of heat-treated NiTi glide path instruments. BMC Oral Health 2022; 22:528. [PMID: 36424555 PMCID: PMC9686033 DOI: 10.1186/s12903-022-02575-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 11/08/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Recently, various kinds of heat-treated nickel-titanium (NiTi) glide path instruments have been manufactured. This study aimed to investigate design, phase transformation behavior, mechanical properties of TruNatomy Glider (#17/02), V Taper 2H (#14/03), and HyFlex EDM (#15/03) and compare torque/force generated during simulated glide path preparation with them. METHODS The designs and phase-transformation behaviors of the instruments were examined via scanning electron microscopy (n = 3) and differential scanning calorimetry (n = 2). Their bending (n = 15), torsional (n = 15), and cyclic fatigue resistances (n = 15) were tested. The ultimate strength and distortion angle were obtained from torsional resistance test. The number of cycles to failure (NCF) was calculated from cyclic fatigue resistance test. The preparation of the glide path was simulated using a double-curved artificial canal (n = 15), and the maximum torque and screw-in forces were measured. Data except NCF was compared between brands with one-way ANOVA with Tukey's honestly significant difference test. NCF was analyzed via Kruskal-Wallis and Mann-Whitney U tests. RESULTS TruNatomy Glider had the greatest number of threads. TruNatomy Glider showed progressive taper, while V Taper 2H and HyFlex EDM had constant taper. The austenitic transformation-finish temperatures of all the instruments were above body temperature. V Taper 2H demonstrated significantly lower ultimate strength, higher distortion angle, and a higher number of cycles to failure compared with HyFlex EDM and TruNatomy Glider (p < 0.05). The maximum torque generated during preparing glide path was lowest for V Taper 2H, and the maximum screw-in force was lowest for HyFlex EDM (p < 0.05). TruNatomy Glider generated the highest torque and screw-in force during the apical preparation. CONCLUSIONS V Taper 2H #14/03 showed superior cyclic fatigue resistance and lower ultimate strength. TruNatomy Glider generated greater clockwise torque and screw-in force during apical preparation. The mechanical properties, torque, and screw-force was affected by design of heat-treated glide path instruments. Cervical pre-flaring prior to glide path instrument is recommended.
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Affiliation(s)
- Soram Oh
- grid.411231.40000 0001 0357 1464Department of Conservative Dentistry, Kyung Hee University Medical Center, 23 Kyungheedae-Ro, Dongdaemun-Gu, Seoul, 02447 Republic of Korea ,grid.289247.20000 0001 2171 7818Department of Conservative Dentistry, Kyung Hee University College of Dentistry, 23 Kyungheedae-Ro, Dongdaemun-Gu, Seoul, 02447 Republic of Korea
| | - Ji-Yeon Seo
- Private Dental Clinic, Seoul, Republic of Korea
| | - Ji-Eun Lee
- Seoul Strong Dental Clinic, 35 Bonghwasan-Ro, Jungnang-Gu, Seoul, 02017 Republic of Korea
| | - Hyun-Jung Kim
- grid.411231.40000 0001 0357 1464Department of Conservative Dentistry, Kyung Hee University Medical Center, 23 Kyungheedae-Ro, Dongdaemun-Gu, Seoul, 02447 Republic of Korea
| | - Ji-Hyun Jang
- grid.411231.40000 0001 0357 1464Department of Conservative Dentistry, Kyung Hee University Medical Center, 23 Kyungheedae-Ro, Dongdaemun-Gu, Seoul, 02447 Republic of Korea ,grid.289247.20000 0001 2171 7818Department of Conservative Dentistry, Kyung Hee University College of Dentistry, 23 Kyungheedae-Ro, Dongdaemun-Gu, Seoul, 02447 Republic of Korea
| | - Seok Woo Chang
- grid.411231.40000 0001 0357 1464Department of Conservative Dentistry, Kyung Hee University Medical Center, 23 Kyungheedae-Ro, Dongdaemun-Gu, Seoul, 02447 Republic of Korea ,grid.289247.20000 0001 2171 7818Department of Conservative Dentistry, Kyung Hee University College of Dentistry, 23 Kyungheedae-Ro, Dongdaemun-Gu, Seoul, 02447 Republic of Korea
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Unno H, Ebihara A, Hirano K, Kasuga Y, Omori S, Nakatsukasa T, Kimura S, Maki K, Okiji T. Mechanical Properties and Root Canal Shaping Ability of a Nickel-Titanium Rotary System for Minimally Invasive Endodontic Treatment: A Comparative In Vitro Study. MATERIALS (BASEL, SWITZERLAND) 2022; 15:7929. [PMID: 36431416 PMCID: PMC9692467 DOI: 10.3390/ma15227929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 06/16/2023]
Abstract
Selection of an appropriate nickel−titanium (NiTi) rotary system is important for minimally invasive endodontic treatment, which aims to preserve as much root canal dentin as possible. This study aimed to evaluate selected mechanical properties and the root canal shaping ability of TruNatomy (TRN), a NiTi rotary system designed for minimally invasive endodontic shaping, in comparison with existing instruments: HyFlex EDM (HEDM), ProTaper Next (PTN), and WaveOne Gold (WOG). Load values measured with a cantilever bending test were ranked as TRN < HEDM < WOG < PTN (p < 0.05). A dynamic cyclic fatigue test revealed that the number of cycles to fracture was ranked as HEDM > WOG > TRN > PTN (p < 0.05). Torque and vertical force generated during instrumentation of J-shaped artificial resin canals were measured using an automated instrumentation device connected to a torque and vertical force measuring system; TRN exhibited smaller torque and vertical force values in most comparisons with the other instruments. The canal centering ratio for TRN was smaller than or comparable to that for the other instruments except for WOG at the apex level. Under the present experimental conditions, TRN showed higher flexibility and lower torque and vertical force values than the other instruments.
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El Abed R, Alshehhi A, Kang YJ, Al Raeesi D, Khamis AH, Jamal M, Kim HC. Fracture Resistance of Heat-Treated Nickel-Titanium Rotary Files After Usage and Autoclave Sterilization: an in vitro study. J Endod 2022; 48:1428-1433. [PMID: 35987385 DOI: 10.1016/j.joen.2022.08.004] [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: 04/23/2022] [Revised: 07/21/2022] [Accepted: 08/10/2022] [Indexed: 10/31/2022]
Abstract
INTRODUCTION This study aimed to evaluate the dynamic cyclic fatigue resistance of heat-treated nickel-titanium (NiTi) files after usage and autoclaving. METHODS Two heat-treated NiTi file systems with the tip sizes of #25 of ProTaper Gold F2 (PG) and TruNatomy Prime (TN) were selected. Files in each system was divided into three experimental subgroups (n=10). For subgroup-1, new files were tested to establish baseline number of cycles to failure (NCF). For subgroup-2, files underwent canal instrumentation in a simulated J-shaped canal block with the 35-degree of curvature with 16.5-mm of length. The simulated canals were pre-enlarged using stainless-steel files, #10K and #15K. After instrumentation, the files were tested. For subgroup-3, files underwent canal instrumentation as in subgroup-2 and followed by autoclave sterilization then were tested for cyclic failure. Cyclic fatigue test was performed in dynamic pecking motion under body temperature. The time to fracture was recorded and calculated into NCF. Fracture fragments lengths were measured using digital microcaliper. Statistical analysis was conducted using independent t-test and multi-factorial analysis of variance with 95% significance. Scanning electron microscopy was used to examine the topographic characteristics after cyclic fatigue tests. RESULTS There were no significant differences between file systems in subgroup-1 using new files (P<.05). While PG reduced the NCF after use, TN showed significantly increased NCF (P<.05). However, after sterilization, TN showed reduced NCF than the used one (P<.05). CONCLUSIONS Cyclic loading by usage and heat treatment during sterilization may result in different cyclic fatigue resistance according to the geometry and alloy characteristics.
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Affiliation(s)
- Rashid El Abed
- Endodontic Department, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates
| | - Aisha Alshehhi
- Endodontic Department, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates
| | - Yoo Jung Kang
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Pusan National University, Yangsan, Korea
| | - Dana Al Raeesi
- Endodontic Department, Emirates Health Services Establishment, Dubai, United Arab Emirates
| | - Amar H Khamis
- Biostatistics Department, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates
| | - Mohamed Jamal
- Endodontic Department, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates
| | - Hyeon-Cheol Kim
- Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Pusan National University, Yangsan, Korea.
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10
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A Comparative Study of Two Martensitic Alloy Systems in Endodontic Files Carried out by Unskilled Hands. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12126289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The aim of this study was to compare the behavior of two heat-treated file systems on resin blocks in unskilled hands. For this purpose, an in vitro, randomized, cross-sectional study was conducted to compare ProTaper Gold (PTG) with BlueShaper (BS) files. A total of 81 resin blocks were used and analyzed photographically to assess the amount of material removed during instrumentation. PTG removed more material on the outside of the curve in the coronal and apical third, while BS removed more material on the inner part of the curve in the middle third. The procedural errors observed in the total sample were apical transportation (33.8%), blockages (4.9%), ledges (3.7%), and canal perforation. PTG produced more apical transportation, and there were no statistically significant differences between the groups in the formation of ledges, canal perforations, or blockages. No file fractures were recorded during the study. Within the limitations of this study, we can affirm that neither file excessively deformed the artificial canals, and the PTG file produced more apical transportation.
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11
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Experimental Analysis on the Impact of Current on the Strength and Lifespan of a Ni-Ti Element. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12063185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Intelligent materials, especially materials with shape memory, are an important discovery, with technical applications in the medical and aerospace field, among others, which led to the development of systems and applications with multiple advantages and disadvantages due to ignorance about their functionality. This paper presents an application developed in the research laboratory for determining and monitoring the behavior of a material element with Ni-Ti shape memory, and its lifespan. The application allows the stress level of the Ni-Ti element subjected to numerous repeated cycles of deformation to be determined by supplying it to a constant electric current. Thus, the results show the variation of the Ni-Ti element force, in the form of a spring, at the ambient temperature variations as well as force variations at different numbers of attempts. The Ni-Ti alloy has both shape retention and superelasticity properties, being the most common in the fields of applicability. Due to its unique properties, it can be used in the most demanding applications in the medical field, usually involving difficult conditions of resistance to fatigue.
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