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Agrawal PR, Chandak M, Nikhade PP, Patel AS, Bhopatkar JK. Revolutionizing endodontics: Advancements in nickel-titanium instrument surfaces. J Conserv Dent Endod 2024; 27:126-133. [PMID: 38463467 PMCID: PMC10923218 DOI: 10.4103/jcde.jcde_248_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 11/19/2023] [Accepted: 12/05/2023] [Indexed: 03/12/2024]
Abstract
Nickel-titanium (NiTi) instruments have become the backbone of endodontics due to their exceptional properties, superelasticity, and shape memory. However, challenges such as unexpected breakage, poor cutting efficiency, and corrosion have prompted researchers to explore innovative surface modifications to enhance their performance. This comprehensive review discusses the latest advancements in NiTi metallurgy and their impact on rotary NiTi file systems. Various surface treatment techniques, including ion implantation, cryogenic treatment (CT), thermal nitridation, electropolishing, and physical or chemical vapor deposition, have been investigated to minimize defects, boost surface hardness, and improve cyclic fatigue resistance. Ion implantation has shown promise by increasing wear resistance and cutting efficiency through nitrogen ion incorporation. Thermal nitridation has successfully formed titanium nitride (TiN) coatings, resulting in improved corrosion resistance and cutting efficiency. CT has demonstrated increased cutting efficiency and overall strength by creating a martensite transformation and finer carbide particles. Electropolishing has yielded mixed results, providing smoother surfaces but varying impacts on fatigue resistance. Physical or chemical vapor deposition has proven effective in forming TiN coatings, enhancing hardness and wear resistance. Furthermore, the concept of surface functionalization with silver ions for antibacterial properties has been explored. These advancements present an exciting future for endodontic procedures, offering the potential for enhanced NiTi instruments with improved performance, durability, and patient outcomes.
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Affiliation(s)
- Paridhi Rajesh Agrawal
- Department of Conservative Dentistry and Endodontics, DMIHER, Sharad Pawar Dental College and Hospital, Wardha, Maharashtra, India
| | - Manoj Chandak
- Department of Conservative Dentistry and Endodontics, DMIHER, Sharad Pawar Dental College and Hospital, Wardha, Maharashtra, India
| | - Pradnya Prashant Nikhade
- Department of Conservative Dentistry and Endodontics, DMIHER, Sharad Pawar Dental College and Hospital, Wardha, Maharashtra, India
| | - Aditya Satyawansingh Patel
- Department of Conservative Dentistry and Endodontics, DMIHER, Sharad Pawar Dental College and Hospital, Wardha, Maharashtra, India
| | - Jay Kailas Bhopatkar
- Department of Conservative Dentistry and Endodontics, DMIHER, Sharad Pawar Dental College and Hospital, Wardha, Maharashtra, India
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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: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [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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Sharroufna R, Mashyakhy M. The Effect of Multiple Autoclave Sterilization on the Cyclic Fatigue of Three Heat-Treated Nickel-Titanium Rotary Files: EdgeFile X7, Vortex Blue, and TRUShape. Biomed Res Int 2020; 2020:8826069. [PMID: 33415159 DOI: 10.1155/2020/8826069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 11/21/2020] [Accepted: 12/06/2020] [Indexed: 11/17/2022]
Abstract
OBJECTIVE The purpose of this study was to evaluate the effect of repeated autoclave sterilization on the cyclic fatigue resistance of heat-treated NiTi rotary endodontic instruments. MATERIALS AND METHODS Three NiTi rotary endodontic instruments (EdgeFile X7, EFX7 0.30/0.4; Vortex Blue, VB 0.30/0.4; and TRUShape, TS 0.30/0.6) were selected. Each group (n = 24 each) was divided into 2 subgroups (n = 12 each): sterilized instruments and nonsterilized instruments. The sterilized instruments were subjected to 10 cycles of autoclave sterilization. Twelve instruments from each different subgroups were tested for cyclic fatigue resistance, and the number of cycles to failure (NCF) was calculated. Means and standard deviations were calculated for each group, and data were statistically analyzed using the SPSS program (P < 0.05). RESULTS Sterilized and nonsterilized EFX7 files showed the highest NCF compared with other file subgroups. Comparing the results between sterilized and nonsterilized instruments for each type of files, there was a statistically significant difference (P < 0.05) only between sterilized and nonsterilized EFX7 files (1198 versus 755 NCF). The other instruments did not show significant differences (P > 0.05) in the mean NCF as a result of sterilization cycles (VB, 606 versus 568 NCF; TS, 487 versus 442 NCF). CONCLUSION Repeated cycles of autoclave sterilization increased the NCF of the new heat-treated files, with EFX7 showing statistically significant superior results compared with other files tested.
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Alshwaimi EO. Effect of Sterilization on Cyclic Fatigue Resistance of Proflexendo Endodontic Rotary Files. Saudi J Med Med Sci 2019; 7:151-155. [PMID: 31543735 PMCID: PMC6734735 DOI: 10.4103/sjmms.sjmms_123_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 11/30/2017] [Accepted: 05/01/2018] [Indexed: 11/04/2022]
Abstract
Background: Proflexendo file (Nexen, Houston, TX, USA) is a recently developed, novel nickel-titanium rotary file. However, several physical properties of the Proflexendo system remain to be investigated. Objectives: The aim of this study was to determine the effect of sterilization on cyclic resistance of Proflexendo files. Material and Methods: A total of 120 unused Proflexendo rotary files (40 each of file sizes 40/0.04, 30/0.04 and 20/0.06) were used in this study. Each set of files was subdivided into four groups of ten files. Group 1 did not undergo any sterilization (control), Group 2 underwent two rounds (2×) of sterilization, Group 3 five rounds (5×) and Group 4 ten rounds (10×). Cyclic fatigue resistance was tested using an artificial canal with a 5-mm radius curve. Results: The nonsterilized size 30/0.04 files had the highest cycles to failure, followed by the nonsterilized size 40/0.04 and 20/0.06 files (P < 0.001). With increasing rounds of sterilization, cycles to failure reduced for sizes 40 (2×, 5× and 10×) and 30 (2×) files compared with nonsterilized sizes 40 (P < 0.05) and 30 files (P < 0.001), respectively. Conclusion: Under the conditions of the current study, the results provide preliminary evidence that autoclave sterilization of Proflexendo rotary files reduced their cyclic fatigue resistance, except for size 20 (2× and 5×) and 30 (10×) files, in which resistance increased. Single use of this file is recommended to reduce the risk of separation.
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Affiliation(s)
- Emad O Alshwaimi
- Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
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Ruiz-Sánchez C, Faus-Matoses V, Alegre-Domingo T, Faus-Matoses I, Faus-Llácer VJ. An in vitro cyclic fatigue resistance comparison of conventional and new generation nickel-titanium rotary files. J Clin Exp Dent 2018; 10:e805-e809. [PMID: 30305880 PMCID: PMC6174015 DOI: 10.4317/jced.55091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Accepted: 07/05/2018] [Indexed: 12/05/2022] Open
Abstract
Background New designs and processing of Niquel-Titanium (NiTi) have been introduced to increase resistance to cyclic fatigue. The purpose of this study was to compare the cyclic fatigue resistance of 3 NiTi rotary instruments, ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), Profile Vortex Blue (PVB; Dentsply Tulsa Dental, Tulsa, OK, USA) and ProTaper Universal (PTU; Dentsply Maillefer, Ballaigues, Switzerland). Material and Methods A cyclic fatigue test was conducted operating instruments from ProTaper Next X2, Profile Vortex Blue 25.06 and ProTaper F2. A total of 234 instruments were rotated in 2 simulated stainless steel curved canals with different angles of curvature (45º and 60°) and 5-mm radius of curvature. The number of cycles to fracture (NCF) was calculated. Data were compared using 2-way analysis of variance and post-hoc Bonferroni test in software (SPSS 15.0, Chicago, IL). Statistical significance was set at P<0.05. Results Profile Vortex Blue showed higher resistance to cyclic fatigue in both curved canals than ProTaper Next and ProTaper Universal (P<0.001). ProTaper Universal obtained the lowest resistance to cyclic fatigue in both canals (P<0.001). Conclusions Profile Vortex Blue was the most resistant to cyclic fatigue failure, followed by ProTaper Next and ProTaper Universal. Anatomical complexity (angle of curvature) and manufacturing process of NiTi are important factors for resistance to cyclic fatigue. Key words:Cyclic fatigue, M-Wire, Protaper Next, ProTaper Universal, Profile Vortex Blue.
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Affiliation(s)
- Celia Ruiz-Sánchez
- Master of Restorative Dentistry and Endodontics, Department of Stomatology, Medicine and Dental School, Valencia University, Spain
| | - Vicente Faus-Matoses
- DDS, MSc, PhD. Co-director of the Master of Restorative Dentistry and Endodontics, Department of Stomatology, Medicine and Dental School, Valencia University, Spain
| | - Teresa Alegre-Domingo
- DDS, MSc, PhD. Professor of the Master of Restorative Dentistry and Endodontics, Department of Stomatology, Medicine and Dental School, Valencia University, Spain
| | - Ignacio Faus-Matoses
- DDS, MSc, PhD. Professor of the Master in Orthodontics, Department of Stomatology, Medicine and Dental School, Valencia University, Spain
| | - Vicente-José Faus-Llácer
- MD, DDS, PhD. Director of the Master of Restorative Dentistry and Endodontics, Department of Stomatology, Medicine and Dental School, Valencia University, Spain
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Qaed NA, Mourshed BD, Al-Shamiri HM, Alaizari N, Alhamdah SS. The Effect of surface topographical changes of two different surface treatments rotary instrument. J Clin Exp Dent 2018; 10:e49-e53. [PMID: 29670715 PMCID: PMC5899810 DOI: 10.4317/jced.54472] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Accepted: 12/06/2017] [Indexed: 11/26/2022] Open
Abstract
Background One of the major innovations in endodontics has been the introduction of nickel-titanium (NiTi) alloy. This study evaluated the surface topographical changes of two different surface treatments rotary instrument after instrumentation and sterilization. Material and Methods 240 Extracted teeth were included in this study. 90 new AlphaKite and Revo-S NiTi rotary instruments were selected and divided into two groups (Group A 45 AlphaKite and group B 45 Revo-S). Each group were divided into three subgroups: (A1, B1) n=5 files were used as a control, (A2,B2) n=20 files were used to prepare three root canals using endodontic rotary motor then sterilized by autoclave for one cycle under 121°C at 15 psi for 30 minutes and (A3,B3) n=20 files were used to prepare nine root canals using the same rotary system then sterilized by autoclave for three cycles under 121°C at 15 psi for 30 minutes. Files were examined under scanning electron microscopy. Results On examining the AlphaKite, A1 revealed gross machining grooves on their surface with no pits, A2 showed disruption of cutting and A3 showed microcracks and deepening of the machining grooves. B1 showed a smoother surface with few machining grooves, B2 showed dulling and blunting of the cutting edges was predominant and B3 files showed plastic deformation in the form of unwinding of the flutes. Conclusions The defects were less distributed along the electropolished Revo-S files than the physical vapor deposition AlphaKite. Key words:Endodontic instruments, electropolished, rotary, sterilization.
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Affiliation(s)
- Nashwan-Ahmed Qaed
- BDS, MSc, Lecturer, Department of restorative Dentistry, Al-Farabi Colleges, Riyadh, Saudi Arabia
| | - Bilal-Diab Mourshed
- BDS, MSc, Lecturer, Department of Prosthetic Dental Sciences, Al-Farabi College for Dentistry and Nursing, Riyadh, Saudi Arabia; Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University at Kiel, Kiel, Germany
| | - Hashem-Motahir Al-Shamiri
- BDS, MSc, Lecturer- Department of Oral and Maxillofacial Surgery, Al-Farabi Colleges, Riyadh, Saudi Arabia
| | - Nader Alaizari
- BDS, MSc, Lecturer, Department of Oral Medicine and Diagnostic Sciences, AlFarabi Colleges, Riyadh, Saudi Arabia
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Abstract
UNLABELLED To improve clinical use of nickel-titanium (NiTi) endodontic rotary instruments by better understanding the alloys that compose them. A large number of engine-driven NiTi shaping instruments already exists on the market and newer generations are being introduced regularly. While emphasis is being put on design and technique, manufacturers are more discreet about alloy characteristics that dictate instrument behavior. Along with design and technique, alloy characteristics of endodontic instruments is one of the main variables affecting clinical performance. Modification in NiTi alloys is numerous and may yield improvements, but also drawbacks. Martensitic instruments seem to display better cyclic fatigue properties at the expense of surface hardness, prompting the need for surface treatments. On the contrary, such surface treatments may improve cutting efficiency but are detrimental to the gain in cyclic fatigue resistance. Although the design of the instrument is vital, it should in no way cloud the importance of the properties of the alloy and how they influence the clinical behavior of NiTi instruments. CLINICAL SIGNIFICANCE Dentists are mostly clinicians rather than engineers. With the advances in instrumentation design and alloys, they have an obligation to deal more intimately with engineering consideration to not only take advantage of their possibilities but also acknowledge their limitations.
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Affiliation(s)
- Hani F Ounsi
- Department of Endodontics, Faculty of Dental Medicine Lebanese University, Beirut, Lebanon; Department of Endodontics and Restorative Dentistry, Siena University, Siena, Italy, e-mail:
| | - Wadih Nassif
- Department of Prosthodontics, Faculty of Dental Medicine Lebanese University, Beirut, Lebanon
| | - Simone Grandini
- Department of Endodontics and Restorative Dentistry, Siena University, Siena, Italy
| | - Ziad Salameh
- Department of Research, Faculty of Dental Medicine, Lebanese University, Beirut, Lebanon
| | - Prasanna Neelakantan
- Department of Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong
| | - Sukumaran Anil
- Department of Dental Health, Dental Biomaterials Research Chair, College of Applied Medical Sciences, King Saud University Riyadh, Kingdom of Saudi Arabia
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Al Jabbari YS, Koutsoukis T, Al Hadlaq S, Berzins DW, Zinelis S. Surface and cross-sectional characterization of titanium-nitride coated nickel-titanium endodontic files. J Dent Sci 2016; 11:48-53. [PMID: 30894945 PMCID: PMC6395189 DOI: 10.1016/j.jds.2015.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 06/25/2015] [Indexed: 11/30/2022] Open
Abstract
Background/purpose Although the effect of experimental surface modifications on various properties (e.g., fatigue, wear) on coated files have been tested in the past, there is no report for the coating quality of commercially available TiN coated files. The aim of this study was to characterize the surface and cross section of TiN coated endodontic files. Materials and methods TiN coated nickel–titanium endodontic files (EasyShape) were surface and cross-sectionally analyzed via scanning electron microscopy backscattered electron imaging and energy-dispersive X-ray spectroscopy analysis in spot, area, and line scan modes. Results Surface imaging revealed parallel oblong regions with higher mean atomic contrast, a finding attributed to increased Ni content. Cross-sectional analysis showed that the coating’s average total thickness was 0.31 μm and consisted of a thin layered film. Energy-dispersive X-ray spectroscopy analysis revealed the presence of Ti, Ni, N, and O in the coating, whereas only Ni and Ti were identified in the bulk of the file. Ti and O showed their peak compositions at the bulk/coating and coating/surface interfaces, respectively, whereas N displayed a rather constant content within the coated region. The N and O contents started increasing inner to the coating/bulk interface, denoting possible diffusion of both elements to the subcoating region. Conclusion Surface and bulk characterization showed no uncoated areas of the files tested. Apart from Ti, Ni, and N, oxygen was also identified within the coating region.
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Affiliation(s)
- Youssef S Al Jabbari
- Dental Biomaterials Research and Development Chair, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia.,Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia
| | - Theodoros Koutsoukis
- Dental Biomaterials Research and Development Chair, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia
| | - Suliman Al Hadlaq
- Dental Biomaterials Research and Development Chair, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia.,Department of Restorative Dental Sciences, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia
| | - David W Berzins
- Dental Biomaterials Research and Development Chair, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia.,Department of Dental Biomaterials, School of Dentistry, Marquette University, Milwaukee, WI, USA
| | - Spiros Zinelis
- Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, 2 Thivon Street, Goudi 11527, Athens, Greece.,Dental Biomaterials Research and Development Chair, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia
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JARDINE AP, ROSA RAD, SANTINI MF, ZACCARA IM, SÓ MVR, KOPPER PMP. Shaping ability of rotatory or reciprocating instruments in curved canals: a micro-computed tomographic study. Braz Oral Res 2016; 30:S1806-83242016000100271. [DOI: 10.1590/1807-3107bor-2016.vol30.0086] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 03/06/2016] [Indexed: 11/22/2022] Open
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Reddy Y P, S K, Subbarao CV. Cyclic fatigue testing of three different rotary nickel titanium endodontic instruments in simulated curved canals - an in vitro sem analysis. J Clin Diagn Res 2014; 8:211-3. [PMID: 24701537 DOI: 10.7860/jcdr/2014/7569.4062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 12/09/2013] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Instrument separation is a serious concern in endodontics. Stainless steel instruments usually deform before they separate whereas Nickel Titanium instruments do not show any sign of deformation. AIM of the present study was to compare the cyclic rotations needed to fracture three different rotary nickel titanium endodontic instruments namely Profile, K3 Endo, RaCe in simulated curved canals having 2 different radii of curvature i.e., 5mm &10mm with a constant angle of curvature of 45°. The fractured surfaces were analysed using Scanning Electron Microscopy (SEM). MATERIALS AND METHODS Sixty rotary nickel titanium instruments were used for analysis in this study. The instruments were divided into three groups based on the different cross sections. Three groups were further divided into two sub groups based on radius of curvatures. Ten files were tested in each sub-group. RESULTS Group A (Profile) showed increased number of cycles to failure i.e., low incidence of fracture at both the radii of curvatures when compared to the other two groups. SEM analysis showed that in Group A the fractured surface of the files tested were characterized by the presence of smooth area on their edges associated with nucleation and slow fatigue crack propagation when compared to Group B and C. Therefore Group A (Profile) demonstrated least cyclic fatigue when compared to the other two groups.
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Affiliation(s)
- Pallavi Reddy Y
- Reader, Department of Conservative Dentistry and Endondontics, Army College of Dental Sciences , Secunderabad, Andhra Pradesh-500087, India
| | - Kavita S
- Professor, Department of Conservative Dentistry and Endondontics, SRM University , India
| | - C V Subbarao
- Professor, Department of Conservative Dentistry and Endondontics, Saveetha University , India
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Ba-Hattab R, Pröhl AK, Lang H, Pahncke D. Comparison of the shaping ability of GT® Series X, Twisted Files and AlphaKite rotary nickel-titanium systems in simulated canals. BMC Oral Health 2013; 13:72. [PMID: 24341354 PMCID: PMC3866935 DOI: 10.1186/1472-6831-13-72] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 12/09/2013] [Indexed: 11/29/2022] Open
Abstract
Background Efforts to improve the performance of rotary NiTi instruments by enhancing the properties of NiTi alloy, or their manufacturing processes rather than changes in instrument geometries have been reported. The aim of this study was to compare in-vitro the shaping ability of three different rotary nickel-titanium instruments produced by different manufacturing methods. Methods Thirty simulated root canals with a curvature of 35˚ in resin blocks were prepared with three different rotary NiTi systems: AK- AlphaKite (Gebr. Brasseler, Germany), GTX- GT® Series X (Dentsply, Germany) and TF- Twisted Files (SybronEndo, USA). The canals were prepared according to the manufacturers’ instructions. Pre- and post-instrumentation images were recorded and assessment of canal curvature modifications was carried out with an image analysis program (GSA, Germany). The preparation time and incidence of procedural errors were recorded. Instruments were evaluated under a microscope with 15 × magnifications (Carl Zeiss OPMI Pro Ergo, Germany) for signs of deformation. The Data were statistically analyzed using SPSS (Wilcoxon and Mann–Whitney U-tests, at a confidence interval of 95%). Results Less canal transportation was produced by TF apically, although the difference among the groups was not statistically significant. GTX removed the greatest amount of resin from the middle and coronal parts of the canal and the difference among the groups was statistically significant (p < 0.05). The shortest preparation time was registered with TF (444 s) and the longest with GTX (714 s), the difference among the groups was statistically significant (p < 0.05). During the preparation of the canals no instrument fractured. Eleven instruments of TF and one of AK were deformed. Conclusion Under the conditions of this study, all rotary NiTi instruments maintained the working length and prepared a well-shaped root canal. The least canal transportation was produced by AK. GTX displayed the greatest cutting efficiency. TF prepared the canals faster than the other two systems.
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Affiliation(s)
- Raidan Ba-Hattab
- Department of Operative Dentistry and Periodontology, Dental School University of Rostock, Strempelstr 13, 18057 Rostock, Germany.
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Abstract
The purpose of this study was to evaluate the influence of electrochemical polishing on the cyclic fatigue, cutting efficiency and surface topography of Miltex nickel-titanium rotary files. A group of files were submitted to electrochemical polishing. New files and polished files were tested for flexural fatigue and for cutting efficiency. Scanning electron microscopy observations of all files were carried out to compare the surface morphologies of polished and new files. The t-test was used to compare the groups for cutting efficiency. Scanning electron microscopy analysis indicated that the polishing resulted in more regular surfaces in relation to the new files. Electropolished files attained a significantly higher number of cycles to fracture than new unpolished files. No statistical difference exists between the groups in relation to the cutting efficiency (t-test, P < 0.05). The polished files keep their integrity for a significantly higher number of cycles to fracture than the new files, without compromising cutting efficiency.
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Affiliation(s)
- Marcio A C da Silva
- Department of Metallurgy and Materials, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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Jabbari YSA, Fehrman J, Barnes AC, Zapf AM, Zinelis S, Berzins DW. Titanium Nitride and Nitrogen Ion Implanted Coated Dental Materials. Coatings 2012; 2:160-78. [DOI: 10.3390/coatings2030160] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Spagnuolo G, Ametrano G, D'Antò V, Rengo C, Simeone M, Riccitiello F, Amato M. Effect of autoclaving on the surfaces of TiN-coated and conventional nickel-titanium rotary instruments. Int Endod J 2012; 45:1148-55. [DOI: 10.1111/j.1365-2591.2012.02088.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 05/27/2012] [Indexed: 11/29/2022]
Affiliation(s)
- G. Spagnuolo
- Department of Oral and Maxillofacial Sciences; University of Napoli “Federico II”; Napoli; Italy
| | - G. Ametrano
- Department of Oral and Maxillofacial Sciences; University of Napoli “Federico II”; Napoli; Italy
| | - V. D'Antò
- Department of Oral and Maxillofacial Sciences; University of Napoli “Federico II”; Napoli; Italy
| | - C. Rengo
- Department of Oral and Maxillofacial Sciences; University of Napoli “Federico II”; Napoli; Italy
| | - M. Simeone
- Department of Oral and Maxillofacial Sciences; University of Napoli “Federico II”; Napoli; Italy
| | - F. Riccitiello
- Department of Oral and Maxillofacial Sciences; University of Napoli “Federico II”; Napoli; Italy
| | - M. Amato
- Department of Medical School; University of Salerno; Salerno; Italy
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dos Santos M, Gavini G, Siqueira EL, da Costa C. Effect of Nitrogen Ion Implantation on the Flexibility of Rotary Nickel-Titanium Instruments. J Endod 2012; 38:673-5. [DOI: 10.1016/j.joen.2012.01.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 01/13/2012] [Accepted: 01/30/2012] [Indexed: 10/28/2022]
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Cecchin D, de Sousa-Neto MD, Pécora JD, Gariba-Silva R. Cutting efficiency of four different rotary nickel: Titanium instruments. J Conserv Dent 2011; 14:117-9. [PMID: 21814349 PMCID: PMC3146100 DOI: 10.4103/0972-0707.82605] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 08/30/2010] [Accepted: 10/05/2010] [Indexed: 12/01/2022] Open
Abstract
Aim: The aim of this study was to evaluate the cutting efficiency of rotary nickel-titanium (NiTi) instruments K3, NiTi Tee, Profile, and Quantec with taper size 04/25. Materials and Methods: The number of samples was 10 for each group (n = 10). The cutting efficiency was measured by the mass loss from each acrylic resin block after instrumentation of a simulated canal using the Crown-down technique. Results: The analysis of variance (ANOVA) showed that there was a statistically significant difference among the studied groups. The Tukey's test showed that the acrylic resin blocks prepared with instruments K3 (0.00369 ± 0.00022), NiTi Tee (0.00368 ± 0.00023), and Profile (0.00351 ± 0.00026) presented the greatest mass loss, showing no statistically significant difference among them (P < 0.05). The lowest mass loss was found in the blocks prepared with Quantec instruments (0.00311 ± 0.0003) (P < 0.05). Conclusions: It could be concluded that the K3, NiTi Tee, and Profile instruments presented a greater cutting efficiency than the Quantec instruments.
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Affiliation(s)
- Doglas Cecchin
- Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
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Subha N, Sikri VK. Comparative evaluation of surface changes in four Ni-Ti instruments with successive uses - An SEM study. J Conserv Dent 2011; 14:282-6. [PMID: 22025834 PMCID: PMC3198560 DOI: 10.4103/0972-0707.85817] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Revised: 12/28/2010] [Accepted: 02/19/2011] [Indexed: 11/04/2022] Open
Abstract
AIM To evaluate the surface alterations seen in four kinds of Nickel-Titanium (Ni-Ti) instruments using a scanning electron microscope (SEM) for five successive uses in preparing root canals of extracted human molars and also to determine whether the design of the instrument influenced the appearance of defects on the instrument surface. MATERIALS AND METHODS Four different types of instruments namely; ProFile, ProTaper Rotary, ProTaper Hand and K3 Endo were used in 300 mesio-buccal canals. The instruments were examined under the SEM, after every use, to assess the progress of changes on their surfaces for a maximum of five uses. STATISTICAL ANALYSIS USED Chi-square test. RESULTS The most prevalent defects observed were pitting, followed by metal strips. Signs of discontinuity, microfractures and disruption of cutting edge were also evident. Number of defects increased with successive uses. CONCLUSIONS ProTaper Hand showed significantly more microfractures and metal strips than other instruments from third use onwards. ProTaper Rotary and K3 Endo also showed significant changes.
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Affiliation(s)
- N Subha
- Departments of Conservative Dentistry and Endodontics, Sri Ramakrishna Dental College and Hospital, Coimbatore, Tamil Nadu, India
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Gavini G, Pessoa OF, Barletta FB, Vasconcellos M, Caldeira CL. Cyclic Fatigue Resistance of Rotary Nickel-Titanium Instruments Submitted to Nitrogen Ion Implantation. J Endod 2010; 36:1183-6. [DOI: 10.1016/j.joen.2010.03.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 03/09/2010] [Accepted: 03/11/2010] [Indexed: 10/19/2022]
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Alapati SB, Brantley WA, Iijima M, Clark WA, Kovarik L, Buie C, Liu J, Ben Johnson W. Metallurgical Characterization of a New Nickel-Titanium Wire for Rotary Endodontic Instruments. J Endod 2009; 35:1589-93. [DOI: 10.1016/j.joen.2009.08.004] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Revised: 07/30/2009] [Accepted: 08/03/2009] [Indexed: 11/30/2022]
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20
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Wolle CFB, Vasconcellos MAZ, Hinrichs R, Becker AN, Barletta FB. The Effect of Argon and Nitrogen Ion Implantation on Nickel-Titanium Rotary Instruments. J Endod 2009; 35:1558-62. [DOI: 10.1016/j.joen.2009.07.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Revised: 07/24/2009] [Accepted: 07/27/2009] [Indexed: 11/30/2022]
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21
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Alapati SB, Brantley WA, Iijima M, Schricker SR, Nusstein JM, Li U, Svec TA. Micro-XRD and temperature-modulated DSC investigation of nickel–titanium rotary endodontic instruments. Dent Mater 2009; 25:1221-9. [DOI: 10.1016/j.dental.2009.04.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Revised: 04/10/2009] [Accepted: 04/20/2009] [Indexed: 11/18/2022]
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Larsen CM, Watanabe I, Glickman GN, He J. Cyclic fatigue analysis of a new generation of nickel titanium rotary instruments. J Endod 2009; 35:401-3. [PMID: 19249604 DOI: 10.1016/j.joen.2008.12.010] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Revised: 12/16/2008] [Accepted: 12/23/2008] [Indexed: 10/21/2022]
Abstract
Recently, a new generation of nickel-titanium (NiTi) rotary instruments including the Twisted File (TF; Sybron Dental Specialties, Orange, CA) and ProFile GT Series X (GTX; Denstply, Tulsa Dental Specialties, Tulsa, OK) was introduced to the market. The purpose of this study was to determine if these new NiTi instruments were more resistant to cyclic fatigue compared with traditionally ground NiTi rotary instruments such as EndoSequence (ES; Brasseler, Savannah, GA) and ProFile (PF; Dentsply, Tulsa Dental Specialties). Size #25 TF, ES, and PF and size #20 GTX with .04 and .06 tapers were tested in a simulated canal with 60 degrees angle of curvature and a 3-mm radius. The number of rotations until fracture was recorded for each instrument. Among both .04 and .06 tapered files, #20 GTX files performed significantly better than all other files tested with tip sizes of #25 (p < 0.001); this may be because of the increased flexibility in the #20 files compared with #25 files. TF was significantly more resistant to cyclic fatigue than ES (p < 0.05) but not different from PF (p > 0.05) with the same tip size. The new manufacturing processes appeared to offer greater resistance to cyclic fatigue in a simulated canal model.
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Affiliation(s)
- C Michael Larsen
- Department of Endodontics, Baylor College of Dentistry, The Texas A&M University System Health Science Center, Dallas, TX 75246, USA
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23
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Boessler C, Paque F, Peters OA. The Effect of Electropolishing on Torque and Force During Simulated Root Canal Preparation with ProTaper Shaping Files. J Endod 2009; 35:102-6. [DOI: 10.1016/j.joen.2008.09.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2008] [Revised: 09/15/2008] [Accepted: 09/16/2008] [Indexed: 11/21/2022]
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Barbosa FOG, Gomes JADCP, de Araújo MCP. Influence of Electrochemical Polishing on the Mechanical Properties of K3 Nickel-Titanium Rotary Instruments. J Endod 2008; 34:1533-6. [DOI: 10.1016/j.joen.2008.08.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 08/12/2008] [Accepted: 08/17/2008] [Indexed: 11/27/2022]
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Alves-Claro APR, Claro FAE, Uzumaki ET. Wear resistance of nickel-titanium endodontic files after surface treatment. J Mater Sci Mater Med 2008; 19:3273-3277. [PMID: 18470705 DOI: 10.1007/s10856-008-3439-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Accepted: 03/19/2008] [Indexed: 05/26/2023]
Abstract
OBJECTIVES The purpose of this work was to submit the Nitinol files to plasma immersion ion implantation (PIII) and evaluate the effects of the surface treatment. MATERIALS AND METHODS Wear resistance was determined in vitro by using an equipment for the application of horizontal movements on previously prepared notched plates made of resin. Vickers microhardness was measured in plates and files, before and after surface treatment and the surface chemical composition of the instruments was determined by X-rays photoelectron spectroscopy. RESULTS The hardness values found for the treated Nitinol files were significantly lower than the hardness values measured before the implantation process. The comparison of commercially available instruments shows that the wear resistance of the stainless steel file is higher than the resistance of the Nitinol. CONCLUSIONS The results found led to the conclusion that the surface treatment significantly increased the Nitinol files wear resistance.
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Affiliation(s)
- A P R Alves-Claro
- Materials and Technology Department, São Paulo State University, Unesp, Av Ariberto Pereira da Cunha, 333 Guaratingueta, SP, Brazil.
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Zinelis S, Akhtar R, Tsakiridis P, Watts DC, Silikas N. In-depth hardness profiles of Stainless Steel and Ni-Ti endodontic instrument cross-sections by nano-indentation. Int Endod J 2008; 41:747-54. [DOI: 10.1111/j.1365-2591.2008.01426.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Schäfer E, Oitzinger M. Cutting Efficiency of Five Different Types of Rotary Nickel–Titanium Instruments. J Endod 2008; 34:198-200. [DOI: 10.1016/j.joen.2007.10.009] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 10/02/2007] [Accepted: 10/20/2007] [Indexed: 11/23/2022]
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Bui TB, Mitchell JC, Baumgartner JC. Effect of Electropolishing ProFile Nickel–Titanium Rotary Instruments on Cyclic Fatigue Resistance, Torsional Resistance, and Cutting Efficiency. J Endod 2008; 34:190-3. [DOI: 10.1016/j.joen.2007.10.007] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 10/16/2007] [Accepted: 10/23/2007] [Indexed: 11/30/2022]
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Bonaccorso A, Tripi TR, Rondelli G, Condorelli GG, Cantatore G, Schäfer E. Pitting Corrosion Resistance of Nickel–Titanium Rotary Instruments with Different Surface Treatments in Seventeen Percent Ethylenediaminetetraacetic Acid and Sodium Chloride Solutions. J Endod 2008; 34:208-11. [DOI: 10.1016/j.joen.2007.11.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Revised: 11/04/2007] [Accepted: 11/12/2007] [Indexed: 10/22/2022]
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30
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Vinothkumar TS, Miglani R, Lakshminarayananan L. Influence of Deep Dry Cryogenic Treatment on Cutting Efficiency and Wear Resistance of Nickel–Titanium Rotary Endodontic Instruments. J Endod 2007; 33:1355-8. [DOI: 10.1016/j.joen.2007.07.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Revised: 06/21/2007] [Accepted: 07/15/2007] [Indexed: 10/22/2022]
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31
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Herold KS, Johnson BR, Wenckus CS. A Scanning Electron Microscopy Evaluation of Microfractures, Deformation and Separation in EndoSequence and Profile Nickel-Titanium Rotary Files Using an Extracted Molar Tooth Model. J Endod 2007; 33:712-4. [PMID: 17509412 DOI: 10.1016/j.joen.2007.03.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2005] [Revised: 03/15/2007] [Accepted: 03/17/2007] [Indexed: 10/23/2022]
Abstract
The development of microfractures in the EndoSequence nickel-titanium rotary (NTR) file (Brassler USA, Savannah, GA) and Profile NTR file was evaluated by using scanning electron microscopy (SEM). Seventy-three maxillary buccal roots and 53 mandibular mesial roots with an average canal curvature of 37 degrees were randomly assigned to one of three groups and prepared with 21-mm .06 taper NTR files as follows: (1) EndoSequence at 300 rpm, (2) EndoSequence at 600 rpm, and (3) ProFile at 300 rpm. File sizes .45 to .20 were used in a crown-down technique to a master apical file (MAF) size of .35/.06. The MAF instruments were evaluated by SEM before use, after completion of 7 canals, and after completion of 14 canals. All EndoSequence instruments developed microfractures by the seven-canal evaluation. The ProFile instruments showed no microfractures at the 7- or 14-canal evaluations. EndoSequence files separated at a higher rate than ProFile instruments. Under the conditions of this study, unique file design and electropolishing did not inhibit the development of microfractures in EndoSequence NTR.
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Affiliation(s)
- Keven S Herold
- Department of Endodontics, University of Illinois at Chicago, Chicago, Illinois 60612, USA
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Li UM, Iijima M, Endo K, Brantley WA, Alapati SB, Lin CP. Application of Plasma Immersion Ion Implantation for Surface Modification of Nickel-titanium Rotary Instruments. Dent Mater J 2007; 26:467-73. [PMID: 17886448 DOI: 10.4012/dmj.26.467] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
By means of X-ray photoelectron spectroscopy (XPS) and differential scanning calorimetry (DSC), this study set out to investigate the application of plasma immersion ion implantation (PIII) for the surface modification of ProTaper NiTi rotary instruments. This study was undertaken because the PIII method was perceived to have the potential of developing into a standard surface modification technique that improves clinical quality and outcome. Specimens received nitrogen ion or nitrogen plus argon ion implantation. XPS analyses with and without argon ion etching were obtained for all specimens. In addition, DSC analysis was performed to investigate the phase transformation behavior of the bulk material. Results indicated that the surfaces of NiTi instruments were successfully modified by nitrogen PIII, whereby a light golden TiN layer was yielded. Moreover, the PIII technique did not alter the superelastic character of NiTi instruments because it was carried out at near-room temperature. We thus concluded that nitrogen PIII is a promising surface modification technique to improve the surface characteristics of NiTi rotary instruments.
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Affiliation(s)
- Uei-Ming Li
- School of Dentistry and Graduate Institute of Clinical Dentistry, College of Medicine, National Taiwan University and National Taiwan University Hospital, Taipei 10016, Taiwan, ROC
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Abstract
The fracture of endodontic instruments is a procedural problem creating a major obstacle to normally routine therapy. With the advent of rotary nickel-titanium (NiTi) instruments this issue seems to have assumed such prominence as to be a considerable hindrance to the adoption of this major technical advancement. Considerable research has been undertaken to understand the mechanisms of failure of NiTi alloy to minimize its occurrence. This has led to changes in instrument design, instrumentation protocols, and manufacturing methods. In addition, factors related to clinician experience, technique, and competence have been shown to be influential. From an assessment of the literature presented, we derive clinical recommendations concerning prevention and management of this complication.
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Affiliation(s)
- Peter Parashos
- School of Dental Science, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia.
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Tripi TR, Bonaccorso A, Condorelli GG. Cyclic fatigue of different nickel-titanium endodontic rotary instruments. ACTA ACUST UNITED AC 2006; 102:e106-14. [PMID: 16997084 DOI: 10.1016/j.tripleo.2005.12.012] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2005] [Revised: 12/13/2005] [Accepted: 12/14/2005] [Indexed: 10/24/2022]
Abstract
OBJECTIVE A comparative study of the fatigue resistance of rotary nickel-titanium endodontic instruments was performed with the aim of assessing the influence of both instrument design and surface treatment on flexural fracture. STUDY DESIGN To evaluate fatigue resistance of different rotary instruments, a total of 120 instruments were tested; these came from different sources: ProFile, RaCe, K3, Hero, and Mtwo. To compare the effect of electro-polishing procedures on fatigue resistance, a group of RaCe instruments (which are normally electro-polished) without surface treatment was used. A scanning electron microscope (SEM) study for each instrument was performed before and after fatigue study to determine the mode of fracture and the aspect of tips and cross-sectional surface areas. RESULTS ProFile instruments gave the best values for fatigue resistance. It was seen that for RaCe instruments the surface treatment reduces the presence of micro-cracks, surface debris, and machining damage. CONCLUSIONS This study shows that the instrument design often proves to be an important factor in the fatigue resistance of NiTi rotary instruments. In RaCe instruments the electro-polishing surface treatment increases the fracture-related fatigue resistance.
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Abstract
AIM To evaluate, by scanning electron microscopy, the deformation and fracture of NiTi RaCe and K3 size 25, 0.04 taper instruments. METHODOLOGY Ten sets of instruments from RaCe and K3 NiTi rotary systems were used to prepare 100 simulated canals in epoxy resin blocks with 20 or 40 degree curvatures beginning 8 or 12 mm from the orifice. Each instrument set was used to prepare five simulated canals using a crowndown technique. The size 25, 0.04 taper instruments were analysed by SEM when new and again after each use. Three observers scored images of the instruments after each use for distortion of the spirals (no distortion, distortion of one spiral or distortion of more than one spiral), wear (no wear, small, moderate or severe wear) and fracture (yes or no). Two-way anova was used to analyse differences between instruments for distortion and wear; Fisher's exact test looked for differences related to fracture of instruments. RESULTS No fractures occurred with K3 instruments, whereas six RaCe instruments fractured (P = 0.005). A statistically significant difference occurred between RaCe and K3 instruments in terms of distortion of spirals and surface wear (P < 0.001). Distortion of spirals and wear increased with progressive use of RaCe instruments, whereas K3 instruments remained relatively undamaged after their fifth use. The simulated canals with smaller radii of curvature were positively associated with fracture of RaCe instruments. CONCLUSIONS A significant difference was found between RaCe and K3 in terms of deformation and fracture of size 25, 0.04 taper instruments; K3 instruments had more favourable results.
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Affiliation(s)
- C H Troian
- Universidade Luterana do Brasil, Canoas, RS, Brazil.
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36
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Alexandrou GB, Chrissafis K, Vasiliadis LP, Pavlidou E, Polychroniadis EK. SEM Observations and Differential Scanning Calorimetric Studies of New and Sterilized Nickel-Titanium Rotary Endodontic Instruments. J Endod 2006; 32:675-9. [PMID: 16793479 DOI: 10.1016/j.joen.2006.01.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2005] [Revised: 01/03/2006] [Accepted: 01/07/2006] [Indexed: 10/24/2022]
Abstract
Scanning electron microscopy (SEM) and differential scanning calorimetric (DSC) studies were utilized to investigate surface and microstructure of two brands of rotary nickel-titanium (NiTi) endodontic instruments, in the as-received condition and after subjection to 1, 6, and 11 sterilization cycles. A total of 66 ProFile (n = 33) and Flexmaster (n = 33) files were examined. SEM observations indicated the presence of surface imperfections and adherent material in all new and sterilized instruments and an increase in surface roughness of the instruments that underwent multiple sterilizations. DSC measurements showed that the specimens of both brands, in the as-received condition and after 11 sterilizations, were completely austenite in the oral environment temperature, suggesting that they are capable of superelastic behavior in appropriate clinical conditions.
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Affiliation(s)
- Georgia B Alexandrou
- Department of Endodontology, Dental School, Aristotle University of Thessaloniki, Thessaloniki, Greece
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37
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Taira Y, Hatono H, Mizukane M, Tokita M, Atsuta M. Effect of Ceramic Coating by Aerosol Deposition on Abrasion Resistance of a Resin Composite Material. Dent Mater J 2006; 25:700-5. [PMID: 17338303 DOI: 10.4012/dmj.25.700] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Aerosol deposition (AD coating) is a novel technique to coat solid substances with a ceramic film. The purpose of the present study was to investigate the effect of AD coating on abrasion resistance of a resin composite material. A 5-microm-thick aluminum oxide layer was created on the polymerized resin composite. The specimen was cyclically abraded using a toothbrush abrasion simulator for 100,000 cycles. Abraded surface was then measured with a profilometer to determine the average roughness (Ra) and maximum roughness (Rmax). It was found that abrasion cycling increased the Ra value of the No-AD-coating group, but decreased the Ra and Rmax values of the AD coating group. Moreover, the AD coating group showed significantly smaller Ra and Rmax values after 100,000 abrasion cycles as compared to the No-coating control group. Microscopic observation supported these findings. In conclusion, the resistance of the resin composite against toothbrush abrasion was improved by AD coating.
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Affiliation(s)
- Yohsuke Taira
- Division of Applied Prosthodontics, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
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Abstract
AIM To investigate the mode of failure of a brand of nickel-titanium instruments separated during clinical use, by detailed examination of the fracture surface. METHODOLOGY A total of 122 ProTaper S1 instruments were discarded from an endodontic clinic at a stomatological school in China over a period of 17 months; 28 had fractured. These fractured instruments were ultrasonically cleaned, autoclaved and then examined under a scanning electron microscope. From the lateral view the fracture was classified into 'torsional' or 'flexural'. The specimens were then re-mounted and the presence of characteristics of shear failure and fatigue striations was recorded under high-power view of the fracture surface. The difference in the mean lengths of fractured segment between the shear and fatigue groups was compared using Student's t-test. RESULTS Twenty-seven separated instruments were available for analysis. Under low-power magnification, only two fell into the category of 'torsional' failure when examined laterally; the others appeared to be 'flexural'. Close examination of the fracture surface revealed the presence of fatigue striations in 18 specimens. Nine instruments (including the two putative 'torsional' failures above) fell into the shear fracture group, in which fatigue striations were absent or characteristics of shear failure of the material were found. The mean length of fractured segments resulting from fatigue failure (4.3+/-1.9 mm) was significantly greater than that for shear failure (2.5+/-0.8 mm) (P<0.001, two-sample t-test). CONCLUSIONS Examination of the fracture surface at high magnification is essential to reveal features that may indicate the possible origin of cracks and the mode of material failure. Macroscopic or lateral examination of separated instruments would fail to reveal the true mechanism of failure. Fatigue seems to be an important reason for the separation of rotary instruments during clinical use.
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Affiliation(s)
- G S P Cheung
- Faculty of Dentistry, The University of Hong Kong, Hong Kong
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39
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Alapati SB, Brantley WA, Svec TA, Powers JM, Nusstein JM, Daehn GS. SEM observations of nickel-titanium rotary endodontic instruments that fractured during clinical Use. J Endod 2005; 31:40-3. [PMID: 15614004 DOI: 10.1097/01.don.0000132301.87637.4a] [Citation(s) in RCA: 180] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Numerous discarded ProFile GT, ProFile, and ProTaper nickel-titanium rotary instruments obtained from two graduate endodontic clinics were examined by scanning electron microscopy. These instruments had an unknown history of clinical use and had fractured or experienced considerable permanent torsional deformation without complete separation. The failure processes generally exhibited substantial ductile character, evidenced by a dimpled rupture fracture surface. Crack propagation at grain boundaries and cleavage surfaces indicative of transgranular fracture were observed for some specimens. It appeared that oxide particles from the manufacturing process served as nucleating sites for the microvoids, leading to dimpled rupture. A previously unreported fracture mode also was observed, in which crack propagation, approximately parallel to the local flute orientation, connected pitted regions on the surface. Combining present and previous scanning electron microscopy observations of clinically failed instruments, suggestions are offered for improving their fracture resistance.
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Affiliation(s)
- Satish B Alapati
- Section of Oral Biology, College of Dentistry, The Ohio State University, Columbus, OH 43218-2357, USA
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40
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Alapati SB, Brantley WA, Svec TA, Powers JM, Nusstein JM, Daehn GS. Proposed Role of Embedded Dentin Chips for the Clinical Failure of Nickel-Titanium Rotary Instruments. J Endod 2004; 30:339-41. [PMID: 15107646 DOI: 10.1097/00004770-200405000-00008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Discarded ProFile and ProTaper nickel-titanium rotary instruments, with unknown history of clinical use, were obtained from graduate endodontic clinics at Ohio State University and University of Texas Health Science Center at Houston Dental Branch. These discarded instruments and as-received instruments of both types were examined with a scanning electron microscope to investigate effects of clinical use and causes of failure. For used ProTaper instruments, dentinal debris was wedged mostly in narrow, radial, land-type regions and less on convex flute surfaces. For used ProFile instruments, dentinal debris was wedged mostly in the metal rollover and on concave flute surfaces. Used instruments of both types exhibited widened machining grooves, and elongated and stretched roll-over. Dentin chips were wedged in surface micro-cracks that appeared to propagate from original machining flaws and widen during in vivo root canal preparation. From our observational study, wedged dentinal deposits seem to play a pivotal role for clinical failure of these instruments.
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Affiliation(s)
- Satish B Alapati
- Dental Materials Science Program, College of Dentistry, The Ohio State University, Columbus, OH 43218-2357, USA
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Abstract
The introduction of nickel-titanium (NiTi) as material for endodontic instruments about 15 years ago opened many new perspectives. Many dentists and scientists see a benefit in using NiFi files. Initial problems such as frequent fractures and the uncertainty of the best way to use them have been solved. Other challenges such as enhancing the cutting ability or optimizing the speed, torque, and fatigue are currently being addressed. Some clinicians are skeptical because they see this approach as too mechanical. Nevertheless, the combination of anatomic, biologic, and pathophysiologic knowledge with the use of NiTi instruments is a large step forward in optimizing the quality of root canal treatment worldwide.
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Affiliation(s)
- Michael A Baumann
- Department of Operative Dentistry and Periodontology, Dental School, University of Cologne, Kerpener Strasse 32, D-50931 Köln, Germany
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Abstract
The appearances of the tip sections of ProFile 0.04 taper and Lightspeed 25-mm long, ISO size 25, nickel-titanium rotary instruments were compared with a scanning electron microscope in the as-received condition and after one, three, and six simulated clinical uses to prepare mesial canals of extracted mandibular molars. For the used ProFile instruments, there was some flattening of the characteristic material rollover and minor apparent wear at the edges of the flutes, but there was little change in the tip regions of the used Lightspeed instruments. Deposits on the surfaces of the instruments were attributed to the manufacturing processes and the in vitro preparation of root canals in the extracted teeth. The simulated clinical use did not cause substantial changes in the regions of these two brands of rotary instruments that are involved in the clinical preparation of root canals.
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Affiliation(s)
- Satish B Alapati
- Dental Materials Science Program, Prosthodontics and Endodontics, College of Dentistry, The Ohio State University, Columbus 4328-2357, USA
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Abstract
The present study was designed to compare the nature of modified surface layers obtained by two different procedures on endodontic files made of NiTi alloy: the procedures were arc evaporation physical vapor deposition and thermal metal organic chemical vapor deposition (MOCVD). Experimental samples were GT Rotary Instruments. The first method was based on the physical deposition of elemental titanium in the presence of nitrogen. The second technique is a typical MOCVD procedure which adopts Ti(Et2N)4 as a titanium and nitrogen precursor. Control samples were not exposed to any process. The chemical composition of the surface and in-depth layers of each sample were examined by X-ray photoelectron spectroscopy and X-ray diffraction measurements. The instruments showed surface chemical compositions that were different from those seen in the control group; samples treated with the first method show a surface Nitrogen/Titanium ratio of 1; MOCVD instruments show a surface Nitrogen/Titanium ratio of 1.7; control samples show a Nitrogen/Titanium ratio of 0.2. Both techniques can produce a high nitrogen concentration on the surface. However, data showed that the morphologies, the in-depth nitrogen distribution, and the chemical nature of the coatings obtained with the two procedures were different. The paper also reports the effects of the two deposition procedures on the nickel/titanium ratio of the surface.
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Affiliation(s)
- Teresa Roberta Tripi
- Cattedra di Odontoiatria Conservatrice, Corso di Laurea in Odontoiatria e Protesi Dentaria, Catania University, Italy
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Abstract
The purpose of this study was to investigate possible changes in cutting efficiency of nickel-titanium K-files that had undergone physical vapor deposition coating. Titanium nitride coatings were deposited using different process parameters. A total of 84 nickel-titanium K-files (size 35) were randomly divided into 7 groups of 12 instruments each. Groups A to F (experimental): instruments were coated with titanium nitride using different process parameters regarding substrate temperature, applied voltage, coating thickness, and ion bombardment. Group K (control): samples were not coated with titanium nitride. The cutting efficiency of all instruments was determined in a rotary working motion by means of a computer-driven testing device. Special plastic samples with a cylindrical canal were used, and the maximum penetration depth of the instruments into the lumen was the criterion for cutting efficiency. Instruments of groups A, F, and C achieved significantly greater penetration depths than the uncoated instruments of the control group (p < 0.05). Cutting efficiency of physical vapor deposition-coated nickel-titanium files was increased by up to 26.2% in comparison with uncoated instruments.
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Abstract
AIM To investigate alterations in cutting efficiency when conventional and titanium nitride (TiN) coated nickel-titanium (NiTi) K-files were exposed to repeated sterilization using an autoclave. METHODOLOGY A total of 96 NiTi K-files (size 35) were randomly divided into two groups (A and B) of 48 instruments each. Whilst the instruments of group B were exposed to physical vapour deposition (PVD) creating a coating of a TiN layer, the files of group A were not coated. The instruments of groups A and B were randomly divided into four subgroups of 12 instruments each. A.1/B.1: Instruments were exposed to five cycles of sterilization. A.2/B.2: Instruments were exposed to 10 cycles of sterilization. A.3/B.3: Instruments were immersed in NaOCl for 30 min, rinsed in water, and exposed to five cycles of sterilization. A.C/B.C: Instruments were not sterilized (controls). The cutting efficiency of all files was determined by means of a computer-driven testing device. Special plastic samples with cylindrical canals were used and the maximum penetration depth of the files into the lumen was assessed. RESULTS The TiN-coated instruments of groups B.1, B.2 and B.3 showed no significant difference in comparison with the penetration depths of the controls (P> 0.05). The uncoated files of groups A.1, A.2 and A.3 displayed significantly lower maximum penetration depths (P< 0.05) when compared to the control files. CONCLUSIONS Repeated sterilization under autoclave or exposure to sodium hypochlorite (NaOCl) prior to sterilization did not alter the cutting efficiency of PVD-coated NiTi K-files.
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Affiliation(s)
- E Schäfer
- Department of Operative Dentistry, University of Münster, Münster, Germany.
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