Background/purpose: Temperature-dependent phase compositional changes influence the mechanical properties of heat-treated nickel-titanium (NiTi) rotary instruments. This study evaluated the phase composition, bending properties, and cyclic fatigue resistance of HyFlex EDM NiTi rotary instruments against differently heat-treated and non-heat-treated NiTi instruments at body temperature (BT).
Materials And Methods: HyFlex EDM OneFile (EDM) instruments, heat-treated HyFlex CM (CM) and Twisted File (TF) instruments, and non-heat-treated K3 instruments (size #25/.08) were subjected to differential scanning calorimetry, and the martensitic, R-phase, and reverse transformation starting and finishing temperatures were determined. A cantilever bending test and a cyclic fatigue test were conducted at BT (37 °C ± 1.0 °C), and the bending load and number of cycles to failure (NCF) were recorded. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U tests (α = 0.05).
Results: TF and K3 had reverse transformation finishing temperatures lower than BT, while those for EDM and CM were higher than BT. The bending loads at a 0.5 mm deflection were in the order of EDM < TF < CM < K3 ( < 0.05), and those at a 2.0 mm deflection were EDM < CM and TF < K3 (P < 0.05). EDM had the highest NCF among the four instruments ( < 0.05).
Conclusion: The EDM instrument had a reverse transformation finishing temperature higher than BT indicating its martensite/R-phase composition at BT. The EDM instrument had superior flexibility and greater resistance to cyclic fatigue than the CM, TF, and K3 instruments at BT.
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http://dx.doi.org/10.1016/j.jds.2023.07.039 | DOI Listing |
Odontology
January 2025
Department of General Surgery and Medical-Surgical Specialties, University of Catania, 95123, Catania, Italy.
The aim of this study was to assess the cyclic fatigue resistance of a single-file system (i.e., Hyflex EDM OneFile), during continuous rotation and reflex dynamic motion with and without irrigation.
View Article and Find Full Text PDFIntroduction: This systematic review and meta-analysis assess the impact of the XP-endo Shaper (XPS) on postoperative pain following root canal treatment (RCTs) and compare its efficacy with other endodontic systems.
Methods: A comprehensive literature search was conducted in MEDLINE, Web of Science, Embase, and the Cochrane Library from January 2000 to August 2024. Randomized controlled trials using XPS and reporting postoperative pain were included.
Med Sci Monit
January 2025
Department of Restorative Dental Sciences, College of Dentistry, Jazan University, Jazan, Saudi Arabia.
BACKGROUND This cone beam computed tomography (CBCT) endodontics study aimed to compare the canal-centering ability and canal transportation of Edgefile X7 and HyFlex EDM files in moderately curved mesiobuccal (MB) root canals of 30 mandibular first permanent molar teeth. MATERIAL AND METHODS Thirty permanent mandibular first molars with 10° and 24° of mesial root curvature were selected and scanned with CBCT. Two experimental groups of 15 each were made: group I: HyFlex EDM, and group II: Edgefile X7.
View Article and Find Full Text PDFCureus
October 2024
Department of Conservative Dentistry and Endodontics, Government Dental College, Kozhikode, IND.
Background and objective Postoperative pain after biomechanical preparation of root canals can be equally distressing to the patient as well as the dentist and can mold the patient's attitude and trust for future dental procedures. This randomized clinical trial aimed to evaluate the effectiveness of rotary and reciprocating single-file systems on postoperative pain after biomechanical preparation in patients with chronic apical periodontitis. Materials and methods In this randomized clinical trial (CTRI Reg No-CTRI/2021/04/032841), 94 patients with chronic apical periodontitis in single straight-rooted teeth were divided equally into two groups, according to a standardized protocol.
View Article and Find Full Text PDFOdontology
November 2024
Clinical Department of Medical Science, Surgery and Health, University of Trieste, Trieste, Italy.
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