scholarly journals Experimental Study of the Effects of Torsional Loading on Three Types of Nickel-Titanium Endodontic Instruments

2021 ◽  
Vol 11 (16) ◽  
pp. 7224
Author(s):  
Andreea-Simona Boscornea-Pușcu ◽  
Laura Orel ◽  
Oana-Alexandra Velea-Barta ◽  
Razvan Mihai Horhat ◽  
Meda-Lavinia Negruțiu ◽  
...  
Keyword(s):  
Cross Sections ◽  
Root Canal ◽  
Large Scale ◽  
Twist Angle ◽  
Nickel Titanium ◽  
Root Canals ◽  
Canal Shaping ◽  
The Moment ◽  
Torque Values ◽  
Twisting Angle

In modern endodontics, nickel-titanium (NiTi) rotary instruments are used on a large scale for root canal shaping. Nevertheless, the separation of an instrument is a serious concern during shaping. The aim of this study is to determine and compare the torsional fracture characteristics of three types of NiTi endodontic instruments, each with different cross-section designs and movements performed during root canal shaping: Endostar E3 (Endostar, Poldent Co. Ltd., Warsaw, Poland); Reciproc R25 (VDW, Munich, Germany); and Protaper Next X2 (Dentsply Maillefer, Ballaigues, Switzerland). Fifteen instruments are used in this study, divided in three groups (n = 5): Group Endostar, Group Reciproc and Group Protaper. For testing, each instrument is used to shape five simulated root canals, following which its torsional stress to failure is measured. The fracture lengths of all three groups are roughly between 2 and 3 mm from the tip. Higher values of the moment of torsion in fracture, and smaller values of the maximum twisting angle are observed for Group Endostar, as well as closer to circular cross-sections. However, the values of the shear tension are similar for all three groups, because the disadvantage given by the fracture section shape for Groups Reciproc and Protaper is compensated either by size or by intrinsic properties of the instrument material. For the shear tension the Endostar values are insignificantly increased (Kruskal–Wallis test, p = 0.207), and in the case of the maximum twist angle the Protaper values are insignificantly increased (Kruskal–Wallis test, p = 0.287). Because of the instruments shape and conicity, the analysis had to be carried out separately with regard to the length of the fractured tip. Rules-of-thumb are extracted from the study for current practice: if a blockage of the first 2 to 3 mm part of the tip can be anticipated (by the excessive curving of the instrument), the handpiece must be adjusted to torque values that do not exceed 1.5 to 2.5 N · cm for Endostar and 1 to 2 N · cm for Reciproc and Protaper instruments.

scholarly journals A comparative study of protaper and twisted file nickel titanium instruments in curved canals preparation

2013 ◽  
Vol 60 (4) ◽  
pp. 175-182
Author(s):  
Lima De ◽  
Giselle Nevares ◽  
Felipe Xavier ◽  
Ferraz Gominho ◽  
Albuquerque de
Keyword(s):  
Cross Sections ◽  
Root Canal ◽  
Nickel Titanium ◽  
Torque Control ◽  
Cross Sectional ◽  
Root Canals ◽  
Group 2 ◽  
Mean Differences ◽  
Root Canal Instrumentation ◽  
Group 1

Introduction. Root canal instrumentation is performed to achieve cleaning and shaping with maximum preservation of its original anatomy. However, in curved canals this approach may cause excessive damage or canal transportation. The present study aimed to evaluate changes in dentin wall caused by instrumentation of curved canals using two nickel titanium rotary systems, ProTaper and Twisted File. Material and Methods. Twenty five extracted human mandibular first molars with two separated mesial root canals were selected. Distal roots were amputated and 50 canals (25 mesiobuccal and 25 mesiolingual) were randomly assigned into two groups: group 1 - ProTaper, and group 2 - Twisted File. All files were used with torque control engine, following the manufacturer instructions. The final instruments were F3 (group 1) and #30/.06 (group 2). Pre and postoperative cross sections were obtained from coronal, middle, and apical portions. Changes in dentin wall were measured and evaluated using Bramante method and digital image software. Statistical analysis was performed using the Mann Whitney U test (p<0.05). Results. The ammount of dentin removed by ProTaper in cervical and middle canal thirds was significantly greater than with Twisted File (p=0.040 and p=0.043). ProTaper eliminated significantly greater ammount of dentin than Twisted File from mesial wall in coronal sections (p=0.039). Mean differences in distance from the center to other walls were not statistically significant in the middle and apical thirds of both groups (p>0.05). Conclusion. ProTaper system produced greater changes in cross sectional area of the root canal compared to Twisted File system.

scholarly journals Nickel-Titanium Single-file System in Endodontics

2015 ◽  
Vol 16 (10) ◽  
pp. 834-839
Author(s):  
Alberto Dagna
Keyword(s):  
Root Canal ◽  
File System ◽  
Nickel Titanium ◽  
Root Canals ◽  
Single File ◽  
Continuous Rotation ◽  
Bending Stresses ◽  
Single Use ◽  
Canal Shaping ◽  
Clinical Cases

ABSTRACT Aim This work describes clinical cases treated with a innovative single-use and single-file nickel-titanium (NiTi) system used in continuous rotation. Background Nickel-titanium files are commonly used for root canal treatment but they tend to break because of bending stresses and torsional stresses. Today new instruments used only for one treatment have been introduced. They help the clinician to make the root canal shaping easier and safer because they do not require sterilization and after use have to be discarded. A new sterile instrument is used for each treatment in order to reduce the possibility of fracture inside the canal. The new One Shape NiTi single-file instrument belongs to this group. Case description One Shape is used for complete shaping of root canal after an adequate preflaring. Its protocol is simple and some clinical cases are presented. It is helpful for easy cases and reliable for difficult canals. Conclusion After 2 years of clinical practice, One Shape seems to be helpful for the treatment of most of the root canals, with low risk of separation. After each treatment, the instrument is discarded and not sterilized in autoclave or re-used. Clinical significance This single-use file simplifies the endodontic therapy, because only one instrument is required for canal shaping of many cases. The respect of clinical protocol guarantees predictable good results. How to cite this article Dagna A. Nickel-Titanium Single-file System in Endodontics. J Contemp Dent Pract 2015;16(10): 834-839.

scholarly journals The shaping advantage of M-wire compared with conventional nickel-titanium rotary instruments in heavy curvature canal

2020 ◽  
Author(s):  
Mika Tanaka-Sato ◽  
Noriko Mutoh ◽  
Kaori Shimojima ◽  
Nobuyuki Tani-Ishii
Keyword(s):  
Root Canal ◽  
Nickel Titanium ◽  
Canal Wall ◽  
Root Canals ◽  
Rotary Instruments ◽  
The Mean ◽  
Canal Shaping ◽  
Shaping Ability

Abstract Background The purpose of this study was to evaluate the shaping advantage of M-wire NiTi ProTaper NEXT (PTN) compared with a conventional NiTi ProTaper Universal (PTU) file in heavy curvature canal. The shaping ability was measured by the amount of canal cutting and transportation between the PTN and conventional PTU. Methods Root canal shaping by the PTN and conventional PTU was classified into two experimental groups according to the final tip size, ISO #25 or ISO #40. Eighty-four J-shaped root canals (10°, 20°, 30° apical curvature) in resin block were used. Results After adjusting for the level and canal wall side, the mean transportation did not significantly decrease between the PTN and PTU with ISO #25. Significantly less deviation occurred with the PTN and PTU between 10° and 30° using ISO #40. Conclusions The M-Wire NiTi PTN improves file flexibility and enables accurate canal shaping for heavy curvature canals.

scholarly journals Root Canal Stripping: Malpractice or Common Procedural Accident—An Ethical Dilemma in Endodontics

2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Ionela Elisabeta Ciobanu ◽  
Darian Rusu ◽  
Stefan-Ioan Stratul ◽  
Andreea Cristina Didilescu ◽  
Corina Marilena Cristache
Keyword(s):  
Risk Factors ◽  
Ethical Dilemma ◽  
Root Canal ◽  
Tooth Extraction ◽  
Nickel Titanium ◽  
Middle Section ◽  
Root Canals ◽  
Legal Consequences ◽  
Curved Root Canals

Root canal stripping is defined as an oblong, vertical perforation that appears especially in the middle section of curved root canals during endodontic treatments with nickel-titanium (Ni-Ti) instruments. Its occurrence may drastically affect the outcome of the treatment, transforming a common otherwise efficient endodontic procedure into a complication such as tooth extraction. In order to discuss the ethical and legal consequences, two cases of dental strip perforations are herewith presented. Due to the existence of risk factors for dental strip perforation, experience of the clinician and the use of magnification and modern imagistic methods (CBCT) may avoid or reduce the frequency of this type of accidents. Under correct working circumstances, dental stripping should not be regarded as a malpractice but as a procedural accident. However, the patient must always be informed, before and during the endodontic procedure, about the event and the possible complications that may occur.

scholarly journals Clinical Update on Nickel-Titanium Rotary Instruments

2015 ◽  
Vol 6 (2) ◽  
pp. 97-103
Author(s):  
Suraj Pawar ◽  
Ekta Keswani ◽  
Priyanka Jain ◽  
Swapna Nayan
Keyword(s):  
Root Canal ◽  
Nickel Titanium ◽  
Root Canal Therapy ◽  
Root Canals ◽  
Rotary Instruments ◽  
Procedural Complications

ABSTRACT In the last decade, nickel-titanium (NiTi) rotary canal instruments have proved to be valuable for root canal therapy because of their exceptional ability to shape root canals with potentially fewer procedural complications. The purpose of this clinical update article is to bring clinicians up to date with the current and popular endodontic rotary NiTi instrument systems. How to cite this article Jain P, Nayan S, Keswani E, Pawar S. Clinical Update on Nickel-Titanium Rotary Instruments. World J Dent 2015;6(2):97-103.

scholarly journals Root canals shaped by nickel-titanium instrumentation with automated computerized numerical control systems

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Liming Wang ◽  
Wenxiang Li ◽  
Yeon-Jee Yoo ◽  
Shin Hye Chung ◽  
Soram Oh ◽  
...  
Keyword(s):  
Root Canal ◽  
Nickel Titanium ◽  
Numerical Control ◽  
Central Axis ◽  
Downward Movement ◽  
Preparation Time ◽  
Root Canals ◽  
Insertion Angle ◽  
Group 4 ◽  
Working Length

Abstract Background To investigate the efficacy of a nickel-titanium (NiTi) file with an automated computerized numerical control (CNC) system for root canal shaping. Methods The movement of the automated device and the insertion angle were investigated. In Experiment 1, simulated resin root canals were randomly divided into four groups (n = 20): manual downward movement using a handpiece (Group 1), vertical downward movement by CNC (Group 2), reciprocating up and down movement by CNC (Group 3), and spiral up and down movement by CNC (Group 4). In Experiment 2, five different insertion angles of the NiTi file were evaluated (n = 20). Four parameters were used to evaluate the shaping ability: change in the working length, central axis offset, curvature variation, and preparation time. Groups were compared using one-way analysis of variance (ANOVA) with significance was set at P < 0.05. Results The change in central axis position in the curved part of the root canal was found to be smaller in Group 4 than in other groups (P < 0.05). The curvature changes and preparation time of Groups 1 and 4 were significantly reduced compared with Groups 2 and 3 (P < 0.05). The variation in working length and curvature in the 5° insertion angle group was significantly smaller than in the other groups (P < 0.05). Conclusions A spiral up and down movement, controlled by the CNC machine, and 5° insertion angle, maintained original root canal shape more precisely than other methods.

scholarly journals Geometric Analysis of Maxillary First Premolar Prepared by Two Nickel-Titanium Rotary Instruments

2014 ◽  
Vol 15 (2) ◽  
pp. 174-180 ◽  
Author(s):  
Dina Al-Sudani ◽  
Majed Almalki ◽  
Saad Al-Shahrani ◽  
Michael Ahlquist
Keyword(s):  
Cross Sections ◽  
Root Canal ◽  
Geometric Analysis ◽  
Microcomputed Tomography ◽  
Nickel Titanium ◽  
Rotary Instruments ◽  
Significant Difference ◽  
Before And After ◽  
Canal Transportation ◽  
Shaping Ability

ABSTRACT Aim The present study was conducted with the aim of evaluating and comparing the shaping ability of two Nickel-titanium rotary instruments, with two disparate design features, on root canal geometry of extracted human maxillary first premolars using microcomputed tomography. Study design Twenty four bifurcated maxillary first premolars were divided into two groups and embedded in a rubber-based impression material. Both groups were submitted to microcomputed tomography before and after canal preparation (buccal and palatal) with either ProFile Vortex or Revo-S rotary instruments. Images were reconstructed and cross-sections corresponding to a distance 1, 2, 3, 4, 5, 6, and 7 mm from the anatomical apex were selected for canal transportation analysis. Volume changes were also measured. Results The degree and direction of canal transportation were non-significant for both instruments. Statistically significant differences were observed only between levels in the buccal canal in both groups. There was no significant difference between the two rotary systems in regards to the volume of dentin removed. Conclusion Our findings showed that ProFile Vortex and Revo-S instruments respected the original root canal anatomy and behaved similarly. ProFile Vortex rotary systems produced with innovative process were concluded to shape the upper maxillary premolar by leading minimal canal transportation, similar to Revo-S, rotary systems produced from traditional process. How to cite this article Al-Sudani D, Almalki M, Al-Shahrani S, Ahlquist M. Geometric Analysis of Maxillary First Premolar Prepared by Two Nickel-Titanium Rotary Instruments. J Contemp Dent Pract 2014;15(2):174-180.

scholarly journals Root canal preparation with reciprocating instruments - A literature review and clinical application

2020 ◽  
Vol 75 (9) ◽  
pp. 493-504
Author(s):  
Christiaan Victor ◽  
Peet J Van der Vyver ◽  
Martin Vorster ◽  
Zunaid I Vally
Keyword(s):  
Root Canal ◽  
Three Dimensional ◽  
File Systems ◽  
Apical Part ◽  
Pulp Tissue ◽  
Root Canals ◽  
Periodontal Tissues ◽  
Endodontic Infection ◽  
Reciprocating Instruments ◽  
Canal Shaping

It is well described that the presence of microbial flora in the pulp space of the tooth, and the inability of the immune system to remove these pathogens, are the major sources of peri-apical and radicular inflam-mation.1 Eradication of these pathogens from the pulp and root canal space by means of cleaning, shaping, disinfecting and complete obturation is necessary to safeguard the health of the periodontal tissues from endodontic infection and subsequent breakdown.2,3 The basic objectives of cleaning and shaping of root canals include: (1) removal of all infected soft and hard tissues; (2) creating space for delivery of disinfectants and medicaments to the apical part of the canal; (3) facilitating three dimensional obturation and (4) preservation of radicular structures.4 Even modern endodontic file systems leave untouched areas on the root canal walls after preparation and show compaction of hard tissue debris.5 This debris consists of pulp tissue remnants, bacteria and dentine chips of which most is found in the apical part of the prepared root canal system.6 Aiming for a centred preparation that corresponds to the original canal anatomy accompanied by the lowest amount of canal transportation, especially in middle and apical parts of curved canals, will result in the most favourable post instrumented canal shape. The four optimal canal shaping objectives are: (1) to have a tapered funnel from orifice to apex, (2) maintenance of original anatomical canal pathway, (3) apical foramen position should remain constant and (4) leaving the apical opening as small as possible.2,7

scholarly journals A comparative study of root canal shaping using protaper universal and protaper next rotary files in preclinical dental education

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7419 ◽  
Author(s):  
Gül Çelik ◽  
Feyza Özdemir Kısacık ◽  
Emir Faruk Yılmaz ◽  
Arife Mersinlioğlu ◽  
İhsan Furkan Ertuğrul ◽  
...  
Keyword(s):  
Root Canal ◽  
Dental Students ◽  
Chi Square ◽  
Significance Level ◽  
Root Canals ◽  
Rotary Instruments ◽  
Working Length ◽  
Chi Square Test ◽  
The Mean ◽  
Canal Shaping

BackgroundDentistry has undergone an evolution in endodontics practice caused by the advancement of rotary techniques for root canal preparation and their subsequent incorporation into the teaching of dentistry undergraduates. This research aimed to evaluate the shaping ability of third-year dental students as their first experience in rotary instrumentation using ProTaper Universal (PTU) and ProTaper Next (PTN) (Dentsply Maillefer) rotary instruments in simulated curved canals.MethodsForty students instrumented 200 simulated canals with a 40° curvature in resin blocks according to the manufacturer’s instructions with PTU and 39 students and 195 canals with PTN files. The canals were prepared at a speed of 300 rpm using a 16:1 reduction hand-piece powered by an electric motor (Xsmart; Dentsply Maillefer). The final apical preparation was set to F2 for the PTU and X2 for the PTN group. The change in canal curvature was evaluated based on Schneider technique using the AutoCAD 2007 software on post-digital photographs. The incidence of instrument fracture and deformation, the incidence of ledge, the change in working length (WL), and the working time were noted. The data were analyzed with Student’st-test and Chi-Square test at a significance level of 0.05 using SPSS.ResultsPTN maintained the original canal curvature better, resulting in fewer fractures and ledges, and shaped the canals faster than the PTU (P < 0.05). The mean curves of the resin canals after the instrumentation for the PTU and PTN groups were 24.03° ± 3.14° and 25.64° ± 2.72°, respectively. Thirty-three (17.4%) PTU and 18 (9.3%) PTN files fractured (p < 0.05). Nine (4.5%) PTU and 2 (2.6%) PTN deformed (p > 0.05). The change in WL after instrumentation was 0.97 mm ± 0.95 mm in PTU and 0.96 mm ± 0.80 mm in PTN (p < 0.05). The mean times were 627 s ± 18 s for PTU and 379 s ± 18 s for PTN (p < 0.000).DiscussionPTN can be recommended in severely curved root canals in terms of maintenance of the original canal curvature, superior instrument fracture and fewer ledges. Even if training before preparation provides an acceptable level of canal shaping for preclinical students, the use of NiTi rotary instruments should be included in the undergraduate dental curriculum, contributing to an increase in the quality of root canal shaping and, consequently, to an improvement of the clinical experience of students.

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