scholarly journals Analysis of Torque and Force Induced by Rotary Nickel-Titanium Instruments during Root Canal Preparation: A Systematic Review

2021 ◽  
Vol 11 (7) ◽  
pp. 3079
Author(s):  
Myint Thu ◽  
Arata Ebihara ◽  
Sherif Adel ◽  
Takashi Okiji
Keyword(s):  
Root Canal ◽  
Nickel Titanium ◽  
Force Generation ◽  
Independent Effect ◽  
Preparation Technique ◽  
Insertion Depth ◽  
Cross Sectional ◽  
Deep Insertion ◽  
Continuous Rotation

The aim of this review was to provide a detailed literature analysis of torque and force generation during nickel-titanium rotary root canal instrumentation. We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. An electronic search was performed using in PubMed and in journals for articles published in English from 1987 to June 2020 on studies that investigated dynamic torque and force in vivo or in vitro. We assessed article titles and abstracts to remove duplicates, and the titles and abstracts of the remaining articles were screened for eligibility. Full texts were read to verify eligibility by considering predetermined inclusion and exclusion criteria. Fifty-two out of 4096 studies met the inclusion criteria, from which we identified 26 factors that influence torque or force generation. Factors associated with higher torque or force generation and supported by multiple studies with mostly consistent results included convex triangle cross-sectional design, regressive taper, short pitch length, large instrument size, small canal size, single-length preparation technique, long preparation time, deep insertion depth, low rate of insertion, continuous rotation (torque), reciprocating motion (force), lower rotational speed and conventional alloy. However, several factors are interrelated, which obscured the independent effect of each factor, and there was insufficient scientific evidence supporting the influence of some factors.

scholarly journals Evaluation of dentinal defects during root canal preparation using thermomechanically processed nickel-titanium files

2017 ◽  
Vol 11 (02) ◽  
pp. 157-161 ◽  
Author(s):  
Bertan Kesim ◽  
Burak Sagsen ◽  
Tugrul Aslan
Keyword(s):  
Root Canal ◽  
In Vitro Study ◽  
Nickel Titanium ◽  
Rotary Motion ◽  
Control Group ◽  
Continuous Rotation ◽  
Significant Difference ◽  
Group 5 ◽  
Group 2

ABSTRACT Objective: The aim of this study was to compare the incidence of root cracks after root canal instrumentation with thermomechanically processed nickel-titanium (Ni-Ti) files with different instrumentation kinematics. Materials and Methods: A total of 150 extracted mandibular premolars with mature apices and straight root canals were divided into five groups and used in this study. In Group 1, 30 teeth were prepared using hand K-files and assigned to control group, Group 2 was instrumented using K3XF Rotary files (SybronEndo, Glendora, CA, USA) with continuous rotary motion. The teeth in Group 3 were instrumented by ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland) rotary files which make asymmetric rotary motion, In Group 4, teeth were instrumented by RECIPROC (VDW, Munich, Germany) with reciprocation motion and in Group 5, teeth were instrumented by Twisted File (TF) Adaptive (SybronEndo, Orange, CA, USA) files that use combination of continuous rotation and reciprocation motion (n = 30/per group). All the roots were horizontally sectioned 3, 6, and 9 mm from the apex with a low speed saw under water cooling. Then, the slices were examined through a stereomicroscope to determine the presence of dentinal microcracks.Results: For the apical (3-mm) and coronal (9-mm) sections, the ProTaper Next and TF Adaptive produced significantly more cracks than the hand files, RECIPROC, and K3XF (P < 0.05). There was no significant difference between the experimental groups and control group at the 6-mm level (P > 0.05). Conclusions: Within the limitations of this in vitro study, all thermal-treated Ni-Ti instruments and hand files caused microcracks in root canal dentin.

scholarly journals Identification of Novel Bacteriophages with Therapeutic Potential That TargetEnterococcus faecalis

2019 ◽  
Vol 87 (11) ◽  
Author(s):  
M. Al-Zubidi ◽  
M. Widziolek ◽  
E. K. Court ◽  
A. F. Gains ◽  
R. E. Smith ◽  
...  
Keyword(s):  
Host Range ◽  
Root Canal ◽  
Therapeutic Potential ◽  
Opportunistic Pathogen ◽  
Cross Sectional ◽  
Antibiotic Resistant ◽  
Content Type ◽  
Endodontic Infection ◽  
Tail Protein

ABSTRACTThe Gram-positive opportunistic pathogenEnterococcus faecalisis frequently responsible for nosocomial infections in humans and represents one of the most common bacteria isolated from recalcitrant endodontic (root canal) infections.E. faecalisis intrinsically resistant to several antibiotics routinely used in clinical settings (such as cephalosporins and aminoglycosides) and can acquire resistance to vancomycin (vancomycin-resistant enterococci). The resistance ofE. faecalisto several classes of antibiotics and its capacity to form biofilms cause serious therapeutic problems. Here, we report the isolation of several bacteriophages that targetE. faecalisstrains isolated from the oral cavity of patients suffering root canal infections. All phages isolated wereSiphoviridaewith similar tail lengths (200 to 250 nm) and icosahedral heads. The genome sequences of three isolated phages were highly conserved with the exception of predicted tail protein genes that diverge in sequence, potentially reflecting the host range. The properties of the phage with the broadest host range (SHEF2) were further characterized. We show that this phage requires interaction with components of the major and variant region enterococcal polysaccharide antigen to engage in lytic infection. Finally, we explored the therapeutic potential of this phage and show that it can eradicateE. faecalisbiofilms formedin vitroon a standard polystyrene surface but also on a cross-sectional tooth slice model of endodontic infection. We also show that SHEF2 cleared a lethal infection of zebrafish when applied in the circulation. We therefore propose that the phage described here could be used to treat a broad range of antibiotic-resistantE. faecalisinfections.

scholarly journals Effectiveness of hand and Mtwo™ instruments in preparing oval-shaped root canals: in vitro study

2016 ◽  
Vol 21 (2) ◽  
Author(s):  
Fernanda Diederichs Coutinho ◽  
Renata Dornelles Morgental ◽  
Simone Bonato Luisi ◽  
Fabiana Vieira Vier-Pelisser ◽  
Patricia Maria Poli Kopper
Keyword(s):  
Root Canal ◽  
In Vitro Study ◽  
Root Apex ◽  
Conventional Technique ◽  
Basic Sequence ◽  
Preparation Technique ◽  
Root Canals ◽  
Canal Area ◽  
Significant Difference

Objective: This study evaluated through stereomicroscopy the effectiveness of hand and rotary instrumentation techniques, either isolated or combined, in the preparation of oval-shaped root canals. Materials and method: Thirty single-rooted human mandibular incisors were selected. After endodontic access and coronal preflaring, teeth were mounted in a modified Bramante muffle and then sectioned transversely at 3 and 6 mm from the root apex. Images of each section were made under a stereomicroscope at 30× magnification. Teeth were reassembled in the muffle and divided into three groups (n=10) according to the root canal preparation technique: GI - rotary preparation with Mtwo™ basic sequence (10/.04; 15/.05; 20/.06; 25/.06), followed by Mtwo™ complementary instruments (30/.05; 35/.04; 40/.04); GII - rotary preparation with Mtwo™ basic sequence, complemented by hand instruments (#30, #35 and #40); GIII - hand instrumentation using the conventional technique (#10 to #40). All instruments were used in brushing motion. The muffles were separated again so that new images of each section could be obtained. The following parameters were evaluated in pre- and postoperative images: root canal area; perimeter; mesiodistal (MD) and buccolingual (BL) diameters; and mesial (M) and distal (D) wall thickness. Next, the values measured in post- and preoperative images were subtracted forcomparison of experimental groups. Data were analyzed using the Kruskal-Wallis test (α=0.05). Results: No significant difference between groups was observed for all parameters. Conclusion: There was no difference among hand, rotary, or combined instrumentation; all techniques were able to increase root canal area, perimeter, and diameter in MD and BL directions. Moreover, the amount of dentin wearon proximal root canal walls was similar for all tested groups.

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 Enhanced root canal-centering ability and reduced screw-in force generation of reciprocating nickel-titanium instruments with a post-machining thermal treatment

2020 ◽  
Vol 39 (2) ◽  
pp. 251-255 ◽  
Author(s):  
Keiichiro MAKI ◽  
Arata EBIHARA ◽  
Shunsuke KIMURA ◽  
Miki NISHIJO ◽  
Daisuke TOKITA ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Root Canal ◽  
Nickel Titanium ◽  
Force Generation

scholarly journals In Vivo and In Vitro Effectiveness of Rotary Nickel-Titanium vs Manual Stainless Steel Instruments for Root Canal Therapy: Systematic Review and Meta-analysis

2018 ◽  
Vol 18 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Massimo Del Fabbro ◽  
Kelvin Ian Afrashtehfar ◽  
Stefano Corbella ◽  
Ahmed El-Kabbaney ◽  
Isabella Perondi ◽  
...  
Keyword(s):  
Systematic Review ◽  
Stainless Steel ◽  
Root Canal ◽  
Meta Analysis ◽  
Nickel Titanium ◽  
Root Canal Therapy

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 A Novel Root Canal Preparation Technique Hybridizing Heat-treated Nickel-Titanium Rotary Instruments

2021 ◽  
Vol 12 (3) ◽  
pp. 258-262
Author(s):  
Shilpa Bhandi ◽  
Gianluca Gambarini ◽  
Marco Seracchiani ◽  
Luca Testarelli ◽  
Dario Di Nardo ◽  
...  
Keyword(s):  
Root Canal ◽  
Nickel Titanium ◽  
Preparation Technique ◽  
Root Canal Preparation ◽  
Heat Treated ◽  
Rotary Instruments

scholarly journals Evaluation of Apical Transportation by Three Rotary Systems in Extracted Teeth with Curved Canals

2018 ◽  
pp. 85-94
Author(s):  
Ana Laura Ortiz-Rocha DDS, MS ◽  
Claudia Dávila-Pérez DDS, PhD ◽  
Marlen Vitales-Noyola MS, PhD ◽  
Verónica Méndez-González DDS, MS ◽  
Ana María González-Amaro MS ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Nickel Titanium ◽  
Preparation Technique ◽  
X Ray ◽  
Root Canals ◽  
Working Length ◽  
Apical Transportation ◽  
Post Hoc

The aim of this study was to compare the apical transportation in extracted teeth using three different rotary nickel-titanium systems (Mtwo, Hyflex CM, and Typhoon). Sixty extracted first molars were randomly divided into three groups (n=20 in each group) with similar root canal curvatures (25-52 degrees). All root canals were prepared to size 30 using a crown-down preparation technique for each rotary system. Loss of working length and apical transportation were determined by X-ray evaluation. Comparisons between the groups were performed using one-way analysis of variance (ANOVA) or Kruskal-Wallis tests, and the post hoc analyses employed were Dunn´s or Tukey´s multiple comparison tests. No significant differences were detected between the different rotary systems in the loss of working length and apical transportation. This in vitro study showed that the use of these three rotary systems are safe and useful for instrumentation in curved canals; however, further in vivo research is essential to compare the effectiveness and safety of these systems for use in curved canals.

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