Abstract:
INTRODUCTION:This study examined the dynamic fracture behavior of nickel-titanium rotary instruments in torsional or cyclic loading at continuous or reciprocating rotation by means of high-speed digital video imaging. METHODS:The ProFile instruments (size 30, 0.06 taper; Dentsply Maillefer, Ballaigues, Switzerland) were categorized into 4 groups (n = 7 in each group) as follows: torsional/continuous (TC), torsional/reciprocating (TR), cyclic/continuous (CC), and cyclic/reciprocating (CR). Torsional loading was performed by rotating the instruments by holding the tip with a vise. For cyclic loading, a custom-made device with a 38° curvature was used. Dynamic fracture behavior was observed with a high-speed camera. The time to fracture was recorded, and the fractured surface was examined with scanning electron microscopy. RESULTS:The TC group initially exhibited necking of the file followed by the development of an initial crack line. The TR group demonstrated opening and closing of a crack according to its rotation in the cutting and noncutting directions, respectively. The CC group separated without any detectable signs of deformation. In the CR group, initial crack formation was recognized in 5 of 7 samples. The reciprocating rotation exhibited a longer time to fracture in both torsional and cyclic fatigue testing (P < .05). The scanning electron microscopic images showed a severely deformed surface in the TR group. CONCLUSIONS:The dynamic fracture behavior of NiTi rotary instruments, as visualized with high-speed digital video imaging, varied between the different modes of rotation and different fatigue testing. Reciprocating rotation induced a slower crack propagation and conferred higher fatigue resistance than continuous rotation in both torsional and cyclic loads.
journal_name
J Endodjournal_title
Journal of endodonticsauthors
Tokita D,Ebihara A,Miyara K,Okiji Tdoi
10.1016/j.joen.2017.03.024subject
Has Abstractpub_date
2017-08-01 00:00:00pages
1337-1342issue
8eissn
0099-2399issn
1878-3554pii
S0099-2399(17)30360-6journal_volume
43pub_type
杂志文章abstract:INTRODUCTION:Candida in endodontic infections has been investigated in a large number of studies, but its role as an endodontic pathogen is still debatable. The aim of this study was to systematically review the literature on the prevalence of Candida species in root canal infections. METHODS:Extensive literature rese...
journal_title:Journal of endodontics
pub_type: 杂志文章,meta分析
doi:10.1016/j.joen.2018.07.016
更新日期:2018-11-01 00:00:00
abstract:INTRODUCTION:Recent evidence finds mineral trioxide aggregate (MTA) more effective than calcium hydroxide (CH) for direct pulp capping (DPC). The present study assessed the cost-effectiveness of MTA versus CH for DPC using a model-based simulation approach. METHODS:A mixed public/private payer perspective in the conte...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2015.08.019
更新日期:2015-12-01 00:00:00
abstract:INTRODUCTION:The purpose of this study was to examine the level of erosion in root dentin caused by different irrigation methods and protocols. METHODS:Thirty-five extracted upper molar teeth were instrumented and divided into 7 groups to undergo treatment by different methods: negative control, GentleWave System (Son...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2016.07.024
更新日期:2016-12-01 00:00:00
abstract::This study compared the effectiveness of four different techniques used for obturation of single rooted-teeth: lateral condensation, low-temperature gutta-percha (Ultrafil), vertical condensation of gutta-percha softened by means of three different laser devices (argon, CO2, and Nd:YAG), or composite resin photopolyme...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/S0099-2399(06)81530-X
更新日期:1995-09-01 00:00:00
abstract::This study assessed in vitro the diagnostic ability of cone beam computed tomography (CBCT) scans with different voxel resolutions in the detection of simulated external root resorption (ERR). For that purpose, 59 teeth were viewed through iCAT tomography (Imaging Sciences International, Inc, Hatfield, PA) following t...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2008.11.005
更新日期:2009-02-01 00:00:00
abstract:INTRODUCTION:We aimed to compare the antimicrobial efficacy of chlorhexidine (CHX) and sodium hypochlorite (NaOCl), 2 irrigants routinely used in root canal therapy of permanent teeth. METHODS:Electronic databases, including PubMed, EMBASE, Web of Science, and Cochrane Library, were searched for randomized controlled ...
journal_title:Journal of endodontics
pub_type: 杂志文章,meta分析
doi:10.1016/j.joen.2020.05.002
更新日期:2020-08-01 00:00:00
abstract::Cyanoacrylate is an extremely strong bonding agent which has many applications in medicine. It is also effective in obtaining a leakproof seal of rubber dam around a structurally compromised tooth requiring endodontic therapy. ...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/S0099-2399(06)81356-7
更新日期:1992-10-01 00:00:00
abstract:INTRODUCTION:Stabilizing sodium hypochlorite (NaOCl) at an alkaline pH is proposed to increase solution stability and tissue dissolution ability; however, a reduction on the flexural strength of dentin discs has been found to be a side effect. This study sought to determine whether a stabilized alkaline NaOCl reduces t...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2014.02.028
更新日期:2014-10-01 00:00:00
abstract:INTRODUCTION:This retrospective cohort study aimed to observe the incidence of pulpitis and necrosis in teeth with cracks that were not endodontically treated. METHODS:One hundred eighty-four patients with 199 cracked teeth that were diagnosed with reversible pulpitis and were treated from January 2010 to December 201...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2019.02.003
更新日期:2019-05-01 00:00:00
abstract:INTRODUCTION:Pulp capping materials allow healing of injured pulp with a layer of reparative dentin. Glucose is needed to cure the injured area. Glucose is transported by glucose transporter (Glut) 2 and Glut4, which are transmembrane proteins that act as gatekeepers. We hypothesized that the transport of glucose via G...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2019.10.003
更新日期:2020-01-01 00:00:00
abstract:INTRODUCTION:Bleeding control is an important aspect in endodontic surgery. Two hemostatic techniques were compared with regard to their efficacy to bleeding control in endodontic surgery. METHODS:A randomized, 2-arm, parallel pilot study involving 30 patients with periradicular lesions was performed including the fol...
journal_title:Journal of endodontics
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.joen.2019.04.011
更新日期:2019-08-01 00:00:00
abstract::This study investigated the retreatment effectiveness of .04 Taper nickel-titanium rotary ProFiles. Thirty extracted single-rooted anterior teeth were instrumented and obturated with gutta-percha/Roth's Sealer using lateral condensation. They were distributed into three groups of 10 each. Retreatment for group A was d...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1097/00004770-200002000-00010
更新日期:2000-02-01 00:00:00
abstract:INTRODUCTION:The purpose of this study was to determine factors and clinical situations that influence an endodontist's decision to use guided tissue regeneration (GTR) techniques during endodontic root-end surgery. METHODS:An invitation to participate in a web-based survey was e-mailed to 3,750 members of the America...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2011.08.017
更新日期:2011-11-01 00:00:00
abstract:INTRODUCTION:This study tested whether heat stress (42 degrees C for 30 minutes) induces reactive oxygen species (ROS), proinflammatory cytokines, Nrf2 activation, and Nrf2 target genes such as antioxidant enzymes in human dental pulp (HDP) cells. METHODS:ROS was evaluated by using flow cytometry. Proteins and messeng...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2009.06.005
更新日期:2009-09-01 00:00:00
abstract::The purpose of the study was to evaluate the biocompatibility of two current adhesive resins and a calcium hydroxide cement. Fifty-four polyethylene tubes were filled with these dental materials, which were hand-mixed or light-cured according to the manufacturer's directions: group 1--Clearfill Liner Bond 2 (Kuraray);...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1097/00004770-200009000-00006
更新日期:2000-09-01 00:00:00
abstract:INTRODUCTION:Sphingosine-1-phosphate receptor 1 (S1P1) is crucial for regulation of immunity and bone metabolism. This study aimed to investigate the expression of S1P1 in rat periapical lesions and its relationship with receptor activator of nuclear factor kappa B ligand (RANKL) and regulatory T (Treg) cells. METHODS...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2014.10.010
更新日期:2015-04-01 00:00:00
abstract:INTRODUCTION:The purpose of this study was to evaluate the effect of chitosan-hydroxyapatite precursor (C-HA) nanocomplex conditioning on the chemical modifications at the tricalcium silicate sealer-dentin interface using time-of-flight secondary ion mass spectrometry. METHODS:Dentin slabs from human premolar root den...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2019.08.011
更新日期:2019-12-01 00:00:00
abstract:INTRODUCTION:This clinical study evaluates the effect of ultrasonic root-end preparations on dentinal defect creation and propagation. METHODS:Eighty-four teeth were treated with periapical microsurgery using a modern microsurgical protocol in a private practice setting. The root apices were resected and inspected for...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2016.07.016
更新日期:2016-10-01 00:00:00
abstract:INTRODUCTION:The purpose of this study was to evaluate and compare, clinically and radiographically, the effects of platelet-rich fibrin (PRF) and mineral trioxide aggregate (MTA) as pulpotomy agents in permanent teeth with incomplete root development. METHODS:A total number of 70 children requiring pulpotomy in 70 pe...
journal_title:Journal of endodontics
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.joen.2014.01.009
更新日期:2014-05-01 00:00:00
abstract:INTRODUCTION:Patient preferences should be taken into account by clinicians when treatment planning. The purposes of this study were to describe the number of visits patients preferred when undergoing root canal therapy (RCT) and to assess whether their preferences were related to hypothetical treatment success rates. ...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2012.06.038
更新日期:2012-10-01 00:00:00
abstract::The external cervical root resorption associated with intracoronal bleaching of pulpless teeth can be a devastating lesion. It often cannot be repaired. To prevent this problem, increasing attention has been focused on placing a barrier between the pulp chamber and the endodontic filling material. The objective of thi...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/s0099-2399(06)80822-8
更新日期:1994-06-01 00:00:00
abstract::Taurodontism is a morphoanatomical change in the shape of a tooth, which usually occurs in multirooted teeth. An enlarged body and pulp chamber, as well as apical displacement of the pulpal floor, are characteristic features. Endodontic treatment of a taurodont tooth is challenging, because it requires special care in...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1097/00004770-200305000-00009
更新日期:2003-05-01 00:00:00
abstract:INTRODUCTION:Outcome studies of endodontic treatment of necrotic immature permanent teeth rely on radiographic measures as surrogates of whether the treatment achieved regeneration/revascularization/revitalization. An increase in radiographic root length and/or width is thought to result in a better long-term prognosis...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2013.09.025
更新日期:2014-01-01 00:00:00
abstract:INTRODUCTION:The aim of this study was to evaluate porcine palatal mucosa dissolution by sodium hypochlorite (NaOCl) with or without an auxiliary dissolving agent containing glycocholic acid and a mixture of surfactants (Keratobacter [KB]; Saint Joseph DID, Valencia, Spain). METHODS:One hundred forty samples were obta...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2018.01.007
更新日期:2018-05-01 00:00:00
abstract::The purpose of this study was to compare the in vitro sealing capacity of five materials, each used as a temporary sealing agent for the walking bleach technique. All teeth received traditional biomechanical root canal instrumentation, after which the walking bleach agent was placed in the pulp chamber space. The occl...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1097/00004770-200012000-00011
更新日期:2000-12-01 00:00:00
abstract::The effect of two different root canal cements and removal of the smear layer on the apical seal in roots obturated with Thermafil obturators was tested. Thirty extracted human mandibular first molars with 60 canals (mesial roots) were instrumented with the use of a step-back technique. Teeth were placed into 6 groups...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/S0099-2399(98)80131-3
更新日期:1998-05-01 00:00:00
abstract:INTRODUCTION:This study addressed the following population, intervention, comparator, outcome, timing, study design and setting question: in patients with preoperative pain who undergo single-visit nonsurgical endodontic treatment, what is the comparative efficacy of corticosteroids compared with other analgesics or pl...
journal_title:Journal of endodontics
pub_type: 杂志文章,meta分析
doi:10.1016/j.joen.2018.05.015
更新日期:2018-09-01 00:00:00
abstract::Root canal bacteria in teeth with apical periodontitis were enumerated after extraction and incubation. Canals in 36 teeth were sampled after: S1, incubation for 2 hours (group A), 2 days (group B), 4 days (group C), and 6 days (group D); S2, subsequent incubation for 1 week; S3, canal disinfection; and S4, final incu...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2008.08.038
更新日期:2008-12-01 00:00:00
abstract::Enterococcus faecalis has been suggested to be an important etiological agent in endodontic failures. The purpose of this study was to evaluate the effectiveness of chlorhexidine- or antibiotics-based medications in eliminating E. faecalis biofilms. One-day and three-day biofilms of E. faecalis were induced on cellulo...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1097/00004770-200110000-00004
更新日期:2001-10-01 00:00:00
abstract::Ten extracted human maxillary first molars were selected with a variety of root curvatures. The distofacial roots were resected and the mesiofacial canals were instrumented to a size #25 K file. Three techniques were used to introduce Ca(OH)2 paste into the instrumented canals. These techniques were evaluated for thei...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/s0099-2399(06)81220-3
更新日期:1992-08-01 00:00:00