Abstract:
INTRODUCTION:This finite element analysis study was aimed at evaluating the effects of rotary systems on stresses in photopolymerized resin root models with oval-shaped canals. METHODS:Among the data collected by computed tomographic imaging, a mandibular second premolar tooth with an oval-shaped canal was selected, recorded as Digital Imaging and Communications in Medicine, and transferred to Materialise's Interactive Medical Image Control System software. Three-dimensional modeling was performed to produce photopolymerized resin root models. Root canals were prepared by OneShape (OS; MicroMega, Besancon, France); ProTaper Universal (PTU; Dentsply Tulsa Dental, Tulsa, OK); WaveOne (WO, Dentsply Maillefer, Ballaigues, Switzerland); Mtwo (MT; VDW, Munich, Germany); Twisted File (TF; Kerr Dental, Orange, CA); ProTaper Next (PTN, Dentsply Tulsa Dental), and hand files (HFs) (control). The models were scanned (micro-computed tomographic imaging; SkyScan 1174; Kontich, Belgium), finite element analysis models were created, and stresses were calculated under 300-N loading (at a 45° angle and vertically). RESULTS:The maximum stress values were found to be higher when the roots were loaded at an angle. The range of the stress values was PTU > MT > WO > HF > PTN > OS > TF. The stresses were forwarded toward the apical area in the PTN, OS, and TF models. When loaded vertically, the highest maximum stress values were recorded in the WO model. High stress concentrations were observed at coronal, thus less stress was forwarded toward the apical, giving an advantage to the root. The range of the others was as follows: PTN ≥ PTU > MT > TF > OS ≥ HF. The TF model showed lower maximum stress values, whereas the HF model showed more homogenous stress distribution. CONCLUSIONS:Considering the stress distributions and stress values within the models, it can be concluded that oval-shaped canals prepared by HFs and WO were less likely to result in root fracture.
journal_name
J Endodjournal_title
Journal of endodonticsauthors
Eken R,Sen OG,Eskitascioglu G,Belli Sdoi
10.1016/j.joen.2016.05.007subject
Has Abstractpub_date
2016-08-01 00:00:00pages
1273-8issue
8eissn
0099-2399issn
1878-3554pii
S0099-2399(16)30251-5journal_volume
42pub_type
杂志文章abstract::The purpose of this in vitro study was to evaluate the accuracy of Root ZX apex locator to determine the working length in teeth with simulated apical root resorption. Fifty extracted, single-rooted, human teeth with mature apices were used in this study. An irregular cavity defect was drilled at the apex of each toot...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1097/00004770-200206000-00011
更新日期:2002-06-01 00:00:00
abstract:INTRODUCTION:Real-time assessment of the microbial status of the root canal system would be useful in clinical endodontic practice for determining endpoints of biomechanical treatment. This laboratory study used an existing laser fluorescence device, the DIAGNOdent (KaVo, Biberach, Germany), in a proof-of-concept study...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2009.07.006
更新日期:2009-10-01 00:00:00
abstract::The aims of this study were to identify microorganisms on the surface of gutta-percha (GP) cones using a polymerase chain reaction (PCR) and to evaluate the sterilization effect of 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and ChloraPrep on these bacteria. Alterations of the surface texture and physic...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2007.01.019
更新日期:2007-05-01 00:00:00
abstract:INTRODUCTION:This article reports on the feasibility of conducting a large-scale endodontic prospective cohort study in The National Dental Practice-Based Research Network. This study was designed to measure pain and burden associated with initial orthograde root canal therapy (RCT) and to explore potential prognostic ...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2012.08.002
更新日期:2012-11-01 00:00:00
abstract::The purpose of this study was to compare three engine driven (nickel-titanium) NiTi instrument systems with hand files for their effect on canal transportation. Mesial roots of mature lower first molars with separate canals were paired on the basis of curvature and morphology. Canal lengths were standardized to 11 mm ...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/S0099-2399(97)80310-X
更新日期:1997-08-01 00:00:00
abstract:INTRODUCTION:The improvement of regenerative endodontic procedures requires an understanding of the key clinical questions combined with a fundamental biological knowledge of how the dental tissues behave during health, disease, and repair. Therefore, partnerships between clinicians and basic scientists are essential t...
journal_title:Journal of endodontics
pub_type: 杂志文章,评审
doi:10.1016/j.joen.2020.06.019
更新日期:2020-09-01 00:00:00
abstract::No information could be found in the dental literature on the hardness or strength of the materials in root canal instruments. Hardness testing is a convenient method for examining these products, and strength properties can be deduced from available strength-hardness data. The Vickers hardness of cross-sections of st...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/S0099-2399(96)80274-3
更新日期:1996-02-01 00:00:00
abstract::Terrein is a bioactive fungal metabolite whose anti-inflammatory properties are virtually unknown. The purpose of this study was to determine the effects of terrein on lipopolysaccharide (LPS)-induced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in human denta...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2008.01.015
更新日期:2008-04-01 00:00:00
abstract:INTRODUCTION:This study evaluated the influence of glide path on canal curvature and axis modification after instrumentation with WaveOne Primary reciprocating files. METHODS:Thirty ISO 15, 0.02 taper Endo Training Blocks were used. In group 1, glide path was created with PathFile 1, 2, and 3 at working length, wherea...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2011.09.030
更新日期:2012-01-01 00:00:00
abstract:INTRODUCTION:Previous studies have suggested that masticatory forces are associated with cracked teeth, but it is not clear which specific poor oral masticatory habits may be more likely to cause cracks. The aim of this study was to quantitatively assess risk factors for cracked teeth among poor oral masticatory habits...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2017.01.007
更新日期:2017-06-01 00:00:00
abstract::A molar-incisor malformation (MIM) is a newly reported type of dental anomaly that involves a characteristic root malformation in permanent first molars and deciduous second molars and a crown defect in permanent central incisors. This case report describes a nonsurgical root canal treatment of a MIM-affected molar by...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2015.11.004
更新日期:2016-04-01 00:00:00
abstract:INTRODUCTION:Clinicians commonly mix mineral trioxide aggregate (MTA) to a desired consistency rather than use the recommended amounts of powder and water. The purpose of this in vitro study was to evaluate how varying the water-to-powder (WP) ratio affects the setting expansion of white MTA (WMTA) and gray MTA (GMTA)....
journal_title:Journal of endodontics
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.joen.2010.03.010
更新日期:2010-08-01 00:00:00
abstract::Apical periodontitis and its concomitant periapical osteolysis is caused by pulpal infection, and bacterial lipopolysaccharide (LPS) is known to play a major role in the bone resorption process. Little is known concerning the effect of root canal intervisit dressings on residual LPS in root canals after bacterial cell...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/S0099-2399(06)81199-4
更新日期:1993-02-01 00:00:00
abstract::Retrograde (or apical/periapical) peri-implantitis (RPI) presents with radiographic signs of bone loss at the periapical area of endosteal implants and may also present with clinical signs of abscess formation or a sinus tract traceable to the implant periapex. The lesion may form days up to several years after the in...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2019.01.002
更新日期:2019-05-01 00:00:00
abstract:INTRODUCTION:The aim of the present study was to compare the immunoexpression of CD34, intercellular adhesion molecule-1 (ICAM-1), and podoplanin and the presence of mast cells with clinical, demographic, radiologic, and histologic features from periapical granulomas, periapical cysts, and residual cysts. METHODS:Thir...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2018.04.013
更新日期:2018-07-01 00:00:00
abstract:INTRODUCTION:This in vitro study compared cone-beam computed tomography (CBCT) exam with different voxel sizes with digital periapical radiography in the detection of vertical root fractures in teeth with and without intracanal metallic posts. METHODS:Eighteen single-rooted human teeth were endodontically treated, pre...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2013.08.031
更新日期:2013-12-01 00:00:00
abstract:INTRODUCTION:The treatment of immature necrotic permanent teeth presents several clinical challenges in endodontics. Regenerative endodontic procedures (REPs) permit root development, increased canal wall thickness, and apical closure. This longitudinal cohort study aimed to evaluate the long-term clinical and radiogra...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2016.10.035
更新日期:2017-03-01 00:00:00
abstract::The aim of the present study was to evaluate the in vivo antimicrobial activity of 2% chlorhexidine gluconate (FCFRP-USP) used as a root canal irrigating solution in teeth with pulp necrosis and radiographically visible chronic periapical reactions. Culture techniques and measurement of the inhibition zone were used. ...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/s0099-2399(99)80135-6
更新日期:1999-03-01 00:00:00
abstract:INTRODUCTION:This in vitro study compared the performance of the XP-endo Shaper (XP; FKG, La Chaux-de-Fonds, Switzerland) in curved canals when used with a higher speed (3000 rpm) without a glide path with the manufacturer's protocol. METHODS:Twenty extracted mandibular molars with separate mesial curved canals were m...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2019.10.014
更新日期:2020-01-01 00:00:00
abstract::This study attempts to evaluate the oral manifestations of and the limited available dental pulp information on diabetes mellitus, a common metabolic disorder of carbohydrate and lipid metabolism affecting over 16 million Americans. Diabetics are particularly prone to bacterial or opportunistic infections. This vulner...
journal_title:Journal of endodontics
pub_type: 杂志文章,评审
doi:10.1097/00004770-200306000-00001
更新日期:2003-06-01 00:00:00
abstract::Previous studies have indicated that vertical root fracture tends to occur in a buccolingual direction, where dentin thickness is greatest. Factors potentially influencing the location and direction of root fracture include root canal shape, external root morphology, and dentin thickness. In this finite-element study,...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1097/00004770-200308000-00008
更新日期:2003-08-01 00:00:00
abstract:INTRODUCTION:The purpose of this study was to investigate if nickel-titanium instruments with similar designs manufactured by different thermal treatments would exhibit significantly different in vitro behavior. METHODS:Thirty-six instruments each of ProTaper Universal (PTU F1; Dentsply Maillefer, Ballaigues, Switzerl...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2014.06.005
更新日期:2015-01-01 00:00:00
abstract::This study investigated the possibility of saliva recontamination occurring between the root canal wall and sealer through dentinal tubules exposed after the cementum was removed at the cervical level by root planing and treatment with citric acid. Thirty-four extracted human maxillary anterior teeth were randomly pla...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/S0099-2399(96)80024-0
更新日期:1996-11-01 00:00:00
abstract::This in vitro study compared the accuracy of file length measurements made on calibrated and uncalibrated direct digital images. Endodontic files of known lengths and ISO sizes were used in 10 single-rooted, relatively straight teeth within cadaver specimens. The crowns of the teeth were ground flat and an orthodontic...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1097/00004770-200112000-00017
更新日期:2001-12-01 00:00:00
abstract::The purposes of this study were to determine quantitatively the amount of debris and irrigant forced in an apical direction, the frequency of apical plug development, and the time required to prepare canals when a step-back technique using K-files was compared with the .04 Taper system. Sixty-nine extracted teeth with...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/S0099-2399(98)80206-9
更新日期:1998-01-01 00:00:00
abstract:INTRODUCTION:This retrospective study aimed to analyze the effect of repairing endodontic access cavities with composite on the survival of single crowns and retainer restorations of fixed or removable dental prostheses. METHODS:Dental records of patients attending a university dental clinic were retrospectively scree...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2019.11.012
更新日期:2020-03-01 00:00:00
abstract:INTRODUCTION:This 2-part study hypothesized that a bioactive scaffold containing a sustained transforming growth factor (TGF)-β1-releasing nanoparticle system will promote migration and enhance differentiation of stem cells from the apical papilla (SCAP). The study aimed to develop and characterize a novel modified chi...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2016.06.017
更新日期:2016-09-01 00:00:00
abstract::Dentin permeability and hypersensitivity are both reduced when the dentinal tubules are occluded. Previous scanning electron microscopic studies showed that Nd:YAG laser could cause melting of dentin and closure of exposed dentinal tubules without dentin surface cracking. Therefore, the aim of the present study was to...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/S0099-2399(97)80403-7
更新日期:1997-11-01 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::This case series reports the outcomes of 8 patients (ages 9-14 years) who presented with 9 immature permanent teeth with pulpal necrosis and apical periodontitis. During treatment, 5 of the teeth were found to have at least some residual vital tissue remaining in the root canal systems. After NaOCl irrigation and medi...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2008.03.023
更新日期:2008-07-01 00:00:00