Abstract：
INTRODUCTION:The purpose of this study was to evaluate the effect of various degrees of cyclic fatigue on torsional failure and torsional preloading on the cyclic fatigue life of heat-treated K3XF nickel-titanium (NiTi) instruments (SybronEndo, Orange, CA). METHODS:The mean number of cycles until failure (Nf) of K3XF and K3 NiTi instruments was examined in a 3-point bending apparatus with a 7-mm radius and 45° curve. Torque and distortion angles at failure of new instruments and instruments stressed to 25%, 50%, and 75% of the Nf were measured according to ISO 3630-1. Other new files were preloaded at 25%, 50%, and 75% of the mean distortion angles before the fatigue test. After torsional preloading, the Nf was examined. The fracture surface of each fragment was examined with a scanning electron microscope. RESULTS:The fatigue resistance of K3XF instruments was 2 times higher than that of K3 instruments (P < .05). The torque and angle of rotation at fracture of K3XF instruments were similar to those of K3 instruments. The 25%, 50%, and 75% torsional preloading significantly lowered the Nf of both K3 and K3XF instruments (P < .05). In the fatigue prestressed groups, K3 instruments with 75% preloading had significantly lower torque and distortion angles than unused K3 instruments (P < .05). The fractographic patterns corresponded to the pattern defined by the last stage test. CONCLUSIONS:A low amount of torsional preloading reduced the fatigue resistance of K3 and K3XF instruments. A high amount of precycling fatigue significantly reduced the torsional resistance of K3 instruments. The torsional resistance of K3XF instruments was less affected by previous load cycling even after extensive precycling.
journal_name
J Endodjournal_title
Journal of endodonticsauthors
Shen Y,Riyahi AM,Campbell L,Zhou H,Du T,Wang Z,Qian W,Haapasalo Mdoi
10.1016/j.joen.2014.10.008subject
Has Abstractpub_date
2015-04-01 00:00:00pages
526-30issue
4eissn
0099-2399issn
1878-3554pii
S0099-2399(14)00966-2journal_volume
41pub_type
杂志文章abstract：:This study evaluated the ability of ultrasonics and calcium hydroxide to remove pulp tissue debris from the mesial root canals of human mandibular molars. All teeth were instrumented using a standard filing technique and irrigated with an equal volume of 2.6% sodium hypochlorite before the application of the experimen...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/s0099-2399(89)80076-7
更新日期：1989-08-01 00:00:00
abstract：:The state of contamination by methicillin-resistant Staphylococci, including methicillin-resistant Staphylococcus aureus (MRSA) at the conservative dentistry section of the School of Dentistry, Aichi-Gakuin University, was investigated. Methicillin-resistant coagulase-negative Staphylococci (MRCNS) were detected in 8 ...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/S0099-2399(06)80552-2
更新日期：1995-01-01 00:00:00
abstract：:A descriptive, cross sectional survey was developed to determine the preferences of endodontists when prescribing analgesics. Eleven clinical scenarios describing common endodontic diagnoses or procedures with specified severity of pain were provided. A survey was sent to 310 AAE members and 63 responded, providing a ...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/j.joen.2006.07.015
更新日期：2006-12-01 00:00:00
abstract：:An in vitro, flow-through optical system was designed to measure hemoglobin (Hb) concentrations in the pulp space. The system included light-emitting diodes and a silicon photodetector positioned on opposing surfaces of human teeth. A syringe pump allowed a controlled flow of blood through the pulp chamber. The Hb con...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/S0099-2399(96)80230-5
更新日期：1996-01-01 00:00:00
abstract：:Adsorption of some paraformaldehyde was noted in a previous study evaluating its sterilizing effect on gutta-percha (GP). This study examined histologically the effect of this adsorption when formaldehyde-exposed GP was implanted into the subcutaneous connective tissue of rats. GP implants were prepared in cylinder sh...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/S0099-2399(06)81372-5
更新日期：1992-02-01 00:00:00
abstract：:The aim of this study was to evaluate and compare the quantitative and qualitative inflammatory responses and bone formation potential after implantation of polyethylene tubes filled with a new calcium hydroxide containing sealer (MBPc) and ProRoot mineral trioxide aggregate (MTA). There were 48 Wistar rats divided in...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/j.joen.2005.07.007
更新日期：2006-06-01 00:00:00
abstract：:A method of using osseointegrated implants as an alternative treatment modality for transverse root fractures near the osseous crest is presented. A 15-mm Branemark implant was placed immediately after extraction of a maxillary central incisor with transverse root fracture. Five months after stage I surgery, the impla...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/S0099-2399(98)80096-4
更新日期：1998-02-01 00:00:00
abstract：INTRODUCTION:The outcome of periapical surgery has been directly improved with the introduction of novel material formulations. The aim of the study was to compare the retrograde obturation quality of the following materials: calcium silicate (Biodentine; Septodont, Saint-Maur-des-Fosses, France), mineral trioxide aggr...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/j.joen.2017.09.022
更新日期：2018-05-01 00:00:00
abstract：INTRODUCTION:Apical root resection is a biologically essential component in endodontic microsurgery. However, because it reduces the total root length and supported root surface, it changes the biomechanical response of the tooth. The purpose of this study was to analyze the biomechanical effect of apical root resectio...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/j.joen.2014.03.006
更新日期：2014-09-01 00:00:00
abstract：INTRODUCTION:The morphogenic complexities of dens invaginatus (DI) Oehlers type 3 in maxillary canines offer significant endodontic challenges. METHODS:A case report is provided of a 14-year-old female patient who presented with an anomalous-looking permanent maxillary canine associated with a sinus tract. Pulp testin...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/j.joen.2014.06.008
更新日期：2014-10-01 00:00:00
abstract：INTRODUCTION:The aim of this study was to investigate the influence of apical filling material and the modification made to the apical preparation design in surgical endodontics on the areas of stress concentration in the mesial root of a mandibular molar using finite element analysis. METHODS:The filling material was...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/j.joen.2019.12.007
更新日期：2020-04-01 00:00:00
abstract：:The sealing properties of three temporary restorative materials, Cavit, IRM, and a polycarboxylate-based cement, Ultratemp Firm, were investigated in vitro. Standardized access cavities were prepared in 45, intact, extracted, human molars. The teeth were randomly assigned to three groups and the access openings filled...
journal_title：Journal of endodontics
pub_type： 临床试验,杂志文章,随机对照试验
doi：10.1097/01.don.0000121610.63000.f2
更新日期：2004-08-01 00:00:00
abstract：:A laboratory study was performed on Gates Glidden and Peeso drills to determine the bending characteristics and related metallurgical properties. Sizes #1 to #6 stainless steel Gates Glidden drills, sizes #1 to #6 stainless steel and carbon steel type P Peeso drills, and sizes #009 to #023 carbon steel-type B-1 Peeso ...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/S0099-2399(06)80530-3
更新日期：1993-09-01 00:00:00
abstract：:The purpose of this study was to compare clinical, radiographic, and histopathologic effects of Nd:YAG laser pulpotomy to formocresol pulpotomy on human primary teeth. Patients with at least two vital primary molar teeth that required pulpotomy, because of pulpal exposure to caries, were selected for this study. After...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/j.joen.2006.12.013
更新日期：2007-04-01 00:00:00
abstract：:The purpose of this study was to examine the effect of the smear layer on apical microleakage over 16 wk. One hundred and four extracted human teeth were assigned to four groups treated as follows: group A1--smear layer was left intact and canals were obturated with gutta-percha and Roth 811; group A2--smear layer was...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/S0099-2399(99)80010-7
更新日期：1999-02-01 00:00:00
abstract：:The purpose of treating furcal perforation is to seal the artificial communication between the endodontic space and the periradicular tissue to prevent alveolar bone resorption and damage to the periodontal ligament. These complications are not infrequent in cases of furcal and/or old perforations, which show a worse ...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/j.joen.2008.05.019
更新日期：2008-09-01 00:00:00
abstract：:The structure of mechanically instrumented intraradicular dentin after irrigation with NaOCl as the initial rinse and BioPure MTAD as the final rinse were examined from the coronal, middle, and apical parts of root canal walls using transmission electron microscopy. Sterile distilled water and EDTA as final rinses wer...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/j.joen.2005.10.035
更新日期：2006-03-01 00:00:00
abstract：INTRODUCTION:The objectives of this review were to assess the methodological quality of published meta-analyses related to endodontics using the assessment of multiple systematic reviews (AMSTAR) tool and to provide a follow-up to previously published reviews. METHODS:Three electronic databases were searched for eligi...
journal_title：Journal of endodontics
pub_type： 杂志文章,评审
doi：10.1016/j.joen.2017.07.019
更新日期：2018-01-01 00:00:00
abstract：INTRODUCTION:Apical extrusion of irrigants and debris is an inherent limitation associated with cleaning and shaping of root canals and has been studied extensively because of its clinical relevance as a cause of flare-ups. Many factors affect the amount of extruded intracanal materials. The purpose of this study was t...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/j.joen.2015.09.002
更新日期：2015-12-01 00:00:00
abstract：INTRODUCTION:Different microbial communities have been associated with acute endodontic infections. The majority of the microorganisms are as yet uncultivable or difficult to grow under current laboratory conditions. Treponema species are strict anaerobic bacteria that are involved in several oral diseases. The aim of ...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/j.joen.2010.08.008
更新日期：2010-11-01 00:00:00
abstract：:The aim of this in vivo study was to find a way to conduct qualitative and quantitative evaluations of radicular apical third apposition in rats. Twenty rats were injected intraperitoneally with tetracycline at weight-adjusted doses. Mesio-distal sections of the first mandibular molar regions were prepared. The 60 to ...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/S0099-2399(99)80153-8
更新日期：1999-04-01 00:00:00
abstract：:The putative hazardous nature of chloroform and xylene implies that safer substitutes should be considered. Standard cylindrical gutta-percha samples were immersed in Hemo-De, a xylene substitute, for 60 s at 37 degrees C. Weight loss of a sample, after drying, was used as a measure of its solubility. Master and acces...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1097/00004770-200007000-00001
更新日期：2000-07-01 00:00:00
abstract：INTRODUCTION:The aim of this study was to investigate the release of growth factors into root canal space after the irrigation procedure of regenerative endodontic procedure. METHODS:Sixty standardized root segments were prepared from extracted single-root teeth. Nail varnish was applied to all surfaces except the roo...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/j.joen.2016.04.029
更新日期：2016-12-01 00:00:00
abstract：:The most striking disadvantage of most apex locators is that if there are electrolytes in the canal the meter shows a reading which is too short or sometimes the measurement itself becomes impossible. To overcome this drawback, a new concept for electrically measuring the root canal length has been developed. The devi...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/S0099-2399(06)80053-1
更新日期：1994-03-01 00:00:00
abstract：INTRODUCTION:The purpose of this study was to analyze the features of lesions obtained from biopsies at the periapical area of teeth with a radiographic or clinical initial diagnosis of apical periodontitis. METHODS:A retrospective study was conducted on biopsies obtained from 1953-2018 at 3 Brazilian oral and maxillo...
journal_title：Journal of endodontics
pub_type： 杂志文章,多中心研究
doi：10.1016/j.joen.2020.01.003
更新日期：2020-04-01 00:00:00
abstract：:When dentin is planed by endodontic instruments, a smear layer forms. Whether this layer should be removed is unknown and controversial. This study was conducted to assess the effect of the smear layer on retention of bacteria using an in vitro root canal bacterial colonization model. Canals of 26 extracted human cani...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/S0099-2399(06)81186-6
更新日期：1994-02-01 00:00:00
abstract：:This study evaluated the effect of three post surface treatments on quartz-fiber post (a) retention and (b) morphology. A control group was not treated. Different treatments were performed for the other posts: silanization; etching by hydrofluoric acid 9.5%; sandblasting with 50 microm Al2O3. Two specimens of each gro...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/j.joen.2006.10.015
更新日期：2007-03-01 00:00:00
abstract：INTRODUCTION:Experimental studies show that dental pulp cells respond unfavorably to contact with resin composite restorative material. Hypothetically, in a random population, the frequency of apical periodontitis should be higher for teeth restored with resin composite than with amalgam. Therefore, the aim was to comp...
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/j.joen.2014.05.002
更新日期：2014-09-01 00:00:00
abstract：:It is a general belief that large cyst-like periapical lesions and apical true cysts caused by root canal infection are less likely to heal after nonsurgical root canal therapy. Nevertheless, there is no direct evidence to support this assumption. A large cyst-like periapical lesion or an apical true cyst is formed wi...
journal_title：Journal of endodontics
pub_type： 杂志文章,评审
doi：10.1016/j.joen.2009.02.012
更新日期：2009-05-01 00:00:00
abstract：:Patients with odontogenic cutaneous sinus tracts usually seek treatment from a physician instead of a dentist and the etiology is frequently misdiagnosed. This case report describes a patient who sought treatment from a dentist because of a history of a previous cutaneous swelling on the ipsilateral side of his cheek....
journal_title：Journal of endodontics
pub_type： 杂志文章
doi：10.1016/s0099-2399(06)80959-3
更新日期：1992-06-01 00:00:00
