Abstract:
INTRODUCTION:The purpose of this study was to evaluate the tooth structure theoretically required to be removed in the coronal and cervical regions to accomplish 3 different endodontic access preparations in a novel digital model. The deviation of the center of access cavity from the central fossa will also be measured and compared among the 3 endodontic cavity designs, which in turn may serve as suggested points of entry for different access openings. METHODS:Twenty-one maxillary molars and 15 mandibular molars were selected and 3-dimensionally imaged with cone-beam computed tomographic imaging. Three-dimensional (3D) volume reconstructions were made and converted into stereolithography files. Digital access cavity preparation was performed on each 3D reconstruction model with the 3 most commonly used endodontic access preparations: minimally invasive (MI), modified straight-line (MS), and traditional straight-line (TS) techniques. After the access cavity outlines were determined, digital sectioning of each reconstructed 3D tooth model was performed orthogonal to the long axis of the tooth at 3 levels: (1) passing through the central fossa, (2) 1.5 mm apical to the central fossa, and (3) 2 mm apical to the cementoenamel junction. The linear distance from the centroid of the access opening to the central fossa was measured to calculate the point of entry, and the amount of tooth structure removal at the pericervical area was measured to calculate the theoretically minimum amount of linear dentin removal required. Two-way repeated measures analysis of variance was performed for the interactions between different access designs and the amount of cervical dentin removal. Other data were statistically analyzed with 1-way repeated measures analysis of variance. The Tukey post hoc test was used for multiple comparisons. Significance was set at .05. RESULTS:The amount of deviation of the center of the access cavity from the central fossa in all test groups was less than 1 mm. The dimensions of access openings differed significantly among the 3 access forms (TS > MS > MI, P < .0001). The amount of required cervical dentin removal was the greatest in the TS method followed by the MS and MI methods (P < .0001). CONCLUSIONS:The central fossa could serve as good starting points in all access preparations in both maxillary and mandibular molars. Dentin removal in the coronal and cervical regions was the greatest in the TS design followed by the MS and MI designs. When comparing different canals in the same access form, less cervical dentin was sacrificed in the palatal canals of maxillary molars and the distal canals of mandibular molars.
journal_name
J Endodjournal_title
Journal of endodonticsauthors
Lin CY,Lin D,He WHdoi
10.1016/j.joen.2020.01.002subject
Has Abstractpub_date
2020-04-01 00:00:00pages
524-530issue
4eissn
0099-2399issn
1878-3554pii
S0099-2399(20)30003-0journal_volume
46pub_type
杂志文章abstract::Vascular casts of cat premolar pulps in various stages of growth were made by injection of low-viscosity resin into the pulpal blood vessels. Examination under a scanning electron microscope revealed that, in the young pulp, the main arterioles ascend in the center of the pulp and venules run along the side of the roo...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/s0099-2399(89)80028-7
更新日期:1989-10-01 00:00:00
abstract::We immunohistologically examined the prevalence and localization of bacteria invading dentinal tubules of the roots of teeth with infected canals. Forty extracted teeth with apical lesions were selected and divided into two groups: a group of untreated teeth and a group of canal-enlarged teeth. The bacteria in the spe...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1097/00004770-200303000-00008
更新日期:2003-03-01 00:00:00
abstract:INTRODUCTION:This study aimed to evaluate the frequency of dentinal microcracks observed after root canal preparation with 2 reciprocating and a conventional full-sequence rotary system using micro-computed tomographic analysis. METHODS:Thirty mesial roots of mandibular molars presenting a type II Vertucci canal confi...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2014.02.019
更新日期:2014-09-01 00:00:00
abstract::Three randomly assigned groups of single-canaled extracted teeth obturated with gutta-percha were retreated using controlled application of one of three organic solvents: chloroform, xylene, or halothane. Two additional groups of teeth served as positive and negative controls. Residual volume of solvent expressed thro...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/S0099-2399(98)80098-8
更新日期:1998-04-01 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:INTRODUCTION:This study was conducted to evaluate and compare the fracture resistance of roots obturated with various contemporary canal-filling systems. METHODS:Fifty single-rooted extracted mandibular premolars were decoronated to obtain 13-mm root segments. Ten roots were left unprepared and unfilled (negative cont...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2011.08.008
更新日期:2011-11-01 00:00:00
abstract:INTRODUCTION:The purpose of this study was to evaluate the fracture strength of roots instrumented with the Self-Adjusting File (SAF; ReDent-Nova, Ra'anana, Israel) and the ProTaper system (Dentsply Maillefer, Ballaigues, Switzerland) and filled with the cold lateral compaction technique. METHODS:In total, 50 mandibul...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2013.08.030
更新日期:2014-04-01 00:00:00
abstract:INTRODUCTION:Odontoblasts produce dentin throughout life and in response to trauma. The purpose of this study was to identify the roles of endogenous Wnt signaling in regulating the rate of dentin accumulation. METHODS:Histology, immunohistochemistry, vital dye labeling, and histomorphometric assays were used to quant...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2019.07.014
更新日期:2019-11-01 00:00:00
abstract::The purpose of this study was to determine the incidence of endodontic services provided to participants in a longitudinal cohort study. The "Florida Dental Care Study" was a prospective cohort study using a representative baseline sample of 873 dentate adults. An in-person interview and clinical dental exam were cond...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1097/00004770-200312000-00005
更新日期:2003-12-01 00:00:00
abstract::The purpose of this study was to compare Schick CDR and Trophy RVGui direct digital radiography (DDR) systems for the ability to detect periapical lesions in human cadaver mandibles. Digital radiographs were exposed of teeth with normal periapical areas and of teeth with artificially prepared periapical lesions using ...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1097/01.don.0000140571.23012.ff
更新日期:2005-04-01 00:00:00
abstract::Ultrasonic root-end preparation techniques have recently been introduced and revolutionized the field of endodontic surgery. The purpose of this study was to compare quantitatively the quality of root-end preparation techniques prepared by a specially designed ultrasonic retrotip with those prepared in a traditional m...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/S0099-2399(98)80152-0
更新日期:1998-10-01 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:INTRODUCTION:The purpose of this study was to compare the accuracy in vivo of 2 electronic apex locators (EALs), the Raypex 5 and the Mini Apex Locator. METHODS:The working length (WL) was determined electronically for 40 human root canals by using a K-file and 1 of the 2 EALs. The files were fixed at the WL, and the ...
journal_title:Journal of endodontics
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.joen.2011.06.021
更新日期:2011-10-01 00:00:00
abstract::The objective of this study was to compare the effectiveness of F-files and ultrasonics to remove the smear layer from instrumented root canals when irrigated with sodium hypochlorite and EDTA. Sixty healthy human premolar teeth were instrumented with ProTaper file series to F3, and the canals were enlarged with Profi...
journal_title:Journal of endodontics
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.joen.2008.07.006
更新日期:2008-10-01 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:INTRODUCTION:This in vitro study compared the cyclic fatigue resistance of ProFile Vortex rotary instruments (DENTSPLY Tulsa Dental, Tulsa, OK) made of two different raw materials: M-Wire and regular superelastic wire (SE-wire) at two different rotational speeds. Two rotary-based Profile Vortex instruments with taper 0...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2010.02.015
更新日期:2010-07-01 00:00:00
abstract::The purpose of this prospective, double-blind, randomized study was to evaluate pain reduction using an intraosseous injection of slow-releasing methylprednisolone in teeth with irreversible pulpitis. Forty subjects presenting for emergency treatment completed the study. Each subject had a tooth with a clinical diagno...
journal_title:Journal of endodontics
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1097/00004770-200011000-00001
更新日期:2000-11-01 00:00:00
abstract::This study evaluated the sealing ability of fast and regular set Super-EBA with different powder-to-liquid ratios as a root-end filling material. Fifty extracted maxillary central incisors were uniformly cleaned and shaped using a crown-down technique with Gates-Glidden drills and Profile series 29.04 taper rotary ins...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/S0099-2399(99)80378-1
更新日期:1999-08-01 00:00:00
abstract:INTRODUCTION:Teeth undergoing initial endodontic therapy have a very high survival rate. Some teeth that continue to show signs of pathosis after the initial therapy will require nonsurgical (orthograde) retreatment. Outcome assessment of endodontic retreatment is crucial for appropriate case selection and treatment pl...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2010.02.009
更新日期:2010-05-01 00:00:00
abstract::This case-control study sought to identify variables predictive of subsequent root canal therapy (RCT) in teeth receiving full coverage restorations. The University of North Carolina School of Dentistry's computerized treatment database was used to identify all patients receiving a single-unit crown on a nonendodontic...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2005.11.001
更新日期:2006-08-01 00:00:00
abstract:INTRODUCTION:The purpose of the present study was to evaluate the thickness and the anatomic characteristics of the Schneiderian membrane and cortical bone using limited cone beam computed tomography (CBCT) scannning in patients referred for planning of apical surgery of maxillary molars. METHODS:This controlled study...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2011.09.023
更新日期:2012-01-01 00:00:00
abstract::The purpose of this study was to evaluate gray mineral trioxide aggregate (MTA), white MTA, and Fuji II LC cement as coronal barriers to bacterial leakage. Seventy-eight, matched, human teeth were obturated with gutta-percha. In group I, 18 pairs received a 3-mm barrier of gray or white MTA. In group II, 18 pairs rece...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1097/00004770-200411000-00008
更新日期:2004-11-01 00:00:00
abstract:INTRODUCTION:The aim of this study was to evaluate and compare the resistance to cyclic fatigue of the new One Curve (OC) instrument in double (S-shaped) and single curvature canals compared with other nickel-titanium rotary instruments. METHODS:Size 25/.06 of OC, 2Shape (TS), Vortex Blue (VB), ProFile Vortex (PV), an...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2018.07.023
更新日期:2018-11-01 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::In the past, measurement of microleakage has been based on measurement of dye or radioactive isotope penetration. A method has been developed to allow electronic monitoring of microflow in the same specimen over a period of time. This method was used to compare previously reported retrograde materials with an amalgam/...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/S0099-2399(06)80072-5
更新日期:1994-11-01 00:00:00
abstract::In vitro root surface temperatures produced during post space preparation were measured. The preparations were made using a GPX bur with rotational speeds of 6,500, 8,000, 9,500, 11,000, and 15,000 rpm. The overall mean temperature increase ranged from 0.66 degree to 4.81 degrees C and was greatest at 8,000 rpm. When ...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/S0099-2399(96)80264-0
更新日期:1996-06-01 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:INTRODUCTION:This study aimed at evaluating the bond strength to root dentin of 2 mineral trioxide aggregate (MTA)-based sealers (Endo-CPM sealer and MTA Fillapex) and of 1 epoxy resin-based sealer (AH Plus sealer). METHODS:Forty-five extracted human teeth with single roots were prepared by using the step-back techniq...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2011.10.018
更新日期:2012-02-01 00:00:00
abstract:INTRODUCTION:The purpose of this in vivo study was to evaluate the accuracy of small-volume cone-beam computed tomographic (CBCT) imaging compared with conventional periapical radiography (CPR) in the diagnosis of vertical root fractures (VRFs) using exploratory surgery as the reference standard. METHODS:Eighty-two de...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1016/j.joen.2020.04.015
更新日期:2020-08-01 00:00:00
abstract::Amalgam cores with cemented dowels are commonly used to restore endodontically treated teeth. These restorations were widely studied for their mechanical properties; however, less is known about their sealing ability. The effect of the cement type used for the dowel and that of a bonding agent application were studied...
journal_title:Journal of endodontics
pub_type: 杂志文章
doi:10.1097/00004770-200104000-00015
更新日期:2001-04-01 00:00:00