Abstract:
:The purpose of the present study was to analyze effective factors including periodontal ligament on vertical root fractures (VRFs). Eighty maxillary central incisors were assigned to eight groups, depending on master apical file (MAF) size, loading point and existence of a simulated periodontal ligament (PDL). The gutta-percha in the root canal was vertically pressed with a Co-Cr rod using a universal testing machine. An ordinal logistic analysis was employed to determine significant factors. VRFs were observed in 88.8% of the specimens but no horizontal fractures were found. There were three types of VRFs: partial fracture not involving the apex (PF, 41.3%), partial fracture involving the apex (AF, 40.0%), and complete fracture (CF, 7.5%). MAF size significantly affected VRFs (p < 0.05); large MAF size exhibited more partial fractures involving the apex. Loading point and existence of PDL did not affect VRFs.
journal_name
Dent Mater Jjournal_title
Dental materials journalauthors
Okitsu M,Takahashi H,Yoshioka T,Iwasaki N,Suda Hdoi
10.4012/dmj.24.66keywords:
subject
Has Abstractpub_date
2005-03-01 00:00:00pages
66-9issue
1eissn
0287-4547issn
1881-1361journal_volume
24pub_type
杂志文章abstract::Enamel and dentin particles were added to an experimental 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-based one-step adhesive to react for 30 s. After enamel and dentin reactants were analyzed using X-ray diffraction (XRD) and phosphorus-31 nuclear magnetic resonance ((31)P NMR) techniques, curve-fitting analys...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2014-260
更新日期:2015-01-01 00:00:00
abstract::The purpose of the present study was to evaluate the effect of four silane coupling agents on the bond strength between two resin-modified glass ionomer cements and a machinable leucite glass ceramic. Ceramic specimens were ground with silicon carbide paper and cleaned with phosphoric acid. They were then conditioned ...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.26.240
更新日期:2007-03-01 00:00:00
abstract::Gold alloys with Cu contents of 10 mass%, 20%, and 30% were used for morphological observation of porous surface structures after heating at 800 degrees C in air followed by pickling with acid solution. With increasing Cu content in the gold alloy, the internal oxidation zone became well-developed in the alloy matrix....
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.24.503
更新日期:2005-12-01 00:00:00
abstract::The purpose of this study was to evaluate the effect of different polymerization cycles on the flexural strengths and microhardness of two denture base materials (Meliodent and Paladent). Heat-polymerized acrylic resin specimens (65.0 mm long×10.0 mm wide×2.5 mm in height) were prepared using different short and long ...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2016-023
更新日期:2017-03-31 00:00:00
abstract::The purpose of this study was to characterize the surface damages of zirconia by Nd:YAG dental laser irradiation through a systematic evaluation of the associated microstructural changes. Disk specimens of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) and ceria-stabilized zirconia/alumina nanocomposite (C...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2009-127
更新日期:2010-10-01 00:00:00
abstract::The effect of acidic fluoride solution on NiTi arch wires was examined by testing crystal structure, tensile strength, morphology after fracture, and element release from wire under four different test solutions after 1 or 3 d immersion. Three-day immersion in a 0.2%/pH 4 solution did not form any new crystal structur...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.23.557
更新日期:2004-12-01 00:00:00
abstract::The aim of this study was to clarify the effect of heating rate on the development of both transient and residual stresses in investment molds. Solid, cylindrical, gypsum-based molds were modeled and theoretical calculations made of temperature distributions with a constant heating rate. These calculations used experi...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.15.121
更新日期:1996-12-01 00:00:00
abstract::The aim of this study was to estimate the flexural properties of three kinds of experimental fiber-reinforced composite (FRC) posts and to evaluate their potential use as posts. Experimental FRC posts were fabricated with glass, aramid, and UHMWP fibers. Commercial FRC posts were used for comparison. A three-point ben...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2010-053
更新日期:2011-01-01 00:00:00
abstract::The torsional fracture strength at the interface between a base plate and veneering material was evaluated for three kinds of veneered restoration: porcelain fused to zirconia (PFZ), porcelain fused to metal (PFM), and composite resin veneered metal (CRVM). The metal and zirconia base plate (30×4×0.4 mm) were prepared...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2016-432
更新日期:2018-07-29 00:00:00
abstract::Ti-6Al-7Nb alloy was cast into three differently designed, removable partial denture frameworks: Palatal strap (PS), Anterior-posterior bar (AP), and Horseshoe-shaped bar (HS). The vertical displacement and local strain of Ti-6Al-7Nb alloy frameworks were investigated to compare against those of Co-Cr alloy frameworks...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.23.497
更新日期:2004-12-01 00:00:00
abstract::The aim of this in vitro study was to evaluate the effects of different preparation angles on the precision of fit of zirconia crown frameworks. Dies were fabricated with three different preparation angles: 4, 8, and 12 degrees total taper. Ten copings were fabricated for each angle by a laboratory and a milling-cente...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.27.814
更新日期:2008-11-01 00:00:00
abstract::Improved osseointegration of dental implants is imperative in clinic. Effect of doxycycline on promoting bone formation after implant placement was expected due to its inhibitory properties on inflammation and osteoclastogenesis. To evaluate new bone formation on the hydroxyapatite (HA)-coated implant surface, which w...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2017-007
更新日期:2018-01-30 00:00:00
abstract::Different types of calcium phosphate compounds are commercially available for medical and dental applications as bone substitute materials. Biological apatites contain several kinds of minor elements such as carbonate (CO3), magnesium (Mg), and fluoride (F) in enamel, dentin, and bone. It has been shown that F ion and...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.24.398
更新日期:2005-09-01 00:00:00
abstract::The bactericidal efficacy of 1.00-4.50% glycine-type amphoteric surfactant (Gly) was evaluated by measuring its microorganism removal rate in denture plaque. Physical and mechanical properties such as surface roughness, color difference, and bending strength of two different denture base resins were determined before ...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.28.307
更新日期:2009-05-01 00:00:00
abstract::Adhesion promoting monomers for dental metals, 5-(4-vinylbenzyl)-2-thiobarbituric acid (5VS), 6- (4-vinylbenzyl-n-propyl) amino-1,3,5-triazine-2,4-dithione (VBATDT) and 9,10-epithiodecyl methacrylate (EP8MA), were synthesized and surface treatment agents were prepared by dissolving each monomer in ethanol or acetone. ...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.22.343
更新日期:2003-09-01 00:00:00
abstract::This study investigated the effects of spherical silica fillers on the physical and mechanical properties of resin-modified glass-ionomer cement (RMGIC). Specimens were fabricated by mixing untreated (UF) or silanized (SF) spherical silica filler into the powder of a commercially prepared RMGIC. The original RMGIC and...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.23.146
更新日期:2004-06-01 00:00:00
abstract::The aim of this study was to evaluate the cytotoxicity of contemporary flowable and paste-like bulk-fill dental composites by using a real-time cell analysis. In the present paper, cytotoxicity levels of five flowable, five paste-like bulk-fill composite materials and one conventional flowable, one conventional paste-...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2018-336
更新日期:2020-01-31 00:00:00
abstract::The aim of this study was to evaluate the trial Teaching Robot for the development of a contact-type measuring apparatus for using directly in the oral cavity. A standard model was used to mimic the dentition by placing an arrangement of three bearing balls. The diameters of the balls were measured. A practical dentit...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.22.168
更新日期:2003-06-01 00:00:00
abstract::The aim of this study was to investigate the relationship between the different mechanical properties with the filler fraction of various resin composites. Mechanical properties of eighteen different resin composites were investigated in this study; flexural strength (FS), flexural modulus (FM), fracture toughness (FT...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2012-178
更新日期:2013-01-01 00:00:00
abstract::In this study, wedge-shaped CP titanium castings and Ti-6Al-7Nb alloy castings were produced by three types of investment. The effects of the castings' thickness on surface reaction layer were investigated by measuring Vickers hardness, observing the microstructure, and analyzing the oxygen concentration. It was found...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.23.387
更新日期:2004-09-01 00:00:00
abstract::The physical properties of experimental visible light-activated resins containing dyestuff, which could be quickly discolored by irradiation was, evaluated by analyzing light absorbance characteristics and measuring micro Vickers hardness. The experimental resin, which was prepared by mixing equivalent weights of Bis ...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.8.147
更新日期:1989-12-01 00:00:00
abstract::To evaluate the cytotoxicity of resin cements on dental pulp-derived cells (bDPCs), Bifix QM (BQM), Choice 2(C2), RelyX U200(RU200), Maxcem Elite(ME), and Multilink Automix(MA) were tested. The materials were incubated in DMEM for 72 h. A real-time cell analyzer was used to evaluate cell survival. The statistical anal...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2014-167
更新日期:2015-01-01 00:00:00
abstract::The reinforcement mechanism of dentin mechanical properties by intracanal medicaments was investigated. The dumbbell-shaped specimens were prepared from a collagen sheet, demineralized dentin and organic dissolved dentin. After immersing the specimens in intracanal medicaments (eugenol and formocresol), the tensile te...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.18.304
更新日期:1999-09-01 00:00:00
abstract::This study investigated the effect of a coating material containing S-PRG fillers on the demineralization of bovine enamel and dentin, by measuring changes in the transmitted ultrasonic velocity. Bovine enamel and dentin specimens with and without coating (n=6 for each condition) were cut into blocks, immersed in 0.1 ...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2012-153
更新日期:2012-01-01 00:00:00
abstract::The use of a single metal for all restorations would be necessary because it protects against metal corrosion caused by the contact of different metals. For this "one-metal rehabilitation" concept, non-alloyed commercially pure (CP) titanium should be used for all restorations. Titanium frameworks have been cast and u...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2017-137
更新日期:2017-09-26 00:00:00
abstract::The fluorescence and physical properties of thulium-doped zirconia were investigated. A standard grade of zirconia (TZ-3Y-E) and two translucent dental zirconia materials (Zpex and Zpex Smile) were examined. The specimens were prepared by addition of 0-1.5 wt% Tm2O3 and then sintering. When exposed to UV light, the Tm...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2017-384
更新日期:2018-11-30 00:00:00
abstract::This study evaluated the effect of resin coating (COA) on dentin bond strength (BS) of five resin cements (RC). Ten groups were tested, according to RC and COA combinations. RCs were applied onto prepolymerized resin discs, which were bonded to dentin surfaces. Teeth were stored in water for 24 h, subjected to 5,000 t...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2015-099
更新日期:2015-01-01 00:00:00
abstract::The aim of this study was to investigate in how far the way the specimen is fixed to the testing device influences the micro-tensile bond strength of adhesives to dentin. Compared to a flat jig, a notched jig enables the specimen to be aligned easier and more accurately perpendicular to the interface, thereby concentr...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.26.694
更新日期:2007-09-01 00:00:00
abstract::The aim of this study was to evaluate temperature changes in the pulp chamber during polymerization of four different pulp-capping materials using a LED-light-curing-unit in the contact and noncontact positions. A pulpal circulation mechanism was simulated to measure increases in temperature in four pulp-capping mater...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2013-274
更新日期:2014-01-01 00:00:00
abstract::Major histocompatibility complex (MHC) class II molecule-expressing cells and macrophages play a pivotal role in mediating the host tissue response to biomaterials. This study investigated the responses of these cells to epoxy resin-based and 4-META-containing, methacrylate resin-based endodontic sealers (AH Plus and ...
journal_title:Dental materials journal
pub_type: 杂志文章
doi:10.4012/dmj.2013-005
更新日期:2013-01-01 00:00:00