bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Luminescent Properties of Ca2Li2BiV3O12:Eu3+ Phosphor
Authors: Chen Si Zhu , Qiu Ke Hui , Yan Guo Yin , Jiang Zi Xu , Zhao Ce
Published: March 2015

A red-emitting phosphor, Eu3+ activated Ca2Li2BiV3O12 was synthesized via combining combustion with solid state method and characterized by X-ray powder diffraction (XRD) and fluorescence spectrophotometer. The influence of synthesis temperature and the concentration of Eu3+ ions, on phase composition and luminescent properties of the synthesized samples was investigated systematically. The results showed that the Ca2Li2BiV3O12:Eu3+ phosphor with high phase purity and good crystallinity can be obtained by this citric acid - assisted sol combustion-solid state route at the synthesis temperature from 600°C to 700°C. The excitation spectrum of Ca2Li2BiV3O12:Eu3+ was composed of a broad band from 200 nm to 385 nm and a number of sharp small peaks extending from 390 nm to 480 nm, and the main peak was at 277 nm. The main emission peak was at 612 nm due to the electric dipole transition of 5D0 → 7F2 of Eu3+, which results in a red emitting. The sample prepared at T=680 °C, Eu3+ mol%=15 mol% has the highest emission intensity in this work.
Dental Resin Composites with Enhanced Properties Bycommercial Silica Particles as Fillers
Authors: Bao Shuang , Wang Rui Li , Sun Bin , Jiang Xiao Ze , Zhu Mei Fang
Published: March 2015

To explore the preparation of novel dental resin composites with enhanced properties, two commercial silica particles with sizes of around 1μm and 40 nm were chosen as inorganic fillers, and firstly surface functionalized by 3-methacryloxypropyltrimethoxysilane (γ-MPS) to incorporate cross-linkable vinyl groups onto the surface of fillers. Then the modified fillers were blended with organic monomers, bisphenolAdiglycidyldimethacrylate (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA), to fabricate the resin compositeswith a three-roll mixer.Resin composites with various weight percentage of fillers and component ratio of microparticle and nanoparticle were prepared. Surface functionalization of silica particles was characterized by fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), and mechanical properties degree of conversion, and depth of cure of the resultant resin composites were investigated byuniversal testing machineand FTIR. The results indicated that surface modification of silica particles was successful and the surface organic contents were 3.29% and 4.34%, respectively. Among the studied resin composites, the resin composite with 75 wt.% silica particles (59 wt.% microparticles and 16 wt.% nanoparticles) presented the highest value of depth of cure (5.52 ± 0.07 mm), and optimum mechanical properties such as flexural strength (149.8 ± 3.3 MPa), flexural modulus (13.8 ± 0.06 GPa), compressive strength (340.6 ± 8.3 MPa) and Vicker’smicrohardness (78.26 ± 2.45 HV). The study of dental resin composites fabricated from commercial silica particles with excellent properties might provide a new sight for realizing the preparation of this kind of dental resin composites in an industrial scale.
Novel Enhanced Acrylic Denture Base Powder by Incorporating with PMMA-Modified Ag/NaZr2(PO4)3 through In Situ Suspension Polymerization
Authors: Du Jun Jun , Yu Hao , Zhu Mei Fang
Published: March 2015

A kind of novel antibacterial denture base powder incorporated with PMMA-modified nanoAg/NaZr2(PO4)3(CBD-300) was prepared by in-situ suspension polymerization and the flexural properties of denture base resin was investigated. CBD-300 was silanized by 3-methacryloxy propyl trimethoxyl silane (γ-MPS), and thenγ-MPS-CBD-300 was grafted with poly (methyl methacrylate) (PMMA) to prepare M-CBD-300 which has a good compatibility with the denture base resin. Denture base powders with different addition of M-CBD-300 were prepared by in-situ suspension polymerization. Thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and water contact angle were used to characterize M-CBD-300. The size of denture base powder was observed by optical microscope. Universal testing apparatus and scanning electron microscope (SEM) were used to investigate flexural properties of denture base resin samples. The results showed that the surface of M-CBD-300 was successfully modified by PMMA, and the incorporation of M-CBD-300 leads to increasing of the denture base powder size. The flexural properties of the denture base resin samples prepared with our antibacterial denture base powders were enhanced greatly compared with the blank sample.
Investigation of Zirconia/Polyacrylamide (ZrO2/PAAm) Based Nanocomposite Hydrogels with Enhanced X-Ray Radiopacity
Authors: Li Wen Jiao , Ma Wu Jun , Meng Zhou Qi , Xia Meng Ge , Wang Xue Fen , Zhu Mei Fang
Published: March 2015

Zirconium oxide (ZrO2) nanoparticles with the sizes of 50 nm were prepared via hydrothermal method and utilized to prepare zirconia/polyacrylamide (ZrO2/PAAm) nanocomposite hydrogels through conventional radical polymerization at mild condition. The morphology and crystalline structure of prepared ZrO2 were characterized by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD), and the resultant ZrO2/PAAm nanocomposite hydrogels were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and dental ray machines. The results show that the ZrO2/PAAm nanocomposite hydrogels have a certain X-ray radiopacity and stability under simulated human oral conditions, which have the great potential to be used as root canal filling materials.
Cytocompatibility of Fe-O Thin Film Prepared by Unbalanced Magnetron Sputtering
Authors: Liu Yan Qiu , Sun Hong , Li Xin , Huang Nan
Published: March 2015

In order to improve the cell biocompatibility of pure iron surface as cardio-vascular stent material, Fe-O film was deposited on single crystal silicon by unbalanced magnetron sputtering. Human umbilical vein endothelial cells were seeded on the 316L SS, pure iron and Fe-O film surface, whereafter cultured in vitro. Adhesion behavior was detected after 2 h incubation. Cell morphology and proliferation activities were assessed at 1, 3 and 5 days. The results show that the endothelial cells are easy to adhere and spread on the surface of Fe-O film. Compared with 316L SS samples, the cells count and area coverage of Fe-O film in 1 and 5 days make a difference significantly. These results demonstrated that the Fe-O film prepared by unbalanced magnetron sputtering technique has good cytocompatibility.
Surface Modified UHMWPE Particles by Direct Fluorination Blended with Polyurethane for Enhancing its Wear-Resistant Performance
Authors: Li Bao Yin , Fan Cong , Ren Meng Meng , Wu Peng , Luo Long Bo , Wang Xu , Liu Xiang Yang
Published: March 2015

In this study, Ultra-high molecular weight polyethylene (UHMWPE) particles were surface treated by F2/N2 and F2/O2/N2 two direct fluorination routes. A great number of polar groups are grafted on the surface of UHMWPE particles after direct fluorination confirmed by FT-IR and X-ray photoelectron spectroscopy (XPS) characterization. Two kinds of surface modified UHMWPE particles were blended with thermoplastic polyurethane (TPU) by dissolving in solvent. The scanning electron microscope (SEM) demonstrates that the interfacial interaction degree between the two polymer phases is correlated with the chemical composition of a fluorinated surface layer. The TPU composite with the UHMWPE particle treated by F2/O2/N2 route obtains excellent tribological performance enhancement with significant decrease in wear loss, ranging from 192.9 mm3 to 97.8 mm3, about 49.3% reduction compared with the virgin TPU.
Effects of the Coupling Agent on the Mechanical Properties of Long Glass Fiber Reinforced Polyphenylene Sulfide Composites
Authors: Liu Zhao , Wu Yu Qian , Wang Xiao Jun , Long Sheng Ru , Yang Jie
Published: March 2015

In this paper, we investigated the effects of a coupling agent (KH560) on the mechanical properties of long glass fiber (LGF) reinforced polyphenylene sulfide (PPS) composites. The LGF reinforced PPS composites were prepared utilizing our self-designed mold. It’s found that KH560 was beneficial for improving the mechanical properties of the composites. Meanwhile, the fiber lengths of glass fibers in the original injection molded sample and near the fracture surface were measured under the optical microscope. Comparing to the untreated sample, the sample with KH560 possessed higher proportion of fiber length on 0.75-1.25 mm. It suggested that KH560 could protect glass fibers from broken. Meanwhile, near the fracture surface, two composites possessed similar proportions of fiber length on 0-0.75 mm. That indicated KH560 improved the interfacial bonding between glass fiber and PPS. Scanning electron microscopy (SEM) images showed that more resin adsorbed on the fiber surface, which was consistent with the above phenomena.
Improvement of Mechanical Properties of Polyphenylene Sulfide/Carbon Fiber Composites Modified by Aminated Reinforcement
Authors: Hong Rui , Zhang Kun , Liu Bao Ying , Zhang Gang , Wang Xiao Jun , Long Sheng Ru , Yang Jie
Published: March 2015

The carbon fiber (CF) reinforced polyphenylene sulfide (PPS) composite was modified by aminated polyphenylene sulfide (PPS-NH2) with different mass fractions. The quantified influence of aminated PPS on PPS/CF composites was investigated. The PPS/CF composite with 7wt% PPS-NH2 showed the best mechanical properties. The tensile strength, flexural strength, flexural modulus and impact strength of the composites increased by 12.5%, 13.0%, 38.5% and 31.5%, respectively. PPS-NH2 hardly influenced the melting process of PPS/CF composite. But the crystallization temperature (Tc) of PPS were obviously increased with the present of aminated PPS.
L-Lysine-Based Dendritic Gelator Modified PMMA Nanocomposite
Authors: Ye Feng , Tang Guo Dong , Chen Si , Wu Bo Zhen , Ma Meng , Shi Yan Qin , Wang Xu
Published: March 2015

L-lysine-based dendritic gelator(G3-C12-G3) was successfully designed and synthesized using a divergent approach and it can self-assemble into nanofibers in MMA followed by gelation. After thermal polymerization of MMA gels, the self-assembly nanofibers modified PMMA nanocomposite can be obtained. SEM studies indicate the embedded supra molecular nanofibres joint each other and form a relative intact gel networkskeleton in PMMA matrix. Impact strength and DMTAmeasurementindicatethe existence of gel network skeleton make PMMA nanocomposite had higher impact strength and storage modulus than pure PMMA. UV-vis spectrophotometer studies indicate PMMA nano-composite retains high light transmittance.
Synthesis of Two-Component Dendritic Gelators and their Self-Assembly Behavior in MMA
Authors: Ye Feng , Chen Si , Tang Guo Dong , Wu Bo Zhen , Ma Meng , Shi Yan Qin , Wang Xu
Published: March 2015

Three kinds of amide dendritic branches, Branch1(COOH), Branch2(COOH) and Branch3(COOH), are successfully synthesized. After mixing with diaminoctane, their self-assembly behavior in methyl methacrylate (MMA) is investigated. The structures of the amide dendritic branches are confirmed by1H-NMR and Mass spectra (MS). The gelation ability of the amide dendritic gelators is researched through tube inversion experiment, the results of which show that different structures led to quite different gelation ability, including gel-sol temperature and critical concentration to form a stable gel. SEM experiments show that three kinds of gelators formed different gel morphologies in MMA.
Investigation of Mechanical Properties and Dye Adsorption Capacities of Novel Hydrophobic Association Nanocomposite Hydrogels
Authors: Cui Wei , Li Ting , Li Hang , Zhu Le Min , Liu Huan , Ran Rong
Published: March 2015

The preparation of high performance hydrogels has always been one of the research focuses in the area of soft matters and functional polymers. In this paper, a facile method was developed for the preparation of high performance hydrophobic association nanocomposite hydrogels (HANC gels) via in situ copolymerization of acrylamide (AM) and octadecyl methacrylate (OMA) in the aqueous suspension of hectorite clay Laponite HZ-200 (clay) with sodium dodecyl benzene sulfonate (SDBS). Tensile hysteresis curves showed that the hysteresis degrees between HANC gels and conventional hydrophobic association hydrogels (HA gels) were almost the same, but the tensile strength of the HANC gel reinforced by just 0.4 wt% clay at the strain of 1500% was already as 630% as the strength of the HA gel, which indicated that the mechanical properties of the HA gel were greatly enhanced by the introduction of a small amount of clay without increasing the internal friction in the hydrogel network. The effects of clay on the structure of HANC gels were further confirmed by swelling test, it was found that the addition of clay effectively maintained the structural integrity of HANC gels in watery environment and prevented the collapse of gel network. Moreover, HANC gels exhibited superior cationic dye adsorption capacity compared to HA gels due to the existence of abundant negative charges on the surfaces of clay nanosheets
Super Hydrophobic Properties of Papers Prepared from Multi-Walled Carbon Nanotubes Functionalized with Polybenzimidazole and AgNPs
Authors: Zhang Yan Li , Hu Zu Ming , Wang Yan
Published: March 2015

The fabrication of multi walled carbon nanotube (MWNT) buckypaper and its silver nanoparticle (AgNP) hybrid is studied with the assist of a high-performance polymer, polybenzimidazole (PBI) by filtration-method. The result of Raman spectra demonstrates the strong π-π interaction between MWNT and PBI. Because of the coordination effect of imidazole groups to metal ions, AgNPs are then deposited on the surface of MWNTs/PBI buckypaper. The Ag/buckypaper hybrid (MPBA) is found to be super-hydrophobic after being treated by 1-Octadecanethiol.
Infrared Spectral Characteristics of Azobenzene Containing Side-Chain Liquid Crystal Polymer
Authors: Chen Wei Xing , Zhang Xiao Long , Luo Chun Yan , Ma Ai Jie , Gu Yong Qiang
Published: March 2015

In order to study the infrared spectral characteristics of side-chain liquid crystal polymer, an infrared monomer containing a permanent dipole azobenzene group spaced from the methacryloyl moiety by a polymethylene segment was synthesized in three steps starting from 4-cyanoaniline. The monomer was polymerized with a push-pull azobenzene monomer, (-)-menthy1 methacrylate in the presence of azobisisobutyronitrile (AIBN) as the radical initiator. Structurally similar amphiphilic polymers were obtained by polymerization of analogous methacrylates in which the polymethylene spacers was replaced by oligo (oxyethy1ene) segments. The obtained polymer was characterized by Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectro photometry (UV-vis), Hot Stage Polarized Microscopy (HS-POM), Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analyzer (TGA). Its infrared emissivity at different temperatures was tested by Bruker-V70 infrared analyzer. The results showed that the azobenzene poly (methyl methacrylate) (azo-PMMA) has high glass transition temperature(about 40°C), good thermal stability(divied in 294°C) and low infrared emission under 70%.
Synthesis of Polythiophene Derivatives with Schiff Base Groups and Use as an Active Layer in Polymer Solar Cell Devices
Authors: Chen Wei Xing , Chui Ping , Ma Ai Jie , Luo Chun Yan , Gu Yong Qian , Mi Qiao Yan
Published: March 2015

Two kinds of Schiff bases polymers named P3TA4A and P3TA4B were prepared by the chemical oxidation method. The structures of Schiff bases polymers were determined by FT-IR and1H NMR. The GPC result showed that the number-average molecular weight of P3TA4A and P3TA4B was 7400 g/mol and 12500 g/mol with a molecular weight distribution of 1.63 and 1.27, respectively. The cyclic voltammetry curves showed that the energy gap of P3TA4A and P3TA4B was 1.929 eV and 1.944 eV, respectively. Ultraviolet-visible spectra and Luminescence spectra showed that the maximum absorption and maximum emission wavelength of was 275 nm, 400 nm for P3TA4A and 448 nm, 451 nm for P3TA4B. The open-circuit voltage of the polymer solar devices was 3 mv and 2.5 mv, respectively. The results indicated that the Schiff bases substituents at the 3-position of polythiophenes play an important role on the photoelectric conversion efficiency of conducting polymers.
Research and Development in Electrospinning Theory and Technology
Authors: Song Qing Song , Liu Yue Xing , Zhang You Chen , Liu Yong
Published: March 2015

Based on the analysis of much related literature, the present article introduced some of the latest theoretical models and technologies. Meanwhile, it sums up two important issues in electrospinning development. One is that more studies will focus on melt fiber refinement and improving position accuracy. Another is orderly collection and spinning efficiency will be emphasized. This study provides a clear direction for further development of electrospinning.
Effect of Acetic Acid/Water Ratio on the Microstructure and Properties of LaNiO3 Thin Films by Metal Organic Solution Deposition
Authors: Zhang Yuan Yuan , Tang Xiao Dong , Wang Gen Shui , Dong Xian Lin
Published: March 2015

Highly (100)-oriented LaNiO3(LNO) thin films were prepared onp-type Si (100) substrates by metal organic solution deposition (MOSD). The LNO thin films were driven by series precursor solutions with different ratio of acetic acid to deionized water (Raaw) and pH values. The dependences of viscosity, pH value and the thermal property of the gel-derived powders of the precursor solution onRaawvalues were systematically investigated. AFM images showed thatRaawcan dramatically influence the surface roughness. WhenRaawchanged from 7:1 to 1:1, the surface roughness decreased from 3.695 nm to 1.488 nm. The resistivities of all the films are less than 2.1×10-3Ω·cm. It shows that the precursor solution has strong effect on the microstructure of the thin films and relatively slight effect on the resistivity.
Distribuzione, consistenza ed evoluzione delle popolazioni di cigno reale, Cygnus olor, nidificanti in Italia nel periodo 1980-2012
Authors: Brichetti Pierandrea , Grattini Nunzio
Published: March 2015

Storicamente, i primi casi di nidificazione di Cigno reale (Cygnus olor) in Italia sono stati accertati in Lombardia e Piemonte negli anni ‘60-’70 del secolo scorso, in seguito ad introduzioni iniziate negli anni ‘30-’40 nelle parti svizzere di alcuni laghi lombardi e continuate nei decenni successivi. La popolazione nidificante risulta attualmente concentrata nelle regioni settentrionali, dal Piemonte orientale alla fascia costiera alto-adriatica, dove si riproduce quasi il 90 % della popolazione nazionale; presenze più frammentate in Liguria, Trentino-Alto Adige, Toscana, Umbria, Lazio, Basilicata e Sardegna. All’inizio degli anni ‘80 del secolo scorso erano state stimate 20-35 coppie nidificanti in meno di 15 siti; di queste, l’80% si trovava in Piemonte e Lombardia. Le coppie sono aumentate a 25-45 nel 1987, poi a 300-500 nei primi anni del 2000, ed attualmente a 500-700 in oltre 150 siti, con un aumento di oltre il 900% rispetto ai valori iniziali. Questi dati confermano la fase di incremento ed espansione territoriale nota a livello europeo negli ultimi decenni. La colonizzazione di molti siti riproduttivi, localizzati in prevalenza nelle regioni settentrionali, è dovuta alla formazione di nuclei svernanti, cui fa seguito la formazione di coppie riproduttrici. Tale fenomeno ha interessato, seppur in misura più limitata, anche le regioni centro-meridionali, dove le osservazioni sono andate aumentando negli ultimi due decenni. Il Cigno reale nidifica a coppie isolate o localmente raggruppate in forma coloniale in zone umide naturali o artificiali, anche di modesta estensione, preferibilmente dal livello del mare fino a 300 m, con un’altitudine massima di 970 m s.l.m., rilevata in Trentino.
Dati storici sulla presenza circummediterranea del francolino nero Francolinus francolinus francolinus (Linnaeus, 1766)
Authors: Oriani Aldo
Published: March 2015

Si espone la distribuzione storica del francolino nero sulle coste del Mediterraneo; da quelle asiatiche, dove era endemico, venne introdotto e si naturalizzò in Grecia fin dall’antichità e dal XIII secolo in Sicilia ed Aragona. In quel secolo ne parlò Federico II di Svevia nel suo trattato di falconeria dimostrandone una approfondita conoscenza e contemporaneamente la specie veniva citata nelle leggi dell’Aragona. Da queste due regioni il francolino venne diffuso in ampie zone della Spagna, della Francia sud-occidentale, della Toscana e forse anche della Lombardia ed è emersa l’ipotesi che la specie fosse presente anche in Egitto.
Il francolino scomparve, tra la fine del Settecento e la metà dell’Ottocento, da tutti i territori dove era stato introdotto a scopo venatorio a causa delle modifiche ambientali conseguenti alle bonifiche e alla antropizzazione e della caccia non regolamentata, ormai non più prerogativa esclusiva della nobiltà che, per secoli, si era adoperata a tutelare la specie. Analoghe cause portarono, nel corso dell’Ottocento, alla scomparsa del francolino anche da quasi tutti gli ambienti costieri del Mediterraneo orientale, tanto che, già negli anni Trenta del secolo scorso, si nutrivano preoccupazioni sulla sua salvaguardia anche nei territori dove era indigeno.
Behold the glory of the King: The chiastic structures of Matthew 21−25
Authors: Scholtz Jacob J.
Published: March 2015

The Olivet Discourse is complex and difficult to interpret, but crucial to any preaching about eschatology. By identifying two chiastic structures that mirror each other, namely in Matthew 21:1−23:39 and 24:1−25:46, the relation and correspondence of the parts to each other and to the whole may be identified. Whereas the centre of the chiastic structure of Matthew 21:1−23:39 emphasises the authority and identity of Jesus Christ, the Lord and Son of David, the centre of the chiastic structure of 24:1−25:46 focuses on the sign and coming of the Son of Man. Matthew 21:1−25:46 could be a major literary unit that emphasises the King’s entrance into, rejection of and exit from the temple and Jerusalem during his first coming, juxtaposed with the sign and coming of the Son of Man to Jerusalem in glory. Until then, the Lord expects his followers to watch, to be ready and prepared as they labour faithfully for him in these last days.Kyk die heerlikheid van die Koning: Die chiastiese strukture van Matteus 21−25. Die Olyfberg-diskoers is kompleks en moeilik om te interpreteer, dog onontbeerlik vir enige prediking oor die eskatologie. Deur die eiening van twee chiastiese strukture wat mekaar weerspieël, naamlik in Matteus 21:1−23:39 en 24:1−25:46, kan die verhouding en ooreenkomste van die dele tot mekaar en die geheel geïdentifiseer word. Waar die middelpunt van die chiastiese struktuur in Matteus 21:1−23:39 die gesag en identiteit van Jesus Christus, die Here en Seun van Dawid, beklemtoon, fokus die middelpunt van die chiastiese struktuur in 24:1−25:46 op die teken en koms van die Seun van die Mens. Matteus 21:1−25:46 sou ’n belangrike literêre eenheid kon wees wat die Koning se ingang na, verwerping en agterlaat van die tempel en Jerusalem tydens sy eerste koms beklemtoon teenoor die teken en koms van die Seun van die Mens na Jerusalem in heerlikheid. Tot dan verwag die Here van sy volgelinge om te waak, om gereed en voorbereid te wees terwyl hulle getrou in hierdie laaste dae vir Hom arbei.
Ambrosiaster se uitleg van die Filemonbrief en die retoriese analise van hierdie brief
Authors: Tolmie D. Francois
Published: March 2015

Die studie van Paulus se brief aan Filemon het gebaat by die hernude belangstelling in die retoriese analise van Nuwe-Testamentiese geskrifte, in die sin dat ’n groot aantal retoriese analises van die brief gepubliseer is. Hierdie retoriese analises is vanuit ’n verskeidenheid perspektiewe gedoen, maar tot dusver het niemand nog die manier sistematies ondersoek waarop die vierde-eeuse outeur, wat later die naam Ambrosiastergekry het, die brief in sy kommentaar op die Pauliniese briewe geïnterpreteer het nie. Hierdie artikel bied dus ’n oorsig van Ambrosiaster se interpretasie van die brief aan Filemon en dui aan watter bydrae dit tot die retoriese analise van die brief kan maak. Ambrosiaster’s exposition of the Letter to Philemon and the rhetorical analysis of the letter. In recent times, the study of Paul’s letter to Philemon benefitted from the renewed interest in the rhetorical analysis of New Testament writings, in the sense that a large number of rhetorical studies of the letter have been published. These rhetorical analyses of the letter have been done from different perspectives, but thus far, no one has systematically investigated the way in which the fourth-century author, who was later called Ambrosiaster, interpreted the letter in his commentary on the Pauline letters. Accordingly, this article offers an overview of Ambrosiaster’s interpretation of the letter to Philemon, and then outlines the contribution that his reading of the letter can make to the rhetorical interpretation of it.
Effectiveness of an Infiltrant on sealing of Composite Restoration Margins with/without Artificial Caries
Authors: Antonson Sibel A , Tulunoglu Ozlem , Tulunoglu Ibrahim Fevzi , Campillo-Funollet Marc , Antonson Donald , Munoz-Viveros Carlos
Published: March 2015

Aim

The aim of this in vitro study was to evaluate the effectiveness of a resin infiltrant (ICON) on marginal sealing ability of class II resin restorations with/without-caries.

Materials and methods

Forty-eight noncarious human premolar teeth were embedded and MO and DO preparations of standard dimensions were prepared. The left side of dentin margins of the cavities were left nonbonded (UB) while the right side were bonded using total etch-bonding agent and all restored with a Nanohybrid composite. The teeth were thermocycled and half of the specimens in the UB and B groups were subjected to an artificial caries process. ICON was applied to caries and noncaries subgroups following the manufacturer's directions. Impressions were made at each step: after the restorations were completed, thermocycling, artificial caries procedures, and infiltrant application and the silicone tag lengths were measured with a stereomicroscope. The specimens were immersed in 0.5% basic fuchsine at 37° C for 24 hours, sectioned and microleakage was evaluated with a stereomicroscope. Selected samples and their replicas were assessed for marginal quality under a stereomicroscope and SEM. Statistical evaluation of the data were made using Kruskal-Wallis, Mann-Whitney U and Wilcoxon Sign Rank tests.

Results

While bonding application did not create a meaningful difference, the thermocycling and artificial caries significantly increased the gap length and microleakage (p < 0.05). ICON application was decreased the microleakage, created gap-free margins and closed the gaps which were previously occurred at the same cavities (p < 0.05).

Conclusion

A resin infiltrant (ICON) application decreased the microleakage, created gap-free margins and closed the gaps, which previously occurred at the same cavities.

Clinical significance

Approximal application of resin infiltrant may increase the success of the class II composite restorations also reduced the risk of needing more complex restoration therapy.

How to cite this article

Tulunoglu O, Tulunoglu IF, Antonson SA, Campillo-Funollet M, Antonson D, Munoz-Viveros C. Effectiveness of an Infiltrant on Sealing of Composite Restoration Margins with/without Artificial Caries. J Contemp Dent Pract 2014;15(6): 717-725.
Is It Possible to use Cross-sectional and Vertical Facial Measurements to establish the Shape of the Mandibular Arch?
Authors: Ramos Adilson Luiz , Haje Ossam Abu El , Pompeo Daniela Daufenback , Furtado Gisela Crippa , Rivera Luciana Monti Lima
Published: March 2015

Background

Given the benefits of radiographic cephalometric studies in determining patterns of dental-skeletal-facial normality in orthodontics, the aim of this study was to investigate the association between mandibular dental arch shape and cross-sectional and vertical facial measurements.

Materials and methods

It was analyzed plaster casts and teleradiographs in frontal and lateral norm belonging to 50 individuals, aged between 15 and 19 years, with no previous history of orthodontic treatment and falling into four of the six Andrews's occlusion keys. The plaster models were scanned (3D) and the images of the dental arches were classified subjectively as oval, triangular and quadrangular by three calibrated examiners, with moderate inter-examiner agreement (Kappa = 0.50). After evaluation of the method error by paired t test (p > 0.05), it was carried out the analysis of cross-sectional and vertical facial measurements to be compared to the shape of the dental arch. Data were subjected to one-way analysis of variance with a significance level of 5%.

Results

When the VERT index was compared with the three arch shapes, no measurement showed statistically significant differences (p > 0.05): triangular (0.54); oval (0.43); and quadrangular (0.73); as well as there were no differences (p > 0.05) in the widths of the face (141.20; 141.26; 143.27); maxilla (77.27; 77.57; 78.59) and mandible (105.13; 103.96; 104.28).

Conclusion

It can be concluded that there was no correlation between different shapes of the mandibular dental arch and the cross-sectional and vertical facial measurements investigated.

How to cite this article

El Haje OA, Pompeo DD, Furtado GC, Rivera LML, Paranhos LR. Is It Possible to use Cross-sectional and Vertical Facial Measurements to establish the Shape of the Mandibular Arch? J Contemp Dent Pract 2014;15(6):735-739.
Evaluation of the Relationship between Mandibular Third Molar and Mandibular Canal by Different Algorithms of Cone-beam Computed Tomography
Authors: Mehdizadeh Mojdeh , Ahmadi Navid , Jamshidi Mahsa
Published: March 2015

Objectives

Exact location of the inferior alveolar nerve (IAN) bundle is very important. The aim of this study is to evaluate the relationship between the mandibular third molar and the mandibular canal by cone-beam computed tomography.

Study design

This was a cross-sectional study with convenience sampling. 94 mandibular CBCTs performed with CSANEX 3D machine (Soredex, Finland) and 3D system chosen. Vertical and horizontal relationship between the mandibular canal and the third molar depicted by 3D, panoramic reformat view of CBCT and cross-sectional view. Cross-sectional view was our gold standard and other view evaluated by it.

Results

There were significant differences between the vertical and horizontal relation of nerve and tooth in all views (p < 0.001).

Conclusion

The results showed differences in the position of the inferior alveolar nerve with different views of CBCT, so CBCT images are not quite reliable and have possibility of error.

How to cite this article

Mehdizadeh M, Ahmadi N, Jamshidi M. Evaluation of the Relationship between Mandibular Third Molar and Mandibular Canal by Different Algorithms of Cone-beam Computed Tomography. J Contemp Dent Pract 2014;15(6):740-745.
Efficacy of Lignocaine in Gel and Spray form during Buccal Infiltration Anesthesia in Children: A Randomized Clinical Trial
Authors: Suprabha BS
Published: March 2015

Aim

To compare the efficacy of 15% lignocaine spray and 8% lignocaine gel as a topical anesthetic, in reducing pain, during buccal infiltration in children.

Materials and methods

Forty-two patients aged between 7 and 12 years requiring restorative procedures/extraction/pulp therapy of primary/ permanent teeth in the maxillary arch, under buccal infiltration anesthesia were selected for the study. The participants were randomly allocated into 2 groups of 21 each. In group A, 8% lignocaine gel and in group B, 15% lignocaine spray was applied prior to buccal infiltration. Pain was assessed using Wong-Baker faces pain rating scale (WBFPRS) and faces legs activity cry and consolability (FLACC) painscale.

Results

Pearson's chi-square test revealed that there was no significant difference in the FLACC scores of the two groups (p = 0.54). Independent t-test demonstrated that there was no significant difference in Wong-Bakers faces pain score between the two agents (p = 0.07).

Conclusion

There is no significant difference in the efficacy of 15% lignocaine spray and 8% lignocaine gel as a topical anesthetic in controlling pain during buccal infiltration anesthesia, in children.

How to cite this article

Sharma A, Suprabha BS, Shenoy R, Rao A. Efficacy of Lignocaine in Gel and Spray form during Buccal Infiltration Anesthesia in Children: A Randomized Clinical Trial. J Contemp Dent Pract 2014;15(6):750-754.
Knowledge, Attitude and Practice of Pediatricians and Pharmacists in Riyadh City toward the use of Sugar free Medications
Authors: Bawazir Omar A , Alsuwayt Bandar , Alqahtani Waleed , Al-Dhafiri Ahmad , Al-Shamrani Mosleh
Published: March 2015

Objective

This study was intended to assess the knowledge, attitude and practice of pediatricians and pharmacists about sugar free medications (SFMs) and their impact on oral health.

Materials and methods

Self-administered close ended questionnaire was handed out to all pediatricians and pharmacists in five tertiary hospitals in Riyadh (King Khalid University Hospital, King Saud Medical City, King Fahad Medical City, Prince Sultan Medical Military City, Security Forces Hospital) to investigate the knowledge, attitude and practice concerning SFMs.

Results

Eighty-five pediatricians and 77 pharmacists participated in this study. The results showed that pediatricians and pharmacists have a good knowledge, but negative attitude toward SFMs. Only (5.9%) of pediatricians had formal undergraduate training which is significantly lower than pharmacists (15.6%) (p = 0.04). One-third of pediatricans and pharmacists prescribe or dispense SFMs. The most influencing factors toward prescription (pediatrician) of SFMs was the medical status of the patient (70.6%), while the most influencing factor of dispensing (pharmacists) SFMs was the availability in the pharmacy (64.9%). Two-third of pediatricians (67%) guide the parents about the risk associated with sugarcontaining medications (SCMs) which is significantly higher than pharmacists (p < 0.0001). Also, 53% of pediatricians recommend oral hygiene instructions when prescribing SCMs which is also significantly higher than pharmacists (p = 0.002).

Conclusion

There is a considerable knowledge about SFMs and its impact on dental caries, among pediatricians and pharmacists participated in this study. However, their attitude toward prescribing or dispensing SFMs was not positive and may be linked to the gap in knowledge. Further training and education of healthcare providers regarding the use of SFMs and its negative impact on dental caries has to be reiterated.

How to cite this article

Bawazir OA, Alsuwayt B, Alqahtani W, Al-Dhafiri A, Al-Shamrani M. Knowledge, Attitude and Practice of Pediatricians and Pharmacists in Riyadh City toward the use of Sugar free Medications. J Contemp Dent Pract 2014; 15(6):755-760.
A Method for retrieving Endodontic or Atypical Nonendodontic separated Instruments from the Root Canal: A Report of Two Cases
Authors: de Toledo Leonardo Renato , Kuga Milton Carlos , Keine Katia Cristina , Dantas Andrea Abi Rached , Faria Gisele , Monteiro Jardel Camilo do Carmo , Jordão-Basso Keren Cristina Fagundes , Ruchaya Prashant Jay
Published: March 2015

Aim

This clinical report presents a new method for retrieving separated instruments from the root canal with minimally invasive procedures.

Background

The presence of separated instrument in root canal may interfere in the endodontic treatment prognosis. There are several recommended methods to retrieve separated instruments, but some are difficult in clinically practice.

Case report

This study describes two cases of separated instrument removal from the root canal using a stainless-steel prepared needle associated with a K-file. Case 1 presented a fractured gutta-percha condenser within the mandibular second premolar, it was separated during incorrect intracanal medication calcium hydroxide placement. Case 2 had a fractured sewing needle within the upper central incisor that the patient used to remove food debris from the root canal. After cervical preparation, the fractured instruments were fitted inside a prepared needle and then an endodontic instrument (#25 K-file) was adapted with clockwise turning motion between the needle inner wall and the fragment.

Conclusion

The endodontic or atypical nonendodontic separated instrument may be easily pull on of the root canal using a single and low cost device.

Clinical significance

The methods for retrieving separated instruments from root canal are difficult and destructive procedures. The present case describes a simple method to solve this problem.

How to cite this article

do Carmo Monteiro JC, Kuga MC, Dantas AAR, Jordão-Basso KCF, Keine KC, Ruchaya PJ, Faria G, de Toledo Leonardo R. A Method for retrieving Endodontic or Atypical Nonendodontic separated Instruments from the Root Canal: A Report of Two Cases. J Contemp Dent Pract 2014;15(6):770-774.
Calcium Phosphate Barrier for Augmentation of Bone in noncontained Periodontal Osseous Defects: A Novel Approach
Authors: Chopra Aditi , Sivaraman Karthik , Awataramaney Tarun K
Published: March 2015

Aim

The aim of this technique is to augment bone in noncontained osseous deformities using a unique self-sustaining calcium phosphate barrier.

Introduction

Bone has the inherent ability to regenerate completely if it is provided with a fracture space or an undisturbed enclosed scaffold. A secluded environment is essential as it provides a secured, sterile and stable wound system that regenerates lost bone by a process of osteopromotion. Reconstructive techniques using bone grafts and barrier membranes utilize this principle for augmentation of deficient bony sites by providing a closed environment that promotes clot stability, graft retention, and facilitates correct cell repopulation. However, in noncontained bone defects like one walled infrabony periodontal defect or sites with horizontal bone loss, regeneration of bone still remains an unrealistic situation since osseous topography at such sites does not favor membrane stability or bone grafts retention. This case report presents a promising technique to augment bone in areas with horizontal loss.

Technique

Augmentation of bone in the interdental area with horizontal bone loss was accomplished by building a contained defect using a unique self sustaining calcium phosphate cement formulation. The calcium phosphate barrier stimulates the lost cortical plates and promotes graft retention and clot stability. At 6 months, there was a significant bone fill and trabecular formation in the interdental area and reduction in tooth mobility.

Conclusion

This promising technique could prove to be a good alternative to the conventional approaches for treating osseous deformities.

Clinical significance

Calcium phosphate is a promising barrier graft for repair of noncontained periodontal osseous defect. This technique cues both the clinicians and manufacturers to develop moldable tissue engineered constructs for osseous repair.

How to cite this article

Chopra A, Sivaraman K, Awataramaney TK. Calcium Phosphate Barrier for Augmentation of Bone in noncontained Periodontal Osseous Defects: A Novel Approach. J Contemp Dent Pract 2014;15(6):779-783.
Early and Immediate Loading Protocols for Overdentures in Completely Edentulous Maxillas: A Comprehensive Review of Clinical Trials
Authors: Alfadda Sara Abdulaziz
Published: March 2015

A comprehensive review was conducted to answer the question ‘Does the immediate loading of dental implants with an overdenture in the maxilla provide predictable clinical and psychological outcomes?’ Detailed search strategies were used to identify pertinent articles in English that were published between 1975 and August 2013 and indexed in PubMed, MEDLINE, Embase, The Cochrane Central Register of Controlled Trials, and a personal library; in addition, relevant journals were manually searched. Only randomized controlled clinical trials (RCTs), controlled clinical trials (CCTs), and prospective studies with a follow-up period of at least one year, all involving 10 or more adult participants, were considered. Six prospective studies reporting on outcomes of up to 2 years were included, five of which employed a bar-retained overdenture, and one of which used a ball attachment as a retention mechanism. Short term reports demonstrate that immediate/early loading of dental implants with a maxillary overdenture is a predictable treatment approach and results in favorable implant/prosthesis survival, soft tissue health, and patient satisfaction outcomes. However, for a definitive conclusion, well-designed long-term trials are required to establish a consensus on treatment planning, longevity, longterm complications and maintenance, cost-effectiveness, and patients-mediated outcomes.

How to cite this article

Alfadda SA. Early and Immediate Loading Protocols for Overdentures in Completely Edentulous Maxillas: A Comprehensive Review of Clinical Trials. J Contemp Dent Pract 2014;15(6):797-805.
Halitosis: A Review of the Etiologic Factors and Association with Systemic Conditions and its Management
Authors: Ahmad Zeeshan H
Published: March 2015

Halitosis is a general term defined as an unpleasant or offensive odor emanating from the breath, arising from either oral or nonoral sources. Extraoral factors, such as ear-nosethroat conditions or gastrointestinal, respiratory, and systemic diseases, may also contribute to oral malodor. Although, halitosis has a multifactorial etiology, local factors play an important role in the majority of cases. Halitosis may lead to significant personal discomfort and social embarrassment. Assessment of halitosis can be performed using organoleptic measurements, sulfide monitoring, gas chromatography, microbial testing and chemical test strips. Management approaches are based on masking oral malodor, reducing the levels of volatile organic compounds (VOCs) and volatile sulfur compounds (VSCs), and mechanical and/or chemical treatment. This review aims to identify the etiology of oral halitosis, describe the methods available for assessment and differential diagnosis and introduce a variety of management strategies. The importance of a multidisciplinary approach for the improvement of overall health and for the management and prevention of halitosis is highlighted.

How to cite this article

Mokeem SA. Halitosis: A Review of the Etiologic Factors and Association with Systemic Conditions and its Management. J Contemp Dent Pract 2014;15(6):806-811.
Evaluation of Medicinal Interventions for the Management of Oral Submucous Fibrosis: A Systematic Review of the Literature
Authors: Awan Kamran Habib , Habib Syed Rashid , Pejcic Ana , Zain Rosnah Binti
Published: March 2015

Oral submucous fibrosis is a chronic, progressive scarring disease associated with both significant morbidity including pain and limited mouth opening and an increased risk for malignancy. This systematic review evaluated the different medicinal (i.e. nonsurgical) interventions available for the management of oral submucous fibrosis.

An automated literature searches of online databases from January 1960 to December 2013 were performed and only studies with high level of evidence based on the guidelines of the Oxford Centre for evidence-based medicine were selected. Thirteen studies (3 randomized controlled trials and 10 clinical trials/controlled clinical trials) were included and drugs like steroids, hyaluronidase, human placenta extracts, chymotrypsin and collagenase, pentoxifylline, nylidrin hydrochloride, iron and multivitamin supplements including lycopene were used. There is a clear lack of evidence on the available drug treatment for oral submucous fibrosis and further high quality randomized controlled trials are needed to evaluate the different therapeutic agents.

How to cite this article

Awan KH, Patil S, Habib SR, Pejcic A, Zain RB. Evaluation of Medicinal Interventions for the Management of Oral Submucous Fibrosis: A Systematic Review of the Literature. J Contemp Dent Pract 2014;15(6):812-817.
Explaining variance in black carbon's aging timescale
Authors: Fierce L. , Riemer N. , Bond T. C.
Published: March 2015

Abstract. The size and composition of particles containing black carbon (BC) are modified soon after emission by condensation of semivolatile substances and coagulation with other particles, known collectively as "aging" processes. Although this change in particle properties is widely recognized, the timescale for transformation is not well constrained. In this work, we simulated aerosol aging with the particle-resolved model PartMC-MOSAIC (Particle Monte Carlo – Model for Simulating Aerosol Interactions and Chemistry) and extracted aging timescales based on changes in particle cloud condensation nuclei (CCN). We simulated nearly 300 scenarios and, through a regression analysis, identified the key parameters driving the value of the aging timescale. We show that BC's aging timescale spans from hours to weeks, depending on the local environmental conditions and the characteristics of the fresh BC-containing particles. Although the simulations presented in this study included many processes and particle interactions, we show that 80% of the variance in the aging timescale is explained by only a few key parameters. The condensation aging timescale decreased with the flux of condensing aerosol and was shortest for the largest fresh particles, while the coagulation aging timescale decreased with the total number concentration of large (D >100 nm), CCN-active particles and was shortest for the smallest fresh particles. Therefore, both condensation and coagulation play important roles in aging, and their relative impact depends on the particle size range.
Potential source regions and processes of the aerosol in the summer Arctic
Authors: Heintzenberg J. , Leck C. , Tunved P.
Published: March 2015

Abstract. Sub-micrometer particle size distributions measured during four summer cruises of the Swedish icebreaker Oden 1991, 1996, 2001, and 2008 were combined with concurrent gas data, back trajectories and daily maps of pack ice cover in order to investigate source areas and aerosol formation processes of the boundary layer aerosol in the central Arctic. With a clustering algorithm potential aerosol source areas were explored. Clustering of particle size distributions together with back-trajectories delineated five potential source regions and three different aerosol types that covered most of the Arctic basin. Clustering the open water information along the trajectories clearly separated marine from pack ice aerosol. Clustering the two subpopulations above and below the 50% value of average open water during the course of the trajectories yielded further details about marine and pack ice aerosol sources. In the pack ice subpopulation three potential source areas over the pack ice with very low percentages of open water from which aged aerosol with only one major mode around 40 nm derived. A significant difference between newly formed and aged aerosol over the pack ice became clear when comparing the course of open water under the trajectories for these two aerosol types. In both subpopulations the air had spent ten days over pack ice with less than 50% open water while traveling over ever more contiguous ice. Trajectories connected with high concentrations of newly formed small particles, however, experienced more open water during the last four days before arrival in heavy ice conditions at Oden. Thus we hypothesize that both, long travel times over the more contiguous ice, combined with more open water conditions during the last days before air mass arrival were an essential factor controlling the formation of ultrafine particles over the central Arctic pack ice. A comparison the Oden data with summer size distribution data from Alert, Nunavut and Mt. Zeppelin, Spitsbergen confirmed the Oden findings with respect to particle sources over the central Arctic.