Background: Maxillary first premolar with wide MOD cavity more susceptible to fracture. The aim of this study was to assess the influence of cavity design for cusp coverage on the fracture resistance of weakened maxillary first premolar restored with CAD/CAM hybrid ceramic versus nanohybide composite. Materials and Methods: Fifty six intact maxillary first premolars of approximately comparable sizes were divided into seven groups eight for each: Group A: Intact teeth (control group); Group B: teeth prepared for MOD inlay; Group C: teeth prepared for MOD onlay covering the lingual cusp; Group D: teeth prepared for MOD covering buccal and lingual cusps ,the previous three groups indirectly restored with nanohybrid composite (3M ESPE Z 250 XT); Group E,F,G prepared with the same design as group B, C, D respectively and restored with CAD/CAM hybrid ceramic (VITA ENAMIC). Results: An axial compression test was used to measure the fracture strength of experimented teeth. The readings were analyzed statistically by t-test, one way ANOVA and LSD, then the mode of fracture had been examined. The results showed that sound teeth in group (A) had more fracture resistance values than all experimental groups and the difference were highly significant with group (B, E, F, G).When the influence of cavity design tested among composite groups it showed highly significant difference between group (B) and (C)and the highest fracture resistance value was for group(C), whereas the influence of cavity design among Enamic groups showed highly significant difference between group (E) and (G) the highest fracture resistance value was for group(E).T-test between similar designs showed non-significant difference between MOD groups and highly difference between other groups. Conclusions: Cusp coverage increased the fracture resistance of composite groups but result in non-restorable fracture, while Enamic total onlay presented promising fracture resistance with favorable mode of fracture. Key words: Fracture resistance, CAD/CAM, hybrid ceramic, VITA ENAMIC, nanohybrid composite, cusp coverage.
The purpose of this paper is to give some results theorems , propositions and corollaries concerning new algebraic systems flower , garden and farm with accustomed algebraic systems groupoid , group and ring.
In the present study a new synthesis method has been introduced for the decoration of platinum(Pt) on the functionalized graphene nanoplatelet (GNP) and also highlighted the preparation method of nanofluids. GNP–Pt uniform nanocomposite was produced from a simple chemical reaction procedure, which included acid treatment for functionalization of GNP. The surface characterization was performed by various techniques such as XRD, FESEMand TEM. The effective thermal conductivity, density, viscosity, specific heat capacity and stability of functionalized GNP–Pt water based nanofluids were investigated in different instruments. The GNP–Pt hybrid nanofluids were prepared by dispersing the nanocomposite in base fluid without adding any surfac
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The experiment was conducted at the plant tissue culture laboratory of the Department of Horticulture and Garden Engineering College of Agricultural Engineering Sciences, University of Baghdad, in order to study the effect of some growth regulators on propagation an stimulation production of volatile oil compounds of rosemary plant Rosmarinus officinlis using two vegetative parts (apical and lateral buds). Factorial experiment was implemented in completely randomized design with twenty replications. The results indicated that culturing the apical meristem on the medium Murashige and Skoog (MS) media with 0.5 mg.l-1 (BA) with 0.1 mg.l-1 of NAA gave the highest response rate of 100%. As for the doubling stage, the levels of BAA and IAA (Indol
... Show MoreBackground: Entamoeba histolytica is the causative agent of amoebic dysentery and hepatic abscesses. Despite the efficacy of metronidazole in alleviating infectious diseases, the global dissemination of drug-resistant parasites raises the possibility that Punica granatum could serve as an effective natural alternative treatment. Objective: To evaluate the effect of P. granatum methanolic and aqueous extracts of various parts against E. histolytica trophozoites in an in vitro setting. Methods: Various concentrations (0.14, 0.7, 1.4, and 2.8 mg/ml) of P. granatum extracts of the flowers, leafs, peels, and seeds were chosen for this purpose. A culture medium containing 0.05x106/ml E. histolytica trophozoites was treated with different
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Catalytic reforming of naphtha occupies an important issue in refineries for obtaining high octane gasoline and aromatic compounds, which are the basic materials of petrochemical industries. In this study, a novel of design parameters for industrial continuous catalytic reforming reactors of naphtha is proposed to increase the aromatics and hydrogen productions. Improving a rigorous mathematical model for industrial catalytic reactors of naphtha is studied here based on industrial data applying a new kinetic and deactivation model. The optimal design variables are obtained utilizing the optimization process in order to build the model with high accuracy and such design parameters are then applied to get the best configuration of this pro
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<p>The popularity, great influence and huge importance made wireless indoor localization has a unique touch, as well its wide successful on positioning and tracking systems for both human and assists also contributing to take the lead from outdoor systems in the scope of the recent research works. In this work, we will attempt to provide a survey of the existing indoor positioning solutions and attempt to classify different its techniques and systems. Five typical location predication approaches (triangulation, fingerprinting, proximity, vision analysis and trilateration) are considered here in order to analysis and provide the reader a review of the recent advances in wireless indoor localization techniques and systems to hav
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Abstract:
Through the research, I have briefly discussed the life of Imam Ali and
indicated the interpretation of the Qur'an by language and terminology, the
importance and characteristics of Sahabas', may Allah be pleased with them,
interpretation of the Qur'an. Also, the sayings of Imam Ali, wich included the
explanatory interpretation of the Qur'an by the Qura'n, Sunnah, language, and
correct opinion. I have also indicated the reasons of the Quran's revelation
and the readings of the Qura'n that had been received from him including the
interpretive meaning these readings revealed. Finally, I concluded my
research with the most important results and recommends.
Background: Humeral diaphyseal fracture usually
heals with closed methods but when nonunion
develops then it needs surgical intervention in the
form of plating and bone grafting, intramedulary
nailing (open or closed simple or interlocking nails)
and external fixators (circular or one plane fixator).
In our unit we treated non union humeral
diaphyseal fracture with plating and bone grafting
shortening of fracture ends up to 4 to 5cm when
needed. Methods: This study was conducted at
Orthopaedic Department of AL-Sadar General
Hospital from January 2004 till December2005 .
We included 20 cases with atrophic non-union in
12(60%) and hypertrophic non-union in 8 (40%)
patients. All atrophic non-union w