Background: This study aimed to evaluate the effect of zirconia different surface treatments (primer, sandblast with 50μmAl2O3, Er,Cr:YSGG laser) on shear bond strength between zirconia surface and resin cement. Material and methods: Sixty presintered Y-TZP zirconia cylinder specimens (IPS e.max ZirCAD, Ivoclar vivadent) will be fabricated and sintered in high temperature furnace of (1500 C for 8 hours) according to manufacturer’s instructions to the selected size and shape of (5mm. in diameter and 6mm in height). All specimens were ground flat using 600.800.1000.1200, aluminum oxide abrasive paper to obtain a standardized surface roughness. Surface roughness values were then recorded in µm using surface roughness tester (profilometer) to obtain a standardized data base line for all samples. The specimens were then randomly divided into three main groups (n=20); group A: no surface treatment (control group), group B: specimens in this group treated with 50μm Al2O3 and group C: specimens in this group treated with Er,Cr:YSGG laser. Sixty sound human premolars were used in this study, after construction of acrylic blocks, the occlusal surface of the teeth were ground flat, with diamond cutting disk to obtain a flat dentine surface . Prior to cementation of zirconia cylinders to tooth specimens subgroups (A1,B1,C1) will receive a coat of metal/zirconia primer and left to react for three minutes, while the subgroups (A2,B2,C2) were left undisturbed. Bonding surface of zirconia cylinder was then luted with SpeedCEM self adhesive resin cement under a static load of 2Kg. placed on the vertical arm of the surveyor and allowed to auto cure for 4minutes.The final cemented specimens were then stored in distilled water at room temperature for 24hours. All specimens were subjected to shear loading force in a universal testing machine at crosshead speed of 1mm/min. The shear bond strength values were analyzed statistically with one-way ANOVA; the fractured surfaces of zirconia cylinders were examined with a stereo-microscope to observe the failure mode. Results: The air borne-particle of 50μm followed by primer application showed significantly the higher bond strength than other groups. Conclusion : Within the limitation of this study, the results showed that sandblasting the bonding surface of zirconium cylinders with 50μmAl2O3 produced the highest values of shear bond strength , also the use of primer enhanced shear bond strength as well. Keyword: zirconia surface treatments, shear bond strength.
In the current study, a direct method was used to create a new series of charge-transfer complexes of chemicals. In a good yield, new charge-transfer complexes were produced when different quinones reacted with acetonitrile as solvent in a 1:1 mole ratio with N-phenyl-3,4-selenadiazo benzophenone imine. By using analysis techniques like UV, IR, and 1H, 13C-NMR, every substance was recognized. The analysis's results matched the chemical structures proposed for the synthesized substances. Functional theory of density (DFT)
has been used to analyze the molecular structure of the produced Charge-Transfer Complexes, and the energy gap, HOMO surfaces, and LUMO surfaces have all been created throughout the geometry optimization process ut
In this article, a numerical study of compressible and weak compressible Newtonian flows is achieved for a time marching, Galerkin algorithm. A comparison between two numerical techniques for such flows, namely the artificial compressibility method (AC–method) and the fully artificial compressibility method (FAC–method) is performed. In the first artificial compressibility parameter ( is added to the continuity equation, while this parameter is added to both continuity and momentum equations in the second technique. This strategy is implemented to treat the governing equations of Newtonian flow in cylindrical coordinates (axisymmetric). Particularly, this study concerns with the effect of the artificial compressibility p
... Show MoreThe research included preparation of new iron(II) complexes with mixed ligands including benzilazine(BA) and semicarbazone ligands {benzilsemicarbazone- BSCH or benzilbis(semicarba-zone)- BBSCH2 or salicylaldehydesemicarbazone- SSCH2 or benzoinsemicarbazone- B'SCH2}.by classical and microwave methods. The resulted complexes have been characterized using chemical and physical methods. The study suggested that the above ligands form ionic complexes having formulae [Fe(SCHi)(BA)(Cl)m](Cl)2-m {where SCH, BSCH, BBSCH2, SSCH¬2 or B'SCH2 ligands; m=1 or 2}. Hexacoordinated mononuclear complexes have been investigated by this study and having octahedral geometries. The effect of laser ray type visible region have been studied on solid ligands and
... Show MoreThe research (Anthropology and Representations of magic in Arab Theatrical Text, Harut and Marut's play as a Model) is concerned with studying magic and the forms of its presence in the theatrical text in different human cultures where it belongs. The research consists of four chapters.
The first chapter includes the research problem that revolves around the following questions: (what is the mechanism of employing magic anthropology and its representations in the Arab theatrical text Harut and Marut's play as a model?), and the research importance which is attributed to the necessity of studying (magic) in the Arab theatrical text as it is considered the inauguration of one of the social phenomena that many researchers in the field o
Suppose that is a finite group and is a non-empty subset of such that and . Suppose that is the Cayley graph whose vertices are all elements of and two vertices and are adjacent if and only if . In this paper, we introduce the generalized Cayley graph denoted by that is a graph with vertex set consists of all column matrices which all components are in and two vertices and are adjacent if and only if , where is a column matrix that each entry is the inverse of similar entry of and is matrix with all entries in , is the transpose of and . In this paper, we clarify some basic properties of the new graph and assign the structure of when is complete graph , complete bipartite graph and complete
... Show MoreUrban land price is the primary indicator of land development in urban areas. Land prices in holly cities have rapidly increased due to tourism and religious activities. Public agencies are usually facing challenges in managing land prices in religious areas. Therefore, they require developed models or tools to understand land prices within religious cities. Predicting land prices can efficiently retain future management and develop urban lands within religious cities. This study proposed a new methodology to predict urban land prices within holy cities. The methodology is based on two models, Linear Regression (LR) and Support Vector Regression (SVR), and nine variables (land price, land area,
... Show MoreThis paper tries to understand the poetic reference in the images of woman, she-camel, horse and their manifestations in Tarafah-ibnulAbd's poetry. There has got my attention the fact that these three images have their own distinct taste which is characterised by a clear rhythm, let alone the lively nature that is filled with liveliness and activity to be in harmony with the poet's youth. For these three images represented the best manifestations of his psychological and artistic poetics. The paper adopts an artistic analysis to arrive at the psychological aspects of these experiences-the woman, the she-camel, and the horse- and to understand the functions of their images and symbolic reference.
A total of 320 samples of vaginal swabs was obtained from women complaining of vaginal infection and attending two hospitals in Al-Sader city, Baghdad, namely Ibn AlBaladi Hospital for Pediatrics and Gynecology and Fatimat Al-Zahraa Hospital for Obstetrics in Al-Habibia district during the period from Desember 1997 till July 1998. Results of direct smear and culture showed that Trichomonas vaginalis infection occurred in 19.1%, in addition to some microorganisms. The most common infection was by Candida spp. (24.7%), followed by Gardnerella vaginalis (13.8%) and Staph. aureus (10.9%). Infection with Escherichia coli, Klebsiella spp. and Prote
... Show Morethe bank sect for any country is very important because its represent a major nerve to feed a verity economic and finance activities .development any state measure by development banking sets and its represent important factor to investors attract . and because important of this subject ,teen accounting rule is a specialized for it .its related by Disclosures in the Financial Statements Of Banks and The Similar Institutions, its accredit by auditing and accounting standard consul in republic of Iraq.in date 10/28/1998. &
... Show More