Preferred Language
Articles
/
jbcd-638
Evaluation of shear bond strength of zirconia to tooth structure after different zirconia surface treatment techniques
...Show More Authors

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.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Nov 01 2019
Journal Name
International Journal Of Computer Science And Mobile Computing
Adaptive Color Image Compression of Hybrid Coding and Inter Differentiation Based Techniques
...Show More Authors

Publication Date
Thu Jul 28 2016
Journal Name
Computer And Information Science
Refinement for Ocular Ultrasound Images Quality by Utilizing Combination of Enhancement Techniques
...Show More Authors

Ultrasound has been used as a diagnostic modality for many intraocular diseases, due its safety, low cost, real time and wide availability. Unfortunately, ultrasound images suffer from speckle artifact that are tissue dependent. In this work, we will offer a method to reduce speckle noise and improve ultrasound image to raise the human diagnostic performance. This method combined undecimated wavelet transform with a wavelet coefficient mapping function: where UDWT used to eliminate the noise and a wavelet coefficient mapping function used to enhance the contrast of denoised images obtained from the first component. This methods can be used not only as a means for improving visual quality of medical images but also as a preprocessing

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon May 15 2023
Journal Name
Iraqi Journal Of Science
Optimal Spatial Distribution of Gasoline Stations in Baghdad Province Utilizing GIS Techniques
...Show More Authors

Studying the spatially distribution pattern of fuel station in province of Baghdad
was done by utilizing GIS techniques which they are the most powerful tools for
design, display and analysis for the spatial data. Nearest Neighbor Analysis method
was applied for analyzing the spatial distributions of the fuel stations. Baghdad was
considered to be divided in to two main parts (outskirts of Baghdad and center of
Baghdad). The nearest neighbour for all parts of Baghdad indicates for the
distribution pattern is random and differs from place to another in randomly rate.

View Publication
Publication Date
Sat Feb 20 2010
Journal Name
Indian Journal Of Science And Technology
Investigation on picosecond laser ablation of dental material using FIB/SEM techniques
...Show More Authors

View Publication
Scopus (1)
Crossref (1)
Scopus Crossref
Publication Date
Thu Jul 20 2023
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Comparison of Some Numerical Simulation Techniques for COVID-19 Model in Iraq
...Show More Authors

The aim of our study is to solve a nonlinear epidemic model, which is the COVID-19 epidemic model in Iraq, through the application of initial value problems in the current study. The model has been presented as a system of ordinary differential equations that has parameters that change with time. Two numerical simulation methods are proposed to solve this model as suitable methods for solving systems whose coefficients change over time. These methods are the Mean Monte Carlo Runge-Kutta method (MMC_RK) and the Mean Latin Hypercube Runge-Kutta method (MLH_RK). The results of numerical simulation methods are compared with the results of the numerical Runge-Kutta 4th order method (RK4) from 2021 to 2025 using the absolute error, which prove

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Dec 18 2017
Journal Name
Al-khwarizmi Engineering Journal
Path Planning of an autonomous Mobile Robot using Swarm Based Optimization Techniques
...Show More Authors

This paper presents a meta-heuristic swarm based optimization technique for solving robot path planning. The natural activities of actual ants inspire which named Ant Colony Optimization. (ACO) has been proposed in this work to find the shortest and safest path for a mobile robot in different static environments with different complexities. A nonzero size for the mobile robot has been considered in the project by taking a tolerance around the obstacle to account for the actual size of the mobile robot. A new concept was added to standard Ant Colony Optimization (ACO) for further modifications. Simulations results, which carried out using MATLAB 2015(a) environment, prove that the suggested algorithm outperforms the standard version of AC

... Show More
View Publication Preview PDF
Crossref (18)
Crossref
Publication Date
Sun Mar 02 2008
Journal Name
Baghdad Science Journal
Developing production techniques of copper powder less than 125 micron without grinding
...Show More Authors

View Publication Preview PDF
Crossref
Publication Date
Sun Jul 02 2023
Journal Name
Iraqi Journal Of Science
Seismic Structural –Stratigraphic Study of Dhufria Area (Mid -Iraq) Using (3D) Techniques
...Show More Authors

This study deals with the seismic reflection interpretation of lower Cretaceous Formations in Dhufria area, including structural and stratigraphic techniques. In the interpretation process, the 3-D seismic data volume and well logs have been used. Based on well logs and synthetic traces two horizons were identified and picked which are the top and bottom of Zubair Formation. These horizons were followed over all the area in order to obtain structural setting as well as studying Kirkuk group Formation of Tertiary age which represents highstand progradational seismic facies.

View Publication Preview PDF
Publication Date
Sat Feb 09 2019
Journal Name
Journal Of The College Of Education For Women
The Effect of Assessment Techniques on EFL Learners’ achievement in TOEFL Test
...Show More Authors

While many educators are highly focused on state test, it is important to consider that
over the course of a year, instructors can build in many opportunities to assess how learners
are learning. Therefore, assessment techniques are considered a good method to get benefit
for both instructors and learners in the process of teaching and learning. The sample consists
of 27 learners who participated in TOEFL training course in the Development and Continuous
Education Centre. Validity and reliability were verified.
To fulfill the aims and verify the hypothesis which reads as follows” It is hypothesized
that the TOEFL learners' scores will not be increased after TOEFL course training.” T-test
for two dependent samp

... Show More
View Publication Preview PDF
Publication Date
Sun Jun 20 2021
Journal Name
Baghdad Science Journal
The Impact of Fear and Rational Appeal Scam Techniques on Individual Susceptibility
...Show More Authors

Scams remain among top cybercrime incidents happening around the world. Individuals with high susceptibility to persuasion are considered as risk-takers and prone to be scam victims. Unfortunately, limited number of research is done to investigate the relationship between appeal techniques and individuals' personality thus hindering a proper and effective campaigns that could help to raise awareness against scam. In this study, the impact of fear and rational appeal were examined as well as to identify suitable approach for individuals with high susceptibility to persuasion. To evaluate the approach, pretest and posttest surveys with 3 separate controlled laboratory experiments were conducted. This study found that rational appeal treatm

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Clarivate Crossref