Background: Esthetic correction represents one of the clinical conditions that required the use of laminate veneers in premolars region. Aim of the study: The purpose of this study was to evaluate the fracture strength of the laminate veneers in maxillary first premolars, fabricated from either composite (direct and indirect techniques) or ceramic CAD/CAM blocks. Materials and Methods: Fifty sound human maxillary premolar teeth were used in this in vitro study. Teeth were divided randomly into one control group and four experimental groups of ten teeth each; Group A: Restored with direct composite veneer (Filtek Z250 XT), Group B: Restored with indirect composite veneers (Filtek Z250 XT), Group C: Restored with lithium disilicate ceramic CAD/CAM blocks (IPS e. max CAD) and Group D: Restored with resin nano ceramic CAD/CAM blocks (Lava Ultimate Restorative). Standard preparations were done using Ceramic Veneer Set (Komet). Indirect laminate veneers were cemented with the Relyx Veneer Cement (3M ESPE) and all specimens were stored in distilled water at 37°C for 2 weeks. The load was applied on the occlusal part of the veneer at 45˚ to long axis of the tooth using universal testing machine. Results were analyzed with one-way ANOVA and LSD tests. Specimens were examined by stereomicroscope at a magnification of 20x to evaluate the mode of failure. Results: Control group showed higher mean of fracture strength with highly significant difference in comparison to the experimental groups (P<0.01). (Group A) showed higher mean of fracture strength with statistically significant difference in comparison to (Group B and Group D). On the other hand the difference between (Group A and Group C) was statistically highly significant. Statistically non-significant difference was found among the three indirectly restored groups. Conclusions: All veneers used in this study can be considered as acceptable treatment in the premolars region for patients with normal biting force. Direct composite veneer is the most favorable technique in term of fracture strength, while IPS e. max CAD laminate veneers were least likely to fracture and most likely to completely debond.
The population density of the insect on Alorat and fruits located in the lower part of the tree more than the middle part of the plant and insect in one place and demonstrates that there is a nest there were conducted laboratory and field studies on citrus Hsasahanwaa and the Alvdaúaa distribution of cortical insect yellow ....
In this study, the performance of the adaptive optics (AO) system was analyzed through a numerical computer simulation implemented in MATLAB. Making a phase screen involved turning computer-generated random numbers into two-dimensional arrays of phase values on a sample point grid with matching statistics. Von Karman turbulence was created depending on the power spectral density. Several simulated point spread functions (PSFs) and modulation transfer functions (MTFs) for different values of the Fried coherent diameter (ro) were used to show how rough the atmosphere was. To evaluate the effectiveness of the optical system (telescope), the Strehl ratio (S) was computed. The compensation procedure for an AO syst
... Show MoreThe extraction of Basil oil from Iraqi Ocimum basillicum leaves using n-hexane and petroleum ether as organic solvents were studied and compared. The concentration of oil has been determined in a variety of extraction temperatures and agitation speed. The solvent to solid ratio effect has been studied in order to evaluate the concentration of Ocimum basillicum oil. The optimum experimental conditions for the oil extraction were established as follows: n-hexane as organic solvent, 60 °C extraction temperature, 300 rpm agitation speed and 40:1mL:g amount of solvent to solid ratio.
This paper investigates the issue of surface-type effects on traffic noise in Baghdad. Since the raw materials for both flexible and rigid paving are available from local sources, the decision on selecting the type of paving which depends on the budget of the project and the road's importance and function. Knowing that for high traffic volumes and a high percentage of heavy vehicles, rigid pavement is more suitable compared to flexible pavement. In Baghdad, some highways consist of flexible pavement and others of combined pavement (flexible segments and rigid segments), so the study of the effect of surface type on traffic noise becomes an important matter. This study selected three highways: one with flexible pavement and two with combined
... Show MoreThe estimation of the amounts of Surface runoff resulting from rainfall in the water basins is of great importance in water resources management. The study area (Bahr Al-Najaf) is located on the western edge of the plateau and the southwestern part of the city center of Najaf, with an area of 2729.4 (km2). The soil and water assessment tool (SWAT) with ArcGIS software was used to simulate the runoff coming from the three main valleys (Kharr (A and B)), Shoaib Al-Rahimawi, and Maleh), that contribute the flow to the study area. The results of the model showed that the SWAT software was successfully simulating the flow conditions based on the coefficient of determination (R2), the Nash coefficient (NS
... Show MoreFive species of Trogoderma Berthold are reported from Iraq. These are: I inclus,n LeCont. T.
granarium Everts, T. variable Ballion. I. bactrianum Zantiev and T. irroraturn Reitter. A key
to the species is presented, with redeseriptions and illustrations of all species.
The design processes in general and the design system in particular need to be studied and knowledge. Based on this vision, we find the need for constant research on the design processes, and the subject of the techniques of the designs of the covers of children magazines did not have the view of the researchers to make them the subject of study, For the subject of this research, the problem of research is determined according to the following question:
- What are the methods used in designing children magazine covers in Iraq?
Through this research we seek to find solutions to this question as well as it will serve the cognitive side of a modern study and development of a broader understanding of the subject. Through four
... Show MoreIn this research, two drugs were bonded through amide and ester attachment, using lactic acid as aspacer binder, produced di pro drug such as Procain and Ciprofloxacin. Since Procain has ailocail anesthetic action and Ciprofloxacin as antibacterial drug was reacted with lactic acid produced ester compound (1), then the carboxylic acid of lactic acid could reacted with free Procain oil produced amide attachment, the controlled drug release in different pH values at 37C˚was studied to improve their characteristic and to minimize the side effect of the drug could be used in broad spectrum activity as atherapeutic material.This mutual prodrug was used with another biological active drug instead of single action. The prepared prodrug was charac
... Show MoreObjective: to assess the Nursing College students' health-protective behaviors (HPBs) and their
association with some sociodemograghic characteristics.
Methodology: A sample of 100 Students (males and females) was selected through a systematic
random sample that were at the third and fourth year of Nursing College in Baghdad University for the
period of April 1st through April 30th 2007. Data were collected through the use of a self-report
instrument that used for Americans as HPBs assessment that contains 23 items. Reliability and validity
of the tool were determined through a pilot study. A descriptive statistical approach (frequencies and
percentages) and inferential statistical approach (chi-square) were used for