Background: 37% phosphoric acid (PA) is the traditional enamel etching technique prior to bracket adhesion, yet it has been implicated in numerous enamel injuries. The purpose of the current study was to create a calcium phosphate (CaP) etching paste in a simplified capsule formula that can underpin clinically adequate bracket bond strength without jeopardizing the integrity of enamel upon the debracketing procedure. Materials and Methods: micro-sized hydroxyapatite (HA) powder was mixed with 40% PA solution to prepare experimental acidic CaP paste. Sixty human premolars were assigned into two groups of 30 each. Enamel conditioning was accomplished using 37% PA-gel for control group and CaP paste for experimental group. Each group was further divided into two subgroups regarding the water storage (WS) period (24 h and 30 days). Shear bond strength (SBS) test conducted with examination of debonded surfaces for adhesive remnants and enamel damage using a digital microscope. Results: CaP paste produced significantly lower SBS values than PA (p < 0.01), yet sufficient for clinical use. PA etching caused often cracked enamel surfaces with excessive retention of adhesive remnants (mainly ARI scores 2 and 3). Contrarily, enamel treated with the experimental CaP paste exhibited smooth, unblemished surfaces mostly clean of adhesives residues (scores 0 and 1). Conclusion: a newly developed CaP paste in a capsule formula fosters clinically adequate bracket adhesion with a sustained bonding performance, allows a harmless bracket removal with minimal or no adhesive residues on debonded surfaces; thus, it can be introduced as a suitable alternative to PA.
The study aims to identify the Traumatic Symptoms (physiological, emotional, and cognitive) of earthquakes among the targeted sample; it also aims to identify the significant differences between psychological, emotional, and cognitive traumatic symptoms of earthquakes according to the gender and age of participants. The study additionally seeks to identify thepsychological positive-negative reactions associated with earthquakes according to gender and age of the participants. To measure the traumatic symptoms of earthquakes, a 4-point Likert scale questionnaire with (20) items (questions) accompanied with a 4-point Likert scale questionnaire with (18) items (questions) were used to measure the Psychological positive-n
... Show MoreLinear programming currently occupies a prominent position in various fields and has wide applications, as its importance lies in being a means of studying the behavior of a large number of systems as well. It is also the simplest and easiest type of models that can be created to address industrial, commercial, military and other dilemmas. Through which to obtain the optimal quantitative value. In this research, we dealt with the post optimality solution, or what is known as sensitivity analysis, using the principle of shadow prices. The scientific solution to any problem is not a complete solution once the optimal solution is reached. Any change in the values of the model constants or what is known as the inputs of the model that will chan
... Show MoreThis research study Blur groups (Fuzzy Sets) which is the perception of the most modern in the application in various practical and theoretical areas and in various fields of life, was addressed to the fuzzy random variable whose value is not real, but the numbers Millbh because it expresses the mysterious phenomena or uncertain with measurements are not assertive. Fuzzy data were presented for binocular test and analysis of variance method of random Fuzzy variables , where this method depends on a number of assumptions, which is a problem that prevents the use of this method in the case of non-realized.
This study was conducted to investigate thyroid function and Anti-Müllerian hormone (AMH) in (Chronic kidney disease) CKD patients by evaluating their levels in CKD patients, 50 patients were diagnosed to have CKD stage-5, their ages ranged between 20-50 years (25 males and 25 females) who attended the Nephrology and Transplant Center in Medical City of Baghdad- Iraq, they were recruited from April 2018 to July 2018 and were enrolled into the study. The control group consisted of 20 healthy individuals, their ages ranged between 20-48 years (10 males and 10 females). The study showed non-significant (p>0.05) increase in AMH level in CKD patients compared to the control group. On the other hand, TSH was recorded a highly significant (
... Show MoreAbstract: The present study aimed to evaluate calcium, potassium, albumin, protein, creatinine, urea, uric acid levels, and the level of total sialic acid in the sera of patients with chronic renal failure who had been infected with Hepatitis C virus and in the sera of patients with chronic renal failure, and compare them with healthy volunteers. A total of 90 subjects with age 25-55 years, were divided into three groups. G1 represents 30 patients with chronic renal failure who had treated by dialysis and infected with chronic Hepatitis C virus (positive group). G2 represents 30 patients with chronic failure who had been treated by dialysis (negative group), while G3 represents 30 healthy volunteers (control group). The results showed
... Show MoreThis study aims at finding out the sentimental smartness of the kindergarten children
and its relationship with some variables.
1- The level of the sentimental smartness of the kindergarten children.
2- Investigating the Zero hypothesis in that there are no significant statistical differences in
the sentimental smartness between the kindergarten children according to the sex variables
(males and females).
Some statistical tools have been used in order to arrive at the results that verify the
hypotheses of this study. The researcher uses (1) the distinctive power between two
distinctive groups; (2) the relationship between the item and the total degree (Pearson
correlation factor); and (3) Elfakronbach formula t
The great scientific progress has led to widespread Information as information accumulates in large databases is important in trying to revise and compile this vast amount of data and, where its purpose to extract hidden information or classified data under their relations with each other in order to take advantage of them for technical purposes.
And work with data mining (DM) is appropriate in this area because of the importance of research in the (K-Means) algorithm for clustering data in fact applied with effect can be observed in variables by changing the sample size (n) and the number of clusters (K)
... Show MoreIn the present work, steady, laminar natural convection in nonrectangular enclosures is analyzed numerically with and without fin. Vertical walls insulated while horizontal walls maintained isothermal at different temperature and the fin was placed on horizontal surface. The length of fin was equal (B/L=0.22, 0.44 and 0.66) and thickness of fin was constant. Various parameters are studied: Rayleigh number (from 104 to 107 ), Prandtl number (0.7), number of fin change from (1-3) and aspect ratio (H/L= 0.15 to 0.5). The problem is formulated in terms of the vorticity-stream function procedure. A numerical solution based on program in Fortran 90 with Tec plot program. The finite difference method is used. Streamlines and isotherms are prese
... Show MoreEnzyme activity were studied in the sera of children with leukemia than healthy children, where 31 cases were studied, including 21 cases of patients with acute lymphatic leukemia
