Background: Reduction in bond strength when bonding was done immediately after intracoronal bleaching procedure has been recognized. The purpose of this study is to assess the effect of antioxidants (10% sodium ascorbate (SA), 0.1M thiourea and7% sodium bicarbonate (SB)) on reversing bonding strength of composite resin to bleached dentin. Materials and method: Sixty upper 1st premolar teeth, were selected, the crowns of the teeth were embedded in acrylic resin blocks exposing a flat dentin from the buccal surface, then divided into 6 groups (10 samples each). Bleaching for the experimental groups was performed using 35% hydrogen peroxide bleaching gel (pola–office).Group A (Negative control group; dentin samples immediately bonded with composite without bleaching)Group B (Positive control group; dentin samples bleached and immediately bonded with composite). Group C (Dentin samples bleached and stored for 14 days in DDW then bonded with composite). Group D (Dentin samples bleached and treated with 10% (SA) then immediately bonded with composite). Group E (Dentin samples bleached and treated with 0.1M thiourea then immediately bonded with composite). Group F (Dentin samples bleached and treated with 7% SB then immediately bonded with composite).The shear bond strength was determine using instron testing machine. Results: Bleaching the dentin with 35 % hydrogen peroxide gel for 24 minutes resulted in reduction in bond strength of the bleached teeth when bonding was performed immediately after bleaching. Delayed bonding of composite to the bleached dentin for 14 days will result in a highly significant increase in the shear bond strength. Conclusion: Treating the bleached dentin with 10% (SA) in water base showed a highly significant increase in the shear bond strength of the composite to dentin and reversing the bond strength value to the level of the unbleached dentin. Treating the bleached dentin with 0.1M thiourea significantly increased the shear bond strength of the composite to dentin.
This study included isolation and characterization of extremely halophilic bacteria from Al-Massab Al-Aam region in South of Iraq Fifty isolates were identified by using numerical taxonomy 40 strains belonged to the genus Halobacterium which inclucted Hb. halobium Hb. cutirubrum Hb. salinarium Hb. saccharovorum Hb. valismortis and Hb. volcanii. Ten strains belonged to the genus Halococcus which included Hc. morrhuae Hc. saccharolyticus. Growth curves were sensitive mutants determined for wild type and salt Generation time in logarthmic phase was measured and found to be (10.37 2hr 7 0.59) for Hb. salinarium / 18 (6.490 hr 0.24) for Hb. cutirubrum / 32, (6.700 hr + 0.488) for Hb. valismortis / 20, (11.243 hr + 0.96) for Hb. volcanii / 7. (7
... Show MoreThe research explain the analysis of finance investments through analyze the finance tables for commercial banks, by using the pointers to indicate the limits of economical benefit for these investments, and fix the negative deviations and as well positive, for the purpose of diagnostic the negative (disadvantage) and develop the advantage deviation, For the importance of finance investments in the development operation and economical growth, further to that the finance investments is represent one of the most activities in the commercial banks in which aim the adequate incomes as a result of the commercial banks act to receipt the banks deposits and then make it growth and develop through commercial advantage o
... Show MoreThe sunrise, sunset, and day length times for Baghdad (Latitude =33.34º N, Longitude =44.43º E) were calculated with high accuracy on a daily basis during 2019. The results showed that the earliest time of sunrise in Baghdad was at 4h: 53m from 5 Jun. to 20 Jun while the latest was at 7h: 07m from 5 Jan. to 11 Jan. The earliest time of sunset in Baghdad was at16 h: 55m from 30 Nov. to 10 Dec. whereas the latest was at 19h: 16m from 25 Jun. to 5 Jul. The minimum period of day length in Baghdad was 9h: 57m) in 17 Dec. whereas the maximum period was 14h: 22m) in 20 Jun. Day length was calculated and compared among regions of different latitudes(0, 15, 30, 45 and 60 north).
The aim of this study is to identify the effectiveness of a rational, emotional, behavioral program in developing self-efficacy to reduce the level of Burnout in 20 teachers of students with autism disorder in Jazan, Saudi Arabia. The proposed program included 12 training sessions. The researcher found that the proposed program has contributed significantly to the development of self-efficacy and reduce the level of Burnout for the targeted subject in this study.
In this work an enzyme linked immunosorbent assay (ELISA) technique has been used for detection of some inflammatory markers in serum of acute coronary syndrome (ACS)-Patients Admitted to the cardiac care unit (CCU) of Iraqi Centre For Heart Diseases and Ibn AlNafees Teaching Hospital. The present method includes quantitative measurement of interleukine-6 (IL-6) and C-reactive protein (CRP), as their increase during symptoms may be responsible for identifying the mechanism of myocardial damag, in addition to their best performance than other quantitative tests perhaps due to their association with atherosclerotic process that belongs to the endothelial dysfunction. Aim of this study is to estimate the prevalence and correlation of IL-6 w
... Show MoreResearch aims to identify the immediate impact of the announcement of mergers in the stockholders and the feasibility of gain abnormal return and benefiting from asymmetric information during the announcement that unite 30 days before the announcement of the merger, and announcement day, and 30 days after the announcement of the merger. It was the largest and most important mergers and acquisitions pick that occurred during the global financial crisis, specifically in health care/pharmaceutical industry, Pfizer and Wyeth merger with Novartis acquisition on Alcon. search has adopted three hypotheses: the first hypothesis that ((achieves the target company's shareholders positive abnormal return (or negative) during and befor
... Show MoreIn this research we study a variance component model, Which is the one of the most important models widely used in the analysis of the data, this model is one type of a multilevel models, and it is considered as linear models , there are three types of linear variance component models ,Fixed effect of linear variance component model, Random effect of linear variance component model and Mixed effect of linear variance component model . In this paper we will examine the model of mixed effect of linear variance component model with one –way random effect ,and the mixed model is a mixture of fixed effect and random effect in the same model, where it contains the parameter (μ) and treatment effect (τi ) which has
... Show MoreTime series is an important statistical method adopted in the analysis of phenomena, practices, and events in all areas during specific time periods and predict future values contribute to give a rough estimate of the status of the study, so the study aimed to adopt the ARIMA models to forecast the volume of cargo handled and achieved in four ports (Umm Qasr Port, Khor Al Zubair Port, Abu Flus Port, and Maqal Port(, Monthly data on the volume of cargo handled for the years (2006-2018) were collected (156) observations. The study found that the most efficient model is ARIMA (1,1,1).
The volume of go
... Show MoreThis research paper attempts to explore problems facing the teaching of written expression among first-year female university students. The focal point behind conducting this research is to show the importance that writing is taking as a skill in learning the language. To achieve this goal, the researcher prepared a questionnaire consisting of 20 items. The sample, whose size is 60 participants, was selected randomly from the department of Arabic, College of Education for Women, University of Baghdad. Through the use of a set of statistical means including weighting means and percentage, the findings revealed that the students face many difficulties in learning writing. The researcher suggested some recommendations, mainly improving the
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