Background: evaluate the effects of three different intracoronal bleaching agents on the shear bond strengths (SBS) and failure site of stainless steel and monocrystalline (sapphire) orthodontic brackets bonded to endodontically treated teeth using light cured orthodontic adhesive in vitro. Materials and methods: Eighty extracted sound human upper first premolars were selected, endondontically treated and randomly divided equally (according to the type of the brackets used) into two main groups (n = 40 per group). Each main group were subdivided (according to the bleaching agent used) into four subgroups 10 teeth each; as following : control (un bleached) group, hydrogen peroxide group (Hp) 35%, carbamide peroxide group (CP) 37% group and sodium perborate (SP) group . The bleaching process was applied three times (4 days intervals) sequentially and the bleached teeth were stored in artificial saliva four weeks before bonding. Orthodontic brackets were bonded with a light cure composite resin and cured with LED light. After passing 24 hours of bonding procedure, the brackets were debonded by a Tinius-Olsen universal testing machine, to measure the shear bond strength. After debonding, each bracket base and the corresponding tooth surface were examined using a stereomicroscope and their Adhesive Remnant Index (ARI) was recorded. Results: The ANOVA test showed that the SBS of stainless brackets was significantly reduced by intracorornal bleaching agents. Furthermore, LSD showed no significant difference in SBS between the three types of bleaching agents used in stainless steel group. Whilst for sapphire group, the results The ANOVA test showed no significant difference in SBS between the bleached groups and the control group. Chi-square comparison no significant difference in failure site between bleached and control groups in both brackets types used. Conclusion: The effect of intracoronal bleaching on SBS was reduced SBS of stainless steel and not for sapphire. However, the intracoronal bleaching had no effect on the failure site of orthodontic brackets used.
The aim of the research is to identify psychological toughness and its relationship to some coordination, physical abilities and accuracy of some basic performance skills among the players of the Iraqi junior national handball team players. The hypothesis is the existence of a correlation between psychological toughness, coordination, physical abilities, and the accuracy of some basic skills performance among the players of the Iraqi junior national handball team players. The descriptive approach in the style of correlational relations used to suit the research problem, as the community was determined by (18) players for the Iraqi junior national handball team players, while the sample was (14) players, and the samp
... Show MoreThe city of Karbala is one of the most important holy places for visitors and pilgrims from the Islamic faith, especially through the Arabian visit, when crowds of millions gather to commemorate the martyrdom of Imam Hussein. Offering services and medical treatments during this time is very important, especially when the crowds head to their destination (the holy shrine of Imam Hussein (a.s)). In recent years, the Arba'in visit has witnessed an obvious growth in the number of participants. The biggest challenge is the health risks, and the preventive measures for both organizers and visitors. Researchers identified various challenges and factors to facilitating the Arba'in visit. The purpose of this research is to deal with the religious an
... Show MoreAutorías: Muwafaq Obayes Khudhair, Sanaa Rabeea Abed, Hayder Talib Jasim. Localización: Revista iberoamericana de psicología del ejercicio y el deporte. Nº. 1, 2023. Artículo de Revista en Dialnet.
In this study, active knife and fixed knife of single-row disc silage machine has three different clearance C1, C2 and C3 (1, 3 and 5 mm) and it is tried in three different working speed V1, V2 and V3 (1.8, 2.5 and 3.7 km / h) and PTO speed (540 min-1) and machine's fuel consumption (l/h), average power consumption (kW), field energy consumption (kW/da), product energy consumption (kW/t), field working capacity (da/h), product working capacity (t/h) and Chopping size distribution characteristics of the fragmented material were determined. It has been found that knife-counter knife clearances smaller than 3 mm (1 mm) and larger (5 mm) have a negative effect on machine performance in general. In terms of fuel and power consumptions, the m
... Show MoreObjectives: The study aims at finding the effectiveness of dietary habits on urolithiatic patients at Urinary Units
in Baghdad Teaching Hospitals.
Methodology: A quantitative descriptive study was conducted to identify the effectiveness of dietary habits on
(100) of urolithiatic patients in Urinary Units at Baghdad Teaching Hospitals starting from May 2011 to Sep.
2012.Data were collected through the use of constructed check list of the questionnaire format, which
consists of two parts: - The first part: is related to the patient's demographic variables ; the second part: is
constructed to serve the purpose of the study (effectiveness of the dietary habits). The total number of items
of the questionnaire is (69) item
The research specialized in examining the role of guarantees and their impact on accounting benefits quality using statistical analysis to the income before and after the impact of guarantee on the accounting profits.This research depended on the inductive approach, which ensures that companies could manipulate in benefits through a variety of means including the guarantees. As it is possible that the companies can use the policy of guarantee as a strategy in business deal. The research aimed to highlight the different companies' practices on policies guarantee and its impact on accounting benefits. The benefit of Dell Company has been chosen as a sample for the research because of the availability of interim data from the company for te
... Show MoreThe calculation of the charge on an isolated dust grain immersed in plasma with different grain sizes is a challenging one, especially under moderately high plasma temperature when secondary electron emission significant. The discrete charging model is used to calculate the charges of dust grain in dusty plasma. In this model, we included the effect of grain size dependence on secondary electron emission. The results show that the secondary electron emission from the glass dust grains due to energetic electron (40eV) can lead to the small grain to be slightly more positive than the large grain. Under these conditions, the smaller and larger grains would be attracted rather than repelled, which possibly lead to enhanced coagulation rates.
... Show MoreTwenty five vaginal swabs from outpatients' healthy women were collected from Kamal Al-Samarai Hospital, Baghdad, to isolate and identify of Lactobacillus acidophilus. Three isolates were diagnosed as L. acidophilus which represents 15% of the total number of lactic acid bacterial (LAB) isolates; other LAB types represent 65% (20 isolates).The ability of L. acidophilus to produce surlactin was detected after measuring its biological activity to inhibit the adhesion of biofilm formed by Pseudomonas aeruginosa to surfaces using test tube method. It was found that all isolates were able to produce surlactin but the activity of surlactin was varying in each isolate. Surlactin produced by isolates 1 and 13 was the most effective. Biological appl
... Show MoreStraight tendons in pretensioned members can cause high-tensile stresses in the concrete extreme fibers at end sections because of the absence of the bending stresses due to self-weight and superimposed loads and the dominance of the moment due to prestressing force alone. Accordingly, the concrete tensile stresses at the ends of a member prestressed with straight tendons may limit the service load capacity of the member. It is therefore important to establish limiting zone in the concrete section within which the prestressing force can be applied without causing tension in the extreme concrete fibers. Two practical methods are available to reduce the stresses at the end sections due to the prestressing force. The first method based
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