Background: The high reactivity of hydrogen peroxide used in bleaching agents have raised important questions on their potential adverse effects on physical properties of restorative materials. The purpose of this in vitro study was to evaluate the effect of in-office bleaching agents on the microhardness of a new Silorane-based restorative material in comparison to methacrylate-based restorative material. Materials and method: Forty specimens of Filtek™ P90 (3M ESPE,USA) and Filtek™ Supreme XT (3M ESPE, USA) of (8mm diameter and 3m height) were prepared. All specimens were polished with Sof-Lex disks (3M ESPE, USA). All samples were rinsed and stored in incubator 37˚C for 24 hours in DDW. Ten sample of each material were subjected to 37.5% hydrogen peroxide gel (Pola office +, SDI)for 8 minutes while exposed to light curing device, this step was repeated three times for 3 weeks. While the other ten samples for each material was served as control. All specimens were subjected to microhardness test using digital microhardness tester to determine the VHN (Vickers Hardness Number) Results : The Filtek™ P90 exhibited higher microhardness value than Filtek™ Supreme XT. After hydrogen peroxide treatment, both types of composites exhibited low microhardness values but still Filtek™ P90 is harder than Filtek™ Supreme XT. Conclusion : In-office hydrogen peroxide bleaching agent resulted in reduction in microhardness values for both composite materials. Silorane- based composite is more affected by the bleaching agent than methacrylate-based composite.
The makers of strife exist in every era and time. They differ in how these temptations are created and the methods used in doing so. In our modern era, they are more; This is due to the presence of information technology and its easy availability at their fingertips, as well as the spread of social networking sites, which are rapidly spreading among ignorant groups and groups that are deficient in their use. Which led the makers of sedition to exploit these matters and create various temptations and spread them among peoples and societies. Today, we cannot predict the future of humanity in light of this huge amount of temptation. What the Holy Qur’an mentioned about the types of temptations in its noble verses and their embodiment in seve
... Show MoreProvisions and controls on the disposal of public funds between Sharia and law
Research Summary
That money is the foundation of life and one of the most important reasons for the reconstruction of the land, and God is the owner
The real value of this money, God has borrowed some individuals on public money, and people
They are charged with preserving it, since it is beneficial to them all, without anyone taking it
To himself, and the guardian is charged by God to protect this money and aggression
Because of its power, authority, various organs and public servants of the province
Upon him; Because the assault on public money by employees and others in the organs of the state
And exploitation of their jobs and this
The educational process depends on the means of conveying information from the teacher to the learner. Whenever appropriate, this means the learning process takes place better, faster, and with less effort, and the problem of research lies. The players lack learning in the meta-knowledge curriculum in basketball offensive skills than offensive skills. The aim of the research is to identify the effect of training exercises for educational numbers based on metacognitive skills in teaching some offensive skills with basketball. As for the research assignment, there are statistically significant differences between the results of the pre and post tests for the experimental group and in favor of the post tests. The experimental approach was used
... Show MoreIn this study, structures damage identification method based on changes in the dynamic characteristics
(frequencies) of the structure are examined, stiffness as well as mass matrices of the curved
(in and out-of-plane vibration) beam elements is formulated using Hamilton's principle. Each node
of both of them possesses seven degrees of freedom including the warping degree of freedom. The
curved beam element had been derived based on the Kang and Yoo’s thin-walled curved beam theory
in 1994. A computer program was developing to carry out free vibration analyses of the curved
beam as well as straight beam. Comparing with the frequencies for other researchers using the general
purpose program MATLAB. Fuzzy logic syste
A fast laser texturing technique has been utilized to produce micro/nano surface textures in Silicon by means of UV femtosecond laser. We have prepared good absorber surface for photovoltaic cells. The textured Silicon surface absorbs the incident light greater than the non-textured surface. The results show a photovoltaic current increase about 21.3% for photovoltaic cell with two-dimensional pattern as compared to the same cell without texturing.
The pre - equilibrium and equilibrium double differential cross
sections are calculated at different energies using Kalbach Systematic
approach in terms of Exciton model with Feshbach, Kerman and
Koonin (FKK) statistical theory. The angular distribution of nucleons
and light nuclei on 27Al target nuclei, at emission energy in the center
of mass system, are considered, using the Multistep Compound
(MSC) and Multistep Direct (MSD) reactions. The two-component
exciton model with different corrections have been implemented in
calculating the particle-hole state density towards calculating the
transition rates of the possible reactions and follow up the calculation
the differential cross-sections, that include MS
The partial level density PLD of pre-equilibrium reactions that are described by Ericson’s formula has been studied using different formulae of single particle level density . The parameter was used from the equidistant spacing model (ESM) model and the non- equidistant spacing model (non-ESM) and another formula of are derived from the relation between and level density parameter . The formulae used to derive are the Roher formula, Egidy formula, Yukawa formula, and Thomas –Fermi formula. The partial level density results that depend on from the Thomas-Fermi formula show a good agreement with the experimental data.
Ulcerative colitis (UC) is a chronic inflammatory bowel disease associated with persistent inflammation, oxidative stress, and epithelial apoptosis. Nicardipine, a dihydropyridine calcium channel blocker, exhibits anti-inflammatory and anti-apoptotic properties, but its therapeutic potential in UC remains unclear. This study evaluated the effects of nicardipine on dextran sulfate sodium (DSS)-induced colitis in mice, focusing on inflammatory, oxidative, and apoptotic pathways. Fifty BALB/c mice were assigned to five groups (n = 10): control, DSS, nicardipine 12 mg/kg, nicardipine 24 mg/kg, and 5-aminosalicylate (ASA) 75 mg/kg. Treatments were administered for 3 days before and 10 days during DSS exposure. Disease severity was assessed by bo
... Show More