Objective: This study evaluated the effect of immediate dentin sealing on the marginal adaptation of lithium disilicate overlays with three different types of resin-luting agents: preheated composite, dual-cure adhesive resin, and flowable composite. Materials and Methods: Forty-eight maxillary first premolars of similar size were prepared with a butt joint preparation design. The teeth were separated into two primary groups, each with twenty-four teeth: Group DDS: Delay dentin sealing (non-IDS) teeth were not treated. Group IDS: dentin sealing was applied immediately after teeth preparation. Each group was subsequently separated into three separate subgroups. Subgroups (DDS+Phc, IDS+Phc): cemented with preheated composite (Enamel plus HRi, Micerium, Italy), Subgroups (DDS+Dcrs, IDS+Dcrs): cemented with dual-cured resin cement (RelyX Ultimate, 3M ESPE, Germany) and Subgroups (DDS+Fc, IDS+Fc): Cemented with flowable composite (Filtek supreme flowable, 3M ESPE, USA). Using a digital microscope with a magnification of 230x, the marginal gap was measured before and after cementation at four different locations from each surface of the tooth, and the mean of measurements was calculated and analyzed statistically using the independent t-test, one-way ANOVA test, Bonferroni correction at a significance level of 0.05. Results: The samples that were immediately sealed with dentin bonding agent showed lower marginal gaps than delayed dentin sealing, both pre-and post-cementation for all subgroups, with a statistically significant difference (p < 0.01). The marginal gap was significantly lower in the IDS+Fc (48.888 ± 5.5 micro m) followed by the IDS+Dcrs group (53.612 ±5.8 micro m) and IDS+Phc (79.19 9±6.9 micro m) respectively, while the largest marginal gaps were observed in the DDS+Phc group (86.505 ± 5.4 micro m). Conclusion: Generally, the teeth with IDS showed better marginal adaptation than teeth without IDS. The marginal gap was smaller with flowable composite and dual-cure resin cement than with preheated composite.
Objective: Evaluation of the poly ether keton keton polymer (PEKK) coating material on the commercial pure titanium disks (CP Ti) with or without laser surface structuring. Design: In vitro experimental study of PEKK polymer coated material on the CP Ti disks with or without laser surface structuring. Materials and methods: coating the surface of the commercial pure titanium (CP Ti) disks with PEKK polymer was performed via using frictional mode CO2 laser, then the samples disks analyzed by using FESEM. Results: the FESEM reveal good adherence and distribution of the PEKK coated material over the CP Ti substrate by using the frictional mode CO2 laser at 2 watt and 6 ms pulse duration. Conclusion: the frictional mode CO2 laser considered an
... Show MoreThe experiment was carried out in the field of botanical garden belonging to the Department of Biology Sciences, College of Education for Pure Science -Ibn AL-Haitham ,Baghdad University. for the growing season. 2014 -2013 to study the effect of the electromagnetic field which included five different intensities (0,5,10,15,20) MT and three periods of time, namely, (1,2,3) an hour and their interaction on some of the morphological characteristics of the safflower plant . designed experiment by Randomized Complete Block Design (RCBD) and three replicates per treatment, compared to the average using less significant difference at the level of probability (0.05) , the results showed the following:- 1-Exposing seeds to diffe
... Show MoreTheoretical study of ten crown ethers substituents were established to investigate some parameters that give clear view about their validity and applicability in the design of anticancer agents. Restricted hartree fock method (RHF/3-21G) were used to determine the energy difference between highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO-LUMO gap) , ionization energy, global hardness and total energy. Strong binding ability with potassium ion were obtained in some of these compounds depend on the type of substituents added to both nitrogen atoms out of the ring cavity. Such binding with potassium in abnormal and divided cancer cells result in inhibition of tumor cell growth by disrupting potassium ion home
... Show MoreA group of amine derivatives [4-aminobenzenesulfonamide derivatives, 2-aminopyridine and 2-aminothiazole] incorporated to α-carbon of diclofenac a well known non-steroidal anti-inflammatory drug (NSAID) to increase bulkiness were designed and synthesized for evaluation as a potential anti-inflammatory agents with expected COX-2 selectivity. In vivo acute anti-inflammatory activity of the selected final compounds (9, 12 and 13) was evaluated in rats using egg-white induced edema model of inflammation in a dose equivalent to (3 mg/Kg) of diclofenac sodium. All tested compounds produced a significant reduction in paw edema with respect to the effect of propylene glycol 50
... Show MoreThis paper deals with estimation of the reliability system in the stress- strength model of the shape parameter for the power distribution. The proposed approach has been including different estimations methods such as Maximum likelihood method, Shrinkage estimation methods, least square method and Moment method. Comparisons process had been carried out between the various employed estimation methods with using the mean square error criteria via Matlab software package.
The Euphrates River Basin in Iraq suffers from climate changes represented by the scarcity of precipitation and the increase in temperatures, which is directly reflected in the discharge rates and the increase in total dissolved solids, and consequently, the increase in the dissolved loads in the river. Four measurement stations (Haditha, Ramadi, Fallujah, and Al-Hindiya) in the upper reach of the Euphrates River were investigated. Available data were analyzed from 1970 to 2020 related to precipitation (mm) and temperatures (°C). The results showed a clear decrease in precipitation rates over the years, while a clear increase in air temperature rates was observed. The discharge rates decreased temporally and spatially downs
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