Background: This study was conducted to assess the effect of sonic activation and bulk placement of resin composite in comparison to horizontal incremental placement on the fracture resistance of weakened premolar teeth. Materials and method: Sixty sound human single-rooted maxillary premolars extracted for orthodontic purposes were used in this study. Teeth were divided into six groups of ten teeth each: Group 1 (sound unprepared teeth as a control group), Group 2 (teeth prepared with MOD cavity and left unrestored), Group 3 (restored with SonicFill™ composite), Group 4 (restored with Quixfil™ composite), Group 5 (restored with Tertic EvoCeram® Bulk Fill composite) and Group 6 (restored with Universal Tetric EvoCeram® composite using horizontal incremental layering technique). Standardized class II MOD cavity was prepared in all teeth except (group 1).After finishing the restorative procedure of each group according to the manufacturer's instructions, all teeth were stored in deionized distilled water in an incubator at 37°C for seven days.All specimens were subjected to compressive axial loading until fracturein a universal testingmachine.Specimens were examined by a stereomicroscope at a magnification of (20X) to evaluate the mode of fracture . Results: The results of this study revealed that the control group exhibited the highest fracture resistance compared to all prepared teeth groups (restored or unrestored) and the differences were statistically highly significant (P<0.01), except with group 3 (which was restored with SonicFill™ composite) where the difference was statistically significant only (P < 0.05).Additionally the results of this study revealed that the prepared unrestored teeth (Group 2) exhibited the lowest fracture resistance compared to all restored groups and the differences were statistically highly significant (P<0.01). Meanwhile, among the restored teeth groups, teeth restored with SonicFill™ composite (group 3) exhibited the highest fracture resistance as compared with all other restored groups and the difference was statistically highly significant (P<0.01). On the other hand, no statistically significant differences in fracture resistance were found among groups 4, 5 and 6, which were restored with Quixfil™ composite, Tetric EvoCeram® Bulk Fill composite and Universal Tetric EvoCeram® composite, respectively (P > 0.05). Group 3and Group 5 showed mostly mixed mode of failure, while Group 4 showed mostly adhesive mode of failure. On the other hand Group 6 teeth showed different modes of failure. Conclusions: SonicFill™ composite can be considered as a viable treatment modality for the restoration of weakened maxillary premolar teeth. On the other hand, the time-consuming incremental layering technique can be substituted with bulk filling, using bulk fill materials (Quixfil™ and Tetric EvoCeram® Bulk Fill) for reinforcement ofweakened maxillary premolars.
Flexible molecular docking is a computational method of structure-based drug design to evaluate binding interactions between receptor and ligand and identify the ligand conformation within the receptor pocket. Currently, various molecular docking programs are extensively applied; therefore, realizing accuracy and performance of the various docking programs could have a significant value. In this comparative study, the performance and accuracy of three widely used non-commercial docking software (AutoDock Vina, 1-Click Docking, and UCSF DOCK) was evaluated through investigations of the predicted binding affinity and binding conformation of the same set of small molecules (HIV-1 protease inhibitors) and a protein target HIV-1 protease enzy
... Show MoreIn this research, the Williamson-Hall method and of size-strain plot method was employed to analyze X- ray lines for evaluating the crystallite size and lattice strain and of cadmium oxide nanoparticles. the crystallite size value is (15.2 nm) and (93.1 nm) and lattice strain (4.2 x10−4 ) and (21x10−4) respectively. Also, other methods have been employed to evaluate the crystallite size. The current methods are (Sherrer and modified Sherrer methods ) and their results are (14.8 nm) and (13.9nm) respectively. Each method of analysis has a different result because the alteration in the crystallite size and lattice strain calculated according to the Williamson-Hall and size-strain plot methods shows that the non-uniform strain in nan
... Show MoreSamples of the ovary and uterus of local breed cats used to investigate the histological, histometrical and hormonal features. The paraffin embedding technique was used for processing of tissue that stained by hematoxyline and eosin stain, and massons trichrom stain. Ovary of at proestrus or oestrus phases composed of outer cortex that covered by cuboidal germinal epithelium and inner medulla. Tunica albuginea composed of a thin layer of characterized by fusiform stromal cells. The cortex content groups of Oogonial cells, numerous primordial follicles, little primary, secondary and tertiary follicles in addition for 1-2 follicular cysts and mature corpus letium. In pregnant cat the thickness of ovarian cortex was significantly incre
... Show MoreSheep are considered as an important part of livestock in the worldwide, particularly in Iraq, as they provide meat, milk, leather, wool, and manure. The present study aim is isolation and identification of staphylococci, enteric bacteria and Pseudomonas spp. Totally, 115 samples were collected from sheep (100 samples were collected from the nasal cavity of local sheep suffering from respiratory infections, and 15 samples were collected from apparently healthy local sheep). All the samples were collected from seven flocks located in Abu Ghraib and Al-Radwaniyah, Baghdad governorate, Iraq. The samples were taken during the period from October 2020 to February 2021. Staphylococcus spp., Pseudomonas spp., and enteric bacteria were detected fi
... Show MoreThe ceramic composite with different proportions of clay and silica was prepared with a grain size of 70 μm and the weight percentage was selected for four groups (clayx silica100-x) were x q15, 25, 30 and 50. In this manuscript, for each pressured sample, a sintering procedure was carried out for 3 hours under static air and at various sintering temperatures (1000, 1100, 1200, 1400)°C. After sintering, the density, porosity, water absorption, compression strength and thermal conductivity were measured. The best results were obtained using a mixture of 15% clay and 85% silica which were sintering at 1400°C for three hours under air.
In this paper, Activated Carbon was successfully prepared from local Iraqi material namely corns stalks .Zinc chloride ZnCl2 was used as activating agent with different concentrations (20%, 40%, 60%) for 72 hours. followed by carbonization at 450 C for (2) hour. UV-Spectrophotometer used for measuring absorbance of methylene blue solutions before and after adsorption. the maximum amount adsorbed for methylene blue material of the prepared activated Carbon was studied by Langmuir adsorption isotherm. Other characteristics of the resulting activated Carbon also discussed, such as pH, Moisture Content and ash content. Finally Activated carbon prepared in this work has good properties compared to the standard samples in such a way it could be
... Show MoreIn this work, zinc oxide nanoparticles (ZnONPs) and sawdust/epoxy composite (20:80) were mixed using a simple molding method with different ZnONPs concentrations of (0.1, 0.3, 0.5, 0.7, and 1.0 %). The samples of the nanocomposites were characterized by the Scanning Electron Microscopy (SEM) technique to demonstrate the homogeneity of the prepared ZnONPs/nanocomposites. The photocatalytic activity of the samples was examined using the methylene blue (MB) dye as a pollutant solution, through evaluation of the efficiency of the prepared compound in the treatment of organic pollutants under illumination by sunlight. The photocatalytic results showed that after 240 minutes of exposure to sunlight, the sample prepared using (0.5 vol.% of ZnON
... Show MoreBackground: In young adults, multiple sclerosis is a prevalent chronic inflammatory demyelinating condition. It is characterized by white matter affection, but many individuals also have significant gray matter involvement. A double-inversion recovery pulse (DIR) pattern was recently proposed to improve the visibility of multiple sclerosis lesions. Objective: To find out how well a DIR sequence, FLAIR, and T2-weighted pulse sequences can find MS lesions in the supratentorial and infratentorial regions. Methods: A total of 37 patients with established diagnoses of multiple sclerosis were included in this cross-sectional study. Brain MRI was done using double inversion recovery, T2, and FLAIR sequences. The number of lesions was count
... Show More