The zirconia ceramic restoration (ZCR) is used as substitutes for the metal-ceramic restoration. Clinical studies demonstrating of ZCRs showed a high fracture incidence of veneering layer than metal-ceramic restorations. This attributed to the low bond strength of zirconia to veneering ceramic as a result of lacking of glass content in its matrix. Surface treatment was proposed to improve the bonding strength between zirconia and veneering ceramic. Several studies revealed that some treatment such as airborne particle abrasion (APA) is responsible for generating chipping of veneering ceramic. The study aimed to develop a new zirconia coatings to increase bonding strength between zirconia substrate and veneering porcelain. Three groups of 150 zirconia specimens (discs, rods and crowns) were divided according to the type of surface treatments; Group M1 designated unsintered zirconia specimens coated with a mixture of glaze porcelain powder and partially-sintered zirconia powder prepared at 1100 °C with two particle sizes; A (26 ± 0.3 μm) and size B (47 ± 0.5 μm), group M2 was coated with mixture of ceramic liner paste and same selected particle sizes of partially-sintered zirconia powders. The coated groups (M1 and M2) subdivided according to powder sizes into M1A, M1B, M2A and M2B. APA group (as control) of sintered zirconia specimens abraded with 50 μm aluminium oxide powder. Surface area roughness (Sa) was measured by surface texture analyser. Surface morphology and elemental composition were analysed by scanning electron microscope (SEM). Crystallographic phases were identified by X-ray diffraction (XRD). The coefficient of thermal expansion (CTE) was assessed by a thermomechanical analyser. For shear bond strength (SBS) test was evaluated by a universal testing machine (UTM). The fracture strength (FS) test prepared and measured by Cercon CAD/CAM system and UTM. Fractographic analysis for SBS and FS were examined by a stereomicroscope and SEM. For each test and measurement, 10 specimens were used per group. Finite element analysis (FEA) was used to simulate and predict the iv stress distributions of the static oblique load in coated and non-coated zirconia crown models. The collected data were analysed by one-way ANOVA and Tukey HSD test at (P<0.05). Surface roughness results showed significant differences among all groups (P<0.000). The M1B group exhibited a higher Sa value (10.33 ± 0.59 μm) among the tested groups. XRD analysis showed tetragonal and monoclinic phases in the control group while only tetragonal was detected in the coated groups. The SBS values for coated groups were higher than the control group. The M1B group showed higher and significant differences in SBS value (37.54 ± 4.38 MPa) among other tested groups (P<0.05). The FS test indicated that coated M1B group (647.92 ± 97.33 N) higher than the other groups (P<0.00). FEA showed the coated crown models have lower stress level than the non-coated model. The new coating (M1B) by airbrush spray technique considered as an alternative way to APA treatment to improve the bond strength of zirconia substrate to veneering ceramic and indicating as an applicable surface treatment for improving the clinical performance of the coated ZCR.
The study of biomechanical indicators in the arc of the run and the upgrading stage is one of the important variables that affect the nature of the upgrading and thus affect the result of the race due to the importance of these stages and the consequent variables during the last steps. That’s why, the jump-trainings based on assistant means or body weight positively affect the step-time for each of the three steps in the acceleration arc. As well as, it focuses on the momentary strength of each step at this stage. It also significantly affects the speed of motor performance to suit the activity in which the runner needs to perform perfect steps with high flow in order to convert the horizontal speed to a vertical one. This is achieved thr
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The study aimed to show the jurisprudential impact of the multiplicity of directing the syntactic movement of the Qur’anic readings, and it was based on the inductive, descriptive and analytical approach. , such as the difference in explaining the ruling on washing the feet, and the one who meditates on the Qur’anic readings notices in it a picture of the Qur’anic miracles, and this is what is manifested by the brevity of the speech. Collapse the research, and the research tried to trace the Qur’anic readings, contained in the verses, and the readings were limited to what is related to the explanatory meaning mentioned by the commentators, by clarifying the explanatory relationship between the Qur’anic readings and the me
... Show MoreA qualitative chemical test was performed on functional groups extracted from fenugreek plant and its extracts (aqueous, alcoholic and volatile oil). Results revealed that fenugreek seeds contain the main functional groups, while extracts are varied accorodihg to their content of functional groups qualitatively and quantitively. Moreover, inhibition activity was tested for extracts of fenugreek seeds (aqueous, alcoholic and volatile oil). against gram negative (Salmonella typhimurium, Escherichia coli and Pseudomonas aeruginosa) and gram positive (Staphylococcus aureus) by the ager well diffusion method. Data have revealed that inhibition activity was different in accoradance with extract solvent and the tested microorgan. Oil extract (15)%
... Show MoreBackground: the oral cavity is consider to be an open ecosystem, with the balance between the microorganism’s entrance and the defenses of the host. The initiation of periodontitis has been associated with restricted kinds of anaerobic bacteria, such as Aggregatibacter actinomycetemcomitans (A.a) and Porphyromonas gingivalis (P.g) in plaque subgingivally. Ozone has a biological effects on bacteria due to oxidation of bio-molecules and its toxins. The aim is to determine and compare the antimicrobial effect of gaseous ozone and ozonized water on the growth of isolated anaerobic bacteria (A.a and P.g) when exposed to different time intervals. Materials and methods:This experiment is done byozone generator OLYMPIC- III(600mg/hr) to gene
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Background: The patient's vital signs must stay stable pre a pulmonary function test since the approach demands the patient to breathe slowly and deeply and exhale quickly. However, events that cause variations in normal vital signs may impact the patient. Many strategies can be utilized to stabilize vital signs, including music treatment. The purpose of this study is to compare the effectiveness of music therapy on the vital signs of client's pre a pulmonary function test. Methods: An experimental design study with an application (pre-test, post-test), to determine the effectiveness of music therapy for clients pre pulmonary function test for 106 clients in Al-Diwaniyah, Al-Shamiya, and Al- Hamza public hospitals In Iraq. Parti
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In this research, analytical study for simulating a Fabry-Perot bistable etalon (F-P cavity) filled with a dispersive optimized nonlinear optical material (Kerr type) such as semiconductors Indium Antimonide (InSb). An optimization procedure using reflective (~85%) InSb etalon (~50µm) thick is described. For this etalon with a (50 µm) spot diameter beam, the minimum switching power is (~0.078 mW) and switching time is (~150 ns), leading to a switching energy of (~11.77 pJ) for this device. Also, the main role played by the temperature to change the etalon characteristic from nonlinear to linear dynamics.
Development of NSAIDS based on inhibiting cyclooxygenase activity. However, the different physiological consequences arrised by appearance of new drugs with different selectivity to COX-2 enzyme upon their administration with their relevant affects on some cardiovascular risk factors. To study the potential effects of relatively diclofenac and highly specific celecoxib COX-2 inhibitors on lipid profile and serum C-reactive protein in type 2 diabetes, whom have hyperlipidemia to be compared by their effects with normolipidemic patients. A total number of 34 type 2 diabetics (14 normolipidemics and 20 hyperlipidemics) treated with either diclofenac 100mg/day or celecoxib 200mg/day for eight weeks. Analysis of results indi
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Background: Considering the antioxidant, anti-inflammatory, and antimicrobial properties of green tea, this study aimed to evaluate the histopathological effect of the sulcular irrigation of green tea extract in the treatment of experimental gingivitis in rabbit.
Materials and methods: For this experimental study, 45 male rabbits, separated in two groups, control non- irrigated group (5rabbits) and study group (40 rabbits), gingivitis induced by ligatures was packed subgingivally in the lower right central incisors of the experimental group for seven days. Then, the animals were randomly designated to two irrigated groups (20 rabbits
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