Background: Change in palatal vault shape and Reinforcement of high impact acrylic denture base resin may in turn affect the dimensional accuracy of acrylic resin and affecting the fitness of the denture. The aim of study is to evaluate the effect of fiber reinforcement for high-impact acrylic resin denture base with different palatal vault shapes on linear dimensional change and effect of palatal vault shapes on linear dimensional changes of non-reinforced and fiber reinforced high impact denture base acrylic resin Material and method: Three different palatal vault shapes were prepared on standard casts using CNC (computer numerical control) machine. 60 samples of heat polymerized high impact acrylic resin maxillary denture base were fabricated onto each definitive cast according to manufacturer instruction. Samples divided into three main experimental groups represented the three different palatal vault shapes (20 samples for each main group); 1st rounded 2nd U-shaped and the 3rd groups V-shaped. Each main group divided into two subgroups (10 samples for each subgroup) representing non fiber reinforced high impact acrylic group as a control and the fiber reinforced high impact acrylic. The measurements of linear dimensional changes of denture bases done at two stages, 1st 24 hour after polymerization and 2nd measurement done after one month storage in distilled water at room temperature. Results and conclusion: Linear dimensional changes of high impact acrylic denture base not affected by glass fiber reinforcement p-value in all reference lines ≥ 0.05, while topographical change in maxillary vault shapes effects on the linear dimensional changes in woven glass fiber reinforced high impact acrylic denture base p-value < 0.05. Key words: High impact acrylic resin, topographical change in vault, woven glass fiber reinforcement.
The effect of chronic exposure to two different levels of cadmium chloride (CdCl2) 30 ppb and 40 ppb in drinking water for 12 weeks on thyroid function of mature male rabbits was studied. Eighteen mature male rabbits were randomly divided into three groups (each of six ) , control group (group I ): were offered ordinary tap water , and treated groups (II and III ) were offered tap water containing 30ppb and 40 ppb respectively for 12 weeks .Serum concentration of thyroxin (T4 ) and triiodothyronine (T3) were measured every six weeks ,as an index of thyroid function , further more , section of thyroid gland were prepared for histological studies. The results showed that chronic exposure of male rabbits
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The current research aims to identify the impact of the (Landa) model on acquiring grammatical concepts among students of the College of Administration and Economics, University of Baghdad, and to achieve the research goal, the researcher has set the following hypotheses: There are no statistically significant differences at the level of significance (0.05) between the average degrees Students of the experimental group who studied the Arabic language according to the (Landa) model and the marks of the students of the control group who studied the same subject in the usual way in the post test, there are no statistically significant differences at the level of significance (0.05) in the average differences between the test scores before and
... Show MoreBackground: The fracture of instruments within root canal during endodontic treatment is a common incidence, fracture because of fatigue through flexure occurs due to metal fatigue, this study aimed to assess the effect of curvature angle and rotational speed on the cyclic fatigue of different type of Endodontic NiTi Rotary Instruments and compare among them. Materials and method: Three types of rotary instruments with tip size 0.25: ProTaPer F2 (Densply, Malifier) Revo-S SU( 0.06 taper, MicroMega) and RaCe system (0.06 taper, FKG, Dentaire), Forty file of each instrument were used within two canals with angle of curvature (40 &60 )at two speed (250&400)RPM, twelve group were formed for all instruments(total number=120),ten file fo
... Show MoreIn this work we study the influence of the laser pulse energy and ablation time on the aluminum nanoparticles productivity during nanosecond laser ablation of bulk aluminum immersed in liquid.
Aluminum nanoparticles were synthesized by pulsed laser ablation of Al targets in ethanol for 3-8 minutes using the 1064 nm wavelength of a Nd:YAG laser with energies of 300-500 mJ per pulse.The laser energy was varied between 300 and 500 mJ/pulse, whereas the ablation time was set to 5 minutes. UV-Visible absorption spectra was used for the characterization and comparison of products.
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Educational services in Iraq face many problems that have reduced the efficiency of the educational process, as a result of the difficult conditions experienced by educational services in Iraq. This led to the accumulation of these problems and their exacerbation significantly over the years, as there was no fundamental solution to these problems. The study proposes a planning method for managing the educational system in Iraq, especially for the primary and secondary levels, where these negative phenomena are very prominent, especially the deficit in school buildings and the phenomenon of overcrowding in classrooms. &am
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Background: The aim of this study was to evaluate the push-out bond strength of four different obturation materials to intraradicular dentin and to determine the failure mode. Materials and method: forty straight palatal roots of the maxillary first molars teeth were used in this study, the roots were instrumented using crown down technique and rotary EndoSequence system, the roots were randomly divided into four groups according to the materials used for obturation (n=10).Group (1): AH Plus sealer and gutta-percha. Group (2): Activ GP glass ionomer sealer and Activ GP gutta-percha (Activ GP system). Group (3): Bioceramic sealer and Bioceramic gutta-percha. Group (4): GuttaFlow2 sealer and gutta-percha. For all groups single cone obturatio
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In this work, a novel single-slope solar distillator of floating perforated absorber inserted with wicks (cotton ribbons), and a stepped distillator are designed and manufactured with the aim of developing the conventional distillator. They are examined experimentally at Baghdad, Iraq (33.3°N Latitude, 44.4°E Longitude) in order to enhance the freshwater productivity and the efficiency of the conventional distillator. Results showed that the daily productivity and efficiency of the stepped distillator are higher than that for conventional solar distillator by 30% and 36.19% respectively. The daily productivity and thermal efficiency for the distillator with the floating absorber are higher than that for the conventional distillator by 16%
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