Background: In capturing a negative image, the digital impression secures a digital record for the purposeof designing and creating restorations. The introduction of scanning system presents a paradigm shift in the way of the dental impression procedure and encourages the accuracy of obtained restoration especially in the marginal area as a result of producing accurate final impression The digital system offers many advantages over the Conventional method.. The objective of this present in vitro study was to evaluate the marginal fitness of all ceramic crowns fabricated by direct digital scanning of the prepared tooth using two types of intra-oral cameras (Bluecam camera with strip light projection technique and Omnicam camera with video sampling technique). Materials and Methods: Sixteen sound upper first premolar teeth of comparable size were collected. Standardized preparation of all teeth samples were carried out to receive all ceramic crown restoration with deep chamfer finishing line (1mm), axial length (4mm) and convergence angle (6â—¦). The specimens divided in to two groups according to the type of digital impression technique: Group A, eight prepared teeth scanned directly by Bluecam camera; Group B, eight prepared teeth scanned directly by Omnicam camera. Then CAD/CAM all ceramic crowns constructed for each tooth sample. Marginal discrepancy was measured at Sixteen points per tooth using digital microscope at (120X) magnification. Results: Independent sample t-test was used to identify and localize the source of difference among the groups. It was found that there is statistically non- significant difference in the marginal gap mean values between (group A and group B). Conclusions: From the above result we can conclude that the two types of direct digitization techniques have the same accuracy.
A series of new aromatic polyesters have been synthesized by polycondensation of different aromatic diols (M1, M2 ,M3) with different dicarboxlic acids (4,4'azo di benzoic acid, malic acid and adipic acid) using dibutyltine dilaurate as catalyst . The preparation of thermally stable polyesters was successfully applied with good yields (60-85%). All polyesters (PE1-PE4) containing aliphatic methylene linkage, and azo group in the main chain. The resulted polymers are readily soluble in aprotic polar solvents , such as (pyridine , CHCl3 , CH2Cl2 , NaOH , H2SO4 , HNO3 , acetone , benzene , DMF , DMSO , THF) without need for heating. Thermal analysis of polyesters by Thermo Gravimetric Analysis (TGA) reveals that these aromatic polyesters po
... Show MoreThe possibility of using activated carbon developed from date palm seeds wastes as a permeable reactive barrier (PRB) to remove copper from polluted shallow groundwater was investigated. The activated carbon has been developed from date palm seeds by dehydrating methods using concentrated sulfuric acid. Batch tests were performed to characterize the equilibrium sorption properties of new activated carbon in copper-containing aqueous solutions, while the sandy soil (aquifer) was assumed to be inert. Under the studied conditions, the Langmuir isotherm model gives a better fit for the sorption data of copper by activated carbon than other models. At a pilot scale, One-dimensional column experiments were performed, and an integrated model ba
... Show MoreIn the present investigation, new polymers of Poly [ N - acryl - N - sulfonic acid - N\ yL - 2 - substitute - 4 - oxo - thiazolidine ] Maleic and Succinic diimide were synthesized by seven steps; first step includes esterification of different cyclic anhydride, using one mole of absolute methanol in the presence few drops of conc. H2SO4, yielded mono group ester [I] , which was reaction with thionyl chloride to give ester acid chloride [II] .Then reacted with sulfanilic acid to product compound [III] , which was condensation with hydrazine hydrate to give acid hydrazide [IV] . The new different Schiff bases [V-VIII] were synthesized by reaction of acid hydraizide with different (aliphatic and aromatic) aldehyedes and ketones in the prese
... Show More4-[(2-Amino-4-phenylazo)-methyl]-cyclo hexane carboxylic acid, a new Azo (LH2) ligand, was synthesized by reaction of the diazonium salt of trans-4-(amino-methyl) cyclo hexane carboxylic acid with 3-amino phenol. The azo ligand was characterized by micro elemental analysis (C.H.N.O.) and TGA as well as spectroscopic techniques (UV-Vis, FTIR, 1H-NMR, and LC-Mass). Atomic absorption, elemental analysis, infrared, LC-Mass, TGA, and UV-Vis spectral methods, as well as conductivity and magnetic susceptibility, were used to characterize the complexes of Ni (II), Pd (II), and Pt (IV). The following general formula has been given for the produced compounds based on the results obtained, which are as followi
... Show MoreHepatitis C virus (HCV) is a liver disease that affects14 million people. Feasible research was conducted for identifying the genotypes and allele frequency of some single nucleotide polymorphisms (SNPs) of the IL-28β genes and their predictive role in disease incidence in Iraqi patients. The SNPs (rs28416813, rs4803219, rs11881222, and rs8103142) of IL-28β have been associated with susceptibility to several diseases. Ninety eight (98) HCV patients were included in this research; with average age ± SE (42.28 ± 3.44) years. Also, 80 healthy people (with average age ± SE (29.40 ± 2.84) years) were included as a control group. The SNPs were detected by allele-specific PCR (polymerase chain reaction) using specific primers. The re
... Show MoreThe Manganese doped zinc sulfide nanoparticles of the cubic zinc blende structure with the average crystallite size of about 3.56 nm were synthesized using a coprecipitation method using Thioglycolic Acid as an external capping agent for surface modification. The ZnS:Mn2+ nanoparticles of diameter 3.56 nm were manufactured through using inexpensive precursors in an efficient and eco-friendly way. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy are used to examine the structure, morphology and chemical composition of the nanoparticles. The antimicrobial activity of (ZnS:Mn2+) nanocrystals was investigated by measuring the diameter of inhibition zone using well diffusion mechanism
... Show MoreMixed ligand metal complexes of CrIII, FeIII,II, NiII and CuII have been synthesized using 5-chlorosalicylic acid (5-CSA) as a primary ligand and L-Valine (L-Val) as secondary ligand. The metal complexes have been characterized by elemental analysis, electrical conductance, magnetic susceptibility measurements and spectral studies. The electrical conductance studies of the complexes indicate their electrolytic nature. Magnetic susceptibility measurements revealed paramagnetic nature of the all complexes. Bonding of the metal ion through –OHand –COOgroups of bidentate to the 5-chlorosalicylic acid and through –NH2 and –COOgroups of bidentate to the L-valine by FT-IR studies . The agar diffusion method has been used to study the antib
... Show MoreMixed ligand metal complexes of CrIII, FeIII,II, NiII and CuII have been synthesized using 5-chlorosalicylic acid (5-CSA) as a primary ligand and L-Valine (L-Val) as secondary ligand. The metal complexes have been characterized by elemental analysis, electrical conductance, magnetic susceptibility measurements and spectral studies. The electrical conductance studies of the complexes indicate their electrolytic nature. Magnetic susceptibility measurements revealed paramagnetic nature of the all complexes. Bonding