Background: The bonded orthodontic retainer constructed from multistrand wire and composite is an efficient esthetic retainer, which can be maintained long-term. Clinical failures of bonded orthodontic retainers, most commonly at the wire/composite interface, have been reported. This in vitro investigation aimed to evaluate the tensile forces of selected multistrand wires and composite materials that are available for use in the construction of bonded fixed retainers. Materials and Methods: The study sample includes 120 wires with three types of retainer wires (3 braided strands\ Orthotechnology, 8 braided strands\ G&H Orthodontics, 6 coaxial strands\ Orthoclassic wires), two types of adhesive (flowable\ Orthotechnology, non flowable\ G&H Orthodontics composites) and two thickness of the adhesive (1mm, 2mm). The samples were prepared for each composite in which a wire was embedded; then the composite was light cured for 40 seconds and the specimens were stored in artificial saliva at 37°C in the incubator for 24 hours. The ends of the wire were drawn up and tensile force was applied through Tinius-Olsen universal testing machine until the resin failed and the results were recorded in Newton (N). Results: Statistical analysis showed that there was a highly significant difference (P ≤ 0.01) among the mean values of tensile forces of the three types of retainer wires in each thickness of composite with exception of a non significant difference (P > 0.05) between (3 braided) and (8 braided) and a non significant difference (P > 0.05) between (3 braided) and (6 coaxial) in both thickness of composite, a highly significant difference (P ≤ 0.01) between the two thickness of both composite types in each wire type and a highly significant difference (P ≤ 0.01) between the two types of composite in each wire type of both thickness of composite. Conclusion: The result of this study revealed that the 8 braided strands retainer wire shows the highest values of tensile force among the tested retainer wires, the non flowable composite demonstrates a higher tensile force than the flowable composite and increasing the thickness of composite overlying the wire increased the force required to detach the wire from the composite.
(6)
(4)
This experiment was conducted to examine the effects of injected gibberellic acid GA3 in subcutaneous of hens neck and supplemental vitamin D3 to control basal diet on productive performance and egg shell thickness ,relative weight of egg shell of aged laying hens. Two hundred and seventy Lohmann Brown laying hens at 73 weeks of age were randomly assigned to three treatments groups. Each treatment consist of three replicates (30 hens / replicate). The treatments were : T1 control were injected subcutaneous with 0.2 ml / kg of body weight of ethanol: sesame oil solution, T2 and T3 were injected subcutaneous with 0.2 ml / kg of body weight of ethanol: sesame oil solution which contained 400 μg GA3/ kg of body weight /week during 8 weeks (tre
... Show MoreStable new derivative of L-ascorbic acid, 5,6-O-iso propylidene 2,3-O,O acetic acid-Lascorbic acid (L) was synthesized in good yield by the reaction of 5,6-O-isopropylidene-Lascorbic acid with chloroacetic acid in presence of potassium hydroxide. The new product (L) was characterized by 1H, 13C–NMR, mass spectrum and fourier transform infrared (FTIR). The reaction of the ligand (L) with metal bivalent ion., M+2 = (Co, Ni, Cu, Cd, Hg, Mg, Ca, Pb) synthesized and characterized by FTIR, UV-Visible, Molar conductance, Atomic absorption and the molar ratio (Ni+2, Cd+2) complexes. Spectroscopic evidence showed that the binding of the M(II) ions with (L) are through the (C–I=O) Lacton and O-2-CH2COO– as a bidentate manar re
... Show MoreOxazepine [1] is non – nomologous seven –member ring that contain two netroatoms (oxygen and nitrogen ). Meanwhile diazepine [2] contains to nitrogen atoms in seven – member ring.
Diazepam (valium) [3] is used to relive anxiety tension associated with anxiety disorder and muscle spasms (1, 2, 3
... Show MoreBackground: Molar Incisor hypomineralisation (MIH) is one of the biggest challenges with great clinical interest. Currently, the etiology of MIH remains unclear. There is no previous study concerning school children aged 7 – 9 years in Al-Najaf governorate in order to estimate the prevalence and severity of molar incisor hypomineralisation and the possible associated risk factors. This study aimed to estimate the prevalence, severity and the possible associated etiological factors of molar incisor hypomineralisation and also to study the correlation between body mass index and molar incisor hypomineralisation. Material and Methods: Across sectional study conducted at Al-Najaf Governorate. A total of 600 children were enrolled those
... Show MoreIn this research we investigated the corrosion behavior of the commertialy pure titanium and Ti-6Al-4V alloy that coated with hydroxyapatite by electrochemical deposition with applied voltage (6,9,12) Volt from aqueous solution containing Ca(NO3)2.H2O =7.0 gm/l , (NH4)2HPO4 =3.5 gm/l , Na(NO3)2 = 8.5 gm/l in order to improve the bonding strength of hydroxyapetite and medical metals and alloys and increasing the biocompatibility. The coating layer morphology was investigated by XRD, Optical microscope , and SEM tests, the corrosio tests was made by use senthesys simulated body fluid (SBF) , and we found that the propreate voltage for coatint on Ti was 9 Volt and for Ti-6Al-4Vwas12Volt.
The research aims to determine the impact of employees’ retention strategy on organizational memory. This research is historical, descriptive, and analytical. The sample consists of 158 faculty members in five private colleges in Baghdad. The technique used to analyze the data is SEM (Structural Equation Modeling), and SPSS (Statistical Package for the Social Sciences). The research concludes that the employees retaining strategy plays a vital role in retaining employees and hence maintains organizational memory. The findings and recommendations of this research assure the administrations of private colleges that employees retention strategy play a vital role in retaining its employee and hence maintains organizational memory. T
... Show More
(3)
(4)
A laboratory experiment studied the effects of the green tea (Camellia sinensis L.) aqueous extract at concentrations of 10, 20, and 30 ppm on the germination and growth traits of the mung bean (Vigna radiata L.), carried out in 2021 at the Department of Biology, College of Education for Pure Sciences, Ibn Al-Haitham, University of Baghdad, Iraq. The results showed that Camellia sinensis green tea extracts played a vital role by significantly boosting all the examined characteristics compared with the control treatment. The aqueous extract of Green tea at concentrations of 10 and 20 ppm gave the best performance in increasing germination rates, germination speed, plant promoter indicator, and seedling strength compared with the control trea
... Show More
(4)
(2)