Background: The present study was conducted to evaluate the effects of different bleaching methods on the shear bond strength of orthodontic Sapphire brackets bonded to human premolars teeth using light cured composite resin and to determine the predominant site of bond failure. Materials and Methods: Thirty freshly extracted human premolars were selected and randomly divided into three groups (10 per group). These groups are: control (unbleached) group, hydrogen peroxide group (HP) 37.5% ; which is the in- office bleaching method group, carbamide peroxide group (CP) 16%; which is the at- home bleaching method group. After bleaching process was performed, all the teeth stored in distilled water in a sealed container at room temperature for 24 hours before bonding was initiated, then orthodontic brackets were bonded with a light cure composite resin, stored in distilled water at room temperature for another 24 hours before debonding then the brackets de-bonded and tested for shear bond strength using an Instron universal testing machine. For adhesive remnant index (ARI) the enamel surface and bracket base of each tooth were inspected under magnifying lens (20X) of a stereomicroscope. Results and Conclusions: Non-statistically significant differences of shear bond strengths were found between the control group and the bleached groups, the dental bleaching in both methods did not affect the SBS of Sapphire brackets. The mode of failure was mostly between the adhesive and the enamel and the bond failure between the bracket base and the adhesive were also observed. Keywords: Shear bond strength, tooth bleaching agents, orthodontic brackets, dental bonding.
Although several drugs are used against Leishmania infection but they are associated with several adverse complications. Therefore, a new effective treatment needed to be found. In this study, the effect of carbonnanotubes nanoparticles (CNTs NPs) on Leishmania donovani promastigotes was assessed. Viability of promastigotes after adding different concentrations of carbonnanotubes (CNTs) nanoparticles (0.05, 0.1, 5, 10, 20, 40, 60 and 80 μg/ml) to the parasite culture was evaluated by growth rate, viability rate assay and morphological changes. The results indicated that the effect of CNTs NPs on growth rate of promastigotes form. After exposed to 80 μg/ml of CNTs, the growth rate of promastigotes clearly decreased compared with promast
... Show MoreSixty samples from saliva and dental plaque were selected from patients with caries active at ages from 4-65years. 22 isolates belong to Streptococcus mutans. All isolates pronounced adhesion and biofilm formation in various degrees. By using Polymerase Chain Reaction ﴾PCR﴿ Techniques, it was found that these isolates had gtfB encode GtfB with 80 bp, gtfC encode GtfC with 81 bp, and gtfD with 324 bp which explain their potential of biofilm formation.
Background: The insertion torque (IT) values and implant stability quotient (ISQ) values are the measurements most used to assess primary implant stability. This study aimed to assess the relationship between ISQ values and IT. Materials and methods: This study included 24 patients with a mean (SD) age of 47.9 (13.64) years (range 25-75 years). The patients received 42 dental implants (DI), 33 in the mandible and 9 in the maxilla. The DI were installed using the motorized method with 35 Ncm torque, When DI could not be inserted to the requisite depth by the motorized method, a hand ratchet was used and the IT was recorded as ˃ 35 Ncm. Implant stability was measured utilizing Osstell® ISQ. The secondary stability was measured after 16
... Show MoreIn this paper, effective slab width for the composite beams is investigated with special emphasis on the effect of web openings. A three dimensional finite element analysis, by using finite element code ANSYS, is employed to investigate shear lag phenomenon and the resulting effective slab width adopted in the classical T-beam approach. According to case studies and comparison with limitations and rules stipulated by different standards and codes of practice it is found that web openings presence and panel proportion are the most critical factors affecting effective slab width, whereas concrete slab thickness and steel beam depth are less significant. The presence of web opening reduces effective slab width by about 21%.
... Show MoreBackground: It is well-known that silicon oil (SO) injection into the vitreous cavity after pars plana vitrectomy is usually associated with high intraocular pressure.
Objectives: To determine the influence of silicon oil (SO) removal on IOP level after pars plana vitrectomy for spontaneous rhegmatogenous retinal detachment (RRD)
Subjects and Methods: A prospective study was conducted at Ibn Al-Haitham eye teaching hospital, Baghdad- Iraq. Intraocular pressure (IOP) was measured pre and post SO removal in patients who have underwent retinal detachment surgery with SO injection of 1000 centistokes (cSt) viscosity. Baseline IOP was measured for all the patient before the SO
... Show MoreA sensitive and environmentally benign spectrometric method was developed for quantifying Meprobamate (MEP). The analyzed MEP was derivatized into a colored complex and determined spectrometrically. The colorimetric analytical parameters were optimized and validated. Low limit of detection (LOD) was achieved down to 1.88×10-6 mol/l while the limit of quantification (LOQ) was extended over the range of 1.97×10-6 - 1.35×10-3 mol/l. The high precision has been denoted by the 1.54% value of the coefficient of variation. The recovery was 96.07%, while the RSD (n=3) was 1.05 - 1.19%. The apparent molar absorptivity (Æ) obtained within 1154.7 - 1691.9 L.mol-1.cm
... Show MoreAcademia Open Vol 8 No 2 (2023): December DOI: 10.21070/acopen.8.2023.8087 . Article type: (Medicine)Impact of COVID-19 on Dental Students' Psychological Health Maryam Hameed Alwan, [email protected], (1) Department of Oral Diagnosis, College of Dentistry, Baghdad University, Iraq, Iraq (1) Corresponding author Abstract This study investigates the psychological impact of the COVID-19 pandemic on dental students at Baghdad University College of Dentistry. Conducted between December 2021 and January 2022, this cross-sectional survey aligns with ethical guidelines and the Helsinki Declaration. The study utilized Cochran's equation to determine a sample size of at least 400, ensuring a 95% confidence level with a 5% margin of e
... Show MoreThe dental amalgam of radioactive materials in the restoration of teeth because of its readily adaptable to existing materials in the oral cavity in addition to mechanical properties such as hardness mechanical resistance Alndgat and others in this study were prepared Almlagm used Guy dental restoration of silver alloy tin plus some elements to improve the characteristicsmechanical such as copper, zinc or indium in addition to mercury
Summery of the Study: The Israeli interest in Iraq was not the result of the 2003 US war, which ended with its occupation, but Iraq was still at the top of Israeli concerns, as it was due to its interest and desire to occupy the Zionist movement for a number of reasons, most importantly its religious position in the Jews and control It is a sacred religious duty, so Israel has employed all its organs, institutions, relations and espionage networks in order to penetrate it and perpetuate its existence, and succeeded in achieving its foreign policy objectives at a time when the area was open to it without opposition or competition thanks to its strategic alliance with the states Of the United States of America, which has been able to penet
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