Background: This review aims to discuss various canine retraction techniques using frictionless mechanics. Methods: Between 1930 and February 2022, searches were conducted about various canine retraction techniques using fixed orthodontic appliances in various databases, including PubMed Central, Science Direct, Wiley Online Library, the Cochrane Library, Textbooks, Google Scholar, Research Gate, and manual searching. Results: After removing the duplicate articles, publications that described how to use archwires to perform canine retraction with the archwires were included. Conclusions: The pros and cons of various canine retraction techniques using archwires were thoroughly discussed. T-loop is the preferred spring of all because of its characteristics
The effect of different Ti additions on the microstructure of Al-Ti alloy prepared by powder metallurgy was investigated. A certain amount of Ti (10wt%, 15wt%, and 20wt%) were added to aluminium and the tests like microhardness, density, scanning electron microscope (SEM), optical microscope (OM) and X-Ray Diffraction (XRD) were conducted to determine the influence of different Ti additives on the Al-Ti alloy properties and microstructure. The results show that the grains of α-Al changed from large grains to roughly spherical and then to small rounded grains with increasing Ti content, the micro-hardness of the alloy increases with increasing Ti, and XRD results confirm the formation of TiAl3 intermetallic co
... Show MoreThe low-pressure sprinklers have been widely used to replace the high-pressure impact sprinklers in the lateral move sprinkler irrigation system due to its low operating cost and high efficiency. However, runoff losses under the low-pressure sprinkler irrigation machine can be significant. This study aims to evaluate the performance of the variable pulsed irrigation algorithm (VPIA) in reducing the runoff losses under low-pressure lateral move sprinkler irrigation machine for three different soil types. The VPIA uses the ON-OFF pulsing technique to reduce the runoff losses by controlling the number and width of the pulses considering the soil and the irrigation machine properties. Als
The current study performs an explicit nonlinear finite element simulation to predict temperature distribution and consequent stresses during the friction stir welding (FSW) of AA 7075-T651 alloy. The ABAQUS® finite element software was used to model and analyze the process steps that involve plunging, dwelling, and traverse stages. Techniques such as Arbitrary Lagrangian–Eulerian (ALE) formulation, adaptive meshing, and computational feature of mass scaling were utilized to simulate sequence events during the friction stir welding process. The contact between the welding tool and workpiece was modelled through applying Coulomb’s friction model with a nonlinear friction coefficient value. Also, the model considered the effect of nonlin
... Show MoreBackground: This study evaluated the influence of different fiber formulations incorporation in resin composite on cuspal deflection (CD) of endodontically-treated teeth with mesio-occluso-distal (MOD) cavities. Materials and Methods: Thirty-two freshly extracted maxillary premolar teeth received MOD cavity preparation followed by endodontic treatment using single cone obturation technique, and divided into: Group I: direct composite resin only using a centripetal technique, Group II: direct composite resin with short fiber-reinforced composite (everX Flow), Group III: direct composite resin with leno wave ultra-high molecular weight polyethylene (LWUHMWPE) fibers placed on the cavity floor, and Group IV: direct composite resin with LWUHMWP
... Show MoreBackground:The demand for esthetic orthodontic appliances is increasing so that the esthetic orthodontic archwires were introduced. This in vitro study was designed to evaluate the surface roughness offiber-reinforced polymer composite (FRPC) archwires compared to coated nickel-titanium (NiTi) archwires immersed in artificial saliva. Materials and Methods:Three types of esthetic orthodontic archwires were used: FRPC (Dentaurum), Teflon coated NiTi (Dentaurum) and epoxy coated NiTi (Orthotechnology). They were round (0.018 inch) in cross section and cut into pieces of 15 mm in length.Forty pieces from each type were divided into four groups; one group was left at a dry condition and the other three groups were immersed in artificial saliva (
... Show MoreMethotrexate (MTX), a folic acid antagonist is widely used for the treatment of a variety of tumors. In the present study, the possible protective effect of aqueous green tea extract (AGTE) in methotrexate-induced haematotoxicity was investigated.Four main groups of white Albino rats were used: control group, (MTX) group, following a single dose of MTX (20 mg/kg, i.p.) saline was administered for 5 days. (AGTE) group, was treated with 1.25% concentration of AGTE only for 12 days and the (MTX+AGTE) group, in thism group rats received different concentrations of AGTE (0.625, 1.25 and 2.5%), as their sole source of drinking water, 7days before and 5 days after MTX treatment. MTX induced significant decreases in RBC, Hb, Hct, WBC and pl
... Show MoreObjective: The objective of the present study was to design and optimize oral fast dissolving film (OFDF) of practically insoluble drug lafutidine in order to enhance bioavailability and patient compliance especially for a geriatric and unconscious patient who are suffering from difficulty in swallowing.Methods: The films were prepared by a solvent casting method using low-grade hydroxyl propyl methyl cellulose (HPMC E5), polyvinyl alcohol (PVA), and sodium carboxymethyl cellulose (SCMC) as film forming polymers. Polyethylene glycol 400 (PEG400), propylene glycol (PG) and glycerin were used as a plasticizer to enhance the film forming properties of the polymer. Tween 80 (1% solution) and poloxamer407 were used as a surfactant, citri
... Show MoreLiposomal amphotericin B (Amph B) has been used effectively to treat leishmaniosis, in spite of its high toxicity appeared in some patients. In our study, Amph B was administered in Leishmania donovani that infected BALB/c male mice using different concentrations to evaluate its efficacy challenge against infection as well as its effect in modulating immunity of the host. We observed that low doses with short duration of Amph B as a therapy regime significantly enhanced the induction of Th1 cytokine (INF-γ), but suppressed Th2 cytokine (IL-10) production. Groups of mice infected with L. donovani and treated with Amph B showed clearly increasing in INF-γ level and reduction in IL-10 level in concentration (3, 4, 5 mg/ml/kg) with best resul
... Show MoreAbstract Background: This study is aimed to assess the maxillary incisors’ root position, angulation, and buccal alveolar bone thickness in both genders and different classes of malocclusion using cone‑beam computed tomography (CBCT). Materials and Methods: Two hundred and six CBCT images were gathered and analyzed by three‑dimensional On‑Demand software to measure the variables of 803 maxillary central and lateral incisors. Genders and class difference was determined by unpaired t‑test, one‑way ANOVA, and Chi‑square tests. Results: Buccal root position of the maxillary incisors accounted for in the majority of the cases followed by the middle and palatal positions. The thickness of alveolar bone appears to have nearly the sam
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