We consider the Gelfand-Dickey (GD) structure defined by the Moyal ⋆product with parameter κ, which not only defines the bi-Hamiltonian structure for the generalized Moyal KdV hierarchy but also provides a W (κ) n algebra containing the Virasoro algebra as a subalgebra with central charge κ2(n3 − n)/3. The free-field realization of the W (κ) n algebra is given through the Miura transformation a...

  Objective: Increased enamel surface roughness following orthodontic bracket debonding leads to increased plaque accumulation and enamel decalcification. Therefore, different methods are employed to achieve smoother enamel surfaces after bracket debonding. This study compared enamel surface roughness following orthodontic bracket debonding and composite resin removal using white stone and tung...

Orthodontic lingual root movement (torque) is an important aspect of treatment biomechanics and is typically achieved by torsion of a rectangular wire within the orthodontic bracket slot which introduces a force couple. The magnitude of the force moment achieved by wire torsion may be influenced by deformation of the orthodontic bracket. A device utilizing an optical image correlation technique...

An in vitro study was conducted to evaluate the accuracy of bracket placement for direct and indirect bonding techniques. Nineteen sets of duplicated Class II malocclusion models were divided into three groups: (1) one set for ideal bracket placement, (2) nine sets for direct bonding on mannequins, and (3) nine sets for indirect bonding. Both direct and indirect bonding were performed on all te...

We will give a generalized framework of derived bracket construction. It will be shown that a deformation differential provides a strong homotopy (sh) Leibniz algebra structure by derived bracket construction. A relationship between the three concepts, homotopy algebra theory, deformation theory and derived bracket construction, will be discussed. We will prove that the derived bracket construc...

This paper aims to explore the antibacterial property of nano Ag/TiO2 coating bracket for the common bacteria in oral cavity, and discuss its biocompatibility. Micro morphology in the surface of nano Ag/TiO2 coating bracket was detected by scanning electron microscope (SEM), and surface roughness of ordinary mental bracket, nano TiO2 coating bracket and nano Ag/TiO2 coating bracket were measure...

In orthodontics bracket positioning is the key to good results beside good diagnosis and treatment planning. All the advocates of different appliance system laid stress on proper positioning of brackets Accurate bracket placement is very important since it affects torque, tip, in/out , vertical positioning and rotation. The purpose of this article is to review the work of notable orthodontists ...

statement of the problem: various methods such as light emitting diode (led) have been used to enhance the polymerization of resin-based orthodontic adhesives. there is a lack of information on the advantages and disadvantages of different light curing systems. purpose: the aim of this study was to compare the effect of led and halogen light curing systems on the shear bond strength of orthodon...