As orthodontic appliances can corrode with time in the oral environment, the aim of this study was to compare the release of metal ions from new and recycled brackets immersed in buffers of different pH values over a 48 week period. To simulate commercial recycling, the stainless steel brackets were divided into two groups: new and recycled. The bases of the latter were coated with adhesive and...

  Objective: Corrosion resistance is among the most important properties of metal alloys used in the oral cavity. Consumption of acidic foods reduces the salivary pH and intensifies the corrosion of brackets and orthodontic wires. This study aimed to compare electro galvanic corrosion of different orthodontic brackets and wires and determine the amount of ions released into acidic artifici...

On the local systems hamiltonian in the weakly nonlocal Poisson brackets. Abstract We consider nonlocal field-theoretical Poisson brackets containing the operator of integration in the nonlocal part. The main attention is given to the nonlocal brackets of Hydrodynamic Type for which we introduce the Physical and Canonical forms. We use the Canonical form of these brackets for the investigation ...

Aim: To estimate and compare the frictional forces engendered by three types of aestheticselfligating brackets with two straight wire alloys. Materials: The study comprised of a total of 90 brackets, of which 30 passive (Damon clear 2),30 active(GAC In-Ovation C) and 30 interactive (Empower clear) orthodontic brackets with a slot size of .022X.028 MBT prescription in combination with stainless ...

AIM To compare early bacterial adhesion and biofilm formation of common and uncommon periodontal pathogens on a variety of commercial brackets in vitro. MATERIALS AND METHODS In vitro adhesion and biofilm formation of 4 bacterial strains on 15 different commercial brackets, in standard culture mediums with and without addition of either serum or human saliva was evaluated by quantitative real...

The purpose of this study was to evaluate in vitro the shear bond strength of recycled orthodontic brackets. S2C-03Z brackets (Dental Morelli, Brazil) were bonded to the buccal surfaces of 50 extracted human premolars using Concise Orthodontic chemically cured composite resin (3M, USA). The teeth were randomly assigned to 5 groups (n=10), as follows. In group I (control), the bonded brackets re...

OBJECTIVE The objective of this study was to compare the surface morphology and dimensional stability of the bracket slot at the onset of treatment and after 12 months of intraoral exposure. The study also compared the amount of calcium at the bracket base which indicates enamel loss among the three orthodontic brackets following debonding after 12 months of intraoral exposure. MATERIALS AND ...

The dynamic of a classical system can be expressed by means of Poisson brackets. In this paper we generalize the relation between the usual non covariant Hamiltonian and the Poisson brackets to a covariant Hamiltonian and new brackets in the frame of the Minkowski space. These brackets can be related to those used by Feynman in his derivation of Maxwell's equations. The case of curved space is ...

We apply new techniques to compute Gerstenhaber brackets on the Hochschild cohomology of a skew group algebra formed from a polynomial ring and a finite group (in characteristic 0). We show that the Gerstenhaber brackets can always be expressed in terms of Schouten brackets on polyvector fields. We obtain as consequences some conditions under which brackets are always 0, and show that the Hochs...