We consider the double field formulation of closed bosonic string theory, and calculate Poisson bracket algebra symmetry generators governing both general coordinate local gauge transformations. Parameters these symmetries depend on a coordinate, defined as direct sum initial T-dual coordinate. When no antisymmetric is present, $C$-bracket appears Lie generalization in theory. With introduction...

OBJECTIVE The aim of this study was to evaluate the effects of tribochemical silica coating and silane surface conditioning on the bond strength of rebonded metal and ceramic brackets. MATERIAL AND METHODS Twenty debonded metal and 20 debonded ceramic brackets were randomly assigned to receive one of the following surface treatments (n=10 for each group): (1) sandblasting (control); (2) tribo...

OBJECTIVE To evaluate the shear bond strength of precoated orthodontic brackets bonded with self-etching primer relative to that of noncoated conventionally-bonded brackets at two different time intervals. METHODS Twenty-one subjects were selected for randomized split-mouth bonding of two types of brackets to the maxillary arch. Half of the teeth had precoated brackets bonded using self-etchi...

Orthodontic treatment with fixed appliances is considered a risk factor for the development of white spot caries lesions (WSL). Traditionally, brackets are bonded to the buccal surfaces. Lingual brackets are developing rapidly and have become more readily available. Buccal surfaces are considered to be more caries prone than lingual surfaces. Furthermore, lingual brackets are shaped to fit the ...

BACKGROUND Orthodontists are commonly faced with the decision of what to do with debonded or inaccurately positioned brackets. An economical option to this dilemma is to recycle the brackets. Many recycling methods have been proposed, but the optimal bond strength of these recycled brackets needs further evaluation. Objectives: To evaluate and compare the effect of three recycling methods: (i) ...

In equation 4, the two brackets surrounding [N-m/d] should be replaced by floor function brackets. Please view the correct equation here.

INTRODUCTION The aim of this in-vitro study was to evaluate the frictional forces generated by various combinations of brackets and orthodontic wires by using an experimental model with 3 nonleveled brackets to gain a better understanding of the resistance to sliding during dental alignment and leveling. METHODS Two kinds of orthodontic brackets were tested: passive self-ligating brackets and...

BACKGROUND The orthodontist seeks an archwire-bracket combination that has both good biocompatibility and low friction. Hence, the aim of this multicenter in vitro study was to evaluate and compare the frictional resistance generated between titanium (Ti), stainless steel (SS), ceramic and ceramic with metal insert (CMI) brackets with SS wires of varying dimensions in a specially designed appar...

Background and Aim: Application of zirconia ceramics has increased. Since the commonly used surface treatment for porcelain, i.e. acid etching is not efficient for zirconia surfaces, evaluation of other surface treatment methods for zirconia is important. The aim of this study was to compare the shear bond strength (SBS) of metal brackets to zirconia treated with different powers of Er:YAG lase...