BACKGROUND Orthodontic treatment with fixed appliances requires - among others - the correct clinical expression of torque, which depends on the precise fitting of archwire and slot. Especially in the lingual technique torque problems become clinically more evident than in labial appliances also with respect to the vertical alignment of teeth due to different distances from the center of resist...

Different techniques have been introduced for the removal of ceramic brackets. Since the early 1990s, lasers have been used experimentally for debonding ceramic brackets. The goal of this study is to give a comprehensive literature review on laser-aided ceramic bracket debonding. PubMed and Google Scholar databases were used to identify dental articles with the following combination of key word...

For any finite Coxeter system (W,S) we construct a certain noncommutative algebra, the so-called bracket algebra, together with a family of commuting elements, the so-called Dunkl elements. The Dunkl elements conjecturally generate an algebra which is canonically isomorphic to the coinvariant algebra of the Coxeter group W. We prove this conjecture for classical Coxeter groups and I2(m). We def...

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 tungst...

Abstract The Barnich–Troessaert bracket is a proposal for modified Poisson on the covariant phase space general relativity. new allows us to compute charges, which are otherwise not integrable. Yet there catch. There clear prescription how evaluate any such charge, but little known extend entire space. This problem, because every gravitational observable also charge. In this paper, we propose a...

The Hamiltonian structure for an infinite class of nonlinear reduced fluid models, derived from a drift-kinetic system, is explicitly provided in terms the N+1 moments evolving each model class, with N arbitrary positive integer. This improves previous results, which existence was shown, but complete explicit expression Poisson bracket not provided. We also show that, whereas functional models ...

BACKGROUND The aim of this study was to compare the torque efficacy of square and rectangular wires in 0.018- and 0.022-in. conventionally ligated brackets. METHODS Brackets of the same prescription were evaluated in both slot dimensions. Identical acrylic resin models of the maxilla were bonded with the brackets and mounted on the Orthodontic Measurement and Simulation System. Ten 0.018 × 0....

We define a graded twisted-coassociative coproduct on the tensor algebra TW of any Zn-graded vector space W . If W is the desuspension space ↓V of a graded vector space V , the coderivations (resp. quadratic “degree 1” codifferentials, arbitrary odd codifferentials) of this coalgebra are 1to-1 with sequences πs, s ≥ 1, of s-linear maps on V (resp. Zn-graded Loday structures on V , sequences tha...

A good adhesive is an important factor to consider in orthodontic bonding. Frequent bracket failure prolongs treatment duration and causes inconvenience to patient and operator. This study aimed to compare the effectiveness of two bonding agents, i.e. the self etching primer (SEP) and the conventional etch and bond (CEB) by monitoring the incidence, time and sites of bracket failure. Eighty ort...

Motivated by the descent equation in string theory, we give a new interpretation for the action of the symmetry charges on the BRST cohomology in terms of what we call the Gerstenhaber bracket. This bracket is compatible with the graded commutative product in cohomology, and hence gives rise to a new class of examples of what mathematicians call a Gerstenhaber algebra. The latter structure was ...