introduction: any decrease in friction between orthodontic wire and bracket can accelerate tooth movement in the sliding technique and result in better control of anchorage. the present study was carried out to decrease this friction by coating of zinc oxide nanoparticles (zno) on orthodontic wires and porcelain brackets. materials and methods: in this in vitro study, a combination of 120 0.019...

introduction a large number of orthodontists prefer to rebond the failed bonded brackets or use recycled brackets in some instances. the aim of this study was to compare the shear bond strength of rebonding with using recycled brackets on enamel surface. methods bonding of brackets on the surface of extracted first bicuspids was tested in five different groups to compare their shear bond streng...

Let A be one of the following commutative associative algebras: the algebra of all smooth functions on the plane: A = C(R), or the algebra of polynomials A = C[p, q] over R or C. There exists a non-trivial formal associative deformation of A called the Moyal ⋆-product (or the standard ⋆-product). It is defined as an associative operation A → A[[h̄]] where h̄ is a formal variable. The explicit for...

We introduce diagrams and Reidemeister moves for links in F ×S, where F is an orientable surface. Using these diagrams we compute (in a new way) the Kauffman Bracket Skein Modules (KBSM ) for D × S and A× S, where D is a disk and A is an annulus. Moreover, we also find the KBSM for the F0,3 × S , where F0,3 denotes a disk with two holes, and thus show that the module is free.

In any 2-category C with zeros (for example the topological 2-category T op∗ of based spaces, based maps and track classes of homotopies) box bracket operations have been defined and studied by Hardie-Marcum-Oda [4]. These are secondary homotopy operations and if (as we will suppose) C admits a suspension functor Σ (see [3]) they take values in morphism groups HC(ΣW,X), here denoted π(ΣW,X), of...

Background. Any decrease in friction between orthodontic wire and bracket can accelerate tooth movement in the sliding technique and result in better control of anchorage. This study was carried out to evaluate frictional forces by coating orthodontic wires and porcelain brackets with zinc oxide nanoparticles (ZnO). Methods . In this in vitro study, we evaluated a combination of 120 samples of ...

A clinical trial was carried out to evaluate and compare the clinical performance of a visible light-cured material with a chemically cured adhesive. This was used in combination with two types of bracket base. Fifty-two patients entered the trial and 542 bracket bases were placed. The incidence and site of bond failure were recorded. The overall failure rate for the light-cured material in com...

After 20 months of clinical testing and more than 600 bonded arches, brief interim conclusions can be drawn on treatment with a new lingual bracket system, one that differs fundamentally from conventional appliances in both design and manufacture. The demand for maximum individuality is met by using state-of-the-art computer-aided design/computer-aided manufacturing technology to fuse the 2 nor...

A new method to derive presentations of skein modules is developed. For the case of homotopy skein modules it will be shown how the topology of a 3-manifold is reflected in the structure of the module. The freeness problem for q-homotopy skein modules is solved, and a natural skein module related to linking numbers is computed.