Search results for "universal"

The effect of orthodontic bracket pad shape on shear bond strength, an in vitro study on human enamel

2018

Background To evaluate the effect of bracket pad shape on shear bond strength (SBS) of orthodontic brackets bonded to human enamel. Material and Methods One hundred and five extracted human maxillary permanent molars were divided into 7 groups of 15 specimens per group (n=15). Each group of teeth was bonded with 6 different shaped WildSmiles® brackets (Star, Heart, Soccer ball, Football, Flower, and Diamond) and GAC® rectangle shaped brackets. Shear debonding force was measured with an Instron universal testing machine using a knife-edged chisel 24 hours after initial bonding. Descriptive statistics (mean, standard deviation, and range) for each bracket pad shape was calculated. Analysis of…

Photoelastic analysis of conventional and locking system for treatment of mandibular angle fractures with a single plate

2021

Made available in DSpace on 2021-06-25T10:28:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-04-01 Background: This photoelastic analysis evaluated stress distribution in different osteosynthesis systems, conventional and locking, used for treatment of mandibular angle fractures with a single plate. Material and Methods: Angle fractures were simulated in mandibles made of photoelastic resin. Following Champy’s method, plate osteosynthesis was performed. The samples were divided into five groups: Group 1, non-fractured mandible; Group 2, two screws were installed in each segment using a conventional system; Group 3, two screws were installed in each segment using a locking system; …

Comparison of torque expression in esthetic brackets

2019

Background The objective of this work is to test the null hypothesis that there is no difference in the torque expression among different esthetic brackets. Material and methods Five ceramic self-ligating brackets (In-Ovation C - GAC, Damon Clear-Ormco, QuicKlear-Forestadent, Click-It -TP Orthodontics, Clarity SL-3M Unitek) and 4 ceramic conventional brackets (Inspire Ice-Ormco, InVu Ceramic-TP Orthodontics, Ceramic Roth-Morelli, Clarity Metal-Reinforced Ceramic Bracket-3M Unitek) were selected. Metallic Damon MX self-ligating bracket (Ormco) was used as control. Third-order moments were measured at 12o, 24o and 36o using an archwire torsion device associated with a Universal Testing Machin…

The effect of dental chair light exposure duration on shear bond strength of orthodontic brackets : an in vitro study

2018

Background The purpose of this study is to determine if the duration of exposure to the halogen overhead dental chair light has an effect on shear bond strength (SBS) of metal orthodontic brackets. Material and Methods One hundred twenty extracted human lower incisor teeth were divided into six groups (n=20/group). Each group was assigned a predetermined duration of exposure to the halogen dental chair light, set at a fixed distance, before being cured. Light exposure times of 0 minutes (Group 1-Control), 1 minute (Group 2), 2.5 minutes (Group 3), 5 minutes (Group 4), 10 minutes (Group 5), and 15 minutes (Group 6) were tested. Each tooth was subjected to an exclusion criteria examination, s…

Astronomical Activities with Disabled People

2010

With this contribution we would like to share our experiences in organizing astronomical activities addressed to people with disabilities. The goal is twofold: we would like to invite all those with similar experiences to contribute to the compilation of a document to guide other astronomers who might be interested in carrying out these kind of activities aimed at groups of people with special needs. We also want to persuade public outreach officers that working with disabled people is not as difficult as it may seem at first, as long as they are provided with adequate educational material and guidelines about how to do it. The final goal is to build a repository that can be used by educato…

Entre el negocio y los derechos humanos

2008

Influence of low concentration acid treatment on lithium disilicate core/veneer ceramic bond strength

2013

Objective: This study evaluated the influence of low concentration acid treatment on the shear bond strength between lithium disilicate (LD) infrastructure and veneering porcelain. The surface morphology characteristic after this acid treatment was also examined. Study Design: LD reinforced ceramic cylinders (n=10) (IPS e.max Press, Ivoclar-Vivadent, Schaan, Liechtenstein) were treated (LD-treated) with a low concentration acid solution (Invex Liquid – Ivoclar-Vivadent, Schaan, Liechtenstein) or not treated with the acid solution (LD-untreated). They were veneered with a glass ceramic (IPS e.max Ceram, Ivoclar-Vivadent, Schaan, Liechtenstein). A metal ceramic group (CoCr) was tested as cont…

On universality of critical behavior in the focusing nonlinear Schrödinger equation, elliptic umbilic catastrophe and the Tritronquée solution to the…

2008

We argue that the critical behavior near the point of “gradient catastrophe” of the solution to the Cauchy problem for the focusing nonlinear Schrodinger equation \(i\epsilon \varPsi _{t}+\frac{\epsilon^{2}}{2}\varPsi _{xx}+|\varPsi |^{2}\varPsi =0\) , e ≪1, with analytic initial data of the form \(\varPsi (x,0;\epsilon)=A(x)e^{\frac{i}{\epsilon}S(x)}\) is approximately described by a particular solution to the Painleve-I equation.

Moros y cristianos. De la batalla festiva a la discursiva

2008

Hace poco más de un año se acordaba en España admitir a trámite en el Congreso de los Diputados la proposición no de ley del Grupo Parlamentario Popular relativa a la proclamación de las "fiestas de moros y cristianos" como obras maestras del patrimonio oral e inmaterial de la humanidad. La solicitud se contextualiza en la democratización y universalización que el patrimonio ha experimentado y se explica por la vertiente cada vez más mercantilista de los procesos de patrimonialización. En el caso que nos ocupa la presentación estuvo envuelta en una interesante discusión política sobre la "tradición", la "libertad" y la "amenaza". Este artículo analiza la polémica sobre estas fiestas y su pr…

Walsh function analysis of 2-D generalized continuous systems

1990

The importance of the generalized or singular 2D continuous systems are demonstrated by showing their use in the solution of partial differential equations in two variables. A technique is presented for solving these systems in terms of Walsh functions. The method replaces the solution of a two-variable partial differential equation with the solution of a linear algebraic generalized 2D Sylvester equation. An efficient technique for the recursive solution of the latter equation is offered. All the results apply also in the usual Roesser 2D state-space case. >