MATERIALS AND METHOD Fig: 1 Extracted Mandibular molars selected for the study

OBJECTIVE Apical deviations are important factors in endodontic therapy, since they can cause the treatment failure. The aim of the present study was to determine the centering capacity of ProTaper Universal™, Twisted File™ and Revo-S® rotary systems using cone beam computed tomography analysis before and after the instrumentation of root canals. MATERIALS AND METHODS Thirty mesiobuccal roots...

This paper reports on the use of bent-beam electrothermal actuators for the purpose of generating rotary and long-throw rectilinear displacements. The rotary displacements are achieved by orthogonally arranged pairs of cascaded actuators that are used to rotate a gear. Devices were fabricated using electroplated Ni, p Si, and polysilicon as structural materials. Displacements of 20–30 m with lo...

introduction: apical transportation changes the physical shape and physiologic environment of the root canal terminus. the aim of the present experimental study was to determine the extent of apical transportation after instrumentation with hand k-flexofile and k3 rotary instruments by means of cone-beam computed tomography (cbct). methods and materials: forty mesiobuccal root canals of maxilla...

The dynamic characteristics and parametric instability of a rotating electrorheological ER sandwich beam with rotary oscillation are numerically analyzed. Assuming that the angular velocity of an ER sandwich beam varies harmonically, the dynamic equation of the rotating beam is first derived based on Hamilton’s principle. Then the coupling and nonlinear equation is discretized and solved by the...

This paper aims at investigating the nonlinear behavior of a system which is consisting of two free-free beams which are connected by a nonlinear joint. The nonlinear system is modelled as an in-extensional beam with Timoshenko beam theory. In addition, large amplitude vibration assumption is taken into account in order to obtain exact results. The nonlinear assumption in the system necessities...

We report a novel rotary piezoelectric motor using bending transducers in this work. Three transducers are used to drive a disk-shaped rotor together by the elliptical movements of their driving tips; these motions are produced by the hybrid of two first bending vibration modes. The proposed piezoelectric transducer has a simple structure as it only contains an aluminum alloy beam and four piec...