introduction: the purpose of the present study was to evaluate the different concentrations of sodium hypochlorite activated with laser in removing of the smear layer in the apical, middle, and coronal segments of root canal walls by scanning electron microscopy analysis. methods: sixty single-rooted human mandibular teeth were decoronated to a standardized length. the samples were prepared by ...

Detailed understanding of the action of biological molecular machines must overcome the challenge of gaining a clear knowledge of the corresponding free-energy landscape. An example for this is the elucidation of the nature of converting chemical energy to torque and work in the rotary molecular motor of F1-ATPase. A major part of the challenge involves understanding the rotary-chemical couplin...

BACKGROUND Endodontic instrumentation carries the risk of over extrusion of debris and bacteria. The technique used and the type of instrumentation influences this risk. AIM The purpose of this study was to evaluate and compare the K-file, ProTaper hand and ProTaper rotary instrumentation systems for the amount of apically extruded debris, irrigant solution and intracanal bacteria. DESIGN E...

This paper proposes a mathematical model of a CNC rotary table driven by a worm gear. The CNC rotary tables are generally utilized as rotary axes of 5-axis machining centres. In this study, a mathematical model which can simulate dynamic behaviours of rotary table is proposed. The model consists of inertia of motor, spur and worm gears, and table. Axial displacement of the worm is also consider...

The aim of this study was to evaluate the performance of undergraduates in their first contact with manual and rotary root canal instrumentation. Forty-two students who had never worked on a root canal before instrumented 42 extracted lower-incisors. Participants were assigned to one of two groups: Rotary instrumentation or manual instrumentation. Pre- and post-operative computed tomography sca...

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...

Reading a rotary dial utility meter can be difficult and, more importantly, inaccurate. This paper has developed a computationally efficient method to read a rotary dial utility meter via image processing. The method has been developed as an algorithm with the ultimate goal of implementing the system with a microprocessor and inexpensive camera. The algorithm registers successive dial images, s...