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...

OBJECTIVE The aim of this study was to evaluate the biomechanical preparation of flattened root canals using the following systems: Endo-Eze AET stainless steel oscillatory instruments (Ultradent) and RaCe rotary NiTi instruments (FKG Dentaire). MATERIAL AND METHODS Twenty extracted human mandibular incisors were randomly assigned to two groups: Group 1 - Instrumentation with oscillatory Endo...

Abstract: Permanent magnetic linear motors(PMLMs) are easier to accelerate and achieve higher precision than rotary motors. Hence, they have a broad range of applications in the manufacturing industry and other motion control fields. Owing to the structural variation, however, the models of permanent magnet linear motors and rotary motors are different. As a result, their motion control systems...

This clinical report introduces a method for safe retrieval of a broken implant abutment screw. A reverse-tapping rotary instrument has been introduced in the market and is widely used to retrieve broken screws; however, it is difficult to use the rotary instrument unless an access hole for engagement of the rotary instrument is positioned directly on the center of the top of the broken screw r...

INTRODUCTION The purpose of this study was to evaluate the efficacy of three methods in removal of Resilon/new Epiphany self-etch (SE) soft resin endodontic obturation system. MATERIALS AND METHODS Thirty extracted single rooted human teeth were prepared for endodontic treatment and obturated with Resilon/Epiphany SE. The roots were randomly divided into three groups; group 1 roots were retre...

Objective: To compare the straightening of root canal curvature, the apical transportation, the loss of working length and the working time using two rotary systems. Study design: Sixty buccal root canals with angles of curvature between 30 to 99o were instrumented with Mtwo and Twisted File rotary instruments. A series of preand post-operative radiographs were superimposed to determine the str...