In this paper, the characteristics of two rotary tables driven by worm gear and roller gear cam are measured and compared. The positioning accuracy and repeatability as specified in ISO 230-2 are measured together with the rotational fluctuation, backlash, friction torque, frequency response of the systems and also the influence of unbalance mass on rotational motion. Two rotary encoders which ...

MEMS (micro-electro-mechanical-systems) device has been a promising and fascinating topic in both mechanical and electrical engineering domains for decades with the revolutionary contributions to the contemporary micro-scale instruments especially for the micro-actuator and micro-sensor. Among the versatile material foundation to build up the MEMS device, silicon wafer is preferred to due to th...

OBJECTIVES Today many clinicians use both stainless-steel hand K-files and nickel- titanium rotary files during endodontic treatment. It is of great importance for the clinician to have confidence in the accuracy of an apex locator even if these files were used interchangeably. The purpose of this in vitro study was to evaluate the accuracy of the Raypex5 electronic apex locator using stainless...

The purpose of this prospective, randomized, single-blind study was to compare the in vivo antibacterial efficacy of a hand/rotary technique versus a hand/rotary/ultrasound technique in mesial root canals of necrotic mandibular molars. The hand/rotary group consisted of 16 mesial roots prepared with a hand/rotary technique. The hand/rotary/ultrasound group consisted of 15 mesial roots prepared ...

AIM The purpose of this study is to achieve an effective method to remove root canal filling material from the root canal system. The study, thus, aims to evaluate the efficacy of the cleaning ability of two different rotary Ni-Ti systems; ProTaper Retreatment files and RaCe System compared to hand instrumentation with Hedstrom files for the removal of gutta-percha during retreatment. MATERIA...

Introduction. The aim of the present study was to evaluate the dentinal cracks after root canal preparation with rotary files: Gates Glidden, ProTaper Universal, ProTaper Next, and HyFlex CM at different instrumentation lengths. Methodology. Sixty-five mandibular premolars were mounted in the acrylic tube with simulated periodontal ligaments and the apex was exposed. The root canals were instru...

The output signals of the rotary incremental encoder are used for motion sense discrimination, angular displacement and rotational speed measurement of the encoder shaft. The angular displacement can be measured with different resolutions. This paper presents an experimental system that enables the study of the rotary incremental encoder: working modes and methods for resolution improvement, di...

The desire to help others in need could be considered to be a fundamental human quality. Yet, with so many suffering from the crushing effects of poverty, hunger, violence and disease, we may wonder if it is possible to make a difference at all. As a Nigerian lawyer, and President of Rotary International, I have solid proof that the answer to this is " yes ". Although they are not always seen, ...