INTRODUCTION High-accuracy rotary encoders are required for rotational axis position measurement in ultraprecision manufacturing and measurement equipments. A typical rotary encoder is made of a glass disk with a fine grating pattern and a scanning read head unit. Digital pulse trains are output from the read head to represent the disk rotary position. The angular measurement accuracy of such a...

AIM To assess two contemporary rotary instrumenting systems subjectively and objectively in a pre-clinical student course setting. METHODOLOGY Undergraduate dental students (n = 44) prepared mesiolingual canals of 3D-printed mandibular molar replicas (RepliDens, Zurich, Switzerland). The HyFlex and BioRace rotary systems, both previously unknown to the students, were used according to the man...

introduction: the aim of this in vitro study was to evaluate the effect(s) of three canal lubricants i.e. sodium hypochlorite, rc-prep as the paste form of ethylenediaminetetraacetic acid (edta) and aqueous edta, on the occurrence/incidence of fracture, deformity and metal slivering of protaper rotary instruments. methods: a total of 120 mesial canals ( i.e. mesiobuccal and mesiolingual) of fir...

BACKGROUND Root canal shaping without any procedural error is of the utmost preference. Therefore, the purpose of this study was to use micro-computed tomography to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files. MATERIAL AND METHODS Sixty extracted upper second premolars were selected and were divided into 2 groups of 30. Be...

OBJECTIVE This study assessed the muscular activity during root canal preparation through kinematics, kinetics, and electromyography (EMG). MATERIAL AND METHODS The operators prepared one canal with RaCe rotary instruments and another with Flexo-files. The kinematics of the major joints was reconstructed using an optoelectronic system and electromyographic responses of the flexor carpi radial...

INTRODUCTION The purpose of this study was to compare dentinal microcrack formation while using hand files (HFs), 4 brands of nickel-titanium (NiTi) rotary files and the self-adjusting file. METHODS One hundred forty mandibular first molars were selected: 20 teeth were left unprepared and served as control, and the remaining 120 teeth were divided into 6 groups. HFs, HERO Shaper (HS; Micro-Me...

As compared with continuous rotary systems, reciprocating motion is believed to increase the fatigue resistance of NiTi instruments. We compared the cyclic fatigue and torsional resistance of reciprocating single-file systems and continuous rotary instrumentation systems in simulated root canals. Eighty instruments from the ProTaper Universal, WaveOne, MTwo, and Reciproc systems (n = 20) were s...

Root canal shaping is of utmost importance in the success of root canal treatment. Numbers of systems available are effective for shaping; accounting from stainless steel hand files to nickel-titanium rotary files to the new single file system concept. Single file technique is developed for shaping vast majority of canals, regardless of their length, diameter or curvature. Therefore, single use...