introduction: the aim of this study was to evaluate the amount of dentine removed after canal preparation using stainless steel (ss) hand instruments or rotary profile instruments. materials and methods: thirty-six extracted human teeth with root canal curvatures less than 30º were embedded in clear polyester resin. the roots were cut horizontally at apical 2, 4 and 7 mm. dentin thickness was m...

The motion planning technique described in this paper has been developed to eliminate or reduce the residual vibrations of belt-driven rotary platforms, while maintaining unchanged the motion time and the total angular displacement of the platform. The proposed approach is based on a suitable choice of the motion command given to the servomotor that drives the mechanical device; this command is...

introduction: the aim of the present study was to compare hand stainless steel k-files and nickel-titanium profile 0.04 taper 29 series rotary instruments for their efficiency, procedural errors and time consumed in preparation of root canal system. materials and methods: a total of 46 maxillary and mandibular first premolars extracted for orthodontic purposes were collected (two contralateral ...

BACKGROUND Root canal preparation using rotary nickel-titanium instruments has been reported to be superior to hand instrumentation in terms of root canal shape, centring and frequency of procedural errors. The purpose of this study was to evaluate canal preparations using a sequential silicone impression technique to assess root canal morphology. METHODS Pre-operative canal impressions were ...

AIM To compare cyclic fatigue resistance of two geometrically similar nickel-titanium instruments, used in conditions similar to clinical use in reciprocating and continuous rotary motion. METHODOLOGY Four groups of eighteen instruments each, Reciproc(®) files sizes ISO 25 and 40 (R25 and R40) and Mtwo(®) files sizes ISO 25 and 40 (M25 and M40), were tested in reciprocating and continuous rot...

While a new tire may have excellent resistance to crack initiation and propagation between the steel belts, an aged tire of the exact same construction can exhibit dramatically reduced crack growth resistance, which in some cases may contribute to tire failure. This article will review the research that has gone into quantifying the rate of oxidation the steel belt rubber oxidizes in different ...

in this paper coupled nonlinear equations of motion of a suspended cable with time dependent tension and velocity are derived by using hamilton’s principal. a modal analysis for a stationary sagged cable is initially carried out in order to identify the dynamic system. the natural solution is directed to compute the natural frequencies and mode shapes of the free vibration of a suspended cable....

The clinical endodontic breakthrough was progressing from utilizing a long series of stainless steel (SS) hand files and several rotary Gates Glidden drills to integrating nickel titanium (NiTi) files for shaping canals. Regardless of the methods utilized, the mechanical objectives for canal preparation were brilliantly outlined almost 40 years ago by Dr. Herbert Schilder.1 When properly perfor...

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...