UNLABELLED   INTRODUCTION Rotary nickel-titanium (NiTi) instruments are thought to allow shaping of narrow, curved root canals more efficiently and more effectively than stainless steel hand instruments. However, the continued search for even more effective and safer instruments has resulted in new rotary systems being introduced on a regular basis. The aim of this study was to compare shapin...

introduction: the purpose of this in-vitro study was to compare shaping ability of niti rotary mtwo and flexmaster with stainless steel hand k-flexofile in curved root canals of extracted teeth. materials and methods: mesiobuccal canals of 45 mandibular molar teeth were balanced into three groups of 15 each, with respect to the schneider angle, canal access angle, height, dis-tance and radius o...

introduction proper cleaning and shaping of the root canal system is one of the most important aspects of endodontic therapy. to estimate the canal length before instrumentation in endodontic treatment, traditionally, conventional radiographic techniques and, recently, direct digital radiography (ddr) are applied. the application of computer technology in radiography has allowed less exposure t...

The aim of this study was to examine the lifespan or number of cycles to failure of tapered rotary nickel-titanium (Ni-Ti) endodontic instruments. Simulated root canals with different curvatures were used to determine a relation between canal curvature and instrument lifespan. Using a novel mathematical model for the deformation of pseudoelastic Ni-Ti alloy, it was shown that maximum stress nee...

The relationship between semicircular canal radius of curvature and afferent sensitivity has not been experimentally determined. We characterized mouse semicircular canal afferent responses to sinusoidal head rotations to facilitate interspecies and intraspecies comparisons of canal size to sensitivity. The interspecies experiment compared the horizontal canal afferent responses among animals r...

The relationship between semicircular canal radius of curvature and afferent sensitivity has not been experimentally determined. We characterized mouse semicircular canal afferent responses to sinusoidal head rotations to facilitate interspecies and intraspecies comparisons of canal size to sensitivity. The interspecies experiment compared the horizontal canal afferent responses among animals r...

This article describes and discusses a method to determine root curvature radius by using cone-beam computed tomography (CBCT). The severity of root canal curvature is essential to select instrument and instrumentation technique. The diagnosis and planning of root canal treatment have traditionally been made based on periapical radiography. However, the higher accuracy of CBCT images to identif...

BACKGROUND The aim of this in vitro study was to compare the shaping characteristics of two types of nickel-titanium endodontic file systems with regard to the following parameters: Canal straightening, Canal deviation and Instrumentation time. MATERIAL AND METHODS Fifty severely curved canals simulated in resin blocks were prepared to an apical size 25 using Protaper Universal orNeolix syste...

OBJECTIVE This study evaluated the wear in the apical third of simulate canals after preparation with ProTaper Universal Rotary System. MATERIAL AND METHODS 24 sets of instruments were used in 24 simulated canals in transparent epoxy resin blocks with degree of curvature of either 20 degrees or 40 degrees. The canals were photographed preoperatively and after preparation of the apical stop wi...