BACKGROUND An in vivo comparative evaluation to determine the accuracy of working length between radiographic and electronic apex locators. AIM The study was aimed at evaluating the accuracy of electronic apex locator, to determine the working length of root canal, and to compare it with the radiographic method of working length determination. MATERIALS AND METHODS A total of 20 teeth selec...

introduction: the purpose of this in vitro study was to compare the accuracy of working length determination using the apex locator versus conventional radiography in c-shaped canals. methods and materials: after confirming the actual c-shaped anatomy using cone-beam computed tomography (cbct), 22 extracted c-shaped mandibular second molars were selected and decoronated at the cemento-enamel ju...

INTRODUCTION The aim of this in vitro study was to evaluate the correlation between accuracy of Root ZX electronic foramen locator and root canal curvature. METHODS AND MATERIALS One hundred and ten extracted mandibular molars were selected. Access cavity was prepared and coronal enlargement of mesiobuccal canal was performed. A #10 Flexofile was inserted into the mesiobuccal canal, and a rad...

In this paper we examine the stability of silicon tip apices by using density functional theory (DFT) calculations. We find that some tip structures - modelled as small, simple clusters - show variations in stability during manipulation dependent on their orientation with respect to the sample surface. Moreover, we observe that unstable structures can be revealed by a characteristic hysteretic ...

Since atomic force microscopy (AFM) images are a composite of probe and sample geometry, accurate size determinationsareproblematic. A relatively straightforwardmathematical procedure for determining tip radius of curvature (RT) for an asymmetrical tip was recently developed by Garcia et al. (ProbeMicrosc. 1997, 1, 107). This study represents an experimental test of that procedure for both sili...

In fluorescence microscopy and spectroscopy, energy transfer processes between single fluorophores and fluorophore quencher pairs play an important role in the investigation of molecular distances or orientations. At distances larger than about 3 nm these effects originate predominantly from dipolar coupling. As these experiments are commonly performed in homogenous media, effects at the interf...

BACKGROUND The eyebrow and eyelid are important sexually dimorphic and ethnic features of the face. In cosmetic surgery, maintenance of these landmarks is important to obtaining satisfactory results. OBJECTIVES The authors quantify the dimension and position of the eyebrow and eyelid in South Indians and Malaysian South Indians and assess whether significant differences exist between the sexe...

A theory for tunneling between a real surface and a model probe tip, applicable to the "scanning tunneling microscope" is presented. The tunneling current is found to be proportional to the local density of states of the surface, at the position of the tip. It can be shown that the tunneling conductance has exponential dependence on the distance of the nearest approach to the surface