Abstract Introduction: The aim of this study was to evaluate the efficacy of two rotary instrument systems (ProTaper and Revo-s File) in removing calcium hydroxide residues from root canal walls Materials and Methods:Thirty human  maxillary incisors were instrumented with the ProTaper System up to the F2 instrument, irrigated with 2.5% NaOCl,and filled with a calcium hydroxide intracanal dr...

A nonuniform-shape photonic crystal taper integrated with a single-mode optical fiber and a photonic crystal waveguide for high-efficiency mode coupling is presented. The curvature of the tapering section is varied by the parameter alpha. For values of alpha set to 2 and 0.5, concave and convex tapers are obtained, respectively. Numerical calculations yield an average coupling efficiency greate...

BACKGROUND AND PURPOSE The cause of syringomyelia in patients with Chiari I remains uncertain. Cervical spine anatomy modifies CSF velocities, flow patterns, and pressure gradients, which may affect the spinal cord. We tested the hypothesis that cervical spinal anatomy differs between Chiari I patients with and without syringomyelia. MATERIALS AND METHODS We identified consecutive patients wi...

We show that high-Q whispering-gallery modes in fused-silica microspheres can be efficiently excited by an optical fiber taper. By adjusting the taper diameter to match the ropagation constant of the mode in the taper with that of the resonant mode of interest, one can couple more than 90% of the light into the sphere. This represents a significant improvement in excitation efficiency compared ...

background: as various implant geometries present different biomechanical behaviors, the purpose of this work was to study stress distribution around tapered and cylindrical threaded implant geometries using three-dimensional finite element stress analysis.     methods: seven implant models were constructed using the cad system. after digitized models of mandibular section, the crowns were crea...

Optical fiber tapers are used to collect photoluminescence emission at approximately 1.5 microm from photonic crystal cavities fabricated in erbium doped silicon nitride on silicon. In the experiment, photoluminescence collection via one arm of the fiber taper is enhanced 2.5 times relative to free space collection, corresponding to a net collection efficiency of 4%. Theoretically, the collecti...