AIM To evaluate the effects of repeated autoclaving on torsional strength of two nickel-titanium (NiTi) rotary endodontic files: Twisted Files (SybronEndo, Orange, CA, USA) and GT Series X files (Dentsply Tulsa Dental Specialties, Tulsa, OK, USA). METHODOLOGY Four groups of 20 GT Series X (size 20, .06 taper) and four groups of 20 Twisted Files (size 25, .06 taper) were subjected to 0, 1, 3 o...

OBJECTIVE To investigate the biomechanical properties of the percutaneous compression plating system for intertrochanteric hip fractures. DESIGN A biomechanical laboratory investigation on human cadaveric upper femora was conducted. SETTING Biomechanical laboratory. PATIENTS Sixteen femora from cadavers of patients aged 60 to 85 years. INTERVENTION An intertrochanteric fracture was perf...

Static head roll about the naso-occipital axis is known to produce an opposite ocular counterroll with a gain of approximately 10%, but the purpose and neural mechanism of this response remain obscure. In theory counterroll could be maintained either by direct tonic vestibular inputs to motoneurons, or by a neurally integrated pulse, as observed in the saccade generator and vestibulo-ocular ref...

Purpose. Comparison of monoaxial and polyaxial screws with the use of subcutaneous anterior pelvic fixation. Methods. Four different groups each having 5 constructs were tested in distraction within the elastic range. Once that was completed, 3 components were tested in torsion within the elastic range, 2 to torsional failure and 3 in distraction until failure. Results. The pedicle screw system...

Sun, Jianzhuo. M.S.A.A., Purdue University, May 2014. Biaxial Shear/Tension Failure Criteria of Spectra single fibers. Major Professor: Weinong Chen. An experimental study was conducted to develop the biaxial failure surface criteria of single Spectra 130d and 100d filaments in a torsion-tension environment. The crosssectional profiles of single Spectra fibers were investigated using scanning e...

Due to lack of theory of elasticity, estimation of ultimate torsional strength of reinforcement concrete beams is a difficult task. Therefore, the finite element methods could be applied for determination of strength of concrete beams. Furthermore, for complicated, highly nonlinear and ambiguous status, artificial neural networks are appropriate tools for prediction of behavior of such states. ...

A COMPARISON OF TORSIONAL STRESS PROPERTIES OF THREE DIFFERENT NICKEL-TITANIUM FILES WITH SIMILAR CROSS-SECTIONAL DESIGN Reid C. Wycoff D.D.S. Marquette University, 2012 The purpose of this study was to compare the in vitro torsional stress characteristics of Twisted Files (SybronEndo, Orange, CA) with two milled files of similar cross section, EndoSequence (Brasseler USA, Savannah, GA) and Pro...

The torsional stress is caused by interaction between electrical transient air-gap torque by electrical disturbances and mechanical torque of turbine-generator shaft system. If a transient shaft torque exceeds a certain threshold, the loss of fatigue life occurs and in the end it is possible to happen shaft failure. This paper discusses that which factors can damage to turbine-generator shaft a...