OBJECTIVE The aim of this study was to compare the cyclic fatigue resistance of two nickel-titanium (NiTi) endodontic instruments from ProTaper and GT series X files. STUDY DESIGN Cyclic fatigue test was realized with instruments from ProTaper: F1 and F3 (Denstply Maillefer, Ballaigues, Switzerland) and GT-X: 20.06 and 30.08 (Dentsply Tulsa Dental, Tulsa, Oklahoma, United States of America). ...

1. The airway and metabolic responses to an intravenous beta 2-agonist salbutamol have been investigated in normal subjects before and after chronic administration of inhaled salbutamol, 1600 micrograms daily for 2 weeks. 2. Before chronic inhalation of salbutamol there was a dose-dependent increase in specific airway conductance after intravenous salbutamol in cumulative doses from 25 to 300 m...

INTRODUCTION The use of reciprocating movement was claimed to increase the resistance of nickel-titanium (NiTi) file to fatigue in comparison with continuous rotation. Recently 2 new brands of NiTi files have been marketed for use in a RM mode. The purpose of this study was to compare the cyclic fatigue resistance and torsional resistance of these 2 files, Reciproc and WaveOne. METHODS Cyclic...

AIM To compare the effect of brushing motion on torsional and cyclic fatigue resistance of TF Adaptive instruments after clinical use. METHODS 20 packs of TFA small sequence (SybronEndo, Orange, CA, USA) were used for this study and divided into two groups. Each instrument prepared one resin tooth, consisting in 4 canals with a complex anatomy. In group A, no brushing motion was performed. In...

OBJECTIVES The aim of this study was to evaluate the cyclic fatigue resistance of the ProTaper Universal D1 file (Dentsply Maillefer) under continuous and adaptive motion. MATERIALS AND METHODS Forty ProTaper Universal D1 files were included in this study. The cyclic fatigue tests were performed using a dynamic cyclic fatigue testing device, which had an artificial stainless steel canal with ...

The AISI 316 L Stainless Steel (SS) specimens were exposed to passivation surface through two different processes including; holding in 40-vol% HNO3 at temperature of 60 ºC for 30 min and 15-vol%H2SO4 at ambient temperature for 1 hour. The corrosion behavior of specimens was evaluated in physiological solutions by electrochemical in vitro tests through linear an...

The objective of the paper is to study the effect of cyclic loading on the fracture resistance of the SA 333 Gr.6 carbon steel material of the primary heat transport (PHT) system piping of Indian pressurized heavy water reactors (PHWR). Tests have been carried out on compact tension specimens machined from the pipe used in the PHT system. The effect of load ratio, incremental plastic displaceme...

Frameworks for estimating soil properties from CPT penetration resistances must account for the effects of overburden stress on both the penetration resistance and the soil property of interest, including how such effects vary with soil type. For example, common procedures for estimating the liquefaction resistance of sands include functional terms that account for the effect of overburden stre...

1. Normal subjects showed a highly reproducible, rapid increase in plasma adenosine 3':5'-cyclic monophosphate (cyclic AMP) after an intravenous injection of 200 MRC units of highly purified bovine parathyroid hormone. 2. No significant increase in plasma cyclic AMP was observed after administration of bovine parathyroid hormone to patients with severe chronic renal failure. 3. Even when renal ...