Marwa Bedier

Objectives: The aim of the present study was to evaluate the effect of the different temperatures on the flexural cyclic fatigue of 2 Shape and OneShape rotary endodontic files.Materials and Methods: Forty-rotary endodontic files were divided according to the type of instrument used and the surrounding temperature (n=10); 2Shape and OneShape rotary endodontic files rotated in a custom made simulated canal model block fixed to a beaker containing water with temperature adjusted to either 37 °C or 60 °C. Time was recorded from the beginning of rotation until the fracture was detected, then the number of cycles to failure (NCF) and the length of the fractured segment (FL) were evaluated. Two representative samples were photographed under scanning electron microscopy. Two-way Analysis of Variance (ANOVA) was used to study the effect of the type of instrument used and temperature on the number of cycles to failure and the length of the fractured segment. Results: 2Shape rotary endodontic...

Aim: The aim of the present study was to compare the cutting efficiency of XP-Endo shaper and iRaCe nickel titanium rotary instruments after different number of uses and to evaluate the surface characteristics. Methodology: Forty-eight mesial roots were divided into two groups (n= 24) according to the type of the file system used (XPS/iRaCe) and was then subdivided into three subgroups (n=8) according to the number of uses (first use, second use and third use). Each specimen was prepared and irrigation was done using 5 ml of freshly prepared 2.5% NOCL, then 3 ml of 17% EDTA followed by 10 ml of distilled water. All root samples were weighted before and after preparation and weight loss was calculated. Two samples (Size 30 and Taper 0.04) from each file system were randomly selected and photographed using Scanning Electron Microscope (SEM) before and after the third use, at magnification 150x and 2000x. Comparing the cutting efficiency of each group at the different number of uses wa...