introduction: blood contamination of the canal during preparation can be a major problem in endodontics; this may result in apical microleakage. the aim of this in vitro study was to evaluate the effect of blood on apical microleakage of a resin-based root canal sealer (ah26) and a polymer-based root canal sealer (epiphany). materials & methods: in this experimental study, 50 decoronated centra...

In rotary machinery, bearings are susceptible to different types of mechanical faults, including ball, inner race, and outer race faults. condition-based monitoring (CBM), several techniques have been proposed in fault diagnostics based on the vibration measurements. For this paper, we studied fractal characteristics non-stationary signals collected from under health conditions. Using detrended...

introduction: the purpose of this study was to evaluate the efficacy of three methods in removal of resilon/new epiphany self-etch (se) soft resin endodontic obturation system. materials and methods: thirty extracted single rooted human teeth were prepared for endodontic treatment and obturated with resilon/epiphany se. the roots were randomly divided into three groups; group 1 roots were retre...

INTRODUCTION This study investigated the fatigue and fracture modes of RaCe and ProTaper rotary instruments. MATERIALS AND METHODS Fatigue resistance was evaluated by rotating the files 30° or 60° and with 2 or 5mm radius of curvature. RaCe taper 06 size 25 and ProTaper F1 files (n=40) were used. The number of rotations to failure was analyzed by two-way ANOVA and independent sample t-test. F...

The output signals of the rotary incremental encoder are used for motion sense discrimination, angular displacement and rotational speed measurement of the encoder shaft. The angular displacement can be measured with different resolutions. This paper presents an experimental system that enables the study of the rotary incremental encoder: working modes and methods for resolution improvement, di...

introduction: one of the most common complications of root canal treatment is postoperative pain. the aim of the present clinical trial was to compare the severity of postoperative pain after root canal preparation with race rotary system and hand k-flexofile. methods and materials: a total of 96 mandibular first and second molars were divided into two groups ( n =48) based on root canal prepar...

canal preparation generates a substantial amount of debris and smear layer (sl). the size and taper of the master apical file (maf) affects on penetration of irrigants and subsequently canal cleaning efficacy. the aim of this study was to evaluate the effect of maf size and taper on penetration of irrigants to the apical third of curved mesiobuccal (mb) canals of mandibular first molars.eighty-...

introduction: bacteria and their byproducts are major etiologic factors in endodontic diseases. prevention or reduction of root canal bacterial contamination is the main aim of endodontic treatment. the purpose of this in vitro study was to evaluate the effect of size and taper of master apical file (maf) in reducing bacteria from the apical third of the curved canals using a quantitative scann...

Wheat-corn cropping system is one of the most important grain production systems in theworld. However, the integrative impacts of soil tillage on crop yield, N use efficiency (NUE)and greenhouse gases (GHGS) emissions are not well documented in this system. Thus, a twoyear field experiment was carried out in a typical wheat-corn cropping system with four tillageregimes during the wheat season, ...