introduction: in this experimental study, the amount of smear layer (sl) remnants in curved root canals after chemomechanical instrumentation with two engine-driven systems or hand instrumentation was evaluated. methods and materials: forty-eight mesiobuccal roots of mandibular first molars with curvatures ranging between 25 and 35 degrees (according to schneider’s method) were divided into thr...

the background of consideration to local and national characteristics of land preparation management in development plans is recently and also of old. it is of old because it is traced back to human presence in land area and definition of the land and curiosity about life. it is recent because it has been begun in the last 100 years and it started mainly in the half of the past century and afte...

in this investigation the thickness of enamel in the gingival, middle, and incisal thirds of the labial surface of the anterior teeth were measured regarding preparation of the teeth for porcelain laminate veneers.part one, 20 extracted intact human maxillary central and lateral incisors ten of each were selected. the teeth were imbedded in autopolimerize acrylic resin. cross section was prefor...

Partially stabilized zirconia (PSZ) agglomerate toughened alumina has been prepared by the "deflocculation-flocculation" technique, using 2 and 3 mol. % Y2O3-doped zirconia powders. Samples containing up to about 30 vol.% zirconia were obtained. The resulting microstructure seems to be mainly influenced by the physical properties of the starting powders, e.g. agglomerate size and the specific s...

Colonoscopy is an important screening and therapeutic modality for colorectal cancer. Unlike other screening tests, colonoscopy is dependent on pre-procedure bowel preparation. If the bowel preparation is poor, significant pathology may be missed. Many factors are known to improve bowel preparation. This review will highlight those factors that may optimize the bowel preparation, including choi...

The aim of this study was to determine the frequency of medication errors happened during the preparation and administration of intravenous (IV) drugs. This study was designed as prospective cross-sectional evaluations by direct unconcealed observation in a setting consisted of orthopedic, general surgery and gastroenterology wards of a teaching hospital. Participants were those patients hospit...

Background: Surgery is a stressful experience in children. Therefore, the familiarization of this population with treatment processes by means of appropriate training tools and techniques can be an effective way to control their anxiety. Aim: The aim of this study was to determine the effect of a preoperative preparation program on anxiety in school-age children undergoing surgery using a facto...

ion 260 Preparation of Dibenzofurafls and Related Hetero-analogues 268 Preparation of Dibenzofurans 268 Preparation of Dibenzothiophenes 281 Attempted Preparation of Carbazoles and N-Methylcarbazoles 289 4.. Preparation of Fluorene and Fluorenone 298