OBJECTIVE Use of rotary Nickel-Titanium (NiTi) instruments for endodontic preparation has introduced a new era in endodontic practice, but this issue has undergone dramatic modifications in order to achieve improved shaping abilities. Cone-beam computed tomography (CBCT) has made it possible to accurately evaluate geometrical changes following canal preparation. This study was carried out to co...

in order to comparison of weeds mechanical control for sugar beet, a rotary cultivator was designed and constructed in first year, and compared with other mechanical control in second year. five treatments, included: rotary hoe cultivator, furrower cultivator, rotary cultivator, no weeding and manual weeding were compared. experiment design was random complete blocks design (rcbd) with three re...

A solid board factory produces rectangular sheets of cardboard in two different formats, namely large formats and small formats. The production process consists of two stages separated by an inventory point. In the first stage a cardboard machine produces the large formats. In the second stage a part of the large formats is cut into small formats by a separate rotary cut machine. Due to very la...

OBJECTIVES The purpose of this study was to compare in-vitro the amount of debris extruded apically from extracted teeth, using K3, Protaper rotary instruments and manual step-back technique. METHODS Forty five human single-rooted mandibular premolar teeth were randomly divided into 3 groups. The teeth in 3 groups were instrumented until reaching the working length with K3, Protaper rotary in...

Background and aims. The superiority of rotary systems has been reported in several clinical studies on permanent teeth. This study consisted of radiographic assessment and chair time of rotary instruments in the pulpectomy of primary second molar teeth. Materials and methods. In this randomized controlled clinical study, 46 children, 3-6 years of age, were selected. The patients were divided r...

A polygon A in a configuration C is called rotary if C admits an automorphism which acts upon A as a one-step rotation. We study rotary polygons and their orbits under the group of automorphisms (and antimorphisms) of C. We determine the number of such orbits for several symmetry types of rotary polygons in the case when C is flag-transitive. As an example, we provide tables of flag-transitive ...