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...

at this study, after designing and manufacturing a rotary tool, its machining parameters and their effects on surface roughness of aluminum alloy of al99 which  is one of the most consumable alloys in aerospace industry, is  studied and optimized. first, the rotary tool is designed and manufactred. then according to taguchi method, the experiments have been designed to record surface roughness,...

introduction: all instrumentation techniques have been reported to be associated with extrusion of infected debris. the aim of this study was to evaluate the number of bacteria extruded apically from extracted teeth ex vivo after canal instrumentation using the two engine-driven techniques utilizing nickel-titanium instruments (flex master and mtwo). materials and methods: seventy extracted max...

introduction: the purpose of the present study was to quantify and compare the amount of extruded debris from apical foramen after instrumentation of the root canal system with hand and rotary instruments. materials and methods: root canals of forty five fresh extracted single rooted human teeth with mature apexes and less than 15 degree of root curvature were instrumented in group a with stain...

Modeling of the RadA family mechanism is crucial to understanding the DNA SOS repair process. In a 2007 report, the archaeal RadA proteins function as rotary motors (linker region: I71-K88) such as shown in Figure 1. Molecular simulations approaches help to shed further light onto this phenomenon. We find 11 rotary residues (R72, T75-K81, M84, V86 and K87) and five zero rotary residues (I71, K7...

The effect of the Superpave defined restricted zone on HMA rutting performance was evaluated. One gradation that violated the restricted zone (TRZ) and two gradations that did not violate the restricted zone (BRZ and ARZ) were evaluated. Mixes evaluated represented a range of maximum aggregate sizes (MAS), design traffic levels, and aggregate types. Three laboratory tests, Asphalt Pavement Anal...

This clinical report introduces a method for safe retrieval of a broken implant abutment screw. A reverse-tapping rotary instrument has been introduced in the market and is widely used to retrieve broken screws; however, it is difficult to use the rotary instrument unless an access hole for engagement of the rotary instrument is positioned directly on the center of the top of the broken screw r...

introduction: root fracture is not an instant phenomenon but a result of gradual development of tiny craze lines in tooth structure. recent studies have shown that canal instrumentation has the potential to cause dentinal cracks. the purpose of this study was to evaluate and compare the formation of dentinal cracks caused by protaper rotary system to hand instrumentation. materials and methods:...

A multi-channel continuous-flow ana]yzer equipped with biosensing deyices was deyeloped for multicomponent measurement and its use in automating routine analysis was evaluated. Biosensing was achieyed by the aid of an immobilized enzyme reactor insta]led in the channel, and the channe] switching process for the sensing of a different compound was made by using a column-switching rotary valve. A...

A rotary reactor and a fluidized bed reactor (both laboratory-scale and operated in batch mode) are used for the treatment of granulates containing SSA and CaCl ) and treating this mixture (possible after granulation) in a rotary kiln at 1000±100°C leads to the formation of volatile heavy metal compounds which evaporate and to Pphases with a high bio-availability. Due to economical and ecologic...