Despite the excellent properties of mineral trioxide aggregate (MTA), the condensation technique may have some influence in its sealing ability. The purpose of this study was to compare the sealing ability of sonic and ultrasonic setting of MTA. Thirty-four extracted human teeth had their canals prepared and filled with Sealapex sealer and gutta-percha using the active lateral condensation tech...

Recently, research works on the bio-engineering actively carried out, and the useful tool for the micromanipulation is also developed. Purpose of this research is to develop the minute size knife for the cutting of the minute object such as the cell. In this paper, we report on the microknife that cuts o the object by using ultrasonic vibration of the sharp needle. We employed the multilayer pi...

ultrasonic assisted drilling (usd) is new technique to drill difficult to machine materials. in this method, tool or workpiece vibrates with amplitude of few microns in addition to conventional drill bite rotation. in this experimental research, the bone was drilled both conventionally and using uad, then the thrust was measured in two methods at feed rates of 50, 75 and 125 mm/s and 500, 710 a...

ultrasonic vibration assisted single point incremental forming (uvaspif) process is an attractive and adaptive method in which a sheet metal is gradually and locally formed by a vibrating hemispherical-head tool. the ultrasonic excitation of forming tool reduces the average of vertical component of forming force and spring-back rate of the formed sample. the spring-back phenomenon is one of the...

This work investigates the potential use of direct ultrasonic vibration as an aid to penetration of granular material. Compared with non-ultrasonic penetration, required forces have been observed to reduce by an order of magnitude. Similarly, total consumed power can be reduced by up to 27%, depending on the substrate and ultrasonic amplitude used. Tests were also carried out in high-gravity co...

We have constructed an atomic force microscope enabling one to image the topography of a sample, and to monitor simultaneously ultrasonic surface vibrations in the MHz range. For detection of the distribution of the ultrasonic vibration amplitude, a part of the position-sensing light beam reflected from the cantilever is directed to an external knife-edge detector. Acoustic images taken on the ...

Preparation of defect-free and well-controlled solution-processed crystalline thin films is highly desirable for emerging technologies, such as perovskite solar cells. In this work, using PbI2 as a model solution with a vast variety of applications, we demonstrate that the excitation of a liquid thin film by imposed ultrasonic vibration on the film substrate significantly affects the nucleation...

AIM To determine whether metal type, cement type and the use of ultrasonic vibration influence the amount of tensile force required to remove parallel-sided, prefabricated, metal posts from tooth roots. METHODOLOGY Ninety extracted canine teeth were sectioned horizontally 1-mm coronal to the labial cemento-enamel junction and embedded in acrylic blocks. Standardized post spaces were prepared ...

One of the great challenges in the processing of materials using Equal Channel Angular Pressing (ECAP) is the high forming forces required to produce large shear deformation in the material. Researchers show that the friction forces between the die and the sample constitute a great part of the total forming forces. Recently, ultrasonic vibrations are successfully implemented into the ECAP proce...