OBJECTIVE The objective of our study is to analyse (with the help of scanning electron microscopes) the quality of the dental root surface and the appearance of dental cracks after performing apical preparations using two different types of ultrasonic tips. STUDY DESIGN We used 32 single-rooted teeth that underwent a root canal and apical resection. Afterwards, the teeth were divided into 4 g...

APRIL 2004 -S 140 ABSTRACT. This article analyzes the mechanics of the metal ultrasonic welding process as a basis for a new solid free-form fabrication technology. Three-dimensional prototypes are constructed by ultrasonic welding of overlaid metal foil laminations, followed by contour cutting of the 2-D layers. This was implemented in the laboratory by a computer-automated ultrasonic welding ...