The extrusion of section from round billet poses a great challenge for theoretical modeling of the process using upper bound method. The greatest difficulty in three-dimensional upper bound method is to determine kinematically admissible velocity field. The SERR (Spatial Elementary Rigid Region) technique is fairly applicable for analyzing extrusion of sections having re-entrant corners. A modi...

Introduction: To investigate Ca(OH)2 extrusion from the apical foramen in relation to the placement mode. Methods: 200 teeth, prepared with ProTaper files with and without apical patency, were divided in Groups A and B respectively, and filled with Ca(OH)2 at 1 and 3 mm short of working length, using K-files manually and with mechanical spiral techniques (Pastinject/Lentulo) at 500 and 700rpm. ...

The wound healing process in skin is studied in human subjects treated with fractional photothermolysis. In-vivo histological evaluation of vacuoles formed over microthermal zones (MTZs) and their content is undertaken. A 30-W, 1550-nm single-mode fiber laser system delivers an array of 60 microm or 140 microm 1e2 incidence microbeam spot size at variable pulse energy and density. Treatments sp...

immature teeth have a large apical opening and thin divergent or parallel dentinal walls; hence, with conventional needle irrigation there is a very high possibility of extrusion. this study was done to compare the apical extrusion of naocl in an immature root delivered using endovac and needle irrigation.eighty freshly extracted maxillary central incisors were decoronated followed by access ca...

OBJECTIVES The objective of this study was to determine the various factors that affect the extrusion rate of ventilation tubes (VTs), including the nature of the middle ear effusion. METHODS A retrospective chart review of 82 pediatric patients (177 ears) who received VT insertion surgery under general anesthesia was carried out to evaluate the relationship between various factors and the VT...

Aim This study was intended to evaluate the amount of apically extruded debris following root canal preparation with three different instrumentation systems. Materials and Methods Sixty mandibular incisor teeth were selected and randomly divided into three groups (n = 20/group) according to the instrumentation system used: the ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), ...