INTRODUCTION This study investigated the fatigue and fracture modes of RaCe and ProTaper rotary instruments. MATERIALS AND METHODS Fatigue resistance was evaluated by rotating the files 30° or 60° and with 2 or 5mm radius of curvature. RaCe taper 06 size 25 and ProTaper F1 files (n=40) were used. The number of rotations to failure was analyzed by two-way ANOVA and independent sample t-test. F...

Today, a substantial part of the dental crown production uses computer-aided design and computer-aided manufacturing (CAD/CAM) technology. A recent step in restorative dentistry is the replacement of natural tooth structure with pre-polymerized and machined resin-based methacrylic polymers. Recently, a new CAD/CAM composite was launched for the crown indication in the load-bearing area, but the...

The moisture absorption behavior and the influence of moisture on thermal and mechanical properties of glass–fiber/polyetherimide (PEI) laminates have been investigated. The laminates were exposed to hydrothermal aging at two different temperatures and high moisture rates. The properties of as-received and hydrothermally aged samples were compared. The hydrothermally aged laminates contained a ...

This work presents an effort to document and describe fracture surfaces for three commercially available amorphous polymers (PC, PMMA and ABS) each subjected to tension, impact and environmental stress cracking (ESC). We present mechanical properties as well as microscopic characterization at low and high magnification to distinguish between slow tensile loading, fast impact loading, and enviro...

SYNOPSIS The mechanical properties and microstructure of AlSilOMg alloy samples that were printed by selective laser melting (SLM) studied to determine the effect processing parameters building orientation. After printing, was stress relieved at 250°C for 2 hours. microstructures analysed optical microscopy scanning electron (SEM) phases distribution. Phase transformation characteristics materi...