Dynamic torque analysis of rotary and reciprocating instruments during root canal instrumentation in simulated canals by an endodontist or a general dentist.

Background: Excessive torque is associated with engine-driven file fracture.

Aims: The aim of this study to evaluate the real-time torque of rotary and reciprocating instruments, working time, and the occurrence of procedural errors during root canal preparation of simulated canals by an endodontist and a general dentist.

Methods: Thirty-six commercially available simulated "J-shaped" root canals in resin blocks were used.

Mesenchymal Stem Cell Marker Expression in Periapical Abscess.

Introduction: There is evidence that acute periapical lesions present a greater potential for cyst formation. Recently, it was found that these lesions have cells with characteristics of pluripotent stem cells, which may influence cyst development. However, a more complete phenotype investigation of stem cells in a specific sample of periapical abscesses is required.