Effect of altering the reciprocation range on the fatigue life and the shaping ability of WaveOne nickel-titanium instruments.

Introduction: The purpose of this study was to investigate the effect of altering the reciprocation range of the WaveOne instrument (Dentsply Maillefer, Ballaigues, Switzerland) on its fatigue life and shaping ability regarding tendency for canal transportation, the canal centering ratio, and preparation time.

Methods: Thirty primary WaveOne instruments were divided into 3 equal groups according to the reciprocation range used: G1: 150 counterclockwise (CCW)-30 clockwise (CW), G2: 120 CCW-30 CW, and G3: 90 CCW-45 CW. They were activated in a cyclic fatigue testing device until fracture.

Mesenchymal stem cells promote hard-tissue repair after direct pulp capping.

Introduction: The aim of this study was to investigate the potential of autologous mesenchymal bone marrow stem cells (BMSCs) to promote hard-tissue formation after direct pulp capping procedures.

Materials And Methods: Bone marrow was aspirated from the iliac crest of healthy dogs of nonspecific race. Mononuclear cells were obtained using the Histopaque (Sigma-Aldrich, St Louis, MO) protocol and cultured for 21 days.

Development of an intracanal mature Enterococcus faecalis biofilm and its susceptibility to some antimicrobial intracanal medications; an in vitro study.

Objectives: To develop a mature biofilm of Enterococcus faecalis inside the root canal system and to test its susceptibility to some antimicrobial medications in vitro.

Methods: Single rooted premolars were mechanically enlarged, sterilized, and then infected with a clinical isolate of E. faecalis.