NiTi loss on the dentinal walls and instrument deformation during root canal preparation.

The purpose of this study was to quantify the presence of nickel (Ni) and titanium (Ti) on dentin walls of prepared root canals using Endosequence (ES) and Wave One (WO) systems, the deformation, and fracture of these instruments. Thirty extracted human premolar teeth were selected and prepared with WO, ES, and manually (control group-CG). Each instrument was used in four root canals.

Effect of calcium hydroxide on the bond strength of two bioactive cements and SEM evaluation of failure patterns.

The aim of this study was to assess the effect of calcium hydroxide on bond strength of two bioactive cements. One-mm thick longitudinal slabs of root dentin were obtained from freshly extracted human monorradicular teeth (n = 60). Simulated root perforations (1 mm in diameter) were prepared in radicular dentin.