Relationship between the size of patency file and apical extrusion of sodium hypochlorite.

Background: Sodium hypochlorite (NaOCl) is the most widely used endodontic irrigant because of its excellent antimicrobial, organic tissue dissolving, and lubricating properties. However, it is highly cytotoxic to the periapical tissues.

Aim: This study evaluated in vitro the extrusion of 5.