Because of the potential for irritant reactions in the periapical region, irrigant solutions must be constrained within the root canal. We examined fluid extrusion beyond the apical constriction by pressure waves generated by pulsed middle infrared lasers using needles and Max-I-Probes (Dentsply) as controls. Both free-running pulsed Erbium: Yttrium Aluminum Garnet (Er:YAG) and Erbium, Chromium: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) lasers with bare or conical fiber tips at distances of 5 or 10 mm from the apex displaced fluid past the apex. Larger apical openings showed greater extrusion of fluid. The volume of extruded fluid was similar to conventional 25-G needles, but fluid was distributed further from the apex. Because pulsed lasers create pressure waves in irrigant fluids within the root canal, the potential for extrusion of fluid from the apex should be considered when assessing intracanal laser treatments in endodontics.