Assessment of apical extrusion in regenerative endodontics: a comparative study of different irrigation methods using three-dimensional immature tooth models.

To investigate the apical extrusion of sodium hypochlorite in immature permanent teeth caused by conventional syringe irrigation (CSI), EDDY, XP-endo Finisher file (XP-F), and a new laser irrigation activation system [shock-wave-enhanced-emission-photo-acoustic-streaming (SWEEPS)]. Three-dimensionally printed forty-nine teeth with immature central incisor morphology were randomly assigned to seven experimental groups, based on the irrigation activation methods and insertion depths (1 mm and 2 mm short of the working length) as follows: CSI-1, CSI-2, EDDY-1, EDDY-2, XP-1, XP-2, and SWEEPS. Prior to the irrigation activation process, samples were placed in metacresol mixed agar gel in Eppendorf tubes.