Postoperative Pain After Ultrasonically and Laser-activated Irrigation During Root Canal Treatment

The root canals and the pulp chamber are filled with NaOCl 3%. Per canal, the laser tip is placed above the root canal entrance and activated (frequency 20 Hz, pulse energy 20 mJ and pulse length 50 μs) for 30s. TThe canal is then rinsed with NaOCl using a 27G needle, followed by a second application of laser, identical to the first.

The root canals and the pulp chamber are filled with NaOCl 3%. An Irrisafe file, driven by an ultrasonic unit according to the manufacturers' instructions, is held at 1-3 mm from WL (precurved if canal is curved) and activated for 30 s. The canal is then rinsed with NaOCl using a 27G needle. This cycle is repeated three times (i.e. 3\*20s).

After rubber dam isolation and field disinfection, the pulp chamber is accessed. The root canal(s) is/are located and shaped using manual and mechanical NiTi instruments in combination with NaOCl (3%) irrigant. The canals are dried using paper points and obturated with gutta percha and epoxy resin sealer. The tooth is sealed with a temporary or permanent filling.