Evaluation of Apical Extrusion During Novel Er:YAG Laser-Activated Irrigation Modality.

To evaluate apical extrusion during a novel erbium-doped yttrium aluminum garnet (Er:YAG) laser-activated irrigation (LAI) modality. : A novel double-pulse Er:YAG modality (AutoSWEEPS) was introduced recently, replacing a single laser pulse with two micropulses that are separated by a varying time delay (which is continuously "swept" between 300 and 600 μsec). Although the proposed method demonstrated increased efficacy, no data were yet available on extrusion. The extrusion was evaluated on simulated canals ( = 6) using particle imaging velocimetry. In the first two groups, the irrigation device was a syringe coupled to either a 30-G open-ended or side-vented needle, with flow rates of 1, 2, 5, and 15 mL/min. In the second two groups, irrigant activation was performed with an Er:YAG laser, using either a super-short pulse (SSP) or AutoSWEEPS modality. The pulse energies were 5, 10, 20, 30, and 40 mJ and the frequency was 10 Hz. The measured extrusion was most prominent during the open-ended needle irrigation, followed by the vented needle irrigation. Compared with the conventional needle irrigation (CNI), all the studied LAI modalities resulted in ∼3-20 times less extrusion. The AutoSWEEPS modality induced the smallest extrusion rate, which was always <1.5 mm/sec and was also independent of the laser energy. Within the limitations of the study, our results demonstrate that the SSP and AutoSWEEPS laser-assisted irrigation methods exhibited less extrusion in comparison with CNI methods.