Comparison of apical irrigant solution extrusion among conventional and laser-activated endodontic irrigation

The aim of this study was to determine the amount of extruded endodontic irrigant among needle-syringe irrigation (NSI) and laser-activated irrigation (LAI) regimens. Twenty extracted maxillary central incisors were prepared utilizing GT professional rotary files (size 40, taper 0.06). Irrigation was performed with two 27 G irrigation needles (notched open ended (ON) and single side vented (SV)) each at two different irrigant volumetric flow rates (VFR)-0.05 ml/s (3 ml/min) and 0.10 ml/s (6 ml/min). LAI was performed with Er:YAG (erbium-doped yttrium aluminum garnet) using different fiber types (X-Pulse-14/400 cylindrical tip, Preciso- 14/300 flat cylindrical tip, PIPS- 14/400 quartz tapered tip). The Er:YAG laser with a wavelength of 2940 nm (Lightwalker AT, Fotona, Ljubljana, Slovenia) was used according to the following protocol: 10 mJ per pulse, 15 Hz, pulse duration 50 μs. Irrigation time was 60 s for all protocols. Precision syringe pump (PSP) maintained constant irrigant volumetric flow rate. Apically extruded irrigant was collected and net weighed for each protocol (N = 10). Data were analyzed by t tests and Kruskal-Wallis. All LAI regimens had statistically significant lower irrigant extrusion compared with NSI except for the SV 27 G needle used with 0.05 ml/s VFR when compared with the Preciso fiber tip (p = 0,230). The largest amount of extruded irrigant was with the ON 27 G needle at the 0.10 ml/s VFR, while the smallest was after LAI with PIPS fiber tip. The lower quantity of apically extruded irrigant during LAI (X-Pulse and PIPS) points out a safer endodontic irrigation method compared with conventional irrigations.