Comparative effects of erbium-doped yttrium aluminum garnet laser, the shock wave-enhanced emission photoacoustic streaming, and the conventional needle irrigation on apical extrusion of irrigants

This study compared the effects of erbium-doped yttrium aluminum garnet (Er:YAG) laser with the shockwave-enhanced emission photoacoustic streaming (SWEEPS) protocol and the conventional needle irrigation (CNI) on extrusion of irrigants through the root apex of molar teeth with different apical diameters. In this ex vivo experimental study, access cavities were prepared in 120 extracted maxillary and mandibular molars in 12 groups of conventional needle irrigation (CNI), auto-SWEEPS, ultra-short pulse (USP), and super-short pulse (SSP), each with 0.25, 0.4 and 0.8 mm apical diameters (n = 10). The root canals were prepared and mounted in resin blocks. Periodontal pressure was simulated by a capillary tube of water in the apex. The volume of extruded irrigant was quantified spectrophotometrically, and analyzed by the Kruskal-Wallis test. Apical extrusion in CNI was the same in the three apical diameters, and was maximum compared with others groups. The amount of extruded irrigant through the apex was different among the three apical diameters in auto-SWEEPS (P = 0.002) and USP (P = 0.001) modes. The SSP mode caused maximum extrusion of irrigant with no significant difference among different apical diameters (P = 0.681) followed by auto-SWEEPS. The USP mode caused the lowest extrusion in 0.25 mm diameter (P = 0.006). In auto-SWEEPS, 0.25 mm diameter had a significant difference with 0.8 mm. In USP, 0.25 mm had a significant difference with 0.4 and 0.8 mm diameters. In 0.25 mm, USP and SSP (P < 0.05), and USP and auto-SWEEPS (P < 0.05) had significant differences. In 0.4 mm, only SSP and USP had a significant difference (P < 0.05). . CNI with a 27-gage needle caused greater irrigant extrusion than the SWEEPS modes. The USP mode caused minimum extrusion of irrigant.