Micro-ct analysis of hard tissue debris using ultrasonic irrigation and xp-endo finisher, alone or associated

The aim of this study was to use micro-computed tomography (CT) analysis to evaluate the efficiency of the XP-endo finisher (XPF) and passive ultrasonic irrigation (PUI), alone or in combination, in reducing accumulated hard tissue debris (AHTD) in the mesial canals of mandibular molars. The teeth were micro-CT scanned preoperatively (S1), after instrumentation (S2), after final irrigation (S3), and after a supplementary activation (S4). The mesial roots were prepared with BT Race sequence to apical size 35/.04 and divided in two groups according to the final irrigation method and the sequential supplementary activation (PUI + XPF group, n = 12; XPF + PUI group, n = 12). The data of percentages of reduction of AHDT after the first irrigation and supplementary activation were statistically analyzed (RM ANOVA). In the apical third, XPF reduced the percentage of remaining AHTD (66.49%) more significantly than the PUI (35.27%) (P < 0.05). The supplementary activation promoted a statistically significant reduction of AHTD in the apical-thirds of both groups (P < 0.05). In the XPF group the middle (90.85%) and apical (80.02%) thirds were affected by the supplementary activation with ultrasonic irrigation (P < 0.05). Both PUI and XPF were efficient in the reduction of AHTD, but in the apical third XPF was more effective. The supplementary activation with both systems reduced the AHTD significantly. The order of application of irrigation systems influences the reduction of accumulated AHTD and the use of XPF followed by PUI proved to be more efficient.