A Micro-Computed Tomography Evaluation of Mineral Trioxide Aggregate Root Canal Fillings

Introduction: The aim of this study was to assess the effect of indirect ultrasonic activation on the incidence of voids within mineral trioxide aggregate (MTA) root canal fillings and at their interface with the canal walls by using a nondestructive 3-dimensional (3D) micro-computed tomography (micro-CT) analysis. Methods: Extracted human teeth with single canals and minimal curvatures were decoronated, instrumented to size 50/05 apically, and randomly allocated into 4 groups (n = 12). MTA was compacted manually by using hand pluggers in group A (MC). Indirect ultrasonic activation was applied to each increment of manually compacted MTA for 1 second in group B (1 sec-UC), 5 seconds in group C (5 sec-UC), and 10 seconds in group D (10 sec-UC). Filled roots were scanned with a micro-CT device, and 3D analysis of void incidence was carried out by using the SkyScan software. Results: Statistical analysis showed a significantly lower incidence of voids (P < .05) in the manual compaction (MC) group (0.7%) compared with the ultrasonic activation for 1 second (3.8%), 5 seconds (1.7%), and 10 seconds (1.6%) groups. Conclusions: Manual compaction produced significantly denser root fillings than those achieved with ultrasonic activation. (J Endod 2012;38:670-672)