Comparative Micro-computed Tomographic Evaluation of the Sealing Quality of ProRoot MTA and MTA Angelus Apical Plugs Placed with Various Techniques

Introduction: This study compared the effects of different mixing and placement techniques on sealing of ProRoot MTA (Dentsply Maillefer, Ballaigues, Switzerland) and MTA Angelus (Solucoes Odontologicas, Londrina, Brazil) apical plugs using micro computed tomographic (micro-CT) imaging. Methods: Standardized divergent open apex models were created using 120 extracted maxillary incisors and divided into 8 groups (n = 15). ProRoot MTA and MTA Angelus were mixed manually or mechanically and introduced to form apical plugs by hand condensation or indirect ultrasonic activation for 10 seconds. The samples were scanned using micro-CT imaging, and volumetric analysis of the voids between the dentin walls and the apical plugs and the porosity inside MTA was performed. Results: Irrespective of the mixing and placement techniques used, the voids between the dentin walls and the apical plugs in the MTA Angelus groups were greater than those in the ProRoot MTA groups (P < .05). The mechanically mixed groups were significantly less porous than the manually mixed groups (P < .05). Combined mechanical mixing and indirect ultrasonic activation yielded a less porous structure for both types of MTA than combined manual mixing and hand condensation (P < .05). Marginal adaptation for ProRoot MTA, both mixed and placed manually, was greater than for MTA Angelus (P < .05), but no difference was found when indirect ultrasonic activation was performed (P > .05). Conclusions: ProRoot MTA showed better marginal adaptation than MTA Angelus. Mechanically mixed products had better handling characteristics than the manually mixed product. Indirect ultrasonic activation did improve the adaptation of manually mixed MTA Angelus to the dentin walls.