Polymicrobial Leakage and Retention of MTA and Portland Cement in a Model of Apexification

Objective:To evaluate the sealing capacity and retention of apical barriers made with mineral trioxide aggregate (MTA) and Portland cement (PC). Material and Methods:Fifty-six bovine incisors were sectioned 8 mm above and 12 mm below the cement-enamel junction. The root canal was enlarged with a diamond drill to create a standard 2.5 mm diameter opening. Apical sheets of 5 mm thickness were placed using white MTA-Angelus or white PC. Fifteen samples of each material were exposed to human saliva in a dual chamber apparatus and casting was evaluated at 30 days. Samples without apical barriers and fully sealed samples were used as positive and negative controls (n = 3), respectively. Data were analyzed by Fisher's exact test (p0.05). Conclusion:Mineral trioxide aggregateand Portland cementapical barriers presented similar sealing ability and bond strength values