Assessment of micro-leakage for light-cure glass ionomer and pro-root mineral trioxide aggregate as coronal barriers in intracoronal bleaching of endodontically treated teeth

Introduction: Cervical root resorption is one of the most important complications of intra coronal bleaching. A way of preventing this type of resorption is using a coronal barrier under the bleaching materials. The aim of this study was to compare the sealing ability of glass ionomer cement and Pro Root Mineral Trioxide Aggregate (MTA) as a coronal barrier in intra coronal bleaching. Materials &Methods: In this study, 40 single-root maxillary anterior teeth were endodontically prepared and divided into two experimental groups (n= 15) and two positive and negative control groups (n=5). In the experimental groups, gutta percha was removed up to 3 mm below the cemento enamel junction (CEJ).RMGI and MTA were placed over gutta percha up to the level of CEJ. After a 24-hour incubation period, the bleaching agent (a mixture of sodium perborate and 30% hydrogen peroxide) was placed in the access cavities. The bleaching agents were replaced every 3 days over 9 days. Then, the access cavity was filled with 2% methylene blue for 48 hours. All samples were longitudinally sectioned and the dye penetration range was evaluated using a stereomicroscope. Data were statistically analyzed using Kruskal-Wallis and Mann–Whitney tests (α=0.05). Results: Leakage mean indicated that there was a significant difference between these two groups and leakage was less in ProRoot than glass ionomer. Conclusion: It seems that the MTA can provide a better coronal seal during the bleaching.