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 singleroot 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 24hour 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 kruskalwallis and mann ndash;whitney tests ( alpha;=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.