Comparison of Coronal Microleakage of Resin Modified Glass Ionomer and Composite Resin As Intraorifice Barriers in Internal Bleaching

Introduction: internal bleaching is a treatment option for wightening endodontically treated discolored teeth. cervical resorption is one of the side effects of this method.the aim of this study was to compare the sealing ability of resin composite and lightcured resin modified glass ionomer (rmgi) as intraorifice barriers in internal bleaching.materials &methods: in this study, 34 singlecanal anterior teeth were used. all samples were endodontically prepared and divided into two experimental groups (n=12) and two control groups (n=5). in the experimental groups, guttapercha was removed up to 3 mm below the cemento enamel junction (cej). rmgi and composite resin was placed over guttapercha in the experimental groups up to the level of cej. after 24hours 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 stereomicroscope. data was statistically analyzed by using tstudent test and variance analysis.results: the microleakage in rmgi group was 0.945mm and in composite resin group was 0.641mm. statistically, no significant difference was observed in microleakage between the experimental groups (p=0.121).conclusion: both materials can be applied as the intraorifice barriers for internal bleaching.