ex-vivo sealing ability of different thicknesses of white and gray angelus mta as an intra-orifice barrier in endodontically treated teeth

introdouction: it is important for the clinician to be aware regarding the necessary thickness of materials used as intra-orifice coronal barriers to prevent microleakage. the purpose of this in vitro study was to compare coronal microleakage of three different thicknesses of white and gray angelus mineral trioxide aggregate (wamta, gamta). materials and methods: a total of 66 canals of extracted maxillary central incisors were instrumented and obturated with gutta percha and ah26 sealer using cold lateral compaction technique. the teeth were randomly divided into two experimental groups of 30 teeth each according to the material tested (wamta and gamta) and two negative and positive control groups of three teeth each. the experimental groups were then subdivided into three groups of 10 teeth each according to the coronal plug thickness (2, 3, and 4 mm). the obturation material was removed upto the experimental depths and was sealed with tested materials. sealing ability was evaluated by the dye penetration method using pelikan ink and a stereomicroscope at ×10 magnification and 0.01 mm accuracy. data were analyzed by analysis of variance (anova) and t-test. results: t-test analysis revealed that there was no significant difference between coronal microleakage of gamta and wamta at depths of 2, 3, and 4 mm (p < 0.88, p < 0.285, p < 0.62). anova test revealed that there was no significant difference between leakage of different thicknesses of wamta (p < 0.365) and gamta (p < 0.217). conclusion: coronal microleakage of 2-mm thickness of wamta and gamta had no statistically significant difference with 3-mm and 4-mm thicknesses of the materials.