ABSTRACT
The purpose of this in vitro study was to compare the apical sealing ability of mineral trioxide aggregate and glass ionomer cement by a dye penetration test. It was carried out at Queen Marry and Westfield College, University of London during 2010-2011 session. Time duration was 6 months. A total of 16 samples of elephant tusk dentine [ivory] were prepared and finished for dye penetration test. Mineral trioxide aggregate and glass ionomer cement were mixed and placed in the prepared samples and were left overnight to set. Then two coats of nail varnish was applied onto the set material and allowed to dry. The samples were then suspended in methylene blue dye for 72 hours. Once dyed the samples were sectioned longitudinally and assessed microscopically with a stereomicro-scope. The dye penetration in the samples was assessed for two endodontic sealers. It was found that mineral trioxide aggregate showed a mean dye penetration value of 7.625mm as compared to mean dye penetration value of glass ionomer cement 3.875mm