ABSTRACT
Objective:To observe apical sealing ability of two kinds of nanomaterial. Methods:40 straight human maxillary anterior teeth were randomly divided into four experimental groups of 8 samples each and two control groups of 4 samples each. The root canals were prepared using step-back technique and obturated with gutta-percha and one of the sealers by the lateral condensation technique. Group 1: Filled with zinc oxide-eugenol sealer and gutta-percha (ZOE); group 2: Filled with hydroxyapatite sealer and gutta-percha (HA); group 3: Filled with nano-zinc-oxide sealer and gutta-percha (NZO); group 4: Filled with nanohydroxyapatite sealer and gutta-percha (NHA). The teeth were placed into microleakage model. Glucose leakage from the coronal to apical was measured by the concentration of glucose in apical reservoir at 1, 2, 4, 7, 10, 15, 20, 25 and 30 days with GOD (glucose oxidase ) method. The apical sealing ability of the materials were assessed according to the concentration of glucose leakage. Results:The glucose leakage of four kinds of materials differed significantly (P