Abstract: PURPOSE: To study the effect of root canal wall moisture and filling techniques on the sealability of iRoot sp. METHODS: Sixty-two undamaged extracted human single-rooted teeth with fully developed apex were selected and prepared by crown-down technique. Two teeth were selected randomly to observe dentin tubules, opening, the residual teeth were randomly assigned to 3 groups: group A (wet), group B (slightly moist),group C(dry).The roots were further divided into 4 subgroups, group a: iRoot sp sealer without a core material (bulk-fill); group b: iRoot sp sealer with single cone obturation techniques; group c: iRoot sp sealer with heated gutta-purcha vertical pressure; group d: iRoot sp sealer with cold gutta-percha lateral compression technique. Glucose microleakage were measured in each group by glucose oxidase method. The differences in distribution of each group were analyzed with SPSS 19.0 software package. RESULTS: Group A and group B always showed the maximum and minimum amount of glucose penetration in the whole experimental process, and the difference was statistically significant at 28d (P<0.05). Under the same degree of moisture of root canal wall, glucose leakage of subgroup Aa was significantly higher than that of subgroup Ab and Ac at 15 d; and significantly higher than Ab, Ac, Ad at 21 d and 28 d(P<0.05). In group B and C, the subgroups a, b, c, d had no significant difference from each other during the experimental process(P>0.05). CONCLUSIONS: iRoot sp sealer has the best sealing effect when root canals were slightly moist. When the root canal wall is completely dry or slightly moist, the sealability of iRoot sp bulk-fill is similar to that of iRoot sp sealer with gutta-percha filling technique.

Key words: iRoot sp, Root canal moisture, Microleakage, Filling techniques