RESUMO
Context: Different factors can affect the marginal adaptation of MTA. Aims: The present study was designed to investigate the effect of two ultrasonic irrigation methods on the marginal adaptation of MTA plug in open apex teeth by scanning electron microscope. Settings and Design: Thirty single mature teeth were included in this in vitro experimental prospective study. Materials and Methods: A total of 5 mm thickness of MTA plug was inserted at the end of the canals and after 24 h an ultrasonic file was used to irrigate the canals and remove the MTA remnants. Teeth were randomly divided into three groups: In the first and second groups, the canals were irrigated for 1 min by 2.5% sodium hypochlorite as #25 ultrasonic file was in direct contact and 1 mm away from MTA plug, respectively. The third group was not irrigated and left as control. A total of 1 mm transverse sections were prepared through the coronal and the apical parts of MTA plug and specimens were prepared for SEM analysis. The extent of gap was measured linearly under SEM device. Statistical Analysis Used: Statistical analysis of the results was performed using the kruskal-Wallis test by SPSS software ver.18(a = 0.05). Results: There was no significant difference between groups regarding the marginal gap size in apical (P: 0.17) and coronal sections (P: 0.33). However, the mean marginal gap size was higher in apical section compared to coronal section. Conclusions: It can be concluded that ultrasonic irrigation dose not adversely affect the marginal adaptation of MTA plugs.