The Seal Ability of Mineral Trioxide Aggregate and Nano Hydroxyapatite Retrograde Filling Material on Internal Apical Bacterial Leakage of Infected Root Canal (an in-Vitro Study)

Background: Most endodontic failures occur as a result of leakage of microorganism and their by-products from pathologically involved filled root canal system. Surgical endodontic therapy with retrograde filling is indicated to obtain an apical seal and save the tooth.Aim: To evaluate the sealing ability of Mineral Trioxide Aggregate (MTA) and Nano Hydroxyapatite (NHA), when used as retrograde filling materials, and the effect of obturation on internal apical bacterial leakage of infected root canal.Material and Methods: 100 recently extracted mature human single-rooted teeth were collected for this study. The crowns were removed and canals were prepared, and then sterilized by autoclaving. 10µl of the bacterial suspension was carefully inoculated into the instrumented canal of each specimen coronally. The apical 3 mm were resected at 90 degree to the long axis, then 3mm deep retrograde cavity (class I) was prepared. The prepared samples were secured with wax within the hole of the cap of an eppendorf tube containing sterile manitol salt broth.Results: No significance difference was observed between MTA and NHA.Conclusion: NHA could be used as an alternative to MTA, being more cheap and available than MTA.