Short-term periradicular tissue response to mineral trioxide aggregate (MTA) as root-end filling material

Aim The aim of the present study was to evaluate the short-term response of periradicular tissues to MTA when used as a root-end filling material in ideal tissue conditions. Methodology The experimental procedures were performed on the healthy teeth of dogs. Pulps were removed and root canals prepared and filled with gutta-percha and sealer. At the same session, buccal mucoperiosteal flaps were reflected and the root ends resected. MTA or IRM were used as root-end filling materials. The periradicular tissue reactions were evaluated histologically from 1 to 5 weeks. Hard tissue formed on the MTA surface was further examined by scanning electron microscopy. Results The most characteristic tissue reaction to MTA was the presence of connective tissue after the first postoperative week. Inflammation was seen occasionally. Early tissue healing events after MTA root-end filling were characterized by hard tissue formation, activated progressively from the peripheral root walls along the MTA-soft tissue interface. In contrast, hard tissue was not seen over the IRM root-end filling. Conclusions MTA is a biocompatible material that stimulates periradicular tissue repair at the root-end situation; however, the nature of the newly formed tissues requires further elucidation.