Hard Tissue Healing Adjacent to Fresh or Set MTA as Root-End Filling Material

Abstract

Mineral trioxide aggregate (MTA) has been shown to promote regeneration of periradicular tissues when used as a root-end filling material. The purpose of this study was to compare the effect of fresh MTA with set MTA on hard tissue healing following periradicular surgery. Under general anesthesia, the root canals of twenty-four mandibular premolars in four 2-year-old beagle dogs were filled with MTA. Two weeks later the root-ends of half of the samples were surgically exposed and resected to the level of set MTA within the canals. After exposing and resecting the other 12 root-ends, class I cavities were prepared in these roots and filled with fresh MTA. Following closure of surgical flaps, the animals were allowed to heal and sacrificed four months later. Hard tissue healing was analyzed histomorphometrically. The frequency of cementum formation in the two groups was compared using a two-sample test for binomial proportions. Mean quantity of cementum formation and bone density were analyzed using the Mann-Whitney U-test at a significance level of alpha = 0.05. The results indicated that although freshly-placed MTA resulted in a significantly higher incidence of cementum formation (12 out of 12 vs. 8 out of 12, p=0.028), there is no significant difference in the quantity of cementum or osseous healing associated with freshly-placed or set MTA when used as root-end filling material