Evaluation of the biological effect of mineral trioxide aggregate in inflamed pulp- in vivo analysis.

The health of dental pulp tissue is critical to maintaining normal tooth function from the eruption of permanent teeth to the formation of the apex. The study evaluated the inflamed pulp response to the mineral trioxide aggregate (MTA) after direct pulp capping with the mechanical pulp exposure in rats' incisor. Forty-eight mandibular central incisors of twenty-four Sprague-Dawley rats which were prepared with the cavities of one mm diameter, and the pulp exposures were randomly assigned into two groups: MTA group and calcium hydroxide (Ca(OH)2 ) group. The direct pulp capping was performed after three days and samples histological observations conduction within eight weeks. In both MTA and Ca(OH)2 groups, dentin -like structures were observed in the pulp tissues of some teeth. The number of teeth with reparative tissue in MTA group was statistically significantly higher than that in Ca(OH)2 group ( p = 0.041). Inflammatory cell infiltration was found in the crown pulp tissues in two groups, and no statistical difference was observed between the two groups ( p = 0.243). Pulp necrosis occurred in both groups, and there was no statistical difference between the two groups ( p = 0.622). The results in this paper suggest that MTA promotes direct pulp capping and hence has certain potential clinical applications value in the treatments for the preservation of inflamed pulp.