mineral trioxide aggregate and portland cement for direct pulp capping in dog: a histopathological evaluation

background and aims. mineral trioxide aggregate and calcium hydroxide are considered the gold standard pulp-capping materials. recently, portland cement has been introduced with properties similar to those of mineral trioxide aggregate. histopathological effects of direct pulp capping using mineral trioxide aggregate and portland cements on dog dental pulp tissue were evaluated in the present study. materials and methods. this histopatological study was carried out on 64 dog premolars. first, the pulp was exposed with a sterile bur. then, the exposed pulp was capped with white or gray mineral trioxide aggregates and white or gray port-land cements in each quadrant and sealed with glass-ionomer. the specimens were evaluated under a light microscope after 6 months. statistical analysis was carried out using kruskal-wallis test. statistical significance was defined at α=5%. results. there was no acute inflammation in any of the specimens. chronic inflammation in white and gray mineral triox-ide aggregates and white and gray portland cements was reported to be 45.5%, 27.3%, 57.1% and 34.1%, respectively. al-though the differences were not statistically significant, severe inflammation was observed mostly adjacent to white mineral trioxide aggregate. the largest extent of increased vascularization (45%) and the least increase in fibrous tissue were ob-served adjacent to white mineral trioxide aggregate, with no significant differences. in addition, the least calcified tissue formed adjacent to white mineral trioxide aggregate, although the difference was not significant. conclusion. the materials used in this study were equally effective as pulp protection materials following direct pulp cap-ping in dog teeth.