Response of dogs' dental pulp to a new endodontic material

Objectives: The purpose of this investigation was to compare the dental pulp responses in dogs after calcium enriched mixture (a new endodontic material), mineral trioxide aggregate, and a calcium hydroxide were applied as direct pulp-capping materials. Methods: twenty four cuspids in six healthy adult dogs were divided into three groups randomly. After pulp exposure calcium enriched mixture (CEM), white mineral trioxide aggregate (WMTA) or calcium hydroxide cement (Dycal) was used to repair the exposed site which was created with a round bur in a high-speed hand piece with copious water spray at the buccal cervical access. Then the cavity was filled with glass ionomer cement. The animals were sacrificed two months later and the specimens were processed for histological examination to observe the amount of pulpal inflammation (type, intensity and extension), hard tissue formation (continuity, morphology and thickness) and general state of the pulp (calcification other than in the area of the bridge, giant cells, hyperemia, necrosis and presence of odontoblastic layer under bridge). Results: all of the samples capped with CEM and WMTA were free of pulpal inflammation, and had complete dentin bridge formation. In contrast, all of samples capped with calcium hydroxide showed pulpal inflammation, and dentin bridge formation occurred incompletely. Conclusion: Based on the data obtained in this study CEM and WMTA show similar comparative results when used in direct pulp capping. They are biocompatible materials which can promote dentin bridge formation. CEM and WMTA exhibited better results than the calcium hydroxide cement for the capping of the healthy pulp in dogs.