Histologic evaluation of tetracalcium phosphate-based cement as a direct pulp-capping agent

Histologic healing processes were observed at 1, 3, 7, and 10 days after application with either tetracalcium phosphate cement or calcium hydroxide cement to the exposed pulp of the rat maxillary incisors. In teeth applied with calcium hydroxide cement, necrotic tissue was present beneath the cement before new hard tissue formed. In contrast, tetracalcium phosphate cement elicited a dentine bridge formation with no evidence of either intervening tissue necrosis or marked inflammation. Furthermore on ultrastructural examination the newly formed hard tissue was in direct contact with the material. This study suggests that 4CP cement possesses a biocompatible property, which indicates its potential for use as a direct pulp-capping agent.