Bone Abstracts

Objective: The aim of this study was to evaluate the pulpal responses to octacalcium phosphate (OCP) and calcium hydroxide (CH) used as direct pulp capping (DPC) materials.

Study design: The pulp of 72 premolars teeth of nine cats were selected for this experiment. After the cats had been anesthetized, the teeth were exposed and capped directly with OCP, CH, and no capping materials used as control group. The cavities of all three groups were filled with glass ionomer cement (GI). Histological evaluations were performed at 2, 4, and 8 weeks after the pulp capping. The results were analyzed statistically by using the Mann–Whitney U and χ² test (P<0.05).

Results: Two weeks after the pulp capping, all speciments in three groups showed mild to sever inflammation. The formation of the hard tissues (dentinal bridge) initiated in the exposed areas of the experimental groups that was more noticeable in the calcium hydroxide than in the octacalcium phosphate group, These differences was statistically significant (P<0.001). At 4 weeks, hard tissues were observed in both groups which was more evident in the CH group and there was statistically significant differences between two experimental groups same as the 2 weeks. At 8 weeks, continuous hard tissues were observed more frequently in the OCP group.

Conclusion: It seems that both capping materials induced hard tissue formation, but OCP group had a better percentage in sealing of the pulp than the CH group.