Histologic evaluation of vital pulp therapy using propolis and platelet-rich plasma (PRP): Evidence from a canine model

The present study evaluated the pulp tissue response following direct pulp capping (DPC) with several materials in dogs’ teeth. This study was performed on four doges with 64 mature healthy premolars and molars. The teeth randomly received the following materials: platelet-rich plasma (PRP), propolis, MTA, and glass-ionomer cement (GIC, negative control group). Afterwards, the teeth were restored with light cure GIC. Half of the animals were sacrificed after seven and half after 30 days. Histologic samples were prepared (n=8 per material/interval), and the levels of inflammation, and fibrous and calcified tissue formation were compared between the groups and intervals. After seven days, inflammation and calcified tissue levels were comparable among the groups (P ). The MTA group showed significantly more fibrous tissue formation than the GIC samples (P<0.05). After 30 days, propolis and MTA showed significantly lower inflammation than GIC (P<0.05). PRP and MTA groups showed significantly higher fibrous tissue formation than the GIC group (P<0.05). Moreover, GIC showed the lowest calcification level among the groups, and PRP had lower calcification than MTA (P<0.05). Inflammation levels of the experimental groups decreased after 30 days, but the change was not significant (P>0.05). Fibrous tissue formation in the MTA and propolis groups decreased significantly after 30 days (P<0.05). Calcification levels of the experimental groups increased significantly over time (P<0.05). The findings suggest that propolis might be a favorable substitute for MTA in DPC procedures, as it produced comparable results to MTA in reducing inflammation and enhancing calcification.