Moringa oleifera Leaf Extracts as a Novel Bioactive Material for Vital Pulp Therapy: A Comparative In Vitro and In Vivo Study

Objectives: The primary objective of vital pulp therapy (VPT) is to induce the formation of tertiary dentin bridge through the application of bioactive materials to maintain pulp vitality. This study aimed to evaluate the odontogenic potential of Moringa oleifera ethanolic and aqueous extracts as sustainable herbal pulp capping materials in comparison to mineral trioxide aggregate (MTA) and a bioceramic putty. The evaluation was conducted in vitro on human dental pulp stem cells (DPSCs) and in vivo using a rat model of direct pulp capping. Methods: Moringa leaf extracts were prepared and the cytotoxicity assessed using MTT assay to measure the IC50, and their odontogenic potential was further evaluated in vitro by measuring alkaline phosphatase (ALP) activity and performing Alizarin Red staining for mineralization in comparison to MTA. For the in vivo study, the exposed rat pulps were capped with the extracts, MTA, the bioceramic putty, or a plain collagen sponge (control). Histological analysis was performed to evaluate inflammation and tertiary dentin bridge formation. Results: The ethanolic, aqueous extracts and MTA showed low cytotoxicity, though the ethanolic extract had significantly enhanced ALP expression (p < 0.05) and mineralized nodule formation (p < 0.05) compared to the other groups. In the in vivo study, the plain collagen sponges failed, resulting in necrosis. Conversely, MTA and the ethanolic extract exhibited the best outcomes, inducing the lowest inflammatory response (mainly score 1 and 2) and the successful formation of an irregular dentin bridge by odontoblast-like cells, whereas the aqueous extract and bioceramic putty showed intermediate results, with higher inflammation levels. Conclusions: Ethanolic Moringa oleifera extract is a highly biocompatible material with potent odontogenic induction capabilities, primarily driven by its flavonoid content. It is a promising, novel, and cost-effective material for use in the VPT as an effective alternative to MTA.