The main component of most root canal sealers is:

The main component of most root canal sealers is zinc oxide eugenol because it provides excellent sealing ability, antimicrobial properties, and biocompatibility. Its setting reaction creates a tight seal between the gutta-percha and the canal walls, preventing microleakage and reinfection. Additionally, its antibacterial effect helps reduce residual bacterial load within the canal system, promoting healing. Zinc oxide eugenol-based sealers also exhibit good manipulation and radiopacity, essential for clinical use. This makes it the preferred and widely used material for root canal obturation.

Reference: Grossman’s Endodontic Practice, James L. Gutmann, 13th Edition.