Which material is classically considered best for stimulating formation of a reparative dentin bridge (e.g., in pulp capping or apexification procedures)?

Calcium hydroxide has long been the classic material associated with stimulating a hard-tissue (reparative/tertiary dentin) bridge response, due to its high alkaline pH promoting odontoblast-like cell activity, in addition to its bactericidal effect. MTA and bioceramic materials are increasingly favored in current practice for superior sealing and more predictable long-term outcomes, but calcium hydroxide remains the traditionally taught answer specifically for dentin bridge formation.