What is the primary function of EDTA in endodontics?

The primary function of EDTA (Ethylenediaminetetraacetic acid) in endodontics is to remove the inorganic portion of the smear layer. This smear layer is a thin film that forms on the walls of the root canal during instrumentation, consisting of debris from dentin and dental cement, and includes a mixture of both organic and inorganic materials.

The removal of the smear layer is crucial because it can inhibit the penetration of irrigants and medicaments into the tubules and can interfere with the bonding of filling materials. EDTA acts by chelating calcium ions present in the inorganic components of the smear layer, thus aiding in its removal and allowing for a cleaner and more effective canal environment.

While it is true that other agents in endodontics may be concerned with killing bacteria, digesting organic debris, or reinforcing tooth structure, these functions do not align with the specific role of EDTA. Its distinct action centers on the clearance of the smear layer, promoting better sealing and disinfection of the canal system.