PAD may be an adjunctive procedure to kill residual bacteria in the dental root canal systems after standard endodontic root canal preparation.

Background:The smear layer is an amorphous film, i.e., always formed by the action of endodontic instruments inside the root canal during chemomechanical preparation. Different solutions have been used and tested for its removal. For the removal of smear layer, demineralization, and softening of root dentin, chelating agents have been preferred.