Efficacy of sodium hypochlorite, ethylenediaminetetraacetic acid, citric acid and phosphoric acid in calcium hydroxide removal from the root canal: A microscopic cleanliness evaluation - da Silva, J M; Silveira, A; Santos, E; Prado, L; Pessoa, O F (Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2011)