Influence of protaper finishing files and sodium hypochlorite on cleaning and shaping of mandibular central incisors: a histological analysis - Baratto Filho, Flares; Leonardi, Denise Piotto; Zielak, João César; Vanni, José Roberto; Sayão-Maia, Sandra Maria Alves; Sousa Neto, Manoel Damião de (Journal of Applied Oral Science, 2009)