An In vitro comparative evaluation of a hand file and three rotary Nill Instruments for removing gutta percha during root canal re-treatmen. Nigerian Dental Journal, [S. l.], v. 22, n. 1, p. 27–31, 2015. DOI: 10.61172/ndj.v22i1.50. Disponível em: https://www.nigeriandentaljournal.ng/index.php/ndj/article/view/50. Acesso em: 3 may. 2025.