New ultrasonic tip for root canal filling of the mesial canals of mandibular molars with isthmus: a laboratory evaluation using computed microtomography - Barreto, Carolina da Costa Galindo; Calefi, Pedro Henrique Souza; Vivacqua-Gomes, Nilton; Alcalde, Murilo Priori; Vivan, Rodrigo Ricci; Duarte, Marco Antonio Hungaro; Vasconcelos, Bruno Carvalho de (Journal of Endodontics, 2023)