Alcota-Rojas, M., Compán-Catenacci, G., Salinas-Castro, J.C. and Palma-Eyzaguirre, A.M. 2011. Comparative in vitro study of root canal transportation, using three nickel-titanium rotary systems: hero shaper, protaper universal. Revista Facultad de Odontología Universidad de Antioquia. 23, 1 (Dec. 2011), 9–21. DOI:https://doi.org/10.17533/udea.rfo.8111.