Nóbrega, Letícia Maria Menezes, et al. “Ultrasonic Irrigation in the Removal of Smear Layer and Enterococcus Faecalis from Root Canals”. Brazilian Journal of Oral Sciences, vol. 10, no. 3, Nov. 2015, pp. 221-5, doi:10.20396/bjos.v10i3.8641637.