The goal of this study was to compare the apical cleaning capabilities of single files from 3 different rotary systems in the presence or absence of prior cervical preparation based on a histological analysis. A total of 84 human single-rooted mandibular permanent incisors were divided into 6 groups (14 canals each). Cleaning and shaping was performed under the following protocols: Group I, F2 ProTaper at working length; Group II, SX ProTaper and F2 ProTaper; Group III, size 25, .06 taper Mtwo at working length; Group IV, SX ProTaper and size 25, .06 taper Mtwo; Group V, size 25, .06 taper BR3 BioRace at working length; and Group VI, SX ProTaper and size 25, .06 taper BR3 BioRace. After cleaning and shaping, the root canals were evaluated by histological analysis. The percentage of remaining debris was evaluated using a cross-hatched grid superimposed over each image. Data were assessed using the Shapiro-Wilk and ANOVA tests. Statistically significant differences were observed between groups (p =0.0001) with respect to amount of remaining debris; use of SX in conjunction with F2 ProTaper yielded a significantly lower mean percentage of debris. It was concluded that cleaning ability improves when root canal preparation with F2 ProTaper is complemented by prior cervical enlargement.