The aim of this study was to assess the efficacy of smear layer/debris removal with EDTA, passive ultrasonic irrigation (PUI), Nd:YAG or GaAlAs laser, using surface topography analysis using scanning electron microscopy (SEM). Forty maxillary canines were decoronated, instrumented and randomly assigned (n = 10): G1 - 17% EDTA; G2 - PUI; G3 - Nd:YAG laser; G4 - GaAlAs laser. The roots were prepared for SEM and the cleanliness of each third of the root canal walls was accessed using a predetermined rating system. Kruskal-Wallis test was performed for statistical analysis. A significant difference was observed for G1 and the other three groups in the coronal third (p < 0.01), between G1, G2 and G4 (p < 0.01) and between G1 and G3 (p < 0.05) for the middle third, and between G1 and G4 (p < 0.01) and G1 and G2 (p < 0.05) in the apical third. Not one sample showed a perfectly clean surface of all levels of the root canal.