Objective: the objective of this experiment was to compare by means of electronic microscopy of sweepings (MEV), the cleanness and conditioning of the walls of the canals after instrumentation with cream Endo PTC associated with the sodium hypochlorite 1%, and EDTA-T 17%. Method: eighteen inferior premolar teeth had been used, divided in 3 groups: G1 - serum, G2 - associated cream Endo PTC and sodium hypochlorite 1%, G3 - EDTA-T 17%. After the instrumentation and longitudinal cleavage for analyze in MEV (500, 1,000 and 2,000 X) had selected two methods of evaluation of the photomicrography; one using the Fotoscore program, with images analyzed for appraisers and classified obeying the criteria: clean, partially clean and dirty surface and as for counting of clear dentinal canaliculae in increase of (2,000 X). Results: the best ones resulted of the cleanness and conditioning of the surface had occurred in specimens of the G3 that the arithmetic mean of the counting of canaliculae gotten in (G1, G2 and G3) was, in cervical third (74, 34 and 80) average third (7, 21 and 64) and apical third (13, 0 and 26). The statistical test of Kruskal-Wallis statistical showed to significant difference to the level of 0,1% in all the interactions. Conclusion: the experimental model made possible to conclude that the best ones resulted had been observed in specimens worked with EDTA-T 17%