Background: To assess and compare the effectiveness of smear layer removal between OCT with sodium hypochlorite and HEDP with sodium hypochlorite. Materials & Methods: 20 human mandibular premolars, freshly extracted and featuring a single root each, underwent decoronation, with their root specimens standardized to a length of 14mm. The p<0.05 was considered significant. Results: Twenty premolars were examined, revealing significant differences in smear layer scores between the treatment groups at all root levels (p<0.001). Conclusion: At the apical level of the root canal, the use of OCT with sodium hypochlorite demonstrated an improvement in smear layer elimination.