The purpose of this study was to evaluate the Thermafil endodontic obturation technique. Extracted single-rooted teeth were treated by the step-back technique. The root canal were obtured by the thermafil method with gutta-percha points containing a central plastic carrier. AH Plus, Therma Seal and Apexit were used as sealers. The filled root canals were cut transversally, and the quality of the obturation was investigated in the apical, middle and coronal thirds respectively. Three teeth of all groups were cut longitudinally. All samples were routinely prepared for SEM investigation. Results of the study in SEM proved obturation of the root canals after using the Thermafil method. Vacuoles between the canal wall and the root filling were found in case of all sealers. The presence of vacuoles depended on the amount of sealer.

        Key words: Thermafil – AH Plus – Therma Seal – Apexit – SEM