Thermafil, as a warm guttapercha technique, is supposed to overcome some disadvantages of cold lateral compaction. To compare whether it also offers a comparable apical seal, was the question/aim of this study. Ketac Endo was applied both as a sealer and paste filling in this study. Extracted teeth were instrumented with K-files and a step-back technique, with master apical file size ISO 40. Filled teeth were immersed in 1% methylene blue for one week. The results showed similar results in all the groups: Thermafil (2.035 mm), lateral compaction (2.225 mm) and Ketac Endo (2.365 mm). There was no statistically significant difference between any of the paired groups (p > 0.05). The use of Ketac Endo with its short working time seems to be preferable in conjunction with warm guttapercha techniques, rather than with time consuming lateral compaction.

        Key words: Thermafil – lateral compaction – leakage – Ketac Endo