Pages 326-331, Language: Englishde Moor, Roeland J. G. / de Bruyne, Mieke A. A.Objective: To evaluate and compare the sealability of root fillings in extracted teeth by using AH 26 and AH Plus in conjunction with three different obturation techniques. Method and materials: Root canals of 940 single-rooted teeth were prepared according to the crown-down/stepback technique (using both 2.5% NaOCl and File-Eze) before lateral condensation and hybrid condensation of gutta percha or obturation with Thermafil. Teeth were immersed in India ink for 90 hours after storage for 1 day, 1 week, 2 weeks, 1 month, and 6 months. The roots were split longitudinally, and the extent of dye penetration was measured using a stereomicroscope. Statistical analysis was performed using Kruskal-Wallis test and Mann-Whitney U test. Results: There were no statistically significant differences in apical leakage within the AH 26 and the AH Plus groups, nor between the two sealer groups, at any observation period. Coronal leakage was significantly higher for Thermafil compared to hybrid condensation at 1 day, 1 week, and 2 weeks both for AH 26 and AH Plus. Coronal leakage was higher only for Thermafil compared to lateral condensation at 1 week for AH 26 and for lateral condensation compared to hybrid condensation at 1 week for AH Plus. Conclusion: Both AH 26 and AH Plus, when used with an identical gutta-percha obturation technique, resulted in comparable sealability at all evaluation times and in comparable coronal sealability at 1 and 6 months.