Evaluation of Thermafil obturation of curved canals prepared by the Canal Master-U system

A dye penetration study was performed to compare the apical seals obtained with laterally condensed gutta-percha and Thermafil. The sample group contained 40 teeth with curved canals which had been prepared with the Canal Master-U System. Canal curvature was measured and the teeth were decalcified, cleared, and linear dye penetration was measured. Thermafil had statistically more linear leakage as verified by a Wilcoxon test (p < 0.001). Thermafil also had greater variability in the apical seal than did laterally condensed gutta-percha as verified by an F test (p < 0.001). A Spearman correlation analysis (p > 0.05) showed that there was no correlation between root curvature and linear dye penetration.