Materials and methods. Sixty-four single-canal teeth were prepared and randomly divided into 5 groups, consisting of three experimental groups (n=16) and two control groups (n=8). In group 1, root canal obturation was performed using gutta-percha with 0.02 taper and AH26 sealer by lateral compaction technique. In groups 2 and 3, single Protaper gutta-percha cone was used for obturation with MTA and CEM cement, respectively. A bacterial leakage apparatus was utilized for leakage assessment for 60 days. Leakage comparison between the experimental groups was performed by one-way ANOVA using SPSS 16 statistical software. 

Results. The mean bacterial leakage intervals in groups 1, 2 and 3 were 33.68±9.39, 40.68±11.03 and 39.56±9.03 days, respectively. One-way ANOVA indicated no significant differences in bacterial leakage between the three experimental groups (P=0.109). 

Conclusion. Single-cone obturation with well-fitted gutta-percha and MTA and CEM cement is an appropriate alternative for traditional lateral compaction technique.