Objective To detect the effects of three root canal filling methods on the apical sealing ability of different root canals using glucose quantitative method. Methods Fresh extracted premolars and molars were selected, and 10 mm roots were cut with a low speed diamond disc as samples. After cone beam CT (CBCT) photography, 3 groups of re-gular straight root canals, elliptical root canals and moderate and severe curved root canals were selected as experimental groups, with 10 samples in each group. iRoot SP was used as the root canal sealer,and the warm vertical compression technique,cold gutta-percha lateral compaction technique and single-cone obturation technique were used to complete the root canal. The apical microleakage was detected by the glucose quantitative method. Results For the regular straight root canals of the three groups, on the 1st, 7th, 14th, 21st and 28th days, for the moderate and severe curved root canals of the three groups, on the 1st, 7th and 14th days, and for the oval-shaped root canals of the three groups, on the first day there was no significant difference in apical microleakage (P>0.05). For the moderate and severe curved root canals of the three groups, on the 21st and 28th day, for the oval-shaped root canals of the three groups, on the 7th, 14th, 21st and 28th day, the microleakage value of the cold gutta-percha lateral compaction technique was significantly higher than that of the warm vertical compression technique group and the single-cone obturation technique group (P<0.05). There was no significant difference in microleakage between the latter two groups (P>0.05). Conclusion When iRoot SP is used as a root canal sealer for root canal filling of regular straight root canals,the apical sealing ability of the warm vertical compression technique, cold gutta-percha lateral compaction technique and single-cone obturation technique group are similar. For oval-shaped root canals, and moderate to severe curved root canals, the apical sea-ling ability of the warm vertical compression technique and single-cone obturation technique group is better than cold gutta-percha lateral compaction technique group.
