A nickel-titanium instrument with big taper angle is gradually applied in clinic due to its excellent taper angle and appearance. However, it is poorly understood whether greater tapered gutta-percha cones has good effect on apical seal.OBJECTIVE:
To verify the effect of gutta-percha cone with different tapered angles on apical area sealing.DESIGN, TIME AND SETTING:
A comparison observation experiment was performed at the Department of Stomatology and Center Laboratory of People's Hospital of Peking University from December 2008 to February 2009.MATERIALS:
Thirty-one extracted the first maxillary premolars teeth with completed root formation were collected.METHODS:
Thirty teeth were randomly divided into 0.02 tapered angle (n=10), 0.04 tapered (n=10) angle 0.06 tapered angle (n=10) groups after MTWO preparation, which was filled with three different master cones and obturated with cold lateral condensation. The remained tooth was served as control group.MAIN OUTCOME MEASURES:
The apical leakage was evaluated by the linear measurement combined with transparent specimen method, and the ability of apical seal was measured.RESULTS:
The dye penetration of positive control group was along the whole canals. The length of penetration were (1.655±0.426) mm, (1.210±0.367) mm and (1.100±0.462) mm in 0.02 tapered angle, 0.04 tapered angle and 0.06 tapered angle groups, respectively. The apical sealing ability of 0.04 tapered angle group and 0.04 tapered angle group had no significant difference (P > 0.05). While the length of penetration had statistical differences between 0.02 tapered angle group and 0.06 tapered angle group (P < 0.05) or 0.02 tapered angle group and 0.06 tapered angle group (P < 0.05).CONCLUSION:
Better apical seal can be obtained when using the big cones and obturated with cold lateral condensation after MTWO treatment.