[The morphology of roots and canals in the C-Shaped mandibular second molars].
OBJECTIVE
To study the morphology of the fused roots and canals.


METHODS
Through th canal transparent specimen and root transverse sections,the shape of canals and the length of roots were observed.


RESULTS
All roots were fused buccally. The length of root was longer than normal,and the difference had significance. Many variations in root canal morphology, only 40 percent demonstrated a continuous C-Shaped canal in the coronal,middle and apical sections of the root. 30 percent exhibited semicolon, and 10 percent were separate canals. 20 percent canal shapes frequently changed at different levels.


CONCLUSIONS
These special morphologies of the C-Shape mandibular second molars would be detrimental to canals debridement and obturation.
Zhu
Xia
X
Stomatology Hospital afficated to Tongji University, Shanghai 200072, China.