Methods: 134 residual roots in 102 cases received by root canal therapy.The roots were divided into supragingival and subgingival groups according to the height of the roots.

• 方法:对102例134颗残根进行根管治疗或根管欠填需要重新进行根管治疗,根据残根根面所处的位置将残存的牙根分为龈上和龈下2种,采取切除牙龈、确定根管工作长度、根管预备、根管充填等方法完成根管治疗。