Results: Among the 47 cases ,33 cases were teeth pulpless tissue including 14 endodentically treated teeth and 14 cases were vital teeth with periodontitis ,cracked tooth and occlusal traumatism.

• 结果:牙冠纵折多见后牙,以上颌第一磨牙为多见,其中无髓牙33例,牙折裂前有近一半曾作过根管治疗,活髓牙14例,存在不同程度的牙隐裂,牙周炎和咬合创伤。