CONCLUSION: Traumatic occlusal force, periodontal lesions, teeth with root canal therapy are the major causes that led to vertical root fractures.
结论：咬颌创伤，牙周疾病，牙髓无活力等是导致牙根纵裂的重要原因。
CONCLUSION: Structure weak area of tooth was the internal cause of cracked-teeth occurrence, and traumatic occlusal force was the external factor tha.
结论：牙结构的薄弱环节是牙隐裂发生的内在因素，创伤性(？)力是促使牙隐裂发生的外在动力。
Results (1)The traumatic contact area was larger and contact force was greater than that of the normal occlusal contact.
结论创伤有以下特点。 ①与正常比较，创伤有明显的异常接触区，该区的接触面积或接触力明显增大。
应用推荐