两种桩核修复上前牙漏斗状残根的疲劳强度实验研究

Resistance to Cyclic Fatigue of Maxillary Incisors Flared Residual Root Restored with Two Post-and-Core Materials

目的探讨不同桩核对修复上前牙漏斗状残根疲劳强度的影响。方法将16颗经根管治疗的离体上颌中切牙,按设定漏斗状根管形态进行牙体预备后,随机均分成2组,各8颗牙,分别用预成玻璃纤维桩和预成镍铬金属桩联合复合树脂桩核2种方法进行修复。测试2组在模拟口腔环境5年使用的存留情况。结果纤维桩组均在模拟周期为3年左右的时间出现失败,失败的类型分别是1例纤维桩折断伴根颈1/3折裂和7例纤维桩脱位;金属桩组有1例失败,失败的类型为桩折断。结论预成镍铬金属桩修复牙的疲劳强度显著高于预成玻璃纤维桩修复牙。

Objective To investigate the resistance to cyclic fatigue of maxillary incisors with flared residual root restored with two post-and-core materials. Methods Sixteen human maxillary central incisors were assigned randomly to two groups with 8 in each group. The two groups were restored with resin composite core combined with prefabricated glass fiber posts and resin composite core combined with prefabricated stainless-steel posts, respectively. The fatigue resistances between two groups were compared in 5-year fatigue test,and their failure modes were analyzed. Results In prefabricated glass fiber posts group all failed including one of the post fracture and seven posts dislocated after about 3-year simulating, while in prefabricated stainless-steel posts group one failure of the post fracture. Conclusion The prefabricated stainless-steel post group was obviously stronger in fatigue resistance than the prefabricated glass fiber post group.