上切牙金属桩冠根折原因分析

目的分析上切牙金属桩冠修复患者根折的原因。方法对2008~2011年上切牙桩冠因根折而拔除金属桩冠及牙根的368例病例进行回顾性分析,按照根桩与牙根长度关系和冠修复方式进行分析。结果金属桩在骨内的长度小于牙根在牙槽骨总长度的1/2牙折病例数多于金属桩在骨内的长度大于牙根在牙槽骨总长度的1/2牙折病例数,单个桩冠根折病例数多于联冠桩冠根折病例数。结论金属桩核冠修复中除要保证桩的长度不短于临床冠的高度外,桩在骨内的长度是否达到牙根在牙槽骨总长度的1/2,单冠相对于联冠修复均可能是根折发生的相关因素。

Analysis of the causes of root fracture in upper incisors with metal dowel crown

Objective To analyze the causes of root fracture in upper incisors with metal post-core crown. Methods Statistical analysis of the 368 cases of root fracture in upper incisors with metal post-core crown for which the metal post-core crown and the root were extracted in our department in 2008~2011. Results The length of metal post which is less than the 1/2 of the total length of the root in the alveolar bone and which is greater than 1/2 have difference in the number of fractured cases, the former is more than the latter. There are also more cases of root fracture with single post-core crown than that with combined crowns. Conclusions In addition to the post-clinical crown ratio, the post length which is greater or less than 1/2 of the total length of the root in the alveolar, as well as the restoration type, namely single crown or multiple teeth combined crowns may be potential critical factors influencing the probability of root fracture occurrence.