不同桩核修复方式对牙体抗折强度和折裂形式影响

目的：比较不同桩核修复方式修复后牙体抗折强度和折裂形式。方法将2013年10～12月拔出的15颗下颌离体前磨牙随机分为三组，每组5颗。A组为铸造金属桩核修复，B组为纤维桩联合树脂核修复，C组为树脂充填修复。所有试件在完成桩核修复后均做金属冠修复，在力学测试机上测试试件的抗折强度，记录试件断裂时的力值和试件折裂形式。结果 A组的破坏载荷值最高，为（1.41±0.29）kN，高于B、C组[（1.20±0.28）、（1.20±0.30）kN]，差异均有统计学意义（P＜0.05）；而B、C组破坏载荷值比较，差异无统计学意义（P＞0.05）。A组折裂形式主要为不可修复性折裂，其他两组主要为可修复性折裂。A组可修复性折裂发生率（0）低于B、C组[80.0%（4/5）、100.0%（5/5）]，差异均有统计学意义（P＜0.05），而B、C组可修复性折裂发生率比较，差异无统计学意义（P＞0.05）。结论临床修复残根、残冠时，可以优先考虑纤维桩联合树脂核修复或者树脂充填修复。

Influence of different post and core restoring systems on the fracture resistance and patterns of teeth

Objective Compare the fracture resistance and jackknifing forms of teeth restored with different post-and-core systems. Methods A total of 15 extracted mandibular premolars with their crowns from October to December in 2013 were were randomly divided into three groups,5 teeth of each,Group A was restored with cast metal post and core,Group B with fiber post and resin core and Group C with resin filling. All the samples were restored with metal-crown after post-core restoring and em-beded in acrylic resin. Their fracture load and fracture mode were recorded. Results The breaking load value[（1.41±0.29）KN] of group A was higher than those of group B, group C [（1.20±0.28）,（1.20±0.30）KN],which had statistical significance in differ-ence（P〈0.05）. There was no statistical significance in differences between group B and group C （P〉0.05）. The facture of group A was irreparable while the other groups repairable. The incidence （0） of the repairable facture was far lower than that of group B and group C[80.0%（4/5）,100.0%（5/5）],whose difference has statistical significance（P〈0.05）. Comparing repairable facture between group B and group C,there was no statistical significance in differences（P〉0.05）. Conclusion When restoring residual crown and root in clinic,it shall prefer to fiber post and resin core.